mtd_dataflash.c 25.0 KB
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/*
 * Atmel AT45xxx DataFlash MTD driver for lightweight SPI framework
 *
 * Largely derived from at91_dataflash.c:
 *  Copyright (C) 2003-2005 SAN People (Pty) Ltd
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/device.h>
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#include <linux/mutex.h>
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#include <linux/err.h>
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#include <linux/math64.h>
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#include <linux/spi/spi.h>
#include <linux/spi/flash.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>


/*
 * DataFlash is a kind of SPI flash.  Most AT45 chips have two buffers in
 * each chip, which may be used for double buffered I/O; but this driver
 * doesn't (yet) use these for any kind of i/o overlap or prefetching.
 *
 * Sometimes DataFlash is packaged in MMC-format cards, although the
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 * MMC stack can't (yet?) distinguish between MMC and DataFlash
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 * protocols during enumeration.
 */

/* reads can bypass the buffers */
#define OP_READ_CONTINUOUS	0xE8
#define OP_READ_PAGE		0xD2

/* group B requests can run even while status reports "busy" */
#define OP_READ_STATUS		0xD7	/* group B */

/* move data between host and buffer */
#define OP_READ_BUFFER1		0xD4	/* group B */
#define OP_READ_BUFFER2		0xD6	/* group B */
#define OP_WRITE_BUFFER1	0x84	/* group B */
#define OP_WRITE_BUFFER2	0x87	/* group B */

/* erasing flash */
#define OP_ERASE_PAGE		0x81
#define OP_ERASE_BLOCK		0x50

/* move data between buffer and flash */
#define OP_TRANSFER_BUF1	0x53
#define OP_TRANSFER_BUF2	0x55
#define OP_MREAD_BUFFER1	0xD4
#define OP_MREAD_BUFFER2	0xD6
#define OP_MWERASE_BUFFER1	0x83
#define OP_MWERASE_BUFFER2	0x86
#define OP_MWRITE_BUFFER1	0x88	/* sector must be pre-erased */
#define OP_MWRITE_BUFFER2	0x89	/* sector must be pre-erased */

/* write to buffer, then write-erase to flash */
#define OP_PROGRAM_VIA_BUF1	0x82
#define OP_PROGRAM_VIA_BUF2	0x85

/* compare buffer to flash */
#define OP_COMPARE_BUF1		0x60
#define OP_COMPARE_BUF2		0x61

/* read flash to buffer, then write-erase to flash */
#define OP_REWRITE_VIA_BUF1	0x58
#define OP_REWRITE_VIA_BUF2	0x59

/* newer chips report JEDEC manufacturer and device IDs; chip
 * serial number and OTP bits; and per-sector writeprotect.
 */
#define OP_READ_ID		0x9F
#define OP_READ_SECURITY	0x77
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#define OP_WRITE_SECURITY_REVC	0x9A
#define OP_WRITE_SECURITY	0x9B	/* revision D */
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struct dataflash {
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	uint8_t			command[4];
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	char			name[24];

	unsigned		partitioned:1;

	unsigned short		page_offset;	/* offset in flash address */
	unsigned int		page_size;	/* of bytes per page */

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	struct mutex		lock;
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	struct spi_device	*spi;

	struct mtd_info		mtd;
};

/* ......................................................................... */

/*
 * Return the status of the DataFlash device.
 */
static inline int dataflash_status(struct spi_device *spi)
{
	/* NOTE:  at45db321c over 25 MHz wants to write
	 * a dummy byte after the opcode...
	 */
	return spi_w8r8(spi, OP_READ_STATUS);
}

/*
 * Poll the DataFlash device until it is READY.
 * This usually takes 5-20 msec or so; more for sector erase.
 */
static int dataflash_waitready(struct spi_device *spi)
{
	int	status;

	for (;;) {
		status = dataflash_status(spi);
		if (status < 0) {
			DEBUG(MTD_DEBUG_LEVEL1, "%s: status %d?\n",
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					dev_name(&spi->dev), status);
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			status = 0;
		}

		if (status & (1 << 7))	/* RDY/nBSY */
			return status;

