[PATCH v1 12/22] drm/panel: samsung-s6e63j0x03: Backlight update

[Sam Ravnborg]

- Use backlight support from drm_panel.
  This shifts this driver away from manually handling of power state.
- Add helper function for registering backlight, like other samsung
  panel drivers do.
- Use devm_ for backlight register thus benefit from automatic
  unregistering. Drop all explicit unregistering.

Signed-off-by: Sam Ravnborg <sam at ravnborg.org>
Cc: Thierry Reding <thierry.reding at gmail.com>
Cc: Hoegeun Kwon <hoegeun.kwon at samsung.com>
Cc: Inki Dae <inki.dae at samsung.com>
Cc: Sam Ravnborg <sam at ravnborg.org>
---
 .../gpu/drm/panel/panel-samsung-s6e63j0x03.c  | 56 +++++++++----------
 1 file changed, 25 insertions(+), 31 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-samsung-s6e63j0x03.c b/drivers/gpu/drm/panel/panel-samsung-s6e63j0x03.c
index a3570e0a90a8..f8dbb1cf1429 100644
--- a/drivers/gpu/drm/panel/panel-samsung-s6e63j0x03.c
+++ b/drivers/gpu/drm/panel/panel-samsung-s6e63j0x03.c
@@ -36,7 +36,6 @@
 struct s6e63j0x03 {
 	struct device *dev;
 	struct drm_panel panel;
-	struct backlight_device *bl_dev;
 
 	struct regulator_bulk_data supplies[2];
 	struct gpio_desc *reset_gpio;
@@ -181,10 +180,8 @@ static unsigned int s6e63j0x03_get_brightness_index(unsigned int brightness)
 	return index;
 }
 
-static int s6e63j0x03_update_gamma(struct s6e63j0x03 *ctx,
-					unsigned int brightness)
+static int s6e63j0x03_update_gamma(struct s6e63j0x03 *ctx, int brightness)
 {
-	struct backlight_device *bl_dev = ctx->bl_dev;
 	unsigned int index = s6e63j0x03_get_brightness_index(brightness);
 	int ret;
 
@@ -200,15 +197,13 @@ static int s6e63j0x03_update_gamma(struct s6e63j0x03 *ctx,
 	if (ret < 0)
 		return ret;
 
-	bl_dev->props.brightness = brightness;
-
 	return 0;
 }
 
 static int s6e63j0x03_set_brightness(struct backlight_device *bl_dev)
 {
 	struct s6e63j0x03 *ctx = bl_get_data(bl_dev);
-	unsigned int brightness = bl_dev->props.brightness;
+	unsigned int brightness = backlight_get_brightness(bl_dev);
 
 	return s6e63j0x03_update_gamma(ctx, brightness);
 }
@@ -227,8 +222,6 @@ static int s6e63j0x03_disable(struct drm_panel *panel)
 	if (ret < 0)
 		return ret;
 
-	ctx->bl_dev->props.power = FB_BLANK_NORMAL;
-
 	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
 	if (ret < 0)
 		return ret;
@@ -247,8 +240,6 @@ static int s6e63j0x03_unprepare(struct drm_panel *panel)
 	if (ret < 0)
 		return ret;
 
-	ctx->bl_dev->props.power = FB_BLANK_POWERDOWN;
-
 	return 0;
 }
 
@@ -334,8 +325,6 @@ static int s6e63j0x03_prepare(struct drm_panel *panel)
 	if (ret < 0)
 		goto err;
 
-	ctx->bl_dev->props.power = FB_BLANK_NORMAL;
-
 	return 0;
 
 err:
@@ -395,8 +384,6 @@ static int s6e63j0x03_enable(struct drm_panel *panel)
 	if (ret < 0)
 		return ret;
 
-	ctx->bl_dev->props.power = FB_BLANK_UNBLANK;
-
 	return 0;
 }
 
@@ -432,6 +419,25 @@ static const struct drm_panel_funcs s6e63j0x03_funcs = {
 	.get_modes = s6e63j0x03_get_modes,
 };
 
+static int s6e63j0x03_backlight_register(struct s6e63j0x03 *ctx)
+{
+	DECLARE_BACKLIGHT_INIT_RAW(props, DEFAULT_BRIGHTNESS, MAX_BRIGHTNESS);
+	struct device *dev = ctx->dev;
+	struct backlight_device *bd;
+	int ret = 0;
+
+	bd = devm_backlight_device_register(dev, "panel", dev, ctx,
+					    &s6e63j0x03_bl_ops, &props);
+	if (IS_ERR(bd)) {
+		ret = PTR_ERR(bd);
+		DRM_DEV_ERROR(dev, "error registering backlight device (%d)\n", ret);
+		return ret;
+	}
+
+	ctx->panel.backlight = bd;
+	return ret;
+}
+
 static int s6e63j0x03_probe(struct mipi_dsi_device *dsi)
 {
 	struct device *dev = &dsi->dev;
@@ -469,20 +475,13 @@ static int s6e63j0x03_probe(struct mipi_dsi_device *dsi)
 	drm_panel_init(&ctx->panel, dev, &s6e63j0x03_funcs,
 		       DRM_MODE_CONNECTOR_DSI);
 
-	ctx->bl_dev = backlight_device_register("s6e63j0x03", dev, ctx,
-						&s6e63j0x03_bl_ops, NULL);
-	if (IS_ERR(ctx->bl_dev)) {
-		dev_err(dev, "failed to register backlight device\n");
-		return PTR_ERR(ctx->bl_dev);
-	}
-
-	ctx->bl_dev->props.max_brightness = MAX_BRIGHTNESS;
-	ctx->bl_dev->props.brightness = DEFAULT_BRIGHTNESS;
-	ctx->bl_dev->props.power = FB_BLANK_POWERDOWN;
+	ret = s6e63j0x03_backlight_register(ctx);
+	if (ret)
+		return ret;
 
 	ret = drm_panel_add(&ctx->panel);
 	if (ret < 0)
-		goto unregister_backlight;
+		return ret;
 
 	ret = mipi_dsi_attach(dsi);
 	if (ret < 0)
@@ -493,9 +492,6 @@ static int s6e63j0x03_probe(struct mipi_dsi_device *dsi)
 remove_panel:
 	drm_panel_remove(&ctx->panel);
 
-unregister_backlight:
-	backlight_device_unregister(ctx->bl_dev);
-
 	return ret;
 }
 
@@ -506,8 +502,6 @@ static int s6e63j0x03_remove(struct mipi_dsi_device *dsi)
 	mipi_dsi_detach(dsi);
 	drm_panel_remove(&ctx->panel);
 
-	backlight_device_unregister(ctx->bl_dev);
-
 	return 0;
 }
 
-- 
2.25.1