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authorKen Chang <kenc@nvidia.com>2014-04-22 12:55:00 +0800
committerMarc Jones <marc.jones@se-eng.com>2014-12-17 20:49:02 +0100
commit5a056d30a1fd609994e0a9aa70f5788c68e3a785 (patch)
tree95e72b64769bdcd741a694555ff72b5c99991d79 /src/soc
parent41359bd230942bea9cea234e147e629a78cbf794 (diff)
tegra124: modify panel init sequence
Panel datasheet defines some delay between PWM signal out and backlight enable. This change fixes the current sequence and makes the delays adjustable by dt setting. BRANCH=none BUG=chrome-os-partner:28008 TEST=Verified on Big DVT and Nyan/Norrin panels. Panel works fine with dev mode, and the measurement of power on sequence meets panel requirements. Original-Change-Id: If6015bbb6015a3b203d425f5e90f676ad786b5e8 Original-Signed-off-by: Ken Chang <kenc@nvidia.com> Original-Reviewed-on: https://chromium-review.googlesource.com/196183 Original-Reviewed-by: Hung-Te Lin <hungte@chromium.org> (cherry picked from commit 2bbcaa7281222ffc0b4026e8b1eb4c210a8e308a) Signed-off-by: Marc Jones <marc.jones@se-eng.com> Change-Id: Id6424f66eb8dc6adeb70eaa33df742f4e57983c3 Reviewed-on: http://review.coreboot.org/7776 Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org> Tested-by: build bot (Jenkins)
Diffstat (limited to 'src/soc')
-rw-r--r--src/soc/nvidia/tegra124/chip.h3
-rw-r--r--src/soc/nvidia/tegra124/display.c30
2 files changed, 19 insertions, 14 deletions
diff --git a/src/soc/nvidia/tegra124/chip.h b/src/soc/nvidia/tegra124/chip.h
index 89a8d977aa..08e96ab809 100644
--- a/src/soc/nvidia/tegra124/chip.h
+++ b/src/soc/nvidia/tegra124/chip.h
@@ -72,6 +72,9 @@ struct soc_nvidia_tegra124_config {
/* Delay before from power on asserting vdd */
int vdd_delay_ms;
+ /* Delay beween pwm and backlight_en_gpio is asserted */
+ int pwm_to_bl_delay_ms;
+
/* Delay before HPD high */
int vdd_to_hpd_delay_ms;
diff --git a/src/soc/nvidia/tegra124/display.c b/src/soc/nvidia/tegra124/display.c
index 87472efd09..898e9b375b 100644
--- a/src/soc/nvidia/tegra124/display.c
+++ b/src/soc/nvidia/tegra124/display.c
@@ -252,20 +252,6 @@ void display_startup(device_t dev)
printk(BIOS_SPEW,"%s: lvds shutdown setting gpio %08x to %d\n",
__func__, config->lvds_shutdown_gpio, 0);
}
- if (config->backlight_en_gpio){
- gpio_output(config->backlight_en_gpio, 1);
- printk(BIOS_SPEW,"%s: backlight enable setting gpio %08x to %d\n",
- __func__, config->backlight_en_gpio, 1);
- }
-
- /* Set up Tegra PWM n (where n is specified in config->pwm) to drive the
- * panel backlight.
- */
- printk(BIOS_SPEW, "%s: enable panel backlight pwm\n", __func__);
- WRITEL(((1 << NV_PWM_CSR_ENABLE_SHIFT) |
- (220 << NV_PWM_CSR_PULSE_WIDTH_SHIFT) | /* 220/256 */
- 0x02e), /* frequency divider */
- &pwm->pwm[config->pwm].csr);
if (framebuffer_size_mb == 0){
framebuffer_size_mb = ALIGN_UP(config->xres * config->yres *
@@ -313,6 +299,22 @@ void display_startup(device_t dev)
update_window(disp_ctrl, config);
+ /* Set up Tegra PWM n (where n is specified in config->pwm) to drive the
+ * panel backlight.
+ */
+ printk(BIOS_SPEW, "%s: enable panel backlight pwm\n", __func__);
+ WRITEL(((1 << NV_PWM_CSR_ENABLE_SHIFT) |
+ (220 << NV_PWM_CSR_PULSE_WIDTH_SHIFT) | /* 220/256 */
+ 0x02e), /* frequency divider */
+ &pwm->pwm[config->pwm].csr);
+
+ udelay(config->pwm_to_bl_delay_ms * 1000);
+ if (config->backlight_en_gpio){
+ gpio_output(config->backlight_en_gpio, 1);
+ printk(BIOS_SPEW,"%s: backlight enable setting gpio %08x to %d\n",
+ __func__, config->backlight_en_gpio, 1);
+ }
+
printk(BIOS_INFO, "%s: display init done.\n", __func__);
/* tell depthcharge ...