1/*
2 * A hwmon driver for ACPI 4.0 power meters
3 * Copyright (C) 2009 IBM
4 *
5 * Author: Darrick J. Wong <darrick.wong@oracle.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
20 */
21
22#include <linux/module.h>
23#include <linux/hwmon.h>
24#include <linux/hwmon-sysfs.h>
25#include <linux/jiffies.h>
26#include <linux/mutex.h>
27#include <linux/dmi.h>
28#include <linux/slab.h>
29#include <linux/kdev_t.h>
30#include <linux/sched.h>
31#include <linux/time.h>
32#include <linux/err.h>
33#include <linux/acpi.h>
34
35#define ACPI_POWER_METER_NAME		"power_meter"
36ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
37#define ACPI_POWER_METER_DEVICE_NAME	"Power Meter"
38#define ACPI_POWER_METER_CLASS		"pwr_meter_resource"
39
40#define NUM_SENSORS			17
41
42#define POWER_METER_CAN_MEASURE	(1 << 0)
43#define POWER_METER_CAN_TRIP	(1 << 1)
44#define POWER_METER_CAN_CAP	(1 << 2)
45#define POWER_METER_CAN_NOTIFY	(1 << 3)
46#define POWER_METER_IS_BATTERY	(1 << 8)
47#define UNKNOWN_HYSTERESIS	0xFFFFFFFF
48
49#define METER_NOTIFY_CONFIG	0x80
50#define METER_NOTIFY_TRIP	0x81
51#define METER_NOTIFY_CAP	0x82
52#define METER_NOTIFY_CAPPING	0x83
53#define METER_NOTIFY_INTERVAL	0x84
54
55#define POWER_AVERAGE_NAME	"power1_average"
56#define POWER_CAP_NAME		"power1_cap"
57#define POWER_AVG_INTERVAL_NAME	"power1_average_interval"
58#define POWER_ALARM_NAME	"power1_alarm"
59
60static int cap_in_hardware;
61static bool force_cap_on;
62
63static int can_cap_in_hardware(void)
64{
65	return force_cap_on || cap_in_hardware;
66}
67
68static const struct acpi_device_id power_meter_ids[] = {
69	{"ACPI000D", 0},
70	{"", 0},
71};
72MODULE_DEVICE_TABLE(acpi, power_meter_ids);
73
74struct acpi_power_meter_capabilities {
75	u64		flags;
76	u64		units;
77	u64		type;
78	u64		accuracy;
79	u64		sampling_time;
80	u64		min_avg_interval;
81	u64		max_avg_interval;
82	u64		hysteresis;
83	u64		configurable_cap;
84	u64		min_cap;
85	u64		max_cap;
86};
87
88struct acpi_power_meter_resource {
89	struct acpi_device	*acpi_dev;
90	acpi_bus_id		name;
91	struct mutex		lock;
92	struct device		*hwmon_dev;
93	struct acpi_power_meter_capabilities	caps;
94	acpi_string		model_number;
95	acpi_string		serial_number;
96	acpi_string		oem_info;
97	u64		power;
98	u64		cap;
99	u64		avg_interval;
100	int			sensors_valid;
101	unsigned long		sensors_last_updated;
102	struct sensor_device_attribute	sensors[NUM_SENSORS];
103	int			num_sensors;
104	s64			trip[2];
105	int			num_domain_devices;
106	struct acpi_device	**domain_devices;
107	struct kobject		*holders_dir;
108};
109
110struct sensor_template {
111	char *label;
112	ssize_t (*show)(struct device *dev,
113			struct device_attribute *devattr,
114			char *buf);
115	ssize_t (*set)(struct device *dev,
116		       struct device_attribute *devattr,
117		       const char *buf, size_t count);
118	int index;
119};
120
121/* Averaging interval */
122static int update_avg_interval(struct acpi_power_meter_resource *resource)
123{
124	unsigned long long data;
125	acpi_status status;
126
127	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GAI",
128				       NULL, &data);
129	if (ACPI_FAILURE(status)) {
130		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GAI"));
131		return -ENODEV;
132	}
133
134	resource->avg_interval = data;
135	return 0;
136}
137
138static ssize_t show_avg_interval(struct device *dev,
139				 struct device_attribute *devattr,
140				 char *buf)
141{
142	struct acpi_device *acpi_dev = to_acpi_device(dev);
143	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
144
145	mutex_lock(&resource->lock);
146	update_avg_interval(resource);
147	mutex_unlock(&resource->lock);
148
149	return sprintf(buf, "%llu\n", resource->avg_interval);
150}
151
