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Commit 13134f48 authored by Rafał Miłecki's avatar Rafał Miłecki Committed by David Woodhouse
Browse files

mtd: bcm47xxsflash: writing support 



Tested with BCM4706.

Signed-off-by: default avatarRafał Miłecki <zajec5@gmail.com>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent c0fcbc56

drivers/mtd/devices/bcm47xxsflash.c

+126 −4
Original line number Diff line number Diff line
@@ -116,6 +116,127 @@ static int bcm47xxsflash_read(struct mtd_info *mtd, loff_t from, size_t len, 
	return len;

}



static int bcm47xxsflash_write_st(struct mtd_info *mtd, u32 offset, size_t len,

				  const u_char *buf)

{

	struct bcm47xxsflash *b47s = mtd->priv;

	int written = 0;



	/* Enable writes */

	bcm47xxsflash_cmd(b47s, OPCODE_ST_WREN);



	/* Write first byte */

	b47s->cc_write(b47s, BCMA_CC_FLASHADDR, offset);

	b47s->cc_write(b47s, BCMA_CC_FLASHDATA, *buf++);



	/* Program page */

	if (b47s->bcma_cc->core->id.rev < 20) {

		bcm47xxsflash_cmd(b47s, OPCODE_ST_PP);

		return 1; /* 1B written */

	}



	/* Program page and set CSA (on newer chips we can continue writing) */

	bcm47xxsflash_cmd(b47s, OPCODE_ST_CSA | OPCODE_ST_PP);

	offset++;

	len--;

	written++;



	while (len > 0) {

		/* Page boundary, another function call is needed */

		if ((offset & 0xFF) == 0)

			break;



		bcm47xxsflash_cmd(b47s, OPCODE_ST_CSA | *buf++);

		offset++;

		len--;

		written++;

	}



	/* All done, drop CSA & poll */

	b47s->cc_write(b47s, BCMA_CC_FLASHCTL, 0);

	udelay(1);

	if (bcm47xxsflash_poll(b47s, HZ / 10))

		pr_err("Flash rejected dropping CSA\n");



	return written;

}



static int bcm47xxsflash_write_at(struct mtd_info *mtd, u32 offset, size_t len,

				  const u_char *buf)

{

	struct bcm47xxsflash *b47s = mtd->priv;

	u32 mask = b47s->blocksize - 1;

	u32 page = (offset & ~mask) << 1;

	u32 byte = offset & mask;

	int written = 0;



	/* If we don't overwrite whole page, read it to the buffer first */

	if (byte || (len < b47s->blocksize)) {

		int err;



		b47s->cc_write(b47s, BCMA_CC_FLASHADDR, page);

		bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_LOAD);

		/* 250 us for AT45DB321B */

		err = bcm47xxsflash_poll(b47s, HZ / 1000);

		if (err) {

			pr_err("Timeout reading page 0x%X info buffer\n", page);

			return err;

		}

	}



	/* Change buffer content with our data */

	while (len > 0) {

		/* Page boundary, another function call is needed */

		if (byte == b47s->blocksize)

			break;



		b47s->cc_write(b47s, BCMA_CC_FLASHADDR, byte++);

		b47s->cc_write(b47s, BCMA_CC_FLASHDATA, *buf++);

		bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_WRITE);

		len--;

		written++;

	}



	/* Program page with the buffer content */

	b47s->cc_write(b47s, BCMA_CC_FLASHADDR, page);

	bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_PROGRAM);



	return written;

}



static int bcm47xxsflash_write(struct mtd_info *mtd, loff_t to, size_t len,

			       size_t *retlen, const u_char *buf)

{

	struct bcm47xxsflash *b47s = mtd->priv;

	int written;



	/* Writing functions can return without writing all passed data, for

	 * example when the hardware is too old or when we git page boundary.

	 */

	while (len > 0) {

		switch (b47s->type) {

		case BCM47XXSFLASH_TYPE_ST:

			written = bcm47xxsflash_write_st(mtd, to, len, buf);

			break;

		case BCM47XXSFLASH_TYPE_ATMEL:

			written = bcm47xxsflash_write_at(mtd, to, len, buf);

			break;

		default:

			BUG_ON(1);

		}

		if (written < 0) {

			pr_err("Error writing at offset 0x%llX\n", to);

			return written;

		}

		to += (loff_t)written;

		len -= written;

		*retlen += written;

		buf += written;

	}



	return 0;

}



static void bcm47xxsflash_fill_mtd(struct bcm47xxsflash *b47s)

{

	struct mtd_info *mtd = &b47s->mtd;
@@ -123,16 +244,17 @@ static void bcm47xxsflash_fill_mtd(struct bcm47xxsflash *b47s) 
	mtd->priv = b47s;

	mtd->name = "bcm47xxsflash";

	mtd->owner = THIS_MODULE;

	mtd->type = MTD_ROM;



	/* TODO: implement writing support and verify/change following code */

	mtd->flags = MTD_CAP_ROM;

	mtd->type = MTD_NORFLASH;

	mtd->flags = MTD_CAP_NORFLASH;

	mtd->size = b47s->size;

	mtd->erasesize = b47s->blocksize;

	mtd->writebufsize = mtd->writesize = 1;

	mtd->writesize = 1;

	mtd->writebufsize = 1;



	mtd->_erase = bcm47xxsflash_erase;

	mtd->_read = bcm47xxsflash_read;

	mtd->_write = bcm47xxsflash_write;

}



/**************************************************