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Commit fb50b58e authored by Robert Jarzmik's avatar Robert Jarzmik Committed by David Woodhouse
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mtd: docg3: add write functions



Add write capability to the docg3 driver. The writes are
possible on a single page (512 bytes + 16 bytes), even if
that page is split on 2 physical pages on 2 blocks (each on
one plane).

Signed-off-by: default avatarRobert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: default avatarIvan Djelic <ivan.djelic@parrot.com>
Reviewed-by: default avatarMike Dunn <mikedunn@newsguy.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 316e627e
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+541 −12
Original line number Diff line number Diff line
@@ -253,6 +253,40 @@ static void doc_read_data_area(struct docg3 *docg3, void *buf, int len,
	}
}

/**
 * doc_write_data_area - Write data into data area
 * @docg3: the device
 * @buf: the buffer to get input bytes from
 * @len: the length to write
 *
 * Writes bytes into flash data. Handles the single byte / even bytes writes.
 */
static void doc_write_data_area(struct docg3 *docg3, const void *buf, int len)
{
	int i, cdr, len4;
	u16 *src16;
	u8 *src8;

	doc_dbg("doc_write_data_area(buf=%p, len=%d)\n", buf, len);
	cdr = len & 0x3;
	len4 = len - cdr;

	doc_writew(docg3, DOC_IOSPACE_DATA, DOC_READADDRESS);
	src16 = (u16 *)buf;
	for (i = 0; i < len4; i += 2) {
		doc_writew(docg3, *src16, DOC_IOSPACE_DATA);
		src16++;
	}

	src8 = (u8 *)src16;
	for (i = 0; i < cdr; i++) {
		doc_writew(docg3, DOC_IOSPACE_DATA | DOC_READADDR_ONE_BYTE,
			   DOC_READADDRESS);
		doc_writeb(docg3, *src8, DOC_IOSPACE_DATA);
		src8++;
	}
}

/**
 * doc_set_data_mode - Sets the flash to reliable data mode
 * @docg3: the device
@@ -342,6 +376,37 @@ static int doc_set_extra_page_mode(struct docg3 *docg3)
		return 0;
}

/**
 * doc_setup_addr_sector - Setup blocks/page/ofs address for one plane
 * @docg3: the device
 * @sector: the sector
 */
static void doc_setup_addr_sector(struct docg3 *docg3, int sector)
{
	doc_delay(docg3, 1);
	doc_flash_address(docg3, sector & 0xff);
	doc_flash_address(docg3, (sector >> 8) & 0xff);
	doc_flash_address(docg3, (sector >> 16) & 0xff);
	doc_delay(docg3, 1);
}

/**
 * doc_setup_writeaddr_sector - Setup blocks/page/ofs address for one plane
 * @docg3: the device
 * @sector: the sector
 * @ofs: the offset in the page, between 0 and (512 + 16 + 512)
 */
static void doc_setup_writeaddr_sector(struct docg3 *docg3, int sector, int ofs)
{
	ofs = ofs >> 2;
	doc_delay(docg3, 1);
	doc_flash_address(docg3, ofs & 0xff);
	doc_flash_address(docg3, sector & 0xff);
	doc_flash_address(docg3, (sector >> 8) & 0xff);
	doc_flash_address(docg3, (sector >> 16) & 0xff);
	doc_delay(docg3, 1);
}

/**
 * doc_seek - Set both flash planes to the specified block, page for reading
 * @docg3: the device
@@ -378,27 +443,73 @@ static int doc_read_seek(struct docg3 *docg3, int block0, int block1, int page,
	if (ret)
		goto out;

	sector = (block0 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
	doc_flash_sequence(docg3, DOC_SEQ_READ);
	sector = (block0 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
	doc_delay(docg3, 1);
	doc_flash_address(docg3, sector & 0xff);
	doc_flash_address(docg3, (sector >> 8) & 0xff);
	doc_flash_address(docg3, (sector >> 16) & 0xff);
	doc_delay(docg3, 1);
	doc_setup_addr_sector(docg3, sector);