		msleep(3);
	}
}

/* ......................................................................... */

/*
 * Erase pages of flash.
 */
static int dataflash_erase(struct mtd_info *mtd, struct erase_info *instr)
{
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	struct dataflash	*priv = mtd->priv;
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	struct spi_device	*spi = priv->spi;
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	struct spi_transfer	x = { .tx_dma = 0, };
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	struct spi_message	msg;
	unsigned		blocksize = priv->page_size << 3;
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	uint8_t			*command;
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	uint32_t		rem;
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	DEBUG(MTD_DEBUG_LEVEL2, "%s: erase addr=0x%llx len 0x%llx\n",
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	      dev_name(&spi->dev), (long long)instr->addr,
	      (long long)instr->len);
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	/* Sanity checks */
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	if (instr->addr + instr->len > mtd->size)
		return -EINVAL;
	div_u64_rem(instr->len, priv->page_size, &rem);
	if (rem)
		return -EINVAL;
	div_u64_rem(instr->addr, priv->page_size, &rem);
	if (rem)
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		return -EINVAL;

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	spi_message_init(&msg);

	x.tx_buf = command = priv->command;
	x.len = 4;
	spi_message_add_tail(&x, &msg);
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	mutex_lock(&priv->lock);
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	while (instr->len > 0) {
		unsigned int	pageaddr;
		int		status;
		int		do_block;

		/* Calculate flash page address; use block erase (for speed) if
		 * we're at a block boundary and need to erase the whole block.
		 */
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		pageaddr = div_u64(instr->addr, priv->page_size);
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		do_block = (pageaddr & 0x7) == 0 && instr->len >= blocksize;
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		pageaddr = pageaddr << priv->page_offset;

		command[0] = do_block ? OP_ERASE_BLOCK : OP_ERASE_PAGE;
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		command[1] = (uint8_t)(pageaddr >> 16);
		command[2] = (uint8_t)(pageaddr >> 8);
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		command[3] = 0;

		DEBUG(MTD_DEBUG_LEVEL3, "ERASE %s: (%x) %x %x %x [%i]\n",
			do_block ? "block" : "page",
			command[0], command[1], command[2], command[3],
			pageaddr);

		status = spi_sync(spi, &msg);
		(void) dataflash_waitready(spi);

		if (status < 0) {
			printk(KERN_ERR "%s: erase %x, err %d\n",
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				dev_name(&spi->dev), pageaddr, status);
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			/* REVISIT:  can retry instr->retries times; or
			 * giveup and instr->fail_addr = instr->addr;
			 */
			continue;
		}

		if (do_block) {
			instr->addr += blocksize;
			instr->len -= blocksize;
		} else {
			instr->addr += priv->page_size;
			instr->len -= priv->page_size;
		}
	}
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	mutex_unlock(&priv->lock);
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	/* Inform MTD subsystem that erase is complete */
	instr->state = MTD_ERASE_DONE;
	mtd_erase_callback(instr);

	return 0;
}

/*
 * Read from the DataFlash device.
 *   from   : Start offset in flash device
 *   len    : Amount to read
 *   retlen : About of data actually read
 *   buf    : Buffer containing the data
 */
static int dataflash_read(struct mtd_info *mtd, loff_t from, size_t len,
			       size_t *retlen, u_char *buf)
{
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	struct dataflash	*priv = mtd->priv;
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	struct spi_transfer	x[2] = { { .tx_dma = 0, }, };
	struct spi_message	msg;
	unsigned int		addr;
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	uint8_t			*command;
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	int			status;

	DEBUG(MTD_DEBUG_LEVEL2, "%s: read 0x%x..0x%x\n",
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		dev_name(&priv->spi->dev), (unsigned)from, (unsigned)(from + len));
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	*retlen = 0;

	/* Sanity checks */
	if (!len)
		return 0;
	if (from + len > mtd->size)
		return -EINVAL;

	/* Calculate flash page/byte address */
	addr = (((unsigned)from / priv->page_size) << priv->page_offset)
		+ ((unsigned)from % priv->page_size);

	command = priv->command;

	DEBUG(MTD_DEBUG_LEVEL3, "READ: (%x) %x %x %x\n",
		command[0], command[1], command[2], command[3]);

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	spi_message_init(&msg);

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	x[0].tx_buf = command;
	x[0].len = 8;
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	spi_message_add_tail(&x[0], &msg);

