path: root/Documentation
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authorLinus Torvalds <torvalds@linux-foundation.org>2012-06-01 16:55:42 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-06-01 16:55:42 -0700
commitf5e7e844a571124ffc117d4696787d6afc4fc5ae (patch)
tree26bb17dc94e9536da540c187b00cedb0c1b24664 /Documentation
parentMerge branch 'for_linus' of git://cavan.codon.org.uk/platform-drivers-x86 (diff)
parentmtd: mxc_nand: move ecc strengh setup before nand_scan_tail (diff)
Merge tag 'for-linus-3.5-20120601' of git://git.infradead.org/linux-mtd
Pull mtd update from David Woodhouse: - More robust parsing especially of xattr data in JFFS2 - Updates to mxc_nand and gpmi drivers to support new boards and device tree - Improve consistency of information about ECC strength in NAND devices - Clean up partition handling of plat_nand - Support NAND drivers without dedicated access to OOB area - BCH hardware ECC support for OMAP - Other fixes and cleanups, and a few new device IDs Fixed trivial conflict in drivers/mtd/nand/gpmi-nand/gpmi-nand.c due to added include files next to each other. * tag 'for-linus-3.5-20120601' of git://git.infradead.org/linux-mtd: (75 commits) mtd: mxc_nand: move ecc strengh setup before nand_scan_tail mtd: block2mtd: fix recursive call of mtd_writev mtd: gpmi-nand: define ecc.strength mtd: of_parts: fix breakage in Kconfig mtd: nand: fix scan_read_raw_oob mtd: docg3 fix in-middle of blocks reads mtd: cfi_cmdset_0002: Slight cleanup of fixup messages mtd: add fixup for S29NS512P NOR flash. jffs2: allow to complete xattr integrity check on first GC scan jffs2: allow to discriminate between recoverable and non-recoverable errors mtd: nand: omap: add support for hardware BCH ecc ARM: OMAP3: gpmc: add BCH ecc api and modes mtd: nand: check the return code of 'read_oob/read_oob_raw' mtd: nand: remove 'sndcmd' parameter of 'read_oob/read_oob_raw' mtd: m25p80: Add support for Winbond W25Q80BW jffs2: get rid of jffs2_sync_super jffs2: remove unnecessary GC pass on sync jffs2: remove unnecessary GC pass on umount jffs2: remove lock_super mtd: gpmi: add gpmi support for mx6q ...
Diffstat (limited to 'Documentation')
4 files changed, 103 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-mtd b/Documentation/ABI/testing/sysfs-class-mtd
index 4d55a1888981..db1ad7e34fc3 100644
--- a/Documentation/ABI/testing/sysfs-class-mtd
+++ b/Documentation/ABI/testing/sysfs-class-mtd
@@ -123,3 +123,54 @@ Description:
half page, or a quarter page).
In the case of ECC NOR, it is the ECC block size.
+What: /sys/class/mtd/mtdX/ecc_strength
+Date: April 2012
+KernelVersion: 3.4
+Contact: linux-mtd@lists.infradead.org
+ Maximum number of bit errors that the device is capable of
+ correcting within each region covering an ecc step. This will
+ always be a non-negative integer. Note that some devices will
+ have multiple ecc steps within each writesize region.
+ In the case of devices lacking any ECC capability, it is 0.
+What: /sys/class/mtd/mtdX/bitflip_threshold
+Date: April 2012
+KernelVersion: 3.4
+Contact: linux-mtd@lists.infradead.org
+ This allows the user to examine and adjust the criteria by which
+ mtd returns -EUCLEAN from mtd_read(). If the maximum number of
+ bit errors that were corrected on any single region comprising
+ an ecc step (as reported by the driver) equals or exceeds this
+ value, -EUCLEAN is returned. Otherwise, absent an error, 0 is
+ returned. Higher layers (e.g., UBI) use this return code as an
+ indication that an erase block may be degrading and should be
+ scrutinized as a candidate for being marked as bad.
+ The initial value may be specified by the flash device driver.
+ If not, then the default value is ecc_strength.