	sector = (block1 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
	doc_flash_command(docg3, DOC_CMD_PROG_BLOCK_ADDR);
	doc_setup_addr_sector(docg3, sector);
	doc_delay(docg3, 1);
	doc_flash_address(docg3, sector & 0xff);
	doc_flash_address(docg3, (sector >> 8) & 0xff);
	doc_flash_address(docg3, (sector >> 16) & 0xff);

out:
	return ret;
}

/**
 * doc_write_seek - Set both flash planes to the specified block, page for writing
 * @docg3: the device
 * @block0: the first plane block index
 * @block1: the second plane block index
 * @page: the page index within the block
 * @ofs: offset in page to write
 *
 * Programs the flash even and odd planes to the specific block and page.
 * Alternatively, programs the flash to the wear area of the specified page.
 */
static int doc_write_seek(struct docg3 *docg3, int block0, int block1, int page,
			 int ofs)
{
	int ret = 0, sector;

	doc_dbg("doc_write_seek(blocks=(%d,%d), page=%d, ofs=%d)\n",
		block0, block1, page, ofs);

	doc_set_reliable_mode(docg3);

	if (ofs < 2 * DOC_LAYOUT_PAGE_SIZE) {
		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE1);
		doc_flash_command(docg3, DOC_CMD_READ_PLANE1);
		doc_delay(docg3, 2);
	} else {
		doc_flash_sequence(docg3, DOC_SEQ_SET_PLANE2);
		doc_flash_command(docg3, DOC_CMD_READ_PLANE2);
		doc_delay(docg3, 2);
	}

	doc_flash_sequence(docg3, DOC_SEQ_PAGE_SETUP);
	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE1);

	sector = (block0 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
	doc_setup_writeaddr_sector(docg3, sector, ofs);

	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE3);
	doc_delay(docg3, 2);
	ret = doc_wait_ready(docg3);
	if (ret)
		goto out;

	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE1);
	sector = (block1 << DOC_ADDR_BLOCK_SHIFT) + (page & DOC_ADDR_PAGE_MASK);
	doc_setup_writeaddr_sector(docg3, sector, ofs);
	doc_delay(docg3, 1);

out:
	return ret;
}


/**
 * doc_read_page_ecc_init - Initialize hardware ECC engine
 * @docg3: the device
@@ -420,6 +531,58 @@ static int doc_read_page_ecc_init(struct docg3 *docg3, int len)
	return doc_wait_ready(docg3);
}

/**
 * doc_write_page_ecc_init - Initialize hardware BCH ECC engine
 * @docg3: the device
 * @len: the number of bytes covered by the ECC (BCH covered)
 *
 * The function does initialize the hardware ECC engine to compute the Hamming
 * ECC (on 1 byte) and the BCH Syndroms (on 7 bytes).
 *
 * Return 0 if succeeded, -EIO on error
 */
static int doc_write_page_ecc_init(struct docg3 *docg3, int len)
{
	doc_writew(docg3, !DOC_ECCCONF0_READ_MODE
		   | DOC_ECCCONF0_BCH_ENABLE | DOC_ECCCONF0_HAMMING_ENABLE
		   | (len & DOC_ECCCONF0_DATA_BYTES_MASK),
		   DOC_ECCCONF0);
	doc_delay(docg3, 4);
	doc_register_readb(docg3, DOC_FLASHCONTROL);
	return doc_wait_ready(docg3);
}

/**
 * doc_ecc_disable - Disable Hamming and BCH ECC hardware calculator
 * @docg3: the device
 *
 * Disables the hardware ECC generator and checker, for unchecked reads (as when
 * reading OOB only or write status byte).
 */
static void doc_ecc_disable(struct docg3 *docg3)
{
	doc_writew(docg3, DOC_ECCCONF0_READ_MODE, DOC_ECCCONF0);
	doc_delay(docg3, 4);
}

