24e39ce27bd8876ce971a86620a1f0983e21ba03
[muen/linux.git] / drivers / base / power / domain.c
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/delay.h>
10 #include <linux/kernel.h>
11 #include <linux/io.h>
12 #include <linux/platform_device.h>
13 #include <linux/pm_runtime.h>
14 #include <linux/pm_domain.h>
15 #include <linux/pm_qos.h>
16 #include <linux/pm_clock.h>
17 #include <linux/slab.h>
18 #include <linux/err.h>
19 #include <linux/sched.h>
20 #include <linux/suspend.h>
21 #include <linux/export.h>
22
23 #include "power.h"
24
25 #define GENPD_RETRY_MAX_MS      250             /* Approximate */
26
27 #define GENPD_DEV_CALLBACK(genpd, type, callback, dev)          \
28 ({                                                              \
29         type (*__routine)(struct device *__d);                  \
30         type __ret = (type)0;                                   \
31                                                                 \
32         __routine = genpd->dev_ops.callback;                    \
33         if (__routine) {                                        \
34                 __ret = __routine(dev);                         \
35         }                                                       \
36         __ret;                                                  \
37 })
38
39 static LIST_HEAD(gpd_list);
40 static DEFINE_MUTEX(gpd_list_lock);
41
42 struct genpd_lock_ops {
43         void (*lock)(struct generic_pm_domain *genpd);
44         void (*lock_nested)(struct generic_pm_domain *genpd, int depth);
45         int (*lock_interruptible)(struct generic_pm_domain *genpd);
46         void (*unlock)(struct generic_pm_domain *genpd);
47 };
48
49 static void genpd_lock_mtx(struct generic_pm_domain *genpd)
50 {
51         mutex_lock(&genpd->mlock);
52 }
53
54 static void genpd_lock_nested_mtx(struct generic_pm_domain *genpd,
55                                         int depth)
56 {
57         mutex_lock_nested(&genpd->mlock, depth);
58 }
59
60 static int genpd_lock_interruptible_mtx(struct generic_pm_domain *genpd)
61 {
62         return mutex_lock_interruptible(&genpd->mlock);
63 }
64
65 static void genpd_unlock_mtx(struct generic_pm_domain *genpd)
66 {
67         return mutex_unlock(&genpd->mlock);
68 }
69
70 static const struct genpd_lock_ops genpd_mtx_ops = {
71         .lock = genpd_lock_mtx,
72         .lock_nested = genpd_lock_nested_mtx,
73         .lock_interruptible = genpd_lock_interruptible_mtx,
74         .unlock = genpd_unlock_mtx,
75 };
76
77 static void genpd_lock_spin(struct generic_pm_domain *genpd)
78         __acquires(&genpd->slock)
79 {
80         unsigned long flags;
81
82         spin_lock_irqsave(&genpd->slock, flags);
83         genpd->lock_flags = flags;
84 }
85
86 static void genpd_lock_nested_spin(struct generic_pm_domain *genpd,
87                                         int depth)
88         __acquires(&genpd->slock)
89 {
90         unsigned long flags;
91
92         spin_lock_irqsave_nested(&genpd->slock, flags, depth);
93         genpd->lock_flags = flags;
94 }
95
96 static int genpd_lock_interruptible_spin(struct generic_pm_domain *genpd)
97         __acquires(&genpd->slock)
98 {
99         unsigned long flags;
100
101         spin_lock_irqsave(&genpd->slock, flags);
102         genpd->lock_flags = flags;
103         return 0;
104 }
105
106 static void genpd_unlock_spin(struct generic_pm_domain *genpd)
107         __releases(&genpd->slock)
108 {
109         spin_unlock_irqrestore(&genpd->slock, genpd->lock_flags);
110 }
111
112 static const struct genpd_lock_ops genpd_spin_ops = {
113         .lock = genpd_lock_spin,
114         .lock_nested = genpd_lock_nested_spin,
115         .lock_interruptible = genpd_lock_interruptible_spin,
116         .unlock = genpd_unlock_spin,
117 };
118
119 #define genpd_lock(p)                   p->lock_ops->lock(p)
120 #define genpd_lock_nested(p, d)         p->lock_ops->lock_nested(p, d)
121 #define genpd_lock_interruptible(p)     p->lock_ops->lock_interruptible(p)
122 #define genpd_unlock(p)                 p->lock_ops->unlock(p)
123
124 #define genpd_status_on(genpd)          (genpd->status == GPD_STATE_ACTIVE)
125 #define genpd_is_irq_safe(genpd)        (genpd->flags & GENPD_FLAG_IRQ_SAFE)
126 #define genpd_is_always_on(genpd)       (genpd->flags & GENPD_FLAG_ALWAYS_ON)
127 #define genpd_is_active_wakeup(genpd)   (genpd->flags & GENPD_FLAG_ACTIVE_WAKEUP)
128
129 static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev,
130                 const struct generic_pm_domain *genpd)
131 {
132         bool ret;
133
134         ret = pm_runtime_is_irq_safe(dev) && !genpd_is_irq_safe(genpd);
135
136         /*
137          * Warn once if an IRQ safe device is attached to a no sleep domain, as
138          * to indicate a suboptimal configuration for PM. For an always on
139          * domain this isn't case, thus don't warn.
