[go: nahoru, domu]

1/*
2 * drivers/base/power/domain.c - Common code related to device power domains.
3 *
4 * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
5 *
6 * This file is released under the GPLv2.
7 */
8
9#include <linux/kernel.h>
10#include <linux/io.h>
11#include <linux/platform_device.h>
12#include <linux/pm_runtime.h>
13#include <linux/pm_domain.h>
14#include <linux/pm_qos.h>
15#include <linux/slab.h>
16#include <linux/err.h>
17#include <linux/sched.h>
18#include <linux/suspend.h>
19#include <linux/export.h>
20
21#define GENPD_DEV_CALLBACK(genpd, type, callback, dev)		\
22({								\
23	type (*__routine)(struct device *__d); 			\
24	type __ret = (type)0;					\
25								\
26	__routine = genpd->dev_ops.callback; 			\
27	if (__routine) {					\
28		__ret = __routine(dev); 			\
29	}							\
30	__ret;							\
31})
32
33#define GENPD_DEV_TIMED_CALLBACK(genpd, type, callback, dev, field, name)	\
34({										\
35	ktime_t __start = ktime_get();						\
36	type __retval = GENPD_DEV_CALLBACK(genpd, type, callback, dev);		\
37	s64 __elapsed = ktime_to_ns(ktime_sub(ktime_get(), __start));		\
38	struct gpd_timing_data *__td = &dev_gpd_data(dev)->td;			\
39	if (!__retval && __elapsed > __td->field) {				\
40		__td->field = __elapsed;					\
41		dev_dbg(dev, name " latency exceeded, new value %lld ns\n",	\
42			__elapsed);						\
43		genpd->max_off_time_changed = true;				\
44		__td->constraint_changed = true;				\
45	}									\
46	__retval;								\
47})
48
49static LIST_HEAD(gpd_list);
50static DEFINE_MUTEX(gpd_list_lock);
51
52static struct generic_pm_domain *pm_genpd_lookup_name(const char *domain_name)
53{
54	struct generic_pm_domain *genpd = NULL, *gpd;
55
56	if (IS_ERR_OR_NULL(domain_name))
57		return NULL;
58
59	mutex_lock(&gpd_list_lock);
60	list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
61		if (!strcmp(gpd->name, domain_name)) {
62			genpd = gpd;
63			break;
64		}
65	}
66	mutex_unlock(&gpd_list_lock);
67	return genpd;
68}
69
70struct generic_pm_domain *dev_to_genpd(struct device *dev)
71{
72	if (IS_ERR_OR_NULL(dev->pm_domain))
73		return ERR_PTR(-EINVAL);
74
75	return pd_to_genpd(dev->pm_domain);
76}
77
78static int genpd_stop_dev(struct generic_pm_domain *genpd, struct device *dev)
79{
80	return GENPD_DEV_TIMED_CALLBACK(genpd, int, stop, dev,
81					stop_latency_ns, "stop");
82}
83
84static int genpd_start_dev(struct generic_pm_domain *genpd, struct device *dev)
85{
86	return GENPD_DEV_TIMED_CALLBACK(genpd, int, start, dev,
87					start_latency_ns, "start");
88}
89
90static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd)
91{
92	bool ret = false;
93
94	if (!WARN_ON(atomic_read(&genpd->sd_count) == 0))
95		ret = !!atomic_dec_and_test(&genpd->sd_count);
96
97	return ret;
98}
99
100static void genpd_sd_counter_inc(struct generic_pm_domain *genpd)
101{
102	atomic_inc(&genpd->sd_count);
103	smp_mb__after_atomic();
104}
105
106static void genpd_acquire_lock(struct generic_pm_domain *genpd)
107{
108	DEFINE_WAIT(wait);
109
110	mutex_lock(&genpd->lock);
111	/*
112	 * Wait for the domain to transition into either the active,
113	 * or the power off state.
114	 */
115	for (;;) {
116		prepare_to_wait(&genpd->status_wait_queue, &wait,
117				TASK_UNINTERRUPTIBLE);
118		if (genpd->status == GPD_STATE_ACTIVE
119		    || genpd->status == GPD_STATE_POWER_OFF)
120			break;
121		mutex_unlock(&genpd->lock);
122
123		schedule();
124
125		mutex_lock(&genpd->lock);
126	}
127	finish_wait(&genpd->status_wait_queue, &wait);
128}
129
130static void genpd_release_lock(struct generic_pm_domain *genpd)
131{
132	mutex_unlock(&genpd->lock);
133}
134
135static void genpd_set_active(struct generic_pm_domain *genpd)
136{
137	if (genpd->resume_count == 0)
138		genpd->status = GPD_STATE_ACTIVE;
139}
140
141static void genpd_recalc_cpu_exit_latency(struct generic_pm_domain *genpd)
142{
143	s64 usecs64;
144
145	if (!genpd->cpuidle_data)
146		return;
147
148	usecs64 = genpd->power_on_latency_ns;
149	do_div(usecs64, NSEC_PER_USEC);
150	usecs64 += genpd->cpuidle_data->saved_exit_latency;
151	genpd->cpuidle_data->idle_state->exit_latency = usecs64;
152}
153
154/**
155 * __pm_genpd_poweron - Restore power to a given PM domain and its masters.
156 * @genpd: PM domain to power up.
157 *
158 * Restore power to @genpd and all of its masters so that it is possible to
159 * resume a device belonging to it.
160 */
161static int __pm_genpd_poweron(struct generic_pm_domain *genpd)
162	__releases(&genpd->lock) __acquires(&genpd->lock)
163{
164	struct gpd_link *link;
165	DEFINE_WAIT(wait);
166	int ret = 0;
167
168	/* If the domain's master is being waited for, we have to wait too. */
169	for (;;) {
170		prepare_to_wait(&genpd->status_wait_queue, &wait,
171				TASK_UNINTERRUPTIBLE);
172		if (genpd->status != GPD_STATE_WAIT_MASTER)
173			break;
174		mutex_unlock(&genpd->lock);
175
176		schedule();
177
178		mutex_lock(&genpd->lock);
179	}
180	finish_wait(&genpd->status_wait_queue, &wait);
181
182	if (genpd->status == GPD_STATE_ACTIVE
183	    || (genpd->prepared_count > 0 && genpd->suspend_power_off))
184		return 0;
185
186	if (genpd->status != GPD_STATE_POWER_OFF) {
187		genpd_set_active(genpd);
188		return 0;
189	}
190
191	if (genpd->cpuidle_data) {
192		cpuidle_pause_and_lock();
193		genpd->cpuidle_data->idle_state->disabled = true;
194		cpuidle_resume_and_unlock();
195		goto out;
196	}
197
198	/*
199	 * The list is guaranteed not to change while the loop below is being
200	 * executed, unless one of the masters' .power_on() callbacks fiddles
201	 * with it.
202	 */
203	list_for_each_entry(link, &genpd->slave_links, slave_node) {
204		genpd_sd_counter_inc(link->master);
205		genpd->status = GPD_STATE_WAIT_MASTER;
206
207		mutex_unlock(&genpd->lock);
208
209		ret = pm_genpd_poweron(link->master);
210
211		mutex_lock(&genpd->lock);
212
213		/*
214		 * The "wait for parent" status is guaranteed not to change
215		 * while the master is powering on.
216		 */
217		genpd->status = GPD_STATE_POWER_OFF;
218		wake_up_all(&genpd->status_wait_queue);
219		if (ret) {
220			genpd_sd_counter_dec(link->master);
221			goto err;
222		}
223	}
224
225	if (genpd->power_on) {
226		ktime_t time_start = ktime_get();
227		s64 elapsed_ns;
228
229		ret = genpd->power_on(genpd);
230		if (ret)
231			goto err;
232
233		elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
234		if (elapsed_ns > genpd->power_on_latency_ns) {
235			genpd->power_on_latency_ns = elapsed_ns;
236			genpd->max_off_time_changed = true;
237			genpd_recalc_cpu_exit_latency(genpd);
238			if (genpd->name)
239				pr_warning("%s: Power-on latency exceeded, "
240					"new value %lld ns\n", genpd->name,
241					elapsed_ns);
242		}
243	}
244
245 out:
246	genpd_set_active(genpd);
247
248	return 0;
249
250 err:
251	list_for_each_entry_continue_reverse(link, &genpd->slave_links, slave_node)
252		genpd_sd_counter_dec(link->master);
253
254	return ret;
255}
256
257/**
258 * pm_genpd_poweron - Restore power to a given PM domain and its masters.
259 * @genpd: PM domain to power up.
260 */
261int pm_genpd_poweron(struct generic_pm_domain *genpd)
262{
263	int ret;
264
265	mutex_lock(&genpd->lock);
266	ret = __pm_genpd_poweron(genpd);
267	mutex_unlock(&genpd->lock);
268	return ret;
269}
270
271/**
272 * pm_genpd_name_poweron - Restore power to a given PM domain and its masters.
273 * @domain_name: Name of the PM domain to power up.
274 */
275int pm_genpd_name_poweron(const char *domain_name)
276{
277	struct generic_pm_domain *genpd;
278
279	genpd = pm_genpd_lookup_name(domain_name);
280	return genpd ? pm_genpd_poweron(genpd) : -EINVAL;
281}
282
283#ifdef CONFIG_PM_RUNTIME
284
285static int genpd_start_dev_no_timing(struct generic_pm_domain *genpd,
286				     struct device *dev)
287{
288	return GENPD_DEV_CALLBACK(genpd, int, start, dev);
289}
290
291static int genpd_save_dev(struct generic_pm_domain *genpd, struct device *dev)
292{
293	return GENPD_DEV_TIMED_CALLBACK(genpd, int, save_state, dev,
294					save_state_latency_ns, "state save");
295}
296
297static int genpd_restore_dev(struct generic_pm_domain *genpd, struct device *dev)
298{
299	return GENPD_DEV_TIMED_CALLBACK(genpd, int, restore_state, dev,
300					restore_state_latency_ns,
301					"state restore");
302}
303
304static int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
305				     unsigned long val, void *ptr)
306{
307	struct generic_pm_domain_data *gpd_data;
308	struct device *dev;
309
310	gpd_data = container_of(nb, struct generic_pm_domain_data, nb);
311
312	mutex_lock(&gpd_data->lock);
313	dev = gpd_data->base.dev;
314	if (!dev) {
315		mutex_unlock(&gpd_data->lock);
316		return NOTIFY_DONE;
317	}
318	mutex_unlock(&gpd_data->lock);
319
320	for (;;) {
321		struct generic_pm_domain *genpd;
322		struct pm_domain_data *pdd;
323
324		spin_lock_irq(&dev->power.lock);
325
326		pdd = dev->power.subsys_data ?
