Initial revision

1 files changed, 1563 insertions, 0 deletions

diff --git a/common/cmd_doc.c b/common/cmd_doc.c
new file mode 100644
index 000000000..37d0fbdfc
--- /dev/null
+++ b/common/cmd_doc.c
@@ -0,0 +1,1563 @@
+/*
+ * 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 1.46 2001/10/02 15:05:13 dwmw2 Exp $
+ */
+
+#include <common.h>
+#include <config.h>
+#include <command.h>
+#include <malloc.h>
+#include <asm/io.h>
+
+#ifdef CONFIG_SHOW_BOOT_PROGRESS
+# include <status_led.h>
+# define SHOW_BOOT_PROGRESS(arg)	show_boot_progress(arg)
+#else
+# define SHOW_BOOT_PROGRESS(arg)
+#endif
+
+#if (CONFIG_COMMANDS & CFG_CMD_DOC)
+
+#include <linux/mtd/nand.h>
+#include <linux/mtd/nand_ids.h>
+#include <linux/mtd/doc2000.h>
+#include <linux/mtd/nftl.h>
+
+#ifdef CFG_DOC_SUPPORT_2000
+#define DoC_is_2000(doc) (doc->ChipID == DOC_ChipID_Doc2k)
+#else
+#define DoC_is_2000(doc) (0)
+#endif
+
+#ifdef CFG_DOC_SUPPORT_MILLENNIUM
+#define DoC_is_Millennium(doc) (doc->ChipID == DOC_ChipID_DocMil)
+#else
+#define DoC_is_Millennium(doc) (0)
+#endif
+
+/* CFG_DOC_PASSIVE_PROBE:
+   In order to ensure that the BIOS checksum is correct at boot time, and
+   hence that the onboard BIOS extension gets executed, the DiskOnChip
+   goes into reset mode when it is read sequentially: all registers
+   return 0xff until the chip is woken up again by writing to the
+   DOCControl register.
+
+   Unfortunately, this means that the probe for the DiskOnChip is unsafe,
+   because one of the first things it does is write to where it thinks
+   the DOCControl register should be - which may well be shared memory
+   for another device. I've had machines which lock up when this is
+   attempted. Hence the possibility to do a passive probe, which will fail
+   to detect a chip in reset mode, but is at least guaranteed not to lock
+   the machine.
+
+   If you have this problem, uncomment the following line:
+#define CFG_DOC_PASSIVE_PROBE
+*/
+
+#undef	DOC_DEBUG
+#undef	ECC_DEBUG
+#undef	PSYCHO_DEBUG
+#undef	NFTL_DEBUG
+
+static struct DiskOnChip doc_dev_desc[CFG_MAX_DOC_DEVICE];
+
+/* Current DOC Device	*/
+static int curr_device = -1;
+
+/* ------------------------------------------------------------------------- */
+
+int do_doc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+{
+    int rcode = 0;
+
+    switch (argc) {
+    case 0:
+    case 1:
+	printf ("Usage:\n%s\n", cmdtp->usage);
+	return 1;
+    case 2:
+        if (strcmp(argv[1],"info") == 0) {
+		int i;
+
+		putc ('\n');
+
+		for (i=0; i<CFG_MAX_DOC_DEVICE; ++i) {
+			if(doc_dev_desc[i].ChipID == DOC_ChipID_UNKNOWN)
+				continue; /* list only known devices */
+			printf ("Device %d: ", i);
+			doc_print(&doc_dev_desc[i]);
+		}
+		return 0;
+
+	} else if (strcmp(argv[1],"device") == 0) {
+		if ((curr_device < 0) || (curr_device >= CFG_MAX_DOC_DEVICE)) {
+			puts ("\nno devices available\n");
+			return 1;
+		}
+		printf ("\nDevice %d: ", curr_device);
+		doc_print(&doc_dev_desc[curr_device]);
+		return 0;
+	}
+	printf ("Usage:\n%s\n", cmdtp->usage);
+	return 1;
+    case 3:
+	if (strcmp(argv[1],"device") == 0) {
+		int dev = (int)simple_strtoul(argv[2], NULL, 10);
+
