patch-2.4.6 linux/drivers/mtd/devices/doc2000.c

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diff -u --recursive --new-file v2.4.5/linux/drivers/mtd/devices/doc2000.c linux/drivers/mtd/devices/doc2000.c
@@ -0,0 +1,1121 @@
+
+/*
+ * Linux driver for Disk-On-Chip 2000 and Millennium
+ * (c) 1999 Machine Vision Holdings, Inc.
+ * (c) 1999, 2000 David Woodhouse <dwmw2@infradead.org>
+ *
+ * $Id: doc2000.c,v 1.43 2001/06/02 14:30:43 dwmw2 Exp $
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/errno.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <linux/miscdevice.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/types.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/nand_ids.h>
+#include <linux/mtd/doc2000.h>
+
+#define DOC_SUPPORT_2000
+#define DOC_SUPPORT_MILLENNIUM
+
+#ifdef DOC_SUPPORT_2000
+#define DoC_is_2000(doc) (doc->ChipID == DOC_ChipID_Doc2k)
+#else
+#define DoC_is_2000(doc) (0)
+#endif
+
+#ifdef DOC_SUPPORT_MILLENNIUM
+#define DoC_is_Millennium(doc) (doc->ChipID == DOC_ChipID_DocMil)
+#else
+#define DoC_is_Millennium(doc) (0)
+#endif
+
+/* #define ECC_DEBUG */
+
+/* I have no idea why some DoC chips can not use memcpy_from|to_io().
+ * This may be due to the different revisions of the ASIC controller built-in or
+ * simplily a QA/Bug issue. Who knows ?? If you have trouble, please uncomment
+ * this:
+ #undef USE_MEMCPY
+*/
+
+static int doc_read(struct mtd_info *mtd, loff_t from, size_t len,
+		    size_t *retlen, u_char *buf);
+static int doc_write(struct mtd_info *mtd, loff_t to, size_t len,
+		     size_t *retlen, const u_char *buf);
+static int doc_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, u_char *buf, u_char *eccbuf);
+static int doc_write_ecc(struct mtd_info *mtd, loff_t to, size_t len,
+			 size_t *retlen, const u_char *buf, u_char *eccbuf);
+static int doc_read_oob(struct mtd_info *mtd, loff_t ofs, size_t len,
+			size_t *retlen, u_char *buf);
+static int doc_write_oob(struct mtd_info *mtd, loff_t ofs, size_t len,
+			 size_t *retlen, const u_char *buf);
+static int doc_erase (struct mtd_info *mtd, struct erase_info *instr);
+
+static struct mtd_info *doc2klist = NULL;
+
+/* Perform the required delay cycles by reading from the appropriate register */
+static void DoC_Delay(struct DiskOnChip *doc, unsigned short cycles)
+{
+	volatile char dummy;
+	int i;
+	
+	for (i = 0; i < cycles; i++) {
+		if (DoC_is_Millennium(doc))
+			dummy = ReadDOC(doc->virtadr, NOP);
+		else
+			dummy = ReadDOC(doc->virtadr, DOCStatus);
+	}
+	
+}
+
+/* DOC_WaitReady: Wait for RDY line to be asserted by the flash chip */
+static int _DoC_WaitReady(struct DiskOnChip *doc)
+{
+	unsigned long docptr = doc->virtadr;
+	unsigned short c = 0xffff;
+
+	DEBUG(MTD_DEBUG_LEVEL3,
+	      "_DoC_WaitReady called for out-of-line wait\n");
+
+	/* Out-of-line routine to wait for chip response */
+	while (!(ReadDOC(docptr, CDSNControl) & CDSN_CTRL_FR_B) && --c)
+		;
+
+	if (c == 0)
+		DEBUG(MTD_DEBUG_LEVEL2, "_DoC_WaitReady timed out.\n");
+
+	return (c == 0);
+}
+
+static inline int DoC_WaitReady(struct DiskOnChip *doc)
+{
+	unsigned long docptr = doc->virtadr;
+	/* This is inline, to optimise the common case, where it's ready instantly */
+	int ret = 0;
+
+	/* 4 read form NOP register should be issued in prior to the read from CDSNControl
+	   see Software Requirement 11.4 item 2. */
+	DoC_Delay(doc, 4);
+
+	if (!(ReadDOC(docptr, CDSNControl) & CDSN_CTRL_FR_B))
+		/* Call the out-of-line routine to wait */
+		ret = _DoC_WaitReady(doc);
+
+	/* issue 2 read from NOP register after reading from CDSNControl register
+	   see Software Requirement 11.4 item 2. */
+	DoC_Delay(doc, 2);
+
+	return ret;
+}
+
+/* DoC_Command: Send a flash command to the flash chip through the CDSN Slow IO register to
+   bypass the internal pipeline. Each of 4 delay cycles (read from the NOP register) is
+   required after writing to CDSN Control register, see Software Requirement 11.4 item 3. */
+
+static inline int DoC_Command(struct DiskOnChip *doc, unsigned char command,
+			      unsigned char xtraflags)
