mb/google/rex/var/rex0: Enable BT offload audio for Intel MtP2 module

Enable the required GPIO and FW_CONFIG support to configure BT offload
audio in discrete mode for Intel Mysty Peak module on google/rex
Proto2 HW.

BUG=b:297125514
Test=Verified BT audio playback on google/rex Proto2.

Change-Id: I560f1700f78f8b653dfcc2f26764f0ebf2652689
Signed-off-by: Anil Kumar <anil.kumar.k@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/77357
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Subrata Banik <subratabanik@google.com>
Reviewed-by: Jakub Czapiga <jacz@semihalf.com>

3 files changed, 21 insertions, 1 deletions

diff --git a/src/mainboard/google/rex/variants/rex0/fw_config.c b/src/mainboard/google/rex/variants/rex0/fw_config.c
index 417bc39f33..ce5fe8d03c 100644
--- a/src/mainboard/google/rex/variants/rex0/fw_config.c
+++ b/src/mainboard/google/rex/variants/rex0/fw_config.c
@@ -53,6 +53,17 @@ static const struct pad_config bt_i2s_enable_pads[] = {
 	PAD_CFG_NF(GPP_VGPIO37, NONE, DEEP, NF1),
 };
 
+static const struct pad_config discrete_bt_i2s_enable_pads[] = {
+	/* GPP_S00 : [] ==> I2S1_SCLK */
+	PAD_CFG_NF(GPP_S00, NONE, DEEP, NF6),
+	/* GPP_S01 : [] ==> I2S1_SFRM */
+	PAD_CFG_NF(GPP_S01, NONE, DEEP, NF6),
+	/* GPP_S02 : [] ==> I2S1_TXD */
+	PAD_CFG_NF(GPP_S02, NONE, DEEP, NF6),
+	/* GPP_S03 : [] ==> I2S1_RXD */
+	PAD_CFG_NF(GPP_S03, NONE, DEEP, NF6),
+};
+
 static const struct pad_config bt_i2s_disable_pads[] = {
 	/* GPP_V30 : [] ==> BT_I2S_BCLK */
 	PAD_NC(GPP_VGPIO30, NONE),
@@ -131,6 +142,11 @@ void fw_config_gpio_padbased_override(struct pad_config *padbased_table)
 		GPIO_PADBASED_OVERRIDE(padbased_table, sndw_disable_pads);
 		printk(BIOS_INFO, "Configure GPIOs for BT offload mode.\n");
 		GPIO_PADBASED_OVERRIDE(padbased_table, bt_i2s_enable_pads);
+	} else if (fw_config_probe(FW_CONFIG(AUDIO, MAX98360_ALC5682I_DISCRETE_I2S_BT))) {
+		printk(BIOS_INFO, "Configure GPIOs for I2S audio.\n");
+		GPIO_PADBASED_OVERRIDE(padbased_table, sndw_disable_pads);
+		printk(BIOS_INFO, "Configure GPIOs for BT offload mode(discrete).\n");
+		GPIO_PADBASED_OVERRIDE(padbased_table, discrete_bt_i2s_enable_pads);
 	}
 
 	if (fw_config_probe(FW_CONFIG(ISH, ISH_ENABLE))) {
diff --git a/src/mainboard/google/rex/variants/rex0/overridetree.cb b/src/mainboard/google/rex/variants/rex0/overridetree.cb
index 5c7958a72f..c08ff2b493 100644
--- a/src/mainboard/google/rex/variants/rex0/overridetree.cb
+++ b/src/mainboard/google/rex/variants/rex0/overridetree.cb
@@ -3,6 +3,7 @@ fw_config
 		option AUDIO_UNKNOWN		0
 		option MAX98360_ALC5682I_I2S	1
 		option MAX98363_CS42L42_SNDW	2
+		option MAX98360_ALC5682I_DISCRETE_I2S_BT	3
 	end
 	field CELLULAR 4 5
 		option CELLULAR_ABSENT		0
@@ -462,6 +463,7 @@ chip soc/intel/meteorlake
 				register "property_list[0].integer" = "1"
 				device i2c 1a on
 					probe AUDIO MAX98360_ALC5682I_I2S
+					probe AUDIO MAX98360_ALC5682I_DISCRETE_I2S_BT
 				end
 			end
 			chip drivers/intel/mipi_camera
@@ -808,6 +810,7 @@ chip soc/intel/meteorlake
 				register "sdmode_delay" = "5"
 				device generic 0 on
 					probe AUDIO MAX98360_ALC5682I_I2S
+					probe AUDIO MAX98360_ALC5682I_DISCRETE_I2S_BT
 				end
 			end
 			chip drivers/intel/soundwire
diff --git a/src/mainboard/google/rex/variants/rex0/variant.c b/src/mainboard/google/rex/variants/rex0/variant.c
index 2441f96cfd..a7e26e69e5 100644
--- a/src/mainboard/google/rex/variants/rex0/variant.c
+++ b/src/mainboard/google/rex/variants/rex0/variant.c
@@ -29,7 +29,8 @@ void variant_generate_s0ix_hook(enum s0ix_entry entry)
 void variant_update_soc_chip_config(struct soc_intel_meteorlake_config *config)
 {
 	if (fw_config_probe(FW_CONFIG(AUDIO, MAX98360_ALC5682I_I2S)) ||
-	    fw_config_probe(FW_CONFIG(AUDIO, MAX98363_CS42L42_SNDW))) {
+	    fw_config_probe(FW_CONFIG(AUDIO, MAX98363_CS42L42_SNDW)) ||
+	    fw_config_probe(FW_CONFIG(AUDIO, MAX98360_ALC5682I_DISCRETE_I2S_BT))) {
 		config->cnvi_bt_audio_offload = true;
 	}