22 files changed, 12217 insertions, 0 deletions

diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig
new file mode 100644
index 000000000..79cb981ec
--- /dev/null
+++ b/drivers/mtd/devices/Kconfig
@@ -0,0 +1,224 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "Self-contained MTD device drivers"
+	depends on MTD!=n
+	depends on HAS_IOMEM
+
+config MTD_PMC551
+	tristate "Ramix PMC551 PCI Mezzanine RAM card support"
+	depends on PCI
+	help
+	  This provides a MTD device driver for the Ramix PMC551 RAM PCI card
+	  from Ramix Inc. <http://www.ramix.com/products/memory/pmc551.html>.
+	  These devices come in memory configurations from 32M - 1G.  If you
+	  have one, you probably want to enable this.
+
+	  If this driver is compiled as a module you get the ability to select
+	  the size of the aperture window pointing into the devices memory.
+	  What this means is that if you have a 1G card, normally the kernel
+	  will use a 1G memory map as its view of the device.  As a module,
+	  you can select a 1M window into the memory and the driver will
+	  "slide" the window around the PMC551's memory.  This was
+	  particularly useful on the 2.2 kernels on PPC architectures as there
+	  was limited kernel space to deal with.
+
+config MTD_PMC551_BUGFIX
+	bool "PMC551 256M DRAM Bugfix"
+	depends on MTD_PMC551
+	help
+	  Some of Ramix's PMC551 boards with 256M configurations have invalid
+	  column and row mux values.  This option will fix them, but will
+	  break other memory configurations.  If unsure say N.
+
+config MTD_PMC551_DEBUG
+	bool "PMC551 Debugging"
+	depends on MTD_PMC551
+	help
+	  This option makes the PMC551 more verbose during its operation and
+	  is only really useful if you are developing on this driver or
+	  suspect a possible hardware or driver bug.  If unsure say N.
+
+config MTD_MS02NV
+	tristate "DEC MS02-NV NVRAM module support"
+	depends on MACH_DECSTATION
+	help
+	  This is an MTD driver for the DEC's MS02-NV (54-20948-01) battery
+	  backed-up NVRAM module.  The module was originally meant as an NFS
+	  accelerator.  Say Y here if you have a DECstation 5000/2x0 or a
+	  DECsystem 5900 equipped with such a module.
+
+	  If you want to compile this driver as a module ( = code which can be
+	  inserted in and removed from the running kernel whenever you want),
+	  say M here and read <file:Documentation/kbuild/modules.rst>.
+	  The module will be called ms02-nv.
+
+config MTD_DATAFLASH
+	tristate "Support for AT45xxx DataFlash"
+	depends on SPI_MASTER
+	help
+	  This enables access to AT45xxx DataFlash chips, using SPI.
+	  Sometimes DataFlash chips are packaged inside MMC-format
+	  cards; at this writing, the MMC stack won't handle those.
+
+config MTD_DATAFLASH_WRITE_VERIFY
+	bool "Verify DataFlash page writes"
+	depends on MTD_DATAFLASH
+	help
+	  This adds an extra check when data is written to the flash.
+	  It may help if you are verifying chip setup (timings etc) on
+	  your board.  There is a rare possibility that even though the
+	  device thinks the write was successful, a bit could have been
+	  flipped accidentally due to device wear or something else.
+
+config MTD_DATAFLASH_OTP
+	bool "DataFlash OTP support (Security Register)"
+	depends on MTD_DATAFLASH
+	help
+	  Newer DataFlash chips (revisions C and D) support 128 bytes of
+	  one-time-programmable (OTP) data.  The first half may be written
+	  (once) with up to 64 bytes of data, such as a serial number or
+	  other key product data.  The second half is programmed with a
+	  unique-to-each-chip bit pattern at the factory.
+
+config MTD_MCHP23K256
+	tristate "Microchip 23K256 SRAM"
+	depends on SPI_MASTER
+	help
+	  This enables access to Microchip 23K256 SRAM chips, using SPI.
+
+	  Set up your spi devices with the right board-specific
+	  platform data, or a device tree description if you want to
+	  specify device partitioning
+
+config MTD_MCHP48L640
+	tristate "Microchip 48L640 EERAM"
+	depends on SPI_MASTER
+	help
+	  This enables access to Microchip 48L640 EERAM chips, using SPI.
+
+config MTD_SPEAR_SMI
+	tristate "SPEAR MTD NOR Support through SMI controller"
+	depends on PLAT_SPEAR || COMPILE_TEST
+	default y
+	help
+	  This enable SNOR support on SPEAR platforms using SMI controller
+
+config MTD_SST25L
+	tristate "Support SST25L (non JEDEC) SPI Flash chips"
+	depends on SPI_MASTER
+	help
+	  This enables access to the non JEDEC SST25L SPI flash chips, used
+	  for program and data storage.
+
+	  Set up your spi devices with the right board-specific platform data,
+	  if you want to specify device partitioning.
+
+config MTD_BCM47XXSFLASH
+	tristate "Support for serial flash on BCMA bus"
+	depends on BCMA_SFLASH && (MIPS || ARM)
+	help
+	  BCMA bus can have various flash memories attached, they are
+	  registered by bcma as platform devices. This enables driver for
+	  serial flash memories.
+
+config MTD_SLRAM
+	tristate "Uncached system RAM"
+	help
+	  If your CPU cannot cache all of the physical memory in your machine,
+	  you can still use it for storage or swap by using this driver to
+	  present it to the system as a Memory Technology Device.
+
+config MTD_PHRAM
+	tristate "Physical system RAM"
+	help
+	  This is a re-implementation of the slram driver above.
+
+	  Use this driver to access physical memory that the kernel proper
+	  doesn't have access to, memory beyond the mem=xxx limit, nvram,
+	  memory on the video card, etc...
+
+config MTD_LART
+	tristate "28F160xx flash driver for LART"
+	depends on SA1100_LART
+	help
+	  This enables the flash driver for LART. Please note that you do
+	  not need any mapping/chip driver for LART. This one does it all
+	  for you, so go disable all of those if you enabled some of them (:
+
+config MTD_MTDRAM
+	tristate "Test driver using RAM"
+	help
+	  This enables a test MTD device driver which uses vmalloc() to
+	  provide storage.  You probably want to say 'N' unless you're
+	  testing stuff.
+
+config MTDRAM_TOTAL_SIZE
+	int "MTDRAM device size in KiB"
+	depends on MTD_MTDRAM
+	default "4096"
+	help
+	  This allows you to configure the total size of the MTD device
+	  emulated by the MTDRAM driver.  If the MTDRAM driver is built
+	  as a module, it is also possible to specify this as a parameter when
+	  loading the module.
+
+config MTDRAM_ERASE_SIZE
+	int "MTDRAM erase block size in KiB"
+	depends on MTD_MTDRAM
+	default "128"
+	help
+	  This allows you to configure the size of the erase blocks in the
+	  device emulated by the MTDRAM driver.  If the MTDRAM driver is built
+	  as a module, it is also possible to specify this as a parameter when
+	  loading the module.
+
+config MTD_BLOCK2MTD
+	tristate "MTD using block device"
+	depends on BLOCK
+	help
+	  This driver allows a block device to appear as an MTD. It would
+	  generally be used in the following cases:
+
+	  Using Compact Flash as an MTD, these usually present themselves to
+	  the system as an ATA drive.
+	  Testing MTD users (eg JFFS2) on large media and media that might
+	  be removed during a write (using the floppy drive).
+
+config MTD_POWERNV_FLASH
+	tristate "powernv flash MTD driver"
+	depends on PPC_POWERNV
+	help
+	  This provides an MTD device to access flash on powernv OPAL
+	  platforms from Linux. This device abstracts away the
+	  firmware interface for flash access.
+
+comment "Disk-On-Chip Device Drivers"
+
+config MTD_DOCG3
+	tristate "M-Systems Disk-On-Chip G3"
+	select BCH
+	select BCH_CONST_PARAMS if !MTD_NAND_ECC_SW_BCH
+	select BITREVERSE
+	help
+	  This provides an MTD device driver for the M-Systems DiskOnChip
+	  G3 devices.
+
+	  The driver provides access to G3 DiskOnChip, distributed by
+	  M-Systems and now Sandisk. The support is very experimental,
+	  and doesn't give access to any write operations.
+
+config MTD_ST_SPI_FSM
+	tristate "ST Microelectronics SPI FSM Serial Flash Controller"
+	depends on ARCH_STI
+	help
+	  This provides an MTD device driver for the ST Microelectronics
+	  SPI Fast Sequence Mode (FSM) Serial Flash Controller and support
+	  for a subset of connected Serial Flash devices.
+
+if MTD_DOCG3
+config BCH_CONST_M
+	default 14
+config BCH_CONST_T
+	default 4
+endif
+
+endmenu
diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile
new file mode 100644
index 000000000..0362cf6bd
--- /dev/null
+++ b/drivers/mtd/devices/Makefile
@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# linux/drivers/mtd/devices/Makefile
+#
+
+obj-$(CONFIG_MTD_DOCG3)		+= docg3.o
+obj-$(CONFIG_MTD_SLRAM)		+= slram.o
+obj-$(CONFIG_MTD_PHRAM)		+= phram.o
+obj-$(CONFIG_MTD_PMC551)	+= pmc551.o
+obj-$(CONFIG_MTD_MS02NV)	+= ms02-nv.o
+obj-$(CONFIG_MTD_MTDRAM)	+= mtdram.o
+obj-$(CONFIG_MTD_LART)		+= lart.o
+obj-$(CONFIG_MTD_BLOCK2MTD)	+= block2mtd.o
+obj-$(CONFIG_MTD_DATAFLASH)	+= mtd_dataflash.o
+obj-$(CONFIG_MTD_MCHP23K256)	+= mchp23k256.o
+obj-$(CONFIG_MTD_MCHP48L640)	+= mchp48l640.o
+obj-$(CONFIG_MTD_SPEAR_SMI)	+= spear_smi.o
+obj-$(CONFIG_MTD_SST25L)	+= sst25l.o
+obj-$(CONFIG_MTD_BCM47XXSFLASH)	+= bcm47xxsflash.o
+obj-$(CONFIG_MTD_ST_SPI_FSM)    += st_spi_fsm.o
+obj-$(CONFIG_MTD_POWERNV_FLASH)	+= powernv_flash.o
+
+
+CFLAGS_docg3.o			+= -I$(src)
diff --git a/drivers/mtd/devices/bcm47xxsflash.c b/drivers/mtd/devices/bcm47xxsflash.c
new file mode 100644
index 000000000..3af50db8b
--- /dev/null
+++ b/drivers/mtd/devices/bcm47xxsflash.c
@@ -0,0 +1,382 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/mtd/mtd.h>
+#include <linux/platform_device.h>
+#include <linux/bcma/bcma.h>
+
+#include "bcm47xxsflash.h"
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Serial flash driver for BCMA bus");
+
+static const char * const probes[] = { "bcm47xxpart", NULL };
+
+/**************************************************
+ * Various helpers
+ **************************************************/
+
+static void bcm47xxsflash_cmd(struct bcm47xxsflash *b47s, u32 opcode)
+{
+	int i;
+
+	b47s->cc_write(b47s, BCMA_CC_FLASHCTL, BCMA_CC_FLASHCTL_START | opcode);
+	for (i = 0; i < 1000; i++) {
+		if (!(b47s->cc_read(b47s, BCMA_CC_FLASHCTL) &
+		      BCMA_CC_FLASHCTL_BUSY))
+			return;
+		cpu_relax();
+	}
+	pr_err("Control command failed (timeout)!\n");
+}
+
+static int bcm47xxsflash_poll(struct bcm47xxsflash *b47s, int timeout)
+{
+	unsigned long deadline = jiffies + timeout;
+
+	do {
+		switch (b47s->type) {
+		case BCM47XXSFLASH_TYPE_ST:
+			bcm47xxsflash_cmd(b47s, OPCODE_ST_RDSR);
+			if (!(b47s->cc_read(b47s, BCMA_CC_FLASHDATA) &
+			      SR_ST_WIP))
+				return 0;
+			break;
+		case BCM47XXSFLASH_TYPE_ATMEL:
+			bcm47xxsflash_cmd(b47s, OPCODE_AT_STATUS);
+			if (b47s->cc_read(b47s, BCMA_CC_FLASHDATA) &
+			    SR_AT_READY)
+				return 0;
+			break;
+		}
+
+		cpu_relax();
+		udelay(1);
+	} while (!time_after_eq(jiffies, deadline));
+
+	pr_err("Timeout waiting for flash to be ready!\n");
+
+	return -EBUSY;
+}
+
+/**************************************************
+ * MTD ops
+ **************************************************/
+
+static int bcm47xxsflash_erase(struct mtd_info *mtd, struct erase_info *erase)
+{
+	struct bcm47xxsflash *b47s = mtd->priv;
+
+	switch (b47s->type) {
+	case BCM47XXSFLASH_TYPE_ST:
+		bcm47xxsflash_cmd(b47s, OPCODE_ST_WREN);
+		b47s->cc_write(b47s, BCMA_CC_FLASHADDR, erase->addr);
+		/* Newer flashes have "sub-sectors" which can be erased
+		 * independently with a new command: ST_SSE. The ST_SE command
+		 * erases 64KB just as before.
+		 */
+		if (b47s->blocksize < (64 * 1024))
+			bcm47xxsflash_cmd(b47s, OPCODE_ST_SSE);
+		else
+			bcm47xxsflash_cmd(b47s, OPCODE_ST_SE);
+		break;
+	case BCM47XXSFLASH_TYPE_ATMEL:
+		b47s->cc_write(b47s, BCMA_CC_FLASHADDR, erase->addr << 1);
+		bcm47xxsflash_cmd(b47s, OPCODE_AT_PAGE_ERASE);
+		break;
+	}
+
+	return bcm47xxsflash_poll(b47s, HZ);
+}
+
+static int bcm47xxsflash_read(struct mtd_info *mtd, loff_t from, size_t len,
+			      size_t *retlen, u_char *buf)
+{
+	struct bcm47xxsflash *b47s = mtd->priv;
+	size_t orig_len = len;
+
+	/* Check address range */
+	if ((from + len) > mtd->size)
+		return -EINVAL;
+
+	/* Read as much as possible using fast MMIO window */
+	if (from < BCM47XXSFLASH_WINDOW_SZ) {
+		size_t memcpy_len;
+
+		memcpy_len = min(len, (size_t)(BCM47XXSFLASH_WINDOW_SZ - from));
+		memcpy_fromio(buf, b47s->window + from, memcpy_len);
+		from += memcpy_len;
+		len -= memcpy_len;
+		buf += memcpy_len;
+	}
+
+	/* Use indirect access for content out of the window */
+	for (; len; len--) {
+		b47s->cc_write(b47s, BCMA_CC_FLASHADDR, from++);
+		bcm47xxsflash_cmd(b47s, OPCODE_ST_READ4B);
+		*buf++ = b47s->cc_read(b47s, BCMA_CC_FLASHDATA);
+	}
+
+	*retlen = orig_len;
+
+	return orig_len;
+}
+
+static int bcm47xxsflash_write_st(struct mtd_info *mtd, u32 offset, size_t len,
+				  const u_char *buf)
+{
+	struct bcm47xxsflash *b47s = mtd->priv;
+	int written = 0;
+
+	/* Enable writes */
+	bcm47xxsflash_cmd(b47s, OPCODE_ST_WREN);
+
+	/* Write first byte */
+	b47s->cc_write(b47s, BCMA_CC_FLASHADDR, offset);
+	b47s->cc_write(b47s, BCMA_CC_FLASHDATA, *buf++);
+
+	/* Program page */
+	if (b47s->bcma_cc->core->id.rev < 20) {
+		bcm47xxsflash_cmd(b47s, OPCODE_ST_PP);
+		return 1; /* 1B written */
+	}
+
+	/* Program page and set CSA (on newer chips we can continue writing) */
+	bcm47xxsflash_cmd(b47s, OPCODE_ST_CSA | OPCODE_ST_PP);
+	offset++;
+	len--;
+	written++;
+
+	while (len > 0) {
+		/* Page boundary, another function call is needed */
+		if ((offset & 0xFF) == 0)
+			break;
+
+		bcm47xxsflash_cmd(b47s, OPCODE_ST_CSA | *buf++);
+		offset++;
+		len--;
+		written++;
+	}
+
+	/* All done, drop CSA & poll */
+	b47s->cc_write(b47s, BCMA_CC_FLASHCTL, 0);
+	udelay(1);
+	if (bcm47xxsflash_poll(b47s, HZ / 10))
+		pr_err("Flash rejected dropping CSA\n");
+
+	return written;
+}
+
+static int bcm47xxsflash_write_at(struct mtd_info *mtd, u32 offset, size_t len,
+				  const u_char *buf)
+{
+	struct bcm47xxsflash *b47s = mtd->priv;
+	u32 mask = b47s->blocksize - 1;
+	u32 page = (offset & ~mask) << 1;
+	u32 byte = offset & mask;
+	int written = 0;
+
+	/* If we don't overwrite whole page, read it to the buffer first */
+	if (byte || (len < b47s->blocksize)) {
+		int err;
+
+		b47s->cc_write(b47s, BCMA_CC_FLASHADDR, page);
+		bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_LOAD);
+		/* 250 us for AT45DB321B */
+		err = bcm47xxsflash_poll(b47s, HZ / 1000);
+		if (err) {
+			pr_err("Timeout reading page 0x%X info buffer\n", page);
+			return err;
+		}
+	}
+
+	/* Change buffer content with our data */
+	while (len > 0) {
+		/* Page boundary, another function call is needed */
+		if (byte == b47s->blocksize)
+			break;
+
+		b47s->cc_write(b47s, BCMA_CC_FLASHADDR, byte++);
+		b47s->cc_write(b47s, BCMA_CC_FLASHDATA, *buf++);
+		bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_WRITE);
+		len--;
+		written++;
+	}
+
+	/* Program page with the buffer content */
+	b47s->cc_write(b47s, BCMA_CC_FLASHADDR, page);
+	bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_PROGRAM);
+
+	return written;
+}
+
+static int bcm47xxsflash_write(struct mtd_info *mtd, loff_t to, size_t len,
+			       size_t *retlen, const u_char *buf)
+{
+	struct bcm47xxsflash *b47s = mtd->priv;
+	int written;
+
+	/* Writing functions can return without writing all passed data, for
+	 * example when the hardware is too old or when we git page boundary.
+	 */
+	while (len > 0) {
+		switch (b47s->type) {
+		case BCM47XXSFLASH_TYPE_ST:
+			written = bcm47xxsflash_write_st(mtd, to, len, buf);
+			break;
+		case BCM47XXSFLASH_TYPE_ATMEL:
+			written = bcm47xxsflash_write_at(mtd, to, len, buf);
+			break;
+		default:
+			BUG_ON(1);
+		}
+		if (written < 0) {
+			pr_err("Error writing at offset 0x%llX\n", to);
+			return written;
+		}
+		to += (loff_t)written;
+		len -= written;
+		*retlen += written;
+		buf += written;
+	}
+
+	return 0;
+}
+
+static void bcm47xxsflash_fill_mtd(struct bcm47xxsflash *b47s,
+				   struct device *dev)
+{
+	struct mtd_info *mtd = &b47s->mtd;
+
+	mtd->priv = b47s;
+	mtd->dev.parent = dev;
+	mtd->name = "bcm47xxsflash";
+
+	mtd->type = MTD_NORFLASH;
+	mtd->flags = MTD_CAP_NORFLASH;
+	mtd->size = b47s->size;
+	mtd->erasesize = b47s->blocksize;
+	mtd->writesize = 1;
+	mtd->writebufsize = 1;
+
+	mtd->_erase = bcm47xxsflash_erase;
+	mtd->_read = bcm47xxsflash_read;
+	mtd->_write = bcm47xxsflash_write;
+}
+
+/**************************************************
+ * BCMA
+ **************************************************/
+
+static int bcm47xxsflash_bcma_cc_read(struct bcm47xxsflash *b47s, u16 offset)
+{
+	return bcma_cc_read32(b47s->bcma_cc, offset);
+}
+
+static void bcm47xxsflash_bcma_cc_write(struct bcm47xxsflash *b47s, u16 offset,
+					u32 value)
+{
+	bcma_cc_write32(b47s->bcma_cc, offset, value);
+}
+
+static int bcm47xxsflash_bcma_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct bcma_sflash *sflash = dev_get_platdata(dev);
+	struct bcm47xxsflash *b47s;
+	struct resource *res;
+	int err;
+
+	b47s = devm_kzalloc(dev, sizeof(*b47s), GFP_KERNEL);
+	if (!b47s)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "invalid resource\n");
+		return -EINVAL;
+	}
+	if (!devm_request_mem_region(dev, res->start, resource_size(res),
+				     res->name)) {
+		dev_err(dev, "can't request region for resource %pR\n", res);
+		return -EBUSY;
+	}
+
+	b47s->bcma_cc = container_of(sflash, struct bcma_drv_cc, sflash);
+	b47s->cc_read = bcm47xxsflash_bcma_cc_read;
+	b47s->cc_write = bcm47xxsflash_bcma_cc_write;
+
+	/*
+	 * On old MIPS devices cache was magically invalidated when needed,
+	 * allowing us to use cached access and gain some performance. Trying
+	 * the same on ARM based BCM53573 results in flash corruptions, we need
+	 * to use uncached access for it.
+	 *
+	 * It may be arch specific, but right now there is only 1 ARM SoC using
+	 * this driver, so let's follow Broadcom's reference code and check
+	 * ChipCommon revision.
+	 */
+	if (b47s->bcma_cc->core->id.rev == 54)
+		b47s->window = ioremap(res->start, resource_size(res));
+	else
+		b47s->window = ioremap_cache(res->start, resource_size(res));
+	if (!b47s->window) {
+		dev_err(dev, "ioremap failed for resource %pR\n", res);
+		return -ENOMEM;
+	}
+
+	switch (b47s->bcma_cc->capabilities & BCMA_CC_CAP_FLASHT) {
+	case BCMA_CC_FLASHT_STSER:
+		b47s->type = BCM47XXSFLASH_TYPE_ST;
+		break;
+	case BCMA_CC_FLASHT_ATSER:
+		b47s->type = BCM47XXSFLASH_TYPE_ATMEL;
+		break;
+	}
+
+	b47s->blocksize = sflash->blocksize;
+	b47s->numblocks = sflash->numblocks;
+	b47s->size = sflash->size;
+	bcm47xxsflash_fill_mtd(b47s, &pdev->dev);
+
+	platform_set_drvdata(pdev, b47s);
+
+	err = mtd_device_parse_register(&b47s->mtd, probes, NULL, NULL, 0);
+	if (err) {
+		pr_err("Failed to register MTD device: %d\n", err);
+		iounmap(b47s->window);
+		return err;
+	}
+
+	if (bcm47xxsflash_poll(b47s, HZ / 10))
+		pr_warn("Serial flash busy\n");
+
+	return 0;
+}
+
+static int bcm47xxsflash_bcma_remove(struct platform_device *pdev)
+{
+	struct bcm47xxsflash *b47s = platform_get_drvdata(pdev);
+
+	mtd_device_unregister(&b47s->mtd);
+	iounmap(b47s->window);
+
+	return 0;
+}
+
+static struct platform_driver bcma_sflash_driver = {
+	.probe	= bcm47xxsflash_bcma_probe,
+	.remove = bcm47xxsflash_bcma_remove,
+	.driver = {
+		.name = "bcma_sflash",
+	},
+};
+
+/**************************************************
+ * Init
+ **************************************************/
+
+module_platform_driver(bcma_sflash_driver);
diff --git a/drivers/mtd/devices/bcm47xxsflash.h b/drivers/mtd/devices/bcm47xxsflash.h
new file mode 100644
index 000000000..fef0d5e42
--- /dev/null
+++ b/drivers/mtd/devices/bcm47xxsflash.h
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __BCM47XXSFLASH_H
+#define __BCM47XXSFLASH_H
+
+#include <linux/mtd/mtd.h>
+
+#define BCM47XXSFLASH_WINDOW_SZ			SZ_16M
+
+/* Used for ST flashes only. */
+#define OPCODE_ST_WREN		0x0006		/* Write Enable */
+#define OPCODE_ST_WRDIS		0x0004		/* Write Disable */
+#define OPCODE_ST_RDSR		0x0105		/* Read Status Register */
+#define OPCODE_ST_WRSR		0x0101		/* Write Status Register */
+#define OPCODE_ST_READ		0x0303		/* Read Data Bytes */
+#define OPCODE_ST_PP		0x0302		/* Page Program */
+#define OPCODE_ST_SE		0x02d8		/* Sector Erase */
+#define OPCODE_ST_BE		0x00c7		/* Bulk Erase */
+#define OPCODE_ST_DP		0x00b9		/* Deep Power-down */
+#define OPCODE_ST_RES		0x03ab		/* Read Electronic Signature */
+#define OPCODE_ST_CSA		0x1000		/* Keep chip select asserted */
+#define OPCODE_ST_SSE		0x0220		/* Sub-sector Erase */
+#define OPCODE_ST_READ4B	0x6313		/* Read Data Bytes in 4Byte addressing mode */
+
+/* Used for Atmel flashes only. */
+#define OPCODE_AT_READ				0x07e8
+#define OPCODE_AT_PAGE_READ			0x07d2
+#define OPCODE_AT_STATUS			0x01d7
+#define OPCODE_AT_BUF1_WRITE			0x0384
+#define OPCODE_AT_BUF2_WRITE			0x0387
+#define OPCODE_AT_BUF1_ERASE_PROGRAM		0x0283
+#define OPCODE_AT_BUF2_ERASE_PROGRAM		0x0286
+#define OPCODE_AT_BUF1_PROGRAM			0x0288
+#define OPCODE_AT_BUF2_PROGRAM			0x0289
+#define OPCODE_AT_PAGE_ERASE			0x0281
+#define OPCODE_AT_BLOCK_ERASE			0x0250
+#define OPCODE_AT_BUF1_WRITE_ERASE_PROGRAM	0x0382
+#define OPCODE_AT_BUF2_WRITE_ERASE_PROGRAM	0x0385
+#define OPCODE_AT_BUF1_LOAD			0x0253
+#define OPCODE_AT_BUF2_LOAD			0x0255
+#define OPCODE_AT_BUF1_COMPARE			0x0260
+#define OPCODE_AT_BUF2_COMPARE			0x0261
+#define OPCODE_AT_BUF1_REPROGRAM		0x0258
+#define OPCODE_AT_BUF2_REPROGRAM		0x0259
+
+/* Status register bits for ST flashes */
+#define SR_ST_WIP		0x01		/* Write In Progress */
+#define SR_ST_WEL		0x02		/* Write Enable Latch */
+#define SR_ST_BP_MASK		0x1c		/* Block Protect */
+#define SR_ST_BP_SHIFT		2
+#define SR_ST_SRWD		0x80		/* Status Register Write Disable */
+
+/* Status register bits for Atmel flashes */
+#define SR_AT_READY		0x80
+#define SR_AT_MISMATCH		0x40
+#define SR_AT_ID_MASK		0x38
+#define SR_AT_ID_SHIFT		3
+
+struct bcma_drv_cc;
+
+enum bcm47xxsflash_type {
+	BCM47XXSFLASH_TYPE_ATMEL,
+	BCM47XXSFLASH_TYPE_ST,
+};
+
+struct bcm47xxsflash {
+	struct bcma_drv_cc *bcma_cc;
+	int (*cc_read)(struct bcm47xxsflash *b47s, u16 offset);
+	void (*cc_write)(struct bcm47xxsflash *b47s, u16 offset, u32 value);
+
+	enum bcm47xxsflash_type type;
+
+	void __iomem *window;
+
+	u32 blocksize;
+	u16 numblocks;
+	u32 size;
+
+	struct mtd_info mtd;
+};
+
+#endif /* BCM47XXSFLASH */
diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
new file mode 100644
index 000000000..4cd37ec45
--- /dev/null
+++ b/drivers/mtd/devices/block2mtd.c
@@ -0,0 +1,511 @@
+/*
+ * block2mtd.c - create an mtd from a block device
+ *
+ * Copyright (C) 2001,2002	Simon Evans <spse@secret.org.uk>
+ * Copyright (C) 2004-2006	Joern Engel <joern@wh.fh-wedel.de>
+ *
+ * Licence: GPL
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+/*
+ * When the first attempt at device initialization fails, we may need to
+ * wait a little bit and retry. This timeout, by default 3 seconds, gives
+ * device time to start up. Required on BCM2708 and a few other chipsets.
+ */
+#define MTD_DEFAULT_TIMEOUT	3
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/fs.h>
+#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
+#include <linux/bio.h>
+#include <linux/pagemap.h>
+#include <linux/list.h>
+#include <linux/init.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mutex.h>
+#include <linux/mount.h>
+#include <linux/slab.h>
+#include <linux/major.h>
+
+/* Maximum number of comma-separated items in the 'block2mtd=' parameter */
+#define BLOCK2MTD_PARAM_MAX_COUNT 3
+
+/* Info for the block device */
+struct block2mtd_dev {
+	struct list_head list;
+	struct block_device *blkdev;
+	struct mtd_info mtd;
+	struct mutex write_mutex;
+};
+
+
+/* Static info about the MTD, used in cleanup_module */
+static LIST_HEAD(blkmtd_device_list);
+
+
+static struct page *page_read(struct address_space *mapping, pgoff_t index)
+{
+	return read_mapping_page(mapping, index, NULL);
+}
+
+/* erase a specified part of the device */
+static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
+{
+	struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
+	struct page *page;
+	pgoff_t index = to >> PAGE_SHIFT;	// page index
+	int pages = len >> PAGE_SHIFT;
+	u_long *p;
+	u_long *max;
+
+	while (pages) {
+		page = page_read(mapping, index);
+		if (IS_ERR(page))
+			return PTR_ERR(page);
+
+		max = page_address(page) + PAGE_SIZE;
+		for (p=page_address(page); p<max; p++)
+			if (*p != -1UL) {
+				lock_page(page);
+				memset(page_address(page), 0xff, PAGE_SIZE);
+				set_page_dirty(page);
+				unlock_page(page);
+				balance_dirty_pages_ratelimited(mapping);
+				break;
+			}
+
+		put_page(page);
+		pages--;
+		index++;
+	}
+	return 0;
+}
+static int block2mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct block2mtd_dev *dev = mtd->priv;
+	size_t from = instr->addr;
+	size_t len = instr->len;
+	int err;
+
+	mutex_lock(&dev->write_mutex);
+	err = _block2mtd_erase(dev, from, len);
+	mutex_unlock(&dev->write_mutex);
+	if (err)
+		pr_err("erase failed err = %d\n", err);
+
+	return err;
+}
+
+
+static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
+		size_t *retlen, u_char *buf)
+{
+	struct block2mtd_dev *dev = mtd->priv;
+	struct page *page;
+	pgoff_t index = from >> PAGE_SHIFT;
+	int offset = from & (PAGE_SIZE-1);
+	int cpylen;
+
+	while (len) {
+		if ((offset + len) > PAGE_SIZE)
+			cpylen = PAGE_SIZE - offset;	// multiple pages
+		else
+			cpylen = len;	// this page
+		len = len - cpylen;
+
+		page = page_read(dev->blkdev->bd_inode->i_mapping, index);
+		if (IS_ERR(page))
+			return PTR_ERR(page);
+
+		memcpy(buf, page_address(page) + offset, cpylen);
+		put_page(page);
+
+		if (retlen)
+			*retlen += cpylen;
+		buf += cpylen;
+		offset = 0;
+		index++;
+	}
+	return 0;
+}
+
+
+/* write data to the underlying device */
+static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
+		loff_t to, size_t len, size_t *retlen)
+{
+	struct page *page;
+	struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
+	pgoff_t index = to >> PAGE_SHIFT;	// page index
+	int offset = to & ~PAGE_MASK;	// page offset
+	int cpylen;
+
+	while (len) {
+		if ((offset+len) > PAGE_SIZE)
+			cpylen = PAGE_SIZE - offset;	// multiple pages
+		else
+			cpylen = len;			// this page
+		len = len - cpylen;
+
+		page = page_read(mapping, index);
+		if (IS_ERR(page))
+			return PTR_ERR(page);
+
+		if (memcmp(page_address(page)+offset, buf, cpylen)) {
+			lock_page(page);
+			memcpy(page_address(page) + offset, buf, cpylen);
+			set_page_dirty(page);
+			unlock_page(page);
+			balance_dirty_pages_ratelimited(mapping);
+		}
+		put_page(page);
+
+		if (retlen)
+			*retlen += cpylen;
+
+		buf += cpylen;
+		offset = 0;
+		index++;
+	}
+	return 0;
+}
+
+
+static int block2mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
+		size_t *retlen, const u_char *buf)
+{
+	struct block2mtd_dev *dev = mtd->priv;
+	int err;
+
+	mutex_lock(&dev->write_mutex);
+	err = _block2mtd_write(dev, buf, to, len, retlen);
+	mutex_unlock(&dev->write_mutex);
+	if (err > 0)
+		err = 0;
+	return err;
+}
+
+
+/* sync the device - wait until the write queue is empty */
+static void block2mtd_sync(struct mtd_info *mtd)
+{
+	struct block2mtd_dev *dev = mtd->priv;
+	sync_blockdev(dev->blkdev);
+	return;
+}
+
+
+static void block2mtd_free_device(struct block2mtd_dev *dev)
+{
+	if (!dev)
+		return;
+
+	kfree(dev->mtd.name);
+
+	if (dev->blkdev) {
+		invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
+					0, -1);
+		blkdev_put(dev->blkdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
+	}
+
+	kfree(dev);
+}
+
+
+static struct block2mtd_dev *add_device(char *devname, int erase_size,
+		char *label, int timeout)
+{
+#ifndef MODULE
+	int i;
+#endif
+	const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
+	struct block_device *bdev;
+	struct block2mtd_dev *dev;
+	char *name;
+
+	if (!devname)
+		return NULL;
+
+	dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
+	if (!dev)
+		return NULL;
+
+	/* Get a handle on the device */
+	bdev = blkdev_get_by_path(devname, mode, dev);
+
+#ifndef MODULE
+	/*
+	 * We might not have the root device mounted at this point.
+	 * Try to resolve the device name by other means.
+	 */
+	for (i = 0; IS_ERR(bdev) && i <= timeout; i++) {
+		dev_t devt;
+
+		if (i)
+			/*
+			 * Calling wait_for_device_probe in the first loop
+			 * was not enough, sleep for a bit in subsequent
+			 * go-arounds.
+			 */
+			msleep(1000);
+		wait_for_device_probe();
+
+		devt = name_to_dev_t(devname);
+		if (!devt)
+			continue;
+		bdev = blkdev_get_by_dev(devt, mode, dev);
+	}
+#endif
+
+	if (IS_ERR(bdev)) {
+		pr_err("error: cannot open device %s\n", devname);
+		goto err_free_block2mtd;
+	}
+	dev->blkdev = bdev;
+
+	if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
+		pr_err("attempting to use an MTD device as a block device\n");
+		goto err_free_block2mtd;
+	}
+
+	if ((long)dev->blkdev->bd_inode->i_size % erase_size) {
+		pr_err("erasesize must be a divisor of device size\n");
+		goto err_free_block2mtd;
+	}
+
+	mutex_init(&dev->write_mutex);
+
+	/* Setup the MTD structure */
+	/* make the name contain the block device in */
+	if (!label)
+		name = kasprintf(GFP_KERNEL, "block2mtd: %s", devname);
+	else
+		name = kstrdup(label, GFP_KERNEL);
+	if (!name)
+		goto err_destroy_mutex;
+
+	dev->mtd.name = name;
+
+	dev->mtd.size = dev->blkdev->bd_inode->i_size & PAGE_MASK;
+	dev->mtd.erasesize = erase_size;
+	dev->mtd.writesize = 1;
+	dev->mtd.writebufsize = PAGE_SIZE;
+	dev->mtd.type = MTD_RAM;
+	dev->mtd.flags = MTD_CAP_RAM;
+	dev->mtd._erase = block2mtd_erase;
+	dev->mtd._write = block2mtd_write;
+	dev->mtd._sync = block2mtd_sync;
+	dev->mtd._read = block2mtd_read;
+	dev->mtd.priv = dev;
+	dev->mtd.owner = THIS_MODULE;
+
+	if (mtd_device_register(&dev->mtd, NULL, 0)) {
+		/* Device didn't get added, so free the entry */
+		goto err_destroy_mutex;
+	}
+
+	list_add(&dev->list, &blkmtd_device_list);
+	pr_info("mtd%d: [%s] erase_size = %dKiB [%d]\n",
+		dev->mtd.index,
+		label ? label : dev->mtd.name + strlen("block2mtd: "),
+		dev->mtd.erasesize >> 10, dev->mtd.erasesize);
+	return dev;
+
+err_destroy_mutex:
+	mutex_destroy(&dev->write_mutex);
+err_free_block2mtd:
+	block2mtd_free_device(dev);
+	return NULL;
+}
+
+
+/* This function works similar to reguler strtoul.  In addition, it
+ * allows some suffixes for a more human-readable number format:
+ * ki, Ki, kiB, KiB	- multiply result with 1024
+ * Mi, MiB		- multiply result with 1024^2
+ * Gi, GiB		- multiply result with 1024^3
+ */
+static int ustrtoul(const char *cp, char **endp, unsigned int base)
+{
+	unsigned long result = simple_strtoul(cp, endp, base);
+	switch (**endp) {
+	case 'G' :
+		result *= 1024;
+		fallthrough;
+	case 'M':
+		result *= 1024;
+		fallthrough;
+	case 'K':
+	case 'k':
+		result *= 1024;
+	/* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
+		if ((*endp)[1] == 'i') {
+			if ((*endp)[2] == 'B')
+				(*endp) += 3;
+			else
+				(*endp) += 2;
+		}
+	}
+	return result;
+}
+
+
+static int parse_num(size_t *num, const char *token)
+{
+	char *endp;
+	size_t n;
+
+	n = (size_t) ustrtoul(token, &endp, 0);
+	if (*endp)
+		return -EINVAL;
+
+	*num = n;
+	return 0;
+}
+
+
+static inline void kill_final_newline(char *str)
+{
+	char *newline = strrchr(str, '\n');
+	if (newline && !newline[1])
+		*newline = 0;
+}
+
+
+#ifndef MODULE
+static int block2mtd_init_called = 0;
+/* 80 for device, 12 for erase size */
+static char block2mtd_paramline[80 + 12];
+#endif
+
+static int block2mtd_setup2(const char *val)
+{
+	/* 80 for device, 12 for erase size, 80 for name, 8 for timeout */
+	char buf[80 + 12 + 80 + 8];
+	char *str = buf;
+	char *token[BLOCK2MTD_PARAM_MAX_COUNT];
+	char *name;
+	char *label = NULL;
+	size_t erase_size = PAGE_SIZE;
+	unsigned long timeout = MTD_DEFAULT_TIMEOUT;
+	int i, ret;
+
+	if (strnlen(val, sizeof(buf)) >= sizeof(buf)) {
+		pr_err("parameter too long\n");
+		return 0;
+	}
+
+	strcpy(str, val);
+	kill_final_newline(str);
+
+	for (i = 0; i < BLOCK2MTD_PARAM_MAX_COUNT; i++)
+		token[i] = strsep(&str, ",");
+
+	if (str) {
+		pr_err("too many arguments\n");
+		return 0;
+	}
+
+	if (!token[0]) {
+		pr_err("no argument\n");
+		return 0;
+	}
+
+	name = token[0];
+	if (strlen(name) + 1 > 80) {
+		pr_err("device name too long\n");
+		return 0;
+	}
+
+	/* Optional argument when custom label is used */
+	if (token[1] && strlen(token[1])) {
+		ret = parse_num(&erase_size, token[1]);
+		if (ret) {
+			pr_err("illegal erase size\n");
+			return 0;
+		}
+	}
+
+	if (token[2]) {
+		label = token[2];
+		pr_info("Using custom MTD label '%s' for dev %s\n", label, name);
+	}
+
+	add_device(name, erase_size, label, timeout);
+
+	return 0;
+}
+
+
+static int block2mtd_setup(const char *val, const struct kernel_param *kp)
+{
+#ifdef MODULE
+	return block2mtd_setup2(val);
+#else
+	/* If more parameters are later passed in via
+	   /sys/module/block2mtd/parameters/block2mtd
+	   and block2mtd_init() has already been called,
+	   we can parse the argument now. */
+
+	if (block2mtd_init_called)
+		return block2mtd_setup2(val);
+
+	/* During early boot stage, we only save the parameters
+	   here. We must parse them later: if the param passed
+	   from kernel boot command line, block2mtd_setup() is
+	   called so early that it is not possible to resolve
+	   the device (even kmalloc() fails). Deter that work to
+	   block2mtd_setup2(). */
+
+	strscpy(block2mtd_paramline, val, sizeof(block2mtd_paramline));
+
+	return 0;
+#endif
+}
+
+
+module_param_call(block2mtd, block2mtd_setup, NULL, NULL, 0200);
+MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,[<erasesize>][,<label>]]\"");
+
+static int __init block2mtd_init(void)
+{
+	int ret = 0;
+
+#ifndef MODULE
+	if (strlen(block2mtd_paramline))
+		ret = block2mtd_setup2(block2mtd_paramline);
+	block2mtd_init_called = 1;
+#endif
+
+	return ret;
+}
+
+
+static void block2mtd_exit(void)
+{
+	struct list_head *pos, *next;
+
+	/* Remove the MTD devices */
+	list_for_each_safe(pos, next, &blkmtd_device_list) {
+		struct block2mtd_dev *dev = list_entry(pos, typeof(*dev), list);
+		block2mtd_sync(&dev->mtd);
+		mtd_device_unregister(&dev->mtd);
+		mutex_destroy(&dev->write_mutex);
+		pr_info("mtd%d: [%s] removed\n",
+			dev->mtd.index,
+			dev->mtd.name + strlen("block2mtd: "));
+		list_del(&dev->list);
+		block2mtd_free_device(dev);
+	}
+}
+
+late_initcall(block2mtd_init);
+module_exit(block2mtd_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Joern Engel <joern@lazybastard.org>");
+MODULE_DESCRIPTION("Emulate an MTD using a block device");
diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
new file mode 100644
index 000000000..a7714e3de
--- /dev/null
+++ b/drivers/mtd/devices/docg3.c
@@ -0,0 +1,2086 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Handles the M-Systems DiskOnChip G3 chip
+ *
+ * Copyright (C) 2011 Robert Jarzmik
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/bitmap.h>
+#include <linux/bitrev.h>
+#include <linux/bch.h>
+
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#define CREATE_TRACE_POINTS
+#include "docg3.h"
+
+/*
+ * This driver handles the DiskOnChip G3 flash memory.
+ *
+ * As no specification is available from M-Systems/Sandisk, this drivers lacks
+ * several functions available on the chip, as :
+ *  - IPL write
+ *
+ * The bus data width (8bits versus 16bits) is not handled (if_cfg flag), and
+ * the driver assumes a 16bits data bus.
+ *
+ * DocG3 relies on 2 ECC algorithms, which are handled in hardware :
+ *  - a 1 byte Hamming code stored in the OOB for each page
+ *  - a 7 bytes BCH code stored in the OOB for each page
+ * The BCH ECC is :
+ *  - BCH is in GF(2^14)
+ *  - BCH is over data of 520 bytes (512 page + 7 page_info bytes
+ *                                   + 1 hamming byte)
+ *  - BCH can correct up to 4 bits (t = 4)
+ *  - BCH syndroms are calculated in hardware, and checked in hardware as well
+ *
+ */
+
+static unsigned int reliable_mode;
+module_param(reliable_mode, uint, 0);
+MODULE_PARM_DESC(reliable_mode, "Set the docg3 mode (0=normal MLC, 1=fast, "
+		 "2=reliable) : MLC normal operations are in normal mode");
+
+static int docg3_ooblayout_ecc(struct mtd_info *mtd, int section,
+			       struct mtd_oob_region *oobregion)
+{
+	if (section)
+		return -ERANGE;
+
+	/* byte 7 is Hamming ECC, byte 8-14 are BCH ECC */
+	oobregion->offset = 7;
+	oobregion->length = 8;
+
+	return 0;
+}
+
+static int docg3_ooblayout_free(struct mtd_info *mtd, int section,
+				struct mtd_oob_region *oobregion)
+{
+	if (section > 1)
+		return -ERANGE;
+
+	/* free bytes: byte 0 until byte 6, byte 15 */
+	if (!section) {
+		oobregion->offset = 0;
+		oobregion->length = 7;
+	} else {
+		oobregion->offset = 15;
+		oobregion->length = 1;
+	}
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops nand_ooblayout_docg3_ops = {
+	.ecc = docg3_ooblayout_ecc,
+	.free = docg3_ooblayout_free,
+};
+
+static inline u8 doc_readb(struct docg3 *docg3, u16 reg)
+{
+	u8 val = readb(docg3->cascade->base + reg);
+
+	trace_docg3_io(0, 8, reg, (int)val);
+	return val;
+}
+
+static inline u16 doc_readw(struct docg3 *docg3, u16 reg)
+{
+	u16 val = readw(docg3->cascade->base + reg);
+
+	trace_docg3_io(0, 16, reg, (int)val);
+	return val;
+}
+
+static inline void doc_writeb(struct docg3 *docg3, u8 val, u16 reg)
+{
+	writeb(val, docg3->cascade->base + reg);
+	trace_docg3_io(1, 8, reg, val);
+}
+
+static inline void doc_writew(struct docg3 *docg3, u16 val, u16 reg)
+{
+	writew(val, docg3->cascade->base + reg);
+	trace_docg3_io(1, 16, reg, val);
+}
+
+static inline void doc_flash_command(struct docg3 *docg3, u8 cmd)
+{
+	doc_writeb(docg3, cmd, DOC_FLASHCOMMAND);
+}
+
+static inline void doc_flash_sequence(struct docg3 *docg3, u8 seq)
+{
+	doc_writeb(docg3, seq, DOC_FLASHSEQUENCE);
+}
+
+static inline void doc_flash_address(struct docg3 *docg3, u8 addr)
+{
+	doc_writeb(docg3, addr, DOC_FLASHADDRESS);
+}
+
+static char const * const part_probes[] = { "cmdlinepart", "saftlpart", NULL };
+
+static int doc_register_readb(struct docg3 *docg3, int reg)
+{
+	u8 val;
+
+	doc_writew(docg3, reg, DOC_READADDRESS);
+	val = doc_readb(docg3, reg);
+	doc_vdbg("Read register %04x : %02x\n", reg, val);
+	return val;
+}
+
+static int doc_register_readw(struct docg3 *docg3, int reg)
+{
+	u16 val;
+
+	doc_writew(docg3, reg, DOC_READADDRESS);
+	val = doc_readw(docg3, reg);
+	doc_vdbg("Read register %04x : %04x\n", reg, val);
+	return val;
+}
+
+/**
+ * doc_delay - delay docg3 operations
+ * @docg3: the device
+ * @nbNOPs: the number of NOPs to issue
+ *
+ * As no specification is available, the right timings between chip commands are
+ * unknown. The only available piece of information are the observed nops on a
+ * working docg3 chip.
+ * Therefore, doc_delay relies on a busy loop of NOPs, instead of scheduler
+ * friendlier msleep() functions or blocking mdelay().
+ */
+static void doc_delay(struct docg3 *docg3, int nbNOPs)
+{
+	int i;
+
+	doc_vdbg("NOP x %d\n", nbNOPs);
+	for (i = 0; i < nbNOPs; i++)
+		doc_writeb(docg3, 0, DOC_NOP);
+}
+
+static int is_prot_seq_error(struct docg3 *docg3)
+{
+	int ctrl;
+
+	ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
+	return ctrl & (DOC_CTRL_PROTECTION_ERROR | DOC_CTRL_SEQUENCE_ERROR);
+}
+
+static int doc_is_ready(struct docg3 *docg3)
+{
+	int ctrl;
+
+	ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
+	return ctrl & DOC_CTRL_FLASHREADY;
+}
+
+static int doc_wait_ready(struct docg3 *docg3)
+{
+	int maxWaitCycles = 100;
+
+	do {
+		doc_delay(docg3, 4);
+		cpu_relax();
+	} while (!doc_is_ready(docg3) && maxWaitCycles--);
+	doc_delay(docg3, 2);
+	if (maxWaitCycles > 0)
+		return 0;
+	else
+		return -EIO;
+}
+
+static int doc_reset_seq(struct docg3 *docg3)
+{
+	int ret;
+
+	doc_writeb(docg3, 0x10, DOC_FLASHCONTROL);
+	doc_flash_sequence(docg3, DOC_SEQ_RESET);
+	doc_flash_command(docg3, DOC_CMD_RESET);
+	doc_delay(docg3, 2);
+	ret = doc_wait_ready(docg3);
+
+	doc_dbg("doc_reset_seq() -> isReady=%s\n", ret ? "false" : "true");
+	return ret;
+}
+
+/**
+ * doc_read_data_area - Read data from data area
+ * @docg3: the device
+ * @buf: the buffer to fill in (might be NULL is dummy reads)
+ * @len: the length to read
+ * @first: first time read, DOC_READADDRESS should be set
+ *
+ * Reads bytes from flash data. Handles the single byte / even bytes reads.
+ */
+static void doc_read_data_area(struct docg3 *docg3, void *buf, int len,
+			       int first)
+{
+	int i, cdr, len4;
+	u16 data16, *dst16;
+	u8 data8, *dst8;
+
+	doc_dbg("doc_read_data_area(buf=%p, len=%d)\n", buf, len);
+	cdr = len & 0x1;
+	len4 = len - cdr;
+
+	if (first)
+		doc_writew(docg3, DOC_IOSPACE_DATA, DOC_READADDRESS);
+	dst16 = buf;
+	for (i = 0; i < len4; i += 2) {
+		data16 = doc_readw(docg3, DOC_IOSPACE_DATA);
+		if (dst16) {
+			*dst16 = data16;
+			dst16++;
+		}
+	}
+
+	if (cdr) {
+		doc_writew(docg3, DOC_IOSPACE_DATA | DOC_READADDR_ONE_BYTE,
+			   DOC_READADDRESS);
+		doc_delay(docg3, 1);
+		dst8 = (u8 *)dst16;
+		for (i = 0; i < cdr; i++) {
+			data8 = doc_readb(docg3, DOC_IOSPACE_DATA);
+			if (dst8) {
+				*dst8 = data8;
+				dst8++;
+			}
+		}
+	}
+}
+
+/**
+ * doc_write_data_area - Write data into data area
+ * @docg3: the device
+ * @buf: the buffer to get input bytes from
+ * @len: the length to write
+ *
+ * Writes bytes into flash data. Handles the single byte / even bytes writes.
+ */
+static void doc_write_data_area(struct docg3 *docg3, const void *buf, int len)
+{
+	int i, cdr, len4;
+	u16 *src16;
+	u8 *src8;
+
+	doc_dbg("doc_write_data_area(buf=%p, len=%d)\n", buf, len);
+	cdr = len & 0x3;
+	len4 = len - cdr;
+
+	doc_writew(docg3, DOC_IOSPACE_DATA, DOC_READADDRESS);
+	src16 = (u16 *)buf;
+	for (i = 0; i < len4; i += 2) {
+		doc_writew(docg3, *src16, DOC_IOSPACE_DATA);
+		src16++;
+	}
+
+	src8 = (u8 *)src16;
+	for (i = 0; i < cdr; i++) {
+		doc_writew(docg3, DOC_IOSPACE_DATA | DOC_READADDR_ONE_BYTE,
+			   DOC_READADDRESS);
+		doc_writeb(docg3, *src8, DOC_IOSPACE_DATA);
+		src8++;
+	}
+}
+
+/**
+ * doc_set_reliable_mode - Sets the flash to normal or reliable data mode
+ * @docg3: the device
+ *
+ * The reliable data mode is a bit slower than the fast mode, but less errors
+ * occur.  Entering the reliable mode cannot be done without entering the fast
+ * mode first.
+ *
+ * In reliable mode, pages 2*n and 2*n+1 are clones. Writing to page 0 of blocks
+ * (4,5) make the hardware write also to page 1 of blocks blocks(4,5). Reading
+ * from page 0 of blocks (4,5) or from page 1 of blocks (4,5) gives the same
+ * result, which is a logical and between bytes from page 0 and page 1 (which is
+ * consistent with the fact that writing to a page is _clearing_ bits of that
+ * page).
+ */
+static void doc_set_reliable_mode(struct docg3 *docg3)
+{
+	static char *strmode[] = { "normal", "fast", "reliable", "invalid" };
+
+	doc_dbg("doc_set_reliable_mode(%s)\n", strmode[docg3->reliable]);
+	switch (docg3->reliable) {
+	case 0:
+		break;
+	case 1:
+		doc_flash_sequence(docg3, DOC_SEQ_SET_FASTMODE);
+		doc_flash_command(docg3, DOC_CMD_FAST_MODE);
+		break;
+	case 2:
+		doc_flash_sequence(docg3, DOC_SEQ_SET_RELIABLEMODE);
+		doc_flash_command(docg3, DOC_CMD_FAST_MODE);
+		doc_flash_command(docg3, DOC_CMD_RELIABLE_MODE);
+		break;
+	default:
+		doc_err("doc_set_reliable_mode(): invalid mode\n");
+		break;
+	}
+	doc_delay(docg3, 2);
+}
+
+/**
+ * doc_set_asic_mode - Set the ASIC mode
+ * @docg3: the device
+ * @mode: the mode
+ *
+ * The ASIC can work in 3 modes :
+ *  - RESET: all registers are zeroed
+ *  - NORMAL: receives and handles commands
+ *  - POWERDOWN: minimal poweruse, flash parts shut off
+ */
+static void doc_set_asic_mode(struct docg3 *docg3, u8 mode)
+{
+	int i;
+
+	for (i = 0; i < 12; i++)
+		doc_readb(docg3, DOC_IOSPACE_IPL);
+
+	mode |= DOC_ASICMODE_MDWREN;
+	doc_dbg("doc_set_asic_mode(%02x)\n", mode);
+	doc_writeb(docg3, mode, DOC_ASICMODE);
+	doc_writeb(docg3, ~mode, DOC_ASICMODECONFIRM);
+	doc_delay(docg3, 1);
+}
+
+/**
+ * doc_set_device_id - Sets the devices id for cascaded G3 chips
+ * @docg3: the device
+ * @id: the chip to select (amongst 0, 1, 2, 3)
+ *
+ * There can be 4 cascaded G3 chips. This function selects the one which will
+ * should be the active one.
+ */
+static void doc_set_device_id(struct docg3 *docg3, int id)
+{
+	u8 ctrl;
+
+	doc_dbg("doc_set_device_id(%d)\n", id);
+	doc_writeb(docg3, id, DOC_DEVICESELECT);
+	ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
+
+	ctrl &= ~DOC_CTRL_VIOLATION;
+	ctrl |= DOC_CTRL_CE;
+	doc_writeb(docg3, ctrl, DOC_FLASHCONTROL);
+}
+
+/**
+ * doc_set_extra_page_mode - Change flash page layout
+ * @docg3: the device
+ *
+ * Normally, the flash page is split into the data (512 bytes) and the out of
+ * band data (16 bytes). For each, 4 more bytes can be accessed, where the wear
+ * leveling counters are stored.  To access this last area of 4 bytes, a special
+ * mode must be input to the flash ASIC.
+ *
+ * Returns 0 if no error occurred, -EIO else.
+ */
+static int doc_set_extra_page_mode(struct docg3 *docg3)
+{
+	int fctrl;
+
+	doc_dbg("doc_set_extra_page_mode()\n");
+	doc_flash_sequence(docg3, DOC_SEQ_PAGE_SIZE_532);
+	doc_flash_command(docg3, DOC_CMD_PAGE_SIZE_532);
+	doc_delay(docg3, 2);
+
+	fctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
+	if (fctrl & (DOC_CTRL_PROTECTION_ERROR | DOC_CTRL_SEQUENCE_ERROR))
+		return -EIO;
+	else
+		return 0;
+}
+
+/**
+ * doc_setup_addr_sector - Setup blocks/page/ofs address for one plane
+ * @docg3: the device
+ * @sector: the sector
+ */
+static void doc_setup_addr_sector(struct docg3 *docg3, int sector)
+{
+	doc_delay(docg3, 1);
+	doc_flash_address(docg3, sector & 0xff);
+	doc_flash_address(docg3, (sector >> 8) & 0xff);
+	doc_flash_address(docg3, (sector >> 16) & 0xff);
+	doc_delay(docg3, 1);
+}
+
+/**
+ * doc_setup_writeaddr_sector - Setup blocks/page/ofs address for one plane
+ * @docg3: the device
+ * @sector: the sector
+ * @ofs: the offset in the page, between 0 and (512 + 16 + 512)
+ */
+static void doc_setup_writeaddr_sector(struct docg3 *docg3, int sector, int ofs)
+{
+	ofs = ofs >> 2;
+	doc_delay(docg3, 1);
+	doc_flash_address(docg3, ofs & 0xff);
+	doc_flash_address(docg3, sector & 0xff);
+	doc_flash_address(docg3, (sector >> 8) & 0xff);
+	doc_flash_address(docg3, (sector >> 16) & 0xff);
+	doc_delay(docg3, 1);
+}
+
+/**
+ * doc_read_seek - Set both flash planes to the specified block, page for reading
+ * @docg3: the device
+ * @block0: the first plane block index
+ * @block1: the second plane block index
+ * @page: the page index within the block
+ * @wear: if true, read will occur on the 4 extra bytes of the wear area
+ * @ofs: offset in page to read
+ *
+ * Programs the flash even and odd planes to the specific block and page.
+ * Alternatively, programs the flash to the wear area of the specified page.
+ */
+static int doc_read_seek(struct docg3 *docg3, int block0, int block1, int page,
+			 int wear, int ofs)
+{
+	int sector, ret = 0;
+
+	doc_dbg("doc_seek(blocks=(%d,%d), page=%d, ofs=%d, wear=%d)\n",
+		block0, block1, page, ofs, wear);
+
+	if (!wear && (ofs < 2 * DOC_LAYOUT_PAGE_SIZE)) {
+		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE1);
+		doc_flash_command(docg3, DOC_CMD_READ_PLANE1);
+		doc_delay(docg3, 2);
+	} else {
+		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE2);
+		doc_flash_command(docg3, DOC_CMD_READ_PLANE2);
+		doc_delay(docg3, 2);
+	}
+
+	doc_set_reliable_mode(docg3);
+	if (wear)
+		ret = doc_set_extra_page_mode(docg3);
+	if (ret)
+		goto out;
+
+	doc_flash_sequence(docg3, DOC_SEQ_READ);
+	sector = (block0 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
+	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
+	doc_setup_addr_sector(docg3, sector);
+
+	sector = (block1 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
+	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
+	doc_setup_addr_sector(docg3, sector);
+	doc_delay(docg3, 1);
+
+out:
+	return ret;
+}
+
+/**
+ * doc_write_seek - Set both flash planes to the specified block, page for writing
+ * @docg3: the device
+ * @block0: the first plane block index
+ * @block1: the second plane block index
+ * @page: the page index within the block
+ * @ofs: offset in page to write
+ *
+ * Programs the flash even and odd planes to the specific block and page.
+ * Alternatively, programs the flash to the wear area of the specified page.
+ */
+static int doc_write_seek(struct docg3 *docg3, int block0, int block1, int page,
+			 int ofs)
+{
+	int ret = 0, sector;
+
+	doc_dbg("doc_write_seek(blocks=(%d,%d), page=%d, ofs=%d)\n",
+		block0, block1, page, ofs);
+
+	doc_set_reliable_mode(docg3);
+
+	if (ofs < 2 * DOC_LAYOUT_PAGE_SIZE) {
+		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE1);
+		doc_flash_command(docg3, DOC_CMD_READ_PLANE1);
+		doc_delay(docg3, 2);
+	} else {
+		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE2);
+		doc_flash_command(docg3, DOC_CMD_READ_PLANE2);
+		doc_delay(docg3, 2);
+	}
+
+	doc_flash_sequence(docg3, DOC_SEQ_PAGE_SETUP);
+	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE1);
+
+	sector = (block0 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
+	doc_setup_writeaddr_sector(docg3, sector, ofs);
+
+	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE3);
+	doc_delay(docg3, 2);
+	ret = doc_wait_ready(docg3);
+	if (ret)
+		goto out;
+
+	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE1);
+	sector = (block1 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
+	doc_setup_writeaddr_sector(docg3, sector, ofs);
+	doc_delay(docg3, 1);
+
+out:
+	return ret;
+}
+
+
+/**
+ * doc_read_page_ecc_init - Initialize hardware ECC engine
+ * @docg3: the device
+ * @len: the number of bytes covered by the ECC (BCH covered)
+ *
+ * The function does initialize the hardware ECC engine to compute the Hamming
+ * ECC (on 1 byte) and the BCH hardware ECC (on 7 bytes).
+ *
+ * Return 0 if succeeded, -EIO on error
+ */
+static int doc_read_page_ecc_init(struct docg3 *docg3, int len)
+{
+	doc_writew(docg3, DOC_ECCCONF0_READ_MODE
+		   | DOC_ECCCONF0_BCH_ENABLE | DOC_ECCCONF0_HAMMING_ENABLE
+		   | (len & DOC_ECCCONF0_DATA_BYTES_MASK),
+		   DOC_ECCCONF0);
+	doc_delay(docg3, 4);
+	doc_register_readb(docg3, DOC_FLASHCONTROL);
+	return doc_wait_ready(docg3);
+}
+
+/**
+ * doc_write_page_ecc_init - Initialize hardware BCH ECC engine
+ * @docg3: the device
+ * @len: the number of bytes covered by the ECC (BCH covered)
+ *
+ * The function does initialize the hardware ECC engine to compute the Hamming
+ * ECC (on 1 byte) and the BCH hardware ECC (on 7 bytes).
+ *
+ * Return 0 if succeeded, -EIO on error
+ */
+static int doc_write_page_ecc_init(struct docg3 *docg3, int len)
+{
+	doc_writew(docg3, DOC_ECCCONF0_WRITE_MODE
+		   | DOC_ECCCONF0_BCH_ENABLE | DOC_ECCCONF0_HAMMING_ENABLE
+		   | (len & DOC_ECCCONF0_DATA_BYTES_MASK),
+		   DOC_ECCCONF0);
+	doc_delay(docg3, 4);
+	doc_register_readb(docg3, DOC_FLASHCONTROL);
+	return doc_wait_ready(docg3);
+}
+
+/**
+ * doc_ecc_disable - Disable Hamming and BCH ECC hardware calculator
+ * @docg3: the device
+ *
+ * Disables the hardware ECC generator and checker, for unchecked reads (as when
+ * reading OOB only or write status byte).
+ */
+static void doc_ecc_disable(struct docg3 *docg3)
+{
+	doc_writew(docg3, DOC_ECCCONF0_READ_MODE, DOC_ECCCONF0);
+	doc_delay(docg3, 4);
+}
+
+/**
+ * doc_hamming_ecc_init - Initialize hardware Hamming ECC engine
+ * @docg3: the device
+ * @nb_bytes: the number of bytes covered by the ECC (Hamming covered)
+ *
+ * This function programs the ECC hardware to compute the hamming code on the
+ * last provided N bytes to the hardware generator.
+ */
+static void doc_hamming_ecc_init(struct docg3 *docg3, int nb_bytes)
+{
+	u8 ecc_conf1;
+
+	ecc_conf1 = doc_register_readb(docg3, DOC_ECCCONF1);
+	ecc_conf1 &= ~DOC_ECCCONF1_HAMMING_BITS_MASK;
+	ecc_conf1 |= (nb_bytes & DOC_ECCCONF1_HAMMING_BITS_MASK);
+	doc_writeb(docg3, ecc_conf1, DOC_ECCCONF1);
+}
+
+/**
+ * doc_ecc_bch_fix_data - Fix if need be read data from flash
+ * @docg3: the device
+ * @buf: the buffer of read data (512 + 7 + 1 bytes)
+ * @hwecc: the hardware calculated ECC.
+ *         It's in fact recv_ecc ^ calc_ecc, where recv_ecc was read from OOB
+ *         area data, and calc_ecc the ECC calculated by the hardware generator.
+ *
+ * Checks if the received data matches the ECC, and if an error is detected,
+ * tries to fix the bit flips (at most 4) in the buffer buf.  As the docg3
+ * understands the (data, ecc, syndroms) in an inverted order in comparison to
+ * the BCH library, the function reverses the order of bits (ie. bit7 and bit0,
+ * bit6 and bit 1, ...) for all ECC data.
+ *
+ * The hardware ecc unit produces oob_ecc ^ calc_ecc.  The kernel's bch
+ * algorithm is used to decode this.  However the hw operates on page
+ * data in a bit order that is the reverse of that of the bch alg,
+ * requiring that the bits be reversed on the result.  Thanks to Ivan
+ * Djelic for his analysis.
+ *
+ * Returns number of fixed bits (0, 1, 2, 3, 4) or -EBADMSG if too many bit
+ * errors were detected and cannot be fixed.
+ */
+static int doc_ecc_bch_fix_data(struct docg3 *docg3, void *buf, u8 *hwecc)
+{
+	u8 ecc[DOC_ECC_BCH_SIZE];
+	int errorpos[DOC_ECC_BCH_T], i, numerrs;
+
+	for (i = 0; i < DOC_ECC_BCH_SIZE; i++)
+		ecc[i] = bitrev8(hwecc[i]);
+	numerrs = bch_decode(docg3->cascade->bch, NULL,
+			     DOC_ECC_BCH_COVERED_BYTES,
+			     NULL, ecc, NULL, errorpos);
+	BUG_ON(numerrs == -EINVAL);
+	if (numerrs < 0)
+		goto out;
+
+	for (i = 0; i < numerrs; i++)
+		errorpos[i] = (errorpos[i] & ~7) | (7 - (errorpos[i] & 7));
+	for (i = 0; i < numerrs; i++)
+		if (errorpos[i] < DOC_ECC_BCH_COVERED_BYTES*8)
+			/* error is located in data, correct it */
+			change_bit(errorpos[i], buf);
+out:
+	doc_dbg("doc_ecc_bch_fix_data: flipped %d bits\n", numerrs);
+	return numerrs;
+}
+
+
+/**
+ * doc_read_page_prepare - Prepares reading data from a flash page
+ * @docg3: the device
+ * @block0: the first plane block index on flash memory
+ * @block1: the second plane block index on flash memory
+ * @page: the page index in the block
+ * @offset: the offset in the page (must be a multiple of 4)
+ *
+ * Prepares the page to be read in the flash memory :
+ *   - tell ASIC to map the flash pages
+ *   - tell ASIC to be in read mode
+ *
+ * After a call to this method, a call to doc_read_page_finish is mandatory,
+ * to end the read cycle of the flash.
+ *
+ * Read data from a flash page. The length to be read must be between 0 and
+ * (page_size + oob_size + wear_size), ie. 532, and a multiple of 4 (because
+ * the extra bytes reading is not implemented).
+ *
+ * As pages are grouped by 2 (in 2 planes), reading from a page must be done
+ * in two steps:
+ *  - one read of 512 bytes at offset 0
+ *  - one read of 512 bytes at offset 512 + 16
+ *
+ * Returns 0 if successful, -EIO if a read error occurred.
+ */
+static int doc_read_page_prepare(struct docg3 *docg3, int block0, int block1,
+				 int page, int offset)
+{
+	int wear_area = 0, ret = 0;
+
+	doc_dbg("doc_read_page_prepare(blocks=(%d,%d), page=%d, ofsInPage=%d)\n",
+		block0, block1, page, offset);
+	if (offset >= DOC_LAYOUT_WEAR_OFFSET)
+		wear_area = 1;
+	if (!wear_area && offset > (DOC_LAYOUT_PAGE_OOB_SIZE * 2))
+		return -EINVAL;
+
+	doc_set_device_id(docg3, docg3->device_id);
+	ret = doc_reset_seq(docg3);
+	if (ret)
+		goto err;
+
+	/* Program the flash address block and page */
+	ret = doc_read_seek(docg3, block0, block1, page, wear_area, offset);
+	if (ret)
+		goto err;
+
+	doc_flash_command(docg3, DOC_CMD_READ_ALL_PLANES);
+	doc_delay(docg3, 2);
+	doc_wait_ready(docg3);
+
+	doc_flash_command(docg3, DOC_CMD_SET_ADDR_READ);
+	doc_delay(docg3, 1);
+	if (offset >= DOC_LAYOUT_PAGE_SIZE * 2)
+		offset -= 2 * DOC_LAYOUT_PAGE_SIZE;
+	doc_flash_address(docg3, offset >> 2);
+	doc_delay(docg3, 1);
+	doc_wait_ready(docg3);
+
+	doc_flash_command(docg3, DOC_CMD_READ_FLASH);
+
+	return 0;
+err:
+	doc_writeb(docg3, 0, DOC_DATAEND);
+	doc_delay(docg3, 2);
+	return -EIO;
+}
+
+/**
+ * doc_read_page_getbytes - Reads bytes from a prepared page
+ * @docg3: the device
+ * @len: the number of bytes to be read (must be a multiple of 4)
+ * @buf: the buffer to be filled in (or NULL is forget bytes)
+ * @first: 1 if first time read, DOC_READADDRESS should be set
+ * @last_odd: 1 if last read ended up on an odd byte
+ *
+ * Reads bytes from a prepared page. There is a trickery here : if the last read
+ * ended up on an odd offset in the 1024 bytes double page, ie. between the 2
+ * planes, the first byte must be read apart. If a word (16bit) read was used,
+ * the read would return the byte of plane 2 as low *and* high endian, which
+ * will mess the read.
+ *
+ */
+static int doc_read_page_getbytes(struct docg3 *docg3, int len, u_char *buf,
+				  int first, int last_odd)
+{
+	if (last_odd && len > 0) {
+		doc_read_data_area(docg3, buf, 1, first);
+		doc_read_data_area(docg3, buf ? buf + 1 : buf, len - 1, 0);
+	} else {
+		doc_read_data_area(docg3, buf, len, first);
+	}
+	doc_delay(docg3, 2);
+	return len;
+}
+
+/**
+ * doc_write_page_putbytes - Writes bytes into a prepared page
+ * @docg3: the device
+ * @len: the number of bytes to be written
+ * @buf: the buffer of input bytes
+ *
+ */
+static void doc_write_page_putbytes(struct docg3 *docg3, int len,
+				    const u_char *buf)
+{
+	doc_write_data_area(docg3, buf, len);
+	doc_delay(docg3, 2);
+}
+
+/**
+ * doc_get_bch_hw_ecc - Get hardware calculated BCH ECC
+ * @docg3: the device
+ * @hwecc:  the array of 7 integers where the hardware ecc will be stored
+ */
+static void doc_get_bch_hw_ecc(struct docg3 *docg3, u8 *hwecc)
+{
+	int i;
+
+	for (i = 0; i < DOC_ECC_BCH_SIZE; i++)
+		hwecc[i] = doc_register_readb(docg3, DOC_BCH_HW_ECC(i));
+}
+
+/**
+ * doc_page_finish - Ends reading/writing of a flash page
+ * @docg3: the device
+ */
+static void doc_page_finish(struct docg3 *docg3)
+{
+	doc_writeb(docg3, 0, DOC_DATAEND);
+	doc_delay(docg3, 2);
+}
+
+/**
+ * doc_read_page_finish - Ends reading of a flash page
+ * @docg3: the device
+ *
+ * As a side effect, resets the chip selector to 0. This ensures that after each
+ * read operation, the floor 0 is selected. Therefore, if the systems halts, the
+ * reboot will boot on floor 0, where the IPL is.
+ */
+static void doc_read_page_finish(struct docg3 *docg3)
+{
+	doc_page_finish(docg3);
+	doc_set_device_id(docg3, 0);
+}
+
+/**
+ * calc_block_sector - Calculate blocks, pages and ofs.
+ *
+ * @from: offset in flash
+ * @block0: first plane block index calculated
+ * @block1: second plane block index calculated
+ * @page: page calculated
+ * @ofs: offset in page
+ * @reliable: 0 if docg3 in normal mode, 1 if docg3 in fast mode, 2 if docg3 in
+ * reliable mode.
+ *
+ * The calculation is based on the reliable/normal mode. In normal mode, the 64
+ * pages of a block are available. In reliable mode, as pages 2*n and 2*n+1 are
+ * clones, only 32 pages per block are available.
+ */
+static void calc_block_sector(loff_t from, int *block0, int *block1, int *page,
+			      int *ofs, int reliable)
+{
+	uint sector, pages_biblock;
+
+	pages_biblock = DOC_LAYOUT_PAGES_PER_BLOCK * DOC_LAYOUT_NBPLANES;
+	if (reliable == 1 || reliable == 2)
+		pages_biblock /= 2;
+
+	sector = from / DOC_LAYOUT_PAGE_SIZE;
+	*block0 = sector / pages_biblock * DOC_LAYOUT_NBPLANES;
+	*block1 = *block0 + 1;
+	*page = sector % pages_biblock;
+	*page /= DOC_LAYOUT_NBPLANES;
+	if (reliable == 1 || reliable == 2)
+		*page *= 2;
+	if (sector % 2)
+		*ofs = DOC_LAYOUT_PAGE_OOB_SIZE;
+	else
+		*ofs = 0;
+}
+
+/**
+ * doc_read_oob - Read out of band bytes from flash
+ * @mtd: the device
+ * @from: the offset from first block and first page, in bytes, aligned on page
+ *        size
+ * @ops: the mtd oob structure
+ *
+ * Reads flash memory OOB area of pages.
+ *
+ * Returns 0 if read successful, of -EIO, -EINVAL if an error occurred
+ */
+static int doc_read_oob(struct mtd_info *mtd, loff_t from,
+			struct mtd_oob_ops *ops)
+{
+	struct docg3 *docg3 = mtd->priv;
+	int block0, block1, page, ret, skip, ofs = 0;
+	u8 *oobbuf = ops->oobbuf;
+	u8 *buf = ops->datbuf;
+	size_t len, ooblen, nbdata, nboob;
+	u8 hwecc[DOC_ECC_BCH_SIZE], eccconf1;
+	struct mtd_ecc_stats old_stats;
+	int max_bitflips = 0;
+
+	if (buf)
+		len = ops->len;
+	else
+		len = 0;
+	if (oobbuf)
+		ooblen = ops->ooblen;
+	else
+		ooblen = 0;
+
+	if (oobbuf && ops->mode == MTD_OPS_PLACE_OOB)
+		oobbuf += ops->ooboffs;
+
+	doc_dbg("doc_read_oob(from=%lld, mode=%d, data=(%p:%zu), oob=(%p:%zu))\n",
+		from, ops->mode, buf, len, oobbuf, ooblen);
+	if (ooblen % DOC_LAYOUT_OOB_SIZE)
+		return -EINVAL;
+
+	ops->oobretlen = 0;
+	ops->retlen = 0;
+	ret = 0;
+	skip = from % DOC_LAYOUT_PAGE_SIZE;
+	mutex_lock(&docg3->cascade->lock);
+	old_stats = mtd->ecc_stats;
+	while (ret >= 0 && (len > 0 || ooblen > 0)) {
+		calc_block_sector(from - skip, &block0, &block1, &page, &ofs,
+			docg3->reliable);
+		nbdata = min_t(size_t, len, DOC_LAYOUT_PAGE_SIZE - skip);
+		nboob = min_t(size_t, ooblen, (size_t)DOC_LAYOUT_OOB_SIZE);
+		ret = doc_read_page_prepare(docg3, block0, block1, page, ofs);
+		if (ret < 0)
+			goto out;
+		ret = doc_read_page_ecc_init(docg3, DOC_ECC_BCH_TOTAL_BYTES);
+		if (ret < 0)
+			goto err_in_read;
+		ret = doc_read_page_getbytes(docg3, skip, NULL, 1, 0);
+		if (ret < skip)
+			goto err_in_read;
+		ret = doc_read_page_getbytes(docg3, nbdata, buf, 0, skip % 2);
+		if (ret < nbdata)
+			goto err_in_read;
+		doc_read_page_getbytes(docg3,
+				       DOC_LAYOUT_PAGE_SIZE - nbdata - skip,
+				       NULL, 0, (skip + nbdata) % 2);
+		ret = doc_read_page_getbytes(docg3, nboob, oobbuf, 0, 0);
+		if (ret < nboob)
+			goto err_in_read;
+		doc_read_page_getbytes(docg3, DOC_LAYOUT_OOB_SIZE - nboob,
+				       NULL, 0, nboob % 2);
+
+		doc_get_bch_hw_ecc(docg3, hwecc);
+		eccconf1 = doc_register_readb(docg3, DOC_ECCCONF1);
+
+		if (nboob >= DOC_LAYOUT_OOB_SIZE) {
+			doc_dbg("OOB - INFO: %*phC\n", 7, oobbuf);
+			doc_dbg("OOB - HAMMING: %02x\n", oobbuf[7]);
+			doc_dbg("OOB - BCH_ECC: %*phC\n", 7, oobbuf + 8);
+			doc_dbg("OOB - UNUSED: %02x\n", oobbuf[15]);
+		}
+		doc_dbg("ECC checks: ECCConf1=%x\n", eccconf1);
+		doc_dbg("ECC HW_ECC: %*phC\n", 7, hwecc);
+
+		ret = -EIO;
+		if (is_prot_seq_error(docg3))
+			goto err_in_read;
+		ret = 0;
+		if ((block0 >= DOC_LAYOUT_BLOCK_FIRST_DATA) &&
+		    (eccconf1 & DOC_ECCCONF1_BCH_SYNDROM_ERR) &&
+		    (eccconf1 & DOC_ECCCONF1_PAGE_IS_WRITTEN) &&
+		    (ops->mode != MTD_OPS_RAW) &&
+		    (nbdata == DOC_LAYOUT_PAGE_SIZE)) {
+			ret = doc_ecc_bch_fix_data(docg3, buf, hwecc);
+			if (ret < 0) {
+				mtd->ecc_stats.failed++;
+				ret = -EBADMSG;
+			}
+			if (ret > 0) {
+				mtd->ecc_stats.corrected += ret;
+				max_bitflips = max(max_bitflips, ret);
+				ret = max_bitflips;
+			}
+		}
+
+		doc_read_page_finish(docg3);
+		ops->retlen += nbdata;
+		ops->oobretlen += nboob;
+		buf += nbdata;
+		oobbuf += nboob;
+		len -= nbdata;
+		ooblen -= nboob;
+		from += DOC_LAYOUT_PAGE_SIZE;
+		skip = 0;
+	}
+
+out:
+	if (ops->stats) {
+		ops->stats->uncorrectable_errors +=
+			mtd->ecc_stats.failed - old_stats.failed;
+		ops->stats->corrected_bitflips +=
+			mtd->ecc_stats.corrected - old_stats.corrected;
+	}
+	mutex_unlock(&docg3->cascade->lock);
+	return ret;
+err_in_read:
+	doc_read_page_finish(docg3);
+	goto out;
+}
+
+static int doc_reload_bbt(struct docg3 *docg3)
+{
+	int block = DOC_LAYOUT_BLOCK_BBT;
+	int ret = 0, nbpages, page;
+	u_char *buf = docg3->bbt;
+
+	nbpages = DIV_ROUND_UP(docg3->max_block + 1, 8 * DOC_LAYOUT_PAGE_SIZE);
+	for (page = 0; !ret && (page < nbpages); page++) {
+		ret = doc_read_page_prepare(docg3, block, block + 1,
+					    page + DOC_LAYOUT_PAGE_BBT, 0);
+		if (!ret)
+			ret = doc_read_page_ecc_init(docg3,
+						     DOC_LAYOUT_PAGE_SIZE);
+		if (!ret)
+			doc_read_page_getbytes(docg3, DOC_LAYOUT_PAGE_SIZE,
+					       buf, 1, 0);
+		buf += DOC_LAYOUT_PAGE_SIZE;
+	}
+	doc_read_page_finish(docg3);
+	return ret;
+}
+
+/**
+ * doc_block_isbad - Checks whether a block is good or not
+ * @mtd: the device
+ * @from: the offset to find the correct block
+ *
+ * Returns 1 if block is bad, 0 if block is good
+ */
+static int doc_block_isbad(struct mtd_info *mtd, loff_t from)
+{
+	struct docg3 *docg3 = mtd->priv;
+	int block0, block1, page, ofs, is_good;
+
+	calc_block_sector(from, &block0, &block1, &page, &ofs,
+		docg3->reliable);
+	doc_dbg("doc_block_isbad(from=%lld) => block=(%d,%d), page=%d, ofs=%d\n",
+		from, block0, block1, page, ofs);
+
+	if (block0 < DOC_LAYOUT_BLOCK_FIRST_DATA)
+		return 0;
+	if (block1 > docg3->max_block)
+		return -EINVAL;
+
+	is_good = docg3->bbt[block0 >> 3] & (1 << (block0 & 0x7));
+	return !is_good;
+}
+
+#if 0
+/**
+ * doc_get_erase_count - Get block erase count
+ * @docg3: the device
+ * @from: the offset in which the block is.
+ *
+ * Get the number of times a block was erased. The number is the maximum of
+ * erase times between first and second plane (which should be equal normally).
+ *
+ * Returns The number of erases, or -EINVAL or -EIO on error.
+ */
+static int doc_get_erase_count(struct docg3 *docg3, loff_t from)
+{
+	u8 buf[DOC_LAYOUT_WEAR_SIZE];
+	int ret, plane1_erase_count, plane2_erase_count;
+	int block0, block1, page, ofs;
+
+	doc_dbg("doc_get_erase_count(from=%lld, buf=%p)\n", from, buf);
+	if (from % DOC_LAYOUT_PAGE_SIZE)
+		return -EINVAL;
+	calc_block_sector(from, &block0, &block1, &page, &ofs, docg3->reliable);
+	if (block1 > docg3->max_block)
+		return -EINVAL;
+
+	ret = doc_reset_seq(docg3);
+	if (!ret)
+		ret = doc_read_page_prepare(docg3, block0, block1, page,
+					    ofs + DOC_LAYOUT_WEAR_OFFSET, 0);
+	if (!ret)
+		ret = doc_read_page_getbytes(docg3, DOC_LAYOUT_WEAR_SIZE,
+					     buf, 1, 0);
+	doc_read_page_finish(docg3);
+
+	if (ret || (buf[0] != DOC_ERASE_MARK) || (buf[2] != DOC_ERASE_MARK))
+		return -EIO;
+	plane1_erase_count = (u8)(~buf[1]) | ((u8)(~buf[4]) << 8)
+		| ((u8)(~buf[5]) << 16);
+	plane2_erase_count = (u8)(~buf[3]) | ((u8)(~buf[6]) << 8)
+		| ((u8)(~buf[7]) << 16);
+
+	return max(plane1_erase_count, plane2_erase_count);
+}
+#endif
+
+/**
+ * doc_get_op_status - get erase/write operation status
+ * @docg3: the device
+ *
+ * Queries the status from the chip, and returns it
+ *
+ * Returns the status (bits DOC_PLANES_STATUS_*)
+ */
+static int doc_get_op_status(struct docg3 *docg3)
+{
+	u8 status;
+
+	doc_flash_sequence(docg3, DOC_SEQ_PLANES_STATUS);
+	doc_flash_command(docg3, DOC_CMD_PLANES_STATUS);
+	doc_delay(docg3, 5);
+
+	doc_ecc_disable(docg3);
+	doc_read_data_area(docg3, &status, 1, 1);
+	return status;
+}
+
+/**
+ * doc_write_erase_wait_status - wait for write or erase completion
+ * @docg3: the device
+ *
+ * Wait for the chip to be ready again after erase or write operation, and check
+ * erase/write status.
+ *
+ * Returns 0 if erase successful, -EIO if erase/write issue, -ETIMEOUT if
+ * timeout
+ */
+static int doc_write_erase_wait_status(struct docg3 *docg3)
+{
+	int i, status, ret = 0;
+
+	for (i = 0; !doc_is_ready(docg3) && i < 5; i++)
+		msleep(20);
+	if (!doc_is_ready(docg3)) {
+		doc_dbg("Timeout reached and the chip is still not ready\n");
+		ret = -EAGAIN;
+		goto out;
+	}
+
+	status = doc_get_op_status(docg3);
+	if (status & DOC_PLANES_STATUS_FAIL) {
+		doc_dbg("Erase/Write failed on (a) plane(s), status = %x\n",
+			status);
+		ret = -EIO;
+	}
+
+out:
+	doc_page_finish(docg3);
+	return ret;
+}
+
+/**
+ * doc_erase_block - Erase a couple of blocks
+ * @docg3: the device
+ * @block0: the first block to erase (leftmost plane)
+ * @block1: the second block to erase (rightmost plane)
+ *
+ * Erase both blocks, and return operation status
+ *
+ * Returns 0 if erase successful, -EIO if erase issue, -ETIMEOUT if chip not
+ * ready for too long
+ */
+static int doc_erase_block(struct docg3 *docg3, int block0, int block1)
+{
+	int ret, sector;
+
+	doc_dbg("doc_erase_block(blocks=(%d,%d))\n", block0, block1);
+	ret = doc_reset_seq(docg3);
+	if (ret)
+		return -EIO;
+
+	doc_set_reliable_mode(docg3);
+	doc_flash_sequence(docg3, DOC_SEQ_ERASE);
+
+	sector = block0 << DOC_ADDR_BLOCK_SHIFT;
+	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
+	doc_setup_addr_sector(docg3, sector);
+	sector = block1 << DOC_ADDR_BLOCK_SHIFT;
+	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
+	doc_setup_addr_sector(docg3, sector);
+	doc_delay(docg3, 1);
+
+	doc_flash_command(docg3, DOC_CMD_ERASECYCLE2);
+	doc_delay(docg3, 2);
+
+	if (is_prot_seq_error(docg3)) {
+		doc_err("Erase blocks %d,%d error\n", block0, block1);
+		return -EIO;
+	}
+
+	return doc_write_erase_wait_status(docg3);
+}
+
+/**
+ * doc_erase - Erase a portion of the chip
+ * @mtd: the device
+ * @info: the erase info
+ *
+ * Erase a bunch of contiguous blocks, by pairs, as a "mtd" page of 1024 is
+ * split into 2 pages of 512 bytes on 2 contiguous blocks.
+ *
+ * Returns 0 if erase successful, -EINVAL if addressing error, -EIO if erase
+ * issue
+ */
+static int doc_erase(struct mtd_info *mtd, struct erase_info *info)
+{
+	struct docg3 *docg3 = mtd->priv;
+	uint64_t len;
+	int block0, block1, page, ret = 0, ofs = 0;
+
+	doc_dbg("doc_erase(from=%lld, len=%lld\n", info->addr, info->len);
+
+	calc_block_sector(info->addr + info->len, &block0, &block1, &page,
+			  &ofs, docg3->reliable);
+	if (info->addr + info->len > mtd->size || page || ofs)
+		return -EINVAL;
+
+	calc_block_sector(info->addr, &block0, &block1, &page, &ofs,
+			  docg3->reliable);
+	mutex_lock(&docg3->cascade->lock);
+	doc_set_device_id(docg3, docg3->device_id);
+	doc_set_reliable_mode(docg3);
+	for (len = info->len; !ret && len > 0; len -= mtd->erasesize) {
+		ret = doc_erase_block(docg3, block0, block1);
+		block0 += 2;
+		block1 += 2;
+	}
+	mutex_unlock(&docg3->cascade->lock);
+
+	return ret;
+}
+
+/**
+ * doc_write_page - Write a single page to the chip
+ * @docg3: the device
+ * @to: the offset from first block and first page, in bytes, aligned on page
+ *      size
+ * @buf: buffer to get bytes from
+ * @oob: buffer to get out of band bytes from (can be NULL if no OOB should be
+ *       written)
+ * @autoecc: if 0, all 16 bytes from OOB are taken, regardless of HW Hamming or
+ *           BCH computations. If 1, only bytes 0-7 and byte 15 are taken,
+ *           remaining ones are filled with hardware Hamming and BCH
+ *           computations. Its value is not meaningfull is oob == NULL.
+ *
+ * Write one full page (ie. 1 page split on two planes), of 512 bytes, with the
+ * OOB data. The OOB ECC is automatically computed by the hardware Hamming and
+ * BCH generator if autoecc is not null.
+ *
+ * Returns 0 if write successful, -EIO if write error, -EAGAIN if timeout
+ */
+static int doc_write_page(struct docg3 *docg3, loff_t to, const u_char *buf,
+			  const u_char *oob, int autoecc)
+{
+	int block0, block1, page, ret, ofs = 0;
+	u8 hwecc[DOC_ECC_BCH_SIZE], hamming;
+
+	doc_dbg("doc_write_page(to=%lld)\n", to);
+	calc_block_sector(to, &block0, &block1, &page, &ofs, docg3->reliable);
+
+	doc_set_device_id(docg3, docg3->device_id);
+	ret = doc_reset_seq(docg3);
+	if (ret)
+		goto err;
+
+	/* Program the flash address block and page */
+	ret = doc_write_seek(docg3, block0, block1, page, ofs);
+	if (ret)
+		goto err;
+
+	doc_write_page_ecc_init(docg3, DOC_ECC_BCH_TOTAL_BYTES);
+	doc_delay(docg3, 2);
+	doc_write_page_putbytes(docg3, DOC_LAYOUT_PAGE_SIZE, buf);
+
+	if (oob && autoecc) {
+		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_PAGEINFO_SZ, oob);
+		doc_delay(docg3, 2);
+		oob += DOC_LAYOUT_OOB_UNUSED_OFS;
+
+		hamming = doc_register_readb(docg3, DOC_HAMMINGPARITY);
+		doc_delay(docg3, 2);
+		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_HAMMING_SZ,
+					&hamming);
+		doc_delay(docg3, 2);
+
+		doc_get_bch_hw_ecc(docg3, hwecc);
+		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_BCH_SZ, hwecc);
+		doc_delay(docg3, 2);
+
+		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_UNUSED_SZ, oob);
+	}
+	if (oob && !autoecc)
+		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_SIZE, oob);
+
+	doc_delay(docg3, 2);
+	doc_page_finish(docg3);
+	doc_delay(docg3, 2);
+	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE2);
+	doc_delay(docg3, 2);
+
+	/*
+	 * The wait status will perform another doc_page_finish() call, but that
+	 * seems to please the docg3, so leave it.
+	 */
+	ret = doc_write_erase_wait_status(docg3);
+	return ret;
+err:
+	doc_read_page_finish(docg3);
+	return ret;
+}
+
+/**
+ * doc_guess_autoecc - Guess autoecc mode from mbd_oob_ops
+ * @ops: the oob operations
+ *
+ * Returns 0 or 1 if success, -EINVAL if invalid oob mode
+ */
+static int doc_guess_autoecc(struct mtd_oob_ops *ops)
+{
+	int autoecc;
+
+	switch (ops->mode) {
+	case MTD_OPS_PLACE_OOB:
+	case MTD_OPS_AUTO_OOB:
+		autoecc = 1;
+		break;
+	case MTD_OPS_RAW:
+		autoecc = 0;
+		break;
+	default:
+		autoecc = -EINVAL;
+	}
+	return autoecc;
+}
+
+/**
+ * doc_fill_autooob - Fill a 16 bytes OOB from 8 non-ECC bytes
+ * @dst: the target 16 bytes OOB buffer
+ * @oobsrc: the source 8 bytes non-ECC OOB buffer
+ *
+ */
+static void doc_fill_autooob(u8 *dst, u8 *oobsrc)
+{
+	memcpy(dst, oobsrc, DOC_LAYOUT_OOB_PAGEINFO_SZ);
+	dst[DOC_LAYOUT_OOB_UNUSED_OFS] = oobsrc[DOC_LAYOUT_OOB_PAGEINFO_SZ];
+}
+
+/**
+ * doc_backup_oob - Backup OOB into docg3 structure
+ * @docg3: the device
+ * @to: the page offset in the chip
+ * @ops: the OOB size and buffer
+ *
+ * As the docg3 should write a page with its OOB in one pass, and some userland
+ * applications do write_oob() to setup the OOB and then write(), store the OOB
+ * into a temporary storage. This is very dangerous, as 2 concurrent
+ * applications could store an OOB, and then write their pages (which will
+ * result into one having its OOB corrupted).
+ *
+ * The only reliable way would be for userland to call doc_write_oob() with both
+ * the page data _and_ the OOB area.
+ *
+ * Returns 0 if success, -EINVAL if ops content invalid
+ */
+static int doc_backup_oob(struct docg3 *docg3, loff_t to,
+			  struct mtd_oob_ops *ops)
+{
+	int ooblen = ops->ooblen, autoecc;
+
+	if (ooblen != DOC_LAYOUT_OOB_SIZE)
+		return -EINVAL;
+	autoecc = doc_guess_autoecc(ops);
+	if (autoecc < 0)
+		return autoecc;
+
+	docg3->oob_write_ofs = to;
+	docg3->oob_autoecc = autoecc;
+	if (ops->mode == MTD_OPS_AUTO_OOB) {
+		doc_fill_autooob(docg3->oob_write_buf, ops->oobbuf);
+		ops->oobretlen = 8;
+	} else {
+		memcpy(docg3->oob_write_buf, ops->oobbuf, DOC_LAYOUT_OOB_SIZE);
+		ops->oobretlen = DOC_LAYOUT_OOB_SIZE;
+	}
+	return 0;
+}
+
+/**
+ * doc_write_oob - Write out of band bytes to flash
+ * @mtd: the device
+ * @ofs: the offset from first block and first page, in bytes, aligned on page
+ *       size
+ * @ops: the mtd oob structure
+ *
+ * Either write OOB data into a temporary buffer, for the subsequent write
+ * page. The provided OOB should be 16 bytes long. If a data buffer is provided
+ * as well, issue the page write.
+ * Or provide data without OOB, and then a all zeroed OOB will be used (ECC will
+ * still be filled in if asked for).
+ *
+ * Returns 0 is successful, EINVAL if length is not 14 bytes
+ */
+static int doc_write_oob(struct mtd_info *mtd, loff_t ofs,
+			 struct mtd_oob_ops *ops)
+{
+	struct docg3 *docg3 = mtd->priv;
+	int ret, autoecc, oobdelta;
+	u8 *oobbuf = ops->oobbuf;
+	u8 *buf = ops->datbuf;
+	size_t len, ooblen;
+	u8 oob[DOC_LAYOUT_OOB_SIZE];
+
+	if (buf)
+		len = ops->len;
+	else
+		len = 0;
+	if (oobbuf)
+		ooblen = ops->ooblen;
+	else
+		ooblen = 0;
+
+	if (oobbuf && ops->mode == MTD_OPS_PLACE_OOB)
+		oobbuf += ops->ooboffs;
+
+	doc_dbg("doc_write_oob(from=%lld, mode=%d, data=(%p:%zu), oob=(%p:%zu))\n",
+		ofs, ops->mode, buf, len, oobbuf, ooblen);
+	switch (ops->mode) {
+	case MTD_OPS_PLACE_OOB:
+	case MTD_OPS_RAW:
+		oobdelta = mtd->oobsize;
+		break;
+	case MTD_OPS_AUTO_OOB:
+		oobdelta = mtd->oobavail;
+		break;
+	default:
+		return -EINVAL;
+	}
+	if ((len % DOC_LAYOUT_PAGE_SIZE) || (ooblen % oobdelta) ||
+	    (ofs % DOC_LAYOUT_PAGE_SIZE))
+		return -EINVAL;
+	if (len && ooblen &&
+	    (len / DOC_LAYOUT_PAGE_SIZE) != (ooblen / oobdelta))
+		return -EINVAL;
+
+	ops->oobretlen = 0;
+	ops->retlen = 0;
+	ret = 0;
+	if (len == 0 && ooblen == 0)
+		return -EINVAL;
+	if (len == 0 && ooblen > 0)
+		return doc_backup_oob(docg3, ofs, ops);
+
+	autoecc = doc_guess_autoecc(ops);
+	if (autoecc < 0)
+		return autoecc;
+
+	mutex_lock(&docg3->cascade->lock);
+	while (!ret && len > 0) {
+		memset(oob, 0, sizeof(oob));
+		if (ofs == docg3->oob_write_ofs)
+			memcpy(oob, docg3->oob_write_buf, DOC_LAYOUT_OOB_SIZE);
+		else if (ooblen > 0 && ops->mode == MTD_OPS_AUTO_OOB)
+			doc_fill_autooob(oob, oobbuf);
+		else if (ooblen > 0)
+			memcpy(oob, oobbuf, DOC_LAYOUT_OOB_SIZE);
+		ret = doc_write_page(docg3, ofs, buf, oob, autoecc);
+
+		ofs += DOC_LAYOUT_PAGE_SIZE;
+		len -= DOC_LAYOUT_PAGE_SIZE;
+		buf += DOC_LAYOUT_PAGE_SIZE;
+		if (ooblen) {
+			oobbuf += oobdelta;
+			ooblen -= oobdelta;
+			ops->oobretlen += oobdelta;
+		}
+		ops->retlen += DOC_LAYOUT_PAGE_SIZE;
+	}
+
+	doc_set_device_id(docg3, 0);
+	mutex_unlock(&docg3->cascade->lock);
+	return ret;
+}
+
+static struct docg3 *sysfs_dev2docg3(struct device *dev,
+				     struct device_attribute *attr)
+{
+	int floor;
+	struct mtd_info **docg3_floors = dev_get_drvdata(dev);
+
+	floor = attr->attr.name[1] - '0';
+	if (floor < 0 || floor >= DOC_MAX_NBFLOORS)
+		return NULL;
+	else
+		return docg3_floors[floor]->priv;
+}
+
+static ssize_t dps0_is_key_locked(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
+	int dps0;
+
+	mutex_lock(&docg3->cascade->lock);
+	doc_set_device_id(docg3, docg3->device_id);
+	dps0 = doc_register_readb(docg3, DOC_DPS0_STATUS);
+	doc_set_device_id(docg3, 0);
+	mutex_unlock(&docg3->cascade->lock);
+
+	return sprintf(buf, "%d\n", !(dps0 & DOC_DPS_KEY_OK));
+}
+
+static ssize_t dps1_is_key_locked(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
+	int dps1;
+
+	mutex_lock(&docg3->cascade->lock);
+	doc_set_device_id(docg3, docg3->device_id);
+	dps1 = doc_register_readb(docg3, DOC_DPS1_STATUS);
+	doc_set_device_id(docg3, 0);
+	mutex_unlock(&docg3->cascade->lock);
+
+	return sprintf(buf, "%d\n", !(dps1 & DOC_DPS_KEY_OK));
+}
+
+static ssize_t dps0_insert_key(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
+	int i;
+
+	if (count != DOC_LAYOUT_DPS_KEY_LENGTH)
+		return -EINVAL;
+
+	mutex_lock(&docg3->cascade->lock);
+	doc_set_device_id(docg3, docg3->device_id);
+	for (i = 0; i < DOC_LAYOUT_DPS_KEY_LENGTH; i++)
+		doc_writeb(docg3, buf[i], DOC_DPS0_KEY);
+	doc_set_device_id(docg3, 0);
+	mutex_unlock(&docg3->cascade->lock);
+	return count;
+}
+
+static ssize_t dps1_insert_key(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);
+	int i;
+
+	if (count != DOC_LAYOUT_DPS_KEY_LENGTH)
+		return -EINVAL;
+
+	mutex_lock(&docg3->cascade->lock);
+	doc_set_device_id(docg3, docg3->device_id);
+	for (i = 0; i < DOC_LAYOUT_DPS_KEY_LENGTH; i++)
+		doc_writeb(docg3, buf[i], DOC_DPS1_KEY);
+	doc_set_device_id(docg3, 0);
+	mutex_unlock(&docg3->cascade->lock);
+	return count;
+}
+
+#define FLOOR_SYSFS(id) { \
+	__ATTR(f##id##_dps0_is_keylocked, S_IRUGO, dps0_is_key_locked, NULL), \
+	__ATTR(f##id##_dps1_is_keylocked, S_IRUGO, dps1_is_key_locked, NULL), \
+	__ATTR(f##id##_dps0_protection_key, S_IWUSR|S_IWGRP, NULL, dps0_insert_key), \
+	__ATTR(f##id##_dps1_protection_key, S_IWUSR|S_IWGRP, NULL, dps1_insert_key), \
+}
+
+static struct device_attribute doc_sys_attrs[DOC_MAX_NBFLOORS][4] = {
+	FLOOR_SYSFS(0), FLOOR_SYSFS(1), FLOOR_SYSFS(2), FLOOR_SYSFS(3)
+};
+
+static int doc_register_sysfs(struct platform_device *pdev,
+			      struct docg3_cascade *cascade)
+{
+	struct device *dev = &pdev->dev;
+	int floor;
+	int ret;
+	int i;
+
+	for (floor = 0;
+	     floor < DOC_MAX_NBFLOORS && cascade->floors[floor];
+	     floor++) {
+		for (i = 0; i < 4; i++) {
+			ret = device_create_file(dev, &doc_sys_attrs[floor][i]);
+			if (ret)
+				goto remove_files;
+		}
+	}
+
+	return 0;
+
+remove_files:
+	do {
+		while (--i >= 0)
+			device_remove_file(dev, &doc_sys_attrs[floor][i]);
+		i = 4;
+	} while (--floor >= 0);
+
+	return ret;
+}
+
+static void doc_unregister_sysfs(struct platform_device *pdev,
+				 struct docg3_cascade *cascade)
+{
+	struct device *dev = &pdev->dev;
+	int floor, i;
+
+	for (floor = 0; floor < DOC_MAX_NBFLOORS && cascade->floors[floor];
+	     floor++)
+		for (i = 0; i < 4; i++)
+			device_remove_file(dev, &doc_sys_attrs[floor][i]);
+}
+
+/*
+ * Debug sysfs entries
+ */
+static int flashcontrol_show(struct seq_file *s, void *p)
+{
+	struct docg3 *docg3 = (struct docg3 *)s->private;
+
+	u8 fctrl;
+
+	mutex_lock(&docg3->cascade->lock);
+	fctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
+	mutex_unlock(&docg3->cascade->lock);
+
+	seq_printf(s, "FlashControl : 0x%02x (%s,CE# %s,%s,%s,flash %s)\n",
+		   fctrl,
+		   fctrl & DOC_CTRL_VIOLATION ? "protocol violation" : "-",
+		   fctrl & DOC_CTRL_CE ? "active" : "inactive",
+		   fctrl & DOC_CTRL_PROTECTION_ERROR ? "protection error" : "-",
+		   fctrl & DOC_CTRL_SEQUENCE_ERROR ? "sequence error" : "-",
+		   fctrl & DOC_CTRL_FLASHREADY ? "ready" : "not ready");
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(flashcontrol);
+
+static int asic_mode_show(struct seq_file *s, void *p)
+{
+	struct docg3 *docg3 = (struct docg3 *)s->private;
+
+	int pctrl, mode;
+
+	mutex_lock(&docg3->cascade->lock);
+	pctrl = doc_register_readb(docg3, DOC_ASICMODE);
+	mode = pctrl & 0x03;
+	mutex_unlock(&docg3->cascade->lock);
+
+	seq_printf(s,
+		   "%04x : RAM_WE=%d,RSTIN_RESET=%d,BDETCT_RESET=%d,WRITE_ENABLE=%d,POWERDOWN=%d,MODE=%d%d (",
+		   pctrl,
+		   pctrl & DOC_ASICMODE_RAM_WE ? 1 : 0,
+		   pctrl & DOC_ASICMODE_RSTIN_RESET ? 1 : 0,
+		   pctrl & DOC_ASICMODE_BDETCT_RESET ? 1 : 0,
+		   pctrl & DOC_ASICMODE_MDWREN ? 1 : 0,
+		   pctrl & DOC_ASICMODE_POWERDOWN ? 1 : 0,
+		   mode >> 1, mode & 0x1);
+
+	switch (mode) {
+	case DOC_ASICMODE_RESET:
+		seq_puts(s, "reset");
+		break;
+	case DOC_ASICMODE_NORMAL:
+		seq_puts(s, "normal");
+		break;
+	case DOC_ASICMODE_POWERDOWN:
+		seq_puts(s, "powerdown");
+		break;
+	}
+	seq_puts(s, ")\n");
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(asic_mode);
+
+static int device_id_show(struct seq_file *s, void *p)
+{
+	struct docg3 *docg3 = (struct docg3 *)s->private;
+	int id;
+
+	mutex_lock(&docg3->cascade->lock);
+	id = doc_register_readb(docg3, DOC_DEVICESELECT);
+	mutex_unlock(&docg3->cascade->lock);
+
+	seq_printf(s, "DeviceId = %d\n", id);
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(device_id);
+
+static int protection_show(struct seq_file *s, void *p)
+{
+	struct docg3 *docg3 = (struct docg3 *)s->private;
+	int protect, dps0, dps0_low, dps0_high, dps1, dps1_low, dps1_high;
+
+	mutex_lock(&docg3->cascade->lock);
+	protect = doc_register_readb(docg3, DOC_PROTECTION);
+	dps0 = doc_register_readb(docg3, DOC_DPS0_STATUS);
+	dps0_low = doc_register_readw(docg3, DOC_DPS0_ADDRLOW);
+	dps0_high = doc_register_readw(docg3, DOC_DPS0_ADDRHIGH);
+	dps1 = doc_register_readb(docg3, DOC_DPS1_STATUS);
+	dps1_low = doc_register_readw(docg3, DOC_DPS1_ADDRLOW);
+	dps1_high = doc_register_readw(docg3, DOC_DPS1_ADDRHIGH);
+	mutex_unlock(&docg3->cascade->lock);
+
+	seq_printf(s, "Protection = 0x%02x (", protect);
+	if (protect & DOC_PROTECT_FOUNDRY_OTP_LOCK)
+		seq_puts(s, "FOUNDRY_OTP_LOCK,");
+	if (protect & DOC_PROTECT_CUSTOMER_OTP_LOCK)
+		seq_puts(s, "CUSTOMER_OTP_LOCK,");
+	if (protect & DOC_PROTECT_LOCK_INPUT)
+		seq_puts(s, "LOCK_INPUT,");
+	if (protect & DOC_PROTECT_STICKY_LOCK)
+		seq_puts(s, "STICKY_LOCK,");
+	if (protect & DOC_PROTECT_PROTECTION_ENABLED)
+		seq_puts(s, "PROTECTION ON,");
+	if (protect & DOC_PROTECT_IPL_DOWNLOAD_LOCK)
+		seq_puts(s, "IPL_DOWNLOAD_LOCK,");
+	if (protect & DOC_PROTECT_PROTECTION_ERROR)
+		seq_puts(s, "PROTECT_ERR,");
+	else
+		seq_puts(s, "NO_PROTECT_ERR");
+	seq_puts(s, ")\n");
+
+	seq_printf(s, "DPS0 = 0x%02x : Protected area [0x%x - 0x%x] : OTP=%d, READ=%d, WRITE=%d, HW_LOCK=%d, KEY_OK=%d\n",
+		   dps0, dps0_low, dps0_high,
+		   !!(dps0 & DOC_DPS_OTP_PROTECTED),
+		   !!(dps0 & DOC_DPS_READ_PROTECTED),
+		   !!(dps0 & DOC_DPS_WRITE_PROTECTED),
+		   !!(dps0 & DOC_DPS_HW_LOCK_ENABLED),
+		   !!(dps0 & DOC_DPS_KEY_OK));
+	seq_printf(s, "DPS1 = 0x%02x : Protected area [0x%x - 0x%x] : OTP=%d, READ=%d, WRITE=%d, HW_LOCK=%d, KEY_OK=%d\n",
+		   dps1, dps1_low, dps1_high,
+		   !!(dps1 & DOC_DPS_OTP_PROTECTED),
+		   !!(dps1 & DOC_DPS_READ_PROTECTED),
+		   !!(dps1 & DOC_DPS_WRITE_PROTECTED),
+		   !!(dps1 & DOC_DPS_HW_LOCK_ENABLED),
+		   !!(dps1 & DOC_DPS_KEY_OK));
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(protection);
+
+static void __init doc_dbg_register(struct mtd_info *floor)
+{
+	struct dentry *root = floor->dbg.dfs_dir;
+	struct docg3 *docg3 = floor->priv;
+
+	if (IS_ERR_OR_NULL(root)) {
+		if (IS_ENABLED(CONFIG_DEBUG_FS) &&
+		    !IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
+			dev_warn(floor->dev.parent,
+				 "CONFIG_MTD_PARTITIONED_MASTER must be enabled to expose debugfs stuff\n");
+		return;
+	}
+
+	debugfs_create_file("docg3_flashcontrol", S_IRUSR, root, docg3,
+			    &flashcontrol_fops);
+	debugfs_create_file("docg3_asic_mode", S_IRUSR, root, docg3,
+			    &asic_mode_fops);
+	debugfs_create_file("docg3_device_id", S_IRUSR, root, docg3,
+			    &device_id_fops);
+	debugfs_create_file("docg3_protection", S_IRUSR, root, docg3,
+			    &protection_fops);
+}
+
+/**
+ * doc_set_driver_info - Fill the mtd_info structure and docg3 structure
+ * @chip_id: The chip ID of the supported chip
+ * @mtd: The structure to fill
+ */
+static int __init doc_set_driver_info(int chip_id, struct mtd_info *mtd)
+{
+	struct docg3 *docg3 = mtd->priv;
+	int cfg;
+
+	cfg = doc_register_readb(docg3, DOC_CONFIGURATION);
+	docg3->if_cfg = (cfg & DOC_CONF_IF_CFG ? 1 : 0);
+	docg3->reliable = reliable_mode;
+
+	switch (chip_id) {
+	case DOC_CHIPID_G3:
+		mtd->name = devm_kasprintf(docg3->dev, GFP_KERNEL, "docg3.%d",
+					   docg3->device_id);
+		if (!mtd->name)
+			return -ENOMEM;
+		docg3->max_block = 2047;
+		break;
+	}
+	mtd->type = MTD_NANDFLASH;
+	mtd->flags = MTD_CAP_NANDFLASH;
+	mtd->size = (docg3->max_block + 1) * DOC_LAYOUT_BLOCK_SIZE;
+	if (docg3->reliable == 2)
+		mtd->size /= 2;
+	mtd->erasesize = DOC_LAYOUT_BLOCK_SIZE * DOC_LAYOUT_NBPLANES;
+	if (docg3->reliable == 2)
+		mtd->erasesize /= 2;
+	mtd->writebufsize = mtd->writesize = DOC_LAYOUT_PAGE_SIZE;
+	mtd->oobsize = DOC_LAYOUT_OOB_SIZE;
+	mtd->_erase = doc_erase;
+	mtd->_read_oob = doc_read_oob;
+	mtd->_write_oob = doc_write_oob;
+	mtd->_block_isbad = doc_block_isbad;
+	mtd_set_ooblayout(mtd, &nand_ooblayout_docg3_ops);
+	mtd->oobavail = 8;
+	mtd->ecc_strength = DOC_ECC_BCH_T;
+
+	return 0;
+}
+
+/**
+ * doc_probe_device - Check if a device is available
+ * @cascade: the cascade of chips this devices will belong to
+ * @floor: the floor of the probed device
+ * @dev: the device
+ *
+ * Checks whether a device at the specified IO range, and floor is available.