152static ssize_t set_avg_interval(struct device *dev,
153				struct device_attribute *devattr,
154				const char *buf, size_t count)
155{
156	struct acpi_device *acpi_dev = to_acpi_device(dev);
157	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
158	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
159	struct acpi_object_list args = { 1, &arg0 };
160	int res;
161	unsigned long temp;
162	unsigned long long data;
163	acpi_status status;
164
165	res = kstrtoul(buf, 10, &temp);
166	if (res)
167		return res;
168
169	if (temp > resource->caps.max_avg_interval ||
170	    temp < resource->caps.min_avg_interval)
171		return -EINVAL;
172	arg0.integer.value = temp;
173
174	mutex_lock(&resource->lock);
175	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PAI",
176				       &args, &data);
177	if (!ACPI_FAILURE(status))
178		resource->avg_interval = temp;
179	mutex_unlock(&resource->lock);
180
181	if (ACPI_FAILURE(status)) {
182		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PAI"));
183		return -EINVAL;
184	}
185
186	/* _PAI returns 0 on success, nonzero otherwise */
187	if (data)
188		return -EINVAL;
189
190	return count;
191}
192
193/* Cap functions */
194static int update_cap(struct acpi_power_meter_resource *resource)
195{
196	unsigned long long data;
197	acpi_status status;
198
199	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_GHL",
200				       NULL, &data);
201	if (ACPI_FAILURE(status)) {
202		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GHL"));
203		return -ENODEV;
204	}
205
206	resource->cap = data;
207	return 0;
208}
209
210static ssize_t show_cap(struct device *dev,
211			struct device_attribute *devattr,
212			char *buf)
213{
214	struct acpi_device *acpi_dev = to_acpi_device(dev);
215	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
216
217	mutex_lock(&resource->lock);
218	update_cap(resource);
219	mutex_unlock(&resource->lock);
220
221	return sprintf(buf, "%llu\n", resource->cap * 1000);
222}
223
224static ssize_t set_cap(struct device *dev, struct device_attribute *devattr,
225		       const char *buf, size_t count)
226{
227	struct acpi_device *acpi_dev = to_acpi_device(dev);
228	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
229	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
230	struct acpi_object_list args = { 1, &arg0 };
231	int res;
232	unsigned long temp;
233	unsigned long long data;
234	acpi_status status;
235
236	res = kstrtoul(buf, 10, &temp);
237	if (res)
238		return res;
239
240	temp = DIV_ROUND_CLOSEST(temp, 1000);
241	if (temp > resource->caps.max_cap || temp < resource->caps.min_cap)
242		return -EINVAL;
243	arg0.integer.value = temp;
244
245	mutex_lock(&resource->lock);
246	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_SHL",
247				       &args, &data);
248	if (!ACPI_FAILURE(status))
249		resource->cap = temp;
250	mutex_unlock(&resource->lock);
251
252	if (ACPI_FAILURE(status)) {
253		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SHL"));
254		return -EINVAL;
255	}
256
257	/* _SHL returns 0 on success, nonzero otherwise */
258	if (data)
259		return -EINVAL;
260
261	return count;
262}
263
264/* Power meter trip points */
265static int set_acpi_trip(struct acpi_power_meter_resource *resource)
266{
267	union acpi_object arg_objs[] = {
268		{ACPI_TYPE_INTEGER},
269		{ACPI_TYPE_INTEGER}
270	};
271	struct acpi_object_list args = { 2, arg_objs };
272	unsigned long long data;
273	acpi_status status;
274
275	/* Both trip levels must be set */
276	if (resource->trip[0] < 0 || resource->trip[1] < 0)
277		return 0;
278
279	/* This driver stores min, max; ACPI wants max, min. */
280	arg_objs[0].integer.value = resource->trip[1];
281	arg_objs[1].integer.value = resource->trip[0];
282
