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thermal: ACPI: Add ACPI trip point routines
Add library routines to populate a generic thermal trip point structure with data obtained by evaluating a specific object in the ACPI Namespace. Signed-off-by: Rafael J. Wysocki <[email protected]> Co-developed-by: Daniel Lezcano <[email protected]> Signed-off-by: Daniel Lezcano <[email protected]> Tested-by: Srinivas Pandruvada <[email protected]>
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‎drivers/thermal/Kconfig

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@@ -76,6 +76,10 @@ config THERMAL_OF
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Say 'Y' here if you need to build thermal infrastructure
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based on device tree.
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config THERMAL_ACPI
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depends on ACPI
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bool
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config THERMAL_WRITABLE_TRIPS
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bool "Enable writable trip points"
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help

‎drivers/thermal/Makefile

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@@ -13,6 +13,7 @@ thermal_sys-$(CONFIG_THERMAL_NETLINK) += thermal_netlink.o
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# interface to/from other layers providing sensors
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thermal_sys-$(CONFIG_THERMAL_HWMON) += thermal_hwmon.o
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thermal_sys-$(CONFIG_THERMAL_OF) += thermal_of.o
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thermal_sys-$(CONFIG_THERMAL_ACPI) += thermal_acpi.o
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# governors
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thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE) += gov_fair_share.o

