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 static const struct acpi_device_id fan_device_ids[] = {
23 	ACPI_FAN_DEVICE_IDS,
24 	{"", 0},
25 };
26 MODULE_DEVICE_TABLE(acpi, fan_device_ids);
27 
28 /* thermal cooling device callbacks */
29 static int fan_get_max_state(struct thermal_cooling_device *cdev, unsigned long
30 			     *state)
31 {
32 	struct acpi_device *device = cdev->devdata;
33 	struct acpi_fan *fan = acpi_driver_data(device);
34 
35 	if (fan->acpi4) {
36 		if (fan->fif.fine_grain_ctrl)
37 			*state = 100 / fan->fif.step_size;
38 		else
39 			*state = fan->fps_count - 1;
40 	} else {
41 		*state = 1;
42 	}
43 
44 	return 0;
45 }
46 
47 int acpi_fan_get_fst(struct acpi_device *device, struct acpi_fan_fst *fst)
48 {
49 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
50 	union acpi_object *obj;
51 	acpi_status status;
52 	int ret = 0;
53 
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");
57 		return -ENODEV;
58 	}
59 
60 	obj = buffer.pointer;
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");
65 		ret = -EINVAL;
66 		goto err;
67 	}
68 
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;
72 
73 err:
74 	kfree(obj);
75 	return ret;
76 }
77 
78 static int fan_get_state_acpi4(struct acpi_device *device, unsigned long *state)
79 {
80 	struct acpi_fan *fan = acpi_driver_data(device);
81 	struct acpi_fan_fst fst;
82 	int status, i;
83 
84 	status = acpi_fan_get_fst(device, &fst);
85 	if (status)
86 		return status;
87 
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");
92 			goto match_fps;
93 		}
94 
95 		*state = (int) fst.control / fan->fif.step_size;
96 		return 0;
97 	}
98 
99 match_fps:
100 	for (i = 0; i < fan->fps_count; i++) {
101 		if (fst.control == fan->fps[i].control)
102 			break;
103 	}
104 	if (i == fan->fps_count) {
105 		dev_dbg(&device->dev, "Invalid control value returned\n");
106 		return -EINVAL;
107 	}
108 
109 	*state = i;
110 
111 	return status;
112 }
113 
114 static int fan_get_state(struct acpi_device *device, unsigned long *state)
115 {
116 	int result;
117 	int acpi_state = ACPI_STATE_D0;
118 
119 	result = acpi_device_update_power(device, &acpi_state);
120 	if (result)
121 		return result;
122 
123 	*state = acpi_state == ACPI_STATE_D3_COLD
124 			|| acpi_state == ACPI_STATE_D3_HOT ?
125 		0 : (acpi_state == ACPI_STATE_D0 ? 1 : -1);
126 	return 0;
127 }
128 
129 static int fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long
130 			     *state)
131 {
132 	struct acpi_device *device = cdev->devdata;
133 	struct acpi_fan *fan = acpi_driver_data(device);
134 
135 	if (fan->acpi4)
136 		return fan_get_state_acpi4(device, state);
137 	else
138 		return fan_get_state(device, state);
139 }
140 
141 static int fan_set_state(struct acpi_device *device, unsigned long state)
142 {
143 	if (state != 0 && state != 1)
144 		return -EINVAL;
145 
146 	return acpi_device_set_power(device,
147 				     state ? ACPI_STATE_D0 : ACPI_STATE_D3_COLD);
148 }
149 
150 static int fan_set_state_acpi4(struct acpi_device *device, unsigned long state)
151 {
152 	struct acpi_fan *fan = acpi_driver_data(device);
153 	acpi_status status;
154 	u64 value = state;
155 	int max_state;
156 
157 	if (fan->fif.fine_grain_ctrl)
158 		max_state = 100 / fan->fif.step_size;
159 	else
160 		max_state = fan->fps_count - 1;
161 
162 	if (state > max_state)
163 		return -EINVAL;
164 
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)
169 			value = 100;
170 	} else {
171 		value = fan->fps[state].control;
172 	}
173 
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");
177 		return -ENODEV;
178 	}
179 
180 	return 0;
181 }
182 
183 static int
184 fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
185 {
186 	struct acpi_device *device = cdev->devdata;
187 	struct acpi_fan *fan = acpi_driver_data(device);
188 
189 	if (fan->acpi4)
190 		return fan_set_state_acpi4(device, state);
191 	else
192 		return fan_set_state(device, state);
193 }
194 