+ *
+ * Returns a mtd_info struct if there is a device, ENODEV if none found, ENOMEM
+ * if a memory allocation failed. If floor 0 is checked, a reset of the ASIC is
+ * launched.
+ */
+static struct mtd_info * __init
+doc_probe_device(struct docg3_cascade *cascade, int floor, struct device *dev)
+{
+	int ret, bbt_nbpages;
+	u16 chip_id, chip_id_inv;
+	struct docg3 *docg3;
+	struct mtd_info *mtd;
+
+	ret = -ENOMEM;
+	docg3 = kzalloc(sizeof(struct docg3), GFP_KERNEL);
+	if (!docg3)
+		goto nomem1;
+	mtd = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
+	if (!mtd)
+		goto nomem2;
+	mtd->priv = docg3;
+	mtd->dev.parent = dev;
+	bbt_nbpages = DIV_ROUND_UP(docg3->max_block + 1,
+				   8 * DOC_LAYOUT_PAGE_SIZE);
+	docg3->bbt = kcalloc(DOC_LAYOUT_PAGE_SIZE, bbt_nbpages, GFP_KERNEL);
+	if (!docg3->bbt)
+		goto nomem3;
+
+	docg3->dev = dev;
+	docg3->device_id = floor;
+	docg3->cascade = cascade;
+	doc_set_device_id(docg3, docg3->device_id);
+	if (!floor)
+		doc_set_asic_mode(docg3, DOC_ASICMODE_RESET);
+	doc_set_asic_mode(docg3, DOC_ASICMODE_NORMAL);
+
+	chip_id = doc_register_readw(docg3, DOC_CHIPID);
+	chip_id_inv = doc_register_readw(docg3, DOC_CHIPID_INV);
+
+	ret = 0;
+	if (chip_id != (u16)(~chip_id_inv)) {
+		goto nomem4;
+	}
+
+	switch (chip_id) {
+	case DOC_CHIPID_G3:
+		doc_info("Found a G3 DiskOnChip at addr %p, floor %d\n",
+			 docg3->cascade->base, floor);
+		break;
+	default:
+		doc_err("Chip id %04x is not a DiskOnChip G3 chip\n", chip_id);
+		goto nomem4;
+	}
+
+	ret = doc_set_driver_info(chip_id, mtd);
+	if (ret)
+		goto nomem4;
+
+	doc_hamming_ecc_init(docg3, DOC_LAYOUT_OOB_PAGEINFO_SZ);
+	doc_reload_bbt(docg3);
+	return mtd;
+
+nomem4:
+	kfree(docg3->bbt);
+nomem3:
+	kfree(mtd);
+nomem2:
+	kfree(docg3);
+nomem1:
+	return ret ? ERR_PTR(ret) : NULL;
+}
+
+/**
+ * doc_release_device - Release a docg3 floor
+ * @mtd: the device
+ */
+static void doc_release_device(struct mtd_info *mtd)
+{
+	struct docg3 *docg3 = mtd->priv;
+
+	mtd_device_unregister(mtd);
+	kfree(docg3->bbt);
+	kfree(docg3);
+	kfree(mtd);
+}
+
+/**
+ * docg3_resume - Awakens docg3 floor
+ * @pdev: platfrom device
+ *
+ * Returns 0 (always successful)
+ */
+static int docg3_resume(struct platform_device *pdev)
+{
+	int i;
+	struct docg3_cascade *cascade;
+	struct mtd_info **docg3_floors, *mtd;
+	struct docg3 *docg3;
+
+	cascade = platform_get_drvdata(pdev);
+	docg3_floors = cascade->floors;
+	mtd = docg3_floors[0];
+	docg3 = mtd->priv;
+
+	doc_dbg("docg3_resume()\n");
+	for (i = 0; i < 12; i++)
+		doc_readb(docg3, DOC_IOSPACE_IPL);
+	return 0;
+}
+
+/**
+ * docg3_suspend - Put in low power mode the docg3 floor
+ * @pdev: platform device
+ * @state: power state
+ *
+ * Shuts off most of docg3 circuitery to lower power consumption.
+ *
+ * Returns 0 if suspend succeeded, -EIO if chip refused suspend
+ */
+static int docg3_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	int floor, i;
+	struct docg3_cascade *cascade;
+	struct mtd_info **docg3_floors, *mtd;
+	struct docg3 *docg3;
+	u8 ctrl, pwr_down;
+
+	cascade = platform_get_drvdata(pdev);
+	docg3_floors = cascade->floors;
+	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) {
+		mtd = docg3_floors[floor];
+		if (!mtd)
+			continue;
+		docg3 = mtd->priv;
+
+		doc_writeb(docg3, floor, DOC_DEVICESELECT);
+		ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
+		ctrl &= ~DOC_CTRL_VIOLATION & ~DOC_CTRL_CE;
+		doc_writeb(docg3, ctrl, DOC_FLASHCONTROL);
+
+		for (i = 0; i < 10; i++) {
+			usleep_range(3000, 4000);
+			pwr_down = doc_register_readb(docg3, DOC_POWERMODE);
+			if (pwr_down & DOC_POWERDOWN_READY)
+				break;
+		}
+		if (pwr_down & DOC_POWERDOWN_READY) {
+			doc_dbg("docg3_suspend(): floor %d powerdown ok\n",
+				floor);
+		} else {
+			doc_err("docg3_suspend(): floor %d powerdown failed\n",
+				floor);
+			return -EIO;
+		}
+	}
+
+	mtd = docg3_floors[0];
+	docg3 = mtd->priv;
+	doc_set_asic_mode(docg3, DOC_ASICMODE_POWERDOWN);
+	return 0;
+}
+
+/**
+ * docg3_probe - Probe the IO space for a DiskOnChip G3 chip
+ * @pdev: platform device
+ *
+ * Probes for a G3 chip at the specified IO space in the platform data
+ * ressources. The floor 0 must be available.
+ *
+ * Returns 0 on success, -ENOMEM, -ENXIO on error
+ */
+static int __init docg3_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mtd_info *mtd;
+	struct resource *ress;
+	void __iomem *base;
+	int ret, floor;
+	struct docg3_cascade *cascade;
+
+	ret = -ENXIO;
+	ress = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!ress) {
+		dev_err(dev, "No I/O memory resource defined\n");
+		return ret;
+	}
+
+	ret = -ENOMEM;
+	base = devm_ioremap(dev, ress->start, DOC_IOSPACE_SIZE);
+	if (!base) {
+		dev_err(dev, "devm_ioremap dev failed\n");
+		return ret;
+	}
+
+	cascade = devm_kcalloc(dev, DOC_MAX_NBFLOORS, sizeof(*cascade),
+			       GFP_KERNEL);
+	if (!cascade)
+		return ret;
+	cascade->base = base;
+	mutex_init(&cascade->lock);
+	cascade->bch = bch_init(DOC_ECC_BCH_M, DOC_ECC_BCH_T,
+				DOC_ECC_BCH_PRIMPOLY, false);
+	if (!cascade->bch)
+		return ret;
+
+	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) {
+		mtd = doc_probe_device(cascade, floor, dev);
+		if (IS_ERR(mtd)) {
+			ret = PTR_ERR(mtd);
+			goto err_probe;
+		}
+		if (!mtd) {
+			if (floor == 0)
+				goto notfound;
+			else
+				continue;
+		}
+		cascade->floors[floor] = mtd;
+		ret = mtd_device_parse_register(mtd, part_probes, NULL, NULL,
+						0);
+		if (ret)
+			goto err_probe;
+
+		doc_dbg_register(cascade->floors[floor]);
+	}
+
+	ret = doc_register_sysfs(pdev, cascade);
+	if (ret)
+		goto err_probe;
+
+	platform_set_drvdata(pdev, cascade);
+	return 0;
+
+notfound:
+	ret = -ENODEV;
+	dev_info(dev, "No supported DiskOnChip found\n");
+err_probe:
+	bch_free(cascade->bch);
+	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
+		if (cascade->floors[floor])
+			doc_release_device(cascade->floors[floor]);
+	return ret;
+}
+
+/**
+ * docg3_release - Release the driver
+ * @pdev: the platform device
+ *
+ * Returns 0
+ */
+static int docg3_release(struct platform_device *pdev)
+{
+	struct docg3_cascade *cascade = platform_get_drvdata(pdev);
+	struct docg3 *docg3 = cascade->floors[0]->priv;
+	int floor;
+
+	doc_unregister_sysfs(pdev, cascade);
+	for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++)
+		if (cascade->floors[floor])
+			doc_release_device(cascade->floors[floor]);
+
+	bch_free(docg3->cascade->bch);
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id docg3_dt_ids[] = {
+	{ .compatible = "m-systems,diskonchip-g3" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, docg3_dt_ids);
+#endif
+
+static struct platform_driver g3_driver = {
+	.driver		= {
+		.name	= "docg3",
+		.of_match_table = of_match_ptr(docg3_dt_ids),
+	},
+	.suspend	= docg3_suspend,
+	.resume		= docg3_resume,
+	.remove		= docg3_release,
+};
+
+module_platform_driver_probe(g3_driver, docg3_probe);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
+MODULE_DESCRIPTION("MTD driver for DiskOnChip G3");
diff --git a/drivers/mtd/devices/docg3.h b/drivers/mtd/devices/docg3.h
new file mode 100644
index 000000000..2c0c5114e
--- /dev/null
+++ b/drivers/mtd/devices/docg3.h
@@ -0,0 +1,343 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Handles the M-Systems DiskOnChip G3 chip
+ *
+ * Copyright (C) 2011 Robert Jarzmik
+ */
+
+#ifndef _MTD_DOCG3_H
+#define _MTD_DOCG3_H
+
+#include <linux/mtd/mtd.h>
+
+/*
+ * Flash memory areas :
+ *   - 0x0000 .. 0x07ff : IPL
+ *   - 0x0800 .. 0x0fff : Data area
+ *   - 0x1000 .. 0x17ff : Registers
+ *   - 0x1800 .. 0x1fff : Unknown
+ */
+#define DOC_IOSPACE_IPL			0x0000
+#define DOC_IOSPACE_DATA		0x0800
+#define DOC_IOSPACE_SIZE		0x2000
+
+/*
+ * DOC G3 layout and adressing scheme
+ *   A page address for the block "b", plane "P" and page "p":
+ *   address = [bbbb bPpp pppp]
+ */
+
+#define DOC_ADDR_PAGE_MASK		0x3f
+#define DOC_ADDR_BLOCK_SHIFT		6
+#define DOC_LAYOUT_NBPLANES		2
+#define DOC_LAYOUT_PAGES_PER_BLOCK	64
+#define DOC_LAYOUT_PAGE_SIZE		512
+#define DOC_LAYOUT_OOB_SIZE		16
+#define DOC_LAYOUT_WEAR_SIZE		8
+#define DOC_LAYOUT_PAGE_OOB_SIZE				\
+	(DOC_LAYOUT_PAGE_SIZE + DOC_LAYOUT_OOB_SIZE)
+#define DOC_LAYOUT_WEAR_OFFSET		(DOC_LAYOUT_PAGE_OOB_SIZE * 2)
+#define DOC_LAYOUT_BLOCK_SIZE					\
+	(DOC_LAYOUT_PAGES_PER_BLOCK * DOC_LAYOUT_PAGE_SIZE)
+
+/*
+ * ECC related constants
+ */
+#define DOC_ECC_BCH_M			14
+#define DOC_ECC_BCH_T			4
+#define DOC_ECC_BCH_PRIMPOLY		0x4443
+#define DOC_ECC_BCH_SIZE		7
+#define DOC_ECC_BCH_COVERED_BYTES				\
+	(DOC_LAYOUT_PAGE_SIZE + DOC_LAYOUT_OOB_PAGEINFO_SZ +	\
+	 DOC_LAYOUT_OOB_HAMMING_SZ)
+#define DOC_ECC_BCH_TOTAL_BYTES					\
+	(DOC_ECC_BCH_COVERED_BYTES + DOC_LAYOUT_OOB_BCH_SZ)
+
+/*
+ * Blocks distribution
+ */
+#define DOC_LAYOUT_BLOCK_BBT		0
+#define DOC_LAYOUT_BLOCK_OTP		0
+#define DOC_LAYOUT_BLOCK_FIRST_DATA	6
+
+#define DOC_LAYOUT_PAGE_BBT		4
+
+/*
+ * Extra page OOB (16 bytes wide) layout
+ */
+#define DOC_LAYOUT_OOB_PAGEINFO_OFS	0
+#define DOC_LAYOUT_OOB_HAMMING_OFS	7
+#define DOC_LAYOUT_OOB_BCH_OFS		8
+#define DOC_LAYOUT_OOB_UNUSED_OFS	15
+#define DOC_LAYOUT_OOB_PAGEINFO_SZ	7
+#define DOC_LAYOUT_OOB_HAMMING_SZ	1
+#define DOC_LAYOUT_OOB_BCH_SZ		7
+#define DOC_LAYOUT_OOB_UNUSED_SZ	1
+
+
+#define DOC_CHIPID_G3			0x200
+#define DOC_ERASE_MARK			0xaa
+#define DOC_MAX_NBFLOORS		4
+/*
+ * Flash registers
+ */
+#define DOC_CHIPID			0x1000
+#define DOC_TEST			0x1004
+#define DOC_BUSLOCK			0x1006
+#define DOC_ENDIANCONTROL		0x1008
+#define DOC_DEVICESELECT		0x100a
+#define DOC_ASICMODE			0x100c
+#define DOC_CONFIGURATION		0x100e
+#define DOC_INTERRUPTCONTROL		0x1010
+#define DOC_READADDRESS			0x101a
+#define DOC_DATAEND			0x101e
+#define DOC_INTERRUPTSTATUS		0x1020
+
+#define DOC_FLASHSEQUENCE		0x1032
+#define DOC_FLASHCOMMAND		0x1034
+#define DOC_FLASHADDRESS		0x1036
+#define DOC_FLASHCONTROL		0x1038
+#define DOC_NOP				0x103e
+
+#define DOC_ECCCONF0			0x1040
+#define DOC_ECCCONF1			0x1042
+#define DOC_ECCPRESET			0x1044
+#define DOC_HAMMINGPARITY		0x1046
+#define DOC_BCH_HW_ECC(idx)		(0x1048 + idx)
+
+#define DOC_PROTECTION			0x1056
+#define DOC_DPS0_KEY			0x105c
+#define DOC_DPS1_KEY			0x105e
+#define DOC_DPS0_ADDRLOW		0x1060
+#define DOC_DPS0_ADDRHIGH		0x1062
+#define DOC_DPS1_ADDRLOW		0x1064
+#define DOC_DPS1_ADDRHIGH		0x1066
+#define DOC_DPS0_STATUS			0x106c
+#define DOC_DPS1_STATUS			0x106e
+
+#define DOC_ASICMODECONFIRM		0x1072
+#define DOC_CHIPID_INV			0x1074
+#define DOC_POWERMODE			0x107c
+
+/*
+ * Flash sequences
+ * A sequence is preset before one or more commands are input to the chip.
+ */
+#define DOC_SEQ_RESET			0x00
+#define DOC_SEQ_PAGE_SIZE_532		0x03
+#define DOC_SEQ_SET_FASTMODE		0x05
+#define DOC_SEQ_SET_RELIABLEMODE	0x09
+#define DOC_SEQ_READ			0x12
+#define DOC_SEQ_SET_PLANE1		0x0e
+#define DOC_SEQ_SET_PLANE2		0x10
+#define DOC_SEQ_PAGE_SETUP		0x1d
+#define DOC_SEQ_ERASE			0x27
+#define DOC_SEQ_PLANES_STATUS		0x31
+
+/*
+ * Flash commands
+ */
+#define DOC_CMD_READ_PLANE1		0x00
+#define DOC_CMD_SET_ADDR_READ		0x05
+#define DOC_CMD_READ_ALL_PLANES		0x30
+#define DOC_CMD_READ_PLANE2		0x50
+#define DOC_CMD_READ_FLASH		0xe0
+#define DOC_CMD_PAGE_SIZE_532		0x3c
+
+#define DOC_CMD_PROG_BLOCK_ADDR		0x60
+#define DOC_CMD_PROG_CYCLE1		0x80
+#define DOC_CMD_PROG_CYCLE2		0x10
+#define DOC_CMD_PROG_CYCLE3		0x11
+#define DOC_CMD_ERASECYCLE2		0xd0
+#define DOC_CMD_READ_STATUS		0x70
+#define DOC_CMD_PLANES_STATUS		0x71
+
+#define DOC_CMD_RELIABLE_MODE		0x22
+#define DOC_CMD_FAST_MODE		0xa2
+
+#define DOC_CMD_RESET			0xff
+
+/*
+ * Flash register : DOC_FLASHCONTROL
+ */
+#define DOC_CTRL_VIOLATION		0x20
+#define DOC_CTRL_CE			0x10
+#define DOC_CTRL_UNKNOWN_BITS		0x08
+#define DOC_CTRL_PROTECTION_ERROR	0x04
+#define DOC_CTRL_SEQUENCE_ERROR		0x02
+#define DOC_CTRL_FLASHREADY		0x01
+
+/*
+ * Flash register : DOC_ASICMODE
+ */
+#define DOC_ASICMODE_RESET		0x00
+#define DOC_ASICMODE_NORMAL		0x01
+#define DOC_ASICMODE_POWERDOWN		0x02
+#define DOC_ASICMODE_MDWREN		0x04
+#define DOC_ASICMODE_BDETCT_RESET	0x08
+#define DOC_ASICMODE_RSTIN_RESET	0x10
+#define DOC_ASICMODE_RAM_WE		0x20
+
+/*
+ * Flash register : DOC_ECCCONF0
+ */
+#define DOC_ECCCONF0_WRITE_MODE		0x0000
+#define DOC_ECCCONF0_READ_MODE		0x8000
+#define DOC_ECCCONF0_AUTO_ECC_ENABLE	0x4000
+#define DOC_ECCCONF0_HAMMING_ENABLE	0x1000
+#define DOC_ECCCONF0_BCH_ENABLE		0x0800
+#define DOC_ECCCONF0_DATA_BYTES_MASK	0x07ff
+
+/*
+ * Flash register : DOC_ECCCONF1
+ */
+#define DOC_ECCCONF1_BCH_SYNDROM_ERR	0x80
+#define DOC_ECCCONF1_UNKOWN1		0x40
+#define DOC_ECCCONF1_PAGE_IS_WRITTEN	0x20
+#define DOC_ECCCONF1_UNKOWN3		0x10
+#define DOC_ECCCONF1_HAMMING_BITS_MASK	0x0f
+
+/*
+ * Flash register : DOC_PROTECTION
+ */
+#define DOC_PROTECT_FOUNDRY_OTP_LOCK	0x01
+#define DOC_PROTECT_CUSTOMER_OTP_LOCK	0x02
+#define DOC_PROTECT_LOCK_INPUT		0x04
+#define DOC_PROTECT_STICKY_LOCK		0x08
+#define DOC_PROTECT_PROTECTION_ENABLED	0x10
+#define DOC_PROTECT_IPL_DOWNLOAD_LOCK	0x20
+#define DOC_PROTECT_PROTECTION_ERROR	0x80
+
+/*
+ * Flash register : DOC_DPS0_STATUS and DOC_DPS1_STATUS
+ */
+#define DOC_DPS_OTP_PROTECTED		0x01
+#define DOC_DPS_READ_PROTECTED		0x02
+#define DOC_DPS_WRITE_PROTECTED		0x04
+#define DOC_DPS_HW_LOCK_ENABLED		0x08
+#define DOC_DPS_KEY_OK			0x80
+
+/*
+ * Flash register : DOC_CONFIGURATION
+ */
+#define DOC_CONF_IF_CFG			0x80
+#define DOC_CONF_MAX_ID_MASK		0x30
+#define DOC_CONF_VCCQ_3V		0x01
+
+/*
+ * Flash register : DOC_READADDRESS
+ */
+#define DOC_READADDR_INC		0x8000
+#define DOC_READADDR_ONE_BYTE		0x4000
+#define DOC_READADDR_ADDR_MASK		0x1fff
+
+/*
+ * Flash register : DOC_POWERMODE
+ */
+#define DOC_POWERDOWN_READY		0x80
+
+/*
+ * Status of erase and write operation
+ */
+#define DOC_PLANES_STATUS_FAIL		0x01
+#define DOC_PLANES_STATUS_PLANE0_KO	0x02
+#define DOC_PLANES_STATUS_PLANE1_KO	0x04
+
+/*
+ * DPS key management
+ *
+ * Each floor of docg3 has 2 protection areas: DPS0 and DPS1. These areas span
+ * across block boundaries, and define whether these blocks can be read or
+ * written.
+ * The definition is dynamically stored in page 0 of blocks (2,3) for DPS0, and
+ * page 0 of blocks (4,5) for DPS1.
+ */
+#define DOC_LAYOUT_DPS_KEY_LENGTH	8
+
+/**
+ * struct docg3_cascade - Cascade of 1 to 4 docg3 chips
+ * @floors: floors (ie. one physical docg3 chip is one floor)
+ * @base: IO space to access all chips in the cascade
+ * @bch: the BCH correcting control structure
+ * @lock: lock to protect docg3 IO space from concurrent accesses
+ */
+struct docg3_cascade {
+	struct mtd_info *floors[DOC_MAX_NBFLOORS];
+	void __iomem *base;
+	struct bch_control *bch;
+	struct mutex lock;
+};
+
+/**
+ * struct docg3 - DiskOnChip driver private data
+ * @dev: the device currently under control
+ * @cascade: the cascade this device belongs to
+ * @device_id: number of the cascaded DoCG3 device (0, 1, 2 or 3)
+ * @if_cfg: if true, reads are on 16bits, else reads are on 8bits
+
+ * @reliable: if 0, docg3 in normal mode, if 1 docg3 in fast mode, if 2 in
+ *            reliable mode
+ *            Fast mode implies more errors than normal mode.
+ *            Reliable mode implies that page 2*n and 2*n+1 are clones.
+ * @bbt: bad block table cache
+ * @oob_write_ofs: offset of the MTD where this OOB should belong (ie. in next
+ *                 page_write)
+ * @oob_autoecc: if 1, use only bytes 0-7, 15, and fill the others with HW ECC
+ *               if 0, use all the 16 bytes.
+ * @oob_write_buf: prepared OOB for next page_write
+ */
+struct docg3 {
+	struct device *dev;
+	struct docg3_cascade *cascade;
+	unsigned int device_id:4;
+	unsigned int if_cfg:1;
+	unsigned int reliable:2;
+	int max_block;
+	u8 *bbt;
+	loff_t oob_write_ofs;
+	int oob_autoecc;
+	u8 oob_write_buf[DOC_LAYOUT_OOB_SIZE];
+};
+
+#define doc_err(fmt, arg...) dev_err(docg3->dev, (fmt), ## arg)
+#define doc_info(fmt, arg...) dev_info(docg3->dev, (fmt), ## arg)
+#define doc_dbg(fmt, arg...) dev_dbg(docg3->dev, (fmt), ## arg)
+#define doc_vdbg(fmt, arg...) dev_vdbg(docg3->dev, (fmt), ## arg)
+#endif
+
+/*
+ * Trace events part
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM docg3
+
+#if !defined(_MTD_DOCG3_TRACE) || defined(TRACE_HEADER_MULTI_READ)
+#define _MTD_DOCG3_TRACE
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(docg3_io,
+	    TP_PROTO(int op, int width, u16 reg, int val),
+	    TP_ARGS(op, width, reg, val),
+	    TP_STRUCT__entry(
+		    __field(int, op)
+		    __field(unsigned char, width)
+		    __field(u16, reg)
+		    __field(int, val)),
+	    TP_fast_assign(
+		    __entry->op = op;
+		    __entry->width = width;
+		    __entry->reg = reg;
+		    __entry->val = val;),
+	    TP_printk("docg3: %s%02d reg=%04x, val=%04x",
+		      __entry->op ? "write" : "read", __entry->width,
+		      __entry->reg, __entry->val)
+	);
+#endif
+
+/* This part must be outside protection */
+#undef TRACE_INCLUDE_PATH
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE docg3
+#include <trace/define_trace.h>
diff --git a/drivers/mtd/devices/lart.c b/drivers/mtd/devices/lart.c
new file mode 100644
index 000000000..aecd441e4
--- /dev/null
+++ b/drivers/mtd/devices/lart.c
@@ -0,0 +1,682 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * MTD driver for the 28F160F3 Flash Memory (non-CFI) on LART.
+ *
+ * Author: Abraham vd Merwe <abraham@2d3d.co.za>
+ *
+ * Copyright (c) 2001, 2d3D, Inc.
+ *
+ * References:
+ *
+ *    [1] 3 Volt Fast Boot Block Flash Memory" Intel Datasheet
+ *           - Order Number: 290644-005
+ *           - January 2000
+ *
+ *    [2] MTD internal API documentation
+ *           - http://www.linux-mtd.infradead.org/ 
+ *
+ * Limitations:
+ *
+ *    Even though this driver is written for 3 Volt Fast Boot
+ *    Block Flash Memory, it is rather specific to LART. With
+ *    Minor modifications, notably the without data/address line
+ *    mangling and different bus settings, etc. it should be
+ *    trivial to adapt to other platforms.
+ *
+ *    If somebody would sponsor me a different board, I'll
+ *    adapt the driver (:
+ */
+
+/* debugging */
+//#define LART_DEBUG
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+
+#ifndef CONFIG_SA1100_LART
+#error This is for LART architecture only
+#endif
+
+static char module_name[] = "lart";
+
+/*
+ * These values is specific to 28Fxxxx3 flash memory.
+ * See section 2.3.1 in "3 Volt Fast Boot Block Flash Memory" Intel Datasheet
+ */
+#define FLASH_BLOCKSIZE_PARAM		(4096 * BUSWIDTH)
+#define FLASH_NUMBLOCKS_16m_PARAM	8
+#define FLASH_NUMBLOCKS_8m_PARAM	8
+
+/*
+ * These values is specific to 28Fxxxx3 flash memory.
+ * See section 2.3.2 in "3 Volt Fast Boot Block Flash Memory" Intel Datasheet
+ */
+#define FLASH_BLOCKSIZE_MAIN		(32768 * BUSWIDTH)
+#define FLASH_NUMBLOCKS_16m_MAIN	31
+#define FLASH_NUMBLOCKS_8m_MAIN		15
+
+/*
+ * These values are specific to LART
+ */
+
+/* general */
+#define BUSWIDTH			4				/* don't change this - a lot of the code _will_ break if you change this */
+#define FLASH_OFFSET		0xe8000000		/* see linux/arch/arm/mach-sa1100/lart.c */
+
+/* blob */
+#define NUM_BLOB_BLOCKS		FLASH_NUMBLOCKS_16m_PARAM
+#define PART_BLOB_START		0x00000000
+#define PART_BLOB_LEN		(NUM_BLOB_BLOCKS * FLASH_BLOCKSIZE_PARAM)
+
+/* kernel */
+#define NUM_KERNEL_BLOCKS	7
+#define PART_KERNEL_START	(PART_BLOB_START + PART_BLOB_LEN)
+#define PART_KERNEL_LEN		(NUM_KERNEL_BLOCKS * FLASH_BLOCKSIZE_MAIN)
+
+/* initial ramdisk */
+#define NUM_INITRD_BLOCKS	24
+#define PART_INITRD_START	(PART_KERNEL_START + PART_KERNEL_LEN)
+#define PART_INITRD_LEN		(NUM_INITRD_BLOCKS * FLASH_BLOCKSIZE_MAIN)
+
+/*
+ * See section 4.0 in "3 Volt Fast Boot Block Flash Memory" Intel Datasheet
+ */
+#define READ_ARRAY			0x00FF00FF		/* Read Array/Reset */
+#define READ_ID_CODES		0x00900090		/* Read Identifier Codes */
+#define ERASE_SETUP			0x00200020		/* Block Erase */
+#define ERASE_CONFIRM		0x00D000D0		/* Block Erase and Program Resume */
+#define PGM_SETUP			0x00400040		/* Program */
+#define STATUS_READ			0x00700070		/* Read Status Register */
+#define STATUS_CLEAR		0x00500050		/* Clear Status Register */
+#define STATUS_BUSY			0x00800080		/* Write State Machine Status (WSMS) */
+#define STATUS_ERASE_ERR	0x00200020		/* Erase Status (ES) */
+#define STATUS_PGM_ERR		0x00100010		/* Program Status (PS) */
+
+/*
+ * See section 4.2 in "3 Volt Fast Boot Block Flash Memory" Intel Datasheet
+ */
+#define FLASH_MANUFACTURER			0x00890089
+#define FLASH_DEVICE_8mbit_TOP		0x88f188f1
+#define FLASH_DEVICE_8mbit_BOTTOM	0x88f288f2
+#define FLASH_DEVICE_16mbit_TOP		0x88f388f3
+#define FLASH_DEVICE_16mbit_BOTTOM	0x88f488f4
+
+/***************************************************************************************************/
+
+/*
+ * The data line mapping on LART is as follows:
+ *
+ *   	 U2  CPU |   U3  CPU
+ *   	 -------------------
+ *   	  0  20  |   0   12
+ *   	  1  22  |   1   14
+ *   	  2  19  |   2   11
+ *   	  3  17  |   3   9
+ *   	  4  24  |   4   0
+ *   	  5  26  |   5   2
+ *   	  6  31  |   6   7
+ *   	  7  29  |   7   5
+ *   	  8  21  |   8   13
+ *   	  9  23  |   9   15
+ *   	  10 18  |   10  10
+ *   	  11 16  |   11  8
+ *   	  12 25  |   12  1
+ *   	  13 27  |   13  3
+ *   	  14 30  |   14  6
+ *   	  15 28  |   15  4
+ */
+
+/* Mangle data (x) */
+#define DATA_TO_FLASH(x)				\
+	(									\
+		(((x) & 0x08009000) >> 11)	+	\
+		(((x) & 0x00002000) >> 10)	+	\
+		(((x) & 0x04004000) >> 8)	+	\
+		(((x) & 0x00000010) >> 4)	+	\
+		(((x) & 0x91000820) >> 3)	+	\
+		(((x) & 0x22080080) >> 2)	+	\
+		((x) & 0x40000400)			+	\
+		(((x) & 0x00040040) << 1)	+	\
+		(((x) & 0x00110000) << 4)	+	\
+		(((x) & 0x00220100) << 5)	+	\
+		(((x) & 0x00800208) << 6)	+	\
+		(((x) & 0x00400004) << 9)	+	\
+		(((x) & 0x00000001) << 12)	+	\
+		(((x) & 0x00000002) << 13)		\
+	)
+
+/* Unmangle data (x) */
+#define FLASH_TO_DATA(x)				\
+	(									\
+		(((x) & 0x00010012) << 11)	+	\
+		(((x) & 0x00000008) << 10)	+	\
+		(((x) & 0x00040040) << 8)	+	\
+		(((x) & 0x00000001) << 4)	+	\
+		(((x) & 0x12200104) << 3)	+	\
+		(((x) & 0x08820020) << 2)	+	\
+		((x) & 0x40000400)			+	\
+		(((x) & 0x00080080) >> 1)	+	\
+		(((x) & 0x01100000) >> 4)	+	\
+		(((x) & 0x04402000) >> 5)	+	\
+		(((x) & 0x20008200) >> 6)	+	\
+		(((x) & 0x80000800) >> 9)	+	\
+		(((x) & 0x00001000) >> 12)	+	\
+		(((x) & 0x00004000) >> 13)		\
+	)
+
+/*
+ * The address line mapping on LART is as follows:
+ *
+ *   	 U3  CPU |   U2  CPU
+ *   	 -------------------
+ *   	  0  2   |   0   2
+ *   	  1  3   |   1   3
+ *   	  2  9   |   2   9
+ *   	  3  13  |   3   8
+ *   	  4  8   |   4   7
+ *   	  5  12  |   5   6
+ *   	  6  11  |   6   5
+ *   	  7  10  |   7   4
+ *   	  8  4   |   8   10
+ *   	  9  5   |   9   11
+ *   	 10  6   |   10  12
+ *   	 11  7   |   11  13
+ *
+ *   	 BOOT BLOCK BOUNDARY
+ *
+ *   	 12  15  |   12  15
+ *   	 13  14  |   13  14
+ *   	 14  16  |   14  16
+ *
+ *   	 MAIN BLOCK BOUNDARY
+ *
+ *   	 15  17  |   15  18
+ *   	 16  18  |   16  17
+ *   	 17  20  |   17  20
+ *   	 18  19  |   18  19
+ *   	 19  21  |   19  21
+ *
+ * As we can see from above, the addresses aren't mangled across
+ * block boundaries, so we don't need to worry about address
+ * translations except for sending/reading commands during
+ * initialization
+ */
+
+/* Mangle address (x) on chip U2 */
+#define ADDR_TO_FLASH_U2(x)				\
+	(									\
+		(((x) & 0x00000f00) >> 4)	+	\
+		(((x) & 0x00042000) << 1)	+	\
+		(((x) & 0x0009c003) << 2)	+	\
+		(((x) & 0x00021080) << 3)	+	\
+		(((x) & 0x00000010) << 4)	+	\
+		(((x) & 0x00000040) << 5)	+	\
+		(((x) & 0x00000024) << 7)	+	\
+		(((x) & 0x00000008) << 10)		\
+	)
+
+/* Unmangle address (x) on chip U2 */
+#define FLASH_U2_TO_ADDR(x)				\
+	(									\
+		(((x) << 4) & 0x00000f00)	+	\
+		(((x) >> 1) & 0x00042000)	+	\
+		(((x) >> 2) & 0x0009c003)	+	\
+		(((x) >> 3) & 0x00021080)	+	\
+		(((x) >> 4) & 0x00000010)	+	\
+		(((x) >> 5) & 0x00000040)	+	\
+		(((x) >> 7) & 0x00000024)	+	\
+		(((x) >> 10) & 0x00000008)		\
+	)
+
+/* Mangle address (x) on chip U3 */
+#define ADDR_TO_FLASH_U3(x)				\
+	(									\
+		(((x) & 0x00000080) >> 3)	+	\
+		(((x) & 0x00000040) >> 1)	+	\
+		(((x) & 0x00052020) << 1)	+	\
+		(((x) & 0x00084f03) << 2)	+	\
+		(((x) & 0x00029010) << 3)	+	\
+		(((x) & 0x00000008) << 5)	+	\
+		(((x) & 0x00000004) << 7)		\
+	)
+
+/* Unmangle address (x) on chip U3 */
+#define FLASH_U3_TO_ADDR(x)				\
+	(									\
+		(((x) << 3) & 0x00000080)	+	\
+		(((x) << 1) & 0x00000040)	+	\
+		(((x) >> 1) & 0x00052020)	+	\
+		(((x) >> 2) & 0x00084f03)	+	\
+		(((x) >> 3) & 0x00029010)	+	\
+		(((x) >> 5) & 0x00000008)	+	\
+		(((x) >> 7) & 0x00000004)		\
+	)
+
+/***************************************************************************************************/
+
+static __u8 read8 (__u32 offset)
+{
+   volatile __u8 *data = (__u8 *) (FLASH_OFFSET + offset);
+#ifdef LART_DEBUG
+   printk (KERN_DEBUG "%s(): 0x%.8x -> 0x%.2x\n", __func__, offset, *data);
+#endif
+   return (*data);
+}
+
+static __u32 read32 (__u32 offset)
+{
+   volatile __u32 *data = (__u32 *) (FLASH_OFFSET + offset);
+#ifdef LART_DEBUG
+   printk (KERN_DEBUG "%s(): 0x%.8x -> 0x%.8x\n", __func__, offset, *data);
+#endif
+   return (*data);
+}
+
+static void write32 (__u32 x,__u32 offset)
+{
+   volatile __u32 *data = (__u32 *) (FLASH_OFFSET + offset);
+   *data = x;
+#ifdef LART_DEBUG
+   printk (KERN_DEBUG "%s(): 0x%.8x <- 0x%.8x\n", __func__, offset, *data);
+#endif
+}
+
+/***************************************************************************************************/
+
+/*
+ * Probe for 16mbit flash memory on a LART board without doing
+ * too much damage. Since we need to write 1 dword to memory,
+ * we're f**cked if this happens to be DRAM since we can't
+ * restore the memory (otherwise we might exit Read Array mode).
+ *
+ * Returns 1 if we found 16mbit flash memory on LART, 0 otherwise.
+ */
+static int flash_probe (void)
+{
+   __u32 manufacturer,devtype;
+
+   /* setup "Read Identifier Codes" mode */
+   write32 (DATA_TO_FLASH (READ_ID_CODES),0x00000000);
+
+   /* probe U2. U2/U3 returns the same data since the first 3
+	* address lines is mangled in the same way */
+   manufacturer = FLASH_TO_DATA (read32 (ADDR_TO_FLASH_U2 (0x00000000)));
+   devtype = FLASH_TO_DATA (read32 (ADDR_TO_FLASH_U2 (0x00000001)));
+
+   /* put the flash back into command mode */
+   write32 (DATA_TO_FLASH (READ_ARRAY),0x00000000);
+
+   return (manufacturer == FLASH_MANUFACTURER && (devtype == FLASH_DEVICE_16mbit_TOP || devtype == FLASH_DEVICE_16mbit_BOTTOM));
+}
+
+/*
+ * Erase one block of flash memory at offset ``offset'' which is any
+ * address within the block which should be erased.
+ *
+ * Returns 1 if successful, 0 otherwise.
+ */
+static inline int erase_block (__u32 offset)
+{
+   __u32 status;
+
+#ifdef LART_DEBUG
+   printk (KERN_DEBUG "%s(): 0x%.8x\n", __func__, offset);
+#endif
+
+   /* erase and confirm */
+   write32 (DATA_TO_FLASH (ERASE_SETUP),offset);
+   write32 (DATA_TO_FLASH (ERASE_CONFIRM),offset);
+
+   /* wait for block erase to finish */
+   do
+	 {
+		write32 (DATA_TO_FLASH (STATUS_READ),offset);
+		status = FLASH_TO_DATA (read32 (offset));
+	 }
+   while ((~status & STATUS_BUSY) != 0);
+
+   /* put the flash back into command mode */
+   write32 (DATA_TO_FLASH (READ_ARRAY),offset);
+
+   /* was the erase successful? */
+   if ((status & STATUS_ERASE_ERR))
+	 {
+		printk (KERN_WARNING "%s: erase error at address 0x%.8x.\n",module_name,offset);
+		return (0);
+	 }
+
+   return (1);
+}
+
+static int flash_erase (struct mtd_info *mtd,struct erase_info *instr)
+{
+   __u32 addr,len;
+   int i,first;
+
+#ifdef LART_DEBUG
+   printk (KERN_DEBUG "%s(addr = 0x%.8x, len = %d)\n", __func__, instr->addr, instr->len);
+#endif
+
+   /*
+	* check that both start and end of the requested erase are
+	* aligned with the erasesize at the appropriate addresses.
+	*
+	* skip all erase regions which are ended before the start of
+	* the requested erase. Actually, to save on the calculations,
+	* we skip to the first erase region which starts after the
+	* start of the requested erase, and then go back one.
+	*/
+   for (i = 0; i < mtd->numeraseregions && instr->addr >= mtd->eraseregions[i].offset; i++) ;
+   i--;
+
+   /*
+	* ok, now i is pointing at the erase region in which this
+	* erase request starts. Check the start of the requested
+	* erase range is aligned with the erase size which is in
+	* effect here.
+	*/
+   if (i < 0 || (instr->addr & (mtd->eraseregions[i].erasesize - 1)))
+      return -EINVAL;
+
+   /* Remember the erase region we start on */
+   first = i;
+
+   /*
+	* next, check that the end of the requested erase is aligned
+	* with the erase region at that address.
+	*
+	* as before, drop back one to point at the region in which
+	* the address actually falls
+	*/
+   for (; i < mtd->numeraseregions && instr->addr + instr->len >= mtd->eraseregions[i].offset; i++) ;
+   i--;
+
+   /* is the end aligned on a block boundary? */
+   if (i < 0 || ((instr->addr + instr->len) & (mtd->eraseregions[i].erasesize - 1)))
+      return -EINVAL;
+
+   addr = instr->addr;
+   len = instr->len;
+
+   i = first;
+
+   /* now erase those blocks */
+   while (len)
+	 {
+		if (!erase_block (addr))
+			 return (-EIO);
+
+		addr += mtd->eraseregions[i].erasesize;
+		len -= mtd->eraseregions[i].erasesize;
+
+		if (addr == mtd->eraseregions[i].offset + (mtd->eraseregions[i].erasesize * mtd->eraseregions[i].numblocks)) i++;
+	 }
+
+   return (0);
+}
+
+static int flash_read (struct mtd_info *mtd,loff_t from,size_t len,size_t *retlen,u_char *buf)
+{
+#ifdef LART_DEBUG
+   printk (KERN_DEBUG "%s(from = 0x%.8x, len = %d)\n", __func__, (__u32)from, len);
+#endif
+
+   /* we always read len bytes */
+   *retlen = len;
+
+   /* first, we read bytes until we reach a dword boundary */
+   if (from & (BUSWIDTH - 1))
+	 {
+		int gap = BUSWIDTH - (from & (BUSWIDTH - 1));
+
+		while (len && gap--) {
+			*buf++ = read8 (from++);
+			len--;
+		}
+	 }
+
+   /* now we read dwords until we reach a non-dword boundary */
+   while (len >= BUSWIDTH)
+	 {
+		*((__u32 *) buf) = read32 (from);
+
+		buf += BUSWIDTH;
+		from += BUSWIDTH;
+		len -= BUSWIDTH;
+	 }
+
+   /* top up the last unaligned bytes */
+   if (len & (BUSWIDTH - 1))
+	 while (len--) *buf++ = read8 (from++);
+
+   return (0);
+}
+
+/*
+ * Write one dword ``x'' to flash memory at offset ``offset''. ``offset''
+ * must be 32 bits, i.e. it must be on a dword boundary.
+ *
+ * Returns 1 if successful, 0 otherwise.
+ */
+static inline int write_dword (__u32 offset,__u32 x)
+{
+   __u32 status;
+
+#ifdef LART_DEBUG
+   printk (KERN_DEBUG "%s(): 0x%.8x <- 0x%.8x\n", __func__, offset, x);
+#endif
+
+   /* setup writing */
+   write32 (DATA_TO_FLASH (PGM_SETUP),offset);
+
+   /* write the data */
+   write32 (x,offset);
+
+   /* wait for the write to finish */
+   do
+	 {
+		write32 (DATA_TO_FLASH (STATUS_READ),offset);
+		status = FLASH_TO_DATA (read32 (offset));
+	 }
+   while ((~status & STATUS_BUSY) != 0);
+
+   /* put the flash back into command mode */
+   write32 (DATA_TO_FLASH (READ_ARRAY),offset);
+
+   /* was the write successful? */
+   if ((status & STATUS_PGM_ERR) || read32 (offset) != x)
+	 {
+		printk (KERN_WARNING "%s: write error at address 0x%.8x.\n",module_name,offset);
+		return (0);
+	 }
+
+   return (1);
+}
+
+static int flash_write (struct mtd_info *mtd,loff_t to,size_t len,size_t *retlen,const u_char *buf)
+{
+   __u8 tmp[4];
+   int i,n;
+
+#ifdef LART_DEBUG
+   printk (KERN_DEBUG "%s(to = 0x%.8x, len = %d)\n", __func__, (__u32)to, len);
+#endif
+
+   /* sanity checks */
+   if (!len) return (0);
+
+   /* first, we write a 0xFF.... padded byte until we reach a dword boundary */
+   if (to & (BUSWIDTH - 1))
+	 {
+		__u32 aligned = to & ~(BUSWIDTH - 1);
+		int gap = to - aligned;
+
+		i = n = 0;
+
+		while (gap--) tmp[i++] = 0xFF;
+		while (len && i < BUSWIDTH) {
+			tmp[i++] = buf[n++];
+			len--;
+		}
+		while (i < BUSWIDTH) tmp[i++] = 0xFF;
+
+		if (!write_dword (aligned,*((__u32 *) tmp))) return (-EIO);
+
+		to += n;
+		buf += n;
+		*retlen += n;
+	 }
+
+   /* now we write dwords until we reach a non-dword boundary */
+   while (len >= BUSWIDTH)
+	 {
+		if (!write_dword (to,*((__u32 *) buf))) return (-EIO);
+
+		to += BUSWIDTH;
+		buf += BUSWIDTH;
+		*retlen += BUSWIDTH;
+		len -= BUSWIDTH;
+	 }
+
+   /* top up the last unaligned bytes, padded with 0xFF.... */
+   if (len & (BUSWIDTH - 1))
+	 {
+		i = n = 0;
+
+		while (len--) tmp[i++] = buf[n++];
+		while (i < BUSWIDTH) tmp[i++] = 0xFF;
+
+		if (!write_dword (to,*((__u32 *) tmp))) return (-EIO);
+
+		*retlen += n;
+	 }
+
+   return (0);
+}
+
+/***************************************************************************************************/
+
+static struct mtd_info mtd;
+
+static struct mtd_erase_region_info erase_regions[] = {
+	/* parameter blocks */
+	{
+		.offset		= 0x00000000,
+		.erasesize	= FLASH_BLOCKSIZE_PARAM,
+		.numblocks	= FLASH_NUMBLOCKS_16m_PARAM,
+	},
+	/* main blocks */
+	{
+		.offset	 = FLASH_BLOCKSIZE_PARAM * FLASH_NUMBLOCKS_16m_PARAM,
+		.erasesize	= FLASH_BLOCKSIZE_MAIN,
+		.numblocks	= FLASH_NUMBLOCKS_16m_MAIN,
+	}
+};
+
+static const struct mtd_partition lart_partitions[] = {
+	/* blob */
+	{
+		.name	= "blob",
+		.offset	= PART_BLOB_START,
+		.size	= PART_BLOB_LEN,
+	},
+	/* kernel */
+	{
+		.name	= "kernel",
+		.offset	= PART_KERNEL_START,	/* MTDPART_OFS_APPEND */
+		.size	= PART_KERNEL_LEN,
+	},
+	/* initial ramdisk / file system */
+	{
+		.name	= "file system",
+		.offset	= PART_INITRD_START,	/* MTDPART_OFS_APPEND */
+		.size	= PART_INITRD_LEN,	/* MTDPART_SIZ_FULL */
+	}
+};
+#define NUM_PARTITIONS ARRAY_SIZE(lart_partitions)
+
+static int __init lart_flash_init (void)
+{
+   int result;
+   memset (&mtd,0,sizeof (mtd));
+   printk ("MTD driver for LART. Written by Abraham vd Merwe <abraham@2d3d.co.za>\n");
+   printk ("%s: Probing for 28F160x3 flash on LART...\n",module_name);
+   if (!flash_probe ())
+	 {
+		printk (KERN_WARNING "%s: Found no LART compatible flash device\n",module_name);
+		return (-ENXIO);
+	 }
+   printk ("%s: This looks like a LART board to me.\n",module_name);
+   mtd.name = module_name;
+   mtd.type = MTD_NORFLASH;
+   mtd.writesize = 1;
+   mtd.writebufsize = 4;
+   mtd.flags = MTD_CAP_NORFLASH;
+   mtd.size = FLASH_BLOCKSIZE_PARAM * FLASH_NUMBLOCKS_16m_PARAM + FLASH_BLOCKSIZE_MAIN * FLASH_NUMBLOCKS_16m_MAIN;
+   mtd.erasesize = FLASH_BLOCKSIZE_MAIN;
+   mtd.numeraseregions = ARRAY_SIZE(erase_regions);
+   mtd.eraseregions = erase_regions;
+   mtd._erase = flash_erase;
+   mtd._read = flash_read;
+   mtd._write = flash_write;
+   mtd.owner = THIS_MODULE;
+
+#ifdef LART_DEBUG
+   printk (KERN_DEBUG
+		   "mtd.name = %s\n"
+		   "mtd.size = 0x%.8x (%uM)\n"
+		   "mtd.erasesize = 0x%.8x (%uK)\n"
+		   "mtd.numeraseregions = %d\n",
+		   mtd.name,
+		   mtd.size,mtd.size / (1024*1024),
+		   mtd.erasesize,mtd.erasesize / 1024,
+		   mtd.numeraseregions);
+
+   if (mtd.numeraseregions)
+	 for (result = 0; result < mtd.numeraseregions; result++)
+	   printk (KERN_DEBUG
+			   "\n\n"
+			   "mtd.eraseregions[%d].offset = 0x%.8x\n"
+			   "mtd.eraseregions[%d].erasesize = 0x%.8x (%uK)\n"
+			   "mtd.eraseregions[%d].numblocks = %d\n",
+			   result,mtd.eraseregions[result].offset,
+			   result,mtd.eraseregions[result].erasesize,mtd.eraseregions[result].erasesize / 1024,
+			   result,mtd.eraseregions[result].numblocks);
+
+   printk ("\npartitions = %d\n", ARRAY_SIZE(lart_partitions));
+
+   for (result = 0; result < ARRAY_SIZE(lart_partitions); result++)
+	 printk (KERN_DEBUG
+			 "\n\n"
+			 "lart_partitions[%d].name = %s\n"
+			 "lart_partitions[%d].offset = 0x%.8x\n"
+			 "lart_partitions[%d].size = 0x%.8x (%uK)\n",
+			 result,lart_partitions[result].name,
+			 result,lart_partitions[result].offset,
+			 result,lart_partitions[result].size,lart_partitions[result].size / 1024);
+#endif
+
+   result = mtd_device_register(&mtd, lart_partitions,
+                                ARRAY_SIZE(lart_partitions));
+
+   return (result);
+}
+
+static void __exit lart_flash_exit (void)
+{
+   mtd_device_unregister(&mtd);
+}
+
+module_init (lart_flash_init);
+module_exit (lart_flash_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Abraham vd Merwe <abraham@2d3d.co.za>");
+MODULE_DESCRIPTION("MTD driver for Intel 28F160F3 on LART board");
diff --git a/drivers/mtd/devices/mchp23k256.c b/drivers/mtd/devices/mchp23k256.c
new file mode 100644
index 000000000..3a6ea7a6a
--- /dev/null
+++ b/drivers/mtd/devices/mchp23k256.c
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * mchp23k256.c
+ *
+ * Driver for Microchip 23k256 SPI RAM chips
+ *
+ * Copyright © 2016 Andrew Lunn <andrew@lunn.ch>
+ */
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/spi/flash.h>
+#include <linux/spi/spi.h>
+#include <linux/of_device.h>
+
+#define MAX_CMD_SIZE		4
+
+struct mchp23_caps {
+	u8 addr_width;
+	unsigned int size;
+};
+
+struct mchp23k256_flash {
+	struct spi_device	*spi;
+	struct mutex		lock;
+	struct mtd_info		mtd;
+	const struct mchp23_caps	*caps;
+};
+
+#define MCHP23K256_CMD_WRITE_STATUS	0x01
+#define MCHP23K256_CMD_WRITE		0x02
+#define MCHP23K256_CMD_READ		0x03
+#define MCHP23K256_MODE_SEQ		BIT(6)
+
+#define to_mchp23k256_flash(x) container_of(x, struct mchp23k256_flash, mtd)
+
+static void mchp23k256_addr2cmd(struct mchp23k256_flash *flash,
+				unsigned int addr, u8 *cmd)
+{
+	int i;
+
+	/*
+	 * Address is sent in big endian (MSB first) and we skip
+	 * the first entry of the cmd array which contains the cmd
+	 * opcode.
+	 */
+	for (i = flash->caps->addr_width; i > 0; i--, addr >>= 8)
+		cmd[i] = addr;
+}
+
+static int mchp23k256_cmdsz(struct mchp23k256_flash *flash)
+{
+	return 1 + flash->caps->addr_width;
+}
+
+static int mchp23k256_write(struct mtd_info *mtd, loff_t to, size_t len,
+			    size_t *retlen, const unsigned char *buf)
+{
+	struct mchp23k256_flash *flash = to_mchp23k256_flash(mtd);
+	struct spi_transfer transfer[2] = {};
+	struct spi_message message;
+	unsigned char command[MAX_CMD_SIZE];
+	int ret, cmd_len;
+
+	spi_message_init(&message);
+
+	cmd_len = mchp23k256_cmdsz(flash);
+
+	command[0] = MCHP23K256_CMD_WRITE;
+	mchp23k256_addr2cmd(flash, to, command);
+
+	transfer[0].tx_buf = command;
+	transfer[0].len = cmd_len;
+	spi_message_add_tail(&transfer[0], &message);
+
+	transfer[1].tx_buf = buf;
+	transfer[1].len = len;
+	spi_message_add_tail(&transfer[1], &message);
+
+	mutex_lock(&flash->lock);
+
+	ret = spi_sync(flash->spi, &message);
+
+	mutex_unlock(&flash->lock);
+
+	if (ret)
+		return ret;
+
+	if (retlen && message.actual_length > cmd_len)
+		*retlen += message.actual_length - cmd_len;
+
+	return 0;
+}
+
+static int mchp23k256_read(struct mtd_info *mtd, loff_t from, size_t len,
+			   size_t *retlen, unsigned char *buf)
+{
+	struct mchp23k256_flash *flash = to_mchp23k256_flash(mtd);
+	struct spi_transfer transfer[2] = {};
+	struct spi_message message;
+	unsigned char command[MAX_CMD_SIZE];
+	int ret, cmd_len;
+
+	spi_message_init(&message);
+
+	cmd_len = mchp23k256_cmdsz(flash);
+
+	memset(&transfer, 0, sizeof(transfer));
+	command[0] = MCHP23K256_CMD_READ;
+	mchp23k256_addr2cmd(flash, from, command);
+
+	transfer[0].tx_buf = command;
+	transfer[0].len = cmd_len;
+	spi_message_add_tail(&transfer[0], &message);
+
+	transfer[1].rx_buf = buf;
+	transfer[1].len = len;
+	spi_message_add_tail(&transfer[1], &message);
+
+	mutex_lock(&flash->lock);
+
+	ret = spi_sync(flash->spi, &message);
+
+	mutex_unlock(&flash->lock);
+
+	if (ret)
+		return ret;
+
+	if (retlen && message.actual_length > cmd_len)
+		*retlen += message.actual_length - cmd_len;
+
+	return 0;
+}
+
+/*
+ * Set the device into sequential mode. This allows read/writes to the
+ * entire SRAM in a single operation
+ */
+static int mchp23k256_set_mode(struct spi_device *spi)
+{
+	struct spi_transfer transfer = {};
+	struct spi_message message;
+	unsigned char command[2];
+
+	spi_message_init(&message);
+
+	command[0] = MCHP23K256_CMD_WRITE_STATUS;
+	command[1] = MCHP23K256_MODE_SEQ;
+
+	transfer.tx_buf = command;
+	transfer.len = sizeof(command);
+	spi_message_add_tail(&transfer, &message);
+
+	return spi_sync(spi, &message);
+}
+
+static const struct mchp23_caps mchp23k256_caps = {
+	.size = SZ_32K,
+	.addr_width = 2,
+};
+
+static const struct mchp23_caps mchp23lcv1024_caps = {
+	.size = SZ_128K,
+	.addr_width = 3,
+};
+
+static int mchp23k256_probe(struct spi_device *spi)
+{
+	struct mchp23k256_flash *flash;
+	struct flash_platform_data *data;
+	int err;
+
+	flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);
+	if (!flash)
+		return -ENOMEM;
+
+	flash->spi = spi;
+	mutex_init(&flash->lock);
+	spi_set_drvdata(spi, flash);
+
+	err = mchp23k256_set_mode(spi);
+	if (err)
+		return err;
+
+	data = dev_get_platdata(&spi->dev);
+
+	flash->caps = of_device_get_match_data(&spi->dev);
+	if (!flash->caps)
+		flash->caps = &mchp23k256_caps;
+
+	mtd_set_of_node(&flash->mtd, spi->dev.of_node);
+	flash->mtd.dev.parent	= &spi->dev;
+	flash->mtd.type		= MTD_RAM;
+	flash->mtd.flags	= MTD_CAP_RAM;
+	flash->mtd.writesize	= 1;
+	flash->mtd.size		= flash->caps->size;
+	flash->mtd._read	= mchp23k256_read;
+	flash->mtd._write	= mchp23k256_write;
+
+	err = mtd_device_register(&flash->mtd, data ? data->parts : NULL,
+				  data ? data->nr_parts : 0);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static void mchp23k256_remove(struct spi_device *spi)
+{
+	struct mchp23k256_flash *flash = spi_get_drvdata(spi);
+
+	WARN_ON(mtd_device_unregister(&flash->mtd));
+}
+
+static const struct of_device_id mchp23k256_of_table[] = {
+	{
+		.compatible = "microchip,mchp23k256",
+		.data = &mchp23k256_caps,
+	},
+	{
+		.compatible = "microchip,mchp23lcv1024",
+		.data = &mchp23lcv1024_caps,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, mchp23k256_of_table);
+
+static const struct spi_device_id mchp23k256_spi_ids[] = {
+	{
+		.name = "mchp23k256",
+		.driver_data = (kernel_ulong_t)&mchp23k256_caps,
+	},
+	{
+		.name = "mchp23lcv1024",
+		.driver_data = (kernel_ulong_t)&mchp23lcv1024_caps,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(spi, mchp23k256_spi_ids);
+
+static struct spi_driver mchp23k256_driver = {
+	.driver = {
+		.name	= "mchp23k256",
+		.of_match_table = mchp23k256_of_table,
+	},
+	.probe		= mchp23k256_probe,
+	.remove		= mchp23k256_remove,
+	.id_table	= mchp23k256_spi_ids,
+};
+
+module_spi_driver(mchp23k256_driver);
+
+MODULE_DESCRIPTION("MTD SPI driver for MCHP23K256 RAM chips");
+MODULE_AUTHOR("Andrew Lunn <andre@lunn.ch>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("spi:mchp23k256");
diff --git a/drivers/mtd/devices/mchp48l640.c b/drivers/mtd/devices/mchp48l640.c
new file mode 100644
index 000000000..40cd50411
--- /dev/null
+++ b/drivers/mtd/devices/mchp48l640.c
@@ -0,0 +1,384 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Microchip 48L640 64 Kb SPI Serial EERAM
+ *
+ * Copyright Heiko Schocher <hs@denx.de>
+ *
+ * datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/20006055B.pdf
+ *
+ * we set continuous mode but reading/writing more bytes than
+ * pagesize seems to bring chip into state where readden values
+ * are wrong ... no idea why.
