Re: [PATCH v3 4/7] gpio: max7360: Add MAX7360 gpio support

[Mathieu Dubois-Briand]

Hi Andy,

Thanks for your review. I've been addressing most of your comments in
this mail and the ones related to regmap-irq. I should be able to send a
new version in a few days.

However I have a few questions regarding some of the points.

On Mon Jan 27, 2025 at 2:07 PM CET, Andy Shevchenko wrote:
> On Mon, Jan 13, 2025 at 01:42:28PM +0100, Mathieu Dubois-Briand wrote:
> > +	parent = to_platform_device(pdev->dev.parent);
>
> Why do you need this? Can't the fwnode be propagated to the children and then
> the respective APIs to be used?
>

I'm not sure to understand this correctly, what do you mean by
propagating the fwnode to the children?

Just a quick summary of the situation and what I try to do. The device
tree looks like this, only keeping the interesting properties:

io-expander@38 {
  ...
  interrupts = <23 IRQ_TYPE_LEVEL_LOW>,
               <24 IRQ_TYPE_LEVEL_LOW>;
  interrupt-names = "inti", "intk";

  max7360_gpio: gpio {
    ...
  };

  max7360_gpo: gpo {
    ...
  };
};

Our pdev fwnode points either to the "gpio" or "gpo" nodes, the one from
our parent device points to "io-expander@38". Here we need to get the
"inti" interrupt from the parent node. What would be the correct way to
do it?

> > +	if (!max7360_gpio)
> > +		return -ENOMEM;
>
> > +	if (of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios)) {
> > +		dev_err(&pdev->dev, "Missing ngpios OF property\n");
> > +		return -ENODEV;
> > +	}
>
> This is not needed, it is already done in GPIOLIB core.
>

I believe this is still needed:
- For gpos, we need the gpio count to correctly set the partition
  between gpo and keypad columns in max7360_set_gpos_count().
- For gpios, we need the gpio count to setup the IRQs.

Best regards,
Mathieu

-- 
Mathieu Dubois-Briand, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com