‎drivers/thermal/thermal_acpi.c

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// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright 2023 Linaro Limited
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* Copyright 2023 Intel Corporation
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*
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* Library routines for populating a generic thermal trip point structure
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* with data obtained by evaluating a specific object in the ACPI Namespace.
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*/
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#include <linux/acpi.h>
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#include <linux/units.h>
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#include "thermal_core.h"
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/*
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* Minimum temperature for full military grade is 218°K (-55°C) and
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* max temperature is 448°K (175°C). We can consider those values as
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* the boundaries for the [trips] temperature returned by the
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* firmware. Any values out of these boundaries may be considered
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* bogus and we can assume the firmware has no data to provide.
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*/
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#define TEMP_MIN_DECIK 2180
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#define TEMP_MAX_DECIK 4480
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static int thermal_acpi_trip_init(struct acpi_device *adev,
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enum thermal_trip_type type, int id,
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struct thermal_trip *trip)
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{
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unsigned long long temp;
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acpi_status status;
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char obj_name[5];
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switch (type) {
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case THERMAL_TRIP_ACTIVE:
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if (id < 0 || id > 9)
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return -EINVAL;
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obj_name[1] = 'A';
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obj_name[2] = 'C';
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obj_name[3] = '0' + id;
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break;
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case THERMAL_TRIP_PASSIVE:
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obj_name[1] = 'P';
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obj_name[2] = 'S';
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obj_name[3] = 'V';
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break;
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case THERMAL_TRIP_HOT:
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obj_name[1] = 'H';
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obj_name[2] = 'O';
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obj_name[3] = 'T';
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break;
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case THERMAL_TRIP_CRITICAL:
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obj_name[1] = 'C';
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obj_name[2] = 'R';
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obj_name[3] = 'T';
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break;
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}
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obj_name[0] = '_';
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obj_name[4] = '\0';
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status = acpi_evaluate_integer(adev->handle, obj_name, NULL, &temp);
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if (ACPI_FAILURE(status)) {
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acpi_handle_debug(adev->handle, "%s evaluation failed\n", obj_name);
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return -ENODATA;
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}
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if (temp < TEMP_MIN_DECIK || temp >= TEMP_MAX_DECIK) {
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acpi_handle_debug(adev->handle, "%s result %llu out of range\n",
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obj_name, temp);
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return -ENODATA;
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}
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trip->temperature = deci_kelvin_to_millicelsius(temp);
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trip->hysteresis = 0;
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trip->type = type;
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return 0;
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}
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/**
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* thermal_acpi_trip_active - Get the specified active trip point
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* @adev: Thermal zone ACPI device object to get the description from.
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* @id: Active cooling level (0 - 9).
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* @trip: Trip point structure to be populated on success.
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*
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* Evaluate the _ACx object for the thermal zone represented by @adev to obtain
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* the temperature of the active cooling trip point corresponding to the active
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* cooling level given by @id and initialize @trip as an active trip point using
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* that temperature value.
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*
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* Return 0 on success or a negative error value on failure.
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*/
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int thermal_acpi_trip_active(struct acpi_device *adev, int id,
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struct thermal_trip *trip)
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{
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return thermal_acpi_trip_init(adev, THERMAL_TRIP_ACTIVE, id, trip);
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}
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EXPORT_SYMBOL_GPL(thermal_acpi_trip_active);
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/**
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* thermal_acpi_trip_passive - Get the passive trip point
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* @adev: Thermal zone ACPI device object to get the description from.
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* @trip: Trip point structure to be populated on success.
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*
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* Evaluate the _PSV object for the thermal zone represented by @adev to obtain
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* the temperature of the passive cooling trip point and initialize @trip as a
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* passive trip point using that temperature value.
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*
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* Return 0 on success or -ENODATA on failure.
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*/
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int thermal_acpi_trip_passive(struct acpi_device *adev, struct thermal_trip *trip)
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{
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return thermal_acpi_trip_init(adev, THERMAL_TRIP_PASSIVE, INT_MAX, trip);
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}
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EXPORT_SYMBOL_GPL(thermal_acpi_trip_passive);
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/**
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* thermal_acpi_trip_hot - Get the near critical trip point
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* @adev: the ACPI device to get the description from.
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* @trip: a &struct thermal_trip to be filled if the function succeed.
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*
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* Evaluate the _HOT object for the thermal zone represented by @adev to obtain
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* the temperature of the trip point at which the system is expected to be put
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* into the S4 sleep state and initialize @trip as a hot trip point using that
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* temperature value.
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*
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* Return 0 on success or -ENODATA on failure.
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*/
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int thermal_acpi_trip_hot(struct acpi_device *adev, struct thermal_trip *trip)
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{
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return thermal_acpi_trip_init(adev, THERMAL_TRIP_HOT, INT_MAX, trip);
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}
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EXPORT_SYMBOL_GPL(thermal_acpi_trip_hot);
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/**
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* thermal_acpi_trip_critical - Get the critical trip point
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* @adev: the ACPI device to get the description from.
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* @trip: a &struct thermal_trip to be filled if the function succeed.
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*
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* Evaluate the _CRT object for the thermal zone represented by @adev to obtain
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* the temperature of the critical cooling trip point and initialize @trip as a
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* critical trip point using that temperature value.
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*
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* Return 0 on success or -ENODATA on failure.
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*/
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int thermal_acpi_trip_critical(struct acpi_device *adev, struct thermal_trip *trip)
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{
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return thermal_acpi_trip_init(adev, THERMAL_TRIP_CRITICAL, INT_MAX, trip);
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}
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EXPORT_SYMBOL_GPL(thermal_acpi_trip_critical);

‎include/linux/thermal.h

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@@ -346,6 +346,14 @@ int thermal_zone_get_num_trips(struct thermal_zone_device *tz);
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int thermal_zone_get_crit_temp(struct thermal_zone_device *tz, int *temp);
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#ifdef CONFIG_THERMAL_ACPI
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int thermal_acpi_trip_active(struct acpi_device *adev, int id,
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struct thermal_trip *trip);
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int thermal_acpi_trip_passive(struct acpi_device *adev, struct thermal_trip *trip);
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int thermal_acpi_trip_hot(struct acpi_device *adev, struct thermal_trip *trip);
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int thermal_acpi_trip_critical(struct acpi_device *adev, struct thermal_trip *trip);
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#endif
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#ifdef CONFIG_THERMAL
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struct thermal_zone_device *thermal_zone_device_register(const char *, int, int,
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void *, struct thermal_zone_device_ops *,

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