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#define ACPI_POWER_METER_DEVICE_NAME	"Power Meter"
24#define ACPI_POWER_METER_CLASS		"pwr_meter_resource"
25
26#define NUM_SENSORS			17
27
28#define POWER_METER_CAN_MEASURE	(1 << 0)
29#define POWER_METER_CAN_TRIP	(1 << 1)
30#define POWER_METER_CAN_CAP	(1 << 2)
31#define POWER_METER_CAN_NOTIFY	(1 << 3)
32#define POWER_METER_IS_BATTERY	(1 << 8)
33#define UNKNOWN_HYSTERESIS	0xFFFFFFFF
34#define UNKNOWN_POWER		0xFFFFFFFF
35
36#define METER_NOTIFY_CONFIG	0x80
37#define METER_NOTIFY_TRIP	0x81
38#define METER_NOTIFY_CAP	0x82
39#define METER_NOTIFY_CAPPING	0x83
40#define METER_NOTIFY_INTERVAL	0x84
41
42#define POWER_AVERAGE_NAME	"power1_average"
43#define POWER_CAP_NAME		"power1_cap"
44#define POWER_AVG_INTERVAL_NAME	"power1_average_interval"
45#define POWER_ALARM_NAME	"power1_alarm"
46
47static int cap_in_hardware;
48static bool force_cap_on;
49
50static int can_cap_in_hardware(void)
51{
52	return force_cap_on || cap_in_hardware;
53}
54
55static const struct acpi_device_id power_meter_ids[] = {
56	{"ACPI000D", 0},
57	{"", 0},
58};
59MODULE_DEVICE_TABLE(acpi, power_meter_ids);
60
61struct acpi_power_meter_capabilities {
62	u64		flags;
63	u64		units;
64	u64		type;
65	u64		accuracy;
66	u64		sampling_time;
67	u64		min_avg_interval;
68	u64		max_avg_interval;
69	u64		hysteresis;
70	u64		configurable_cap;
71	u64		min_cap;
72	u64		max_cap;
73};
74
75struct acpi_power_meter_resource {
76	struct acpi_device	*acpi_dev;
77	acpi_bus_id		name;
78	struct mutex		lock;
79	struct device		*hwmon_dev;
80	struct acpi_power_meter_capabilities	caps;
81	acpi_string		model_number;
82	acpi_string		serial_number;
83	acpi_string		oem_info;
84	u64		power;
85	u64		cap;
86	u64		avg_interval;
87	int			sensors_valid;
88	unsigned long		sensors_last_updated;
89	struct sensor_device_attribute	sensors[NUM_SENSORS];
90	int			num_sensors;
91	s64			trip[2];
92	int			num_domain_devices;
93	struct acpi_device	**domain_devices;
94	struct kobject		*holders_dir;
95};
96
97struct sensor_template {
98	char *label;
99	ssize_t (*show)(struct device *dev,
100			struct device_attribute *devattr,
101			char *buf);
102	ssize_t (*set)(struct device *dev,
103		       struct device_attribute *devattr,
104		       const char *buf, size_t count);
105	int index;
106};
107
108/* Averaging interval */
109static int update_avg_interval(struct acpi_power_meter_resource *resource)
110{
111	unsigned long long data;
112	acpi_status status;
113
114	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
115				       NULL, &data);
116	if (ACPI_FAILURE(status)) {
117		acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_GAI",
118					     status);
119		return -ENODEV;
120	}
121
122	resource->avg_interval = data;
123	return 0;
124}
125
126static 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
140static 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_SUCCESS(status))
166		resource->avg_interval = temp;
167	mutex_unlock(&resource->lock);
168
169	if (ACPI_FAILURE(status)) {
170		acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PAI",
171					     status);
172		return -EINVAL;
173	}
174
175	/* _PAI returns 0 on success, nonzero otherwise */
176	if (data)
177		return -EINVAL;
178
179	return count;
180}
181
182/* Cap functions */
183static int update_cap(struct acpi_power_meter_resource *resource)
184{
185	unsigned long long data;
186	acpi_status status;
187
188	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
189				       NULL, &data);
190	if (ACPI_FAILURE(status)) {
191		acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_GHL",
192					     status);
193		return -ENODEV;
194	}
195
196	resource->cap = data;
197	return 0;
198}
199
200static ssize_t show_cap(struct device *dev,
201			struct device_attribute *devattr,
202			char *buf)
203{
204	struct acpi_device *acpi_dev = to_acpi_device(dev);
205	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
206
207	mutex_lock(&resource->lock);
208	update_cap(resource);
209	mutex_unlock(&resource->lock);
210
211	return sprintf(buf, "%llu\n", resource->cap * 1000);
212}
213
214static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
