Re: [PATCH] regulator: gpio: Reword the binding document

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 2/18/19 11:18 PM, Harald Geyer wrote:
> Marek Vasut writes:
>> So what about
>>
>> gpios-states : Initial state of GPIO pins in "gpios" array, set on
>> system start and retained until consumer changes the state. 0: LOW, 1:
>> HIGH. Default is LOW if nothing else is specified.
> 
> No. "retained until consumer changes the state" is promising more then
> is guaranteed.
> 
> From the explanations provided by Mark it is clear that this property
> is an artifact of the implementation in linux. I think we should document
> is as such. How about:
> 
> gpios-states : On operating systems, that don't support reading back gpio
> 	       values in output mode (most notably linux), this array
> 	       provides the state of GPIO pins set when requesting them
> 	       from the gpio controller.

That's good.

> Systems, that are capable of
> 	       preserving state when requesting the lines, are free to
> 	       ignore this property.

Are they ? I think there are systems which depend on preconfiguring the
GPIO according to this property.

> 0: LOW, 1: HIGH. Default is LOW if
> 	       nothing else is specified.
> 
> HTH,
> Harald
> 


-- 
Best regards,
Marek Vasut



[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]


  Powered by Linux