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,
199 };
200 
201 /* --------------------------------------------------------------------------
202  *                               Driver Interface
203  * --------------------------------------------------------------------------
204 */
205 
206 static bool acpi_fan_has_fst(struct acpi_device *device)
207 {
208 	return acpi_has_method(device->handle, "_FST");
209 }
210 
211 static bool acpi_fan_is_acpi4(struct acpi_device *device)
212 {
213 	return acpi_has_method(device->handle, "_FIF") &&
214 	       acpi_has_method(device->handle, "_FPS") &&
215 	       acpi_has_method(device->handle, "_FSL");
216 }
217 
218 static int acpi_fan_get_fif(struct acpi_device *device)
219 {
220 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
221 	struct acpi_fan *fan = acpi_driver_data(device);
222 	struct acpi_buffer format = { sizeof("NNNN"), "NNNN" };
223 	u64 fields[4];
224 	struct acpi_buffer fif = { sizeof(fields), fields };
225 	union acpi_object *obj;
226 	acpi_status status;
227 
228 	status = acpi_evaluate_object(device->handle, "_FIF", NULL, &buffer);
229 	if (ACPI_FAILURE(status))
230 		return status;
231 
232 	obj = buffer.pointer;
233 	if (!obj || obj->type != ACPI_TYPE_PACKAGE) {
234 		dev_err(&device->dev, "Invalid _FIF data\n");
235 		status = -EINVAL;
236 		goto err;
237 	}
238 
239 	status = acpi_extract_package(obj, &format, &fif);
240 	if (ACPI_FAILURE(status)) {
241 		dev_err(&device->dev, "Invalid _FIF element\n");
242 		status = -EINVAL;
243 		goto err;
244 	}
245 
246 	fan->fif.revision = fields[0];
247 	fan->fif.fine_grain_ctrl = fields[1];
248 	fan->fif.step_size = fields[2];
249 	fan->fif.low_speed_notification = fields[3];
250 
251 	/* If there is a bug in step size and set as 0, change to 1 */
252 	if (!fan->fif.step_size)
253 		fan->fif.step_size = 1;
254 	/* If step size > 9, change to 9 (by spec valid values 1-9) */
255 	else if (fan->fif.step_size > 9)
256 		fan->fif.step_size = 9;
257 err:
258 	kfree(obj);
259 	return status;
260 }
261 
262 static int acpi_fan_speed_cmp(const void *a, const void *b)
263 {
264 	const struct acpi_fan_fps *fps1 = a;
265 	const struct acpi_fan_fps *fps2 = b;
266 	return fps1->speed - fps2->speed;
267 }
268 
269 static int acpi_fan_get_fps(struct acpi_device *device)
270 {
271 	struct acpi_fan *fan = acpi_driver_data(device);
272 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
273 	union acpi_object *obj;
274 	acpi_status status;
275 	int i;
276 
277 	status = acpi_evaluate_object(device->handle, "_FPS", NULL, &buffer);
278 	if (ACPI_FAILURE(status))
279 		return status;
280 
281 	obj = buffer.pointer;
282 	if (!obj || obj->type != ACPI_TYPE_PACKAGE || obj->package.count < 2) {
283 		dev_err(&device->dev, "Invalid _FPS data\n");
284 		status = -EINVAL;
285 		goto err;
286 	}
287 
288 	fan->fps_count = obj->package.count - 1; /* minus revision field */
289 	fan->fps = devm_kcalloc(&device->dev,
290 				fan->fps_count, sizeof(struct acpi_fan_fps),
291 				GFP_KERNEL);
292 	if (!fan->fps) {
293 		dev_err(&device->dev, "Not enough memory\n");
294 		status = -ENOMEM;
295 		goto err;
296 	}
297 	for (i = 0; i < fan->fps_count; i++) {
298 		struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
299 		struct acpi_buffer fps = { offsetof(struct acpi_fan_fps, name),
300 						&fan->fps[i] };
301 		status = acpi_extract_package(&obj->package.elements[i + 1],
302 					      &format, &fps);
303 		if (ACPI_FAILURE(status)) {
304 			dev_err(&device->dev, "Invalid _FPS element\n");
305 			goto err;
306 		}
307 	}
308 
309 	/* sort the state array according to fan speed in increase order */
310 	sort(fan->fps, fan->fps_count, sizeof(*fan->fps),
311 	     acpi_fan_speed_cmp, NULL);
312 
313 err:
314 	kfree(obj);
315 	return status;
316 }
317 
318 static int acpi_fan_probe(struct platform_device *pdev)
319 {
320 	int result = 0;
321 	struct thermal_cooling_device *cdev;
322 	struct acpi_fan *fan;
323 	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
