mb/google/dedede/var/metaknight: Add LTE power on/off sequence

LTE module used in metaknight has a specific power on/off sequence.
GPIOs related to power sequence are:
* GPP_A10 - LTE_PWR_OFF_R_ODL
* GPP_H17 - LTE_RESET_R_ODL
1. Power on: GPP_A10 -> 20ms -> GPP_H17
2. Power off: GPP_H17 -> 10ms -> GPP_A10
3. Warm reset: GPP_A10 keeps high, GPP_H17 goes low at least 2ms
Configure the GPIOs based on these requirements.

BUG=b:173671094
TEST=Build and boot Metaknight to OS. Ensure that the LTE module power
sequence requirements are met.

Change-Id: Ibff16129dfe2f1de2b1519049244aba4b3123e52
Signed-off-by: Tim Chen <tim-chen@quanta.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/48195
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>

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

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+ramstage-y += gpio.c
+
+smm-y += variant.c

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

@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <baseboard/gpio.h>
+#include <baseboard/variants.h>
+#include <commonlib/helpers.h>
+#include <vendorcode/google/chromeos/chromeos.h>
+
+/* Pad configuration in ramstage*/
+static const struct pad_config gpio_table[] = {
+	/* A10 : WWAN_EN => LTE_PWR_OFF_ODL */
+	PAD_CFG_GPO(GPP_A10, 1, PWROK),
+
+	/* H17 : WWAN_RST_L => LTE_RESET_R_ODL */
+	PAD_CFG_GPO(GPP_H17, 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/metaknight/overridetree.cb

@@ -68,6 +68,16 @@ chip soc/intel/jasperlake
 		device pci 14.0 on
 			chip drivers/usb/acpi
 				device usb 0.0 on
+					chip drivers/usb/acpi
+						register "desc" = ""LTE""
+						register "type" = "UPC_TYPE_INTERNAL"
+						register "has_power_resource" = "1"
+						register "reset_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_LOW(GPP_H17)"
+						register "reset_off_delay_ms" = "10"
+						register "enable_gpio" = "ACPI_GPIO_OUTPUT_ACTIVE_HIGH(GPP_A10)"
+						register "enable_delay_ms" = "20"
+						device usb 2.3 on end
+					end
 					chip drivers/usb/acpi
 						register "desc" = ""User Facing Camera""
 						register "type" = "UPC_TYPE_INTERNAL"
@@ -78,6 +88,11 @@ chip soc/intel/jasperlake
 						register "type" = "UPC_TYPE_INTERNAL"
 						device usb 2.6 on end
 					end
+					chip drivers/usb/acpi
+						register "desc" = ""LTE""
+						register "type" = "UPC_TYPE_INTERNAL"
+						device usb 3.3 on end
+					end
 				end
 			end
 		end # USB xHCI

src/mainboard/google/dedede/variants/metaknight/variant.c

@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <acpi/acpi.h>
+#include <baseboard/variants.h>
+#include <delay.h>
+#include <gpio.h>
+
+static void power_off_lte_module(void)
+{
+	gpio_output(GPP_H17, 0);
+	mdelay(10);
+	gpio_output(GPP_A10, 0);
+}
+
+void variant_smi_sleep(u8 slp_typ)
+{
+	/*
+	 * Once the FW_CONFIG is provisioned, power off LTE module only under
+	 * the situation where it is stuffed.
+	 */
+	if (slp_typ == ACPI_S5)
+		power_off_lte_module();
+}