xref: /linux/drivers/platform/x86/dell/dell-wmi-ddv.c (revision 0e9ab8e4d44ae9d9aaf213bfd2c90bbe7289337b)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Linux driver for WMI sensor information on Dell notebooks.
4  *
5  * Copyright (C) 2022 Armin Wolf <W_Armin@gmx.de>
6  */
7 
8 #define pr_format(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/acpi.h>
11 #include <linux/debugfs.h>
12 #include <linux/device.h>
13 #include <linux/device/driver.h>
14 #include <linux/dev_printk.h>
15 #include <linux/errno.h>
16 #include <linux/kconfig.h>
17 #include <linux/kernel.h>
18 #include <linux/hwmon.h>
19 #include <linux/kstrtox.h>
20 #include <linux/math.h>
21 #include <linux/math64.h>
22 #include <linux/module.h>
23 #include <linux/mutex.h>
24 #include <linux/limits.h>
25 #include <linux/pm.h>
26 #include <linux/power_supply.h>
27 #include <linux/printk.h>
28 #include <linux/seq_file.h>
29 #include <linux/sysfs.h>
30 #include <linux/types.h>
31 #include <linux/wmi.h>
32 
33 #include <acpi/battery.h>
34 
35 #include <asm/unaligned.h>
36 
37 #define DRIVER_NAME	"dell-wmi-ddv"
38 
39 #define DELL_DDV_SUPPORTED_VERSION_MIN	2
40 #define DELL_DDV_SUPPORTED_VERSION_MAX	3
41 #define DELL_DDV_GUID	"8A42EA14-4F2A-FD45-6422-0087F7A7E608"
42 
43 #define DELL_EPPID_LENGTH	20
44 #define DELL_EPPID_EXT_LENGTH	23
45 
46 static bool force;
47 module_param_unsafe(force, bool, 0);
48 MODULE_PARM_DESC(force, "Force loading without checking for supported WMI interface versions");
49 
50 enum dell_ddv_method {
51 	DELL_DDV_BATTERY_DESIGN_CAPACITY	= 0x01,
52 	DELL_DDV_BATTERY_FULL_CHARGE_CAPACITY	= 0x02,
53 	DELL_DDV_BATTERY_MANUFACTURE_NAME	= 0x03,
54 	DELL_DDV_BATTERY_MANUFACTURE_DATE	= 0x04,
55 	DELL_DDV_BATTERY_SERIAL_NUMBER		= 0x05,
56 	DELL_DDV_BATTERY_CHEMISTRY_VALUE	= 0x06,
57 	DELL_DDV_BATTERY_TEMPERATURE		= 0x07,
58 	DELL_DDV_BATTERY_CURRENT		= 0x08,
59 	DELL_DDV_BATTERY_VOLTAGE		= 0x09,
60 	DELL_DDV_BATTERY_MANUFACTURER_ACCESS	= 0x0A,
61 	DELL_DDV_BATTERY_RELATIVE_CHARGE_STATE	= 0x0B,
62 	DELL_DDV_BATTERY_CYCLE_COUNT		= 0x0C,
63 	DELL_DDV_BATTERY_EPPID			= 0x0D,
64 	DELL_DDV_BATTERY_RAW_ANALYTICS_START	= 0x0E,
65 	DELL_DDV_BATTERY_RAW_ANALYTICS		= 0x0F,
66 	DELL_DDV_BATTERY_DESIGN_VOLTAGE		= 0x10,
67 	DELL_DDV_BATTERY_RAW_ANALYTICS_A_BLOCK	= 0x11, /* version 3 */
68 
69 	DELL_DDV_INTERFACE_VERSION		= 0x12,
70 
71 	DELL_DDV_FAN_SENSOR_INFORMATION		= 0x20,
72 	DELL_DDV_THERMAL_SENSOR_INFORMATION	= 0x22,
73 };
74 
75 struct fan_sensor_entry {
76 	u8 type;
77 	__le16 rpm;
78 } __packed;
79 
80 struct thermal_sensor_entry {
81 	u8 type;
82 	s8 now;
83 	s8 min;
84 	s8 max;
85 	u8 unknown;
86 } __packed;
87 
88 struct combined_channel_info {
89 	struct hwmon_channel_info info;
90 	u32 config[];
91 };
92 
93 struct combined_chip_info {
94 	struct hwmon_chip_info chip;
95 	const struct hwmon_channel_info *info[];
96 };
97 
98 struct dell_wmi_ddv_sensors {
99 	struct mutex lock;	/* protect caching */
100 	unsigned long timestamp;
101 	union acpi_object *obj;
102 	u64 entries;
103 };
104 
105 struct dell_wmi_ddv_data {
106 	struct acpi_battery_hook hook;
107 	struct device_attribute temp_attr;
108 	struct device_attribute eppid_attr;
