[PATCH v8 5/6] pwm: add documentation for pwm push-pull mode

[<Claudiu.Beznea@microchip.com>]

From: Claudiu Beznea <claudiu.beznea@microchip.com>

Add documentation for PWM push-pull mode.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 Documentation/pwm.txt | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/Documentation/pwm.txt b/Documentation/pwm.txt
index 669fd4c9cc8e..80552627627d 100644
--- a/Documentation/pwm.txt
+++ b/Documentation/pwm.txt
@@ -130,6 +130,22 @@ channel that was exported. The following properties will then be available:
     PWMx_1   |__|    |__|    |__|    |__|
              ^       ^       ^       ^
 
+    Push-pull mode - for PWM channels with two outputs; output waveforms
+        for a PWM channel in push-pull mode, with normal polarity looks like
+        this:
+              __              __
+    PWMx_0 __|  |____________|  |__________
+                      __              __
+    PWMx_1 __________|  |____________|  |__
+             ^       ^       ^       ^
+
+    If polarity is inversed:
+           __    ____________    __________
+    PWMx_0   |__|            |__|
+           __________    ____________    __
+    PWMx_1           |__|            |__|
+             ^       ^       ^       ^
+
     Where '^' specifies the beginning of a period.
 
 Implementing a PWM driver
-- 
2.7.4