arm: tegra: kai: Fix panel power on/off sequence

Panel power on/off sequence should meet the panel spec as below.

power on:
1. EN_VDD_PNL
2. PCLK
3. LVDS_EN
4. LCD_BL_PWN

power off:
1. LCD_BL_PWN
2. LVDS_EN
3. PCLK
4. EN_VDD_PNL

Pixel clock on/off is controlled by dc driver, we need to separate the
setting of panel enable/disable into two parts. The first, i.e., before
pclk on/off, is done in kai_panel_enable()/kai_panel_prepoweroff().
And the second part, i.e., after pclk on/off, is done in
kai_panel_postpoweron()/kai_panel_disable().

bug 976081

Signed-off-by: Ken Chang <kenc@nvidia.com>
Reviewed-on: http://git-master/r/102555
Reviewed-by: Artiste Hsu <chhsu@nvidia.com>
Reviewed-by: Prajakta Gudadhe <pgudadhe@nvidia.com>
(cherry picked from commit 8149532e20729c359eb1680297f19a8f46343054)

Change-Id: Ifc0d60c2caabf60f4186179e64756a4caabf9af6
Reviewed-on: http://git-master/r/110297
Tested-by: Ken Chang <kenc@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Artiste Hsu <chhsu@nvidia.com>
Reviewed-by: Jon Mayo <jmayo@nvidia.com>

1 files changed, 26 insertions, 14 deletions

diff --git a/arch/arm/mach-tegra/board-kai-panel.c b/arch/arm/mach-tegra/board-kai-panel.c
index d98550faf123..e16b17c919ee 100644
--- a/arch/arm/mach-tegra/board-kai-panel.c
+++ b/arch/arm/mach-tegra/board-kai-panel.c
@@ -173,7 +173,7 @@ static struct platform_device kai_backlight_device = {
 	},
 };
 
-static int kai_panel_enable(void)
+static int kai_panel_postpoweron(void)
 {
 	if (kai_lvds_reg == NULL) {
 		kai_lvds_reg = regulator_get(NULL, "vdd_lvds");
@@ -184,15 +184,6 @@ static int kai_panel_enable(void)
 			regulator_enable(kai_lvds_reg);
 	}
 
-	if (kai_lvds_vdd_panel == NULL) {
-		kai_lvds_vdd_panel = regulator_get(NULL, "vdd_lcd_panel");
-		if (WARN_ON(IS_ERR(kai_lvds_vdd_panel)))
-			pr_err("%s: couldn't get regulator vdd_lcd_panel: %ld\n",
-			       __func__, PTR_ERR(kai_lvds_vdd_panel));
-		else
-			regulator_enable(kai_lvds_vdd_panel);
-	}
-
 	mdelay(5);
 
 	gpio_set_value(kai_lvds_avdd_en, 1);
@@ -208,8 +199,31 @@ static int kai_panel_enable(void)
 	return 0;
 }
 
+static int kai_panel_enable(void)
+{
+	if (kai_lvds_vdd_panel == NULL) {
+		kai_lvds_vdd_panel = regulator_get(NULL, "vdd_lcd_panel");
+		if (WARN_ON(IS_ERR(kai_lvds_vdd_panel)))
+			pr_err("%s: couldn't get regulator vdd_lcd_panel: %ld\n",
+			       __func__, PTR_ERR(kai_lvds_vdd_panel));
+		else
+			regulator_enable(kai_lvds_vdd_panel);
+	}
+
+	return 0;
+}
+
 static int kai_panel_disable(void)
 {
+	regulator_disable(kai_lvds_vdd_panel);
+	regulator_put(kai_lvds_vdd_panel);
+	kai_lvds_vdd_panel = NULL;
+
+	return 0;
+}
+
+static int kai_panel_prepoweroff(void)
+{
 	gpio_set_value(kai_lvds_lr, 0);
 	gpio_set_value(kai_lvds_shutdown, 0);
 	gpio_set_value(kai_lvds_rst, 0);
@@ -223,10 +237,6 @@ static int kai_panel_disable(void)
 	regulator_put(kai_lvds_reg);
 	kai_lvds_reg = NULL;
 
-	regulator_disable(kai_lvds_vdd_panel);
-	regulator_put(kai_lvds_vdd_panel);
-	kai_lvds_vdd_panel = NULL;
-
 	return 0;
 }
 
@@ -526,6 +536,8 @@ static struct tegra_dc_out kai_disp1_out = {
 	.n_modes	= ARRAY_SIZE(kai_panel_modes),
 
 	.enable		= kai_panel_enable,
+	.postpoweron	= kai_panel_postpoweron,
+	.prepoweroff	= kai_panel_prepoweroff,
 	.disable	= kai_panel_disable,
 };