324 	char *name;
325 
326 	fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
327 	if (!fan) {
328 		dev_err(&device->dev, "No memory for fan\n");
329 		return -ENOMEM;
330 	}
331 	device->driver_data = fan;
332 	platform_set_drvdata(pdev, fan);
333 
334 	if (acpi_fan_has_fst(device)) {
335 		fan->has_fst = true;
336 		fan->acpi4 = acpi_fan_is_acpi4(device);
337 	}
338 
339 	if (fan->acpi4) {
340 		result = acpi_fan_get_fif(device);
341 		if (result)
342 			return result;
343 
344 		result = acpi_fan_get_fps(device);
345 		if (result)
346 			return result;
347 	}
348 
349 	if (fan->has_fst) {
350 		result = devm_acpi_fan_create_hwmon(device);
351 		if (result)
352 			return result;
353 
354 		result = acpi_fan_create_attributes(device);
355 		if (result)
356 			return result;
357 	}
358 
359 	if (!fan->acpi4) {
360 		result = acpi_device_update_power(device, NULL);
361 		if (result) {
362 			dev_err(&device->dev, "Failed to set initial power state\n");
363 			goto err_end;
364 		}
365 	}
366 
367 	if (!strncmp(pdev->name, "PNP0C0B", strlen("PNP0C0B")))
368 		name = "Fan";
369 	else
370 		name = acpi_device_bid(device);
371 
372 	cdev = thermal_cooling_device_register(name, device,
373 						&fan_cooling_ops);
374 	if (IS_ERR(cdev)) {
375 		result = PTR_ERR(cdev);
376 		goto err_end;
377 	}
378 
379 	dev_dbg(&pdev->dev, "registered as cooling_device%d\n", cdev->id);
380 
381 	fan->cdev = cdev;
382 	result = sysfs_create_link(&pdev->dev.kobj,
383 				   &cdev->device.kobj,
384 				   "thermal_cooling");
385 	if (result) {
386 		dev_err(&pdev->dev, "Failed to create sysfs link 'thermal_cooling'\n");
387 		goto err_unregister;
388 	}
389 
390 	result = sysfs_create_link(&cdev->device.kobj,
391 				   &pdev->dev.kobj,
392 				   "device");
393 	if (result) {
394 		dev_err(&pdev->dev, "Failed to create sysfs link 'device'\n");
395 		goto err_remove_link;
396 	}
397 
398 	return 0;
399 
400 err_remove_link:
401 	sysfs_remove_link(&pdev->dev.kobj, "thermal_cooling");
402 err_unregister:
403 	thermal_cooling_device_unregister(cdev);
404 err_end:
405 	if (fan->has_fst)
406 		acpi_fan_delete_attributes(device);
407 
408 	return result;
409 }
410 
411 static void acpi_fan_remove(struct platform_device *pdev)
412 {
413 	struct acpi_fan *fan = platform_get_drvdata(pdev);
414 
415 	if (fan->has_fst) {
416 		struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
417 
418 		acpi_fan_delete_attributes(device);
419 	}
420 	sysfs_remove_link(&pdev->dev.kobj, "thermal_cooling");
421 	sysfs_remove_link(&fan->cdev->device.kobj, "device");
422 	thermal_cooling_device_unregister(fan->cdev);
423 }
424 
425 #ifdef CONFIG_PM_SLEEP
426 static int acpi_fan_suspend(struct device *dev)
427 {
428 	struct acpi_fan *fan = dev_get_drvdata(dev);
429 	if (fan->acpi4)
430 		return 0;
431 
432 	acpi_device_set_power(ACPI_COMPANION(dev), ACPI_STATE_D0);
433 
434 	return AE_OK;
435 }
436 
437 static int acpi_fan_resume(struct device *dev)
438 {
439 	int result;
440 	struct acpi_fan *fan = dev_get_drvdata(dev);
441 
442 	if (fan->acpi4)
443 		return 0;
444 
445 	result = acpi_device_update_power(ACPI_COMPANION(dev), NULL);
446 	if (result)
447 		dev_err(dev, "Error updating fan power state\n");
448 
449 	return result;
450 }
451 
452 static const struct dev_pm_ops acpi_fan_pm = {
453 	.resume = acpi_fan_resume,
454 	.freeze = acpi_fan_suspend,
455 	.thaw = acpi_fan_resume,
456 	.restore = acpi_fan_resume,
457 };
458 #define FAN_PM_OPS_PTR (&acpi_fan_pm)
459 
460 #else
461 
462 #define FAN_PM_OPS_PTR NULL
463 
464 #endif
465 
466 static struct platform_driver acpi_fan_driver = {
467 	.probe = acpi_fan_probe,
468 	.remove = acpi_fan_remove,
469 	.driver = {
470 		.name = "acpi-fan",
471 		.acpi_match_table = fan_device_ids,
472 		.pm = FAN_PM_OPS_PTR,
473 	},
474 };
475 
476 module_platform_driver(acpi_fan_driver);
477 
478 MODULE_AUTHOR("Paul Diefenbaugh");
479 MODULE_DESCRIPTION("ACPI Fan Driver");
480 MODULE_LICENSE("GPL");
481