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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  acpi_fan.c - ACPI Fan Driver ($Revision: 29 $)
4  *
5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/types.h>
13 #include <linux/uaccess.h>
14 #include <linux/thermal.h>
15 #include <linux/acpi.h>
16 #include <linux/platform_device.h>
17 #include <linux/sort.h>
18 
19 MODULE_AUTHOR("Paul Diefenbaugh");
20 MODULE_DESCRIPTION("ACPI Fan Driver");
21 MODULE_LICENSE("GPL");
22 
23 static int acpi_fan_probe(struct platform_device *pdev);
24 static int acpi_fan_remove(struct platform_device *pdev);
25 
26 static const struct acpi_device_id fan_device_ids[] = {
27 	{"PNP0C0B", 0},
28 	{"INT3404", 0},
29 	{"", 0},
30 };
31 MODULE_DEVICE_TABLE(acpi, fan_device_ids);
32 
33 #ifdef CONFIG_PM_SLEEP
34 static int acpi_fan_suspend(struct device *dev);
35 static int acpi_fan_resume(struct device *dev);
36 static const struct dev_pm_ops acpi_fan_pm = {
37 	.resume = acpi_fan_resume,
38 	.freeze = acpi_fan_suspend,
39 	.thaw = acpi_fan_resume,
40 	.restore = acpi_fan_resume,
41 };
42 #define FAN_PM_OPS_PTR (&acpi_fan_pm)
43 #else
44 #define FAN_PM_OPS_PTR NULL
45 #endif
46 
47 struct acpi_fan_fps {
48 	u64 control;
49 	u64 trip_point;
50 	u64 speed;
51 	u64 noise_level;
52 	u64 power;
53 };
54 
55 struct acpi_fan_fif {
56 	u64 revision;
57 	u64 fine_grain_ctrl;
58 	u64 step_size;
59 	u64 low_speed_notification;
60 };
61 
62 struct acpi_fan {
63 	bool acpi4;
64 	struct acpi_fan_fif fif;
65 	struct acpi_fan_fps *fps;
66 	int fps_count;
67 	struct thermal_cooling_device *cdev;
68 };
69 
70 static struct platform_driver acpi_fan_driver = {
71 	.probe = acpi_fan_probe,
72 	.remove = acpi_fan_remove,
73 	.driver = {
74 		.name = "acpi-fan",
75 		.acpi_match_table = fan_device_ids,
76 		.pm = FAN_PM_OPS_PTR,
77 	},
78 };
79 
80 /* thermal cooling device callbacks */
fan_get_max_state(struct thermal_cooling_device * cdev,unsigned long * state)81 static int fan_get_max_state(struct thermal_cooling_device *cdev, unsigned long
82 			     *state)
83 {
84 	struct acpi_device *device = cdev->devdata;
85 	struct acpi_fan *fan = acpi_driver_data(device);
86 
87 	if (fan->acpi4)
88 		*state = fan->fps_count - 1;
89 	else
90 		*state = 1;
91 	return 0;
92 }
93 
fan_get_state_acpi4(struct acpi_device * device,unsigned long * state)94 static int fan_get_state_acpi4(struct acpi_device *device, unsigned long *state)
95 {
96 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
97 	struct acpi_fan *fan = acpi_driver_data(device);
98 	union acpi_object *obj;
99 	acpi_status status;
100 	int control, i;
101 
102 	status = acpi_evaluate_object(device->handle, "_FST", NULL, &buffer);
103 	if (ACPI_FAILURE(status)) {
104 		dev_err(&device->dev, "Get fan state failed\n");
105 		return status;
106 	}
107 
108 	obj = buffer.pointer;
109 	if (!obj || obj->type != ACPI_TYPE_PACKAGE ||
110 	    obj->package.count != 3 ||
111 	    obj->package.elements[1].type != ACPI_TYPE_INTEGER) {
112 		dev_err(&device->dev, "Invalid _FST data\n");
113 		status = -EINVAL;
114 		goto err;
115 	}
116 
117 	control = obj->package.elements[1].integer.value;
118 	for (i = 0; i < fan->fps_count; i++) {
119 		/*
120 		 * When Fine Grain Control is set, return the state
121 		 * corresponding to maximum fan->fps[i].control
122 		 * value compared to the current speed. Here the
123 		 * fan->fps[] is sorted array with increasing speed.
124 		 */
125 		if (fan->fif.fine_grain_ctrl && control < fan->fps[i].control) {
126 			i = (i > 0) ? i - 1 : 0;
127 			break;
128 		} else if (control == fan->fps[i].control) {
129 			break;
130 		}
131 	}
132 	if (i == fan->fps_count) {
133 		dev_dbg(&device->dev, "Invalid control value returned\n");
134 		status = -EINVAL;
135 		goto err;
136 	}
137 
138 	*state = i;
139 
140 err:
141 	kfree(obj);
142 	return status;
143 }
144 
fan_get_state(struct acpi_device * device,unsigned long * state)145 static int fan_get_state(struct acpi_device *device, unsigned long *state)
146 {
147 	int result;
148 	int acpi_state = ACPI_STATE_D0;
149 
150 	result = acpi_device_update_power(device, &acpi_state);
151 	if (result)
152 		return result;
153 
154 	*state = acpi_state == ACPI_STATE_D3_COLD
155 			|| acpi_state == ACPI_STATE_D3_HOT ?