327				dev->power.subsys_data->domain_data : NULL;
328		if (pdd && pdd->dev) {
329			to_gpd_data(pdd)->td.constraint_changed = true;
330			genpd = dev_to_genpd(dev);
331		} else {
332			genpd = ERR_PTR(-ENODATA);
333		}
334
335		spin_unlock_irq(&dev->power.lock);
336
337		if (!IS_ERR(genpd)) {
338			mutex_lock(&genpd->lock);
339			genpd->max_off_time_changed = true;
340			mutex_unlock(&genpd->lock);
341		}
342
343		dev = dev->parent;
344		if (!dev || dev->power.ignore_children)
345			break;
346	}
347
348	return NOTIFY_DONE;
349}
350
351/**
352 * __pm_genpd_save_device - Save the pre-suspend state of a device.
353 * @pdd: Domain data of the device to save the state of.
354 * @genpd: PM domain the device belongs to.
355 */
356static int __pm_genpd_save_device(struct pm_domain_data *pdd,
357				  struct generic_pm_domain *genpd)
358	__releases(&genpd->lock) __acquires(&genpd->lock)
359{
360	struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
361	struct device *dev = pdd->dev;
362	int ret = 0;
363
364	if (gpd_data->need_restore > 0)
365		return 0;
366
367	/*
368	 * If the value of the need_restore flag is still unknown at this point,
369	 * we trust that pm_genpd_poweroff() has verified that the device is
370	 * already runtime PM suspended.
371	 */
372	if (gpd_data->need_restore < 0) {
373		gpd_data->need_restore = 1;
374		return 0;
375	}
376
377	mutex_unlock(&genpd->lock);
378
379	genpd_start_dev(genpd, dev);
380	ret = genpd_save_dev(genpd, dev);
381	genpd_stop_dev(genpd, dev);
382
383	mutex_lock(&genpd->lock);
384
385	if (!ret)
386		gpd_data->need_restore = 1;
387
388	return ret;
389}
390
391/**
392 * __pm_genpd_restore_device - Restore the pre-suspend state of a device.
393 * @pdd: Domain data of the device to restore the state of.
394 * @genpd: PM domain the device belongs to.
395 */
396static void __pm_genpd_restore_device(struct pm_domain_data *pdd,
397				      struct generic_pm_domain *genpd)
398	__releases(&genpd->lock) __acquires(&genpd->lock)
399{
400	struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
401	struct device *dev = pdd->dev;
402	int need_restore = gpd_data->need_restore;
403
404	gpd_data->need_restore = 0;
405	mutex_unlock(&genpd->lock);
406
407	genpd_start_dev(genpd, dev);
408
409	/*
410	 * Call genpd_restore_dev() for recently added devices too (need_restore
411	 * is negative then).
412	 */
413	if (need_restore)
414		genpd_restore_dev(genpd, dev);
415
416	mutex_lock(&genpd->lock);
417}
418
419/**
420 * genpd_abort_poweroff - Check if a PM domain power off should be aborted.
421 * @genpd: PM domain to check.
422 *
423 * Return true if a PM domain's status changed to GPD_STATE_ACTIVE during
424 * a "power off" operation, which means that a "power on" has occured in the
425 * meantime, or if its resume_count field is different from zero, which means
426 * that one of its devices has been resumed in the meantime.
427 */
428static bool genpd_abort_poweroff(struct generic_pm_domain *genpd)
429{
430	return genpd->status == GPD_STATE_WAIT_MASTER
431		|| genpd->status == GPD_STATE_ACTIVE || genpd->resume_count > 0;
432}
433
434/**
435 * genpd_queue_power_off_work - Queue up the execution of pm_genpd_poweroff().
436 * @genpd: PM domait to power off.
437 *
438 * Queue up the execution of pm_genpd_poweroff() unless it's already been done
439 * before.
440 */
441static void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
442{
443	queue_work(pm_wq, &genpd->power_off_work);
444}
445
446/**
447 * pm_genpd_poweroff - Remove power from a given PM domain.
448 * @genpd: PM domain to power down.
449 *
450 * If all of the @genpd's devices have been suspended and all of its subdomains
451 * have been powered down, run the runtime suspend callbacks provided by all of
452 * the @genpd's devices' drivers and remove power from @genpd.
453 */
454static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
455	__releases(&genpd->lock) __acquires(&genpd->lock)
456{
457	struct pm_domain_data *pdd;
458	struct gpd_link *link;
459	unsigned int not_suspended;
460	int ret = 0;
461
462 start:
463	/*
464	 * Do not try to power off the domain in the following situations:
465	 * (1) The domain is already in the "power off" state.
466	 * (2) The domain is waiting for its master to power up.
467	 * (3) One of the domain's devices is being resumed right now.
468	 * (4) System suspend is in progress.
469	 */
470	if (genpd->status == GPD_STATE_POWER_OFF
471	    || genpd->status == GPD_STATE_WAIT_MASTER
472	    || genpd->resume_count > 0 || genpd->prepared_count > 0)
473		return 0;
474
475	if (atomic_read(&genpd->sd_count) > 0)
476		return -EBUSY;
477
478	not_suspended = 0;
479	list_for_each_entry(pdd, &genpd->dev_list, list_node) {
480		enum pm_qos_flags_status stat;
481
482		stat = dev_pm_qos_flags(pdd->dev,
483					PM_QOS_FLAG_NO_POWER_OFF
484						| PM_QOS_FLAG_REMOTE_WAKEUP);
485		if (stat > PM_QOS_FLAGS_NONE)
486			return -EBUSY;
487
488		if (pdd->dev->driver && (!pm_runtime_suspended(pdd->dev)
489		    || pdd->dev->power.irq_safe))
490			not_suspended++;
491	}
492
493	if (not_suspended > genpd->in_progress)
494		return -EBUSY;
495
496	if (genpd->poweroff_task) {
497		/*
498		 * Another instance of pm_genpd_poweroff() is executing
499		 * callbacks, so tell it to start over and return.
500		 */
501		genpd->status = GPD_STATE_REPEAT;
502		return 0;
503	}
504
505	if (genpd->gov && genpd->gov->power_down_ok) {
506		if (!genpd->gov->power_down_ok(&genpd->domain))
507			return -EAGAIN;
508	}
509
510	genpd->status = GPD_STATE_BUSY;
511	genpd->poweroff_task = current;
512
513	list_for_each_entry_reverse(pdd, &genpd->dev_list, list_node) {
514		ret = atomic_read(&genpd->sd_count) == 0 ?
515			__pm_genpd_save_device(pdd, genpd) : -EBUSY;
516
517		if (genpd_abort_poweroff(genpd))
518			goto out;
519
520		if (ret) {
521			genpd_set_active(genpd);
522			goto out;
523		}
524
525		if (genpd->status == GPD_STATE_REPEAT) {
526			genpd->poweroff_task = NULL;
527			goto start;
528		}
529	}
530
531	if (genpd->cpuidle_data) {
532		/*
533		 * If cpuidle_data is set, cpuidle should turn the domain off
534		 * when the CPU in it is idle.  In that case we don't decrement
535		 * the subdomain counts of the master domains, so that power is
536		 * not removed from the current domain prematurely as a result
537		 * of cutting off the masters' power.
538		 */
539		genpd->status = GPD_STATE_POWER_OFF;
540		cpuidle_pause_and_lock();
541		genpd->cpuidle_data->idle_state->disabled = false;
542		cpuidle_resume_and_unlock();
543		goto out;
544	}
545
546	if (genpd->power_off) {
547		ktime_t time_start;
548		s64 elapsed_ns;
549
550		if (atomic_read(&genpd->sd_count) > 0) {
551			ret = -EBUSY;
552			goto out;
553		}
554
555		time_start = ktime_get();
556
557		/*
558		 * If sd_count > 0 at this point, one of the subdomains hasn't
559		 * managed to call pm_genpd_poweron() for the master yet after
560		 * incrementing it.  In that case pm_genpd_poweron() will wait
561		 * for us to drop the lock, so we can call .power_off() and let
562		 * the pm_genpd_poweron() restore power for us (this shouldn't
563		 * happen very often).
564		 */
565		ret = genpd->power_off(genpd);
566		if (ret == -EBUSY) {
567			genpd_set_active(genpd);
568			goto out;
569		}
570
571		elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
572		if (elapsed_ns > genpd->power_off_latency_ns) {
573			genpd->power_off_latency_ns = elapsed_ns;
574			genpd->max_off_time_changed = true;
575			if (genpd->name)
576				pr_warning("%s: Power-off latency exceeded, "
577					"new value %lld ns\n", genpd->name,
578					elapsed_ns);
579		}
580	}
581
582	genpd->status = GPD_STATE_POWER_OFF;
583
584	list_for_each_entry(link, &genpd->slave_links, slave_node) {
585		genpd_sd_counter_dec(link->master);
586		genpd_queue_power_off_work(link->master);
587	}
588
589 out:
590	genpd->poweroff_task = NULL;
591	wake_up_all(&genpd->status_wait_queue);
592	return ret;
593}
594
595/**
596 * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0.
597 * @work: Work structure used for scheduling the execution of this function.
598 */
599static void genpd_power_off_work_fn(struct work_struct *work)
600{
601	struct generic_pm_domain *genpd;
602
603	genpd = container_of(work, struct generic_pm_domain, power_off_work);
604
605	genpd_acquire_lock(genpd);
606	pm_genpd_poweroff(genpd);
607	genpd_release_lock(genpd);
608}
609
610/**
611 * pm_genpd_runtime_suspend - Suspend a device belonging to I/O PM domain.
612 * @dev: Device to suspend.
613 *
614 * Carry out a runtime suspend of a device under the assumption that its
615 * pm_domain field points to the domain member of an object of type
616 * struct generic_pm_domain representing a PM domain consisting of I/O devices.