140          */
141         if (ret && !genpd_is_always_on(genpd))
142                 dev_warn_once(dev, "PM domain %s will not be powered off\n",
143                                 genpd->name);
144
145         return ret;
146 }
147
148 /*
149  * Get the generic PM domain for a particular struct device.
150  * This validates the struct device pointer, the PM domain pointer,
151  * and checks that the PM domain pointer is a real generic PM domain.
152  * Any failure results in NULL being returned.
153  */
154 static struct generic_pm_domain *genpd_lookup_dev(struct device *dev)
155 {
156         struct generic_pm_domain *genpd = NULL, *gpd;
157
158         if (IS_ERR_OR_NULL(dev) || IS_ERR_OR_NULL(dev->pm_domain))
159                 return NULL;
160
161         mutex_lock(&gpd_list_lock);
162         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
163                 if (&gpd->domain == dev->pm_domain) {
164                         genpd = gpd;
165                         break;
166                 }
167         }
168         mutex_unlock(&gpd_list_lock);
169
170         return genpd;
171 }
172
173 /*
174  * This should only be used where we are certain that the pm_domain
175  * attached to the device is a genpd domain.
176  */
177 static struct generic_pm_domain *dev_to_genpd(struct device *dev)
178 {
179         if (IS_ERR_OR_NULL(dev->pm_domain))
180                 return ERR_PTR(-EINVAL);
181
182         return pd_to_genpd(dev->pm_domain);
183 }
184
185 static int genpd_stop_dev(const struct generic_pm_domain *genpd,
186                           struct device *dev)
187 {
188         return GENPD_DEV_CALLBACK(genpd, int, stop, dev);
189 }
190
191 static int genpd_start_dev(const struct generic_pm_domain *genpd,
192                            struct device *dev)
193 {
194         return GENPD_DEV_CALLBACK(genpd, int, start, dev);
195 }
196
197 static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd)
198 {
199         bool ret = false;
200
201         if (!WARN_ON(atomic_read(&genpd->sd_count) == 0))
202                 ret = !!atomic_dec_and_test(&genpd->sd_count);
203
204         return ret;
205 }
206
207 static void genpd_sd_counter_inc(struct generic_pm_domain *genpd)
208 {
209         atomic_inc(&genpd->sd_count);
210         smp_mb__after_atomic();
211 }
212
213 #ifdef CONFIG_DEBUG_FS
214 static void genpd_update_accounting(struct generic_pm_domain *genpd)
215 {
216         ktime_t delta, now;
217
218         now = ktime_get();
219         delta = ktime_sub(now, genpd->accounting_time);
220
221         /*
222          * If genpd->status is active, it means we are just
223          * out of off and so update the idle time and vice
224          * versa.
225          */
226         if (genpd->status == GPD_STATE_ACTIVE) {
227                 int state_idx = genpd->state_idx;
228
229                 genpd->states[state_idx].idle_time =
230                         ktime_add(genpd->states[state_idx].idle_time, delta);
231         } else {
232                 genpd->on_time = ktime_add(genpd->on_time, delta);
233         }
234
235         genpd->accounting_time = now;
236 }
237 #else
238 static inline void genpd_update_accounting(struct generic_pm_domain *genpd) {}
239 #endif
240
241 /**
242  * dev_pm_genpd_set_performance_state- Set performance state of device's power
243  * domain.
244  *
245  * @dev: Device for which the performance-state needs to be set.