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	x[1].rx_buf = buf;
	x[1].len = len;
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	spi_message_add_tail(&x[1], &msg);
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	mutex_lock(&priv->lock);
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	/* Continuous read, max clock = f(car) which may be less than
	 * the peak rate available.  Some chips support commands with
	 * fewer "don't care" bytes.  Both buffers stay unchanged.
	 */
	command[0] = OP_READ_CONTINUOUS;
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	command[1] = (uint8_t)(addr >> 16);
	command[2] = (uint8_t)(addr >> 8);
	command[3] = (uint8_t)(addr >> 0);
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	/* plus 4 "don't care" bytes */

	status = spi_sync(priv->spi, &msg);
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	mutex_unlock(&priv->lock);
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	if (status >= 0) {
		*retlen = msg.actual_length - 8;
		status = 0;
	} else
		DEBUG(MTD_DEBUG_LEVEL1, "%s: read %x..%x --> %d\n",
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			dev_name(&priv->spi->dev),
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			(unsigned)from, (unsigned)(from + len),
			status);
	return status;
}

/*
 * Write to the DataFlash device.
 *   to     : Start offset in flash device
 *   len    : Amount to write
 *   retlen : Amount of data actually written
 *   buf    : Buffer containing the data
 */
static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len,
				size_t * retlen, const u_char * buf)
{
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	struct dataflash	*priv = mtd->priv;
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	struct spi_device	*spi = priv->spi;
	struct spi_transfer	x[2] = { { .tx_dma = 0, }, };
	struct spi_message	msg;
	unsigned int		pageaddr, addr, offset, writelen;
	size_t			remaining = len;
	u_char			*writebuf = (u_char *) buf;
	int			status = -EINVAL;
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	uint8_t			*command;
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	DEBUG(MTD_DEBUG_LEVEL2, "%s: write 0x%x..0x%x\n",
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		dev_name(&spi->dev), (unsigned)to, (unsigned)(to + len));
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	*retlen = 0;

	/* Sanity checks */
	if (!len)
		return 0;
	if ((to + len) > mtd->size)
		return -EINVAL;

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	spi_message_init(&msg);

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	x[0].tx_buf = command = priv->command;
	x[0].len = 4;
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	spi_message_add_tail(&x[0], &msg);
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	pageaddr = ((unsigned)to / priv->page_size);
	offset = ((unsigned)to % priv->page_size);
	if (offset + len > priv->page_size)
		writelen = priv->page_size - offset;
	else
		writelen = len;

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	mutex_lock(&priv->lock);
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	while (remaining > 0) {
		DEBUG(MTD_DEBUG_LEVEL3, "write @ %i:%i len=%i\n",
			pageaddr, offset, writelen);

		/* REVISIT:
		 * (a) each page in a sector must be rewritten at least
		 *     once every 10K sibling erase/program operations.
		 * (b) for pages that are already erased, we could
		 *     use WRITE+MWRITE not PROGRAM for ~30% speedup.
		 * (c) WRITE to buffer could be done while waiting for
		 *     a previous MWRITE/MWERASE to complete ...
		 * (d) error handling here seems to be mostly missing.
		 *
		 * Two persistent bits per page, plus a per-sector counter,
		 * could support (a) and (b) ... we might consider using
		 * the second half of sector zero, which is just one block,
		 * to track that state.  (On AT91, that sector should also
		 * support boot-from-DataFlash.)
		 */

		addr = pageaddr << priv->page_offset;

		/* (1) Maybe transfer partial page to Buffer1 */
		if (writelen != priv->page_size) {
			command[0] = OP_TRANSFER_BUF1;
			command[1] = (addr & 0x00FF0000) >> 16;
			command[2] = (addr & 0x0000FF00) >> 8;
			command[3] = 0;

			DEBUG(MTD_DEBUG_LEVEL3, "TRANSFER: (%x) %x %x %x\n",
				command[0], command[1], command[2], command[3]);

			status = spi_sync(spi, &msg);
			if (status < 0)
				DEBUG(MTD_DEBUG_LEVEL1, "%s: xfer %u -> %d \n",
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					dev_name(&spi->dev), addr, status);
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			(void) dataflash_waitready(priv->spi);
		}

		/* (2) Program full page via Buffer1 */
		addr += offset;
		command[0] = OP_PROGRAM_VIA_BUF1;
		command[1] = (addr & 0x00FF0000) >> 16;
		command[2] = (addr & 0x0000FF00) >> 8;
		command[3] = (addr & 0x000000FF);

