From 6436356ba156b909c34a72e2905d9a9a874ca8e1 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Mon, 23 Apr 2012 11:23:41 +0200 Subject: mtd: mxc_nand: implement device tree probing MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This is tested on i.MX27. Signed-off-by: Uwe Kleine-König Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- Documentation/devicetree/bindings/mtd/mxc-nand.txt | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 Documentation/devicetree/bindings/mtd/mxc-nand.txt (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/mtd/mxc-nand.txt b/Documentation/devicetree/bindings/mtd/mxc-nand.txt new file mode 100644 index 0000000..b5833d1 --- /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"; + }; -- cgit v1.1 From a9b672e82bca47bf2b37ee869b8095000cf3ca88 Mon Sep 17 00:00:00 2001 From: Mike Dunn Date: Wed, 25 Apr 2012 12:06:07 -0700 Subject: mtd: expose ecc_strength through sysfs ecc_strength element of struct mtd_info is exposed as a read-only variable in sysfs. Signed-off-by: Mike Dunn Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- Documentation/ABI/testing/sysfs-class-mtd | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-class-mtd b/Documentation/ABI/testing/sysfs-class-mtd index 4d55a18..43d1818 100644 --- a/Documentation/ABI/testing/sysfs-class-mtd +++ b/Documentation/ABI/testing/sysfs-class-mtd @@ -123,3 +123,15 @@ 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. -- cgit v1.1 From d062d4ede877fcd2ecc4c6262abad09a6f32950a Mon Sep 17 00:00:00 2001 From: Mike Dunn Date: Wed, 25 Apr 2012 12:06:08 -0700 Subject: mtd: bitflip_threshold added to mtd_info and sysfs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit An element 'bitflip_threshold' is added to struct mtd_info, and also exposed as a read/write variable in sysfs. This will be used to determine whether or not mtd_read() returns -EUCLEAN or 0 (absent a hard error). If the driver leaves it as zero, mtd will set it to a default value of ecc_strength. This v2 adds the line that propagates bitflip_threshold from the master to the partitions - thanks Ivan¹. ¹ http://lists.infradead.org/pipermail/linux-mtd/2012-April/040900.html Signed-off-by: Mike Dunn Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- Documentation/ABI/testing/sysfs-class-mtd | 36 +++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-class-mtd b/Documentation/ABI/testing/sysfs-class-mtd index 43d1818..7883508 100644 --- a/Documentation/ABI/testing/sysfs-class-mtd +++ b/Documentation/ABI/testing/sysfs-class-mtd @@ -135,3 +135,39 @@ Description: 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 the read functions. + + This is generally applicable only to NAND flash devices with ECC + capability. It is ignored on devices lacking ECC capability. -- cgit v1.1 From edbc4540e02c201bdd4f4d498ebb6ed517fd36e2 Mon Sep 17 00:00:00 2001 From: Mike Dunn Date: Wed, 25 Apr 2012 12:06:11 -0700 Subject: mtd: driver _read() returns max_bitflips; mtd_read() returns -EUCLEAN MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The drivers' _read() method, absent an error, returns a non-negative integer indicating the maximum number of bit errors that were corrected in any one region comprising an ecc step. MTD returns -EUCLEAN if this is >= bitflip_threshold, 0 otherwise. If bitflip_threshold is zero, the comparison is not made since these devices lack ECC and always return zero in the non-error case (thanks Brian)¹. Note that this is a subtle change to the driver interface. This and the preceding patches in this set were tested with ubi on top of the nandsim and docg4 devices, running the ubi test io_basic from mtd-utils. ¹ http://lists.infradead.org/pipermail/linux-mtd/2012-March/040468.html Signed-off-by: Mike Dunn Acked-by: Robert Jarzmik Acked-by: Brian Norris Ivan Djelic Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- Documentation/ABI/testing/sysfs-class-mtd | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-class-mtd b/Documentation/ABI/testing/sysfs-class-mtd index 7883508..db1ad7e 100644 --- a/Documentation/ABI/testing/sysfs-class-mtd +++ b/Documentation/ABI/testing/sysfs-class-mtd @@ -167,7 +167,10 @@ Description: 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 the read functions. + 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. + capability. It is ignored on devices lacking ECC capability; + i.e., devices for which ecc_strength is zero. -- cgit v1.1 From 1826dbccebc9a58a0b0c0a9b7c09e47b19d97398 Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Tue, 1 May 2012 17:12:55 -0700 Subject: mtd: nand: kill NAND_NO_AUTOINCR option No drivers use auto-increment NAND, so kill the NO_AUTOINCR option entirely. Signed-off-by: Brian Norris Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- Documentation/DocBook/mtdnand.tmpl | 2 -- 1 file changed, 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/DocBook/mtdnand.tmpl b/Documentation/DocBook/mtdnand.tmpl index 0c674be..e0aedb7 100644 --- a/Documentation/DocBook/mtdnand.tmpl +++ b/Documentation/DocBook/mtdnand.tmpl @@ -1119,8 +1119,6 @@ in this page 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 */ -- cgit v1.1 From e10db1f00a5e3c2ec04d7fe26c7444dc55a59b19 Mon Sep 17 00:00:00 2001 From: Huang Shijie Date: Fri, 4 May 2012 21:42:05 -0400 Subject: mtd: gpmi: add device tree support to gpmi-nand This patch just adds the DT support to gpmi-nand. Signed-off-by: Huang Shijie Signed-off-by: Huang Shijie Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- .../devicetree/bindings/mtd/gpmi-nand.txt | 33 ++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 Documentation/devicetree/bindings/mtd/gpmi-nand.txt (limited to 'Documentation') diff --git a/Documentation/devicetree/bindings/mtd/gpmi-nand.txt b/Documentation/devicetree/bindings/mtd/gpmi-nand.txt new file mode 100644 index 0000000..1a5bbd3 --- /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,-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 { + ... + }; +}; -- cgit v1.1