109 	struct dell_wmi_ddv_sensors fans;
110 	struct dell_wmi_ddv_sensors temps;
111 	struct wmi_device *wdev;
112 };
113 
114 static const char * const fan_labels[] = {
115 	"CPU Fan",
116 	"Chassis Motherboard Fan",
117 	"Video Fan",
118 	"Power Supply Fan",
119 	"Chipset Fan",
120 	"Memory Fan",
121 	"PCI Fan",
122 	"HDD Fan",
123 };
124 
125 static const char * const fan_dock_labels[] = {
126 	"Docking Chassis/Motherboard Fan",
127 	"Docking Video Fan",
128 	"Docking Power Supply Fan",
129 	"Docking Chipset Fan",
130 };
131 
132 static int dell_wmi_ddv_query_type(struct wmi_device *wdev, enum dell_ddv_method method, u32 arg,
133 				   union acpi_object **result, acpi_object_type type)
134 {
135 	struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
136 	const struct acpi_buffer in = {
137 		.length = sizeof(arg),
138 		.pointer = &arg,
139 	};
140 	union acpi_object *obj;
141 	acpi_status ret;
142 
143 	ret = wmidev_evaluate_method(wdev, 0x0, method, &in, &out);
144 	if (ACPI_FAILURE(ret))
145 		return -EIO;
146 
147 	obj = out.pointer;
148 	if (!obj)
149 		return -ENODATA;
150 
151 	if (obj->type != type) {
152 		kfree(obj);
153 		return -ENOMSG;
154 	}
155 
156 	*result = obj;
157 
158 	return 0;
159 }
160 
161 static int dell_wmi_ddv_query_integer(struct wmi_device *wdev, enum dell_ddv_method method,
162 				      u32 arg, u32 *res)
163 {
164 	union acpi_object *obj;
165 	int ret;
166 
167 	ret = dell_wmi_ddv_query_type(wdev, method, arg, &obj, ACPI_TYPE_INTEGER);
168 	if (ret < 0)
169 		return ret;
170 
171 	if (obj->integer.value <= U32_MAX)
172 		*res = (u32)obj->integer.value;
173 	else
174 		ret = -ERANGE;
175 
176 	kfree(obj);
177 
178 	return ret;
179 }
180 
181 static int dell_wmi_ddv_query_buffer(struct wmi_device *wdev, enum dell_ddv_method method,
182 				     u32 arg, union acpi_object **result)
183 {
184 	union acpi_object *obj;
185 	u64 buffer_size;
186 	int ret;
187 
188 	ret = dell_wmi_ddv_query_type(wdev, method, arg, &obj, ACPI_TYPE_PACKAGE);
189 	if (ret < 0)
190 		return ret;
191 
192 	if (obj->package.count != 2 ||
193 	    obj->package.elements[0].type != ACPI_TYPE_INTEGER ||
194 	    obj->package.elements[1].type != ACPI_TYPE_BUFFER) {
195 		ret = -ENOMSG;
196 
197 		goto err_free;
198 	}
199 
200 	buffer_size = obj->package.elements[0].integer.value;
201 
202 	if (!buffer_size) {
203 		ret = -ENODATA;
204 
205 		goto err_free;
206 	}
207 
208 	if (buffer_size > obj->package.elements[1].buffer.length) {
209 		dev_warn(&wdev->dev,
210 			 FW_WARN "WMI buffer size (%llu) exceeds ACPI buffer size (%d)\n",
211 			 buffer_size, obj->package.elements[1].buffer.length);
212 		ret = -EMSGSIZE;
213 
214 		goto err_free;
215 	}
216 
217 	*result = obj;
218 
219 	return 0;
220 
221 err_free:
222 	kfree(obj);
223 
224 	return ret;
225 }
226 
227 static int dell_wmi_ddv_query_string(struct wmi_device *wdev, enum dell_ddv_method method,
228 				     u32 arg, union acpi_object **result)
229 {
230 	return dell_wmi_ddv_query_type(wdev, method, arg, result, ACPI_TYPE_STRING);
231 }
232 
233 /*
234  * Needs to be called with lock held, except during initialization.
