Change in coreboot[master]: Google/Nipperkin: Add board specific value for eDP tunning

[Bao Zheng (Code Review)]

Attention is currently required from: Zheng Bao.
Hello Zheng Bao,

I'd like you to do a code review. Please visit

https://review.coreboot.org/c/coreboot/+/59919

to review the following change.

Change subject: Google/Nipperkin: Add board specific value for eDP tunning
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Google/Nipperkin: Add board specific value for eDP tunning

BUG=b:203061533

Change-Id: I7aa8c594d9f5caa6b2523dac079aef89e623c56f
Signed-off-by: Zheng Bao 
---
M src/mainboard/google/guybrush/variants/nipperkin/overridetree.cb
1 file changed, 13 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/19/59919/1

diff --git a/src/mainboard/google/guybrush/variants/nipperkin/overridetree.cb b/src/mainboard/google/guybrush/variants/nipperkin/overridetree.cb
index 2d3b162..6cc7bba 100644
--- a/src/mainboard/google/guybrush/variants/nipperkin/overridetree.cb
+++ b/src/mainboard/google/guybrush/variants/nipperkin/overridetree.cb
@@ -92,6 +92,19 @@
    	.early_init = true,
    }"

+	register "edp_phy_override" = "1"
+
+	#bit vector of phy, bit0=1: DP0, bit1=1: DP1, bit2=1: DP2, bit3=1: DP3
+	register "edp_physel" = "0x1"
+
+	register "edp_tuningset" = "{
+		.dp_vs_pemph_level = 0x00,
+		.tx_eq_main = 0x1F,
+		.tx_eq_pre = 0x0,
+		.tx_eq_post = 0x0,
+		.tx_vboost_lvl = 0x5,
+	}"
+
    device ref i2c_0 on
    	chip drivers/i2c/generic
    		register "hid" = ""ELAN0000""