Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1579 insertions, 0 deletions

diff --git a/drivers/mtd/nand/raw/diskonchip.c b/drivers/mtd/nand/raw/diskonchip.c
new file mode 100644
index 000000000..5d2ddb037
--- /dev/null
+++ b/drivers/mtd/nand/raw/diskonchip.c
@@ -0,0 +1,1579 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * (C) 2003 Red Hat, Inc.
+ * (C) 2004 Dan Brown <dan_brown@ieee.org>
+ * (C) 2004 Kalev Lember <kalev@smartlink.ee>
+ *
+ * Author: David Woodhouse <dwmw2@infradead.org>
+ * Additional Diskonchip 2000 and Millennium support by Dan Brown <dan_brown@ieee.org>
+ * Diskonchip Millennium Plus support by Kalev Lember <kalev@smartlink.ee>
+ *
+ * Error correction code lifted from the old docecc code
+ * Author: Fabrice Bellard (fabrice.bellard@netgem.com)
+ * Copyright (C) 2000 Netgem S.A.
+ * converted to the generic Reed-Solomon library by Thomas Gleixner <tglx@linutronix.de>
+ *
+ * Interface to generic NAND code for M-Systems DiskOnChip devices
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/rslib.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/rawnand.h>
+#include <linux/mtd/doc2000.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/inftl.h>
+#include <linux/module.h>
+
+/* Where to look for the devices? */
+#ifndef CONFIG_MTD_NAND_DISKONCHIP_PROBE_ADDRESS
+#define CONFIG_MTD_NAND_DISKONCHIP_PROBE_ADDRESS 0
+#endif
+
+static unsigned long doc_locations[] __initdata = {
+#if defined (__alpha__) || defined(__i386__) || defined(__x86_64__)
+#ifdef CONFIG_MTD_NAND_DISKONCHIP_PROBE_HIGH
+	0xfffc8000, 0xfffca000, 0xfffcc000, 0xfffce000,
+	0xfffd0000, 0xfffd2000, 0xfffd4000, 0xfffd6000,
+	0xfffd8000, 0xfffda000, 0xfffdc000, 0xfffde000,
+	0xfffe0000, 0xfffe2000, 0xfffe4000, 0xfffe6000,
+	0xfffe8000, 0xfffea000, 0xfffec000, 0xfffee000,
+#else
+	0xc8000, 0xca000, 0xcc000, 0xce000,
+	0xd0000, 0xd2000, 0xd4000, 0xd6000,
+	0xd8000, 0xda000, 0xdc000, 0xde000,
+	0xe0000, 0xe2000, 0xe4000, 0xe6000,
+	0xe8000, 0xea000, 0xec000, 0xee000,
+#endif
+#endif
+	0xffffffff };
+
+static struct mtd_info *doclist = NULL;
+
+struct doc_priv {
+	struct nand_controller base;
+	void __iomem *virtadr;
+	unsigned long physadr;
+	u_char ChipID;
+	u_char CDSNControl;
+	int chips_per_floor;	/* The number of chips detected on each floor */
+	int curfloor;
+	int curchip;
+	int mh0_page;
+	int mh1_page;
+	struct rs_control *rs_decoder;
+	struct mtd_info *nextdoc;
+	bool supports_32b_reads;
+
+	/* Handle the last stage of initialization (BBT scan, partitioning) */
+	int (*late_init)(struct mtd_info *mtd);
+};
+
+/* This is the ecc value computed by the HW ecc generator upon writing an empty
+   page, one with all 0xff for data. */
+static u_char empty_write_ecc[6] = { 0x4b, 0x00, 0xe2, 0x0e, 0x93, 0xf7 };
+
+#define INFTL_BBT_RESERVED_BLOCKS 4
+
+#define DoC_is_MillenniumPlus(doc) ((doc)->ChipID == DOC_ChipID_DocMilPlus16 || (doc)->ChipID == DOC_ChipID_DocMilPlus32)
+#define DoC_is_Millennium(doc) ((doc)->ChipID == DOC_ChipID_DocMil)
+#define DoC_is_2000(doc) ((doc)->ChipID == DOC_ChipID_Doc2k)
+
+static int debug = 0;
+module_param(debug, int, 0);
+
+static int try_dword = 1;
+module_param(try_dword, int, 0);
+
+static int no_ecc_failures = 0;
+module_param(no_ecc_failures, int, 0);
+
+static int no_autopart = 0;
+module_param(no_autopart, int, 0);
+
+static int show_firmware_partition = 0;
+module_param(show_firmware_partition, int, 0);
+
+#ifdef CONFIG_MTD_NAND_DISKONCHIP_BBTWRITE
+static int inftl_bbt_write = 1;
+#else
+static int inftl_bbt_write = 0;
+#endif
+module_param(inftl_bbt_write, int, 0);
+
+static unsigned long doc_config_location = CONFIG_MTD_NAND_DISKONCHIP_PROBE_ADDRESS;
+module_param(doc_config_location, ulong, 0);
+MODULE_PARM_DESC(doc_config_location, "Physical memory address at which to probe for DiskOnChip");
+
+/* Sector size for HW ECC */
+#define SECTOR_SIZE 512
+/* The sector bytes are packed into NB_DATA 10 bit words */
+#define NB_DATA (((SECTOR_SIZE + 1) * 8 + 6) / 10)
+/* Number of roots */
+#define NROOTS 4
+/* First consective root */
+#define FCR 510
+/* Number of symbols */
+#define NN 1023
+
+/*
+ * The HW decoder in the DoC ASIC's provides us a error syndrome,
+ * which we must convert to a standard syndrome usable by the generic
+ * Reed-Solomon library code.
+ *
+ * Fabrice Bellard figured this out in the old docecc code. I added
+ * some comments, improved a minor bit and converted it to make use
+ * of the generic Reed-Solomon library. tglx
+ */
+static int doc_ecc_decode(struct rs_control *rs, uint8_t *data, uint8_t *ecc)
+{
+	int i, j, nerr, errpos[8];
+	uint8_t parity;
+	uint16_t ds[4], s[5], tmp, errval[8], syn[4];
+	struct rs_codec *cd = rs->codec;
+
+	memset(syn, 0, sizeof(syn));
+	/* Convert the ecc bytes into words */
+	ds[0] = ((ecc[4] & 0xff) >> 0) | ((ecc[5] & 0x03) << 8);
+	ds[1] = ((ecc[5] & 0xfc) >> 2) | ((ecc[2] & 0x0f) << 6);
+	ds[2] = ((ecc[2] & 0xf0) >> 4) | ((ecc[3] & 0x3f) << 4);
+	ds[3] = ((ecc[3] & 0xc0) >> 6) | ((ecc[0] & 0xff) << 2);
+	parity = ecc[1];
+
+	/* Initialize the syndrome buffer */
+	for (i = 0; i < NROOTS; i++)
+		s[i] = ds[0];
+	/*
+	 *  Evaluate
+	 *  s[i] = ds[3]x^3 + ds[2]x^2 + ds[1]x^1 + ds[0]
+	 *  where x = alpha^(FCR + i)
+	 */
+	for (j = 1; j < NROOTS; j++) {
+		if (ds[j] == 0)
+			continue;
+		tmp = cd->index_of[ds[j]];
+		for (i = 0; i < NROOTS; i++)
+			s[i] ^= cd->alpha_to[rs_modnn(cd, tmp + (FCR + i) * j)];
+	}
+
+	/* Calc syn[i] = s[i] / alpha^(v + i) */
+	for (i = 0; i < NROOTS; i++) {
+		if (s[i])
+			syn[i] = rs_modnn(cd, cd->index_of[s[i]] + (NN - FCR - i));
+	}
+	/* Call the decoder library */
+	nerr = decode_rs16(rs, NULL, NULL, 1019, syn, 0, errpos, 0, errval);
+
+	/* Incorrectable errors ? */
+	if (nerr < 0)
+		return nerr;
+
+	/*
+	 * Correct the errors. The bitpositions are a bit of magic,
+	 * but they are given by the design of the de/encoder circuit
+	 * in the DoC ASIC's.
