1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * A hwmon driver for ACPI 4.0 power meters
4  * Copyright (C) 2009 IBM
5  *
6  * Author: Darrick J. Wong <darrick.wong@oracle.com>
7  */
8 
9 #include <linux/module.h>
10 #include <linux/hwmon.h>
11 #include <linux/hwmon-sysfs.h>
12 #include <linux/jiffies.h>
13 #include <linux/mutex.h>
14 #include <linux/dmi.h>
15 #include <linux/slab.h>
16 #include <linux/kdev_t.h>
17 #include <linux/sched.h>
18 #include <linux/time.h>
19 #include <linux/err.h>
20 #include <linux/acpi.h>
21 
22 #define ACPI_POWER_METER_NAME		"power_meter"
23 ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
24 #define ACPI_POWER_METER_DEVICE_NAME	"Power Meter"
25 #define ACPI_POWER_METER_CLASS		"pwr_meter_resource"
26 
27 #define NUM_SENSORS			17
28 
29 #define POWER_METER_CAN_MEASURE	(1 << 0)
30 #define POWER_METER_CAN_TRIP	(1 << 1)
31 #define POWER_METER_CAN_CAP	(1 << 2)
32 #define POWER_METER_CAN_NOTIFY	(1 << 3)
33 #define POWER_METER_IS_BATTERY	(1 << 8)
34 #define UNKNOWN_HYSTERESIS	0xFFFFFFFF
35 #define UNKNOWN_POWER		0xFFFFFFFF
36 
37 #define METER_NOTIFY_CONFIG	0x80
38 #define METER_NOTIFY_TRIP	0x81
39 #define METER_NOTIFY_CAP	0x82
40 #define METER_NOTIFY_CAPPING	0x83
41 #define METER_NOTIFY_INTERVAL	0x84
42 
43 #define POWER_AVERAGE_NAME	"power1_average"
44 #define POWER_CAP_NAME		"power1_cap"
45 #define POWER_AVG_INTERVAL_NAME	"power1_average_interval"
46 #define POWER_ALARM_NAME	"power1_alarm"
47 
48 static int cap_in_hardware;
49 static bool force_cap_on;
50 
can_cap_in_hardware(void)51 static int can_cap_in_hardware(void)
52 {
53 	return force_cap_on || cap_in_hardware;
54 }
55 
56 static const struct acpi_device_id power_meter_ids[] = {
57 	{"ACPI000D", 0},
58 	{"", 0},
59 };
60 MODULE_DEVICE_TABLE(acpi, power_meter_ids);
61 
62 struct acpi_power_meter_capabilities {
63 	u64		flags;
64 	u64		units;
65 	u64		type;
66 	u64		accuracy;
67 	u64		sampling_time;
68 	u64		min_avg_interval;
69 	u64		max_avg_interval;
70 	u64		hysteresis;
71 	u64		configurable_cap;
72 	u64		min_cap;
73 	u64		max_cap;
74 };
75 
76 struct acpi_power_meter_resource {
77 	struct acpi_device	*acpi_dev;
78 	acpi_bus_id		name;
79 	struct mutex		lock;
80 	struct device		*hwmon_dev;
81 	struct acpi_power_meter_capabilities	caps;
82 	acpi_string		model_number;
83 	acpi_string		serial_number;
84 	acpi_string		oem_info;
85 	u64		power;
86 	u64		cap;
87 	u64		avg_interval;
88 	int			sensors_valid;
89 	unsigned long		sensors_last_updated;
90 	struct sensor_device_attribute	sensors[NUM_SENSORS];
91 	int			num_sensors;
92 	s64			trip[2];
93 	int			num_domain_devices;
94 	struct acpi_device	**domain_devices;
95 	struct kobject		*holders_dir;
96 };
97 
98 struct sensor_template {
99 	char *label;
100 	ssize_t (*show)(struct device *dev,
101 			struct device_attribute *devattr,
102 			char *buf);
103 	ssize_t (*set)(struct device *dev,
104 		       struct device_attribute *devattr,
105 		       const char *buf, size_t count);
106 	int index;
107 };
108 
109 /* Averaging interval */
update_avg_interval(struct acpi_power_meter_resource *resource)110 static int update_avg_interval(struct acpi_power_meter_resource *resource)
111 {
112 	unsigned long long data;
113 	acpi_status status;
114 
115 	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
116 				       NULL, &data);
117 	if (ACPI_FAILURE(status)) {
118 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
119 		return -ENODEV;
120 	}
121 
122 	resource->avg_interval = data;
123 	return 0;
124 }
125 
show_avg_interval(struct device *dev, struct device_attribute *devattr, char *buf)126 static ssize_t show_avg_interval(struct device *dev,