/**
 * doc_hamming_ecc_init - Initialize hardware Hamming ECC engine
 * @docg3: the device
 * @nb_bytes: the number of bytes covered by the ECC (Hamming covered)
 *
 * This function programs the ECC hardware to compute the hamming code on the
 * last provided N bytes to the hardware generator.
 */
static void doc_hamming_ecc_init(struct docg3 *docg3, int nb_bytes)
{
	u8 ecc_conf1;

	ecc_conf1 = doc_register_readb(docg3, DOC_ECCCONF1);
	ecc_conf1 &= ~DOC_ECCCONF1_HAMMING_BITS_MASK;
	ecc_conf1 |= (nb_bytes & DOC_ECCCONF1_HAMMING_BITS_MASK);
	doc_writeb(docg3, ecc_conf1, DOC_ECCCONF1);
}

/**
 * doc_read_page_prepare - Prepares reading data from a flash page
 * @docg3: the device
@@ -505,12 +668,26 @@ static int doc_read_page_getbytes(struct docg3 *docg3, int len, u_char *buf,
	return len;
}

/**
 * doc_write_page_putbytes - Writes bytes into a prepared page
 * @docg3: the device
 * @len: the number of bytes to be written
 * @buf: the buffer of input bytes
 *
 */
static void doc_write_page_putbytes(struct docg3 *docg3, int len,
				    const u_char *buf)
{
	doc_write_data_area(docg3, buf, len);
	doc_delay(docg3, 2);
}

/**
 * doc_get_hw_bch_syndroms - Get hardware calculated BCH syndroms
 * @docg3: the device
 * @syns:  the array of 7 integers where the syndroms will be stored
 */
static void doc_get_hw_bch_syndroms(struct docg3 *docg3, int *syns)
static void doc_get_hw_bch_syndroms(struct docg3 *docg3, u8 *syns)
{
	int i;

@@ -518,6 +695,16 @@ static void doc_get_hw_bch_syndroms(struct docg3 *docg3, int *syns)
		syns[i] = doc_register_readb(docg3, DOC_BCH_SYNDROM(i));
}

/**
 * doc_page_finish - Ends reading/writing of a flash page
 * @docg3: the device
 */
static void doc_page_finish(struct docg3 *docg3)
{
	doc_writeb(docg3, 0, DOC_DATAEND);
	doc_delay(docg3, 2);
}

/**
 * doc_read_page_finish - Ends reading of a flash page
 * @docg3: the device
@@ -528,8 +715,7 @@ static void doc_get_hw_bch_syndroms(struct docg3 *docg3, int *syns)
 */
static void doc_read_page_finish(struct docg3 *docg3)
{
	doc_writeb(docg3, 0, DOC_DATAEND);
	doc_delay(docg3, 2);
	doc_page_finish(docg3);
	doc_set_device_id(docg3, 0);
}

@@ -791,6 +977,348 @@ static int doc_get_erase_count(struct docg3 *docg3, loff_t from)
	return max(plane1_erase_count, plane2_erase_count);
}

/**
 * doc_get_op_status - get erase/write operation status
 * @docg3: the device
 *
 * Queries the status from the chip, and returns it
 *
 * Returns the status (bits DOC_PLANES_STATUS_*)
 */
static int doc_get_op_status(struct docg3 *docg3)
{
	u8 status;

	doc_flash_sequence(docg3, DOC_SEQ_PLANES_STATUS);
	doc_flash_command(docg3, DOC_CMD_PLANES_STATUS);
	doc_delay(docg3, 5);

	doc_ecc_disable(docg3);
	doc_read_data_area(docg3, &status, 1, 1);
	return status;
}