617 */
618static int pm_genpd_runtime_suspend(struct device *dev)
619{
620	struct generic_pm_domain *genpd;
621	struct generic_pm_domain_data *gpd_data;
622	bool (*stop_ok)(struct device *__dev);
623	int ret;
624
625	dev_dbg(dev, "%s()\n", __func__);
626
627	genpd = dev_to_genpd(dev);
628	if (IS_ERR(genpd))
629		return -EINVAL;
630
631	stop_ok = genpd->gov ? genpd->gov->stop_ok : NULL;
632	if (stop_ok && !stop_ok(dev))
633		return -EBUSY;
634
635	ret = genpd_stop_dev(genpd, dev);
636	if (ret)
637		return ret;
638
639	/*
640	 * If power.irq_safe is set, this routine will be run with interrupts
641	 * off, so it can't use mutexes.
642	 */
643	if (dev->power.irq_safe)
644		return 0;
645
646	mutex_lock(&genpd->lock);
647
648	/*
649	 * If we have an unknown state of the need_restore flag, it means none
650	 * of the runtime PM callbacks has been invoked yet. Let's update the
651	 * flag to reflect that the current state is active.
652	 */
653	gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
654	if (gpd_data->need_restore < 0)
655		gpd_data->need_restore = 0;
656
657	genpd->in_progress++;
658	pm_genpd_poweroff(genpd);
659	genpd->in_progress--;
660	mutex_unlock(&genpd->lock);
661
662	return 0;
663}
664
665/**
666 * pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain.
667 * @dev: Device to resume.
668 *
669 * Carry out a runtime resume of a device under the assumption that its
670 * pm_domain field points to the domain member of an object of type
671 * struct generic_pm_domain representing a PM domain consisting of I/O devices.
672 */
673static int pm_genpd_runtime_resume(struct device *dev)
674{
675	struct generic_pm_domain *genpd;
676	DEFINE_WAIT(wait);
677	int ret;
678
679	dev_dbg(dev, "%s()\n", __func__);
680
681	genpd = dev_to_genpd(dev);
682	if (IS_ERR(genpd))
683		return -EINVAL;
684
685	/* If power.irq_safe, the PM domain is never powered off. */
686	if (dev->power.irq_safe)
687		return genpd_start_dev_no_timing(genpd, dev);
688
689	mutex_lock(&genpd->lock);
690	ret = __pm_genpd_poweron(genpd);
691	if (ret) {
692		mutex_unlock(&genpd->lock);
693		return ret;
694	}
695	genpd->status = GPD_STATE_BUSY;
696	genpd->resume_count++;
697	for (;;) {
698		prepare_to_wait(&genpd->status_wait_queue, &wait,
699				TASK_UNINTERRUPTIBLE);
700		/*
701		 * If current is the powering off task, we have been called
702		 * reentrantly from one of the device callbacks, so we should
703		 * not wait.
704		 */
705		if (!genpd->poweroff_task || genpd->poweroff_task == current)
706			break;
707		mutex_unlock(&genpd->lock);
708
709		schedule();
710
711		mutex_lock(&genpd->lock);
712	}
713	finish_wait(&genpd->status_wait_queue, &wait);
714	__pm_genpd_restore_device(dev->power.subsys_data->domain_data, genpd);
715	genpd->resume_count--;
716	genpd_set_active(genpd);
717	wake_up_all(&genpd->status_wait_queue);
718	mutex_unlock(&genpd->lock);
719
720	return 0;
721}
722
723static bool pd_ignore_unused;
724static int __init pd_ignore_unused_setup(char *__unused)
725{
726	pd_ignore_unused = true;
727	return 1;
728}
729__setup("pd_ignore_unused", pd_ignore_unused_setup);
730
731/**
732 * pm_genpd_poweroff_unused - Power off all PM domains with no devices in use.
733 */
734void pm_genpd_poweroff_unused(void)
735{
736	struct generic_pm_domain *genpd;
737
738	if (pd_ignore_unused) {
739		pr_warn("genpd: Not disabling unused power domains\n");
740		return;
741	}
742
743	mutex_lock(&gpd_list_lock);
744
745	list_for_each_entry(genpd, &gpd_list, gpd_list_node)
746		genpd_queue_power_off_work(genpd);
747
748	mutex_unlock(&gpd_list_lock);
749}
750
751static int __init genpd_poweroff_unused(void)
752{
753	pm_genpd_poweroff_unused();
754	return 0;
755}
756late_initcall(genpd_poweroff_unused);
757
758#else
759
760static inline int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
761					    unsigned long val, void *ptr)
762{
763	return NOTIFY_DONE;
764}
765
766static inline void
767genpd_queue_power_off_work(struct generic_pm_domain *genpd) {}
768
769static inline void genpd_power_off_work_fn(struct work_struct *work) {}
770
771#define pm_genpd_runtime_suspend	NULL
772#define pm_genpd_runtime_resume		NULL
773
774#endif /* CONFIG_PM_RUNTIME */
775
776#ifdef CONFIG_PM_SLEEP
777
778/**
779 * pm_genpd_present - Check if the given PM domain has been initialized.
780 * @genpd: PM domain to check.
781 */
782static bool pm_genpd_present(struct generic_pm_domain *genpd)
783{
784	struct generic_pm_domain *gpd;
785
786	if (IS_ERR_OR_NULL(genpd))
787		return false;
788
789	list_for_each_entry(gpd, &gpd_list, gpd_list_node)
790		if (gpd == genpd)
791			return true;
792
793	return false;
794}
795
796static bool genpd_dev_active_wakeup(struct generic_pm_domain *genpd,
797				    struct device *dev)
798{
799	return GENPD_DEV_CALLBACK(genpd, bool, active_wakeup, dev);
800}
801
802/**
803 * pm_genpd_sync_poweroff - Synchronously power off a PM domain and its masters.
804 * @genpd: PM domain to power off, if possible.
805 *
806 * Check if the given PM domain can be powered off (during system suspend or
807 * hibernation) and do that if so.  Also, in that case propagate to its masters.
808 *
809 * This function is only called in "noirq" and "syscore" stages of system power
810 * transitions, so it need not acquire locks (all of the "noirq" callbacks are
811 * executed sequentially, so it is guaranteed that it will never run twice in
812 * parallel).
813 */
814static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd)
815{
816	struct gpd_link *link;
817
818	if (genpd->status == GPD_STATE_POWER_OFF)
819		return;
820
821	if (genpd->suspended_count != genpd->device_count
822	    || atomic_read(&genpd->sd_count) > 0)
823		return;
824
825	if (genpd->power_off)
826		genpd->power_off(genpd);
827
828	genpd->status = GPD_STATE_POWER_OFF;
829
830	list_for_each_entry(link, &genpd->slave_links, slave_node) {
831		genpd_sd_counter_dec(link->master);
832		pm_genpd_sync_poweroff(link->master);
833	}
834}
835
836/**
837 * pm_genpd_sync_poweron - Synchronously power on a PM domain and its masters.
838 * @genpd: PM domain to power on.
839 *
840 * This function is only called in "noirq" and "syscore" stages of system power
841 * transitions, so it need not acquire locks (all of the "noirq" callbacks are
842 * executed sequentially, so it is guaranteed that it will never run twice in
843 * parallel).
844 */
845static void pm_genpd_sync_poweron(struct generic_pm_domain *genpd)
846{
847	struct gpd_link *link;
848
849	if (genpd->status != GPD_STATE_POWER_OFF)
850		return;
851
852	list_for_each_entry(link, &genpd->slave_links, slave_node) {
853		pm_genpd_sync_poweron(link->master);
854		genpd_sd_counter_inc(link->master);
855	}
856
857	if (genpd->power_on)
858		genpd->power_on(genpd);
859
860	genpd->status = GPD_STATE_ACTIVE;
861}
862
863/**
864 * resume_needed - Check whether to resume a device before system suspend.
865 * @dev: Device to check.
866 * @genpd: PM domain the device belongs to.
867 *
868 * There are two cases in which a device that can wake up the system from sleep
869 * states should be resumed by pm_genpd_prepare(): (1) if the device is enabled
870 * to wake up the system and it has to remain active for this purpose while the
871 * system is in the sleep state and (2) if the device is not enabled to wake up
872 * the system from sleep states and it generally doesn't generate wakeup signals
873 * by itself (those signals are generated on its behalf by other parts of the
874 * system).  In the latter case it may be necessary to reconfigure the device's
875 * wakeup settings during system suspend, because it may have been set up to
876 * signal remote wakeup from the system's working state as needed by runtime PM.
877 * Return 'true' in either of the above cases.
878 */
879static bool resume_needed(struct device *dev, struct generic_pm_domain *genpd)
880{
881	bool active_wakeup;
882
883	if (!device_can_wakeup(dev))
884		return false;
885
886	active_wakeup = genpd_dev_active_wakeup(genpd, dev);
887	return device_may_wakeup(dev) ? active_wakeup : !active_wakeup;
888}
889
890/**
891 * pm_genpd_prepare - Start power transition of a device in a PM domain.
892 * @dev: Device to start the transition of.
893 *
894 * Start a power transition of a device (during a system-wide power transition)
895 * under the assumption that its pm_domain field points to the domain member of
896 * an object of type struct generic_pm_domain representing a PM domain
897 * consisting of I/O devices.
898 */
899static int pm_genpd_prepare(struct device *dev)
900{
901	struct generic_pm_domain *genpd;
902	int ret;
903
904	dev_dbg(dev, "%s()\n", __func__);
905
906	genpd = dev_to_genpd(dev);
907	if (IS_ERR(genpd))
908		return -EINVAL;
909
910	/*
911	 * If a wakeup request is pending for the device, it should be woken up
912	 * at this point and a system wakeup event should be reported if it's
913	 * set up to wake up the system from sleep states.
914	 */
915	pm_runtime_get_noresume(dev);
916	if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
917		pm_wakeup_event(dev, 0);
918
919	if (pm_wakeup_pending()) {
920		pm_runtime_put(dev);
921		return -EBUSY;
922	}
923
924	if (resume_needed(dev, genpd))
925		pm_runtime_resume(dev);
926
927	genpd_acquire_lock(genpd);
928
929	if (genpd->prepared_count++ == 0) {
930		genpd->suspended_count = 0;
931		genpd->suspend_power_off = genpd->status == GPD_STATE_POWER_OFF;
932	}
933
934	genpd_release_lock(genpd);
935
936	if (genpd->suspend_power_off) {
937		pm_runtime_put_noidle(dev);
938		return 0;
939	}
940
941	/*
942	 * The PM domain must be in the GPD_STATE_ACTIVE state at this point,
943	 * so pm_genpd_poweron() will return immediately, but if the device
944	 * is suspended (e.g. it's been stopped by genpd_stop_dev()), we need
945	 * to make it operational.
