ACPI: fan: Expose fan performance state information (d19e470b) · Commits · 戴 / test

Documentation/admin-guide/acpi/fan_performance_states.rst

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		.. SPDX-License-Identifier: GPL-2.0

		===========================
		ACPI Fan Performance States
		===========================

		When the optional _FPS object is present under an ACPI device representing a
		fan (for example, PNP0C0B or INT3404), the ACPI fan driver creates additional
		"state*" attributes in the sysfs directory of the ACPI device in question.
		These attributes list properties of fan performance states.

		For more information on _FPS refer to the ACPI specification at:

		http://uefi.org/specifications

		For instance, the contents of the INT3404 ACPI device sysfs directory
		may look as follows::

		$ ls -l /sys/bus/acpi/devices/INT3404:00/
		total 0
		...
		-r--r--r-- 1 root root 4096 Dec 13 20:38 state0
		-r--r--r-- 1 root root 4096 Dec 13 20:38 state1
		-r--r--r-- 1 root root 4096 Dec 13 20:38 state10
		-r--r--r-- 1 root root 4096 Dec 13 20:38 state11
		-r--r--r-- 1 root root 4096 Dec 13 20:38 state2
		-r--r--r-- 1 root root 4096 Dec 13 20:38 state3
		-r--r--r-- 1 root root 4096 Dec 13 20:38 state4
		-r--r--r-- 1 root root 4096 Dec 13 20:38 state5
		-r--r--r-- 1 root root 4096 Dec 13 20:38 state6
		-r--r--r-- 1 root root 4096 Dec 13 20:38 state7
		-r--r--r-- 1 root root 4096 Dec 13 20:38 state8
		-r--r--r-- 1 root root 4096 Dec 13 20:38 state9
		-r--r--r-- 1 root root 4096 Dec 13 01:00 status
		...

		where each of the "state*" files represents one performance state of the fan
		and contains a colon-separated list of 5 integer numbers (fields) with the
		following interpretation::

		control_percent:trip_point_index:speed_rpm:noise_level_mdb:power_mw

		* ``control_percent``: The percent value to be used to set the fan speed to a
		specific level using the _FSL object (0-100).

		* ``trip_point_index``: The active cooling trip point number that corresponds
		to this performance state (0-9).

		* ``speed_rpm``: Speed of the fan in rotations per minute.

		* ``noise_level_mdb``: Audible noise emitted by the fan in this state in
		millidecibels.

		* ``power_mw``: Power draw of the fan in this state in milliwatts.

		For example::

		$cat /sys/bus/acpi/devices/INT3404:00/state1
		25:0:3200:12500:1250

		When a given field is not populated or its value provided by the platform
		firmware is invalid, the "not-defined" string is shown instead of the value.

Documentation/admin-guide/acpi/index.rst

+1 −0

Original line number	Diff line number	Diff line
		@@ -12,3 +12,4 @@ the Linux ACPI support.
		dsdt-override
		ssdt-overlays
		cppc_sysfs
		fan_performance_states

drivers/acpi/fan.c

+88 −8

Original line number	Diff line number	Diff line
		@@ -44,12 +44,16 @@ static const struct dev_pm_ops acpi_fan_pm = {
		#define FAN_PM_OPS_PTR NULL
		#endif

		#define ACPI_FPS_NAME_LEN 20

		struct acpi_fan_fps {
		u64 control;
		u64 trip_point;
		u64 speed;
		u64 noise_level;
		u64 power;
		char name[ACPI_FPS_NAME_LEN];
		struct device_attribute dev_attr;
		};

		struct acpi_fan_fif {
		@@ -265,6 +269,39 @@ static int acpi_fan_speed_cmp(const void a, const void b)
		return fps1->speed - fps2->speed;
		}

		static ssize_t show_state(struct device dev, struct device_attribute attr, char *buf)
		{
		struct acpi_fan_fps *fps = container_of(attr, struct acpi_fan_fps, dev_attr);
		int count;

		if (fps->control == 0xFFFFFFFF \|\| fps->control > 100)
		count = snprintf(buf, PAGE_SIZE, "not-defined:");
		else
		count = snprintf(buf, PAGE_SIZE, "%lld:", fps->control);

		if (fps->trip_point == 0xFFFFFFFF \|\| fps->trip_point > 9)
		count += snprintf(&buf[count], PAGE_SIZE, "not-defined:");
		else
		count += snprintf(&buf[count], PAGE_SIZE, "%lld:", fps->trip_point);

		if (fps->speed == 0xFFFFFFFF)
		count += snprintf(&buf[count], PAGE_SIZE, "not-defined:");
		else
		count += snprintf(&buf[count], PAGE_SIZE, "%lld:", fps->speed);

