[Query] should pinmux setting be put into board specific dts or SoC specific dtsi?

[Query] should pinmux setting be put into board specific dts or SoC specific dtsi?

[Jisheng Zhang]

Hi,

IIUC, the pinmux setting is board specific. So my question is where to put the
pinmux settings? Board specific dts or SoC specific dtsi? Could anyone kindly
help me?

Thanks in advance,
Jisheng

[Query] should pinmux setting be put into board specific dts or SoC specific dtsi?

[Sebastian Hesselbarth]

On 01/21/2015 08:30 AM, Jisheng Zhang wrote:
> IIUC, the pinmux setting is board specific. So my question is where to put the
> pinmux settings? Board specific dts or SoC specific dtsi? Could anyone kindly
> help me?

Jisheng,

it depends on the pinmux setting whether it should go in to SoC dtsi or
board dts. For example, the pinmux setting for internal devices like
UART - where there is only one or two possible settings - should go
into SoC dtsi. Also, if there is only one possible setting or one
default/common setting, the SoC dtsi node should already have the
corresponding pinctrl properties. If a specific board uses another
setting, it can always overwrite the default property with the
one used at board level.

A good example for board specific pinmux settings clearly is GPIO,
e.g. you have a regulator for USB power that is controlled by GPIO
then you'll have the regulator node on board level and also the
corresponding pinmux settings for that very GPIO pin.

If you give a specific example of what pinmux setting bothers you,
we can try to find a good place for it.

Sebastian

[Query] should pinmux setting be put into board specific dts or SoC specific dtsi?

[Jisheng Zhang]

Dear Sebastian,

On Wed, 21 Jan 2015 02:38:27 -0800
Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> wrote:

> On 01/21/2015 08:30 AM, Jisheng Zhang wrote:
> > IIUC, the pinmux setting is board specific. So my question is where to
> > put the pinmux settings? Board specific dts or SoC specific dtsi? Could
> > anyone kindly help me?
> 
> Jisheng,
> 
> it depends on the pinmux setting whether it should go in to SoC dtsi or
> board dts. For example, the pinmux setting for internal devices like
> UART - where there is only one or two possible settings - should go
> into SoC dtsi. Also, if there is only one possible setting or one
> default/common setting, the SoC dtsi node should already have the
> corresponding pinctrl properties. If a specific board uses another
> setting, it can always overwrite the default property with the
> one used at board level.
> 
> A good example for board specific pinmux settings clearly is GPIO,
> e.g. you have a regulator for USB power that is controlled by GPIO
> then you'll have the regulator node on board level and also the
> corresponding pinmux settings for that very GPIO pin.

Thanks very much for the detailed explanation. The regulator is the case
I care ;)

> 
> If you give a specific example of what pinmux setting bothers you,
> we can try to find a good place for it.
> 
> Sebastian