xref: /openbmc/linux/drivers/acpi/fan_core.c (revision fbb6b31a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  fan_core.c - ACPI Fan core Driver
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  *  Copyright (C) 2022 Intel Corporation. All rights reserved.
8  */
9 
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>
19 
20 #include "fan.h"
21 
22 MODULE_AUTHOR("Paul Diefenbaugh");
23 MODULE_DESCRIPTION("ACPI Fan Driver");
24 MODULE_LICENSE("GPL");
25 
26 static int acpi_fan_probe(struct platform_device *pdev);
27 static int acpi_fan_remove(struct platform_device *pdev);
28 
29 static const struct acpi_device_id fan_device_ids[] = {
30 	ACPI_FAN_DEVICE_IDS,
31 	{"", 0},
32 };
33 MODULE_DEVICE_TABLE(acpi, fan_device_ids);
34 
35 #ifdef CONFIG_PM_SLEEP
36 static int acpi_fan_suspend(struct device *dev);
37 static int acpi_fan_resume(struct device *dev);
38 static const struct dev_pm_ops acpi_fan_pm = {
39 	.resume = acpi_fan_resume,
40 	.freeze = acpi_fan_suspend,
41 	.thaw = acpi_fan_resume,
42 	.restore = acpi_fan_resume,
43 };
44 #define FAN_PM_OPS_PTR (&acpi_fan_pm)
45 #else
46 #define FAN_PM_OPS_PTR NULL
47 #endif
48 
49 static struct platform_driver acpi_fan_driver = {
50 	.probe = acpi_fan_probe,
51 	.remove = acpi_fan_remove,
52 	.driver = {
53 		.name = "acpi-fan",
54 		.acpi_match_table = fan_device_ids,
55 		.pm = FAN_PM_OPS_PTR,
56 	},
57 };
58 
59 /* thermal cooling device callbacks */
60 static int fan_get_max_state(struct thermal_cooling_device *cdev, unsigned long
61 			     *state)
62 {
63 	struct acpi_device *device = cdev->devdata;
64 	struct acpi_fan *fan = acpi_driver_data(device);
65 
66 	if (fan->acpi4) {
67 		if (fan->fif.fine_grain_ctrl)
68 			*state = 100 / fan->fif.step_size;
69 		else
70 			*state = fan->fps_count - 1;
71 	} else {
72 		*state = 1;
73 	}
74 
75 	return 0;
76 }
77 
78 int acpi_fan_get_fst(struct acpi_device *device, struct acpi_fan_fst *fst)
79 {
80 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
81 	union acpi_object *obj;
82 	acpi_status status;
83 	int ret = 0;
84 
85 	status = acpi_evaluate_object(device->handle, "_FST", NULL, &buffer);
86 	if (ACPI_FAILURE(status)) {
87 		dev_err(&device->dev, "Get fan state failed\n");
88 		return -ENODEV;
89 	}
90 
91 	obj = buffer.pointer;
92 	if (!obj || obj->type != ACPI_TYPE_PACKAGE ||
93 	    obj->package.count != 3 ||
94 	    obj->package.elements[1].type != ACPI_TYPE_INTEGER) {
95 		dev_err(&device->dev, "Invalid _FST data\n");
96 		ret = -EINVAL;
97 		goto err;
98 	}
99 
100 	fst->revision = obj->package.elements[0].integer.value;
101 	fst->control = obj->package.elements[1].integer.value;
102 	fst->speed = obj->package.elements[2].integer.value;
103 
104 err:
105 	kfree(obj);
106 	return ret;
107 }
108 
109 static int fan_get_state_acpi4(struct acpi_device *device, unsigned long *state)
110 {
111 	struct acpi_fan *fan = acpi_driver_data(device);
112 	struct acpi_fan_fst fst;
113 	int status, i;
114 
115 	status = acpi_fan_get_fst(device, &fst);
116 	if (status)
117 		return status;
118 
119 	if (fan->fif.fine_grain_ctrl) {
120 		/* This control should be same what we set using _FSL by spec */
121 		if (fst.control > 100) {
122 			dev_dbg(&device->dev, "Invalid control value returned\n");
123 			goto match_fps;
124 		}
125 
126 		*state = (int) fst.control / fan->fif.step_size;
127 		return 0;
128 	}
129 
130 match_fps:
131 	for (i = 0; i < fan->fps_count; i++) {
132 		if (fst.control == fan->fps[i].control)
133 			break;
134 	}
135 	if (i == fan->fps_count) {
136 		dev_dbg(&device->dev, "Invalid control value returned\n");
137 		return -EINVAL;
138 	}
139 
140 	*state = i;
141 
142 	return status;
143 }
144 
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 
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 
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 
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 	u64 value = state;
186 	int max_state;
187 
188 	if (fan->fif.fine_grain_ctrl)
