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| author | Pekon Gupta <pekon@ti.com> | 2013-10-24 18:20:17 +0530 |
|---|---|---|
| committer | Brian Norris <computersforpeace@gmail.com> | 2013-11-06 23:33:07 -0800 |
| commit | ac65caf514ec3e55e8d3d510ee37f80dd97418fe (patch) | |
| tree | 68a56895371738d7ce6b3f005bf6bce04beafda2 /Documentation | |
| parent | dc525ff4705cee2291b1637a650489aca86ac937 (diff) | |
| download | op-kernel-dev-ac65caf514ec3e55e8d3d510ee37f80dd97418fe.zip op-kernel-dev-ac65caf514ec3e55e8d3d510ee37f80dd97418fe.tar.gz | |
ARM: OMAP2+: cleaned-up DT support of various ECC schemes
OMAP NAND driver support multiple ECC scheme, which can used in different
flavours, depending on in-build Hardware engines present on SoC.
This patch updates following in DT bindings related to sectionion of ecc-schemes
- ti,elm-id: replaces elm_id (maintains backward compatibility)
- ti,nand-ecc-opts: selection of h/w or s/w implementation of an ecc-scheme
depends on ti,elm-id. (supported values ham1, bch4, and bch8)
- maintain backward compatibility to deprecated DT bindings (sw, hw, hw-romcode)
Below table shows different flavours of ecc-schemes supported by OMAP devices
+---------------------------------------+---------------+---------------+
| ECC scheme |ECC calculation|Error detection|
+---------------------------------------+---------------+---------------+
|OMAP_ECC_HAM1_CODE_HW |H/W (GPMC) |S/W |
+---------------------------------------+---------------+---------------+
|OMAP_ECC_BCH8_CODE_HW_DETECTION_SW |H/W (GPMC) |S/W |
|(requires CONFIG_MTD_NAND_ECC_BCH) | | |
+---------------------------------------+---------------+---------------+
|OMAP_ECC_BCH8_CODE_HW |H/W (GPMC) |H/W (ELM) |
|(requires CONFIG_MTD_NAND_OMAP_BCH && | | |
| ti,elm-id in DT) | | |
+---------------------------------------+---------------+---------------+
To optimize footprint of omap2-nand driver, selection of some ECC schemes
also require enabling following Kconfigs, in addition to setting appropriate
DT bindings
- Kconfig:CONFIG_MTD_NAND_ECC_BCH error detection done in software
- Kconfig:CONFIG_MTD_NAND_OMAP_BCH error detection done by h/w engine
Signed-off-by: Pekon Gupta <pekon@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/mtd/gpmc-nand.txt | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt index df338cb..bfe07e1 100644 --- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt +++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt @@ -36,8 +36,12 @@ Optional properties: "prefetch-dma" Prefetch enabled sDMA mode "prefetch-irq" Prefetch enabled irq mode - - elm_id: Specifies elm device node. This is required to support BCH - error correction using ELM module. + - elm_id: <deprecated> use "ti,elm-id" instead + - ti,elm-id: Specifies phandle of the ELM devicetree node. + ELM is an on-chip hardware engine on TI SoC which is used for + locating ECC errors for BCHx algorithms. SoC devices which have + ELM hardware engines should specify this device node in .dtsi + Using ELM for ECC error correction frees some CPU cycles. For inline partiton table parsing (optional): |
