Re: Use of pinctrl-single for external device over I2C

[Vaibhav Hiremath]

On Thursday 25 June 2015 11:16 AM, Vaibhav Hiremath wrote:
> On Thursday 25 June 2015 10:08 AM, Tony Lindgren wrote:
> > * Vaibhav Hiremath <vaibhav.hiremath@xxxxxxxxxx> [150624 10:12]:
> > > I do not like this, as this is not HW feature, so DT may not be right
> > > approach.
> > >
> > > So I will dig more from either runtime or Compile time option to use
> > > regmap_ Vs raw read/writes.
> >
> > Can't you just check if the pinctrl node has compatible = "syscon"
> > property?
> >
> > A compile time option won't work for sure. I don't know what you
> > would check at runtime as you do not know what the bus is behind
> > syscon.
>
> Although, I haven't gone through syscon, but not sure whether syscon
> would be useful.
>
> As you rightly stated, we need to know the bus behind regmap.

Trying to understand what is the right way of doing pinctrl of external
device on board,

I feel it would not be good idea to pollute pinctrl-single driver, and 
also I am still not able to figure out how can I have access to bus
behind regmap.


How about having separate driver (generic for all I2C), say pinctrl-
i2c.c, which is i2c_client driver and would support pinctrl and pinmux
on I2C client device.


The current usecase which I have is pretty simple in nature,

88PM860 has few GPIO pins which can be configured to different
functionality, based on board design.
In most of the cases they are one/init/boot time settings.

GPIO_0:
=======
  000 = GPIO input mode
  001 = GPIO output mode
  010 = SLEEPOUTN mirror mode
  011 = Buck4 FPWM enable
  100 = 32 Khz output buffer mode
  101 = PMICINTN output mode
  110 = HW_RESET1 mode
  111 = HW_RESET2 mode


Thanks,
Vaibhav
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