283	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PTP",
284				       &args, &data);
285	if (ACPI_FAILURE(status)) {
286		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTP"));
287		return -EINVAL;
288	}
289
290	/* _PTP returns 0 on success, nonzero otherwise */
291	if (data)
292		return -EINVAL;
293
294	return 0;
295}
296
297static ssize_t set_trip(struct device *dev, struct device_attribute *devattr,
298			const char *buf, size_t count)
299{
300	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
301	struct acpi_device *acpi_dev = to_acpi_device(dev);
302	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
303	int res;
304	unsigned long temp;
305
306	res = kstrtoul(buf, 10, &temp);
307	if (res)
308		return res;
309
310	temp = DIV_ROUND_CLOSEST(temp, 1000);
311
312	mutex_lock(&resource->lock);
313	resource->trip[attr->index - 7] = temp;
314	res = set_acpi_trip(resource);
315	mutex_unlock(&resource->lock);
316
317	if (res)
318		return res;
319
320	return count;
321}
322
323/* Power meter */
324static int update_meter(struct acpi_power_meter_resource *resource)
325{
326	unsigned long long data;
327	acpi_status status;
328	unsigned long local_jiffies = jiffies;
329
330	if (time_before(local_jiffies, resource->sensors_last_updated +
331			msecs_to_jiffies(resource->caps.sampling_time)) &&
332			resource->sensors_valid)
333		return 0;
334
335	status = acpi_evaluate_integer(resource->acpi_dev->handle, "_PMM",
336				       NULL, &data);
337	if (ACPI_FAILURE(status)) {
338		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMM"));
339		return -ENODEV;
340	}
341
342	resource->power = data;
343	resource->sensors_valid = 1;
344	resource->sensors_last_updated = jiffies;
345	return 0;
346}
347
348static ssize_t show_power(struct device *dev,
349			  struct device_attribute *devattr,
350			  char *buf)
351{
352	struct acpi_device *acpi_dev = to_acpi_device(dev);
353	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
354
355	mutex_lock(&resource->lock);
356	update_meter(resource);
357	mutex_unlock(&resource->lock);
358
359	return sprintf(buf, "%llu\n", resource->power * 1000);
360}
361
362/* Miscellaneous */
363static ssize_t show_str(struct device *dev,
364			struct device_attribute *devattr,
365			char *buf)
366{
367	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
368	struct acpi_device *acpi_dev = to_acpi_device(dev);
369	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
370	acpi_string val;
371
372	switch (attr->index) {
373	case 0:
374		val = resource->model_number;
375		break;
376	case 1:
377		val = resource->serial_number;
378		break;
379	case 2:
380		val = resource->oem_info;
381		break;
382	default:
383		WARN(1, "Implementation error: unexpected attribute index %d\n",
384		     attr->index);
385		val = "";
386		break;
387	}
388
389	return sprintf(buf, "%s\n", val);
390}
391
392static ssize_t show_val(struct device *dev,
393			struct device_attribute *devattr,
394			char *buf)
395{
396	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
397	struct acpi_device *acpi_dev = to_acpi_device(dev);
398	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
399	u64 val = 0;
400
401	switch (attr->index) {
402	case 0:
403		val = resource->caps.min_avg_interval;
404		break;
405	case 1:
406		val = resource->caps.max_avg_interval;
407		break;
408	case 2:
409		val = resource->caps.min_cap * 1000;
410		break;
411	case 3:
412		val = resource->caps.max_cap * 1000;
413		break;
414	case 4:
415		if (resource->caps.hysteresis == UNKNOWN_HYSTERESIS)
416			return sprintf(buf, "unknown\n");
417
418		val = resource->caps.hysteresis * 1000;
419		break;
420	case 5:
421		if (resource->caps.flags & POWER_METER_IS_BATTERY)
422			val = 1;
423		else
424			val = 0;
425		break;