+{
+	unsigned long docptr = doc->virtadr;
+
+	if (DoC_is_2000(doc))
+		xtraflags |= CDSN_CTRL_FLASH_IO;
+
+	/* Assert the CLE (Command Latch Enable) line to the flash chip */
+	WriteDOC(xtraflags | CDSN_CTRL_CLE | CDSN_CTRL_CE, docptr, CDSNControl);
+	DoC_Delay(doc, 4);	/* Software requirement 11.4.3 for Millennium */
+
+	if (DoC_is_Millennium(doc))
+		WriteDOC(command, docptr, CDSNSlowIO);
+
+	/* Send the command */
+	WriteDOC_(command, docptr, doc->ioreg);
+
+	/* Lower the CLE line */
+	WriteDOC(xtraflags | CDSN_CTRL_CE, docptr, CDSNControl);
+	DoC_Delay(doc, 4);	/* Software requirement 11.4.3 for Millennium */
+
+	/* Wait for the chip to respond - Software requirement 11.4.1 (extended for any command) */
+	return DoC_WaitReady(doc);
+}
+
+/* DoC_Address: Set the current address for the flash chip through the CDSN Slow IO register to
+   bypass the internal pipeline. Each of 4 delay cycles (read from the NOP register) is
+   required after writing to CDSN Control register, see Software Requirement 11.4 item 3. */
+
+static int DoC_Address(struct DiskOnChip *doc, int numbytes, unsigned long ofs,
+		       unsigned char xtraflags1, unsigned char xtraflags2)
+{
+	unsigned long docptr;
+	int i;
+
+	docptr = doc->virtadr;
+
+	if (DoC_is_2000(doc))
+		xtraflags1 |= CDSN_CTRL_FLASH_IO;
+
+	/* Assert the ALE (Address Latch Enable) line to the flash chip */
+	WriteDOC(xtraflags1 | CDSN_CTRL_ALE | CDSN_CTRL_CE, docptr, CDSNControl);
+
+	DoC_Delay(doc, 4);	/* Software requirement 11.4.3 for Millennium */
+
+	/* Send the address */
+	/* Devices with 256-byte page are addressed as:
+	   Column (bits 0-7), Page (bits 8-15, 16-23, 24-31)
+	   * there is no device on the market with page256
+	   and more than 24 bits.
+	   Devices with 512-byte page are addressed as:
+	   Column (bits 0-7), Page (bits 9-16, 17-24, 25-31)
+	   * 25-31 is sent only if the chip support it.
+	   * bit 8 changes the read command to be sent
+	   (NAND_CMD_READ0 or NAND_CMD_READ1).
+	 */
+
+	if (numbytes == ADDR_COLUMN || numbytes == ADDR_COLUMN_PAGE) {
+		if (DoC_is_Millennium(doc))
+			WriteDOC(ofs & 0xff, docptr, CDSNSlowIO);
+		WriteDOC_(ofs & 0xff, docptr, doc->ioreg);
+	}
+
+	if (doc->page256) {
+		ofs = ofs >> 8;
+	} else {
+		ofs = ofs >> 9;
+	}
+
+	if (numbytes == ADDR_PAGE || numbytes == ADDR_COLUMN_PAGE) {
+		for (i = 0; i < doc->pageadrlen; i++, ofs = ofs >> 8) {
+			if (DoC_is_Millennium(doc))
+				WriteDOC(ofs & 0xff, docptr, CDSNSlowIO);
+			WriteDOC_(ofs & 0xff, docptr, doc->ioreg);
+		}
+	}
+
+	DoC_Delay(doc, 2);	/* Needed for some slow flash chips. mf. */
+	
+	/* FIXME: The SlowIO's for millennium could be replaced by 
+	   a single WritePipeTerm here. mf. */
+
+	/* Lower the ALE line */
+	WriteDOC(xtraflags1 | xtraflags2 | CDSN_CTRL_CE, docptr,
+		 CDSNControl);
+
+	DoC_Delay(doc, 4);	/* Software requirement 11.4.3 for Millennium */
+
+	/* Wait for the chip to respond - Software requirement 11.4.1 */
+	return DoC_WaitReady(doc);
+}
+
+/* Read a buffer from DoC, taking care of Millennium odditys */
+static void DoC_ReadBuf(struct DiskOnChip *doc, u_char * buf, int len)
+{
+	int dummy;
+	int modulus = 0xffff;
+	unsigned long docptr;
+	int i;
+
+	docptr = doc->virtadr;
+
+	if (len <= 0)
+		return;
+
+	if (DoC_is_Millennium(doc)) {
+		/* Read the data via the internal pipeline through CDSN IO register,
+		   see Pipelined Read Operations 11.3 */
+		dummy = ReadDOC(docptr, ReadPipeInit);
+
+		/* Millennium should use the LastDataRead register - Pipeline Reads */
+		len--;
+
+		/* This is needed for correctly ECC calculation */
+		modulus = 0xff;
+	}
+
+	for (i = 0; i < len; i++)
+		buf[i] = ReadDOC_(docptr, doc->ioreg + (i & modulus));
+
+	if (DoC_is_Millennium(doc)) {
+		buf[i] = ReadDOC(docptr, LastDataRead);
+	}
+}
+
+/* Write a buffer to DoC, taking care of Millennium odditys */
+static void DoC_WriteBuf(struct DiskOnChip *doc, const u_char * buf, int len)
+{
+	unsigned long docptr;
+	int i;
+
+	docptr = doc->virtadr;
+
+	if (len <= 0)
+		return;
+
+	for (i = 0; i < len; i++)