+		printf ("\nDevice %d: ", dev);
+		if (dev >= CFG_MAX_DOC_DEVICE) {
+			puts ("unknown device\n");
+			return 1;
+		}
+		doc_print(&doc_dev_desc[dev]);
+		/*doc_print (dev);*/
+
+		if (doc_dev_desc[dev].ChipID == DOC_ChipID_UNKNOWN) {
+			return 1;
+		}
+
+		curr_device = dev;
+
+		puts ("... is now current device\n");
+
+		return 0;
+	}
+
+	printf ("Usage:\n%s\n", cmdtp->usage);
+	return 1;
+    default:
+	/* at least 4 args */
+
+	if (strcmp(argv[1],"read") == 0 || strcmp(argv[1],"write") == 0) {
+		ulong addr = simple_strtoul(argv[2], NULL, 16);
+		ulong off  = simple_strtoul(argv[3], NULL, 16);
+		ulong size = simple_strtoul(argv[4], NULL, 16);
+		int cmd    = (strcmp(argv[1],"read") == 0);
+		int ret, total;
+
+		printf ("\nDOC %s: device %d offset %ld, size %ld ... ",
+			cmd ? "read" : "write", curr_device, off, size);
+
+		ret = doc_rw(doc_dev_desc + curr_device, cmd, off, size,
+			     &total, (u_char*)addr);
+
+		printf ("%d bytes %s: %s\n", total, cmd ? "read" : "write",
+			ret ? "ERROR" : "OK");
+
+		return ret;
+	} else if (strcmp(argv[1],"erase") == 0) {
+		ulong off = simple_strtoul(argv[2], NULL, 16);
+		ulong size = simple_strtoul(argv[3], NULL, 16);
+		int ret;
+
+		printf ("\nDOC erase: device %d offset %ld, size %ld ... ",
+			curr_device, off, size);
+
+		ret = doc_erase (doc_dev_desc + curr_device, off, size);
+
+		printf("%s\n", ret ? "ERROR" : "OK");
+
+		return ret;
+	} else {
+		printf ("Usage:\n%s\n", cmdtp->usage);
+		rcode = 1;
+	}
+
+	return rcode;
+    }
+}
+
+int do_docboot (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+{
+	char *boot_device = NULL;
+	char *ep;
+	int dev;
+	ulong cnt;
+	ulong addr;
+	ulong offset = 0;
+	image_header_t *hdr;
+	int rcode = 0;
+
+	switch (argc) {
+	case 1:
+		addr = CFG_LOAD_ADDR;
+		boot_device = getenv ("bootdevice");
+		break;
+	case 2:
+		addr = simple_strtoul(argv[1], NULL, 16);
+		boot_device = getenv ("bootdevice");
+		break;
+	case 3:
+		addr = simple_strtoul(argv[1], NULL, 16);
+		boot_device = argv[2];
+		break;
+	case 4:
+		addr = simple_strtoul(argv[1], NULL, 16);
+		boot_device = argv[2];
+		offset = simple_strtoul(argv[3], NULL, 16);
+		break;
+	default:
+		printf ("Usage:\n%s\n", cmdtp->usage);
+		SHOW_BOOT_PROGRESS (-1);
+		return 1;
+	}
+
+	if (!boot_device) {
+		puts ("\n** No boot device **\n");
+		SHOW_BOOT_PROGRESS (-1);
+		return 1;
+	}
+
+	dev = simple_strtoul(boot_device, &ep, 16);
+
+	if ((dev >= CFG_MAX_DOC_DEVICE) ||
+	    (doc_dev_desc[dev].ChipID == DOC_ChipID_UNKNOWN)) {
+		printf ("\n** Device %d not available\n", dev);
+		SHOW_BOOT_PROGRESS (-1);
+		return 1;
+	}
+
+	printf ("\nLoading from device %d: %s at 0x%lX (offset 0x%lX)\n",
+		dev, doc_dev_desc[dev].name, doc_dev_desc[dev].physadr,
+		offset);
+
+	if (doc_rw (doc_dev_desc + dev, 1, offset,
+		    SECTORSIZE, NULL, (u_char *)addr)) {
+		printf ("** Read error on %d\n", dev);
+		SHOW_BOOT_PROGRESS (-1);
+		return 1;
+	}
+
+	hdr = (image_header_t *)addr;
+
+	if (hdr->ih_magic == IH_MAGIC) {
+
+		print_image_hdr (hdr);
+
+		cnt = (hdr->ih_size + sizeof(image_header_t));
+		cnt -= SECTORSIZE;
+	} else {
+		puts ("\n** Bad Magic Number **\n");
