Add documentation for STMicroelectronics STM32 Low-Power Timer
PWM binding.

Signed-off-by: Fabrice Gasnier <redacted>
---
Changes in v2:
- s/Low Power/Low-Power/
- remove 0x in example (parent node)
- improve properties description
---
 .../devicetree/bindings/pwm/pwm-stm32-lp.txt       | 24 ++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/pwm-stm32-lp.txt

diff --git a/Documentation/devicetree/bindings/pwm/pwm-stm32-lp.txt b/Documentation/devicetree/bindings/pwm/pwm-stm32-lp.txt
new file mode 100644
index 0000000..941c990
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-stm32-lp.txt

@@ -0,0 +1,24 @@
+STMicroelectronics STM32 Low-Power Timer PWM
+
+STM32 Low-Power Timer provides single channel PWM.
+
+Must be a sub-node of an STM32 Low-Power Timer device tree node.
+See ../mfd/stm32-lptimer.txt for details about the parent node.
+
+Required parameters:
+- compatible:		Must be "st,stm32-pwm-lp".
+
+Optional properties:
+- pinctrl-names: 	Set to "default".
+- pinctrl-0: 		Phandle pointing to pin configuration node for PWM.
+
+Example:
+	lptimer1: lptimer at 40002400 {