board: imx53: Always disable display before starting kernel

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@denx.de>

diff --git a/arch/arm/dts/imx53-kp.dts b/arch/arm/dts/imx53-kp.dts
index fd64a9f2f6dd00147e2bab13c65ba19bdf3c5412..6322ef13232d9c5a0fe5cd3f9f80c8955454bc71 100644 (file)
--- 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 c80eed36c62304ed904c108435f019178c9370e1..6b0db6b8de10ef22f8b10e5bf3e5ace2f9bf3355 100644 (file)
--- 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())