From mboxrd@z Thu Jan 1 00:00:00 1970 From: ben@smart-cactus.org (Ben Gamari) Date: Fri, 10 Apr 2015 13:25:52 -0400 Subject: [PATCH 6/6] hwmon: pwm-fan: Update the duty cycle inorder to control the pwm-fan In-Reply-To: <20150410135844.GA20147@ulmo.nvidia.com> References: <20150408104415.07e1c821@amdc2363> <20150408153214.GA15942@roeck-us.net> <20150408165351.GA22846@roeck-us.net> <1428667201.22057.20.camel@collabora.co.uk> <5527CB78.4040002@roeck-us.net> <1428672601.22057.25.camel@collabora.co.uk> <20150410135844.GA20147@ulmo.nvidia.com> Message-ID: <87h9snvqsf.fsf@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Thierry Reding 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. Cheers, - Ben -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 472 bytes Desc: not available URL: