drm/panel: use gpiod interface for enable GPIO

Use the new GPIO descriptor interface to handle the panel's enable GPIO.
This considerably simplifies the code.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
[treding@nvidia.com: rework to improve readability]
Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 0231945c29340ceb083915e8ebdf6d04a94309a8..87cc238c8a8515c3c899818a5af366837d6bb96f 100644 (file)
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -22,9 +22,8 @@
  */
 
 #include <linux/backlight.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/module.h>
-#include <linux/of_gpio.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
@@ -44,9 +43,6 @@ struct panel_desc {
        } size;
 };
 
-/* TODO: convert to gpiod_*() API once it's been merged */
-#define GPIO_ACTIVE_LOW        (1 << 0)
-
 struct panel_simple {
        struct drm_panel base;
        bool enabled;
@@ -57,8 +53,7 @@ struct panel_simple {
        struct regulator *supply;
        struct i2c_adapter *ddc;
 
-       unsigned long enable_gpio_flags;
-       int enable_gpio;
+       struct gpio_desc *enable_gpio;
 };
 
 static inline struct panel_simple *to_panel_simple(struct drm_panel *panel)
@@ -110,12 +105,8 @@ static int panel_simple_disable(struct drm_panel *panel)
                backlight_update_status(p->backlight);
        }
 
-       if (gpio_is_valid(p->enable_gpio)) {
-               if (p->enable_gpio_flags & GPIO_ACTIVE_LOW)
-                       gpio_set_value(p->enable_gpio, 1);
-               else
-                       gpio_set_value(p->enable_gpio, 0);
-       }
+       if (p->enable_gpio)
+               gpiod_set_value(p->enable_gpio, 0);
 
        regulator_disable(p->supply);
        p->enabled = false;
@@ -137,12 +128,8 @@ static int panel_simple_enable(struct drm_panel *panel)
                return err;
        }
 
-       if (gpio_is_valid(p->enable_gpio)) {
-               if (p->enable_gpio_flags & GPIO_ACTIVE_LOW)
-                       gpio_set_value(p->enable_gpio, 0);
-               else
-                       gpio_set_value(p->enable_gpio, 1);
-       }
+       if (p->enable_gpio)
+               gpiod_set_value(p->enable_gpio, 1);
 
        if (p->backlight) {
                p->backlight->props.power = FB_BLANK_UNBLANK;
@@ -185,7 +172,6 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
 {
        struct device_node *backlight, *ddc;
        struct panel_simple *panel;
-       enum of_gpio_flags flags;
        int err;
 
        panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
@@ -199,29 +185,20 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
        if (IS_ERR(panel->supply))
                return PTR_ERR(panel->supply);
 
-       panel->enable_gpio = of_get_named_gpio_flags(dev->of_node,
-                                                    "enable-gpios", 0,
-                                                    &flags);
-       if (gpio_is_valid(panel->enable_gpio)) {
-               unsigned int value;
-
-               if (flags & OF_GPIO_ACTIVE_LOW)
-                       panel->enable_gpio_flags |= GPIO_ACTIVE_LOW;
-
-               err = gpio_request(panel->enable_gpio, "enable");
-               if (err < 0) {
-                       dev_err(dev, "failed to request GPIO#%u: %d\n",
-                               panel->enable_gpio, err);
+       panel->enable_gpio = devm_gpiod_get(dev, "enable");
+       if (IS_ERR(panel->enable_gpio)) {
+               err = PTR_ERR(panel->enable_gpio);
+               if (err != -ENOENT) {
+                       dev_err(dev, "failed to request GPIO: %d\n", err);
                        return err;
                }
 
-               value = (panel->enable_gpio_flags & GPIO_ACTIVE_LOW) != 0;
-
-               err = gpio_direction_output(panel->enable_gpio, value);
+               panel->enable_gpio = NULL;
+       } else {
+               err = gpiod_direction_output(panel->enable_gpio, 0);
                if (err < 0) {
-                       dev_err(dev, "failed to setup GPIO%u: %d\n",
-                               panel->enable_gpio, err);
-                       goto free_gpio;
+                       dev_err(dev, "failed to setup GPIO: %d\n", err);
+                       return err;
                }
        }
 
@@ -230,10 +207,8 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
                panel->backlight = of_find_backlight_by_node(backlight);
                of_node_put(backlight);
 
-               if (!panel->backlight) {
-                       err = -EPROBE_DEFER;
-                       goto free_gpio;
-               }
+               if (!panel->backlight)
+                       return -EPROBE_DEFER;
        }
 
        ddc = of_parse_phandle(dev->of_node, "ddc-i2c-bus", 0);
@@ -265,9 +240,6 @@ free_ddc:
 free_backlight:
        if (panel->backlight)
                put_device(&panel->backlight->dev);
-free_gpio:
-       if (gpio_is_valid(panel->enable_gpio))
-               gpio_free(panel->enable_gpio);
 
        return err;
 }
@@ -287,9 +259,6 @@ static int panel_simple_remove(struct device *dev)
        if (panel->backlight)
                put_device(&panel->backlight->dev);
 
-       if (gpio_is_valid(panel->enable_gpio))
-               gpio_free(panel->enable_gpio);
-
        regulator_disable(panel->supply);
 
        return 0;