+		WriteDOC_(buf[i], docptr, doc->ioreg + i);
+
+	if (DoC_is_Millennium(doc)) {
+		WriteDOC(0x00, docptr, WritePipeTerm);
+	}
+}
+
+
+/* DoC_SelectChip: Select a given flash chip within the current floor */
+
+static inline int DoC_SelectChip(struct DiskOnChip *doc, int chip)
+{
+	unsigned long docptr = doc->virtadr;
+
+	/* Software requirement 11.4.4 before writing DeviceSelect */
+	/* Deassert the CE line to eliminate glitches on the FCE# outputs */
+	WriteDOC(CDSN_CTRL_WP, docptr, CDSNControl);
+	DoC_Delay(doc, 4);	/* Software requirement 11.4.3 for Millennium */
+
+	/* Select the individual flash chip requested */
+	WriteDOC(chip, docptr, CDSNDeviceSelect);
+	DoC_Delay(doc, 4);
+
+	/* Reassert the CE line */
+	WriteDOC(CDSN_CTRL_CE | CDSN_CTRL_FLASH_IO | CDSN_CTRL_WP, docptr,
+		 CDSNControl);
+	DoC_Delay(doc, 4);	/* Software requirement 11.4.3 for Millennium */
+
+	/* Wait for it to be ready */
+	return DoC_WaitReady(doc);
+}
+
+/* DoC_SelectFloor: Select a given floor (bank of flash chips) */
+
+static inline int DoC_SelectFloor(struct DiskOnChip *doc, int floor)
+{
+	unsigned long docptr = doc->virtadr;
+
+	/* Select the floor (bank) of chips required */
+	WriteDOC(floor, docptr, FloorSelect);
+
+	/* Wait for the chip to be ready */
+	return DoC_WaitReady(doc);
+}
+
+/* DoC_IdentChip: Identify a given NAND chip given {floor,chip} */
+
+static int DoC_IdentChip(struct DiskOnChip *doc, int floor, int chip)
+{
+	int mfr, id, i;
+	volatile char dummy;
+
+	/* Page in the required floor/chip */
+	DoC_SelectFloor(doc, floor);
+	DoC_SelectChip(doc, chip);
+
+	/* Reset the chip */
+	if (DoC_Command(doc, NAND_CMD_RESET, CDSN_CTRL_WP)) {
+		DEBUG(MTD_DEBUG_LEVEL2,
+		      "DoC_Command (reset) for %d,%d returned true\n",
+		      floor, chip);
+		return 0;
+	}
+
+
+	/* Read the NAND chip ID: 1. Send ReadID command */
+	if (DoC_Command(doc, NAND_CMD_READID, CDSN_CTRL_WP)) {
+		DEBUG(MTD_DEBUG_LEVEL2,
+		      "DoC_Command (ReadID) for %d,%d returned true\n",
+		      floor, chip);
+		return 0;
+	}
+
+	/* Read the NAND chip ID: 2. Send address byte zero */
+	DoC_Address(doc, ADDR_COLUMN, 0, CDSN_CTRL_WP, 0);
+
+	/* Read the manufacturer and device id codes from the device */
+
+	/* CDSN Slow IO register see Software Requirement 11.4 item 5. */
+	dummy = ReadDOC(doc->virtadr, CDSNSlowIO);
+	DoC_Delay(doc, 2);
+	mfr = ReadDOC_(doc->virtadr, doc->ioreg);
+
+	/* CDSN Slow IO register see Software Requirement 11.4 item 5. */
+	dummy = ReadDOC(doc->virtadr, CDSNSlowIO);
+	DoC_Delay(doc, 2);
+	id = ReadDOC_(doc->virtadr, doc->ioreg);
+
+	/* No response - return failure */
+	if (mfr == 0xff || mfr == 0)
+		return 0;
+
+	/* Check it's the same as the first chip we identified. 
+	 * M-Systems say that any given DiskOnChip device should only
+	 * contain _one_ type of flash part, although that's not a 
+	 * hardware restriction. */
+	if (doc->mfr) {
+		if (doc->mfr == mfr && doc->id == id)
+			return 1;	/* This is another the same the first */
+		else
+			printk(KERN_WARNING
+			       "Flash chip at floor %d, chip %d is different:\n",
+			       floor, chip);
+	}
+
+	/* Print and store the manufacturer and ID codes. */
+	for (i = 0; nand_flash_ids[i].name != NULL; i++) {
+		if (mfr == nand_flash_ids[i].manufacture_id &&
+		    id == nand_flash_ids[i].model_id) {
+			printk(KERN_INFO
+			       "Flash chip found: Manufacturer ID: %2.2X, "
+			       "Chip ID: %2.2X (%s)\n", mfr, id,
+			       nand_flash_ids[i].name);
+			if (!doc->mfr) {
+				doc->mfr = mfr;
+				doc->id = id;
+				doc->chipshift =
+				    nand_flash_ids[i].chipshift;
+				doc->page256 = nand_flash_ids[i].page256;
+				doc->pageadrlen =
+				    nand_flash_ids[i].pageadrlen;
+				doc->erasesize =
+				    nand_flash_ids[i].erasesize;
+				return 1;
+			}
+			return 0;
+		}
+	}
+
+
+	/* We haven't fully identified the chip. Print as much as we know. */
+	printk(KERN_WARNING "Unknown flash chip found: %2.2X %2.2X\n",
+	       id, mfr);
+
+	printk(KERN_WARNING "Please report to dwmw2@infradead.org\n");
+	return 0;
+}
+
