mb/google/volteer/var/volet: Update gpio and devicetree settings

Based on schematic and gpio table of volet, update gpio and
devicetree settings for volet Proto.

BUG=b:186334008
TEST=FW_NAME=volet emerge-volteer coreboot chromeos-bootimage

Signed-off-by: Sheng-Liang Pan <sheng-liang.pan@quanta.corp-partner.google.com>
Change-Id: Ia0e9557e01ce1e7a49a3dddf6da3e4a29587a8b7
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55113
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

4 files changed, 530 insertions, 1 deletions

diff --git a/src/mainboard/google/volteer/variants/volet/Makefile.inc b/src/mainboard/google/volteer/variants/volet/Makefile.inc
index 9064208bff..3488dc6cc2 100644
--- a/src/mainboard/google/volteer/variants/volet/Makefile.inc
+++ b/src/mainboard/google/volteer/variants/volet/Makefile.inc
@@ -1,3 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
+bootblock-y += gpio.c
+
 romstage-y += memory.c
+
+ramstage-y += gpio.c
+ramstage-y += ramstage.c
diff --git a/src/mainboard/google/volteer/variants/volet/gpio.c b/src/mainboard/google/volteer/variants/volet/gpio.c
new file mode 100644
index 0000000000..4ec02c5167
--- /dev/null
+++ b/src/mainboard/google/volteer/variants/volet/gpio.c
@@ -0,0 +1,294 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <acpi/acpi.h>
+#include <baseboard/gpio.h>
+#include <baseboard/variants.h>
+#include <commonlib/helpers.h>
+
+/* Pad configuration in ramstage */
+static const struct pad_config override_gpio_table[] = {
+	/* A7  : I2S2_SCLK ==> EN_PP3300_TRACKPAD */
+	PAD_CFG_GPO(GPP_A7, 1, DEEP),
+	/* A8  : I2S2_SFRM ==> EN_PP3300_TOUCHSCREEN */
+	PAD_CFG_GPO(GPP_A8, 1, DEEP),
+	/* A10 : I2S2_RXD ==> EN_SPKR_PA */
+	PAD_CFG_GPO(GPP_A10, 1, DEEP),
+	/* A13 : PMC_I2C_SCL ==> BT_DISABLE_L */
+	PAD_CFG_GPO(GPP_A13, 1, DEEP),
+	/* A16 : USB_OC3# ==> USB_C0_OC_ODL */
+	PAD_CFG_NF(GPP_A16, NONE, DEEP, NF1),
+	/* A18 : DDSP_HPDB ==> HDMI_HPD */
+	PAD_CFG_NF(GPP_A18, NONE, DEEP, NF1),
+	/* A22 : DDPC_CTRLDATA ==> EN_HDMI_PWR */
+	PAD_CFG_GPO(GPP_A22, 1, DEEP),
+	/* A23 : I2S1_SCLK ==> I2S1_SPKR_SCLK */
+	PAD_CFG_NF(GPP_A23, NONE, DEEP, NF1),
+
+	/* B2  : VRALERT# ==> EN_PP3300_SSD */
+	PAD_CFG_GPO(GPP_B2, 1, DEEP),
+	/* B3  : CPU_GP2 ==> PEN_DET_ODL */
+	PAD_CFG_GPI_GPIO_DRIVER(GPP_B3, NONE, PLTRST),
+	/* B5  : ISH_I2C0_CVF_SDA */
+	PAD_CFG_NF(GPP_B5, NONE, DEEP, NF1),
+	/* B6  : ISH_I2C0_CVF_SCL */
+	PAD_CFG_NF(GPP_B6, NONE, DEEP, NF1),
+	/* B7  : ISH_12C1_SDA ==> ISH_I2C0_SENSOR_SDA */
+	PAD_CFG_NF(GPP_B7, NONE, DEEP, NF1),
+	/* B8  : ISH_I2C1_SCL ==> ISH_I2C0_SENSOR_SCL */
+	PAD_CFG_NF(GPP_B8, NONE, DEEP, NF1),
+	/* B9  : I2C5_SDA ==> PCH_I2C5_TRACKPAD_SDA */
+	PAD_CFG_NF(GPP_B9, NONE, DEEP, NF1),
+	/* B10 : I2C5_SCL ==> PCH_I2C5_TRACKPAD_SCL */
+	PAD_CFG_NF(GPP_B10, NONE, DEEP, NF1),
+	/* B18 : GSPI0_MOSI ==> PCH_GSPI0_H1_TPM_MOSI_STRAP */
+	PAD_CFG_NF(GPP_B18, DN_20K, DEEP, NF1),
+	/* B19 : GSPI1_CS0# ==> PCH_GSPI1_FPMCU_CS_L */
+	PAD_CFG_NF(GPP_B19, NONE, DEEP, NF1),
+	/* B20 : GSPI1_CLK ==> PCH_GSPI1_FPMCU_CLK */
+	PAD_CFG_NF(GPP_B20, NONE, DEEP, NF1),
+	/* B21 : GSPI1_MISO ==> PCH_GSPI1_FPMCU_MISO */
+	PAD_CFG_NF(GPP_B21, NONE, DEEP, NF1),
+	/* B23 : SML1ALERT# ==> GPP_B23_STRAP # */
+	PAD_NC(GPP_B23, DN_20K),
+
+	/* C0  : SMBCLK ==> EN_PP3300_WLAN */
+	PAD_CFG_GPO(GPP_C0, 1, DEEP),
+	/* C2  : SMBALERT# ==> GPP_C2_STRAP */
+	PAD_NC(GPP_C2, DN_20K),
+	/* C3  : SML0CLK ==> USB4_SMB_SCL */
+	PAD_CFG_NF(GPP_C3, NONE, DEEP, NF1),
+	/* C4  : SML0DATA ==> USB4_SMB_SDA */
+	PAD_CFG_NF(GPP_C4, NONE, DEEP, NF1),
+	/* C5  : SML0ALERT# ==> GPP_C5_BOOT_STRAP0 */
+	PAD_NC(GPP_C5, DN_20K),
+	/* C7  : SML1DATA ==> EN_PP5000_PEN */
+	PAD_CFG_GPO(GPP_C7, 1, DEEP),
+	/* C10 : UART0_RTS# ==> USI_RST_L */
+	PAD_CFG_GPO(GPP_C10, 1, DEEP),
+	/* C13 : UART1_TXD ==> EN_PP5000_TRACKPAD */
+	PAD_CFG_GPO(GPP_C13, 1, DEEP),
+	/* C16 : I2C0_SDA ==> PCH_I2C0_1V8_AUDIO_SDA */
+	PAD_CFG_NF(GPP_C16, NONE, DEEP, NF1),
+	/* C17 : I2C0_SCL ==> PCH_I2C0_1V8_AUDIO_SCL */
+	PAD_CFG_NF(GPP_C17, NONE, DEEP, NF1),
+	/* C18 : I2C1_SDA ==> PCH_I2C1_TOUCH_USI_SDA */
+	PAD_CFG_NF(GPP_C18, NONE, DEEP, NF1),
+	/* C19 : I2C1_SCL ==> PCH_I2C1_TOUCH_USI_SCL */
+	PAD_CFG_NF(GPP_C19, NONE, DEEP, NF1),
+	/* C20 : UART2_RXD ==> FPMCU_INT_L */
+	PAD_CFG_GPI_INT(GPP_C20, NONE, PLTRST, LEVEL),
+	/* C22 : UART2_RTS# ==> PCH_FPMCU_BOOT0 */
+	PAD_CFG_GPO(GPP_C22, 0, DEEP),
+
+	/* D0  : ISH_GP0 ==> ISH_IMU_INT_L */
+	PAD_CFG_GPI(GPP_D0, NONE, DEEP),
+	/* D1  : ISH_GP1 ==> ISH_ACCEL_INT_L */
+	PAD_CFG_GPI(GPP_D1, NONE, DEEP),
+	/* D2  : ISH_GP2 ==> ISH_LID_OPEN */
+	PAD_CFG_GPI(GPP_D2, NONE, DEEP),
+	/* D3  : ISH_GP3 ==> ISH_ALS_RGB_INT_L */
+	PAD_CFG_GPI(GPP_D3, NONE, DEEP),
+	/* D4  : IMGCLKOUT0 ==> FCAM_RST_L */
+	PAD_CFG_GPO(GPP_D4, 0, PLTRST),
+	/* D6  : SRCCLKREQ1# ==> WLAN_CLKREQ_ODL */
+	PAD_CFG_NF(GPP_D6, NONE, DEEP, NF1),
+	/* D7  : SRCCLKREQ2# ==> WWAN_CLKREQ_ODL */
+	PAD_CFG_NF(GPP_D7, NONE, DEEP, NF1),
+	/* D8  : SRCCLKREQ3# ==> SD_CLKREQ_ODL */