246  * @state: Target performance state of the device. This can be set as 0 when the
247  *         device doesn't have any performance state constraints left (And so
248  *         the device wouldn't participate anymore to find the target
249  *         performance state of the genpd).
250  *
251  * It is assumed that the users guarantee that the genpd wouldn't be detached
252  * while this routine is getting called.
253  *
254  * Returns 0 on success and negative error values on failures.
255  */
256 int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state)
257 {
258         struct generic_pm_domain *genpd;
259         struct generic_pm_domain_data *gpd_data, *pd_data;
260         struct pm_domain_data *pdd;
261         unsigned int prev;
262         int ret = 0;
263
264         genpd = dev_to_genpd(dev);
265         if (IS_ERR(genpd))
266                 return -ENODEV;
267
268         if (unlikely(!genpd->set_performance_state))
269                 return -EINVAL;
270
271         if (unlikely(!dev->power.subsys_data ||
272                      !dev->power.subsys_data->domain_data)) {
273                 WARN_ON(1);
274                 return -EINVAL;
275         }
276
277         genpd_lock(genpd);
278
279         gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
280         prev = gpd_data->performance_state;
281         gpd_data->performance_state = state;
282
283         /* New requested state is same as Max requested state */
284         if (state == genpd->performance_state)
285                 goto unlock;
286
287         /* New requested state is higher than Max requested state */
288         if (state > genpd->performance_state)
289                 goto update_state;
290
291         /* Traverse all devices within the domain */
292         list_for_each_entry(pdd, &genpd->dev_list, list_node) {
293                 pd_data = to_gpd_data(pdd);
294
295                 if (pd_data->performance_state > state)
296                         state = pd_data->performance_state;
297         }
298
299         if (state == genpd->performance_state)
300                 goto unlock;
301
302         /*
303          * We aren't propagating performance state changes of a subdomain to its
304          * masters as we don't have hardware that needs it. Over that, the
305          * performance states of subdomain and its masters may not have
306          * one-to-one mapping and would require additional information. We can
307          * get back to this once we have hardware that needs it. For that
308          * reason, we don't have to consider performance state of the subdomains
309          * of genpd here.
310          */
311
312 update_state:
313         if (genpd_status_on(genpd)) {
314                 ret = genpd->set_performance_state(genpd, state);
315                 if (ret) {
316                         gpd_data->performance_state = prev;
317                         goto unlock;
318                 }
319         }
320
321         genpd->performance_state = state;
322
323 unlock:
324         genpd_unlock(genpd);
325
326         return ret;
327 }
328 EXPORT_SYMBOL_GPL(dev_pm_genpd_set_performance_state);
329
330 static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed)
331 {
332         unsigned int state_idx = genpd->state_idx;
333         ktime_t time_start;
334         s64 elapsed_ns;
335         int ret;
336
337         if (!genpd->power_on)
338                 return 0;
339
340         if (!timed)
341                 return genpd->power_on(genpd);
342
343         time_start = ktime_get();
344         ret = genpd->power_on(genpd);
345         if (ret)
346                 return ret;
347
348         elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
349
350         if (unlikely(genpd->set_performance_state)) {
351                 ret = genpd->set_performance_state(genpd, genpd->performance_state);
352                 if (ret) {
353                         pr_warn("%s: Failed to set performance state %d (%d)\n",
354                                 genpd->name, genpd->performance_state, ret);
355                 }
356         }
357
358         if (elapsed_ns <= genpd->states[state_idx].power_on_latency_ns)
359                 return ret;
360
361         genpd->states[state_idx].power_on_latency_ns = elapsed_ns;
362         genpd->max_off_time_changed = true;
363         pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
364                  genpd->name, "on", elapsed_ns);
365
366         return ret;
367 }
368
369 static int _genpd_power_off(struct generic_pm_domain *genpd, bool timed)
370 {
371         unsigned int state_idx = genpd->state_idx;
372         ktime_t time_start;
373         s64 elapsed_ns;
374         int ret;
375
376         if (!genpd->power_off)
377                 return 0;
378
379         if (!timed)
380                 return genpd->power_off(genpd);
381
382         time_start = ktime_get();
383         ret = genpd->power_off(genpd);
384         if (ret == -EBUSY)
385                 return ret;
386
387         elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
388         if (elapsed_ns <= genpd->states[state_idx].power_off_latency_ns)
389                 return ret;
390
391         genpd->states[state_idx].power_off_latency_ns = elapsed_ns;
392         genpd->max_off_time_changed = true;
393         pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
394                  genpd->name, "off", elapsed_ns);
395
396         return ret;
397 }
398
399 /**
400  * genpd_queue_power_off_work - Queue up the execution of genpd_power_off().