127 				 struct device_attribute *devattr,
128 				 char *buf)
129 {
130 	struct acpi_device *acpi_dev = to_acpi_device(dev);
131 	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
132 
133 	mutex_lock(&resource->lock);
134 	update_avg_interval(resource);
135 	mutex_unlock(&resource->lock);
136 
137 	return sprintf(buf, "%llu\n", resource->avg_interval);
138 }
139 
set_avg_interval(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count)140 static ssize_t set_avg_interval(struct device *dev,
141 				struct device_attribute *devattr,
142 				const char *buf, size_t count)
143 {
144 	struct acpi_device *acpi_dev = to_acpi_device(dev);
145 	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
146 	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
147 	struct acpi_object_list args = { 1, &arg0 };
148 	int res;
149 	unsigned long temp;
150 	unsigned long long data;
151 	acpi_status status;
152 
153 	res = kstrtoul(buf, 10, &temp);
154 	if (res)
155 		return res;
156 
157 	if (temp > resource->caps.max_avg_interval ||
158 	    temp < resource->caps.min_avg_interval)
159 		return -EINVAL;
160 	arg0.integer.value = temp;
161 
162 	mutex_lock(&resource->lock);
163 	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
164 				       &args, &data);
165 	if (!ACPI_FAILURE(status))
166 		resource->avg_interval = temp;
167 	mutex_unlock(&resource->lock);
168 
169 	if (ACPI_FAILURE(status)) {
170 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
171 		return -EINVAL;
172 	}
173 
174 	/* _PAI returns 0 on success, nonzero otherwise */
175 	if (data)
176 		return -EINVAL;
177 
178 	return count;
179 }
180 
181 /* Cap functions */
update_cap(struct acpi_power_meter_resource *resource)182 static int update_cap(struct acpi_power_meter_resource *resource)
183 {
184 	unsigned long long data;
185 	acpi_status status;
186 
187 	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
188 				       NULL, &data);
189 	if (ACPI_FAILURE(status)) {
190 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
191 		return -ENODEV;
192 	}
193 
194 	resource->cap = data;
195 	return 0;
196 }
197 
show_cap(struct device *dev, struct device_attribute *devattr, char *buf)198 static ssize_t show_cap(struct device *dev,
199 			struct device_attribute *devattr,
200 			char *buf)
201 {
202 	struct acpi_device *acpi_dev = to_acpi_device(dev);
203 	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
204 
205 	mutex_lock(&resource->lock);
206 	update_cap(resource);
207 	mutex_unlock(&resource->lock);
208 
209 	return sprintf(buf, "%llu\n", resource->cap * 1000);
210 }
211 
set_cap(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count)212 static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
213 		       const char *buf, size_t count)
214 {
215 	struct acpi_device *acpi_dev = to_acpi_device(dev);
216 	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
217 	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
218 	struct acpi_object_list args = { 1, &arg0 };
219 	int res;
220 	unsigned long temp;
221 	unsigned long long data;
222 	acpi_status status;
223 
224 	res = kstrtoul(buf, 10, &temp);
225 	if (res)
226 		return res;
227 
228 	temp = DIV_ROUND_CLOSEST(temp, 1000);
229 	if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
230 		return -EINVAL;
231 	arg0.integer.value = temp;
232 
233 	mutex_lock(&resource->lock);
234 	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
235 				       &args, &data);
236 	if (!ACPI_FAILURE(status))
237 		resource->cap = temp;
238 	mutex_unlock(&resource->lock);
239 
240 	if (ACPI_FAILURE(status)) {
241 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
