tree 9831fc05aad7280b76944a4d7ca809070f81ebef
parent e42617b825f8073569da76dc4510bfa019b1c35a
author Thierry Reding <thierry.reding@gmail.com> 1571655116 +0200
committer Thierry Reding <thierry.reding@gmail.com> 1575882341 +0100

pwm: Read initial hardware state at request time

Drivers that support reading the hardware state (using ->get_state())
may want to rely on per-PWM data to do so. Defer reading the hardware
state for the first time until the PWM has been requested and after
drivers have had a chance to allocate per-PWM data.

Conceptually this is also a more natural place to read the hardware
state because the PWM core doesn't need to know the hardware state of a
PWM unless there is a user for it. This also ensures that the state is
read everytime a user requests a PWM. If the PWM changes between users
for some reason, the PWM core will reload the state from hardware and
keep its copy of the state up-to-date.

Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Michal Vokáč <michal.vokac@ysoft.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>