[coreboot-gerrit] New patch to review for coreboot: df2e2de veyron_danger: Turn on backlight enable before VCC_LCD

[Patrick Georgi (pgeorgi@google.com)]

Patrick Georgi (pgeorgi at google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/10089

-gerrit

commit df2e2deddeb7e5e79e5b3ea33a47dc4dd39cc4f8
Author: David Hendricks <dhendrix at chromium.org>
Date:   Wed Apr 22 15:05:18 2015 -0700

    veyron_danger: Turn on backlight enable before VCC_LCD
    
    On current Danger boards, VCC_LCD is gated by BL_EN. Thus we
    need to enable BL_EN in order to power on the display so that
    we can read the EDID and set things up.
    
    Later board revisions may change this ordering, but for now it
    doesn't seem to be causing a significant issues (no noticable
    "snow" or other corruption using Pepto display).
    
    BUG=none
    BRANCH=none
    TEST=booted on Danger, saw dev mode screen come up
    
    Change-Id: I70aab8c1f6da2d0fce310d59073026eef0f67821
    Signed-off-by: Patrick Georgi <pgeorgi at chromium.org>
    Original-Commit-Id: 1a918824e747600a2f3a88602320f4f563ce17b7
    Original-Signed-off-by: David Hendricks <dhendrix at chromium.org>
    Original-Change-Id: Iaf17cc4682bd3c46f62cba789e3ecf8d5a474362
    Original-Reviewed-on: https://chromium-review.googlesource.com/266913
    Original-Reviewed-by: Julius Werner <jwerner at chromium.org>
---
 src/mainboard/google/veyron_danger/board.h     |  1 +
 src/mainboard/google/veyron_danger/mainboard.c | 13 ++++++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/mainboard/google/veyron_danger/board.h b/src/mainboard/google/veyron_danger/board.h
index 10bcf45..a2f4000 100644
--- a/src/mainboard/google/veyron_danger/board.h
+++ b/src/mainboard/google/veyron_danger/board.h
@@ -25,6 +25,7 @@
 
 #define GPIO_BACKLIGHT	GPIO(7, A, 3)
 #define GPIO_RESET	GPIO(0, B, 5)
+#define GPIO_LCDC_BL	GPIO(7, A, 7)
 
 void setup_chromeos_gpios(void);
 
diff --git a/src/mainboard/google/veyron_danger/mainboard.c b/src/mainboard/google/veyron_danger/mainboard.c
index b664d55..9bb5cb1 100644
--- a/src/mainboard/google/veyron_danger/mainboard.c
+++ b/src/mainboard/google/veyron_danger/mainboard.c
@@ -93,6 +93,17 @@ static void configure_vop(void)
 	/* lcdc(vop) iodomain select 1.8V */
 	write32(&rk3288_grf->io_vsel, RK_SETBITS(1 << 0));
 
+	/*
+	 * BL_EN gates VCC_LCD. This might be changed in future revisions
+	 * of the board so that the display can be stablized before we
+	 * turn on the backlight.
+	 *
+	 * To minimize display corruption, turn off LCDC_BL before
+	 * powering on the backlight.
+	 */
+	gpio_output(GPIO_BACKLIGHT, 1);	/* BL_EN */
+	gpio_output(GPIO_LCDC_BL, 0);
+
 	rk808_configure_switch(2, 1);	/* VCC18_LCD (HDMI_AVDD_1V8) */
 	rk808_configure_ldo(7, 1000);	/* VDD10_LCD (HDMI_AVDD_1V0) */
 	rk808_configure_switch(1, 1);	/* VCC33_LCD */
@@ -135,5 +146,5 @@ void lb_board(struct lb_header *header)
 
 void mainboard_power_on_backlight(void)
 {
-	gpio_output(GPIO_BACKLIGHT, 1);	/* BL_EN */
+	gpio_output(GPIO_LCDC_BL, 1);
 }