+	 */
+	for (i = 0; i < nerr; i++) {
+		int index, bitpos, pos = 1015 - errpos[i];
+		uint8_t val;
+		if (pos >= NB_DATA && pos < 1019)
+			continue;
+		if (pos < NB_DATA) {
+			/* extract bit position (MSB first) */
+			pos = 10 * (NB_DATA - 1 - pos) - 6;
+			/* now correct the following 10 bits. At most two bytes
+			   can be modified since pos is even */
+			index = (pos >> 3) ^ 1;
+			bitpos = pos & 7;
+			if ((index >= 0 && index < SECTOR_SIZE) || index == (SECTOR_SIZE + 1)) {
+				val = (uint8_t) (errval[i] >> (2 + bitpos));
+				parity ^= val;
+				if (index < SECTOR_SIZE)
+					data[index] ^= val;
+			}
+			index = ((pos >> 3) + 1) ^ 1;
+			bitpos = (bitpos + 10) & 7;
+			if (bitpos == 0)
+				bitpos = 8;
+			if ((index >= 0 && index < SECTOR_SIZE) || index == (SECTOR_SIZE + 1)) {
+				val = (uint8_t) (errval[i] << (8 - bitpos));
+				parity ^= val;
+				if (index < SECTOR_SIZE)
+					data[index] ^= val;
+			}
+		}
+	}
+	/* If the parity is wrong, no rescue possible */
+	return parity ? -EBADMSG : nerr;
+}
+
+static void DoC_Delay(struct doc_priv *doc, unsigned short cycles)
+{
+	volatile char __always_unused dummy;
+	int i;
+
+	for (i = 0; i < cycles; i++) {
+		if (DoC_is_Millennium(doc))
+			dummy = ReadDOC(doc->virtadr, NOP);
+		else if (DoC_is_MillenniumPlus(doc))
+			dummy = ReadDOC(doc->virtadr, Mplus_NOP);
+		else
+			dummy = ReadDOC(doc->virtadr, DOCStatus);
+	}
+
+}
+
+#define CDSN_CTRL_FR_B_MASK	(CDSN_CTRL_FR_B0 | CDSN_CTRL_FR_B1)
+
+/* DOC_WaitReady: Wait for RDY line to be asserted by the flash chip */
+static int _DoC_WaitReady(struct doc_priv *doc)
+{
+	void __iomem *docptr = doc->virtadr;
+	unsigned long timeo = jiffies + (HZ * 10);
+
+	if (debug)
+		printk("_DoC_WaitReady...\n");
+	/* Out-of-line routine to wait for chip response */
+	if (DoC_is_MillenniumPlus(doc)) {
+		while ((ReadDOC(docptr, Mplus_FlashControl) & CDSN_CTRL_FR_B_MASK) != CDSN_CTRL_FR_B_MASK) {
+			if (time_after(jiffies, timeo)) {
+				printk("_DoC_WaitReady timed out.\n");
+				return -EIO;
+			}
+			udelay(1);
+			cond_resched();
+		}
+	} else {
+		while (!(ReadDOC(docptr, CDSNControl) & CDSN_CTRL_FR_B)) {
+			if (time_after(jiffies, timeo)) {
+				printk("_DoC_WaitReady timed out.\n");
+				return -EIO;
+			}
+			udelay(1);
+			cond_resched();
+		}
+	}
+
+	return 0;
+}
+
+static inline int DoC_WaitReady(struct doc_priv *doc)
+{
+	void __iomem *docptr = doc->virtadr;
+	int ret = 0;
+
+	if (DoC_is_MillenniumPlus(doc)) {
+		DoC_Delay(doc, 4);
+
+		if ((ReadDOC(docptr, Mplus_FlashControl) & CDSN_CTRL_FR_B_MASK) != CDSN_CTRL_FR_B_MASK)
+			/* Call the out-of-line routine to wait */
+			ret = _DoC_WaitReady(doc);
+	} else {
+		DoC_Delay(doc, 4);
+
+		if (!(ReadDOC(docptr, CDSNControl) & CDSN_CTRL_FR_B))
+			/* Call the out-of-line routine to wait */
+			ret = _DoC_WaitReady(doc);
+		DoC_Delay(doc, 2);
+	}
+
+	if (debug)
+		printk("DoC_WaitReady OK\n");
+	return ret;
+}
+
+static void doc2000_write_byte(struct nand_chip *this, u_char datum)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	void __iomem *docptr = doc->virtadr;
+
+	if (debug)
+		printk("write_byte %02x\n", datum);
+	WriteDOC(datum, docptr, CDSNSlowIO);
+	WriteDOC(datum, docptr, 2k_CDSN_IO);
+}
+
+static void doc2000_writebuf(struct nand_chip *this, const u_char *buf,
+			     int len)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	void __iomem *docptr = doc->virtadr;
+	int i;
+	if (debug)
+		printk("writebuf of %d bytes: ", len);
+	for (i = 0; i < len; i++) {
+		WriteDOC_(buf[i], docptr, DoC_2k_CDSN_IO + i);
+		if (debug && i < 16)
+			printk("%02x ", buf[i]);
+	}
+	if (debug)
+		printk("\n");
+}
+
+static void doc2000_readbuf(struct nand_chip *this, u_char *buf, int len)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	void __iomem *docptr = doc->virtadr;
+	u32 *buf32 = (u32 *)buf;
+	int i;
+
+	if (debug)
+		printk("readbuf of %d bytes: ", len);
+
+	if (!doc->supports_32b_reads ||
+	    ((((unsigned long)buf) | len) & 3)) {
+		for (i = 0; i < len; i++)
+			buf[i] = ReadDOC(docptr, 2k_CDSN_IO + i);
+	} else {
+		for (i = 0; i < len / 4; i++)
+			buf32[i] = readl(docptr + DoC_2k_CDSN_IO + i);
+	}
+}
+
+/*
+ * We need our own readid() here because it's called before the NAND chip
+ * has been initialized, and calling nand_op_readid() would lead to a NULL
+ * pointer exception when dereferencing the NAND timings.
