dt-bindings: pwm: stm32: Add #pwm-cells

STM32 Timers support generic 3 cells PWM bindings to encode PWM number,
period and polarity as defined in pwm.txt.

Fixes: cd9a99c2f8e8 ("dt-bindings: pwm: Add STM32 bindings")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

diff --git a/Documentation/devicetree/bindings/pwm/pwm-stm32.txt b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt
index 3e6d55018d7ac40d8484e60e9566dedaff38e30d..a8690bfa5e1fa0bae8bc0ecdcfdf0f307c8030a1 100644 (file)
--- a/Documentation/devicetree/bindings/pwm/pwm-stm32.txt
+++ b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt
@@ -8,6 +8,8 @@ Required parameters:
 - pinctrl-names:       Set to "default".
 - pinctrl-0:           List of phandles pointing to pin configuration nodes for PWM module.
                        For Pinctrl properties see ../pinctrl/pinctrl-bindings.txt
+- #pwm-cells:          Should be set to 3. This PWM chip uses the default 3 cells
+                       bindings defined in pwm.txt.
 
 Optional parameters:
 - st,breakinput:       One or two <index level filter> to describe break input configurations.
@@ -28,6 +30,7 @@ Example:
 
                pwm {
                        compatible = "st,stm32-pwm";
+                       #pwm-cells = <3>;
                        pinctrl-0       = <&pwm1_pins>;
                        pinctrl-names   = "default";
                        st,breakinput = <0 1 5>;