xref: /linux/drivers/acpi/power.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
1 /*
2  *  acpi_power.c - ACPI Bus Power Management ($Revision: 39 $)
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
48 ACPI_MODULE_NAME("acpi_power")
49 #define ACPI_POWER_COMPONENT		0x00800000
50 #define ACPI_POWER_CLASS		"power_resource"
51 #define ACPI_POWER_DRIVER_NAME		"ACPI Power Resource Driver"
52 #define ACPI_POWER_DEVICE_NAME		"Power Resource"
53 #define ACPI_POWER_FILE_INFO		"info"
54 #define ACPI_POWER_FILE_STATUS		"state"
55 #define ACPI_POWER_RESOURCE_STATE_OFF	0x00
56 #define ACPI_POWER_RESOURCE_STATE_ON	0x01
57 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
58 static int acpi_power_add(struct acpi_device *device);
59 static int acpi_power_remove(struct acpi_device *device, int type);
60 static int acpi_power_open_fs(struct inode *inode, struct file *file);
61 
62 static struct acpi_driver acpi_power_driver = {
63 	.name = ACPI_POWER_DRIVER_NAME,
64 	.class = ACPI_POWER_CLASS,
65 	.ids = ACPI_POWER_HID,
66 	.ops = {
67 		.add = acpi_power_add,
68 		.remove = acpi_power_remove,
69 		},
70 };
71 
72 struct acpi_power_resource {
73 	struct acpi_device * device;
74 	acpi_bus_id name;
75 	u32 system_level;
76 	u32 order;
77 	int state;
78 	int references;
79 };
80 
81 static struct list_head acpi_power_resource_list;
82 
83 static struct file_operations acpi_power_fops = {
84 	.open = acpi_power_open_fs,
85 	.read = seq_read,
86 	.llseek = seq_lseek,
87 	.release = single_release,
88 };
89 
90 /* --------------------------------------------------------------------------
91                              Power Resource Management
92    -------------------------------------------------------------------------- */
93 
94 static int
95 acpi_power_get_context(acpi_handle handle,
96 		       struct acpi_power_resource **resource)
97 {
98 	int result = 0;
99 	struct acpi_device *device = NULL;
100 
101 
102 	if (!resource)
103 		return -ENODEV;
104 
105 	result = acpi_bus_get_device(handle, &device);
106 	if (result) {
107 		printk(KERN_WARNING PREFIX "Getting context [%p]\n", handle);
108 		return result;
109 	}
110 
111 	*resource = (struct acpi_power_resource *)acpi_driver_data(device);
112 	if (!resource)
113 		return -ENODEV;
114 
115 	return 0;
116 }
117 
118 static int acpi_power_get_state(struct acpi_power_resource *resource)
119 {
120 	acpi_status status = AE_OK;
121 	unsigned long sta = 0;
122 
123 
124 	if (!resource)
125 		return -EINVAL;
126 
127 	status = acpi_evaluate_integer(resource->device->handle, "_STA", NULL, &sta);
128 	if (ACPI_FAILURE(status))
129 		return -ENODEV;
130 
131 	if (sta & 0x01)
132 		resource->state = ACPI_POWER_RESOURCE_STATE_ON;
133 	else
134 		resource->state = ACPI_POWER_RESOURCE_STATE_OFF;
135 
136 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
137 			  resource->name, resource->state ? "on" : "off"));
138 
139 	return 0;
140 }
141 
142 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
143 {
144 	int result = 0;
145 	struct acpi_power_resource *resource = NULL;
146 	u32 i = 0;
147 
148 
149 	if (!list || !state)
150 		return -EINVAL;
151 
152 	/* The state of the list is 'on' IFF all resources are 'on'. */
153 
154 	for (i = 0; i < list->count; i++) {
155 		result = acpi_power_get_context(list->handles[i], &resource);
156 		if (result)
157 			return result;
158 		result = acpi_power_get_state(resource);
159 		if (result)
160 			return result;
161 
162 		*state = resource->state;
163 
164 		if (*state != ACPI_POWER_RESOURCE_STATE_ON)
165 			break;
166 	}
167 
168 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
169 			  *state ? "on" : "off"));
170 
171 	return result;
172 }
173 
174 static int acpi_power_on(acpi_handle handle)
175 {
176 	int result = 0;
177 	acpi_status status = AE_OK;
178 	struct acpi_device *device = NULL;
179 	struct acpi_power_resource *resource = NULL;
180 
181 
182 	result = acpi_power_get_context(handle, &resource);
183 	if (result)
184 		return result;
185 
186 	resource->references++;
187 
188 	if ((resource->references > 1)
189 	    || (resource->state == ACPI_POWER_RESOURCE_STATE_ON)) {
190 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already on\n",
191 				  resource->name));
192 		return 0;
193 	}
194 
195 	status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
196 	if (ACPI_FAILURE(status))
197 		return -ENODEV;
198 
199 	result = acpi_power_get_state(resource);
200 	if (result)
201 		return result;
202 	if (resource->state != ACPI_POWER_RESOURCE_STATE_ON)
