[U-Boot] [PATCH] pico-imx7: Disable video support

[Fabio Estevam]

Hi Michael,

On Mon, Mar 25, 2019 at 1:56 PM Fabio Estevam <festevam at gmail.com> wrote:

> U-Boot 2019.04-rc4-00047-gcfb3e102c4 (Mar 23 2019 - 10:45:10 -0300)
>
> CPU:   Freescale i.MX7D rev1.2 1000 MHz (running at 792 MHz)
> CPU:   Commercial temperature grade (0C to 95C) at 40C
> Reset cause: POR
> Board: i.MX7D PICOSOM
> I2C:   ready
> DRAM:  512 MiB
>
> (Hangs here)

It seems this hangs is related to the GPIO that enables the LCD.

If I change the code like this:

diff --git a/board/technexion/pico-imx7d/pico-imx7d.c
b/board/technexion/pico-imx7d/pico-imx7d.c
index 767d13dfe5..ba1c6f9740 100644
--- a/board/technexion/pico-imx7d/pico-imx7d.c
+++ b/board/technexion/pico-imx7d/pico-imx7d.c
@@ -294,7 +294,7 @@ void setup_lcd(void)
        /* Set Brightness to high */
        gpio_direction_output(IMX_GPIO_NR(1, 11) , 1);
        /* Set LCD enable to high */
-       gpio_direction_output(IMX_GPIO_NR(1, 6) , 1);
+       gpio_direction_output(IMX_GPIO_NR(1, 6) , 0);
 }
 #endif

Then I can load U-Boot via USB without problem.

However, in order to turn on the LCD we need to turn on GPIO1_6.

If I do this from the U-Boot prompt:

=> gpio set 6

Then the board hangs.

Not sure why setting GPIO1_6 is causing the board to hang.