From 5717b9a050a123d3e1eafa7c0883810847e74d2c Mon Sep 17 00:00:00 2001 From: Gerard Salvatella Date: Fri, 31 Aug 2018 09:47:44 +0200 Subject: board: toradex: turn off lcd backlight before OS handover U-Boot typically tears down the display controller before handing control over to Linux. On LCD displays disabling pixel clock leads to a fading out effect with vertical/horizontal lines. Make sure to disable back light before booting Linux. Signed-off-by: Gerard Salvatella Acked-by: Marcel Ziswiler --- board/toradex/colibri_t20/colibri_t20.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'board/toradex/colibri_t20/colibri_t20.c') diff --git a/board/toradex/colibri_t20/colibri_t20.c b/board/toradex/colibri_t20/colibri_t20.c index 15ab2f586c..67b21d67f6 100644 --- a/board/toradex/colibri_t20/colibri_t20.c +++ b/board/toradex/colibri_t20/colibri_t20.c @@ -232,4 +232,13 @@ void pin_mux_display(void) pinmux_set_func(PMUX_PINGRP_SDC, PMUX_FUNC_PWM); pinmux_tristate_disable(PMUX_PINGRP_SDC); } + +/* + * Backlight off before OS handover + */ +void board_preboot_os(void) +{ + gpio_request(TEGRA_GPIO(T, 4), "BL_ON"); + gpio_direction_output(TEGRA_GPIO(T, 4), 0); +} #endif -- cgit v1.2.3