156 		0 : (acpi_state == ACPI_STATE_D0 ? 1 : -1);
157 	return 0;
158 }
159 
fan_get_cur_state(struct thermal_cooling_device * cdev,unsigned long * state)160 static int fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long
161 			     *state)
162 {
163 	struct acpi_device *device = cdev->devdata;
164 	struct acpi_fan *fan = acpi_driver_data(device);
165 
166 	if (fan->acpi4)
167 		return fan_get_state_acpi4(device, state);
168 	else
169 		return fan_get_state(device, state);
170 }
171 
fan_set_state(struct acpi_device * device,unsigned long state)172 static int fan_set_state(struct acpi_device *device, unsigned long state)
173 {
174 	if (state != 0 && state != 1)
175 		return -EINVAL;
176 
177 	return acpi_device_set_power(device,
178 				     state ? ACPI_STATE_D0 : ACPI_STATE_D3_COLD);
179 }
180 
fan_set_state_acpi4(struct acpi_device * device,unsigned long state)181 static int fan_set_state_acpi4(struct acpi_device *device, unsigned long state)
182 {
183 	struct acpi_fan *fan = acpi_driver_data(device);
184 	acpi_status status;
185 
186 	if (state >= fan->fps_count)
187 		return -EINVAL;
188 
189 	status = acpi_execute_simple_method(device->handle, "_FSL",
190 					    fan->fps[state].control);
191 	if (ACPI_FAILURE(status)) {
192 		dev_dbg(&device->dev, "Failed to set state by _FSL\n");
193 		return status;
194 	}
195 
196 	return 0;
197 }
198 
199 static int
fan_set_cur_state(struct thermal_cooling_device * cdev,unsigned long state)200 fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
201 {
202 	struct acpi_device *device = cdev->devdata;
203 	struct acpi_fan *fan = acpi_driver_data(device);
204 
205 	if (fan->acpi4)
206 		return fan_set_state_acpi4(device, state);
207 	else
208 		return fan_set_state(device, state);
209 }
210 
211 static const struct thermal_cooling_device_ops fan_cooling_ops = {
212 	.get_max_state = fan_get_max_state,
213 	.get_cur_state = fan_get_cur_state,
214 	.set_cur_state = fan_set_cur_state,
215 };
216 
217 /* --------------------------------------------------------------------------
218  *                               Driver Interface
219  * --------------------------------------------------------------------------
220 */
221 
acpi_fan_is_acpi4(struct acpi_device * device)222 static bool acpi_fan_is_acpi4(struct acpi_device *device)
223 {
224 	return acpi_has_method(device->handle, "_FIF") &&
225 	       acpi_has_method(device->handle, "_FPS") &&
226 	       acpi_has_method(device->handle, "_FSL") &&
227 	       acpi_has_method(device->handle, "_FST");
228 }
229 
acpi_fan_get_fif(struct acpi_device * device)230 static int acpi_fan_get_fif(struct acpi_device *device)
231 {
232 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
233 	struct acpi_fan *fan = acpi_driver_data(device);
234 	struct acpi_buffer format = { sizeof("NNNN"), "NNNN" };
235 	struct acpi_buffer fif = { sizeof(fan->fif), &fan->fif };
236 	union acpi_object *obj;
237 	acpi_status status;
238 
239 	status = acpi_evaluate_object(device->handle, "_FIF", NULL, &buffer);
240 	if (ACPI_FAILURE(status))
241 		return status;
242 
243 	obj = buffer.pointer;
244 	if (!obj || obj->type != ACPI_TYPE_PACKAGE) {
245 		dev_err(&device->dev, "Invalid _FIF data\n");
246 		status = -EINVAL;
247 		goto err;
248 	}
249 
250 	status = acpi_extract_package(obj, &format, &fif);
251 	if (ACPI_FAILURE(status)) {
252 		dev_err(&device->dev, "Invalid _FIF element\n");
253 		status = -EINVAL;
254 	}
255 
256 err:
257 	kfree(obj);
258 	return status;
259 }
260 
acpi_fan_speed_cmp(const void * a,const void * b)261 static int acpi_fan_speed_cmp(const void *a, const void *b)
262 {
263 	const struct acpi_fan_fps *fps1 = a;
264 	const struct acpi_fan_fps *fps2 = b;
265 	return fps1->speed - fps2->speed;
266 }
267 
acpi_fan_get_fps(struct acpi_device * device)268 static int acpi_fan_get_fps(struct acpi_device *device)
269 {
270 	struct acpi_fan *fan = acpi_driver_data(device);
271 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
272 	union acpi_object *obj;
273 	acpi_status status;
274 	int i;
275 
