Re: [PATCH v6 01/13] pinctrl: core: Add pinctrl_get_device()

[Andy Shevchenko <andy.shevchenko@xxxxxxxxx>]

On Tue, Mar 7, 2023 at 10:13 AM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> > Subject: Re: [PATCH v6 01/13] pinctrl: core: Add pinctrl_get_device()
> > Mon, Mar 06, 2023 at 09:00:02AM +0000, Biju Das kirjoitti:

...

> > > Add pinctrl_get_device() to find a device handle associated with a
> > > pincontrol group(i.e. by matching function name and group name for a
> > > device). This device handle can then be used for finding match for the
> > > pin output disable device that protects device against short circuits
> > > on the pins.
> >
> > Not sure I understand the use case. Please, create a better commit message.
>
> OK, Basically pinmux_enable_setting allows exclusive access of pin to a device.
> It won't allow multiple devices to claim a pin.

Which is correct. No? Show me the schematics of the real use case for that.

The owner of the pin is the host side. I can't imagine how the same
pin is shared inside the SoC. Is it broken hardware design?

...

> > Also it is missing the explanation why there will be no collisions when
> > looking by the same pair of function and group name from different device.
>
> setting->data.mux will be unique for a pin. So there won't be a collision when
> looking by the same pair of function and group name from different device.
>
> > (Always imagine that you have 2+ same IP blocks on the platform before doing
> > any pin control core work. This will help you to design it properly. )

Not sure how the pair function_name group_name makes the device unique.

-- 
With Best Regards,
Andy Shevchenko