		DEBUG(MTD_DEBUG_LEVEL3, "PROGRAM: (%x) %x %x %x\n",
			command[0], command[1], command[2], command[3]);

		x[1].tx_buf = writebuf;
		x[1].len = writelen;
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		spi_message_add_tail(x + 1, &msg);
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		status = spi_sync(spi, &msg);
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		spi_transfer_del(x + 1);
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		if (status < 0)
			DEBUG(MTD_DEBUG_LEVEL1, "%s: pgm %u/%u -> %d \n",
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				dev_name(&spi->dev), addr, writelen, status);
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		(void) dataflash_waitready(priv->spi);

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#ifdef CONFIG_MTD_DATAFLASH_WRITE_VERIFY
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		/* (3) Compare to Buffer1 */
		addr = pageaddr << priv->page_offset;
		command[0] = OP_COMPARE_BUF1;
		command[1] = (addr & 0x00FF0000) >> 16;
		command[2] = (addr & 0x0000FF00) >> 8;
		command[3] = 0;

		DEBUG(MTD_DEBUG_LEVEL3, "COMPARE: (%x) %x %x %x\n",
			command[0], command[1], command[2], command[3]);

		status = spi_sync(spi, &msg);
		if (status < 0)
			DEBUG(MTD_DEBUG_LEVEL1, "%s: compare %u -> %d \n",
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				dev_name(&spi->dev), addr, status);
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		status = dataflash_waitready(priv->spi);

		/* Check result of the compare operation */
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		if (status & (1 << 6)) {
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			printk(KERN_ERR "%s: compare page %u, err %d\n",
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				dev_name(&spi->dev), pageaddr, status);
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			remaining = 0;
			status = -EIO;
			break;
		} else
			status = 0;

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#endif	/* CONFIG_MTD_DATAFLASH_WRITE_VERIFY */
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		remaining = remaining - writelen;
		pageaddr++;
		offset = 0;
		writebuf += writelen;
		*retlen += writelen;

		if (remaining > priv->page_size)
			writelen = priv->page_size;
		else
			writelen = remaining;
	}
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	mutex_unlock(&priv->lock);
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	return status;
}

/* ......................................................................... */

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#ifdef CONFIG_MTD_DATAFLASH_OTP

static int dataflash_get_otp_info(struct mtd_info *mtd,
		struct otp_info *info, size_t len)
{
	/* Report both blocks as identical:  bytes 0..64, locked.
	 * Unless the user block changed from all-ones, we can't
	 * tell whether it's still writable; so we assume it isn't.
	 */
	info->start = 0;
	info->length = 64;
	info->locked = 1;
	return sizeof(*info);
}

static ssize_t otp_read(struct spi_device *spi, unsigned base,
		uint8_t *buf, loff_t off, size_t len)
{
	struct spi_message	m;
	size_t			l;
	uint8_t			*scratch;
	struct spi_transfer	t;
	int			status;

	if (off > 64)
		return -EINVAL;

	if ((off + len) > 64)
		len = 64 - off;
	if (len == 0)
		return len;

	spi_message_init(&m);

	l = 4 + base + off + len;
	scratch = kzalloc(l, GFP_KERNEL);
	if (!scratch)
		return -ENOMEM;

	/* OUT: OP_READ_SECURITY, 3 don't-care bytes, zeroes
	 * IN:  ignore 4 bytes, data bytes 0..N (max 127)
	 */
	scratch[0] = OP_READ_SECURITY;

	memset(&t, 0, sizeof t);
	t.tx_buf = scratch;
	t.rx_buf = scratch;
	t.len = l;
	spi_message_add_tail(&t, &m);

	dataflash_waitready(spi);

	status = spi_sync(spi, &m);
	if (status >= 0) {
		memcpy(buf, scratch + 4 + base + off, len);
		status = len;
	}

	kfree(scratch);
	return status;
}

static int dataflash_read_fact_otp(struct mtd_info *mtd,
		loff_t from, size_t len, size_t *retlen, u_char *buf)
{
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	struct dataflash	*priv = mtd->priv;
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	int			status;

