soc/intel/common: Implement power-failure-state handling

This is a consolidation of the respective feature in `soc/intel/*lake/`,
including additional support for MAINBOARD_POWER_STATE_PREVIOUS.

For the latter, firmware has to keep track of the `previous` state. The
feature was already advertised in Kconfig long ago, but not implemented.

SoC code has to call pmc_set_power_failure_state() at least once during
boot and needs to implement pmc_soc_set_afterg3_en() for the actual
register write.

Change-Id: Ic6970a79d9b95373c2855f4c92232d2aa05963bb
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34724
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/soc/intel/common/block/include/intelblocks/pmclib.h

@@ -16,6 +16,7 @@
 #ifndef SOC_INTEL_COMMON_BLOCK_PMCLIB_H
 #define SOC_INTEL_COMMON_BLOCK_PMCLIB_H
 
+#include <device/pci_type.h>
 #include <stdint.h>
 
 /* Forward declare the power state struct here */
@@ -214,4 +215,20 @@ enum {
 	MAINBOARD_POWER_STATE_PREVIOUS,
 };
 
+/*
+ * Implemented by SoC code to set PMC register to know which state
+ * system should go into after power is reapplied.
+ */
+void pmc_soc_set_afterg3_en(bool on);
+/*
+ * Configure power state to go into when power is reapplied.
+ *
+ * To be called by SoC code once during boot and will be called by
+ * the "sleep" SMI handler when going into S5.
+ *
+ * `target_on` signifies that we are currently powering on, so that
+ * MAINBOARD_POWER_STATE_PREVIOUS can be handled accordingly.
+ */
+void pmc_set_power_failure_state(bool target_on);
+
 #endif /* SOC_INTEL_COMMON_BLOCK_PMCLIB_H */

src/soc/intel/common/block/pmc/pmclib.c

@@ -579,3 +579,30 @@ void pmc_gpe_init(void)
 	/* Set the routes in the GPIO communities as well. */
 	gpio_route_gpe(dw0, dw1, dw2);
 }
+
+void pmc_set_power_failure_state(const bool target_on)
+{
+	const int state = CONFIG_MAINBOARD_POWER_FAILURE_STATE;
+	bool on;
+
+	switch (state) {
+	case MAINBOARD_POWER_STATE_OFF:
+		printk(BIOS_INFO, "Set power off after power failure.\n");
+		on = false;
+		break;
+	case MAINBOARD_POWER_STATE_ON:
+		printk(BIOS_INFO, "Set power on after power failure.\n");
+		on = true;
+		break;
+	case MAINBOARD_POWER_STATE_PREVIOUS:
+		printk(BIOS_INFO, "Keep power state after power failure.\n");
+		on = target_on;
+		break;
+	default:
+		printk(BIOS_WARNING, "WARNING: Unknown power-failure state: %d\n", state);
+		on = false;
+		break;
+	}
+
+	pmc_soc_set_afterg3_en(on);
+}