189 		max_state = 100 / fan->fif.step_size;
190 	else
191 		max_state = fan->fps_count - 1;
192 
193 	if (state > max_state)
194 		return -EINVAL;
195 
196 	if (fan->fif.fine_grain_ctrl) {
197 		value *= fan->fif.step_size;
198 		/* Spec allows compensate the last step only */
199 		if (value + fan->fif.step_size > 100)
200 			value = 100;
201 	} else {
202 		value = fan->fps[state].control;
203 	}
204 
205 	status = acpi_execute_simple_method(device->handle, "_FSL", value);
206 	if (ACPI_FAILURE(status)) {
207 		dev_dbg(&device->dev, "Failed to set state by _FSL\n");
208 		return -ENODEV;
209 	}
210 
211 	return 0;
212 }
213 
214 static int
215 fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
216 {
217 	struct acpi_device *device = cdev->devdata;
218 	struct acpi_fan *fan = acpi_driver_data(device);
219 
220 	if (fan->acpi4)
221 		return fan_set_state_acpi4(device, state);
222 	else
223 		return fan_set_state(device, state);
224 }
225 
226 static const struct thermal_cooling_device_ops fan_cooling_ops = {
227 	.get_max_state = fan_get_max_state,
228 	.get_cur_state = fan_get_cur_state,
229 	.set_cur_state = fan_set_cur_state,
230 };
231 
232 /* --------------------------------------------------------------------------
233  *                               Driver Interface
234  * --------------------------------------------------------------------------
235 */
236 
237 static bool acpi_fan_is_acpi4(struct acpi_device *device)
238 {
239 	return acpi_has_method(device->handle, "_FIF") &&
240 	       acpi_has_method(device->handle, "_FPS") &&
241 	       acpi_has_method(device->handle, "_FSL") &&
242 	       acpi_has_method(device->handle, "_FST");
243 }
244 
245 static int acpi_fan_get_fif(struct acpi_device *device)
246 {
247 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
248 	struct acpi_fan *fan = acpi_driver_data(device);
249 	struct acpi_buffer format = { sizeof("NNNN"), "NNNN" };
250 	u64 fields[4];
251 	struct acpi_buffer fif = { sizeof(fields), fields };
252 	union acpi_object *obj;
253 	acpi_status status;
254 
255 	status = acpi_evaluate_object(device->handle, "_FIF", NULL, &buffer);
256 	if (ACPI_FAILURE(status))
257 		return status;
258 
259 	obj = buffer.pointer;
260 	if (!obj || obj->type != ACPI_TYPE_PACKAGE) {
261 		dev_err(&device->dev, "Invalid _FIF data\n");
262 		status = -EINVAL;
263 		goto err;
264 	}
265 
266 	status = acpi_extract_package(obj, &format, &fif);
267 	if (ACPI_FAILURE(status)) {
268 		dev_err(&device->dev, "Invalid _FIF element\n");
269 		status = -EINVAL;
270 	}
271 
272 	fan->fif.revision = fields[0];
273 	fan->fif.fine_grain_ctrl = fields[1];
274 	fan->fif.step_size = fields[2];
275 	fan->fif.low_speed_notification = fields[3];
276 
277 	/* If there is a bug in step size and set as 0, change to 1 */
278 	if (!fan->fif.step_size)
279 		fan->fif.step_size = 1;
280 	/* If step size > 9, change to 9 (by spec valid values 1-9) */
281 	else if (fan->fif.step_size > 9)
282 		fan->fif.step_size = 9;
283 err:
284 	kfree(obj);
285 	return status;
286 }
287 
288 static int acpi_fan_speed_cmp(const void *a, const void *b)
289 {
290 	const struct acpi_fan_fps *fps1 = a;
291 	const struct acpi_fan_fps *fps2 = b;
292 	return fps1->speed - fps2->speed;
293 }
294 
295 static int acpi_fan_get_fps(struct acpi_device *device)
296 {
297 	struct acpi_fan *fan = acpi_driver_data(device);
298 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
299 	union acpi_object *obj;
300 	acpi_status status;
301 	int i;
302 
303 	status = acpi_evaluate_object(device->handle, "_FPS", NULL, &buffer);
304 	if (ACPI_FAILURE(status))
305 		return status;
306 
307 	obj = buffer.pointer;
308 	if (!obj || obj->type != ACPI_TYPE_PACKAGE || obj->package.count < 2) {
309 		dev_err(&device->dev, "Invalid _FPS data\n");
310 		status = -EINVAL;
311 		goto err;
312 	}
313 
314 	fan->fps_count = obj->package.count - 1; /* minus revision field */
315 	fan->fps = devm_kcalloc(&device->dev,
