Users might want to signal the ACPI firmware whether active or passive cooling is preferred. This is already possible under Windows using the Windows power settings. Add a new "cooling_mode" sysfs attribute which can be used by users to change the cooling mode of a given thermal zone. Only thermal zones supporting the _SCP control method will expose this new attribute. Signed-off-by: Armin Wolf <W_Armin@xxxxxx> --- .../ABI/testing/sysfs-driver-thermal | 14 ++ MAINTAINERS | 1 + drivers/acpi/thermal.c | 129 ++++++++++++++++-- 3 files changed, 132 insertions(+), 12 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-driver-thermal diff --git a/Documentation/ABI/testing/sysfs-driver-thermal b/Documentation/ABI/testing/sysfs-driver-thermal new file mode 100644 index 000000000000..bf2349f31863 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-driver-thermal @@ -0,0 +1,14 @@ +What: /sys/bus/acpi/devices/LNXTHERM:*/cooling_mode +Date: April 2025 +KernelVersion: 6.16 +Contact: Armin Wolf <W_Armin@xxxxxx> +Description: + A string representing the preferred cooling mode of the + associated ACPI thermal zone: + + - "active" for preferring active cooling + + - "passive" for preferring passive cooling + + The exact characteristics of both cooling modes depend + on the underlying ACPI firmware implementation. diff --git a/MAINTAINERS b/MAINTAINERS index 96b827049501..fd3102723518 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -382,6 +382,7 @@ R: Zhang Rui <rui.zhang@xxxxxxxxx> L: linux-acpi@xxxxxxxxxxxxxxx S: Supported B: https://bugzilla.kernel.org +F: Documentation/ABI/testing/sysfs-driver-thermal F: drivers/acpi/*thermal* ACPI VIOT DRIVER diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c index 5c2defe55898..52d0c777a93a 100644 --- a/drivers/acpi/thermal.c +++ b/drivers/acpi/thermal.c @@ -15,11 +15,14 @@ #define pr_fmt(fmt) "ACPI: thermal: " fmt +#include <linux/cleanup.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/dmi.h> #include <linux/init.h> #include <linux/slab.h> +#include <linux/string.h> +#include <linux/sysfs.h> #include <linux/types.h> #include <linux/jiffies.h> #include <linux/kmod.h> @@ -40,7 +43,6 @@ #define ACPI_THERMAL_NOTIFY_DEVICES 0x82 #define ACPI_THERMAL_NOTIFY_CRITICAL 0xF0 #define ACPI_THERMAL_NOTIFY_HOT 0xF1 -#define ACPI_THERMAL_MODE_ACTIVE 0x00 #define ACPI_THERMAL_MAX_ACTIVE 10 #define ACPI_THERMAL_MAX_LIMIT_STR_LEN 65 @@ -85,6 +87,16 @@ MODULE_PARM_DESC(psv, "Disable or override all passive trip points."); static struct workqueue_struct *acpi_thermal_pm_queue; +enum acpi_thermal_cooling_mode { + ACPI_THERMAL_MODE_ACTIVE = 0x00, + ACPI_THERMAL_MODE_PASSIVE = 0x01, +}; + +static const char * const acpi_thermal_cooling_mode_strings[] = { + [ACPI_THERMAL_MODE_ACTIVE] = "active", + [ACPI_THERMAL_MODE_PASSIVE] = "passive", +}; + struct acpi_thermal_trip { unsigned long temp_dk; struct acpi_handle_list devices; @@ -119,6 +131,9 @@ struct acpi_thermal { struct work_struct thermal_check_work; struct mutex thermal_check_lock; refcount_t thermal_check_count; + bool supports_cooling_mode; + struct mutex cooling_mode_lock; /* Protects cooling mode updates */ + enum acpi_thermal_cooling_mode cooling_mode; }; /* -------------------------------------------------------------------------- @@ -328,7 +343,6 @@ static void acpi_queue_thermal_check(struct acpi_thermal *tz) static void acpi_thermal_trips_update(struct acpi_thermal *tz, u32 event) { struct adjust_trip_data atd = { .tz = tz, .event = event }; - struct acpi_device *adev = tz->device; /* * Use thermal_zone_for_each_trip() to carry out the trip points @@ -340,8 +354,6 @@ static void acpi_thermal_trips_update(struct acpi_thermal *tz, u32 event) thermal_zone_for_each_trip(tz->thermal_zone, acpi_thermal_adjust_trip, &atd); acpi_queue_thermal_check(tz); - acpi_bus_generate_netlink_event(adev->pnp.device_class, - dev_name(&adev->dev), event, 0); } static int acpi_thermal_get_critical_trip(struct acpi_thermal *tz) @@ -473,6 +485,18 @@ static void acpi_thermal_get_trip_points(struct acpi_thermal *tz) tz->trips.active[i].trip.temp_dk = THERMAL_TEMP_INVALID; } +static int acpi_thermal_set_cooling_mode(struct acpi_thermal *tz, + enum acpi_thermal_cooling_mode mode) +{ + acpi_status status; + + status = acpi_execute_simple_method(tz->device->handle, "_SCP", mode); + if (ACPI_FAILURE(status)) + return -EIO; + + return 0; +} + /* sys I/F for generic thermal sysfs support */ static