gpiolib: rework quirk handling in of_find_gpio()

Instead of having a string of "if" statements let's put all quirks into
an array and iterate over them.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

drivers/gpio/gpiolib-of.c

@@ -372,14 +372,12 @@ EXPORT_SYMBOL_GPL(gpiod_get_from_of_node);
  * properties should be named "foo-gpios" so we have this special kludge for
  * them.
  */
-static struct gpio_desc *of_find_spi_gpio(struct device *dev,
+static struct gpio_desc *of_find_spi_gpio(struct device_node *np,
 					  const char *con_id,
 					  unsigned int idx,
 					  enum of_gpio_flags *of_flags)
 {
 	char prop_name[32]; /* 32 is max size of property name */
-	const struct device_node *np = dev->of_node;
-	struct gpio_desc *desc;
 
 	/*
 	 * Hopefully the compiler stubs the rest of the function if this
@@ -395,8 +393,7 @@ static struct gpio_desc *of_find_spi_gpio(struct device *dev,
 	/* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
 	snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
 
-	desc = of_get_named_gpiod_flags(np, prop_name, idx, of_flags);
-	return desc;
+	return of_get_named_gpiod_flags(np, prop_name, idx, of_flags);
 }
 
 /*
@@ -404,13 +401,11 @@ static struct gpio_desc *of_find_spi_gpio(struct device *dev,
  * lines rather than "cs-gpios" like all other SPI hardware. Account for this
  * with a special quirk.
  */
-static struct gpio_desc *of_find_spi_cs_gpio(struct device *dev,
+static struct gpio_desc *of_find_spi_cs_gpio(struct device_node *np,
 					     const char *con_id,
 					     unsigned int idx,
 					     enum of_gpio_flags *of_flags)
 {
-	const struct device_node *np = dev->of_node;
-
 	if (!IS_ENABLED(CONFIG_SPI_MASTER))
 		return ERR_PTR(-ENOENT);
 
@@ -428,7 +423,7 @@ static struct gpio_desc *of_find_spi_cs_gpio(struct device *dev,
 	 * uses just "gpios" so translate to that when "cs-gpios" is
 	 * requested.
 	 */
-	return of_get_named_gpiod_flags(dev->of_node, "gpios", idx, of_flags);
+	return of_get_named_gpiod_flags(np, "gpios", idx, of_flags);
 }
 
 /*
@@ -436,7 +431,7 @@ static struct gpio_desc *of_find_spi_cs_gpio(struct device *dev,
  * properties should be named "foo-gpios" so we have this special kludge for
  * them.
  */
-static struct gpio_desc *of_find_regulator_gpio(struct device *dev,
+static struct gpio_desc *of_find_regulator_gpio(struct device_node *np,
 						const char *con_id,
 						unsigned int idx,
 						enum of_gpio_flags *of_flags)
@@ -447,8 +442,6 @@ static struct gpio_desc *of_find_regulator_gpio(struct device *dev,
 		"wlf,ldo1ena", /* WM8994 */
 		"wlf,ldo2ena", /* WM8994 */
 	};
-	const struct device_node *np = dev->of_node;
-	struct gpio_desc *desc;
 	int i;
 
 	if (!IS_ENABLED(CONFIG_REGULATOR))
@@ -461,11 +454,10 @@ static struct gpio_desc *of_find_regulator_gpio(struct device *dev,
 	if (i < 0)
 		return ERR_PTR(-ENOENT);
 
-	desc = of_get_named_gpiod_flags(np, con_id, idx, of_flags);
-	return desc;
+	return of_get_named_gpiod_flags(np, con_id, idx, of_flags);
 }
 
-static struct gpio_desc *of_find_arizona_gpio(struct device *dev,
+static struct gpio_desc *of_find_arizona_gpio(struct device_node *np,
 					      const char *con_id,
 					      unsigned int idx,
 					      enum of_gpio_flags *of_flags)
@@ -476,10 +468,10 @@ static struct gpio_desc *of_find_arizona_gpio(struct device *dev,
 	if (!con_id || strcmp(con_id, "wlf,reset"))
 		return ERR_PTR(-ENOENT);
 
-	return of_get_named_gpiod_flags(dev->of_node, con_id, idx, of_flags);
+	return of_get_named_gpiod_flags(np, con_id, idx, of_flags);
 }
 
-static struct gpio_desc *of_find_usb_gpio(struct device *dev,
+static struct gpio_desc *of_find_usb_gpio(struct device_node *np,
 					  const char *con_id,
 					  unsigned int idx,
 					  enum of_gpio_flags *of_flags)
@@ -495,14 +487,27 @@ static struct gpio_desc *of_find_usb_gpio(struct device *dev,
 	if (!con_id || strcmp(con_id, "fcs,int_n"))
 		return ERR_PTR(-ENOENT);
 
-	return of_get_named_gpiod_flags(dev->of_node, con_id, idx, of_flags);
+	return of_get_named_gpiod_flags(np, con_id, idx, of_flags);
 }
 
+typedef struct gpio_desc *(*of_find_gpio_quirk)(struct device_node *np,
+						const char *con_id,
+						unsigned int idx,
+						enum of_gpio_flags *of_flags);
+static const of_find_gpio_quirk of_find_gpio_quirks[] = {
+	of_find_spi_gpio,
+	of_find_spi_cs_gpio,
+	of_find_regulator_gpio,
+	of_find_arizona_gpio,
+	of_find_usb_gpio,
+};
+
 struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
 			       unsigned int idx, unsigned long *flags)
 {
 	char prop_name[32]; /* 32 is max size of property name */
 	enum of_gpio_flags of_flags;
+	const of_find_gpio_quirk *q;
 	struct gpio_desc *desc;
 	unsigned int i;
 
@@ -522,24 +527,9 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
 			break;
 	}
 
-	if (gpiod_not_found(desc)) {
-		/* Special handling for SPI GPIOs if used */
-		desc = of_find_spi_gpio(dev, con_id, idx, &of_flags);
-	}
-
-	if (gpiod_not_found(desc))
-		desc = of_find_spi_cs_gpio(dev, con_id, idx, &of_flags);
-
-	if (gpiod_not_found(desc)) {
-		/* Special handling for regulator GPIOs if used */
-		desc = of_find_regulator_gpio(dev, con_id, idx, &of_flags);
-	}
-
-	if (gpiod_not_found(desc))
-		desc = of_find_arizona_gpio(dev, con_id, idx, &of_flags);
-
-	if (gpiod_not_found(desc))
-		desc = of_find_usb_gpio(dev, con_id, idx, &of_flags);
+	/* Properly named GPIO was not found, try workarounds */
+	for (q = of_find_gpio_quirks; gpiod_not_found(desc) && *q; q++)
+		desc = (*q)(dev->of_node, con_id, idx, &of_flags);
 
 	if (IS_ERR(desc))
 		return desc;