On 09/28/2013 04:46 AM, Alexandre Belloni wrote:
On 27/09/2013 20:34, Alexandre Belloni wrote:
Ok, I tested that and it seems to be working fine.
One last question though. What about power management ?
For example, in pwm_bl, pwm_backlight_suspend calls:
pwm_config(pb->pwm, 0, pb->period);
pwm_disable(pb->pwm);
Which is fine because it will correctly set up the PWM to a low level.
OK.
Then, to disable the pwm itself and its clock, I suppose we would have
to define some pm_ops in atmel_pwm, am I right ?
Maybe the suspend/resume() can be handled by the PWM driver.
However, not every PWM consumer of atmel-pwm needs the PM code.
I think it would be better if those are handled by each the PWM consumer.
So we will have to be extra careful to correctly set a low level on the
pin at that time.
If you only care about the leds-pwm, then no additional handling is
required.
The LED subsystem provides a 'LED_CORE_SUSPENDRESUME' flag which enables
the PM automatically.
The brightness is set to 0 forcedly on the suspend, and the stored
brightness is recovered on the resume.
The leds-pwm driver enables this flag.
On the suspend mode, pwm_config() and pwm_disable() are called in
__led_pwm_set(). That's exactly what you need.
Best regards,
Milo
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