+	PAD_CFG_NF(GPP_D8, NONE, DEEP, NF1),
+	/* D9  : ISH_SPI_CS# ==> PCH_GSPI2_CVF_CS_L */
+	PAD_CFG_NF(GPP_D9, NONE, DEEP, NF7),
+	/* D10 : ISH_SPI_CLK ==> PCH_GSPI2_CVF_CLK_STRAP */
+	PAD_CFG_NF(GPP_D10, DN_20K, DEEP, NF7),
+	/* D11 : ISH_SPI_MISO ==> PCH_GSPI2_CVF_MISO */
+	PAD_CFG_NF(GPP_D11, NONE, DEEP, NF7),
+	/* D12 : ISH_SPI_MOSI ==> PCH_GSPI2_CVF_MISO_STRAP */
+	PAD_CFG_NF(GPP_D12, DN_20K, DEEP, NF7),
+	/* D13 : ISH_UART0_RXD ==> UART_ISH_RX_DEBUG_TX */
+	PAD_CFG_NF(GPP_D13, NONE, DEEP, NF1),
+	/* D14 : ISH_UART0_TXD ==> UART_ISH_TX_DEBUG_RX */
+	PAD_CFG_NF(GPP_D14, NONE, DEEP, NF1),
+	/* D16 : ISH_UART0_CTS# ==> EN_PP3300_SD */
+	PAD_CFG_GPO(GPP_D16, 1, DEEP),
+	/* D17 : ISH_GP4 ==> EN_FCAM_PWR */
+	PAD_CFG_GPO(GPP_D17, 1, DEEP),
+
+	/* E1  : SPI1_IO2 ==> PEN_DET_ODL */
+	PAD_CFG_GPI_SCI(GPP_E1, NONE, DEEP, EDGE_SINGLE, NONE),
+	/* E2  : SPI1_IO3 ==> WLAN_PCIE_WAKE_ODL */
+	PAD_CFG_GPI(GPP_E2, NONE, DEEP),
+	/* E3  : CPU_GP0 ==> USI_REPORT_EN */
+	PAD_CFG_GPO(GPP_E3, 1, DEEP),
+	/* E7  : CPU_GP1 ==> USI_INT */
+	PAD_CFG_GPI_APIC(GPP_E7, NONE, PLTRST, LEVEL, NONE),
+	/* E8  : SPI1_CS1# ==> SLP_S0IX */
+	PAD_CFG_GPO(GPP_E8, 0, DEEP),
+	/* E11 : SPI1_CLK ==> SD_PE_WAKE_ODL */
+	PAD_CFG_GPI(GPP_E11, NONE, DEEP),
+	/* E12 : SPI1_MISO_IO1 ==> PEN_OC_ODL */
+	PAD_CFG_GPI(GPP_E12, NONE, DEEP),
+	/* E15 : ISH_GP6 ==> TRACKPAD_INT_ODL */
+	PAD_CFG_GPI_APIC(GPP_E15, NONE, PLTRST, LEVEL, INVERT),
+	/* E16 : ISH_GP7 ==> WWAN_SIM1_DET_OD */
+	PAD_CFG_GPI(GPP_E16, NONE, DEEP),
+	/* E17 : THC0_SPI1_INT# ==> WWAN_PERST_L */
+	PAD_CFG_GPO(GPP_E17, 1, DEEP),
+	/* E19 : DDP1_CTRLDATA ==> USB0_C0_LSX_SOC_RX_STRAP */
+	PAD_CFG_NF(GPP_E19, DN_20K, DEEP, NF4),
+
+	/* F6  : CNV_PA_BLANKING ==> WWAN_WLAN_COEX3 */
+	PAD_CFG_NF(GPP_F6, NONE, DEEP, NF1),
+	/* F7  : GPPF7_STRAP */
+	PAD_NC(GPP_F7, DN_20K),
+	/* F8  : I2S_MCLK2_INOUT ==> HP_INT_L */
+	PAD_CFG_GPI_INT(GPP_F8, NONE, PLTRST, EDGE_BOTH),
+	/* F11 : THC1_SPI2_CLK ==> EN_PP3300_WWAN */
+	PAD_CFG_GPO(GPP_F11, 1, DEEP),
+	/* F12 : GSXDOUT ==> WWAN_RST_ODL */
+	PAD_CFG_GPI(GPP_F12, NONE, DEEP),
+	/* F13 : GSXDOUT ==> WiFi_DISABLE_L */
+	PAD_CFG_GPO(GPP_F13, 1, DEEP),
+	/* F14 : GSXDIN ==> SAR0_INT_L */
+	PAD_CFG_GPI_SCI_LOW(GPP_F14, NONE, PLTRST, EDGE_SINGLE),
+	/* F16 : GSXCLK ==> WWAN_DPR_SAR_ODL */
+	PAD_CFG_GPO(GPP_F16, 1, DEEP),
+	/* F17 : WWAN_RF_DISABLE_ODL */
+	PAD_CFG_GPO(GPP_F17, 1, DEEP),
+	/* F18 : THC1_SPI2_INT# ==> WWAN_PCIE_WAKE_ODL */
