Add documentation for PWM push-pull mode.
Signed-off-by: Claudiu Beznea claudiu.beznea@microchip.com Reviewed-by: Rob Herring robh@kernel.org --- Documentation/devicetree/bindings/pwm/pwm.txt | 2 ++ Documentation/pwm.txt | 16 ++++++++++++++++ include/dt-bindings/pwm/pwm.h | 1 + 3 files changed, 19 insertions(+)
diff --git a/Documentation/devicetree/bindings/pwm/pwm.txt b/Documentation/devicetree/bindings/pwm/pwm.txt index c2b4b9ba0e3f..968dd786ad7c 100644 --- a/Documentation/devicetree/bindings/pwm/pwm.txt +++ b/Documentation/devicetree/bindings/pwm/pwm.txt @@ -49,6 +49,8 @@ Optionally, the pwm-specifier can encode a number of flags (defined in - PWM_DTMODE_COMPLEMENTARY: PWM complementary working mode (for PWM channels two outputs); if not specified, the default for PWM channel will be used +- PWM_DTMODE_PUSH_PULL: PWM push-pull working modes (for PWM channels with +two outputs); if not specified the default for PWM channel will be used
Example with optional PWM specifier for inverse polarity and complementary mode: diff --git a/Documentation/pwm.txt b/Documentation/pwm.txt index 59592f8cc381..174c371583b6 100644 --- a/Documentation/pwm.txt +++ b/Documentation/pwm.txt @@ -128,6 +128,22 @@ channel that was exported. The following properties will then be available: PWML1 |__| |__| |__| |__| <--T-->
+ Push-pull mode - for PWM channels with two outputs; output waveforms + for a PWM channel with 2 outputs, in push-pull mode, with normal + polarity looks like this: + __ __ + PWMH __| |________| |________ + __ __ + PWML ________| |________| |__ + <--T--> + + If polarity is inversed: + __ ________ ________ + PWMH |__| |__| + ________ ________ __ + PWML |__| |__| + <--T--> + Where T is the signal period.
Implementing a PWM driver diff --git a/include/dt-bindings/pwm/pwm.h b/include/dt-bindings/pwm/pwm.h index b4d61269aced..674dfdd59595 100644 --- a/include/dt-bindings/pwm/pwm.h +++ b/include/dt-bindings/pwm/pwm.h @@ -12,5 +12,6 @@
#define PWM_POLARITY_INVERTED (1 << 0) #define PWM_DTMODE_COMPLEMENTARY (1 << 1) +#define PWM_DTMODE_PUSH_PULL (1 << 2)
#endif