+/* DoC_ScanChips: Find all NAND chips present in a DiskOnChip, and identify them */
+
+static void DoC_ScanChips(struct DiskOnChip *this)
+{
+	int floor, chip;
+	int numchips[MAX_FLOORS];
+	int maxchips = MAX_CHIPS;
+	int ret = 1;
+
+	this->numchips = 0;
+	this->mfr = 0;
+	this->id = 0;
+
+	if (DoC_is_Millennium(this))
+		maxchips = MAX_CHIPS_MIL;
+
+	/* For each floor, find the number of valid chips it contains */
+	for (floor = 0; floor < MAX_FLOORS; floor++) {
+		ret = 1;
+		numchips[floor] = 0;
+		for (chip = 0; chip < maxchips && ret != 0; chip++) {
+
+			ret = DoC_IdentChip(this, floor, chip);
+			if (ret) {
+				numchips[floor]++;
+				this->numchips++;
+			}
+		}
+	}
+
+	/* If there are none at all that we recognise, bail */
+	if (!this->numchips) {
+		printk("No flash chips recognised.\n");
+		return;
+	}
+
+	/* Allocate an array to hold the information for each chip */
+	this->chips = kmalloc(sizeof(struct Nand) * this->numchips, GFP_KERNEL);
+	if (!this->chips) {
+		printk("No memory for allocating chip info structures\n");
+		return;
+	}
+
+	ret = 0;
+
+	/* Fill out the chip array with {floor, chipno} for each 
+	 * detected chip in the device. */
+	for (floor = 0; floor < MAX_FLOORS; floor++) {
+		for (chip = 0; chip < numchips[floor]; chip++) {
+			this->chips[ret].floor = floor;
+			this->chips[ret].chip = chip;
+			this->chips[ret].curadr = 0;
+			this->chips[ret].curmode = 0x50;
+			ret++;
+		}
+	}
+
+	/* Calculate and print the total size of the device */
+	this->totlen = this->numchips * (1 << this->chipshift);
+
+	printk(KERN_INFO "%d flash chips found. Total DiskOnChip size: %ld MiB\n",
+	       this->numchips, this->totlen >> 20);
+}
+
+static int DoC2k_is_alias(struct DiskOnChip *doc1, struct DiskOnChip *doc2)
+{
+	int tmp1, tmp2, retval;
+	if (doc1->physadr == doc2->physadr)
+		return 1;
+
+	/* Use the alias resolution register which was set aside for this
+	 * purpose. If it's value is the same on both chips, they might
+	 * be the same chip, and we write to one and check for a change in
+	 * the other. It's unclear if this register is usuable in the
+	 * DoC 2000 (it's in the Millennium docs), but it seems to work. */
+	tmp1 = ReadDOC(doc1->virtadr, AliasResolution);
+	tmp2 = ReadDOC(doc2->virtadr, AliasResolution);
+	if (tmp1 != tmp2)
+		return 0;
+
+	WriteDOC((tmp1 + 1) % 0xff, doc1->virtadr, AliasResolution);
+	tmp2 = ReadDOC(doc2->virtadr, AliasResolution);
+	if (tmp2 == (tmp1 + 1) % 0xff)
+		retval = 1;
+	else
+		retval = 0;
+
+	/* Restore register contents.  May not be necessary, but do it just to
+	 * be safe. */
+	WriteDOC(tmp1, doc1->virtadr, AliasResolution);
+
+	return retval;
+}
+
+static const char im_name[] = "DoC2k_init";
+
+/* This routine is made available to other mtd code via
+ * inter_module_register.  It must only be accessed through
+ * inter_module_get which will bump the use count of this module.  The
+ * addresses passed back in mtd are valid as long as the use count of
+ * this module is non-zero, i.e. between inter_module_get and
+ * inter_module_put.  Keith Owens <kaos@ocs.com.au> 29 Oct 2000.
+ */
+static void DoC2k_init(struct mtd_info *mtd)
+{
+	struct DiskOnChip *this = (struct DiskOnChip *) mtd->priv;
+	struct DiskOnChip *old = NULL;
+
+	/* We must avoid being called twice for the same device. */
+
+	if (doc2klist)
+		old = (struct DiskOnChip *) doc2klist->priv;
+
+	while (old) {
+		if (DoC2k_is_alias(old, this)) {
+			printk(KERN_NOTICE
+			       "Ignoring DiskOnChip 2000 at 0x%lX - already configured\n",
+			       this->physadr);
+			iounmap((void *) this->virtadr);
+			kfree(mtd);
+			return;
+		}
+		if (old->nextdoc)
+			old = (struct DiskOnChip *) old->nextdoc->priv;
+		else
+			old = NULL;
+	}
+
+
+	switch (this->ChipID) {
+	case DOC_ChipID_Doc2k:
+		mtd->name = "DiskOnChip 2000";
+		this->ioreg = DoC_2k_CDSN_IO;
+		break;
+	case DOC_ChipID_DocMil:
+		mtd->name = "DiskOnChip Millennium";
+		this->ioreg = DoC_Mil_CDSN_IO;
+		break;
+	}
+
+	printk(KERN_NOTICE "%s found at address 0x%lX\n", mtd->name,
+	       this->physadr);
+
+	mtd->type = MTD_NANDFLASH;