946	 */
947	pm_runtime_resume(dev);
948	__pm_runtime_disable(dev, false);
949
950	ret = pm_generic_prepare(dev);
951	if (ret) {
952		mutex_lock(&genpd->lock);
953
954		if (--genpd->prepared_count == 0)
955			genpd->suspend_power_off = false;
956
957		mutex_unlock(&genpd->lock);
958		pm_runtime_enable(dev);
959	}
960
961	pm_runtime_put(dev);
962	return ret;
963}
964
965/**
966 * pm_genpd_suspend - Suspend a device belonging to an I/O PM domain.
967 * @dev: Device to suspend.
968 *
969 * Suspend a device under the assumption that its pm_domain field points to the
970 * domain member of an object of type struct generic_pm_domain representing
971 * a PM domain consisting of I/O devices.
972 */
973static int pm_genpd_suspend(struct device *dev)
974{
975	struct generic_pm_domain *genpd;
976
977	dev_dbg(dev, "%s()\n", __func__);
978
979	genpd = dev_to_genpd(dev);
980	if (IS_ERR(genpd))
981		return -EINVAL;
982
983	return genpd->suspend_power_off ? 0 : pm_generic_suspend(dev);
984}
985
986/**
987 * pm_genpd_suspend_late - Late suspend of a device from an I/O PM domain.
988 * @dev: Device to suspend.
989 *
990 * Carry out a late suspend of a device under the assumption that its
991 * pm_domain field points to the domain member of an object of type
992 * struct generic_pm_domain representing a PM domain consisting of I/O devices.
993 */
994static int pm_genpd_suspend_late(struct device *dev)
995{
996	struct generic_pm_domain *genpd;
997
998	dev_dbg(dev, "%s()\n", __func__);
999
1000	genpd = dev_to_genpd(dev);
1001	if (IS_ERR(genpd))
1002		return -EINVAL;
1003
1004	return genpd->suspend_power_off ? 0 : pm_generic_suspend_late(dev);
1005}
1006
1007/**
1008 * pm_genpd_suspend_noirq - Completion of suspend of device in an I/O PM domain.
1009 * @dev: Device to suspend.
1010 *
1011 * Stop the device and remove power from the domain if all devices in it have
1012 * been stopped.
1013 */
1014static int pm_genpd_suspend_noirq(struct device *dev)
1015{
1016	struct generic_pm_domain *genpd;
1017
1018	dev_dbg(dev, "%s()\n", __func__);
1019
1020	genpd = dev_to_genpd(dev);
1021	if (IS_ERR(genpd))
1022		return -EINVAL;
1023
1024	if (genpd->suspend_power_off
1025	    || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
1026		return 0;
1027
1028	genpd_stop_dev(genpd, dev);
1029
1030	/*
1031	 * Since all of the "noirq" callbacks are executed sequentially, it is
1032	 * guaranteed that this function will never run twice in parallel for
1033	 * the same PM domain, so it is not necessary to use locking here.
1034	 */
1035	genpd->suspended_count++;
1036	pm_genpd_sync_poweroff(genpd);
1037
1038	return 0;
1039}
1040
1041/**
1042 * pm_genpd_resume_noirq - Start of resume of device in an I/O PM domain.
1043 * @dev: Device to resume.
1044 *
1045 * Restore power to the device's PM domain, if necessary, and start the device.
1046 */
1047static int pm_genpd_resume_noirq(struct device *dev)
1048{
1049	struct generic_pm_domain *genpd;
1050
1051	dev_dbg(dev, "%s()\n", __func__);
1052
1053	genpd = dev_to_genpd(dev);
1054	if (IS_ERR(genpd))
1055		return -EINVAL;
1056
1057	if (genpd->suspend_power_off
1058	    || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
1059		return 0;
1060
1061	/*
1062	 * Since all of the "noirq" callbacks are executed sequentially, it is
1063	 * guaranteed that this function will never run twice in parallel for
1064	 * the same PM domain, so it is not necessary to use locking here.
1065	 */
1066	pm_genpd_sync_poweron(genpd);
1067	genpd->suspended_count--;
1068
1069	return genpd_start_dev(genpd, dev);
1070}
1071
1072/**
1073 * pm_genpd_resume_early - Early resume of a device in an I/O PM domain.
1074 * @dev: Device to resume.
1075 *
1076 * Carry out an early resume of a device under the assumption that its
1077 * pm_domain field points to the domain member of an object of type
1078 * struct generic_pm_domain representing a power domain consisting of I/O
1079 * devices.
1080 */
1081static int pm_genpd_resume_early(struct device *dev)
1082{
1083	struct generic_pm_domain *genpd;
1084
1085	dev_dbg(dev, "%s()\n", __func__);
1086
1087	genpd = dev_to_genpd(dev);
1088	if (IS_ERR(genpd))
1089		return -EINVAL;
1090
1091	return genpd->suspend_power_off ? 0 : pm_generic_resume_early(dev);
1092}
1093
1094/**
1095 * pm_genpd_resume - Resume of device in an I/O PM domain.
1096 * @dev: Device to resume.
1097 *
1098 * Resume a device under the assumption that its pm_domain field points to the
1099 * domain member of an object of type struct generic_pm_domain representing
1100 * a power domain consisting of I/O devices.
1101 */
1102static int pm_genpd_resume(struct device *dev)
1103{
1104	struct generic_pm_domain *genpd;
1105
1106	dev_dbg(dev, "%s()\n", __func__);
1107
1108	genpd = dev_to_genpd(dev);
1109	if (IS_ERR(genpd))
1110		return -EINVAL;
1111
1112	return genpd->suspend_power_off ? 0 : pm_generic_resume(dev);
1113}
1114
1115/**
1116 * pm_genpd_freeze - Freezing a device in an I/O PM domain.
1117 * @dev: Device to freeze.
1118 *
1119 * Freeze a device under the assumption that its pm_domain field points to the
1120 * domain member of an object of type struct generic_pm_domain representing
1121 * a power domain consisting of I/O devices.
1122 */
1123static int pm_genpd_freeze(struct device *dev)
1124{
1125	struct generic_pm_domain *genpd;
1126
1127	dev_dbg(dev, "%s()\n", __func__);
1128
1129	genpd = dev_to_genpd(dev);
1130	if (IS_ERR(genpd))
1131		return -EINVAL;
1132
1133	return genpd->suspend_power_off ? 0 : pm_generic_freeze(dev);
1134}
1135
1136/**
1137 * pm_genpd_freeze_late - Late freeze of a device in an I/O PM domain.
1138 * @dev: Device to freeze.
1139 *
1140 * Carry out a late freeze of a device under the assumption that its
1141 * pm_domain field points to the domain member of an object of type
1142 * struct generic_pm_domain representing a power domain consisting of I/O
1143 * devices.
1144 */
1145static int pm_genpd_freeze_late(struct device *dev)
1146{
1147	struct generic_pm_domain *genpd;
1148
1149	dev_dbg(dev, "%s()\n", __func__);
1150
1151	genpd = dev_to_genpd(dev);
1152	if (IS_ERR(genpd))
1153		return -EINVAL;
1154
1155	return genpd->suspend_power_off ? 0 : pm_generic_freeze_late(dev);
1156}
1157
1158/**
1159 * pm_genpd_freeze_noirq - Completion of freezing a device in an I/O PM domain.
1160 * @dev: Device to freeze.
1161 *
1162 * Carry out a late freeze of a device under the assumption that its
1163 * pm_domain field points to the domain member of an object of type
1164 * struct generic_pm_domain representing a power domain consisting of I/O
1165 * devices.
1166 */
1167static int pm_genpd_freeze_noirq(struct device *dev)
1168{
1169	struct generic_pm_domain *genpd;
1170
1171	dev_dbg(dev, "%s()\n", __func__);
1172
1173	genpd = dev_to_genpd(dev);
1174	if (IS_ERR(genpd))
1175		return -EINVAL;
1176
1177	return genpd->suspend_power_off ? 0 : genpd_stop_dev(genpd, dev);
1178}
1179
1180/**
1181 * pm_genpd_thaw_noirq - Early thaw of device in an I/O PM domain.
1182 * @dev: Device to thaw.
1183 *
1184 * Start the device, unless power has been removed from the domain already
1185 * before the system transition.
1186 */
1187static int pm_genpd_thaw_noirq(struct device *dev)
1188{
1189	struct generic_pm_domain *genpd;
1190
1191	dev_dbg(dev, "%s()\n", __func__);
1192
1193	genpd = dev_to_genpd(dev);
1194	if (IS_ERR(genpd))
1195		return -EINVAL;
1196
1197	return genpd->suspend_power_off ? 0 : genpd_start_dev(genpd, dev);
1198}
1199
1200/**
1201 * pm_genpd_thaw_early - Early thaw of device in an I/O PM domain.
1202 * @dev: Device to thaw.
1203 *
1204 * Carry out an early thaw of a device under the assumption that its
1205 * pm_domain field points to the domain member of an object of type
1206 * struct generic_pm_domain representing a power domain consisting of I/O
1207 * devices.
1208 */
1209static int pm_genpd_thaw_early(struct device *dev)
1210{
1211	struct generic_pm_domain *genpd;
1212
1213	dev_dbg(dev, "%s()\n", __func__);
1214
1215	genpd = dev_to_genpd(dev);
1216	if (IS_ERR(genpd))
1217		return -EINVAL;
1218
1219	return genpd->suspend_power_off ? 0 : pm_generic_thaw_early(dev);
1220}
1221
1222/**
1223 * pm_genpd_thaw - Thaw a device belonging to an I/O power domain.
1224 * @dev: Device to thaw.
1225 *
1226 * Thaw a device under the assumption that its pm_domain field points to the
1227 * domain member of an object of type struct generic_pm_domain representing
1228 * a power domain consisting of I/O devices.