/**
 * doc_write_erase_wait_status - wait for write or erase completion
 * @docg3: the device
 *
 * Wait for the chip to be ready again after erase or write operation, and check
 * erase/write status.
 *
 * Returns 0 if erase successfull, -EIO if erase/write issue, -ETIMEOUT if
 * timeout
 */
static int doc_write_erase_wait_status(struct docg3 *docg3)
{
	int status, ret = 0;

	if (!doc_is_ready(docg3))
		usleep_range(3000, 3000);
	if (!doc_is_ready(docg3)) {
		doc_dbg("Timeout reached and the chip is still not ready\n");
		ret = -EAGAIN;
		goto out;
	}

	status = doc_get_op_status(docg3);
	if (status & DOC_PLANES_STATUS_FAIL) {
		doc_dbg("Erase/Write failed on (a) plane(s), status = %x\n",
			status);
		ret = -EIO;
	}

out:
	doc_page_finish(docg3);
	return ret;
}

/**
 * doc_write_page - Write a single page to the chip
 * @docg3: the device
 * @to: the offset from first block and first page, in bytes, aligned on page
 *      size
 * @buf: buffer to get bytes from
 * @oob: buffer to get out of band bytes from (can be NULL if no OOB should be
 *       written)
 * @autoecc: if 0, all 16 bytes from OOB are taken, regardless of HW Hamming or
 *           BCH computations. If 1, only bytes 0-7 and byte 15 are taken,
 *           remaining ones are filled with hardware Hamming and BCH
 *           computations. Its value is not meaningfull is oob == NULL.
 *
 * Write one full page (ie. 1 page split on two planes), of 512 bytes, with the
 * OOB data. The OOB ECC is automatically computed by the hardware Hamming and
 * BCH generator if autoecc is not null.
 *
 * Returns 0 if write successful, -EIO if write error, -EAGAIN if timeout
 */
static int doc_write_page(struct docg3 *docg3, loff_t to, const u_char *buf,
			  const u_char *oob, int autoecc)
{
	int block0, block1, page, ret, ofs = 0;
	u8 syn[DOC_ECC_BCH_SIZE], hamming;

	doc_dbg("doc_write_page(to=%lld)\n", to);
	calc_block_sector(to, &block0, &block1, &page, &ofs);

	doc_set_device_id(docg3, docg3->device_id);
	ret = doc_reset_seq(docg3);
	if (ret)
		goto err;

	/* Program the flash address block and page */
	ret = doc_write_seek(docg3, block0, block1, page, ofs);
	if (ret)
		goto err;

	doc_write_page_ecc_init(docg3, DOC_ECC_BCH_COVERED_BYTES);
	doc_delay(docg3, 2);
	doc_write_page_putbytes(docg3, DOC_LAYOUT_PAGE_SIZE, buf);

	if (oob && autoecc) {
		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_PAGEINFO_SZ, oob);
		doc_delay(docg3, 2);
		oob += DOC_LAYOUT_OOB_UNUSED_OFS;

		hamming = doc_register_readb(docg3, DOC_HAMMINGPARITY);
		doc_delay(docg3, 2);
		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_HAMMING_SZ,
					&hamming);
		doc_delay(docg3, 2);

		doc_get_hw_bch_syndroms(docg3, syn);
		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_BCH_SZ, syn);
		doc_delay(docg3, 2);

		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_UNUSED_SZ, oob);
	}
	if (oob && !autoecc)
		doc_write_page_putbytes(docg3, DOC_LAYOUT_OOB_SIZE, oob);

	doc_delay(docg3, 2);
	doc_page_finish(docg3);
	doc_delay(docg3, 2);
	doc_flash_command(docg3, DOC_CMD_PROG_CYCLE2);
	doc_delay(docg3, 2);

	/*
	 * The wait status will perform another doc_page_finish() call, but that
	 * seems to please the docg3, so leave it.
	 */
	ret = doc_write_erase_wait_status(docg3);
	return ret;
err:
	doc_read_page_finish(docg3);
	return ret;
}

