[PATCH v2 1/3] dt-bindings: add multidomain support to i.MX GPC DT binding

[Rob Herring]

On Wed, Mar 16, 2016 at 12:41:52PM +0100, Lucas Stach wrote:
> This adds a new binding for the Freescale i.MX GPC block, which allows
> to describe multiple power domains in a more natural way. The driver
> will continue to support the old binding for existing DTBs, but new
> features like the additional domains present on i.MX6SX will only be
> usable with the new binding.
> 
> Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
> ---
> v2: clarify the number of interrupts (1)
> ---
>  .../devicetree/bindings/power/fsl,imx-gpc.txt      | 81 ++++++++++++++--------
>  1 file changed, 54 insertions(+), 27 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/power/fsl,imx-gpc.txt b/Documentation/devicetree/bindings/power/fsl,imx-gpc.txt
> index 65cc0345747d..e5b660018d63 100644
> --- a/Documentation/devicetree/bindings/power/fsl,imx-gpc.txt
> +++ b/Documentation/devicetree/bindings/power/fsl,imx-gpc.txt
> @@ -1,22 +1,41 @@
>  Freescale i.MX General Power Controller
>  =======================================
>  
> -The i.MX6Q General Power Control (GPC) block contains DVFS load tracking
> -counters and Power Gating Control (PGC) for the CPU and PU (GPU/VPU) power
> -domains.
> +The i.MX6 General Power Control (GPC) block contains DVFS load tracking
> +counters and Power Gating Control (PGC).
>  
>  Required properties:
>  - compatible: Should be "fsl,imx6q-gpc" or "fsl,imx6sl-gpc"
>  - reg: should be register base and length as documented in the
>    datasheet
> -- interrupts: Should contain GPC interrupt request 1
> -- pu-supply: Link to the LDO regulator powering the PU power domain
> -- clocks: Clock phandles to devices in the PU power domain that need
> -	  to be enabled during domain power-up for reset propagation.
> -- #power-domain-cells: Should be 1, see below:
> +- interrupts: Should contain one interrupt specifier for the GPC interrupt
> +- clocks: Must contain an entry for each entry in clock-names.
> +  See Documentation/devicetree/bindings/clocks/clock-bindings.txt for details.
> +- clock-names: Must include the following entries:
> +  - ipg
> +- pgc: a list of child nodes describing the SoC power domains controlled by the
> +  power gating controller.

Why do you need this when you can iterate over the child nodes?

>  
> -The gpc node is a power-controller as documented by the generic power domain
> -bindings in Documentation/devicetree/bindings/power/power_domain.txt.
> +The power domains are generic power domain providers as documented in
> +Documentation/devicetree/bindings/power/power_domain.txt. They are described as
> +subnodes of the GPC and should contain the following
> +
> +Required properties:
> +- reg: the DOMAIN_INDEX as used by the client devices to refer to this
> +  power domain
> +  The following DOMAIN_INDEX values are valid for i.MX6Q:
> +  ARM_DOMAIN     0
> +  PU_DOMAIN      1
> +  The following additional DOMAIN_INDEX value is valid for i.MX6SL:
> +  DISPLAY_DOMAIN 2

This shouldn't be needed now as cells is 0.

> +
> +- #power-domain-cells: Should be 0
> +
> +Optional properties:
> +- clocks: a number of phandles to clocks that need to be enabled during domain
> +  power-up sequencing to ensure reset propagation into devices located inside
> +  this power domain
> +- domain-supply: a phandle to the regulator powering this domain
>  
>  Example:
>  
> @@ -25,14 +44,29 @@ Example:
>  		reg = <0x020dc000 0x4000>;
>  		interrupts = <0 89 IRQ_TYPE_LEVEL_HIGH>,
>  			     <0 90 IRQ_TYPE_LEVEL_HIGH>;
> -		pu-supply = <&reg_pu>;
> -		clocks = <&clks IMX6QDL_CLK_GPU3D_CORE>,
> -			 <&clks IMX6QDL_CLK_GPU3D_SHADER>,
> -			 <&clks IMX6QDL_CLK_GPU2D_CORE>,
> -			 <&clks IMX6QDL_CLK_GPU2D_AXI>,
> -			 <&clks IMX6QDL_CLK_OPENVG_AXI>,
> -			 <&clks IMX6QDL_CLK_VPU_AXI>;
> -		#power-domain-cells = <1>;
> +		clocks = <&clks IMX6QDL_CLK_IPG>;
> +		clock-names = "ipg";
> +		
> +		pgc {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			power-domain at 0 {
> +				reg = <0>;
> +				#power-domain-cells = <0>;
> +			};
> +			pd_pu: power-domain at 1 {
> +				reg = <1>;
> +				#power-domain-cells = <0>;
> +				domain-supply = <&reg_pu>;
> +				clocks = <&clks IMX6QDL_CLK_GPU3D_CORE>,
> +				         <&clks IMX6QDL_CLK_GPU3D_SHADER>,
> +				         <&clks IMX6QDL_CLK_GPU2D_CORE>,
> +				         <&clks IMX6QDL_CLK_GPU2D_AXI>,
> +				         <&clks IMX6QDL_CLK_OPENVG_AXI>,
> +				         <&clks IMX6QDL_CLK_VPU_AXI>;
> +			};
> +		};
>  	};
>  
>  
> @@ -40,20 +74,13 @@ Specifying power domain for IP modules
>  ======================================
>  
>  IP cores belonging to a power domain should contain a 'power-domains' property
> -that is a phandle pointing to the gpc device node and a DOMAIN_INDEX specifying
> -the power domain the device belongs to.
> +that is a phandle pointing to the power domain the device belongs to.
>  
>  Example of a device that is part of the PU power domain:
>  
>  	vpu: vpu at 02040000 {
>  		reg = <0x02040000 0x3c000>;
>  		/* ... */
> -		power-domains = <&gpc 1>;
> +		power-domains = <&pd_pu>;
>  		/* ... */
>  	};
> -
> -The following DOMAIN_INDEX values are valid for i.MX6Q:
> -ARM_DOMAIN     0
> -PU_DOMAIN      1
> -The following additional DOMAIN_INDEX value is valid for i.MX6SL:
> -DISPLAY_DOMAIN 2
> -- 
> 2.7.0
>