From 321a7cea973b4f63bb7e3baaea8428dfb8b424a9 Mon Sep 17 00:00:00 2001 From: Yoshihiro Shimoda Date: Fri, 31 May 2019 18:54:58 +0900 Subject: pwm: Add power management descriptions This patch adds power management descriptions that consumers should implement it. Signed-off-by: Yoshihiro Shimoda Reviewed-by: Geert Uytterhoeven Reviewed-by: Simon Horman Signed-off-by: Thierry Reding --- Documentation/pwm.txt | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/Documentation/pwm.txt b/Documentation/pwm.txt index 8fbf0aa3ba2d..ab62f1bb0366 100644 --- a/Documentation/pwm.txt +++ b/Documentation/pwm.txt @@ -65,6 +65,10 @@ period). struct pwm_args contains 2 fields (period and polarity) and should be used to set the initial PWM config (usually done in the probe function of the PWM user). PWM arguments are retrieved with pwm_get_args(). +All consumers should really be reconfiguring the PWM upon resume as +appropriate. This is the only way to ensure that everything is resumed in +the proper order. + Using PWMs with the sysfs interface ----------------------------------- @@ -141,6 +145,9 @@ The implementation of ->get_state() (a method used to retrieve initial PWM state) is also encouraged for the same reason: letting the PWM user know about the current PWM state would allow him to avoid glitches. +Drivers should not implement any power management. In other words, +consumers should implement it as described in the "Using PWMs" section. + Locking ------- -- cgit v1.2.3-59-g8ed1b