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Commit 1da8869a authored by Andrey Smirnov's avatar Andrey Smirnov Committed by Brian Norris
Browse files

mtd: dataflash: Make use of "extened device information" 



In anticipation of supporting chips that need it, extend the size of
struct flash_info's 'jedec_id' field to make room 2 byte of extended
device information as well as add code to fetch this data during
jedec_probe().

Cc: cphealy@gmail.com
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Marek Vasut <marek.vasut@gmail.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Cc: linux-kernel@vger.kernel.org
Acked-by: default avatarMarek Vasut <marek.vasut@gmail.com>
Tested-by: default avatarChris Healy <cphealy@gmail.com>
Signed-off-by: default avatarAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
parent a296a1bc

drivers/mtd/devices/mtd_dataflash.c

+57 −31
Original line number Diff line number Diff line
@@ -84,6 +84,9 @@ 


#define CFI_MFR_ATMEL		0x1F



#define DATAFLASH_SHIFT_EXTID	24

#define DATAFLASH_SHIFT_ID	40



struct dataflash {

	u8			command[4];

	char			name[24];
@@ -687,7 +690,7 @@ struct flash_info { 
	/* JEDEC id has a high byte of zero plus three data bytes:

	 * the manufacturer id, then a two byte device id.

	 */

	u32		jedec_id;

	u64		jedec_id;



	/* The size listed here is what works with OP_ERASE_PAGE. */

	unsigned	nr_pages;
@@ -695,6 +698,7 @@ struct flash_info { 
	u16		pageoffset;



	u16		flags;

#define SUP_EXTID	0x0004		/* supports extended ID data */

#define SUP_POW2PS	0x0002		/* supports 2^N byte pages */

#define IS_POW2PS	0x0001		/* uses 2^N byte pages */

};
@@ -734,42 +738,18 @@ static struct flash_info dataflash_data[] = { 
	{ "at45db642d",  0x1f2800, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS},

};



static struct flash_info *jedec_probe(struct spi_device *spi)

static struct flash_info *jedec_lookup(struct spi_device *spi,

				       u64 jedec, bool use_extid)

{

	int ret;

	u8 code = OP_READ_ID;

	u8 id[3];

	u32 jedec;

	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.

	 *

	 * 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.

	 */

	ret = spi_write_then_read(spi, &code, 1, id, 3);

	if (ret < 0) {

		dev_dbg(&spi->dev, "error %d reading JEDEC ID\n", ret);

		return ERR_PTR(ret);

	}



	if (id[0] != CFI_MFR_ATMEL)

		return NULL;



	jedec = id[0];

	jedec = jedec << 8;

	jedec |= id[1];

	jedec = jedec << 8;

	jedec |= id[2];



	for (info = dataflash_data;

	     info < dataflash_data + ARRAY_SIZE(dataflash_data);

	     info++) {

		if (use_extid && !(info->flags & SUP_EXTID))

			continue;



		if (info->jedec_id == jedec) {

			dev_dbg(&spi->dev, "OTP, sector protect%s\n",

				(info->flags & SUP_POW2PS) ?
@@ -793,12 +773,58 @@ static struct flash_info *jedec_probe(struct spi_device *spi) 
		}

	}



	return ERR_PTR(-ENODEV);

}



static struct flash_info *jedec_probe(struct spi_device *spi)

{

	int ret;

	u8 code = OP_READ_ID;

	u64 jedec;

	u8 id[sizeof(jedec)] = {0};

	const unsigned int id_size = 5;

	struct flash_info *info;



	/*

	 * 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.

	 *

	 * 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.

	 */

	ret = spi_write_then_read(spi, &code, 1, id, id_size);

	if (ret < 0) {

		dev_dbg(&spi->dev, "error %d reading JEDEC ID\n", ret);

		return ERR_PTR(ret);

	}



	if (id[0] != CFI_MFR_ATMEL)

		return NULL;



	jedec = be64_to_cpup((__be64 *)id);



	/*

	 * First, try to match device using extended device

	 * information

	 */

	info = jedec_lookup(spi, jedec >> DATAFLASH_SHIFT_EXTID, true);

	if (!IS_ERR(info))

		return info;

	/*

	 * If that fails, make another pass using regular ID

	 * information

	 */

	info = jedec_lookup(spi, jedec >> DATAFLASH_SHIFT_ID, false);

	if (!IS_ERR(info))

		return info;

	/*

	 * 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);

	dev_warn(&spi->dev, "JEDEC id %016llx not handled\n", jedec);

	return ERR_PTR(-ENODEV);

}