mb/google/dedede/var/waddledee: Enable GPIO based I2C Multiplexer

The camera sensor component chosen for UFC and WFC have an address
conflict. Resolve it by enabling GPIO based I2C Multiplexer. Also
configure the GPIO that is used as select line.

BUG=b:169444894
TEST=Build and boot waddledee to OS. Ensure that the ACPI identifiers
are added for I2C devices multiplexed using I2C MUX under the
appropriate scope.

Change-Id: I9b09e063b4377587019ade9e6e194f4aadcdd312
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45912
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/mainboard/google/dedede/Kconfig

@@ -4,6 +4,7 @@ config BOARD_GOOGLE_BASEBOARD_DEDEDE
 	select CR50_USE_LONG_INTERRUPT_PULSES
 	select DPTF_USE_EISA_HID
 	select DRIVERS_I2C_GENERIC
+	select DRIVERS_I2C_GPIO_MUX
 	select DRIVERS_I2C_HID
 	select DRIVERS_INTEL_DPTF
 	select DRIVERS_SPI_ACPI

src/mainboard/google/dedede/variants/waddledee/Makefile.inc

@@ -2,4 +2,5 @@
 
 romstage-y += memory.c
 
+ramstage-y += gpio.c
 ramstage-y += variant.c

src/mainboard/google/dedede/variants/waddledee/gpio.c

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <baseboard/gpio.h>
+#include <baseboard/variants.h>
+
+/* Pad configuration in ramstage*/
+static const struct pad_config gpio_table[] = {
+	/* E5  : AP_SUB_IO_2 */
+	PAD_CFG_GPO(GPP_E5, 0, PLTRST),
+};
+
+const struct pad_config *variant_override_gpio_table(size_t *num)
+{
+	*num = ARRAY_SIZE(gpio_table);
+	return gpio_table;
+}

src/mainboard/google/dedede/variants/waddledee/overridetree.cb

@@ -119,6 +119,20 @@ chip soc/intel/jasperlake
 				device i2c 0x5d on end
 			end
 		end # I2C 2
+		device pci 15.3 on
+			chip drivers/i2c/gpiomux/mux
+				register "mux_gpio_count" = "1"
+				register "mux_gpio[0]" = "ACPI_GPIO_OUTPUT(GPP_E5)"
+				device generic 0 on
+					chip drivers/i2c/gpiomux/bus
+						device generic 0 on end # I2C Mux Bus 0
+					end
+					chip drivers/i2c/gpiomux/bus
+						device generic 1 on end # I2C Mux Bus 1
+					end
+				end # I2C MUX
+			end
+		end # I2C 3
 		device pci 19.0 on
 			chip drivers/i2c/generic
 				register "hid" = ""10EC5682""