+	PAD_CFG_GPI_SCI_LOW(GPP_F18, NONE, DEEP, EDGE_SINGLE),
+	/* F19 : SRCCLKREQ6# ==> WLAN_INT_L */
+	PAD_CFG_GPI_SCI_LOW(GPP_F19, NONE, DEEP, EDGE_SINGLE),
+
+	/* H0  : GPPH0_BOOT_STRAP1 */
+	PAD_NC(GPP_H0, DN_20K),
+	/* H1  : GPPH1_BOOT_STRAP2 */
+	PAD_NC(GPP_H1, DN_20K),
+	/* H2  : GPPH2_BOOT_STRAP3 */
+	PAD_NC(GPP_H2, DN_20K),
+	/* H3  : SX_EXIT_HOLDOFF# ==> SD_PERST_L */
+	PAD_CFG_GPO(GPP_H3, 1, DEEP),
+	/* H6  : I2C3_SDA ==> PCH_I2C3_CAM_SAR1_SDA */
+	PAD_CFG_NF(GPP_H6, NONE, DEEP, NF1),
+	/* H7  : I2C3_SCL ==> PCH_I2C3_CAM_SAR1_SCL */
+	PAD_CFG_NF(GPP_H7, NONE, DEEP, NF1),
+	/* H8  : I2C4_SDA ==> WWAN_WLAN_COEX1 */
+	PAD_CFG_NF(GPP_H8, NONE, DEEP, NF2),
+	/* H9  : I2C4_SCL ==> WWAN_WLAN_COEX2 */
+	PAD_CFG_NF(GPP_H9, NONE, DEEP, NF2),
+	/* H12 : M2_SKT2_CFG0 ==> WWAN_CONFIG0 */
+	PAD_CFG_GPI(GPP_H12, NONE, DEEP),
+	/* H13 : M2_SKT2_CFG1 # ==> SPKR_INT_L */
+	PAD_CFG_GPI(GPP_H13, NONE, DEEP),
+	/* H15 : M2_SKT2_CFG3 # ==> WWAN_CONFIG3 */
+	PAD_CFG_GPI(GPP_H15, NONE, DEEP),
+	/* H16 : DDPB_CTRLCLK ==> DDPB_HDMI_CTRLCLK */
+	PAD_CFG_NF(GPP_H16, NONE, DEEP, NF1),
+	/* H17 : DDPB_CTRLDATA ==> DDPB_HDMI_CTRLDATA */
+	PAD_CFG_NF(GPP_H17, NONE, DEEP, NF1),
+	/* H19 : TIME_SYNC0 ==> USER_PRES_FP_ODL_R */
+	PAD_CFG_GPI(GPP_H19, NONE, DEEP),
+	/* H20 : IMGCLKOUT1 ==> EN_MIPI_RCAM_PWR */
+	PAD_CFG_GPO(GPP_H20, 0, DEEP),
+	/* H21 : IMGCLKOUT2 ==> CAM_MCLK1 */
+	PAD_CFG_NF(GPP_H21, NONE, DEEP, NF1),
+	/* H22 : IMGCLKOUT3 ==> CAM_MCLK0 */
+	PAD_CFG_NF(GPP_H22, NONE, DEEP, NF1),
+
+	/* R0 : HDA_BCLK ==> I2S0_HP_SCLK */
+	PAD_CFG_NF(GPP_R0, NONE, DEEP, NF2),
+	/* R1 : HDA_SYNC ==> I2S0_HP_SFRM */
+	PAD_CFG_NF(GPP_R1, NONE, DEEP, NF2),
+	/* R2 : HDA_SDO ==> I2S0_PCH_TX_HP_RX_STRAP */
+	PAD_CFG_NF(GPP_R2, DN_20K, DEEP, NF2),
+	/* R3 : HDA_SDIO ==> I2S0_PCH_RX_HP_TX */
+	PAD_CFG_NF(GPP_R3, NONE, DEEP, NF2),
+	/* R5 : HDA_SDI1 ==> I2S1_PCH_RX_SPKR_TX */
+	PAD_CFG_NF(GPP_R5, NONE, DEEP, NF2),
+	/* R6 : I2S1_TXD ==> I2S1_PCH_RX_SPKR_RX */
+	PAD_CFG_NF(GPP_R6, NONE, DEEP, NF2),
+	/* R7 : I2S1_SFRM ==> I2S1_SPKR_SFRM */
+	PAD_CFG_NF(GPP_R7, NONE, DEEP, NF2),
+
+	/* S0 : SNDW0_CLK ==> SNDW0_HP_CLK */
+	PAD_CFG_NF(GPP_S0, NONE, DEEP, NF1),
+	/* S1 : SNDW0_DATA ==> SNDW0_HP_DATA */
+	PAD_CFG_NF(GPP_S1, NONE, DEEP, NF1),
+	/* S2 : SNDW1_CLK ==> SNDW1_SPKR_CLK */
+	PAD_CFG_NF(GPP_S2, NONE, DEEP, NF1),
+	/* S3 : SNDW1_DATA ==> SNDW1_SPKR_DATA */
+	PAD_CFG_NF(GPP_S3, NONE, DEEP, NF1),
+	/* S6 : SNDW3_CLK ==> DMIC_CLK0 */
+	PAD_CFG_NF(GPP_S6, NONE, DEEP, NF2),
