diff options
Diffstat (limited to 'drivers/mtd/devices/mtd_dataflash.c')
| -rw-r--r-- | drivers/mtd/devices/mtd_dataflash.c | 206 |
1 files changed, 199 insertions, 7 deletions
diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c index 8bd0dea6885f..17c9b20dca87 100644 --- a/drivers/mtd/devices/mtd_dataflash.c +++ b/drivers/mtd/devices/mtd_dataflash.c @@ -80,7 +80,8 @@ */ #define OP_READ_ID 0x9F #define OP_READ_SECURITY 0x77 -#define OP_WRITE_SECURITY 0x9A /* OTP bits */ +#define OP_WRITE_SECURITY_REVC 0x9A +#define OP_WRITE_SECURITY 0x9B /* revision D */ struct dataflash { @@ -451,16 +452,192 @@ static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len, /* ......................................................................... */ +#ifdef CONFIG_MTD_DATAFLASH_OTP + +static int dataflash_get_otp_info(struct mtd_info *mtd, + struct otp_info *info, size_t len) +{ + /* Report both blocks as identical: bytes 0..64, locked. + * Unless the user block changed from all-ones, we can't + * tell whether it's still writable; so we assume it isn't. + */ + info->start = 0; + info->length = 64; + info->locked = 1; + return sizeof(*info); +} + +static ssize_t otp_read(struct spi_device *spi, unsigned base, + uint8_t *buf, loff_t off, size_t len) +{ + struct spi_message m; + size_t l; + uint8_t *scratch; + struct spi_transfer t; + int status; + + if (off > 64) + return -EINVAL; + + if ((off + len) > 64) + len = 64 - off; + if (len == 0) + return len; + + spi_message_init(&m); + + l = 4 + base + off + len; + scratch = kzalloc(l, GFP_KERNEL); + if (!scratch) + return -ENOMEM; + + /* OUT: OP_READ_SECURITY, 3 don't-care bytes, zeroes + * IN: ignore 4 bytes, data bytes 0..N (max 127) + */ + scratch[0] = OP_READ_SECURITY; + + memset(&t, 0, sizeof t); + t.tx_buf = scratch; + t.rx_buf = scratch; + t.len = l; + spi_message_add_tail(&t, &m); + + dataflash_waitready(spi); + + status = spi_sync(spi, &m); + if (status >= 0) { + memcpy(buf, scratch + 4 + base + off, len); + status = len; + } + + kfree(scratch); + return status; +} + +static int dataflash_read_fact_otp(struct mtd_info *mtd, + loff_t from, size_t len, size_t *retlen, u_char *buf) +{ + struct dataflash *priv = (struct dataflash *)mtd->priv; + int status; + + /* 64 bytes, from 0..63 ... start at 64 on-chip */ + mutex_lock(&priv->lock); + status = otp_read(priv->spi, 64, buf, from, len); + mutex_unlock(&priv->lock); + + if (status < 0) + return status; + *retlen = status; + return 0; +} + +static int dataflash_read_user_otp(struct mtd_info *mtd, + loff_t from, size_t len, size_t *retlen, u_char *buf) +{ + struct dataflash *priv = (struct dataflash *)mtd->priv; + int status; + + /* 64 bytes, from 0..63 ... start at 0 on-chip */ + mutex_lock(&priv->lock); + status = otp_read(priv->spi, 0, buf, from, len); + mutex_unlock(&priv->lock); + + if (status < 0) + return status; + *retlen = status; + return 0; +} + +static int dataflash_write_user_otp(struct mtd_info *mtd, + loff_t from, size_t len, size_t *retlen, u_char *buf) +{ + struct spi_message m; + const size_t l = 4 + 64; + uint8_t *scratch; + struct spi_transfer t; + struct dataflash *priv = (struct dataflash *)mtd->priv; + int status; + + if (len > 64) + return -EINVAL; + + /* Strictly speaking, we *could* truncate the write ... but + * let's not do that for the only write that's ever possible. + */ + if ((from + len) > 64) + return -EINVAL; + + /* OUT: OP_WRITE_SECURITY, 3 zeroes, 64 data-or-zero bytes + * IN: ignore all + */ + scratch = kzalloc(l, GFP_KERNEL); + if (!scratch) + return -ENOMEM; + scratch[0] = OP_WRITE_SECURITY; + memcpy(scratch + 4 + from, buf, len); + + spi_message_init(&m); + + memset(&t, 0, sizeof t); + t.tx_buf = scratch; + t.len = l; + spi_message_add_tail(&t, &m); + + /* Write the OTP bits, if they've not yet been written. + * This modifies SRAM buffer1. + */ + mutex_lock(&priv->lock); + dataflash_waitready(priv->spi); + status = spi_sync(priv->spi, &m); + mutex_unlock(&priv->lock); + + kfree(scratch); + + if (status >= 0) { + status = 0; + *retlen = len; + } + return status; +} + +static char *otp_setup(struct mtd_info *device, char revision) +{ + device->get_fact_prot_info = dataflash_get_otp_info; + device->read_fact_prot_reg = dataflash_read_fact_otp; + device->get_user_prot_info = dataflash_get_otp_info; + device->read_user_prot_reg = dataflash_read_user_otp; + + /* rev c parts (at45db321c and at45db1281 only!) use a + * different write procedure; not (yet?) implemented. + */ + if (revision > 'c') + device->write_user_prot_reg = dataflash_write_user_otp; + + return ", OTP"; +} + +#else + +static char *otp_setup(struct mtd_info *device) +{ + return " (OTP)"; +} + +#endif + +/* ......................................................................... */ + /* * Register DataFlash device with MTD subsystem. */ static int __devinit -add_dataflash(struct spi_device *spi, char *name, - int nr_pages, int pagesize, int pageoffset) +add_dataflash_otp(struct spi_device *spi, char *name, + int nr_pages, int pagesize, int pageoffset, char revision) { struct dataflash *priv; struct mtd_info *device; struct flash_platform_data *pdata = spi->dev.platform_data; + char *otp_tag = ""; priv = kzalloc(sizeof *priv, GFP_KERNEL); if (!priv) @@ -489,8 +666,12 @@ add_dataflash(struct spi_device *spi, char *name, device->write = dataflash_write; device->priv = priv; - dev_info(&spi->dev, "%s (%d KBytes) pagesize %d bytes\n", - name, DIV_ROUND_UP(device->size, 1024), pagesize); + if (revision >= 'c') + otp_tag = otp_setup(device, revision); + + dev_info(&spi->dev, "%s (%d KBytes) pagesize %d bytes%s\n", + name, DIV_ROUND_UP(device->size, 1024), + pagesize, otp_tag); dev_set_drvdata(&spi->dev, priv); if (mtd_has_partitions()) { @@ -519,6 +700,14 @@ add_dataflash(struct spi_device *spi, char *name, return add_mtd_device(device) == 1 ? -ENODEV : 0; } +static inline int __devinit +add_dataflash(struct spi_device *spi, char *name, + int nr_pages, int pagesize, int pageoffset) +{ + return add_dataflash_otp(spi, name, nr_pages, pagesize, + pageoffset, 0); +} + struct flash_info { char *name; @@ -664,13 +853,16 @@ static int __devinit dataflash_probe(struct spi_device *spi) * Try to detect dataflash by JEDEC ID. * If it succeeds we know we have either a C or D part. * D will support power of 2 pagesize option. + * Both support the security register, though with different + * write procedures. */ info = jedec_probe(spi); if (IS_ERR(info)) return PTR_ERR(info); if (info != NULL) - return add_dataflash(spi, info->name, info->nr_pages, - info->pagesize, info->pageoffset); + return add_dataflash_otp(spi, info->name, info->nr_pages, + info->pagesize, info->pageoffset, + (info->flags & SUP_POW2PS) ? 'd' : 'c'); /* * Older chips support only legacy commands, identifing |