diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-mtd | 51 | ||||
| -rw-r--r-- | Documentation/DocBook/mtdnand.tmpl | 2 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/mtd/gpmi-nand.txt | 33 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/mtd/mxc-nand.txt | 19 |
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 +Description: + 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 +Description: + 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. <programlisting> -/* 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. + +Examples: + +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 + +Example: + + nand@d8000000 { + compatible = "fsl,imx27-nand"; + reg = <0xd8000000 0x1000>; + interrupts = <29>; + nand-bus-width = <8>; + nand-ecc-mode = "hw"; + }; |