drm/omap: encoder-tfp410: Convert to the GPIO descriptors API

The GPIO descriptor API is favoured over the plain GPIO API for consumer
drivers. Using it simplifies the driver code.

As the descriptor API handles the active-low flag internally we need to
invert the polarity of all GPIO operations in the driver.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/displays/encoder-tfp410.c

@@ -13,14 +13,13 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
-#include <linux/of_gpio.h>
 
 #include "../dss/omapdss.h"
 
 struct panel_drv_data {
 	struct omap_dss_device dssdev;
 
-	int pd_gpio;
+	struct gpio_desc *pd_gpio;
 
 	struct videomode vm;
 };
@@ -57,8 +56,8 @@ static int tfp410_enable(struct omap_dss_device *dssdev)
 	if (r)
 		return r;
 
-	if (gpio_is_valid(ddata->pd_gpio))
-		gpio_set_value_cansleep(ddata->pd_gpio, 1);
+	if (ddata->pd_gpio)
+		gpiod_set_value_cansleep(ddata->pd_gpio, 0);
 
 	dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
 
@@ -73,8 +72,8 @@ static void tfp410_disable(struct omap_dss_device *dssdev)
 	if (!omapdss_device_is_enabled(dssdev))
 		return;
 
-	if (gpio_is_valid(ddata->pd_gpio))
-		gpio_set_value_cansleep(ddata->pd_gpio, 0);
+	if (ddata->pd_gpio)
+		gpiod_set_value_cansleep(ddata->pd_gpio, 0);
 
 	src->ops->disable(src);
 
@@ -119,30 +118,11 @@ static const struct omap_dss_device_ops tfp410_ops = {
 	.set_timings	= tfp410_set_timings,
 };
 
-static int tfp410_probe_of(struct platform_device *pdev)
-{
-	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
-	struct device_node *node = pdev->dev.of_node;
-	int gpio;
-
-	gpio = of_get_named_gpio(node, "powerdown-gpios", 0);
-
-	if (gpio_is_valid(gpio) || gpio == -ENOENT) {
-		ddata->pd_gpio = gpio;
-	} else {
-		if (gpio != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "failed to parse PD gpio\n");
-		return gpio;
-	}
-
-	return 0;
-}
-
 static int tfp410_probe(struct platform_device *pdev)
 {
 	struct panel_drv_data *ddata;
 	struct omap_dss_device *dssdev;
-	int r;
+	struct gpio_desc *gpio;
 
 	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
 	if (!ddata)
@@ -150,20 +130,15 @@ static int tfp410_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, ddata);
 
-	r = tfp410_probe_of(pdev);
-	if (r)
-		return r;
-
-	if (gpio_is_valid(ddata->pd_gpio)) {
-		r = devm_gpio_request_one(&pdev->dev, ddata->pd_gpio,
-				GPIOF_OUT_INIT_LOW, "tfp410 PD");
-		if (r) {
-			dev_err(&pdev->dev, "Failed to request PD GPIO %d\n",
-					ddata->pd_gpio);
-			return r;
-		}
+	/* Powerdown GPIO */
+	gpio = devm_gpiod_get_optional(&pdev->dev, "powerdown", GPIOD_OUT_HIGH);
+	if (IS_ERR(gpio)) {
+		dev_err(&pdev->dev, "failed to parse powerdown gpio\n");
+		return PTR_ERR(gpio);
 	}
 
+	ddata->pd_gpio = gpio;
+
 	dssdev = &ddata->dssdev;
 	dssdev->ops = &tfp410_ops;
 	dssdev->dev = &pdev->dev;