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

[Jules Maselbas <jmaselbas@zdiv.net>]

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?

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

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);