Add Spreadtrum PWM controller documentation.
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
---
Changes from v1:
- Use assigned-clock-parents and assigned-clocks to set PWM clock parent.
---
Documentation/devicetree/bindings/pwm/pwm-sprd.txt | 38 ++++++++++++++++++++
1 file changed, 38 insertions(+)
create mode 100644 Documentation/devicetree/bindings/pwm/pwm-sprd.txt
diff --git a/Documentation/devicetree/bindings/pwm/pwm-sprd.txt b/Documentation/devicetree/bindings/pwm/pwm-sprd.txt
new file mode 100644
index 0000000..e6cf312
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-sprd.txt
@@ -0,0 +1,38 @@
+Spreadtrum PWM controller
+
+Spreadtrum SoCs PWM controller provides 4 PWM channels.
+
+Required porperties:
+- compatible : Should be "sprd,ums512-pwm".
+- reg: Physical base address and length of the controller's registers.
+- clocks: The phandle and specifier referencing the controller's clocks.
+- clock-names: Should contain following entries:
+ "pwmn": used to derive the functional clock for PWM channel n (n range: 0 ~ 3).
+ "enablen": for PWM channel n enable clock (n range: 0 ~ 3).
+- assigned-clocks: Reference to the PWM clock entroes.
+- assigned-clock-parents: The phandle of the parent clock of PWM clock.
+- #pwm-cells: Should be 2. See pwm.txt in this directory for a description of
+ the cells format.
+
+Example:
+ pwms: pwm@32260000 {
+ compatible = "sprd,ums512-pwm";
+ reg = <0 0x32260000 0 0x10000>;
+ clock-names = "pwm0", "enable0",
+ "pwm1", "enable1",
+ "pwm2", "enable2",
+ "pwm3", "enable3";
+ clocks = <&aon_clk CLK_PWM0>, <&aonapb_gate CLK_PWM0_EB>,
+ <&aon_clk CLK_PWM1>, <&aonapb_gate CLK_PWM1_EB>,
+ <&aon_clk CLK_PWM2>, <&aonapb_gate CLK_PWM2_EB>,
+ <&aon_clk CLK_PWM3>, <&aonapb_gate CLK_PWM3_EB>;
+ assigned-clocks = <&aon_clk CLK_PWM0>,
+ <&aon_clk CLK_PWM1>,
+ <&aon_clk CLK_PWM2>,
+ <&aon_clk CLK_PWM3>;
+ assigned-clock-parents = <&ext_26m>,
+ <&ext_26m>,
+ <&ext_26m>,
+ <&ext_26m>;
+ #pwm-cells = <2>;
+ };
--
1.7.9.5