+ The introduction of this feature brings a subtle change to the
+ meaning of the -EUCLEAN return code. Previously, it was
+ interpreted to mean simply "one or more bit errors were
+ corrected". Its new interpretation can be phrased as "a
+ dangerously high number of bit errors were corrected on one or
+ more regions comprising an ecc step". The precise definition of
+ "dangerously high" can be adjusted by the user with
+ bitflip_threshold. Users are discouraged from doing this,
+ however, unless they know what they are doing and have intimate
+ knowledge of the properties of their device. Broadly speaking,
+ bitflip_threshold should be low enough to detect genuine erase
+ block degradation, but high enough to avoid the consequences of
+ a persistent return value of -EUCLEAN on devices where sticky
+ bitflips occur. Note that if bitflip_threshold exceeds
+ ecc_strength, -EUCLEAN is never returned by mtd_read().
+ Conversely, if bitflip_threshold is zero, -EUCLEAN is always
+ returned, absent a hard error.
+ This is generally applicable only to NAND flash devices with ECC
+ capability. It is ignored on devices lacking ECC capability;
+ i.e., devices for which ecc_strength is zero.
diff --git a/Documentation/DocBook/mtdnand.tmpl b/Documentation/DocBook/mtdnand.tmpl
index 0c674be0d3c6..e0aedb7a7827 100644
--- a/Documentation/DocBook/mtdnand.tmpl
+++ b/Documentation/DocBook/mtdnand.tmpl
@@ -1119,8 +1119,6 @@ in this page</entry>
These constants are defined in nand.h. They are ored together to describe
the chip functionality.
-/* Chip can not auto increment pages */
-#define NAND_NO_AUTOINCR 0x00000001
/* Buswitdh is 16 bit */
#define NAND_BUSWIDTH_16 0x00000002
/* Device supports partial programming without padding */
diff --git a/Documentation/devicetree/bindings/mtd/gpmi-nand.txt b/Documentation/devicetree/bindings/mtd/gpmi-nand.txt
new file mode 100644
index 000000000000..1a5bbd346d22
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/gpmi-nand.txt
@@ -0,0 +1,33 @@
+* Freescale General-Purpose Media Interface (GPMI)
+The GPMI nand controller provides an interface to control the
+NAND flash chips. We support only one NAND chip now.
+Required properties:
+ - compatible : should be "fsl,<chip>-gpmi-nand"
+ - reg : should contain registers location and length for gpmi and bch.
+ - reg-names: Should contain the reg names "gpmi-nand" and "bch"
+ - interrupts : The first is the DMA interrupt number for GPMI.
+ The second is the BCH interrupt number.
+ - interrupt-names : The interrupt names "gpmi-dma", "bch";
+ - fsl,gpmi-dma-channel : Should contain the dma channel it uses.
+The device tree may optionally contain sub-nodes describing partitions of the
+address space. See partition.txt for more detail.
+gpmi-nand@8000c000 {
+ compatible = "fsl,imx28-gpmi-nand";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ reg = <0x8000c000 2000>, <0x8000a000 2000>;
+ reg-names = "gpmi-nand", "bch";
+ interrupts = <88>, <41>;
+ interrupt-names = "gpmi-dma", "bch";
+ fsl,gpmi-dma-channel = <4>;
+ partition@0 {
+ ...
+ };
diff --git a/Documentation/devicetree/bindings/mtd/mxc-nand.txt b/Documentation/devicetree/bindings/mtd/mxc-nand.txt
new file mode 100644
index 000000000000..b5833d11c7be
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/mxc-nand.txt
@@ -0,0 +1,19 @@
+* Freescale's mxc_nand
+Required properties:
+- compatible: "fsl,imxXX-nand"
+- reg: address range of the nfc block
+- interrupts: irq to be used
+- nand-bus-width: see nand.txt
+- nand-ecc-mode: see nand.txt
+- nand-on-flash-bbt: see nand.txt
+ nand@d8000000 {
+ compatible = "fsl,imx27-nand";
+ reg = <0xd8000000 0x1000>;
+ interrupts = <29>;
+ nand-bus-width = <8>;
+ nand-ecc-mode = "hw";
+ };