	/* 64 bytes, from 0..63 ... start at 64 on-chip */
	mutex_lock(&priv->lock);
	status = otp_read(priv->spi, 64, buf, from, len);
	mutex_unlock(&priv->lock);

	if (status < 0)
		return status;
	*retlen = status;
	return 0;
}

static int dataflash_read_user_otp(struct mtd_info *mtd,
		loff_t from, size_t len, size_t *retlen, u_char *buf)
{
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	struct dataflash	*priv = mtd->priv;
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	int			status;

	/* 64 bytes, from 0..63 ... start at 0 on-chip */
	mutex_lock(&priv->lock);
	status = otp_read(priv->spi, 0, buf, from, len);
	mutex_unlock(&priv->lock);

	if (status < 0)
		return status;
	*retlen = status;
	return 0;
}

static int dataflash_write_user_otp(struct mtd_info *mtd,
		loff_t from, size_t len, size_t *retlen, u_char *buf)
{
	struct spi_message	m;
	const size_t		l = 4 + 64;
	uint8_t			*scratch;
	struct spi_transfer	t;
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	struct dataflash	*priv = mtd->priv;
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	int			status;

	if (len > 64)
		return -EINVAL;

	/* Strictly speaking, we *could* truncate the write ... but
	 * let's not do that for the only write that's ever possible.
	 */
	if ((from + len) > 64)
		return -EINVAL;

	/* OUT: OP_WRITE_SECURITY, 3 zeroes, 64 data-or-zero bytes
	 * IN:  ignore all
	 */
	scratch = kzalloc(l, GFP_KERNEL);
	if (!scratch)
		return -ENOMEM;
	scratch[0] = OP_WRITE_SECURITY;
	memcpy(scratch + 4 + from, buf, len);

	spi_message_init(&m);

	memset(&t, 0, sizeof t);
	t.tx_buf = scratch;
	t.len = l;
	spi_message_add_tail(&t, &m);

	/* Write the OTP bits, if they've not yet been written.
	 * This modifies SRAM buffer1.
	 */
	mutex_lock(&priv->lock);
	dataflash_waitready(priv->spi);
	status = spi_sync(priv->spi, &m);
	mutex_unlock(&priv->lock);

	kfree(scratch);

	if (status >= 0) {
		status = 0;
		*retlen = len;
	}
	return status;
}

static char *otp_setup(struct mtd_info *device, char revision)
{
	device->get_fact_prot_info = dataflash_get_otp_info;
	device->read_fact_prot_reg = dataflash_read_fact_otp;
	device->get_user_prot_info = dataflash_get_otp_info;
	device->read_user_prot_reg = dataflash_read_user_otp;

	/* rev c parts (at45db321c and at45db1281 only!) use a
	 * different write procedure; not (yet?) implemented.
	 */
	if (revision > 'c')
		device->write_user_prot_reg = dataflash_write_user_otp;

	return ", OTP";
}

#else

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static char *otp_setup(struct mtd_info *device, char revision)
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{
	return " (OTP)";
}

#endif

/* ......................................................................... */

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/*
 * Register DataFlash device with MTD subsystem.
 */
static int __devinit
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add_dataflash_otp(struct spi_device *spi, char *name,
		int nr_pages, int pagesize, int pageoffset, char revision)
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{
	struct dataflash		*priv;
	struct mtd_info			*device;
	struct flash_platform_data	*pdata = spi->dev.platform_data;
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	char				*otp_tag = "";
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	int				err = 0;
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	struct mtd_partition		*parts;
	int				nr_parts = 0;
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	priv = kzalloc(sizeof *priv, GFP_KERNEL);
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	if (!priv)
		return -ENOMEM;

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	mutex_init(&priv->lock);
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	priv->spi = spi;
	priv->page_size = pagesize;
	priv->page_offset = pageoffset;

	/* name must be usable with cmdlinepart */
	sprintf(priv->name, "spi%d.%d-%s",
			spi->master->bus_num, spi->chip_select,
			name);

	device = &priv->mtd;
	device->name = (pdata && pdata->name) ? pdata->name : priv->name;
	device->size = nr_pages * pagesize;
	device->erasesize = pagesize;
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	device->writesize = pagesize;
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	device->owner = THIS_MODULE;
	device->type = MTD_DATAFLASH;
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	device->flags = MTD_WRITEABLE;
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	device->erase = dataflash_erase;
	device->read = dataflash_read;
	device->write = dataflash_write;
	device->priv = priv;

