1/*
2 *  acpi_power.c - ACPI Bus Power Management ($Revision: 1.1.1.1 $)
3 *
4 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 *
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8 *
9 *  This program is free software; you can redistribute it and/or modify
10 *  it under the terms of the GNU General Public License as published by
11 *  the Free Software Foundation; either version 2 of the License, or (at
12 *  your option) any later version.
13 *
14 *  This program is distributed in the hope that it will be useful, but
15 *  WITHOUT ANY WARRANTY; without even the implied warranty of
16 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 *  General Public License for more details.
18 *
19 *  You should have received a copy of the GNU General Public License along
20 *  with this program; if not, write to the Free Software Foundation, Inc.,
21 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
22 *
23 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
24 */
25
26/*
27 * ACPI power-managed devices may be controlled in two ways:
28 * 1. via "Device Specific (D-State) Control"
29 * 2. via "Power Resource Control".
30 * This module is used to manage devices relying on Power Resource Control.
31 *
32 * An ACPI "power resource object" describes a software controllable power
33 * plane, clock plane, or other resource used by a power managed device.
34 * A device may rely on multiple power resources, and a power resource
35 * may be shared by multiple devices.
36 */
37
38#include <linux/kernel.h>
39#include <linux/module.h>
40#include <linux/init.h>
41#include <linux/types.h>
42#include <linux/proc_fs.h>
43#include <linux/seq_file.h>
44#include <acpi/acpi_bus.h>
45#include <acpi/acpi_drivers.h>
46
47#define _COMPONENT		ACPI_POWER_COMPONENT
48ACPI_MODULE_NAME("power");
49#define ACPI_POWER_COMPONENT		0x00800000
50#define ACPI_POWER_CLASS		"power_resource"
51#define ACPI_POWER_DEVICE_NAME		"Power Resource"
52#define ACPI_POWER_FILE_INFO		"info"
53#define ACPI_POWER_FILE_STATUS		"state"
54#define ACPI_POWER_RESOURCE_STATE_OFF	0x00
55#define ACPI_POWER_RESOURCE_STATE_ON	0x01
56#define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
57static int acpi_power_add(struct acpi_device *device);
58static int acpi_power_remove(struct acpi_device *device, int type);
59static int acpi_power_resume(struct acpi_device *device);
60static int acpi_power_open_fs(struct inode *inode, struct file *file);
61
62static struct acpi_driver acpi_power_driver = {
63	.name = "power",
64	.class = ACPI_POWER_CLASS,
65	.ids = ACPI_POWER_HID,
66	.ops = {
67		.add = acpi_power_add,
68		.remove = acpi_power_remove,
69		.resume = acpi_power_resume,
70		},
71};
72
73struct acpi_power_reference {
74	struct list_head node;
75	struct acpi_device *device;
76};
77
78struct acpi_power_resource {
79	struct acpi_device * device;
80	acpi_bus_id name;
81	u32 system_level;
82	u32 order;
83	int state;
84	struct mutex resource_lock;
85	struct list_head reference;
86};
87
88static struct list_head acpi_power_resource_list;
89
90static const struct file_operations acpi_power_fops = {
91	.open = acpi_power_open_fs,
92	.read = seq_read,
93	.llseek = seq_lseek,
94	.release = single_release,
95};
96
97/* --------------------------------------------------------------------------
98                             Power Resource Management
99   -------------------------------------------------------------------------- */
100
101static int
102acpi_power_get_context(acpi_handle handle,
103		       struct acpi_power_resource **resource)
104{
105	int result = 0;
106	struct acpi_device *device = NULL;
107
108
109	if (!resource)
110		return -ENODEV;
111
112	result = acpi_bus_get_device(handle, &device);
113	if (result) {
114		printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
115		return result;
116	}
117
118	*resource = acpi_driver_data(device);
119	if (!resource)
120		return -ENODEV;
121
122	return 0;
123}
124
125static int acpi_power_get_state(struct acpi_power_resource *resource)
126{
127	acpi_status status = AE_OK;
128	unsigned long sta = 0;
129
130
131	if (!resource)
132		return -EINVAL;
133
134	status = acpi_evaluate_integer(resource->device->handle, "_STA", NULL, &sta);
135	if (ACPI_FAILURE(status))
136		return -ENODEV;
137
138	if (sta & 0x01)
139		resource->state = ACPI_POWER_RESOURCE_STATE_ON;
140	else
141		resource->state = ACPI_POWER_RESOURCE_STATE_OFF;
142