215		       const char *buf, size_t count)
216{
217	struct acpi_device *acpi_dev = to_acpi_device(dev);
218	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
219	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
220	struct acpi_object_list args = { 1, &arg0 };
221	int res;
222	unsigned long temp;
223	unsigned long long data;
224	acpi_status status;
225
226	res = kstrtoul(buf, 10, &temp);
227	if (res)
228		return res;
229
230	temp = DIV_ROUND_CLOSEST(temp, 1000);
231	if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
232		return -EINVAL;
233	arg0.integer.value = temp;
234
235	mutex_lock(&resource->lock);
236	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
237				       &args, &data);
238	if (ACPI_SUCCESS(status))
239		resource->cap = temp;
240	mutex_unlock(&resource->lock);
241
242	if (ACPI_FAILURE(status)) {
243		acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_SHL",
244					     status);
245		return -EINVAL;
246	}
247
248	/* _SHL returns 0 on success, nonzero otherwise */
249	if (data)
250		return -EINVAL;
251
252	return count;
253}
254
255/* Power meter trip points */
256static int set_acpi_trip(struct acpi_power_meter_resource *resource)
257{
258	union acpi_object arg_objs[] = {
259		{ACPI_TYPE_INTEGER},
260		{ACPI_TYPE_INTEGER}
261	};
262	struct acpi_object_list args = { 2, arg_objs };
263	unsigned long long data;
264	acpi_status status;
265
266	/* Both trip levels must be set */
267	if (resource->trip[0] < 0 || resource->trip[1] < 0)
268		return 0;
269
270	/* This driver stores min, max; ACPI wants max, min. */
271	arg_objs[0].integer.value = resource->trip[1];
272	arg_objs[1].integer.value = resource->trip[0];
273
274	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
275				       &args, &data);
276	if (ACPI_FAILURE(status)) {
277		acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PTP",
278					     status);
279		return -EINVAL;
280	}
281
282	/* _PTP returns 0 on success, nonzero otherwise */
283	if (data)
284		return -EINVAL;
285
286	return 0;
287}
288
289static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
290			const char *buf, size_t count)
291{
292	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
293	struct acpi_device *acpi_dev = to_acpi_device(dev);
294	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
295	int res;
296	unsigned long temp;
297
298	res = kstrtoul(buf, 10, &temp);
299	if (res)
300		return res;
301
302	temp = DIV_ROUND_CLOSEST(temp, 1000);
303
304	mutex_lock(&resource->lock);
305	resource->trip[attr->index - 7] = temp;
306	res = set_acpi_trip(resource);
307	mutex_unlock(&resource->lock);
308
309	if (res)
310		return res;
311
312	return count;
313}
314
315/* Power meter */
316static int update_meter(struct acpi_power_meter_resource *resource)
317{
318	unsigned long long data;
319	acpi_status status;
320	unsigned long local_jiffies = jiffies;
321
322	if (time_before(local_jiffies, resource->sensors_last_updated +
323			msecs_to_jiffies(resource->caps.sampling_time)) &&
324			resource->sensors_valid)
325		return 0;
326
327	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
328				       NULL, &data);
329	if (ACPI_FAILURE(status)) {
330		acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMM",
331					     status);
332		return -ENODEV;
333	}
334
335	resource->power = data;
336	resource->sensors_valid = 1;
337	resource->sensors_last_updated = jiffies;
338	return 0;
339}
340
341static ssize_t show_power(struct device *dev,
342			  struct device_attribute *devattr,
343			  char *buf)
344{
345	struct acpi_device *acpi_dev = to_acpi_device(dev);
346	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
347
348	mutex_lock(&resource->lock);
349	update_meter(resource);
350	mutex_unlock(&resource->lock);
351
352	if (resource->power == UNKNOWN_POWER)
353		return -ENODATA;
354
355	return sprintf(buf, "%llu\n", resource->power * 1000);
356}
357
358/* Miscellaneous */
359static ssize_t show_str(struct device *dev,
360			struct device_attribute *devattr,
361			char *buf)
362{
363	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
364	struct acpi_device *acpi_dev = to_acpi_device(dev);
