1 files changed, 701 insertions, 0 deletions

diff --git a/drivers/acpi/fan_core.c b/drivers/acpi/fan_core.c
new file mode 100644
index 000000000000..fb08b8549ed7
--- /dev/null
+++ b/drivers/acpi/fan_core.c
@@ -0,0 +1,701 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  fan_core.c - ACPI Fan core Driver
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *  Copyright (C) 2022 Intel Corporation. All rights reserved.
+ */
+
+#include <linux/bits.h>
+#include <linux/kernel.h>
+#include <linux/limits.h>
+#include <linux/math.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/uuid.h>
+#include <linux/thermal.h>
+#include <linux/acpi.h>
+#include <linux/platform_device.h>
+#include <linux/sort.h>
+
+#include "fan.h"
+
+#define ACPI_FAN_NOTIFY_STATE_CHANGED	0x80
+
+/*
+ * Defined inside the "Fan Noise Signal" section at
+ * https://learn.microsoft.com/en-us/windows-hardware/design/device-experiences/design-guide.
+ */
+static const guid_t acpi_fan_microsoft_guid = GUID_INIT(0xA7611840, 0x99FE, 0x41AE, 0xA4, 0x88,
+							0x35, 0xC7, 0x59, 0x26, 0xC8, 0xEB);
+#define ACPI_FAN_DSM_GET_TRIP_POINT_GRANULARITY 1
+#define ACPI_FAN_DSM_SET_TRIP_POINTS		2
+#define ACPI_FAN_DSM_GET_OPERATING_RANGES	3
+
+/*
+ * Ensures that fans with a very low trip point granularity
+ * do not send too many notifications.
+ */
+static uint min_trip_distance = 100;
+module_param(min_trip_distance, uint, 0);
+MODULE_PARM_DESC(min_trip_distance, "Minimum distance between fan speed trip points in RPM");
+
+static const struct acpi_device_id fan_device_ids[] = {
+	ACPI_FAN_DEVICE_IDS,
+	{"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, fan_device_ids);
+
+/* thermal cooling device callbacks */
+static int fan_get_max_state(struct thermal_cooling_device *cdev, unsigned long
+			     *state)
+{
+	struct acpi_device *device = cdev->devdata;
+	struct acpi_fan *fan = acpi_driver_data(device);
+
+	if (fan->acpi4) {
+		if (fan->fif.fine_grain_ctrl)
+			*state = 100 / fan->fif.step_size;
+		else
+			*state = fan->fps_count - 1;
+	} else {
+		*state = 1;
+	}
+
+	return 0;
+}
+
+int acpi_fan_get_fst(acpi_handle handle, struct acpi_fan_fst *fst)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *obj;
+	acpi_status status;
+	int ret = 0;
+
+	status = acpi_evaluate_object(handle, "_FST", NULL, &buffer);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	obj = buffer.pointer;
+	if (!obj)
+		return -ENODATA;
+
+	if (obj->type != ACPI_TYPE_PACKAGE || obj->package.count != 3) {
+		ret = -EPROTO;
+		goto err;
+	}
+
+	if (obj->package.elements[0].type != ACPI_TYPE_INTEGER ||
+	    obj->package.elements[1].type != ACPI_TYPE_INTEGER ||
+	    obj->package.elements[2].type != ACPI_TYPE_INTEGER) {
+		ret = -EPROTO;
+		goto err;
+	}
+
+	fst->revision = obj->package.elements[0].integer.value;
+	fst->control = obj->package.elements[1].integer.value;
+	fst->speed = obj->package.elements[2].integer.value;
+
+err:
+	kfree(obj);
+	return ret;
+}
+
+static int fan_get_state_acpi4(struct acpi_device *device, unsigned long *state)
+{
+	struct acpi_fan *fan = acpi_driver_data(device);
+	struct acpi_fan_fst fst;
+	int status, i;
+
+	status = acpi_fan_get_fst(device->handle, &fst);
+	if (status)
+		return status;
+
+	if (fan->fif.fine_grain_ctrl) {
+		/* This control should be same what we set using _FSL by spec */
+		if (fst.control > 100) {
+			dev_dbg(&device->dev, "Invalid control value returned\n");
+			goto match_fps;
+		}
+
+		*state = (int) fst.control / fan->fif.step_size;
+		return 0;
+	}
+
+match_fps:
+	for (i = 0; i < fan->fps_count; i++) {
+		if (fst.control == fan->fps[i].control)
+			break;
+	}
+	if (i == fan->fps_count) {
+		dev_dbg(&device->dev, "No matching fps control value\n");
+		return -EINVAL;
+	}
+
+	*state = i;
+
+	return status;
+}
+
+static int fan_get_state(struct acpi_device *device, unsigned long *state)
+{
+	int result;
+	int acpi_state = ACPI_STATE_D0;
+
+	result = acpi_device_update_power(device, &acpi_state);
+	if (result)
+		return result;
+
+	*state = acpi_state == ACPI_STATE_D3_COLD
+			|| acpi_state == ACPI_STATE_D3_HOT ?
+		0 : (acpi_state == ACPI_STATE_D0 ? 1 : -1);
+	return 0;
+}
+
+static int fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long
+			     *state)
+{
+	struct acpi_device *device = cdev->devdata;
+	struct acpi_fan *fan = acpi_driver_data(device);
+
+	if (fan->acpi4)
+		return fan_get_state_acpi4(device, state);
+	else
+		return fan_get_state(device, state);
+}
+
+static int fan_set_state(struct acpi_device *device, unsigned long state)
+{
+	if (state != 0 && state != 1)
+		return -EINVAL;
+
+	return acpi_device_set_power(device,
+				     state ? ACPI_STATE_D0 : ACPI_STATE_D3_COLD);
+}
+
+static int fan_set_state_acpi4(struct acpi_device *device, unsigned long state)
+{
+	struct acpi_fan *fan = acpi_driver_data(device);
+	acpi_status status;
+	u64 value = state;
+	int max_state;
+
+	if (fan->fif.fine_grain_ctrl)
+		max_state = 100 / fan->fif.step_size;
+	else
+		max_state = fan->fps_count - 1;
+
+	if (state > max_state)
+		return -EINVAL;
+
+	if (fan->fif.fine_grain_ctrl) {
+		value *= fan->fif.step_size;
+		/* Spec allows compensate the last step only */
+		if (value + fan->fif.step_size > 100)
+			value = 100;
+	} else {
+		value = fan->fps[state].control;
+	}
+
+	status = acpi_execute_simple_method(device->handle, "_FSL", value);
+	if (ACPI_FAILURE(status)) {
+		dev_dbg(&device->dev, "Failed to set state by _FSL\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int
+fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
+{
+	struct acpi_device *device = cdev->devdata;
+	struct acpi_fan *fan = acpi_driver_data(device);
+
+	if (fan->acpi4)
+		return fan_set_state_acpi4(device, state);
+	else
+		return fan_set_state(device, state);
+}
+
+static const struct thermal_cooling_device_ops fan_cooling_ops = {
+	.get_max_state = fan_get_max_state,
+	.get_cur_state = fan_get_cur_state,
+	.set_cur_state = fan_set_cur_state,
+};
+
+/* --------------------------------------------------------------------------
+ *                               Driver Interface
+ * --------------------------------------------------------------------------
+*/
+
+static int acpi_fan_get_fif(struct acpi_device *device)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct acpi_fan *fan = acpi_driver_data(device);
+	struct acpi_buffer format = { sizeof("NNNN"), "NNNN" };
+	u64 fields[4];
+	struct acpi_buffer fif = { sizeof(fields), fields };
+	union acpi_object *obj;
+	acpi_status status;
+
+	status = acpi_evaluate_object(device->handle, "_FIF", NULL, &buffer);
+	if (ACPI_FAILURE(status))
+		return status;
+
+	obj = buffer.pointer;
+	if (!obj || obj->type != ACPI_TYPE_PACKAGE) {
+		dev_err(&device->dev, "Invalid _FIF data\n");
+		status = -EINVAL;
+		goto err;
+	}
+
+	status = acpi_extract_package(obj, &format, &fif);
+	if (ACPI_FAILURE(status)) {
+		dev_err(&device->dev, "Invalid _FIF element\n");
+		status = -EINVAL;
+		goto err;
+	}
+
+	fan->fif.revision = fields[0];
+	fan->fif.fine_grain_ctrl = fields[1];
+	fan->fif.step_size = fields[2];
+	fan->fif.low_speed_notification = fields[3];
+
+	/* If there is a bug in step size and set as 0, change to 1 */
+	if (!fan->fif.step_size)
+		fan->fif.step_size = 1;
+	/* If step size > 9, change to 9 (by spec valid values 1-9) */
+	else if (fan->fif.step_size > 9)
+		fan->fif.step_size = 9;
+err:
+	kfree(obj);
+	return status;
+}
+
+static int acpi_fan_speed_cmp(const void *a, const void *b)
