// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2023 Linaro Limited
 * Copyright 2023 Intel Corporation
 *
 * Library routines for retrieving trip point temperature values from the
 * platform firmware via ACPI.
 */
#include <linux/acpi.h>
#include <linux/units.h>
#include <linux/thermal.h>
#include "internal.h"

/*
 * Minimum temperature for full military grade is 218°K (-55°C) and
 * max temperature is 448°K (175°C). We can consider those values as
 * the boundaries for the [trips] temperature returned by the
 * firmware. Any values out of these boundaries may be considered
 * bogus and we can assume the firmware has no data to provide.
 */
#define TEMP_MIN_DECIK  2180ULL
#define TEMP_MAX_DECIK  4480ULL

static int acpi_trip_temp(struct acpi_device *adev, char *obj_name,
                          int *ret_temp)
{
        unsigned long long temp;
        acpi_status status;

        status = acpi_evaluate_integer(adev->handle, obj_name, NULL, &temp);
        if (ACPI_FAILURE(status)) {
                acpi_handle_debug(adev->handle, "%s evaluation failed\n", obj_name);
                return -ENODATA;
        }

        if (temp >= TEMP_MIN_DECIK && temp <= TEMP_MAX_DECIK) {
                *ret_temp = temp;
        } else {
                acpi_handle_debug(adev->handle, "%s result %llu out of range\n",
                                  obj_name, temp);
                *ret_temp = THERMAL_TEMP_INVALID;
        }

        return 0;
}

int acpi_active_trip_temp(struct acpi_device *adev, int id, int *ret_temp)
{
        char obj_name[] = {'_', 'A', 'C', '0' + id, '\0'};

        if (id < 0 || id > 9)
                return -EINVAL;

        return acpi_trip_temp(adev, obj_name, ret_temp);
}
EXPORT_SYMBOL_NS_GPL(acpi_active_trip_temp, "ACPI_THERMAL");

int acpi_passive_trip_temp(struct acpi_device *adev, int *ret_temp)
{
        return acpi_trip_temp(adev, "_PSV", ret_temp);
}
EXPORT_SYMBOL_NS_GPL(acpi_passive_trip_temp, "ACPI_THERMAL");

int acpi_hot_trip_temp(struct acpi_device *adev, int *ret_temp)
{
        return acpi_trip_temp(adev, "_HOT", ret_temp);
}
EXPORT_SYMBOL_NS_GPL(acpi_hot_trip_temp, "ACPI_THERMAL");

int acpi_critical_trip_temp(struct acpi_device *adev, int *ret_temp)
{
        return acpi_trip_temp(adev, "_CRT", ret_temp);
}
EXPORT_SYMBOL_NS_GPL(acpi_critical_trip_temp, "ACPI_THERMAL");

static int thermal_temp(int error, int temp_decik, int *ret_temp)
{
        if (error)
                return error;

        if (temp_decik == THERMAL_TEMP_INVALID)
                *ret_temp = THERMAL_TEMP_INVALID;
        else
                *ret_temp = deci_kelvin_to_millicelsius(temp_decik);

        return 0;
}

/**
 * thermal_acpi_active_trip_temp - Retrieve active trip point temperature
 * @adev: Target thermal zone ACPI device object.
 * @id: Active cooling level (0 - 9).
 * @ret_temp: Address to store the retrieved temperature value on success.
 *
 * Evaluate the _ACx object for the thermal zone represented by @adev to obtain
 * the temperature of the active cooling trip point corresponding to the active
 * cooling level given by @id.
 *
 * Return 0 on success or a negative error value on failure.
 */
int thermal_acpi_active_trip_temp(struct acpi_device *adev, int id, int *ret_temp)
{
        int temp_decik = 0;
        int ret = acpi_active_trip_temp(adev, id, &temp_decik);

        return thermal_temp(ret, temp_decik, ret_temp);
}
EXPORT_SYMBOL_GPL(thermal_acpi_active_trip_temp);

/**
 * thermal_acpi_passive_trip_temp - Retrieve passive trip point temperature
 * @adev: Target thermal zone ACPI device object.
 * @ret_temp: Address to store the retrieved temperature value on success.
 *
 * Evaluate the _PSV object for the thermal zone represented by @adev to obtain
 * the temperature of the passive cooling trip point.
 *
 * Return 0 on success or -ENODATA on failure.
 */
int thermal_acpi_passive_trip_temp(struct acpi_device *adev, int *ret_temp)
{
        int temp_decik = 0;
        int ret = acpi_passive_trip_temp(adev, &temp_decik);

        return thermal_temp(ret, temp_decik, ret_temp);
}
EXPORT_SYMBOL_GPL(thermal_acpi_passive_trip_temp);

/**
 * thermal_acpi_hot_trip_temp - Retrieve hot trip point temperature
 * @adev: Target thermal zone ACPI device object.
 * @ret_temp: Address to store the retrieved temperature value on success.
 *
 * Evaluate the _HOT object for the thermal zone represented by @adev to obtain
 * the temperature of the trip point at which the system is expected to be put
 * into the S4 sleep state.
 *
 * Return 0 on success or -ENODATA on failure.
 */
int thermal_acpi_hot_trip_temp(struct acpi_device *adev, int *ret_temp)
{
        int temp_decik = 0;
        int ret = acpi_hot_trip_temp(adev, &temp_decik);

        return thermal_temp(ret, temp_decik, ret_temp);
}
EXPORT_SYMBOL_GPL(thermal_acpi_hot_trip_temp);

/**
 * thermal_acpi_critical_trip_temp - Retrieve critical trip point temperature
 * @adev: Target thermal zone ACPI device object.
 * @ret_temp: Address to store the retrieved temperature value on success.
 *
 * Evaluate the _CRT object for the thermal zone represented by @adev to obtain
 * the temperature of the critical cooling trip point.
 *
 * Return 0 on success or -ENODATA on failure.
 */
int thermal_acpi_critical_trip_temp(struct acpi_device *adev, int *ret_temp)
{
        int temp_decik = 0;
        int ret = acpi_critical_trip_temp(adev, &temp_decik);

        return thermal_temp(ret, temp_decik, ret_temp);
}
EXPORT_SYMBOL_GPL(thermal_acpi_critical_trip_temp);