From 19fe7f1a00023d2aa97617655b7ea56eb72f4db8 Mon Sep 17 00:00:00 2001 From: Kevin Cernekee Date: Wed, 8 Apr 2009 22:51:43 -0700 Subject: Documentation: add MTD sysfs docs Signed-off-by: Kevin Cernekee Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- Documentation/ABI/testing/sysfs-class-mtd | 125 ++++++++++++++++++++++++++++++ 1 file changed, 125 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-mtd (limited to 'Documentation/ABI/testing/sysfs-class-mtd') diff --git a/Documentation/ABI/testing/sysfs-class-mtd b/Documentation/ABI/testing/sysfs-class-mtd new file mode 100644 index 00000000000..4d55a188898 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-mtd @@ -0,0 +1,125 @@ +What: /sys/class/mtd/ +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + The mtd/ class subdirectory belongs to the MTD subsystem + (MTD core). + +What: /sys/class/mtd/mtdX/ +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + The /sys/class/mtd/mtd{0,1,2,3,...} directories correspond + to each /dev/mtdX character device. These may represent + physical/simulated flash devices, partitions on a flash + device, or concatenated flash devices. They exist regardless + of whether CONFIG_MTD_CHAR is actually enabled. + +What: /sys/class/mtd/mtdXro/ +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + These directories provide the corresponding read-only device + nodes for /sys/class/mtd/mtdX/ . They are only created + (for the benefit of udev) if CONFIG_MTD_CHAR is enabled. + +What: /sys/class/mtd/mtdX/dev +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + Major and minor numbers of the character device corresponding + to this MTD device (in : format). This is the + read-write device so will be even. + +What: /sys/class/mtd/mtdXro/dev +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + Major and minor numbers of the character device corresponding + to the read-only variant of thie MTD device (in + : format). In this case will be odd. + +What: /sys/class/mtd/mtdX/erasesize +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + "Major" erase size for the device. If numeraseregions is + zero, this is the eraseblock size for the entire device. + Otherwise, the MEMGETREGIONCOUNT/MEMGETREGIONINFO ioctls + can be used to determine the actual eraseblock layout. + +What: /sys/class/mtd/mtdX/flags +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + A hexadecimal value representing the device flags, ORed + together: + + 0x0400: MTD_WRITEABLE - device is writable + 0x0800: MTD_BIT_WRITEABLE - single bits can be flipped + 0x1000: MTD_NO_ERASE - no erase necessary + 0x2000: MTD_POWERUP_LOCK - always locked after reset + +What: /sys/class/mtd/mtdX/name +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + A human-readable ASCII name for the device or partition. + This will match the name in /proc/mtd . + +What: /sys/class/mtd/mtdX/numeraseregions +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + For devices that have variable eraseblock sizes, this + provides the total number of erase regions. Otherwise, + it will read back as zero. + +What: /sys/class/mtd/mtdX/oobsize +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + Number of OOB bytes per page. + +What: /sys/class/mtd/mtdX/size +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + Total size of the device/partition, in bytes. + +What: /sys/class/mtd/mtdX/type +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + One of the following ASCII strings, representing the device + type: + + absent, ram, rom, nor, nand, dataflash, ubi, unknown + +What: /sys/class/mtd/mtdX/writesize +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + Minimal writable flash unit size. This will always be + a positive integer. + + In the case of NOR flash it is 1 (even though individual + bits can be cleared). + + In the case of NAND flash it is one NAND page (or a + half page, or a quarter page). + + In the case of ECC NOR, it is the ECC block size. -- cgit v1.2.3-70-g09d2