+{
+	const struct acpi_fan_fps *fps1 = a;
+	const struct acpi_fan_fps *fps2 = b;
+	return fps1->speed - fps2->speed;
+}
+
+static int acpi_fan_get_fps(struct acpi_device *device)
+{
+	struct acpi_fan *fan = acpi_driver_data(device);
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *obj;
+	acpi_status status;
+	int i;
+
+	status = acpi_evaluate_object(device->handle, "_FPS", NULL, &buffer);
+	if (ACPI_FAILURE(status))
+		return status;
+
+	obj = buffer.pointer;
+	if (!obj || obj->type != ACPI_TYPE_PACKAGE || obj->package.count < 2) {
+		dev_err(&device->dev, "Invalid _FPS data\n");
+		status = -EINVAL;
+		goto err;
+	}
+
+	fan->fps_count = obj->package.count - 1; /* minus revision field */
+	fan->fps = devm_kcalloc(&device->dev,
+				fan->fps_count, sizeof(struct acpi_fan_fps),
+				GFP_KERNEL);
+	if (!fan->fps) {
+		dev_err(&device->dev, "Not enough memory\n");
+		status = -ENOMEM;
+		goto err;
+	}
+	for (i = 0; i < fan->fps_count; i++) {
+		struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
+		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");
+			goto err;
+		}
+	}
+
+	/* sort the state array according to fan speed in increase order */
+	sort(fan->fps, fan->fps_count, sizeof(*fan->fps),
+	     acpi_fan_speed_cmp, NULL);
+
+err:
+	kfree(obj);
+	return status;
+}
+
+static int acpi_fan_dsm_init(struct device *dev)
+{
+	union acpi_object dummy = {
+		.package = {
+			.type = ACPI_TYPE_PACKAGE,
+			.count = 0,
+			.elements = NULL,
+		},
+	};
+	struct acpi_fan *fan = dev_get_drvdata(dev);
+	union acpi_object *obj;
+	int ret = 0;
+
+	if (!acpi_check_dsm(fan->handle, &acpi_fan_microsoft_guid, 0,
+			    BIT(ACPI_FAN_DSM_GET_TRIP_POINT_GRANULARITY) |
+			    BIT(ACPI_FAN_DSM_SET_TRIP_POINTS)))
+		return 0;
+
+	dev_info(dev, "Using Microsoft fan extensions\n");
+
+	obj = acpi_evaluate_dsm_typed(fan->handle, &acpi_fan_microsoft_guid, 0,
+				      ACPI_FAN_DSM_GET_TRIP_POINT_GRANULARITY, &dummy,
+				      ACPI_TYPE_INTEGER);
+	if (!obj)
+		return -EIO;
+
+	if (obj->integer.value > U32_MAX)
+		ret = -EOVERFLOW;
+	else
+		fan->fan_trip_granularity = obj->integer.value;
+
+	kfree(obj);
+
+	return ret;
+}
+
+static int acpi_fan_dsm_set_trip_points(struct device *dev, u64 upper, u64 lower)
+{
+	union acpi_object args[2] = {
+		{
+			.integer = {
+				.type = ACPI_TYPE_INTEGER,
+				.value = lower,
+			},
+		},
+		{
+			.integer = {
+				.type = ACPI_TYPE_INTEGER,
+				.value = upper,
+			},
+		},
+	};
+	struct acpi_fan *fan = dev_get_drvdata(dev);
+	union acpi_object in = {
+		.package = {
+			.type = ACPI_TYPE_PACKAGE,
+			.count = ARRAY_SIZE(args),
+			.elements = args,
+		},
+	};
+	union acpi_object *obj;
+
+	obj = acpi_evaluate_dsm(fan->handle, &acpi_fan_microsoft_guid, 0,
+				ACPI_FAN_DSM_SET_TRIP_POINTS, &in);
+	kfree(obj);
+
+	return 0;
+}
+
+static int acpi_fan_dsm_start(struct device *dev)
+{
+	struct acpi_fan *fan = dev_get_drvdata(dev);
+	int ret;
+
+	if (!fan->fan_trip_granularity)
+		return 0;
+
+	/*
+	 * Some firmware implementations only update the values returned by the
+	 * _FST control method when a notification is received. This usually
+	 * works with Microsoft Windows as setting up trip points will keep
+	 * triggering said notifications, but will cause issues when using _FST
+	 * without the Microsoft-specific trip point extension.
