Re: [PATCH] ARM: vexpress: bindings: Add generic PD awareness to the spc controller
From: Rob Herring
Date: Tue Jan 06 2015 - 12:03:04 EST
On Tue, Jan 6, 2015 at 10:45 AM, <mathieu.poirier@xxxxxxxxxx> wrote:
> From: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>
> Among other things, the serial power controller (SPC) controls power to
> the A7 and A15 clusters. Theses clusters also happen to contains the
> coresight tracers used for HW assisted tracing.
>
> By modellling these to power domains in a way that is comprehensible to
> the generic power domain sub-system and using the runtime PM API in the
> coresight drivers, we can prevent power to the domains from being
> turned off while tracing related operations are still pending.
>
> Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> ---
> .../bindings/arm/vexpress-power-controller.txt | 54 ++++++++++++++++++++++
> 1 file changed, 54 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/arm/vexpress-power-controller.txt
>
> diff --git a/Documentation/devicetree/bindings/arm/vexpress-power-controller.txt b/Documentation/devicetree/bindings/arm/vexpress-power-controller.txt
> new file mode 100644
> index 000000000000..3af5624dc5cb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/vexpress-power-controller.txt
> @@ -0,0 +1,54 @@
> +ARM Versatile Express Power Controller
> +--------------------------------------
> +
> +This binding models the serial power controller (SPC) in a way that is
> +intelligible to the generic power domain subsystem and in accordance
> +with the guidelines from:
> +
> +Documentation/devicetree/bindings/power/power_domain.txt
> +
> +The binding doesn't have a '<reg>' property as the base address for HW
> +access is provided by the vexpress-scc sub-system.
> +
> +Required node properties:
> +- compatible value : = "arm,vexpress-power-controller";
> +- #power-domain-cells : = Number of cells in a PM domain specifier, as
> + specified in "power_domain.txt" referenced above.
> +
> +Example:
> + A7_A15_cluster_pd: A7-A15-cluster-pd {
This is more a description of the power domain than the power
controller IP block.
> + compatible = "arm,vexpress-power-controller";
> + #power-domain-cells = <1>;
You need to define what goes in the cell. That is specific to the
power controller. It could be generic in that N corresponds to power
domain N in the controller if the controller is generic in that way
(i.e. all the register accesses are just indexed).
> + };
> +
> + ....
> +
> + ptm@0,2201d000 {
Drop the comma.
> + compatible = "arm,coresight-etm3x", "arm,primecell";
> + reg = <0 0x2201d000 0 0x1000>;
> +
> + cpu = <&cpu1>;
> + clocks = <&oscclk6a>;
> + clock-names = "apb_pclk";
> + power-domains = <&A7_A15_cluster_pd 0>;
> + port {
> + ptm1_out_port: endpoint {
> + remote-endpoint = <&funnel_in_port1>;
> + };
> + };
> + };
> +
> + etm@0,2203c000 {
ditto
> + compatible = "arm,coresight-etm3x", "arm,primecell";
> + reg = <0 0x2203c000 0 0x1000>;
> +
> + cpu = <&cpu2>;
> + clocks = <&oscclk6a>;
> + clock-names = "apb_pclk";
> + power-domains = <&A7_A15_cluster_pd 1>;
> + port {
> + etm0_out_port: endpoint {
> + remote-endpoint = <&funnel_in_port2>;
> + };
> + };
> + };
> --
> 1.9.1
>
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