143	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
144			  resource->name, resource->state ? "on" : "off"));
145
146	return 0;
147}
148
149static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
150{
151	int result = 0;
152	struct acpi_power_resource *resource = NULL;
153	u32 i = 0;
154
155
156	if (!list || !state)
157		return -EINVAL;
158
159	/* The state of the list is 'on' IFF all resources are 'on'. */
160
161	for (i = 0; i < list->count; i++) {
162		result = acpi_power_get_context(list->handles[i], &resource);
163		if (result)
164			return result;
165		result = acpi_power_get_state(resource);
166		if (result)
167			return result;
168
169		*state = resource->state;
170
171		if (*state != ACPI_POWER_RESOURCE_STATE_ON)
172			break;
173	}
174
175	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
176			  *state ? "on" : "off"));
177
178	return result;
179}
180
181static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
182{
183	int result = 0;
184	int found = 0;
185	acpi_status status = AE_OK;
186	struct acpi_power_resource *resource = NULL;
187	struct list_head *node, *next;
188	struct acpi_power_reference *ref;
189
190
191	result = acpi_power_get_context(handle, &resource);
192	if (result)
193		return result;
194
195	mutex_lock(&resource->resource_lock);
196	list_for_each_safe(node, next, &resource->reference) {
197		ref = container_of(node, struct acpi_power_reference, node);
198		if (dev->handle == ref->device->handle) {
199			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already referenced by resource [%s]\n",
200				  dev->pnp.bus_id, resource->name));
201			found = 1;
202			break;
203		}
204	}
205
206	if (!found) {
207		ref = kmalloc(sizeof (struct acpi_power_reference),
208		    irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
209		if (!ref) {
210			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "kmalloc() failed\n"));
211			mutex_unlock(&resource->resource_lock);
212			return -ENOMEM;
213		}
214		list_add_tail(&ref->node, &resource->reference);
215		ref->device = dev;
216		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] added to resource [%s] references\n",
217			  dev->pnp.bus_id, resource->name));
218	}
219	mutex_unlock(&resource->resource_lock);
220
221	if (resource->state == ACPI_POWER_RESOURCE_STATE_ON) {
222		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already on\n",
223				  resource->name));
224		return 0;
225	}
226
227	status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
228	if (ACPI_FAILURE(status))
229		return -ENODEV;
230
231	result = acpi_power_get_state(resource);
232	if (result)
233		return result;
234	if (resource->state != ACPI_POWER_RESOURCE_STATE_ON)
235		return -ENOEXEC;
236
237	/* Update the power resource's _device_ power state */
238	resource->device->power.state = ACPI_STATE_D0;
239
240	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
241			  resource->name));
242	return 0;
243}
244
245static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
246{
247	int result = 0;
248	acpi_status status = AE_OK;
249	struct acpi_power_resource *resource = NULL;
250	struct list_head *node, *next;
251	struct acpi_power_reference *ref;
252
253
254	result = acpi_power_get_context(handle, &resource);
255	if (result)
256		return result;
257
258	mutex_lock(&resource->resource_lock);
259	list_for_each_safe(node, next, &resource->reference) {
260		ref = container_of(node, struct acpi_power_reference, node);
261		if (dev->handle == ref->device->handle) {
262			list_del(&ref->node);
263			kfree(ref);
264			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] removed from resource [%s] references\n",
265			    dev->pnp.bus_id, resource->name));
266			break;
267		}
268	}
269
270	if (!list_empty(&resource->reference)) {
271		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Cannot turn resource [%s] off - resource is in use\n",
272		    resource->name));
273		mutex_unlock(&resource->resource_lock);
274		return 0;
275	}
276	mutex_unlock(&resource->resource_lock);
277
278	if (resource->state == ACPI_POWER_RESOURCE_STATE_OFF) {
279		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already off\n",
280				  resource->name));
281		return 0;
282	}
283
284	status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
285	if (ACPI_FAILURE(status))
286		return -ENODEV;
287
288	result = acpi_power_get_state(resource);
289	if (result)
290		return result;