365	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
366	acpi_string val;
367	int ret;
368
369	mutex_lock(&resource->lock);
370	switch (attr->index) {
371	case 0:
372		val = resource->model_number;
373		break;
374	case 1:
375		val = resource->serial_number;
376		break;
377	case 2:
378		val = resource->oem_info;
379		break;
380	default:
381		WARN(1, "Implementation error: unexpected attribute index %d\n",
382		     attr->index);
383		val = "";
384		break;
385	}
386	ret = sprintf(buf, "%s\n", val);
387	mutex_unlock(&resource->lock);
388	return ret;
389}
390
391static ssize_t show_val(struct device *dev,
392			struct device_attribute *devattr,
393			char *buf)
394{
395	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
396	struct acpi_device *acpi_dev = to_acpi_device(dev);
397	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
398	u64 val = 0;
399
400	switch (attr->index) {
401	case 0:
402		val = resource->caps.min_avg_interval;
403		break;
404	case 1:
405		val = resource->caps.max_avg_interval;
406		break;
407	case 2:
408		val = resource->caps.min_cap * 1000;
409		break;
410	case 3:
411		val = resource->caps.max_cap * 1000;
412		break;
413	case 4:
414		if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
415			return sprintf(buf, "unknown\n");
416
417		val = resource->caps.hysteresis * 1000;
418		break;
419	case 5:
420		if (resource->caps.flags & POWER_METER_IS_BATTERY)
421			val = 1;
422		else
423			val = 0;
424		break;
425	case 6:
426		if (resource->power > resource->cap)
427			val = 1;
428		else
429			val = 0;
430		break;
431	case 7:
432	case 8:
433		if (resource->trip[attr->index - 7] < 0)
434			return sprintf(buf, "unknown\n");
435
436		val = resource->trip[attr->index - 7] * 1000;
437		break;
438	default:
439		WARN(1, "Implementation error: unexpected attribute index %d\n",
440		     attr->index);
441		break;
442	}
443
444	return sprintf(buf, "%llu\n", val);
445}
446
447static ssize_t show_accuracy(struct device *dev,
448			     struct device_attribute *devattr,
449			     char *buf)
450{
451	struct acpi_device *acpi_dev = to_acpi_device(dev);
452	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
453	unsigned int acc = resource->caps.accuracy;
454
455	return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
456}
457
458static ssize_t show_name(struct device *dev,
459			 struct device_attribute *devattr,
460			 char *buf)
461{
462	return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
463}
464
465#define RO_SENSOR_TEMPLATE(_label, _show, _index)	\
466	{						\
467		.label = _label,			\
468		.show  = _show,				\
469		.index = _index,			\
470	}
471
472#define RW_SENSOR_TEMPLATE(_label, _show, _set, _index)	\
473	{						\
474		.label = _label,			\
475		.show  = _show,				\
476		.set   = _set,				\
477		.index = _index,			\
478	}
479
480/* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
481static struct sensor_template meter_attrs[] = {
482	RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
483	RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
484	RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
485	RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
486	RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
487	RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
488			   set_avg_interval, 0),
489	{},
490};
491
492static struct sensor_template misc_cap_attrs[] = {
493	RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
494	RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
495	RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
496	RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
497	{},
498};
499
500static struct sensor_template ro_cap_attrs[] = {
501	RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
502	{},
503};
504
505static struct sensor_template rw_cap_attrs[] = {
506	RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
507	{},
508};
509
510static struct sensor_template trip_attrs[] = {
511	RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
512	RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
513	{},
514};
515
516static struct sensor_template misc_attrs[] = {
