gpio: Factor out DT flag translation

The generic GPIO flags binding is shared across many drivers, some of
which need their own xlate function. Factor out the flag translation
code from gpio_xlate_offs_flags so it does not need to be duplicated.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index fde046e..1c5e2e7 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -186,6 +186,34 @@
 	return 0;
 }
 
+unsigned long gpio_flags_xlate(uint32_t arg)
+{
+	unsigned long flags = 0;
+
+	if (arg & GPIO_ACTIVE_LOW)
+		flags |= GPIOD_ACTIVE_LOW;
+
+	/*
+	 * need to test 2 bits for gpio output binding:
+	 * OPEN_DRAIN (0x6) = SINGLE_ENDED (0x2) | LINE_OPEN_DRAIN (0x4)
+	 * OPEN_SOURCE (0x2) = SINGLE_ENDED (0x2) | LINE_OPEN_SOURCE (0x0)
+	 */
+	if (arg & GPIO_SINGLE_ENDED) {
+		if (arg & GPIO_LINE_OPEN_DRAIN)
+			flags |= GPIOD_OPEN_DRAIN;
+		else
+			flags |= GPIOD_OPEN_SOURCE;
+	}
+
+	if (arg & GPIO_PULL_UP)
+		flags |= GPIOD_PULL_UP;
+
+	if (arg & GPIO_PULL_DOWN)
+		flags |= GPIOD_PULL_DOWN;
+
+	return flags;
+}
+
 int gpio_xlate_offs_flags(struct udevice *dev, struct gpio_desc *desc,
 			  struct ofnode_phandle_args *args)
 {
@@ -201,27 +229,7 @@
 	if (args->args_count < 2)
 		return 0;
 
-	desc->flags = 0;
-	if (args->args[1] & GPIO_ACTIVE_LOW)
-		desc->flags |= GPIOD_ACTIVE_LOW;
-
-	/*
-	 * need to test 2 bits for gpio output binding:
-	 * OPEN_DRAIN (0x6) = SINGLE_ENDED (0x2) | LINE_OPEN_DRAIN (0x4)
-	 * OPEN_SOURCE (0x2) = SINGLE_ENDED (0x2) | LINE_OPEN_SOURCE (0x0)
-	 */
-	if (args->args[1] & GPIO_SINGLE_ENDED) {
-		if (args->args[1] & GPIO_LINE_OPEN_DRAIN)
-			desc->flags |= GPIOD_OPEN_DRAIN;
-		else
-			desc->flags |= GPIOD_OPEN_SOURCE;
-	}
-
-	if (args->args[1] & GPIO_PULL_UP)
-		desc->flags |= GPIOD_PULL_UP;
-
-	if (args->args[1] & GPIO_PULL_DOWN)
-		desc->flags |= GPIOD_PULL_DOWN;
+	desc->flags = gpio_flags_xlate(args->args[1]);
 
 	return 0;
 }