int thermal_get_temp(struct thermal_zone_device *thermal, int *temp) @@ -683,6 +707,8 @@ static void acpi_thermal_notify(acpi_handle handle, u32 event, void *data) case ACPI_THERMAL_NOTIFY_THRESHOLDS: case ACPI_THERMAL_NOTIFY_DEVICES: acpi_thermal_trips_update(tz, event); + acpi_bus_generate_netlink_event(device->pnp.device_class, dev_name(&device->dev), + event, 0); break; default: acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n", @@ -777,6 +803,65 @@ static void acpi_thermal_free_thermal_zone(struct acpi_thermal *tz) kfree(tz); } +static ssize_t cooling_mode_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct acpi_thermal *tz = acpi_driver_data(to_acpi_device(dev)); + + guard(mutex)(&tz->cooling_mode_lock); + + return sysfs_emit(buf, "%s\n", acpi_thermal_cooling_mode_strings[tz->cooling_mode]); +} + +static ssize_t cooling_mode_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct acpi_thermal *tz = acpi_driver_data(to_acpi_device(dev)); + int ret, mode; + + mode = sysfs_match_string(acpi_thermal_cooling_mode_strings, buf); + if (mode < 0) + return mode; + + guard(mutex)(&tz->cooling_mode_lock); + + ret = acpi_thermal_set_cooling_mode(tz, mode); + if (ret < 0) + return ret; + + tz->cooling_mode = mode; + acpi_thermal_trips_update(tz, ACPI_THERMAL_NOTIFY_THRESHOLDS); + + return count; +} + +static DEVICE_ATTR_RW(cooling_mode); + +static struct attribute *acpi_thermal_attrs[] = { + &dev_attr_cooling_mode.attr, + NULL +}; + +static umode_t acpi_thermal_group_is_visible(struct kobject *kobj, struct attribute *attr, int idx) +{ + struct device *dev = kobj_to_dev(kobj); + struct acpi_thermal *tz = acpi_driver_data(to_acpi_device(dev)); + + if (tz->supports_cooling_mode) + return attr->mode; + + return 0; +} + +static const struct attribute_group acpi_thermal_group = { + .is_visible = acpi_thermal_group_is_visible, + .attrs = acpi_thermal_attrs, +}; + +static const struct attribute_group *acpi_thermal_groups[] = { + &acpi_thermal_group, + NULL +}; + static int acpi_thermal_add(struct acpi_device *device) { struct thermal_trip trip_table[ACPI_THERMAL_MAX_NR_TRIPS] = { 0 }; @@ -786,7 +871,7 @@ static int acpi_thermal_add(struct acpi_device *device) int crit_temp, hot_temp; int passive_delay = 0; int result; - int i; + int ret, i; if (!device) return -EINVAL; @@ -795,6 +880,10 @@ static int acpi_thermal_add(struct acpi_device *device) if (!tz) return -ENOMEM; + ret = devm_mutex_init(&device->dev, &tz->cooling_mode_lock); + if (ret < 0) + return ret; + tz->device = device; strscpy(tz->name, device->pnp.bus_id); strscpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME); @@ -803,11 +892,18 @@ static int acpi_thermal_add(struct acpi_device *device) acpi_thermal_aml_dependency_fix(tz); - /* - * Set the cooling mode [_SCP] to active cooling. This needs to happen before - * we retrieve the trip point values. - */ - acpi_execute_simple_method(tz->device->handle, "_SCP", ACPI_THERMAL_MODE_ACTIVE); + tz->supports_cooling_mode = acpi_has_method(tz->device->handle, "_SCP"); + if (tz->supports_cooling_mode) { + /* + * Set the initial cooling mode to active cooling. This needs to happen + * before we retrieve the trip point values. + */ + ret = acpi_thermal_set_cooling_mode(tz, ACPI_THERMAL_MODE_ACTIVE); + if (ret < 0) + dev_err(&tz->device->dev, "Failed to set initial cooling mode\n"); + + tz->cooling_mode = ACPI_THERMAL_MODE_ACTIVE; + } /* Get trip points [_ACi, _PSV, etc.] (required). */ acpi_thermal_get_trip_points(tz); @@ -924,7 +1020,7 @@ static int acpi_thermal_suspend(struct device *dev) static int acpi_thermal_resume(struct device *dev) { struct acpi_thermal *tz; - int i, j, power_state; + int ret, i, j, power_state; if (!dev) return -EINVAL; @@ -933,6 +1029,12 @@ static int acpi_thermal_resume(struct device *dev) if (!tz) return -EINVAL; + if (tz->supports_cooling_mode) { + ret = acpi_thermal_set_cooling_mode(tz, tz->cooling_mode); + if (ret < 0) + dev_err(&tz->device->dev, "Failed to restore cooling mode\n"); + } + for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) { struct acpi_thermal_trip *acpi_trip = &tz->trips.active[i].trip; @@ -969,7 +1071,10 @@ static struct acpi_driver acpi_thermal_driver = { .add = acpi_thermal_add, .remove = acpi_thermal_remove, }, - .drv.pm = &acpi_thermal_pm, + .drv = { + .dev_groups = acpi_thermal_groups, + .pm = &acpi_thermal_pm, + }, }; static int thermal_act(const struct dmi_system_id *d) -- 2.39.5
