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[MTD] m25p80: fix bug - ATmel spi flash fails to be copied to 

Atmel serial flash tends to power up with the protection status bits set.
http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=4089

[michael.hennerich@analog.com: remove duplicate code]
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Michael Hennerich 2008-07-03 23:54:42 -07:00 committed by David Woodhouse
parent a8931ef380
commit 7228982442
1 changed files with 22 additions and 0 deletions
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22
drivers/mtd/devices/m25p80.c
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@ -33,6 +33,7 @@
/* Flash opcodes. */ /* Flash opcodes. */
#define OPCODE_WREN 0x06 /* Write enable */ #define OPCODE_WREN 0x06 /* Write enable */
#define OPCODE_RDSR 0x05 /* Read status register */ #define OPCODE_RDSR 0x05 /* Read status register */
#define OPCODE_WRSR 0x01 /* Write status register 1 byte */
#define OPCODE_NORM_READ 0x03 /* Read data bytes (low frequency) */ #define OPCODE_NORM_READ 0x03 /* Read data bytes (low frequency) */
#define OPCODE_FAST_READ 0x0b /* Read data bytes (high frequency) */ #define OPCODE_FAST_READ 0x0b /* Read data bytes (high frequency) */
#define OPCODE_PP 0x02 /* Page program (up to 256 bytes) */ #define OPCODE_PP 0x02 /* Page program (up to 256 bytes) */
@ -112,6 +113,17 @@ static int read_sr(struct m25p *flash)
return val; return val;
} }
/*
* Write status register 1 byte
* Returns negative if error occurred.
*/
static int write_sr(struct m25p *flash, u8 val)
{
flash->command[0] = OPCODE_WRSR;
flash->command[1] = val;
return spi_write(flash->spi, flash->command, 2);
}
/* /*
* Set write enable latch with Write Enable command. * Set write enable latch with Write Enable command.
@ -589,6 +601,16 @@ static int __devinit m25p_probe(struct spi_device *spi)
mutex_init(&flash->lock); mutex_init(&flash->lock);
dev_set_drvdata(&spi->dev, flash); dev_set_drvdata(&spi->dev, flash);
/*
* Atmel serial flash tend to power up
* with the software protection bits set
*/
if (info->jedec_id >> 16 == 0x1f) {
write_enable(flash);
write_sr(flash, 0);
}
if (data && data->name) if (data && data->name)
flash->mtd.name = data->name; flash->mtd.name = data->name;
else else