+	/* S7 : SNDW3_DATA ==> DMIC_DATA0 */
+	PAD_CFG_NF(GPP_S7, NONE, DEEP, NF2),
+
+	/* GPD9: SLP_WLAN# ==> SLP_WLAN_L */
+	PAD_CFG_NF(GPD9, NONE, DEEP, NF1),
+};
+
+const struct pad_config *variant_override_gpio_table(size_t *num)
+{
+	*num = ARRAY_SIZE(override_gpio_table);
+	return override_gpio_table;
+}
+
+/* Early pad configuration in bootblock */
+static const struct pad_config early_gpio_table[] = {
+	/* C8 : UART0 RX */
+	PAD_CFG_NF(GPP_C8, NONE, DEEP, NF1),
+	/* C9 : UART0 TX */
+	PAD_CFG_NF(GPP_C9, NONE, DEEP, NF1),
+
+	/* A12 : SATAXPCIE1 ==> M2_SSD_PEDET */
+	PAD_CFG_NF(GPP_A12, NONE, DEEP, NF1),
+	/* A13 : PMC_I2C_SCL ==> BT_DISABLE_L */
+	/* assert reset on reboot */
+	PAD_CFG_GPO(GPP_A13, 0, DEEP),
+	/* A17 : DDSP_HPDC ==> MEM_CH_SEL */
+	PAD_CFG_GPI(GPP_A17, NONE, DEEP),
+
+	/* B2  : VRALERT# ==> EN_PP3300_SSD */
+	PAD_CFG_GPO(GPP_B2, 1, DEEP),
+	/* B11 : PMCALERT# ==> PCH_WP_OD */
+	PAD_CFG_GPI_GPIO_DRIVER(GPP_B11, NONE, DEEP),
+	/* B15 : GSPI0_CS0# ==> PCH_GSPI0_H1_TPM_CS_L */
+	PAD_CFG_NF(GPP_B15, NONE, DEEP, NF1),
+	/* B16 : GSPI0_CLK ==> PCH_GSPI0_H1_TPM_CLK */
+	PAD_CFG_NF(GPP_B16, NONE, DEEP, NF1),
+	/* B17 : GSPI0_MISO ==> PCH_GSPIO_H1_TPM_MISO */
+	PAD_CFG_NF(GPP_B17, NONE, DEEP, NF1),
+	/* B18 : GSPI0_MOSI ==> PCH_GSPI0_H1_TPM_MOSI_STRAP */
+	PAD_CFG_NF(GPP_B18, DN_20K, DEEP, NF1),
+
+	/* C0  : SMBCLK ==> EN_PP3300_WLAN */
+	PAD_CFG_GPO(GPP_C0, 1, DEEP),
+	/* C21 : UART2_TXD ==> H1_PCH_INT_ODL */
+	PAD_CFG_GPI_APIC(GPP_C21, NONE, PLTRST, LEVEL, INVERT),
+	/* C22 : UART2_RTS# ==> PCH_FPMCU_BOOT0 */
+	PAD_CFG_GPO(GPP_C22, 0, DEEP),
+
+	/* D16 : ISH_UART0_CTS# ==> EN_PP3300_SD */
+	PAD_CFG_GPO(GPP_D16, 1, DEEP),
+};
+
+const struct pad_config *variant_early_gpio_table(size_t *num)
+{
+	*num = ARRAY_SIZE(early_gpio_table);
+	return early_gpio_table;
+}
+
+/* GPIO settings before entering S5 */
+static const struct pad_config s5_sleep_gpio_table[] = {
+	PAD_CFG_GPO(GPP_C23, 0, DEEP), /* FPMCU_RST_ODL */
+	PAD_CFG_GPO(GPP_A21, 0, DEEP), /* EN_FP_PWR */
+};
+
+const struct pad_config *variant_sleep_gpio_table(u8 slp_typ, size_t *num)
+{
+	if (slp_typ == ACPI_S5) {
+		*num = ARRAY_SIZE(s5_sleep_gpio_table);
+		return s5_sleep_gpio_table;
+	}
+	*num = 0;
+	return NULL;
+}
diff --git a/src/mainboard/google/volteer/variants/volet/overridetree.cb b/src/mainboard/google/volteer/variants/volet/overridetree.cb
index 32204c58e7..bc8cb499e4 100644
--- a/src/mainboard/google/volteer/variants/volet/overridetree.cb
