[U-Boot] [PATCH v1 1/6] board: imx53: Always disable display before starting kernel

[Lukasz Majewski]

This patch prevents from the situation where we may end up with garbage
displayed on the LCD panel.

Such situation occurs when one performs "reboot -f" in Linux and then
stop in U-boot (or observe the garbage on the screen during boot up).

To prevent from such situation - the PWM pin is configured as GPIO and set
to LOW.

Signed-off-by: Lukasz Majewski <lukma at denx.de>

---

 arch/arm/dts/imx53-kp.dts     | 2 ++
 board/k+p/kp_imx53/kp_imx53.c | 8 ++++++++
 2 files changed, 10 insertions(+)

diff --git a/arch/arm/dts/imx53-kp.dts b/arch/arm/dts/imx53-kp.dts
index fd64a9f2f6..6322ef1323 100644
--- a/arch/arm/dts/imx53-kp.dts
+++ b/arch/arm/dts/imx53-kp.dts
@@ -86,6 +86,8 @@
 				MX53_PAD_PATA_DA_2__GPIO7_8 0x1e4
 				/* BOOSTER_OFF */
 				MX53_PAD_EIM_CS0__GPIO2_23 0x1e4
+				/* LCD BACKLIGHT */
+				MX53_PAD_GPIO_1__GPIO1_1 0x1e4
 			>;
 		};
 
diff --git a/board/k+p/kp_imx53/kp_imx53.c b/board/k+p/kp_imx53/kp_imx53.c
index c80eed36c6..6b0db6b8de 100644
--- a/board/k+p/kp_imx53/kp_imx53.c
+++ b/board/k+p/kp_imx53/kp_imx53.c
@@ -22,6 +22,7 @@
 #define VBUS_PWR_EN IMX_GPIO_NR(7, 8)
 #define PHY_nRST IMX_GPIO_NR(7, 6)
 #define BOOSTER_OFF IMX_GPIO_NR(2, 23)
+#define LCD_BACKLIGHT IMX_GPIO_NR(1, 1)
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -189,10 +190,17 @@ void eth_phy_reset(void)
 	udelay(50);
 }
 
+void board_disable_display(void)
+{
+	gpio_request(LCD_BACKLIGHT, "LCD_BACKLIGHT");
+	gpio_direction_output(LCD_BACKLIGHT, 0);
+}
+
 int board_late_init(void)
 {
 	int ret = 0;
 
+	board_disable_display();
 	setup_ups();
 
 	if (!power_init())
-- 
2.11.0