401  * @genpd: PM domain to power off.
402  *
403  * Queue up the execution of genpd_power_off() unless it's already been done
404  * before.
405  */
406 static void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
407 {
408         queue_work(pm_wq, &genpd->power_off_work);
409 }
410
411 /**
412  * genpd_power_off - Remove power from a given PM domain.
413  * @genpd: PM domain to power down.
414  * @one_dev_on: If invoked from genpd's ->runtime_suspend|resume() callback, the
415  * RPM status of the releated device is in an intermediate state, not yet turned
416  * into RPM_SUSPENDED. This means genpd_power_off() must allow one device to not
417  * be RPM_SUSPENDED, while it tries to power off the PM domain.
418  *
419  * If all of the @genpd's devices have been suspended and all of its subdomains
420  * have been powered down, remove power from @genpd.
421  */
422 static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on,
423                            unsigned int depth)
424 {
425         struct pm_domain_data *pdd;
426         struct gpd_link *link;
427         unsigned int not_suspended = 0;
428
429         /*
430          * Do not try to power off the domain in the following situations:
431          * (1) The domain is already in the "power off" state.
432          * (2) System suspend is in progress.
433          */
434         if (!genpd_status_on(genpd) || genpd->prepared_count > 0)
435                 return 0;
436
437         /*
438          * Abort power off for the PM domain in the following situations:
439          * (1) The domain is configured as always on.
440          * (2) When the domain has a subdomain being powered on.
441          */
442         if (genpd_is_always_on(genpd) || atomic_read(&genpd->sd_count) > 0)
443                 return -EBUSY;
444
445         list_for_each_entry(pdd, &genpd->dev_list, list_node) {
446                 enum pm_qos_flags_status stat;
447
448                 stat = dev_pm_qos_flags(pdd->dev, PM_QOS_FLAG_NO_POWER_OFF);
449                 if (stat > PM_QOS_FLAGS_NONE)
450                         return -EBUSY;
451
452                 /*
453                  * Do not allow PM domain to be powered off, when an IRQ safe
454                  * device is part of a non-IRQ safe domain.
455                  */
456                 if (!pm_runtime_suspended(pdd->dev) ||
457                         irq_safe_dev_in_no_sleep_domain(pdd->dev, genpd))
458                         not_suspended++;
459         }
460
461         if (not_suspended > 1 || (not_suspended == 1 && !one_dev_on))
462                 return -EBUSY;
463
464         if (genpd->gov && genpd->gov->power_down_ok) {
465                 if (!genpd->gov->power_down_ok(&genpd->domain))
466                         return -EAGAIN;
467         }
468
469         if (genpd->power_off) {
470                 int ret;
471
472                 if (atomic_read(&genpd->sd_count) > 0)
473                         return -EBUSY;
474
475                 /*
476                  * If sd_count > 0 at this point, one of the subdomains hasn't
477                  * managed to call genpd_power_on() for the master yet after
478                  * incrementing it.  In that case genpd_power_on() will wait
479                  * for us to drop the lock, so we can call .power_off() and let
480                  * the genpd_power_on() restore power for us (this shouldn't
481                  * happen very often).
482                  */
483                 ret = _genpd_power_off(genpd, true);
484                 if (ret)
485                         return ret;
486         }
487
488         genpd->status = GPD_STATE_POWER_OFF;
489         genpd_update_accounting(genpd);
490
491         list_for_each_entry(link, &genpd->slave_links, slave_node) {
492                 genpd_sd_counter_dec(link->master);
493                 genpd_lock_nested(link->master, depth + 1);
494                 genpd_power_off(link->master, false, depth + 1);
495                 genpd_unlock(link->master);
496         }
497
498         return 0;
499 }
500
501 /**
502  * genpd_power_on - Restore power to a given PM domain and its masters.
503  * @genpd: PM domain to power up.
504  * @depth: nesting count for lockdep.
505  *
506  * Restore power to @genpd and all of its masters so that it is possible to
507  * resume a device belonging to it.