1229 */
1230static int pm_genpd_thaw(struct device *dev)
1231{
1232	struct generic_pm_domain *genpd;
1233
1234	dev_dbg(dev, "%s()\n", __func__);
1235
1236	genpd = dev_to_genpd(dev);
1237	if (IS_ERR(genpd))
1238		return -EINVAL;
1239
1240	return genpd->suspend_power_off ? 0 : pm_generic_thaw(dev);
1241}
1242
1243/**
1244 * pm_genpd_restore_noirq - Start of restore of device in an I/O PM domain.
1245 * @dev: Device to resume.
1246 *
1247 * Make sure the domain will be in the same power state as before the
1248 * hibernation the system is resuming from and start the device if necessary.
1249 */
1250static int pm_genpd_restore_noirq(struct device *dev)
1251{
1252	struct generic_pm_domain *genpd;
1253
1254	dev_dbg(dev, "%s()\n", __func__);
1255
1256	genpd = dev_to_genpd(dev);
1257	if (IS_ERR(genpd))
1258		return -EINVAL;
1259
1260	/*
1261	 * Since all of the "noirq" callbacks are executed sequentially, it is
1262	 * guaranteed that this function will never run twice in parallel for
1263	 * the same PM domain, so it is not necessary to use locking here.
1264	 *
1265	 * At this point suspended_count == 0 means we are being run for the
1266	 * first time for the given domain in the present cycle.
1267	 */
1268	if (genpd->suspended_count++ == 0) {
1269		/*
1270		 * The boot kernel might put the domain into arbitrary state,
1271		 * so make it appear as powered off to pm_genpd_sync_poweron(),
1272		 * so that it tries to power it on in case it was really off.
1273		 */
1274		genpd->status = GPD_STATE_POWER_OFF;
1275		if (genpd->suspend_power_off) {
1276			/*
1277			 * If the domain was off before the hibernation, make
1278			 * sure it will be off going forward.
1279			 */
1280			if (genpd->power_off)
1281				genpd->power_off(genpd);
1282
1283			return 0;
1284		}
1285	}
1286
1287	if (genpd->suspend_power_off)
1288		return 0;
1289
1290	pm_genpd_sync_poweron(genpd);
1291
1292	return genpd_start_dev(genpd, dev);
1293}
1294
1295/**
1296 * pm_genpd_complete - Complete power transition of a device in a power domain.
1297 * @dev: Device to complete the transition of.
1298 *
1299 * Complete a power transition of a device (during a system-wide power
1300 * transition) under the assumption that its pm_domain field points to the
1301 * domain member of an object of type struct generic_pm_domain representing
1302 * a power domain consisting of I/O devices.
1303 */
1304static void pm_genpd_complete(struct device *dev)
1305{
1306	struct generic_pm_domain *genpd;
1307	bool run_complete;
1308
1309	dev_dbg(dev, "%s()\n", __func__);
1310
1311	genpd = dev_to_genpd(dev);
1312	if (IS_ERR(genpd))
1313		return;
1314
1315	mutex_lock(&genpd->lock);
1316
1317	run_complete = !genpd->suspend_power_off;
1318	if (--genpd->prepared_count == 0)
1319		genpd->suspend_power_off = false;
1320
1321	mutex_unlock(&genpd->lock);
1322
1323	if (run_complete) {
1324		pm_generic_complete(dev);
1325		pm_runtime_set_active(dev);
1326		pm_runtime_enable(dev);
1327		pm_request_idle(dev);
1328	}
1329}
1330
1331/**
1332 * genpd_syscore_switch - Switch power during system core suspend or resume.
1333 * @dev: Device that normally is marked as "always on" to switch power for.
1334 *
1335 * This routine may only be called during the system core (syscore) suspend or
1336 * resume phase for devices whose "always on" flags are set.
1337 */
1338static void genpd_syscore_switch(struct device *dev, bool suspend)
1339{
1340	struct generic_pm_domain *genpd;
1341
1342	genpd = dev_to_genpd(dev);
1343	if (!pm_genpd_present(genpd))
1344		return;
1345
1346	if (suspend) {
1347		genpd->suspended_count++;
1348		pm_genpd_sync_poweroff(genpd);
1349	} else {
1350		pm_genpd_sync_poweron(genpd);
1351		genpd->suspended_count--;
1352	}
1353}
1354
1355void pm_genpd_syscore_poweroff(struct device *dev)
1356{
1357	genpd_syscore_switch(dev, true);
1358}
1359EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweroff);
1360
1361void pm_genpd_syscore_poweron(struct device *dev)
1362{
1363	genpd_syscore_switch(dev, false);
1364}
1365EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweron);
1366
1367#else
1368
1369#define pm_genpd_prepare		NULL
1370#define pm_genpd_suspend		NULL
1371#define pm_genpd_suspend_late		NULL
1372#define pm_genpd_suspend_noirq		NULL
1373#define pm_genpd_resume_early		NULL
1374#define pm_genpd_resume_noirq		NULL
1375#define pm_genpd_resume			NULL
1376#define pm_genpd_freeze			NULL
1377#define pm_genpd_freeze_late		NULL
1378#define pm_genpd_freeze_noirq		NULL
1379#define pm_genpd_thaw_early		NULL
1380#define pm_genpd_thaw_noirq		NULL
1381#define pm_genpd_thaw			NULL
1382#define pm_genpd_restore_noirq		NULL
1383#define pm_genpd_complete		NULL
1384
1385#endif /* CONFIG_PM_SLEEP */
1386
1387static struct generic_pm_domain_data *__pm_genpd_alloc_dev_data(struct device *dev)
1388{
1389	struct generic_pm_domain_data *gpd_data;
1390
1391	gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL);
1392	if (!gpd_data)
1393		return NULL;
1394
1395	mutex_init(&gpd_data->lock);
1396	gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
1397	dev_pm_qos_add_notifier(dev, &gpd_data->nb);
1398	return gpd_data;
1399}
1400
1401static void __pm_genpd_free_dev_data(struct device *dev,
1402				     struct generic_pm_domain_data *gpd_data)
1403{
1404	dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
1405	kfree(gpd_data);
1406}
1407
1408/**
1409 * __pm_genpd_add_device - Add a device to an I/O PM domain.
1410 * @genpd: PM domain to add the device to.
1411 * @dev: Device to be added.
1412 * @td: Set of PM QoS timing parameters to attach to the device.
1413 */
1414int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
1415			  struct gpd_timing_data *td)
1416{
1417	struct generic_pm_domain_data *gpd_data_new, *gpd_data = NULL;
1418	struct pm_domain_data *pdd;
1419	int ret = 0;
1420
1421	dev_dbg(dev, "%s()\n", __func__);
1422
1423	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
1424		return -EINVAL;
1425
1426	gpd_data_new = __pm_genpd_alloc_dev_data(dev);
1427	if (!gpd_data_new)
1428		return -ENOMEM;
1429
1430	genpd_acquire_lock(genpd);
1431
1432	if (genpd->prepared_count > 0) {
1433		ret = -EAGAIN;
1434		goto out;
1435	}
1436
1437	list_for_each_entry(pdd, &genpd->dev_list, list_node)
1438		if (pdd->dev == dev) {
1439			ret = -EINVAL;
1440			goto out;
1441		}
1442
1443	ret = dev_pm_get_subsys_data(dev);
1444	if (ret)
1445		goto out;
1446
1447	genpd->device_count++;
1448	genpd->max_off_time_changed = true;
1449
1450	spin_lock_irq(&dev->power.lock);
1451
1452	dev->pm_domain = &genpd->domain;
1453	if (dev->power.subsys_data->domain_data) {
1454		gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
1455	} else {
1456		gpd_data = gpd_data_new;
1457		dev->power.subsys_data->domain_data = &gpd_data->base;
1458	}
1459	gpd_data->refcount++;
1460	if (td)
1461		gpd_data->td = *td;
1462
1463	spin_unlock_irq(&dev->power.lock);
1464
1465	if (genpd->attach_dev)
1466		genpd->attach_dev(genpd, dev);
1467
1468	mutex_lock(&gpd_data->lock);
1469	gpd_data->base.dev = dev;
1470	list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
1471	gpd_data->need_restore = -1;
1472	gpd_data->td.constraint_changed = true;
1473	gpd_data->td.effective_constraint_ns = -1;
1474	mutex_unlock(&gpd_data->lock);
1475
1476 out:
1477	genpd_release_lock(genpd);
1478
1479	if (gpd_data != gpd_data_new)
1480		__pm_genpd_free_dev_data(dev, gpd_data_new);
1481
1482	return ret;
1483}
1484
1485/**
1486 * __pm_genpd_name_add_device - Find I/O PM domain and add a device to it.
1487 * @domain_name: Name of the PM domain to add the device to.
1488 * @dev: Device to be added.
1489 * @td: Set of PM QoS timing parameters to attach to the device.
1490 */
1491int __pm_genpd_name_add_device(const char *domain_name, struct device *dev,
1492			       struct gpd_timing_data *td)
1493{
1494	return __pm_genpd_add_device(pm_genpd_lookup_name(domain_name), dev, td);
1495}
1496
1497/**
1498 * pm_genpd_remove_device - Remove a device from an I/O PM domain.
1499 * @genpd: PM domain to remove the device from.
1500 * @dev: Device to be removed.
1501 */
1502int pm_genpd_remove_device(struct generic_pm_domain *genpd,
1503			   struct device *dev)
1504{
1505	struct generic_pm_domain_data *gpd_data;
1506	struct pm_domain_data *pdd;
1507	bool remove = false;
1508	int ret = 0;
1509
1510	dev_dbg(dev, "%s()\n", __func__);
1511
1512	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)
1513	    ||  IS_ERR_OR_NULL(dev->pm_domain)
1514	    ||  pd_to_genpd(dev->pm_domain) != genpd)
1515		return -EINVAL;
1516
1517	genpd_acquire_lock(genpd);
1518
1519	if (genpd->prepared_count > 0) {
1520		ret = -EAGAIN;
1521		goto out;
1522	}
1523
1524	genpd->device_count--;
1525	genpd->max_off_time_changed = true;
1526
1527	if (genpd->detach_dev)
1528		genpd->detach_dev(genpd, dev);
1529
1530	spin_lock_irq(&dev->power.lock);
1531
1532	dev->pm_domain = NULL;
1533	pdd = dev->power.subsys_data->domain_data;
1534	list_del_init(&pdd->list_node);
1535	gpd_data = to_gpd_data(pdd);
1536	if (--gpd_data->refcount == 0) {
1537		dev->power.subsys_data->domain_data = NULL;
1538		remove = true;
1539	}
1540
1541	spin_unlock_irq(&dev->power.lock);
1542
1543	mutex_lock(&gpd_data->lock);
1544	pdd->dev = NULL;
1545	mutex_unlock(&gpd_data->lock);
1546
1547	genpd_release_lock(genpd);
1548
1549	dev_pm_put_subsys_data(dev);
1550	if (remove)
1551		__pm_genpd_free_dev_data(dev, gpd_data);
1552
1553	return 0;
1554
1555 out:
1556	genpd_release_lock(genpd);
1557
1558	return ret;
1559}
1560
1561/**
1562 * pm_genpd_dev_need_restore - Set/unset the device's "need restore" flag.