+	 *
+	 * Because of this, an initial notification needs to be triggered to
+	 * start the cycle of trip points updates. This is achieved by setting
+	 * the trip points sequencially to two separate ranges. As by the
+	 * Microsoft specification the firmware should trigger a notification
+	 * immediately if the fan speed is outside the trip point range. This
+	 * _should_ result in at least one notification as both ranges do not
+	 * overlap, meaning that the current fan speed needs to be outside at
+	 * least one range.
+	 */
+	ret = acpi_fan_dsm_set_trip_points(dev, fan->fan_trip_granularity, 0);
+	if (ret < 0)
+		return ret;
+
+	return acpi_fan_dsm_set_trip_points(dev, fan->fan_trip_granularity * 3,
+					    fan->fan_trip_granularity * 2);
+}
+
+static int acpi_fan_dsm_update_trips_points(struct device *dev, struct acpi_fan_fst *fst)
+{
+	struct acpi_fan *fan = dev_get_drvdata(dev);
+	u64 upper, lower;
+
+	if (!fan->fan_trip_granularity)
+		return 0;
+
+	if (!acpi_fan_speed_valid(fst->speed))
+		return -EINVAL;
+
+	upper = roundup_u64(fst->speed + min_trip_distance, fan->fan_trip_granularity);
+	if (fst->speed <= min_trip_distance) {
+		lower = 0;
+	} else {
+		/*
+		 * Valid fan speed values cannot be larger than 32 bit, so
+		 * we can safely assume that no overflow will happen here.
+		 */
+		lower = rounddown((u32)fst->speed - min_trip_distance, fan->fan_trip_granularity);
+	}
+
+	return acpi_fan_dsm_set_trip_points(dev, upper, lower);
+}
+
+static void acpi_fan_notify_handler(acpi_handle handle, u32 event, void *context)
+{
+	struct device *dev = context;
+	struct acpi_fan_fst fst;
+	int ret;
+
+	switch (event) {
+	case ACPI_FAN_NOTIFY_STATE_CHANGED:
+		/*
+		 * The ACPI specification says that we must evaluate _FST when we
+		 * receive an ACPI event indicating that the fan state has changed.
+		 */
+		ret = acpi_fan_get_fst(handle, &fst);
+		if (ret < 0) {
+			dev_err(dev, "Error retrieving current fan status: %d\n", ret);
+		} else {
+			ret = acpi_fan_dsm_update_trips_points(dev, &fst);
+			if (ret < 0)
+				dev_err(dev, "Failed to update trip points: %d\n", ret);
+		}
+
+		acpi_fan_notify_hwmon(dev);
+		acpi_bus_generate_netlink_event("fan", dev_name(dev), event, 0);
+		break;
+	default:
+		dev_dbg(dev, "Unsupported ACPI notification 0x%x\n", event);
+		break;
+	}
+}
+
+static void acpi_fan_notify_remove(void *data)
+{
+	struct acpi_fan *fan = data;
+
+	acpi_remove_notify_handler(fan->handle, ACPI_DEVICE_NOTIFY, acpi_fan_notify_handler);
+}
+
+static int devm_acpi_fan_notify_init(struct device *dev)
+{
+	struct acpi_fan *fan = dev_get_drvdata(dev);
+	acpi_status status;
+
+	status = acpi_install_notify_handler(fan->handle, ACPI_DEVICE_NOTIFY,
+					     acpi_fan_notify_handler, dev);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	return devm_add_action_or_reset(dev, acpi_fan_notify_remove, fan);
+}
+
+static int acpi_fan_probe(struct platform_device *pdev)
+{
+	int result = 0;
+	struct thermal_cooling_device *cdev;
+	struct acpi_fan *fan;
+	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
+	char *name;
+
+	if (!device)
+		return -ENODEV;
+
+	fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
+	if (!fan) {
+		dev_err(&device->dev, "No memory for fan\n");
+		return -ENOMEM;
+	}
+
+	fan->handle = device->handle;
+	device->driver_data = fan;
+	platform_set_drvdata(pdev, fan);
+
+	if (acpi_has_method(device->handle, "_FST")) {
+		fan->has_fst = true;
+		fan->acpi4 = acpi_has_method(device->handle, "_FIF") &&
+				acpi_has_method(device->handle, "_FPS") &&
+				acpi_has_method(device->handle, "_FSL");
+	}
+
+	if (fan->acpi4) {
