Re: [PATCH 6/6] hwmon: pwm-fan: Update the duty cycle inorder to control the pwm-fan

[Ben Gamari <ben@smart-cactus.org>]

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Thierry Reding <thierry.reding@gmail.com> 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

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