242 		return -EINVAL;
243 	}
244 
245 	/* _SHL returns 0 on success, nonzero otherwise */
246 	if (data)
247 		return -EINVAL;
248 
249 	return count;
250 }
251 
252 /* Power meter trip points */
set_acpi_trip(struct acpi_power_meter_resource *resource)253 static int set_acpi_trip(struct acpi_power_meter_resource *resource)
254 {
255 	union acpi_object arg_objs[] = {
256 		{ACPI_TYPE_INTEGER},
257 		{ACPI_TYPE_INTEGER}
258 	};
259 	struct acpi_object_list args = { 2, arg_objs };
260 	unsigned long long data;
261 	acpi_status status;
262 
263 	/* Both trip levels must be set */
264 	if (resource->trip[0] < 0 || resource->trip[1] < 0)
265 		return 0;
266 
267 	/* This driver stores min, max; ACPI wants max, min. */
268 	arg_objs[0].integer.value = resource->trip[1];
269 	arg_objs[1].integer.value = resource->trip[0];
270 
271 	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
272 				       &args, &data);
273 	if (ACPI_FAILURE(status)) {
274 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
275 		return -EINVAL;
276 	}
277 
278 	/* _PTP returns 0 on success, nonzero otherwise */
279 	if (data)
280 		return -EINVAL;
281 
282 	return 0;
283 }
284 
set_trip(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count)285 static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
286 			const char *buf, size_t count)
287 {
288 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
289 	struct acpi_device *acpi_dev = to_acpi_device(dev);
290 	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
291 	int res;
292 	unsigned long temp;
293 
294 	res = kstrtoul(buf, 10, &temp);
295 	if (res)
296 		return res;
297 
298 	temp = DIV_ROUND_CLOSEST(temp, 1000);
299 
300 	mutex_lock(&resource->lock);
301 	resource->trip[attr->index - 7] = temp;
302 	res = set_acpi_trip(resource);
303 	mutex_unlock(&resource->lock);
304 
305 	if (res)
306 		return res;
307 
308 	return count;
309 }
310 
311 /* Power meter */
update_meter(struct acpi_power_meter_resource *resource)312 static int update_meter(struct acpi_power_meter_resource *resource)
313 {
314 	unsigned long long data;
315 	acpi_status status;
316 	unsigned long local_jiffies = jiffies;
317 
318 	if (time_before(local_jiffies, resource->sensors_last_updated +
319 			msecs_to_jiffies(resource->caps.sampling_time)) &&
320 			resource->sensors_valid)
321 		return 0;
322 
323 	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
324 				       NULL, &data);
325 	if (ACPI_FAILURE(status)) {
326 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
327 		return -ENODEV;
328 	}
329 
330 	resource->power = data;
331 	resource->sensors_valid = 1;
332 	resource->sensors_last_updated = jiffies;
333 	return 0;
334 }
335 
show_power(struct device *dev, struct device_attribute *devattr, char *buf)336 static ssize_t show_power(struct device *dev,
337 			  struct device_attribute *devattr,
338 			  char *buf)
339 {
340 	struct acpi_device *acpi_dev = to_acpi_device(dev);
341 	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
342 
343 	mutex_lock(&resource->lock);
344 	update_meter(resource);
345 	mutex_unlock(&resource->lock);
346 
347 	if (resource->power == UNKNOWN_POWER)
348 		return -ENODATA;
349 
350 	return sprintf(buf, "%llu\n", resource->power * 1000);
351 }
352 
353 /* Miscellaneous */
show_str(struct device *dev, struct device_attribute *devattr, char *buf)354 static ssize_t show_str(struct device *dev,
355 			struct device_attribute *devattr,
356 			char *buf)
357 {
358 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
359 	struct acpi_device *acpi_dev = to_acpi_device(dev);