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	device->dev.parent = &spi->dev;

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	if (revision >= 'c')
		otp_tag = otp_setup(device, revision);

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	dev_info(&spi->dev, "%s (%lld KBytes) pagesize %d bytes%s\n",
			name, (long long)((device->size + 1023) >> 10),
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			pagesize, otp_tag);
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	dev_set_drvdata(&spi->dev, priv);

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	if (mtd_has_cmdlinepart()) {
		static const char *part_probes[] = { "cmdlinepart", NULL, };
682

683 684 685
		nr_parts = parse_mtd_partitions(device, part_probes, &parts,
						0);
	}
686

687 688 689 690
	if (nr_parts <= 0 && pdata && pdata->parts) {
		parts = pdata->parts;
		nr_parts = pdata->nr_parts;
	}
691

692 693 694 695 696
	if (nr_parts > 0) {
		priv->partitioned = 1;
		err = mtd_device_register(device, parts, nr_parts);
		goto out;
	}
697

698
	if (mtd_device_register(device, NULL, 0) == 1)
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		err = -ENODEV;

out:
	if (!err)
		return 0;

	dev_set_drvdata(&spi->dev, NULL);
	kfree(priv);
	return err;
708 709
}

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static inline int __devinit
add_dataflash(struct spi_device *spi, char *name,
		int nr_pages, int pagesize, int pageoffset)
{
	return add_dataflash_otp(spi, name, nr_pages, pagesize,
			pageoffset, 0);
}

718 719 720
struct flash_info {
	char		*name;

721 722
	/* JEDEC id has a high byte of zero plus three data bytes:
	 * the manufacturer id, then a two byte device id.
723
	 */
724
	uint32_t	jedec_id;
725

726
	/* The size listed here is what works with OP_ERASE_PAGE. */
727
	unsigned	nr_pages;
728 729
	uint16_t	pagesize;
	uint16_t	pageoffset;
730

731
	uint16_t	flags;
732 733
#define SUP_POW2PS	0x0002		/* supports 2^N byte pages */
#define IS_POW2PS	0x0001		/* uses 2^N byte pages */
734 735 736 737
};

static struct flash_info __devinitdata dataflash_data [] = {

738 739 740 741 742 743 744 745 746 747
	/*
	 * NOTE:  chips with SUP_POW2PS (rev D and up) need two entries,
	 * one with IS_POW2PS and the other without.  The entry with the
	 * non-2^N byte page size can't name exact chip revisions without
	 * losing backwards compatibility for cmdlinepart.
	 *
	 * These newer chips also support 128-byte security registers (with
	 * 64 bytes one-time-programmable) and software write-protection.
	 */
	{ "AT45DB011B",  0x1f2200, 512, 264, 9, SUP_POW2PS},
748 749
	{ "at45db011d",  0x1f2200, 512, 256, 8, SUP_POW2PS | IS_POW2PS},

750
	{ "AT45DB021B",  0x1f2300, 1024, 264, 9, SUP_POW2PS},
751 752
	{ "at45db021d",  0x1f2300, 1024, 256, 8, SUP_POW2PS | IS_POW2PS},

753
	{ "AT45DB041x",  0x1f2400, 2048, 264, 9, SUP_POW2PS},
754 755
	{ "at45db041d",  0x1f2400, 2048, 256, 8, SUP_POW2PS | IS_POW2PS},

756
	{ "AT45DB081B",  0x1f2500, 4096, 264, 9, SUP_POW2PS},
757 758
	{ "at45db081d",  0x1f2500, 4096, 256, 8, SUP_POW2PS | IS_POW2PS},

759
	{ "AT45DB161x",  0x1f2600, 4096, 528, 10, SUP_POW2PS},
760 761
	{ "at45db161d",  0x1f2600, 4096, 512, 9, SUP_POW2PS | IS_POW2PS},

762
	{ "AT45DB321x",  0x1f2700, 8192, 528, 10, 0},		/* rev C */
763

764
	{ "AT45DB321x",  0x1f2701, 8192, 528, 10, SUP_POW2PS},
765 766
	{ "at45db321d",  0x1f2701, 8192, 512, 9, SUP_POW2PS | IS_POW2PS},

