[S] Change in coreboot[main]: mb/google/nissa/var/anraggar: Force audio mute to avoid screen flick

[Felix Held (Code Review)]

Felix Held has submitted this change. ( https://review.coreboot.org/c/coreboot/+/84098?usp=email )

Change subject: mb/google/nissa/var/anraggar: Force audio mute to avoid screen flick
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mb/google/nissa/var/anraggar: Force audio mute to avoid screen flick

Panel CSOT MNB601LS1-3 will flicker once during enter Chrome login
screen, it is because it inserts 12 blank frames if it receives the
unmute in VB-ID.

Always override the mute in VB-ID to avoid Tcon EC detected the
audiomute_flag change.

BUG:b=357764688
BRANCH=firmware-nissa-15217.B
TEST:Verfied on Anraggar and cannot reproduce the issue

Change-Id: I711dfd0803440e4b04f02849fed529c3872e023d
Signed-off-by: Simon Yang 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/84098
Tested-by: build bot (Jenkins) 
Reviewed-by: Subrata Banik 
---
M src/mainboard/google/brya/variants/anraggar/variant.c
1 file changed, 18 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Subrata Banik: Looks good to me, approved

diff --git a/src/mainboard/google/brya/variants/anraggar/variant.c b/src/mainboard/google/brya/variants/anraggar/variant.c
index 0615618..a9a5589 100644
--- a/src/mainboard/google/brya/variants/anraggar/variant.c
+++ b/src/mainboard/google/brya/variants/anraggar/variant.c
@@ -5,6 +5,11 @@
 #include <fw_config.h>
 #include <sar.h>
 #include <soc/gpio_soc_defs.h>
+#include <intelblocks/graphics.h>
+
+/* Per-pipe DDI Function Control 2 */
+#define TRANS_DDI_FUNC_CTL2_A					0x60404
+#define TRANS_DDI_AUDIO_MUTE_OVERRIDE_BITS_FIELDS		(3 << 6)

const char *get_wifi_sar_cbfs_filename(void)
 {
@@ -37,3 +42,16 @@
    	config->typec_aux_bias_pads[1].pad_auxn_dc = GPP_E23;
    }
 }
+
+void variant_finalize(void)
+{
+	/*
+	 * Panel CSOT MNB601LS1-3 will flicker once during enter Chrome login screen,
+	 * it is because it inserts 12 blank frames if it receives the unmute in VB-ID.
+	 *
+	 * Always override the mute in VB-ID to avoid Tcon EC detected the
+	 * audiomute_flag change.
+	 */
+	graphics_gtt_rmw(TRANS_DDI_FUNC_CTL2_A, ~TRANS_DDI_AUDIO_MUTE_OVERRIDE_BITS_FIELDS,
+		TRANS_DDI_AUDIO_MUTE_OVERRIDE_BITS_FIELDS);
+}