+ *
+ */
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/spi/flash.h>
+#include <linux/spi/spi.h>
+#include <linux/of_device.h>
+
+struct mchp48_caps {
+	unsigned int size;
+	unsigned int page_size;
+};
+
+struct mchp48l640_flash {
+	struct spi_device	*spi;
+	struct mutex		lock;
+	struct mtd_info		mtd;
+	const struct mchp48_caps	*caps;
+};
+
+#define MCHP48L640_CMD_WREN		0x06
+#define MCHP48L640_CMD_WRDI		0x04
+#define MCHP48L640_CMD_WRITE		0x02
+#define MCHP48L640_CMD_READ		0x03
+#define MCHP48L640_CMD_WRSR		0x01
+#define MCHP48L640_CMD_RDSR		0x05
+
+#define MCHP48L640_STATUS_RDY		0x01
+#define MCHP48L640_STATUS_WEL		0x02
+#define MCHP48L640_STATUS_BP0		0x04
+#define MCHP48L640_STATUS_BP1		0x08
+#define MCHP48L640_STATUS_SWM		0x10
+#define MCHP48L640_STATUS_PRO		0x20
+#define MCHP48L640_STATUS_ASE		0x40
+
+#define MCHP48L640_TIMEOUT		100
+
+#define MAX_CMD_SIZE			0x10
+
+#define to_mchp48l640_flash(x) container_of(x, struct mchp48l640_flash, mtd)
+
+static int mchp48l640_mkcmd(struct mchp48l640_flash *flash, u8 cmd, loff_t addr, char *buf)
+{
+	buf[0] = cmd;
+	buf[1] = addr >> 8;
+	buf[2] = addr;
+
+	return 3;
+}
+
+static int mchp48l640_read_status(struct mchp48l640_flash *flash, int *status)
+{
+	unsigned char cmd[2];
+	int ret;
+
+	cmd[0] = MCHP48L640_CMD_RDSR;
+	cmd[1] = 0x00;
+	mutex_lock(&flash->lock);
+	ret = spi_write_then_read(flash->spi, &cmd[0], 1, &cmd[1], 1);
+	mutex_unlock(&flash->lock);
+	if (!ret)
+		*status = cmd[1];
+	dev_dbg(&flash->spi->dev, "read status ret: %d status: %x", ret, *status);
+
+	return ret;
+}
+
+static int mchp48l640_waitforbit(struct mchp48l640_flash *flash, int bit, bool set)
+{
+	int ret, status;
+	unsigned long deadline;
+
+	deadline = jiffies + msecs_to_jiffies(MCHP48L640_TIMEOUT);
+	do {
+		ret = mchp48l640_read_status(flash, &status);
+		dev_dbg(&flash->spi->dev, "read status ret: %d bit: %x %sset status: %x",
+			ret, bit, (set ? "" : "not"), status);
+		if (ret)
+			return ret;
+
+		if (set) {
+			if ((status & bit) == bit)
+				return 0;
+		} else {
+			if ((status & bit) == 0)
+				return 0;
+		}
+
+		usleep_range(1000, 2000);
+	} while (!time_after_eq(jiffies, deadline));
+
+	dev_err(&flash->spi->dev, "Timeout waiting for bit %x %s set in status register.",
+		bit, (set ? "" : "not"));
+	return -ETIMEDOUT;
+}
+
+static int mchp48l640_write_prepare(struct mchp48l640_flash *flash, bool enable)
+{
+	unsigned char cmd[2];
+	int ret;
+
+	if (enable)
+		cmd[0] = MCHP48L640_CMD_WREN;
+	else
+		cmd[0] = MCHP48L640_CMD_WRDI;
+
+	mutex_lock(&flash->lock);
+	ret = spi_write(flash->spi, cmd, 1);
+	mutex_unlock(&flash->lock);
+
+	if (ret)
+		dev_err(&flash->spi->dev, "write %sable failed ret: %d",
+			(enable ? "en" : "dis"), ret);
+
+	dev_dbg(&flash->spi->dev, "write %sable success ret: %d",
+		(enable ? "en" : "dis"), ret);
+	if (enable)
+		return mchp48l640_waitforbit(flash, MCHP48L640_STATUS_WEL, true);
+
+	return ret;
+}
+
+static int mchp48l640_set_mode(struct mchp48l640_flash *flash)
+{
+	unsigned char cmd[2];
+	int ret;
+
+	ret = mchp48l640_write_prepare(flash, true);
+	if (ret)
+		return ret;
+
+	cmd[0] = MCHP48L640_CMD_WRSR;
+	cmd[1] = MCHP48L640_STATUS_PRO;
+
+	mutex_lock(&flash->lock);
+	ret = spi_write(flash->spi, cmd, 2);
+	mutex_unlock(&flash->lock);
+	if (ret)
+		dev_err(&flash->spi->dev, "Could not set continuous mode ret: %d", ret);
+
+	return mchp48l640_waitforbit(flash, MCHP48L640_STATUS_PRO, true);
+}
+
+static int mchp48l640_wait_rdy(struct mchp48l640_flash *flash)
+{
+	return mchp48l640_waitforbit(flash, MCHP48L640_STATUS_RDY, false);
+};
+
+static int mchp48l640_write_page(struct mtd_info *mtd, loff_t to, size_t len,
+			    size_t *retlen, const unsigned char *buf)
+{
+	struct mchp48l640_flash *flash = to_mchp48l640_flash(mtd);
+	unsigned char *cmd;
+	int ret;
+	int cmdlen;
+
+	cmd = kmalloc((3 + len), GFP_KERNEL | GFP_DMA);
+	if (!cmd)
+		return -ENOMEM;
+
+	ret = mchp48l640_wait_rdy(flash);
+	if (ret)
+		goto fail;
+
+	ret = mchp48l640_write_prepare(flash, true);
+	if (ret)
+		goto fail;
+
+	mutex_lock(&flash->lock);
+	cmdlen = mchp48l640_mkcmd(flash, MCHP48L640_CMD_WRITE, to, cmd);
+	memcpy(&cmd[cmdlen], buf, len);
+	ret = spi_write(flash->spi, cmd, cmdlen + len);
+	mutex_unlock(&flash->lock);
+	if (!ret)
+		*retlen += len;
+	else
+		goto fail;
+
+	ret = mchp48l640_waitforbit(flash, MCHP48L640_STATUS_WEL, false);
+	if (ret)
+		goto fail;
+
+	kfree(cmd);
+	return 0;
+fail:
+	kfree(cmd);
+	dev_err(&flash->spi->dev, "write fail with: %d", ret);
+	return ret;
+};
+
+static int mchp48l640_write(struct mtd_info *mtd, loff_t to, size_t len,
+			    size_t *retlen, const unsigned char *buf)
+{
+	struct mchp48l640_flash *flash = to_mchp48l640_flash(mtd);
+	int ret;
+	size_t wlen = 0;
+	loff_t woff = to;
+	size_t ws;
+	size_t page_sz = flash->caps->page_size;
+
+	/*
+	 * we set PRO bit (page rollover), but writing length > page size
+	 * does result in total chaos, so write in 32 byte chunks.
+	 */
+	while (wlen < len) {
+		ws = min((len - wlen), page_sz);
+		ret = mchp48l640_write_page(mtd, woff, ws, retlen, &buf[wlen]);
+		if (ret)
+			return ret;
+		wlen += ws;
+		woff += ws;
+	}
+
+	return 0;
+}
+
+static int mchp48l640_read_page(struct mtd_info *mtd, loff_t from, size_t len,
+			   size_t *retlen, unsigned char *buf)
+{
+	struct mchp48l640_flash *flash = to_mchp48l640_flash(mtd);
+	unsigned char *cmd;
+	int ret;
+	int cmdlen;
+
+	cmd = kmalloc((3 + len), GFP_KERNEL | GFP_DMA);
+	if (!cmd)
+		return -ENOMEM;
+
+	ret = mchp48l640_wait_rdy(flash);
+	if (ret)
+		goto fail;
+
+	mutex_lock(&flash->lock);
+	cmdlen = mchp48l640_mkcmd(flash, MCHP48L640_CMD_READ, from, cmd);
+	ret = spi_write_then_read(flash->spi, cmd, cmdlen, buf, len);
+	mutex_unlock(&flash->lock);
+	if (!ret)
+		*retlen += len;
+
+	kfree(cmd);
+	return ret;
+
+fail:
+	kfree(cmd);
+	dev_err(&flash->spi->dev, "read fail with: %d", ret);
+	return ret;
+}
+
+static int mchp48l640_read(struct mtd_info *mtd, loff_t from, size_t len,
+			   size_t *retlen, unsigned char *buf)
+{
+	struct mchp48l640_flash *flash = to_mchp48l640_flash(mtd);
+	int ret;
+	size_t wlen = 0;
+	loff_t woff = from;
+	size_t ws;
+	size_t page_sz = flash->caps->page_size;
+
+	/*
+	 * we set PRO bit (page rollover), but if read length > page size
+	 * does result in total chaos in result ...
+	 */
+	while (wlen < len) {
+		ws = min((len - wlen), page_sz);
+		ret = mchp48l640_read_page(mtd, woff, ws, retlen, &buf[wlen]);
+		if (ret)
+			return ret;
+		wlen += ws;
+		woff += ws;
+	}
+
+	return 0;
+};
+
+static const struct mchp48_caps mchp48l640_caps = {
+	.size = SZ_8K,
+	.page_size = 32,
+};
+
+static int mchp48l640_probe(struct spi_device *spi)
+{
+	struct mchp48l640_flash *flash;
+	struct flash_platform_data *data;
+	int err;
+	int status;
+
+	flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);
+	if (!flash)
+		return -ENOMEM;
+
+	flash->spi = spi;
+	mutex_init(&flash->lock);
+	spi_set_drvdata(spi, flash);
+
+	err = mchp48l640_read_status(flash, &status);
+	if (err)
+		return err;
+
+	err = mchp48l640_set_mode(flash);
+	if (err)
+		return err;
+
+	data = dev_get_platdata(&spi->dev);
+
+	flash->caps = of_device_get_match_data(&spi->dev);
+	if (!flash->caps)
+		flash->caps = &mchp48l640_caps;
+
+	mtd_set_of_node(&flash->mtd, spi->dev.of_node);
+	flash->mtd.dev.parent	= &spi->dev;
+	flash->mtd.type		= MTD_RAM;
+	flash->mtd.flags	= MTD_CAP_RAM;
+	flash->mtd.writesize	= flash->caps->page_size;
+	flash->mtd.size		= flash->caps->size;
+	flash->mtd._read	= mchp48l640_read;
+	flash->mtd._write	= mchp48l640_write;
+
+	err = mtd_device_register(&flash->mtd, data ? data->parts : NULL,
+				  data ? data->nr_parts : 0);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static void mchp48l640_remove(struct spi_device *spi)
+{
+	struct mchp48l640_flash *flash = spi_get_drvdata(spi);
+
+	WARN_ON(mtd_device_unregister(&flash->mtd));
+}
+
+static const struct of_device_id mchp48l640_of_table[] = {
+	{
+		.compatible = "microchip,48l640",
+		.data = &mchp48l640_caps,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, mchp48l640_of_table);
+
+static const struct spi_device_id mchp48l640_spi_ids[] = {
+	{
+		.name = "48l640",
+		.driver_data = (kernel_ulong_t)&mchp48l640_caps,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(spi, mchp48l640_spi_ids);
+
+static struct spi_driver mchp48l640_driver = {
+	.driver = {
+		.name	= "mchp48l640",
+		.of_match_table = mchp48l640_of_table,
+	},
+	.probe		= mchp48l640_probe,
+	.remove		= mchp48l640_remove,
+	.id_table	= mchp48l640_spi_ids,
+};
+
+module_spi_driver(mchp48l640_driver);
+
+MODULE_DESCRIPTION("MTD SPI driver for Microchip 48l640 EERAM chips");
+MODULE_AUTHOR("Heiko Schocher <hs@denx.de>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("spi:mchp48l640");
diff --git a/drivers/mtd/devices/ms02-nv.c b/drivers/mtd/devices/ms02-nv.c
new file mode 100644
index 000000000..08f76ff83
--- /dev/null
+++ b/drivers/mtd/devices/ms02-nv.c
@@ -0,0 +1,306 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	Copyright (c) 2001 Maciej W. Rozycki
+ */
+
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <asm/addrspace.h>
+#include <asm/bootinfo.h>
+#include <asm/dec/ioasic_addrs.h>
+#include <asm/dec/kn02.h>
+#include <asm/dec/kn03.h>
+#include <asm/io.h>
+#include <asm/paccess.h>
+
+#include "ms02-nv.h"
+
+
+static char version[] __initdata =
+	"ms02-nv.c: v.1.0.0  13 Aug 2001  Maciej W. Rozycki.\n";
+
+MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>");
+MODULE_DESCRIPTION("DEC MS02-NV NVRAM module driver");
+MODULE_LICENSE("GPL");
+
+
+/*
+ * Addresses we probe for an MS02-NV at.  Modules may be located
+ * at any 8MiB boundary within a 0MiB up to 112MiB range or at any 32MiB
+ * boundary within a 0MiB up to 448MiB range.  We don't support a module
+ * at 0MiB, though.
+ */
+static ulong ms02nv_addrs[] __initdata = {
+	0x07000000, 0x06800000, 0x06000000, 0x05800000, 0x05000000,
+	0x04800000, 0x04000000, 0x03800000, 0x03000000, 0x02800000,
+	0x02000000, 0x01800000, 0x01000000, 0x00800000
+};
+
+static const char ms02nv_name[] = "DEC MS02-NV NVRAM";
+static const char ms02nv_res_diag_ram[] = "Diagnostic RAM";
+static const char ms02nv_res_user_ram[] = "General-purpose RAM";
+static const char ms02nv_res_csr[] = "Control and status register";
+
+static struct mtd_info *root_ms02nv_mtd;
+
+
+static int ms02nv_read(struct mtd_info *mtd, loff_t from,
+			size_t len, size_t *retlen, u_char *buf)
+{
+	struct ms02nv_private *mp = mtd->priv;
+
+	memcpy(buf, mp->uaddr + from, len);
+	*retlen = len;
+	return 0;
+}
+
+static int ms02nv_write(struct mtd_info *mtd, loff_t to,
+			size_t len, size_t *retlen, const u_char *buf)
+{
+	struct ms02nv_private *mp = mtd->priv;
+
+	memcpy(mp->uaddr + to, buf, len);
+	*retlen = len;
+	return 0;
+}
+
+
+static inline uint ms02nv_probe_one(ulong addr)
+{
+	ms02nv_uint *ms02nv_diagp;
+	ms02nv_uint *ms02nv_magicp;
+	uint ms02nv_diag;
+	uint ms02nv_magic;
+	size_t size;
+
+	int err;
+
+	/*
+	 * The firmware writes MS02NV_ID at MS02NV_MAGIC and also
+	 * a diagnostic status at MS02NV_DIAG.
+	 */
+	ms02nv_diagp = (ms02nv_uint *)(CKSEG1ADDR(addr + MS02NV_DIAG));
+	ms02nv_magicp = (ms02nv_uint *)(CKSEG1ADDR(addr + MS02NV_MAGIC));
+	err = get_dbe(ms02nv_magic, ms02nv_magicp);
+	if (err)
+		return 0;
+	if (ms02nv_magic != MS02NV_ID)
+		return 0;
+
+	ms02nv_diag = *ms02nv_diagp;
+	size = (ms02nv_diag & MS02NV_DIAG_SIZE_MASK) << MS02NV_DIAG_SIZE_SHIFT;
+	if (size > MS02NV_CSR)
+		size = MS02NV_CSR;
+
+	return size;
+}
+
+static int __init ms02nv_init_one(ulong addr)
+{
+	struct mtd_info *mtd;
+	struct ms02nv_private *mp;
+	struct resource *mod_res;
+	struct resource *diag_res;
+	struct resource *user_res;
+	struct resource *csr_res;
+	ulong fixaddr;
+	size_t size, fixsize;
+
+	static int version_printed;
+
+	int ret = -ENODEV;
+
+	/* The module decodes 8MiB of address space. */
+	mod_res = kzalloc(sizeof(*mod_res), GFP_KERNEL);
+	if (!mod_res)
+		return -ENOMEM;
+
+	mod_res->name = ms02nv_name;
+	mod_res->start = addr;
+	mod_res->end = addr + MS02NV_SLOT_SIZE - 1;
+	mod_res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+	if (request_resource(&iomem_resource, mod_res) < 0)
+		goto err_out_mod_res;
+
+	size = ms02nv_probe_one(addr);
+	if (!size)
+		goto err_out_mod_res_rel;
+
+	if (!version_printed) {
+		printk(KERN_INFO "%s", version);
+		version_printed = 1;
+	}
+
+	ret = -ENOMEM;
+	mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
+	if (!mtd)
+		goto err_out_mod_res_rel;
+	mp = kzalloc(sizeof(*mp), GFP_KERNEL);
+	if (!mp)
+		goto err_out_mtd;
+
+	mtd->priv = mp;
+	mp->resource.module = mod_res;
+
+	/* Firmware's diagnostic NVRAM area. */
+	diag_res = kzalloc(sizeof(*diag_res), GFP_KERNEL);
+	if (!diag_res)
+		goto err_out_mp;
+
+	diag_res->name = ms02nv_res_diag_ram;
+	diag_res->start = addr;
+	diag_res->end = addr + MS02NV_RAM - 1;
+	diag_res->flags = IORESOURCE_BUSY;
+	request_resource(mod_res, diag_res);
+
+	mp->resource.diag_ram = diag_res;
+
+	/* User-available general-purpose NVRAM area. */
+	user_res = kzalloc(sizeof(*user_res), GFP_KERNEL);
+	if (!user_res)
+		goto err_out_diag_res;
+
+	user_res->name = ms02nv_res_user_ram;
+	user_res->start = addr + MS02NV_RAM;
+	user_res->end = addr + size - 1;
+	user_res->flags = IORESOURCE_BUSY;
+	request_resource(mod_res, user_res);
+
+	mp->resource.user_ram = user_res;
+
+	/* Control and status register. */
+	csr_res = kzalloc(sizeof(*csr_res), GFP_KERNEL);
+	if (!csr_res)
+		goto err_out_user_res;
+
+	csr_res->name = ms02nv_res_csr;
+	csr_res->start = addr + MS02NV_CSR;
+	csr_res->end = addr + MS02NV_CSR + 3;
+	csr_res->flags = IORESOURCE_BUSY;
+	request_resource(mod_res, csr_res);
+
+	mp->resource.csr = csr_res;
+
+	mp->addr = phys_to_virt(addr);
+	mp->size = size;
+
+	/*
+	 * Hide the firmware's diagnostic area.  It may get destroyed
+	 * upon a reboot.  Take paging into account for mapping support.
+	 */
+	fixaddr = (addr + MS02NV_RAM + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
+	fixsize = (size - (fixaddr - addr)) & ~(PAGE_SIZE - 1);
+	mp->uaddr = phys_to_virt(fixaddr);
+
+	mtd->type = MTD_RAM;
+	mtd->flags = MTD_CAP_RAM;
+	mtd->size = fixsize;
+	mtd->name = ms02nv_name;
+	mtd->owner = THIS_MODULE;
+	mtd->_read = ms02nv_read;
+	mtd->_write = ms02nv_write;
+	mtd->writesize = 1;
+
+	ret = -EIO;
+	if (mtd_device_register(mtd, NULL, 0)) {
+		printk(KERN_ERR
+			"ms02-nv: Unable to register MTD device, aborting!\n");
+		goto err_out_csr_res;
+	}
+
+	printk(KERN_INFO "mtd%d: %s at 0x%08lx, size %zuMiB.\n",
+		mtd->index, ms02nv_name, addr, size >> 20);
+
+	mp->next = root_ms02nv_mtd;
+	root_ms02nv_mtd = mtd;
+
+	return 0;
+
+
+err_out_csr_res:
+	release_resource(csr_res);
+	kfree(csr_res);
+err_out_user_res:
+	release_resource(user_res);
+	kfree(user_res);
+err_out_diag_res:
+	release_resource(diag_res);
+	kfree(diag_res);
+err_out_mp:
+	kfree(mp);
+err_out_mtd:
+	kfree(mtd);
+err_out_mod_res_rel:
+	release_resource(mod_res);
+err_out_mod_res:
+	kfree(mod_res);
+	return ret;
+}
+
+static void __exit ms02nv_remove_one(void)
+{
+	struct mtd_info *mtd = root_ms02nv_mtd;
+	struct ms02nv_private *mp = mtd->priv;
+
+	root_ms02nv_mtd = mp->next;
+
+	mtd_device_unregister(mtd);
+
+	release_resource(mp->resource.csr);
+	kfree(mp->resource.csr);
+	release_resource(mp->resource.user_ram);
+	kfree(mp->resource.user_ram);
+	release_resource(mp->resource.diag_ram);
+	kfree(mp->resource.diag_ram);
+	release_resource(mp->resource.module);
+	kfree(mp->resource.module);
+	kfree(mp);
+	kfree(mtd);
+}
+
+
+static int __init ms02nv_init(void)
+{
+	volatile u32 *csr;
+	uint stride = 0;
+	int count = 0;
+	int i;
+
+	switch (mips_machtype) {
+	case MACH_DS5000_200:
+		csr = (volatile u32 *)CKSEG1ADDR(KN02_SLOT_BASE + KN02_CSR);
+		if (*csr & KN02_CSR_BNK32M)
+			stride = 2;
+		break;
+	case MACH_DS5000_2X0:
+	case MACH_DS5900:
+		csr = (volatile u32 *)CKSEG1ADDR(KN03_SLOT_BASE + IOASIC_MCR);
+		if (*csr & KN03_MCR_BNK32M)
+			stride = 2;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(ms02nv_addrs); i++)
+		if (!ms02nv_init_one(ms02nv_addrs[i] << stride))
+			count++;
+
+	return (count > 0) ? 0 : -ENODEV;
+}
+
+static void __exit ms02nv_cleanup(void)
+{
+	while (root_ms02nv_mtd)
+		ms02nv_remove_one();
+}
+
+
+module_init(ms02nv_init);
+module_exit(ms02nv_cleanup);
diff --git a/drivers/mtd/devices/ms02-nv.h b/drivers/mtd/devices/ms02-nv.h
new file mode 100644
index 000000000..737e4735d
--- /dev/null
+++ b/drivers/mtd/devices/ms02-nv.h
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *	Copyright (c) 2001, 2003  Maciej W. Rozycki
+ *
+ *	DEC MS02-NV (54-20948-01) battery backed-up NVRAM module for
+ *	DECstation/DECsystem 5000/2x0 and DECsystem 5900 and 5900/260
+ *	systems.
+ */
+
+#include <linux/ioport.h>
+#include <linux/mtd/mtd.h>
+
+/*
+ * Addresses are decoded as follows:
+ *
+ * 0x000000 - 0x3fffff	SRAM
+ * 0x400000 - 0x7fffff	CSR
+ *
+ * Within the SRAM area the following ranges are forced by the system
+ * firmware:
+ *
+ * 0x000000 - 0x0003ff	diagnostic area, destroyed upon a reboot
+ * 0x000400 - ENDofRAM	storage area, available to operating systems
+ *
+ * but we can't really use the available area right from 0x000400 as
+ * the first word is used by the firmware as a status flag passed
+ * from an operating system.  If anything but the valid data magic
+ * ID value is found, the firmware considers the SRAM clean, i.e.
+ * containing no valid data, and disables the battery resulting in
+ * data being erased as soon as power is switched off.  So the choice
+ * for the start address of the user-available is 0x001000 which is
+ * nicely page aligned.  The area between 0x000404 and 0x000fff may
+ * be used by the driver for own needs.
+ *
+ * The diagnostic area defines two status words to be read by an
+ * operating system, a magic ID to distinguish a MS02-NV board from
+ * anything else and a status information providing results of tests
+ * as well as the size of SRAM available, which can be 1MiB or 2MiB
+ * (that's what the firmware handles; no idea if 2MiB modules ever
+ * existed).
+ *
+ * The firmware only handles the MS02-NV board if installed in the
+ * last (15th) slot, so for any other location the status information
+ * stored in the SRAM cannot be relied upon.  But from the hardware
+ * point of view there is no problem using up to 14 such boards in a
+ * system -- only the 1st slot needs to be filled with a DRAM module.
+ * The MS02-NV board is ECC-protected, like other MS02 memory boards.
+ *
+ * The state of the battery as provided by the CSR is reflected on
+ * the two onboard LEDs.  When facing the battery side of the board,
+ * with the LEDs at the top left and the battery at the bottom right
+ * (i.e. looking from the back side of the system box), their meaning
+ * is as follows (the system has to be powered on):
+ *
+ * left LED		battery disable status: lit = enabled
+ * right LED		battery condition status: lit = OK
+ */
+
+/* MS02-NV iomem register offsets. */
+#define MS02NV_CSR		0x400000	/* control & status register */
+
+/* MS02-NV CSR status bits. */
+#define MS02NV_CSR_BATT_OK	0x01		/* battery OK */
+#define MS02NV_CSR_BATT_OFF	0x02		/* battery disabled */
+
+
+/* MS02-NV memory offsets. */
+#define MS02NV_DIAG		0x0003f8	/* diagnostic status */
+#define MS02NV_MAGIC		0x0003fc	/* MS02-NV magic ID */
+#define MS02NV_VALID		0x000400	/* valid data magic ID */
+#define MS02NV_RAM		0x001000	/* user-exposed RAM start */
+
+/* MS02-NV diagnostic status bits. */
+#define MS02NV_DIAG_TEST	0x01		/* SRAM test done (?) */
+#define MS02NV_DIAG_RO		0x02		/* SRAM r/o test done */
+#define MS02NV_DIAG_RW		0x04		/* SRAM r/w test done */
+#define MS02NV_DIAG_FAIL	0x08		/* SRAM test failed */
+#define MS02NV_DIAG_SIZE_MASK	0xf0		/* SRAM size mask */
+#define MS02NV_DIAG_SIZE_SHIFT	0x10		/* SRAM size shift (left) */
+
+/* MS02-NV general constants. */
+#define MS02NV_ID		0x03021966	/* MS02-NV magic ID value */
+#define MS02NV_VALID_ID		0xbd100248	/* valid data magic ID value */
+#define MS02NV_SLOT_SIZE	0x800000	/* size of the address space
+						   decoded by the module */
+
+
+typedef volatile u32 ms02nv_uint;
+
+struct ms02nv_private {
+	struct mtd_info *next;
+	struct {
+		struct resource *module;
+		struct resource *diag_ram;
+		struct resource *user_ram;
+		struct resource *csr;
+	} resource;
+	u_char *addr;
+	size_t size;
+	u_char *uaddr;
+};
diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c
new file mode 100644
index 000000000..25bad4318
--- /dev/null
+++ b/drivers/mtd/devices/mtd_dataflash.c
@@ -0,0 +1,956 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Atmel AT45xxx DataFlash MTD driver for lightweight SPI framework
+ *
+ * Largely derived from at91_dataflash.c:
+ *  Copyright (C) 2003-2005 SAN People (Pty) Ltd
+*/
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <linux/math64.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/flash.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+
+/*
+ * DataFlash is a kind of SPI flash.  Most AT45 chips have two buffers in
+ * each chip, which may be used for double buffered I/O; but this driver
+ * doesn't (yet) use these for any kind of i/o overlap or prefetching.
+ *
+ * Sometimes DataFlash is packaged in MMC-format cards, although the
+ * MMC stack can't (yet?) distinguish between MMC and DataFlash
+ * protocols during enumeration.
+ */
+
+/* reads can bypass the buffers */
+#define OP_READ_CONTINUOUS	0xE8
+#define OP_READ_PAGE		0xD2
+
+/* group B requests can run even while status reports "busy" */
+#define OP_READ_STATUS		0xD7	/* group B */
+
+/* move data between host and buffer */
+#define OP_READ_BUFFER1		0xD4	/* group B */
+#define OP_READ_BUFFER2		0xD6	/* group B */
+#define OP_WRITE_BUFFER1	0x84	/* group B */
+#define OP_WRITE_BUFFER2	0x87	/* group B */
+
+/* erasing flash */
+#define OP_ERASE_PAGE		0x81
+#define OP_ERASE_BLOCK		0x50
+
+/* move data between buffer and flash */
+#define OP_TRANSFER_BUF1	0x53
+#define OP_TRANSFER_BUF2	0x55
+#define OP_MREAD_BUFFER1	0xD4
+#define OP_MREAD_BUFFER2	0xD6
+#define OP_MWERASE_BUFFER1	0x83
+#define OP_MWERASE_BUFFER2	0x86
+#define OP_MWRITE_BUFFER1	0x88	/* sector must be pre-erased */
+#define OP_MWRITE_BUFFER2	0x89	/* sector must be pre-erased */
+
+/* write to buffer, then write-erase to flash */
+#define OP_PROGRAM_VIA_BUF1	0x82
+#define OP_PROGRAM_VIA_BUF2	0x85
+
+/* compare buffer to flash */
+#define OP_COMPARE_BUF1		0x60
+#define OP_COMPARE_BUF2		0x61
+
+/* read flash to buffer, then write-erase to flash */
+#define OP_REWRITE_VIA_BUF1	0x58
+#define OP_REWRITE_VIA_BUF2	0x59
+
+/* newer chips report JEDEC manufacturer and device IDs; chip
+ * serial number and OTP bits; and per-sector writeprotect.
+ */
+#define OP_READ_ID		0x9F
+#define OP_READ_SECURITY	0x77
+#define OP_WRITE_SECURITY_REVC	0x9A
+#define OP_WRITE_SECURITY	0x9B	/* revision D */
+
+#define CFI_MFR_ATMEL		0x1F
+
+#define DATAFLASH_SHIFT_EXTID	24
+#define DATAFLASH_SHIFT_ID	40
+
+struct dataflash {
+	u8			command[4];
+	char			name[24];
+
+	unsigned short		page_offset;	/* offset in flash address */
+	unsigned int		page_size;	/* of bytes per page */
+
+	struct mutex		lock;
+	struct spi_device	*spi;
+
+	struct mtd_info		mtd;
+};
+
+static const struct spi_device_id dataflash_dev_ids[] = {
+	{ "at45" },
+	{ "dataflash" },
+	{ },
+};
+MODULE_DEVICE_TABLE(spi, dataflash_dev_ids);
+
+#ifdef CONFIG_OF
+static const struct of_device_id dataflash_dt_ids[] = {
+	{ .compatible = "atmel,at45", },
+	{ .compatible = "atmel,dataflash", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, dataflash_dt_ids);
+#endif
+
+static const struct spi_device_id dataflash_spi_ids[] = {
+	{ .name = "at45", },
+	{ .name = "dataflash", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(spi, dataflash_spi_ids);
+
+/* ......................................................................... */
+
+/*
+ * Return the status of the DataFlash device.
+ */
+static inline int dataflash_status(struct spi_device *spi)
+{
+	/* NOTE:  at45db321c over 25 MHz wants to write
+	 * a dummy byte after the opcode...
+	 */
+	return spi_w8r8(spi, OP_READ_STATUS);
+}
+
+/*
+ * Poll the DataFlash device until it is READY.
+ * This usually takes 5-20 msec or so; more for sector erase.
+ */
+static int dataflash_waitready(struct spi_device *spi)
+{
+	int	status;
+
+	for (;;) {
+		status = dataflash_status(spi);
+		if (status < 0) {
+			dev_dbg(&spi->dev, "status %d?\n", status);
+			status = 0;
+		}
+
+		if (status & (1 << 7))	/* RDY/nBSY */
+			return status;
+
+		usleep_range(3000, 4000);
+	}
+}
+
+/* ......................................................................... */
+
+/*
+ * Erase pages of flash.
+ */
+static int dataflash_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct dataflash	*priv = mtd->priv;
+	struct spi_device	*spi = priv->spi;
+	struct spi_transfer	x = { };
+	struct spi_message	msg;
+	unsigned		blocksize = priv->page_size << 3;
+	u8			*command;
+	u32			rem;
+
+	dev_dbg(&spi->dev, "erase addr=0x%llx len 0x%llx\n",
+		(long long)instr->addr, (long long)instr->len);
+
+	div_u64_rem(instr->len, priv->page_size, &rem);
+	if (rem)
+		return -EINVAL;
+	div_u64_rem(instr->addr, priv->page_size, &rem);
+	if (rem)
+		return -EINVAL;
+
+	spi_message_init(&msg);
+
+	x.tx_buf = command = priv->command;
+	x.len = 4;
+	spi_message_add_tail(&x, &msg);
+
+	mutex_lock(&priv->lock);
+	while (instr->len > 0) {
+		unsigned int	pageaddr;
+		int		status;
+		int		do_block;
+
+		/* Calculate flash page address; use block erase (for speed) if
+		 * we're at a block boundary and need to erase the whole block.
+		 */
+		pageaddr = div_u64(instr->addr, priv->page_size);
+		do_block = (pageaddr & 0x7) == 0 && instr->len >= blocksize;
+		pageaddr = pageaddr << priv->page_offset;
+
+		command[0] = do_block ? OP_ERASE_BLOCK : OP_ERASE_PAGE;
+		command[1] = (u8)(pageaddr >> 16);
+		command[2] = (u8)(pageaddr >> 8);
+		command[3] = 0;
+
+		dev_dbg(&spi->dev, "ERASE %s: (%x) %x %x %x [%i]\n",
+			do_block ? "block" : "page",
+			command[0], command[1], command[2], command[3],
+			pageaddr);
+
+		status = spi_sync(spi, &msg);
+		(void) dataflash_waitready(spi);
+
+		if (status < 0) {
+			dev_err(&spi->dev, "erase %x, err %d\n",
+				pageaddr, status);
+			/* REVISIT:  can retry instr->retries times; or
+			 * giveup and instr->fail_addr = instr->addr;
+			 */
+			continue;
+		}
+
+		if (do_block) {
+			instr->addr += blocksize;
+			instr->len -= blocksize;
+		} else {
+			instr->addr += priv->page_size;
+			instr->len -= priv->page_size;
+		}
+	}
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+/*
+ * Read from the DataFlash device.
+ *   from   : Start offset in flash device
+ *   len    : Amount to read
+ *   retlen : About of data actually read
+ *   buf    : Buffer containing the data
+ */
+static int dataflash_read(struct mtd_info *mtd, loff_t from, size_t len,
+			       size_t *retlen, u_char *buf)
+{
+	struct dataflash	*priv = mtd->priv;
+	struct spi_transfer	x[2] = { };
+	struct spi_message	msg;
+	unsigned int		addr;
+	u8			*command;
+	int			status;
+
+	dev_dbg(&priv->spi->dev, "read 0x%x..0x%x\n",
+		  (unsigned int)from, (unsigned int)(from + len));
+
+	/* Calculate flash page/byte address */
+	addr = (((unsigned)from / priv->page_size) << priv->page_offset)
+		+ ((unsigned)from % priv->page_size);
+
+	command = priv->command;
+
+	dev_dbg(&priv->spi->dev, "READ: (%x) %x %x %x\n",
+		command[0], command[1], command[2], command[3]);
+
+	spi_message_init(&msg);
+
+	x[0].tx_buf = command;
+	x[0].len = 8;
+	spi_message_add_tail(&x[0], &msg);
+
+	x[1].rx_buf = buf;
+	x[1].len = len;
+	spi_message_add_tail(&x[1], &msg);
+
+	mutex_lock(&priv->lock);
+
+	/* Continuous read, max clock = f(car) which may be less than
+	 * the peak rate available.  Some chips support commands with
+	 * fewer "don't care" bytes.  Both buffers stay unchanged.
+	 */
+	command[0] = OP_READ_CONTINUOUS;
+	command[1] = (u8)(addr >> 16);
+	command[2] = (u8)(addr >> 8);
+	command[3] = (u8)(addr >> 0);
+	/* plus 4 "don't care" bytes */
+
+	status = spi_sync(priv->spi, &msg);
+	mutex_unlock(&priv->lock);
+
+	if (status >= 0) {
+		*retlen = msg.actual_length - 8;
+		status = 0;
+	} else
+		dev_dbg(&priv->spi->dev, "read %x..%x --> %d\n",
+			(unsigned)from, (unsigned)(from + len),
+			status);
+	return status;
+}
+
+/*
+ * Write to the DataFlash device.
+ *   to     : Start offset in flash device
+ *   len    : Amount to write
+ *   retlen : Amount of data actually written
+ *   buf    : Buffer containing the data
+ */
+static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len,
+				size_t * retlen, const u_char * buf)
+{
+	struct dataflash	*priv = mtd->priv;
+	struct spi_device	*spi = priv->spi;
+	struct spi_transfer	x[2] = { };
+	struct spi_message	msg;
+	unsigned int		pageaddr, addr, offset, writelen;
+	size_t			remaining = len;
+	u_char			*writebuf = (u_char *) buf;
+	int			status = -EINVAL;
+	u8			*command;
+
+	dev_dbg(&spi->dev, "write 0x%x..0x%x\n",
+		(unsigned int)to, (unsigned int)(to + len));
+
+	spi_message_init(&msg);
+
+	x[0].tx_buf = command = priv->command;
+	x[0].len = 4;
+	spi_message_add_tail(&x[0], &msg);
+
+	pageaddr = ((unsigned)to / priv->page_size);
+	offset = ((unsigned)to % priv->page_size);
+	if (offset + len > priv->page_size)
+		writelen = priv->page_size - offset;
+	else
+		writelen = len;
+
+	mutex_lock(&priv->lock);
+	while (remaining > 0) {
+		dev_dbg(&spi->dev, "write @ %i:%i len=%i\n",
+			pageaddr, offset, writelen);
+
+		/* REVISIT:
+		 * (a) each page in a sector must be rewritten at least
+		 *     once every 10K sibling erase/program operations.
+		 * (b) for pages that are already erased, we could
+		 *     use WRITE+MWRITE not PROGRAM for ~30% speedup.
+		 * (c) WRITE to buffer could be done while waiting for
+		 *     a previous MWRITE/MWERASE to complete ...
+		 * (d) error handling here seems to be mostly missing.
+		 *
+		 * Two persistent bits per page, plus a per-sector counter,
+		 * could support (a) and (b) ... we might consider using
+		 * the second half of sector zero, which is just one block,
+		 * to track that state.  (On AT91, that sector should also
+		 * support boot-from-DataFlash.)
+		 */
+
+		addr = pageaddr << priv->page_offset;
+
+		/* (1) Maybe transfer partial page to Buffer1 */
+		if (writelen != priv->page_size) {
+			command[0] = OP_TRANSFER_BUF1;
+			command[1] = (addr & 0x00FF0000) >> 16;
+			command[2] = (addr & 0x0000FF00) >> 8;
+			command[3] = 0;
+
+			dev_dbg(&spi->dev, "TRANSFER: (%x) %x %x %x\n",
+				command[0], command[1], command[2], command[3]);
+
+			status = spi_sync(spi, &msg);
+			if (status < 0)
+				dev_dbg(&spi->dev, "xfer %u -> %d\n",
+					addr, status);
+
+			(void) dataflash_waitready(priv->spi);
+		}
+
+		/* (2) Program full page via Buffer1 */
+		addr += offset;
+		command[0] = OP_PROGRAM_VIA_BUF1;
+		command[1] = (addr & 0x00FF0000) >> 16;
+		command[2] = (addr & 0x0000FF00) >> 8;
+		command[3] = (addr & 0x000000FF);
+
+		dev_dbg(&spi->dev, "PROGRAM: (%x) %x %x %x\n",
+			command[0], command[1], command[2], command[3]);
+
+		x[1].tx_buf = writebuf;
+		x[1].len = writelen;
+		spi_message_add_tail(x + 1, &msg);
+		status = spi_sync(spi, &msg);
+		spi_transfer_del(x + 1);
+		if (status < 0)
+			dev_dbg(&spi->dev, "pgm %u/%u -> %d\n",
+				addr, writelen, status);
+
+		(void) dataflash_waitready(priv->spi);
+
+
+#ifdef CONFIG_MTD_DATAFLASH_WRITE_VERIFY
+
+		/* (3) Compare to Buffer1 */
+		addr = pageaddr << priv->page_offset;
+		command[0] = OP_COMPARE_BUF1;
+		command[1] = (addr & 0x00FF0000) >> 16;
+		command[2] = (addr & 0x0000FF00) >> 8;
+		command[3] = 0;
+
+		dev_dbg(&spi->dev, "COMPARE: (%x) %x %x %x\n",
+			command[0], command[1], command[2], command[3]);
+
+		status = spi_sync(spi, &msg);
+		if (status < 0)
+			dev_dbg(&spi->dev, "compare %u -> %d\n",
+				addr, status);
+
+		status = dataflash_waitready(priv->spi);
+
+		/* Check result of the compare operation */
+		if (status & (1 << 6)) {
+			dev_err(&spi->dev, "compare page %u, err %d\n",
+				pageaddr, status);
+			remaining = 0;
+			status = -EIO;
+			break;
+		} else
+			status = 0;
+
+#endif	/* CONFIG_MTD_DATAFLASH_WRITE_VERIFY */
+
+		remaining = remaining - writelen;
+		pageaddr++;
+		offset = 0;
+		writebuf += writelen;
+		*retlen += writelen;
+
+		if (remaining > priv->page_size)
+			writelen = priv->page_size;
+		else
+			writelen = remaining;
+	}
+	mutex_unlock(&priv->lock);
+
+	return status;
+}
+
+/* ......................................................................... */
+
+#ifdef CONFIG_MTD_DATAFLASH_OTP
+
+static int dataflash_get_otp_info(struct mtd_info *mtd, size_t len,
+				  size_t *retlen, struct otp_info *info)
+{
+	/* Report both blocks as identical:  bytes 0..64, locked.
+	 * Unless the user block changed from all-ones, we can't
+	 * tell whether it's still writable; so we assume it isn't.
+	 */
+	info->start = 0;
+	info->length = 64;
+	info->locked = 1;
+	*retlen = sizeof(*info);
+	return 0;
+}
+
+static ssize_t otp_read(struct spi_device *spi, unsigned base,
+		u8 *buf, loff_t off, size_t len)
+{
+	struct spi_message	m;
+	size_t			l;
+	u8			*scratch;
+	struct spi_transfer	t;
+	int			status;
+
+	if (off > 64)
+		return -EINVAL;
+
+	if ((off + len) > 64)
+		len = 64 - off;
+
+	spi_message_init(&m);
+
+	l = 4 + base + off + len;
+	scratch = kzalloc(l, GFP_KERNEL);
+	if (!scratch)
+		return -ENOMEM;
+
+	/* OUT: OP_READ_SECURITY, 3 don't-care bytes, zeroes
+	 * IN:  ignore 4 bytes, data bytes 0..N (max 127)
+	 */
+	scratch[0] = OP_READ_SECURITY;
+
+	memset(&t, 0, sizeof t);
+	t.tx_buf = scratch;
+	t.rx_buf = scratch;
+	t.len = l;
+	spi_message_add_tail(&t, &m);
+
+	dataflash_waitready(spi);
+
+	status = spi_sync(spi, &m);
+	if (status >= 0) {
+		memcpy(buf, scratch + 4 + base + off, len);
+		status = len;
+	}
+
+	kfree(scratch);
+	return status;
+}
+
+static int dataflash_read_fact_otp(struct mtd_info *mtd,
+		loff_t from, size_t len, size_t *retlen, u_char *buf)
+{
+	struct dataflash	*priv = mtd->priv;
+	int			status;
+
+	/* 64 bytes, from 0..63 ... start at 64 on-chip */
+	mutex_lock(&priv->lock);
+	status = otp_read(priv->spi, 64, buf, from, len);
+	mutex_unlock(&priv->lock);
+
+	if (status < 0)
+		return status;
+	*retlen = status;
+	return 0;
+}
+
+static int dataflash_read_user_otp(struct mtd_info *mtd,
+		loff_t from, size_t len, size_t *retlen, u_char *buf)
+{
+	struct dataflash	*priv = mtd->priv;
+	int			status;
+
+	/* 64 bytes, from 0..63 ... start at 0 on-chip */
+	mutex_lock(&priv->lock);
+	status = otp_read(priv->spi, 0, buf, from, len);
+	mutex_unlock(&priv->lock);
+
+	if (status < 0)
+		return status;
+	*retlen = status;
+	return 0;
+}
+
+static int dataflash_write_user_otp(struct mtd_info *mtd,
+		loff_t from, size_t len, size_t *retlen, const u_char *buf)
+{
+	struct spi_message	m;
+	const size_t		l = 4 + 64;
+	u8			*scratch;
+	struct spi_transfer	t;
+	struct dataflash	*priv = mtd->priv;
+	int			status;
+
+	if (from >= 64) {
+		/*
+		 * Attempting to write beyond the end of OTP memory,
+		 * no data can be written.
+		 */
+		*retlen = 0;
+		return 0;
+	}
+
+	/* Truncate the write to fit into OTP memory. */
+	if ((from + len) > 64)
+		len = 64 - from;
+
+	/* OUT: OP_WRITE_SECURITY, 3 zeroes, 64 data-or-zero bytes
+	 * IN:  ignore all
+	 */
+	scratch = kzalloc(l, GFP_KERNEL);
+	if (!scratch)
+		return -ENOMEM;
+	scratch[0] = OP_WRITE_SECURITY;
+	memcpy(scratch + 4 + from, buf, len);
+
+	spi_message_init(&m);
+
+	memset(&t, 0, sizeof t);
+	t.tx_buf = scratch;
+	t.len = l;
+	spi_message_add_tail(&t, &m);
+
+	/* Write the OTP bits, if they've not yet been written.
+	 * This modifies SRAM buffer1.
+	 */
+	mutex_lock(&priv->lock);
+	dataflash_waitready(priv->spi);
+	status = spi_sync(priv->spi, &m);
+	mutex_unlock(&priv->lock);
+
+	kfree(scratch);
+
+	if (status >= 0) {
+		status = 0;
+		*retlen = len;
+	}
+	return status;
+}
+
+static char *otp_setup(struct mtd_info *device, char revision)
+{
+	device->_get_fact_prot_info = dataflash_get_otp_info;
+	device->_read_fact_prot_reg = dataflash_read_fact_otp;
+	device->_get_user_prot_info = dataflash_get_otp_info;
+	device->_read_user_prot_reg = dataflash_read_user_otp;
+
+	/* rev c parts (at45db321c and at45db1281 only!) use a
+	 * different write procedure; not (yet?) implemented.
+	 */
+	if (revision > 'c')
+		device->_write_user_prot_reg = dataflash_write_user_otp;
+
+	return ", OTP";
+}
+
+#else
+
+static char *otp_setup(struct mtd_info *device, char revision)
+{
+	return " (OTP)";
+}
+
+#endif
+
+/* ......................................................................... */
+
+/*
+ * Register DataFlash device with MTD subsystem.
+ */
+static int add_dataflash_otp(struct spi_device *spi, char *name, int nr_pages,
+			     int pagesize, int pageoffset, char revision)
+{
+	struct dataflash		*priv;
+	struct mtd_info			*device;
+	struct flash_platform_data	*pdata = dev_get_platdata(&spi->dev);
+	char				*otp_tag = "";
+	int				err = 0;
+
+	priv = kzalloc(sizeof *priv, GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	mutex_init(&priv->lock);
+	priv->spi = spi;
+	priv->page_size = pagesize;
+	priv->page_offset = pageoffset;
+
+	/* name must be usable with cmdlinepart */
+	sprintf(priv->name, "spi%d.%d-%s",
+			spi->master->bus_num, spi->chip_select,
+			name);
+
+	device = &priv->mtd;
+	device->name = (pdata && pdata->name) ? pdata->name : priv->name;
+	device->size = nr_pages * pagesize;
+	device->erasesize = pagesize;
+	device->writesize = pagesize;
+	device->type = MTD_DATAFLASH;
+	device->flags = MTD_WRITEABLE;
+	device->_erase = dataflash_erase;
+	device->_read = dataflash_read;
+	device->_write = dataflash_write;
+	device->priv = priv;
+
+	device->dev.parent = &spi->dev;
+	mtd_set_of_node(device, spi->dev.of_node);
+
+	if (revision >= 'c')
+		otp_tag = otp_setup(device, revision);
+
+	dev_info(&spi->dev, "%s (%lld KBytes) pagesize %d bytes%s\n",
+			name, (long long)((device->size + 1023) >> 10),
+			pagesize, otp_tag);
+	spi_set_drvdata(spi, priv);
+
+	err = mtd_device_register(device,
+			pdata ? pdata->parts : NULL,
+			pdata ? pdata->nr_parts : 0);
+
+	if (!err)
+		return 0;
+
+	kfree(priv);
+	return err;
+}
+
+static inline int add_dataflash(struct spi_device *spi, char *name,
+				int nr_pages, int pagesize, int pageoffset)
+{
+	return add_dataflash_otp(spi, name, nr_pages, pagesize,
+			pageoffset, 0);
+}
+
+struct flash_info {
+	char		*name;
+
+	/* JEDEC id has a high byte of zero plus three data bytes:
+	 * the manufacturer id, then a two byte device id.
+	 */
+	u64		jedec_id;
+
+	/* The size listed here is what works with OP_ERASE_PAGE. */
+	unsigned	nr_pages;
+	u16		pagesize;
+	u16		pageoffset;
+
+	u16		flags;
+#define SUP_EXTID	0x0004		/* supports extended ID data */
+#define SUP_POW2PS	0x0002		/* supports 2^N byte pages */
+#define IS_POW2PS	0x0001		/* uses 2^N byte pages */
+};
+
+static struct flash_info dataflash_data[] = {
+
+	/*
+	 * NOTE:  chips with SUP_POW2PS (rev D and up) need two entries,
+	 * one with IS_POW2PS and the other without.  The entry with the
+	 * non-2^N byte page size can't name exact chip revisions without
+	 * losing backwards compatibility for cmdlinepart.
+	 *
+	 * These newer chips also support 128-byte security registers (with
+	 * 64 bytes one-time-programmable) and software write-protection.
+	 */
+	{ "AT45DB011B",  0x1f2200, 512, 264, 9, SUP_POW2PS},
+	{ "at45db011d",  0x1f2200, 512, 256, 8, SUP_POW2PS | IS_POW2PS},
+
+	{ "AT45DB021B",  0x1f2300, 1024, 264, 9, SUP_POW2PS},
+	{ "at45db021d",  0x1f2300, 1024, 256, 8, SUP_POW2PS | IS_POW2PS},
+
+	{ "AT45DB041x",  0x1f2400, 2048, 264, 9, SUP_POW2PS},
+	{ "at45db041d",  0x1f2400, 2048, 256, 8, SUP_POW2PS | IS_POW2PS},
+
+	{ "AT45DB081B",  0x1f2500, 4096, 264, 9, SUP_POW2PS},
+	{ "at45db081d",  0x1f2500, 4096, 256, 8, SUP_POW2PS | IS_POW2PS},
+
+	{ "AT45DB161x",  0x1f2600, 4096, 528, 10, SUP_POW2PS},
+	{ "at45db161d",  0x1f2600, 4096, 512, 9, SUP_POW2PS | IS_POW2PS},
+
+	{ "AT45DB321x",  0x1f2700, 8192, 528, 10, 0},		/* rev C */
+
+	{ "AT45DB321x",  0x1f2701, 8192, 528, 10, SUP_POW2PS},
+	{ "at45db321d",  0x1f2701, 8192, 512, 9, SUP_POW2PS | IS_POW2PS},
+
+	{ "AT45DB642x",  0x1f2800, 8192, 1056, 11, SUP_POW2PS},
+	{ "at45db642d",  0x1f2800, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS},
+
+	{ "AT45DB641E",  0x1f28000100ULL, 32768, 264, 9, SUP_EXTID | SUP_POW2PS},
+	{ "at45db641e",  0x1f28000100ULL, 32768, 256, 8, SUP_EXTID | SUP_POW2PS | IS_POW2PS},
+};
+
+static struct flash_info *jedec_lookup(struct spi_device *spi,
+				       u64 jedec, bool use_extid)
+{
+	struct flash_info *info;
+	int status;
+
+	for (info = dataflash_data;
+	     info < dataflash_data + ARRAY_SIZE(dataflash_data);
+	     info++) {
+		if (use_extid && !(info->flags & SUP_EXTID))
+			continue;
+
+		if (info->jedec_id == jedec) {
+			dev_dbg(&spi->dev, "OTP, sector protect%s\n",
+				(info->flags & SUP_POW2PS) ?
