Re: [LINUX PATCH v10 1/2] dt-bindings: mtd: arasan: Add device tree binding documentation

[Boris Brezillon]

On Fri, 17 Aug 2018 18:49:23 +0530
Naga Sureshkumar Relli <naga.sureshkumar.relli@xxxxxxxxxx> wrote:

> This patch adds the dts binding document for arasan nand flash
> controller.
> 
> Signed-off-by: Naga Sureshkumar Relli <naga.sureshkumar.relli@xxxxxxxxxx>
> ---
> Changes in v10:
> - None
> Changes in v9:
> - None
> Changes in v8:
> - Updated compatible and clock-names as per Boris comments
> Changes in v7:
> - Corrected the acronyms those should be in caps 
> changes in v6:
> - Removed num-cs property
> - Separated nandchip from nand controller
> changes in v5:
> - None
> Changes in v4:
> - Added num-cs property
> - Added clock support
> Changes in v3:
> - None
> Changes in v2:
> - None
> ---
>  .../devicetree/bindings/mtd/arasan_nand.txt        | 38 ++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mtd/arasan_nand.txt
> 
> diff --git a/Documentation/devicetree/bindings/mtd/arasan_nand.txt b/Documentation/devicetree/bindings/mtd/arasan_nand.txt
> new file mode 100644
> index 0000000..234d7ca
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/arasan_nand.txt
> @@ -0,0 +1,38 @@
> +Arasan NAND Flash Controller with ONFI 3.1 support
> +
> +Required properties:
> +- compatible:		Should be "xlnx,zynqmp-nand" or "arasan,nfc-v3p10"

In your example it's not an "or" since both are defined.

> +- reg:			Memory map for module access
> +- interrupt-parent:	Interrupt controller the interrupt is routed through
> +- interrupts:		Should contain the interrupt for the device
> +- clock-name:		List of input clocks - "sys", "flash"

     clock-names

> +			(See clock bindings for details)
> +- clocks:		Clock phandles (see clock bindings for details)
> +
> +Optional properties:
> +- arasan,has-mdma: Enables DMA support

Can't you detect that based on the compatible (or thanks to a
register). If it's something you choose when configuring the IP and
can't detect at runtime I guess it's fine.

> +
> +For NAND partition information please refer the below file
> +Documentation/devicetree/bindings/mtd/partition.txt
> +
> +Example:
> +	nand0: nand@ff100000 {
> +		compatible = "xlnx,zynqmp-nand", "arasan,nfc-v3p10"
> +		reg = <0x0 0xff100000 0x1000>;
> +		clock-name = "sys", "flash"
> +		clocks = <&misc_clk &misc_clk>;
> +		interrupt-parent = <&gic>;
> +		interrupts = <0 14 4>;
> +		arasan,has-mdma;
> +		#address-cells = <1>;
> +		#size-cells = <0>
> +
> +		nand@0 {
> +			reg = <0>
> +			partition@0 {
> +				label = "filesystem";
> +				reg = <0x0 0x0 0x1000000>;
> +			};

Hm, not sure you need to define partitions in this example, but if
you do, please define your partitions in a 'partitions' subnode:

			partitions {
				compatible = "fixed-partitions";
				#address-cells = <1>;
				#size-cells = <1>;

				partition@0 {
					reg = <0x0 0x1000000>;
					...
				};
				...
			};

> +			(...)
> +		};
> +	};