+ */
+static void doc200x_readid(struct nand_chip *this, unsigned int cs, u8 *id)
+{
+	u8 addr = 0;
+	struct nand_op_instr instrs[] = {
+		NAND_OP_CMD(NAND_CMD_READID, 0),
+		NAND_OP_ADDR(1, &addr, 50),
+		NAND_OP_8BIT_DATA_IN(2, id, 0),
+	};
+
+	struct nand_operation op = NAND_OPERATION(cs, instrs);
+
+	if (!id)
+		op.ninstrs--;
+
+	this->controller->ops->exec_op(this, &op, false);
+}
+
+static uint16_t __init doc200x_ident_chip(struct mtd_info *mtd, int nr)
+{
+	struct nand_chip *this = mtd_to_nand(mtd);
+	struct doc_priv *doc = nand_get_controller_data(this);
+	uint16_t ret;
+	u8 id[2];
+
+	doc200x_readid(this, nr, id);
+
+	ret = ((u16)id[0] << 8) | id[1];
+
+	if (doc->ChipID == DOC_ChipID_Doc2k && try_dword && !nr) {
+		/* First chip probe. See if we get same results by 32-bit access */
+		union {
+			uint32_t dword;
+			uint8_t byte[4];
+		} ident;
+		void __iomem *docptr = doc->virtadr;
+
+		doc200x_readid(this, nr, NULL);
+
+		ident.dword = readl(docptr + DoC_2k_CDSN_IO);
+		if (((ident.byte[0] << 8) | ident.byte[1]) == ret) {
+			pr_info("DiskOnChip 2000 responds to DWORD access\n");
+			doc->supports_32b_reads = true;
+		}
+	}
+
+	return ret;
+}
+
+static void __init doc2000_count_chips(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd_to_nand(mtd);
+	struct doc_priv *doc = nand_get_controller_data(this);
+	uint16_t mfrid;
+	int i;
+
+	/* Max 4 chips per floor on DiskOnChip 2000 */
+	doc->chips_per_floor = 4;
+
+	/* Find out what the first chip is */
+	mfrid = doc200x_ident_chip(mtd, 0);
+
+	/* Find how many chips in each floor. */
+	for (i = 1; i < 4; i++) {
+		if (doc200x_ident_chip(mtd, i) != mfrid)
+			break;
+	}
+	doc->chips_per_floor = i;
+	pr_debug("Detected %d chips per floor.\n", i);
+}
+
+static void doc2001_write_byte(struct nand_chip *this, u_char datum)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	void __iomem *docptr = doc->virtadr;
+
+	WriteDOC(datum, docptr, CDSNSlowIO);
+	WriteDOC(datum, docptr, Mil_CDSN_IO);
+	WriteDOC(datum, docptr, WritePipeTerm);
+}
+
+static void doc2001_writebuf(struct nand_chip *this, const u_char *buf, int len)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	void __iomem *docptr = doc->virtadr;
+	int i;
+
+	for (i = 0; i < len; i++)
+		WriteDOC_(buf[i], docptr, DoC_Mil_CDSN_IO + i);
+	/* Terminate write pipeline */
+	WriteDOC(0x00, docptr, WritePipeTerm);
+}
+
+static void doc2001_readbuf(struct nand_chip *this, u_char *buf, int len)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	void __iomem *docptr = doc->virtadr;
+	int i;
+
+	/* Start read pipeline */
+	ReadDOC(docptr, ReadPipeInit);
+
+	for (i = 0; i < len - 1; i++)
+		buf[i] = ReadDOC(docptr, Mil_CDSN_IO + (i & 0xff));
+
+	/* Terminate read pipeline */
+	buf[i] = ReadDOC(docptr, LastDataRead);
+}
+
+static void doc2001plus_writebuf(struct nand_chip *this, const u_char *buf, int len)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	void __iomem *docptr = doc->virtadr;
+	int i;
+
+	if (debug)
+		printk("writebuf of %d bytes: ", len);
+	for (i = 0; i < len; i++) {
+		WriteDOC_(buf[i], docptr, DoC_Mil_CDSN_IO + i);
+		if (debug && i < 16)
+			printk("%02x ", buf[i]);
+	}
+	if (debug)
+		printk("\n");
+}
+
+static void doc2001plus_readbuf(struct nand_chip *this, u_char *buf, int len)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	void __iomem *docptr = doc->virtadr;
+	int i;
+
+	if (debug)
+		printk("readbuf of %d bytes: ", len);
+
+	/* Start read pipeline */
+	ReadDOC(docptr, Mplus_ReadPipeInit);
+	ReadDOC(docptr, Mplus_ReadPipeInit);
+
+	for (i = 0; i < len - 2; i++) {
+		buf[i] = ReadDOC(docptr, Mil_CDSN_IO);
+		if (debug && i < 16)
+			printk("%02x ", buf[i]);
+	}
+
+	/* Terminate read pipeline */
+	if (len >= 2) {
+		buf[len - 2] = ReadDOC(docptr, Mplus_LastDataRead);
+		if (debug && i < 16)
+			printk("%02x ", buf[len - 2]);
+	}
+
+	buf[len - 1] = ReadDOC(docptr, Mplus_LastDataRead);
+	if (debug && i < 16)
+		printk("%02x ", buf[len - 1]);
+	if (debug)
+		printk("\n");
+}
+
+static void doc200x_write_control(struct doc_priv *doc, u8 value)
+{
+	WriteDOC(value, doc->virtadr, CDSNControl);
+	/* 11.4.3 -- 4 NOPs after CSDNControl write */
+	DoC_Delay(doc, 4);
+}
+
+static void doc200x_exec_instr(struct nand_chip *this,
+			       const struct nand_op_instr *instr)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	unsigned int i;
+
+	switch (instr->type) {
+	case NAND_OP_CMD_INSTR:
+		doc200x_write_control(doc, CDSN_CTRL_CE | CDSN_CTRL_CLE);
+		doc2000_write_byte(this, instr->ctx.cmd.opcode);
+		break;
+
+	case NAND_OP_ADDR_INSTR:
+		doc200x_write_control(doc, CDSN_CTRL_CE | CDSN_CTRL_ALE);
+		for (i = 0; i < instr->ctx.addr.naddrs; i++) {
+			u8 addr = instr->ctx.addr.addrs[i];
+
+			if (DoC_is_2000(doc))
+				doc2000_write_byte(this, addr);
+			else
+				doc2001_write_byte(this, addr);
+		}
+		break;
+
+	case NAND_OP_DATA_IN_INSTR:
+		doc200x_write_control(doc, CDSN_CTRL_CE);
+		if (DoC_is_2000(doc))
+			doc2000_readbuf(this, instr->ctx.data.buf.in,
+					instr->ctx.data.len);
+		else
+			doc2001_readbuf(this, instr->ctx.data.buf.in,
+					instr->ctx.data.len);
+		break;
+
+	case NAND_OP_DATA_OUT_INSTR:
+		doc200x_write_control(doc, CDSN_CTRL_CE);
+		if (DoC_is_2000(doc))
+			doc2000_writebuf(this, instr->ctx.data.buf.out,
+					 instr->ctx.data.len);
+		else
+			doc2001_writebuf(this, instr->ctx.data.buf.out,
+					 instr->ctx.data.len);
+		break;
+
+	case NAND_OP_WAITRDY_INSTR:
+		DoC_WaitReady(doc);
+		break;
+	}
+
+	if (instr->delay_ns)
+		ndelay(instr->delay_ns);
+}
+
+static int doc200x_exec_op(struct nand_chip *this,
+			   const struct nand_operation *op,
+			   bool check_only)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	unsigned int i;
+
+	if (check_only)
+		return true;
+
+	doc->curchip = op->cs % doc->chips_per_floor;
+	doc->curfloor = op->cs / doc->chips_per_floor;
+
+	WriteDOC(doc->curfloor, doc->virtadr, FloorSelect);
+	WriteDOC(doc->curchip, doc->virtadr, CDSNDeviceSelect);
+
+	/* Assert CE pin */
+	doc200x_write_control(doc, CDSN_CTRL_CE);
+
+	for (i = 0; i < op->ninstrs; i++)
+		doc200x_exec_instr(this, &op->instrs[i]);
+
+	/* De-assert CE pin */
+	doc200x_write_control(doc, 0);
+
+	return 0;
+}
+
+static void doc2001plus_write_pipe_term(struct doc_priv *doc)
+{
+	WriteDOC(0x00, doc->virtadr, Mplus_WritePipeTerm);
+	WriteDOC(0x00, doc->virtadr, Mplus_WritePipeTerm);
+}
+
+static void doc2001plus_exec_instr(struct nand_chip *this,
+				   const struct nand_op_instr *instr)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	unsigned int i;
+
+	switch (instr->type) {
+	case NAND_OP_CMD_INSTR:
+		WriteDOC(instr->ctx.cmd.opcode, doc->virtadr, Mplus_FlashCmd);
