diff options
Diffstat (limited to 'Documentation/devicetree/bindings/mtd/marvell-nand.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/mtd/marvell-nand.txt | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/mtd/marvell-nand.txt b/Documentation/devicetree/bindings/mtd/marvell-nand.txt new file mode 100644 index 000000000..a2d9a0f2b --- /dev/null +++ b/Documentation/devicetree/bindings/mtd/marvell-nand.txt @@ -0,0 +1,126 @@ +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) + Compatibles marked deprecated support only the old bindings described + at the bottom. +- 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 clocks, the second one is + is only needed for the Armada 7K/8K SoCs +- clock-names: mandatory if there is a second clock, in this case there + should be one clock named "core" and another one named "reg" +- 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. + This property is only used with "marvell,pxa3xx-nand[-controller]" + compatible strings. +- dma-names: shall be "rxtx". + This property is only used with "marvell,pxa3xx-nand[-controller]" + compatible strings. + +Optional children nodes: +Children nodes represent the available NAND chips. + +Required properties: +- reg: shall contain the native Chip Select ids (0-3). +- nand-rb: see nand-controller.yaml (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. +- label: MTD name. +- nand-on-flash-bbt: see nand-controller.yaml. +- nand-ecc-mode: see nand-controller.yaml. Will use hardware ECC if not specified. +- nand-ecc-algo: see nand-controller.yaml. This property is essentially useful when + not using hardware ECC. Howerver, it 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-controller.yaml. +- nand-ecc-step-size: see nand-controller.yaml. Marvell's NAND flash controller does + use fixed strength (1-bit for Hamming, 16-bit for BCH), so the actual + 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-controller.yaml 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>; + label = "main-storage"; + nand-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>; + }; + }; + }; +}; + + +Note on legacy bindings: One can find, in not-updated device trees, +bindings slightly different than described above with other properties +described below as well as the partitions node at the root of a so +called "nand" node (without clear controller/chip separation). + +Legacy properties: +- marvell,nand-enable-arbiter: To enable the arbiter, all boards blindly + used it, this bit was set by the bootloader for many boards and even if + it is marked reserved in several datasheets, it might be needed to set + it (otherwise it is harmless) so whether or not this property is set, + the bit is selected by the driver. +- num-cs: Number of chip-select lines to use, all boards blindly set 1 + to this and for a reason, other values would have failed. The value of + this property is ignored. + +Example: + + nand0: nand@43100000 { + compatible = "marvell,pxa3xx-nand"; + reg = <0x43100000 90>; + interrupts = <45>; + dmas = <&pdma 97 0>; + dma-names = "rxtx"; + #address-cells = <1>; + marvell,nand-keep-config; + marvell,nand-enable-arbiter; + num-cs = <1>; + /* Partitions (optional) */ + }; |