235  */
236 static int dell_wmi_ddv_update_sensors(struct wmi_device *wdev, enum dell_ddv_method method,
237 				       struct dell_wmi_ddv_sensors *sensors, size_t entry_size)
238 {
239 	u64 buffer_size, rem, entries;
240 	union acpi_object *obj;
241 	u8 *buffer;
242 	int ret;
243 
244 	if (sensors->obj) {
245 		if (time_before(jiffies, sensors->timestamp + HZ))
246 			return 0;
247 
248 		kfree(sensors->obj);
249 		sensors->obj = NULL;
250 	}
251 
252 	ret = dell_wmi_ddv_query_buffer(wdev, method, 0, &obj);
253 	if (ret < 0)
254 		return ret;
255 
256 	/* buffer format sanity check */
257 	buffer_size = obj->package.elements[0].integer.value;
258 	buffer = obj->package.elements[1].buffer.pointer;
259 	entries = div64_u64_rem(buffer_size, entry_size, &rem);
260 	if (rem != 1 || buffer[buffer_size - 1] != 0xff) {
261 		ret = -ENOMSG;
262 		goto err_free;
263 	}
264 
265 	if (!entries) {
266 		ret = -ENODATA;
267 		goto err_free;
268 	}
269 
270 	sensors->obj = obj;
271 	sensors->entries = entries;
272 	sensors->timestamp = jiffies;
273 
274 	return 0;
275 
276 err_free:
277 	kfree(obj);
278 
279 	return ret;
280 }
281 
282 static umode_t dell_wmi_ddv_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
283 				       int channel)
284 {
285 	return 0444;
286 }
287 
288 static int dell_wmi_ddv_fan_read_channel(struct dell_wmi_ddv_data *data, u32 attr, int channel,
289 					 long *val)
290 {
291 	struct fan_sensor_entry *entry;
292 	int ret;
293 
294 	ret = dell_wmi_ddv_update_sensors(data->wdev, DELL_DDV_FAN_SENSOR_INFORMATION,
295 					  &data->fans, sizeof(*entry));
296 	if (ret < 0)
297 		return ret;
298 
299 	if (channel >= data->fans.entries)
300 		return -ENXIO;
301 
302 	entry = (struct fan_sensor_entry *)data->fans.obj->package.elements[1].buffer.pointer;
303 	switch (attr) {
304 	case hwmon_fan_input:
305 		*val = get_unaligned_le16(&entry[channel].rpm);
306 		return 0;
307 	default:
308 		break;
309 	}
310 
311 	return -EOPNOTSUPP;
312 }
313 
314 static int dell_wmi_ddv_temp_read_channel(struct dell_wmi_ddv_data *data, u32 attr, int channel,
315 					  long *val)
316 {
317 	struct thermal_sensor_entry *entry;
318 	int ret;
319 
320 	ret = dell_wmi_ddv_update_sensors(data->wdev, DELL_DDV_THERMAL_SENSOR_INFORMATION,
321 					  &data->temps, sizeof(*entry));
322 	if (ret < 0)
323 		return ret;
324 
325 	if (channel >= data->temps.entries)
326 		return -ENXIO;
327 
328 	entry = (struct thermal_sensor_entry *)data->temps.obj->package.elements[1].buffer.pointer;
329 	switch (attr) {
330 	case hwmon_temp_input:
331 		*val = entry[channel].now * 1000;
332 		return 0;
333 	case hwmon_temp_min:
334 		*val = entry[channel].min * 1000;
335 		return 0;
336 	case hwmon_temp_max:
337 		*val = entry[channel].max * 1000;
338 		return 0;
339 	default:
340 		break;
341 	}
342 
343 	return -EOPNOTSUPP;
344 }
345 
346 static int dell_wmi_ddv_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
347 			     int channel, long *val)
348 {
349 	struct dell_wmi_ddv_data *data = dev_get_drvdata(dev);
