Document the legacy and the new bindings for Marvell NAND controller. The pxa3xx_nand.c driver does only support legacy bindings, which are incomplete and inaccurate. A rework of this controller (called marvell_nand.c) does support both. Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxxxxxxxxx> --- .../devicetree/bindings/mtd/marvell-nand.txt | 84 ++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 Documentation/devicetree/bindings/mtd/marvell-nand.txt diff --git a/Documentation/devicetree/bindings/mtd/marvell-nand.txt b/Documentation/devicetree/bindings/mtd/marvell-nand.txt new file mode 100644 index 000000000000..0b3d5e0bab83 --- /dev/null +++ b/Documentation/devicetree/bindings/mtd/marvell-nand.txt @@ -0,0 +1,84 @@ +Marvell NAND Flash Controller (NFC) + +Required properties: +- compatible: can be one of the following: + * "marvell,armada-8k-nand-controller" + * "marvell,armada370-nand-controller" + * "marvell,pxa3xx-nand-controller" + * "marvell,armada-8k-nand" (deprecated) + * "marvell,armada370-nand" (deprecated) + * "marvell,pxa3xx-nand" (deprecated) +- reg: NAND flash controller memory area. +- #address-cells: shall be set to 1. Encode the NAND CS. +- #size-cells: shall be set to 0. +- interrupts: shall define the NAND controller interrupt. +- clocks: shall reference the NAND controller clock. +- marvell,system-controller: Set to retrieve the syscon node that handles + NAND controller related registers (only required with the + "marvell,armada-8k-nand[-controller]" compatibles). + +Optional properties: +- label: see partition.txt. New platforms shall omit this property. +- dmas: shall reference DMA channel associated to the NAND controller. +- dma-names: shall be "rxtx". + +Optional children nodes: +Children nodes represent the available NAND chips. + +Required properties: +- reg: shall contain the native Chip Select ids (0-3) +- marvell,rb: shall contain the native Ready/Busy ids (0-1) + +Optional properties: +- marvell,nand-keep-config: orders the driver not to take the timings + from the core and leaving them completely untouched. Bootloader + timings will then be used. +- nand-on-flash-bbt: see nand.txt. +- nand-ecc-mode: see nand.txt. Will use hardware ECC if not specified. +- nand-ecc-algo: see nand.txt. This property may be added when using + hardware ECC for clarification but will be ignored by the driver + because ECC mode is chosen depending on the page size and the strength + required by the NAND chip. This value may be overwritten with + nand-ecc-strength property. +- nand-ecc-strength: see nand.txt. +- nand-ecc-step-size: see nand.txt. This has no effect and will be + ignored by the driver when using hardware ECC because Marvell's NAND + flash controller does use fixed strength (1-bit for Hamming, 16-bit + for BCH), so the step size will shrink or grow in order to fit the + required strength. Step sizes are not completely random for all and + follow certain patterns described in AN-379, "Marvell SoC NFC ECC". + +See Documentation/devicetree/bindings/mtd/nand.txt for more details on +generic bindings. + + +Example: +nand_controller: nand-controller@d0000 { + compatible = "marvell,armada370-nand-controller"; + reg = <0xd0000 0x54>; + #address-cells = <1>; + #size-cells = <0>; + interrupts = <GIC_SPI 84 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&coredivclk 0>; + + nand@0 { + reg = <0>; + marvell,rb = <0>; + nand-ecc-mode = "hw"; + marvell,nand-keep-config; + nand-on-flash-bbt; + nand-ecc-strength = <4>; + nand-ecc-step-size = <512>; + + partitions { + compatible = "fixed-partitions"; + #address-cells = <1>; + #size-cells = <1>; + + partition@0 { + label = "Rootfs"; + reg = <0x00000000 0x40000000>; + }; + }; + }; +}; -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html