426	case 6:
427		if (resource->power > resource->cap)
428			val = 1;
429		else
430			val = 0;
431		break;
432	case 7:
433	case 8:
434		if (resource->trip[attr->index - 7] < 0)
435			return sprintf(buf, "unknown\n");
436
437		val = resource->trip[attr->index - 7] * 1000;
438		break;
439	default:
440		WARN(1, "Implementation error: unexpected attribute index %d\n",
441		     attr->index);
442		break;
443	}
444
445	return sprintf(buf, "%llu\n", val);
446}
447
448static ssize_t show_accuracy(struct device *dev,
449			     struct device_attribute *devattr,
450			     char *buf)
451{
452	struct acpi_device *acpi_dev = to_acpi_device(dev);
453	struct acpi_power_meter_resource *resource = acpi_dev->driver_data;
454	unsigned int acc = resource->caps.accuracy;
455
456	return sprintf(buf, "%u.%u%%\n", acc / 1000, acc % 1000);
457}
458
459static ssize_t show_name(struct device *dev,
460			 struct device_attribute *devattr,
461			 char *buf)
462{
463	return sprintf(buf, "%s\n", ACPI_POWER_METER_NAME);
464}
465
466#define RO_SENSOR_TEMPLATE(_label, _show, _index)	\
467	{						\
468		.label = _label,			\
469		.show  = _show,				\
470		.index = _index,			\
471	}
472
473#define RW_SENSOR_TEMPLATE(_label, _show, _set, _index)	\
474	{						\
475		.label = _label,			\
476		.show  = _show,				\
477		.set   = _set,				\
478		.index = _index,			\
479	}
480
481/* Sensor descriptions.  If you add a sensor, update NUM_SENSORS above! */
482static struct sensor_template meter_attrs[] = {
483	RO_SENSOR_TEMPLATE(POWER_AVERAGE_NAME, show_power, 0),
484	RO_SENSOR_TEMPLATE("power1_accuracy", show_accuracy, 0),
485	RO_SENSOR_TEMPLATE("power1_average_interval_min", show_val, 0),
486	RO_SENSOR_TEMPLATE("power1_average_interval_max", show_val, 1),
487	RO_SENSOR_TEMPLATE("power1_is_battery", show_val, 5),
488	RW_SENSOR_TEMPLATE(POWER_AVG_INTERVAL_NAME, show_avg_interval,
489		set_avg_interval, 0),
490	{},
491};
492
493static struct sensor_template misc_cap_attrs[] = {
494	RO_SENSOR_TEMPLATE("power1_cap_min", show_val, 2),
495	RO_SENSOR_TEMPLATE("power1_cap_max", show_val, 3),
496	RO_SENSOR_TEMPLATE("power1_cap_hyst", show_val, 4),
497	RO_SENSOR_TEMPLATE(POWER_ALARM_NAME, show_val, 6),
498	{},
499};
500
501static struct sensor_template ro_cap_attrs[] = {
502	RO_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, 0),
503	{},
504};
505
506static struct sensor_template rw_cap_attrs[] = {
507	RW_SENSOR_TEMPLATE(POWER_CAP_NAME, show_cap, set_cap, 0),
508	{},
509};
510
511static struct sensor_template trip_attrs[] = {
512	RW_SENSOR_TEMPLATE("power1_average_min", show_val, set_trip, 7),
513	RW_SENSOR_TEMPLATE("power1_average_max", show_val, set_trip, 8),
514	{},
515};
516
517static struct sensor_template misc_attrs[] = {
518	RO_SENSOR_TEMPLATE("name", show_name, 0),
519	RO_SENSOR_TEMPLATE("power1_model_number", show_str, 0),
520	RO_SENSOR_TEMPLATE("power1_oem_info", show_str, 2),
521	RO_SENSOR_TEMPLATE("power1_serial_number", show_str, 1),
522	{},
523};
524
525#undef RO_SENSOR_TEMPLATE
526#undef RW_SENSOR_TEMPLATE
527
528/* Read power domain data */
529static void remove_domain_devices(struct acpi_power_meter_resource *resource)
530{
531	int i;
532
533	if (!resource->num_domain_devices)
534		return;
535
536	for (i = 0; i < resource->num_domain_devices; i++) {
537		struct acpi_device *obj = resource->domain_devices[i];
538		if (!obj)
539			continue;
540
541		sysfs_remove_link(resource->holders_dir,
542				  kobject_name(&obj->dev.kobj));
543		put_device(&obj->dev);
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_EXCEPTION((AE_INFO, status, "Evaluating _PMD"));
563		return -ENODEV;
564	}
565
566	pss = buffer.pointer;
567	if (!pss ||
568	    pss->type != ACPI_TYPE_PACKAGE) {
