[PATCH] drivers/pwm: add PXA pulse width modulator controller
Robert Jarzmik
robert.jarzmik at free.fr
Wed Feb 8 10:26:21 EST 2012
Robert Jarzmik <robert.jarzmik at free.fr> writes:
> Sascha Hauer <s.hauer at pengutronix.de> writes:
>
>> Hi Robert,
>>
>> Why not implement it as a regular driver? If we ever want to implement
>> a commandline control of the pwms via pwm0.dutyns=xx we'll need
>> a struct device.
>
> This is because in my own case, I need pwm to be registered before other devices
> are probed. The trouble (in my case) is that for drivers/video/pxa.c, I have the
> following call path :
> - pxafb_probe()
> -> pxafb_enable_controller()
> -> pxafb_backlight_power()
> -> mioa701_lcd_backlight()
> => struct pwm_device *pwm0 = pwm_request("pxa_pwm0");
> pwm_enable(pwm0);
> pwm_config(pwm0, 2000 * 1024, 4000 * 1024);
>
> I'm a bit afraid that the pxafb driver will be probed first, before pwm_pxa, and
> therefore the backlight setting won't work. I haven't found a clean way to
> specify this dependency.
Sascha, ping ?
Do you have a way to specify the dependency, and do you want me to adapt the
driver ?
Cheers.
--
Robert
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