350 	int ret;
351 
352 	switch (type) {
353 	case hwmon_fan:
354 		mutex_lock(&data->fans.lock);
355 		ret = dell_wmi_ddv_fan_read_channel(data, attr, channel, val);
356 		mutex_unlock(&data->fans.lock);
357 		return ret;
358 	case hwmon_temp:
359 		mutex_lock(&data->temps.lock);
360 		ret = dell_wmi_ddv_temp_read_channel(data, attr, channel, val);
361 		mutex_unlock(&data->temps.lock);
362 		return ret;
363 	default:
364 		break;
365 	}
366 
367 	return -EOPNOTSUPP;
368 }
369 
370 static int dell_wmi_ddv_fan_read_string(struct dell_wmi_ddv_data *data, int channel,
371 					const char **str)
372 {
373 	struct fan_sensor_entry *entry;
374 	int ret;
375 	u8 type;
376 
377 	ret = dell_wmi_ddv_update_sensors(data->wdev, DELL_DDV_FAN_SENSOR_INFORMATION,
378 					  &data->fans, sizeof(*entry));
379 	if (ret < 0)
380 		return ret;
381 
382 	if (channel >= data->fans.entries)
383 		return -ENXIO;
384 
385 	entry = (struct fan_sensor_entry *)data->fans.obj->package.elements[1].buffer.pointer;
386 	type = entry[channel].type;
387 	switch (type) {
388 	case 0x00 ... 0x07:
389 		*str = fan_labels[type];
390 		break;
391 	case 0x11 ... 0x14:
392 		*str = fan_dock_labels[type - 0x11];
393 		break;
394 	default:
395 		*str = "Unknown Fan";
396 		break;
397 	}
398 
399 	return 0;
400 }
401 
402 static int dell_wmi_ddv_temp_read_string(struct dell_wmi_ddv_data *data, int channel,
403 					 const char **str)
404 {
405 	struct thermal_sensor_entry *entry;
406 	int ret;
407 
408 	ret = dell_wmi_ddv_update_sensors(data->wdev, DELL_DDV_THERMAL_SENSOR_INFORMATION,
409 					  &data->temps, sizeof(*entry));
410 	if (ret < 0)
411 		return ret;
412 
413 	if (channel >= data->temps.entries)
414 		return -ENXIO;
415 
416 	entry = (struct thermal_sensor_entry *)data->temps.obj->package.elements[1].buffer.pointer;
417 	switch (entry[channel].type) {
418 	case 0x00:
419 		*str = "CPU";
420 		break;
421 	case 0x11:
422 		*str = "Video";
423 		break;
424 	case 0x22:
425 		*str = "Memory"; /* sometimes called DIMM */
426 		break;
427 	case 0x33:
428 		*str = "Other";
429 		break;
430 	case 0x44:
431 		*str = "Ambient"; /* sometimes called SKIN */
432 		break;
433 	case 0x52:
434 		*str = "SODIMM";
435 		break;
436 	case 0x55:
437 		*str = "HDD";
438 		break;
439 	case 0x62:
440 		*str = "SODIMM 2";
441 		break;
442 	case 0x73:
443 		*str = "NB";
444 		break;
445 	case 0x83:
446 		*str = "Charger";
447 		break;
448 	case 0xbb:
449 		*str = "Memory 3";
450 		break;
451 	default:
452 		*str = "Unknown";
453 		break;
454 	}
455 
456 	return 0;
457 }
458 
459 static int dell_wmi_ddv_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
460 				    int channel, const char **str)
461 {
462 	struct dell_wmi_ddv_data *data = dev_get_drvdata(dev);
463 	int ret;
464 
465 	switch (type) {
466 	case hwmon_fan:
467 		switch (attr) {
468 		case hwmon_fan_label:
469 			mutex_lock(&data->fans.lock);
470 			ret = dell_wmi_ddv_fan_read_string(data, channel, str);
471 			mutex_unlock(&data->fans.lock);