569		dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
570			"Invalid _PMD data\n");
571		res = -EFAULT;
572		goto end;
573	}
574
575	if (!pss->package.count)
576		goto end;
577
578	resource->domain_devices = kzalloc(sizeof(struct acpi_device *) *
579					   pss->package.count, GFP_KERNEL);
580	if (!resource->domain_devices) {
581		res = -ENOMEM;
582		goto end;
583	}
584
585	resource->holders_dir = kobject_create_and_add("measures",
586					&resource->acpi_dev->dev.kobj);
587	if (!resource->holders_dir) {
588		res = -ENOMEM;
589		goto exit_free;
590	}
591
592	resource->num_domain_devices = pss->package.count;
593
594	for (i = 0; i < pss->package.count; i++) {
595		struct acpi_device *obj;
596		union acpi_object *element = &(pss->package.elements[i]);
597
598		/* Refuse non-references */
599		if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
600			continue;
601
602		/* Create a symlink to domain objects */
603		resource->domain_devices[i] = NULL;
604		if (acpi_bus_get_device(element->reference.handle,
605					&resource->domain_devices[i]))
606			continue;
607
608		obj = resource->domain_devices[i];
609		get_device(&obj->dev);
610
611		res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
612				      kobject_name(&obj->dev.kobj));
613		if (res) {
614			put_device(&obj->dev);
615			resource->domain_devices[i] = NULL;
616		}
617	}
618
619	res = 0;
620	goto end;
621
622exit_free:
623	kfree(resource->domain_devices);
624end:
625	kfree(buffer.pointer);
626	return res;
627}
628
629/* Registration and deregistration */
630static int register_attrs(struct acpi_power_meter_resource *resource,
631			  struct sensor_template *attrs)
632{
633	struct device *dev = &resource->acpi_dev->dev;
634	struct sensor_device_attribute *sensors =
635		&resource->sensors[resource->num_sensors];
636	int res = 0;
637
638	while (attrs->label) {
639		sensors->dev_attr.attr.name = attrs->label;
640		sensors->dev_attr.attr.mode = S_IRUGO;
641		sensors->dev_attr.show = attrs->show;
642		sensors->index = attrs->index;
643
644		if (attrs->set) {
645			sensors->dev_attr.attr.mode |= S_IWUSR;
646			sensors->dev_attr.store = attrs->set;
647		}
648
649		sysfs_attr_init(&sensors->dev_attr.attr);
650		res = device_create_file(dev, &sensors->dev_attr);
651		if (res) {
652			sensors->dev_attr.attr.name = NULL;
653			goto error;
654		}
655		sensors++;
656		resource->num_sensors++;
657		attrs++;
658	}
659
660error:
661	return res;
662}
663
664static void remove_attrs(struct acpi_power_meter_resource *resource)
665{
666	int i;
667
668	for (i = 0; i < resource->num_sensors; i++) {
669		if (!resource->sensors[i].dev_attr.attr.name)
670			continue;
671		device_remove_file(&resource->acpi_dev->dev,
672				   &resource->sensors[i].dev_attr);
673	}
674
675	remove_domain_devices(resource);
676
677	resource->num_sensors = 0;
678}
679
680static int setup_attrs(struct acpi_power_meter_resource *resource)
681{
682	int res = 0;
683
684	res = read_domain_devices(resource);
685	if (res)
686		return res;
687
688	if (resource->caps.flags & POWER_METER_CAN_MEASURE) {
689		res = register_attrs(resource, meter_attrs);
690		if (res)
691			goto error;
692	}
693
694	if (resource->caps.flags & POWER_METER_CAN_CAP) {
695		if (!can_cap_in_hardware()) {
696			dev_err(&resource->acpi_dev->dev,
697				"Ignoring unsafe software power cap!\n");
698			goto skip_unsafe_cap;
699		}
700
701		if (resource->caps.configurable_cap)
702			res = register_attrs(resource, rw_cap_attrs);
703		else
704			res = register_attrs(resource, ro_cap_attrs);
705
706		if (res)
707			goto error;
708
709		res = register_attrs(resource, misc_cap_attrs);
710		if (res)
711			goto error;
712	}
713
714skip_unsafe_cap:
715	if (resource->caps.flags & POWER_METER_CAN_TRIP) {
