Re: [PATCH 5/8] pinctrl-tz1090: add TZ1090 pinctrl driver

From: Linus Walleij
Date: Tue May 14 2013 - 07:52:39 EST


On Fri, May 3, 2013 at 5:06 PM, James Hogan <james.hogan@xxxxxxxxxx> wrote:
> [me]
>> Thus this part of the problem (poking that "select" bit)
>> should be handled by the pinmux part of the driver.
>>
>> The pinconf part does not need to know about it.
>
> Okay, so how would you recommend handling the case of a pin in a muxing
> pingroup that shouldn't be put into peripheral mode?
>
> E.g. imagine an 18bit display is wired to the (24bit) tft pins (which
> are muxed as a group to "tft" function), and the least significant tft
> pins are used as GPIOs to control something like board power supplies.
>
> Without using pinconf I think the muxing pingroups would have to overlap
> like below (is that acceptable?):

I don't know if I understand your example correctly but are you after
this part of the documentation from Documentation/pinctrl.txt:

Pinmux conventions
==================
(...)
It is possible to map several groups to the same combination of device,
pin controller and function. This is for cases where a certain function on
a certain pin controller may use different sets of pins in different
configurations.

Yours,
Linus Walleij
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