[XS] Change in coreboot[master]: mb/siemens/mc_ehl5: Enable PWMI pass through mode on PTN3460

[Mario Scheithauer (Code Review)]

Attention is currently required from: Mario Scheithauer, Werner Zeh.

Hello Jan Samek, Werner Zeh, build bot (Jenkins),

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/77702?usp=email

to look at the new patch set (#3).

Change subject: mb/siemens/mc_ehl5: Enable PWMI pass through mode on PTN3460
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mb/siemens/mc_ehl5: Enable PWMI pass through mode on PTN3460

The connected panel on this mainboard get the PWM frequency directly
from the Elkhart Lake CPU. The PWM controls the brightness of the
backlight. Therefore, it is necessary to activate the PWM pass through
mode into the PTN3460 eDP-to-LVDS bridge (see PTN3460 Programming Guide
- 5. Configuration Registers).

Link to PTN3460 Programming Guide:
https://web.archive.org/web/20230908074244/https://www.nxp.com/docs/en/appli...

BUG=none
TEST=Boot into Linux and change the brightness of the screen

Change-Id: Iec9d8ae22fced40c45e5bfa8989ad655a722d7ef
Signed-off-by: Mario Scheithauer 
---
M src/mainboard/siemens/mc_ehl/variants/mc_ehl5/lcd_panel.c
1 file changed, 2 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/02/77702/3