clk: shmobile: rz: Add CPG/MSTP Clock Domain support

Add Clock Domain support to the RZ Clock Pulse Generator (CPG) driver
using the generic PM Domain.  This allows to power-manage the module
clocks of SoC devices that are part of the CPG/MSTP Clock Domain using
Runtime PM, or for system suspend/resume.

SoC devices that are part of the CPG/MSTP Clock Domain and can be
power-managed through an MSTP clock should be tagged in DT with a proper
"power-domains" property.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

1 files changed, 27 insertions, 2 deletions

diff --git a/Documentation/devicetree/bindings/clock/renesas,rz-cpg-clocks.txt b/Documentation/devicetree/bindings/clock/renesas,rz-cpg-clocks.txt
index b0f7ddb..bb51a33 100644
--- a/Documentation/devicetree/bindings/clock/renesas,rz-cpg-clocks.txt
+++ b/Documentation/devicetree/bindings/clock/renesas,rz-cpg-clocks.txt
@@ -2,6 +2,8 @@
 
 The CPG generates core clocks for the RZ SoCs. It includes the PLL, variable
 CPU and GPU clocks, and several fixed ratio dividers.
+The CPG also provides a Clock Domain for SoC devices, in combination with the
+CPG Module Stop (MSTP) Clocks.
 
 Required Properties:
 
@@ -14,10 +16,18 @@ Required Properties:
   - #clock-cells: Must be 1
   - clock-output-names: The names of the clocks. Supported clocks are "pll",
     "i", and "g"
+  - #power-domain-cells: Must be 0
 
+SoC devices that are part of the CPG/MSTP Clock Domain and can be power-managed
+through an MSTP clock should refer to the CPG device node in their
+"power-domains" property, as documented by the generic PM domain bindings in
+Documentation/devicetree/bindings/power/power_domain.txt.
 
-Example
--------
+
+Examples
+--------
+
+  - CPG device node:
 
 	cpg_clocks: cpg_clocks@fcfe0000 {
 		#clock-cells = <1>;
@@ -26,4 +36,19 @@ Example
 		reg = <0xfcfe0000 0x18>;
 		clocks = <&extal_clk>, <&usb_x1_clk>;
 		clock-output-names = "pll", "i", "g";
+		#power-domain-cells = <0>;
+	};
+
+
+  - CPG/MSTP Clock Domain member device node:
+
+	mtu2: timer@fcff0000 {
+		compatible = "renesas,mtu2-r7s72100", "renesas,mtu2";
+		reg = <0xfcff0000 0x400>;
+		interrupts = <0 107 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-names = "tgi0a";
+		clocks = <&mstp3_clks R7S72100_CLK_MTU2>;
+		clock-names = "fck";
+		power-domains = <&cpg_clocks>;
+		status = "disabled";
 	};