From 40e53d108391d5692a4e57ff4cb41d76dcc78c8f Mon Sep 17 00:00:00 2001
From: Sandy Huang <hjc@rock-chips.com>
Date: Mon, 1 Jul 2019 17:59:06 +0800
Subject: [PATCH] drm/panel: add panel loader protest

Change-Id: I4abb3739144b5a3c99fd57d76e0ff87ccb664667
Signed-off-by: Sandy Huang <hjc@rock-chips.com>
---
 drivers/gpu/drm/panel/panel-simple.c | 72 +++++++++++++++++++++++++++-
 include/drm/drm_panel.h              | 10 ++++
 2 files changed, 80 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 29342ed5ea9e..3486431dd935 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -80,6 +80,7 @@ struct panel_simple {
 	struct drm_panel base;
 	bool prepared;
 	bool enabled;
+	bool power_invert;
 
 	const struct panel_desc *desc;
 
@@ -160,6 +161,69 @@ static int panel_simple_get_fixed_modes(struct panel_simple *panel)
 	return num;
 }
 
+static int panel_simple_regulator_enable(struct drm_panel *panel)
+{
+	struct panel_simple *p = to_panel_simple(panel);
+	int err = 0;
+
+	if (p->power_invert) {
+		if (regulator_is_enabled(p->supply) > 0)
+			regulator_disable(p->supply);
+	} else {
+		err = regulator_enable(p->supply);
+		if (err < 0) {
+			dev_err(panel->dev, "failed to enable supply: %d\n",
+				err);
+			return err;
+		}
+	}
+
+	return err;
+}
+
+static int panel_simple_regulator_disable(struct drm_panel *panel)
+{
+	struct panel_simple *p = to_panel_simple(panel);
+	int err = 0;
+
+	if (p->power_invert) {
+		if (!regulator_is_enabled(p->supply)) {
+			err = regulator_enable(p->supply);
+			if (err < 0) {
+				dev_err(panel->dev, "failed to enable supply: %d\n",
+					err);
+				return err;
+			}
+		}
+	} else {
+		regulator_disable(p->supply);
+	}
+
+	return err;
+}
+
+static int panel_simple_loader_protect(struct drm_panel *panel, bool on)
+{
+	struct panel_simple *p = to_panel_simple(panel);
+	int err;
+
+	if (on) {
+		err = panel_simple_regulator_enable(panel);
+		if (err < 0) {
+			dev_err(panel->dev, "failed to enable supply: %d\n",
+				err);
+			return err;
+		}
+
+		p->prepared = true;
+		p->enabled = true;
+	} else {
+		/* do nothing */
+	}
+
+	return 0;
+}
+
 static int panel_simple_disable(struct drm_panel *panel)
 {
 	struct panel_simple *p = to_panel_simple(panel);
@@ -190,7 +254,7 @@ static int panel_simple_unprepare(struct drm_panel *panel)
 
 	gpiod_set_value_cansleep(p->enable_gpio, 0);
 
-	regulator_disable(p->supply);
+	panel_simple_regulator_disable(panel);
 
 	if (p->desc->delay.unprepare)
 		msleep(p->desc->delay.unprepare);
@@ -208,7 +272,7 @@ static int panel_simple_prepare(struct drm_panel *panel)
 	if (p->prepared)
 		return 0;
 
-	err = regulator_enable(p->supply);
+	err = panel_simple_regulator_enable(panel);
 	if (err < 0) {
 		dev_err(panel->dev, "failed to enable supply: %d\n", err);
 		return err;
@@ -284,6 +348,7 @@ static int panel_simple_get_timings(struct drm_panel *panel,
 }
 
 static const struct drm_panel_funcs panel_simple_funcs = {
+	.loader_protect = panel_simple_loader_protect,
 	.disable = panel_simple_disable,
 	.unprepare = panel_simple_unprepare,
 	.prepare = panel_simple_prepare,
@@ -319,6 +384,9 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
 		return err;
 	}
 
+	panel->power_invert =
+			of_property_read_bool(dev->of_node, "power-invert");
+
 	backlight = of_parse_phandle(dev->of_node, "backlight", 0);
 	if (backlight) {
 		panel->backlight = of_find_backlight_by_node(backlight);
diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h
index 777814755fa6..233efacc2863 100644
--- a/include/drm/drm_panel.h
+++ b/include/drm/drm_panel.h
@@ -34,6 +34,7 @@ struct drm_panel;
 struct display_timing;
 
 /**
+ * @loader_protect: protect loader logo panel's power
  * struct drm_panel_funcs - perform operations on a given panel
  * @disable: disable panel (turn off back light, etc.)
  * @unprepare: turn off panel
@@ -68,6 +69,7 @@ struct display_timing;
  * the panel. This is the job of the .unprepare() function.
  */
 struct drm_panel_funcs {
+	int (*loader_protect)(struct drm_panel *panel, bool on);
 	int (*disable)(struct drm_panel *panel);
 	int (*unprepare)(struct drm_panel *panel);
 	int (*prepare)(struct drm_panel *panel);
@@ -95,6 +97,14 @@ struct drm_panel {
 	struct list_head list;
 };
 
+static inline int drm_panel_loader_protect(struct drm_panel *panel, bool on)
+{
+	if (panel && panel->funcs && panel->funcs->loader_protect)
+		return panel->funcs->loader_protect(panel, on);
+
+	return -EINVAL;
+}
+
 /**
  * drm_disable_unprepare - power off a panel
  * @panel: DRM panel