767 768
	{ "AT45DB642x",  0x1f2800, 8192, 1056, 11, SUP_POW2PS},
	{ "at45db642d",  0x1f2800, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS},
769 770 771 772 773
};

static struct flash_info *__devinit jedec_probe(struct spi_device *spi)
{
	int			tmp;
774 775 776
	uint8_t			code = OP_READ_ID;
	uint8_t			id[3];
	uint32_t		jedec;
777 778 779 780 781 782
	struct flash_info	*info;
	int status;

	/* JEDEC also defines an optional "extended device information"
	 * string for after vendor-specific data, after the three bytes
	 * we use here.  Supporting some chips might require using it.
783 784 785 786
	 *
	 * If the vendor ID isn't Atmel's (0x1f), assume this call failed.
	 * That's not an error; only rev C and newer chips handle it, and
	 * only Atmel sells these chips.
787 788 789 790
	 */
	tmp = spi_write_then_read(spi, &code, 1, id, 3);
	if (tmp < 0) {
		DEBUG(MTD_DEBUG_LEVEL0, "%s: error %d reading JEDEC ID\n",
791
			dev_name(&spi->dev), tmp);
792
		return ERR_PTR(tmp);
793
	}
794 795 796
	if (id[0] != 0x1f)
		return NULL;

797 798 799 800 801 802 803 804 805 806
	jedec = id[0];
	jedec = jedec << 8;
	jedec |= id[1];
	jedec = jedec << 8;
	jedec |= id[2];

	for (tmp = 0, info = dataflash_data;
			tmp < ARRAY_SIZE(dataflash_data);
			tmp++, info++) {
		if (info->jedec_id == jedec) {
807 808 809 810 811
			DEBUG(MTD_DEBUG_LEVEL1, "%s: OTP, sector protect%s\n",
				dev_name(&spi->dev),
				(info->flags & SUP_POW2PS)
					? ", binary pagesize" : ""
				);
812 813
			if (info->flags & SUP_POW2PS) {
				status = dataflash_status(spi);
814 815 816 817 818 819 820 821 822 823 824 825 826
				if (status < 0) {
					DEBUG(MTD_DEBUG_LEVEL1,
						"%s: status error %d\n",
						dev_name(&spi->dev), status);
					return ERR_PTR(status);
				}
				if (status & 0x1) {
					if (info->flags & IS_POW2PS)
						return info;
				} else {
					if (!(info->flags & IS_POW2PS))
						return info;
				}
827 828
			} else
				return info;
829 830
		}
	}
831 832 833 834 835 836 837 838

	/*
	 * Treat other chips as errors ... we won't know the right page
	 * size (it might be binary) even when we can tell which density
	 * class is involved (legacy chip id scheme).
	 */
	dev_warn(&spi->dev, "JEDEC id %06x not handled\n", jedec);
	return ERR_PTR(-ENODEV);
839 840
}

841 842 843 844 845 846 847 848 849 850 851 852 853 854
/*
 * Detect and initialize DataFlash device, using JEDEC IDs on newer chips
 * or else the ID code embedded in the status bits:
 *
 *   Device      Density         ID code          #Pages PageSize  Offset
 *   AT45DB011B  1Mbit   (128K)  xx0011xx (0x0c)    512    264      9
 *   AT45DB021B  2Mbit   (256K)  xx0101xx (0x14)   1024    264      9
 *   AT45DB041B  4Mbit   (512K)  xx0111xx (0x1c)   2048    264      9
 *   AT45DB081B  8Mbit   (1M)    xx1001xx (0x24)   4096    264      9
 *   AT45DB0161B 16Mbit  (2M)    xx1011xx (0x2c)   4096    528     10
 *   AT45DB0321B 32Mbit  (4M)    xx1101xx (0x34)   8192    528     10
 *   AT45DB0642  64Mbit  (8M)    xx111xxx (0x3c)   8192   1056     11
 *   AT45DB1282  128Mbit (16M)   xx0100xx (0x10)  16384   1056     11
 */
855 856 857
static int __devinit dataflash_probe(struct spi_device *spi)
{
	int status;
858 859 860 861 862 863
	struct flash_info	*info;