517	RO_SENSOR_TEMPLATE("name", show_name, 0),
518	RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
519	RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
520	RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
521	{},
522};
523
524#undef RO_SENSOR_TEMPLATE
525#undef RW_SENSOR_TEMPLATE
526
527/* Read power domain data */
528static void remove_domain_devices(struct acpi_power_meter_resource *resource)
529{
530	int i;
531
532	if (!resource->num_domain_devices)
533		return;
534
535	for (i = 0; i < resource->num_domain_devices; i++) {
536		struct acpi_device *obj = resource->domain_devices[i];
537
538		if (!obj)
539			continue;
540
541		sysfs_remove_link(resource->holders_dir,
542				  kobject_name(&obj->dev.kobj));
543		acpi_dev_put(obj);
544	}
545
546	kfree(resource->domain_devices);
547	kobject_put(resource->holders_dir);
548	resource->num_domain_devices = 0;
549}
550
551static int read_domain_devices(struct acpi_power_meter_resource *resource)
552{
553	int res = 0;
554	int i;
555	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
556	union acpi_object *pss;
557	acpi_status status;
558
559	status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMD", NULL,
560				      &buffer);
561	if (ACPI_FAILURE(status)) {
562		acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMD",
563					     status);
564		return -ENODEV;
565	}
566
567	pss = buffer.pointer;
568	if (!pss ||
569	    pss->type != ACPI_TYPE_PACKAGE) {
570		dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
571			"Invalid _PMD data\n");
572		res = -EFAULT;
573		goto end;
574	}
575
576	if (!pss->package.count)
577		goto end;
578
579	resource->domain_devices = kcalloc(pss->package.count,
580					   sizeof(struct acpi_device *),
581					   GFP_KERNEL);
582	if (!resource->domain_devices) {
583		res = -ENOMEM;
584		goto end;
585	}
586
587	resource->holders_dir = kobject_create_and_add("measures",
588						       &resource->acpi_dev->dev.kobj);
589	if (!resource->holders_dir) {
590		res = -ENOMEM;
591		goto exit_free;
592	}
593
594	resource->num_domain_devices = pss->package.count;
595
596	for (i = 0; i < pss->package.count; i++) {
597		struct acpi_device *obj;
598		union acpi_object *element = &pss->package.elements[i];
599
600		/* Refuse non-references */
601		if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
602			continue;
603
604		/* Create a symlink to domain objects */
605		obj = acpi_get_acpi_dev(element->reference.handle);
606		resource->domain_devices[i] = obj;
607		if (!obj)
608			continue;
609
610		res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
611					kobject_name(&obj->dev.kobj));
612		if (res) {
613			acpi_dev_put(obj);
614			resource->domain_devices[i] = NULL;
615		}
616	}
617
618	res = 0;
619	goto end;
620
621exit_free:
622	kfree(resource->domain_devices);
623end:
624	kfree(buffer.pointer);
625	return res;
626}
627
628/* Registration and deregistration */
629static int register_attrs(struct acpi_power_meter_resource *resource,
630			  struct sensor_template *attrs)
631{
632	struct device *dev = &resource->acpi_dev->dev;
633	struct sensor_device_attribute *sensors =
634		&resource->sensors[resource->num_sensors];
635	int res = 0;
636
637	while (attrs->label) {
638		sensors->dev_attr.attr.name = attrs->label;
639		sensors->dev_attr.attr.mode = 0444;
640		sensors->dev_attr.show = attrs->show;
641		sensors->index = attrs->index;
642
643		if (attrs->set) {
644			sensors->dev_attr.attr.mode |= 0200;
645			sensors->dev_attr.store = attrs->set;
646		}
647
648		sysfs_attr_init(&sensors->dev_attr.attr);
649		res = device_create_file(dev, &sensors->dev_attr);
650		if (res) {
651			sensors->dev_attr.attr.name = NULL;
652			goto error;
653		}
654		sensors++;
655		resource->num_sensors++;
656		attrs++;
657	}
658
659error:
660	return res;
661}
662
663static void remove_attrs(struct acpi_power_meter_resource *resource)
664{
665	int i;
666
667	for (i = 0; i < resource->num_sensors; i++) {
668		if (!resource->sensors[i].dev_attr.attr.name)
669			continue;
670		device_remove_file(&resource->acpi_dev->dev,
671				   &resource->sensors[i].dev_attr);
