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/Kconfig | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'drivers/mtd/devices/Kconfig') diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig index 9c613f06623..88f4df04746 100644 --- a/drivers/mtd/devices/Kconfig +++ b/drivers/mtd/devices/Kconfig @@ -59,6 +59,17 @@ 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_OTP + bool "DataFlash OTP support (Security Register)" + depends on MTD_DATAFLASH + select HAVE_MTD_OTP + help + Newer DataFlash chips (revisions C and D) support 128 bytes of + one-time-programmable (OTP) data. The first half may be written + (once) with up to 64 bytes of data, such as a serial number or + other key product data. The second half is programmed with a + unique-to-each-chip bit pattern at the factory. + config MTD_M25P80 tristate "Support most SPI Flash chips (AT26DF, M25P, W25X, ...)" depends on SPI_MASTER && EXPERIMENTAL -- 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/Kconfig') 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