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>

1 files changed, 18 insertions, 49 deletions

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 0231945c2934..87cc238c8a85 100644
--- 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;