On Tue, Jul 02, 2019 at 10:03:41AM +0000, Jacky Bai wrote:
> Add the binding doc of power domain for i.MX8M SOC family.
>
> Signed-off-by: Jacky Bai <ping.bai@xxxxxxx>
> ---
> .../bindings/power/fsl,imx8m-genpd.txt | 46 +++++++++++++++++++
> 1 file changed, 46 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/power/fsl,imx8m-genpd.txt
>
> diff --git a/Documentation/devicetree/bindings/power/fsl,imx8m-genpd.txt b/Documentation/devicetree/bindings/power/fsl,imx8m-genpd.txt
> new file mode 100644
> index 000000000000..a92a7103de38
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/power/fsl,imx8m-genpd.txt
> @@ -0,0 +1,46 @@
> +Device Tree Bindings for Freescale i.MX8M Generic Power Domain
> +==============================================================
> +The binding for the i.MX8M Generic power Domain[1].
> +
> +[1] Documentation/devicetree/bindings/power/power_domain.txt
> +
> +Required properties:
> +
> + - compatible: should be of:
> + - "fsl,imx8m-power-domain"
> + - #power-domain-cells: Number of cells in a PM domain Specifier, must be 0
> + - domain-index: should be the domain index number need to pass to TF-A
> + - domain-name: the name of this pm domain
> +
> +Optional properties:
> + - clocks: a number of phandles to clocks that need to be enabled during
> + domain power-up sequence to ensure reset propagation into devices
> + located inside this power domain
Isn't that firmware's problem?
> + - power-supply: Power supply used to power the domain
> + - parent-domains: the phandle to the parent power domain
> +
> +example:
> + vpu_g1_pd: vpug1-pd {
What's this a child of?
Use generic node names.
> + compatible = "fsl,imx8mm-pm-domain";
> + #power-domain-cells = <0>;
I'm usually not a fan when I see a single domain per provider. Why can't
you have firmware be a single provider with multiple domains?
> + domain-index = <6>;
Don't create your own index properties.
> + domain-name = "vpu_g1";
Not a standard name. Why do you need this? (Hint: we'd already have a
standard name if you did.)
> + parent-domains = <&vpumix_pd>;
We already have a standard way to do this.
> + clocks = <&clk IMX8MM_CLK_VPU_G1_ROOT>;
> + };
> +
> +
> +Specifying Power domain for IP modules
> +======================================
> +
> +IP cores belonging to a power domain should contain a 'power-domains'
> +property that is a phandle for PGC node representing the domain.
> +
> +Example of a device that is part of the vpu_g1 power domain:
> + vpu_g1: vpu_g1@38300000 {
video-codec@...
> + /* ... */
> + interrupts = <GIC_SPI 7 IRQ_TYPE_LEVEL_HIGH>;
> + interrupt-names = "irq_hantro";
> + /* ... */
> + power-domains = <&vpu_g1_pd>;
> + };
> --
> 2.21.0
>