+				", binary pagesize" : "");
+			if (info->flags & SUP_POW2PS) {
+				status = dataflash_status(spi);
+				if (status < 0) {
+					dev_dbg(&spi->dev, "status error %d\n",
+						status);
+					return ERR_PTR(status);
+				}
+				if (status & 0x1) {
+					if (info->flags & IS_POW2PS)
+						return info;
+				} else {
+					if (!(info->flags & IS_POW2PS))
+						return info;
+				}
+			} else
+				return info;
+		}
+	}
+
+	return ERR_PTR(-ENODEV);
+}
+
+static struct flash_info *jedec_probe(struct spi_device *spi)
+{
+	int ret;
+	u8 code = OP_READ_ID;
+	u64 jedec;
+	u8 id[sizeof(jedec)] = {0};
+	const unsigned int id_size = 5;
+	struct flash_info *info;
+
+	/*
+	 * JEDEC also defines an optional "extended device information"
+	 * string for after vendor-specific data, after the three bytes
+	 * we use here.  Supporting some chips might require using it.
+	 *
+	 * If the vendor ID isn't Atmel's (0x1f), assume this call failed.
+	 * That's not an error; only rev C and newer chips handle it, and
+	 * only Atmel sells these chips.
+	 */
+	ret = spi_write_then_read(spi, &code, 1, id, id_size);
+	if (ret < 0) {
+		dev_dbg(&spi->dev, "error %d reading JEDEC ID\n", ret);
+		return ERR_PTR(ret);
+	}
+
+	if (id[0] != CFI_MFR_ATMEL)
+		return NULL;
+
+	jedec = be64_to_cpup((__be64 *)id);
+
+	/*
+	 * First, try to match device using extended device
+	 * information
+	 */
+	info = jedec_lookup(spi, jedec >> DATAFLASH_SHIFT_EXTID, true);
+	if (!IS_ERR(info))
+		return info;
+	/*
+	 * If that fails, make another pass using regular ID
+	 * information
+	 */
+	info = jedec_lookup(spi, jedec >> DATAFLASH_SHIFT_ID, false);
+	if (!IS_ERR(info))
+		return info;
+	/*
+	 * Treat other chips as errors ... we won't know the right page
+	 * size (it might be binary) even when we can tell which density
+	 * class is involved (legacy chip id scheme).
+	 */
+	dev_warn(&spi->dev, "JEDEC id %016llx not handled\n", jedec);
+	return ERR_PTR(-ENODEV);
+}
+
+/*
+ * Detect and initialize DataFlash device, using JEDEC IDs on newer chips
+ * or else the ID code embedded in the status bits:
+ *
+ *   Device      Density         ID code          #Pages PageSize  Offset
+ *   AT45DB011B  1Mbit   (128K)  xx0011xx (0x0c)    512    264      9
+ *   AT45DB021B  2Mbit   (256K)  xx0101xx (0x14)   1024    264      9
+ *   AT45DB041B  4Mbit   (512K)  xx0111xx (0x1c)   2048    264      9
+ *   AT45DB081B  8Mbit   (1M)    xx1001xx (0x24)   4096    264      9
+ *   AT45DB0161B 16Mbit  (2M)    xx1011xx (0x2c)   4096    528     10
+ *   AT45DB0321B 32Mbit  (4M)    xx1101xx (0x34)   8192    528     10
+ *   AT45DB0642  64Mbit  (8M)    xx111xxx (0x3c)   8192   1056     11
+ *   AT45DB1282  128Mbit (16M)   xx0100xx (0x10)  16384   1056     11
+ */
+static int dataflash_probe(struct spi_device *spi)
+{
+	int status;
+	struct flash_info	*info;
+
+	/*
+	 * Try to detect dataflash by JEDEC ID.
+	 * If it succeeds we know we have either a C or D part.
+	 * D will support power of 2 pagesize option.
+	 * Both support the security register, though with different
+	 * write procedures.
+	 */
+	info = jedec_probe(spi);
+	if (IS_ERR(info))
+		return PTR_ERR(info);
+	if (info != NULL)
+		return add_dataflash_otp(spi, info->name, info->nr_pages,
+				info->pagesize, info->pageoffset,
+				(info->flags & SUP_POW2PS) ? 'd' : 'c');
+
+	/*
+	 * Older chips support only legacy commands, identifing
+	 * capacity using bits in the status byte.
+	 */
+	status = dataflash_status(spi);
+	if (status <= 0 || status == 0xff) {
+		dev_dbg(&spi->dev, "status error %d\n", status);
+		if (status == 0 || status == 0xff)
+			status = -ENODEV;
+		return status;
+	}
+
+	/* if there's a device there, assume it's dataflash.
+	 * board setup should have set spi->max_speed_max to
+	 * match f(car) for continuous reads, mode 0 or 3.
+	 */
+	switch (status & 0x3c) {
+	case 0x0c:	/* 0 0 1 1 x x */
+		status = add_dataflash(spi, "AT45DB011B", 512, 264, 9);
+		break;
+	case 0x14:	/* 0 1 0 1 x x */
+		status = add_dataflash(spi, "AT45DB021B", 1024, 264, 9);
+		break;
+	case 0x1c:	/* 0 1 1 1 x x */
+		status = add_dataflash(spi, "AT45DB041x", 2048, 264, 9);
+		break;
+	case 0x24:	/* 1 0 0 1 x x */
+		status = add_dataflash(spi, "AT45DB081B", 4096, 264, 9);
+		break;
+	case 0x2c:	/* 1 0 1 1 x x */
+		status = add_dataflash(spi, "AT45DB161x", 4096, 528, 10);
+		break;
+	case 0x34:	/* 1 1 0 1 x x */
+		status = add_dataflash(spi, "AT45DB321x", 8192, 528, 10);
+		break;
+	case 0x38:	/* 1 1 1 x x x */
+	case 0x3c:
+		status = add_dataflash(spi, "AT45DB642x", 8192, 1056, 11);
+		break;
+	/* obsolete AT45DB1282 not (yet?) supported */
+	default:
+		dev_info(&spi->dev, "unsupported device (%x)\n",
+				status & 0x3c);
+		status = -ENODEV;
+	}
+
+	if (status < 0)
+		dev_dbg(&spi->dev, "add_dataflash --> %d\n", status);
+
+	return status;
+}
+
+static void dataflash_remove(struct spi_device *spi)
+{
+	struct dataflash	*flash = spi_get_drvdata(spi);
+
+	dev_dbg(&spi->dev, "remove\n");
+
+	WARN_ON(mtd_device_unregister(&flash->mtd));
+
+	kfree(flash);
+}
+
+static struct spi_driver dataflash_driver = {
+	.driver = {
+		.name		= "mtd_dataflash",
+		.of_match_table = of_match_ptr(dataflash_dt_ids),
+	},
+	.id_table = dataflash_dev_ids,
+
+	.probe		= dataflash_probe,
+	.remove		= dataflash_remove,
+	.id_table	= dataflash_spi_ids,
+
+	/* FIXME:  investigate suspend and resume... */
+};
+
+module_spi_driver(dataflash_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Andrew Victor, David Brownell");
+MODULE_DESCRIPTION("MTD DataFlash driver");
+MODULE_ALIAS("spi:mtd_dataflash");
diff --git a/drivers/mtd/devices/mtdram.c b/drivers/mtd/devices/mtdram.c
new file mode 100644
index 000000000..1c97fabc4
--- /dev/null
+++ b/drivers/mtd/devices/mtdram.c
@@ -0,0 +1,187 @@
+/*
+ * mtdram - a test mtd device
+ * Author: Alexander Larsson <alex@cendio.se>
+ *
+ * Copyright (c) 1999 Alexander Larsson <alex@cendio.se>
+ * Copyright (c) 2005 Joern Engel <joern@wh.fh-wedel.de>
+ *
+ * This code is GPL
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/mtdram.h>
+
+static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE;
+static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE;
+static unsigned long writebuf_size = 64;
+#define MTDRAM_TOTAL_SIZE (total_size * 1024)
+#define MTDRAM_ERASE_SIZE (erase_size * 1024)
+
+module_param(total_size, ulong, 0);
+MODULE_PARM_DESC(total_size, "Total device size in KiB");
+module_param(erase_size, ulong, 0);
+MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");
+module_param(writebuf_size, ulong, 0);
+MODULE_PARM_DESC(writebuf_size, "Device write buf size in Bytes (Default: 64)");
+
+// We could store these in the mtd structure, but we only support 1 device..
+static struct mtd_info *mtd_info;
+
+static int check_offs_len(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+	int ret = 0;
+
+	/* Start address must align on block boundary */
+	if (mtd_mod_by_eb(ofs, mtd)) {
+		pr_debug("%s: unaligned address\n", __func__);
+		ret = -EINVAL;
+	}
+
+	/* Length must align on block boundary */
+	if (mtd_mod_by_eb(len, mtd)) {
+		pr_debug("%s: length not block aligned\n", __func__);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	if (check_offs_len(mtd, instr->addr, instr->len))
+		return -EINVAL;
+	memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
+
+	return 0;
+}
+
+static int ram_point(struct mtd_info *mtd, loff_t from, size_t len,
+		size_t *retlen, void **virt, resource_size_t *phys)
+{
+	*virt = mtd->priv + from;
+	*retlen = len;
+
+	if (phys) {
+		/* limit retlen to the number of contiguous physical pages */
+		unsigned long page_ofs = offset_in_page(*virt);
+		void *addr = *virt - page_ofs;
+		unsigned long pfn1, pfn0 = vmalloc_to_pfn(addr);
+
+		*phys = __pfn_to_phys(pfn0) + page_ofs;
+		len += page_ofs;
+		while (len > PAGE_SIZE) {
+			len -= PAGE_SIZE;
+			addr += PAGE_SIZE;
+			pfn0++;
+			pfn1 = vmalloc_to_pfn(addr);
+			if (pfn1 != pfn0) {
+				*retlen = addr - *virt;
+				break;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
+{
+	return 0;
+}
+
+static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
+		size_t *retlen, u_char *buf)
+{
+	memcpy(buf, mtd->priv + from, len);
+	*retlen = len;
+	return 0;
+}
+
+static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
+		size_t *retlen, const u_char *buf)
+{
+	memcpy((char *)mtd->priv + to, buf, len);
+	*retlen = len;
+	return 0;
+}
+
+static void __exit cleanup_mtdram(void)
+{
+	if (mtd_info) {
+		mtd_device_unregister(mtd_info);
+		vfree(mtd_info->priv);
+		kfree(mtd_info);
+	}
+}
+
+int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
+		unsigned long size, const char *name)
+{
+	memset(mtd, 0, sizeof(*mtd));
+
+	/* Setup the MTD structure */
+	mtd->name = name;
+	mtd->type = MTD_RAM;
+	mtd->flags = MTD_CAP_RAM;
+	mtd->size = size;
+	mtd->writesize = 1;
+	mtd->writebufsize = writebuf_size;
+	mtd->erasesize = MTDRAM_ERASE_SIZE;
+	mtd->priv = mapped_address;
+
+	mtd->owner = THIS_MODULE;
+	mtd->_erase = ram_erase;
+	mtd->_point = ram_point;
+	mtd->_unpoint = ram_unpoint;
+	mtd->_read = ram_read;
+	mtd->_write = ram_write;
+
+	if (mtd_device_register(mtd, NULL, 0))
+		return -EIO;
+
+	return 0;
+}
+
+static int __init init_mtdram(void)
+{
+	void *addr;
+	int err;
+
+	if (!total_size)
+		return -EINVAL;
+
+	/* Allocate some memory */
+	mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
+	if (!mtd_info)
+		return -ENOMEM;
+
+	addr = vmalloc(MTDRAM_TOTAL_SIZE);
+	if (!addr) {
+		kfree(mtd_info);
+		mtd_info = NULL;
+		return -ENOMEM;
+	}
+	err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device");
+	if (err) {
+		vfree(addr);
+		kfree(mtd_info);
+		mtd_info = NULL;
+		return err;
+	}
+	memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
+	return err;
+}
+
+module_init(init_mtdram);
+module_exit(cleanup_mtdram);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
+MODULE_DESCRIPTION("Simulated MTD driver for testing");
diff --git a/drivers/mtd/devices/phram.c b/drivers/mtd/devices/phram.c
new file mode 100644
index 000000000..208bd4d87
--- /dev/null
+++ b/drivers/mtd/devices/phram.c
@@ -0,0 +1,442 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) ????		Jochen Schäuble <psionic@psionic.de>
+ * Copyright (c) 2003-2004	Joern Engel <joern@wh.fh-wedel.de>
+ *
+ * Usage:
+ *
+ * one commend line parameter per device, each in the form:
+ *   phram=<name>,<start>,<len>[,<erasesize>]
+ * <name> may be up to 63 characters.
+ * <start>, <len>, and <erasesize> can be octal, decimal or hexadecimal.  If followed
+ * by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or
+ * gigabytes. <erasesize> is optional and defaults to PAGE_SIZE.
+ *
+ * Example:
+ *	phram=swap,64Mi,128Mi phram=test,900Mi,1Mi,64Ki
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <asm/div64.h>
+#include <linux/platform_device.h>
+#include <linux/of_address.h>
+#include <linux/of.h>
+
+struct phram_mtd_list {
+	struct mtd_info mtd;
+	struct list_head list;
+	bool cached;
+};
+
+static LIST_HEAD(phram_list);
+
+static int phram_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	u_char *start = mtd->priv;
+
+	memset(start + instr->addr, 0xff, instr->len);
+
+	return 0;
+}
+
+static int phram_point(struct mtd_info *mtd, loff_t from, size_t len,
+		size_t *retlen, void **virt, resource_size_t *phys)
+{
+	*virt = mtd->priv + from;
+	*retlen = len;
+	return 0;
+}
+
+static int phram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
+{
+	return 0;
+}
+
+static int phram_read(struct mtd_info *mtd, loff_t from, size_t len,
+		size_t *retlen, u_char *buf)
+{
+	u_char *start = mtd->priv;
+
+	memcpy(buf, start + from, len);
+	*retlen = len;
+	return 0;
+}
+
+static int phram_write(struct mtd_info *mtd, loff_t to, size_t len,
+		size_t *retlen, const u_char *buf)
+{
+	u_char *start = mtd->priv;
+
+	memcpy(start + to, buf, len);
+	*retlen = len;
+	return 0;
+}
+
+static int phram_map(struct phram_mtd_list *phram, phys_addr_t start, size_t len)
+{
+	void *addr = NULL;
+
+	if (phram->cached)
+		addr = memremap(start, len, MEMREMAP_WB);
+	else
+		addr = (void __force *)ioremap(start, len);
+	if (!addr)
+		return -EIO;
+
+	phram->mtd.priv = addr;
+
+	return 0;
+}
+
+static void phram_unmap(struct phram_mtd_list *phram)
+{
+	void *addr = phram->mtd.priv;
+
+	if (phram->cached) {
+		memunmap(addr);
+		return;
+	}
+
+	iounmap((void __iomem *)addr);
+}
+
+static void unregister_devices(void)
+{
+	struct phram_mtd_list *this, *safe;
+
+	list_for_each_entry_safe(this, safe, &phram_list, list) {
+		mtd_device_unregister(&this->mtd);
+		phram_unmap(this);
+		kfree(this->mtd.name);
+		kfree(this);
+	}
+}
+
+static int register_device(struct platform_device *pdev, const char *name,
+			   phys_addr_t start, size_t len, uint32_t erasesize)
+{
+	struct device_node *np = pdev ? pdev->dev.of_node : NULL;
+	bool cached = np ? !of_property_read_bool(np, "no-map") : false;
+	struct phram_mtd_list *new;
+	int ret = -ENOMEM;
+
+	new = kzalloc(sizeof(*new), GFP_KERNEL);
+	if (!new)
+		goto out0;
+
+	new->cached = cached;
+
+	ret = phram_map(new, start, len);
+	if (ret) {
+		pr_err("ioremap failed\n");
+		goto out1;
+	}
+
+
+	new->mtd.name = name;
+	new->mtd.size = len;
+	new->mtd.flags = MTD_CAP_RAM;
+	new->mtd._erase = phram_erase;
+	new->mtd._point = phram_point;
+	new->mtd._unpoint = phram_unpoint;
+	new->mtd._read = phram_read;
+	new->mtd._write = phram_write;
+	new->mtd.owner = THIS_MODULE;
+	new->mtd.type = MTD_RAM;
+	new->mtd.erasesize = erasesize;
+	new->mtd.writesize = 1;
+
+	mtd_set_of_node(&new->mtd, np);
+
+	ret = -EAGAIN;
+	if (mtd_device_register(&new->mtd, NULL, 0)) {
+		pr_err("Failed to register new device\n");
+		goto out2;
+	}
+
+	if (pdev)
+		platform_set_drvdata(pdev, new);
+	else
+		list_add_tail(&new->list, &phram_list);
+
+	return 0;
+
+out2:
+	phram_unmap(new);
+out1:
+	kfree(new);
+out0:
+	return ret;
+}
+
+static int parse_num64(uint64_t *num64, char *token)
+{
+	size_t len;
+	int shift = 0;
+	int ret;
+
+	len = strlen(token);
+	/* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
+	if (len > 2) {
+		if (token[len - 1] == 'i') {
+			switch (token[len - 2]) {
+			case 'G':
+				shift += 10;
+				fallthrough;
+			case 'M':
+				shift += 10;
+				fallthrough;
+			case 'k':
+				shift += 10;
+				token[len - 2] = 0;
+				break;
+			default:
+				return -EINVAL;
+			}
+		}
+	}
+
+	ret = kstrtou64(token, 0, num64);
+	*num64 <<= shift;
+
+	return ret;
+}
+
+static int parse_name(char **pname, const char *token)
+{
+	size_t len;
+	char *name;
+
+	len = strlen(token) + 1;
+	if (len > 64)
+		return -ENOSPC;
+
+	name = kstrdup(token, GFP_KERNEL);
+	if (!name)
+		return -ENOMEM;
+
+	*pname = name;
+	return 0;
+}
+
+
+static inline void kill_final_newline(char *str)
+{
+	char *newline = strrchr(str, '\n');
+
+	if (newline && !newline[1])
+		*newline = 0;
+}
+
+
+#define parse_err(fmt, args...) do {	\
+	pr_err(fmt , ## args);	\
+	return 1;		\
+} while (0)
+
+#ifndef MODULE
+static int phram_init_called;
+/*
+ * This shall contain the module parameter if any. It is of the form:
+ * - phram=<device>,<address>,<size>[,<erasesize>] for module case
+ * - phram.phram=<device>,<address>,<size>[,<erasesize>] for built-in case
+ * We leave 64 bytes for the device name, 20 for the address , 20 for the
+ * size and 20 for the erasesize.
+ * Example: phram.phram=rootfs,0xa0000000,512Mi,65536
+ */
+static char phram_paramline[64 + 20 + 20 + 20];
+#endif
+
+static int phram_setup(const char *val)
+{
+	char buf[64 + 20 + 20 + 20], *str = buf;
+	char *token[4];
+	char *name;
+	uint64_t start;
+	uint64_t len;
+	uint64_t erasesize = PAGE_SIZE;
+	uint32_t rem;
+	int i, ret;
+
+	if (strnlen(val, sizeof(buf)) >= sizeof(buf))
+		parse_err("parameter too long\n");
+
+	strcpy(str, val);
+	kill_final_newline(str);
+
+	for (i = 0; i < 4; i++)
+		token[i] = strsep(&str, ",");
+
+	if (str)
+		parse_err("too many arguments\n");
+
+	if (!token[2])
+		parse_err("not enough arguments\n");
+
+	ret = parse_name(&name, token[0]);
+	if (ret)
+		return ret;
+
+	ret = parse_num64(&start, token[1]);
+	if (ret) {
+		parse_err("illegal start address\n");
+		goto error;
+	}
+
+	ret = parse_num64(&len, token[2]);
+	if (ret) {
+		parse_err("illegal device length\n");
+		goto error;
+	}
+
+	if (token[3]) {
+		ret = parse_num64(&erasesize, token[3]);
+		if (ret) {
+			parse_err("illegal erasesize\n");
+			goto error;
+		}
+	}
+
+	if (len == 0 || erasesize == 0 || erasesize > len
+	    || erasesize > UINT_MAX) {
+		parse_err("illegal erasesize or len\n");
+		ret = -EINVAL;
+		goto error;
+	}
+
+	div_u64_rem(len, (uint32_t)erasesize, &rem);
+	if (rem) {
+		parse_err("len is not multiple of erasesize\n");
+		ret = -EINVAL;
+		goto error;
+	}
+
+	ret = register_device(NULL, name, start, len, (uint32_t)erasesize);
+	if (ret)
+		goto error;
+
+	pr_info("%s device: %#llx at %#llx for erasesize %#llx\n", name, len, start, erasesize);
+	return 0;
+
+error:
+	kfree(name);
+	return ret;
+}
+
+static int phram_param_call(const char *val, const struct kernel_param *kp)
+{
+#ifdef MODULE
+	return phram_setup(val);
+#else
+	/*
+	 * If more parameters are later passed in via
+	 * /sys/module/phram/parameters/phram
+	 * and init_phram() has already been called,
+	 * we can parse the argument now.
+	 */
+
+	if (phram_init_called)
+		return phram_setup(val);
+
+	/*
+	 * During early boot stage, we only save the parameters
+	 * here. We must parse them later: if the param passed
+	 * from kernel boot command line, phram_param_call() is
+	 * called so early that it is not possible to resolve
+	 * the device (even kmalloc() fails). Defer that work to
+	 * phram_setup().
+	 */
+
+	if (strlen(val) >= sizeof(phram_paramline))
+		return -ENOSPC;
+	strcpy(phram_paramline, val);
+
+	return 0;
+#endif
+}
+
+module_param_call(phram, phram_param_call, NULL, NULL, 0200);
+MODULE_PARM_DESC(phram, "Memory region to map. \"phram=<name>,<start>,<length>[,<erasesize>]\"");
+
+#ifdef CONFIG_OF
+static const struct of_device_id phram_of_match[] = {
+	{ .compatible = "phram" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, phram_of_match);
+#endif
+
+static int phram_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENOMEM;
+
+	/* mtd_set_of_node() reads name from "label" */
+	return register_device(pdev, NULL, res->start, resource_size(res),
+			       PAGE_SIZE);
+}
+
+static int phram_remove(struct platform_device *pdev)
+{
+	struct phram_mtd_list *phram = platform_get_drvdata(pdev);
+
+	mtd_device_unregister(&phram->mtd);
+	phram_unmap(phram);
+	kfree(phram);
+
+	return 0;
+}
+
+static struct platform_driver phram_driver = {
+	.probe		= phram_probe,
+	.remove		= phram_remove,
+	.driver		= {
+		.name		= "phram",
+		.of_match_table	= of_match_ptr(phram_of_match),
+	},
+};
+
+static int __init init_phram(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&phram_driver);
+	if (ret)
+		return ret;
+
+#ifndef MODULE
+	if (phram_paramline[0])
+		ret = phram_setup(phram_paramline);
+	phram_init_called = 1;
+#endif
+
+	if (ret)
+		platform_driver_unregister(&phram_driver);
+
+	return ret;
+}
+
+static void __exit cleanup_phram(void)
+{
+	unregister_devices();
+	platform_driver_unregister(&phram_driver);
+}
+
+module_init(init_phram);
+module_exit(cleanup_phram);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Joern Engel <joern@wh.fh-wedel.de>");
+MODULE_DESCRIPTION("MTD driver for physical RAM");
diff --git a/drivers/mtd/devices/pmc551.c b/drivers/mtd/devices/pmc551.c
new file mode 100644
index 000000000..6597fc2aa
--- /dev/null
+++ b/drivers/mtd/devices/pmc551.c
@@ -0,0 +1,847 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PMC551 PCI Mezzanine Ram Device
+ *
+ * Author:
+ *	Mark Ferrell <mferrell@mvista.com>
+ *	Copyright 1999,2000 Nortel Networks
+ *
+ * Description:
+ *	This driver is intended to support the PMC551 PCI Ram device
+ *	from Ramix Inc.  The PMC551 is a PMC Mezzanine module for
+ *	cPCI embedded systems.  The device contains a single SROM
+ *	that initially programs the V370PDC chipset onboard the
+ *	device, and various banks of DRAM/SDRAM onboard.  This driver
+ *	implements this PCI Ram device as an MTD (Memory Technology
+ *	Device) so that it can be used to hold a file system, or for
+ *	added swap space in embedded systems.  Since the memory on
+ *	this board isn't as fast as main memory we do not try to hook
+ *	it into main memory as that would simply reduce performance
+ *	on the system.  Using it as a block device allows us to use
+ *	it as high speed swap or for a high speed disk device of some
+ *	sort.  Which becomes very useful on diskless systems in the
+ *	embedded market I might add.
+ *
+ * Notes:
+ *	Due to what I assume is more buggy SROM, the 64M PMC551 I
+ *	have available claims that all 4 of its DRAM banks have 64MiB
+ *	of ram configured (making a grand total of 256MiB onboard).
+ *	This is slightly annoying since the BAR0 size reflects the
+ *	aperture size, not the dram size, and the V370PDC supplies no
+ *	other method for memory size discovery.  This problem is
+ *	mostly only relevant when compiled as a module, as the
+ *	unloading of the module with an aperture size smaller than
+ *	the ram will cause the driver to detect the onboard memory
+ *	size to be equal to the aperture size when the module is
+ *	reloaded.  Soooo, to help, the module supports an msize
+ *	option to allow the specification of the onboard memory, and
+ *	an asize option, to allow the specification of the aperture
+ *	size.  The aperture must be equal to or less then the memory
+ *	size, the driver will correct this if you screw it up.  This
+ *	problem is not relevant for compiled in drivers as compiled
+ *	in drivers only init once.
+ *
+ * Credits:
+ *	Saeed Karamooz <saeed@ramix.com> of Ramix INC. for the
+ *	initial example code of how to initialize this device and for
+ *	help with questions I had concerning operation of the device.
+ *
+ *	Most of the MTD code for this driver was originally written
+ *	for the slram.o module in the MTD drivers package which
+ *	allows the mapping of system memory into an MTD device.
+ *	Since the PMC551 memory module is accessed in the same
+ *	fashion as system memory, the slram.c code became a very nice
+ *	fit to the needs of this driver.  All we added was PCI
+ *	detection/initialization to the driver and automatically figure
+ *	out the size via the PCI detection.o, later changes by Corey
+ *	Minyard set up the card to utilize a 1M sliding apature.
+ *
+ *	Corey Minyard <minyard@nortelnetworks.com>
+ *	* Modified driver to utilize a sliding aperture instead of
+ *	 mapping all memory into kernel space which turned out to
+ *	 be very wasteful.
+ *	* Located a bug in the SROM's initialization sequence that
+ *	 made the memory unusable, added a fix to code to touch up
+ *	 the DRAM some.
+ *
+ * Bugs/FIXMEs:
+ *	* MUST fix the init function to not spin on a register
+ *	waiting for it to set .. this does not safely handle busted
+ *	devices that never reset the register correctly which will
+ *	cause the system to hang w/ a reboot being the only chance at
+ *	recover. [sort of fixed, could be better]
+ *	* Add I2C handling of the SROM so we can read the SROM's information
+ *	about the aperture size.  This should always accurately reflect the
+ *	onboard memory size.
+ *	* Comb the init routine.  It's still a bit cludgy on a few things.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/major.h>
+#include <linux/fs.h>
+#include <linux/ioctl.h>
+#include <asm/io.h>
+#include <linux/pci.h>
+#include <linux/mtd/mtd.h>
+
+#define PMC551_VERSION \
+	"Ramix PMC551 PCI Mezzanine Ram Driver. (C) 1999,2000 Nortel Networks.\n"
+
+#define PCI_VENDOR_ID_V3_SEMI 0x11b0
+#define PCI_DEVICE_ID_V3_SEMI_V370PDC 0x0200
+
+#define PMC551_PCI_MEM_MAP0 0x50
+#define PMC551_PCI_MEM_MAP1 0x54
+#define PMC551_PCI_MEM_MAP_MAP_ADDR_MASK 0x3ff00000
+#define PMC551_PCI_MEM_MAP_APERTURE_MASK 0x000000f0
+#define PMC551_PCI_MEM_MAP_REG_EN 0x00000002
+#define PMC551_PCI_MEM_MAP_ENABLE 0x00000001
+
+#define PMC551_SDRAM_MA  0x60
+#define PMC551_SDRAM_CMD 0x62
+#define PMC551_DRAM_CFG  0x64
+#define PMC551_SYS_CTRL_REG 0x78
+
+#define PMC551_DRAM_BLK0 0x68
+#define PMC551_DRAM_BLK1 0x6c
+#define PMC551_DRAM_BLK2 0x70
+#define PMC551_DRAM_BLK3 0x74
+#define PMC551_DRAM_BLK_GET_SIZE(x) (524288 << ((x >> 4) & 0x0f))
+#define PMC551_DRAM_BLK_SET_COL_MUX(x, v) (((x) & ~0x00007000) | (((v) & 0x7) << 12))
+#define PMC551_DRAM_BLK_SET_ROW_MUX(x, v) (((x) & ~0x00000f00) | (((v) & 0xf) << 8))
+
+struct mypriv {
+	struct pci_dev *dev;
+	u_char *start;
+	u32 base_map0;
+	u32 curr_map0;
+	u32 asize;
+	struct mtd_info *nextpmc551;
+};
+
+static struct mtd_info *pmc551list;
+
+static int pmc551_point(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, void **virt, resource_size_t *phys);
+
+static int pmc551_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct mypriv *priv = mtd->priv;
+	u32 soff_hi;		/* start address offset hi */
+	u32 eoff_hi, eoff_lo;	/* end address offset hi/lo */
+	unsigned long end;
+	u_char *ptr;
+	size_t retlen;
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_erase(pos:%ld, len:%ld)\n", (long)instr->addr,
+		(long)instr->len);
+#endif
+
+	end = instr->addr + instr->len - 1;
+	eoff_hi = end & ~(priv->asize - 1);
+	soff_hi = instr->addr & ~(priv->asize - 1);
+	eoff_lo = end & (priv->asize - 1);
+
+	pmc551_point(mtd, instr->addr, instr->len, &retlen,
+		     (void **)&ptr, NULL);
+
+	if (soff_hi == eoff_hi || mtd->size == priv->asize) {
+		/* The whole thing fits within one access, so just one shot
+		   will do it. */
+		memset(ptr, 0xff, instr->len);
+	} else {
+		/* We have to do multiple writes to get all the data
+		   written. */
+		while (soff_hi != eoff_hi) {
+#ifdef CONFIG_MTD_PMC551_DEBUG
+			printk(KERN_DEBUG "pmc551_erase() soff_hi: %ld, "
+				"eoff_hi: %ld\n", (long)soff_hi, (long)eoff_hi);
+#endif
+			memset(ptr, 0xff, priv->asize);
+			if (soff_hi + priv->asize >= mtd->size) {
+				goto out;
+			}
+			soff_hi += priv->asize;
+			pmc551_point(mtd, (priv->base_map0 | soff_hi),
+				     priv->asize, &retlen,
+				     (void **)&ptr, NULL);
+		}
+		memset(ptr, 0xff, eoff_lo);
+	}
+
+      out:
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_erase() done\n");
+#endif
+
+	return 0;
+}
+
+static int pmc551_point(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, void **virt, resource_size_t *phys)
+{
+	struct mypriv *priv = mtd->priv;
+	u32 soff_hi;
+	u32 soff_lo;
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_point(%ld, %ld)\n", (long)from, (long)len);
+#endif
+
+	soff_hi = from & ~(priv->asize - 1);
+	soff_lo = from & (priv->asize - 1);
+
+	/* Cheap hack optimization */
+	if (priv->curr_map0 != from) {
+		pci_write_config_dword(priv->dev, PMC551_PCI_MEM_MAP0,
+					(priv->base_map0 | soff_hi));
+		priv->curr_map0 = soff_hi;
+	}
+
+	*virt = priv->start + soff_lo;
+	*retlen = len;
+	return 0;
+}
+
+static int pmc551_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
+{
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_unpoint()\n");
+#endif
+	return 0;
+}
+
+static int pmc551_read(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t * retlen, u_char * buf)
+{
+	struct mypriv *priv = mtd->priv;
+	u32 soff_hi;		/* start address offset hi */
+	u32 eoff_hi, eoff_lo;	/* end address offset hi/lo */
+	unsigned long end;
+	u_char *ptr;
+	u_char *copyto = buf;
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_read(pos:%ld, len:%ld) asize: %ld\n",
+		(long)from, (long)len, (long)priv->asize);
+#endif
+
+	end = from + len - 1;
+	soff_hi = from & ~(priv->asize - 1);
+	eoff_hi = end & ~(priv->asize - 1);
+	eoff_lo = end & (priv->asize - 1);
+
+	pmc551_point(mtd, from, len, retlen, (void **)&ptr, NULL);
+
+	if (soff_hi == eoff_hi) {
+		/* The whole thing fits within one access, so just one shot
+		   will do it. */
+		memcpy(copyto, ptr, len);
+		copyto += len;
+	} else {
+		/* We have to do multiple writes to get all the data
+		   written. */
+		while (soff_hi != eoff_hi) {
+#ifdef CONFIG_MTD_PMC551_DEBUG
+			printk(KERN_DEBUG "pmc551_read() soff_hi: %ld, "
+				"eoff_hi: %ld\n", (long)soff_hi, (long)eoff_hi);
+#endif
+			memcpy(copyto, ptr, priv->asize);
+			copyto += priv->asize;
+			if (soff_hi + priv->asize >= mtd->size) {
+				goto out;
+			}
+			soff_hi += priv->asize;
+			pmc551_point(mtd, soff_hi, priv->asize, retlen,
+				     (void **)&ptr, NULL);
+		}
+		memcpy(copyto, ptr, eoff_lo);
+		copyto += eoff_lo;
+	}
+
+      out:
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_read() done\n");
+#endif
+	*retlen = copyto - buf;
+	return 0;
+}
+
+static int pmc551_write(struct mtd_info *mtd, loff_t to, size_t len,
+			size_t * retlen, const u_char * buf)
+{
+	struct mypriv *priv = mtd->priv;
+	u32 soff_hi;		/* start address offset hi */
+	u32 eoff_hi, eoff_lo;	/* end address offset hi/lo */
+	unsigned long end;
+	u_char *ptr;
+	const u_char *copyfrom = buf;
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_write(pos:%ld, len:%ld) asize:%ld\n",
+		(long)to, (long)len, (long)priv->asize);
+#endif
+
+	end = to + len - 1;
+	soff_hi = to & ~(priv->asize - 1);
+	eoff_hi = end & ~(priv->asize - 1);
+	eoff_lo = end & (priv->asize - 1);
+
+	pmc551_point(mtd, to, len, retlen, (void **)&ptr, NULL);
+
+	if (soff_hi == eoff_hi) {
+		/* The whole thing fits within one access, so just one shot
+		   will do it. */
+		memcpy(ptr, copyfrom, len);
+		copyfrom += len;
+	} else {
+		/* We have to do multiple writes to get all the data
+		   written. */
+		while (soff_hi != eoff_hi) {
+#ifdef CONFIG_MTD_PMC551_DEBUG
+			printk(KERN_DEBUG "pmc551_write() soff_hi: %ld, "
+				"eoff_hi: %ld\n", (long)soff_hi, (long)eoff_hi);
+#endif
+			memcpy(ptr, copyfrom, priv->asize);
+			copyfrom += priv->asize;
+			if (soff_hi >= mtd->size) {
+				goto out;
+			}
+			soff_hi += priv->asize;
+			pmc551_point(mtd, soff_hi, priv->asize, retlen,
+				     (void **)&ptr, NULL);
+		}
+		memcpy(ptr, copyfrom, eoff_lo);
+		copyfrom += eoff_lo;
+	}
+
+      out:
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	printk(KERN_DEBUG "pmc551_write() done\n");
+#endif
+	*retlen = copyfrom - buf;
+	return 0;
+}
+
+/*
+ * Fixup routines for the V370PDC
+ * PCI device ID 0x020011b0
+ *
+ * This function basically kick starts the DRAM oboard the card and gets it
+ * ready to be used.  Before this is done the device reads VERY erratic, so
+ * much that it can crash the Linux 2.2.x series kernels when a user cat's
+ * /proc/pci .. though that is mainly a kernel bug in handling the PCI DEVSEL
+ * register.  FIXME: stop spinning on registers .. must implement a timeout
+ * mechanism
+ * returns the size of the memory region found.
+ */
+static int __init fixup_pmc551(struct pci_dev *dev)
+{
+#ifdef CONFIG_MTD_PMC551_BUGFIX
+	u32 dram_data;
+#endif
+	u32 size, dcmd, cfg, dtmp;
+	u16 cmd, tmp, i;
+	u8 bcmd, counter;
+
+	/* Sanity Check */
+	if (!dev) {
+		return -ENODEV;
+	}
+
+	/*
+	 * Attempt to reset the card
+	 * FIXME: Stop Spinning registers
+	 */
+	counter = 0;
+	/* unlock registers */
+	pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, 0xA5);
+	/* read in old data */
+	pci_read_config_byte(dev, PMC551_SYS_CTRL_REG, &bcmd);
+	/* bang the reset line up and down for a few */
+	for (i = 0; i < 10; i++) {
+		counter = 0;
+		bcmd &= ~0x80;
+		while (counter++ < 100) {
+			pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, bcmd);
+		}
+		counter = 0;
+		bcmd |= 0x80;
+		while (counter++ < 100) {
+			pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, bcmd);
+		}
+	}
+	bcmd |= (0x40 | 0x20);
+	pci_write_config_byte(dev, PMC551_SYS_CTRL_REG, bcmd);
+
+	/*
+	 * Take care and turn off the memory on the device while we
+	 * tweak the configurations
+	 */
+	pci_read_config_word(dev, PCI_COMMAND, &cmd);
+	tmp = cmd & ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
+	pci_write_config_word(dev, PCI_COMMAND, tmp);
+
+	/*
+	 * Disable existing aperture before probing memory size
+	 */
+	pci_read_config_dword(dev, PMC551_PCI_MEM_MAP0, &dcmd);
+	dtmp = (dcmd | PMC551_PCI_MEM_MAP_ENABLE | PMC551_PCI_MEM_MAP_REG_EN);
+	pci_write_config_dword(dev, PMC551_PCI_MEM_MAP0, dtmp);
+	/*
+	 * Grab old BAR0 config so that we can figure out memory size
+	 * This is another bit of kludge going on.  The reason for the
+	 * redundancy is I am hoping to retain the original configuration
+	 * previously assigned to the card by the BIOS or some previous
+	 * fixup routine in the kernel.  So we read the old config into cfg,
+	 * then write all 1's to the memory space, read back the result into
+	 * "size", and then write back all the old config.
+	 */
+	pci_read_config_dword(dev, PCI_BASE_ADDRESS_0, &cfg);
+#ifndef CONFIG_MTD_PMC551_BUGFIX
+	pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, ~0);
+	pci_read_config_dword(dev, PCI_BASE_ADDRESS_0, &size);
+	size = (size & PCI_BASE_ADDRESS_MEM_MASK);
+	size &= ~(size - 1);
+	pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, cfg);
+#else
+	/*
+	 * Get the size of the memory by reading all the DRAM size values
+	 * and adding them up.
+	 *
+	 * KLUDGE ALERT: the boards we are using have invalid column and
+	 * row mux values.  We fix them here, but this will break other
+	 * memory configurations.
+	 */
+	pci_read_config_dword(dev, PMC551_DRAM_BLK0, &dram_data);
+	size = PMC551_DRAM_BLK_GET_SIZE(dram_data);
+	dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
+	dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
+	pci_write_config_dword(dev, PMC551_DRAM_BLK0, dram_data);
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK1, &dram_data);
+	size += PMC551_DRAM_BLK_GET_SIZE(dram_data);
+	dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
+	dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
+	pci_write_config_dword(dev, PMC551_DRAM_BLK1, dram_data);
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK2, &dram_data);
+	size += PMC551_DRAM_BLK_GET_SIZE(dram_data);
+	dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
+	dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
+	pci_write_config_dword(dev, PMC551_DRAM_BLK2, dram_data);
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK3, &dram_data);
+	size += PMC551_DRAM_BLK_GET_SIZE(dram_data);
+	dram_data = PMC551_DRAM_BLK_SET_COL_MUX(dram_data, 0x5);
+	dram_data = PMC551_DRAM_BLK_SET_ROW_MUX(dram_data, 0x9);
+	pci_write_config_dword(dev, PMC551_DRAM_BLK3, dram_data);
+
+	/*
+	 * Oops .. something went wrong
+	 */
+	if ((size &= PCI_BASE_ADDRESS_MEM_MASK) == 0) {
+		return -ENODEV;
+	}
+#endif				/* CONFIG_MTD_PMC551_BUGFIX */
+
+	if ((cfg & PCI_BASE_ADDRESS_SPACE) != PCI_BASE_ADDRESS_SPACE_MEMORY) {
+		return -ENODEV;
+	}
+
+	/*
+	 * Precharge Dram
+	 */
+	pci_write_config_word(dev, PMC551_SDRAM_MA, 0x0400);
+	pci_write_config_word(dev, PMC551_SDRAM_CMD, 0x00bf);
+
+	/*
+	 * Wait until command has gone through
+	 * FIXME: register spinning issue
+	 */
+	do {
+		pci_read_config_word(dev, PMC551_SDRAM_CMD, &cmd);
+		if (counter++ > 100)
+			break;
+	} while ((PCI_COMMAND_IO) & cmd);
+
+	/*
+	 * Turn on auto refresh
+	 * The loop is taken directly from Ramix's example code.  I assume that
+	 * this must be held high for some duration of time, but I can find no
+	 * documentation refrencing the reasons why.
+	 */
+	for (i = 1; i <= 8; i++) {
+		pci_write_config_word(dev, PMC551_SDRAM_CMD, 0x0df);
+
+		/*
+		 * Make certain command has gone through
+		 * FIXME: register spinning issue
+		 */
+		counter = 0;
+		do {
+			pci_read_config_word(dev, PMC551_SDRAM_CMD, &cmd);
+			if (counter++ > 100)
+				break;
+		} while ((PCI_COMMAND_IO) & cmd);
+	}
+
+	pci_write_config_word(dev, PMC551_SDRAM_MA, 0x0020);
+	pci_write_config_word(dev, PMC551_SDRAM_CMD, 0x0ff);
+
+	/*
+	 * Wait until command completes
+	 * FIXME: register spinning issue
+	 */
+	counter = 0;
+	do {
+		pci_read_config_word(dev, PMC551_SDRAM_CMD, &cmd);
+		if (counter++ > 100)
+			break;
+	} while ((PCI_COMMAND_IO) & cmd);
+
+	pci_read_config_dword(dev, PMC551_DRAM_CFG, &dcmd);
+	dcmd |= 0x02000000;
+	pci_write_config_dword(dev, PMC551_DRAM_CFG, dcmd);
+
+	/*
+	 * Check to make certain fast back-to-back, if not
+	 * then set it so
+	 */
+	pci_read_config_word(dev, PCI_STATUS, &cmd);
+	if ((cmd & PCI_COMMAND_FAST_BACK) == 0) {
+		cmd |= PCI_COMMAND_FAST_BACK;
+		pci_write_config_word(dev, PCI_STATUS, cmd);
+	}
+
+	/*
+	 * Check to make certain the DEVSEL is set correctly, this device
+	 * has a tendency to assert DEVSEL and TRDY when a write is performed
+	 * to the memory when memory is read-only
+	 */
+	if ((cmd & PCI_STATUS_DEVSEL_MASK) != 0x0) {
+		cmd &= ~PCI_STATUS_DEVSEL_MASK;
+		pci_write_config_word(dev, PCI_STATUS, cmd);
+	}
+	/*
+	 * Set to be prefetchable and put everything back based on old cfg.
+	 * it's possible that the reset of the V370PDC nuked the original
+	 * setup
+	 */
+	/*
+	   cfg |= PCI_BASE_ADDRESS_MEM_PREFETCH;
+	   pci_write_config_dword( dev, PCI_BASE_ADDRESS_0, cfg );
+	 */
+
+	/*
+	 * Turn PCI memory and I/O bus access back on
+	 */
+	pci_write_config_word(dev, PCI_COMMAND,
+			      PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
+#ifdef CONFIG_MTD_PMC551_DEBUG
+	/*
+	 * Some screen fun
+	 */
+	printk(KERN_DEBUG "pmc551: %d%sB (0x%x) of %sprefetchable memory at "
+		"0x%llx\n", (size < 1024) ? size : (size < 1048576) ?
+		size >> 10 : size >> 20,
+		(size < 1024) ? "" : (size < 1048576) ? "Ki" : "Mi", size,
+		((dcmd & (0x1 << 3)) == 0) ? "non-" : "",
+		(unsigned long long)pci_resource_start(dev, 0));
+
+	/*
+	 * Check to see the state of the memory
+	 */
+	pci_read_config_dword(dev, PMC551_DRAM_BLK0, &dcmd);
+	printk(KERN_DEBUG "pmc551: DRAM_BLK0 Flags: %s,%s\n"
+		"pmc551: DRAM_BLK0 Size: %d at %d\n"
+		"pmc551: DRAM_BLK0 Row MUX: %d, Col MUX: %d\n",
+		(((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
+		(((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
+		PMC551_DRAM_BLK_GET_SIZE(dcmd),
+		((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
+		((dcmd >> 9) & 0xF));
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK1, &dcmd);
+	printk(KERN_DEBUG "pmc551: DRAM_BLK1 Flags: %s,%s\n"
+		"pmc551: DRAM_BLK1 Size: %d at %d\n"
+		"pmc551: DRAM_BLK1 Row MUX: %d, Col MUX: %d\n",
+		(((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
+		(((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
+		PMC551_DRAM_BLK_GET_SIZE(dcmd),
+		((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
+		((dcmd >> 9) & 0xF));
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK2, &dcmd);
+	printk(KERN_DEBUG "pmc551: DRAM_BLK2 Flags: %s,%s\n"
+		"pmc551: DRAM_BLK2 Size: %d at %d\n"
+		"pmc551: DRAM_BLK2 Row MUX: %d, Col MUX: %d\n",
+		(((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
+		(((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
+		PMC551_DRAM_BLK_GET_SIZE(dcmd),
+		((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
+		((dcmd >> 9) & 0xF));
+
+	pci_read_config_dword(dev, PMC551_DRAM_BLK3, &dcmd);
+	printk(KERN_DEBUG "pmc551: DRAM_BLK3 Flags: %s,%s\n"
+		"pmc551: DRAM_BLK3 Size: %d at %d\n"
+		"pmc551: DRAM_BLK3 Row MUX: %d, Col MUX: %d\n",
+		(((0x1 << 1) & dcmd) == 0) ? "RW" : "RO",
+		(((0x1 << 0) & dcmd) == 0) ? "Off" : "On",
+		PMC551_DRAM_BLK_GET_SIZE(dcmd),
+		((dcmd >> 20) & 0x7FF), ((dcmd >> 13) & 0x7),
+		((dcmd >> 9) & 0xF));
+
+	pci_read_config_word(dev, PCI_COMMAND, &cmd);
+	printk(KERN_DEBUG "pmc551: Memory Access %s\n",
+		(((0x1 << 1) & cmd) == 0) ? "off" : "on");
+	printk(KERN_DEBUG "pmc551: I/O Access %s\n",
+		(((0x1 << 0) & cmd) == 0) ? "off" : "on");
+
+	pci_read_config_word(dev, PCI_STATUS, &cmd);
+	printk(KERN_DEBUG "pmc551: Devsel %s\n",
+		((PCI_STATUS_DEVSEL_MASK & cmd) == 0x000) ? "Fast" :
+		((PCI_STATUS_DEVSEL_MASK & cmd) == 0x200) ? "Medium" :
+		((PCI_STATUS_DEVSEL_MASK & cmd) == 0x400) ? "Slow" : "Invalid");
+
+	printk(KERN_DEBUG "pmc551: %sFast Back-to-Back\n",
+		((PCI_COMMAND_FAST_BACK & cmd) == 0) ? "Not " : "");
+
+	pci_read_config_byte(dev, PMC551_SYS_CTRL_REG, &bcmd);
+	printk(KERN_DEBUG "pmc551: EEPROM is under %s control\n"
+		"pmc551: System Control Register is %slocked to PCI access\n"
+		"pmc551: System Control Register is %slocked to EEPROM access\n",
+		(bcmd & 0x1) ? "software" : "hardware",
+		(bcmd & 0x20) ? "" : "un", (bcmd & 0x40) ? "" : "un");
+#endif
+	return size;
+}
+
+/*
+ * Kernel version specific module stuffages
+ */
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mark Ferrell <mferrell@mvista.com>");
+MODULE_DESCRIPTION(PMC551_VERSION);
+
+/*
+ * Stuff these outside the ifdef so as to not bust compiled in driver support
+ */
+static int msize = 0;
+static int asize = 0;
+
+module_param(msize, int, 0);
+MODULE_PARM_DESC(msize, "memory size in MiB [1 - 1024]");
+module_param(asize, int, 0);
+MODULE_PARM_DESC(asize, "aperture size, must be <= memsize [1-1024]");
+
+/*
+ * PMC551 Card Initialization
+ */
+static int __init init_pmc551(void)
+{
+	struct pci_dev *PCI_Device = NULL;
+	struct mypriv *priv;
+	int found = 0;
+	struct mtd_info *mtd;
+	int length = 0;
+
+	if (msize) {
+		msize = (1 << (ffs(msize) - 1)) << 20;
+		if (msize > (1 << 30)) {
+			printk(KERN_NOTICE "pmc551: Invalid memory size [%d]\n",
+				msize);
+			return -EINVAL;
+		}
+	}
+
+	if (asize) {
+		asize = (1 << (ffs(asize) - 1)) << 20;
+		if (asize > (1 << 30)) {
+			printk(KERN_NOTICE "pmc551: Invalid aperture size "
+				"[%d]\n", asize);
+			return -EINVAL;
+		}
+	}
+
+	printk(KERN_INFO PMC551_VERSION);
+
+	/*
+	 * PCU-bus chipset probe.
+	 */
+	for (;;) {
+
+		if ((PCI_Device = pci_get_device(PCI_VENDOR_ID_V3_SEMI,
+						  PCI_DEVICE_ID_V3_SEMI_V370PDC,
+						  PCI_Device)) == NULL) {
+			break;
+		}
+
+		printk(KERN_NOTICE "pmc551: Found PCI V370PDC at 0x%llx\n",
+			(unsigned long long)pci_resource_start(PCI_Device, 0));
+
+		/*
+		 * The PMC551 device acts VERY weird if you don't init it
+		 * first.  i.e. it will not correctly report devsel.  If for
+		 * some reason the sdram is in a wrote-protected state the
+		 * device will DEVSEL when it is written to causing problems
+		 * with the oldproc.c driver in
+		 * some kernels (2.2.*)
+		 */
+		if ((length = fixup_pmc551(PCI_Device)) <= 0) {
+			printk(KERN_NOTICE "pmc551: Cannot init SDRAM\n");
+			break;
+		}
+
+		/*
+		 * This is needed until the driver is capable of reading the
+		 * onboard I2C SROM to discover the "real" memory size.
+		 */
+		if (msize) {
+			length = msize;
+			printk(KERN_NOTICE "pmc551: Using specified memory "
+				"size 0x%x\n", length);
+		} else {
+			msize = length;
+		}
+
+		mtd = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
+		if (!mtd)
+			break;
+
+		priv = kzalloc(sizeof(struct mypriv), GFP_KERNEL);
+		if (!priv) {
+			kfree(mtd);
+			break;
+		}
+		mtd->priv = priv;
+		priv->dev = PCI_Device;
+
+		if (asize > length) {
+			printk(KERN_NOTICE "pmc551: reducing aperture size to "
+				"fit %dM\n", length >> 20);
+			priv->asize = asize = length;
+		} else if (asize == 0 || asize == length) {
+			printk(KERN_NOTICE "pmc551: Using existing aperture "
+				"size %dM\n", length >> 20);
+			priv->asize = asize = length;
+		} else {
+			printk(KERN_NOTICE "pmc551: Using specified aperture "
+				"size %dM\n", asize >> 20);
+			priv->asize = asize;
+		}
+		priv->start = pci_iomap(PCI_Device, 0, priv->asize);
+
+		if (!priv->start) {
+			printk(KERN_NOTICE "pmc551: Unable to map IO space\n");
+			kfree(mtd->priv);
+			kfree(mtd);
+			break;
+		}
+#ifdef CONFIG_MTD_PMC551_DEBUG
+		printk(KERN_DEBUG "pmc551: setting aperture to %d\n",
+			ffs(priv->asize >> 20) - 1);
+#endif
+
+		priv->base_map0 = (PMC551_PCI_MEM_MAP_REG_EN
+				   | PMC551_PCI_MEM_MAP_ENABLE
+				   | (ffs(priv->asize >> 20) - 1) << 4);
+		priv->curr_map0 = priv->base_map0;
+		pci_write_config_dword(priv->dev, PMC551_PCI_MEM_MAP0,
+					priv->curr_map0);
+
+#ifdef CONFIG_MTD_PMC551_DEBUG
+		printk(KERN_DEBUG "pmc551: aperture set to %d\n",
+			(priv->base_map0 & 0xF0) >> 4);
+#endif
+
+		mtd->size = msize;
+		mtd->flags = MTD_CAP_RAM;
+		mtd->_erase = pmc551_erase;
+		mtd->_read = pmc551_read;
+		mtd->_write = pmc551_write;
+		mtd->_point = pmc551_point;
+		mtd->_unpoint = pmc551_unpoint;
+		mtd->type = MTD_RAM;
+		mtd->name = "PMC551 RAM board";
+		mtd->erasesize = 0x10000;
+		mtd->writesize = 1;
+		mtd->owner = THIS_MODULE;
+
+		if (mtd_device_register(mtd, NULL, 0)) {
+			printk(KERN_NOTICE "pmc551: Failed to register new device\n");
+			pci_iounmap(PCI_Device, priv->start);
+			kfree(mtd->priv);
+			kfree(mtd);
+			break;
+		}
+
+		/* Keep a reference as the mtd_device_register worked */
+		pci_dev_get(PCI_Device);
+
+		printk(KERN_NOTICE "Registered pmc551 memory device.\n");
+		printk(KERN_NOTICE "Mapped %dMiB of memory from 0x%p to 0x%p\n",
+			priv->asize >> 20,
+			priv->start, priv->start + priv->asize);
+		printk(KERN_NOTICE "Total memory is %d%sB\n",
+			(length < 1024) ? length :
+			(length < 1048576) ? length >> 10 : length >> 20,
+			(length < 1024) ? "" : (length < 1048576) ? "Ki" : "Mi");
+		priv->nextpmc551 = pmc551list;
+		pmc551list = mtd;
+		found++;
+	}
+
+	/* Exited early, reference left over */
+	pci_dev_put(PCI_Device);
+
+	if (!pmc551list) {
+		printk(KERN_NOTICE "pmc551: not detected\n");
+		return -ENODEV;
+	} else {
+		printk(KERN_NOTICE "pmc551: %d pmc551 devices loaded\n", found);
+		return 0;
+	}
+}
+
+/*
+ * PMC551 Card Cleanup
+ */
+static void __exit cleanup_pmc551(void)
+{
+	int found = 0;
+	struct mtd_info *mtd;
+	struct mypriv *priv;
+
+	while ((mtd = pmc551list)) {
+		priv = mtd->priv;
+		pmc551list = priv->nextpmc551;
+
+		if (priv->start) {
+			printk(KERN_DEBUG "pmc551: unmapping %dMiB starting at "
+				"0x%p\n", priv->asize >> 20, priv->start);
+			pci_iounmap(priv->dev, priv->start);
+		}
+		pci_dev_put(priv->dev);
+
+		kfree(mtd->priv);
+		mtd_device_unregister(mtd);
+		kfree(mtd);
+		found++;
+	}
+
+	printk(KERN_NOTICE "pmc551: %d pmc551 devices unloaded\n", found);
+}
+
+module_init(init_pmc551);
+module_exit(cleanup_pmc551);
diff --git a/drivers/mtd/devices/powernv_flash.c b/drivers/mtd/devices/powernv_flash.c
new file mode 100644
index 000000000..36e060386
--- /dev/null
+++ b/drivers/mtd/devices/powernv_flash.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * OPAL PNOR flash MTD abstraction
+ *
+ * Copyright IBM 2015
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#include <asm/opal.h>
+
+
+/*
+ * This driver creates the a Linux MTD abstraction for platform PNOR flash
+ * backed by OPAL calls
+ */
+
+struct powernv_flash {
+	struct mtd_info	mtd;
+	u32 id;
+};
+
+enum flash_op {
+	FLASH_OP_READ,
+	FLASH_OP_WRITE,
+	FLASH_OP_ERASE,
+};
+
+/*
+ * Don't return -ERESTARTSYS if we can't get a token, the MTD core
+ * might have split up the call from userspace and called into the
+ * driver more than once, we'll already have done some amount of work.