+		doc2001plus_write_pipe_term(doc);
+		break;
+
+	case NAND_OP_ADDR_INSTR:
+		for (i = 0; i < instr->ctx.addr.naddrs; i++) {
+			u8 addr = instr->ctx.addr.addrs[i];
+
+			WriteDOC(addr, doc->virtadr, Mplus_FlashAddress);
+		}
+		doc2001plus_write_pipe_term(doc);
+		/* deassert ALE */
+		WriteDOC(0, doc->virtadr, Mplus_FlashControl);
+		break;
+
+	case NAND_OP_DATA_IN_INSTR:
+		doc2001plus_readbuf(this, instr->ctx.data.buf.in,
+				    instr->ctx.data.len);
+		break;
+	case NAND_OP_DATA_OUT_INSTR:
+		doc2001plus_writebuf(this, instr->ctx.data.buf.out,
+				     instr->ctx.data.len);
+		doc2001plus_write_pipe_term(doc);
+		break;
+	case NAND_OP_WAITRDY_INSTR:
+		DoC_WaitReady(doc);
+		break;
+	}
+
+	if (instr->delay_ns)
+		ndelay(instr->delay_ns);
+}
+
+static int doc2001plus_exec_op(struct nand_chip *this,
+			       const struct nand_operation *op,
+			       bool check_only)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	unsigned int i;
+
+	if (check_only)
+		return true;
+
+	doc->curchip = op->cs % doc->chips_per_floor;
+	doc->curfloor = op->cs / doc->chips_per_floor;
+
+	/* Assert ChipEnable and deassert WriteProtect */
+	WriteDOC(DOC_FLASH_CE, doc->virtadr, Mplus_FlashSelect);
+
+	for (i = 0; i < op->ninstrs; i++)
+		doc2001plus_exec_instr(this, &op->instrs[i]);
+
+	/* De-assert ChipEnable */
+	WriteDOC(0, doc->virtadr, Mplus_FlashSelect);
+
+	return 0;
+}
+
+static void doc200x_enable_hwecc(struct nand_chip *this, int mode)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	void __iomem *docptr = doc->virtadr;
+
+	/* Prime the ECC engine */
+	switch (mode) {
+	case NAND_ECC_READ:
+		WriteDOC(DOC_ECC_RESET, docptr, ECCConf);
+		WriteDOC(DOC_ECC_EN, docptr, ECCConf);
+		break;
+	case NAND_ECC_WRITE:
+		WriteDOC(DOC_ECC_RESET, docptr, ECCConf);
+		WriteDOC(DOC_ECC_EN | DOC_ECC_RW, docptr, ECCConf);
+		break;
+	}
+}
+
+static void doc2001plus_enable_hwecc(struct nand_chip *this, int mode)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	void __iomem *docptr = doc->virtadr;
+
+	/* Prime the ECC engine */
+	switch (mode) {
+	case NAND_ECC_READ:
+		WriteDOC(DOC_ECC_RESET, docptr, Mplus_ECCConf);
+		WriteDOC(DOC_ECC_EN, docptr, Mplus_ECCConf);
+		break;
+	case NAND_ECC_WRITE:
+		WriteDOC(DOC_ECC_RESET, docptr, Mplus_ECCConf);
+		WriteDOC(DOC_ECC_EN | DOC_ECC_RW, docptr, Mplus_ECCConf);
+		break;
+	}
+}
+
+/* This code is only called on write */
+static int doc200x_calculate_ecc(struct nand_chip *this, const u_char *dat,
+				 unsigned char *ecc_code)
+{
+	struct doc_priv *doc = nand_get_controller_data(this);
+	void __iomem *docptr = doc->virtadr;
+	int i;
+	int __always_unused emptymatch = 1;
+
+	/* flush the pipeline */
+	if (DoC_is_2000(doc)) {
+		WriteDOC(doc->CDSNControl & ~CDSN_CTRL_FLASH_IO, docptr, CDSNControl);
+		WriteDOC(0, docptr, 2k_CDSN_IO);
+		WriteDOC(0, docptr, 2k_CDSN_IO);
+		WriteDOC(0, docptr, 2k_CDSN_IO);
+		WriteDOC(doc->CDSNControl, docptr, CDSNControl);
+	} else if (DoC_is_MillenniumPlus(doc)) {
+		WriteDOC(0, docptr, Mplus_NOP);
+		WriteDOC(0, docptr, Mplus_NOP);
+		WriteDOC(0, docptr, Mplus_NOP);
+	} else {
+		WriteDOC(0, docptr, NOP);
+		WriteDOC(0, docptr, NOP);
+		WriteDOC(0, docptr, NOP);
+	}
+
+	for (i = 0; i < 6; i++) {
+		if (DoC_is_MillenniumPlus(doc))
+			ecc_code[i] = ReadDOC_(docptr, DoC_Mplus_ECCSyndrome0 + i);
+		else
+			ecc_code[i] = ReadDOC_(docptr, DoC_ECCSyndrome0 + i);
+		if (ecc_code[i] != empty_write_ecc[i])
+			emptymatch = 0;
+	}
+	if (DoC_is_MillenniumPlus(doc))
+		WriteDOC(DOC_ECC_DIS, docptr, Mplus_ECCConf);
+	else
+		WriteDOC(DOC_ECC_DIS, docptr, ECCConf);
+#if 0
+	/* If emptymatch=1, we might have an all-0xff data buffer.  Check. */
+	if (emptymatch) {
+		/* Note: this somewhat expensive test should not be triggered
+		   often.  It could be optimized away by examining the data in
+		   the writebuf routine, and remembering the result. */
+		for (i = 0; i < 512; i++) {
+			if (dat[i] == 0xff)
+				continue;
+			emptymatch = 0;
+			break;
+		}
+	}
+	/* If emptymatch still =1, we do have an all-0xff data buffer.
+	   Return all-0xff ecc value instead of the computed one, so
+	   it'll look just like a freshly-erased page. */
+	if (emptymatch)
+		memset(ecc_code, 0xff, 6);
+#endif
+	return 0;
+}
+
+static int doc200x_correct_data(struct nand_chip *this, u_char *dat,
+				u_char *read_ecc, u_char *isnull)
+{
+	int i, ret = 0;
+	struct doc_priv *doc = nand_get_controller_data(this);
+	void __iomem *docptr = doc->virtadr;
+	uint8_t calc_ecc[6];
+	volatile u_char dummy;
+
+	/* flush the pipeline */
+	if (DoC_is_2000(doc)) {
+		dummy = ReadDOC(docptr, 2k_ECCStatus);
+		dummy = ReadDOC(docptr, 2k_ECCStatus);
+		dummy = ReadDOC(docptr, 2k_ECCStatus);
+	} else if (DoC_is_MillenniumPlus(doc)) {
+		dummy = ReadDOC(docptr, Mplus_ECCConf);
+		dummy = ReadDOC(docptr, Mplus_ECCConf);
+		dummy = ReadDOC(docptr, Mplus_ECCConf);
+	} else {
+		dummy = ReadDOC(docptr, ECCConf);
+		dummy = ReadDOC(docptr, ECCConf);
+		dummy = ReadDOC(docptr, ECCConf);
+	}
+
+	/* Error occurred ? */
+	if (dummy & 0x80) {
+		for (i = 0; i < 6; i++) {
+			if (DoC_is_MillenniumPlus(doc))
+				calc_ecc[i] = ReadDOC_(docptr, DoC_Mplus_ECCSyndrome0 + i);
+			else
+				calc_ecc[i] = ReadDOC_(docptr, DoC_ECCSyndrome0 + i);
+		}
+
+		ret = doc_ecc_decode(doc->rs_decoder, dat, calc_ecc);
+		if (ret > 0)
+			pr_err("doc200x_correct_data corrected %d errors\n",
+			       ret);
+	}
+	if (DoC_is_MillenniumPlus(doc))
+		WriteDOC(DOC_ECC_DIS, docptr, Mplus_ECCConf);
+	else
+		WriteDOC(DOC_ECC_DIS, docptr, ECCConf);
+	if (no_ecc_failures && mtd_is_eccerr(ret)) {
+		pr_err("suppressing ECC failure\n");
+		ret = 0;
+	}
+	return ret;
+}
+
+//u_char mydatabuf[528];
+
+static int doc200x_ooblayout_ecc(struct mtd_info *mtd, int section,
+				 struct mtd_oob_region *oobregion)
+{
+	if (section)
+		return -ERANGE;
+
+	oobregion->offset = 0;
+	oobregion->length = 6;
+
+	return 0;
+}
+
+static int doc200x_ooblayout_free(struct mtd_info *mtd, int section,
+				  struct mtd_oob_region *oobregion)
+{
+	if (section > 1)
+		return -ERANGE;
+
+	/*
+	 * The strange out-of-order free bytes definition is a (possibly
+	 * unneeded) attempt to retain compatibility.  It used to read:
+	 *	.oobfree = { {8, 8} }
+	 * Since that leaves two bytes unusable, it was changed.  But the
+	 * following scheme might affect existing jffs2 installs by moving the
+	 * cleanmarker:
+	 *	.oobfree = { {6, 10} }
+	 * jffs2 seems to handle the above gracefully, but the current scheme
+	 * seems safer. The only problem with it is that any code retrieving
+	 * free bytes position must be able to handle out-of-order segments.