360 	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
361 	acpi_string val;
362 	int ret;
363 
364 	mutex_lock(&resource->lock);
365 	switch (attr->index) {
366 	case 0:
367 		val = resource->model_number;
368 		break;
369 	case 1:
370 		val = resource->serial_number;
371 		break;
372 	case 2:
373 		val = resource->oem_info;
374 		break;
375 	default:
376 		WARN(1, "Implementation error: unexpected attribute index %d\n",
377 		     attr->index);
378 		val = "";
379 		break;
380 	}
381 	ret = sprintf(buf, "%s\n", val);
382 	mutex_unlock(&resource->lock);
383 	return ret;
384 }
385 
show_val(struct device *dev, struct device_attribute *devattr, char *buf)386 static ssize_t show_val(struct device *dev,
387 			struct device_attribute *devattr,
388 			char *buf)
389 {
390 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
391 	struct acpi_device *acpi_dev = to_acpi_device(dev);
392 	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
393 	u64 val = 0;
394 
395 	switch (attr->index) {
396 	case 0:
397 		val = resource->caps.min_avg_interval;
398 		break;
399 	case 1:
400 		val = resource->caps.max_avg_interval;
401 		break;
402 	case 2:
403 		val = resource->caps.min_cap * 1000;
404 		break;
405 	case 3:
406 		val = resource->caps.max_cap * 1000;
407 		break;
408 	case 4:
409 		if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
410 			return sprintf(buf, "unknown\n");
411 
412 		val = resource->caps.hysteresis * 1000;
413 		break;
414 	case 5:
415 		if (resource->caps.flags & POWER_METER_IS_BATTERY)
416 			val = 1;
417 		else
418 			val = 0;
419 		break;
420 	case 6:
421 		if (resource->power > resource->cap)
422 			val = 1;
423 		else
424 			val = 0;
425 		break;
426 	case 7:
427 	case 8:
428 		if (resource->trip[attr->index - 7] < 0)
429 			return sprintf(buf, "unknown\n");
430 
431 		val = resource->trip[attr->index - 7] * 1000;
432 		break;
433 	default:
434 		WARN(1, "Implementation error: unexpected attribute index %d\n",
435 		     attr->index);
436 		break;
437 	}
438 
439 	return sprintf(buf, "%llu\n", val);
440 }
441 
show_accuracy(struct device *dev, struct device_attribute *devattr, char *buf)442 static ssize_t show_accuracy(struct device *dev,
443 			     struct device_attribute *devattr,
444 			     char *buf)
445 {
446 	struct acpi_device *acpi_dev = to_acpi_device(dev);
447 	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
448 	unsigned int acc = resource->caps.accuracy;
449 
450 	return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
451 }
452 
show_name(struct device *dev, struct device_attribute *devattr, char *buf)453 static ssize_t show_name(struct device *dev,
454 			 struct device_attribute *devattr,
455 			 char *buf)
456 {
457 	return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
458 }
459 
460 #define RO_SENSOR_TEMPLATE(_label, _show, _index)	\
461 	{						\
462 		.label = _label,			\
463 		.show  = _show,				\
464 		.index = _index,			\
465 	}
466 
467 #define RW_SENSOR_TEMPLATE(_label, _show, _set, _index)	\
468 	{						\
469 		.label = _label,			\
470 		.show  = _show,				\
471 		.set   = _set,				\
472 		.index = _index,			\
473 	}
474 
475 /* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
476 static struct sensor_template meter_attrs[] = {
477 	RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
478 	RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
479 	RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
480 	RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
481 	RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
482 	RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
483 		set_avg_interval, 0),
484 	{},
485 };
