On Fri, Apr 10, 2015 at 01:25:52PM -0400, Ben Gamari wrote: > Thierry Reding <thierry.reding@xxxxxxxxx> writes: > > > On Fri, Apr 10, 2015 at 03:30:01PM +0200, Sjoerd Simons wrote: > >> > >> Yes/no/maybe :). Imho this is something to clarify in the pwm API > >> documentation. As currently all it says is: > >> "pwm_disable - stop a PWM output toggling", > >> > >> Which is what the exynos driver does. > >> > >> Thierry, could you clearify what the intention is here? I'm happy to > >> prepare a pwm driver patch if needed to solve this? > > > > I think the safest thing to do is for users to do both. You call > > pwm_config() with a zero duty cycle to make it clear what the status is > > that you want. Then you call pwm_disable() to state that you don't need > > the output signal anymore, so that any clocks needed by the PWM can be > > stopped. Doing so gives the driver the most information and should make > > the user more resilient against any possible quirks in drivers. > > > It would be great if the documentation were more clear on this matter > regardless. This is something I can imagine having to spend substantial > amounts of time Googling whereas a simple note in the documentation would > have removed all ambiguity. > Especially since, in this case, the output signal _is_ still needed. It appears that pwm_disable() is only expected to stop the clock, not the signal itself. Guenter -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