508  */
509 static int genpd_power_on(struct generic_pm_domain *genpd, unsigned int depth)
510 {
511         struct gpd_link *link;
512         int ret = 0;
513
514         if (genpd_status_on(genpd))
515                 return 0;
516
517         /*
518          * The list is guaranteed not to change while the loop below is being
519          * executed, unless one of the masters' .power_on() callbacks fiddles
520          * with it.
521          */
522         list_for_each_entry(link, &genpd->slave_links, slave_node) {
523                 struct generic_pm_domain *master = link->master;
524
525                 genpd_sd_counter_inc(master);
526
527                 genpd_lock_nested(master, depth + 1);
528                 ret = genpd_power_on(master, depth + 1);
529                 genpd_unlock(master);
530
531                 if (ret) {
532                         genpd_sd_counter_dec(master);
533                         goto err;
534                 }
535         }
536
537         ret = _genpd_power_on(genpd, true);
538         if (ret)
539                 goto err;
540
541         genpd->status = GPD_STATE_ACTIVE;
542         genpd_update_accounting(genpd);
543
544         return 0;
545
546  err:
547         list_for_each_entry_continue_reverse(link,
548                                         &genpd->slave_links,
549                                         slave_node) {
550                 genpd_sd_counter_dec(link->master);
551                 genpd_lock_nested(link->master, depth + 1);
552                 genpd_power_off(link->master, false, depth + 1);
553                 genpd_unlock(link->master);
554         }
555
556         return ret;
557 }
558
559 static int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
560                                      unsigned long val, void *ptr)
561 {
562         struct generic_pm_domain_data *gpd_data;
563         struct device *dev;
564
565         gpd_data = container_of(nb, struct generic_pm_domain_data, nb);
566         dev = gpd_data->base.dev;
567
568         for (;;) {
569                 struct generic_pm_domain *genpd;
570                 struct pm_domain_data *pdd;
571
572                 spin_lock_irq(&dev->power.lock);
573
574                 pdd = dev->power.subsys_data ?
575                                 dev->power.subsys_data->domain_data : NULL;
576                 if (pdd) {
577                         to_gpd_data(pdd)->td.constraint_changed = true;
578                         genpd = dev_to_genpd(dev);
579                 } else {
580                         genpd = ERR_PTR(-ENODATA);
581                 }
582
583                 spin_unlock_irq(&dev->power.lock);
584
585                 if (!IS_ERR(genpd)) {
586                         genpd_lock(genpd);
587                         genpd->max_off_time_changed = true;
588                         genpd_unlock(genpd);
589                 }
590
591                 dev = dev->parent;
592                 if (!dev || dev->power.ignore_children)
593                         break;
594         }
595
596         return NOTIFY_DONE;
597 }
598
599 /**
600  * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0.
601  * @work: Work structure used for scheduling the execution of this function.
602  */
603 static void genpd_power_off_work_fn(struct work_struct *work)
604 {
605         struct generic_pm_domain *genpd;
606
607         genpd = container_of(work, struct generic_pm_domain, power_off_work);
608
609         genpd_lock(genpd);
610         genpd_power_off(genpd, false, 0);
611         genpd_unlock(genpd);
612 }
613
614 /**
615  * __genpd_runtime_suspend - walk the hierarchy of ->runtime_suspend() callbacks
616  * @dev: Device to handle.
617  */
618 static int __genpd_runtime_suspend(struct device *dev)
619 {
620         int (*cb)(struct device *__dev);
621
622         if (dev->type && dev->type->pm)
623                 cb = dev->type->pm->runtime_suspend;
624         else if (dev->class && dev->class->pm)
625                 cb = dev->class->pm->runtime_suspend;
626         else if (dev->bus && dev->bus->pm)
627                 cb = dev->bus->pm->runtime_suspend;
628         else
629                 cb = NULL;
630
631         if (!cb && dev->driver && dev->driver->pm)
632                 cb = dev->driver->pm->runtime_suspend;
633
634         return cb ? cb(dev) : 0;
635 }
636
637 /**
638  * __genpd_runtime_resume - walk the hierarchy of ->runtime_resume() callbacks
639  * @dev: Device to handle.