+		SHOW_BOOT_PROGRESS (-1);
+		return 1;
+	}
+
+	if (doc_rw (doc_dev_desc + dev, 1, offset + SECTORSIZE, cnt,
+		    NULL, (u_char *)(addr+SECTORSIZE))) {
+		printf ("** Read error on %d\n", dev);
+		SHOW_BOOT_PROGRESS (-1);
+		return 1;
+	}
+
+	/* Loading ok, update default load address */
+
+	load_addr = addr;
+
+	/* Check if we should attempt an auto-start */
+	if (((ep = getenv("autostart")) != NULL) && (strcmp(ep,"yes") == 0)) {
+		char *local_args[2];
+		extern int do_bootm (cmd_tbl_t *, int, int, char *[]);
+
+		local_args[0] = argv[0];
+		local_args[1] = NULL;
+
+		printf ("Automatic boot of image at addr 0x%08lX ...\n", addr);
+
+		do_bootm (cmdtp, 0, 1, local_args);
+		rcode = 1;
+	}
+	return rcode;
+}
+
+int doc_rw (struct DiskOnChip* this, int cmd,
+	    loff_t from, size_t len,
+	    size_t * retlen, u_char * buf)
+{
+	int noecc, ret = 0, n, total = 0;
+	char eccbuf[6];
+
+	while(len) {
+		/* The ECC will not be calculated correctly if
+		   less than 512 is written or read */
+		noecc = (from != (from | 0x1ff) + 1) ||	(len < 0x200);
+
+		if (cmd)
+			ret = doc_read_ecc(this, from, len,
+					   &n, (u_char*)buf,
+					   noecc ? NULL : eccbuf);
+		else
+			ret = doc_write_ecc(this, from, len,
+					    &n, (u_char*)buf,
+					    noecc ? NULL : eccbuf);
+
+		if (ret)
+			break;
+
+		from  += n;
+		buf   += n;
+		total += n;
+		len   -= n;
+	}
+
+	if (retlen)
+		*retlen = total;
+
+	return ret;
+}
+
+void doc_print(struct DiskOnChip *this) {
+	printf("%s at 0x%lX,\n"
+	       "\t  %d chip%s %s, size %d MB, \n"
+	       "\t  total size %ld MB, sector size %ld kB\n",
+	       this->name, this->physadr, this->numchips,
+	       this->numchips>1 ? "s" : "", this->chips_name,
+	       1 << (this->chipshift - 20),
+	       this->totlen >> 20, this->erasesize >> 10);
+
+	if (this->nftl_found) {
+		struct NFTLrecord *nftl = &this->nftl;
+		unsigned long bin_size, flash_size;
+
+		bin_size = nftl->nb_boot_blocks * this->erasesize;
+		flash_size = (nftl->nb_blocks - nftl->nb_boot_blocks) * this->erasesize;
+
+		printf("\t  NFTL boot record:\n"
+		       "\t    Binary partition: size %ld%s\n"
+		       "\t    Flash disk partition: size %ld%s, offset 0x%lx\n",
+		       bin_size > (1 << 20) ? bin_size >> 20 : bin_size >> 10,
+		       bin_size > (1 << 20) ? "MB" : "kB",
+		       flash_size > (1 << 20) ? flash_size >> 20 : flash_size >> 10,
+		       flash_size > (1 << 20) ? "MB" : "kB", bin_size);
+	} else {
+		puts ("\t  No NFTL boot record found.\n");
+	}
+}
+
+/* ------------------------------------------------------------------------- */
+
+/* This function is needed to avoid calls of the __ashrdi3 function. */
+static int shr(int val, int shift) {
+	return val >> shift;
+}
+
+/* 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 long start = get_timer(0);
+
+#ifdef PSYCHO_DEBUG
+	puts ("_DoC_WaitReady called for out-of-line wait\n");
+#endif
+
+	/* Out-of-line routine to wait for chip response */
+	while (!(ReadDOC(docptr, CDSNControl) & CDSN_CTRL_FR_B)) {
+#ifdef CFG_DOC_SHORT_TIMEOUT
+		/* it seems that after a certain time the DoC deasserts
+		 * the CDSN_CTRL_FR_B although it is not ready...
