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 */
fan_get_max_state(struct thermal_cooling_device * cdev,unsigned long * state)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 
acpi_fan_get_fst(struct acpi_device * device,struct acpi_fan_fst * fst)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 
fan_get_state_acpi4(struct acpi_device * device,unsigned long * state)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 
fan_get_state(struct acpi_device * device,unsigned long * state)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 
fan_get_cur_state(struct thermal_cooling_device * cdev,unsigned long * state)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 
fan_set_state(struct acpi_device * device,unsigned long state)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 
fan_set_state_acpi4(struct acpi_device * device,unsigned long state)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
fan_set_cur_state(struct thermal_cooling_device * cdev,unsigned long state)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 
acpi_fan_is_acpi4(struct acpi_device * device)206 static bool acpi_fan_is_acpi4(struct acpi_device *device)
207 {
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");
212 }
213 
acpi_fan_get_fif(struct acpi_device * device)214 static int acpi_fan_get_fif(struct acpi_device *device)
215 {
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" };
219 	u64 fields[4];
220 	struct acpi_buffer fif = { sizeof(fields), fields };
221 	union acpi_object *obj;
222 	acpi_status status;
223 
224 	status = acpi_evaluate_object(device->handle, "_FIF", NULL, &buffer);
225 	if (ACPI_FAILURE(status))
226 		return status;
227 
228 	obj = buffer.pointer;
229 	if (!obj || obj->type != ACPI_TYPE_PACKAGE) {
230 		dev_err(&device->dev, "Invalid _FIF data\n");
231 		status = -EINVAL;
232 		goto err;
233 	}
234 
235 	status = acpi_extract_package(obj, &format, &fif);
236 	if (ACPI_FAILURE(status)) {
237 		dev_err(&device->dev, "Invalid _FIF element\n");
238 		status = -EINVAL;
239 		goto err;
240 	}
241 
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];
246 
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;
253 err:
254 	kfree(obj);
255 	return status;
256 }
257 
acpi_fan_speed_cmp(const void * a,const void * b)258 static int acpi_fan_speed_cmp(const void *a, const void *b)
259 {
260 	const struct acpi_fan_fps *fps1 = a;
261 	const struct acpi_fan_fps *fps2 = b;
262 	return fps1->speed - fps2->speed;
263 }
264 
acpi_fan_get_fps(struct acpi_device * device)265 static int acpi_fan_get_fps(struct acpi_device *device)
266 {
267 	struct acpi_fan *fan = acpi_driver_data(device);
268 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
269 	union acpi_object *obj;
270 	acpi_status status;
271 	int i;
272 
273 	status = acpi_evaluate_object(device->handle, "_FPS", NULL, &buffer);
274 	if (ACPI_FAILURE(status))
275 		return status;
276 
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");
280 		status = -EINVAL;
281 		goto err;
282 	}
283 
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),
287 				GFP_KERNEL);
288 	if (!fan->fps) {
289 		dev_err(&device->dev, "Not enough memory\n");
290 		status = -ENOMEM;
291 		goto err;
292 	}
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),
296 						&fan->fps[i] };
297 		status = acpi_extract_package(&obj->package.elements[i + 1],
298 					      &format, &fps);
299 		if (ACPI_FAILURE(status)) {
300 			dev_err(&device->dev, "Invalid _FPS element\n");
301 			goto err;
302 		}
303 	}
304 
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);
308 
309 err:
310 	kfree(obj);
311 	return status;
312 }
313 
acpi_fan_probe(struct platform_device * pdev)314 static int acpi_fan_probe(struct platform_device *pdev)