+ */
+static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op,
+		loff_t offset, size_t len, size_t *retlen, u_char *buf)
+{
+	struct powernv_flash *info = (struct powernv_flash *)mtd->priv;
+	struct device *dev = &mtd->dev;
+	int token;
+	struct opal_msg msg;
+	int rc;
+
+	dev_dbg(dev, "%s(op=%d, offset=0x%llx, len=%zu)\n",
+			__func__, op, offset, len);
+
+	token = opal_async_get_token_interruptible();
+	if (token < 0) {
+		if (token != -ERESTARTSYS)
+			dev_err(dev, "Failed to get an async token\n");
+		else
+			token = -EINTR;
+		return token;
+	}
+
+	switch (op) {
+	case FLASH_OP_READ:
+		rc = opal_flash_read(info->id, offset, __pa(buf), len, token);
+		break;
+	case FLASH_OP_WRITE:
+		rc = opal_flash_write(info->id, offset, __pa(buf), len, token);
+		break;
+	case FLASH_OP_ERASE:
+		rc = opal_flash_erase(info->id, offset, len, token);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		opal_async_release_token(token);
+		return -EIO;
+	}
+
+	if (rc == OPAL_ASYNC_COMPLETION) {
+		rc = opal_async_wait_response_interruptible(token, &msg);
+		if (rc) {
+			/*
+			 * If we return the mtd core will free the
+			 * buffer we've just passed to OPAL but OPAL
+			 * will continue to read or write from that
+			 * memory.
+			 * It may be tempting to ultimately return 0
+			 * if we're doing a read or a write since we
+			 * are going to end up waiting until OPAL is
+			 * done. However, because the MTD core sends
+			 * us the userspace request in chunks, we need
+			 * it to know we've been interrupted.
+			 */
+			rc = -EINTR;
+			if (opal_async_wait_response(token, &msg))
+				dev_err(dev, "opal_async_wait_response() failed\n");
+			goto out;
+		}
+		rc = opal_get_async_rc(msg);
+	}
+
+	/*
+	 * OPAL does mutual exclusion on the flash, it will return
+	 * OPAL_BUSY.
+	 * During firmware updates by the service processor OPAL may
+	 * be (temporarily) prevented from accessing the flash, in
+	 * this case OPAL will also return OPAL_BUSY.
+	 * Both cases aren't errors exactly but the flash could have
+	 * changed, userspace should be informed.
+	 */
+	if (rc != OPAL_SUCCESS && rc != OPAL_BUSY)
+		dev_err(dev, "opal_flash_async_op(op=%d) failed (rc %d)\n",
+				op, rc);
+
+	if (rc == OPAL_SUCCESS && retlen)
+		*retlen = len;
+
+	rc = opal_error_code(rc);
+out:
+	opal_async_release_token(token);
+	return rc;
+}
+
+/**
+ * powernv_flash_read
+ * @mtd: the device
+ * @from: the offset to read from
+ * @len: the number of bytes to read
+ * @retlen: the number of bytes actually read
+ * @buf: the filled in buffer
+ *
+ * Returns 0 if read successful, or -ERRNO if an error occurred
+ */
+static int powernv_flash_read(struct mtd_info *mtd, loff_t from, size_t len,
+	     size_t *retlen, u_char *buf)
+{
+	return powernv_flash_async_op(mtd, FLASH_OP_READ, from,
+			len, retlen, buf);
+}
+
+/**
+ * powernv_flash_write
+ * @mtd: the device
+ * @to: the offset to write to
+ * @len: the number of bytes to write
+ * @retlen: the number of bytes actually written
+ * @buf: the buffer to get bytes from
+ *
+ * Returns 0 if write successful, -ERRNO if error occurred
+ */
+static int powernv_flash_write(struct mtd_info *mtd, loff_t to, size_t len,
+		     size_t *retlen, const u_char *buf)
+{
+	return powernv_flash_async_op(mtd, FLASH_OP_WRITE, to,
+			len, retlen, (u_char *)buf);
+}
+
+/**
+ * powernv_flash_erase
+ * @mtd: the device
+ * @erase: the erase info
+ * Returns 0 if erase successful or -ERRNO if an error occurred
+ */
+static int powernv_flash_erase(struct mtd_info *mtd, struct erase_info *erase)
+{
+	int rc;
+
+	rc =  powernv_flash_async_op(mtd, FLASH_OP_ERASE, erase->addr,
+			erase->len, NULL, NULL);
+	if (rc)
+		erase->fail_addr = erase->addr;
+
+	return rc;
+}
+
+/**
+ * powernv_flash_set_driver_info - Fill the mtd_info structure and docg3
+ * @dev: The device structure
+ * @mtd: The structure to fill
+ */
+static int powernv_flash_set_driver_info(struct device *dev,
+		struct mtd_info *mtd)
+{
+	u64 size;
+	u32 erase_size;
+	int rc;
+
+	rc = of_property_read_u32(dev->of_node, "ibm,flash-block-size",
+			&erase_size);
+	if (rc) {
+		dev_err(dev, "couldn't get resource block size information\n");
+		return rc;
+	}
+
+	rc = of_property_read_u64(dev->of_node, "reg", &size);
+	if (rc) {
+		dev_err(dev, "couldn't get resource size information\n");
+		return rc;
+	}
+
+	/*
+	 * Going to have to check what details I need to set and how to
+	 * get them
+	 */
+	mtd->name = devm_kasprintf(dev, GFP_KERNEL, "%pOFP", dev->of_node);
+	mtd->type = MTD_NORFLASH;
+	mtd->flags = MTD_WRITEABLE;
+	mtd->size = size;
+	mtd->erasesize = erase_size;
+	mtd->writebufsize = mtd->writesize = 1;
+	mtd->owner = THIS_MODULE;
+	mtd->_erase = powernv_flash_erase;
+	mtd->_read = powernv_flash_read;
+	mtd->_write = powernv_flash_write;
+	mtd->dev.parent = dev;
+	mtd_set_of_node(mtd, dev->of_node);
+	return 0;
+}
+
+/**
+ * powernv_flash_probe
+ * @pdev: platform device
+ *
+ * Returns 0 on success, -ENOMEM, -ENXIO on error
+ */
+static int powernv_flash_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct powernv_flash *data;
+	int ret;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->mtd.priv = data;
+
+	ret = of_property_read_u32(dev->of_node, "ibm,opal-id", &(data->id));
+	if (ret) {
+		dev_err(dev, "no device property 'ibm,opal-id'\n");
+		return ret;
+	}
+
+	ret = powernv_flash_set_driver_info(dev, &data->mtd);
+	if (ret)
+		return ret;
+
+	dev_set_drvdata(dev, data);
+
+	/*
+	 * The current flash that skiboot exposes is one contiguous flash chip
+	 * with an ffs partition at the start, it should prove easier for users
+	 * to deal with partitions or not as they see fit
+	 */
+	return mtd_device_register(&data->mtd, NULL, 0);
+}
+
+/**
+ * op_release - Release the driver
+ * @pdev: the platform device
+ *
+ * Returns 0
+ */
+static int powernv_flash_release(struct platform_device *pdev)
+{
+	struct powernv_flash *data = dev_get_drvdata(&(pdev->dev));
+
+	/* All resources should be freed automatically */
+	WARN_ON(mtd_device_unregister(&data->mtd));
+
+	return 0;
+}
+
+static const struct of_device_id powernv_flash_match[] = {
+	{ .compatible = "ibm,opal-flash" },
+	{}
+};
+
+static struct platform_driver powernv_flash_driver = {
+	.driver		= {
+		.name		= "powernv_flash",
+		.of_match_table	= powernv_flash_match,
+	},
+	.remove		= powernv_flash_release,
+	.probe		= powernv_flash_probe,
+};
+
+module_platform_driver(powernv_flash_driver);
+
+MODULE_DEVICE_TABLE(of, powernv_flash_match);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Cyril Bur <cyril.bur@au1.ibm.com>");
+MODULE_DESCRIPTION("MTD abstraction for OPAL flash");
diff --git a/drivers/mtd/devices/serial_flash_cmds.h b/drivers/mtd/devices/serial_flash_cmds.h
new file mode 100644
index 000000000..8b51a872f
--- /dev/null
+++ b/drivers/mtd/devices/serial_flash_cmds.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Generic/SFDP Flash Commands and Device Capabilities
+ *
+ * Copyright (C) 2013 Lee Jones <lee.jones@lianro.org>
+ */
+
+#ifndef _MTD_SERIAL_FLASH_CMDS_H
+#define _MTD_SERIAL_FLASH_CMDS_H
+
+/* Generic Flash Commands/OPCODEs */
+#define SPINOR_OP_WRVCR		0x81
+#define SPINOR_OP_RDVCR		0x85
+
+/* JEDEC Standard - Serial Flash Discoverable Parmeters (SFDP) Commands */
+#define SPINOR_OP_WRITE		0x02	/* PAGE PROGRAM */
+#define SPINOR_OP_WRITE_1_1_2	0xa2	/* DUAL INPUT PROGRAM */
+#define SPINOR_OP_WRITE_1_2_2	0xd2	/* DUAL INPUT EXT PROGRAM */
+#define SPINOR_OP_WRITE_1_1_4	0x32	/* QUAD INPUT PROGRAM */
+#define SPINOR_OP_WRITE_1_4_4	0x12	/* QUAD INPUT EXT PROGRAM */
+
+/* Configuration flags */
+#define FLASH_FLAG_SINGLE	0x000000ff
+#define FLASH_FLAG_READ_WRITE	0x00000001
+#define FLASH_FLAG_READ_FAST	0x00000002
+#define FLASH_FLAG_SE_4K	0x00000004
+#define FLASH_FLAG_SE_32K	0x00000008
+#define FLASH_FLAG_CE		0x00000010
+#define FLASH_FLAG_32BIT_ADDR	0x00000020
+#define FLASH_FLAG_RESET	0x00000040
+#define FLASH_FLAG_DYB_LOCKING	0x00000080
+
+#define FLASH_FLAG_DUAL		0x0000ff00
+#define FLASH_FLAG_READ_1_1_2	0x00000100
+#define FLASH_FLAG_READ_1_2_2	0x00000200
+#define FLASH_FLAG_READ_2_2_2	0x00000400
+#define FLASH_FLAG_WRITE_1_1_2	0x00001000
+#define FLASH_FLAG_WRITE_1_2_2	0x00002000
+#define FLASH_FLAG_WRITE_2_2_2	0x00004000
+
+#define FLASH_FLAG_QUAD		0x00ff0000
+#define FLASH_FLAG_READ_1_1_4	0x00010000
+#define FLASH_FLAG_READ_1_4_4	0x00020000
+#define FLASH_FLAG_READ_4_4_4	0x00040000
+#define FLASH_FLAG_WRITE_1_1_4	0x00100000
+#define FLASH_FLAG_WRITE_1_4_4	0x00200000
+#define FLASH_FLAG_WRITE_4_4_4	0x00400000
+
+#endif /* _MTD_SERIAL_FLASH_CMDS_H */
diff --git a/drivers/mtd/devices/slram.c b/drivers/mtd/devices/slram.c
new file mode 100644
index 000000000..28131a127
--- /dev/null
+++ b/drivers/mtd/devices/slram.c
@@ -0,0 +1,344 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*======================================================================
+
+  This driver provides a method to access memory not used by the kernel
+  itself (i.e. if the kernel commandline mem=xxx is used). To actually
+  use slram at least mtdblock or mtdchar is required (for block or
+  character device access).
+
+  Usage:
+
+  if compiled as loadable module:
+    modprobe slram map=<name>,<start>,<end/offset>
+  if statically linked into the kernel use the following kernel cmd.line
+    slram=<name>,<start>,<end/offset>
+
+  <name>: name of the device that will be listed in /proc/mtd
+  <start>: start of the memory region, decimal or hex (0xabcdef)
+  <end/offset>: end of the memory region. It's possible to use +0x1234
+                to specify the offset instead of the absolute address
+
+  NOTE:
+  With slram it's only possible to map a contiguous memory region. Therefore
+  if there's a device mapped somewhere in the region specified slram will
+  fail to load (see kernel log if modprobe fails).
+
+  -
+
+  Jochen Schaeuble <psionic@psionic.de>
+
+======================================================================*/
+
+
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/ptrace.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/major.h>
+#include <linux/fs.h>
+#include <linux/ioctl.h>
+#include <linux/init.h>
+#include <linux/io.h>
+
+#include <linux/mtd/mtd.h>
+
+#define SLRAM_MAX_DEVICES_PARAMS 6		/* 3 parameters / device */
+#define SLRAM_BLK_SZ 0x4000
+
+#define T(fmt, args...) printk(KERN_DEBUG fmt, ## args)
+#define E(fmt, args...) printk(KERN_NOTICE fmt, ## args)
+
+typedef struct slram_priv {
+	u_char *start;
+	u_char *end;
+} slram_priv_t;
+
+typedef struct slram_mtd_list {
+	struct mtd_info *mtdinfo;
+	struct slram_mtd_list *next;
+} slram_mtd_list_t;
+
+#ifdef MODULE
+static char *map[SLRAM_MAX_DEVICES_PARAMS];
+
+module_param_array(map, charp, NULL, 0);
+MODULE_PARM_DESC(map, "List of memory regions to map. \"map=<name>, <start>, <length / end>\"");
+#else
+static char *map;
+#endif
+
+static slram_mtd_list_t *slram_mtdlist = NULL;
+
+static int slram_erase(struct mtd_info *, struct erase_info *);
+static int slram_point(struct mtd_info *, loff_t, size_t, size_t *, void **,
+		resource_size_t *);
+static int slram_unpoint(struct mtd_info *, loff_t, size_t);
+static int slram_read(struct mtd_info *, loff_t, size_t, size_t *, u_char *);
+static int slram_write(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
+
+static int slram_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	slram_priv_t *priv = mtd->priv;
+
+	memset(priv->start + instr->addr, 0xff, instr->len);
+
+	return(0);
+}
+
+static int slram_point(struct mtd_info *mtd, loff_t from, size_t len,
+		size_t *retlen, void **virt, resource_size_t *phys)
+{
+	slram_priv_t *priv = mtd->priv;
+
+	*virt = priv->start + from;
+	*retlen = len;
+	return(0);
+}
+
+static int slram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
+{
+	return 0;
+}
+
+static int slram_read(struct mtd_info *mtd, loff_t from, size_t len,
+		size_t *retlen, u_char *buf)
+{
+	slram_priv_t *priv = mtd->priv;
+
+	memcpy(buf, priv->start + from, len);
+	*retlen = len;
+	return(0);
+}
+
+static int slram_write(struct mtd_info *mtd, loff_t to, size_t len,
+		size_t *retlen, const u_char *buf)
+{
+	slram_priv_t *priv = mtd->priv;
+
+	memcpy(priv->start + to, buf, len);
+	*retlen = len;
+	return(0);
+}
+
+/*====================================================================*/
+
+static int register_device(char *name, unsigned long start, unsigned long length)
+{
+	slram_mtd_list_t **curmtd;
+
+	curmtd = &slram_mtdlist;
+	while (*curmtd) {
+		curmtd = &(*curmtd)->next;
+	}
+
+	*curmtd = kmalloc(sizeof(slram_mtd_list_t), GFP_KERNEL);
+	if (!(*curmtd)) {
+		E("slram: Cannot allocate new MTD device.\n");
+		return(-ENOMEM);
+	}
+	(*curmtd)->mtdinfo = kzalloc(sizeof(struct mtd_info), GFP_KERNEL);
+	(*curmtd)->next = NULL;
+
+	if ((*curmtd)->mtdinfo)	{
+		(*curmtd)->mtdinfo->priv =
+			kzalloc(sizeof(slram_priv_t), GFP_KERNEL);
+
+		if (!(*curmtd)->mtdinfo->priv) {
+			kfree((*curmtd)->mtdinfo);
+			(*curmtd)->mtdinfo = NULL;
+		}
+	}
+
+	if (!(*curmtd)->mtdinfo) {
+		E("slram: Cannot allocate new MTD device.\n");
+		return(-ENOMEM);
+	}
+
+	if (!(((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start =
+		memremap(start, length,
+			 MEMREMAP_WB | MEMREMAP_WT | MEMREMAP_WC))) {
+		E("slram: memremap failed\n");
+		return -EIO;
+	}
+	((slram_priv_t *)(*curmtd)->mtdinfo->priv)->end =
+		((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start + length;
+
+
+	(*curmtd)->mtdinfo->name = name;
+	(*curmtd)->mtdinfo->size = length;
+	(*curmtd)->mtdinfo->flags = MTD_CAP_RAM;
+	(*curmtd)->mtdinfo->_erase = slram_erase;
+	(*curmtd)->mtdinfo->_point = slram_point;
+	(*curmtd)->mtdinfo->_unpoint = slram_unpoint;
+	(*curmtd)->mtdinfo->_read = slram_read;
+	(*curmtd)->mtdinfo->_write = slram_write;
+	(*curmtd)->mtdinfo->owner = THIS_MODULE;
+	(*curmtd)->mtdinfo->type = MTD_RAM;
+	(*curmtd)->mtdinfo->erasesize = SLRAM_BLK_SZ;
+	(*curmtd)->mtdinfo->writesize = 1;
+
+	if (mtd_device_register((*curmtd)->mtdinfo, NULL, 0))	{
+		E("slram: Failed to register new device\n");
+		memunmap(((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start);
+		kfree((*curmtd)->mtdinfo->priv);
+		kfree((*curmtd)->mtdinfo);
+		return(-EAGAIN);
+	}
+	T("slram: Registered device %s from %luKiB to %luKiB\n", name,
+			(start / 1024), ((start + length) / 1024));
+	T("slram: Mapped from 0x%p to 0x%p\n",
+			((slram_priv_t *)(*curmtd)->mtdinfo->priv)->start,
+			((slram_priv_t *)(*curmtd)->mtdinfo->priv)->end);
+	return(0);
+}
+
+static void unregister_devices(void)
+{
+	slram_mtd_list_t *nextitem;
+
+	while (slram_mtdlist) {
+		nextitem = slram_mtdlist->next;
+		mtd_device_unregister(slram_mtdlist->mtdinfo);
+		memunmap(((slram_priv_t *)slram_mtdlist->mtdinfo->priv)->start);
+		kfree(slram_mtdlist->mtdinfo->priv);
+		kfree(slram_mtdlist->mtdinfo);
+		kfree(slram_mtdlist);
+		slram_mtdlist = nextitem;
+	}
+}
+
+static unsigned long handle_unit(unsigned long value, char *unit)
+{
+	if ((*unit == 'M') || (*unit == 'm')) {
+		return(value * 1024 * 1024);
+	} else if ((*unit == 'K') || (*unit == 'k')) {
+		return(value * 1024);
+	}
+	return(value);
+}
+
+static int parse_cmdline(char *devname, char *szstart, char *szlength)
+{
+	char *buffer;
+	unsigned long devstart;
+	unsigned long devlength;
+
+	if ((!devname) || (!szstart) || (!szlength)) {
+		unregister_devices();
+		return(-EINVAL);
+	}
+
+	devstart = simple_strtoul(szstart, &buffer, 0);
+	devstart = handle_unit(devstart, buffer);
+
+	if (*(szlength) != '+') {
+		devlength = simple_strtoul(szlength, &buffer, 0);
+		devlength = handle_unit(devlength, buffer);
+		if (devlength < devstart)
+			goto err_out;
+
+		devlength -= devstart;
+	} else {
+		devlength = simple_strtoul(szlength + 1, &buffer, 0);
+		devlength = handle_unit(devlength, buffer);
+	}
+	T("slram: devname=%s, devstart=0x%lx, devlength=0x%lx\n",
+			devname, devstart, devlength);
+	if (devlength % SLRAM_BLK_SZ != 0)
+		goto err_out;
+
+	if ((devstart = register_device(devname, devstart, devlength))){
+		unregister_devices();
+		return((int)devstart);
+	}
+	return(0);
+
+err_out:
+	E("slram: Illegal length parameter.\n");
+	return(-EINVAL);
+}
+
+#ifndef MODULE
+
+static int __init mtd_slram_setup(char *str)
+{
+	map = str;
+	return(1);
+}
+
+__setup("slram=", mtd_slram_setup);
+
+#endif
+
+static int __init init_slram(void)
+{
+	char *devname;
+
+#ifndef MODULE
+	char *devstart;
+	char *devlength;
+
+	if (!map) {
+		E("slram: not enough parameters.\n");
+		return(-EINVAL);
+	}
+	while (map) {
+		devname = devstart = devlength = NULL;
+
+		if (!(devname = strsep(&map, ","))) {
+			E("slram: No devicename specified.\n");
+			break;
+		}
+		T("slram: devname = %s\n", devname);
+		if ((!map) || (!(devstart = strsep(&map, ",")))) {
+			E("slram: No devicestart specified.\n");
+		}
+		T("slram: devstart = %s\n", devstart);
+		if ((!map) || (!(devlength = strsep(&map, ",")))) {
+			E("slram: No devicelength / -end specified.\n");
+		}
+		T("slram: devlength = %s\n", devlength);
+		if (parse_cmdline(devname, devstart, devlength) != 0) {
+			return(-EINVAL);
+		}
+	}
+#else
+	int count;
+	int i;
+
+	for (count = 0; count < SLRAM_MAX_DEVICES_PARAMS && map[count];
+			count++) {
+	}
+
+	if ((count % 3 != 0) || (count == 0)) {
+		E("slram: not enough parameters.\n");
+		return(-EINVAL);
+	}
+	for (i = 0; i < (count / 3); i++) {
+		devname = map[i * 3];
+
+		if (parse_cmdline(devname, map[i * 3 + 1], map[i * 3 + 2])!=0) {
+			return(-EINVAL);
+		}
+
+	}
+#endif /* !MODULE */
+
+	return(0);
+}
+
+static void __exit cleanup_slram(void)
+{
+	unregister_devices();
+}
+
+module_init(init_slram);
+module_exit(cleanup_slram);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jochen Schaeuble <psionic@psionic.de>");
+MODULE_DESCRIPTION("MTD driver for uncached system RAM");
diff --git a/drivers/mtd/devices/spear_smi.c b/drivers/mtd/devices/spear_smi.c
new file mode 100644
index 000000000..f58742486
--- /dev/null
+++ b/drivers/mtd/devices/spear_smi.c
@@ -0,0 +1,1116 @@
+/*
+ * SMI (Serial Memory Controller) device driver for Serial NOR Flash on
+ * SPEAr platform
+ * The serial nor interface is largely based on m25p80.c, however the SPI
+ * interface has been replaced by SMI.
+ *
+ * Copyright © 2010 STMicroelectronics.
+ * Ashish Priyadarshi
+ * Shiraz Hashim <shiraz.linux.kernel@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/param.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/spear_smi.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+/* SMI clock rate */
+#define SMI_MAX_CLOCK_FREQ	50000000 /* 50 MHz */
+
+/* MAX time out to safely come out of a erase or write busy conditions */
+#define SMI_PROBE_TIMEOUT	(HZ / 10)
+#define SMI_MAX_TIME_OUT	(3 * HZ)
+
+/* timeout for command completion */
+#define SMI_CMD_TIMEOUT		(HZ / 10)
+
+/* registers of smi */
+#define SMI_CR1		0x0	/* SMI control register 1 */
+#define SMI_CR2		0x4	/* SMI control register 2 */
+#define SMI_SR		0x8	/* SMI status register */
+#define SMI_TR		0xC	/* SMI transmit register */
+#define SMI_RR		0x10	/* SMI receive register */
+
+/* defines for control_reg 1 */
+#define BANK_EN		(0xF << 0)	/* enables all banks */
+#define DSEL_TIME	(0x6 << 4)	/* Deselect time 6 + 1 SMI_CK periods */
+#define SW_MODE		(0x1 << 28)	/* enables SW Mode */
+#define WB_MODE		(0x1 << 29)	/* Write Burst Mode */
+#define FAST_MODE	(0x1 << 15)	/* Fast Mode */
+#define HOLD1		(0x1 << 16)	/* Clock Hold period selection */
+
+/* defines for control_reg 2 */
+#define SEND		(0x1 << 7)	/* Send data */
+#define TFIE		(0x1 << 8)	/* Transmission Flag Interrupt Enable */
+#define WCIE		(0x1 << 9)	/* Write Complete Interrupt Enable */
+#define RD_STATUS_REG	(0x1 << 10)	/* reads status reg */
+#define WE		(0x1 << 11)	/* Write Enable */
+
+#define TX_LEN_SHIFT	0
+#define RX_LEN_SHIFT	4
+#define BANK_SHIFT	12
+
+/* defines for status register */
+#define SR_WIP		0x1	/* Write in progress */
+#define SR_WEL		0x2	/* Write enable latch */
+#define SR_BP0		0x4	/* Block protect 0 */
+#define SR_BP1		0x8	/* Block protect 1 */
+#define SR_BP2		0x10	/* Block protect 2 */
+#define SR_SRWD		0x80	/* SR write protect */
+#define TFF		0x100	/* Transfer Finished Flag */
+#define WCF		0x200	/* Transfer Finished Flag */
+#define ERF1		0x400	/* Forbidden Write Request */
+#define ERF2		0x800	/* Forbidden Access */
+
+#define WM_SHIFT	12
+
+/* flash opcodes */
+#define OPCODE_RDID	0x9f	/* Read JEDEC ID */
+
+/* Flash Device Ids maintenance section */
+
+/* data structure to maintain flash ids from different vendors */
+struct flash_device {
+	char *name;
+	u8 erase_cmd;
+	u32 device_id;
+	u32 pagesize;
+	unsigned long sectorsize;
+	unsigned long size_in_bytes;
+};
+
+#define FLASH_ID(n, es, id, psize, ssize, size)	\
+{				\
+	.name = n,		\
+	.erase_cmd = es,	\
+	.device_id = id,	\
+	.pagesize = psize,	\
+	.sectorsize = ssize,	\
+	.size_in_bytes = size	\
+}
+
+static struct flash_device flash_devices[] = {
+	FLASH_ID("st m25p16"     , 0xd8, 0x00152020, 0x100, 0x10000, 0x200000),
+	FLASH_ID("st m25p32"     , 0xd8, 0x00162020, 0x100, 0x10000, 0x400000),
+	FLASH_ID("st m25p64"     , 0xd8, 0x00172020, 0x100, 0x10000, 0x800000),
+	FLASH_ID("st m25p128"    , 0xd8, 0x00182020, 0x100, 0x40000, 0x1000000),
+	FLASH_ID("st m25p05"     , 0xd8, 0x00102020, 0x80 , 0x8000 , 0x10000),
+	FLASH_ID("st m25p10"     , 0xd8, 0x00112020, 0x80 , 0x8000 , 0x20000),
+	FLASH_ID("st m25p20"     , 0xd8, 0x00122020, 0x100, 0x10000, 0x40000),
+	FLASH_ID("st m25p40"     , 0xd8, 0x00132020, 0x100, 0x10000, 0x80000),
+	FLASH_ID("st m25p80"     , 0xd8, 0x00142020, 0x100, 0x10000, 0x100000),
+	FLASH_ID("st m45pe10"    , 0xd8, 0x00114020, 0x100, 0x10000, 0x20000),
+	FLASH_ID("st m45pe20"    , 0xd8, 0x00124020, 0x100, 0x10000, 0x40000),
+	FLASH_ID("st m45pe40"    , 0xd8, 0x00134020, 0x100, 0x10000, 0x80000),
+	FLASH_ID("st m45pe80"    , 0xd8, 0x00144020, 0x100, 0x10000, 0x100000),
+	FLASH_ID("sp s25fl004"   , 0xd8, 0x00120201, 0x100, 0x10000, 0x80000),
+	FLASH_ID("sp s25fl008"   , 0xd8, 0x00130201, 0x100, 0x10000, 0x100000),
+	FLASH_ID("sp s25fl016"   , 0xd8, 0x00140201, 0x100, 0x10000, 0x200000),
+	FLASH_ID("sp s25fl032"   , 0xd8, 0x00150201, 0x100, 0x10000, 0x400000),
+	FLASH_ID("sp s25fl064"   , 0xd8, 0x00160201, 0x100, 0x10000, 0x800000),
+	FLASH_ID("atmel 25f512"  , 0x52, 0x0065001F, 0x80 , 0x8000 , 0x10000),
+	FLASH_ID("atmel 25f1024" , 0x52, 0x0060001F, 0x100, 0x8000 , 0x20000),
+	FLASH_ID("atmel 25f2048" , 0x52, 0x0063001F, 0x100, 0x10000, 0x40000),
+	FLASH_ID("atmel 25f4096" , 0x52, 0x0064001F, 0x100, 0x10000, 0x80000),
+	FLASH_ID("atmel 25fs040" , 0xd7, 0x0004661F, 0x100, 0x10000, 0x80000),
+	FLASH_ID("mac 25l512"    , 0xd8, 0x001020C2, 0x010, 0x10000, 0x10000),
+	FLASH_ID("mac 25l1005"   , 0xd8, 0x001120C2, 0x010, 0x10000, 0x20000),
+	FLASH_ID("mac 25l2005"   , 0xd8, 0x001220C2, 0x010, 0x10000, 0x40000),
+	FLASH_ID("mac 25l4005"   , 0xd8, 0x001320C2, 0x010, 0x10000, 0x80000),
+	FLASH_ID("mac 25l4005a"  , 0xd8, 0x001320C2, 0x010, 0x10000, 0x80000),
+	FLASH_ID("mac 25l8005"   , 0xd8, 0x001420C2, 0x010, 0x10000, 0x100000),
+	FLASH_ID("mac 25l1605"   , 0xd8, 0x001520C2, 0x100, 0x10000, 0x200000),
+	FLASH_ID("mac 25l1605a"  , 0xd8, 0x001520C2, 0x010, 0x10000, 0x200000),
+	FLASH_ID("mac 25l3205"   , 0xd8, 0x001620C2, 0x100, 0x10000, 0x400000),
+	FLASH_ID("mac 25l3205a"  , 0xd8, 0x001620C2, 0x100, 0x10000, 0x400000),
+	FLASH_ID("mac 25l6405"   , 0xd8, 0x001720C2, 0x100, 0x10000, 0x800000),
+};
+
+/* Define spear specific structures */
+
+struct spear_snor_flash;
+
+/**
+ * struct spear_smi - Structure for SMI Device
+ *
+ * @clk: functional clock
+ * @status: current status register of SMI.
+ * @clk_rate: functional clock rate of SMI (default: SMI_MAX_CLOCK_FREQ)
+ * @lock: lock to prevent parallel access of SMI.
+ * @io_base: base address for registers of SMI.
+ * @pdev: platform device
+ * @cmd_complete: queue to wait for command completion of NOR-flash.
+ * @num_flashes: number of flashes actually present on board.
+ * @flash: separate structure for each Serial NOR-flash attached to SMI.
+ */
+struct spear_smi {
+	struct clk *clk;
+	u32 status;
+	unsigned long clk_rate;
+	struct mutex lock;
+	void __iomem *io_base;
+	struct platform_device *pdev;
+	wait_queue_head_t cmd_complete;
+	u32 num_flashes;
+	struct spear_snor_flash *flash[MAX_NUM_FLASH_CHIP];
+};
+
+/**
+ * struct spear_snor_flash - Structure for Serial NOR Flash
+ *
+ * @bank: Bank number(0, 1, 2, 3) for each NOR-flash.
+ * @dev_id: Device ID of NOR-flash.
+ * @lock: lock to manage flash read, write and erase operations
+ * @mtd: MTD info for each NOR-flash.
+ * @num_parts: Total number of partition in each bank of NOR-flash.
+ * @parts: Partition info for each bank of NOR-flash.
+ * @page_size: Page size of NOR-flash.
+ * @base_addr: Base address of NOR-flash.
+ * @erase_cmd: erase command may vary on different flash types
+ * @fast_mode: flash supports read in fast mode
+ */
+struct spear_snor_flash {
+	u32 bank;
+	u32 dev_id;
+	struct mutex lock;
+	struct mtd_info mtd;
+	u32 num_parts;
+	struct mtd_partition *parts;
+	u32 page_size;
+	void __iomem *base_addr;
+	u8 erase_cmd;
+	u8 fast_mode;
+};
+
+static inline struct spear_snor_flash *get_flash_data(struct mtd_info *mtd)
+{
+	return container_of(mtd, struct spear_snor_flash, mtd);
+}
+
+/**
+ * spear_smi_read_sr - Read status register of flash through SMI
+ * @dev: structure of SMI information.
+ * @bank: bank to which flash is connected
+ *
+ * This routine will return the status register of the flash chip present at the
+ * given bank.
+ */
+static int spear_smi_read_sr(struct spear_smi *dev, u32 bank)
+{
+	int ret;
+	u32 ctrlreg1;
+
+	mutex_lock(&dev->lock);
+	dev->status = 0; /* Will be set in interrupt handler */
+
+	ctrlreg1 = readl(dev->io_base + SMI_CR1);
+	/* program smi in hw mode */
+	writel(ctrlreg1 & ~(SW_MODE | WB_MODE), dev->io_base + SMI_CR1);
+
+	/* performing a rsr instruction in hw mode */
+	writel((bank << BANK_SHIFT) | RD_STATUS_REG | TFIE,
+			dev->io_base + SMI_CR2);
+
+	/* wait for tff */
+	ret = wait_event_interruptible_timeout(dev->cmd_complete,
+			dev->status & TFF, SMI_CMD_TIMEOUT);
+
+	/* copy dev->status (lower 16 bits) in order to release lock */
+	if (ret > 0)
+		ret = dev->status & 0xffff;
+	else if (ret == 0)
+		ret = -ETIMEDOUT;
+
+	/* restore the ctrl regs state */
+	writel(ctrlreg1, dev->io_base + SMI_CR1);
+	writel(0, dev->io_base + SMI_CR2);
+	mutex_unlock(&dev->lock);
+
+	return ret;
+}
+
+/**
+ * spear_smi_wait_till_ready - wait till flash is ready
+ * @dev: structure of SMI information.
+ * @bank: flash corresponding to this bank
+ * @timeout: timeout for busy wait condition
+ *
+ * This routine checks for WIP (write in progress) bit in Status register
+ * If successful the routine returns 0 else -EBUSY
+ */
+static int spear_smi_wait_till_ready(struct spear_smi *dev, u32 bank,
+		unsigned long timeout)
+{
+	unsigned long finish;
+	int status;
+
+	finish = jiffies + timeout;
+	do {
+		status = spear_smi_read_sr(dev, bank);
+		if (status < 0) {
+			if (status == -ETIMEDOUT)
+				continue; /* try till finish */
+			return status;
+		} else if (!(status & SR_WIP)) {
+			return 0;
+		}
+
+		cond_resched();
+	} while (!time_after_eq(jiffies, finish));
+
+	dev_err(&dev->pdev->dev, "smi controller is busy, timeout\n");
+	return -EBUSY;
+}
+
+/**
+ * spear_smi_int_handler - SMI Interrupt Handler.
+ * @irq: irq number
+ * @dev_id: structure of SMI device, embedded in dev_id.
+ *
+ * The handler clears all interrupt conditions and records the status in
+ * dev->status which is used by the driver later.
+ */
+static irqreturn_t spear_smi_int_handler(int irq, void *dev_id)
+{
+	u32 status = 0;
+	struct spear_smi *dev = dev_id;
+
+	status = readl(dev->io_base + SMI_SR);
+
+	if (unlikely(!status))
+		return IRQ_NONE;
+
+	/* clear all interrupt conditions */
+	writel(0, dev->io_base + SMI_SR);
+
+	/* copy the status register in dev->status */
+	dev->status |= status;
+
+	/* send the completion */
+	wake_up_interruptible(&dev->cmd_complete);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * spear_smi_hw_init - initializes the smi controller.
+ * @dev: structure of smi device
+ *
+ * this routine initializes the smi controller wit the default values
+ */
+static void spear_smi_hw_init(struct spear_smi *dev)
+{
+	unsigned long rate = 0;
+	u32 prescale = 0;
+	u32 val;
+
+	rate = clk_get_rate(dev->clk);
+
+	/* functional clock of smi */
+	prescale = DIV_ROUND_UP(rate, dev->clk_rate);
+
+	/*
+	 * setting the standard values, fast mode, prescaler for
+	 * SMI_MAX_CLOCK_FREQ (50MHz) operation and bank enable
+	 */
+	val = HOLD1 | BANK_EN | DSEL_TIME | (prescale << 8);
+
+	mutex_lock(&dev->lock);
+	/* clear all interrupt conditions */
+	writel(0, dev->io_base + SMI_SR);
+
+	writel(val, dev->io_base + SMI_CR1);
+	mutex_unlock(&dev->lock);
+}
+
+/**
+ * get_flash_index - match chip id from a flash list.
+ * @flash_id: a valid nor flash chip id obtained from board.
+ *
+ * try to validate the chip id by matching from a list, if not found then simply
+ * returns negative. In case of success returns index in to the flash devices
+ * array.
+ */
+static int get_flash_index(u32 flash_id)
+{
+	int index;
+
+	/* Matches chip-id to entire list of 'serial-nor flash' ids */
+	for (index = 0; index < ARRAY_SIZE(flash_devices); index++) {
+		if (flash_devices[index].device_id == flash_id)
+			return index;
+	}
+
+	/* Memory chip is not listed and not supported */
+	return -ENODEV;
+}
+
+/**
+ * spear_smi_write_enable - Enable the flash to do write operation
+ * @dev: structure of SMI device
+ * @bank: enable write for flash connected to this bank
+ *
+ * Set write enable latch with Write Enable command.
+ * Returns 0 on success.
+ */
+static int spear_smi_write_enable(struct spear_smi *dev, u32 bank)
+{
+	int ret;
+	u32 ctrlreg1;
+
+	mutex_lock(&dev->lock);
+	dev->status = 0; /* Will be set in interrupt handler */
+
+	ctrlreg1 = readl(dev->io_base + SMI_CR1);
+	/* program smi in h/w mode */
+	writel(ctrlreg1 & ~SW_MODE, dev->io_base + SMI_CR1);
+
+	/* give the flash, write enable command */
+	writel((bank << BANK_SHIFT) | WE | TFIE, dev->io_base + SMI_CR2);
+
+	ret = wait_event_interruptible_timeout(dev->cmd_complete,
+			dev->status & TFF, SMI_CMD_TIMEOUT);
+
+	/* restore the ctrl regs state */
+	writel(ctrlreg1, dev->io_base + SMI_CR1);
+	writel(0, dev->io_base + SMI_CR2);
+
+	if (ret == 0) {
+		ret = -EIO;
+		dev_err(&dev->pdev->dev,
+			"smi controller failed on write enable\n");
+	} else if (ret > 0) {
+		/* check whether write mode status is set for required bank */
+		if (dev->status & (1 << (bank + WM_SHIFT)))
+			ret = 0;
+		else {
+			dev_err(&dev->pdev->dev, "couldn't enable write\n");
+			ret = -EIO;
+		}
+	}
+
+	mutex_unlock(&dev->lock);
+	return ret;
+}
+
+static inline u32
+get_sector_erase_cmd(struct spear_snor_flash *flash, u32 offset)
+{
+	u32 cmd;
+	u8 *x = (u8 *)&cmd;
+
+	x[0] = flash->erase_cmd;
+	x[1] = offset >> 16;
+	x[2] = offset >> 8;
+	x[3] = offset;
+
+	return cmd;
+}
+
+/**
+ * spear_smi_erase_sector - erase one sector of flash
+ * @dev: structure of SMI information
+ * @command: erase command to be send
+ * @bank: bank to which this command needs to be send
+ * @bytes: size of command
+ *
+ * Erase one sector of flash memory at offset ``offset'' which is any
+ * address within the sector which should be erased.
+ * Returns 0 if successful, non-zero otherwise.
+ */
+static int spear_smi_erase_sector(struct spear_smi *dev,
+		u32 bank, u32 command, u32 bytes)
+{
+	u32 ctrlreg1 = 0;
+	int ret;
+
+	ret = spear_smi_wait_till_ready(dev, bank, SMI_MAX_TIME_OUT);
+	if (ret)
+		return ret;
+
+	ret = spear_smi_write_enable(dev, bank);
+	if (ret)
+		return ret;
+
+	mutex_lock(&dev->lock);
+
+	ctrlreg1 = readl(dev->io_base + SMI_CR1);
+	writel((ctrlreg1 | SW_MODE) & ~WB_MODE, dev->io_base + SMI_CR1);
+
+	/* send command in sw mode */
+	writel(command, dev->io_base + SMI_TR);
+
+	writel((bank << BANK_SHIFT) | SEND | TFIE | (bytes << TX_LEN_SHIFT),
+			dev->io_base + SMI_CR2);
+
+	ret = wait_event_interruptible_timeout(dev->cmd_complete,
+			dev->status & TFF, SMI_CMD_TIMEOUT);
+
+	if (ret == 0) {
+		ret = -EIO;
+		dev_err(&dev->pdev->dev, "sector erase failed\n");
+	} else if (ret > 0)
+		ret = 0; /* success */
+
+	/* restore ctrl regs */
+	writel(ctrlreg1, dev->io_base + SMI_CR1);
+	writel(0, dev->io_base + SMI_CR2);
+
+	mutex_unlock(&dev->lock);
+	return ret;
+}
+
+/**
+ * spear_mtd_erase - perform flash erase operation as requested by user
+ * @mtd: Provides the memory characteristics
+ * @e_info: Provides the erase information
+ *
+ * Erase an address range on the flash chip. The address range may extend
+ * one or more erase sectors. Return an error is there is a problem erasing.
+ */
+static int spear_mtd_erase(struct mtd_info *mtd, struct erase_info *e_info)
+{
+	struct spear_snor_flash *flash = get_flash_data(mtd);
+	struct spear_smi *dev = mtd->priv;
+	u32 addr, command, bank;
+	int len, ret;
+
+	if (!flash || !dev)
+		return -ENODEV;
+
+	bank = flash->bank;
+	if (bank > dev->num_flashes - 1) {
+		dev_err(&dev->pdev->dev, "Invalid Bank Num");
+		return -EINVAL;
+	}
+
+	addr = e_info->addr;
+	len = e_info->len;
+
+	mutex_lock(&flash->lock);
+
+	/* now erase sectors in loop */
+	while (len) {
+		command = get_sector_erase_cmd(flash, addr);
+		/* preparing the command for flash */
+		ret = spear_smi_erase_sector(dev, bank, command, 4);
+		if (ret) {
+			mutex_unlock(&flash->lock);
+			return ret;
+		}
+		addr += mtd->erasesize;
+		len -= mtd->erasesize;
+	}
+
+	mutex_unlock(&flash->lock);
+
+	return 0;
+}
+
+/**
+ * spear_mtd_read - performs flash read operation as requested by the user
+ * @mtd: MTD information of the memory bank
+ * @from: Address from which to start read
+ * @len: Number of bytes to be read
+ * @retlen: Fills the Number of bytes actually read
+ * @buf: Fills this after reading
+ *
+ * Read an address range from the flash chip. The address range
+ * may be any size provided it is within the physical boundaries.
+ * Returns 0 on success, non zero otherwise
+ */
+static int spear_mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
+		size_t *retlen, u8 *buf)
+{
+	struct spear_snor_flash *flash = get_flash_data(mtd);
+	struct spear_smi *dev = mtd->priv;
+	void __iomem *src;
+	u32 ctrlreg1, val;
+	int ret;
+
+	if (!flash || !dev)
+		return -ENODEV;
+
+	if (flash->bank > dev->num_flashes - 1) {
+		dev_err(&dev->pdev->dev, "Invalid Bank Num");
+		return -EINVAL;
+	}
+
+	/* select address as per bank number */
+	src = flash->base_addr + from;
+
+	mutex_lock(&flash->lock);
+
+	/* wait till previous write/erase is done. */
+	ret = spear_smi_wait_till_ready(dev, flash->bank, SMI_MAX_TIME_OUT);
+	if (ret) {
+		mutex_unlock(&flash->lock);
+		return ret;
+	}
+
+	mutex_lock(&dev->lock);
+	/* put smi in hw mode not wbt mode */
+	ctrlreg1 = val = readl(dev->io_base + SMI_CR1);
+	val &= ~(SW_MODE | WB_MODE);
+	if (flash->fast_mode)
+		val |= FAST_MODE;
+
+	writel(val, dev->io_base + SMI_CR1);
+
+	memcpy_fromio(buf, src, len);
+
+	/* restore ctrl reg1 */
+	writel(ctrlreg1, dev->io_base + SMI_CR1);
+	mutex_unlock(&dev->lock);
+
+	*retlen = len;
+	mutex_unlock(&flash->lock);
+
+	return 0;
+}
+
+/*
+ * The purpose of this function is to ensure a memcpy_toio() with byte writes
+ * only. Its structure is inspired from the ARM implementation of _memcpy_toio()
+ * which also does single byte writes but cannot be used here as this is just an
+ * implementation detail and not part of the API. Not mentioning the comment
+ * stating that _memcpy_toio() should be optimized.
+ */
+static void spear_smi_memcpy_toio_b(volatile void __iomem *dest,
+				    const void *src, size_t len)
+{
+	const unsigned char *from = src;
+
+	while (len) {
+		len--;
+		writeb(*from, dest);
+		from++;
+		dest++;
+	}
+}
+
+static inline int spear_smi_cpy_toio(struct spear_smi *dev, u32 bank,
+		void __iomem *dest, const void *src, size_t len)
+{
+	int ret;
+	u32 ctrlreg1;
+
+	/* wait until finished previous write command. */
+	ret = spear_smi_wait_till_ready(dev, bank, SMI_MAX_TIME_OUT);
+	if (ret)
+		return ret;
+
+	/* put smi in write enable */
+	ret = spear_smi_write_enable(dev, bank);
+	if (ret)
+		return ret;
+
+	/* put smi in hw, write burst mode */
+	mutex_lock(&dev->lock);
+
+	ctrlreg1 = readl(dev->io_base + SMI_CR1);
+	writel((ctrlreg1 | WB_MODE) & ~SW_MODE, dev->io_base + SMI_CR1);
+
+	/*
+	 * In Write Burst mode (WB_MODE), the specs states that writes must be:
+	 * - incremental
+	 * - of the same size
+	 * The ARM implementation of memcpy_toio() will optimize the number of
+	 * I/O by using as much 4-byte writes as possible, surrounded by
+	 * 2-byte/1-byte access if:
+	 * - the destination is not 4-byte aligned
+	 * - the length is not a multiple of 4-byte.
+	 * Avoid this alternance of write access size by using our own 'byte
+	 * access' helper if at least one of the two conditions above is true.
+	 */
+	if (IS_ALIGNED(len, sizeof(u32)) &&
+	    IS_ALIGNED((uintptr_t)dest, sizeof(u32)))
+		memcpy_toio(dest, src, len);
+	else
+		spear_smi_memcpy_toio_b(dest, src, len);
+
+	writel(ctrlreg1, dev->io_base + SMI_CR1);
+
+	mutex_unlock(&dev->lock);
+	return 0;
+}
+
+/**
+ * spear_mtd_write - performs write operation as requested by the user.
+ * @mtd: MTD information of the memory bank.
+ * @to:	Address to write.
+ * @len: Number of bytes to be written.
+ * @retlen: Number of bytes actually wrote.
+ * @buf: Buffer from which the data to be taken.
+ *
+ * Write an address range to the flash chip. Data must be written in
+ * flash_page_size chunks. The address range may be any size provided
+ * it is within the physical boundaries.
+ * Returns 0 on success, non zero otherwise
+ */
+static int spear_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
+		size_t *retlen, const u8 *buf)
+{
+	struct spear_snor_flash *flash = get_flash_data(mtd);
+	struct spear_smi *dev = mtd->priv;
+	void __iomem *dest;
+	u32 page_offset, page_size;
+	int ret;
+
+	if (!flash || !dev)
+		return -ENODEV;
+
+	if (flash->bank > dev->num_flashes - 1) {
+		dev_err(&dev->pdev->dev, "Invalid Bank Num");
+		return -EINVAL;
+	}
+
+	/* select address as per bank number */
+	dest = flash->base_addr + to;
+	mutex_lock(&flash->lock);
+
+	page_offset = (u32)to % flash->page_size;
+
+	/* do if all the bytes fit onto one page */
+	if (page_offset + len <= flash->page_size) {
+		ret = spear_smi_cpy_toio(dev, flash->bank, dest, buf, len);
+		if (!ret)
+			*retlen += len;
+	} else {
+		u32 i;
+
+		/* the size of data remaining on the first page */
+		page_size = flash->page_size - page_offset;
+
+		ret = spear_smi_cpy_toio(dev, flash->bank, dest, buf,
+				page_size);
+		if (ret)
+			goto err_write;
+		else
+			*retlen += page_size;
+
+		/* write everything in pagesize chunks */
+		for (i = page_size; i < len; i += page_size) {
+			page_size = len - i;
+			if (page_size > flash->page_size)
+				page_size = flash->page_size;
+
+			ret = spear_smi_cpy_toio(dev, flash->bank, dest + i,
+					buf + i, page_size);
+			if (ret)
+				break;
+			else
+				*retlen += page_size;
+		}
+	}
+
+err_write:
+	mutex_unlock(&flash->lock);
+
+	return ret;
+}
+
+/**
+ * spear_smi_probe_flash - Detects the NOR Flash chip.
+ * @dev: structure of SMI information.
+ * @bank: bank on which flash must be probed
+ *
+ * This routine will check whether there exists a flash chip on a given memory
+ * bank ID.
+ * Return index of the probed flash in flash devices structure
+ */
+static int spear_smi_probe_flash(struct spear_smi *dev, u32 bank)
+{
+	int ret;
+	u32 val = 0;
+
+	ret = spear_smi_wait_till_ready(dev, bank, SMI_PROBE_TIMEOUT);
+	if (ret)
+		return ret;
+
+	mutex_lock(&dev->lock);
+
+	dev->status = 0; /* Will be set in interrupt handler */
+	/* put smi in sw mode */
+	val = readl(dev->io_base + SMI_CR1);
+	writel(val | SW_MODE, dev->io_base + SMI_CR1);
+
+	/* send readid command in sw mode */
+	writel(OPCODE_RDID, dev->io_base + SMI_TR);
+
+	val = (bank << BANK_SHIFT) | SEND | (1 << TX_LEN_SHIFT) |
+		(3 << RX_LEN_SHIFT) | TFIE;
+	writel(val, dev->io_base + SMI_CR2);
+
+	/* wait for TFF */
+	ret = wait_event_interruptible_timeout(dev->cmd_complete,
+			dev->status & TFF, SMI_CMD_TIMEOUT);
+	if (ret <= 0) {
+		ret = -ENODEV;
+		goto err_probe;
+	}
+
+	/* get memory chip id */
+	val = readl(dev->io_base + SMI_RR);
+	val &= 0x00ffffff;
+	ret = get_flash_index(val);
+
+err_probe:
+	/* clear sw mode */
+	val = readl(dev->io_base + SMI_CR1);
+	writel(val & ~SW_MODE, dev->io_base + SMI_CR1);
+
+	mutex_unlock(&dev->lock);
+	return ret;
+}
+
+
+#ifdef CONFIG_OF
+static int spear_smi_probe_config_dt(struct platform_device *pdev,
+				     struct device_node *np)
+{
+	struct spear_smi_plat_data *pdata = dev_get_platdata(&pdev->dev);
+	struct device_node *pp;
+	const __be32 *addr;
+	u32 val;
+	int len;
+	int i = 0;
+
+	if (!np)
+		return -ENODEV;
+
+	of_property_read_u32(np, "clock-rate", &val);
+	pdata->clk_rate = val;
+
+	pdata->board_flash_info = devm_kzalloc(&pdev->dev,
+					       sizeof(*pdata->board_flash_info),
+					       GFP_KERNEL);
+	if (!pdata->board_flash_info)
+		return -ENOMEM;
+
+	/* Fill structs for each subnode (flash device) */
+	for_each_child_of_node(np, pp) {
+		pdata->np[i] = pp;
+
+		/* Read base-addr and size from DT */
+		addr = of_get_property(pp, "reg", &len);
+		pdata->board_flash_info->mem_base = be32_to_cpup(&addr[0]);
+		pdata->board_flash_info->size = be32_to_cpup(&addr[1]);
+
+		if (of_get_property(pp, "st,smi-fast-mode", NULL))
+			pdata->board_flash_info->fast_mode = 1;
+
+		i++;
+	}
+
+	pdata->num_flashes = i;
+
+	return 0;
+}
+#else
+static int spear_smi_probe_config_dt(struct platform_device *pdev,
+				     struct device_node *np)
+{
+	return -ENOSYS;
+}
+#endif
+
+static int spear_smi_setup_banks(struct platform_device *pdev,
+				 u32 bank, struct device_node *np)
+{
+	struct spear_smi *dev = platform_get_drvdata(pdev);
+	struct spear_smi_flash_info *flash_info;
+	struct spear_smi_plat_data *pdata;
+	struct spear_snor_flash *flash;
+	struct mtd_partition *parts = NULL;
+	int count = 0;
+	int flash_index;
+	int ret = 0;
+
+	pdata = dev_get_platdata(&pdev->dev);
+	if (bank > pdata->num_flashes - 1)
+		return -EINVAL;
+
+	flash_info = &pdata->board_flash_info[bank];
+	if (!flash_info)
+		return -ENODEV;
+
+	flash = devm_kzalloc(&pdev->dev, sizeof(*flash), GFP_ATOMIC);
+	if (!flash)
+		return -ENOMEM;
+	flash->bank = bank;
+	flash->fast_mode = flash_info->fast_mode ? 1 : 0;
+	mutex_init(&flash->lock);
+
+	/* verify whether nor flash is really present on board */
+	flash_index = spear_smi_probe_flash(dev, bank);
+	if (flash_index < 0) {
+		dev_info(&dev->pdev->dev, "smi-nor%d not found\n", bank);
+		return flash_index;
+	}
+	/* map the memory for nor flash chip */
+	flash->base_addr = devm_ioremap(&pdev->dev, flash_info->mem_base,
+					flash_info->size);
+	if (!flash->base_addr)
+		return -EIO;
+
+	dev->flash[bank] = flash;
+	flash->mtd.priv = dev;
+
+	if (flash_info->name)
+		flash->mtd.name = flash_info->name;
+	else
+		flash->mtd.name = flash_devices[flash_index].name;
+
+	flash->mtd.dev.parent = &pdev->dev;
+	mtd_set_of_node(&flash->mtd, np);
+	flash->mtd.type = MTD_NORFLASH;
+	flash->mtd.writesize = 1;
+	flash->mtd.flags = MTD_CAP_NORFLASH;
+	flash->mtd.size = flash_info->size;
+	flash->mtd.erasesize = flash_devices[flash_index].sectorsize;
+	flash->page_size = flash_devices[flash_index].pagesize;
+	flash->mtd.writebufsize = flash->page_size;
+	flash->erase_cmd = flash_devices[flash_index].erase_cmd;
+	flash->mtd._erase = spear_mtd_erase;
+	flash->mtd._read = spear_mtd_read;
+	flash->mtd._write = spear_mtd_write;
+	flash->dev_id = flash_devices[flash_index].device_id;
+
+	dev_info(&dev->pdev->dev, "mtd .name=%s .size=%llx(%lluM)\n",
+			flash->mtd.name, flash->mtd.size,
+			flash->mtd.size / (1024 * 1024));
+
+	dev_info(&dev->pdev->dev, ".erasesize = 0x%x(%uK)\n",
+			flash->mtd.erasesize, flash->mtd.erasesize / 1024);
+
+#ifndef CONFIG_OF
+	if (flash_info->partitions) {
+		parts = flash_info->partitions;
+		count = flash_info->nr_partitions;
+	}
+#endif
+
+	ret = mtd_device_register(&flash->mtd, parts, count);
+	if (ret) {
+		dev_err(&dev->pdev->dev, "Err MTD partition=%d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * spear_smi_probe - Entry routine
+ * @pdev: platform device structure
+ *
+ * This is the first routine which gets invoked during booting and does all
+ * initialization/allocation work. The routine looks for available memory banks,
+ * and do proper init for any found one.