472 			return ret;
473 		default:
474 			break;
475 		}
476 		break;
477 	case hwmon_temp:
478 		switch (attr) {
479 		case hwmon_temp_label:
480 			mutex_lock(&data->temps.lock);
481 			ret = dell_wmi_ddv_temp_read_string(data, channel, str);
482 			mutex_unlock(&data->temps.lock);
483 			return ret;
484 		default:
485 			break;
486 		}
487 		break;
488 	default:
489 		break;
490 	}
491 
492 	return -EOPNOTSUPP;
493 }
494 
495 static const struct hwmon_ops dell_wmi_ddv_ops = {
496 	.is_visible = dell_wmi_ddv_is_visible,
497 	.read = dell_wmi_ddv_read,
498 	.read_string = dell_wmi_ddv_read_string,
499 };
500 
501 static struct hwmon_channel_info *dell_wmi_ddv_channel_create(struct device *dev, u64 count,
502 							      enum hwmon_sensor_types type,
503 							      u32 config)
504 {
505 	struct combined_channel_info *cinfo;
506 	int i;
507 
508 	cinfo = devm_kzalloc(dev, struct_size(cinfo, config, count + 1), GFP_KERNEL);
509 	if (!cinfo)
510 		return ERR_PTR(-ENOMEM);
511 
512 	cinfo->info.type = type;
513 	cinfo->info.config = cinfo->config;
514 
515 	for (i = 0; i < count; i++)
516 		cinfo->config[i] = config;
517 
518 	return &cinfo->info;
519 }
520 
521 static void dell_wmi_ddv_hwmon_cache_invalidate(struct dell_wmi_ddv_sensors *sensors)
522 {
523 	mutex_lock(&sensors->lock);
524 	kfree(sensors->obj);
525 	sensors->obj = NULL;
526 	mutex_unlock(&sensors->lock);
527 }
528 
529 static void dell_wmi_ddv_hwmon_cache_destroy(void *data)
530 {
531 	struct dell_wmi_ddv_sensors *sensors = data;
532 
533 	mutex_destroy(&sensors->lock);
534 	kfree(sensors->obj);
535 }
536 
537 static struct hwmon_channel_info *dell_wmi_ddv_channel_init(struct wmi_device *wdev,
538 							    enum dell_ddv_method method,
539 							    struct dell_wmi_ddv_sensors *sensors,
540 							    size_t entry_size,
541 							    enum hwmon_sensor_types type,
542 							    u32 config)
543 {
544 	struct hwmon_channel_info *info;
545 	int ret;
546 
547 	ret = dell_wmi_ddv_update_sensors(wdev, method, sensors, entry_size);
548 	if (ret < 0)
549 		return ERR_PTR(ret);
550 
551 	mutex_init(&sensors->lock);
552 
553 	ret = devm_add_action_or_reset(&wdev->dev, dell_wmi_ddv_hwmon_cache_destroy, sensors);
554 	if (ret < 0)
555 		return ERR_PTR(ret);
556 
557 	info = dell_wmi_ddv_channel_create(&wdev->dev, sensors->entries, type, config);
558 	if (IS_ERR(info))
559 		devm_release_action(&wdev->dev, dell_wmi_ddv_hwmon_cache_destroy, sensors);
560 
561 	return info;
562 }
563 
564 static int dell_wmi_ddv_hwmon_add(struct dell_wmi_ddv_data *data)
565 {
566 	struct wmi_device *wdev = data->wdev;
567 	struct combined_chip_info *cinfo;
568 	struct hwmon_channel_info *info;
569 	struct device *hdev;
570 	int index = 0;
571 	int ret;
572 
573 	if (!devres_open_group(&wdev->dev, dell_wmi_ddv_hwmon_add, GFP_KERNEL))
574 		return -ENOMEM;
575 
576 	cinfo = devm_kzalloc(&wdev->dev, struct_size(cinfo, info, 4), GFP_KERNEL);
577 	if (!cinfo) {
578 		ret = -ENOMEM;
579 
580 		goto err_release;
581 	}
