[U-Boot] [PATCH] board: toradex: turn off lcd backlight before OS handover

[Philippe Schenker]

From: Gerard Salvatella <gerard.salvatella at toradex.com>

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 <gerard.salvatella at toradex.com>
Signed-off-by: Philippe Schenker <philippe.schenker at toradex.com>
---
 board/toradex/apalis-tk1/apalis-tk1.c     |  9 +++++++++
 board/toradex/apalis_imx6/apalis_imx6.c   |  9 +++++++++
 board/toradex/apalis_t30/apalis_t30.c     |  9 +++++++++
 board/toradex/colibri_imx6/colibri_imx6.c |  9 +++++++++
 board/toradex/colibri_imx7/colibri_imx7.c |  9 +++++++++
 board/toradex/colibri_t20/colibri_t20.c   |  9 +++++++++
 board/toradex/colibri_t30/colibri_t30.c   |  9 +++++++++
 board/toradex/colibri_vf/colibri_vf.c     | 12 +++++++++++-
 8 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/board/toradex/apalis-tk1/apalis-tk1.c b/board/toradex/apalis-tk1/apalis-tk1.c
index d6a736d8aa..b87e9e7a3e 100644
--- a/board/toradex/apalis-tk1/apalis-tk1.c
+++ b/board/toradex/apalis-tk1/apalis-tk1.c
@@ -240,3 +240,12 @@ void tegra_pcie_board_port_reset(struct tegra_pcie_port *port)
 	}
 }
 #endif /* CONFIG_PCI_TEGRA */
+
+/*
+ * Backlight off before OS handover
+ */
+void board_preboot_os(void)
+{
+	gpio_request(TEGRA_GPIO(BB, 5), "BL_ON");
+	gpio_direction_output(TEGRA_GPIO(BB, 5), 0);
+}
diff --git a/board/toradex/apalis_imx6/apalis_imx6.c b/board/toradex/apalis_imx6/apalis_imx6.c
index 368db9c488..d11207c7f4 100644
--- a/board/toradex/apalis_imx6/apalis_imx6.c
+++ b/board/toradex/apalis_imx6/apalis_imx6.c
@@ -745,6 +745,15 @@ static void setup_display(void)
 	gpio_direction_output(RGB_BACKLIGHTPWM_OE, 0);
 	gpio_direction_output(RGB_BACKLIGHT_GP, 1);
 }
+
+/*
+ * Backlight off before OS handover
+ */
+void board_preboot_os(void)
+{
+	gpio_direction_output(RGB_BACKLIGHTPWM_GP, 1);
+	gpio_direction_output(RGB_BACKLIGHT_GP, 0);
+}
 #endif /* defined(CONFIG_VIDEO_IPUV3) */
 
 int board_early_init_f(void)
diff --git a/board/toradex/apalis_t30/apalis_t30.c b/board/toradex/apalis_t30/apalis_t30.c
index ace9c5b168..df9bc8e707 100644
--- a/board/toradex/apalis_t30/apalis_t30.c
+++ b/board/toradex/apalis_t30/apalis_t30.c
@@ -164,3 +164,12 @@ void tegra_pcie_board_port_reset(struct tegra_pcie_port *port)
 #endif /* CONFIG_APALIS_T30_PCIE_EVALBOARD_INIT */
 }
 #endif /* CONFIG_PCI_TEGRA */
+
+/*
+ * Backlight off before OS handover
+ */
+void board_preboot_os(void)
+{
+	gpio_request(TEGRA_GPIO(V, 2), "BKL1_ON");
+	gpio_direction_output(TEGRA_GPIO(V, 2), 0);
+}
diff --git a/board/toradex/colibri_imx6/colibri_imx6.c b/board/toradex/colibri_imx6/colibri_imx6.c
index 68c0c02a8a..17876f27e9 100644
--- a/board/toradex/colibri_imx6/colibri_imx6.c
+++ b/board/toradex/colibri_imx6/colibri_imx6.c
@@ -622,6 +622,15 @@ static void setup_display(void)
 	gpio_direction_output(RGB_BACKLIGHTPWM_GP, 0);
 	gpio_direction_output(RGB_BACKLIGHT_GP, 1);
 }
+
+/*
+ * Backlight off before OS handover
+ */
+void board_preboot_os(void)
+{
+	gpio_direction_output(RGB_BACKLIGHTPWM_GP, 1);
+	gpio_direction_output(RGB_BACKLIGHT_GP, 0);
+}
 #endif /* defined(CONFIG_VIDEO_IPUV3) */
 