716		res = register_attrs(resource, trip_attrs);
717		if (res)
718			goto error;
719	}
720
721	res = register_attrs(resource, misc_attrs);
722	if (res)
723		goto error;
724
725	return res;
726error:
727	remove_attrs(resource);
728	return res;
729}
730
731static void free_capabilities(struct acpi_power_meter_resource *resource)
732{
733	acpi_string *str;
734	int i;
735
736	str = &resource->model_number;
737	for (i = 0; i < 3; i++, str++)
738		kfree(*str);
739}
740
741static int read_capabilities(struct acpi_power_meter_resource *resource)
742{
743	int res = 0;
744	int i;
745	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
746	struct acpi_buffer state = { 0, NULL };
747	struct acpi_buffer format = { sizeof("NNNNNNNNNNN"), "NNNNNNNNNNN" };
748	union acpi_object *pss;
749	acpi_string *str;
750	acpi_status status;
751
752	status = acpi_evaluate_object(resource->acpi_dev->handle, "_PMC", NULL,
753				      &buffer);
754	if (ACPI_FAILURE(status)) {
755		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PMC"));
756		return -ENODEV;
757	}
758
759	pss = buffer.pointer;
760	if (!pss ||
761	    pss->type != ACPI_TYPE_PACKAGE ||
762	    pss->package.count != 14) {
763		dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
764			"Invalid _PMC data\n");
765		res = -EFAULT;
766		goto end;
767	}
768
769	/* Grab all the integer data at once */
770	state.length = sizeof(struct acpi_power_meter_capabilities);
771	state.pointer = &resource->caps;
772
773	status = acpi_extract_package(pss, &format, &state);
774	if (ACPI_FAILURE(status)) {
775		ACPI_EXCEPTION((AE_INFO, status, "Invalid data"));
776		res = -EFAULT;
777		goto end;
778	}
779
780	if (resource->caps.units) {
781		dev_err(&resource->acpi_dev->dev, ACPI_POWER_METER_NAME
782			"Unknown units %llu.\n",
783			resource->caps.units);
784		res = -EINVAL;
785		goto end;
786	}
787
788	/* Grab the string data */
789	str = &resource->model_number;
790
791	for (i = 11; i < 14; i++) {
792		union acpi_object *element = &(pss->package.elements[i]);
793
794		if (element->type != ACPI_TYPE_STRING) {
795			res = -EINVAL;
796			goto error;
797		}
798
799		*str = kzalloc(sizeof(u8) * (element->string.length + 1),
800			       GFP_KERNEL);
801		if (!*str) {
802			res = -ENOMEM;
803			goto error;
804		}
805
806		strncpy(*str, element->string.pointer, element->string.length);
807		str++;
808	}
809
810	dev_info(&resource->acpi_dev->dev, "Found ACPI power meter.\n");
811	goto end;
812error:
813	str = &resource->model_number;
814	for (i = 0; i < 3; i++, str++)
815		kfree(*str);
816end:
817	kfree(buffer.pointer);
818	return res;
819}
820
821/* Handle ACPI event notifications */
822static void acpi_power_meter_notify(struct acpi_device *device, u32 event)
823{
824	struct acpi_power_meter_resource *resource;
825	int res;
826
827	if (!device || !acpi_driver_data(device))
828		return;
829
830	resource = acpi_driver_data(device);
831
832	mutex_lock(&resource->lock);
833	switch (event) {
834	case METER_NOTIFY_CONFIG:
835		free_capabilities(resource);
836		res = read_capabilities(resource);
837		if (res)
838			break;
839
840		remove_attrs(resource);
841		setup_attrs(resource);
842		break;
843	case METER_NOTIFY_TRIP:
844		sysfs_notify(&device->dev.kobj, NULL, POWER_AVERAGE_NAME);
845		update_meter(resource);
846		break;
847	case METER_NOTIFY_CAP:
848		sysfs_notify(&device->dev.kobj, NULL, POWER_CAP_NAME);
849		update_cap(resource);
850		break;
851	case METER_NOTIFY_INTERVAL:
852		sysfs_notify(&device->dev.kobj, NULL, POWER_AVG_INTERVAL_NAME);
853		update_avg_interval(resource);
854		break;
855	case METER_NOTIFY_CAPPING:
856		sysfs_notify(&device->dev.kobj, NULL, POWER_ALARM_NAME);
857		dev_info(&device->dev, "Capping in progress.\n");
858		break;
