[PATCH 1/2] dt-bindings: nand: meson: add Amlogic NAND controller driver

Boris Brezillon
2018-06-24T13:57:27Z

Hi Yixun,

On Wed, 13 Jun 2018 16:13:13 +0000
Yixun Lan <yixun.lan@amlogic.com> wrote:

> From: Liang Yang <liang.yang@amlogic.com>
>
> Add Amlogic NAND controller dt-bindings for Meson SoC,
> Current this driver support GXBB/GXL/AXG platform.
>
> Signed-off-by: Liang Yang <liang.yang@amlogic.com>
> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
> ---
> .../bindings/mtd/amlogic,meson-nand.txt | 118 ++++++++++++++++++
> 1 file changed, 118 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mtd/amlogic,meson-nand.txt
>
> diff --git a/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.txt b/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.txt
> new file mode 100644
> index 000000000000..eac9f9433d5d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.txt
> @@ -0,0 +1,118 @@
> +Amlogic NAND Flash Controller (NFC) for GXBB/GXL/AXG family SoCs
> +
> +This file documents the properties in addition to those available in
> +the MTD NAND bindings.
> +
> +Required properties:
> +- compatible : contains one of:
> + - "amlogic,meson-gxl-nfc"
> + - "amlogic,meson-axg-nfc"
> +- clocks :
> + A list of phandle + clock-specifier pairs for the clocks listed
> + in clock-names.
> +
> +- clock-names: Should contain the following:
> + "core" - NFC module gate clock
> + "clkin0" - Parent clock of internal mux
> + "clkin1" - Other parent clock of internal mux
> +
> +- pins : Select pins which NFC need.
> +- nand_pins: Detail NAND pins information.
> + nand_pins: nand {
> + mux {
> + groups = "emmc_nand_d0",
> + "emmc_nand_d1",
> + "emmc_nand_d2",
> + "emmc_nand_d3",
> + "emmc_nand_d4",
> + "emmc_nand_d5",
> + "emmc_nand_d6",
> + "emmc_nand_d7",
> + "nand_ce0",
> + "nand_rb0",
> + "nand_ale",
> + "nand_cle",
> + "nand_wen_clk",
> + "nand_ren_wr";
> + function = "nand";
> + };
> + };

Not sure, but I think you can drop the pinmux description.

> +
> +- amlogic,mmc-syscon : Required for NAND clocks, it's shared with SD/eMMC
> + controller port C
> +
> +Optional children nodes:
> +Children nodes represent the available nand chips.
> +
> +Optional properties:
> +- meson-nand-user-mode :
> + only set 2 or 16 which mean the way of reading OOB bytes by NFC.

I haven't checked the driver but this prop looks like a reg field value
you're directly copying in the reg at init time. We usually avoid
exposing such details in the DT. I'm not even sure you should have a
property to select how you want to read OOB (need to check the driver
before giving a definitive answer on this aspect).

> +- meson-nand-ran-mode :
> + setting 0 or 1, means disable/enable scrambler which keeps the balence
> + of 0 and 1

You don't need that one. The NAND chip will tell you whether it requires
scrambling or not (see NAND_NEED_SCRAMBLING [1]).

> +
> +Other properties:
> +see Documentation/devicetree/bindings/mtd/nand.txt for generic bindings.
> +
> +Example demonstrate on AXG SoC:
> +
> + sd_emmc_c: mmc at 7000 {
> + compatible = "simple-bus", "syscon";
> + reg = <0x0 0x7000 0x0 0x800>;
> + status = "okay";
> + };
> +
> + nand: nfc at 7800 {
> + compatible = "amlogic,meson-axg-nfc";
> + reg = <0x0 0x7800 0x0 0x100>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + interrupts = <GIC_SPI 34 IRQ_TYPE_EDGE_RISING>;
> + status = "disabled";
> + clocks = <&clkc CLKID_SD_EMMC_C>,
> + <&clkc CLKID_SD_EMMC_C_CLK0>,
> + <&clkc CLKID_FCLK_DIV2>;
> + clock-names = "core", "clkin0", "clkin1";
> + amlogic,mmc-syscon = <&sd_mmc_c>;
> +
> + status = "okay";
> +
> + pinctrl-names = "default";
> + pinctrl-0 = <&nand_pins>;
> +
> + nand at 0 {
> + reg = <0>;
> + #address-cells = <1>;
> + #size-cells = <1>;
> +
> + nand-on-flash-bbt;
> + nand-ecc-mode = "hw";
> + nand-ecc-strength = <8>;
> + nand-ecc-step-size = <1024>;
> +
> + meson-nand-user-mode = <2>;
> + meson-nand-ran-mode = <1>;
> +
> + partition at 0 {
> + label = "boot";
> + reg = <0x00000000 0x00200000>;
> + read-only;
> + };
> + partition at 200000 {
> + label = "env";
> + reg = <0x00200000 0x00400000>;
> + };
> + partition at 600000 {
> + label = "system";
> + reg = <0x00600000 0x00a00000>;
> + };
> + partition at 1000000 {
> + label = "rootfs";
> + reg = <0x01000000 0x03000000>;
> + };
> + partition at 4000000 {
> + label = "media";
> + reg = <0x04000000 0x8000000>;
> + };

Partitions should be places in a "partitions" subnode:

partitions {
compatible = "fixed-partitions";

...
};

Also, I'm not sure you need to put that in your example.

> + };
> + };

Regards,

Boris