+	mtd->flags = MTD_CAP_NANDFLASH;
+	mtd->size = 0;
+	mtd->erasesize = 0;
+	mtd->oobblock = 512;
+	mtd->oobsize = 16;
+	mtd->module = THIS_MODULE;
+	mtd->erase = doc_erase;
+	mtd->point = NULL;
+	mtd->unpoint = NULL;
+	mtd->read = doc_read;
+	mtd->write = doc_write;
+	mtd->read_ecc = doc_read_ecc;
+	mtd->write_ecc = doc_write_ecc;
+	mtd->read_oob = doc_read_oob;
+	mtd->write_oob = doc_write_oob;
+	mtd->sync = NULL;
+
+	this->totlen = 0;
+	this->numchips = 0;
+
+	this->curfloor = -1;
+	this->curchip = -1;
+
+	/* Ident all the chips present. */
+	DoC_ScanChips(this);
+
+	if (!this->totlen) {
+		kfree(mtd);
+		iounmap((void *) this->virtadr);
+	} else {
+		this->nextdoc = doc2klist;
+		doc2klist = mtd;
+		mtd->size = this->totlen;
+		mtd->erasesize = this->erasesize;
+		add_mtd_device(mtd);
+		return;
+	}
+}
+
+static int doc_read(struct mtd_info *mtd, loff_t from, size_t len,
+		    size_t * retlen, u_char * buf)
+{
+	/* Just a special case of doc_read_ecc */
+	return doc_read_ecc(mtd, from, len, retlen, buf, NULL);
+}
+
+static int doc_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t * retlen, u_char * buf, u_char * eccbuf)
+{
+	struct DiskOnChip *this = (struct DiskOnChip *) mtd->priv;
+	unsigned long docptr;
+	struct Nand *mychip;
+	unsigned char syndrome[6];
+	volatile char dummy;
+	int i, len256 = 0, ret=0;
+
+	docptr = this->virtadr;
+
+	/* Don't allow read past end of device */
+	if (from >= this->totlen)
+		return -EINVAL;
+
+	/* Don't allow a single read to cross a 512-byte block boundary */
+	if (from + len > ((from | 0x1ff) + 1))
+		len = ((from | 0x1ff) + 1) - from;
+
+	/* The ECC will not be calculated correctly if less than 512 is read */
+	if (len != 0x200 && eccbuf)
+		printk(KERN_WARNING
+		       "ECC needs a full sector read (adr: %lx size %lx)\n",
+		       (long) from, (long) len);
+
+	/* printk("DoC_Read (adr: %lx size %lx)\n", (long) from, (long) len); */
+
+
+	/* Find the chip which is to be used and select it */
+	mychip = &this->chips[from >> (this->chipshift)];
+
+	if (this->curfloor != mychip->floor) {
+		DoC_SelectFloor(this, mychip->floor);
+		DoC_SelectChip(this, mychip->chip);
+	} else if (this->curchip != mychip->chip) {
+		DoC_SelectChip(this, mychip->chip);
+	}
+
+	this->curfloor = mychip->floor;
+	this->curchip = mychip->chip;
+
+	DoC_Command(this,
+		    (!this->page256
+		     && (from & 0x100)) ? NAND_CMD_READ1 : NAND_CMD_READ0,
+		    CDSN_CTRL_WP);
+	DoC_Address(this, ADDR_COLUMN_PAGE, from, CDSN_CTRL_WP,
+		    CDSN_CTRL_ECC_IO);
+
+	if (eccbuf) {
+		/* Prime the ECC engine */
+		WriteDOC(DOC_ECC_RESET, docptr, ECCConf);
+		WriteDOC(DOC_ECC_EN, docptr, ECCConf);
+	} else {
+		/* disable the ECC engine */
+		WriteDOC(DOC_ECC_RESET, docptr, ECCConf);
+		WriteDOC(DOC_ECC_DIS, docptr, ECCConf);
+	}
+
+	/* treat crossing 256-byte sector for 2M x 8bits devices */
+	if (this->page256 && from + len > (from | 0xff) + 1) {
+		len256 = (from | 0xff) + 1 - from;
+		DoC_ReadBuf(this, buf, len256);
+
+		DoC_Command(this, NAND_CMD_READ0, CDSN_CTRL_WP);
+		DoC_Address(this, ADDR_COLUMN_PAGE, from + len256,
+			    CDSN_CTRL_WP, CDSN_CTRL_ECC_IO);
+	}
+
+	DoC_ReadBuf(this, &buf[len256], len - len256);
+
+	/* Let the caller know we completed it */
+	*retlen = len;
+
+	if (eccbuf) {
+		/* Read the ECC data through the DiskOnChip ECC logic */
+		/* Note: this will work even with 2M x 8bit devices as   */
+		/*       they have 8 bytes of OOB per 256 page. mf.      */
+		DoC_ReadBuf(this, eccbuf, 6);
+
+		/* Flush the pipeline */
+		if (DoC_is_Millennium(this)) {
+			dummy = ReadDOC(docptr, ECCConf);
+			dummy = ReadDOC(docptr, ECCConf);
+			i = ReadDOC(docptr, ECCConf);
+		} else {
+			dummy = ReadDOC(docptr, 2k_ECCStatus);
+			dummy = ReadDOC(docptr, 2k_ECCStatus);
+			i = ReadDOC(docptr, 2k_ECCStatus);
+		}
+
+		/* Check the ECC Status */
+		if (i & 0x80) {
+			int nb_errors;
+			/* There was an ECC error */
+#ifdef ECC_DEBUG
+			printk("DiskOnChip ECC Error: Read at %lx\n", (long)from);
+#endif
+			/* Read the ECC syndrom through the DiskOnChip ECC logic.
