diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/mtd/devices/bcm47xxsflash.c | 382 |
1 files changed, 382 insertions, 0 deletions
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); |