dm: exynos: Add a GPIO translation function

This deals with the polarity bit. It also changes the GPIO devices so that
the correct device tree node is linked to each one. This allows us to use
the new uclass phandle functionality to implement a proper GPIO binding.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/gpio/s5p_gpio.c

@@ -13,6 +13,7 @@
 #include <asm/io.h>
 #include <asm/gpio.h>
 #include <dm/device-internal.h>
+#include <dt-bindings/gpio/gpio.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -275,12 +276,22 @@ static int exynos_gpio_get_function(struct udevice *dev, unsigned offset)
 		return GPIOF_FUNC;
 }
 
+static int exynos_gpio_xlate(struct udevice *dev, struct gpio_desc *desc,
+			     struct fdtdec_phandle_args *args)
+{
+	desc->offset = args->args[0];
+	desc->flags = args->args[1] & GPIO_ACTIVE_LOW ? GPIOD_ACTIVE_LOW : 0;
+
+	return 0;
+}
+
 static const struct dm_gpio_ops gpio_exynos_ops = {
 	.direction_input	= exynos_gpio_direction_input,
 	.direction_output	= exynos_gpio_direction_output,
 	.get_value		= exynos_gpio_get_value,
 	.set_value		= exynos_gpio_set_value,
 	.get_function		= exynos_gpio_get_function,
+	.xlate			= exynos_gpio_xlate,
 };
 
 static int gpio_exynos_probe(struct udevice *dev)
@@ -342,7 +353,7 @@ static int gpio_exynos_bind(struct udevice *parent)
 					plat->bank_name, plat, -1, &dev);
 		if (ret)
 			return ret;
-		dev->of_offset = parent->of_offset;
+		dev->of_offset = node;
 	}
 
 	return 0;