+++ b/src/mainboard/google/volteer/variants/volet/overridetree.cb
@@ -1,6 +1,216 @@
 chip soc/intel/tigerlake
+	register "DdiPort1Hpd" = "0"
+	register "DdiPort2Hpd" = "0"
+
+	register "usb2_ports[3]" = "USB2_PORT_TYPE_C(OC_SKIP)"     # Type-A / Type-C Cl
+	register "usb2_ports[8]" = "USB2_PORT_TYPE_C(OC_SKIP)"     # Type-A / Type-C C0
+
+	register "TcssAuxOri" = "1"
+	register "typec_aux_bias_pads[0]" = "{.pad_auxp_dc = GPP_E10, .pad_auxn_dc = GPP_E13}"
+
+	# Disable SRCCLKREQ1#
+	register "PcieClkSrcUsage[1]" = "PCIE_CLK_NOTUSED"
 
 	device domain 0 on
+		device ref i2c0 on
+			chip drivers/i2c/generic
+				register "hid" = ""10EC5682""
+				register "name" = ""RT58""
+				register "desc" = ""Headset Codec""
+				register "irq_gpio" = "ACPI_GPIO_IRQ_EDGE_BOTH(GPP_F8)"
+				# Set the jd_src to RT5668_JD1 for jack detection
+				register "property_count" = "1"
+				register "property_list[0].type" = "ACPI_DP_TYPE_INTEGER"
+				register "property_list[0].name" = ""realtek,jd-src""
+				register "property_list[0].integer" = "1"
+				device i2c 1a on end
+			end
+			chip drivers/i2c/max98373
+				register "vmon_slot_no" = "0"
+				register "imon_slot_no" = "1"
+				register "uid" = "0"
+				register "desc" = ""Right Speaker Amp""
+				register "name" = ""MAXR""
+				device i2c 31 on end
+			end
+			chip drivers/i2c/max98373
+				register "vmon_slot_no" = "2"
+				register "imon_slot_no" = "3"
+				register "uid" = "1"
+				register "desc" = ""Left Speaker Amp""
+				register "name" = ""MAXL""
+				device i2c 32 on end
+			end
+		end
+		device ref i2c1 on
+			chip drivers/i2c/hid
+				register "generic.hid" = ""ELAN90FC""
+				register "generic.desc" = ""ELAN Touchscreen""
+				register "generic.irq" = "ACPI_IRQ_LEVEL_LOW(GPP_E7_IRQ)"
+				register "generic.probed" = "1"
+				register "generic.reset_gpio" =
+							"ACPI_GPIO_OUTPUT_ACTIVE_LOW(GPP_C10)"
+				register "generic.enable_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_HIGH(GPP_A8)"
+				register "generic.reset_delay_ms" = "20"
+				register "generic.has_power_resource" = "1"
+				register "generic.disable_gpio_export_in_crs" = "1"
+				register "hid_desc_reg_offset" = "0x01"
+				device i2c 10 on end
+			end
+			chip drivers/i2c/generic
+				register "hid" = ""RAYD0001""
+				register "desc" = ""Raydium Touchscreen""
+				register "irq" = "ACPI_IRQ_EDGE_LOW(GPP_E7_IRQ)"
+				register "probed" = "1"
+				register "reset_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_LOW(GPP_C10)"