+		 * using a short timout solve this (timer increments every ms) */
+		if (get_timer(start) > 10) {
+			return DOC_ETIMEOUT;
+		}
+#else
+		if (get_timer(start) > 10 * 1000) {
+			puts ("_DoC_WaitReady timed out.\n");
+			return DOC_ETIMEOUT;
+		}
+#endif
+		udelay(1);
+        }
+
+	return 0;
+}
+
+static 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)
+{
+	volatile 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)) {
+#ifdef DOC_DEBUG
+		printf("DoC_Command (reset) for %d,%d returned true\n",
+		       floor, chip);
+#endif
+		return 0;
+	}
+
+
+	/* Read the NAND chip ID: 1. Send ReadID command */
+	if (DoC_Command(doc, NAND_CMD_READID, CDSN_CTRL_WP)) {
+#ifdef DOC_DEBUG
+		printf("DoC_Command (ReadID) for %d,%d returned true\n",
+		       floor, chip);
+#endif
+		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
+			printf("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) {
+#ifdef DOC_DEBUG
+			printf("Flash chip found: Manufacturer ID: %2.2X, "
+			       "Chip ID: %2.2X (%s)\n", mfr, id,
+			       nand_flash_ids[i].name);
+#endif
+			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;
+				doc->chips_name =
+				    nand_flash_ids[i].name;
+				return 1;
+			}
+			return 0;
+		}
+	}
+
+
+#ifdef DOC_DEBUG
+	/* We haven't fully identified the chip. Print as much as we know. */
+	printf("Unknown flash chip found: %2.2X %2.2X\n",
+	       id, mfr);
+#endif
+
+	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) {
+		puts ("No flash chips recognised.\n");
+		return;
+	}
+
+	/* Allocate an array to hold the information for each chip */
+	this->chips = malloc(sizeof(struct Nand) * this->numchips);
+	if (!this->chips) {
+		puts ("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);
+
+#ifdef DOC_DEBUG
+	printf("%d flash chips found. Total DiskOnChip size: %ld MB\n",
+	       this->numchips, this->totlen >> 20);
+#endif
+}
+
+/* find_boot_record: Find the NFTL Media Header and its Spare copy which contains the
+ *	various device information of the NFTL partition and Bad Unit Table. Update
+ *	the ReplUnitTable[] table accroding to the Bad Unit Table. ReplUnitTable[]
+ *	is used for management of Erase Unit in other routines in nftl.c and nftlmount.c
+ */
+static int find_boot_record(struct NFTLrecord *nftl)
+{
+	struct nftl_uci1 h1;
+	struct nftl_oob oob;
+	unsigned int block, boot_record_count = 0;
+	int retlen;
+	u8 buf[SECTORSIZE];
+	struct NFTLMediaHeader *mh = &nftl->MediaHdr;
+	unsigned int i;
+
+	nftl->MediaUnit = BLOCK_NIL;
+	nftl->SpareMediaUnit = BLOCK_NIL;
+
+	/* search for a valid boot record */
+	for (block = 0; block < nftl->nb_blocks; block++) {
+		int ret;
+
+		/* Check for ANAND header first. Then can whinge if it's found but later
+		   checks fail */
+		if ((ret = doc_read_ecc(nftl->mtd, block * nftl->EraseSize, SECTORSIZE,
+					&retlen, buf, NULL))) {
+			static int warncount = 5;
+
+			if (warncount) {
+				printf("Block read at 0x%x failed\n", block * nftl->EraseSize);
+				if (!--warncount)
+					puts ("Further failures for this block will not be printed\n");
+			}
+			continue;
+		}
+
+		if (retlen < 6 || memcmp(buf, "ANAND", 6)) {
+			/* ANAND\0 not found. Continue */
+#ifdef PSYCHO_DEBUG
+			printf("ANAND header not found at 0x%x\n", block * nftl->EraseSize);
+#endif
+			continue;
+		}
+
+#ifdef NFTL_DEBUG
+		printf("ANAND header found at 0x%x\n", block * nftl->EraseSize);
+#endif
+
+		/* To be safer with BIOS, also use erase mark as discriminant */
+		if ((ret = doc_read_oob(nftl->mtd, block * nftl->EraseSize + SECTORSIZE + 8,
+				8, &retlen, (char *)&h1) < 0)) {
+#ifdef NFTL_DEBUG
+			printf("ANAND header found at 0x%x, but OOB data read failed\n",
+			       block * nftl->EraseSize);
+#endif
+			continue;
+		}
+
+		/* OK, we like it. */
+
+		if (boot_record_count) {
+			/* We've already processed one. So we just check if
+			   this one is the same as the first one we found */
+			if (memcmp(mh, buf, sizeof(struct NFTLMediaHeader))) {
+#ifdef NFTL_DEBUG
+				printf("NFTL Media Headers at 0x%x and 0x%x disagree.\n",
+				       nftl->MediaUnit * nftl->EraseSize, block * nftl->EraseSize);
+#endif
+				/* if (debug) Print both side by side */
+				return -1;
+			}
+			if (boot_record_count == 1)
+				nftl->SpareMediaUnit = block;
+
+			boot_record_count++;
+			continue;
+		}
+
+		/* This is the first we've seen. Copy the media header structure into place */
+		memcpy(mh, buf, sizeof(struct NFTLMediaHeader));
+
+		/* Do some sanity checks on it */
+		if (mh->UnitSizeFactor != 0xff) {
+			puts ("Sorry, we don't support UnitSizeFactor "
+			      "of != 1 yet.\n");
+			return -1;
+		}
+
+		nftl->nb_boot_blocks = le16_to_cpu(mh->FirstPhysicalEUN);
+		if ((nftl->nb_boot_blocks + 2) >= nftl->nb_blocks) {
+			printf ("NFTL Media Header sanity check failed:\n"
+				"nb_boot_blocks (%d) + 2 > nb_blocks (%d)\n",
+				nftl->nb_boot_blocks, nftl->nb_blocks);
+			return -1;
+		}
+
+		nftl->numvunits = le32_to_cpu(mh->FormattedSize) / nftl->EraseSize;
+		if (nftl->numvunits > (nftl->nb_blocks - nftl->nb_boot_blocks - 2)) {
+			printf ("NFTL Media Header sanity check failed:\n"
+				"numvunits (%d) > nb_blocks (%d) - nb_boot_blocks(%d) - 2\n",
+				nftl->numvunits,
+				nftl->nb_blocks,
+				nftl->nb_boot_blocks);
+			return -1;
+		}
+
+		nftl->nr_sects  = nftl->numvunits * (nftl->EraseSize / SECTORSIZE);
+
+		/* If we're not using the last sectors in the device for some reason,
+		   reduce nb_blocks accordingly so we forget they're there */
+		nftl->nb_blocks = le16_to_cpu(mh->NumEraseUnits) + le16_to_cpu(mh->FirstPhysicalEUN);
+
+		/* read the Bad Erase Unit Table and modify ReplUnitTable[] accordingly */
+		for (i = 0; i < nftl->nb_blocks; i++) {
+			if ((i & (SECTORSIZE - 1)) == 0) {
+				/* read one sector for every SECTORSIZE of blocks */
+				if ((ret = doc_read_ecc(nftl->mtd, block * nftl->EraseSize +
+						       i + SECTORSIZE, SECTORSIZE,
+						       &retlen, buf, (char *)&oob)) < 0) {
+					puts ("Read of bad sector table failed\n");
+					return -1;
+				}
+			}
+			/* mark the Bad Erase Unit as RESERVED in ReplUnitTable */
+			if (buf[i & (SECTORSIZE - 1)] != 0xff)
+				nftl->ReplUnitTable[i] = BLOCK_RESERVED;
+		}
+
+		nftl->MediaUnit = block;
+		boot_record_count++;
+
+	} /* foreach (block) */
+
+	return boot_record_count?0:-1;
+}
+
+/* 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 DiskOnChip* this)
+{
+	struct NFTLrecord *nftl;
+
+	switch (this->ChipID) {
+	case DOC_ChipID_Doc2k:
+		this->name = "DiskOnChip 2000";
+		this->ioreg = DoC_2k_CDSN_IO;
+		break;
+	case DOC_ChipID_DocMil:
+		this->name = "DiskOnChip Millennium";
+		this->ioreg = DoC_Mil_CDSN_IO;
+		break;
+	}
+
+#ifdef DOC_DEBUG
+	printf("%s found at address 0x%lX\n", this->name,
+	       this->physadr);
+#endif
+
+	this->totlen = 0;
+	this->numchips = 0;
+
+	this->curfloor = -1;
+	this->curchip = -1;
+
+	/* Ident all the chips present. */
+	DoC_ScanChips(this);
+
+	nftl = &this->nftl;
+
+	/* Get physical parameters */
+	nftl->EraseSize = this->erasesize;
+        nftl->nb_blocks = this->totlen / this->erasesize;
+	nftl->mtd = this;
+
+	if (find_boot_record(nftl) != 0)
+		this->nftl_found = 0;
+	else
+		this->nftl_found = 1;
+
+	printf("%s @ 0x%lX, %ld MB\n", this->name, this->physadr, this->totlen >> 20);