 int board_early_init_f(void)
diff --git a/board/toradex/colibri_imx7/colibri_imx7.c b/board/toradex/colibri_imx7/colibri_imx7.c
index a4c99626b4..be027afd10 100644
--- a/board/toradex/colibri_imx7/colibri_imx7.c
+++ b/board/toradex/colibri_imx7/colibri_imx7.c
@@ -182,6 +182,15 @@ static int setup_lcd(void)
 }
 #endif
 
+/*
+ * Backlight off before OS handover
+ */
+void board_preboot_os(void)
+{
+	gpio_direction_output(GPIO_PWM_A, 1);
+	gpio_direction_output(GPIO_BL_ON, 0);
+}
+
 #ifdef CONFIG_FEC_MXC
 static iomux_v3_cfg_t const fec1_pads[] = {
 #ifndef CONFIG_COLIBRI_IMX7_EXT_PHYCLK
diff --git a/board/toradex/colibri_t20/colibri_t20.c b/board/toradex/colibri_t20/colibri_t20.c
index 5dd0f288ed..e0b27e92f8 100644
--- a/board/toradex/colibri_t20/colibri_t20.c
+++ b/board/toradex/colibri_t20/colibri_t20.c
@@ -150,4 +150,13 @@ 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
diff --git a/board/toradex/colibri_t30/colibri_t30.c b/board/toradex/colibri_t30/colibri_t30.c
index 8ea96188f6..b6b00e3860 100644
--- a/board/toradex/colibri_t30/colibri_t30.c
+++ b/board/toradex/colibri_t30/colibri_t30.c
@@ -66,3 +66,12 @@ void pin_mux_usb(void)
 	udelay(5);
 	gpio_set_value(TEGRA_GPIO(DD, 0), 1);
 }
+
+/*
+ * Backlight off before OS handover
+ */
+void board_preboot_os(void)
+{
+	gpio_request(TEGRA_GPIO(V, 2), "BL_ON");
+	gpio_direction_output(TEGRA_GPIO(V, 2), 0);
+}
diff --git a/board/toradex/colibri_vf/colibri_vf.c b/board/toradex/colibri_vf/colibri_vf.c
index 4db1757469..176c5201f9 100644
--- a/board/toradex/colibri_vf/colibri_vf.c
+++ b/board/toradex/colibri_vf/colibri_vf.c
@@ -38,8 +38,9 @@ DECLARE_GLOBAL_DATA_PTR;
 #define ENET_PAD_CTRL	(PAD_CTL_PUS_47K_UP | PAD_CTL_SPEED_HIGH | \
 			PAD_CTL_DSE_50ohm | PAD_CTL_OBE_IBE_ENABLE)
 
-#define USB_PEN_GPIO           83
+#define USB_PEN_GPIO		83
 #define USB_CDET_GPIO		102
+#define PTC0_GPIO_45		45
 
 static struct ddrmc_cr_setting colibri_vf_cr_settings[] = {
 	/* levelling */
@@ -640,3 +641,12 @@ int board_usb_phy_mode(int port)
 	}
 }
 #endif
+
+/*
+ * Backlight off before OS handover
+ */
+void board_preboot_os(void)
+{
+	gpio_request(PTC0_GPIO_45, "BL_ON");
+	gpio_direction_output(PTC0_GPIO_45, 0);
+}
-- 
2.19.1