+				register "reset_delay_ms" = "1"
+				register "reset_off_delay_ms" = "2"
+				register "enable_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_HIGH(GPP_A8)"
+				register "enable_delay_ms" = "10"
+				register "enable_off_delay_ms" = "1"
+				register "has_power_resource" = "1"
+				device i2c 39 on end
+			end
+		end
+		device ref i2c2 on
+			chip drivers/i2c/sx9310
+				register "desc" = ""SAR0 Proximity Sensor""
+				register "irq" = "ACPI_IRQ_LEVEL_LOW(GPP_F14_IRQ)"
+				register "speed" = "I2C_SPEED_FAST"
+				register "uid" = "0"
+				register "cs0_ground" = "0x0"
+				register "combined_sensors_count" = "3"
+				register "combined_sensors[0]" = "0"
+				register "combined_sensors[1]" = "1"
+				register "combined_sensors[2]" = "2"
+				register "resolution" = "SX9310_FINEST"
+				register "avg_pos_strength" = "512"
+				register "startup_sensor" = "0"
+				register "proxraw_strength" = "0"
+				device i2c 28 on end
+			end
+		end
+		device ref i2c5 on
+			chip drivers/i2c/generic
+				register "hid" = ""ELAN0000""
+				register "desc" = ""ELAN Touchpad""
+				register "irq" = "ACPI_IRQ_WAKE_LEVEL_LOW(GPP_E15_IRQ)"
+				register "wake" = "GPE0_DW2_15"
+				register "probed" = "1"
+				device i2c 15 on end
+			end
+			chip drivers/i2c/hid
+				register "generic.hid" = ""PNP0C50""
+				register "generic.desc" = ""Synaptics Touchpad""
+				register "generic.irq" = "ACPI_IRQ_WAKE_LEVEL_LOW(GPP_E15_IRQ)"
+				register "generic.wake" = "GPE0_DW2_15"
+				register "generic.probed" = "1"
+				register "hid_desc_reg_offset" = "0x20"
+				device i2c 2c on end
+			end
+		end
+		device ref pch_espi on
+			chip ec/google/chromeec
+				use conn0 as mux_conn[0]
+				use conn1 as mux_conn[1]
+				device pnp 0c09.0 on end
+			end
+		end
+		device ref pcie_rp9 on
+			chip soc/intel/common/block/pcie/rtd3
+				register "enable_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_HIGH(GPP_B2)"
+				register "reset_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_LOW(GPP_A11)"
+				register "srcclk_pin" = "0"
+				device generic 0 on end
+			end
+		end
+		# This variant has USB4/PCIe on both ports so RP0 must be enabled
+		# in order for hotplug resources to be assigned to Type-C Port C0.
+		device ref tbt_pcie_rp0 on
+			probe DB_USB USB4_GEN3
+		end
+		device ref pmc hidden
+			# The pmc_mux chip driver is a placeholder for the
+			# PMC.MUX device in the ACPI hierarchy.