1563 * @dev: Device to set/unset the flag for.
1564 * @val: The new value of the device's "need restore" flag.
1565 */
1566void pm_genpd_dev_need_restore(struct device *dev, bool val)
1567{
1568	struct pm_subsys_data *psd;
1569	unsigned long flags;
1570
1571	spin_lock_irqsave(&dev->power.lock, flags);
1572
1573	psd = dev_to_psd(dev);
1574	if (psd && psd->domain_data)
1575		to_gpd_data(psd->domain_data)->need_restore = val ? 1 : 0;
1576
1577	spin_unlock_irqrestore(&dev->power.lock, flags);
1578}
1579EXPORT_SYMBOL_GPL(pm_genpd_dev_need_restore);
1580
1581/**
1582 * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
1583 * @genpd: Master PM domain to add the subdomain to.
1584 * @subdomain: Subdomain to be added.
1585 */
1586int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
1587			   struct generic_pm_domain *subdomain)
1588{
1589	struct gpd_link *link;
1590	int ret = 0;
1591
1592	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)
1593	    || genpd == subdomain)
1594		return -EINVAL;
1595
1596 start:
1597	genpd_acquire_lock(genpd);
1598	mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
1599
1600	if (subdomain->status != GPD_STATE_POWER_OFF
1601	    && subdomain->status != GPD_STATE_ACTIVE) {
1602		mutex_unlock(&subdomain->lock);
1603		genpd_release_lock(genpd);
1604		goto start;
1605	}
1606
1607	if (genpd->status == GPD_STATE_POWER_OFF
1608	    &&  subdomain->status != GPD_STATE_POWER_OFF) {
1609		ret = -EINVAL;
1610		goto out;
1611	}
1612
1613	list_for_each_entry(link, &genpd->master_links, master_node) {
1614		if (link->slave == subdomain && link->master == genpd) {
1615			ret = -EINVAL;
1616			goto out;
1617		}
1618	}
1619
1620	link = kzalloc(sizeof(*link), GFP_KERNEL);
1621	if (!link) {
1622		ret = -ENOMEM;
1623		goto out;
1624	}
1625	link->master = genpd;
1626	list_add_tail(&link->master_node, &genpd->master_links);
1627	link->slave = subdomain;
1628	list_add_tail(&link->slave_node, &subdomain->slave_links);
1629	if (subdomain->status != GPD_STATE_POWER_OFF)
1630		genpd_sd_counter_inc(genpd);
1631
1632 out:
1633	mutex_unlock(&subdomain->lock);
1634	genpd_release_lock(genpd);
1635
1636	return ret;
1637}
1638
1639/**
1640 * pm_genpd_add_subdomain_names - Add a subdomain to an I/O PM domain.
1641 * @master_name: Name of the master PM domain to add the subdomain to.
1642 * @subdomain_name: Name of the subdomain to be added.
1643 */
1644int pm_genpd_add_subdomain_names(const char *master_name,
1645				 const char *subdomain_name)
1646{
1647	struct generic_pm_domain *master = NULL, *subdomain = NULL, *gpd;
1648
1649	if (IS_ERR_OR_NULL(master_name) || IS_ERR_OR_NULL(subdomain_name))
1650		return -EINVAL;
1651
1652	mutex_lock(&gpd_list_lock);
1653	list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
1654		if (!master && !strcmp(gpd->name, master_name))
1655			master = gpd;
1656
1657		if (!subdomain && !strcmp(gpd->name, subdomain_name))
1658			subdomain = gpd;
1659
1660		if (master && subdomain)
1661			break;
1662	}
1663	mutex_unlock(&gpd_list_lock);
1664
1665	return pm_genpd_add_subdomain(master, subdomain);
1666}
1667
1668/**
1669 * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain.
1670 * @genpd: Master PM domain to remove the subdomain from.
1671 * @subdomain: Subdomain to be removed.
1672 */
1673int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
1674			      struct generic_pm_domain *subdomain)
1675{
1676	struct gpd_link *link;
1677	int ret = -EINVAL;
1678
1679	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain))
1680		return -EINVAL;
1681
1682 start:
1683	genpd_acquire_lock(genpd);
1684
1685	list_for_each_entry(link, &genpd->master_links, master_node) {
1686		if (link->slave != subdomain)
1687			continue;
1688
1689		mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
1690
1691		if (subdomain->status != GPD_STATE_POWER_OFF
1692		    && subdomain->status != GPD_STATE_ACTIVE) {
1693			mutex_unlock(&subdomain->lock);
1694			genpd_release_lock(genpd);
1695			goto start;
1696		}
1697
1698		list_del(&link->master_node);
1699		list_del(&link->slave_node);
1700		kfree(link);
1701		if (subdomain->status != GPD_STATE_POWER_OFF)
1702			genpd_sd_counter_dec(genpd);
1703
1704		mutex_unlock(&subdomain->lock);
1705
1706		ret = 0;
1707		break;
1708	}
1709
1710	genpd_release_lock(genpd);
1711
1712	return ret;
1713}
1714
1715/**
1716 * pm_genpd_attach_cpuidle - Connect the given PM domain with cpuidle.
1717 * @genpd: PM domain to be connected with cpuidle.
1718 * @state: cpuidle state this domain can disable/enable.
1719 *
1720 * Make a PM domain behave as though it contained a CPU core, that is, instead
1721 * of calling its power down routine it will enable the given cpuidle state so
1722 * that the cpuidle subsystem can power it down (if possible and desirable).
1723 */
1724int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state)
1725{
1726	struct cpuidle_driver *cpuidle_drv;
1727	struct gpd_cpuidle_data *cpuidle_data;
1728	struct cpuidle_state *idle_state;
1729	int ret = 0;
1730
1731	if (IS_ERR_OR_NULL(genpd) || state < 0)
1732		return -EINVAL;
1733
1734	genpd_acquire_lock(genpd);
1735
1736	if (genpd->cpuidle_data) {
1737		ret = -EEXIST;
1738		goto out;
1739	}
1740	cpuidle_data = kzalloc(sizeof(*cpuidle_data), GFP_KERNEL);
1741	if (!cpuidle_data) {
1742		ret = -ENOMEM;
1743		goto out;
1744	}
1745	cpuidle_drv = cpuidle_driver_ref();
1746	if (!cpuidle_drv) {
1747		ret = -ENODEV;
1748		goto err_drv;
1749	}
1750	if (cpuidle_drv->state_count <= state) {
1751		ret = -EINVAL;
1752		goto err;
1753	}
1754	idle_state = &cpuidle_drv->states[state];
1755	if (!idle_state->disabled) {
1756		ret = -EAGAIN;
1757		goto err;
1758	}
1759	cpuidle_data->idle_state = idle_state;
1760	cpuidle_data->saved_exit_latency = idle_state->exit_latency;
1761	genpd->cpuidle_data = cpuidle_data;
1762	genpd_recalc_cpu_exit_latency(genpd);
1763
1764 out:
1765	genpd_release_lock(genpd);
1766	return ret;
1767
1768 err:
1769	cpuidle_driver_unref();
1770
1771 err_drv:
1772	kfree(cpuidle_data);
1773	goto out;
1774}
1775
1776/**
1777 * pm_genpd_name_attach_cpuidle - Find PM domain and connect cpuidle to it.
1778 * @name: Name of the domain to connect to cpuidle.
1779 * @state: cpuidle state this domain can manipulate.
1780 */
1781int pm_genpd_name_attach_cpuidle(const char *name, int state)
1782{
1783	return pm_genpd_attach_cpuidle(pm_genpd_lookup_name(name), state);
1784}
1785
1786/**
1787 * pm_genpd_detach_cpuidle - Remove the cpuidle connection from a PM domain.
1788 * @genpd: PM domain to remove the cpuidle connection from.
1789 *
1790 * Remove the cpuidle connection set up by pm_genpd_attach_cpuidle() from the
1791 * given PM domain.
1792 */
1793int pm_genpd_detach_cpuidle(struct generic_pm_domain *genpd)
1794{
1795	struct gpd_cpuidle_data *cpuidle_data;
1796	struct cpuidle_state *idle_state;
1797	int ret = 0;
1798
1799	if (IS_ERR_OR_NULL(genpd))
1800		return -EINVAL;
1801
1802	genpd_acquire_lock(genpd);
1803
1804	cpuidle_data = genpd->cpuidle_data;
1805	if (!cpuidle_data) {
1806		ret = -ENODEV;
1807		goto out;
1808	}
1809	idle_state = cpuidle_data->idle_state;
1810	if (!idle_state->disabled) {
1811		ret = -EAGAIN;
1812		goto out;
1813	}
1814	idle_state->exit_latency = cpuidle_data->saved_exit_latency;
1815	cpuidle_driver_unref();
1816	genpd->cpuidle_data = NULL;
1817	kfree(cpuidle_data);
1818
1819 out:
1820	genpd_release_lock(genpd);
1821	return ret;
1822}
1823
1824/**
1825 * pm_genpd_name_detach_cpuidle - Find PM domain and disconnect cpuidle from it.
1826 * @name: Name of the domain to disconnect cpuidle from.
1827 */
1828int pm_genpd_name_detach_cpuidle(const char *name)
1829{
1830	return pm_genpd_detach_cpuidle(pm_genpd_lookup_name(name));
1831}
1832
1833/* Default device callbacks for generic PM domains. */
1834
1835/**
1836 * pm_genpd_default_save_state - Default "save device state" for PM domains.
1837 * @dev: Device to handle.