672	}
673
674	remove_domain_devices(resource);
675
676	resource->num_sensors = 0;
677}
678
679static int setup_attrs(struct acpi_power_meter_resource *resource)
680{
681	int res = 0;
682
683	res = read_domain_devices(resource);
684	if (res)
685		return res;
686
687	if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
688		res = register_attrs(resource, meter_attrs);
689		if (res)
690			goto error;
691	}
692
693	if (resource->caps.flags & POWER_METER_CAN_CAP) {
694		if (!can_cap_in_hardware()) {
695			dev_warn(&resource->acpi_dev->dev,
696				 "Ignoring unsafe software power cap!\n");
697			goto skip_unsafe_cap;
698		}
699
700		if (resource->caps.configurable_cap)
701			res = register_attrs(resource, rw_cap_attrs);
702		else
703			res = register_attrs(resource, ro_cap_attrs);
704
705		if (res)
706			goto error;
707
708		res = register_attrs(resource, misc_cap_attrs);
709		if (res)
710			goto error;
711	}
712
713skip_unsafe_cap:
714	if (resource->caps.flags & POWER_METER_CAN_TRIP) {
715		res = register_attrs(resource, trip_attrs);
716		if (res)
717			goto error;
718	}
719
720	res = register_attrs(resource, misc_attrs);
721	if (res)
722		goto error;
723
724	return res;
725error:
726	remove_attrs(resource);
727	return res;
728}
729
730static void free_capabilities(struct acpi_power_meter_resource *resource)
731{
732	acpi_string *str;
733	int i;
734
735	str = &resource->model_number;
736	for (i = 0; i < 3; i++, str++) {
737		kfree(*str);
738		*str = NULL;
739	}
740}
741
742static int read_capabilities(struct acpi_power_meter_resource *resource)
743{
744	int res = 0;
745	int i;
746	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
747	struct acpi_buffer state = { 0, NULL };
748	struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
749	union acpi_object *pss;
750	acpi_string *str;
751	acpi_status status;
752
753	status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
754				      &buffer);
755	if (ACPI_FAILURE(status)) {
756		acpi_evaluation_failure_warn(resource->acpi_dev->handle, "_PMC",
757					     status);
758		return -ENODEV;
759	}
760
761	pss = buffer.pointer;
762	if (!pss ||
763	    pss->type != ACPI_TYPE_PACKAGE ||
764	    pss->package.count != 14) {
765		dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
766			"Invalid _PMC data\n");
767		res = -EFAULT;
768		goto end;
769	}
770
771	/* Grab all the integer data at once */
772	state.length = sizeof(struct acpi_power_meter_capabilities);
773	state.pointer = &resource->caps;
774
775	status = acpi_extract_package(pss, &format, &state);
776	if (ACPI_FAILURE(status)) {
777		dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
778			"_PMC package parsing failed: %s\n",
779			acpi_format_exception(status));
780		res = -EFAULT;
781		goto end;
782	}
783
784	if (resource->caps.units) {
785		dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
786			"Unknown units %llu.\n",
787			resource->caps.units);
788		res = -EINVAL;
789		goto end;
790	}
791
792	/* Grab the string data */
793	str = &resource->model_number;
794
795	for (i = 11; i < 14; i++) {
796		union acpi_object *element = &pss->package.elements[i];
797
798		if (element->type != ACPI_TYPE_STRING) {
799			res = -EINVAL;
800			goto error;
801		}
802
803		*str = kmemdup_nul(element->string.pointer, element->string.length,
804				   GFP_KERNEL);
805		if (!*str) {
806			res = -ENOMEM;
807			goto error;
808		}
809
810		str++;
811	}
812
813	dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
814	goto end;
815error:
816	free_capabilities(resource);
817end:
818	kfree(buffer.pointer);
819	return res;
820}
821
822/* Handle ACPI event notifications */
823static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
824{
825	struct acpi_power_meter_resource *resource;
826	int res;
827
828	if (!device || !acpi_driver_data(device))
829		return;
830
831	resource = acpi_driver_data(device);
832
833	switch (event) {
834	case METER_NOTIFY_CONFIG:
835		mutex_lock(&resource->lock);
836		free_capabilities(resource);
837		res = read_capabilities(resource);
838		mutex_unlock(&resource->lock);
839		if (res)
840			break;
841
842		remove_attrs(resource);
