[PATCH 4/4] Documentation: Add device tree bindings for Freescale FTM PWM

Stephen Warren swarren at wwwdotorg.org
Tue Aug 27 00:04:01 EDT 2013


On 08/26/2013 09:48 PM, Xiubo Li-B47053 wrote:
> Hi Stephen,
> 
> 
>> Subject: Re: [PATCH 4/4] Documentation: Add device tree bindings for
>> Freescale FTM PWM
>>
>> On 08/25/2013 11:35 PM, Xiubo Li-B47053 wrote:
>>>> Subject: Re: [PATCH 4/4] Documentation: Add device tree bindings for
>> ...
>>>>> Why do you need to manipulate the pinctrl to en/disable a channel?
>>>>
>>>> This is because in Vybrid VF610 TOWER board, there are 4 leds, and
>>>> each led's one point(diode's positive pole) is connected to 3.3V, and
>>>> the other point is connected to pwm's one channel. When the 4
>>>> pinctrls are configured as enable at the same time, the 4 pinctrls is
>>>> low valtage, and the 4 leds will be lighted up as default, then when
>>>> you enable/disable one led will effects others.
>>>>
>>>> These pinctrls are belong to pwm, and I don't think led or other
>>>> customer could control them directly.
>>>> So, here I authorize the 4 pinctrls to each channel controls.
>>>>
>>> "
>>> For the reason above, I have to control the pinctrls separately.
>>>
>>> If all the pinctrls set as default state, the 8 pinctrls must be
>> controlled together.
>>> And the 4 leds will all be lighted up as default and will influence
>> each other.
>>
>> Sorry, that still doesn't make much sense. ...

What may help here is to show the exact content you expect the various
en/dis states to have, so that we can see exactly which pinctrl options
get set when and why.



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