+}
+
+int doc_read_ecc(struct DiskOnChip* this, loff_t from, size_t len,
+		 size_t * retlen, u_char * buf, u_char * eccbuf)
+{
+	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) {
+		puts ("Out of flash\n");
+		return DOC_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)
+		printf("ECC needs a full sector read (adr: %lx size %lx)\n",
+		       (long) from, (long) len);
+
+#ifdef PHYCH_DEBUG
+	printf("DoC_Read (adr: %lx size %lx)\n", (long) from, (long) len);
+#endif
+
+	/* Find the chip which is to be used and select it */
+	mychip = &this->chips[shr(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
+			printf("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
+			printf("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 */
+				printf("ECC Errors at %lx\n", (long)from);
+				ret = DOC_EECC;
+                        }
+		}
+
+#ifdef PSYCHO_DEBUG
+		printf("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;
+}
+
+int doc_write_ecc(struct DiskOnChip* this, loff_t to, size_t len,
+		  size_t * retlen, const u_char * buf,
+		  u_char * eccbuf)
+{
+	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) {
+		puts ("Out of flash\n");
+		return DOC_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)
+		printf("ECC needs a full sector write (adr: %lx size %lx)\n",
+		       (long) to, (long) len);
+
+	/* printf("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[shr(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) {
+			puts ("Error programming flash\n");
+			/* Error in programming */
+			*retlen = 0;
+			return DOC_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
+		printf
+		    ("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) {
+		puts ("Error programming flash\n");
+		/* Error in programming */
+		*retlen = 0;
+		return DOC_EIO;
+	}
+
+	/* Let the caller know we completed it */
+	*retlen = len;
+
+	if (eccbuf) {
+		unsigned char x[8];
+		size_t dummy;
+		int ret;
+
+		/* Write the ECC data to flash */
+		for (di=0; di<6; di++)
+			x[di] = eccbuf[di];
+
+		x[6]=0x55;
+		x[7]=0x55;
+
+		ret = doc_write_oob(this, to, 8, &dummy, x);
+		return ret;
+	}
+	return 0;
+}
+
+int doc_read_oob(struct DiskOnChip* this, loff_t ofs, size_t len,
+		 size_t * retlen, u_char * buf)
+{
+	int len256 = 0, ret;
+	unsigned long docptr;
+	struct Nand *mychip;
+
+	docptr = this->virtadr;
+
+	mychip = &this->chips[shr(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 */
+
+	ret = DoC_WaitReady(this);
+
+	return ret;
+
+}
+
+int doc_write_oob(struct DiskOnChip* this, loff_t ofs, size_t len,
+		  size_t * retlen, const u_char * buf)
+{
+	int len256 = 0;
+	unsigned long docptr = this->virtadr;
+	struct Nand *mychip = &this->chips[shr(ofs, this->chipshift)];
+	volatile int dummy;
+
+#ifdef PSYCHO_DEBUG
+	printf("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]);
+#endif
+
+	/* 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) {
+			puts ("Error programming oob data\n");
+			/* There was an error */
+			*retlen = 0;
+			return DOC_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) {
+		puts ("Error programming oob data\n");
+		/* There was an error */
+		*retlen = 0;
+		return DOC_EIO;
+	}
+
+	*retlen = len;
+	return 0;
+
+}
+
+int doc_erase(struct DiskOnChip* this, loff_t ofs, size_t len)
+{
+	volatile int dummy;
+	unsigned long docptr;
+	struct Nand *mychip;
+
+	if (ofs & (this->erasesize-1) || len & (this->erasesize-1)) {
+		puts ("Offset and size must be sector aligned\n");
+		return DOC_EINVAL;
+	}
+
+	docptr = this->virtadr;
+
+	/* FIXME: Do this in the background. Use timers or schedule_task() */