486 
487 static struct sensor_template misc_cap_attrs[] = {
488 	RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
489 	RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
490 	RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
491 	RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
492 	{},
493 };
494 
495 static struct sensor_template ro_cap_attrs[] = {
496 	RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
497 	{},
498 };
499 
500 static struct sensor_template rw_cap_attrs[] = {
501 	RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
502 	{},
503 };
504 
505 static struct sensor_template trip_attrs[] = {
506 	RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
507 	RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
508 	{},
509 };
510 
511 static struct sensor_template misc_attrs[] = {
512 	RO_SENSOR_TEMPLATE("name", show_name, 0),
513 	RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
514 	RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
515 	RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
516 	{},
517 };
518 
519 #undef RO_SENSOR_TEMPLATE
520 #undef RW_SENSOR_TEMPLATE
521 
522 /* Read power domain data */
remove_domain_devices(struct acpi_power_meter_resource *resource)523 static void remove_domain_devices(struct acpi_power_meter_resource *resource)
524 {
525 	int i;
526 
527 	if (!resource->num_domain_devices)
528 		return;
529 
530 	for (i = 0; i < resource->num_domain_devices; i++) {
531 		struct acpi_device *obj = resource->domain_devices[i];
532 		if (!obj)
533 			continue;
534 
535 		sysfs_remove_link(resource->holders_dir,
536 				  kobject_name(&obj->dev.kobj));
537 		put_device(&obj->dev);
538 	}
539 
540 	kfree(resource->domain_devices);
541 	kobject_put(resource->holders_dir);
542 	resource->num_domain_devices = 0;
543 }
544 
read_domain_devices(struct acpi_power_meter_resource *resource)545 static int read_domain_devices(struct acpi_power_meter_resource *resource)
546 {
547 	int res = 0;
548 	int i;
549 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
550 	union acpi_object *pss;
551 	acpi_status status;
552 
553 	status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
554 				      &buffer);
555 	if (ACPI_FAILURE(status)) {
556 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
557 		return -ENODEV;
558 	}
559 
560 	pss = buffer.pointer;
561 	if (!pss ||
562 	    pss->type != ACPI_TYPE_PACKAGE) {
563 		dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
564 			"Invalid _PMD data\n");
565 		res = -EFAULT;
566 		goto end;
567 	}
568 
569 	if (!pss->package.count)
570 		goto end;
571 
572 	resource->domain_devices = kcalloc(pss->package.count,
573 					   sizeof(struct acpi_device *),
574 					   GFP_KERNEL);
575 	if (!resource->domain_devices) {
576 		res = -ENOMEM;
577 		goto end;
578 	}
579 
580 	resource->holders_dir = kobject_create_and_add("measures",
581 					&resource->acpi_dev->dev.kobj);
582 	if (!resource->holders_dir) {
583 		res = -ENOMEM;
584 		goto exit_free;
585 	}
586 
587 	resource->num_domain_devices = pss->package.count;
588 
589 	for (i = 0; i < pss->package.count; i++) {
590 		struct acpi_device *obj;
591 		union acpi_object *element = &(pss->package.elements[i]);
592 
593 		/* Refuse non-references */
594 		if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
595 			continue;
596 
597 		/* Create a symlink to domain objects */
598 		resource->domain_devices[i] = NULL;
599 		if (acpi_bus_get_device(element->reference.handle,
600 					&resource->domain_devices[i]))
601 			continue;
602 
603 		obj = resource->domain_devices[i];
604 		get_device(&obj->dev);
605 
