From 83af24027b3df1af5c5a9aa9adcdcfeb3429d3be Mon Sep 17 00:00:00 2001 From: "Philip, Avinash" Date: Wed, 21 Nov 2012 13:10:44 +0530 Subject: pwm: Device tree support for PWM polarity Add support for encoding PWM properties in bit encoded form with of_pwm_xlate_with_flags() function support. Platforms require platform specific PWM properties has to populate in 3rd cell of the pwm-specifier and PWM driver should also set .of_xlate support with this function. Currently PWM property polarity encoded in bit position 0 of the third cell in pwm-specifier. Signed-off-by: Philip, Avinash Acked-by: Grant Likely Signed-off-by: Thierry Reding --- Documentation/devicetree/bindings/pwm/pwm.txt | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) (limited to 'Documentation/devicetree/bindings/pwm') diff --git a/Documentation/devicetree/bindings/pwm/pwm.txt b/Documentation/devicetree/bindings/pwm/pwm.txt index 73ec962bfe8..06e67247859 100644 --- a/Documentation/devicetree/bindings/pwm/pwm.txt +++ b/Documentation/devicetree/bindings/pwm/pwm.txt @@ -37,10 +37,21 @@ device: pwm-names = "backlight"; }; +Note that in the example above, specifying the "pwm-names" is redundant +because the name "backlight" would be used as fallback anyway. + pwm-specifier typically encodes the chip-relative PWM number and the PWM -period in nanoseconds. Note that in the example above, specifying the -"pwm-names" is redundant because the name "backlight" would be used as -fallback anyway. +period in nanoseconds. + +Optionally, the pwm-specifier can encode a number of flags in a third cell: +- bit 0: PWM signal polarity (0: normal polarity, 1: inverse polarity) + +Example with optional PWM specifier for inverse polarity + + bl: backlight { + pwms = <&pwm 0 5000000 1>; + pwm-names = "backlight"; + }; 2) PWM controller nodes ----------------------- -- cgit v1.2.3