582 
583 	cinfo->chip.ops = &dell_wmi_ddv_ops;
584 	cinfo->chip.info = cinfo->info;
585 
586 	info = dell_wmi_ddv_channel_create(&wdev->dev, 1, hwmon_chip, HWMON_C_REGISTER_TZ);
587 	if (IS_ERR(info)) {
588 		ret = PTR_ERR(info);
589 
590 		goto err_release;
591 	}
592 
593 	cinfo->info[index] = info;
594 	index++;
595 
596 	info = dell_wmi_ddv_channel_init(wdev, DELL_DDV_FAN_SENSOR_INFORMATION, &data->fans,
597 					 sizeof(struct fan_sensor_entry), hwmon_fan,
598 					 (HWMON_F_INPUT | HWMON_F_LABEL));
599 	if (!IS_ERR(info)) {
600 		cinfo->info[index] = info;
601 		index++;
602 	}
603 
604 	info = dell_wmi_ddv_channel_init(wdev, DELL_DDV_THERMAL_SENSOR_INFORMATION, &data->temps,
605 					 sizeof(struct thermal_sensor_entry), hwmon_temp,
606 					 (HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
607 					 HWMON_T_LABEL));
608 	if (!IS_ERR(info)) {
609 		cinfo->info[index] = info;
610 		index++;
611 	}
612 
613 	if (index < 2) {
614 		ret = -ENODEV;
615 
616 		goto err_release;
617 	}
618 
619 	hdev = devm_hwmon_device_register_with_info(&wdev->dev, "dell_ddv", data, &cinfo->chip,
620 						    NULL);
621 	if (IS_ERR(hdev)) {
622 		ret = PTR_ERR(hdev);
623 
624 		goto err_release;
625 	}
626 
627 	devres_close_group(&wdev->dev, dell_wmi_ddv_hwmon_add);
628 
629 	return 0;
630 
631 err_release:
632 	devres_release_group(&wdev->dev, dell_wmi_ddv_hwmon_add);
633 
634 	return ret;
635 }
636 
637 static int dell_wmi_ddv_battery_index(struct acpi_device *acpi_dev, u32 *index)
638 {
639 	const char *uid_str;
640 
641 	uid_str = acpi_device_uid(acpi_dev);
642 	if (!uid_str)
643 		return -ENODEV;
644 
645 	return kstrtou32(uid_str, 10, index);
646 }
647 
648 static ssize_t temp_show(struct device *dev, struct device_attribute *attr, char *buf)
649 {
650 	struct dell_wmi_ddv_data *data = container_of(attr, struct dell_wmi_ddv_data, temp_attr);
651 	u32 index, value;
652 	int ret;
653 
654 	ret = dell_wmi_ddv_battery_index(to_acpi_device(dev->parent), &index);
655 	if (ret < 0)
656 		return ret;
657 
658 	ret = dell_wmi_ddv_query_integer(data->wdev, DELL_DDV_BATTERY_TEMPERATURE, index, &value);
659 	if (ret < 0)
660 		return ret;
661 
662 	return sysfs_emit(buf, "%d\n", DIV_ROUND_CLOSEST(value, 10));
663 }
664 
665 static ssize_t eppid_show(struct device *dev, struct device_attribute *attr, char *buf)
666 {
667 	struct dell_wmi_ddv_data *data = container_of(attr, struct dell_wmi_ddv_data, eppid_attr);
668 	union acpi_object *obj;
669 	u32 index;
670 	int ret;
671 
672 	ret = dell_wmi_ddv_battery_index(to_acpi_device(dev->parent), &index);
673 	if (ret < 0)
674 		return ret;
675 
676 	ret = dell_wmi_ddv_query_string(data->wdev, DELL_DDV_BATTERY_EPPID, index, &obj);
677 	if (ret < 0)
678 		return ret;
679 
680 	if (obj->string.length != DELL_EPPID_LENGTH && obj->string.length != DELL_EPPID_EXT_LENGTH)
681 		dev_info_once(&data->wdev->dev, FW_INFO "Suspicious ePPID length (%d)\n",
682 			      obj->string.length);
683 
684 	ret = sysfs_emit(buf, "%s\n", obj->string.pointer);