+	 */
+	if (!section) {
+		oobregion->offset = 8;
+		oobregion->length = 8;
+	} else {
+		oobregion->offset = 6;
+		oobregion->length = 2;
+	}
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops doc200x_ooblayout_ops = {
+	.ecc = doc200x_ooblayout_ecc,
+	.free = doc200x_ooblayout_free,
+};
+
+/* Find the (I)NFTL Media Header, and optionally also the mirror media header.
+   On successful return, buf will contain a copy of the media header for
+   further processing.  id is the string to scan for, and will presumably be
+   either "ANAND" or "BNAND".  If findmirror=1, also look for the mirror media
+   header.  The page #s of the found media headers are placed in mh0_page and
+   mh1_page in the DOC private structure. */
+static int __init find_media_headers(struct mtd_info *mtd, u_char *buf, const char *id, int findmirror)
+{
+	struct nand_chip *this = mtd_to_nand(mtd);
+	struct doc_priv *doc = nand_get_controller_data(this);
+	unsigned offs;
+	int ret;
+	size_t retlen;
+
+	for (offs = 0; offs < mtd->size; offs += mtd->erasesize) {
+		ret = mtd_read(mtd, offs, mtd->writesize, &retlen, buf);
+		if (retlen != mtd->writesize)
+			continue;
+		if (ret) {
+			pr_warn("ECC error scanning DOC at 0x%x\n", offs);
+		}
+		if (memcmp(buf, id, 6))
+			continue;
+		pr_info("Found DiskOnChip %s Media Header at 0x%x\n", id, offs);
+		if (doc->mh0_page == -1) {
+			doc->mh0_page = offs >> this->page_shift;
+			if (!findmirror)
+				return 1;
+			continue;
+		}
+		doc->mh1_page = offs >> this->page_shift;
+		return 2;
+	}
+	if (doc->mh0_page == -1) {
+		pr_warn("DiskOnChip %s Media Header not found.\n", id);
+		return 0;
+	}
+	/* Only one mediaheader was found.  We want buf to contain a
+	   mediaheader on return, so we'll have to re-read the one we found. */
+	offs = doc->mh0_page << this->page_shift;
+	ret = mtd_read(mtd, offs, mtd->writesize, &retlen, buf);
+	if (retlen != mtd->writesize) {
+		/* Insanity.  Give up. */
+		pr_err("Read DiskOnChip Media Header once, but can't reread it???\n");
+		return 0;
+	}
+	return 1;
+}
+
+static inline int __init nftl_partscan(struct mtd_info *mtd, struct mtd_partition *parts)
+{
+	struct nand_chip *this = mtd_to_nand(mtd);
+	struct doc_priv *doc = nand_get_controller_data(this);
+	struct nand_memory_organization *memorg;
+	int ret = 0;
+	u_char *buf;
+	struct NFTLMediaHeader *mh;
+	const unsigned psize = 1 << this->page_shift;
+	int numparts = 0;
+	unsigned blocks, maxblocks;
+	int offs, numheaders;
+
+	memorg = nanddev_get_memorg(&this->base);
+
+	buf = kmalloc(mtd->writesize, GFP_KERNEL);
+	if (!buf) {
+		return 0;
+	}
+	if (!(numheaders = find_media_headers(mtd, buf, "ANAND", 1)))
+		goto out;
+	mh = (struct NFTLMediaHeader *)buf;
+
+	le16_to_cpus(&mh->NumEraseUnits);
+	le16_to_cpus(&mh->FirstPhysicalEUN);
+	le32_to_cpus(&mh->FormattedSize);
+
+	pr_info("    DataOrgID        = %s\n"
+		"    NumEraseUnits    = %d\n"
+		"    FirstPhysicalEUN = %d\n"
+		"    FormattedSize    = %d\n"
+		"    UnitSizeFactor   = %d\n",
+		mh->DataOrgID, mh->NumEraseUnits,
+		mh->FirstPhysicalEUN, mh->FormattedSize,
+		mh->UnitSizeFactor);
+
+	blocks = mtd->size >> this->phys_erase_shift;
+	maxblocks = min(32768U, mtd->erasesize - psize);
+
+	if (mh->UnitSizeFactor == 0x00) {
+		/* Auto-determine UnitSizeFactor.  The constraints are:
+		   - There can be at most 32768 virtual blocks.
+		   - There can be at most (virtual block size - page size)
+		   virtual blocks (because MediaHeader+BBT must fit in 1).
+		 */
+		mh->UnitSizeFactor = 0xff;
+		while (blocks > maxblocks) {
+			blocks >>= 1;
+			maxblocks = min(32768U, (maxblocks << 1) + psize);
+			mh->UnitSizeFactor--;
+		}
+		pr_warn("UnitSizeFactor=0x00 detected.  Correct value is assumed to be 0x%02x.\n", mh->UnitSizeFactor);
+	}
+
+	/* NOTE: The lines below modify internal variables of the NAND and MTD
+	   layers; variables with have already been configured by nand_scan.
