Re: [PATCH 10/10] gpiolib: add of_xlate support

[Marco Felsch <m.felsch@pengutronix.de>]

Hi Jules,

On 23-06-05, Jules Maselbas wrote:
> Hi Marco,
> 
> I tried this patch series on my sunxi branch and it applies nicely
> but failed to get the gpio with the following message:
> of_get_named_gpio_flags: unable to get gpio num of device 1c20800.pinctrl@1c20800.of: -22
> 
> The error -22 is for -EINVAL which comes form of_xlate_and_get_gpiod_flags
> because the test `chip->of_gpio_n_cells != gpiospec->args_count` fails,
> `of_gpio_n_cells` hasn't been set by the driver and it value was 0.
> 
> I wonder if `of_gpio_n_cells` should be set by the driver or by parsing the
> #gpio-cells property from device-tree?

The driver need to define the cells since the driver is the one
interpreting the cells, please have a look on:

https://elixir.bootlin.com/linux/v6.4-rc1/source/drivers/pinctrl/sunxi/pinctrl-sunxi.c#L1583

> By setting the expected value in the driver resolves this "issue".

Cool :) so you are able to controll the sunxi-gpios? :)

Thanks a lot for testing. I will send a v2 with your found spelling
issues.

Regards,
  Marco

> Cheers,
> -- Jules
> 
> > diff --git a/drivers/of/of_gpio.c b/drivers/of/of_gpio.c
> > +static int of_xlate_and_get_gpiod_flags(struct gpio_chip *chip,
> > +					struct of_phandle_args *gpiospec,
> > +					enum of_gpio_flags *flags)
> > +{
> > +	if (chip->of_gpio_n_cells != gpiospec->args_count)
> > +		return -EINVAL;
> error message caused by this ^
> 
> > +
> > +	return chip->ops->of_xlate(chip, gpiospec, flags);
> > +}
> > +
> >  /**
> >   * of_get_named_gpio_flags() - Get a GPIO number and flags to use with GPIO API
> >   * @np:		device node to get GPIO from
> > @@ -61,7 +99,7 @@ int of_get_named_gpio_flags(struct device_node *np, const char *propname,
> >  			   int index, enum of_gpio_flags *flags)
> >  {
> >  	struct of_phandle_args gpiospec;
> > -	struct device *dev;
> > +	struct gpio_chip *chip;
> >  	int ret;
> >  
> >  	ret = of_parse_phandle_with_args(np, propname, "#gpio-cells",
> > @@ -72,27 +110,21 @@ int of_get_named_gpio_flags(struct device_node *np, const char *propname,
> >  		return ret;
> >  	}
> >  
> > -	dev = of_find_device_by_node(gpiospec.np);
> > -	if (!dev) {
> > -		pr_debug("%s: unable to find device of node %s\n",
> > -			 __func__, gpiospec.np->full_name);
> > +	chip = of_find_gpiochip_by_xlate(&gpiospec);
> > +	if (!chip) {
> >  		ret = -EPROBE_DEFER;
> >  		goto out;
> >  	}
> >  
> > -	ret = gpio_get_num(dev, gpiospec.args[0]);
> > -	if (ret == -EPROBE_DEFER)
> > -		goto out;
> > +	ret = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
> >  	if (ret < 0) {
> >  		pr_err("%s: unable to get gpio num of device %s: %d\n",
> got this error message here
> 
> > -			__func__, dev_name(dev), ret);
> > +			__func__, dev_name(chip->dev), ret);
> >  		goto out;
> >  	}
> >  
> > -	if (flags) {
> > -		*flags = gpiospec.args[1];
> > +	if (flags)
> >  		of_gpio_flags_quirks(np, propname, flags, index);
> > -	}
> >  
> >  out:
> >  	of_node_put(gpiospec.np);
>