203 		return -ENOEXEC;
204 
205 	/* Update the power resource's _device_ power state */
206 	device = resource->device;
207 	resource->device->power.state = ACPI_STATE_D0;
208 
209 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned on\n",
210 			  resource->name));
211 
212 	return 0;
213 }
214 
215 static int acpi_power_off_device(acpi_handle handle)
216 {
217 	int result = 0;
218 	acpi_status status = AE_OK;
219 	struct acpi_device *device = NULL;
220 	struct acpi_power_resource *resource = NULL;
221 
222 
223 	result = acpi_power_get_context(handle, &resource);
224 	if (result)
225 		return result;
226 
227 	if (resource->references)
228 		resource->references--;
229 
230 	if (resource->references) {
231 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
232 				  "Resource [%s] is still in use, dereferencing\n",
233 				  device->pnp.bus_id));
234 		return 0;
235 	}
236 
237 	if (resource->state == ACPI_POWER_RESOURCE_STATE_OFF) {
238 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already off\n",
239 				  device->pnp.bus_id));
240 		return 0;
241 	}
242 
243 	status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
244 	if (ACPI_FAILURE(status))
245 		return -ENODEV;
246 
247 	result = acpi_power_get_state(resource);
248 	if (result)
249 		return result;
250 	if (resource->state != ACPI_POWER_RESOURCE_STATE_OFF)
251 		return -ENOEXEC;
252 
253 	/* Update the power resource's _device_ power state */
254 	device = resource->device;
255 	device->power.state = ACPI_STATE_D3;
256 
257 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] turned off\n",
258 			  resource->name));
259 
260 	return 0;
261 }
262 
263 /*
264  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
265  * 1. Power on the power resources required for the wakeup device
266  * 2. Enable _PSW (power state wake) for the device if present
267  */
268 int acpi_enable_wakeup_device_power(struct acpi_device *dev)
269 {
270 	union acpi_object arg = { ACPI_TYPE_INTEGER };
271 	struct acpi_object_list arg_list = { 1, &arg };
272 	acpi_status status = AE_OK;
273 	int i;
274 	int ret = 0;
275 
276 	if (!dev || !dev->wakeup.flags.valid)
277 		return -1;
278 
279 	arg.integer.value = 1;
280 	/* Open power resource */
281 	for (i = 0; i < dev->wakeup.resources.count; i++) {
282 		ret = acpi_power_on(dev->wakeup.resources.handles[i]);
283 		if (ret) {
284 			printk(KERN_ERR PREFIX "Transition power state\n");
285 			dev->wakeup.flags.valid = 0;
286 			return -1;
287 		}
288 	}
289 
290 	/* Execute PSW */
291 	status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
292 	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
293 		printk(KERN_ERR PREFIX "Evaluate _PSW\n");
294 		dev->wakeup.flags.valid = 0;
295 		ret = -1;
296 	}
297 
298 	return ret;
299 }
300 
301 /*
302  * Shutdown a wakeup device, counterpart of above method
303  * 1. Disable _PSW (power state wake)
304  * 2. Shutdown down the power resources
305  */
306 int acpi_disable_wakeup_device_power(struct acpi_device *dev)
307 {
308 	union acpi_object arg = { ACPI_TYPE_INTEGER };
309 	struct acpi_object_list arg_list = { 1, &arg };
310 	acpi_status status = AE_OK;
311 	int i;
312 	int ret = 0;
313 
314 
315 	if (!dev || !dev->wakeup.flags.valid)
316 		return -1;
317 
318 	arg.integer.value = 0;
319 	/* Execute PSW */
320 	status = acpi_evaluate_object(dev->handle, "_PSW", &arg_list, NULL);
321 	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
322 		printk(KERN_ERR PREFIX "Evaluate _PSW\n");
323 		dev->wakeup.flags.valid = 0;
324 		return -1;
325 	}
326 
327 	/* Close power resource */
328 	for (i = 0; i < dev->wakeup.resources.count; i++) {
329 		ret = acpi_power_off_device(dev->wakeup.resources.handles[i]);
330 		if (ret) {
331 			printk(KERN_ERR PREFIX "Transition power state\n");
332 			dev->wakeup.flags.valid = 0;
333 			return -1;
334 		}
335 	}
336 
337 	return ret;
338 }
339 
340 /* --------------------------------------------------------------------------
341                              Device Power Management
342    -------------------------------------------------------------------------- */
343 
344 int acpi_power_get_inferred_state(struct acpi_device *device)
345 {
346 	int result = 0;
347 	struct acpi_handle_list *list = NULL;
348 	int list_state = 0;
349 	int i = 0;
350 
351 
352 	if (!device)
353 		return -EINVAL;
354 
355 	device->power.state = ACPI_STATE_UNKNOWN;
356 
357 	/*
358 	 * We know a device's inferred power state when all the resources
359 	 * required for a given D-state are 'on'.