		if (fps->noise_level == 0xFFFFFFFF)
		count += snprintf(&buf[count], PAGE_SIZE, "not-defined:");
		else
		count += snprintf(&buf[count], PAGE_SIZE, "%lld:", fps->noise_level * 100);

		if (fps->power == 0xFFFFFFFF)
		count += snprintf(&buf[count], PAGE_SIZE, "not-defined\n");
		else
		count += snprintf(&buf[count], PAGE_SIZE, "%lld\n", fps->power);

		return count;
		}

		static int acpi_fan_get_fps(struct acpi_device *device)
		{
		struct acpi_fan *fan = acpi_driver_data(device);
		@@ -295,12 +332,13 @@ static int acpi_fan_get_fps(struct acpi_device *device)
		}
		for (i = 0; i < fan->fps_count; i++) {
		struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
		struct acpi_buffer fps = { sizeof(fan->fps[i]), &fan->fps[i] };
		struct acpi_buffer fps = { offsetof(struct acpi_fan_fps, name),
		&fan->fps[i] };
		status = acpi_extract_package(&obj->package.elements[i + 1],
		&format, &fps);
		if (ACPI_FAILURE(status)) {
		dev_err(&device->dev, "Invalid _FPS element\n");
		break;
		goto err;
		}
		}

		@@ -308,6 +346,24 @@ static int acpi_fan_get_fps(struct acpi_device *device)
		sort(fan->fps, fan->fps_count, sizeof(*fan->fps),
		acpi_fan_speed_cmp, NULL);

		for (i = 0; i < fan->fps_count; ++i) {
		struct acpi_fan_fps *fps = &fan->fps[i];

		snprintf(fps->name, ACPI_FPS_NAME_LEN, "state%d", i);
		fps->dev_attr.show = show_state;
		fps->dev_attr.store = NULL;
		fps->dev_attr.attr.name = fps->name;
		fps->dev_attr.attr.mode = 0444;
		status = sysfs_create_file(&device->dev.kobj, &fps->dev_attr.attr);
		if (status) {
		int j;

		for (j = 0; j < i; ++j)
		sysfs_remove_file(&device->dev.kobj, &fan->fps[j].dev_attr.attr);
		break;
		}
		}

		err:
		kfree(obj);
		return status;
		@@ -330,14 +386,20 @@ static int acpi_fan_probe(struct platform_device *pdev)
		platform_set_drvdata(pdev, fan);

		if (acpi_fan_is_acpi4(device)) {
		if (acpi_fan_get_fif(device) \|\| acpi_fan_get_fps(device))
		goto end;
		result = acpi_fan_get_fif(device);
		if (result)
		return result;

		result = acpi_fan_get_fps(device);
		if (result)
		return result;

		fan->acpi4 = true;
		} else {
		result = acpi_device_update_power(device, NULL);
		if (result) {
		dev_err(&device->dev, "Failed to set initial power state\n");
		goto end;
		goto err_end;
		}
		}

		@@ -350,7 +412,7 @@ static int acpi_fan_probe(struct platform_device *pdev)
		&fan_cooling_ops);
		if (IS_ERR(cdev)) {
		result = PTR_ERR(cdev);
		goto end;
		goto err_end;
		}

		dev_dbg(&pdev->dev, "registered as cooling_device%d\n", cdev->id);
		@@ -365,10 +427,21 @@ static int acpi_fan_probe(struct platform_device *pdev)
		result = sysfs_create_link(&cdev->device.kobj,
		&pdev->dev.kobj,
		"device");
		if (result)
		if (result) {
		dev_err(&pdev->dev, "Failed to create sysfs link 'device'\n");
		goto err_end;
		}

		return 0;

		err_end:
		if (fan->acpi4) {
		int i;

		for (i = 0; i < fan->fps_count; ++i)
		sysfs_remove_file(&device->dev.kobj, &fan->fps[i].dev_attr.attr);
		}

		end:
		return result;
		}

		@@ -376,6 +449,13 @@ static int acpi_fan_remove(struct platform_device *pdev)
		{
		struct acpi_fan *fan = platform_get_drvdata(pdev);

		if (fan->acpi4) {
		struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
		int i;

		for (i = 0; i < fan->fps_count; ++i)
		sysfs_remove_file(&device->dev.kobj, &fan->fps[i].dev_attr.attr);
		}
		sysfs_remove_link(&pdev->dev.kobj, "thermal_cooling");
		sysfs_remove_link(&fan->cdev->device.kobj, "device");
		thermal_cooling_device_unregister(fan->cdev);

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