640  */
641 static int __genpd_runtime_resume(struct device *dev)
642 {
643         int (*cb)(struct device *__dev);
644
645         if (dev->type && dev->type->pm)
646                 cb = dev->type->pm->runtime_resume;
647         else if (dev->class && dev->class->pm)
648                 cb = dev->class->pm->runtime_resume;
649         else if (dev->bus && dev->bus->pm)
650                 cb = dev->bus->pm->runtime_resume;
651         else
652                 cb = NULL;
653
654         if (!cb && dev->driver && dev->driver->pm)
655                 cb = dev->driver->pm->runtime_resume;
656
657         return cb ? cb(dev) : 0;
658 }
659
660 /**
661  * genpd_runtime_suspend - Suspend a device belonging to I/O PM domain.
662  * @dev: Device to suspend.
663  *
664  * Carry out a runtime suspend of a device under the assumption that its
665  * pm_domain field points to the domain member of an object of type
666  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
667  */
668 static int genpd_runtime_suspend(struct device *dev)
669 {
670         struct generic_pm_domain *genpd;
671         bool (*suspend_ok)(struct device *__dev);
672         struct gpd_timing_data *td = &dev_gpd_data(dev)->td;
673         bool runtime_pm = pm_runtime_enabled(dev);
674         ktime_t time_start;
675         s64 elapsed_ns;
676         int ret;
677
678         dev_dbg(dev, "%s()\n", __func__);
679
680         genpd = dev_to_genpd(dev);
681         if (IS_ERR(genpd))
682                 return -EINVAL;
683
684         /*
685          * A runtime PM centric subsystem/driver may re-use the runtime PM
686          * callbacks for other purposes than runtime PM. In those scenarios
687          * runtime PM is disabled. Under these circumstances, we shall skip
688          * validating/measuring the PM QoS latency.
689          */
690         suspend_ok = genpd->gov ? genpd->gov->suspend_ok : NULL;
691         if (runtime_pm && suspend_ok && !suspend_ok(dev))
692                 return -EBUSY;
693
694         /* Measure suspend latency. */
695         time_start = 0;
696         if (runtime_pm)
697                 time_start = ktime_get();
698
699         ret = __genpd_runtime_suspend(dev);
700         if (ret)
701                 return ret;
702
703         ret = genpd_stop_dev(genpd, dev);
704         if (ret) {
705                 __genpd_runtime_resume(dev);
706                 return ret;
707         }
708
709         /* Update suspend latency value if the measured time exceeds it. */
710         if (runtime_pm) {
711                 elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
712                 if (elapsed_ns > td->suspend_latency_ns) {
713                         td->suspend_latency_ns = elapsed_ns;
714                         dev_dbg(dev, "suspend latency exceeded, %lld ns\n",
715                                 elapsed_ns);
716                         genpd->max_off_time_changed = true;
717                         td->constraint_changed = true;
718                 }
719         }
720
721         /*
722          * If power.irq_safe is set, this routine may be run with
723          * IRQs disabled, so suspend only if the PM domain also is irq_safe.
724          */
725         if (irq_safe_dev_in_no_sleep_domain(dev, genpd))
726                 return 0;
727
728         genpd_lock(genpd);
729         genpd_power_off(genpd, true, 0);
730         genpd_unlock(genpd);
731
732         return 0;
733 }
734
735 /**
736  * genpd_runtime_resume - Resume a device belonging to I/O PM domain.
737  * @dev: Device to resume.
738  *
739  * Carry out a runtime resume of a device under the assumption that its
740  * pm_domain field points to the domain member of an object of type
741  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
742  */
743 static int genpd_runtime_resume(struct device *dev)
744 {
745         struct generic_pm_domain *genpd;
746         struct gpd_timing_data *td = &dev_gpd_data(dev)->td;
747         bool runtime_pm = pm_runtime_enabled(dev);
748         ktime_t time_start;
749         s64 elapsed_ns;
750         int ret;
751         bool timed = true;
752
753         dev_dbg(dev, "%s()\n", __func__);
754
755         genpd = dev_to_genpd(dev);
756         if (IS_ERR(genpd))
757                 return -EINVAL;
758
759         /*
760          * As we don't power off a non IRQ safe domain, which holds
761          * an IRQ safe device, we don't need to restore power to it.
