doc2000.c

基于linux-2.6.28的mtd驱动

/*
 * Linux driver for Disk-On-Chip 2000 and Millennium
 * (c) 1999 Machine Vision Holdings, Inc.
 * (c) 1999, 2000 David Woodhouse <[e-mail]>
 */

#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/delay.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/mutex.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/doc2000.h>

#define DOC_SUPPORT_2000
#define DOC_SUPPORT_2000TSOP
#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

#if defined(DOC_SUPPORT_2000TSOP) || defined(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_oob(struct mtd_info *mtd, loff_t ofs,
			struct mtd_oob_ops *ops);
static int doc_write_oob(struct mtd_info *mtd, loff_t ofs,
			 struct mtd_oob_ops *ops);
static int doc_write_oob_nolock(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)
{
	void __iomem *docptr = doc->virtadr;
	unsigned long timeo = jiffies + (HZ * 10);

	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)) {
		/* issue 2 read from NOP register after reading from CDSNControl register
	   	see Software Requirement 11.4 item 2. */
		DoC_Delay(doc, 2);

		if (time_after(jiffies, timeo)) {
			DEBUG(MTD_DEBUG_LEVEL2, "_DoC_WaitReady timed out.\n");
			return -EIO;
		}
		udelay(1);
		cond_resched();
	}

	return 0;
}

static inline int DoC_WaitReady(struct DiskOnChip *doc)
{
	void __iomem *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 int DoC_Command(struct DiskOnChip *doc, unsigned char command,
			      unsigned char xtraflags)
{
	void __iomem *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);
	if (DoC_is_Millennium(doc))
		WriteDOC(command, docptr, WritePipeTerm);

	/* 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)
{
	int i;
	void __iomem *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);
		}
	}

	if (DoC_is_Millennium(doc))
		WriteDOC(ofs & 0xff, docptr, WritePipeTerm);

	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;
	void __iomem *docptr = doc->virtadr;
	int i;

	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)
{
	void __iomem *docptr = doc->virtadr;
	int i;

	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)
{
	void __iomem *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)
{
	void __iomem *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, j;
	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 */

	if (DoC_is_Millennium(doc)) {
		DoC_Delay(doc, 2);
		dummy = ReadDOC(doc->virtadr, ReadPipeInit);
		mfr = ReadDOC(doc->virtadr, LastDataRead);

		DoC_Delay(doc, 2);
		dummy = ReadDOC(doc->virtadr, ReadPipeInit);
		id = ReadDOC(doc->virtadr, LastDataRead);
	} else {
		/* CDSN Slow IO register see Software Req 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 Req 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 the same as 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 (id == nand_flash_ids[i].id) {
			/* Try to identify manufacturer */
			for (j = 0; nand_manuf_ids[j].id != 0x0; j++) {
				if (nand_manuf_ids[j].id == mfr)
					break;
			}
			printk(KERN_INFO
			       "Flash chip found: Manufacturer ID: %2.2X, "
			       "Chip ID: %2.2X (%s:%s)\n", mfr, id,
			       nand_manuf_ids[j].name, nand_flash_ids[i].name);
			if (!doc->mfr) {
				doc->mfr = mfr;
				doc->id = id;
				doc->chipshift =
					ffs((nand_flash_ids[i].chipsize << 20)) - 1;
				doc->page256 = (nand_flash_ids[i].pagesize == 256) ? 1 : 0;