erebion/coreboot
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

mb/google/skywalker: Extend MIPI panel delay to meet T3 timing

Browse source 
Measured on Padme, the T3 (AVEE-to-RESET) timing in the current MIPI
panel power-on sequence is only ~120us, which is significantly shorter
than the panel specification requirement (>=3ms). This may cause panel
initialization instability due to RESET being asserted too early after
AVEE is enabled.

Increase the delay between AVEE enable and panel reset from 1ms to 5ms
to satisfy the panel T3 (AVEE-to-RESET) timing requirement.

IL79900A Power on off sequence V1.pdf

BUG=b:451746079
TEST=Boot Padme and confirm panel power-on timing is correct.
BRANCH=skywalker

Change-Id: Ided93c34f7c6695a2928c23eea679f32a0ee9a17
Signed-off-by: Yang Wu <wuyang5@huaqin.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/90664
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Yidi Lin <yidilin@google.com>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
This commit is contained in:
Yang Wu 2025-12-31 21:13:30 +08:00 • committed by Yidi Lin
commit 6966885290
1 changed files with 1 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

2
src/mainboard/google/skywalker/panel.c
View file

@ -60,7 +60,7 @@ void mipi_panel_power_on(void)
mdelay(10);
}
gpio_output(GPIO_EN_PP3300_EDP_X, 0);
mdelay(1);
mdelay(5);
gpio_output(GPIO_EN_PP3300_EDP_X, 1);
mdelay(1);
gpio_output(GPIO_TCHSCR_RST_1V8_L, 0);