+			   These syndrome will be all ZERO when there is no error */
+			for (i = 0; i < 6; i++) {
+				syndrome[i] =
+				    ReadDOC(docptr, ECCSyndrome0 + i);
+			}
+                        nb_errors = doc_decode_ecc(buf, syndrome);
+
+#ifdef ECC_DEBUG
+			printk("Errors corrected: %x\n", nb_errors);
+#endif
+                        if (nb_errors < 0) {
+				/* We return error, but have actually done the read. Not that
+				   this can be told to user-space, via sys_read(), but at least
+				   MTD-aware stuff can know about it by checking *retlen */
+				ret = -EIO;
+                        }
+		}
+
+#ifdef PSYCHO_DEBUG
+		printk("ECC DATA at %lxB: %2.2X %2.2X %2.2X %2.2X %2.2X %2.2X\n",
+			     (long)from, eccbuf[0], eccbuf[1], eccbuf[2],
+			     eccbuf[3], eccbuf[4], eccbuf[5]);
+#endif
+		
+		/* disable the ECC engine */
+		WriteDOC(DOC_ECC_DIS, docptr , ECCConf);
+	}
+
+	/* according to 11.4.1, we need to wait for the busy line 
+         * drop if we read to the end of the page.  */
+	if(0 == ((from + *retlen) & 0x1ff))
+	{
+	    DoC_WaitReady(this);
+	}
+
+	return ret;
+}
+
+static int doc_write(struct mtd_info *mtd, loff_t to, size_t len,
+		     size_t * retlen, const u_char * buf)
+{
+	char eccbuf[6];
+	return doc_write_ecc(mtd, to, len, retlen, buf, eccbuf);
+}
+
+static int doc_write_ecc(struct mtd_info *mtd, loff_t to, size_t len,
+			 size_t * retlen, const u_char * buf,
+			 u_char * eccbuf)
+{
+	struct DiskOnChip *this = (struct DiskOnChip *) mtd->priv;
+	int di; /* Yes, DI is a hangover from when I was disassembling the binary driver */
+	unsigned long docptr;
+	volatile char dummy;
+	int len256 = 0;
+	struct Nand *mychip;
+
+	docptr = this->virtadr;
+
+	/* Don't allow write past end of device */
+	if (to >= this->totlen)
+		return -EINVAL;
+
+	/* Don't allow a single write to cross a 512-byte block boundary */
+	if (to + len > ((to | 0x1ff) + 1))
+		len = ((to | 0x1ff) + 1) - to;
+
+	/* The ECC will not be calculated correctly if less than 512 is written */
+	if (len != 0x200 && eccbuf)
+		printk(KERN_WARNING
+		       "ECC needs a full sector write (adr: %lx size %lx)\n",
+		       (long) to, (long) len);
+
+	/* printk("DoC_Write (adr: %lx size %lx)\n", (long) to, (long) len); */
+
+	/* Find the chip which is to be used and select it */
+	mychip = &this->chips[to >> (this->chipshift)];
+
+	if (this->curfloor != mychip->floor) {
+		DoC_SelectFloor(this, mychip->floor);
+		DoC_SelectChip(this, mychip->chip);
+	} else if (this->curchip != mychip->chip) {
+		DoC_SelectChip(this, mychip->chip);
+	}
+
+	this->curfloor = mychip->floor;
+	this->curchip = mychip->chip;
+
+	/* Set device to main plane of flash */
+	DoC_Command(this, NAND_CMD_RESET, CDSN_CTRL_WP);
+	DoC_Command(this,
+		    (!this->page256
+		     && (to & 0x100)) ? NAND_CMD_READ1 : NAND_CMD_READ0,
+		    CDSN_CTRL_WP);
+
+	DoC_Command(this, NAND_CMD_SEQIN, 0);
+	DoC_Address(this, ADDR_COLUMN_PAGE, to, 0, CDSN_CTRL_ECC_IO);
+
+	if (eccbuf) {
+		/* Prime the ECC engine */
+		WriteDOC(DOC_ECC_RESET, docptr, ECCConf);
+		WriteDOC(DOC_ECC_EN | DOC_ECC_RW, docptr, ECCConf);
+	} else {
+		/* disable the ECC engine */
+		WriteDOC(DOC_ECC_RESET, docptr, ECCConf);
+		WriteDOC(DOC_ECC_DIS, docptr, ECCConf);
+	}
+
+	/* treat crossing 256-byte sector for 2M x 8bits devices */
+	if (this->page256 && to + len > (to | 0xff) + 1) {
+		len256 = (to | 0xff) + 1 - to;
+		DoC_WriteBuf(this, buf, len256);
+
+		DoC_Command(this, NAND_CMD_PAGEPROG, 0);
+
+		DoC_Command(this, NAND_CMD_STATUS, CDSN_CTRL_WP);
+		/* There's an implicit DoC_WaitReady() in DoC_Command */
+
+		dummy = ReadDOC(docptr, CDSNSlowIO);
+		DoC_Delay(this, 2);
+
+		if (ReadDOC_(docptr, this->ioreg) & 1) {
+			printk("Error programming flash\n");
+			/* Error in programming */
+			*retlen = 0;
+			return -EIO;
+		}
+
+		DoC_Command(this, NAND_CMD_SEQIN, 0);
+		DoC_Address(this, ADDR_COLUMN_PAGE, to + len256, 0,
+			    CDSN_CTRL_ECC_IO);
+	}
+
+	DoC_WriteBuf(this, &buf[len256], len - len256);
+
+	if (eccbuf) {
+		WriteDOC(CDSN_CTRL_ECC_IO | CDSN_CTRL_CE, docptr,