291	if (resource->state != ACPI_POWER_RESOURCE_STATE_OFF)
292		return -ENOEXEC;
293
294	/* Update the power resource's _device_ power state */
295	resource->device->power.state = ACPI_STATE_D3;
296
297	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
298			  resource->name));
299
300	return 0;
301}
302
303/*
304 * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
305 * 1. Power on the power resources required for the wakeup device
306 * 2. Enable _PSW (power state wake) for the device if present
307 */
308int acpi_enable_wakeup_device_power(struct acpi_device *dev)
309{
310	union acpi_object arg = { ACPI_TYPE_INTEGER };
311	struct acpi_object_list arg_list = { 1, &arg };
312	acpi_status status = AE_OK;
313	int i;
314	int ret = 0;
315
316	if (!dev || !dev->wakeup.flags.valid)
317		return -1;
318
319	arg.integer.value = 1;
320	/* Open power resource */
321	for (i = 0; i < dev->wakeup.resources.count; i++) {
322		ret = acpi_power_on(dev->wakeup.resources.handles[i], dev);
323		if (ret) {
324			printk(KERN_ERR PREFIX "Transition power state\n");
325			dev->wakeup.flags.valid = 0;
326			return -1;
327		}
328	}
329
330	/* Execute PSW */
331	status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
332	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
333		printk(KERN_ERR PREFIX "Evaluate _PSW\n");
334		dev->wakeup.flags.valid = 0;
335		ret = -1;
336	}
337
338	return ret;
339}
340
341/*
342 * Shutdown a wakeup device, counterpart of above method
343 * 1. Disable _PSW (power state wake)
344 * 2. Shutdown down the power resources
345 */
346int acpi_disable_wakeup_device_power(struct acpi_device *dev)
347{
348	union acpi_object arg = { ACPI_TYPE_INTEGER };
349	struct acpi_object_list arg_list = { 1, &arg };
350	acpi_status status = AE_OK;
351	int i;
352	int ret = 0;
353
354
355	if (!dev || !dev->wakeup.flags.valid)
356		return -1;
357
358	arg.integer.value = 0;
359	/* Execute PSW */
360	status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
361	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
362		printk(KERN_ERR PREFIX "Evaluate _PSW\n");
363		dev->wakeup.flags.valid = 0;
364		return -1;
365	}
366
367	/* Close power resource */
368	for (i = 0; i < dev->wakeup.resources.count; i++) {
369		ret = acpi_power_off_device(dev->wakeup.resources.handles[i], dev);
370		if (ret) {
371			printk(KERN_ERR PREFIX "Transition power state\n");
372			dev->wakeup.flags.valid = 0;
373			return -1;
374		}
375	}
376
377	return ret;
378}
379
380/* --------------------------------------------------------------------------
381                             Device Power Management
382   -------------------------------------------------------------------------- */
383
384int acpi_power_get_inferred_state(struct acpi_device *device)
385{
386	int result = 0;
387	struct acpi_handle_list *list = NULL;
388	int list_state = 0;
389	int i = 0;
390
391
392	if (!device)
393		return -EINVAL;
394
395	device->power.state = ACPI_STATE_UNKNOWN;
396
397	/*
398	 * We know a device's inferred power state when all the resources
399	 * required for a given D-state are 'on'.
400	 */
401	for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
402		list = &device->power.states[i].resources;
403		if (list->count < 1)
404			continue;
405
406		result = acpi_power_get_list_state(list, &list_state);
407		if (result)
408			return result;
409
410		if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
411			device->power.state = i;
412			return 0;
413		}
414	}
415
416	device->power.state = ACPI_STATE_D3;
417
418	return 0;
419}
420
421int acpi_power_transition(struct acpi_device *device, int state)
422{
423	int result = 0;
424	struct acpi_handle_list *cl = NULL;	/* Current Resources */
425	struct acpi_handle_list *tl = NULL;	/* Target Resources */
426	int i = 0;
427
428
429	if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
430		return -EINVAL;
431
432	if ((device->power.state < ACPI_STATE_D0)
433	    || (device->power.state > ACPI_STATE_D3))
434		return -ENODEV;
435
436	cl = &device->power.states[device->power.state].resources;
437	tl = &device->power.states[state].resources;
438
439	if (!cl->count && !tl->count) {
440		result = -ENODEV;
441		goto end;
442	}
443
444	/* TBD: Resources must be ordered. */
445
446	/*
447	 * First we reference all power resources required in the target list
448	 * (e.g. so the device doesn't lose power while transitioning).