685 
686 	kfree(obj);
687 
688 	return ret;
689 }
690 
691 static int dell_wmi_ddv_add_battery(struct power_supply *battery, struct acpi_battery_hook *hook)
692 {
693 	struct dell_wmi_ddv_data *data = container_of(hook, struct dell_wmi_ddv_data, hook);
694 	u32 index;
695 	int ret;
696 
697 	/* Return 0 instead of error to avoid being unloaded */
698 	ret = dell_wmi_ddv_battery_index(to_acpi_device(battery->dev.parent), &index);
699 	if (ret < 0)
700 		return 0;
701 
702 	ret = device_create_file(&battery->dev, &data->temp_attr);
703 	if (ret < 0)
704 		return ret;
705 
706 	ret = device_create_file(&battery->dev, &data->eppid_attr);
707 	if (ret < 0) {
708 		device_remove_file(&battery->dev, &data->temp_attr);
709 
710 		return ret;
711 	}
712 
713 	return 0;
714 }
715 
716 static int dell_wmi_ddv_remove_battery(struct power_supply *battery, struct acpi_battery_hook *hook)
717 {
718 	struct dell_wmi_ddv_data *data = container_of(hook, struct dell_wmi_ddv_data, hook);
719 
720 	device_remove_file(&battery->dev, &data->temp_attr);
721 	device_remove_file(&battery->dev, &data->eppid_attr);
722 
723 	return 0;
724 }
725 
726 static void dell_wmi_ddv_battery_remove(void *data)
727 {
728 	struct acpi_battery_hook *hook = data;
729 
730 	battery_hook_unregister(hook);
731 }
732 
733 static int dell_wmi_ddv_battery_add(struct dell_wmi_ddv_data *data)
734 {
735 	data->hook.name = "Dell DDV Battery Extension";
736 	data->hook.add_battery = dell_wmi_ddv_add_battery;
737 	data->hook.remove_battery = dell_wmi_ddv_remove_battery;
738 
739 	sysfs_attr_init(&data->temp_attr.attr);
740 	data->temp_attr.attr.name = "temp";
741 	data->temp_attr.attr.mode = 0444;
742 	data->temp_attr.show = temp_show;
743 
744 	sysfs_attr_init(&data->eppid_attr.attr);
745 	data->eppid_attr.attr.name = "eppid";
746 	data->eppid_attr.attr.mode = 0444;
747 	data->eppid_attr.show = eppid_show;
748 
749 	battery_hook_register(&data->hook);
750 
751 	return devm_add_action_or_reset(&data->wdev->dev, dell_wmi_ddv_battery_remove, &data->hook);
752 }
753 
754 static int dell_wmi_ddv_buffer_read(struct seq_file *seq, enum dell_ddv_method method)
755 {
756 	struct device *dev = seq->private;
757 	struct dell_wmi_ddv_data *data = dev_get_drvdata(dev);
758 	union acpi_object *obj;
759 	u64 size;
760 	u8 *buf;
761 	int ret;
762 
763 	ret = dell_wmi_ddv_query_buffer(data->wdev, method, 0, &obj);
764 	if (ret < 0)
765 		return ret;
766 
767 	size = obj->package.elements[0].integer.value;
768 	buf = obj->package.elements[1].buffer.pointer;
769 	ret = seq_write(seq, buf, size);
770 	kfree(obj);
771 
772 	return ret;
773 }
774 
775 static int dell_wmi_ddv_fan_read(struct seq_file *seq, void *offset)
776 {
777 	return dell_wmi_ddv_buffer_read(seq, DELL_DDV_FAN_SENSOR_INFORMATION);
778 }
779 
780 static int dell_wmi_ddv_temp_read(struct seq_file *seq, void *offset)
781 {
782 	return dell_wmi_ddv_buffer_read(seq, DELL_DDV_THERMAL_SENSOR_INFORMATION);
783 }
784 
785 static void dell_wmi_ddv_debugfs_remove(void *data)