+			 CDSNControl);
+
+		if (DoC_is_Millennium(this)) {
+			WriteDOC(0, docptr, NOP);
+			WriteDOC(0, docptr, NOP);
+			WriteDOC(0, docptr, NOP);
+		} else {
+			WriteDOC_(0, docptr, this->ioreg);
+			WriteDOC_(0, docptr, this->ioreg);
+			WriteDOC_(0, docptr, this->ioreg);
+		}
+
+		/* Read the ECC data through the DiskOnChip ECC logic */
+		for (di = 0; di < 6; di++) {
+			eccbuf[di] = ReadDOC(docptr, ECCSyndrome0 + di);
+		}
+
+		/* Reset the ECC engine */
+		WriteDOC(DOC_ECC_DIS, docptr, ECCConf);
+
+#ifdef PSYCHO_DEBUG
+		printk
+		    ("OOB data at %lx is %2.2X %2.2X %2.2X %2.2X %2.2X %2.2X\n",
+		     (long) to, eccbuf[0], eccbuf[1], eccbuf[2], eccbuf[3],
+		     eccbuf[4], eccbuf[5]);
+#endif
+	}
+
+	DoC_Command(this, NAND_CMD_PAGEPROG, 0);
+
+	DoC_Command(this, NAND_CMD_STATUS, CDSN_CTRL_WP);
+	/* There's an implicit DoC_WaitReady() in DoC_Command */
+
+	dummy = ReadDOC(docptr, CDSNSlowIO);
+	DoC_Delay(this, 2);
+
+	if (ReadDOC_(docptr, this->ioreg) & 1) {
+		printk("Error programming flash\n");
+		/* Error in programming */
+		*retlen = 0;
+		return -EIO;
+	}
+
+	/* Let the caller know we completed it */
+	*retlen = len;
+		
+	if (eccbuf) {
+		unsigned char x[8];
+		size_t dummy;
+
+		/* Write the ECC data to flash */
+		for (di=0; di<6; di++)
+			x[di] = eccbuf[di];
+		
+		x[6]=0x55;
+		x[7]=0x55;
+		
+		return doc_write_oob(mtd, to, 8, &dummy, x);
+	}
+
+	return 0;
+}
+
+static int doc_read_oob(struct mtd_info *mtd, loff_t ofs, size_t len,
+			size_t * retlen, u_char * buf)
+{
+	struct DiskOnChip *this = (struct DiskOnChip *) mtd->priv;
+	int len256 = 0;
+	unsigned long docptr;
+	struct Nand *mychip;
+
+	docptr = this->virtadr;
+
+	mychip = &this->chips[ofs >> this->chipshift];
+
+	if (this->curfloor != mychip->floor) {
+		DoC_SelectFloor(this, mychip->floor);
+		DoC_SelectChip(this, mychip->chip);
+	} else if (this->curchip != mychip->chip) {
+		DoC_SelectChip(this, mychip->chip);
+	}
+	this->curfloor = mychip->floor;
+	this->curchip = mychip->chip;
+
+	/* update address for 2M x 8bit devices. OOB starts on the second */
+	/* page to maintain compatibility with doc_read_ecc. */
+	if (this->page256) {
+		if (!(ofs & 0x8))
+			ofs += 0x100;
+		else
+			ofs -= 0x8;
+	}
+
+	DoC_Command(this, NAND_CMD_READOOB, CDSN_CTRL_WP);
+	DoC_Address(this, ADDR_COLUMN_PAGE, ofs, CDSN_CTRL_WP, 0);
+
+	/* treat crossing 8-byte OOB data for 2M x 8bit devices */
+	/* Note: datasheet says it should automaticaly wrap to the */
+	/*       next OOB block, but it didn't work here. mf.      */
+	if (this->page256 && ofs + len > (ofs | 0x7) + 1) {
+		len256 = (ofs | 0x7) + 1 - ofs;
+		DoC_ReadBuf(this, buf, len256);
+
+		DoC_Command(this, NAND_CMD_READOOB, CDSN_CTRL_WP);
+		DoC_Address(this, ADDR_COLUMN_PAGE, ofs & (~0x1ff),
+			    CDSN_CTRL_WP, 0);
+	}
+
+	DoC_ReadBuf(this, &buf[len256], len - len256);
+
+	*retlen = len;
+	/* Reading the full OOB data drops us off of the end of the page,
+         * causing the flash device to go into busy mode, so we need
+         * to wait until ready 11.4.1 and Toshiba TC58256FT docs */
+	return DoC_WaitReady(this);
+
+}
+
+static int doc_write_oob(struct mtd_info *mtd, loff_t ofs, size_t len,
+			 size_t * retlen, const u_char * buf)
+{
+	struct DiskOnChip *this = (struct DiskOnChip *) mtd->priv;
+	int len256 = 0;
+	unsigned long docptr = this->virtadr;
+	struct Nand *mychip = &this->chips[ofs >> this->chipshift];
+	int dummy;
+
+	//      printk("doc_write_oob(%lx, %d): %2.2X %2.2X %2.2X %2.2X ... %2.2X %2.2X .. %2.2X %2.2X\n",(long)ofs, len,
+	//   buf[0], buf[1], buf[2], buf[3], buf[8], buf[9], buf[14],buf[15]);
+
+	/* Find the chip which is to be used and select it */
+	if (this->curfloor != mychip->floor) {
+		DoC_SelectFloor(this, mychip->floor);
+		DoC_SelectChip(this, mychip->chip);
+	} else if (this->curchip != mychip->chip) {
+		DoC_SelectChip(this, mychip->chip);
+	}
+	this->curfloor = mychip->floor;
+	this->curchip = mychip->chip;
+
+	/* disable the ECC engine */
+	WriteDOC (DOC_ECC_RESET, docptr, ECCConf);
