diff options
Diffstat (limited to 'drivers/mtd/devices/m25p80.c')
| -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 b402269301f..b35c3333e21 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 |