dptf: Add support for generation of Active Policies

This change adds support for generating the different pieces of DPTF
Active Policies. This includes the Active Relationship Table, in
addition to _ACx methods.

BUG=b:143539650
TEST=compiles

Change-Id: Iea0ccbd96f88d0f3a8f2c77a7d0f3a284e5ee463
Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41885
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Sumeet R Pawnikar <sumeet.r.pawnikar@intel.com>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>

src/include/acpi/acpigen_dptf.h

@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef ACPI_ACPIGEN_DPTF_H
+#define ACPI_ACPIGEN_DPTF_H
+
+#include <device/device.h>
+#include <stdbool.h>
+
+/* A common idiom is to use a default value if none is provided (i.e., == 0) */
+#define DEFAULT_IF_0(thing, default_) ((thing) ? (thing) : (default_))
+
+/* List of available participants (i.e., they can participate in policies) */
+enum dptf_participant {
+	DPTF_NONE,
+	DPTF_CPU,
+	DPTF_CHARGER,
+	DPTF_FAN,
+	DPTF_TEMP_SENSOR_0,
+	DPTF_TEMP_SENSOR_1,
+	DPTF_TEMP_SENSOR_2,
+	DPTF_TEMP_SENSOR_3,
+	DPTF_PARTICIPANT_COUNT,
+};
+
+/* DPTF compile-time constants */
+enum {
+	/* A device can only define _AC0 .. _AC9 i.e. between 0 and 10 Active Cooling Methods */
+	DPTF_MAX_ACX			= 10,
+	DPTF_MAX_ACTIVE_POLICIES	= (DPTF_PARTICIPANT_COUNT-1),
+};
+
+/* Active Policy */
+struct dptf_active_policy {
+	/* Device capable of being affected by the fan */
+	enum dptf_participant target;
+	/* Source's contribution to the Target's cooling capability as a percentage */
+	uint8_t weight;
+	/* When target reaches temperature 'temp', the source will turn on at 'fan_pct' % */
+	struct {
+		/* (degrees C) */
+		uint8_t temp;
+		/* 0 - 100 */
+		uint8_t fan_pct;
+	} thresholds[DPTF_MAX_ACX];
+};
+
+/*
+ * This function provides tables of temperature and corresponding fan or percent.  When the
+ * temperature thresholds are met (_AC0 - _AC9), the fan is driven to corresponding percentage
+ * of full speed.
+ */
+void dptf_write_active_policies(const struct dptf_active_policy *policies, int max_count);
+
+/* Helper method to open the scope for a given participant. */
+void dptf_write_scope(enum dptf_participant participant);
+
+/*
+ * Write out a _STA that will check the value of the DPTE field in GNVS, and return 0xF if DPTE
+ * is 1, otherwise it will return 0.
+ */
+void dptf_write_STA(void);
+
+#endif /* ACPI_ACPIGEN_DPTF_H */