/**
 * doc_guess_autoecc - Guess autoecc mode from mbd_oob_ops
 * @ops: the oob operations
 *
 * Returns 0 or 1 if success, -EINVAL if invalid oob mode
 */
static int doc_guess_autoecc(struct mtd_oob_ops *ops)
{
	int autoecc;

	switch (ops->mode) {
	case MTD_OPS_PLACE_OOB:
	case MTD_OPS_AUTO_OOB:
		autoecc = 1;
		break;
	case MTD_OPS_RAW:
		autoecc = 0;
		break;
	default:
		autoecc = -EINVAL;
	}
	return autoecc;
}

/**
 * doc_fill_autooob - Fill a 16 bytes OOB from 8 non-ECC bytes
 * @dst: the target 16 bytes OOB buffer
 * @oobsrc: the source 8 bytes non-ECC OOB buffer
 *
 */
static void doc_fill_autooob(u8 *dst, u8 *oobsrc)
{
	memcpy(dst, oobsrc, DOC_LAYOUT_OOB_PAGEINFO_SZ);
	dst[DOC_LAYOUT_OOB_UNUSED_OFS] = oobsrc[DOC_LAYOUT_OOB_PAGEINFO_SZ];
}

/**
 * doc_backup_oob - Backup OOB into docg3 structure
 * @docg3: the device
 * @to: the page offset in the chip
 * @ops: the OOB size and buffer
 *
 * As the docg3 should write a page with its OOB in one pass, and some userland
 * applications do write_oob() to setup the OOB and then write(), store the OOB
 * into a temporary storage. This is very dangerous, as 2 concurrent
 * applications could store an OOB, and then write their pages (which will
 * result into one having its OOB corrupted).
 *
 * The only reliable way would be for userland to call doc_write_oob() with both
 * the page data _and_ the OOB area.
 *
 * Returns 0 if success, -EINVAL if ops content invalid
 */
static int doc_backup_oob(struct docg3 *docg3, loff_t to,
			  struct mtd_oob_ops *ops)
{
	int ooblen = ops->ooblen, autoecc;

	if (ooblen != DOC_LAYOUT_OOB_SIZE)
		return -EINVAL;
	autoecc = doc_guess_autoecc(ops);
	if (autoecc < 0)
		return autoecc;

	docg3->oob_write_ofs = to;
	docg3->oob_autoecc = autoecc;
	if (ops->mode == MTD_OPS_AUTO_OOB) {
		doc_fill_autooob(docg3->oob_write_buf, ops->oobbuf);
		ops->oobretlen = 8;
	} else {
		memcpy(docg3->oob_write_buf, ops->oobbuf, DOC_LAYOUT_OOB_SIZE);
		ops->oobretlen = DOC_LAYOUT_OOB_SIZE;
	}
	return 0;
}

/**
 * doc_write_oob - Write out of band bytes to flash
 * @mtd: the device
 * @ofs: the offset from first block and first page, in bytes, aligned on page
 *       size
 * @ops: the mtd oob structure
 *
 * Either write OOB data into a temporary buffer, for the subsequent write
 * page. The provided OOB should be 16 bytes long. If a data buffer is provided
 * as well, issue the page write.
 * Or provide data without OOB, and then a all zeroed OOB will be used (ECC will
 * still be filled in if asked for).
 *
 * Returns 0 is successfull, EINVAL if length is not 14 bytes
 */
static int doc_write_oob(struct mtd_info *mtd, loff_t ofs,
			 struct mtd_oob_ops *ops)
{
	struct docg3 *docg3 = mtd->priv;
	int block0, block1, page, ret, pofs = 0, autoecc, oobdelta;
	u8 *oobbuf = ops->oobbuf;
	u8 *buf = ops->datbuf;
	size_t len, ooblen;
	u8 oob[DOC_LAYOUT_OOB_SIZE];

	if (buf)
		len = ops->len;
	else
		len = 0;
	if (oobbuf)
		ooblen = ops->ooblen;
	else
		ooblen = 0;

	if (oobbuf && ops->mode == MTD_OPS_PLACE_OOB)
		oobbuf += ops->ooboffs;