762          */
763         if (irq_safe_dev_in_no_sleep_domain(dev, genpd)) {
764                 timed = false;
765                 goto out;
766         }
767
768         genpd_lock(genpd);
769         ret = genpd_power_on(genpd, 0);
770         genpd_unlock(genpd);
771
772         if (ret)
773                 return ret;
774
775  out:
776         /* Measure resume latency. */
777         time_start = 0;
778         if (timed && runtime_pm)
779                 time_start = ktime_get();
780
781         ret = genpd_start_dev(genpd, dev);
782         if (ret)
783                 goto err_poweroff;
784
785         ret = __genpd_runtime_resume(dev);
786         if (ret)
787                 goto err_stop;
788
789         /* Update resume latency value if the measured time exceeds it. */
790         if (timed && runtime_pm) {
791                 elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
792                 if (elapsed_ns > td->resume_latency_ns) {
793                         td->resume_latency_ns = elapsed_ns;
794                         dev_dbg(dev, "resume latency exceeded, %lld ns\n",
795                                 elapsed_ns);
796                         genpd->max_off_time_changed = true;
797                         td->constraint_changed = true;
798                 }
799         }
800
801         return 0;
802
803 err_stop:
804         genpd_stop_dev(genpd, dev);
805 err_poweroff:
806         if (!pm_runtime_is_irq_safe(dev) ||
807                 (pm_runtime_is_irq_safe(dev) && genpd_is_irq_safe(genpd))) {
808                 genpd_lock(genpd);
809                 genpd_power_off(genpd, true, 0);
810                 genpd_unlock(genpd);
811         }
812
813         return ret;
814 }
815
816 static bool pd_ignore_unused;
817 static int __init pd_ignore_unused_setup(char *__unused)
818 {
819         pd_ignore_unused = true;
820         return 1;
821 }
822 __setup("pd_ignore_unused", pd_ignore_unused_setup);
823
824 /**
825  * genpd_power_off_unused - Power off all PM domains with no devices in use.
826  */
827 static int __init genpd_power_off_unused(void)
828 {
829         struct generic_pm_domain *genpd;
830
831         if (pd_ignore_unused) {
832                 pr_warn("genpd: Not disabling unused power domains\n");
833                 return 0;
834         }
835
836         mutex_lock(&gpd_list_lock);
837
838         list_for_each_entry(genpd, &gpd_list, gpd_list_node)
839                 genpd_queue_power_off_work(genpd);
840
841         mutex_unlock(&gpd_list_lock);
842
843         return 0;
844 }
845 late_initcall(genpd_power_off_unused);
846
847 #if defined(CONFIG_PM_SLEEP) || defined(CONFIG_PM_GENERIC_DOMAINS_OF)
848
849 static bool genpd_present(const struct generic_pm_domain *genpd)
850 {
851         const struct generic_pm_domain *gpd;
852
853         if (IS_ERR_OR_NULL(genpd))
854                 return false;
855
856         list_for_each_entry(gpd, &gpd_list, gpd_list_node)
857                 if (gpd == genpd)
858                         return true;
859
860         return false;
861 }
862
863 #endif
864
865 #ifdef CONFIG_PM_SLEEP
866
867 /**
868  * genpd_sync_power_off - Synchronously power off a PM domain and its masters.
869  * @genpd: PM domain to power off, if possible.
870  * @use_lock: use the lock.
871  * @depth: nesting count for lockdep.
872  *
873  * Check if the given PM domain can be powered off (during system suspend or
874  * hibernation) and do that if so.  Also, in that case propagate to its masters.
875  *
876  * This function is only called in "noirq" and "syscore" stages of system power
877  * transitions. The "noirq" callbacks may be executed asynchronously, thus in
878  * these cases the lock must be held.
879  */
880 static void genpd_sync_power_off(struct generic_pm_domain *genpd, bool use_lock,
881                                  unsigned int depth)
882 {
883         struct gpd_link *link;
884
885         if (!genpd_status_on(genpd) || genpd_is_always_on(genpd))
886                 return;
887
888         if (genpd->suspended_count != genpd->device_count
889             || atomic_read(&genpd->sd_count) > 0)
890                 return;
891
892         /* Choose the deepest state when suspending */
893         genpd->state_idx = genpd->state_count - 1;
894         if (_genpd_power_off(genpd, false))
895                 return;
896
897         genpd->status = GPD_STATE_POWER_OFF;
898
899         list_for_each_entry(link, &genpd->slave_links, slave_node) {
900                 genpd_sd_counter_dec(link->master);
901
902                 if (use_lock)
903                         genpd_lock_nested(link->master, depth + 1);
904
905                 genpd_sync_power_off(link->master, use_lock, depth + 1);
906
907                 if (use_lock)
908                         genpd_unlock(link->master);
909         }
910 }
911
912 /**
913  * genpd_sync_power_on - Synchronously power on a PM domain and its masters.