786 {
787 	struct dentry *entry = data;
788 
789 	debugfs_remove(entry);
790 }
791 
792 static void dell_wmi_ddv_debugfs_init(struct wmi_device *wdev)
793 {
794 	struct dentry *entry;
795 	char name[64];
796 
797 	scnprintf(name, ARRAY_SIZE(name), "%s-%s", DRIVER_NAME, dev_name(&wdev->dev));
798 	entry = debugfs_create_dir(name, NULL);
799 
800 	debugfs_create_devm_seqfile(&wdev->dev, "fan_sensor_information", entry,
801 				    dell_wmi_ddv_fan_read);
802 	debugfs_create_devm_seqfile(&wdev->dev, "thermal_sensor_information", entry,
803 				    dell_wmi_ddv_temp_read);
804 
805 	devm_add_action_or_reset(&wdev->dev, dell_wmi_ddv_debugfs_remove, entry);
806 }
807 
808 static int dell_wmi_ddv_probe(struct wmi_device *wdev, const void *context)
809 {
810 	struct dell_wmi_ddv_data *data;
811 	u32 version;
812 	int ret;
813 
814 	ret = dell_wmi_ddv_query_integer(wdev, DELL_DDV_INTERFACE_VERSION, 0, &version);
815 	if (ret < 0)
816 		return ret;
817 
818 	dev_dbg(&wdev->dev, "WMI interface version: %d\n", version);
819 	if (version < DELL_DDV_SUPPORTED_VERSION_MIN || version > DELL_DDV_SUPPORTED_VERSION_MAX) {
820 		if (!force)
821 			return -ENODEV;
822 
823 		dev_warn(&wdev->dev, "Loading despite unsupported WMI interface version (%u)\n",
824 			 version);
825 	}
826 
827 	data = devm_kzalloc(&wdev->dev, sizeof(*data), GFP_KERNEL);
828 	if (!data)
829 		return -ENOMEM;
830 
831 	dev_set_drvdata(&wdev->dev, data);
832 	data->wdev = wdev;
833 
834 	dell_wmi_ddv_debugfs_init(wdev);
835 
836 	if (IS_REACHABLE(CONFIG_ACPI_BATTERY)) {
837 		ret = dell_wmi_ddv_battery_add(data);
838 		if (ret < 0 && ret != -ENODEV)
839 			dev_warn(&wdev->dev, "Unable to register ACPI battery hook: %d\n", ret);
840 	}
841 
842 	if (IS_REACHABLE(CONFIG_HWMON)) {
843 		ret = dell_wmi_ddv_hwmon_add(data);
844 		if (ret < 0 && ret != -ENODEV)
845 			dev_warn(&wdev->dev, "Unable to register hwmon interface: %d\n", ret);
846 	}
847 
848 	return 0;
849 }
850 
851 static int dell_wmi_ddv_resume(struct device *dev)
852 {
853 	struct dell_wmi_ddv_data *data = dev_get_drvdata(dev);
854 
855 	/* Force re-reading of all sensors */
856 	dell_wmi_ddv_hwmon_cache_invalidate(&data->fans);
857 	dell_wmi_ddv_hwmon_cache_invalidate(&data->temps);
858 
859 	return 0;
860 }
861 
862 static DEFINE_SIMPLE_DEV_PM_OPS(dell_wmi_ddv_dev_pm_ops, NULL, dell_wmi_ddv_resume);
863 
864 static const struct wmi_device_id dell_wmi_ddv_id_table[] = {
865 	{ DELL_DDV_GUID, NULL },
866 	{ }
867 };
868 MODULE_DEVICE_TABLE(wmi, dell_wmi_ddv_id_table);
869 
870 static struct wmi_driver dell_wmi_ddv_driver = {
871 	.driver = {
872 		.name = DRIVER_NAME,
873 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
874 		.pm = pm_sleep_ptr(&dell_wmi_ddv_dev_pm_ops),
875 	},
876 	.id_table = dell_wmi_ddv_id_table,
877 	.probe = dell_wmi_ddv_probe,
878 };
879 module_wmi_driver(dell_wmi_ddv_driver);
880 
881 MODULE_AUTHOR("Armin Wolf <W_Armin@gmx.de>");
882 MODULE_DESCRIPTION("Dell WMI sensor driver");
883 MODULE_LICENSE("GPL");
884