drivers/net/r8168: Add SSDT Power Resource Methods

Turns out when going into S0ix we want the kernel to toggle de-assert to 0 for
the ISOLATE# pin on the NIC for S0ix not to be woken by PCIe traffic on PCH.
Upon resume the ISOLATE# pin on the NIC is then re-asserted for it to become
lively again.

V.2: Ensure reset_gpio && enable_gpio are optional.

BUG=b:147026979
BRANCH=none
TEST=Boot puff and do 100 cycles of S0ix.

Change-Id: I3ae8dc30f45f55eec23f45e7b5fbc67a4542f87d
Signed-off-by: Edward O'Callaghan <quasisec@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38494
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/drivers/net/chip.h

@@ -15,10 +15,22 @@
 #define __DRIVERS_R8168_CHIP_H__
 
 #include <stdint.h>
+#include <arch/acpi_device.h>
 
 struct drivers_net_config {
 	uint16_t customized_leds;
 	unsigned int wake;	/* Wake pin for ACPI _PRW */
+
+	/* Does the device have a power resource? */
+	bool has_power_resource;
+
+	/* GPIO used to stop operation of device. */
+	struct acpi_gpio stop_gpio;
+	/* Delay to be inserted after disabling stop. */
+	unsigned int stop_delay_ms;
+	/* Delay to be inserted after enabling stop. */
+	unsigned int stop_off_delay_ms;
+
 	/*
 	 * There maybe many NIC cards in a system.
 	 * This parameter is for driver to identify what

src/drivers/net/r8168.c

@@ -317,6 +317,16 @@ static void r8168_net_fill_ssdt(struct device *dev)
 	if (dev->chip_ops)
 		acpigen_write_name_string("_DDN", dev->chip_ops->name);
 
+	/* Power Resource */
+	if (config->has_power_resource) {
+		const struct acpi_power_res_params power_res_params = {
+			.stop_gpio = &config->stop_gpio,
+			.stop_delay_ms = config->stop_delay_ms,
+			.stop_off_delay_ms = config->stop_off_delay_ms
+		};
+		acpi_device_add_power_res(&power_res_params);
+	}
+
 	/* Address */
 	address = PCI_SLOT(dev->path.pci.devfn) & 0xffff;
 	address <<= 16;