1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * fan_core.c - ACPI Fan core Driver
7 * Copyright (C) 2022 Intel Corporation. All rights reserved.
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/types.h>
14 #include <linux/uaccess.h>
15 #include <linux/thermal.h>
16 #include <linux/acpi.h>
17 #include <linux/platform_device.h>
18 #include <linux/sort.h>
22 static const struct acpi_device_id fan_device_ids[] = {
26 MODULE_DEVICE_TABLE(acpi, fan_device_ids);
28 /* thermal cooling device callbacks */
29 static int fan_get_max_state(struct thermal_cooling_device *cdev, unsigned long
32 struct acpi_device *device = cdev->devdata;
33 struct acpi_fan *fan = acpi_driver_data(device);
36 if (fan->fif.fine_grain_ctrl)
37 *state = 100 / fan->fif.step_size;
39 *state = fan->fps_count - 1;
47 int acpi_fan_get_fst(struct acpi_device *device, struct acpi_fan_fst *fst)
49 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
50 union acpi_object *obj;
54 status = acpi_evaluate_object(device->handle, "_FST", NULL, &buffer);
55 if (ACPI_FAILURE(status)) {
56 dev_err(&device->dev, "Get fan state failed\n");
61 if (!obj || obj->type != ACPI_TYPE_PACKAGE ||
62 obj->package.count != 3 ||
63 obj->package.elements[1].type != ACPI_TYPE_INTEGER) {
64 dev_err(&device->dev, "Invalid _FST data\n");
69 fst->revision = obj->package.elements[0].integer.value;
70 fst->control = obj->package.elements[1].integer.value;
71 fst->speed = obj->package.elements[2].integer.value;
78 static int fan_get_state_acpi4(struct acpi_device *device, unsigned long *state)
80 struct acpi_fan *fan = acpi_driver_data(device);
81 struct acpi_fan_fst fst;
84 status = acpi_fan_get_fst(device, &fst);
88 if (fan->fif.fine_grain_ctrl) {
89 /* This control should be same what we set using _FSL by spec */
90 if (fst.control > 100) {
91 dev_dbg(&device->dev, "Invalid control value returned\n");
95 *state = (int) fst.control / fan->fif.step_size;
100 for (i = 0; i < fan->fps_count; i++) {
101 if (fst.control == fan->fps[i].control)
104 if (i == fan->fps_count) {
105 dev_dbg(&device->dev, "Invalid control value returned\n");
114 static int fan_get_state(struct acpi_device *device, unsigned long *state)
117 int acpi_state = ACPI_STATE_D0;
119 result = acpi_device_update_power(device, &acpi_state);
123 *state = acpi_state == ACPI_STATE_D3_COLD
124 || acpi_state == ACPI_STATE_D3_HOT ?
125 0 : (acpi_state == ACPI_STATE_D0 ? 1 : -1);
129 static int fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long
132 struct acpi_device *device = cdev->devdata;
133 struct acpi_fan *fan = acpi_driver_data(device);
136 return fan_get_state_acpi4(device, state);
138 return fan_get_state(device, state);
141 static int fan_set_state(struct acpi_device *device, unsigned long state)
143 if (state != 0 && state != 1)
146 return acpi_device_set_power(device,
147 state ? ACPI_STATE_D0 : ACPI_STATE_D3_COLD);
150 static int fan_set_state_acpi4(struct acpi_device *device, unsigned long state)
152 struct acpi_fan *fan = acpi_driver_data(device);
157 if (fan->fif.fine_grain_ctrl)
158 max_state = 100 / fan->fif.step_size;
160 max_state = fan->fps_count - 1;
162 if (state > max_state)
165 if (fan->fif.fine_grain_ctrl) {
166 value *= fan->fif.step_size;
167 /* Spec allows compensate the last step only */
168 if (value + fan->fif.step_size > 100)
171 value = fan->fps[state].control;
174 status = acpi_execute_simple_method(device->handle, "_FSL", value);
175 if (ACPI_FAILURE(status)) {
176 dev_dbg(&device->dev, "Failed to set state by _FSL\n");
184 fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
186 struct acpi_device *device = cdev->devdata;
187 struct acpi_fan *fan = acpi_driver_data(device);
190 return fan_set_state_acpi4(device, state);
192 return fan_set_state(device, state);
195 static const struct thermal_cooling_device_ops fan_cooling_ops = {
196 .get_max_state = fan_get_max_state,
197 .get_cur_state = fan_get_cur_state,
198 .set_cur_state = fan_set_cur_state,
201 /* --------------------------------------------------------------------------
203 * --------------------------------------------------------------------------
206 static bool acpi_fan_is_acpi4(struct acpi_device *device)
208 return acpi_has_method(device->handle, "_FIF") &&
209 acpi_has_method(device->handle, "_FPS") &&
210 acpi_has_method(device->handle, "_FSL") &&
211 acpi_has_method(device->handle, "_FST");
214 static int acpi_fan_get_fif(struct acpi_device *device)
216 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
217 struct acpi_fan *fan = acpi_driver_data(device);
218 struct acpi_buffer format = { sizeof("NNNN"), "NNNN" };
220 struct acpi_buffer fif = { sizeof(fields), fields };
221 union acpi_object *obj;