843		setup_attrs(resource);
844		break;
845	case METER_NOTIFY_TRIP:
846		sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
847		break;
848	case METER_NOTIFY_CAP:
849		sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
850		break;
851	case METER_NOTIFY_INTERVAL:
852		sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
853		break;
854	case METER_NOTIFY_CAPPING:
855		sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
856		dev_info(&device->dev, "Capping in progress.\n");
857		break;
858	default:
859		WARN(1, "Unexpected event %d\n", event);
860		break;
861	}
862
863	acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
864					dev_name(&device->dev), event, 0);
865}
866
867static int acpi_power_meter_add(struct acpi_device *device)
868{
869	int res;
870	struct acpi_power_meter_resource *resource;
871
872	if (!device)
873		return -EINVAL;
874
875	resource = kzalloc(sizeof(*resource), GFP_KERNEL);
876	if (!resource)
877		return -ENOMEM;
878
879	resource->sensors_valid = 0;
880	resource->acpi_dev = device;
881	mutex_init(&resource->lock);
882	strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
883	strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
884	device->driver_data = resource;
885
886	res = read_capabilities(resource);
887	if (res)
888		goto exit_free;
889
890	resource->trip[0] = -1;
891	resource->trip[1] = -1;
892
893	res = setup_attrs(resource);
894	if (res)
895		goto exit_free_capability;
896
897	resource->hwmon_dev = hwmon_device_register(&device->dev);
898	if (IS_ERR(resource->hwmon_dev)) {
899		res = PTR_ERR(resource->hwmon_dev);
900		goto exit_remove;
901	}
902
903	res = 0;
904	goto exit;
905
906exit_remove:
907	remove_attrs(resource);
908exit_free_capability:
909	free_capabilities(resource);
910exit_free:
911	kfree(resource);
912exit:
913	return res;
914}
915
916static void acpi_power_meter_remove(struct acpi_device *device)
917{
918	struct acpi_power_meter_resource *resource;
919
920	if (!device || !acpi_driver_data(device))
921		return;
922
923	resource = acpi_driver_data(device);
924	hwmon_device_unregister(resource->hwmon_dev);
925
926	remove_attrs(resource);
927	free_capabilities(resource);
928
929	kfree(resource);
930}
931
932static int acpi_power_meter_resume(struct device *dev)
933{
934	struct acpi_power_meter_resource *resource;
935
936	if (!dev)
937		return -EINVAL;
938
939	resource = acpi_driver_data(to_acpi_device(dev));
940	if (!resource)
941		return -EINVAL;
942
943	free_capabilities(resource);
944	read_capabilities(resource);
945
946	return 0;
947}
948
949static DEFINE_SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL,
950				acpi_power_meter_resume);
951
952static struct acpi_driver acpi_power_meter_driver = {
953	.name = "power_meter",
954	.class = ACPI_POWER_METER_CLASS,
955	.ids = power_meter_ids,
956	.ops = {
957		.add = acpi_power_meter_add,
958		.remove = acpi_power_meter_remove,
959		.notify = acpi_power_meter_notify,
960		},
961	.drv.pm = pm_sleep_ptr(&acpi_power_meter_pm),
962};
963
964/* Module init/exit routines */
965static int __init enable_cap_knobs(const struct dmi_system_id *d)
966{
967	cap_in_hardware = 1;
968	return 0;
969}
970
971static const struct dmi_system_id pm_dmi_table[] __initconst = {
972	{
973		enable_cap_knobs, "IBM Active Energy Manager",
974		{
975			DMI_MATCH(DMI_SYS_VENDOR, "IBM")
976		},
977	},
978	{}
979};
980
981static int __init acpi_power_meter_init(void)
982{
983	int result;
984
985	if (acpi_disabled)
986		return -ENODEV;
987
988	dmi_check_system(pm_dmi_table);
989
990	result = acpi_bus_register_driver(&acpi_power_meter_driver);
991	if (result < 0)
992		return result;
993
994	return 0;
995}
996
997static void __exit acpi_power_meter_exit(void)
998{
999	acpi_bus_unregister_driver(&acpi_power_meter_driver);
1000}
1001
1002MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
1003MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1004MODULE_LICENSE("GPL");
1005
1006module_param(force_cap_on, bool, 0644);
1007MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1008
1009module_init(acpi_power_meter_init);
1010module_exit(acpi_power_meter_exit);
1011