[U-Boot] [PATCH 09/10] exynos: Enable the LCD backlight for snow

[Simon Glass]

The backlight uses FETs on the TPS65090. Enable this so that the display
is visible.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

 board/samsung/smdk5250/exynos5-dt.c | 90 +++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)

diff --git a/board/samsung/smdk5250/exynos5-dt.c b/board/samsung/smdk5250/exynos5-dt.c
index c83b034..a0ae641 100644
--- a/board/samsung/smdk5250/exynos5-dt.c
+++ b/board/samsung/smdk5250/exynos5-dt.c
@@ -20,6 +20,7 @@
 #include <asm/arch/sromc.h>
 #include <power/pmic.h>
 #include <power/max77686_pmic.h>
+#include <power/tps65090_pmic.h>
 #include <tmu.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -60,6 +61,52 @@ int checkboard(void)
 #endif
 
 #ifdef CONFIG_LCD
+static int board_dp_bridge_setup(void)
+{
+	struct exynos5_gpio_part1 *gpio1 =
+		(struct exynos5_gpio_part1 *)samsung_get_base_gpio_part1();
+	const int MAX_TRIES = 10;
+	int num_tries;
+
+	debug("%s\n", __func__);
+
+	/* Setup the GPIOs */
+
+	/* PD is ACTIVE_LOW, and initially de-asserted */
+	s5p_gpio_set_pull(&gpio1->y2, 5, GPIO_PULL_NONE);
+	s5p_gpio_direction_output(&gpio1->y2, 5, 1);
+
+	/* Reset is ACTIVE_LOW */
+	s5p_gpio_set_pull(&gpio1->x1, 5, GPIO_PULL_NONE);
+	s5p_gpio_direction_output(&gpio1->x1, 5, 0);
+
+	udelay(10);
+	s5p_gpio_set_value(&gpio1->x1, 5, 1);
+
+	s5p_gpio_direction_input(&gpio1->x0, 7);
+
+	/*
+	 * We need to wait for 90ms after bringing up the bridge since there
+	 * is a phantom "high" on the HPD chip during its bootup.  The phantom
+	 * high comes within 7ms of de-asserting PD and persists for at least
+	 * 15ms.  The real high comes roughly 50ms after PD is de-asserted. The
+	 * phantom high makes it hard for us to know when the NXP chip is up.
+	 */
+	mdelay(90);
+
+	for (num_tries = 0; num_tries < MAX_TRIES; num_tries++) {
+		/* Check HPD.  If it's high, we're all good. */
+		if (s5p_gpio_get_value(&gpio1->x0, 7))
+				return 0;
+
+		debug("%s: eDP bridge failed to come up; try %d of %d\n",
+		      __func__, num_tries, MAX_TRIES);
+	}
+
+	/* Immediately go into bridge reset if the hp line is not high */
+	return -ENODEV;
+}
+
 void exynos_cfg_lcd_gpio(void)
 {
 	struct exynos5_gpio_part1 *gpio1 =
@@ -81,4 +128,47 @@ void exynos_set_dp_phy(unsigned int onoff)
 {
 	set_dp_phy_ctrl(onoff);
 }
+
+void exynos_backlight_on(unsigned int onoff)
+{
+	debug("%s(%u)\n", __func__, onoff);
+
+	if (onoff) {
+#ifdef CONFIG_POWER_TPS65090
+		struct exynos5_gpio_part1 *gpio1 =
+			(struct exynos5_gpio_part1 *)
+					samsung_get_base_gpio_part1();
+		int ret;
+
+		ret = tps65090_fet_enable(1); /* Enable FET1, backlight */
+		if (ret)
+			return;
+
+		/* T5 in the LCD timing spec (defined as > 10ms) */
+		mdelay(10);
+
+		/* board_dp_backlight_pwm */
+		s5p_gpio_direction_output(&gpio1->b2, 0, 1);
+
+		/* T6 in the LCD timing spec (defined as > 10ms) */
+		mdelay(10);
+
+		/* board_dp_backlight_en */
+		s5p_gpio_direction_output(&gpio1->x3, 0, 1);
+#endif
+	}
+}
+
+void exynos_lcd_power_on(void)
+{
+	debug("%s\n", __func__);
+
+#ifdef CONFIG_POWER_TPS65090
+	/* board_dp_lcd_vdd */
+	tps65090_fet_enable(6); /* Enable FET6, lcd panel */
+#endif
+
+	board_dp_bridge_setup();
+}
+
 #endif
-- 
1.9.1.423.g4596e3a