606 		res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
607 				      kobject_name(&obj->dev.kobj));
608 		if (res) {
609 			put_device(&obj->dev);
610 			resource->domain_devices[i] = NULL;
611 		}
612 	}
613 
614 	res = 0;
615 	goto end;
616 
617 exit_free:
618 	kfree(resource->domain_devices);
619 end:
620 	kfree(buffer.pointer);
621 	return res;
622 }
623 
624 /* Registration and deregistration */
register_attrs(struct acpi_power_meter_resource *resource, struct sensor_template *attrs)625 static int register_attrs(struct acpi_power_meter_resource *resource,
626 			  struct sensor_template *attrs)
627 {
628 	struct device *dev = &resource->acpi_dev->dev;
629 	struct sensor_device_attribute *sensors =
630 		&resource->sensors[resource->num_sensors];
631 	int res = 0;
632 
633 	while (attrs->label) {
634 		sensors->dev_attr.attr.name = attrs->label;
635 		sensors->dev_attr.attr.mode = 0444;
636 		sensors->dev_attr.show = attrs->show;
637 		sensors->index = attrs->index;
638 
639 		if (attrs->set) {
640 			sensors->dev_attr.attr.mode |= 0200;
641 			sensors->dev_attr.store = attrs->set;
642 		}
643 
644 		sysfs_attr_init(&sensors->dev_attr.attr);
645 		res = device_create_file(dev, &sensors->dev_attr);
646 		if (res) {
647 			sensors->dev_attr.attr.name = NULL;
648 			goto error;
649 		}
650 		sensors++;
651 		resource->num_sensors++;
652 		attrs++;
653 	}
654 
655 error:
656 	return res;
657 }
658 
remove_attrs(struct acpi_power_meter_resource *resource)659 static void remove_attrs(struct acpi_power_meter_resource *resource)
660 {
661 	int i;
662 
663 	for (i = 0; i < resource->num_sensors; i++) {
664 		if (!resource->sensors[i].dev_attr.attr.name)
665 			continue;
666 		device_remove_file(&resource->acpi_dev->dev,
667 				   &resource->sensors[i].dev_attr);
668 	}
669 
670 	remove_domain_devices(resource);
671 
672 	resource->num_sensors = 0;
673 }
674 
setup_attrs(struct acpi_power_meter_resource *resource)675 static int setup_attrs(struct acpi_power_meter_resource *resource)
676 {
677 	int res = 0;
678 
679 	res = read_domain_devices(resource);
680 	if (res)
681 		return res;
682 
683 	if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
684 		res = register_attrs(resource, meter_attrs);
685 		if (res)
686 			goto error;
687 	}
688 
689 	if (resource->caps.flags & POWER_METER_CAN_CAP) {
690 		if (!can_cap_in_hardware()) {
691 			dev_warn(&resource->acpi_dev->dev,
692 				 "Ignoring unsafe software power cap!\n");
693 			goto skip_unsafe_cap;
694 		}
695 
696 		if (resource->caps.configurable_cap)
697 			res = register_attrs(resource, rw_cap_attrs);
698 		else
699 			res = register_attrs(resource, ro_cap_attrs);
700 
701 		if (res)
702 			goto error;
703 
704 		res = register_attrs(resource, misc_cap_attrs);
705 		if (res)
706 			goto error;
707 	}
708 
709 skip_unsafe_cap:
710 	if (resource->caps.flags & POWER_METER_CAN_TRIP) {
711 		res = register_attrs(resource, trip_attrs);
712 		if (res)
713 			goto error;
714 	}
715 
716 	res = register_attrs(resource, misc_attrs);
717 	if (res)
718 		goto error;
719 
720 	return res;
721 error:
722 	remove_attrs(resource);
723 	return res;
724 }
725 
free_capabilities(struct acpi_power_meter_resource *resource)726 static void free_capabilities(struct acpi_power_meter_resource *resource)
727 {
728 	acpi_string *str;
729 	int i;
730 
731 	str = &resource->model_number;
732 	for (i = 0; i < 3; i++, str++)
733 		kfree(*str);
734 }
735 
read_capabilities(struct acpi_power_meter_resource *resource)736 static int read_capabilities(struct acpi_power_meter_resource *resource)
737 {
738 	int res = 0;
739 	int i;
