drivers/thermal/thermal_helpers.c

Source file repositories/reference/linux-study-clean/drivers/thermal/thermal_helpers.c

File Facts

System
Linux kernel
Corpus path
drivers/thermal/thermal_helpers.c
Extension
.c
Size
6215 bytes
Lines
241
Domain
Driver Families
Bucket
drivers/thermal
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

for_each_trip_desc(tz, td) {
			const struct thermal_trip *trip = &td->trip;

			if (trip->type == THERMAL_TRIP_CRITICAL) {
				crit_temp = trip->temperature;
				break;
			}
		}

		/*
		 * Only allow emulating a temperature when the real temperature
		 * is below the critical temperature so that the emulation code
		 * cannot hide critical conditions.
		 */
		if (!ret && *temp < crit_temp)
			*temp = tz->emul_temperature;
	}

	if (ret)
		dev_dbg(&tz->device, "Failed to get temperature: %d\n", ret);

	return ret;
}

/**
 * thermal_zone_get_temp() - returns the temperature of a thermal zone
 * @tz: a valid pointer to a struct thermal_zone_device
 * @temp: a valid pointer to where to store the resulting temperature.
 *
 * When a valid thermal zone reference is passed, it will fetch its
 * temperature and fill @temp.
 *
 * Return: On success returns 0, an error code otherwise
 */
int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
{
	int ret;

	if (IS_ERR_OR_NULL(tz))
		return -EINVAL;

	guard(thermal_zone)(tz);

	if (!tz->ops.get_temp)
		return -EINVAL;

	ret = __thermal_zone_get_temp(tz, temp);
	if (!ret && *temp <= THERMAL_TEMP_INVALID)
		return -ENODATA;

	return ret;
}
EXPORT_SYMBOL_GPL(thermal_zone_get_temp);

static int thermal_cdev_set_cur_state(struct thermal_cooling_device *cdev, int state)
{
	int ret;

	/*
	 * No check is needed for the ops->set_cur_state as the
	 * registering function checked the ops are correctly set
	 */
	ret = cdev->ops->set_cur_state(cdev, state);
	if (ret)
		return ret;

	thermal_notify_cdev_state_update(cdev, state);
	thermal_cooling_device_stats_update(cdev, state);
	thermal_debug_cdev_state_update(cdev, state);

	return 0;
}

void __thermal_cdev_update(struct thermal_cooling_device *cdev)
{
	struct thermal_instance *instance;
	unsigned long target = 0;

	/* Make sure cdev enters the deepest cooling state */
	list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) {
		if (instance->target == THERMAL_NO_TARGET)
			continue;
		if (instance->target > target)
			target = instance->target;
	}

	thermal_cdev_set_cur_state(cdev, target);

	trace_cdev_update(cdev, target);
	dev_dbg(&cdev->device, "set to state %lu\n", target);

Annotation

Implementation Notes