859	default:
860		WARN(1, "Unexpected event %d\n", event);
861		break;
862	}
863	mutex_unlock(&resource->lock);
864
865	acpi_bus_generate_netlink_event(ACPI_POWER_METER_CLASS,
866					dev_name(&device->dev), event, 0);
867}
868
869static int acpi_power_meter_add(struct acpi_device *device)
870{
871	int res;
872	struct acpi_power_meter_resource *resource;
873
874	if (!device)
875		return -EINVAL;
876
877	resource = kzalloc(sizeof(struct acpi_power_meter_resource),
878			   GFP_KERNEL);
879	if (!resource)
880		return -ENOMEM;
881
882	resource->sensors_valid = 0;
883	resource->acpi_dev = device;
884	mutex_init(&resource->lock);
885	strcpy(acpi_device_name(device), ACPI_POWER_METER_DEVICE_NAME);
886	strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);
887	device->driver_data = resource;
888
889	free_capabilities(resource);
890	res = read_capabilities(resource);
891	if (res)
892		goto exit_free;
893
894	resource->trip[0] = resource->trip[1] = -1;
895
896	res = setup_attrs(resource);
897	if (res)
898		goto exit_free;
899
900	resource->hwmon_dev = hwmon_device_register(&device->dev);
901	if (IS_ERR(resource->hwmon_dev)) {
902		res = PTR_ERR(resource->hwmon_dev);
903		goto exit_remove;
904	}
905
906	res = 0;
907	goto exit;
908
909exit_remove:
910	remove_attrs(resource);
911exit_free:
912	kfree(resource);
913exit:
914	return res;
915}
916
917static int acpi_power_meter_remove(struct acpi_device *device)
918{
919	struct acpi_power_meter_resource *resource;
920
921	if (!device || !acpi_driver_data(device))
922		return -EINVAL;
923
924	resource = acpi_driver_data(device);
925	hwmon_device_unregister(resource->hwmon_dev);
926
927	free_capabilities(resource);
928	remove_attrs(resource);
929
930	kfree(resource);
931	return 0;
932}
933
934#ifdef CONFIG_PM_SLEEP
935
936static int acpi_power_meter_resume(struct device *dev)
937{
938	struct acpi_power_meter_resource *resource;
939
940	if (!dev)
941		return -EINVAL;
942
943	resource = acpi_driver_data(to_acpi_device(dev));
944	if (!resource)
945		return -EINVAL;
946
947	free_capabilities(resource);
948	read_capabilities(resource);
949
950	return 0;
951}
952
953#endif /* CONFIG_PM_SLEEP */
954
955static SIMPLE_DEV_PM_OPS(acpi_power_meter_pm, NULL, acpi_power_meter_resume);
956
957static struct acpi_driver acpi_power_meter_driver = {
958	.name = "power_meter",
959	.class = ACPI_POWER_METER_CLASS,
960	.ids = power_meter_ids,
961	.ops = {
962		.add = acpi_power_meter_add,
963		.remove = acpi_power_meter_remove,
964		.notify = acpi_power_meter_notify,
965		},
966	.drv.pm = &acpi_power_meter_pm,
967};
968
969/* Module init/exit routines */
970static int __init enable_cap_knobs(const struct dmi_system_id *d)
971{
972	cap_in_hardware = 1;
973	return 0;
974}
975
976static struct dmi_system_id __initdata pm_dmi_table[] = {
977	{
978		enable_cap_knobs, "IBM Active Energy Manager",
979		{
980			DMI_MATCH(DMI_SYS_VENDOR, "IBM")
981		},
982	},
983	{}
984};
985
986static int __init acpi_power_meter_init(void)
987{
988	int result;
989
990	if (acpi_disabled)
991		return -ENODEV;
992
993	dmi_check_system(pm_dmi_table);
994
995	result = acpi_bus_register_driver(&acpi_power_meter_driver);
996	if (result < 0)
997		return result;
998
999	return 0;
1000}
1001
1002static void __exit acpi_power_meter_exit(void)
1003{
1004	acpi_bus_unregister_driver(&acpi_power_meter_driver);
1005}
1006
1007MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
1008MODULE_DESCRIPTION("ACPI 4.0 power meter driver");
1009MODULE_LICENSE("GPL");
1010
1011module_param(force_cap_on, bool, 0644);
1012MODULE_PARM_DESC(force_cap_on, "Enable power cap even it is unsafe to do so.");
1013
1014module_init(acpi_power_meter_init);
1015module_exit(acpi_power_meter_exit);
1016