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| author | Michael Hennerich <michael.hennerich@analog.com> | 2008-07-03 23:54:42 -0700 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2008-07-11 14:44:32 +0100 |
| commit | 72289824423655e67993c25c91a7a86a34917209 (patch) | |
| tree | 6afeeae0ca8ce251ede891f2b9ccf3b8779d3930 | |
| parent | a8931ef380c92d121ae74ecfb03b2d63f72eea6f (diff) | |
| download | linux-72289824423655e67993c25c91a7a86a34917209.tar.gz linux-72289824423655e67993c25c91a7a86a34917209.tar.bz2 linux-72289824423655e67993c25c91a7a86a34917209.zip | |
[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>
| -rw-r--r-- | drivers/mtd/devices/m25p80.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c index b402269301f6..b35c3333e210 100644 --- a/drivers/mtd/devices/m25p80.c +++ b/drivers/mtd/devices/m25p80.c @@ -33,6 +33,7 @@ /* Flash opcodes. */ #define OPCODE_WREN 0x06 /* Write enable */ #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_FAST_READ 0x0b /* Read data bytes (high frequency) */ #define OPCODE_PP 0x02 /* Page program (up to 256 bytes) */ @@ -112,6 +113,17 @@ static int read_sr(struct m25p *flash) 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. @@ -589,6 +601,16 @@ static int __devinit m25p_probe(struct spi_device *spi) mutex_init(&flash->lock); 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) flash->mtd.name = data->name; else |