Re: [PATCH linux-next v6 04/13] dt-bindings: Add a document of PECI adapter driver for ASPEED AST24xx/25xx SoCs

From: Rob Herring
Date: Tue Jul 03 2018 - 12:52:01 EST


On Thu, Jun 21, 2018 at 12:40:24PM -0700, Jae Hyun Yoo wrote:
> This commit adds a dt-bindings document of PECI adapter driver for ASPEED
> AST24xx/25xx SoCs.
>
> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxxxxxxxx>
> Reviewed-by: Haiyue Wang <haiyue.wang@xxxxxxxxxxxxxxx>
> Reviewed-by: James Feist <james.feist@xxxxxxxxxxxxxxx>
> Reviewed-by: Vernon Mauery <vernon.mauery@xxxxxxxxxxxxxxx>
> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Jason M Biils <jason.m.bills@xxxxxxxxxxxxxxx>
> Cc: Milton Miller II <miltonm@xxxxxxxxxx>
> Cc: Pavel Machek <pavel@xxxxxx>
> Cc: Robin Murphy <robin.murphy@xxxxxxx>
> Cc: Ryan Chen <ryan_chen@xxxxxxxxxxxxxx>
> ---
> .../devicetree/bindings/peci/peci-aspeed.txt | 57 +++++++++++++++++++
> 1 file changed, 57 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/peci/peci-aspeed.txt
>
> diff --git a/Documentation/devicetree/bindings/peci/peci-aspeed.txt b/Documentation/devicetree/bindings/peci/peci-aspeed.txt
> new file mode 100644
> index 000000000000..8c35f905589d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/peci/peci-aspeed.txt
> @@ -0,0 +1,57 @@
> +Device tree configuration for PECI buses on the AST24XX and AST25XX SoCs.
> +
> +Required properties:
> +- compatible : Should be "aspeed,ast2400-peci" or "aspeed,ast2500-peci"
> + - aspeed,ast2400-peci: ASPEED AST2400 family PECI
> + controller
> + - aspeed,ast2500-peci: ASPEED AST2500 family PECI
> + controller

Just this is sufficient:

Should be one of:
"aspeed,ast2400-peci"
"aspeed,ast2500-peci"

With that,

Reviewed-by: Rob Herring <robh@xxxxxxxxxx>

> +- reg : Should contain PECI controller registers location and
> + length.
> +- #address-cells : Should be <1> required to define a client address.
> +- #size-cells : Should be <0> required to define a client address.
> +- interrupts : Should contain PECI controller interrupt.
> +- clocks : Should contain clock source for PECI controller. Should
> + reference the external oscillator clock in the second
> + cell.
> +- resets : Should contain phandle to reset controller with the reset
> + number in the second cell.
> +- clock-frequency : Should contain the operation frequency of PECI controller
> + in units of Hz.
> + 187500 ~ 24000000
> +
> +Optional properties:
> +- msg-timing : Message timing negotiation period. This value will
> + determine the period of message timing negotiation to be
> + issued by PECI controller. The unit of the programmed
> + value is four times of PECI clock period.
> + 0 ~ 255 (default: 1)
> +- addr-timing : Address timing negotiation period. This value will
> + determine the period of address timing negotiation to be
> + issued by PECI controller. The unit of the programmed
> + value is four times of PECI clock period.
> + 0 ~ 255 (default: 1)
> +- rd-sampling-point : Read sampling point selection. The whole period of a bit
> + time will be divided into 16 time frames. This value will
> + determine the time frame in which the controller will
> + sample PECI signal for data read back. Usually in the
> + middle of a bit time is the best.
> + 0 ~ 15 (default: 8)
> +- cmd-timeout-ms : Command timeout in units of ms.
> + 1 ~ 60000 (default: 1000)
> +
> +Example:
> + peci0: peci-bus@0 {
> + compatible = "aspeed,ast2500-peci";
> + reg = <0x0 0x60>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + interrupts = <15>;
> + clocks = <&syscon ASPEED_CLK_GATE_REFCLK>;
> + resets = <&syscon ASPEED_RESET_PECI>;
> + clock-frequency = <24000000>;
> + msg-timing = <1>;
> + addr-timing = <1>;
> + rd-sampling-point = <8>;
> + cmd-timeout-ms = <1000>;
> + };
> --
> 2.17.1
>