316 				fan->fps_count, sizeof(struct acpi_fan_fps),
317 				GFP_KERNEL);
318 	if (!fan->fps) {
319 		dev_err(&device->dev, "Not enough memory\n");
320 		status = -ENOMEM;
321 		goto err;
322 	}
323 	for (i = 0; i < fan->fps_count; i++) {
324 		struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
325 		struct acpi_buffer fps = { offsetof(struct acpi_fan_fps, name),
326 						&fan->fps[i] };
327 		status = acpi_extract_package(&obj->package.elements[i + 1],
328 					      &format, &fps);
329 		if (ACPI_FAILURE(status)) {
330 			dev_err(&device->dev, "Invalid _FPS element\n");
331 			goto err;
332 		}
333 	}
334 
335 	/* sort the state array according to fan speed in increase order */
336 	sort(fan->fps, fan->fps_count, sizeof(*fan->fps),
337 	     acpi_fan_speed_cmp, NULL);
338 
339 err:
340 	kfree(obj);
341 	return status;
342 }
343 
344 static int acpi_fan_probe(struct platform_device *pdev)
345 {
346 	int result = 0;
347 	struct thermal_cooling_device *cdev;
348 	struct acpi_fan *fan;
349 	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
350 	char *name;
351 
352 	fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
353 	if (!fan) {
354 		dev_err(&device->dev, "No memory for fan\n");
355 		return -ENOMEM;
356 	}
357 	device->driver_data = fan;
358 	platform_set_drvdata(pdev, fan);
359 
360 	if (acpi_fan_is_acpi4(device)) {
361 		result = acpi_fan_get_fif(device);
362 		if (result)
363 			return result;
364 
365 		result = acpi_fan_get_fps(device);
366 		if (result)
367 			return result;
368 
369 		result = acpi_fan_create_attributes(device);
370 		if (result)
371 			return result;
372 
373 		fan->acpi4 = true;
374 	} else {
375 		result = acpi_device_update_power(device, NULL);
376 		if (result) {
377 			dev_err(&device->dev, "Failed to set initial power state\n");
378 			goto err_end;
379 		}
380 	}
381 
382 	if (!strncmp(pdev->name, "PNP0C0B", strlen("PNP0C0B")))
383 		name = "Fan";
384 	else
385 		name = acpi_device_bid(device);
386 
387 	cdev = thermal_cooling_device_register(name, device,
388 						&fan_cooling_ops);
389 	if (IS_ERR(cdev)) {
390 		result = PTR_ERR(cdev);
391 		goto err_end;
392 	}
393 
394 	dev_dbg(&pdev->dev, "registered as cooling_device%d\n", cdev->id);
395 
396 	fan->cdev = cdev;
397 	result = sysfs_create_link(&pdev->dev.kobj,
398 				   &cdev->device.kobj,
399 				   "thermal_cooling");
400 	if (result)
401 		dev_err(&pdev->dev, "Failed to create sysfs link 'thermal_cooling'\n");
402 
403 	result = sysfs_create_link(&cdev->device.kobj,
404 				   &pdev->dev.kobj,
405 				   "device");
406 	if (result) {
407 		dev_err(&pdev->dev, "Failed to create sysfs link 'device'\n");
408 		goto err_end;
409 	}
410 
411 	return 0;
412 
413 err_end:
414 	if (fan->acpi4)
415 		acpi_fan_delete_attributes(device);
416 
417 	return result;
418 }
419 
420 static int acpi_fan_remove(struct platform_device *pdev)
421 {
422 	struct acpi_fan *fan = platform_get_drvdata(pdev);
423 
424 	if (fan->acpi4) {
425 		struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
426 
427 		acpi_fan_delete_attributes(device);
428 	}
429 	sysfs_remove_link(&pdev->dev.kobj, "thermal_cooling");
430 	sysfs_remove_link(&fan->cdev->device.kobj, "device");
431 	thermal_cooling_device_unregister(fan->cdev);
432 
433 	return 0;
434 }
435 
436 #ifdef CONFIG_PM_SLEEP
437 static int acpi_fan_suspend(struct device *dev)
438 {
439 	struct acpi_fan *fan = dev_get_drvdata(dev);
440 	if (fan->acpi4)
441 		return 0;
442 
443 	acpi_device_set_power(ACPI_COMPANION(dev), ACPI_STATE_D0);
444 
445 	return AE_OK;
446 }
447 
448 static int acpi_fan_resume(struct device *dev)
449 {
450 	int result;
451 	struct acpi_fan *fan = dev_get_drvdata(dev);
452 
453 	if (fan->acpi4)
454 		return 0;
455 
456 	result = acpi_device_update_power(ACPI_COMPANION(dev), NULL);
457 	if (result)
458 		dev_err(dev, "Error updating fan power state\n");
459 
460 	return result;
461 }
462 #endif
463 
464 module_platform_driver(acpi_fan_driver);
465