+ * Returns 0 on success, non zero otherwise
+ */
+static int spear_smi_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct spear_smi_plat_data *pdata = NULL;
+	struct spear_smi *dev;
+	struct resource *smi_base;
+	int irq, ret = 0;
+	int i;
+
+	if (np) {
+		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+		if (!pdata) {
+			ret = -ENOMEM;
+			goto err;
+		}
+		pdev->dev.platform_data = pdata;
+		ret = spear_smi_probe_config_dt(pdev, np);
+		if (ret) {
+			ret = -ENODEV;
+			dev_err(&pdev->dev, "no platform data\n");
+			goto err;
+		}
+	} else {
+		pdata = dev_get_platdata(&pdev->dev);
+		if (!pdata) {
+			ret = -ENODEV;
+			dev_err(&pdev->dev, "no platform data\n");
+			goto err;
+		}
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		ret = -ENODEV;
+		goto err;
+	}
+
+	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+	if (!dev) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	smi_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	dev->io_base = devm_ioremap_resource(&pdev->dev, smi_base);
+	if (IS_ERR(dev->io_base)) {
+		ret = PTR_ERR(dev->io_base);
+		goto err;
+	}
+
+	dev->pdev = pdev;
+	dev->clk_rate = pdata->clk_rate;
+
+	if (dev->clk_rate > SMI_MAX_CLOCK_FREQ)
+		dev->clk_rate = SMI_MAX_CLOCK_FREQ;
+
+	dev->num_flashes = pdata->num_flashes;
+
+	if (dev->num_flashes > MAX_NUM_FLASH_CHIP) {
+		dev_err(&pdev->dev, "exceeding max number of flashes\n");
+		dev->num_flashes = MAX_NUM_FLASH_CHIP;
+	}
+
+	dev->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(dev->clk)) {
+		ret = PTR_ERR(dev->clk);
+		goto err;
+	}
+
+	ret = clk_prepare_enable(dev->clk);
+	if (ret)
+		goto err;
+
+	ret = devm_request_irq(&pdev->dev, irq, spear_smi_int_handler, 0,
+			       pdev->name, dev);
+	if (ret) {
+		dev_err(&dev->pdev->dev, "SMI IRQ allocation failed\n");
+		goto err_irq;
+	}
+
+	mutex_init(&dev->lock);
+	init_waitqueue_head(&dev->cmd_complete);
+	spear_smi_hw_init(dev);
+	platform_set_drvdata(pdev, dev);
+
+	/* loop for each serial nor-flash which is connected to smi */
+	for (i = 0; i < dev->num_flashes; i++) {
+		ret = spear_smi_setup_banks(pdev, i, pdata->np[i]);
+		if (ret) {
+			dev_err(&dev->pdev->dev, "bank setup failed\n");
+			goto err_irq;
+		}
+	}
+
+	return 0;
+
+err_irq:
+	clk_disable_unprepare(dev->clk);
+err:
+	return ret;
+}
+
+/**
+ * spear_smi_remove - Exit routine
+ * @pdev: platform device structure
+ *
+ * free all allocations and delete the partitions.
+ */
+static int spear_smi_remove(struct platform_device *pdev)
+{
+	struct spear_smi *dev;
+	struct spear_snor_flash *flash;
+	int i;
+
+	dev = platform_get_drvdata(pdev);
+
+	/* clean up for all nor flash */
+	for (i = 0; i < dev->num_flashes; i++) {
+		flash = dev->flash[i];
+		if (!flash)
+			continue;
+
+		/* clean up mtd stuff */
+		WARN_ON(mtd_device_unregister(&flash->mtd));
+	}
+
+	clk_disable_unprepare(dev->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int spear_smi_suspend(struct device *dev)
+{
+	struct spear_smi *sdev = dev_get_drvdata(dev);
+
+	if (sdev && sdev->clk)
+		clk_disable_unprepare(sdev->clk);
+
+	return 0;
+}
+
+static int spear_smi_resume(struct device *dev)
+{
+	struct spear_smi *sdev = dev_get_drvdata(dev);
+	int ret = -EPERM;
+
+	if (sdev && sdev->clk)
+		ret = clk_prepare_enable(sdev->clk);
+
+	if (!ret)
+		spear_smi_hw_init(sdev);
+	return ret;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(spear_smi_pm_ops, spear_smi_suspend, spear_smi_resume);
+
+#ifdef CONFIG_OF
+static const struct of_device_id spear_smi_id_table[] = {
+	{ .compatible = "st,spear600-smi" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, spear_smi_id_table);
+#endif
+
+static struct platform_driver spear_smi_driver = {
+	.driver = {
+		.name = "smi",
+		.bus = &platform_bus_type,
+		.of_match_table = of_match_ptr(spear_smi_id_table),
+		.pm = &spear_smi_pm_ops,
+	},
+	.probe = spear_smi_probe,
+	.remove = spear_smi_remove,
+};
+module_platform_driver(spear_smi_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Ashish Priyadarshi, Shiraz Hashim <shiraz.linux.kernel@gmail.com>");
+MODULE_DESCRIPTION("MTD SMI driver for serial nor flash chips");
diff --git a/drivers/mtd/devices/sst25l.c b/drivers/mtd/devices/sst25l.c
new file mode 100644
index 000000000..8813994ce
--- /dev/null
+++ b/drivers/mtd/devices/sst25l.c
@@ -0,0 +1,421 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * sst25l.c
+ *
+ * Driver for SST25L SPI Flash chips
+ *
+ * Copyright © 2009 Bluewater Systems Ltd
+ * Author: Andre Renaud <andre@bluewatersys.com>
+ * Author: Ryan Mallon
+ *
+ * Based on m25p80.c
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/flash.h>
+
+/* Erases can take up to 3 seconds! */
+#define MAX_READY_WAIT_JIFFIES	msecs_to_jiffies(3000)
+
+#define SST25L_CMD_WRSR		0x01	/* Write status register */
+#define SST25L_CMD_WRDI		0x04	/* Write disable */
+#define SST25L_CMD_RDSR		0x05	/* Read status register */
+#define SST25L_CMD_WREN		0x06	/* Write enable */
+#define SST25L_CMD_READ		0x03	/* High speed read */
+
+#define SST25L_CMD_EWSR		0x50	/* Enable write status register */
+#define SST25L_CMD_SECTOR_ERASE	0x20	/* Erase sector */
+#define SST25L_CMD_READ_ID	0x90	/* Read device ID */
+#define SST25L_CMD_AAI_PROGRAM	0xaf	/* Auto address increment */
+
+#define SST25L_STATUS_BUSY	(1 << 0)	/* Chip is busy */
+#define SST25L_STATUS_WREN	(1 << 1)	/* Write enabled */
+#define SST25L_STATUS_BP0	(1 << 2)	/* Block protection 0 */
+#define SST25L_STATUS_BP1	(1 << 3)	/* Block protection 1 */
+
+struct sst25l_flash {
+	struct spi_device	*spi;
+	struct mutex		lock;
+	struct mtd_info		mtd;
+};
+
+struct flash_info {
+	const char		*name;
+	uint16_t		device_id;
+	unsigned		page_size;
+	unsigned		nr_pages;
+	unsigned		erase_size;
+};
+
+#define to_sst25l_flash(x) container_of(x, struct sst25l_flash, mtd)
+
+static struct flash_info sst25l_flash_info[] = {
+	{"sst25lf020a", 0xbf43, 256, 1024, 4096},
+	{"sst25lf040a",	0xbf44,	256, 2048, 4096},
+};
+
+static int sst25l_status(struct sst25l_flash *flash, int *status)
+{
+	struct spi_message m;
+	struct spi_transfer t;
+	unsigned char cmd_resp[2];
+	int err;
+
+	spi_message_init(&m);
+	memset(&t, 0, sizeof(struct spi_transfer));
+
+	cmd_resp[0] = SST25L_CMD_RDSR;
+	cmd_resp[1] = 0xff;
+	t.tx_buf = cmd_resp;
+	t.rx_buf = cmd_resp;
+	t.len = sizeof(cmd_resp);
+	spi_message_add_tail(&t, &m);
+	err = spi_sync(flash->spi, &m);
+	if (err < 0)
+		return err;
+
+	*status = cmd_resp[1];
+	return 0;
+}
+
+static int sst25l_write_enable(struct sst25l_flash *flash, int enable)
+{
+	unsigned char command[2];
+	int status, err;
+
+	command[0] = enable ? SST25L_CMD_WREN : SST25L_CMD_WRDI;
+	err = spi_write(flash->spi, command, 1);
+	if (err)
+		return err;
+
+	command[0] = SST25L_CMD_EWSR;
+	err = spi_write(flash->spi, command, 1);
+	if (err)
+		return err;
+
+	command[0] = SST25L_CMD_WRSR;
+	command[1] = enable ? 0 : SST25L_STATUS_BP0 | SST25L_STATUS_BP1;
+	err = spi_write(flash->spi, command, 2);
+	if (err)
+		return err;
+
+	if (enable) {
+		err = sst25l_status(flash, &status);
+		if (err)
+			return err;
+		if (!(status & SST25L_STATUS_WREN))
+			return -EROFS;
+	}
+
+	return 0;
+}
+
+static int sst25l_wait_till_ready(struct sst25l_flash *flash)
+{
+	unsigned long deadline;
+	int status, err;
+
+	deadline = jiffies + MAX_READY_WAIT_JIFFIES;
+	do {
+		err = sst25l_status(flash, &status);
+		if (err)
+			return err;
+		if (!(status & SST25L_STATUS_BUSY))
+			return 0;
+
+		cond_resched();
+	} while (!time_after_eq(jiffies, deadline));
+
+	return -ETIMEDOUT;
+}
+
+static int sst25l_erase_sector(struct sst25l_flash *flash, uint32_t offset)
+{
+	unsigned char command[4];
+	int err;
+
+	err = sst25l_write_enable(flash, 1);
+	if (err)
+		return err;
+
+	command[0] = SST25L_CMD_SECTOR_ERASE;
+	command[1] = offset >> 16;
+	command[2] = offset >> 8;
+	command[3] = offset;
+	err = spi_write(flash->spi, command, 4);
+	if (err)
+		return err;
+
+	err = sst25l_wait_till_ready(flash);
+	if (err)
+		return err;
+
+	return sst25l_write_enable(flash, 0);
+}
+
+static int sst25l_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct sst25l_flash *flash = to_sst25l_flash(mtd);
+	uint32_t addr, end;
+	int err;
+
+	/* Sanity checks */
+	if ((uint32_t)instr->len % mtd->erasesize)
+		return -EINVAL;
+
+	if ((uint32_t)instr->addr % mtd->erasesize)
+		return -EINVAL;
+
+	addr = instr->addr;
+	end = addr + instr->len;
+
+	mutex_lock(&flash->lock);
+
+	err = sst25l_wait_till_ready(flash);
+	if (err) {
+		mutex_unlock(&flash->lock);
+		return err;
+	}
+
+	while (addr < end) {
+		err = sst25l_erase_sector(flash, addr);
+		if (err) {
+			mutex_unlock(&flash->lock);
+			dev_err(&flash->spi->dev, "Erase failed\n");
+			return err;
+		}
+
+		addr += mtd->erasesize;
+	}
+
+	mutex_unlock(&flash->lock);
+
+	return 0;
+}
+
+static int sst25l_read(struct mtd_info *mtd, loff_t from, size_t len,
+		       size_t *retlen, unsigned char *buf)
+{
+	struct sst25l_flash *flash = to_sst25l_flash(mtd);
+	struct spi_transfer transfer[2];
+	struct spi_message message;
+	unsigned char command[4];
+	int ret;
+
+	spi_message_init(&message);
+	memset(&transfer, 0, sizeof(transfer));
+
+	command[0] = SST25L_CMD_READ;
+	command[1] = from >> 16;
+	command[2] = from >> 8;
+	command[3] = from;
+
+	transfer[0].tx_buf = command;
+	transfer[0].len = sizeof(command);
+	spi_message_add_tail(&transfer[0], &message);
+
+	transfer[1].rx_buf = buf;
+	transfer[1].len = len;
+	spi_message_add_tail(&transfer[1], &message);
+
+	mutex_lock(&flash->lock);
+
+	/* Wait for previous write/erase to complete */
+	ret = sst25l_wait_till_ready(flash);
+	if (ret) {
+		mutex_unlock(&flash->lock);
+		return ret;
+	}
+
+	spi_sync(flash->spi, &message);
+
+	if (retlen && message.actual_length > sizeof(command))
+		*retlen += message.actual_length - sizeof(command);
+
+	mutex_unlock(&flash->lock);
+	return 0;
+}
+
+static int sst25l_write(struct mtd_info *mtd, loff_t to, size_t len,
+			size_t *retlen, const unsigned char *buf)
+{
+	struct sst25l_flash *flash = to_sst25l_flash(mtd);
+	int i, j, ret, bytes, copied = 0;
+	unsigned char command[5];
+
+	if ((uint32_t)to % mtd->writesize)
+		return -EINVAL;
+
+	mutex_lock(&flash->lock);
+
+	ret = sst25l_write_enable(flash, 1);
+	if (ret)
+		goto out;
+
+	for (i = 0; i < len; i += mtd->writesize) {
+		ret = sst25l_wait_till_ready(flash);
+		if (ret)
+			goto out;
+
+		/* Write the first byte of the page */
+		command[0] = SST25L_CMD_AAI_PROGRAM;
+		command[1] = (to + i) >> 16;
+		command[2] = (to + i) >> 8;
+		command[3] = (to + i);
+		command[4] = buf[i];
+		ret = spi_write(flash->spi, command, 5);
+		if (ret < 0)
+			goto out;
+		copied++;
+
+		/*
+		 * Write the remaining bytes using auto address
+		 * increment mode
+		 */
+		bytes = min_t(uint32_t, mtd->writesize, len - i);
+		for (j = 1; j < bytes; j++, copied++) {
+			ret = sst25l_wait_till_ready(flash);
+			if (ret)
+				goto out;
+
+			command[1] = buf[i + j];
+			ret = spi_write(flash->spi, command, 2);
+			if (ret)
+				goto out;
+		}
+	}
+
+out:
+	ret = sst25l_write_enable(flash, 0);
+
+	if (retlen)
+		*retlen = copied;
+
+	mutex_unlock(&flash->lock);
+	return ret;
+}
+
+static struct flash_info *sst25l_match_device(struct spi_device *spi)
+{
+	struct flash_info *flash_info = NULL;
+	struct spi_message m;
+	struct spi_transfer t;
+	unsigned char cmd_resp[6];
+	int i, err;
+	uint16_t id;
+
+	spi_message_init(&m);
+	memset(&t, 0, sizeof(struct spi_transfer));
+
+	cmd_resp[0] = SST25L_CMD_READ_ID;
+	cmd_resp[1] = 0;
+	cmd_resp[2] = 0;
+	cmd_resp[3] = 0;
+	cmd_resp[4] = 0xff;
+	cmd_resp[5] = 0xff;
+	t.tx_buf = cmd_resp;
+	t.rx_buf = cmd_resp;
+	t.len = sizeof(cmd_resp);
+	spi_message_add_tail(&t, &m);
+	err = spi_sync(spi, &m);
+	if (err < 0) {
+		dev_err(&spi->dev, "error reading device id\n");
+		return NULL;
+	}
+
+	id = (cmd_resp[4] << 8) | cmd_resp[5];
+
+	for (i = 0; i < ARRAY_SIZE(sst25l_flash_info); i++)
+		if (sst25l_flash_info[i].device_id == id)
+			flash_info = &sst25l_flash_info[i];
+
+	if (!flash_info)
+		dev_err(&spi->dev, "unknown id %.4x\n", id);
+
+	return flash_info;
+}
+
+static int sst25l_probe(struct spi_device *spi)
+{
+	struct flash_info *flash_info;
+	struct sst25l_flash *flash;
+	struct flash_platform_data *data;
+	int ret;
+
+	flash_info = sst25l_match_device(spi);
+	if (!flash_info)
+		return -ENODEV;
+
+	flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);
+	if (!flash)
+		return -ENOMEM;
+
+	flash->spi = spi;
+	mutex_init(&flash->lock);
+	spi_set_drvdata(spi, flash);
+
+	data = dev_get_platdata(&spi->dev);
+	if (data && data->name)
+		flash->mtd.name = data->name;
+
+	flash->mtd.dev.parent   = &spi->dev;
+	flash->mtd.type		= MTD_NORFLASH;
+	flash->mtd.flags	= MTD_CAP_NORFLASH;
+	flash->mtd.erasesize	= flash_info->erase_size;
+	flash->mtd.writesize	= flash_info->page_size;
+	flash->mtd.writebufsize	= flash_info->page_size;
+	flash->mtd.size		= flash_info->page_size * flash_info->nr_pages;
+	flash->mtd._erase	= sst25l_erase;
+	flash->mtd._read		= sst25l_read;
+	flash->mtd._write 	= sst25l_write;
+
+	dev_info(&spi->dev, "%s (%lld KiB)\n", flash_info->name,
+		 (long long)flash->mtd.size >> 10);
+
+	pr_debug("mtd .name = %s, .size = 0x%llx (%lldMiB) "
+	      ".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n",
+	      flash->mtd.name,
+	      (long long)flash->mtd.size, (long long)(flash->mtd.size >> 20),
+	      flash->mtd.erasesize, flash->mtd.erasesize / 1024,
+	      flash->mtd.numeraseregions);
+
+
+	ret = mtd_device_register(&flash->mtd, data ? data->parts : NULL,
+				  data ? data->nr_parts : 0);
+	if (ret)
+		return -ENODEV;
+
+	return 0;
+}
+
+static void sst25l_remove(struct spi_device *spi)
+{
+	struct sst25l_flash *flash = spi_get_drvdata(spi);
+
+	WARN_ON(mtd_device_unregister(&flash->mtd));
+}
+
+static struct spi_driver sst25l_driver = {
+	.driver = {
+		.name	= "sst25l",
+	},
+	.probe		= sst25l_probe,
+	.remove		= sst25l_remove,
+};
+
+module_spi_driver(sst25l_driver);
+
+MODULE_DESCRIPTION("MTD SPI driver for SST25L Flash chips");
+MODULE_AUTHOR("Andre Renaud <andre@bluewatersys.com>, "
+	      "Ryan Mallon");
+MODULE_LICENSE("GPL");
diff --git a/drivers/mtd/devices/st_spi_fsm.c b/drivers/mtd/devices/st_spi_fsm.c
new file mode 100644
index 000000000..54861d889
--- /dev/null
+++ b/drivers/mtd/devices/st_spi_fsm.c
@@ -0,0 +1,2174 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * st_spi_fsm.c	- ST Fast Sequence Mode (FSM) Serial Flash Controller
+ *
+ * Author: Angus Clark <angus.clark@st.com>
+ *
+ * Copyright (C) 2010-2014 STMicroelectronics Limited
+ *
+ * JEDEC probe based on drivers/mtd/devices/m25p80.c
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/spi-nor.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/clk.h>
+
+#include "serial_flash_cmds.h"
+
+/*
+ * FSM SPI Controller Registers
+ */
+#define SPI_CLOCKDIV			0x0010
+#define SPI_MODESELECT			0x0018
+#define SPI_CONFIGDATA			0x0020
+#define SPI_STA_MODE_CHANGE		0x0028
+#define SPI_FAST_SEQ_TRANSFER_SIZE	0x0100
+#define SPI_FAST_SEQ_ADD1		0x0104
+#define SPI_FAST_SEQ_ADD2		0x0108
+#define SPI_FAST_SEQ_ADD_CFG		0x010c
+#define SPI_FAST_SEQ_OPC1		0x0110
+#define SPI_FAST_SEQ_OPC2		0x0114
+#define SPI_FAST_SEQ_OPC3		0x0118
+#define SPI_FAST_SEQ_OPC4		0x011c
+#define SPI_FAST_SEQ_OPC5		0x0120
+#define SPI_MODE_BITS			0x0124
+#define SPI_DUMMY_BITS			0x0128
+#define SPI_FAST_SEQ_FLASH_STA_DATA	0x012c
+#define SPI_FAST_SEQ_1			0x0130
+#define SPI_FAST_SEQ_2			0x0134
+#define SPI_FAST_SEQ_3			0x0138
+#define SPI_FAST_SEQ_4			0x013c
+#define SPI_FAST_SEQ_CFG		0x0140
+#define SPI_FAST_SEQ_STA		0x0144
+#define SPI_QUAD_BOOT_SEQ_INIT_1	0x0148
+#define SPI_QUAD_BOOT_SEQ_INIT_2	0x014c
+#define SPI_QUAD_BOOT_READ_SEQ_1	0x0150
+#define SPI_QUAD_BOOT_READ_SEQ_2	0x0154
+#define SPI_PROGRAM_ERASE_TIME		0x0158
+#define SPI_MULT_PAGE_REPEAT_SEQ_1	0x015c
+#define SPI_MULT_PAGE_REPEAT_SEQ_2	0x0160
+#define SPI_STATUS_WR_TIME_REG		0x0164
+#define SPI_FAST_SEQ_DATA_REG		0x0300
+
+/*
+ * Register: SPI_MODESELECT
+ */
+#define SPI_MODESELECT_CONTIG		0x01
+#define SPI_MODESELECT_FASTREAD		0x02
+#define SPI_MODESELECT_DUALIO		0x04
+#define SPI_MODESELECT_FSM		0x08
+#define SPI_MODESELECT_QUADBOOT		0x10
+
+/*
+ * Register: SPI_CONFIGDATA
+ */
+#define SPI_CFG_DEVICE_ST		0x1
+#define SPI_CFG_DEVICE_ATMEL		0x4
+#define SPI_CFG_MIN_CS_HIGH(x)		(((x) & 0xfff) << 4)
+#define SPI_CFG_CS_SETUPHOLD(x)		(((x) & 0xff) << 16)
+#define SPI_CFG_DATA_HOLD(x)		(((x) & 0xff) << 24)
+
+#define SPI_CFG_DEFAULT_MIN_CS_HIGH    SPI_CFG_MIN_CS_HIGH(0x0AA)
+#define SPI_CFG_DEFAULT_CS_SETUPHOLD   SPI_CFG_CS_SETUPHOLD(0xA0)
+#define SPI_CFG_DEFAULT_DATA_HOLD      SPI_CFG_DATA_HOLD(0x00)
+
+/*
+ * Register: SPI_FAST_SEQ_TRANSFER_SIZE
+ */
+#define TRANSFER_SIZE(x)		((x) * 8)
+
+/*
+ * Register: SPI_FAST_SEQ_ADD_CFG
+ */
+#define ADR_CFG_CYCLES_ADD1(x)		((x) << 0)
+#define ADR_CFG_PADS_1_ADD1		(0x0 << 6)
+#define ADR_CFG_PADS_2_ADD1		(0x1 << 6)
+#define ADR_CFG_PADS_4_ADD1		(0x3 << 6)
+#define ADR_CFG_CSDEASSERT_ADD1		(1   << 8)
+#define ADR_CFG_CYCLES_ADD2(x)		((x) << (0+16))
+#define ADR_CFG_PADS_1_ADD2		(0x0 << (6+16))
+#define ADR_CFG_PADS_2_ADD2		(0x1 << (6+16))
+#define ADR_CFG_PADS_4_ADD2		(0x3 << (6+16))
+#define ADR_CFG_CSDEASSERT_ADD2		(1   << (8+16))
+
+/*
+ * Register: SPI_FAST_SEQ_n
+ */
+#define SEQ_OPC_OPCODE(x)		((x) << 0)
+#define SEQ_OPC_CYCLES(x)		((x) << 8)
+#define SEQ_OPC_PADS_1			(0x0 << 14)
+#define SEQ_OPC_PADS_2			(0x1 << 14)
+#define SEQ_OPC_PADS_4			(0x3 << 14)
+#define SEQ_OPC_CSDEASSERT		(1   << 16)
+
+/*
+ * Register: SPI_FAST_SEQ_CFG
+ */
+#define SEQ_CFG_STARTSEQ		(1 << 0)
+#define SEQ_CFG_SWRESET			(1 << 5)
+#define SEQ_CFG_CSDEASSERT		(1 << 6)
+#define SEQ_CFG_READNOTWRITE		(1 << 7)
+#define SEQ_CFG_ERASE			(1 << 8)
+#define SEQ_CFG_PADS_1			(0x0 << 16)
+#define SEQ_CFG_PADS_2			(0x1 << 16)
+#define SEQ_CFG_PADS_4			(0x3 << 16)
+
+/*
+ * Register: SPI_MODE_BITS
+ */
+#define MODE_DATA(x)			(x & 0xff)
+#define MODE_CYCLES(x)			((x & 0x3f) << 16)
+#define MODE_PADS_1			(0x0 << 22)
+#define MODE_PADS_2			(0x1 << 22)
+#define MODE_PADS_4			(0x3 << 22)
+#define DUMMY_CSDEASSERT		(1   << 24)
+
+/*
+ * Register: SPI_DUMMY_BITS
+ */
+#define DUMMY_CYCLES(x)			((x & 0x3f) << 16)
+#define DUMMY_PADS_1			(0x0 << 22)
+#define DUMMY_PADS_2			(0x1 << 22)
+#define DUMMY_PADS_4			(0x3 << 22)
+#define DUMMY_CSDEASSERT		(1   << 24)
+
+/*
+ * Register: SPI_FAST_SEQ_FLASH_STA_DATA
+ */
+#define STA_DATA_BYTE1(x)		((x & 0xff) << 0)
+#define STA_DATA_BYTE2(x)		((x & 0xff) << 8)
+#define STA_PADS_1			(0x0 << 16)
+#define STA_PADS_2			(0x1 << 16)
+#define STA_PADS_4			(0x3 << 16)
+#define STA_CSDEASSERT			(0x1 << 20)
+#define STA_RDNOTWR			(0x1 << 21)
+
+/*
+ * FSM SPI Instruction Opcodes
+ */
+#define STFSM_OPC_CMD			0x1
+#define STFSM_OPC_ADD			0x2
+#define STFSM_OPC_STA			0x3
+#define STFSM_OPC_MODE			0x4
+#define STFSM_OPC_DUMMY		0x5
+#define STFSM_OPC_DATA			0x6
+#define STFSM_OPC_WAIT			0x7
+#define STFSM_OPC_JUMP			0x8
+#define STFSM_OPC_GOTO			0x9
+#define STFSM_OPC_STOP			0xF
+
+/*
+ * FSM SPI Instructions (== opcode + operand).
+ */
+#define STFSM_INSTR(cmd, op)		((cmd) | ((op) << 4))
+
+#define STFSM_INST_CMD1			STFSM_INSTR(STFSM_OPC_CMD,	1)
+#define STFSM_INST_CMD2			STFSM_INSTR(STFSM_OPC_CMD,	2)
+#define STFSM_INST_CMD3			STFSM_INSTR(STFSM_OPC_CMD,	3)
+#define STFSM_INST_CMD4			STFSM_INSTR(STFSM_OPC_CMD,	4)
+#define STFSM_INST_CMD5			STFSM_INSTR(STFSM_OPC_CMD,	5)
+#define STFSM_INST_ADD1			STFSM_INSTR(STFSM_OPC_ADD,	1)
+#define STFSM_INST_ADD2			STFSM_INSTR(STFSM_OPC_ADD,	2)
+
+#define STFSM_INST_DATA_WRITE		STFSM_INSTR(STFSM_OPC_DATA,	1)
+#define STFSM_INST_DATA_READ		STFSM_INSTR(STFSM_OPC_DATA,	2)
+
+#define STFSM_INST_STA_RD1		STFSM_INSTR(STFSM_OPC_STA,	0x1)
+#define STFSM_INST_STA_WR1		STFSM_INSTR(STFSM_OPC_STA,	0x1)
+#define STFSM_INST_STA_RD2		STFSM_INSTR(STFSM_OPC_STA,	0x2)
+#define STFSM_INST_STA_WR1_2		STFSM_INSTR(STFSM_OPC_STA,	0x3)
+
+#define STFSM_INST_MODE			STFSM_INSTR(STFSM_OPC_MODE,	0)
+#define STFSM_INST_DUMMY		STFSM_INSTR(STFSM_OPC_DUMMY,	0)
+#define STFSM_INST_WAIT			STFSM_INSTR(STFSM_OPC_WAIT,	0)
+#define STFSM_INST_STOP			STFSM_INSTR(STFSM_OPC_STOP,	0)
+
+#define STFSM_DEFAULT_EMI_FREQ 100000000UL                        /* 100 MHz */
+#define STFSM_DEFAULT_WR_TIME  (STFSM_DEFAULT_EMI_FREQ * (15/1000)) /* 15ms */
+
+#define STFSM_FLASH_SAFE_FREQ  10000000UL                         /* 10 MHz */
+
+#define STFSM_MAX_WAIT_SEQ_MS  1000     /* FSM execution time */
+
+/* S25FLxxxS commands */
+#define S25FL_CMD_WRITE4_1_1_4 0x34
+#define S25FL_CMD_SE4          0xdc
+#define S25FL_CMD_CLSR         0x30
+#define S25FL_CMD_DYBWR                0xe1
+#define S25FL_CMD_DYBRD                0xe0
+#define S25FL_CMD_WRITE4       0x12    /* Note, opcode clashes with
+					* 'SPINOR_OP_WRITE_1_4_4'
+					* as found on N25Qxxx devices! */
+
+/* Status register */
+#define FLASH_STATUS_BUSY      0x01
+#define FLASH_STATUS_WEL       0x02
+#define FLASH_STATUS_BP0       0x04
+#define FLASH_STATUS_BP1       0x08
+#define FLASH_STATUS_BP2       0x10
+#define FLASH_STATUS_SRWP0     0x80
+#define FLASH_STATUS_TIMEOUT   0xff
+/* S25FL Error Flags */
+#define S25FL_STATUS_E_ERR     0x20
+#define S25FL_STATUS_P_ERR     0x40
+
+#define N25Q_CMD_WRVCR         0x81
+#define N25Q_CMD_RDVCR         0x85
+#define N25Q_CMD_RDVECR        0x65
+#define N25Q_CMD_RDNVCR        0xb5
+#define N25Q_CMD_WRNVCR        0xb1
+
+#define FLASH_PAGESIZE         256			/* In Bytes    */
+#define FLASH_PAGESIZE_32      (FLASH_PAGESIZE / 4)	/* In uint32_t */
+#define FLASH_MAX_BUSY_WAIT    (300 * HZ)	/* Maximum 'CHIPERASE' time */
+
+/*
+ * Flags to tweak operation of default read/write/erase routines
+ */
+#define CFG_READ_TOGGLE_32BIT_ADDR     0x00000001
+#define CFG_WRITE_TOGGLE_32BIT_ADDR    0x00000002
+#define CFG_ERASESEC_TOGGLE_32BIT_ADDR 0x00000008
+#define CFG_S25FL_CHECK_ERROR_FLAGS    0x00000010
+
+struct stfsm_seq {
+	uint32_t data_size;
+	uint32_t addr1;
+	uint32_t addr2;
+	uint32_t addr_cfg;
+	uint32_t seq_opc[5];
+	uint32_t mode;
+	uint32_t dummy;
+	uint32_t status;
+	uint8_t  seq[16];
+	uint32_t seq_cfg;
+} __packed __aligned(4);
+
+struct stfsm {
+	struct device		*dev;
+	void __iomem		*base;
+	struct mtd_info		mtd;
+	struct mutex		lock;
+	struct flash_info       *info;
+	struct clk              *clk;
+
+	uint32_t                configuration;
+	uint32_t                fifo_dir_delay;
+	bool                    booted_from_spi;
+	bool                    reset_signal;
+	bool                    reset_por;
+
+	struct stfsm_seq stfsm_seq_read;
+	struct stfsm_seq stfsm_seq_write;
+	struct stfsm_seq stfsm_seq_en_32bit_addr;
+};
+
+/* Parameters to configure a READ or WRITE FSM sequence */
+struct seq_rw_config {
+	uint32_t        flags;          /* flags to support config */
+	uint8_t         cmd;            /* FLASH command */
+	int             write;          /* Write Sequence */
+	uint8_t         addr_pads;      /* No. of addr pads (MODE & DUMMY) */
+	uint8_t         data_pads;      /* No. of data pads */
+	uint8_t         mode_data;      /* MODE data */
+	uint8_t         mode_cycles;    /* No. of MODE cycles */
+	uint8_t         dummy_cycles;   /* No. of DUMMY cycles */
+};
+
+/* SPI Flash Device Table */
+struct flash_info {
+	char            *name;
+	/*
+	 * JEDEC id zero means "no ID" (most older chips); otherwise it has
+	 * a high byte of zero plus three data bytes: the manufacturer id,
+	 * then a two byte device id.
+	 */
+	u32             jedec_id;
+	u16             ext_id;
+	/*
+	 * The size listed here is what works with SPINOR_OP_SE, which isn't
+	 * necessarily called a "sector" by the vendor.
+	 */
+	unsigned        sector_size;
+	u16             n_sectors;
+	u32             flags;
+	/*
+	 * Note, where FAST_READ is supported, freq_max specifies the
+	 * FAST_READ frequency, not the READ frequency.
+	 */
+	u32             max_freq;
+	int             (*config)(struct stfsm *);
+};
+
+static int stfsm_n25q_config(struct stfsm *fsm);
+static int stfsm_mx25_config(struct stfsm *fsm);
+static int stfsm_s25fl_config(struct stfsm *fsm);
+static int stfsm_w25q_config(struct stfsm *fsm);
+
+static struct flash_info flash_types[] = {
+	/*
+	 * ST Microelectronics/Numonyx --
+	 * (newer production versions may have feature updates
+	 * (eg faster operating frequency)
+	 */
+#define M25P_FLAG (FLASH_FLAG_READ_WRITE | FLASH_FLAG_READ_FAST)
+	{ "m25p40",  0x202013, 0,  64 * 1024,   8, M25P_FLAG, 25, NULL },
+	{ "m25p80",  0x202014, 0,  64 * 1024,  16, M25P_FLAG, 25, NULL },
+	{ "m25p16",  0x202015, 0,  64 * 1024,  32, M25P_FLAG, 25, NULL },
+	{ "m25p32",  0x202016, 0,  64 * 1024,  64, M25P_FLAG, 50, NULL },
+	{ "m25p64",  0x202017, 0,  64 * 1024, 128, M25P_FLAG, 50, NULL },
+	{ "m25p128", 0x202018, 0, 256 * 1024,  64, M25P_FLAG, 50, NULL },
+
+#define M25PX_FLAG (FLASH_FLAG_READ_WRITE      |	\
+		    FLASH_FLAG_READ_FAST        |	\
+		    FLASH_FLAG_READ_1_1_2       |	\
+		    FLASH_FLAG_WRITE_1_1_2)
+	{ "m25px32", 0x207116, 0,  64 * 1024,  64, M25PX_FLAG, 75, NULL },
+	{ "m25px64", 0x207117, 0,  64 * 1024, 128, M25PX_FLAG, 75, NULL },
+
+	/* Macronix MX25xxx
+	 *     - Support for 'FLASH_FLAG_WRITE_1_4_4' is omitted for devices
+	 *       where operating frequency must be reduced.
+	 */
+#define MX25_FLAG (FLASH_FLAG_READ_WRITE       |	\
+		   FLASH_FLAG_READ_FAST         |	\
+		   FLASH_FLAG_READ_1_1_2        |	\
+		   FLASH_FLAG_READ_1_2_2        |	\
+		   FLASH_FLAG_READ_1_1_4        |	\
+		   FLASH_FLAG_SE_4K             |	\
+		   FLASH_FLAG_SE_32K)
+	{ "mx25l3255e",  0xc29e16, 0, 64 * 1024, 64,
+	  (MX25_FLAG | FLASH_FLAG_WRITE_1_4_4), 86,
+	  stfsm_mx25_config},
+	{ "mx25l25635e", 0xc22019, 0, 64*1024, 512,
+	  (MX25_FLAG | FLASH_FLAG_32BIT_ADDR | FLASH_FLAG_RESET), 70,
+	  stfsm_mx25_config },
+	{ "mx25l25655e", 0xc22619, 0, 64*1024, 512,
+	  (MX25_FLAG | FLASH_FLAG_32BIT_ADDR | FLASH_FLAG_RESET), 70,
+	  stfsm_mx25_config},
+
+#define N25Q_FLAG (FLASH_FLAG_READ_WRITE       |	\
+		   FLASH_FLAG_READ_FAST         |	\
+		   FLASH_FLAG_READ_1_1_2        |	\
+		   FLASH_FLAG_READ_1_2_2        |	\
+		   FLASH_FLAG_READ_1_1_4        |	\
+		   FLASH_FLAG_READ_1_4_4        |	\
+		   FLASH_FLAG_WRITE_1_1_2       |	\
+		   FLASH_FLAG_WRITE_1_2_2       |	\
+		   FLASH_FLAG_WRITE_1_1_4       |	\
+		   FLASH_FLAG_WRITE_1_4_4)
+	{ "n25q128", 0x20ba18, 0, 64 * 1024,  256, N25Q_FLAG, 108,
+	  stfsm_n25q_config },
+	{ "n25q256", 0x20ba19, 0, 64 * 1024,  512,
+	  N25Q_FLAG | FLASH_FLAG_32BIT_ADDR, 108, stfsm_n25q_config },
+
+	/*
+	 * Spansion S25FLxxxP
+	 *     - 256KiB and 64KiB sector variants (identified by ext. JEDEC)
+	 */
+#define S25FLXXXP_FLAG (FLASH_FLAG_READ_WRITE  |	\
+			FLASH_FLAG_READ_1_1_2   |	\
+			FLASH_FLAG_READ_1_2_2   |	\
+			FLASH_FLAG_READ_1_1_4   |	\
+			FLASH_FLAG_READ_1_4_4   |	\
+			FLASH_FLAG_WRITE_1_1_4  |	\
+			FLASH_FLAG_READ_FAST)
+	{ "s25fl032p",  0x010215, 0x4d00,  64 * 1024,  64, S25FLXXXP_FLAG, 80,
+	  stfsm_s25fl_config},
+	{ "s25fl129p0", 0x012018, 0x4d00, 256 * 1024,  64, S25FLXXXP_FLAG, 80,
+	  stfsm_s25fl_config },
+	{ "s25fl129p1", 0x012018, 0x4d01,  64 * 1024, 256, S25FLXXXP_FLAG, 80,
+	  stfsm_s25fl_config },
+
+	/*
+	 * Spansion S25FLxxxS
+	 *     - 256KiB and 64KiB sector variants (identified by ext. JEDEC)
+	 *     - RESET# signal supported by die but not bristled out on all
+	 *       package types.  The package type is a function of board design,
+	 *       so this information is captured in the board's flags.
+	 *     - Supports 'DYB' sector protection. Depending on variant, sectors
+	 *       may default to locked state on power-on.
+	 */
+#define S25FLXXXS_FLAG (S25FLXXXP_FLAG         |	\
+			FLASH_FLAG_RESET        |	\
+			FLASH_FLAG_DYB_LOCKING)
+	{ "s25fl128s0", 0x012018, 0x0300,  256 * 1024, 64, S25FLXXXS_FLAG, 80,
+	  stfsm_s25fl_config },
+	{ "s25fl128s1", 0x012018, 0x0301,  64 * 1024, 256, S25FLXXXS_FLAG, 80,
+	  stfsm_s25fl_config },
+	{ "s25fl256s0", 0x010219, 0x4d00, 256 * 1024, 128,
+	  S25FLXXXS_FLAG | FLASH_FLAG_32BIT_ADDR, 80, stfsm_s25fl_config },
+	{ "s25fl256s1", 0x010219, 0x4d01,  64 * 1024, 512,
+	  S25FLXXXS_FLAG | FLASH_FLAG_32BIT_ADDR, 80, stfsm_s25fl_config },
+
+	/* Winbond -- w25x "blocks" are 64K, "sectors" are 4KiB */
+#define W25X_FLAG (FLASH_FLAG_READ_WRITE       |	\
+		   FLASH_FLAG_READ_FAST         |	\
+		   FLASH_FLAG_READ_1_1_2        |	\
+		   FLASH_FLAG_WRITE_1_1_2)
+	{ "w25x40",  0xef3013, 0,  64 * 1024,   8, W25X_FLAG, 75, NULL },
+	{ "w25x80",  0xef3014, 0,  64 * 1024,  16, W25X_FLAG, 75, NULL },
+	{ "w25x16",  0xef3015, 0,  64 * 1024,  32, W25X_FLAG, 75, NULL },
+	{ "w25x32",  0xef3016, 0,  64 * 1024,  64, W25X_FLAG, 75, NULL },
+	{ "w25x64",  0xef3017, 0,  64 * 1024, 128, W25X_FLAG, 75, NULL },
+
+	/* Winbond -- w25q "blocks" are 64K, "sectors" are 4KiB */
+#define W25Q_FLAG (FLASH_FLAG_READ_WRITE       |	\
+		   FLASH_FLAG_READ_FAST         |	\
+		   FLASH_FLAG_READ_1_1_2        |	\
+		   FLASH_FLAG_READ_1_2_2        |	\
+		   FLASH_FLAG_READ_1_1_4        |	\
+		   FLASH_FLAG_READ_1_4_4        |	\
+		   FLASH_FLAG_WRITE_1_1_4)
+	{ "w25q80",  0xef4014, 0,  64 * 1024,  16, W25Q_FLAG, 80,
+	  stfsm_w25q_config },
+	{ "w25q16",  0xef4015, 0,  64 * 1024,  32, W25Q_FLAG, 80,
+	  stfsm_w25q_config },
+	{ "w25q32",  0xef4016, 0,  64 * 1024,  64, W25Q_FLAG, 80,
+	  stfsm_w25q_config },
+	{ "w25q64",  0xef4017, 0,  64 * 1024, 128, W25Q_FLAG, 80,
+	  stfsm_w25q_config },
+
+	/* Sentinel */
+	{ NULL, 0x000000, 0, 0, 0, 0, 0, NULL },
+};
+
+/*
+ * FSM message sequence configurations:
+ *
+ * All configs are presented in order of preference
+ */
+
+/* Default READ configurations, in order of preference */
+static struct seq_rw_config default_read_configs[] = {
+	{FLASH_FLAG_READ_1_4_4, SPINOR_OP_READ_1_4_4,	0, 4, 4, 0x00, 2, 4},
+	{FLASH_FLAG_READ_1_1_4, SPINOR_OP_READ_1_1_4,	0, 1, 4, 0x00, 4, 0},
+	{FLASH_FLAG_READ_1_2_2, SPINOR_OP_READ_1_2_2,	0, 2, 2, 0x00, 4, 0},
+	{FLASH_FLAG_READ_1_1_2, SPINOR_OP_READ_1_1_2,	0, 1, 2, 0x00, 0, 8},
+	{FLASH_FLAG_READ_FAST,	SPINOR_OP_READ_FAST,	0, 1, 1, 0x00, 0, 8},
+	{FLASH_FLAG_READ_WRITE, SPINOR_OP_READ,		0, 1, 1, 0x00, 0, 0},
+	{0x00,			0,			0, 0, 0, 0x00, 0, 0},
+};
+
+/* Default WRITE configurations */
+static struct seq_rw_config default_write_configs[] = {
+	{FLASH_FLAG_WRITE_1_4_4, SPINOR_OP_WRITE_1_4_4, 1, 4, 4, 0x00, 0, 0},
+	{FLASH_FLAG_WRITE_1_1_4, SPINOR_OP_WRITE_1_1_4, 1, 1, 4, 0x00, 0, 0},
+	{FLASH_FLAG_WRITE_1_2_2, SPINOR_OP_WRITE_1_2_2, 1, 2, 2, 0x00, 0, 0},
+	{FLASH_FLAG_WRITE_1_1_2, SPINOR_OP_WRITE_1_1_2, 1, 1, 2, 0x00, 0, 0},
+	{FLASH_FLAG_READ_WRITE,  SPINOR_OP_WRITE,       1, 1, 1, 0x00, 0, 0},
+	{0x00,			 0,			0, 0, 0, 0x00, 0, 0},
+};
+
+/*
+ * [N25Qxxx] Configuration
+ */
+#define N25Q_VCR_DUMMY_CYCLES(x)	(((x) & 0xf) << 4)
+#define N25Q_VCR_XIP_DISABLED		((uint8_t)0x1 << 3)
+#define N25Q_VCR_WRAP_CONT		0x3
+
+/* N25Q 3-byte Address READ configurations
+ *	- 'FAST' variants configured for 8 dummy cycles.
+ *
+ * Note, the number of dummy cycles used for 'FAST' READ operations is
+ * configurable and would normally be tuned according to the READ command and
+ * operating frequency.  However, this applies universally to all 'FAST' READ
+ * commands, including those used by the SPIBoot controller, and remains in
+ * force until the device is power-cycled.  Since the SPIBoot controller is
+ * hard-wired to use 8 dummy cycles, we must configure the device to also use 8
+ * cycles.
+ */
+static struct seq_rw_config n25q_read3_configs[] = {
+	{FLASH_FLAG_READ_1_4_4, SPINOR_OP_READ_1_4_4,	0, 4, 4, 0x00, 0, 8},
+	{FLASH_FLAG_READ_1_1_4, SPINOR_OP_READ_1_1_4,	0, 1, 4, 0x00, 0, 8},
+	{FLASH_FLAG_READ_1_2_2, SPINOR_OP_READ_1_2_2,	0, 2, 2, 0x00, 0, 8},
+	{FLASH_FLAG_READ_1_1_2, SPINOR_OP_READ_1_1_2,	0, 1, 2, 0x00, 0, 8},
+	{FLASH_FLAG_READ_FAST,	SPINOR_OP_READ_FAST,	0, 1, 1, 0x00, 0, 8},
+	{FLASH_FLAG_READ_WRITE, SPINOR_OP_READ,	        0, 1, 1, 0x00, 0, 0},
+	{0x00,			0,			0, 0, 0, 0x00, 0, 0},
+};
+
+/* N25Q 4-byte Address READ configurations
+ *	- use special 4-byte address READ commands (reduces overheads, and
+ *        reduces risk of hitting watchdog reset issues).
+ *	- 'FAST' variants configured for 8 dummy cycles (see note above.)
+ */
+static struct seq_rw_config n25q_read4_configs[] = {
+	{FLASH_FLAG_READ_1_4_4, SPINOR_OP_READ_1_4_4_4B, 0, 4, 4, 0x00, 0, 8},
+	{FLASH_FLAG_READ_1_1_4, SPINOR_OP_READ_1_1_4_4B, 0, 1, 4, 0x00, 0, 8},
+	{FLASH_FLAG_READ_1_2_2, SPINOR_OP_READ_1_2_2_4B, 0, 2, 2, 0x00, 0, 8},
+	{FLASH_FLAG_READ_1_1_2, SPINOR_OP_READ_1_1_2_4B, 0, 1, 2, 0x00, 0, 8},
+	{FLASH_FLAG_READ_FAST,	SPINOR_OP_READ_FAST_4B,  0, 1, 1, 0x00, 0, 8},
+	{FLASH_FLAG_READ_WRITE, SPINOR_OP_READ_4B,       0, 1, 1, 0x00, 0, 0},
+	{0x00,			0,                       0, 0, 0, 0x00, 0, 0},
+};
+
+/*
+ * [MX25xxx] Configuration
+ */
+#define MX25_STATUS_QE			(0x1 << 6)
+
+static int stfsm_mx25_en_32bit_addr_seq(struct stfsm_seq *seq)
+{
+	seq->seq_opc[0] = (SEQ_OPC_PADS_1 |
+			   SEQ_OPC_CYCLES(8) |
+			   SEQ_OPC_OPCODE(SPINOR_OP_EN4B) |
+			   SEQ_OPC_CSDEASSERT);
+
+	seq->seq[0] = STFSM_INST_CMD1;
+	seq->seq[1] = STFSM_INST_WAIT;
+	seq->seq[2] = STFSM_INST_STOP;
+
+	seq->seq_cfg = (SEQ_CFG_PADS_1 |
+			SEQ_CFG_ERASE |
+			SEQ_CFG_READNOTWRITE |
+			SEQ_CFG_CSDEASSERT |
+			SEQ_CFG_STARTSEQ);
+
+	return 0;
+}
+
+/*
+ * [S25FLxxx] Configuration
+ */
+#define STFSM_S25FL_CONFIG_QE		(0x1 << 1)
+
+/*
+ * S25FLxxxS devices provide three ways of supporting 32-bit addressing: Bank
+ * Register, Extended Address Modes, and a 32-bit address command set.  The
+ * 32-bit address command set is used here, since it avoids any problems with
+ * entering a state that is incompatible with the SPIBoot Controller.