1838 */
1839static int pm_genpd_default_save_state(struct device *dev)
1840{
1841	int (*cb)(struct device *__dev);
1842
1843	if (dev->type && dev->type->pm)
1844		cb = dev->type->pm->runtime_suspend;
1845	else if (dev->class && dev->class->pm)
1846		cb = dev->class->pm->runtime_suspend;
1847	else if (dev->bus && dev->bus->pm)
1848		cb = dev->bus->pm->runtime_suspend;
1849	else
1850		cb = NULL;
1851
1852	if (!cb && dev->driver && dev->driver->pm)
1853		cb = dev->driver->pm->runtime_suspend;
1854
1855	return cb ? cb(dev) : 0;
1856}
1857
1858/**
1859 * pm_genpd_default_restore_state - Default PM domains "restore device state".
1860 * @dev: Device to handle.
1861 */
1862static int pm_genpd_default_restore_state(struct device *dev)
1863{
1864	int (*cb)(struct device *__dev);
1865
1866	if (dev->type && dev->type->pm)
1867		cb = dev->type->pm->runtime_resume;
1868	else if (dev->class && dev->class->pm)
1869		cb = dev->class->pm->runtime_resume;
1870	else if (dev->bus && dev->bus->pm)
1871		cb = dev->bus->pm->runtime_resume;
1872	else
1873		cb = NULL;
1874
1875	if (!cb && dev->driver && dev->driver->pm)
1876		cb = dev->driver->pm->runtime_resume;
1877
1878	return cb ? cb(dev) : 0;
1879}
1880
1881/**
1882 * pm_genpd_init - Initialize a generic I/O PM domain object.
1883 * @genpd: PM domain object to initialize.
1884 * @gov: PM domain governor to associate with the domain (may be NULL).
1885 * @is_off: Initial value of the domain's power_is_off field.
1886 */
1887void pm_genpd_init(struct generic_pm_domain *genpd,
1888		   struct dev_power_governor *gov, bool is_off)
1889{
1890	if (IS_ERR_OR_NULL(genpd))
1891		return;
1892
1893	INIT_LIST_HEAD(&genpd->master_links);
1894	INIT_LIST_HEAD(&genpd->slave_links);
1895	INIT_LIST_HEAD(&genpd->dev_list);
1896	mutex_init(&genpd->lock);
1897	genpd->gov = gov;
1898	INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
1899	genpd->in_progress = 0;
1900	atomic_set(&genpd->sd_count, 0);
1901	genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE;
1902	init_waitqueue_head(&genpd->status_wait_queue);
1903	genpd->poweroff_task = NULL;
1904	genpd->resume_count = 0;
1905	genpd->device_count = 0;
1906	genpd->max_off_time_ns = -1;
1907	genpd->max_off_time_changed = true;
1908	genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend;
1909	genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume;
1910	genpd->domain.ops.prepare = pm_genpd_prepare;
1911	genpd->domain.ops.suspend = pm_genpd_suspend;
1912	genpd->domain.ops.suspend_late = pm_genpd_suspend_late;
1913	genpd->domain.ops.suspend_noirq = pm_genpd_suspend_noirq;
1914	genpd->domain.ops.resume_noirq = pm_genpd_resume_noirq;
1915	genpd->domain.ops.resume_early = pm_genpd_resume_early;
1916	genpd->domain.ops.resume = pm_genpd_resume;
1917	genpd->domain.ops.freeze = pm_genpd_freeze;
1918	genpd->domain.ops.freeze_late = pm_genpd_freeze_late;
1919	genpd->domain.ops.freeze_noirq = pm_genpd_freeze_noirq;
1920	genpd->domain.ops.thaw_noirq = pm_genpd_thaw_noirq;
1921	genpd->domain.ops.thaw_early = pm_genpd_thaw_early;
1922	genpd->domain.ops.thaw = pm_genpd_thaw;
1923	genpd->domain.ops.poweroff = pm_genpd_suspend;
1924	genpd->domain.ops.poweroff_late = pm_genpd_suspend_late;
1925	genpd->domain.ops.poweroff_noirq = pm_genpd_suspend_noirq;
1926	genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq;
1927	genpd->domain.ops.restore_early = pm_genpd_resume_early;
1928	genpd->domain.ops.restore = pm_genpd_resume;
1929	genpd->domain.ops.complete = pm_genpd_complete;
1930	genpd->dev_ops.save_state = pm_genpd_default_save_state;
1931	genpd->dev_ops.restore_state = pm_genpd_default_restore_state;
1932	mutex_lock(&gpd_list_lock);
1933	list_add(&genpd->gpd_list_node, &gpd_list);
1934	mutex_unlock(&gpd_list_lock);
1935}
1936
1937#ifdef CONFIG_PM_GENERIC_DOMAINS_OF
1938/*
1939 * Device Tree based PM domain providers.
1940 *
1941 * The code below implements generic device tree based PM domain providers that
1942 * bind device tree nodes with generic PM domains registered in the system.
1943 *
1944 * Any driver that registers generic PM domains and needs to support binding of
1945 * devices to these domains is supposed to register a PM domain provider, which
1946 * maps a PM domain specifier retrieved from the device tree to a PM domain.
1947 *
1948 * Two simple mapping functions have been provided for convenience:
1949 *  - __of_genpd_xlate_simple() for 1:1 device tree node to PM domain mapping.
1950 *  - __of_genpd_xlate_onecell() for mapping of multiple PM domains per node by
1951 *    index.
1952 */
1953
1954/**
1955 * struct of_genpd_provider - PM domain provider registration structure
1956 * @link: Entry in global list of PM domain providers
1957 * @node: Pointer to device tree node of PM domain provider
1958 * @xlate: Provider-specific xlate callback mapping a set of specifier cells
1959 *         into a PM domain.
1960 * @data: context pointer to be passed into @xlate callback
1961 */
1962struct of_genpd_provider {
1963	struct list_head link;
1964	struct device_node *node;
1965	genpd_xlate_t xlate;
1966	void *data;
1967};
1968
1969/* List of registered PM domain providers. */
1970static LIST_HEAD(of_genpd_providers);
1971/* Mutex to protect the list above. */
1972static DEFINE_MUTEX(of_genpd_mutex);
1973
1974/**
1975 * __of_genpd_xlate_simple() - Xlate function for direct node-domain mapping
1976 * @genpdspec: OF phandle args to map into a PM domain
1977 * @data: xlate function private data - pointer to struct generic_pm_domain
1978 *
1979 * This is a generic xlate function that can be used to model PM domains that
1980 * have their own device tree nodes. The private data of xlate function needs
1981 * to be a valid pointer to struct generic_pm_domain.
1982 */
1983struct generic_pm_domain *__of_genpd_xlate_simple(
1984					struct of_phandle_args *genpdspec,
1985					void *data)
1986{
1987	if (genpdspec->args_count != 0)
1988		return ERR_PTR(-EINVAL);
1989	return data;
1990}
1991EXPORT_SYMBOL_GPL(__of_genpd_xlate_simple);
1992
1993/**
1994 * __of_genpd_xlate_onecell() - Xlate function using a single index.
1995 * @genpdspec: OF phandle args to map into a PM domain
1996 * @data: xlate function private data - pointer to struct genpd_onecell_data
1997 *
1998 * This is a generic xlate function that can be used to model simple PM domain
1999 * controllers that have one device tree node and provide multiple PM domains.
2000 * A single cell is used as an index into an array of PM domains specified in
2001 * the genpd_onecell_data struct when registering the provider.
2002 */
2003struct generic_pm_domain *__of_genpd_xlate_onecell(
2004					struct of_phandle_args *genpdspec,
2005					void *data)
2006{
2007	struct genpd_onecell_data *genpd_data = data;
2008	unsigned int idx = genpdspec->args[0];
2009
2010	if (genpdspec->args_count != 1)
2011		return ERR_PTR(-EINVAL);
2012
2013	if (idx >= genpd_data->num_domains) {
2014		pr_err("%s: invalid domain index %u\n", __func__, idx);
2015		return ERR_PTR(-EINVAL);
2016	}
2017
2018	if (!genpd_data->domains[idx])
2019		return ERR_PTR(-ENOENT);
2020
2021	return genpd_data->domains[idx];
2022}
2023EXPORT_SYMBOL_GPL(__of_genpd_xlate_onecell);
2024
2025/**
2026 * __of_genpd_add_provider() - Register a PM domain provider for a node
2027 * @np: Device node pointer associated with the PM domain provider.
2028 * @xlate: Callback for decoding PM domain from phandle arguments.
2029 * @data: Context pointer for @xlate callback.
2030 */
2031int __of_genpd_add_provider(struct device_node *np, genpd_xlate_t xlate,
2032			void *data)
2033{
2034	struct of_genpd_provider *cp;
2035
2036	cp = kzalloc(sizeof(*cp), GFP_KERNEL);
2037	if (!cp)
2038		return -ENOMEM;
2039
2040	cp->node = of_node_get(np);
2041	cp->data = data;
2042	cp->xlate = xlate;
2043
2044	mutex_lock(&of_genpd_mutex);
2045	list_add(&cp->link, &of_genpd_providers);
2046	mutex_unlock(&of_genpd_mutex);
2047	pr_debug("Added domain provider from %s\n", np->full_name);
2048
2049	return 0;
2050}
2051EXPORT_SYMBOL_GPL(__of_genpd_add_provider);
2052
2053/**
2054 * of_genpd_del_provider() - Remove a previously registered PM domain provider
2055 * @np: Device node pointer associated with the PM domain provider
2056 */
2057void of_genpd_del_provider(struct device_node *np)
2058{
2059	struct of_genpd_provider *cp;
2060
2061	mutex_lock(&of_genpd_mutex);
2062	list_for_each_entry(cp, &of_genpd_providers, link) {
2063		if (cp->node == np) {
2064			list_del(&cp->link);
2065			of_node_put(cp->node);
2066			kfree(cp);
2067			break;
2068		}
2069	}
2070	mutex_unlock(&of_genpd_mutex);
2071}
2072EXPORT_SYMBOL_GPL(of_genpd_del_provider);
2073
2074/**
2075 * of_genpd_get_from_provider() - Look-up PM domain
2076 * @genpdspec: OF phandle args to use for look-up
2077 *
2078 * Looks for a PM domain provider under the node specified by @genpdspec and if
2079 * found, uses xlate function of the provider to map phandle args to a PM
2080 * domain.