	/*
	 * Try to detect dataflash by JEDEC ID.
	 * If it succeeds we know we have either a C or D part.
	 * D will support power of 2 pagesize option.
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	 * Both support the security register, though with different
	 * write procedures.
866 867
	 */
	info = jedec_probe(spi);
868 869
	if (IS_ERR(info))
		return PTR_ERR(info);
870
	if (info != NULL)
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		return add_dataflash_otp(spi, info->name, info->nr_pages,
				info->pagesize, info->pageoffset,
				(info->flags & SUP_POW2PS) ? 'd' : 'c');
874

875 876 877 878
	/*
	 * Older chips support only legacy commands, identifing
	 * capacity using bits in the status byte.
	 */
879 880 881
	status = dataflash_status(spi);
	if (status <= 0 || status == 0xff) {
		DEBUG(MTD_DEBUG_LEVEL1, "%s: status error %d\n",
882
				dev_name(&spi->dev), status);
883
		if (status == 0 || status == 0xff)
884 885 886 887 888 889 890 891 892 893 894 895 896
			status = -ENODEV;
		return status;
	}

	/* if there's a device there, assume it's dataflash.
	 * board setup should have set spi->max_speed_max to
	 * match f(car) for continuous reads, mode 0 or 3.
	 */
	switch (status & 0x3c) {
	case 0x0c:	/* 0 0 1 1 x x */
		status = add_dataflash(spi, "AT45DB011B", 512, 264, 9);
		break;
	case 0x14:	/* 0 1 0 1 x x */
897
		status = add_dataflash(spi, "AT45DB021B", 1024, 264, 9);
898 899
		break;
	case 0x1c:	/* 0 1 1 1 x x */
900
		status = add_dataflash(spi, "AT45DB041x", 2048, 264, 9);
901 902 903 904 905
		break;
	case 0x24:	/* 1 0 0 1 x x */
		status = add_dataflash(spi, "AT45DB081B", 4096, 264, 9);
		break;
	case 0x2c:	/* 1 0 1 1 x x */
906
		status = add_dataflash(spi, "AT45DB161x", 4096, 528, 10);
907 908 909 910 911 912 913 914 915 916 917
		break;
	case 0x34:	/* 1 1 0 1 x x */
		status = add_dataflash(spi, "AT45DB321x", 8192, 528, 10);
		break;
	case 0x38:	/* 1 1 1 x x x */
	case 0x3c:
		status = add_dataflash(spi, "AT45DB642x", 8192, 1056, 11);
		break;
	/* obsolete AT45DB1282 not (yet?) supported */
	default:
		DEBUG(MTD_DEBUG_LEVEL1, "%s: unsupported device (%x)\n",
918
				dev_name(&spi->dev), status & 0x3c);
919 920 921 922 923
		status = -ENODEV;
	}

	if (status < 0)
		DEBUG(MTD_DEBUG_LEVEL1, "%s: add_dataflash --> %d\n",
924
				dev_name(&spi->dev), status);
925 926 927 928 929 930 931 932 933

	return status;
}

static int __devexit dataflash_remove(struct spi_device *spi)
{
	struct dataflash	*flash = dev_get_drvdata(&spi->dev);
	int			status;

934
	DEBUG(MTD_DEBUG_LEVEL1, "%s: remove\n", dev_name(&spi->dev));
935

936
	status = mtd_device_unregister(&flash->mtd);
937 938
	if (status == 0) {
		dev_set_drvdata(&spi->dev, NULL);
939
		kfree(flash);
940
	}
941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972
	return status;
}

static struct spi_driver dataflash_driver = {
	.driver = {
		.name		= "mtd_dataflash",
		.bus		= &spi_bus_type,
		.owner		= THIS_MODULE,
	},

	.probe		= dataflash_probe,
	.remove		= __devexit_p(dataflash_remove),

	/* FIXME:  investigate suspend and resume... */
};

static int __init dataflash_init(void)
{
	return spi_register_driver(&dataflash_driver);
}
module_init(dataflash_init);

static void __exit dataflash_exit(void)
{
	spi_unregister_driver(&dataflash_driver);
}
module_exit(dataflash_exit);


MODULE_LICENSE("GPL");
MODULE_AUTHOR("Andrew Victor, David Brownell");
MODULE_DESCRIPTION("MTD DataFlash driver");
973
MODULE_ALIAS("spi:mtd_dataflash");