[PATCH v1 1/3] drm/panel: update backlight handling for samsung-s6e3ha2

[Sam Ravnborg]

The samsung-s6e3ha2 had a local way to handle backlight.

Update the driver to use a devm_ based register function
and utilize drm_panel backlight support. The changes results
in a simpler driver with the same functionality.

Signed-off-by: Sam Ravnborg <sam at ravnborg.org>
Cc: Joonas Kylmälä <joonas.kylmala at iki.fi>
Cc: Andrzej Hajda <a.hajda at samsung.com>
Cc: Thierry Reding <thierry.reding at gmail.com>
Cc: Inki Dae <inki.dae at samsung.com>
Cc: Hyungwon Hwang <human.hwang at samsung.com>
Cc: Hoegeun Kwon <hoegeun.kwon at samsung.com>
---
 drivers/gpu/drm/panel/panel-samsung-s6e3ha2.c | 55 +++++++++++--------
 1 file changed, 31 insertions(+), 24 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-samsung-s6e3ha2.c b/drivers/gpu/drm/panel/panel-samsung-s6e3ha2.c
index 36ebd5a4ac7b..08862146aec3 100644
--- a/drivers/gpu/drm/panel/panel-samsung-s6e3ha2.c
+++ b/drivers/gpu/drm/panel/panel-samsung-s6e3ha2.c
@@ -233,7 +233,6 @@ struct s6e3ha2_panel_desc {
 struct s6e3ha2 {
 	struct device *dev;
 	struct drm_panel panel;
-	struct backlight_device *bl_dev;
 
 	struct regulator_bulk_data supplies[2];
 	struct gpio_desc *reset_gpio;
@@ -415,7 +414,7 @@ static int s6e3ha2_get_brightness(struct backlight_device *bl_dev)
 
 static int s6e3ha2_set_vint(struct s6e3ha2 *ctx)
 {
-	struct backlight_device *bl_dev = ctx->bl_dev;
+	struct backlight_device *bl_dev = ctx->panel.backlight;
 	unsigned int brightness = bl_dev->props.brightness;
 	unsigned char data[] = { 0xf4, 0x8b,
 			vint_table[brightness * (S6E3HA2_VINT_STATUS_MAX - 1) /
@@ -432,7 +431,7 @@ static unsigned int s6e3ha2_get_brightness_index(unsigned int brightness)
 
 static int s6e3ha2_update_gamma(struct s6e3ha2 *ctx, unsigned int brightness)
 {
-	struct backlight_device *bl_dev = ctx->bl_dev;
+	struct backlight_device *bl_dev = ctx->panel.backlight;
 	unsigned int index = s6e3ha2_get_brightness_index(brightness);
 	u8 data[S6E3HA2_GAMMA_CMD_CNT + 1] = { 0xca, };
 	int ret;
@@ -476,6 +475,30 @@ static const struct backlight_ops s6e3ha2_bl_ops = {
 	.update_status = s6e3ha2_set_brightness,
 };
 
+static int s6e3ha2_backlight_register(struct s6e3ha2 *ctx)
+{
+	struct backlight_properties props = {
+		.type		= BACKLIGHT_RAW,
+		.brightness	= S6E3HA2_DEFAULT_BRIGHTNESS,
+		.max_brightness	= S6E3HA2_MAX_BRIGHTNESS,
+	};
+	struct backlight_device *backlight;
+	struct device *dev = ctx->dev;
+	int ret = 0;
+
+	backlight = devm_backlight_device_register(dev, "panel", dev, ctx,
+						   &s6e3ha2_bl_ops,
+						   &props);
+	if (IS_ERR(backlight)) {
+		ret = PTR_ERR(backlight);
+		DRM_DEV_ERROR(dev, "error registering backlight device (%d)\n",
+			      ret);
+	}
+	ctx->panel.backlight = backlight;
+
+	return ret;
+}
+
 static int s6e3ha2_panel_init(struct s6e3ha2 *ctx)
 {
 	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
@@ -509,7 +532,6 @@ static int s6e3ha2_disable(struct drm_panel *panel)
 	s6e3ha2_call_write_func(ret, mipi_dsi_dcs_set_display_off(dsi));
 
 	msleep(40);
-	ctx->bl_dev->props.power = FB_BLANK_NORMAL;
 
 	return 0;
 }
@@ -555,8 +577,6 @@ static int s6e3ha2_prepare(struct drm_panel *panel)
 	if (ret < 0)
 		goto err;
 
-	ctx->bl_dev->props.power = FB_BLANK_NORMAL;
-
 	return 0;
 
 err:
@@ -588,7 +608,6 @@ static int s6e3ha2_enable(struct drm_panel *panel)
 	s6e3ha2_call_write_func(ret, s6e3ha2_te_start_setting(ctx));
 
 	/* brightness setting */
-	s6e3ha2_call_write_func(ret, s6e3ha2_set_brightness(ctx->bl_dev));
 	s6e3ha2_call_write_func(ret, s6e3ha2_aor_control(ctx));
 	s6e3ha2_call_write_func(ret, s6e3ha2_caps_elvss_set(ctx));
 	s6e3ha2_call_write_func(ret, s6e3ha2_gamma_update(ctx));
@@ -602,7 +621,6 @@ static int s6e3ha2_enable(struct drm_panel *panel)
 	s6e3ha2_call_write_func(ret, s6e3ha2_test_key_off_f0(ctx));
 
 	s6e3ha2_call_write_func(ret, mipi_dsi_dcs_set_display_on(dsi));
-	ctx->bl_dev->props.power = FB_BLANK_UNBLANK;
 
 	return 0;
 }
@@ -721,23 +739,16 @@ static int s6e3ha2_probe(struct mipi_dsi_device *dsi)
 		return PTR_ERR(ctx->enable_gpio);
 	}
 
-	ctx->bl_dev = backlight_device_register("s6e3ha2", dev, ctx,
-						&s6e3ha2_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 = S6E3HA2_MAX_BRIGHTNESS;
-	ctx->bl_dev->props.brightness = S6E3HA2_DEFAULT_BRIGHTNESS;
-	ctx->bl_dev->props.power = FB_BLANK_POWERDOWN;
-
 	drm_panel_init(&ctx->panel, dev, &s6e3ha2_drm_funcs,
 		       DRM_MODE_CONNECTOR_DSI);
 
+	ret = s6e3ha2_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)
@@ -748,9 +759,6 @@ static int s6e3ha2_probe(struct mipi_dsi_device *dsi)
 remove_panel:
 	drm_panel_remove(&ctx->panel);
 
-unregister_backlight:
-	backlight_device_unregister(ctx->bl_dev);
-
 	return ret;
 }
 
@@ -760,7 +768,6 @@ static int s6e3ha2_remove(struct mipi_dsi_device *dsi)
 
 	mipi_dsi_detach(dsi);
 	drm_panel_remove(&ctx->panel);
-	backlight_device_unregister(ctx->bl_dev);
 
 	return 0;
 }
-- 
2.20.1