449	 */
450	for (i = 0; i < tl->count; i++) {
451		result = acpi_power_on(tl->handles[i], device);
452		if (result)
453			goto end;
454	}
455
456	if (device->power.state == state) {
457		goto end;
458	}
459
460	/*
461	 * Then we dereference all power resources used in the current list.
462	 */
463	for (i = 0; i < cl->count; i++) {
464		result = acpi_power_off_device(cl->handles[i], device);
465		if (result)
466			goto end;
467	}
468
469     end:
470	if (result) {
471		device->power.state = ACPI_STATE_UNKNOWN;
472		printk(KERN_WARNING PREFIX "Transitioning device [%s] to D%d\n",
473			      device->pnp.bus_id, state);
474	} else {
475	/* We shouldn't change the state till all above operations succeed */
476		device->power.state = state;
477	}
478
479	return result;
480}
481
482/* --------------------------------------------------------------------------
483                              FS Interface (/proc)
484   -------------------------------------------------------------------------- */
485
486static struct proc_dir_entry *acpi_power_dir;
487
488static int acpi_power_seq_show(struct seq_file *seq, void *offset)
489{
490	int count = 0;
491	int result = 0;
492	struct acpi_power_resource *resource = NULL;
493	struct list_head *node, *next;
494	struct acpi_power_reference *ref;
495
496
497	resource = seq->private;
498
499	if (!resource)
500		goto end;
501
502	result = acpi_power_get_state(resource);
503	if (result)
504		goto end;
505
506	seq_puts(seq, "state:                   ");
507	switch (resource->state) {
508	case ACPI_POWER_RESOURCE_STATE_ON:
509		seq_puts(seq, "on\n");
510		break;
511	case ACPI_POWER_RESOURCE_STATE_OFF:
512		seq_puts(seq, "off\n");
513		break;
514	default:
515		seq_puts(seq, "unknown\n");
516		break;
517	}
518
519	mutex_lock(&resource->resource_lock);
520	list_for_each_safe(node, next, &resource->reference) {
521		ref = container_of(node, struct acpi_power_reference, node);
522		count++;
523	}
524	mutex_unlock(&resource->resource_lock);
525
526	seq_printf(seq, "system level:            S%d\n"
527		   "order:                   %d\n"
528		   "reference count:         %d\n",
529		   resource->system_level,
530		   resource->order, count);
531
532      end:
533	return 0;
534}
535
536static int acpi_power_open_fs(struct inode *inode, struct file *file)
537{
538	return single_open(file, acpi_power_seq_show, PDE(inode)->data);
539}
540
541static int acpi_power_add_fs(struct acpi_device *device)
542{
543	struct proc_dir_entry *entry = NULL;
544
545
546	if (!device)
547		return -EINVAL;
548
549	if (!acpi_device_dir(device)) {
550		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
551						     acpi_power_dir);
552		if (!acpi_device_dir(device))
553			return -ENODEV;
554	}
555
556	/* 'status' [R] */
557	entry = create_proc_entry(ACPI_POWER_FILE_STATUS,
558				  S_IRUGO, acpi_device_dir(device));
559	if (!entry)
560		return -EIO;
561	else {
562		entry->proc_fops = &acpi_power_fops;
563		entry->data = acpi_driver_data(device);
564	}
565
566	return 0;
567}
568
569static int acpi_power_remove_fs(struct acpi_device *device)
570{
571
572	if (acpi_device_dir(device)) {
573		remove_proc_entry(ACPI_POWER_FILE_STATUS,
574				  acpi_device_dir(device));
575		remove_proc_entry(acpi_device_bid(device), acpi_power_dir);
576		acpi_device_dir(device) = NULL;
577	}
578
579	return 0;
580}
581
582/* --------------------------------------------------------------------------
583                                Driver Interface
584   -------------------------------------------------------------------------- */
585
586static int acpi_power_add(struct acpi_device *device)
587{
588	int result = 0;
589	acpi_status status = AE_OK;