+	while(len) {
+		mychip = &this->chips[shr(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;
+
+		DoC_Command(this, NAND_CMD_ERASE1, 0);
+		DoC_Address(this, ADDR_PAGE, ofs, 0, 0);
+		DoC_Command(this, NAND_CMD_ERASE2, 0);
+
+		DoC_Command(this, NAND_CMD_STATUS, CDSN_CTRL_WP);
+
+		dummy = ReadDOC(docptr, CDSNSlowIO);
+		DoC_Delay(this, 2);
+
+		if (ReadDOC_(docptr, this->ioreg) & 1) {
+			printf("Error erasing at 0x%lx\n", (long)ofs);
+			/* There was an error */
+			goto callback;
+		}
+		ofs += this->erasesize;
+		len -= this->erasesize;
+	}
+
+ callback:
+	return 0;
+}
+
+static inline int doccheck(unsigned long potential, unsigned long physadr)
+{
+	unsigned long window=potential;
+	unsigned char tmp, ChipID;
+#ifndef DOC_PASSIVE_PROBE
+	unsigned char tmp2;
+#endif
+
+	/* Routine copied from the Linux DOC driver */
+
+#ifdef CFG_DOCPROBE_55AA
+	/* Check for 0x55 0xAA signature at beginning of window,
+	   this is no longer true once we remove the IPL (for Millennium */
+	if (ReadDOC(window, Sig1) != 0x55 || ReadDOC(window, Sig2) != 0xaa)
+		return 0;
+#endif /* CFG_DOCPROBE_55AA */
+
+#ifndef DOC_PASSIVE_PROBE
+	/* 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.
+	 */
+	tmp2 = ReadDOC(window, DOCControl);
+
+	/* Reset the DiskOnChip ASIC */
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET,
+		 window, DOCControl);
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET,
+		 window, DOCControl);
+
+	/* Enable the DiskOnChip ASIC */
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL,
+		 window, DOCControl);
+	WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL,
+		 window, DOCControl);
+#endif /* !DOC_PASSIVE_PROBE */
+
+	ChipID = ReadDOC(window, ChipID);
+
+	switch (ChipID) {
+	case DOC_ChipID_Doc2k:
+		/* Check the TOGGLE bit in the ECC register */
+		tmp = ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT;
+		if ((ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT) != tmp)
+				return ChipID;
+		break;
+
+	case DOC_ChipID_DocMil:
+		/* Check the TOGGLE bit in the ECC register */
+		tmp = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT;
+		if ((ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT) != tmp)
+				return ChipID;
+		break;
+
+	default:
+#ifndef CFG_DOCPROBE_55AA
+/*
+ * if the ID isn't the DoC2000 or DoCMillenium ID, so we can assume
+ * the DOC is missing
+ */
+# if 0
+		printf("Possible DiskOnChip with unknown ChipID %2.2X found at 0x%lx\n",
+		       ChipID, physadr);
+# endif
+#endif
+#ifndef DOC_PASSIVE_PROBE
+		/* Put back the contents of the DOCControl register, in case it's not
+		 * actually a DiskOnChip.
+		 */
+		WriteDOC(tmp2, window, DOCControl);
+#endif
+		return 0;
+	}
+
+	puts ("DiskOnChip failed TOGGLE test, dropping.\n");
+
+#ifndef DOC_PASSIVE_PROBE
+	/* Put back the contents of the DOCControl register: it's not a DiskOnChip */
+	WriteDOC(tmp2, window, DOCControl);
+#endif
+	return 0;
+}
+
+void doc_probe(unsigned long physadr)
+{
+	struct DiskOnChip *this = NULL;
+	int i=0, ChipID;
+
+	if ((ChipID = doccheck(physadr, physadr))) {
+
+		for (i=0; i<CFG_MAX_DOC_DEVICE; i++) {
+			if (doc_dev_desc[i].ChipID == DOC_ChipID_UNKNOWN) {
+				this = doc_dev_desc + i;
+				break;
+			}
+		}
+
+		if (!this) {
+			puts ("Cannot allocate memory for data structures.\n");
+			return;
+		}
+
+		if (curr_device == -1)
+			curr_device = i;
+
+		memset((char *)this, 0, sizeof(struct DiskOnChip));
+
+		this->virtadr = physadr;
+		this->physadr = physadr;
+		this->ChipID = ChipID;
+
+		DoC2k_init(this);
+	} else {
+		puts ("No DiskOnChip found\n");
+	}
+}
+
+#endif /* (CONFIG_COMMANDS & CFG_CMD_DOC) */