+		result = acpi_fan_get_fif(device);
+		if (result)
+			return result;
+
+		result = acpi_fan_get_fps(device);
+		if (result)
+			return result;
+	}
+
+	if (fan->has_fst) {
+		result = acpi_fan_dsm_init(&pdev->dev);
+		if (result)
+			return result;
+
+		result = devm_acpi_fan_create_hwmon(&pdev->dev);
+		if (result)
+			return result;
+
+		result = devm_acpi_fan_notify_init(&pdev->dev);
+		if (result)
+			return result;
+
+		result = acpi_fan_dsm_start(&pdev->dev);
+		if (result) {
+			dev_err(&pdev->dev, "Failed to start Microsoft fan extensions\n");
+			return result;
+		}
+
+		result = acpi_fan_create_attributes(device);
+		if (result)
+			return result;
+	}
+
+	if (!fan->acpi4) {
+		result = acpi_device_update_power(device, NULL);
+		if (result) {
+			dev_err(&device->dev, "Failed to set initial power state\n");
+			goto err_end;
+		}
+	}
+
+	if (!strncmp(pdev->name, "PNP0C0B", strlen("PNP0C0B")))
+		name = "Fan";
+	else
+		name = acpi_device_bid(device);
+
+	cdev = thermal_cooling_device_register(name, device,
+						&fan_cooling_ops);
+	if (IS_ERR(cdev)) {
+		result = PTR_ERR(cdev);
+		goto err_end;
+	}
+
+	dev_dbg(&pdev->dev, "registered as cooling_device%d\n", cdev->id);
+
+	fan->cdev = cdev;
+	result = sysfs_create_link(&pdev->dev.kobj,
+				   &cdev->device.kobj,
+				   "thermal_cooling");
+	if (result) {
+		dev_err(&pdev->dev, "Failed to create sysfs link 'thermal_cooling'\n");
+		goto err_unregister;
+	}
+
+	result = sysfs_create_link(&cdev->device.kobj,
+				   &pdev->dev.kobj,
+				   "device");
+	if (result) {
+		dev_err(&pdev->dev, "Failed to create sysfs link 'device'\n");
+		goto err_remove_link;
+	}
+
+	return 0;
+
+err_remove_link:
+	sysfs_remove_link(&pdev->dev.kobj, "thermal_cooling");
+err_unregister:
+	thermal_cooling_device_unregister(cdev);
+err_end:
+	if (fan->has_fst)
+		acpi_fan_delete_attributes(device);
+
+	return result;
+}
+
+static void acpi_fan_remove(struct platform_device *pdev)
+{
+	struct acpi_fan *fan = platform_get_drvdata(pdev);
+
+	if (fan->has_fst) {
+		struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
+
+		acpi_fan_delete_attributes(device);
+	}
+	sysfs_remove_link(&pdev->dev.kobj, "thermal_cooling");
+	sysfs_remove_link(&fan->cdev->device.kobj, "device");
+	thermal_cooling_device_unregister(fan->cdev);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int acpi_fan_suspend(struct device *dev)
+{
+	struct acpi_fan *fan = dev_get_drvdata(dev);
+	if (fan->acpi4)
+		return 0;
+
+	acpi_device_set_power(ACPI_COMPANION(dev), ACPI_STATE_D0);
+
+	return AE_OK;
+}
+
+static int acpi_fan_resume(struct device *dev)
+{
+	struct acpi_fan *fan = dev_get_drvdata(dev);
+	int result;
+
+	if (fan->has_fst) {
+		result = acpi_fan_dsm_start(dev);
+		if (result)
+			dev_err(dev, "Failed to start Microsoft fan extensions: %d\n", result);
+	}
+
+	if (fan->acpi4)
+		return 0;
+
+	result = acpi_device_update_power(ACPI_COMPANION(dev), NULL);
+	if (result)
+		dev_err(dev, "Error updating fan power state\n");
+
+	return result;
+}
+
+static const struct dev_pm_ops acpi_fan_pm = {
+	.resume = acpi_fan_resume,
+	.freeze = acpi_fan_suspend,
+	.thaw = acpi_fan_resume,
+	.restore = acpi_fan_resume,
+};
+#define FAN_PM_OPS_PTR (&acpi_fan_pm)
+
+#else
+
+#define FAN_PM_OPS_PTR NULL
+
+#endif
+
+static struct platform_driver acpi_fan_driver = {
+	.probe = acpi_fan_probe,
+	.remove = acpi_fan_remove,
+	.driver = {
+		.name = "acpi-fan",
+		.acpi_match_table = fan_device_ids,
+		.pm = FAN_PM_OPS_PTR,
+	},
+};
+
+module_platform_driver(acpi_fan_driver);
+
+MODULE_AUTHOR("Paul Diefenbaugh");
+MODULE_DESCRIPTION("ACPI Fan Driver");
+MODULE_LICENSE("GPL");