drm/omap: panel-tpo-td043mtea1: 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. Rename the
nreset_gpio field to reset_gpio to reflect that.

The reset GPIO is mandatory, so drop conditional tests through 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/panel-tpo-td043mtea1.c

@@ -10,14 +10,13 @@
  * (at your option) any later version.
  */
 
-#include <linux/module.h>
 #include <linux/delay.h>
-#include <linux/spi/spi.h>
-#include <linux/regulator/consumer.h>
-#include <linux/gpio/consumer.h>
 #include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
 #include <linux/slab.h>
-#include <linux/of_gpio.h>
+#include <linux/spi/spi.h>
 
 #include "../dss/omapdss.h"
 
@@ -59,7 +58,7 @@ struct panel_drv_data {
 
 	struct spi_device *spi;
 	struct regulator *vcc_reg;
-	int nreset_gpio;
+	struct gpio_desc *reset_gpio;
 	u16 gamma[12];
 	u32 mode;
 	u32 vmirror:1;
@@ -282,8 +281,7 @@ static int tpo_td043_power_on(struct panel_drv_data *ddata)
 	/* wait for panel to stabilize */
 	msleep(160);
 
-	if (gpio_is_valid(ddata->nreset_gpio))
-		gpio_set_value(ddata->nreset_gpio, 1);
+	gpiod_set_value(ddata->reset_gpio, 0);
 
 	tpo_td043_write(ddata->spi, 2,
 			TPO_R02_MODE(ddata->mode) | TPO_R02_NCLK_RISING);
@@ -305,8 +303,7 @@ static void tpo_td043_power_off(struct panel_drv_data *ddata)
 	tpo_td043_write(ddata->spi, 3,
 			TPO_R03_VAL_STANDBY | TPO_R03_EN_PWM);
 
-	if (gpio_is_valid(ddata->nreset_gpio))
-		gpio_set_value(ddata->nreset_gpio, 0);
+	gpiod_set_value(ddata->reset_gpio, 1);
 
 	/* wait for at least 2 vsyncs before cutting off power */
 	msleep(50);
@@ -419,26 +416,11 @@ static const struct omap_dss_driver tpo_td043_ops = {
 	.check_timings	= tpo_td043_check_timings,
 };
 
-static int tpo_td043_probe_of(struct spi_device *spi)
-{
-	struct device_node *node = spi->dev.of_node;
-	struct panel_drv_data *ddata = dev_get_drvdata(&spi->dev);
-	int gpio;
-
-	gpio = of_get_named_gpio(node, "reset-gpios", 0);
-	if (!gpio_is_valid(gpio)) {
-		dev_err(&spi->dev, "failed to parse enable gpio\n");
-		return gpio;
-	}
-	ddata->nreset_gpio = gpio;
-
-	return 0;
-}
-
 static int tpo_td043_probe(struct spi_device *spi)
 {
 	struct panel_drv_data *ddata;
 	struct omap_dss_device *dssdev;
+	struct gpio_desc *gpio;
 	int r;
 
 	dev_dbg(&spi->dev, "%s\n", __func__);
@@ -460,10 +442,6 @@ static int tpo_td043_probe(struct spi_device *spi)
 
 	ddata->spi = spi;
 
-	r = tpo_td043_probe_of(spi);
-	if (r)
-		return r;
-
 	ddata->mode = TPO_R02_MODE_800x480;
 	memcpy(ddata->gamma, tpo_td043_def_gamma, sizeof(ddata->gamma));
 
@@ -473,16 +451,14 @@ static int tpo_td043_probe(struct spi_device *spi)
 		return PTR_ERR(ddata->vcc_reg);
 	}
 
-	if (gpio_is_valid(ddata->nreset_gpio)) {
-		r = devm_gpio_request_one(&spi->dev,
-				ddata->nreset_gpio, GPIOF_OUT_INIT_LOW,
-				"lcd reset");
-		if (r < 0) {
-			dev_err(&spi->dev, "couldn't request reset GPIO\n");
-			return r;
-		}
+	gpio = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(gpio)) {
+		dev_err(&spi->dev, "failed to get reset gpio\n");
+		return PTR_ERR(gpio);
 	}
 
+	ddata->reset_gpio = gpio;
+
 	r = sysfs_create_group(&spi->dev.kobj, &tpo_td043_attr_group);
 	if (r) {
 		dev_err(&spi->dev, "failed to create sysfs files\n");