740 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
741 	struct acpi_buffer state = { 0, NULL };
742 	struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
743 	union acpi_object *pss;
744 	acpi_string *str;
745 	acpi_status status;
746 
747 	status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
748 				      &buffer);
749 	if (ACPI_FAILURE(status)) {
750 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
751 		return -ENODEV;
752 	}
753 
754 	pss = buffer.pointer;
755 	if (!pss ||
756 	    pss->type != ACPI_TYPE_PACKAGE ||
757 	    pss->package.count != 14) {
758 		dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
759 			"Invalid _PMC data\n");
760 		res = -EFAULT;
761 		goto end;
762 	}
763 
764 	/* Grab all the integer data at once */
765 	state.length = sizeof(struct acpi_power_meter_capabilities);
766 	state.pointer = &resource->caps;
767 
768 	status = acpi_extract_package(pss, &format, &state);
769 	if (ACPI_FAILURE(status)) {
770 		ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
771 		res = -EFAULT;
772 		goto end;
773 	}
774 
775 	if (resource->caps.units) {
776 		dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
777 			"Unknown units %llu.\n",
778 			resource->caps.units);
779 		res = -EINVAL;
780 		goto end;
781 	}
782 
783 	/* Grab the string data */
784 	str = &resource->model_number;
785 
786 	for (i = 11; i < 14; i++) {
787 		union acpi_object *element = &(pss->package.elements[i]);
788 
789 		if (element->type != ACPI_TYPE_STRING) {
790 			res = -EINVAL;
791 			goto error;
792 		}
793 
794 		*str = kcalloc(element->string.length + 1, sizeof(u8),
795 			       GFP_KERNEL);
796 		if (!*str) {
797 			res = -ENOMEM;
798 			goto error;
799 		}
800 
801 		strncpy(*str, element->string.pointer, element->string.length);
802 		str++;
803 	}
804 
805 	dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
806 	goto end;
807 error:
808 	str = &resource->model_number;
809 	for (i = 0; i < 3; i++, str++)
810 		kfree(*str);
811 end:
812 	kfree(buffer.pointer);
813 	return res;
814 }
815 
816 /* Handle ACPI event notifications */
acpi_power_meter_notify(struct acpi_device *device, u32 event)817 static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
818 {
819 	struct acpi_power_meter_resource *resource;
820 	int res;
821 
822 	if (!device || !acpi_driver_data(device))
823 		return;
824 
825 	resource = acpi_driver_data(device);
826 
827 	switch (event) {
828 	case METER_NOTIFY_CONFIG:
829 		mutex_lock(&resource->lock);
830 		free_capabilities(resource);
831 		res = read_capabilities(resource);
832 		mutex_unlock(&resource->lock);
833 		if (res)
834 			break;
835 
836 		remove_attrs(resource);
837 		setup_attrs(resource);
838 		break;
839 	case METER_NOTIFY_TRIP:
840 		sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
841 		break;
842 	case METER_NOTIFY_CAP:
843 		sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
844 		break;
845 	case METER_NOTIFY_INTERVAL:
846 		sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
847 		break;
848 	case METER_NOTIFY_CAPPING:
849 		sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
850 		dev_info(&device->dev, "Capping in progress.\n");
851 		break;
852 	default:
853 		WARN(1, "Unexpected event %d\n", event);
854 		break;
855 	}
856 
857 	acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
858 					dev_name(&device->dev), event, 0);
859 }
860 
acpi_power_meter_add(struct acpi_device *device)861 static int acpi_power_meter_add(struct acpi_device *device)
862 {
863 	int res;
864 	struct acpi_power_meter_resource *resource;
865 
866 	if (!device)
867 		return -EINVAL;
868 
869 	resource = kzalloc(sizeof(struct acpi_power_meter_resource),