+ */
+static struct seq_rw_config stfsm_s25fl_read4_configs[] = {
+	{FLASH_FLAG_READ_1_4_4,  SPINOR_OP_READ_1_4_4_4B,  0, 4, 4, 0x00, 2, 4},
+	{FLASH_FLAG_READ_1_1_4,  SPINOR_OP_READ_1_1_4_4B,  0, 1, 4, 0x00, 0, 8},
+	{FLASH_FLAG_READ_1_2_2,  SPINOR_OP_READ_1_2_2_4B,  0, 2, 2, 0x00, 4, 0},
+	{FLASH_FLAG_READ_1_1_2,  SPINOR_OP_READ_1_1_2_4B,  0, 1, 2, 0x00, 0, 8},
+	{FLASH_FLAG_READ_FAST,   SPINOR_OP_READ_FAST_4B,   0, 1, 1, 0x00, 0, 8},
+	{FLASH_FLAG_READ_WRITE,  SPINOR_OP_READ_4B,        0, 1, 1, 0x00, 0, 0},
+	{0x00,                   0,                        0, 0, 0, 0x00, 0, 0},
+};
+
+static struct seq_rw_config stfsm_s25fl_write4_configs[] = {
+	{FLASH_FLAG_WRITE_1_1_4, S25FL_CMD_WRITE4_1_1_4, 1, 1, 4, 0x00, 0, 0},
+	{FLASH_FLAG_READ_WRITE,  S25FL_CMD_WRITE4,       1, 1, 1, 0x00, 0, 0},
+	{0x00,                   0,                      0, 0, 0, 0x00, 0, 0},
+};
+
+/*
+ * [W25Qxxx] Configuration
+ */
+#define W25Q_STATUS_QE			(0x1 << 1)
+
+static struct stfsm_seq stfsm_seq_read_jedec = {
+	.data_size = TRANSFER_SIZE(8),
+	.seq_opc[0] = (SEQ_OPC_PADS_1 |
+		       SEQ_OPC_CYCLES(8) |
+		       SEQ_OPC_OPCODE(SPINOR_OP_RDID)),
+	.seq = {
+		STFSM_INST_CMD1,
+		STFSM_INST_DATA_READ,
+		STFSM_INST_STOP,
+	},
+	.seq_cfg = (SEQ_CFG_PADS_1 |
+		    SEQ_CFG_READNOTWRITE |
+		    SEQ_CFG_CSDEASSERT |
+		    SEQ_CFG_STARTSEQ),
+};
+
+static struct stfsm_seq stfsm_seq_read_status_fifo = {
+	.data_size = TRANSFER_SIZE(4),
+	.seq_opc[0] = (SEQ_OPC_PADS_1 |
+		       SEQ_OPC_CYCLES(8) |
+		       SEQ_OPC_OPCODE(SPINOR_OP_RDSR)),
+	.seq = {
+		STFSM_INST_CMD1,
+		STFSM_INST_DATA_READ,
+		STFSM_INST_STOP,
+	},
+	.seq_cfg = (SEQ_CFG_PADS_1 |
+		    SEQ_CFG_READNOTWRITE |
+		    SEQ_CFG_CSDEASSERT |
+		    SEQ_CFG_STARTSEQ),
+};
+
+static struct stfsm_seq stfsm_seq_erase_sector = {
+	/* 'addr_cfg' configured during initialisation */
+	.seq_opc = {
+		(SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+		 SEQ_OPC_OPCODE(SPINOR_OP_WREN) | SEQ_OPC_CSDEASSERT),
+
+		(SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+		 SEQ_OPC_OPCODE(SPINOR_OP_SE)),
+	},
+	.seq = {
+		STFSM_INST_CMD1,
+		STFSM_INST_CMD2,
+		STFSM_INST_ADD1,
+		STFSM_INST_ADD2,
+		STFSM_INST_STOP,
+	},
+	.seq_cfg = (SEQ_CFG_PADS_1 |
+		    SEQ_CFG_READNOTWRITE |
+		    SEQ_CFG_CSDEASSERT |
+		    SEQ_CFG_STARTSEQ),
+};
+
+static struct stfsm_seq stfsm_seq_erase_chip = {
+	.seq_opc = {
+		(SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+		 SEQ_OPC_OPCODE(SPINOR_OP_WREN) | SEQ_OPC_CSDEASSERT),
+
+		(SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+		 SEQ_OPC_OPCODE(SPINOR_OP_CHIP_ERASE) | SEQ_OPC_CSDEASSERT),
+	},
+	.seq = {
+		STFSM_INST_CMD1,
+		STFSM_INST_CMD2,
+		STFSM_INST_WAIT,
+		STFSM_INST_STOP,
+	},
+	.seq_cfg = (SEQ_CFG_PADS_1 |
+		    SEQ_CFG_ERASE |
+		    SEQ_CFG_READNOTWRITE |
+		    SEQ_CFG_CSDEASSERT |
+		    SEQ_CFG_STARTSEQ),
+};
+
+static struct stfsm_seq stfsm_seq_write_status = {
+	.seq_opc[0] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+		       SEQ_OPC_OPCODE(SPINOR_OP_WREN) | SEQ_OPC_CSDEASSERT),
+	.seq_opc[1] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+		       SEQ_OPC_OPCODE(SPINOR_OP_WRSR)),
+	.seq = {
+		STFSM_INST_CMD1,
+		STFSM_INST_CMD2,
+		STFSM_INST_STA_WR1,
+		STFSM_INST_STOP,
+	},
+	.seq_cfg = (SEQ_CFG_PADS_1 |
+		    SEQ_CFG_READNOTWRITE |
+		    SEQ_CFG_CSDEASSERT |
+		    SEQ_CFG_STARTSEQ),
+};
+
+/* Dummy sequence to read one byte of data from flash into the FIFO */
+static const struct stfsm_seq stfsm_seq_load_fifo_byte = {
+	.data_size = TRANSFER_SIZE(1),
+	.seq_opc[0] = (SEQ_OPC_PADS_1 |
+		       SEQ_OPC_CYCLES(8) |
+		       SEQ_OPC_OPCODE(SPINOR_OP_RDID)),
+	.seq = {
+		STFSM_INST_CMD1,
+		STFSM_INST_DATA_READ,
+		STFSM_INST_STOP,
+	},
+	.seq_cfg = (SEQ_CFG_PADS_1 |
+		    SEQ_CFG_READNOTWRITE |
+		    SEQ_CFG_CSDEASSERT |
+		    SEQ_CFG_STARTSEQ),
+};
+
+static int stfsm_n25q_en_32bit_addr_seq(struct stfsm_seq *seq)
+{
+	seq->seq_opc[0] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+			   SEQ_OPC_OPCODE(SPINOR_OP_EN4B));
+	seq->seq_opc[1] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+			   SEQ_OPC_OPCODE(SPINOR_OP_WREN) |
+			   SEQ_OPC_CSDEASSERT);
+
+	seq->seq[0] = STFSM_INST_CMD2;
+	seq->seq[1] = STFSM_INST_CMD1;
+	seq->seq[2] = STFSM_INST_WAIT;
+	seq->seq[3] = STFSM_INST_STOP;
+
+	seq->seq_cfg = (SEQ_CFG_PADS_1 |
+			SEQ_CFG_ERASE |
+			SEQ_CFG_READNOTWRITE |
+			SEQ_CFG_CSDEASSERT |
+			SEQ_CFG_STARTSEQ);
+
+	return 0;
+}
+
+static inline int stfsm_is_idle(struct stfsm *fsm)
+{
+	return readl(fsm->base + SPI_FAST_SEQ_STA) & 0x10;
+}
+
+static inline uint32_t stfsm_fifo_available(struct stfsm *fsm)
+{
+	return (readl(fsm->base + SPI_FAST_SEQ_STA) >> 5) & 0x7f;
+}
+
+static inline void stfsm_load_seq(struct stfsm *fsm,
+				  const struct stfsm_seq *seq)
+{
+	void __iomem *dst = fsm->base + SPI_FAST_SEQ_TRANSFER_SIZE;
+	const uint32_t *src = (const uint32_t *)seq;
+	int words = sizeof(*seq) / sizeof(*src);
+
+	BUG_ON(!stfsm_is_idle(fsm));
+
+	while (words--) {
+		writel(*src, dst);
+		src++;
+		dst += 4;
+	}
+}
+
+static void stfsm_wait_seq(struct stfsm *fsm)
+{
+	unsigned long deadline;
+	int timeout = 0;
+
+	deadline = jiffies + msecs_to_jiffies(STFSM_MAX_WAIT_SEQ_MS);
+
+	while (!timeout) {
+		if (time_after_eq(jiffies, deadline))
+			timeout = 1;
+
+		if (stfsm_is_idle(fsm))
+			return;
+
+		cond_resched();
+	}
+
+	dev_err(fsm->dev, "timeout on sequence completion\n");
+}
+
+static void stfsm_read_fifo(struct stfsm *fsm, uint32_t *buf, uint32_t size)
+{
+	uint32_t remaining = size >> 2;
+	uint32_t avail;
+	uint32_t words;
+
+	dev_dbg(fsm->dev, "Reading %d bytes from FIFO\n", size);
+
+	BUG_ON((((uintptr_t)buf) & 0x3) || (size & 0x3));
+
+	while (remaining) {
+		for (;;) {
+			avail = stfsm_fifo_available(fsm);
+			if (avail)
+				break;
+			udelay(1);
+		}
+		words = min(avail, remaining);
+		remaining -= words;
+
+		readsl(fsm->base + SPI_FAST_SEQ_DATA_REG, buf, words);
+		buf += words;
+	}
+}
+
+/*
+ * Clear the data FIFO
+ *
+ * Typically, this is only required during driver initialisation, where no
+ * assumptions can be made regarding the state of the FIFO.
+ *
+ * The process of clearing the FIFO is complicated by fact that while it is
+ * possible for the FIFO to contain an arbitrary number of bytes [1], the
+ * SPI_FAST_SEQ_STA register only reports the number of complete 32-bit words
+ * present.  Furthermore, data can only be drained from the FIFO by reading
+ * complete 32-bit words.
+ *
+ * With this in mind, a two stage process is used to the clear the FIFO:
+ *
+ *     1. Read any complete 32-bit words from the FIFO, as reported by the
+ *        SPI_FAST_SEQ_STA register.
+ *
+ *     2. Mop up any remaining bytes.  At this point, it is not known if there
+ *        are 0, 1, 2, or 3 bytes in the FIFO.  To handle all cases, a dummy FSM
+ *        sequence is used to load one byte at a time, until a complete 32-bit
+ *        word is formed; at most, 4 bytes will need to be loaded.
+ *
+ * [1] It is theoretically possible for the FIFO to contain an arbitrary number
+ *     of bits.  However, since there are no known use-cases that leave
+ *     incomplete bytes in the FIFO, only words and bytes are considered here.
+ */
+static void stfsm_clear_fifo(struct stfsm *fsm)
+{
+	const struct stfsm_seq *seq = &stfsm_seq_load_fifo_byte;
+	uint32_t words, i;
+
+	/* 1. Clear any 32-bit words */
+	words = stfsm_fifo_available(fsm);
+	if (words) {
+		for (i = 0; i < words; i++)
+			readl(fsm->base + SPI_FAST_SEQ_DATA_REG);
+		dev_dbg(fsm->dev, "cleared %d words from FIFO\n", words);
+	}
+
+	/*
+	 * 2. Clear any remaining bytes
+	 *    - Load the FIFO, one byte at a time, until a complete 32-bit word
+	 *      is available.
+	 */
+	for (i = 0, words = 0; i < 4 && !words; i++) {
+		stfsm_load_seq(fsm, seq);
+		stfsm_wait_seq(fsm);
+		words = stfsm_fifo_available(fsm);
+	}
+
+	/*    - A single word must be available now */
+	if (words != 1) {
+		dev_err(fsm->dev, "failed to clear bytes from the data FIFO\n");
+		return;
+	}
+
+	/*    - Read the 32-bit word */
+	readl(fsm->base + SPI_FAST_SEQ_DATA_REG);
+
+	dev_dbg(fsm->dev, "cleared %d byte(s) from the data FIFO\n", 4 - i);
+}
+
+static int stfsm_write_fifo(struct stfsm *fsm, const uint32_t *buf,
+			    uint32_t size)
+{
+	uint32_t words = size >> 2;
+
+	dev_dbg(fsm->dev, "writing %d bytes to FIFO\n", size);
+
+	BUG_ON((((uintptr_t)buf) & 0x3) || (size & 0x3));
+
+	writesl(fsm->base + SPI_FAST_SEQ_DATA_REG, buf, words);
+
+	return size;
+}
+
+static int stfsm_enter_32bit_addr(struct stfsm *fsm, int enter)
+{
+	struct stfsm_seq *seq = &fsm->stfsm_seq_en_32bit_addr;
+	uint32_t cmd = enter ? SPINOR_OP_EN4B : SPINOR_OP_EX4B;
+
+	seq->seq_opc[0] = (SEQ_OPC_PADS_1 |
+			   SEQ_OPC_CYCLES(8) |
+			   SEQ_OPC_OPCODE(cmd) |
+			   SEQ_OPC_CSDEASSERT);
+
+	stfsm_load_seq(fsm, seq);
+
+	stfsm_wait_seq(fsm);
+
+	return 0;
+}
+
+static uint8_t stfsm_wait_busy(struct stfsm *fsm)
+{
+	struct stfsm_seq *seq = &stfsm_seq_read_status_fifo;
+	unsigned long deadline;
+	uint32_t status;
+	int timeout = 0;
+
+	/* Use RDRS1 */
+	seq->seq_opc[0] = (SEQ_OPC_PADS_1 |
+			   SEQ_OPC_CYCLES(8) |
+			   SEQ_OPC_OPCODE(SPINOR_OP_RDSR));
+
+	/* Load read_status sequence */
+	stfsm_load_seq(fsm, seq);
+
+	/*
+	 * Repeat until busy bit is deasserted, or timeout, or error (S25FLxxxS)
+	 */
+	deadline = jiffies + FLASH_MAX_BUSY_WAIT;
+	while (!timeout) {
+		if (time_after_eq(jiffies, deadline))
+			timeout = 1;
+
+		stfsm_wait_seq(fsm);
+
+		stfsm_read_fifo(fsm, &status, 4);
+
+		if ((status & FLASH_STATUS_BUSY) == 0)
+			return 0;
+
+		if ((fsm->configuration & CFG_S25FL_CHECK_ERROR_FLAGS) &&
+		    ((status & S25FL_STATUS_P_ERR) ||
+		     (status & S25FL_STATUS_E_ERR)))
+			return (uint8_t)(status & 0xff);
+
+		if (!timeout)
+			/* Restart */
+			writel(seq->seq_cfg, fsm->base + SPI_FAST_SEQ_CFG);
+
+		cond_resched();
+	}
+
+	dev_err(fsm->dev, "timeout on wait_busy\n");
+
+	return FLASH_STATUS_TIMEOUT;
+}
+
+static int stfsm_read_status(struct stfsm *fsm, uint8_t cmd,
+			     uint8_t *data, int bytes)
+{
+	struct stfsm_seq *seq = &stfsm_seq_read_status_fifo;
+	uint32_t tmp;
+	uint8_t *t = (uint8_t *)&tmp;
+	int i;
+
+	dev_dbg(fsm->dev, "read 'status' register [0x%02x], %d byte(s)\n",
+		cmd, bytes);
+
+	BUG_ON(bytes != 1 && bytes != 2);
+
+	seq->seq_opc[0] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+			   SEQ_OPC_OPCODE(cmd));
+
+	stfsm_load_seq(fsm, seq);
+
+	stfsm_read_fifo(fsm, &tmp, 4);
+
+	for (i = 0; i < bytes; i++)
+		data[i] = t[i];
+
+	stfsm_wait_seq(fsm);
+
+	return 0;
+}
+
+static int stfsm_write_status(struct stfsm *fsm, uint8_t cmd,
+			    uint16_t data, int bytes, int wait_busy)
+{
+	struct stfsm_seq *seq = &stfsm_seq_write_status;
+
+	dev_dbg(fsm->dev,
+		"write 'status' register [0x%02x], %d byte(s), 0x%04x\n"
+		" %s wait-busy\n", cmd, bytes, data, wait_busy ? "with" : "no");
+
+	BUG_ON(bytes != 1 && bytes != 2);
+
+	seq->seq_opc[1] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+			   SEQ_OPC_OPCODE(cmd));
+
+	seq->status = (uint32_t)data | STA_PADS_1 | STA_CSDEASSERT;
+	seq->seq[2] = (bytes == 1) ? STFSM_INST_STA_WR1 : STFSM_INST_STA_WR1_2;
+
+	stfsm_load_seq(fsm, seq);
+
+	stfsm_wait_seq(fsm);
+
+	if (wait_busy)
+		stfsm_wait_busy(fsm);
+
+	return 0;
+}
+
+/*
+ * SoC reset on 'boot-from-spi' systems
+ *
+ * Certain modes of operation cause the Flash device to enter a particular state
+ * for a period of time (e.g. 'Erase Sector', 'Quad Enable', and 'Enter 32-bit
+ * Addr' commands).  On boot-from-spi systems, it is important to consider what
+ * happens if a warm reset occurs during this period.  The SPIBoot controller
+ * assumes that Flash device is in its default reset state, 24-bit address mode,
+ * and ready to accept commands.  This can be achieved using some form of
+ * on-board logic/controller to force a device POR in response to a SoC-level
+ * reset or by making use of the device reset signal if available (limited
+ * number of devices only).
+ *
+ * Failure to take such precautions can cause problems following a warm reset.
+ * For some operations (e.g. ERASE), there is little that can be done.  For
+ * other modes of operation (e.g. 32-bit addressing), options are often
+ * available that can help minimise the window in which a reset could cause a
+ * problem.
+ *
+ */
+static bool stfsm_can_handle_soc_reset(struct stfsm *fsm)
+{
+	/* Reset signal is available on the board and supported by the device */
+	if (fsm->reset_signal && fsm->info->flags & FLASH_FLAG_RESET)
+		return true;
+
+	/* Board-level logic forces a power-on-reset */
+	if (fsm->reset_por)
+		return true;
+
+	/* Reset is not properly handled and may result in failure to reboot */
+	return false;
+}
+
+/* Configure 'addr_cfg' according to addressing mode */
+static void stfsm_prepare_erasesec_seq(struct stfsm *fsm,
+				       struct stfsm_seq *seq)
+{
+	int addr1_cycles = fsm->info->flags & FLASH_FLAG_32BIT_ADDR ? 16 : 8;
+
+	seq->addr_cfg = (ADR_CFG_CYCLES_ADD1(addr1_cycles) |
+			 ADR_CFG_PADS_1_ADD1 |
+			 ADR_CFG_CYCLES_ADD2(16) |
+			 ADR_CFG_PADS_1_ADD2 |
+			 ADR_CFG_CSDEASSERT_ADD2);
+}
+
+/* Search for preferred configuration based on available flags */
+static struct seq_rw_config *
+stfsm_search_seq_rw_configs(struct stfsm *fsm,
+			    struct seq_rw_config cfgs[])
+{
+	struct seq_rw_config *config;
+	int flags = fsm->info->flags;
+
+	for (config = cfgs; config->cmd != 0; config++)
+		if ((config->flags & flags) == config->flags)
+			return config;
+
+	return NULL;
+}
+
+/* Prepare a READ/WRITE sequence according to configuration parameters */
+static void stfsm_prepare_rw_seq(struct stfsm *fsm,
+				 struct stfsm_seq *seq,
+				 struct seq_rw_config *cfg)
+{
+	int addr1_cycles, addr2_cycles;
+	int i = 0;
+
+	memset(seq, 0, sizeof(*seq));
+
+	/* Add READ/WRITE OPC  */
+	seq->seq_opc[i++] = (SEQ_OPC_PADS_1 |
+			     SEQ_OPC_CYCLES(8) |
+			     SEQ_OPC_OPCODE(cfg->cmd));
+
+	/* Add WREN OPC for a WRITE sequence */
+	if (cfg->write)
+		seq->seq_opc[i++] = (SEQ_OPC_PADS_1 |
+				     SEQ_OPC_CYCLES(8) |
+				     SEQ_OPC_OPCODE(SPINOR_OP_WREN) |
+				     SEQ_OPC_CSDEASSERT);
+
+	/* Address configuration (24 or 32-bit addresses) */
+	addr1_cycles  = (fsm->info->flags & FLASH_FLAG_32BIT_ADDR) ? 16 : 8;
+	addr1_cycles /= cfg->addr_pads;
+	addr2_cycles  = 16 / cfg->addr_pads;
+	seq->addr_cfg = ((addr1_cycles & 0x3f) << 0 |	/* ADD1 cycles */
+			 (cfg->addr_pads - 1) << 6 |	/* ADD1 pads */
+			 (addr2_cycles & 0x3f) << 16 |	/* ADD2 cycles */
+			 ((cfg->addr_pads - 1) << 22));	/* ADD2 pads */
+
+	/* Data/Sequence configuration */
+	seq->seq_cfg = ((cfg->data_pads - 1) << 16 |
+			SEQ_CFG_STARTSEQ |
+			SEQ_CFG_CSDEASSERT);
+	if (!cfg->write)
+		seq->seq_cfg |= SEQ_CFG_READNOTWRITE;
+
+	/* Mode configuration (no. of pads taken from addr cfg) */
+	seq->mode = ((cfg->mode_data & 0xff) << 0 |	/* data */
+		     (cfg->mode_cycles & 0x3f) << 16 |	/* cycles */
+		     (cfg->addr_pads - 1) << 22);	/* pads */
+
+	/* Dummy configuration (no. of pads taken from addr cfg) */
+	seq->dummy = ((cfg->dummy_cycles & 0x3f) << 16 |	/* cycles */
+		      (cfg->addr_pads - 1) << 22);		/* pads */
+
+
+	/* Instruction sequence */
+	i = 0;
+	if (cfg->write)
+		seq->seq[i++] = STFSM_INST_CMD2;
+
+	seq->seq[i++] = STFSM_INST_CMD1;
+
+	seq->seq[i++] = STFSM_INST_ADD1;
+	seq->seq[i++] = STFSM_INST_ADD2;
+
+	if (cfg->mode_cycles)
+		seq->seq[i++] = STFSM_INST_MODE;
+
+	if (cfg->dummy_cycles)
+		seq->seq[i++] = STFSM_INST_DUMMY;
+
+	seq->seq[i++] =
+		cfg->write ? STFSM_INST_DATA_WRITE : STFSM_INST_DATA_READ;
+	seq->seq[i++] = STFSM_INST_STOP;
+}
+
+static int stfsm_search_prepare_rw_seq(struct stfsm *fsm,
+				       struct stfsm_seq *seq,
+				       struct seq_rw_config *cfgs)
+{
+	struct seq_rw_config *config;
+
+	config = stfsm_search_seq_rw_configs(fsm, cfgs);
+	if (!config) {
+		dev_err(fsm->dev, "failed to find suitable config\n");
+		return -EINVAL;
+	}
+
+	stfsm_prepare_rw_seq(fsm, seq, config);
+
+	return 0;
+}
+
+/* Prepare a READ/WRITE/ERASE 'default' sequences */
+static int stfsm_prepare_rwe_seqs_default(struct stfsm *fsm)
+{
+	uint32_t flags = fsm->info->flags;
+	int ret;
+
+	/* Configure 'READ' sequence */
+	ret = stfsm_search_prepare_rw_seq(fsm, &fsm->stfsm_seq_read,
+					  default_read_configs);
+	if (ret) {
+		dev_err(fsm->dev,
+			"failed to prep READ sequence with flags [0x%08x]\n",
+			flags);
+		return ret;
+	}
+
+	/* Configure 'WRITE' sequence */
+	ret = stfsm_search_prepare_rw_seq(fsm, &fsm->stfsm_seq_write,
+					  default_write_configs);
+	if (ret) {
+		dev_err(fsm->dev,
+			"failed to prep WRITE sequence with flags [0x%08x]\n",
+			flags);
+		return ret;
+	}
+
+	/* Configure 'ERASE_SECTOR' sequence */
+	stfsm_prepare_erasesec_seq(fsm, &stfsm_seq_erase_sector);
+
+	return 0;
+}
+
+static int stfsm_mx25_config(struct stfsm *fsm)
+{
+	uint32_t flags = fsm->info->flags;
+	uint32_t data_pads;
+	uint8_t sta;
+	int ret;
+	bool soc_reset;
+
+	/*
+	 * Use default READ/WRITE sequences
+	 */
+	ret = stfsm_prepare_rwe_seqs_default(fsm);
+	if (ret)
+		return ret;
+
+	/*
+	 * Configure 32-bit Address Support
+	 */
+	if (flags & FLASH_FLAG_32BIT_ADDR) {
+		/* Configure 'enter_32bitaddr' FSM sequence */
+		stfsm_mx25_en_32bit_addr_seq(&fsm->stfsm_seq_en_32bit_addr);
+
+		soc_reset = stfsm_can_handle_soc_reset(fsm);
+		if (soc_reset || !fsm->booted_from_spi)
+			/* If we can handle SoC resets, we enable 32-bit address
+			 * mode pervasively */
+			stfsm_enter_32bit_addr(fsm, 1);
+
+		else
+			/* Else, enable/disable 32-bit addressing before/after
+			 * each operation */
+			fsm->configuration = (CFG_READ_TOGGLE_32BIT_ADDR |
+					      CFG_WRITE_TOGGLE_32BIT_ADDR |
+					      CFG_ERASESEC_TOGGLE_32BIT_ADDR);
+	}
+
+	/* Check status of 'QE' bit, update if required. */
+	stfsm_read_status(fsm, SPINOR_OP_RDSR, &sta, 1);
+	data_pads = ((fsm->stfsm_seq_read.seq_cfg >> 16) & 0x3) + 1;
+	if (data_pads == 4) {
+		if (!(sta & MX25_STATUS_QE)) {
+			/* Set 'QE' */
+			sta |= MX25_STATUS_QE;
+
+			stfsm_write_status(fsm, SPINOR_OP_WRSR, sta, 1, 1);
+		}
+	} else {
+		if (sta & MX25_STATUS_QE) {
+			/* Clear 'QE' */
+			sta &= ~MX25_STATUS_QE;
+
+			stfsm_write_status(fsm, SPINOR_OP_WRSR, sta, 1, 1);
+		}
+	}
+
+	return 0;
+}
+
+static int stfsm_n25q_config(struct stfsm *fsm)
+{
+	uint32_t flags = fsm->info->flags;
+	uint8_t vcr;
+	int ret = 0;
+	bool soc_reset;
+
+	/* Configure 'READ' sequence */
+	if (flags & FLASH_FLAG_32BIT_ADDR)
+		ret = stfsm_search_prepare_rw_seq(fsm, &fsm->stfsm_seq_read,
+						  n25q_read4_configs);
+	else
+		ret = stfsm_search_prepare_rw_seq(fsm, &fsm->stfsm_seq_read,
+						  n25q_read3_configs);
+	if (ret) {
+		dev_err(fsm->dev,
+			"failed to prepare READ sequence with flags [0x%08x]\n",
+			flags);
+		return ret;
+	}
+
+	/* Configure 'WRITE' sequence (default configs) */
+	ret = stfsm_search_prepare_rw_seq(fsm, &fsm->stfsm_seq_write,
+					  default_write_configs);
+	if (ret) {
+		dev_err(fsm->dev,
+			"preparing WRITE sequence using flags [0x%08x] failed\n",
+			flags);
+		return ret;
+	}
+
+	/* * Configure 'ERASE_SECTOR' sequence */
+	stfsm_prepare_erasesec_seq(fsm, &stfsm_seq_erase_sector);
+
+	/* Configure 32-bit address support */
+	if (flags & FLASH_FLAG_32BIT_ADDR) {
+		stfsm_n25q_en_32bit_addr_seq(&fsm->stfsm_seq_en_32bit_addr);
+
+		soc_reset = stfsm_can_handle_soc_reset(fsm);
+		if (soc_reset || !fsm->booted_from_spi) {
+			/*
+			 * If we can handle SoC resets, we enable 32-bit
+			 * address mode pervasively
+			 */
+			stfsm_enter_32bit_addr(fsm, 1);
+		} else {
+			/*
+			 * If not, enable/disable for WRITE and ERASE
+			 * operations (READ uses special commands)
+			 */
+			fsm->configuration = (CFG_WRITE_TOGGLE_32BIT_ADDR |
+					      CFG_ERASESEC_TOGGLE_32BIT_ADDR);
+		}
+	}
+
+	/*
+	 * Configure device to use 8 dummy cycles
+	 */
+	vcr = (N25Q_VCR_DUMMY_CYCLES(8) | N25Q_VCR_XIP_DISABLED |
+	       N25Q_VCR_WRAP_CONT);
+	stfsm_write_status(fsm, N25Q_CMD_WRVCR, vcr, 1, 0);
+
+	return 0;
+}
+
+static void stfsm_s25fl_prepare_erasesec_seq_32(struct stfsm_seq *seq)
+{
+	seq->seq_opc[1] = (SEQ_OPC_PADS_1 |
+			   SEQ_OPC_CYCLES(8) |
+			   SEQ_OPC_OPCODE(S25FL_CMD_SE4));
+
+	seq->addr_cfg = (ADR_CFG_CYCLES_ADD1(16) |
+			 ADR_CFG_PADS_1_ADD1 |
+			 ADR_CFG_CYCLES_ADD2(16) |
+			 ADR_CFG_PADS_1_ADD2 |
+			 ADR_CFG_CSDEASSERT_ADD2);
+}
+
+static void stfsm_s25fl_read_dyb(struct stfsm *fsm, uint32_t offs, uint8_t *dby)
+{
+	uint32_t tmp;
+	struct stfsm_seq seq = {
+		.data_size = TRANSFER_SIZE(4),
+		.seq_opc[0] = (SEQ_OPC_PADS_1 |
+			       SEQ_OPC_CYCLES(8) |
+			       SEQ_OPC_OPCODE(S25FL_CMD_DYBRD)),
+		.addr_cfg = (ADR_CFG_CYCLES_ADD1(16) |
+			     ADR_CFG_PADS_1_ADD1 |
+			     ADR_CFG_CYCLES_ADD2(16) |
+			     ADR_CFG_PADS_1_ADD2),
+		.addr1 = (offs >> 16) & 0xffff,
+		.addr2 = offs & 0xffff,
+		.seq = {
+			STFSM_INST_CMD1,
+			STFSM_INST_ADD1,
+			STFSM_INST_ADD2,
+			STFSM_INST_DATA_READ,
+			STFSM_INST_STOP,
+		},
+		.seq_cfg = (SEQ_CFG_PADS_1 |
+			    SEQ_CFG_READNOTWRITE |
+			    SEQ_CFG_CSDEASSERT |
+			    SEQ_CFG_STARTSEQ),
+	};
+
+	stfsm_load_seq(fsm, &seq);
+
+	stfsm_read_fifo(fsm, &tmp, 4);
+
+	*dby = (uint8_t)(tmp >> 24);
+
+	stfsm_wait_seq(fsm);
+}
+
+static void stfsm_s25fl_write_dyb(struct stfsm *fsm, uint32_t offs, uint8_t dby)
+{
+	struct stfsm_seq seq = {
+		.seq_opc[0] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+			       SEQ_OPC_OPCODE(SPINOR_OP_WREN) |
+			       SEQ_OPC_CSDEASSERT),
+		.seq_opc[1] = (SEQ_OPC_PADS_1 | SEQ_OPC_CYCLES(8) |
+			       SEQ_OPC_OPCODE(S25FL_CMD_DYBWR)),
+		.addr_cfg = (ADR_CFG_CYCLES_ADD1(16) |
+			     ADR_CFG_PADS_1_ADD1 |
+			     ADR_CFG_CYCLES_ADD2(16) |
+			     ADR_CFG_PADS_1_ADD2),
+		.status = (uint32_t)dby | STA_PADS_1 | STA_CSDEASSERT,
+		.addr1 = (offs >> 16) & 0xffff,
+		.addr2 = offs & 0xffff,
+		.seq = {
+			STFSM_INST_CMD1,
+			STFSM_INST_CMD2,
+			STFSM_INST_ADD1,
+			STFSM_INST_ADD2,
+			STFSM_INST_STA_WR1,
+			STFSM_INST_STOP,
+		},
+		.seq_cfg = (SEQ_CFG_PADS_1 |
+			    SEQ_CFG_READNOTWRITE |
+			    SEQ_CFG_CSDEASSERT |
+			    SEQ_CFG_STARTSEQ),
+	};
+
+	stfsm_load_seq(fsm, &seq);
+	stfsm_wait_seq(fsm);
+
+	stfsm_wait_busy(fsm);
+}
+
+static int stfsm_s25fl_clear_status_reg(struct stfsm *fsm)
+{
+	struct stfsm_seq seq = {
+		.seq_opc[0] = (SEQ_OPC_PADS_1 |
+			       SEQ_OPC_CYCLES(8) |
+			       SEQ_OPC_OPCODE(S25FL_CMD_CLSR) |
+			       SEQ_OPC_CSDEASSERT),
+		.seq_opc[1] = (SEQ_OPC_PADS_1 |
+			       SEQ_OPC_CYCLES(8) |
+			       SEQ_OPC_OPCODE(SPINOR_OP_WRDI) |
+			       SEQ_OPC_CSDEASSERT),
+		.seq = {
+			STFSM_INST_CMD1,
+			STFSM_INST_CMD2,
+			STFSM_INST_WAIT,
+			STFSM_INST_STOP,
+		},
+		.seq_cfg = (SEQ_CFG_PADS_1 |
+			    SEQ_CFG_ERASE |
+			    SEQ_CFG_READNOTWRITE |
+			    SEQ_CFG_CSDEASSERT |
+			    SEQ_CFG_STARTSEQ),
+	};
+
+	stfsm_load_seq(fsm, &seq);
+
+	stfsm_wait_seq(fsm);
+
+	return 0;
+}
+
+static int stfsm_s25fl_config(struct stfsm *fsm)
+{
+	struct flash_info *info = fsm->info;
+	uint32_t flags = info->flags;
+	uint32_t data_pads;
+	uint32_t offs;
+	uint16_t sta_wr;
+	uint8_t sr1, cr1, dyb;
+	int update_sr = 0;
+	int ret;
+
+	if (flags & FLASH_FLAG_32BIT_ADDR) {
+		/*
+		 * Prepare Read/Write/Erase sequences according to S25FLxxx
+		 * 32-bit address command set
+		 */
+		ret = stfsm_search_prepare_rw_seq(fsm, &fsm->stfsm_seq_read,
+						  stfsm_s25fl_read4_configs);
+		if (ret)
+			return ret;
+
+		ret = stfsm_search_prepare_rw_seq(fsm, &fsm->stfsm_seq_write,
+						  stfsm_s25fl_write4_configs);
+		if (ret)
+			return ret;
+
+		stfsm_s25fl_prepare_erasesec_seq_32(&stfsm_seq_erase_sector);
+
+	} else {
+		/* Use default configurations for 24-bit addressing */
+		ret = stfsm_prepare_rwe_seqs_default(fsm);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * For devices that support 'DYB' sector locking, check lock status and
+	 * unlock sectors if necessary (some variants power-on with sectors
+	 * locked by default)
+	 */
+	if (flags & FLASH_FLAG_DYB_LOCKING) {
+		offs = 0;
+		for (offs = 0; offs < info->sector_size * info->n_sectors;) {
+			stfsm_s25fl_read_dyb(fsm, offs, &dyb);
+			if (dyb == 0x00)
+				stfsm_s25fl_write_dyb(fsm, offs, 0xff);
+
+			/* Handle bottom/top 4KiB parameter sectors */
+			if ((offs < info->sector_size * 2) ||
+			    (offs >= (info->sector_size - info->n_sectors * 4)))
+				offs += 0x1000;
+			else
+				offs += 0x10000;
+		}
+	}
+
+	/* Check status of 'QE' bit, update if required. */
+	stfsm_read_status(fsm, SPINOR_OP_RDCR, &cr1, 1);
+	data_pads = ((fsm->stfsm_seq_read.seq_cfg >> 16) & 0x3) + 1;
+	if (data_pads == 4) {
+		if (!(cr1 & STFSM_S25FL_CONFIG_QE)) {
+			/* Set 'QE' */
+			cr1 |= STFSM_S25FL_CONFIG_QE;
+
+			update_sr = 1;
+		}
+	} else {
+		if (cr1 & STFSM_S25FL_CONFIG_QE) {
+			/* Clear 'QE' */
+			cr1 &= ~STFSM_S25FL_CONFIG_QE;
+
+			update_sr = 1;
+		}
+	}
+	if (update_sr) {
+		stfsm_read_status(fsm, SPINOR_OP_RDSR, &sr1, 1);
+		sta_wr = ((uint16_t)cr1  << 8) | sr1;
+		stfsm_write_status(fsm, SPINOR_OP_WRSR, sta_wr, 2, 1);
+	}
+
+	/*
+	 * S25FLxxx devices support Program and Error error flags.
+	 * Configure driver to check flags and clear if necessary.
+	 */
+	fsm->configuration |= CFG_S25FL_CHECK_ERROR_FLAGS;
+
+	return 0;
+}
+
+static int stfsm_w25q_config(struct stfsm *fsm)
+{
+	uint32_t data_pads;
+	uint8_t sr1, sr2;
+	uint16_t sr_wr;
+	int update_sr = 0;
+	int ret;
+
+	ret = stfsm_prepare_rwe_seqs_default(fsm);
+	if (ret)
+		return ret;
+
+	/* Check status of 'QE' bit, update if required. */
+	stfsm_read_status(fsm, SPINOR_OP_RDCR, &sr2, 1);
+	data_pads = ((fsm->stfsm_seq_read.seq_cfg >> 16) & 0x3) + 1;
+	if (data_pads == 4) {
+		if (!(sr2 & W25Q_STATUS_QE)) {
+			/* Set 'QE' */
+			sr2 |= W25Q_STATUS_QE;
+			update_sr = 1;
+		}
+	} else {
+		if (sr2 & W25Q_STATUS_QE) {
+			/* Clear 'QE' */
+			sr2 &= ~W25Q_STATUS_QE;
+			update_sr = 1;
+		}
+	}
+	if (update_sr) {
+		/* Write status register */
+		stfsm_read_status(fsm, SPINOR_OP_RDSR, &sr1, 1);
+		sr_wr = ((uint16_t)sr2 << 8) | sr1;
+		stfsm_write_status(fsm, SPINOR_OP_WRSR, sr_wr, 2, 1);
+	}
+
+	return 0;
+}
+
+static int stfsm_read(struct stfsm *fsm, uint8_t *buf, uint32_t size,
+		      uint32_t offset)
+{
+	struct stfsm_seq *seq = &fsm->stfsm_seq_read;
+	uint32_t data_pads;
+	uint32_t read_mask;
+	uint32_t size_ub;
+	uint32_t size_lb;
+	uint32_t size_mop;
+	uint32_t tmp[4];
+	uint32_t page_buf[FLASH_PAGESIZE_32];
+	uint8_t *p;
+
+	dev_dbg(fsm->dev, "reading %d bytes from 0x%08x\n", size, offset);
+
+	/* Enter 32-bit address mode, if required */
+	if (fsm->configuration & CFG_READ_TOGGLE_32BIT_ADDR)
+		stfsm_enter_32bit_addr(fsm, 1);
+
+	/* Must read in multiples of 32 cycles (or 32*pads/8 Bytes) */
+	data_pads = ((seq->seq_cfg >> 16) & 0x3) + 1;
+	read_mask = (data_pads << 2) - 1;
+
+	/* Handle non-aligned buf */
+	p = ((uintptr_t)buf & 0x3) ? (uint8_t *)page_buf : buf;
+
+	/* Handle non-aligned size */
+	size_ub = (size + read_mask) & ~read_mask;
+	size_lb = size & ~read_mask;
+	size_mop = size & read_mask;
+
+	seq->data_size = TRANSFER_SIZE(size_ub);
+	seq->addr1 = (offset >> 16) & 0xffff;
+	seq->addr2 = offset & 0xffff;
+
+	stfsm_load_seq(fsm, seq);
+
+	if (size_lb)
+		stfsm_read_fifo(fsm, (uint32_t *)p, size_lb);
+
+	if (size_mop) {
+		stfsm_read_fifo(fsm, tmp, read_mask + 1);
+		memcpy(p + size_lb, &tmp, size_mop);
+	}
+
+	/* Handle non-aligned buf */
+	if ((uintptr_t)buf & 0x3)
+		memcpy(buf, page_buf, size);
+
+	/* Wait for sequence to finish */
+	stfsm_wait_seq(fsm);
+
+	stfsm_clear_fifo(fsm);
+
+	/* Exit 32-bit address mode, if required */
+	if (fsm->configuration & CFG_READ_TOGGLE_32BIT_ADDR)
+		stfsm_enter_32bit_addr(fsm, 0);
+
+	return 0;
+}
+
+static int stfsm_write(struct stfsm *fsm, const uint8_t *buf,
+		       uint32_t size, uint32_t offset)
+{
+	struct stfsm_seq *seq = &fsm->stfsm_seq_write;
+	uint32_t data_pads;
+	uint32_t write_mask;
+	uint32_t size_ub;
+	uint32_t size_lb;
+	uint32_t size_mop;
+	uint32_t tmp[4];
+	uint32_t i;
+	uint32_t page_buf[FLASH_PAGESIZE_32];
+	uint8_t *t = (uint8_t *)&tmp;
+	const uint8_t *p;
+	int ret;
+
+	dev_dbg(fsm->dev, "writing %d bytes to 0x%08x\n", size, offset);
+
+	/* Enter 32-bit address mode, if required */
+	if (fsm->configuration & CFG_WRITE_TOGGLE_32BIT_ADDR)
+		stfsm_enter_32bit_addr(fsm, 1);
+
+	/* Must write in multiples of 32 cycles (or 32*pads/8 bytes) */
+	data_pads = ((seq->seq_cfg >> 16) & 0x3) + 1;
+	write_mask = (data_pads << 2) - 1;
+
+	/* Handle non-aligned buf */
+	if ((uintptr_t)buf & 0x3) {
+		memcpy(page_buf, buf, size);
+		p = (uint8_t *)page_buf;
+	} else {
+		p = buf;
+	}
+
+	/* Handle non-aligned size */
+	size_ub = (size + write_mask) & ~write_mask;
+	size_lb = size & ~write_mask;
+	size_mop = size & write_mask;
+
+	seq->data_size = TRANSFER_SIZE(size_ub);
+	seq->addr1 = (offset >> 16) & 0xffff;
+	seq->addr2 = offset & 0xffff;
+
+	/* Need to set FIFO to write mode, before writing data to FIFO (see
+	 * GNBvb79594)
+	 */
+	writel(0x00040000, fsm->base + SPI_FAST_SEQ_CFG);
+
+	/*
+	 * Before writing data to the FIFO, apply a small delay to allow a
+	 * potential change of FIFO direction to complete.
+	 */
+	if (fsm->fifo_dir_delay == 0)
+		readl(fsm->base + SPI_FAST_SEQ_CFG);
+	else
+		udelay(fsm->fifo_dir_delay);
+
+
+	/* Write data to FIFO, before starting sequence (see GNBvd79593) */
+	if (size_lb) {
+		stfsm_write_fifo(fsm, (uint32_t *)p, size_lb);
+		p += size_lb;
+	}
+
+	/* Handle non-aligned size */
+	if (size_mop) {
+		memset(t, 0xff, write_mask + 1);	/* fill with 0xff's */
+		for (i = 0; i < size_mop; i++)
+			t[i] = *p++;
+
+		stfsm_write_fifo(fsm, tmp, write_mask + 1);
+	}
+
+	/* Start sequence */
+	stfsm_load_seq(fsm, seq);
+
+	/* Wait for sequence to finish */
+	stfsm_wait_seq(fsm);
+
+	/* Wait for completion */
+	ret = stfsm_wait_busy(fsm);
+	if (ret && fsm->configuration & CFG_S25FL_CHECK_ERROR_FLAGS)
+		stfsm_s25fl_clear_status_reg(fsm);
+
+	/* Exit 32-bit address mode, if required */
+	if (fsm->configuration & CFG_WRITE_TOGGLE_32BIT_ADDR)
+		stfsm_enter_32bit_addr(fsm, 0);
+
+	return 0;
+}
+
+/*
+ * Read an address range from the flash chip. The address range
+ * may be any size provided it is within the physical boundaries.
+ */
+static int stfsm_mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
+			  size_t *retlen, u_char *buf)
+{
+	struct stfsm *fsm = dev_get_drvdata(mtd->dev.parent);
+	uint32_t bytes;
+
+	dev_dbg(fsm->dev, "%s from 0x%08x, len %zd\n",
+		__func__, (u32)from, len);
+
+	mutex_lock(&fsm->lock);
+
+	while (len > 0) {
+		bytes = min_t(size_t, len, FLASH_PAGESIZE);
+
+		stfsm_read(fsm, buf, bytes, from);
+
+		buf += bytes;
+		from += bytes;
+		len -= bytes;
+
+		*retlen += bytes;
+	}
+
+	mutex_unlock(&fsm->lock);
+
+	return 0;
+}
+
+static int stfsm_erase_sector(struct stfsm *fsm, uint32_t offset)
+{
+	struct stfsm_seq *seq = &stfsm_seq_erase_sector;
+	int ret;
+
+	dev_dbg(fsm->dev, "erasing sector at 0x%08x\n", offset);
+
+	/* Enter 32-bit address mode, if required */
+	if (fsm->configuration & CFG_ERASESEC_TOGGLE_32BIT_ADDR)
+		stfsm_enter_32bit_addr(fsm, 1);
+
+	seq->addr1 = (offset >> 16) & 0xffff;
+	seq->addr2 = offset & 0xffff;
+
+	stfsm_load_seq(fsm, seq);
+
+	stfsm_wait_seq(fsm);
+
+	/* Wait for completion */
+	ret = stfsm_wait_busy(fsm);
+	if (ret && fsm->configuration & CFG_S25FL_CHECK_ERROR_FLAGS)
+		stfsm_s25fl_clear_status_reg(fsm);
+
+	/* Exit 32-bit address mode, if required */
+	if (fsm->configuration & CFG_ERASESEC_TOGGLE_32BIT_ADDR)
+		stfsm_enter_32bit_addr(fsm, 0);
+
+	return ret;
+}
+
+static int stfsm_erase_chip(struct stfsm *fsm)
+{
+	const struct stfsm_seq *seq = &stfsm_seq_erase_chip;
+
+	dev_dbg(fsm->dev, "erasing chip\n");
+
+	stfsm_load_seq(fsm, seq);
+
+	stfsm_wait_seq(fsm);
+
+	return stfsm_wait_busy(fsm);
+}
+
+/*
+ * Write an address range to the flash chip.  Data must be written in
+ * FLASH_PAGESIZE chunks.  The address range may be any size provided
+ * it is within the physical boundaries.
+ */
+static int stfsm_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
+			   size_t *retlen, const u_char *buf)
+{
+	struct stfsm *fsm = dev_get_drvdata(mtd->dev.parent);
+
+	u32 page_offs;
+	u32 bytes;
+	uint8_t *b = (uint8_t *)buf;
+	int ret = 0;
+
+	dev_dbg(fsm->dev, "%s to 0x%08x, len %zd\n", __func__, (u32)to, len);
+
+	/* Offset within page */
+	page_offs = to % FLASH_PAGESIZE;
+
+	mutex_lock(&fsm->lock);
+
+	while (len) {
+		/* Write up to page boundary */
+		bytes = min_t(size_t, FLASH_PAGESIZE - page_offs, len);
+
+		ret = stfsm_write(fsm, b, bytes, to);
+		if (ret)
+			goto out1;
+
+		b += bytes;
+		len -= bytes;
+		to += bytes;
+
+		/* We are now page-aligned */
+		page_offs = 0;
+
+		*retlen += bytes;
+
+	}
+
+out1:
+	mutex_unlock(&fsm->lock);
+
+	return ret;
+}
+
+/*
+ * Erase an address range on the flash chip. The address range may extend
+ * one or more erase sectors.  Return an error is there is a problem erasing.
+ */
+static int stfsm_mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct stfsm *fsm = dev_get_drvdata(mtd->dev.parent);
+	u32 addr, len;
+	int ret;
+
+	dev_dbg(fsm->dev, "%s at 0x%llx, len %lld\n", __func__,
+		(long long)instr->addr, (long long)instr->len);
+
+	addr = instr->addr;
+	len = instr->len;
+
+	mutex_lock(&fsm->lock);
+
+	/* Whole-chip erase? */
+	if (len == mtd->size) {
+		ret = stfsm_erase_chip(fsm);
+		if (ret)
+			goto out1;
+	} else {
+		while (len) {
+			ret = stfsm_erase_sector(fsm, addr);
+			if (ret)
+				goto out1;
+
+			addr += mtd->erasesize;
+			len -= mtd->erasesize;
+		}
+	}
+
+	mutex_unlock(&fsm->lock);
+
+	return 0;
+
+out1:
+	mutex_unlock(&fsm->lock);
+
+	return ret;
+}
+
+static void stfsm_read_jedec(struct stfsm *fsm, uint8_t *jedec)
+{
+	const struct stfsm_seq *seq = &stfsm_seq_read_jedec;
+	uint32_t tmp[2];
+
+	stfsm_load_seq(fsm, seq);
+
+	stfsm_read_fifo(fsm, tmp, 8);
+
+	memcpy(jedec, tmp, 5);
+
+	stfsm_wait_seq(fsm);
+}
+
+static struct flash_info *stfsm_jedec_probe(struct stfsm *fsm)
+{
+	struct flash_info	*info;
+	u16                     ext_jedec;
+	u32			jedec;
+	u8			id[5];
+
+	stfsm_read_jedec(fsm, id);
+
+	jedec     = id[0] << 16 | id[1] << 8 | id[2];
+	/*
+	 * JEDEC also defines an optional "extended device information"
+	 * string for after vendor-specific data, after the three bytes
+	 * we use here. Supporting some chips might require using it.
+	 */
+	ext_jedec = id[3] << 8  | id[4];
+
+	dev_dbg(fsm->dev, "JEDEC =  0x%08x [%5ph]\n", jedec, id);
+
+	for (info = flash_types; info->name; info++) {
+		if (info->jedec_id == jedec) {
+			if (info->ext_id && info->ext_id != ext_jedec)
+				continue;
+			return info;
+		}
+	}
+	dev_err(fsm->dev, "Unrecognized JEDEC id %06x\n", jedec);
+
+	return NULL;
+}
+
+static int stfsm_set_mode(struct stfsm *fsm, uint32_t mode)
+{
+	int ret, timeout = 10;
+
+	/* Wait for controller to accept mode change */
+	while (--timeout) {
+		ret = readl(fsm->base + SPI_STA_MODE_CHANGE);
+		if (ret & 0x1)
+			break;
+		udelay(1);
+	}
+
+	if (!timeout)
+		return -EBUSY;
+
+	writel(mode, fsm->base + SPI_MODESELECT);
+
+	return 0;
+}
+
+static void stfsm_set_freq(struct stfsm *fsm, uint32_t spi_freq)
+{
+	uint32_t emi_freq;
+	uint32_t clk_div;
+
+	emi_freq = clk_get_rate(fsm->clk);
+
+	/*
+	 * Calculate clk_div - values between 2 and 128
+	 * Multiple of 2, rounded up
+	 */
+	clk_div = 2 * DIV_ROUND_UP(emi_freq, 2 * spi_freq);
+	if (clk_div < 2)
+		clk_div = 2;
+	else if (clk_div > 128)
+		clk_div = 128;
+
+	/*
+	 * Determine a suitable delay for the IP to complete a change of
+	 * direction of the FIFO. The required delay is related to the clock
+	 * divider used. The following heuristics are based on empirical tests,
+	 * using a 100MHz EMI clock.
+	 */
+	if (clk_div <= 4)
+		fsm->fifo_dir_delay = 0;
+	else if (clk_div <= 10)
+		fsm->fifo_dir_delay = 1;
+	else
+		fsm->fifo_dir_delay = DIV_ROUND_UP(clk_div, 10);
+
+	dev_dbg(fsm->dev, "emi_clk = %uHZ, spi_freq = %uHZ, clk_div = %u\n",
+		emi_freq, spi_freq, clk_div);
+
+	writel(clk_div, fsm->base + SPI_CLOCKDIV);
+}
+
+static int stfsm_init(struct stfsm *fsm)
+{
+	int ret;
+
+	/* Perform a soft reset of the FSM controller */
+	writel(SEQ_CFG_SWRESET, fsm->base + SPI_FAST_SEQ_CFG);
+	udelay(1);
+	writel(0, fsm->base + SPI_FAST_SEQ_CFG);
+
+	/* Set clock to 'safe' frequency initially */
+	stfsm_set_freq(fsm, STFSM_FLASH_SAFE_FREQ);
+
+	/* Switch to FSM */
+	ret = stfsm_set_mode(fsm, SPI_MODESELECT_FSM);
+	if (ret)
+		return ret;
+
+	/* Set timing parameters */
+	writel(SPI_CFG_DEVICE_ST            |
+	       SPI_CFG_DEFAULT_MIN_CS_HIGH  |
+	       SPI_CFG_DEFAULT_CS_SETUPHOLD |
+	       SPI_CFG_DEFAULT_DATA_HOLD,
+	       fsm->base + SPI_CONFIGDATA);
+	writel(STFSM_DEFAULT_WR_TIME, fsm->base + SPI_STATUS_WR_TIME_REG);
+
+	/*
+	 * Set the FSM 'WAIT' delay to the minimum workable value.  Note, for
+	 * our purposes, the WAIT instruction is used purely to achieve
+	 * "sequence validity" rather than actually implement a delay.
+	 */
+	writel(0x00000001, fsm->base + SPI_PROGRAM_ERASE_TIME);
+
+	/* Clear FIFO, just in case */
+	stfsm_clear_fifo(fsm);
+
+	return 0;
+}
+
+static void stfsm_fetch_platform_configs(struct platform_device *pdev)
+{
+	struct stfsm *fsm = platform_get_drvdata(pdev);
+	struct device_node *np = pdev->dev.of_node;
+	struct regmap *regmap;
+	uint32_t boot_device_reg;
+	uint32_t boot_device_spi;
+	uint32_t boot_device;     /* Value we read from *boot_device_reg */
+	int ret;
+
+	/* Booting from SPI NOR Flash is the default */
+	fsm->booted_from_spi = true;
+
+	regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
+	if (IS_ERR(regmap))
+		goto boot_device_fail;
+
+	fsm->reset_signal = of_property_read_bool(np, "st,reset-signal");
+
+	fsm->reset_por = of_property_read_bool(np, "st,reset-por");
+
+	/* Where in the syscon the boot device information lives */
+	ret = of_property_read_u32(np, "st,boot-device-reg", &boot_device_reg);
+	if (ret)
+		goto boot_device_fail;
+
+	/* Boot device value when booted from SPI NOR */
+	ret = of_property_read_u32(np, "st,boot-device-spi", &boot_device_spi);
+	if (ret)
+		goto boot_device_fail;
+
+	ret = regmap_read(regmap, boot_device_reg, &boot_device);
+	if (ret)
+		goto boot_device_fail;
+
+	if (boot_device != boot_device_spi)
+		fsm->booted_from_spi = false;
+
+	return;
+
+boot_device_fail:
+	dev_warn(&pdev->dev,
+		 "failed to fetch boot device, assuming boot from SPI\n");
+}
+
+static int stfsm_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct flash_info *info;
+	struct resource *res;
+	struct stfsm *fsm;
+	int ret;
+
+	if (!np) {
+		dev_err(&pdev->dev, "No DT found\n");
+		return -EINVAL;
+	}
+
+	fsm = devm_kzalloc(&pdev->dev, sizeof(*fsm), GFP_KERNEL);
+	if (!fsm)
+		return -ENOMEM;
+
+	fsm->dev = &pdev->dev;
+
+	platform_set_drvdata(pdev, fsm);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "Resource not found\n");
+		return -ENODEV;
+	}
+
+	fsm->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(fsm->base)) {
+		dev_err(&pdev->dev,
+			"Failed to reserve memory region %pR\n", res);
+		return PTR_ERR(fsm->base);
+	}
+
+	fsm->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(fsm->clk)) {
+		dev_err(fsm->dev, "Couldn't find EMI clock.\n");
+		return PTR_ERR(fsm->clk);
+	}
+
+	ret = clk_prepare_enable(fsm->clk);
+	if (ret) {
+		dev_err(fsm->dev, "Failed to enable EMI clock.\n");
+		return ret;
+	}
+
+	mutex_init(&fsm->lock);
+
+	ret = stfsm_init(fsm);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to initialise FSM Controller\n");
+		goto err_clk_unprepare;
+	}
+
+	stfsm_fetch_platform_configs(pdev);
+
+	/* Detect SPI FLASH device */
+	info = stfsm_jedec_probe(fsm);
+	if (!info) {
+		ret = -ENODEV;
+		goto err_clk_unprepare;
+	}
+	fsm->info = info;
+
+	/* Use device size to determine address width */
+	if (info->sector_size * info->n_sectors > 0x1000000)
+		info->flags |= FLASH_FLAG_32BIT_ADDR;
+
+	/*
+	 * Configure READ/WRITE/ERASE sequences according to platform and
+	 * device flags.
+	 */
+	if (info->config)
+		ret = info->config(fsm);
+	else
+		ret = stfsm_prepare_rwe_seqs_default(fsm);
+	if (ret)
+		goto err_clk_unprepare;
+
+	fsm->mtd.name		= info->name;
+	fsm->mtd.dev.parent	= &pdev->dev;
+	mtd_set_of_node(&fsm->mtd, np);
+	fsm->mtd.type		= MTD_NORFLASH;
+	fsm->mtd.writesize	= 4;
+	fsm->mtd.writebufsize	= fsm->mtd.writesize;
+	fsm->mtd.flags		= MTD_CAP_NORFLASH;
+	fsm->mtd.size		= info->sector_size * info->n_sectors;
+	fsm->mtd.erasesize	= info->sector_size;
+
+	fsm->mtd._read  = stfsm_mtd_read;
+	fsm->mtd._write = stfsm_mtd_write;
+	fsm->mtd._erase = stfsm_mtd_erase;
+
+	dev_info(&pdev->dev,
+		"Found serial flash device: %s\n"
+		" size = %llx (%lldMiB) erasesize = 0x%08x (%uKiB)\n",
+		info->name,
+		(long long)fsm->mtd.size, (long long)(fsm->mtd.size >> 20),
+		fsm->mtd.erasesize, (fsm->mtd.erasesize >> 10));
+
+	ret = mtd_device_register(&fsm->mtd, NULL, 0);
+	if (ret) {
+err_clk_unprepare:
+		clk_disable_unprepare(fsm->clk);
+	}
+
+	return ret;
+}
+
+static int stfsm_remove(struct platform_device *pdev)
+{
+	struct stfsm *fsm = platform_get_drvdata(pdev);
+
+	WARN_ON(mtd_device_unregister(&fsm->mtd));
+
+	clk_disable_unprepare(fsm->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int stfsmfsm_suspend(struct device *dev)
+{
+	struct stfsm *fsm = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(fsm->clk);
+
+	return 0;
+}
+
+static int stfsmfsm_resume(struct device *dev)
+{
+	struct stfsm *fsm = dev_get_drvdata(dev);
+
+	return clk_prepare_enable(fsm->clk);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(stfsm_pm_ops, stfsmfsm_suspend, stfsmfsm_resume);
+
+static const struct of_device_id stfsm_match[] = {
+	{ .compatible = "st,spi-fsm", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, stfsm_match);
+
+static struct platform_driver stfsm_driver = {
+	.probe		= stfsm_probe,
+	.remove		= stfsm_remove,
+	.driver		= {
+		.name	= "st-spi-fsm",
+		.of_match_table = stfsm_match,
+		.pm     = &stfsm_pm_ops,
+	},
+};
+module_platform_driver(stfsm_driver);
+
+MODULE_AUTHOR("Angus Clark <angus.clark@st.com>");
+MODULE_DESCRIPTION("ST SPI FSM driver");
+MODULE_LICENSE("GPL");