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Commit 29072b96 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Artem Bityutskiy
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[MTD] NAND: add subpage write support 



Many SLC NANDs support up to 4 writes at one NAND page. Add support
of this feature.

Signed-off-by: default avatarArtem Bityutskiy <dedekind@infradead.org>
parent f6a7ecb1

drivers/mtd/mtdconcat.c

+1 −0
Original line number Diff line number Diff line
@@ -772,6 +772,7 @@ struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to c 
		concat->mtd.ecc_stats.badblocks +=

			subdev[i]->ecc_stats.badblocks;

		if (concat->mtd.writesize   !=  subdev[i]->writesize ||

		    concat->mtd.subpage_sft != subdev[i]->subpage_sft ||

		    concat->mtd.oobsize    !=  subdev[i]->oobsize ||

		    concat->mtd.ecctype    !=  subdev[i]->ecctype ||

		    concat->mtd.eccsize    !=  subdev[i]->eccsize ||

drivers/mtd/mtdpart.c

+1 −0
Original line number Diff line number Diff line
@@ -340,6 +340,7 @@ int add_mtd_partitions(struct mtd_info *master, 
		slave->mtd.oobsize = master->oobsize;

		slave->mtd.ecctype = master->ecctype;

		slave->mtd.eccsize = master->eccsize;

		slave->mtd.subpage_sft = master->subpage_sft;



		slave->mtd.name = parts[i].name;

		slave->mtd.bank_size = master->bank_size;

drivers/mtd/nand/nand_base.c

+44 −9
Original line number Diff line number Diff line
@@ -1590,7 +1590,7 @@ static uint8_t *nand_fill_oob(struct nand_chip *chip, uint8_t *oob, 
	return NULL;

}



#define NOTALIGNED(x) (x & (mtd->writesize-1)) != 0

#define NOTALIGNED(x)	(x & (chip->subpagesize - 1)) != 0



/**

 * nand_do_write_ops - [Internal] NAND write with ECC
@@ -1603,15 +1603,16 @@ static uint8_t *nand_fill_oob(struct nand_chip *chip, uint8_t *oob, 
static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,

			     struct mtd_oob_ops *ops)

{

	int chipnr, realpage, page, blockmask;

	int chipnr, realpage, page, blockmask, column;

	struct nand_chip *chip = mtd->priv;

	uint32_t writelen = ops->len;

	uint8_t *oob = ops->oobbuf;

	uint8_t *buf = ops->datbuf;

	int bytes = mtd->writesize;

	int ret;

	int ret, subpage;



	ops->retlen = 0;

	if (!writelen)

		return 0;



	/* reject writes, which are not page aligned */

	if (NOTALIGNED(to) || NOTALIGNED(ops->len)) {
@@ -1620,8 +1621,11 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to, 
		return -EINVAL;

	}



	if (!writelen)

		return 0;

	column = to & (mtd->writesize - 1);

	subpage = column || (writelen & (mtd->writesize - 1));



	if (subpage && oob)

		return -EINVAL;



	chipnr = (int)(to >> chip->chip_shift);

	chip->select_chip(mtd, chipnr);
@@ -1644,12 +1648,24 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to, 
		memset(chip->oob_poi, 0xff, mtd->oobsize);



	while(1) {

		int bytes = mtd->writesize;

		int cached = writelen > bytes && page != blockmask;

		uint8_t *wbuf = buf;



		/* Partial page write ? */

		if (unlikely(column || writelen < (mtd->writesize - 1))) {

			cached = 0;

			bytes = min_t(int, bytes - column, (int) writelen);

			chip->pagebuf = -1;

			memset(chip->buffers->databuf, 0xff, mtd->writesize);

			memcpy(&chip->buffers->databuf[column], buf, bytes);

			wbuf = chip->buffers->databuf;

		}



		if (unlikely(oob))

			oob = nand_fill_oob(chip, oob, ops);



		ret = chip->write_page(mtd, chip, buf, page, cached,

		ret = chip->write_page(mtd, chip, wbuf, page, cached,

				       (ops->mode == MTD_OOB_RAW));

		if (ret)

			break;
@@ -1658,6 +1674,7 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to, 
		if (!writelen)

			break;



		column = 0;

		buf += bytes;

		realpage++;
@@ -2201,8 +2218,8 @@ static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd, 
	/* Newer devices have all the information in additional id bytes */

	if (!type->pagesize) {

		int extid;

		/* The 3rd id byte contains non relevant data ATM */

		extid = chip->read_byte(mtd);

		/* The 3rd id byte holds MLC / multichip data */

		chip->cellinfo = chip->read_byte(mtd);

		/* The 4th id byte is the important one */

		extid = chip->read_byte(mtd);

		/* Calc pagesize */
@@ -2482,6 +2499,24 @@ int nand_scan_tail(struct mtd_info *mtd) 
	}

	chip->ecc.total = chip->ecc.steps * chip->ecc.bytes;



	/*

	 * Allow subpage writes up to ecc.steps. Not possible for MLC

	 * FLASH.

	 */

	if (!(chip->options & NAND_NO_SUBPAGE_WRITE) &&

	    !(chip->cellinfo & NAND_CI_CELLTYPE_MSK)) {

		switch(chip->ecc.steps) {

		case 2:

			mtd->subpage_sft = 1;

			break;

		case 4:

		case 8:

			mtd->subpage_sft = 2;

			break;

		}

	}

	chip->subpagesize = mtd->writesize >> mtd->subpage_sft;



	/* Initialize state */

	chip->state = FL_READY;

include/linux/mtd/mtd.h

+2 −0
Original line number Diff line number Diff line
@@ -200,6 +200,8 @@ struct mtd_info { 


	/* ECC status information */

	struct mtd_ecc_stats ecc_stats;

	/* Subpage shift (NAND) */

	int subpage_sft;



	void *priv;

include/linux/mtd/nand.h

+9 −0
Original line number Diff line number Diff line
@@ -166,6 +166,9 @@ typedef enum { 
 * for all large page devices, as they do not support

 * autoincrement.*/

#define NAND_NO_READRDY		0x00000100

/* Chip does not allow subpage writes */

#define NAND_NO_SUBPAGE_WRITE	0x00000200





/* Options valid for Samsung large page devices */

#define NAND_SAMSUNG_LP_OPTIONS \
@@ -193,6 +196,9 @@ typedef enum { 
/* Nand scan has allocated controller struct */

#define NAND_CONTROLLER_ALLOC	0x80000000



/* Cell info constants */

#define NAND_CI_CHIPNR_MSK	0x03

#define NAND_CI_CELLTYPE_MSK	0x0C



/*

 * nand_state_t - chip states
@@ -341,6 +347,7 @@ struct nand_buffers { 
 * @chipsize:		[INTERN] the size of one chip for multichip arrays

 * @pagemask:		[INTERN] page number mask = number of (pages / chip) - 1

 * @pagebuf:		[INTERN] holds the pagenumber which is currently in data_buf

 * @subpagesize:	[INTERN] holds the subpagesize

 * @ecclayout:		[REPLACEABLE] the default ecc placement scheme

 * @bbt:		[INTERN] bad block table pointer

 * @bbt_td:		[REPLACEABLE] bad block table descriptor for flash lookup
@@ -388,6 +395,8 @@ struct nand_chip { 
	unsigned long	chipsize;

	int		pagemask;

	int		pagebuf;

	int		subpagesize;

	uint8_t		cellinfo;

	int		badblockpos;



	nand_state_t	state;