360 	 */
361 	for (i = ACPI_STATE_D0; i < ACPI_STATE_D3; i++) {
362 		list = &device->power.states[i].resources;
363 		if (list->count < 1)
364 			continue;
365 
366 		result = acpi_power_get_list_state(list, &list_state);
367 		if (result)
368 			return result;
369 
370 		if (list_state == ACPI_POWER_RESOURCE_STATE_ON) {
371 			device->power.state = i;
372 			return 0;
373 		}
374 	}
375 
376 	device->power.state = ACPI_STATE_D3;
377 
378 	return 0;
379 }
380 
381 int acpi_power_transition(struct acpi_device *device, int state)
382 {
383 	int result = 0;
384 	struct acpi_handle_list *cl = NULL;	/* Current Resources */
385 	struct acpi_handle_list *tl = NULL;	/* Target Resources */
386 	int i = 0;
387 
388 
389 	if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
390 		return -EINVAL;
391 
392 	if ((device->power.state < ACPI_STATE_D0)
393 	    || (device->power.state > ACPI_STATE_D3))
394 		return -ENODEV;
395 
396 	cl = &device->power.states[device->power.state].resources;
397 	tl = &device->power.states[state].resources;
398 
399 	device->power.state = ACPI_STATE_UNKNOWN;
400 
401 	if (!cl->count && !tl->count) {
402 		result = -ENODEV;
403 		goto end;
404 	}
405 
406 	/* TBD: Resources must be ordered. */
407 
408 	/*
409 	 * First we reference all power resources required in the target list
410 	 * (e.g. so the device doesn't lose power while transitioning).
411 	 */
412 	for (i = 0; i < tl->count; i++) {
413 		result = acpi_power_on(tl->handles[i]);
414 		if (result)
415 			goto end;
416 	}
417 
418 	/*
419 	 * Then we dereference all power resources used in the current list.
420 	 */
421 	for (i = 0; i < cl->count; i++) {
422 		result = acpi_power_off_device(cl->handles[i]);
423 		if (result)
424 			goto end;
425 	}
426 
427 	/* We shouldn't change the state till all above operations succeed */
428 	device->power.state = state;
429       end:
430 	if (result)
431 		printk(KERN_WARNING PREFIX "Transitioning device [%s] to D%d\n",
432 			      device->pnp.bus_id, state);
433 
434 	return result;
435 }
436 
437 /* --------------------------------------------------------------------------
438                               FS Interface (/proc)
439    -------------------------------------------------------------------------- */
440 
441 static struct proc_dir_entry *acpi_power_dir;
442 
443 static int acpi_power_seq_show(struct seq_file *seq, void *offset)
444 {
445 	struct acpi_power_resource *resource = NULL;
446 
447 
448 	resource = (struct acpi_power_resource *)seq->private;
449 
450 	if (!resource)
451 		goto end;
452 
453 	seq_puts(seq, "state:                   ");
454 	switch (resource->state) {
455 	case ACPI_POWER_RESOURCE_STATE_ON:
456 		seq_puts(seq, "on\n");
457 		break;
458 	case ACPI_POWER_RESOURCE_STATE_OFF:
459 		seq_puts(seq, "off\n");
460 		break;
461 	default:
462 		seq_puts(seq, "unknown\n");
463 		break;
464 	}
465 
466 	seq_printf(seq, "system level:            S%d\n"
467 		   "order:                   %d\n"
468 		   "reference count:         %d\n",
469 		   resource->system_level,
470 		   resource->order, resource->references);
471 
472       end:
473 	return 0;
474 }
475 
476 static int acpi_power_open_fs(struct inode *inode, struct file *file)
477 {
478 	return single_open(file, acpi_power_seq_show, PDE(inode)->data);
479 }
480 
481 static int acpi_power_add_fs(struct acpi_device *device)
482 {
483 	struct proc_dir_entry *entry = NULL;
484 
485 
486 	if (!device)
487 		return -EINVAL;
488 
489 	if (!acpi_device_dir(device)) {
490 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
491 						     acpi_power_dir);
492 		if (!acpi_device_dir(device))
