pwm: atmel: Rework tracking updates pending in hardware
This improves the driver's behavior in several ways:
- The lock is held for shorter periods and so a channel that is currently
waited for doesn't block disabling another channel.
- It's easier to understand because the procedure is split into more
semantic units and documentation is improved
- A channel is only set to pending when such an event is actually
scheduled in hardware (by writing the CUPD register).
- Also wait in .get_state() to report the last configured state instead
of (maybe) the previous one. This fixes the read back duty cycle and so
prevents a warning being emitted when PWM_DEBUG is on.
Tested on an AriettaG25.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
1 file changed