gpiolib: of: add a fallback for wlf,reset GPIO name

The old Arizona binding did not use -gpio or -gpios suffix, so
devm_gpiod_get() does not work for it. As it is the one of a few users
of devm_gpiod_get_from_of_node() API that I want to remove, I'd rather
have a small quirk in the gpiolib OF handler, and switch Arizona
driver to devm_gpiod_get().
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Link: https://lore.kernel.org/r/20190911075215.78047-2-dmitry.torokhov@gmail.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpiolib-of.c

@@ -438,6 +438,19 @@ static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *
 	return desc;
 }
 
+static struct gpio_desc *of_find_arizona_gpio(struct device *dev,
+					      const char *con_id,
+					      enum of_gpio_flags *of_flags)
+{
+	if (!IS_ENABLED(CONFIG_MFD_ARIZONA))
+		return ERR_PTR(-ENOENT);
+
+	if (!con_id || strcmp(con_id, "wlf,reset"))
+		return ERR_PTR(-ENOENT);
+
+	return of_get_named_gpiod_flags(dev->of_node, con_id, 0, of_flags);
+}
+
 struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
 			       unsigned int idx, unsigned long *flags)
 {
@@ -488,6 +501,9 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
 	if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER)
 		desc = of_find_regulator_gpio(dev, con_id, &of_flags);
 
+	if (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
+		desc = of_find_arizona_gpio(dev, con_id, &of_flags);
+
 	if (IS_ERR(desc))
 		return desc;