Re: [PATCH 1/3] pinctrl: mediatek: Add gpio-range record in pinctrl driver

[Deep Pani <Deep.Pani@mediatek.com>]

Hi Andy,

You mean gpiochip_add_pin_range(), correct?

IIRC, that adds to gpiochip's range, not the range we are using for our
pinctrl driver. 

The range we are utilizing inside our hardware is of the type struct
pinctrl_gpio_range. There is no callback in gpiochip that handles this
type of range

I also recall that gpiochip_add_data() doesn't initialize the hw but
rather initializes the gpiochip from the hw data we will provide in
mtk_build_gpiochip(). Thus  we need a function which will help
initialize the pinctrl_gpio_range inside our pinctrl driver structure.
This is why we make the mtk_pinctrl_gpio_range_init function here.

For the second question, we are keeping it because before ACPI is
invoked we still need some other pins to be configured, especially if
different pins have different styles of pull configuration. The method
we use is to define those configurations in the pinctrl-mt8901.c file
which determines the gpio ranges and maps pinctrl device to acpi, one
set of gpio ranges per configuration, for different type of pull
configurations we have different gpio ranges, this callback helps add
them into the pinctrl subsystem such that other device maintainers can
easily leverage that subsystem to add their resources in their _CRS
calls using the common interfaces. 

Thus we need to keep both the functions.

Thanks and Regards,
Deep Pani



On Thu, 2026-03-26 at 12:33 +0000, Fred-WY Chen (陳威宇) wrote:
> On Wed, 2025-11-26 at 19:06 +0100, Andy Shevchenko wrote:
> > 
> > External email : Please do not click links or open attachments
> > until
> > you have verified the sender or the content.
> > 
> > 
> > On Tue, Nov 25, 2025 at 10:36:34AM +0800, Lei Xue wrote:
> > > Kernel GPIO subsystem mapping hardware pin number to a different
> > > range of gpio number. Add gpio-range structure to hold
> > > the mapped gpio range in pinctrl driver. That enables the kernel
> > > to search a range of mapped gpio range against a pinctrl device.
> > 
> > ...
> > 
> > >  static int mtk_build_gpiochip(struct mtk_pinctrl *hw)
> > >  {
> > >       struct gpio_chip *chip = &hw->chip;
> > 
> > >       if (ret < 0)
> > >               return ret;
> > > 
> > > +     mtk_pinctrl_gpio_range_init(hw, chip);
> > > +
> > >       return 0;
> > 
> > We have a callback for that in struct gpio_chip. Any reason not to
> > use it?
> > 
> > >  }
> > 
> > ...
> > 
> > > +     pinctrl_add_gpio_range(hw->pctrl, &hw->range);
> > 
> > Not sure if this is needed.
> > 
> 
> Hi Deep,
> 
> Could you please check this and feedback?
> 
> Regards,
> Fred-WY Chen
> 
> > --
> > With Best Regards,
> > Andy Shevchenko
> > 
> > 
>