	doc_dbg("doc_write_oob(from=%lld, mode=%d, data=(%p:%zu), oob=(%p:%zu))\n",
		ofs, ops->mode, buf, len, oobbuf, ooblen);
	switch (ops->mode) {
	case MTD_OPS_PLACE_OOB:
	case MTD_OPS_RAW:
		oobdelta = mtd->oobsize;
		break;
	case MTD_OPS_AUTO_OOB:
		oobdelta = mtd->ecclayout->oobavail;
		break;
	default:
		oobdelta = 0;
	}
	if ((len % DOC_LAYOUT_PAGE_SIZE) || (ooblen % oobdelta) ||
	    (ofs % DOC_LAYOUT_PAGE_SIZE))
		return -EINVAL;
	if (len && ooblen &&
	    (len / DOC_LAYOUT_PAGE_SIZE) != (ooblen / oobdelta))
		return -EINVAL;

	ret = -EINVAL;
	calc_block_sector(ofs + len, &block0, &block1, &page, &pofs);
	if (block1 > docg3->max_block)
		goto err;

	ops->oobretlen = 0;
	ops->retlen = 0;
	ret = 0;
	if (len == 0 && ooblen == 0)
		return -EINVAL;
	if (len == 0 && ooblen > 0)
		return doc_backup_oob(docg3, ofs, ops);

	autoecc = doc_guess_autoecc(ops);
	if (autoecc < 0)
		return autoecc;

	while (!ret && len > 0) {
		memset(oob, 0, sizeof(oob));
		if (ofs == docg3->oob_write_ofs)
			memcpy(oob, docg3->oob_write_buf, DOC_LAYOUT_OOB_SIZE);
		else if (ooblen > 0 && ops->mode == MTD_OPS_AUTO_OOB)
			doc_fill_autooob(oob, oobbuf);
		else if (ooblen > 0)
			memcpy(oob, oobbuf, DOC_LAYOUT_OOB_SIZE);
		ret = doc_write_page(docg3, ofs, buf, oob, autoecc);

		ofs += DOC_LAYOUT_PAGE_SIZE;
		len -= DOC_LAYOUT_PAGE_SIZE;
		buf += DOC_LAYOUT_PAGE_SIZE;
		if (ooblen) {
			oobbuf += oobdelta;
			ooblen -= oobdelta;
			ops->oobretlen += oobdelta;
		}
		ops->retlen += DOC_LAYOUT_PAGE_SIZE;
	}
err:
	doc_set_device_id(docg3, 0);
	return ret;
}

/**
 * doc_write - Write a buffer to the chip
 * @mtd: the device
 * @to: the offset from first block and first page, in bytes, aligned on page
 *      size
 * @len: the number of bytes to write (must be a full page size, ie. 512)
 * @retlen: the number of bytes actually written (0 or 512)
 * @buf: the buffer to get bytes from
 *
 * Writes data to the chip.
 *
 * Returns 0 if write successful, -EIO if write error
 */
static int doc_write(struct mtd_info *mtd, loff_t to, size_t len,
		     size_t *retlen, const u_char *buf)
{
	struct docg3 *docg3 = mtd->priv;
	int ret;
	struct mtd_oob_ops ops;

	doc_dbg("doc_write(to=%lld, len=%zu)\n", to, len);
	ops.datbuf = (char *)buf;
	ops.len = len;
	ops.mode = MTD_OPS_PLACE_OOB;
	ops.oobbuf = NULL;
	ops.ooblen = 0;
	ops.ooboffs = 0;

	ret = doc_write_oob(mtd, to, &ops);
	*retlen = ops.retlen;
	return ret;
}

/*
 * Debug sysfs entries
 */
@@ -1052,6 +1580,7 @@ static struct mtd_info *doc_probe_device(void __iomem *base, int floor,

	doc_set_driver_info(chip_id, mtd);

	doc_hamming_ecc_init(docg3, DOC_LAYOUT_OOB_PAGEINFO_SZ);
	doc_reload_bbt(docg3);
	return mtd;