315 {
316 	int result = 0;
317 	struct thermal_cooling_device *cdev;
318 	struct acpi_fan *fan;
319 	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
320 	char *name;
321 
322 	fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
323 	if (!fan) {
324 		dev_err(&device->dev, "No memory for fan\n");
325 		return -ENOMEM;
326 	}
327 	device->driver_data = fan;
328 	platform_set_drvdata(pdev, fan);
329 
330 	if (acpi_fan_is_acpi4(device)) {
331 		result = acpi_fan_get_fif(device);
332 		if (result)
333 			return result;
334 
335 		result = acpi_fan_get_fps(device);
336 		if (result)
337 			return result;
338 
339 		result = devm_acpi_fan_create_hwmon(device);
340 		if (result)
341 			return result;
342 
343 		result = acpi_fan_create_attributes(device);
344 		if (result)
345 			return result;
346 
347 		fan->acpi4 = true;
348 	} else {
349 		result = acpi_device_update_power(device, NULL);
350 		if (result) {
351 			dev_err(&device->dev, "Failed to set initial power state\n");
352 			goto err_end;
353 		}
354 	}
355 
356 	if (!strncmp(pdev->name, "PNP0C0B", strlen("PNP0C0B")))
357 		name = "Fan";
358 	else
359 		name = acpi_device_bid(device);
360 
361 	cdev = thermal_cooling_device_register(name, device,
362 						&fan_cooling_ops);
363 	if (IS_ERR(cdev)) {
364 		result = PTR_ERR(cdev);
365 		goto err_end;
366 	}
367 
368 	dev_dbg(&pdev->dev, "registered as cooling_device%d\n", cdev->id);
369 
370 	fan->cdev = cdev;
371 	result = sysfs_create_link(&pdev->dev.kobj,
372 				   &cdev->device.kobj,
373 				   "thermal_cooling");
374 	if (result)
375 		dev_err(&pdev->dev, "Failed to create sysfs link 'thermal_cooling'\n");
376 
377 	result = sysfs_create_link(&cdev->device.kobj,
378 				   &pdev->dev.kobj,
379 				   "device");
380 	if (result) {
381 		dev_err(&pdev->dev, "Failed to create sysfs link 'device'\n");
382 		goto err_end;
383 	}
384 
385 	return 0;
386 
387 err_end:
388 	if (fan->acpi4)
389 		acpi_fan_delete_attributes(device);
390 
391 	return result;
392 }
393 
acpi_fan_remove(struct platform_device * pdev)394 static void acpi_fan_remove(struct platform_device *pdev)
395 {
396 	struct acpi_fan *fan = platform_get_drvdata(pdev);
397 
398 	if (fan->acpi4) {
399 		struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
400 
401 		acpi_fan_delete_attributes(device);
402 	}
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);
406 }
407 
408 #ifdef CONFIG_PM_SLEEP
acpi_fan_suspend(struct device * dev)409 static int acpi_fan_suspend(struct device *dev)
410 {
411 	struct acpi_fan *fan = dev_get_drvdata(dev);
412 	if (fan->acpi4)
413 		return 0;
414 
415 	acpi_device_set_power(ACPI_COMPANION(dev), ACPI_STATE_D0);
416 
417 	return AE_OK;
418 }
419 
acpi_fan_resume(struct device * dev)420 static int acpi_fan_resume(struct device *dev)
421 {
422 	int result;
423 	struct acpi_fan *fan = dev_get_drvdata(dev);
424 
425 	if (fan->acpi4)
426 		return 0;
427 
428 	result = acpi_device_update_power(ACPI_COMPANION(dev), NULL);
429 	if (result)
430 		dev_err(dev, "Error updating fan power state\n");
431 
432 	return result;
433 }
434 
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,
440 };
441 #define FAN_PM_OPS_PTR (&acpi_fan_pm)
442 
443 #else
444 
445 #define FAN_PM_OPS_PTR NULL
446 
447 #endif
448 
449 static struct platform_driver acpi_fan_driver = {
450 	.probe = acpi_fan_probe,
451 	.remove_new = acpi_fan_remove,
452 	.driver = {
453 		.name = "acpi-fan",
454 		.acpi_match_table = fan_device_ids,
455 		.pm = FAN_PM_OPS_PTR,
456 	},
457 };
458 
459 module_platform_driver(acpi_fan_driver);
460 
461 MODULE_AUTHOR("Paul Diefenbaugh");
462 MODULE_DESCRIPTION("ACPI Fan Driver");
463 MODULE_LICENSE("GPL");
464