+	   Unfortunately, we didn't know before this point what these values
+	   should be.  Thus, this code is somewhat dependent on the exact
+	   implementation of the NAND layer.  */
+	if (mh->UnitSizeFactor != 0xff) {
+		this->bbt_erase_shift += (0xff - mh->UnitSizeFactor);
+		memorg->pages_per_eraseblock <<= (0xff - mh->UnitSizeFactor);
+		mtd->erasesize <<= (0xff - mh->UnitSizeFactor);
+		pr_info("Setting virtual erase size to %d\n", mtd->erasesize);
+		blocks = mtd->size >> this->bbt_erase_shift;
+		maxblocks = min(32768U, mtd->erasesize - psize);
+	}
+
+	if (blocks > maxblocks) {
+		pr_err("UnitSizeFactor of 0x%02x is inconsistent with device size.  Aborting.\n", mh->UnitSizeFactor);
+		goto out;
+	}
+
+	/* Skip past the media headers. */
+	offs = max(doc->mh0_page, doc->mh1_page);
+	offs <<= this->page_shift;
+	offs += mtd->erasesize;
+
+	if (show_firmware_partition == 1) {
+		parts[0].name = " DiskOnChip Firmware / Media Header partition";
+		parts[0].offset = 0;
+		parts[0].size = offs;
+		numparts = 1;
+	}
+
+	parts[numparts].name = " DiskOnChip BDTL partition";
+	parts[numparts].offset = offs;
+	parts[numparts].size = (mh->NumEraseUnits - numheaders) << this->bbt_erase_shift;
+
+	offs += parts[numparts].size;
+	numparts++;
+
+	if (offs < mtd->size) {
+		parts[numparts].name = " DiskOnChip Remainder partition";
+		parts[numparts].offset = offs;
+		parts[numparts].size = mtd->size - offs;
+		numparts++;
+	}
+
+	ret = numparts;
+ out:
+	kfree(buf);
+	return ret;
+}
+
+/* This is a stripped-down copy of the code in inftlmount.c */
+static inline int __init inftl_partscan(struct mtd_info *mtd, struct mtd_partition *parts)
+{
+	struct nand_chip *this = mtd_to_nand(mtd);
+	struct doc_priv *doc = nand_get_controller_data(this);
+	int ret = 0;
+	u_char *buf;
+	struct INFTLMediaHeader *mh;
+	struct INFTLPartition *ip;
+	int numparts = 0;
+	int blocks;
+	int vshift, lastvunit = 0;
+	int i;
+	int end = mtd->size;
+
+	if (inftl_bbt_write)
+		end -= (INFTL_BBT_RESERVED_BLOCKS << this->phys_erase_shift);
+
+	buf = kmalloc(mtd->writesize, GFP_KERNEL);
+	if (!buf) {
+		return 0;
+	}
+
+	if (!find_media_headers(mtd, buf, "BNAND", 0))
+		goto out;
+	doc->mh1_page = doc->mh0_page + (4096 >> this->page_shift);
+	mh = (struct INFTLMediaHeader *)buf;
+
+	le32_to_cpus(&mh->NoOfBootImageBlocks);
+	le32_to_cpus(&mh->NoOfBinaryPartitions);
+	le32_to_cpus(&mh->NoOfBDTLPartitions);
+	le32_to_cpus(&mh->BlockMultiplierBits);
+	le32_to_cpus(&mh->FormatFlags);
+	le32_to_cpus(&mh->PercentUsed);
+
+	pr_info("    bootRecordID          = %s\n"
+		"    NoOfBootImageBlocks   = %d\n"
+		"    NoOfBinaryPartitions  = %d\n"
+		"    NoOfBDTLPartitions    = %d\n"
+		"    BlockMultiplierBits   = %d\n"
+		"    FormatFlgs            = %d\n"
+		"    OsakVersion           = %d.%d.%d.%d\n"
+		"    PercentUsed           = %d\n",
+		mh->bootRecordID, mh->NoOfBootImageBlocks,
+		mh->NoOfBinaryPartitions,
+		mh->NoOfBDTLPartitions,
+		mh->BlockMultiplierBits, mh->FormatFlags,
+		((unsigned char *) &mh->OsakVersion)[0] & 0xf,
+		((unsigned char *) &mh->OsakVersion)[1] & 0xf,
+		((unsigned char *) &mh->OsakVersion)[2] & 0xf,
+		((unsigned char *) &mh->OsakVersion)[3] & 0xf,
+		mh->PercentUsed);
+
+	vshift = this->phys_erase_shift + mh->BlockMultiplierBits;
+
+	blocks = mtd->size >> vshift;
+	if (blocks > 32768) {
+		pr_err("BlockMultiplierBits=%d is inconsistent with device size.  Aborting.\n", mh->BlockMultiplierBits);
+		goto out;
+	}
+
+	blocks = doc->chips_per_floor << (this->chip_shift - this->phys_erase_shift);
+	if (inftl_bbt_write && (blocks > mtd->erasesize)) {
+		pr_err("Writeable BBTs spanning more than one erase block are not yet supported.  FIX ME!\n");
+		goto out;
+	}
+
+	/* Scan the partitions */
+	for (i = 0; (i < 4); i++) {
+		ip = &(mh->Partitions[i]);
+		le32_to_cpus(&ip->virtualUnits);
+		le32_to_cpus(&ip->firstUnit);
+		le32_to_cpus(&ip->lastUnit);
+		le32_to_cpus(&ip->flags);
+		le32_to_cpus(&ip->spareUnits);
+		le32_to_cpus(&ip->Reserved0);
+
+		pr_info("    PARTITION[%d] ->\n"
+			"        virtualUnits    = %d\n"
+			"        firstUnit       = %d\n"
+			"        lastUnit        = %d\n"
+			"        flags           = 0x%x\n"
+			"        spareUnits      = %d\n",
+			i, ip->virtualUnits, ip->firstUnit,
+			ip->lastUnit, ip->flags,
+			ip->spareUnits);
+
+		if ((show_firmware_partition == 1) &&
+		    (i == 0) && (ip->firstUnit > 0)) {
+			parts[0].name = " DiskOnChip IPL / Media Header partition";
+			parts[0].offset = 0;
+			parts[0].size = mtd->erasesize * ip->firstUnit;
+			numparts = 1;
+		}
+
+		if (ip->flags & INFTL_BINARY)
+			parts[numparts].name = " DiskOnChip BDK partition";
+		else
+			parts[numparts].name = " DiskOnChip BDTL partition";
+		parts[numparts].offset = ip->firstUnit << vshift;
+		parts[numparts].size = (1 + ip->lastUnit - ip->firstUnit) << vshift;
+		numparts++;
+		if (ip->lastUnit > lastvunit)
+			lastvunit = ip->lastUnit;
+		if (ip->flags & INFTL_LAST)
+			break;
+	}
+	lastvunit++;
+	if ((lastvunit << vshift) < end) {
+		parts[numparts].name = " DiskOnChip Remainder partition";
+		parts[numparts].offset = lastvunit << vshift;
+		parts[numparts].size = end - parts[numparts].offset;
+		numparts++;
+	}
+	ret = numparts;
+ out:
+	kfree(buf);
+	return ret;
+}
+
+static int __init nftl_scan_bbt(struct mtd_info *mtd)
+{
+	int ret, numparts;
+	struct nand_chip *this = mtd_to_nand(mtd);
+	struct doc_priv *doc = nand_get_controller_data(this);
+	struct mtd_partition parts[2];
+
+	memset((char *)parts, 0, sizeof(parts));
+	/* On NFTL, we have to find the media headers before we can read the
+	   BBTs, since they're stored in the media header eraseblocks. */
+	numparts = nftl_partscan(mtd, parts);
+	if (!numparts)