+	WriteDOC (DOC_ECC_DIS, docptr, ECCConf);
+
+	/* Reset the chip, see Software Requirement 11.4 item 1. */
+	DoC_Command(this, NAND_CMD_RESET, CDSN_CTRL_WP);
+
+	/* issue the Read2 command to set the pointer to the Spare Data Area. */
+	DoC_Command(this, NAND_CMD_READOOB, CDSN_CTRL_WP);
+
+	/* update address for 2M x 8bit devices. OOB starts on the second */
+	/* page to maintain compatibility with doc_read_ecc. */
+	if (this->page256) {
+		if (!(ofs & 0x8))
+			ofs += 0x100;
+		else
+			ofs -= 0x8;
+	}
+
+	/* issue the Serial Data In command to initial the Page Program process */
+	DoC_Command(this, NAND_CMD_SEQIN, 0);
+	DoC_Address(this, ADDR_COLUMN_PAGE, ofs, 0, 0);
+
+	/* treat crossing 8-byte OOB data for 2M x 8bit devices */
+	/* Note: datasheet says it should automaticaly wrap to the */
+	/*       next OOB block, but it didn't work here. mf.      */
+	if (this->page256 && ofs + len > (ofs | 0x7) + 1) {
+		len256 = (ofs | 0x7) + 1 - ofs;
+		DoC_WriteBuf(this, buf, len256);
+
+		DoC_Command(this, NAND_CMD_PAGEPROG, 0);
+		DoC_Command(this, NAND_CMD_STATUS, 0);
+		/* DoC_WaitReady() is implicit in DoC_Command */
+
+		dummy = ReadDOC(docptr, CDSNSlowIO);
+		DoC_Delay(this, 2);
+
+		if (ReadDOC_(docptr, this->ioreg) & 1) {
+			printk("Error programming oob data\n");
+			/* There was an error */
+			*retlen = 0;
+			return -EIO;
+		}
+		DoC_Command(this, NAND_CMD_SEQIN, 0);
+		DoC_Address(this, ADDR_COLUMN_PAGE, ofs & (~0x1ff), 0, 0);
+	}
+
+	DoC_WriteBuf(this, &buf[len256], len - len256);
+
+	DoC_Command(this, NAND_CMD_PAGEPROG, 0);
+	DoC_Command(this, NAND_CMD_STATUS, 0);
+	/* DoC_WaitReady() is implicit in DoC_Command */
+
+	dummy = ReadDOC(docptr, CDSNSlowIO);
+	DoC_Delay(this, 2);
+
+	if (ReadDOC_(docptr, this->ioreg) & 1) {
+		printk("Error programming oob data\n");
+		/* There was an error */
+		*retlen = 0;
+		return -EIO;
+	}
+
+	*retlen = len;
+	return 0;
+
+}
+
+int doc_erase(struct mtd_info *mtd, struct erase_info *instr)
+{
+	struct DiskOnChip *this = (struct DiskOnChip *) mtd->priv;
+	__u32 ofs = instr->addr;
+	__u32 len = instr->len;
+	unsigned long docptr;
+	struct Nand *mychip;
+
+	if (len != mtd->erasesize)
+		printk(KERN_WARNING "Erase not right size (%x != %x)n",
+		       len, mtd->erasesize);
+
+	docptr = this->virtadr;
+
+	mychip = &this->chips[ofs >> this->chipshift];
+
+	if (this->curfloor != mychip->floor) {
+		DoC_SelectFloor(this, mychip->floor);
+		DoC_SelectChip(this, mychip->chip);
+	} else if (this->curchip != mychip->chip) {
+		DoC_SelectChip(this, mychip->chip);
+	}
+	this->curfloor = mychip->floor;
+	this->curchip = mychip->chip;
+
+	instr->state = MTD_ERASE_PENDING;
+
+	DoC_Command(this, NAND_CMD_ERASE1, 0);
+	DoC_Address(this, ADDR_PAGE, ofs, 0, 0);
+	DoC_Command(this, NAND_CMD_ERASE2, 0);
+
+	instr->state = MTD_ERASING;
+
+	DoC_Command(this, NAND_CMD_STATUS, CDSN_CTRL_WP);
+
+	if (ReadDOC_(docptr, this->ioreg) & 1) {
+		printk("Error writing\n");
+		/* There was an error */
+		instr->state = MTD_ERASE_FAILED;
+	} else
+		instr->state = MTD_ERASE_DONE;
+
+	if (instr->callback)
+		instr->callback(instr);
+
+	return 0;
+}
+
+
+/****************************************************************************
+ *
+ * Module stuff
+ *
+ ****************************************************************************/
+
+#if LINUX_VERSION_CODE < 0x20212 && defined(MODULE)
+#define cleanup_doc2000 cleanup_module
+#define init_doc2000 init_module
+#endif
+
+int __init init_doc2000(void)
+{
+       inter_module_register(im_name, THIS_MODULE, &DoC2k_init);
+       return 0;
+}
+
+static void __exit cleanup_doc2000(void)
+{
+	struct mtd_info *mtd;
+	struct DiskOnChip *this;
+
+	while ((mtd = doc2klist)) {
+		this = (struct DiskOnChip *) mtd->priv;
+		doc2klist = this->nextdoc;
+
+		del_mtd_device(mtd);
+
+		iounmap((void *) this->virtadr);
+		kfree(this->chips);
+		kfree(mtd);
+	}
+	inter_module_unregister(im_name);
+}
+
+module_exit(cleanup_doc2000);
+module_init(init_doc2000);

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)