+			chip drivers/intel/pmc_mux
+				device generic 0 on
+					chip drivers/intel/pmc_mux/conn
+						register "usb2_port_number" = "9"
+						register "usb3_port_number" = "1"
+						device generic 0 alias conn0 on end
+					end
+					chip drivers/intel/pmc_mux/conn
+						register "usb2_port_number" = "4"
+						register "usb3_port_number" = "2"
+						# SBU is fixed, HSL follows CC
+						register "sbu_orientation" = "TYPEC_ORIENTATION_NORMAL"
+						device generic 1 alias conn1 on end
+					end
+				end
+			end
+		end
+		device ref north_xhci on
+			chip drivers/usb/acpi
+				device ref tcss_root_hub on
+					chip drivers/usb/acpi
+						register "desc" = ""USB3 Type-C Port C0 (MLB)""
+						register "type" = "UPC_TYPE_C_USB2_SS_SWITCH"
+						register "group" = "ACPI_PLD_GROUP(3, 2)"
+						device ref tcss_usb3_port1 on end
+					end
+					chip drivers/usb/acpi
+						register "desc" = ""USB3 Type-C Port C1 (MLB)""
+						register "type" = "UPC_TYPE_C_USB2_SS_SWITCH"
+						register "group" = "ACPI_PLD_GROUP(2, 2)"
+						device ref tcss_usb3_port2 on end
+					end
+				end
+			end
+		end
+		device ref south_xhci on
+			chip drivers/usb/acpi
+				device ref xhci_root_hub on
+					chip drivers/usb/acpi
+						register "desc" = ""USB2 Type-A Port A1 (DB)""
+						register "type" = "UPC_TYPE_A"
+						register "group" = "ACPI_PLD_GROUP(1, 1)"
+						device ref usb2_port2 on
+							probe DB_USB USB4_GEN3
+						end
+					end
+					chip drivers/usb/acpi
+						register "desc" = ""USB2 Type-C Port C1 (MLB)""
+						register "type" = "UPC_TYPE_C_USB2_SS_SWITCH"
+						register "group" = "ACPI_PLD_GROUP(2, 1)"
+						device ref usb2_port4 on end
+					end
+					chip drivers/usb/acpi
+						register "desc" = ""USB2 Camera""
+						register "type" = "UPC_TYPE_INTERNAL"
+						device ref usb2_port5 on end
+					end
+					chip drivers/usb/acpi
+						register "desc" = ""USB2 Type-C Port C0 (MLB)""
+						register "type" = "UPC_TYPE_C_USB2_SS_SWITCH"
+						register "group" = "ACPI_PLD_GROUP(3, 1)"
+						device ref usb2_port9 on end
+					end
+					chip drivers/usb/acpi
+						register "desc" = ""USB2 Bluetooth""
+						register "type" = "UPC_TYPE_INTERNAL"
+						register "reset_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_LOW(GPP_A13)"
+						device ref usb2_port10 on end
+					end
+					chip drivers/usb/acpi
+						register "desc" = ""USB3 Type-A Port A1 (DB)""
+						register "type" = "UPC_TYPE_USB3_A"
+						register "group" = "ACPI_PLD_GROUP(1, 2)"
+						device ref usb3_port2 on
+							probe DB_USB USB4_GEN3
+						end
+					end
+				end
+			end
+		end
 	end
-
 end
diff --git a/src/mainboard/google/volteer/variants/volet/ramstage.c b/src/mainboard/google/volteer/variants/volet/ramstage.c
new file mode 100644
index 0000000000..b198992824
--- /dev/null
+++ b/src/mainboard/google/volteer/variants/volet/ramstage.c
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <delay.h>
+#include <gpio.h>
+#include <baseboard/variants.h>
+#include <soc/gpio.h>
+
+void variant_ramstage_init(void)
+{
+	/*
+	 * Assert FPMCU reset and enable power to FPMCU,
+	 * wait for power rail to stabilize,
+	 * and then deassert FPMCU reset.
+	 * Waiting for the power rail to stabilize can take a while.
+	 */
+	gpio_output(GPP_C23, 0);
+	gpio_output(GPP_A21, 1);
+	mdelay(1);
+	gpio_output(GPP_C23, 1);
+}