+		return -EIO;
+	this->bbt_td->options = NAND_BBT_ABSPAGE | NAND_BBT_8BIT |
+				NAND_BBT_SAVECONTENT | NAND_BBT_WRITE |
+				NAND_BBT_VERSION;
+	this->bbt_td->veroffs = 7;
+	this->bbt_td->pages[0] = doc->mh0_page + 1;
+	if (doc->mh1_page != -1) {
+		this->bbt_md->options = NAND_BBT_ABSPAGE | NAND_BBT_8BIT |
+					NAND_BBT_SAVECONTENT | NAND_BBT_WRITE |
+					NAND_BBT_VERSION;
+		this->bbt_md->veroffs = 7;
+		this->bbt_md->pages[0] = doc->mh1_page + 1;
+	} else {
+		this->bbt_md = NULL;
+	}
+
+	ret = nand_create_bbt(this);
+	if (ret)
+		return ret;
+
+	return mtd_device_register(mtd, parts, no_autopart ? 0 : numparts);
+}
+
+static int __init inftl_scan_bbt(struct mtd_info *mtd)
+{
+	int ret, numparts;
+	struct nand_chip *this = mtd_to_nand(mtd);
+	struct doc_priv *doc = nand_get_controller_data(this);
+	struct mtd_partition parts[5];
+
+	if (nanddev_ntargets(&this->base) > doc->chips_per_floor) {
+		pr_err("Multi-floor INFTL devices not yet supported.\n");
+		return -EIO;
+	}
+
+	if (DoC_is_MillenniumPlus(doc)) {
+		this->bbt_td->options = NAND_BBT_2BIT | NAND_BBT_ABSPAGE;
+		if (inftl_bbt_write)
+			this->bbt_td->options |= NAND_BBT_WRITE;
+		this->bbt_td->pages[0] = 2;
+		this->bbt_md = NULL;
+	} else {
+		this->bbt_td->options = NAND_BBT_LASTBLOCK | NAND_BBT_8BIT | NAND_BBT_VERSION;
+		if (inftl_bbt_write)
+			this->bbt_td->options |= NAND_BBT_WRITE;
+		this->bbt_td->offs = 8;
+		this->bbt_td->len = 8;
+		this->bbt_td->veroffs = 7;
+		this->bbt_td->maxblocks = INFTL_BBT_RESERVED_BLOCKS;
+		this->bbt_td->reserved_block_code = 0x01;
+		this->bbt_td->pattern = "MSYS_BBT";
+
+		this->bbt_md->options = NAND_BBT_LASTBLOCK | NAND_BBT_8BIT | NAND_BBT_VERSION;
+		if (inftl_bbt_write)
+			this->bbt_md->options |= NAND_BBT_WRITE;
+		this->bbt_md->offs = 8;
+		this->bbt_md->len = 8;
+		this->bbt_md->veroffs = 7;
+		this->bbt_md->maxblocks = INFTL_BBT_RESERVED_BLOCKS;
+		this->bbt_md->reserved_block_code = 0x01;
+		this->bbt_md->pattern = "TBB_SYSM";
+	}
+
+	ret = nand_create_bbt(this);
+	if (ret)
+		return ret;
+
+	memset((char *)parts, 0, sizeof(parts));
+	numparts = inftl_partscan(mtd, parts);
+	/* At least for now, require the INFTL Media Header.  We could probably
+	   do without it for non-INFTL use, since all it gives us is
+	   autopartitioning, but I want to give it more thought. */
+	if (!numparts)
+		return -EIO;
+	return mtd_device_register(mtd, parts, no_autopart ? 0 : numparts);
+}
+
+static inline int __init doc2000_init(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd_to_nand(mtd);
+	struct doc_priv *doc = nand_get_controller_data(this);
+
+	doc->late_init = nftl_scan_bbt;
+
+	doc->CDSNControl = CDSN_CTRL_FLASH_IO | CDSN_CTRL_ECC_IO;
+	doc2000_count_chips(mtd);
+	mtd->name = "DiskOnChip 2000 (NFTL Model)";
+	return (4 * doc->chips_per_floor);
+}
+
+static inline int __init doc2001_init(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd_to_nand(mtd);
+	struct doc_priv *doc = nand_get_controller_data(this);
+
+	ReadDOC(doc->virtadr, ChipID);
+	ReadDOC(doc->virtadr, ChipID);
+	ReadDOC(doc->virtadr, ChipID);
+	if (ReadDOC(doc->virtadr, ChipID) != DOC_ChipID_DocMil) {
+		/* It's not a Millennium; it's one of the newer
+		   DiskOnChip 2000 units with a similar ASIC.
+		   Treat it like a Millennium, except that it
+		   can have multiple chips. */
+		doc2000_count_chips(mtd);
+		mtd->name = "DiskOnChip 2000 (INFTL Model)";
+		doc->late_init = inftl_scan_bbt;
+		return (4 * doc->chips_per_floor);
+	} else {
+		/* Bog-standard Millennium */
+		doc->chips_per_floor = 1;
+		mtd->name = "DiskOnChip Millennium";
+		doc->late_init = nftl_scan_bbt;
+		return 1;
+	}
+}
+
+static inline int __init doc2001plus_init(struct mtd_info *mtd)
+{
+	struct nand_chip *this = mtd_to_nand(mtd);
+	struct doc_priv *doc = nand_get_controller_data(this);
+
+	doc->late_init = inftl_scan_bbt;
+	this->ecc.hwctl = doc2001plus_enable_hwecc;
+
+	doc->chips_per_floor = 1;
+	mtd->name = "DiskOnChip Millennium Plus";
+
+	return 1;
+}
+
+static int doc200x_attach_chip(struct nand_chip *chip)
+{
+	if (chip->ecc.engine_type != NAND_ECC_ENGINE_TYPE_ON_HOST)
+		return 0;
+
+	chip->ecc.placement = NAND_ECC_PLACEMENT_INTERLEAVED;
+	chip->ecc.size = 512;
+	chip->ecc.bytes = 6;
+	chip->ecc.strength = 2;
+	chip->ecc.options = NAND_ECC_GENERIC_ERASED_CHECK;
+	chip->ecc.hwctl = doc200x_enable_hwecc;
+	chip->ecc.calculate = doc200x_calculate_ecc;
+	chip->ecc.correct = doc200x_correct_data;
+
+	return 0;
+}
+
+static const struct nand_controller_ops doc200x_ops = {
+	.exec_op = doc200x_exec_op,
+	.attach_chip = doc200x_attach_chip,
+};
+
+static const struct nand_controller_ops doc2001plus_ops = {
+	.exec_op = doc2001plus_exec_op,
+	.attach_chip = doc200x_attach_chip,
+};
+
+static int __init doc_probe(unsigned long physadr)
+{
+	struct nand_chip *nand = NULL;
+	struct doc_priv *doc = NULL;
+	unsigned char ChipID;
+	struct mtd_info *mtd;
+	void __iomem *virtadr;
+	unsigned char save_control;
+	unsigned char tmp, tmpb, tmpc;
+	int reg, len, numchips;
+	int ret = 0;
+
+	if (!request_mem_region(physadr, DOC_IOREMAP_LEN, "DiskOnChip"))
+		return -EBUSY;
+	virtadr = ioremap(physadr, DOC_IOREMAP_LEN);
+	if (!virtadr) {
+		pr_err("Diskonchip ioremap failed: 0x%x bytes at 0x%lx\n",
+		       DOC_IOREMAP_LEN, physadr);
+		ret = -EIO;
+		goto error_ioremap;
+	}
+
+	/* It's not possible to cleanly detect the DiskOnChip - the
+	 * bootup procedure will put the device into reset mode, and
+	 * it's not possible to talk to it without actually writing
+	 * to the DOCControl register. So we store the current contents
+	 * of the DOCControl register's location, in case we later decide
+	 * that it's not a DiskOnChip, and want to put it back how we
+	 * found it.
