From 34a82443b79dcda4304b229d555586296da40c16 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Wed, 30 Jul 2008 12:35:05 -0700 Subject: [MTD] dataflash OTP support Now that we can tell when we have one of the newer DataFlash chips, optionally expose the 128 bytes of OTP memory they provide. Tested on at45db642 revision B and D chips. Switch mtdchar over to a generic HAVE_MTD_OTP flag instead of adding another #ifdef for each type of chip whose driver has OTP support. Signed-off-by: David Brownell Cc: Bryan Wu Cc: Michael Hennerich Signed-off-by: Andrew Morton Signed-off-by: David Woodhouse --- drivers/mtd/devices/mtd_dataflash.c | 206 ++++++++++++++++++++++++++++++++++-- 1 file changed, 199 insertions(+), 7 deletions(-) (limited to 'drivers/mtd/devices/mtd_dataflash.c') diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c index 8bd0dea6885..17c9b20dca8 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 -- cgit v1.2.3-70-g09d2 From cf93ae02600e2c752bf2570085e7970a1c0f2b94 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Wed, 6 Aug 2008 13:12:04 -0700 Subject: [MTD] Compile fix for dataflash OTP support > > linux-next-20080805/drivers/mtd/devices/mtd_dataflash.c: In function 'add_dataflash_otp': > > linux-next-20080805/drivers/mtd/devices/mtd_dataflash.c:670: error: too many arguments to function 'otp_setup' Whoops, sorry ... I see what was going on. My bad. Signed-off-by: David Brownell Signed-off-by: David Woodhouse --- drivers/mtd/devices/mtd_dataflash.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/mtd/devices/mtd_dataflash.c') diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c index 17c9b20dca8..90161277902 100644 --- a/drivers/mtd/devices/mtd_dataflash.c +++ b/drivers/mtd/devices/mtd_dataflash.c @@ -618,7 +618,7 @@ static char *otp_setup(struct mtd_info *device, char revision) #else -static char *otp_setup(struct mtd_info *device) +static char *otp_setup(struct mtd_info *device, char revision) { return " (OTP)"; } -- cgit v1.2.3-70-g09d2 From 8c64038e4c077b2b37c6b27d0c40c77a3ddfaeef Mon Sep 17 00:00:00 2001 From: David Brownell Date: Wed, 6 Aug 2008 21:55:14 -0700 Subject: [MTD] make dataflash write-verify be optional This adds a WRITE_VERIFY Kconfig option to the DataFlash driver, closely mirroring the similar NAND and ONENAND options, giving an option to disable some code that's currently always enabled. Removing this step probably saves a millisecond or so per page when writing data, which will add up quickly since these pages are small (the largest is 1 KiB). It doesn't seem to add a lot in terms of reliability, and wouldn't detect errors which crop up when transferring data to the on-chip SRAM buffer. Signed-off-by: David Brownell Acked-by: Haavard Skinnemoen Acked-by: Andrew Victor Signed-off-by: David Woodhouse --- drivers/mtd/devices/Kconfig | 10 ++++++++++ drivers/mtd/devices/mtd_dataflash.c | 8 +++----- 2 files changed, 13 insertions(+), 5 deletions(-) (limited to 'drivers/mtd/devices/mtd_dataflash.c') diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig index 88f4df04746..6fde0a2e356 100644 --- a/drivers/mtd/devices/Kconfig +++ b/drivers/mtd/devices/Kconfig @@ -59,6 +59,16 @@ config MTD_DATAFLASH Sometimes DataFlash chips are packaged inside MMC-format cards; at this writing, the MMC stack won't handle those. +config MTD_DATAFLASH_WRITE_VERIFY + bool "Verify DataFlash page writes" + depends on MTD_DATAFLASH + help + This adds an extra check when data is written to the flash. + It may help if you are verifying chip setup (timings etc) on + your board. There is a rare possibility that even though the + device thinks the write was successful, a bit could have been + flipped accidentally due to device wear or something else. + config MTD_DATAFLASH_OTP bool "DataFlash OTP support (Security Register)" depends on MTD_DATAFLASH diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c index 90161277902..6dd9aff8bb2 100644 --- a/drivers/mtd/devices/mtd_dataflash.c +++ b/drivers/mtd/devices/mtd_dataflash.c @@ -30,12 +30,10 @@ * doesn't (yet) use these for any kind of i/o overlap or prefetching. * * Sometimes DataFlash is packaged in MMC-format cards, although the - * MMC stack can't use SPI (yet), or distinguish between MMC and DataFlash + * MMC stack can't (yet?) distinguish between MMC and DataFlash * protocols during enumeration. */ -#define CONFIG_DATAFLASH_WRITE_VERIFY - /* reads can bypass the buffers */ #define OP_READ_CONTINUOUS 0xE8 #define OP_READ_PAGE 0xD2 @@ -403,7 +401,7 @@ static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len, (void) dataflash_waitready(priv->spi); -#ifdef CONFIG_DATAFLASH_WRITE_VERIFY +#ifdef CONFIG_MTD_DATAFLASH_VERIFY_WRITE /* (3) Compare to Buffer1 */ addr = pageaddr << priv->page_offset; @@ -432,7 +430,7 @@ static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len, } else status = 0; -#endif /* CONFIG_DATAFLASH_WRITE_VERIFY */ +#endif /* CONFIG_MTD_DATAFLASH_VERIFY_WRITE */ remaining = remaining - writelen; pageaddr++; -- cgit v1.2.3-70-g09d2