mb/google/nissa/var/xivu: Fine-tune eMMC DLL

Fine-tune eMMC DLL based on Xivu EVT system.

BUG=b:256538132
TEST=executed 3000 cycles of cold boot successfully

Change-Id: Iaa8338fd0faa0e01f42ee77dea135c7a241ed3be
Signed-off-by: Lawrence Chang <lawrence.chang@intel.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/69892
Reviewed-by: Jamie Chen <jamie.chen@intel.com>
Reviewed-by: Kangheui Won <khwon@chromium.org>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/google/brya/variants/xivu/overridetree.cb b/src/mainboard/google/brya/variants/xivu/overridetree.cb
index ac23c68..bfaa639 100644
--- a/src/mainboard/google/brya/variants/xivu/overridetree.cb
+++ b/src/mainboard/google/brya/variants/xivu/overridetree.cb
@@ -16,6 +16,51 @@
 chip soc/intel/alderlake
 	register "sagv" = "SaGv_Enabled"
 
+	# EMMC Tx CMD Delay
+	# Refer to EDS-Vol2-42.3.7.
+	# [14:8] steps of delay for DDR mode, each 125ps, range: 0 - 39.
+	# [6:0] steps of delay for SDR mode, each 125ps, range: 0 - 39.
+	register "common_soc_config.emmc_dll.emmc_tx_cmd_cntl" = "0x00000505"
+
+	# EMMC TX DATA Delay 1
+	# Refer to EDS-Vol2-42.3.8.
+	# [14:8] steps of delay for HS400, each 125ps, range: 0 - 78.
+	# [6:0] steps of delay for SDR104/HS200, each 125ps, range: 0 - 79.
+	register "common_soc_config.emmc_dll.emmc_tx_data_cntl1" = "0x00000a12"
+
+	# EMMC TX DATA Delay 2
+	# Refer to EDS-Vol2-42.3.9.
+	# [30:24] steps of delay for SDR50, each 125ps, range: 0 - 79.
+	# [22:16] steps of delay for DDR50, each 125ps, range: 0 - 78.
+	# [14:8] steps of delay for SDR25/HS50, each 125ps, range: 0 -79.
+	# [6:0] steps of delay for SDR12, each 125ps. Range: 0 - 79.
+	register "common_soc_config.emmc_dll.emmc_tx_data_cntl2" = "0x1c292828"
+
+	# EMMC RX CMD/DATA Delay 1
+	# Refer to EDS-Vol2-42.3.10.
+	# [30:24] steps of delay for SDR50, each 125ps, range: 0 - 119.
+	# [22:16] steps of delay for DDR50, each 125ps, range: 0 - 78.
+	# [14:8] steps of delay for SDR25/HS50, each 125ps, range: 0 - 119.
+	# [6:0] steps of delay for SDR12, each 125ps, range: 0 - 119.
+	register "common_soc_config.emmc_dll.emmc_rx_cmd_data_cntl1" = "0x1c175a3b"
+
+	# EMMC RX CMD/DATA Delay 2
+	# Refer to EDS-Vol2-42.3.12.
+	# [17:16] stands for Rx Clock before Output Buffer,
+	#         00: Rx clock after output buffer,
+	#         01: Rx clock before output buffer,
+	#         10: Automatic selection based on working mode.
+	#         11: Reserved
+	# [14:8] steps of delay for Auto Tuning Mode, each 125ps, range: 0 - 39.
+	# [6:0] steps of delay for HS200, each 125ps, range: 0 - 79.
+	register "common_soc_config.emmc_dll.emmc_rx_cmd_data_cntl2" = "0x00010023"
+
+	# EMMC Rx Strobe Delay
+	# Refer to EDS-Vol2-42.3.11.
+	# [14:8] Rx Strobe Delay DLL 1(HS400 Mode), each 125ps, range: 0 - 39.
+	# [6:0] Rx Strobe Delay DLL 2(HS400 Mode), each 125ps, range: 0 - 39.
+	register "common_soc_config.emmc_dll.emmc_rx_strobe_cntl" = "0x00011111"
+
 	# Disable CNVi BT
 	register "cnvi_bt_core" = "false"