870 			   GFP_KERNEL);
871 	if (!resource)
872 		return -ENOMEM;
873 
874 	resource->sensors_valid = 0;
875 	resource->acpi_dev = device;
876 	mutex_init(&resource->lock);
877 	strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
878 	strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
879 	device->driver_data = resource;
880 
881 	free_capabilities(resource);
882 	res = read_capabilities(resource);
883 	if (res)
884 		goto exit_free;
885 
886 	resource->trip[0] = resource->trip[1] = -1;
887 
888 	res = setup_attrs(resource);
889 	if (res)
890 		goto exit_free_capability;
891 
892 	resource->hwmon_dev = hwmon_device_register(&device->dev);
893 	if (IS_ERR(resource->hwmon_dev)) {
894 		res = PTR_ERR(resource->hwmon_dev);
895 		goto exit_remove;
896 	}
897 
898 	res = 0;
899 	goto exit;
900 
901 exit_remove:
902 	remove_attrs(resource);
903 exit_free_capability:
904 	free_capabilities(resource);
905 exit_free:
906 	kfree(resource);
907 exit:
908 	return res;
909 }
910 
acpi_power_meter_remove(struct acpi_device *device)911 static int acpi_power_meter_remove(struct acpi_device *device)
912 {
913 	struct acpi_power_meter_resource *resource;
914 
915 	if (!device || !acpi_driver_data(device))
916 		return -EINVAL;
917 
918 	resource = acpi_driver_data(device);
919 	hwmon_device_unregister(resource->hwmon_dev);
920 
921 	remove_attrs(resource);
922 	free_capabilities(resource);
923 
924 	kfree(resource);
925 	return 0;
926 }
927 
928 #ifdef CONFIG_PM_SLEEP
929 
acpi_power_meter_resume(struct device *dev)930 static int acpi_power_meter_resume(struct device *dev)
931 {
932 	struct acpi_power_meter_resource *resource;
933 
934 	if (!dev)
935 		return -EINVAL;
936 
937 	resource = acpi_driver_data(to_acpi_device(dev));
938 	if (!resource)
939 		return -EINVAL;
940 
941 	free_capabilities(resource);
942 	read_capabilities(resource);
943 
944 	return 0;
945 }
946 
947 #endif /* CONFIG_PM_SLEEP */
948 
949 static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
950 
951 static struct acpi_driver acpi_power_meter_driver = {
952 	.name = "power_meter",
953 	.class = ACPI_POWER_METER_CLASS,
954 	.ids = power_meter_ids,
955 	.ops = {
956 		.add = acpi_power_meter_add,
957 		.remove = acpi_power_meter_remove,
958 		.notify = acpi_power_meter_notify,
959 		},
960 	.drv.pm = &acpi_power_meter_pm,
961 };
962 
963 /* Module init/exit routines */
enable_cap_knobs(const struct dmi_system_id *d)964 static int __init enable_cap_knobs(const struct dmi_system_id *d)
965 {
966 	cap_in_hardware = 1;
967 	return 0;
968 }
969 
970 static const struct dmi_system_id pm_dmi_table[] __initconst = {
971 	{
972 		enable_cap_knobs, "IBM Active Energy Manager",
973 		{
974 			DMI_MATCH(DMI_SYS_VENDOR, "IBM")
975 		},
976 	},
977 	{}
978 };
979 
acpi_power_meter_init(void)980 static int __init acpi_power_meter_init(void)
981 {
982 	int result;
983 
984 	if (acpi_disabled)
985 		return -ENODEV;
986 
987 	dmi_check_system(pm_dmi_table);
988 
989 	result = acpi_bus_register_driver(&acpi_power_meter_driver);
990 	if (result < 0)
991 		return result;
992 
993 	return 0;
994 }
995 
acpi_power_meter_exit(void)996 static void __exit acpi_power_meter_exit(void)
997 {
998 	acpi_bus_unregister_driver(&acpi_power_meter_driver);
999 }
1000 
1001 MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
1002 MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1003 MODULE_LICENSE("GPL");
1004 
1005 module_param(force_cap_on, bool, 0644);
1006 MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1007 
1008 module_init(acpi_power_meter_init);
1009 module_exit(acpi_power_meter_exit);
1010