493 			return -ENODEV;
494 	}
495 
496 	/* 'status' [R] */
497 	entry = create_proc_entry(ACPI_POWER_FILE_STATUS,
498 				  S_IRUGO, acpi_device_dir(device));
499 	if (!entry)
500 		return -EIO;
501 	else {
502 		entry->proc_fops = &acpi_power_fops;
503 		entry->data = acpi_driver_data(device);
504 	}
505 
506 	return 0;
507 }
508 
509 static int acpi_power_remove_fs(struct acpi_device *device)
510 {
511 
512 	if (acpi_device_dir(device)) {
513 		remove_proc_entry(ACPI_POWER_FILE_STATUS,
514 				  acpi_device_dir(device));
515 		remove_proc_entry(acpi_device_bid(device), acpi_power_dir);
516 		acpi_device_dir(device) = NULL;
517 	}
518 
519 	return 0;
520 }
521 
522 /* --------------------------------------------------------------------------
523                                 Driver Interface
524    -------------------------------------------------------------------------- */
525 
526 static int acpi_power_add(struct acpi_device *device)
527 {
528 	int result = 0;
529 	acpi_status status = AE_OK;
530 	struct acpi_power_resource *resource = NULL;
531 	union acpi_object acpi_object;
532 	struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
533 
534 
535 	if (!device)
536 		return -EINVAL;
537 
538 	resource = kmalloc(sizeof(struct acpi_power_resource), GFP_KERNEL);
539 	if (!resource)
540 		return -ENOMEM;
541 	memset(resource, 0, sizeof(struct acpi_power_resource));
542 
543 	resource->device = device;
544 	strcpy(resource->name, device->pnp.bus_id);
545 	strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
546 	strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
547 	acpi_driver_data(device) = resource;
548 
549 	/* Evalute the object to get the system level and resource order. */
550 	status = acpi_evaluate_object(device->handle, NULL, NULL, &buffer);
551 	if (ACPI_FAILURE(status)) {
552 		result = -ENODEV;
553 		goto end;
554 	}
555 	resource->system_level = acpi_object.power_resource.system_level;
556 	resource->order = acpi_object.power_resource.resource_order;
557 
558 	result = acpi_power_get_state(resource);
559 	if (result)
560 		goto end;
561 
562 	switch (resource->state) {
563 	case ACPI_POWER_RESOURCE_STATE_ON:
564 		device->power.state = ACPI_STATE_D0;
565 		break;
566 	case ACPI_POWER_RESOURCE_STATE_OFF:
567 		device->power.state = ACPI_STATE_D3;
568 		break;
569 	default:
570 		device->power.state = ACPI_STATE_UNKNOWN;
571 		break;
572 	}
573 
574 	result = acpi_power_add_fs(device);
575 	if (result)
576 		goto end;
577 
578 	printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
579 	       acpi_device_bid(device), resource->state ? "on" : "off");
580 
581       end:
582 	if (result)
583 		kfree(resource);
584 
585 	return result;
586 }
587 
588 static int acpi_power_remove(struct acpi_device *device, int type)
589 {
590 	struct acpi_power_resource *resource = NULL;
591 
592 
593 	if (!device || !acpi_driver_data(device))
594 		return -EINVAL;
595 
596 	resource = (struct acpi_power_resource *)acpi_driver_data(device);
597 
598 	acpi_power_remove_fs(device);
599 
600 	kfree(resource);
601 
602 	return 0;
603 }
604 
605 static int __init acpi_power_init(void)
606 {
607 	int result = 0;
608 
609 
610 	if (acpi_disabled)
611 		return 0;
612 
613 	INIT_LIST_HEAD(&acpi_power_resource_list);
614 
615 	acpi_power_dir = proc_mkdir(ACPI_POWER_CLASS, acpi_root_dir);
616 	if (!acpi_power_dir)
617 		return -ENODEV;
618 
619 	result = acpi_bus_register_driver(&acpi_power_driver);
620 	if (result < 0) {
621 		remove_proc_entry(ACPI_POWER_CLASS, acpi_root_dir);
622 		return -ENODEV;
623 	}
624 
625 	return 0;
626 }
627 
628 subsys_initcall(acpi_power_init);
629