224 status = acpi_evaluate_object(device->handle, "_FIF", NULL, &buffer);
225 if (ACPI_FAILURE(status))
228 obj = buffer.pointer;
229 if (!obj || obj->type != ACPI_TYPE_PACKAGE) {
230 dev_err(&device->dev, "Invalid _FIF data\n");
235 status = acpi_extract_package(obj, &format, &fif);
236 if (ACPI_FAILURE(status)) {
237 dev_err(&device->dev, "Invalid _FIF element\n");
242 fan->fif.revision = fields[0];
243 fan->fif.fine_grain_ctrl = fields[1];
244 fan->fif.step_size = fields[2];
245 fan->fif.low_speed_notification = fields[3];
247 /* If there is a bug in step size and set as 0, change to 1 */
248 if (!fan->fif.step_size)
249 fan->fif.step_size = 1;
250 /* If step size > 9, change to 9 (by spec valid values 1-9) */
251 else if (fan->fif.step_size > 9)
252 fan->fif.step_size = 9;
258 static int acpi_fan_speed_cmp(const void *a, const void *b)
260 const struct acpi_fan_fps *fps1 = a;
261 const struct acpi_fan_fps *fps2 = b;
262 return fps1->speed - fps2->speed;
265 static int acpi_fan_get_fps(struct acpi_device *device)
267 struct acpi_fan *fan = acpi_driver_data(device);
268 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
269 union acpi_object *obj;
273 status = acpi_evaluate_object(device->handle, "_FPS", NULL, &buffer);
274 if (ACPI_FAILURE(status))
277 obj = buffer.pointer;
278 if (!obj || obj->type != ACPI_TYPE_PACKAGE || obj->package.count < 2) {
279 dev_err(&device->dev, "Invalid _FPS data\n");
284 fan->fps_count = obj->package.count - 1; /* minus revision field */
285 fan->fps = devm_kcalloc(&device->dev,
286 fan->fps_count, sizeof(struct acpi_fan_fps),
289 dev_err(&device->dev, "Not enough memory\n");
293 for (i = 0; i < fan->fps_count; i++) {
294 struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
295 struct acpi_buffer fps = { offsetof(struct acpi_fan_fps, name),
297 status = acpi_extract_package(&obj->package.elements[i + 1],
299 if (ACPI_FAILURE(status)) {
300 dev_err(&device->dev, "Invalid _FPS element\n");
305 /* sort the state array according to fan speed in increase order */
306 sort(fan->fps, fan->fps_count, sizeof(*fan->fps),
307 acpi_fan_speed_cmp, NULL);
314 static int acpi_fan_probe(struct platform_device *pdev)
317 struct thermal_cooling_device *cdev;
318 struct acpi_fan *fan;
319 struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
322 fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
324 dev_err(&device->dev, "No memory for fan\n");
327 device->driver_data = fan;
328 platform_set_drvdata(pdev, fan);
330 if (acpi_fan_is_acpi4(device)) {
331 result = acpi_fan_get_fif(device);
335 result = acpi_fan_get_fps(device);
339 result = devm_acpi_fan_create_hwmon(device);
343 result = acpi_fan_create_attributes(device);
349 result = acpi_device_update_power(device, NULL);
351 dev_err(&device->dev, "Failed to set initial power state\n");
356 if (!strncmp(pdev->name, "PNP0C0B", strlen("PNP0C0B")))
359 name = acpi_device_bid(device);
361 cdev = thermal_cooling_device_register(name, device,
364 result = PTR_ERR(cdev);
368 dev_dbg(&pdev->dev, "registered as cooling_device%d\n", cdev->id);
371 result = sysfs_create_link(&pdev->dev.kobj,
375 dev_err(&pdev->dev, "Failed to create sysfs link 'thermal_cooling'\n");
377 result = sysfs_create_link(&cdev->device.kobj,
381 dev_err(&pdev->dev, "Failed to create sysfs link 'device'\n");
389 acpi_fan_delete_attributes(device);
394 static void acpi_fan_remove(struct platform_device *pdev)
396 struct acpi_fan *fan = platform_get_drvdata(pdev);
399 struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
401 acpi_fan_delete_attributes(device);
403 sysfs_remove_link(&pdev->dev.kobj, "thermal_cooling");
404 sysfs_remove_link(&fan->cdev->device.kobj, "device");
405 thermal_cooling_device_unregister(fan->cdev);
408 #ifdef CONFIG_PM_SLEEP
409 static int acpi_fan_suspend(struct device *dev)
411 struct acpi_fan *fan = dev_get_drvdata(dev);
415 acpi_device_set_power(ACPI_COMPANION(dev), ACPI_STATE_D0);
420 static int acpi_fan_resume(struct device *dev)
423 struct acpi_fan *fan = dev_get_drvdata(dev);
428 result = acpi_device_update_power(ACPI_COMPANION(dev), NULL);
430 dev_err(dev, "Error updating fan power state\n");
435 static const struct dev_pm_ops acpi_fan_pm = {
436 .resume = acpi_fan_resume,
437 .freeze = acpi_fan_suspend,
438 .thaw = acpi_fan_resume,
439 .restore = acpi_fan_resume,
441 #define FAN_PM_OPS_PTR (&acpi_fan_pm)
445 #define FAN_PM_OPS_PTR NULL
449 static struct platform_driver acpi_fan_driver = {
450 .probe = acpi_fan_probe,
451 .remove = acpi_fan_remove,
454 .acpi_match_table = fan_device_ids,
455 .pm = FAN_PM_OPS_PTR,
459 module_platform_driver(acpi_fan_driver);
461 MODULE_AUTHOR("Paul Diefenbaugh");
462 MODULE_DESCRIPTION("ACPI Fan Driver");
463 MODULE_LICENSE("GPL");