276 	status = acpi_evaluate_object(device->handle, "_FPS", NULL, &buffer);
277 	if (ACPI_FAILURE(status))
278 		return status;
279 
280 	obj = buffer.pointer;
281 	if (!obj || obj->type != ACPI_TYPE_PACKAGE || obj->package.count < 2) {
282 		dev_err(&device->dev, "Invalid _FPS data\n");
283 		status = -EINVAL;
284 		goto err;
285 	}
286 
287 	fan->fps_count = obj->package.count - 1; /* minus revision field */
288 	fan->fps = devm_kcalloc(&device->dev,
289 				fan->fps_count, sizeof(struct acpi_fan_fps),
290 				GFP_KERNEL);
291 	if (!fan->fps) {
292 		dev_err(&device->dev, "Not enough memory\n");
293 		status = -ENOMEM;
294 		goto err;
295 	}
296 	for (i = 0; i < fan->fps_count; i++) {
297 		struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
298 		struct acpi_buffer fps = { sizeof(fan->fps[i]), &fan->fps[i] };
299 		status = acpi_extract_package(&obj->package.elements[i + 1],
300 					      &format, &fps);
301 		if (ACPI_FAILURE(status)) {
302 			dev_err(&device->dev, "Invalid _FPS element\n");
303 			break;
304 		}
305 	}
306 
307 	/* sort the state array according to fan speed in increase order */
308 	sort(fan->fps, fan->fps_count, sizeof(*fan->fps),
309 	     acpi_fan_speed_cmp, NULL);
310 
311 err:
312 	kfree(obj);
313 	return status;
314 }
315 
acpi_fan_probe(struct platform_device * pdev)316 static int acpi_fan_probe(struct platform_device *pdev)
317 {
318 	int result = 0;
319 	struct thermal_cooling_device *cdev;
320 	struct acpi_fan *fan;
321 	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
322 	char *name;
323 
324 	fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
325 	if (!fan) {
326 		dev_err(&device->dev, "No memory for fan\n");
327 		return -ENOMEM;
328 	}
329 	device->driver_data = fan;
330 	platform_set_drvdata(pdev, fan);
331 
332 	if (acpi_fan_is_acpi4(device)) {
333 		if (acpi_fan_get_fif(device) || acpi_fan_get_fps(device))
334 			goto end;
335 		fan->acpi4 = true;
336 	} else {
337 		result = acpi_device_update_power(device, NULL);
338 		if (result) {
339 			dev_err(&device->dev, "Failed to set initial power state\n");
340 			goto end;
341 		}
342 	}
343 
344 	if (!strncmp(pdev->name, "PNP0C0B", strlen("PNP0C0B")))
345 		name = "Fan";
346 	else
347 		name = acpi_device_bid(device);
348 
349 	cdev = thermal_cooling_device_register(name, device,
350 						&fan_cooling_ops);
351 	if (IS_ERR(cdev)) {
352 		result = PTR_ERR(cdev);
353 		goto end;
354 	}
355 
356 	dev_dbg(&pdev->dev, "registered as cooling_device%d\n", cdev->id);
357 
358 	fan->cdev = cdev;
359 	result = sysfs_create_link(&pdev->dev.kobj,
360 				   &cdev->device.kobj,
361 				   "thermal_cooling");
362 	if (result)
363 		dev_err(&pdev->dev, "Failed to create sysfs link 'thermal_cooling'\n");
364 
365 	result = sysfs_create_link(&cdev->device.kobj,
366 				   &pdev->dev.kobj,
367 				   "device");
368 	if (result)
369 		dev_err(&pdev->dev, "Failed to create sysfs link 'device'\n");
370 
371 end:
372 	return result;
373 }
374 
acpi_fan_remove(struct platform_device * pdev)375 static int acpi_fan_remove(struct platform_device *pdev)
376 {
377 	struct acpi_fan *fan = platform_get_drvdata(pdev);
378 
379 	sysfs_remove_link(&pdev->dev.kobj, "thermal_cooling");
380 	sysfs_remove_link(&fan->cdev->device.kobj, "device");
381 	thermal_cooling_device_unregister(fan->cdev);
382 
383 	return 0;
384 }
385 
386 #ifdef CONFIG_PM_SLEEP
acpi_fan_suspend(struct device * dev)387 static int acpi_fan_suspend(struct device *dev)
388 {
389 	struct acpi_fan *fan = dev_get_drvdata(dev);
390 	if (fan->acpi4)
391 		return 0;
392 
393 	acpi_device_set_power(ACPI_COMPANION(dev), ACPI_STATE_D0);
394 
395 	return AE_OK;
396 }
397 
acpi_fan_resume(struct device * dev)398 static int acpi_fan_resume(struct device *dev)
399 {
400 	int result;
401 	struct acpi_fan *fan = dev_get_drvdata(dev);
402 
403 	if (fan->acpi4)
404 		return 0;
405 
406 	result = acpi_device_update_power(ACPI_COMPANION(dev), NULL);
407 	if (result)
408 		dev_err(dev, "Error updating fan power state\n");
409 
410 	return result;
411 }
412 #endif
413 
414 module_platform_driver(acpi_fan_driver);
415