/* 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),
	DPTF_MAX_PASSIVE_POLICIES	= (DPTF_PARTICIPANT_COUNT-1),
	DPTF_MAX_CRITICAL_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];
};

/* Passive Policy */
struct dptf_passive_policy {
	/* The device that can be throttled */
	enum dptf_participant source;
	/* The device that controls the throttling */
	enum dptf_participant target;
	/* How often to check the temperature for required throttling (ms) */
	uint16_t period;
	/* The trip point for turning on throttling (degrees C) */
	uint8_t temp;
	/* Relative priority between Policies */
	uint8_t priority;
};

/* Critical Policy type: graceful S4 transition or graceful shutdown */
enum dptf_critical_policy_type {
	DPTF_CRITICAL_S4,
	DPTF_CRITICAL_SHUTDOWN,
};

/* Critical Policy */
struct dptf_critical_policy {
	/* The device that can trigger a critical event */
	enum dptf_participant source;
	/* What type of critical policy */
	enum dptf_critical_policy_type type;
	/* Temperature to activate policy, degrees C */
	uint8_t temp;
};

/*
 * 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);

/*
 * This function uses the definition of the passive policies to write out _PSV Methods on all
 * participants that define it.  It also writes out the Thermal Relationship Table
 * (\_SB.DPTF._TRT), which describes various passive (i.e., throttling) policies that can be
 * applies when temperature sensors reach the _PSV threshold.
 */
void dptf_write_passive_policies(const struct dptf_passive_policy *policies, int max_count);

/*
 * Critical policies are temperature thresholds that, when reached, will cause the system to
 * take some emergency action in order to eliminate excess temperatures from damaging the
 * system. The emergency actions are a graceful suspend or a graceful shutdown.
 */
void dptf_write_critical_policies(const struct dptf_critical_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 */