gpiolib: Extract gpiod_not_found() helper

Several places in the code are using same idiom, i.e.
	IS_ERR(desc) && PTR_ERR(desc) == -ENOENT
which meaning is GPIO description is not found.

For better readability extract gpiod_not_found() helper and use it.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

drivers/gpio/gpiolib-devres.c

@@ -246,10 +246,8 @@ struct gpio_desc *__must_check devm_gpiod_get_index_optional(struct device *dev,
 	struct gpio_desc *desc;
 
 	desc = devm_gpiod_get_index(dev, con_id, index, flags);
-	if (IS_ERR(desc)) {
-		if (PTR_ERR(desc) == -ENOENT)
+	if (gpiod_not_found(desc))
 		return NULL;
-	}
 
 	return desc;
 }
@@ -308,7 +306,7 @@ devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
 	struct gpio_descs *descs;
 
 	descs = devm_gpiod_get_array(dev, con_id, flags);
-	if (PTR_ERR(descs) == -ENOENT)
+	if (gpiod_not_found(descs))
 		return NULL;
 
 	return descs;

drivers/gpio/gpiolib-of.c

@@ -509,31 +509,31 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
 		desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
 						&of_flags);
 
-		if (!IS_ERR(desc) || PTR_ERR(desc) != -ENOENT)
+		if (!gpiod_not_found(desc))
 			break;
 	}
 
-	if (PTR_ERR(desc) == -ENOENT) {
+	if (gpiod_not_found(desc)) {
 		/* Special handling for SPI GPIOs if used */
 		desc = of_find_spi_gpio(dev, con_id, &of_flags);
 	}
 
-	if (PTR_ERR(desc) == -ENOENT) {
+	if (gpiod_not_found(desc)) {
 		/* This quirk looks up flags and all */
 		desc = of_find_spi_cs_gpio(dev, con_id, idx, flags);
 		if (!IS_ERR(desc))
 			return desc;
 	}
 
-	if (PTR_ERR(desc) == -ENOENT) {
+	if (gpiod_not_found(desc)) {
 		/* Special handling for regulator GPIOs if used */
 		desc = of_find_regulator_gpio(dev, con_id, &of_flags);
 	}
 
-	if (PTR_ERR(desc) == -ENOENT)
+	if (gpiod_not_found(desc))
 		desc = of_find_arizona_gpio(dev, con_id, &of_flags);
 
-	if (PTR_ERR(desc) == -ENOENT)
+	if (gpiod_not_found(desc))
 		desc = of_find_usb_gpio(dev, con_id, &of_flags);
 
 	if (IS_ERR(desc))

drivers/gpio/gpiolib.c

@@ -3767,7 +3767,7 @@ struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
 
 		desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
 					      label);
-		if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
+		if (!gpiod_not_found(desc))
 			break;
 	}
 
@@ -3943,7 +3943,7 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
 	 * Either we are not using DT or ACPI, or their lookup did not return
 	 * a result. In that case, use platform lookup as a fallback.
 	 */
-	if (!desc || desc == ERR_PTR(-ENOENT)) {
+	if (!desc || gpiod_not_found(desc)) {
 		dev_dbg(dev, "using lookup tables for GPIO lookup\n");
 		desc = gpiod_find(dev, con_id, idx, &lookupflags);
 	}
@@ -4078,10 +4078,8 @@ struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
 	struct gpio_desc *desc;
 
 	desc = gpiod_get_index(dev, con_id, index, flags);
-	if (IS_ERR(desc)) {
-		if (PTR_ERR(desc) == -ENOENT)
+	if (gpiod_not_found(desc))
 		return NULL;
-	}
 
 	return desc;
 }
@@ -4283,7 +4281,7 @@ struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
 	struct gpio_descs *descs;
 
 	descs = gpiod_get_array(dev, con_id, flags);
-	if (PTR_ERR(descs) == -ENOENT)
+	if (gpiod_not_found(descs))
 		return NULL;
 
 	return descs;

drivers/gpio/gpiolib.h

@@ -130,6 +130,8 @@ struct gpio_desc {
 #endif
 };
 
+#define gpiod_not_found(desc)		(IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
+
 int gpiod_request(struct gpio_desc *desc, const char *label);
 void gpiod_free(struct gpio_desc *desc);
 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,