590	struct acpi_power_resource *resource = NULL;
591	union acpi_object acpi_object;
592	struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
593
594
595	if (!device)
596		return -EINVAL;
597
598	resource = kzalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
599	if (!resource)
600		return -ENOMEM;
601
602	resource->device = device;
603	mutex_init(&resource->resource_lock);
604	INIT_LIST_HEAD(&resource->reference);
605	strcpy(resource->name, device->pnp.bus_id);
606	strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
607	strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
608	acpi_driver_data(device) = resource;
609
610	/* Evalute the object to get the system level and resource order. */
611	status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
612	if (ACPI_FAILURE(status)) {
613		result = -ENODEV;
614		goto end;
615	}
616	resource->system_level = acpi_object.power_resource.system_level;
617	resource->order = acpi_object.power_resource.resource_order;
618
619	result = acpi_power_get_state(resource);
620	if (result)
621		goto end;
622
623	switch (resource->state) {
624	case ACPI_POWER_RESOURCE_STATE_ON:
625		device->power.state = ACPI_STATE_D0;
626		break;
627	case ACPI_POWER_RESOURCE_STATE_OFF:
628		device->power.state = ACPI_STATE_D3;
629		break;
630	default:
631		device->power.state = ACPI_STATE_UNKNOWN;
632		break;
633	}
634
635	result = acpi_power_add_fs(device);
636	if (result)
637		goto end;
638
639	printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
640	       acpi_device_bid(device), resource->state ? "on" : "off");
641
642      end:
643	if (result)
644		kfree(resource);
645
646	return result;
647}
648
649static int acpi_power_remove(struct acpi_device *device, int type)
650{
651	struct acpi_power_resource *resource = NULL;
652	struct list_head *node, *next;
653
654
655	if (!device || !acpi_driver_data(device))
656		return -EINVAL;
657
658	resource = acpi_driver_data(device);
659
660	acpi_power_remove_fs(device);
661
662	mutex_lock(&resource->resource_lock);
663	list_for_each_safe(node, next, &resource->reference) {
664		struct acpi_power_reference *ref = container_of(node, struct acpi_power_reference, node);
665		list_del(&ref->node);
666		kfree(ref);
667	}
668	mutex_unlock(&resource->resource_lock);
669
670	kfree(resource);
671
672	return 0;
673}
674
675static int acpi_power_resume(struct acpi_device *device)
676{
677	int result = 0;
678	struct acpi_power_resource *resource = NULL;
679	struct acpi_power_reference *ref;
680
681	if (!device || !acpi_driver_data(device))
682		return -EINVAL;
683
684	resource = (struct acpi_power_resource *)acpi_driver_data(device);
685
686	result = acpi_power_get_state(resource);
687	if (result)
688		return result;
689
690	mutex_lock(&resource->resource_lock);
691	if ((resource->state == ACPI_POWER_RESOURCE_STATE_OFF) &&
692	    !list_empty(&resource->reference)) {
693		ref = container_of(resource->reference.next, struct acpi_power_reference, node);
694		mutex_unlock(&resource->resource_lock);
695		result = acpi_power_on(device->handle, ref->device);
696		return result;
697	}
698
699	mutex_unlock(&resource->resource_lock);
700	return 0;
701}
702
703static int __init acpi_power_init(void)
704{
705	int result = 0;
706
707
708	if (acpi_disabled)
709		return 0;
710
711	INIT_LIST_HEAD(&acpi_power_resource_list);
712
713	acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir);
714	if (!acpi_power_dir)
715		return -ENODEV;
716
717	result = acpi_bus_register_driver(&acpi_power_driver);
718	if (result < 0) {
719		remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir);
720		return -ENODEV;
721	}
722
723	return 0;
724}
725
726subsys_initcall(acpi_power_init);
727