Hello Linus, On Mon, Nov 19, 2018 at 08:44:38AM +0100, Linus Walleij wrote: > There is quite a discussion you folks have going on here. I tried to > grasp it but I can't. I can try to answer the above question specifically. To sumarize: When the pwm driver probes it is not yet clear if the idle state of the output pin is high or low. Even when the pinctrl device has an "init" and a "default" pinctrl, it is not yet fixed when its "default" is configured. The way Thierry wants to fix that is by disabling the output driver until the pwm is in use und rely on a pull-up or pull-down in hardware. The way I want to fix this is to only configure the pwm pin as part of the consumer. This is late enough that the consumer already requested and configured the pwm such that the idle level is known. Thierry's and Lothar's claim was that putting the pin setup of the pwm pin into the pwm consumer's pinctrl was forbidden. That's why I asked you as pinctrl maintainer if there is a requirement that I don't know of. > So compared to things like that (that we still have to support > forever) whatever you are doing here you're doing great as long > as it is consumer controlled. > > Whether that consumer is the previous driver thingie in the > daisy-chain of consumers or the final end user consumer of > the pin doesn't really matter to pin control, as long as it is a > consumer. I would tend to say it is up to the subsystem, > and the old IETF motto "rough consensus and running code". So I understand that from the pinctrl side there is no hard requirement that the PWM pin must be muxed as part of the pwm device. And if things work better when the pin is only configured as part of its consumer this is legitimate. Thanks for your feedback. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |
