Re: [PATCH v2 1/2] soc: qcom: Add device tree binding for GLINK RPM

[Rob Herring]

On Mon, Mar 20, 2017 at 02:09:55PM -0700, Bjorn Andersson wrote:
> Add device tree binding documentation for the Qualcomm GLINK RPM, used
> for communication with the Resource Power Management subsystem in
> various Qualcomm SoCs.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> ---
> 
> Changes since v1:
> - None
> 
>  .../devicetree/bindings/soc/qcom/qcom,glink.txt    | 73 ++++++++++++++++++++++
>  1 file changed, 73 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,glink.txt
> 
> diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,glink.txt b/Documentation/devicetree/bindings/soc/qcom/qcom,glink.txt
> new file mode 100644
> index 000000000000..da92c4f787f3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,glink.txt
> @@ -0,0 +1,73 @@
> +Qualcomm RPM GLINK binding
> +
> +This binding describes the Qualcomm RPM GLINK, a fifo based mechanism for
> +communication with the Resource Power Management system on various Qualcomm
> +platforms.
> +
> +- compatible:
> +	Usage: required
> +	Value type: <stringlist>
> +	Definition: must be "qcom,glink-rpm"

SoC specific compatibles please.

> +
> +- interrupts:
> +	Usage: required
> +	Value type: <prop-encoded-array>
> +	Definition: should specify the IRQ used by the remote processor to
> +		    signal this processor about communication related events
> +
> +- qcom,rpm-msg-ram:
> +	Usage: required
> +	Value type: <prop-encoded-array>
> +	Definition: handle to RPM message memory resource
> +
> +- qcom,ipc:
> +	Usage: required
> +	Value type: <prop-encoded-array>
> +	Definition: three entries specifying the outgoing ipc bit used for
> +		    signaling the remote processor:
> +		    - phandle to a syscon node representing the apcs registers
> +		    - u32 representing offset to the register within the syscon
> +		    - u32 representing the ipc bit within the register
> +
> += GLINK DEVICES
> +Each subnode of the GLINK node represent function tied to a virtual
> +communication channel. The name of the nodes are not important. The properties
> +of these nodes are defined by the individual bindings for the specific function
> +- but must contain the following property:
> +
> +- qcom,glink-channels:
> +	Usage: required
> +	Value type: <stringlist>
> +	Definition: a list of channels tied to this function, used for matching
> +		    the function to a set of virtual channels
> +
> += EXAMPLE
> +The following example represents the GLINK RPM node on a MSM8996 device, with
> +the function for the "rpm_request" channel defined, which is used for
> +regualtors and root clocks.
> +
> +	apcs: syscon@f9011000 {
> +		compatible = "syscon";

syscon alone is not valid.

> +		reg = <0xf9011000 0x1000>;
> +	};
> +
> +	rpm_msg_ram: memory@68000 {
> +		compatible = "qcom,rpm-msg-ram";

Is this more than just mmio-sram?

Or with a fixed use could be part of another node?

> +		reg = <0x68000 0x6000>;
> +	};
> +
> +        rpm-glink {
> +		compatible = "qcom,glink-rpm";
> +
> +		interrupts = <GIC_SPI 168 IRQ_TYPE_EDGE_RISING>;
> +
> +		qcom,rpm-msg-ram = <&rpm_msg_ram>;
> +		qcom,ipc = <&apcs 0x10 0>;
> +
> +		rpm-requests {
> +			compatible = "qcom,rpm-msm8996";
> +			qcom,glink-channels = "rpm_requests";
> +
> +			...
> +		};
> +	};
> -- 
> 2.12.0
>