Re: [PATCH v4 13/14] pwm: jz4740: Let the pinctrl driver configure the pins

Thierry Reding
2017-04-06T14:40:34Z

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On Sun, Apr 02, 2017 at 10:42:43PM +0200, Paul Cercueil wrote:
> Now that the JZ4740 and similar SoCs have a pinctrl driver, we rely on
> the pins being properly configured before the driver probes.
>
> One inherent problem of this new approach is that the pinctrl framework
> does not allow us to configure each pin on demand, when the various PWM
> channels are requested or released. For instance, the PWM channels can
> be configured from sysfs, which would require all PWM pins to be configured
> properly beforehand for the PWM function, eventually causing conflicts
> with other platform or board drivers.
>
> The proper solution here would be to modify the pwm-jz4740 driver to
> handle only one PWM channel, and create an instance of this driver
> for each one of the 8 PWM channels. Then, it could use the pinctrl
> framework to dynamically configure the PWM pin it controls.
>
> Until this can be done, the only jz4740 board supported upstream
> (Qi lb60) can configure all of its connected PWM pins in PWM function
> mode, since those are not used by other drivers nor by GPIOs on the
> board.
>
> Signed-off-by: Paul Cercueil <paul@crapouillou.net>
> ---
> drivers/pwm/pwm-jz4740.c | 29 -----------------------------
> 1 file changed, 29 deletions(-)

Assuming that you want to take this through the pinctrl tree along with
the remainder of the series:

Acked-by: Thierry Reding <thierry.reding@gmail.com>

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