2081 *
2082 * Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR()
2083 * on failure.
2084 */
2085static struct generic_pm_domain *of_genpd_get_from_provider(
2086					struct of_phandle_args *genpdspec)
2087{
2088	struct generic_pm_domain *genpd = ERR_PTR(-ENOENT);
2089	struct of_genpd_provider *provider;
2090
2091	mutex_lock(&of_genpd_mutex);
2092
2093	/* Check if we have such a provider in our array */
2094	list_for_each_entry(provider, &of_genpd_providers, link) {
2095		if (provider->node == genpdspec->np)
2096			genpd = provider->xlate(genpdspec, provider->data);
2097		if (!IS_ERR(genpd))
2098			break;
2099	}
2100
2101	mutex_unlock(&of_genpd_mutex);
2102
2103	return genpd;
2104}
2105
2106/**
2107 * genpd_dev_pm_detach - Detach a device from its PM domain.
2108 * @dev: Device to attach.
2109 * @power_off: Currently not used
2110 *
2111 * Try to locate a corresponding generic PM domain, which the device was
2112 * attached to previously. If such is found, the device is detached from it.
2113 */
2114static void genpd_dev_pm_detach(struct device *dev, bool power_off)
2115{
2116	struct generic_pm_domain *pd = NULL, *gpd;
2117	int ret = 0;
2118
2119	if (!dev->pm_domain)
2120		return;
2121
2122	mutex_lock(&gpd_list_lock);
2123	list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
2124		if (&gpd->domain == dev->pm_domain) {
2125			pd = gpd;
2126			break;
2127		}
2128	}
2129	mutex_unlock(&gpd_list_lock);
2130
2131	if (!pd)
2132		return;
2133
2134	dev_dbg(dev, "removing from PM domain %s\n", pd->name);
2135
2136	while (1) {
2137		ret = pm_genpd_remove_device(pd, dev);
2138		if (ret != -EAGAIN)
2139			break;
2140		cond_resched();
2141	}
2142
2143	if (ret < 0) {
2144		dev_err(dev, "failed to remove from PM domain %s: %d",
2145			pd->name, ret);
2146		return;
2147	}
2148
2149	/* Check if PM domain can be powered off after removing this device. */
2150	genpd_queue_power_off_work(pd);
2151}
2152
2153/**
2154 * genpd_dev_pm_attach - Attach a device to its PM domain using DT.
2155 * @dev: Device to attach.
2156 *
2157 * Parse device's OF node to find a PM domain specifier. If such is found,
2158 * attaches the device to retrieved pm_domain ops.
2159 *
2160 * Both generic and legacy Samsung-specific DT bindings are supported to keep
2161 * backwards compatibility with existing DTBs.
2162 *
2163 * Returns 0 on successfully attached PM domain or negative error code.
2164 */
2165int genpd_dev_pm_attach(struct device *dev)
2166{
2167	struct of_phandle_args pd_args;
2168	struct generic_pm_domain *pd;
2169	int ret;
2170
2171	if (!dev->of_node)
2172		return -ENODEV;
2173
2174	if (dev->pm_domain)
2175		return -EEXIST;
2176
2177	ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
2178					"#power-domain-cells", 0, &pd_args);
2179	if (ret < 0) {
2180		if (ret != -ENOENT)
2181			return ret;
2182
2183		/*
2184		 * Try legacy Samsung-specific bindings
2185		 * (for backwards compatibility of DT ABI)
2186		 */
2187		pd_args.args_count = 0;
2188		pd_args.np = of_parse_phandle(dev->of_node,
2189						"samsung,power-domain", 0);
2190		if (!pd_args.np)
2191			return -ENOENT;
2192	}
2193
2194	pd = of_genpd_get_from_provider(&pd_args);
2195	if (IS_ERR(pd)) {
2196		dev_dbg(dev, "%s() failed to find PM domain: %ld\n",
2197			__func__, PTR_ERR(pd));
2198		of_node_put(dev->of_node);
2199		return PTR_ERR(pd);
2200	}
2201
2202	dev_dbg(dev, "adding to PM domain %s\n", pd->name);
2203
2204	while (1) {
2205		ret = pm_genpd_add_device(pd, dev);
2206		if (ret != -EAGAIN)
2207			break;
2208		cond_resched();
2209	}
2210
2211	if (ret < 0) {
2212		dev_err(dev, "failed to add to PM domain %s: %d",
2213			pd->name, ret);
2214		of_node_put(dev->of_node);
2215		return ret;
2216	}
2217
2218	dev->pm_domain->detach = genpd_dev_pm_detach;
2219
2220	return 0;
2221}
2222EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
2223#endif
2224
2225
2226/***        debugfs support        ***/
2227
2228#ifdef CONFIG_PM_ADVANCED_DEBUG
2229#include <linux/pm.h>
2230#include <linux/device.h>
2231#include <linux/debugfs.h>
2232#include <linux/seq_file.h>
2233#include <linux/init.h>
2234#include <linux/kobject.h>
2235static struct dentry *pm_genpd_debugfs_dir;
2236
2237/*
2238 * TODO: This function is a slightly modified version of rtpm_status_show
2239 * from sysfs.c, but dependencies between PM_GENERIC_DOMAINS and PM_RUNTIME
2240 * are too loose to generalize it.
2241 */
2242#ifdef CONFIG_PM_RUNTIME
2243static void rtpm_status_str(struct seq_file *s, struct device *dev)
2244{
2245	static const char * const status_lookup[] = {
2246		[RPM_ACTIVE] = "active",
2247		[RPM_RESUMING] = "resuming",
2248		[RPM_SUSPENDED] = "suspended",
2249		[RPM_SUSPENDING] = "suspending"
2250	};
2251	const char *p = "";
2252
2253	if (dev->power.runtime_error)
2254		p = "error";
2255	else if (dev->power.disable_depth)
2256		p = "unsupported";
2257	else if (dev->power.runtime_status < ARRAY_SIZE(status_lookup))
2258		p = status_lookup[dev->power.runtime_status];
2259	else
2260		WARN_ON(1);
2261
2262	seq_puts(s, p);
2263}
2264#else
2265static void rtpm_status_str(struct seq_file *s, struct device *dev)
2266{
2267	seq_puts(s, "active");
2268}
2269#endif
2270
2271static int pm_genpd_summary_one(struct seq_file *s,
2272		struct generic_pm_domain *gpd)
2273{
2274	static const char * const status_lookup[] = {
2275		[GPD_STATE_ACTIVE] = "on",
2276		[GPD_STATE_WAIT_MASTER] = "wait-master",
2277		[GPD_STATE_BUSY] = "busy",
2278		[GPD_STATE_REPEAT] = "off-in-progress",
2279		[GPD_STATE_POWER_OFF] = "off"
2280	};
2281	struct pm_domain_data *pm_data;
2282	const char *kobj_path;
2283	struct gpd_link *link;
2284	int ret;
2285
2286	ret = mutex_lock_interruptible(&gpd->lock);
2287	if (ret)
2288		return -ERESTARTSYS;
2289
2290	if (WARN_ON(gpd->status >= ARRAY_SIZE(status_lookup)))
2291		goto exit;
2292	seq_printf(s, "%-30s  %-15s  ", gpd->name, status_lookup[gpd->status]);
2293
2294	/*
2295	 * Modifications on the list require holding locks on both
2296	 * master and slave, so we are safe.
2297	 * Also gpd->name is immutable.
2298	 */
2299	list_for_each_entry(link, &gpd->master_links, master_node) {
2300		seq_printf(s, "%s", link->slave->name);
2301		if (!list_is_last(&link->master_node, &gpd->master_links))
2302			seq_puts(s, ", ");
2303	}
2304
2305	list_for_each_entry(pm_data, &gpd->dev_list, list_node) {
2306		kobj_path = kobject_get_path(&pm_data->dev->kobj, GFP_KERNEL);
2307		if (kobj_path == NULL)
2308			continue;
2309
2310		seq_printf(s, "\n    %-50s  ", kobj_path);
2311		rtpm_status_str(s, pm_data->dev);
2312		kfree(kobj_path);
2313	}
2314
2315	seq_puts(s, "\n");
2316exit:
2317	mutex_unlock(&gpd->lock);
2318
2319	return 0;
2320}
2321
2322static int pm_genpd_summary_show(struct seq_file *s, void *data)
2323{
2324	struct generic_pm_domain *gpd;
2325	int ret = 0;
2326
2327	seq_puts(s, "    domain                      status         slaves\n");
2328	seq_puts(s, "           /device                                      runtime status\n");
2329	seq_puts(s, "----------------------------------------------------------------------\n");
2330
2331	ret = mutex_lock_interruptible(&gpd_list_lock);
2332	if (ret)
2333		return -ERESTARTSYS;
2334
2335	list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
2336		ret = pm_genpd_summary_one(s, gpd);
2337		if (ret)
2338			break;
2339	}
2340	mutex_unlock(&gpd_list_lock);
2341
2342	return ret;
2343}
2344
2345static int pm_genpd_summary_open(struct inode *inode, struct file *file)
2346{
2347	return single_open(file, pm_genpd_summary_show, NULL);
2348}
2349
2350static const struct file_operations pm_genpd_summary_fops = {
2351	.open = pm_genpd_summary_open,
2352	.read = seq_read,
2353	.llseek = seq_lseek,
2354	.release = single_release,
2355};
2356
2357static int __init pm_genpd_debug_init(void)
2358{
2359	struct dentry *d;
2360
2361	pm_genpd_debugfs_dir = debugfs_create_dir("pm_genpd", NULL);
2362
2363	if (!pm_genpd_debugfs_dir)
2364		return -ENOMEM;
2365
2366	d = debugfs_create_file("pm_genpd_summary", S_IRUGO,
2367			pm_genpd_debugfs_dir, NULL, &pm_genpd_summary_fops);
2368	if (!d)
2369		return -ENOMEM;
2370
2371	return 0;
2372}
2373late_initcall(pm_genpd_debug_init);
2374
2375static void __exit pm_genpd_debug_exit(void)
2376{
2377	debugfs_remove_recursive(pm_genpd_debugfs_dir);
2378}
2379__exitcall(pm_genpd_debug_exit);
2380#endif /* CONFIG_PM_ADVANCED_DEBUG */
2381