+	 */
+	save_control = ReadDOC(virtadr, DOCControl);
+
+	/* Reset the DiskOnChip ASIC */
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET, virtadr, DOCControl);
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET, virtadr, DOCControl);
+
+	/* Enable the DiskOnChip ASIC */
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL, virtadr, DOCControl);
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL, virtadr, DOCControl);
+
+	ChipID = ReadDOC(virtadr, ChipID);
+
+	switch (ChipID) {
+	case DOC_ChipID_Doc2k:
+		reg = DoC_2k_ECCStatus;
+		break;
+	case DOC_ChipID_DocMil:
+		reg = DoC_ECCConf;
+		break;
+	case DOC_ChipID_DocMilPlus16:
+	case DOC_ChipID_DocMilPlus32:
+	case 0:
+		/* Possible Millennium Plus, need to do more checks */
+		/* Possibly release from power down mode */
+		for (tmp = 0; (tmp < 4); tmp++)
+			ReadDOC(virtadr, Mplus_Power);
+
+		/* Reset the Millennium Plus ASIC */
+		tmp = DOC_MODE_RESET | DOC_MODE_MDWREN | DOC_MODE_RST_LAT | DOC_MODE_BDECT;
+		WriteDOC(tmp, virtadr, Mplus_DOCControl);
+		WriteDOC(~tmp, virtadr, Mplus_CtrlConfirm);
+
+		usleep_range(1000, 2000);
+		/* Enable the Millennium Plus ASIC */
+		tmp = DOC_MODE_NORMAL | DOC_MODE_MDWREN | DOC_MODE_RST_LAT | DOC_MODE_BDECT;
+		WriteDOC(tmp, virtadr, Mplus_DOCControl);
+		WriteDOC(~tmp, virtadr, Mplus_CtrlConfirm);
+		usleep_range(1000, 2000);
+
+		ChipID = ReadDOC(virtadr, ChipID);
+
+		switch (ChipID) {
+		case DOC_ChipID_DocMilPlus16:
+			reg = DoC_Mplus_Toggle;
+			break;
+		case DOC_ChipID_DocMilPlus32:
+			pr_err("DiskOnChip Millennium Plus 32MB is not supported, ignoring.\n");
+			fallthrough;
+		default:
+			ret = -ENODEV;
+			goto notfound;
+		}
+		break;
+
+	default:
+		ret = -ENODEV;
+		goto notfound;
+	}
+	/* Check the TOGGLE bit in the ECC register */
+	tmp = ReadDOC_(virtadr, reg) & DOC_TOGGLE_BIT;
+	tmpb = ReadDOC_(virtadr, reg) & DOC_TOGGLE_BIT;
+	tmpc = ReadDOC_(virtadr, reg) & DOC_TOGGLE_BIT;
+	if ((tmp == tmpb) || (tmp != tmpc)) {
+		pr_warn("Possible DiskOnChip at 0x%lx failed TOGGLE test, dropping.\n", physadr);
+		ret = -ENODEV;
+		goto notfound;
+	}
+
+	for (mtd = doclist; mtd; mtd = doc->nextdoc) {
+		unsigned char oldval;
+		unsigned char newval;
+		nand = mtd_to_nand(mtd);
+		doc = nand_get_controller_data(nand);
+		/* Use the alias resolution register to determine if this is
+		   in fact the same DOC aliased to a new address.  If writes
+		   to one chip's alias resolution register change the value on
+		   the other chip, they're the same chip. */
+		if (ChipID == DOC_ChipID_DocMilPlus16) {
+			oldval = ReadDOC(doc->virtadr, Mplus_AliasResolution);
+			newval = ReadDOC(virtadr, Mplus_AliasResolution);
+		} else {
+			oldval = ReadDOC(doc->virtadr, AliasResolution);
+			newval = ReadDOC(virtadr, AliasResolution);
+		}
+		if (oldval != newval)
+			continue;
+		if (ChipID == DOC_ChipID_DocMilPlus16) {
+			WriteDOC(~newval, virtadr, Mplus_AliasResolution);
+			oldval = ReadDOC(doc->virtadr, Mplus_AliasResolution);
+			WriteDOC(newval, virtadr, Mplus_AliasResolution);	// restore it
+		} else {
+			WriteDOC(~newval, virtadr, AliasResolution);
+			oldval = ReadDOC(doc->virtadr, AliasResolution);
+			WriteDOC(newval, virtadr, AliasResolution);	// restore it
+		}
+		newval = ~newval;
+		if (oldval == newval) {
+			pr_debug("Found alias of DOC at 0x%lx to 0x%lx\n",
+				 doc->physadr, physadr);
+			goto notfound;
+		}
+	}
+
+	pr_notice("DiskOnChip found at 0x%lx\n", physadr);
+
+	len = sizeof(struct nand_chip) + sizeof(struct doc_priv) +
+	      (2 * sizeof(struct nand_bbt_descr));
+	nand = kzalloc(len, GFP_KERNEL);
+	if (!nand) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	/*
+	 * Allocate a RS codec instance
+	 *
+	 * Symbolsize is 10 (bits)
+	 * Primitve polynomial is x^10+x^3+1
+	 * First consecutive root is 510
+	 * Primitve element to generate roots = 1
+	 * Generator polinomial degree = 4
+	 */
+	doc = (struct doc_priv *) (nand + 1);
+	doc->rs_decoder = init_rs(10, 0x409, FCR, 1, NROOTS);
+	if (!doc->rs_decoder) {
+		pr_err("DiskOnChip: Could not create a RS codec\n");
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	nand_controller_init(&doc->base);
+	if (ChipID == DOC_ChipID_DocMilPlus16)
+		doc->base.ops = &doc2001plus_ops;
+	else
+		doc->base.ops = &doc200x_ops;
+
+	mtd			= nand_to_mtd(nand);
+	nand->bbt_td		= (struct nand_bbt_descr *) (doc + 1);
+	nand->bbt_md		= nand->bbt_td + 1;
+
+	mtd->owner		= THIS_MODULE;
+	mtd_set_ooblayout(mtd, &doc200x_ooblayout_ops);
+
+	nand->controller	= &doc->base;
+	nand_set_controller_data(nand, doc);
+	nand->bbt_options	= NAND_BBT_USE_FLASH;
+	/* Skip the automatic BBT scan so we can run it manually */
+	nand->options		|= NAND_SKIP_BBTSCAN | NAND_NO_BBM_QUIRK;
+
+	doc->physadr		= physadr;
+	doc->virtadr		= virtadr;
+	doc->ChipID		= ChipID;
+	doc->curfloor		= -1;
+	doc->curchip		= -1;
+	doc->mh0_page		= -1;
+	doc->mh1_page		= -1;
+	doc->nextdoc		= doclist;
+
+	if (ChipID == DOC_ChipID_Doc2k)
+		numchips = doc2000_init(mtd);
+	else if (ChipID == DOC_ChipID_DocMilPlus16)
+		numchips = doc2001plus_init(mtd);
+	else
+		numchips = doc2001_init(mtd);
+
+	if ((ret = nand_scan(nand, numchips)) || (ret = doc->late_init(mtd))) {
+		/* DBB note: i believe nand_cleanup is necessary here, as
+		   buffers may have been allocated in nand_base.  Check with
+		   Thomas. FIX ME! */
+		nand_cleanup(nand);
+		goto fail;
+	}
+
+	/* Success! */
+	doclist = mtd;
+	return 0;
+
+ notfound:
+	/* Put back the contents of the DOCControl register, in case it's not
+	   actually a DiskOnChip.  */
+	WriteDOC(save_control, virtadr, DOCControl);
+ fail:
+	if (doc)
+		free_rs(doc->rs_decoder);
+	kfree(nand);
+	iounmap(virtadr);
+
+error_ioremap:
+	release_mem_region(physadr, DOC_IOREMAP_LEN);
+
+	return ret;
+}
+
+static void release_nanddoc(void)
+{
+	struct mtd_info *mtd, *nextmtd;
+	struct nand_chip *nand;
+	struct doc_priv *doc;
+	int ret;
+
+	for (mtd = doclist; mtd; mtd = nextmtd) {
+		nand = mtd_to_nand(mtd);
+		doc = nand_get_controller_data(nand);
+
+		nextmtd = doc->nextdoc;
+		ret = mtd_device_unregister(mtd);
+		WARN_ON(ret);
+		nand_cleanup(nand);
+		iounmap(doc->virtadr);
+		release_mem_region(doc->physadr, DOC_IOREMAP_LEN);
+		free_rs(doc->rs_decoder);
+		kfree(nand);
+	}
+}
+
+static int __init init_nanddoc(void)
+{
+	int i, ret = 0;
+
+	if (doc_config_location) {
+		pr_info("Using configured DiskOnChip probe address 0x%lx\n",
+			doc_config_location);
+		ret = doc_probe(doc_config_location);
+		if (ret < 0)
+			return ret;
+	} else {
+		for (i = 0; (doc_locations[i] != 0xffffffff); i++) {
+			doc_probe(doc_locations[i]);
+		}
+	}
+	/* No banner message any more. Print a message if no DiskOnChip
+	   found, so the user knows we at least tried. */
+	if (!doclist) {
+		pr_info("No valid DiskOnChip devices found\n");
+		ret = -ENODEV;
+	}
+	return ret;
+}
+
+static void __exit cleanup_nanddoc(void)
+{
+	/* Cleanup the nand/DoC resources */
+	release_nanddoc();
+}
+
+module_init(init_nanddoc);
+module_exit(cleanup_nanddoc);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
+MODULE_DESCRIPTION("M-Systems DiskOnChip 2000, Millennium and Millennium Plus device driver");