914  * @genpd: PM domain to power on.
915  * @use_lock: use the lock.
916  * @depth: nesting count for lockdep.
917  *
918  * This function is only called in "noirq" and "syscore" stages of system power
919  * transitions. The "noirq" callbacks may be executed asynchronously, thus in
920  * these cases the lock must be held.
921  */
922 static void genpd_sync_power_on(struct generic_pm_domain *genpd, bool use_lock,
923                                 unsigned int depth)
924 {
925         struct gpd_link *link;
926
927         if (genpd_status_on(genpd))
928                 return;
929
930         list_for_each_entry(link, &genpd->slave_links, slave_node) {
931                 genpd_sd_counter_inc(link->master);
932
933                 if (use_lock)
934                         genpd_lock_nested(link->master, depth + 1);
935
936                 genpd_sync_power_on(link->master, use_lock, depth + 1);
937
938                 if (use_lock)
939                         genpd_unlock(link->master);
940         }
941
942         _genpd_power_on(genpd, false);
943
944         genpd->status = GPD_STATE_ACTIVE;
945 }
946
947 /**
948  * resume_needed - Check whether to resume a device before system suspend.
949  * @dev: Device to check.
950  * @genpd: PM domain the device belongs to.
951  *
952  * There are two cases in which a device that can wake up the system from sleep
953  * states should be resumed by genpd_prepare(): (1) if the device is enabled
954  * to wake up the system and it has to remain active for this purpose while the
955  * system is in the sleep state and (2) if the device is not enabled to wake up
956  * the system from sleep states and it generally doesn't generate wakeup signals
957  * by itself (those signals are generated on its behalf by other parts of the
958  * system).  In the latter case it may be necessary to reconfigure the device's
959  * wakeup settings during system suspend, because it may have been set up to
960  * signal remote wakeup from the system's working state as needed by runtime PM.
961  * Return 'true' in either of the above cases.
962  */
963 static bool resume_needed(struct device *dev,
964                           const struct generic_pm_domain *genpd)
965 {
966         bool active_wakeup;
967
968         if (!device_can_wakeup(dev))
969                 return false;
970
971         active_wakeup = genpd_is_active_wakeup(genpd);
972         return device_may_wakeup(dev) ? active_wakeup : !active_wakeup;
973 }
974
975 /**
976  * genpd_prepare - Start power transition of a device in a PM domain.
977  * @dev: Device to start the transition of.
978  *
979  * Start a power transition of a device (during a system-wide power transition)
980  * under the assumption that its pm_domain field points to the domain member of
981  * an object of type struct generic_pm_domain representing a PM domain
982  * consisting of I/O devices.
983  */
984 static int genpd_prepare(struct device *dev)
985 {
986         struct generic_pm_domain *genpd;
987         int ret;
988
989         dev_dbg(dev, "%s()\n", __func__);
990
991         genpd = dev_to_genpd(dev);
992         if (IS_ERR(genpd))
993                 return -EINVAL;
994
995         /*
996          * If a wakeup request is pending for the device, it should be woken up
997          * at this point and a system wakeup event should be reported if it's
998          * set up to wake up the system from sleep states.
999          */
1000         if (resume_needed(dev, genpd))
1001                 pm_runtime_resume(dev);
1002
1003         genpd_lock(genpd);
1004
1005         if (genpd->prepared_count++ == 0)
1006                 genpd->suspended_count = 0;
1007
1008         genpd_unlock(genpd);
1009
1010         ret = pm_generic_prepare(dev);
1011         if (ret) {
1012                 genpd_lock(genpd);
1013
1014                 genpd->prepared_count--;
1015
1016                 genpd_unlock(genpd);
1017         }
1018
1019         return ret;
1020 }
1021
1022 /**
1023  * genpd_finish_suspend - Completion of suspend or hibernation of device in an
1024  *   I/O pm domain.
1025  * @dev: Device to suspend.
1026  * @poweroff: Specifies if this is a poweroff_noirq or suspend_noirq callback.
1027  *
1028  * Stop the device and remove power from the domain if all devices in it have
1029  * been stopped.
1030  */
1031 static int genpd_finish_suspend(struct device *dev, bool poweroff)
1032 {
1033         struct generic_pm_domain *genpd;
1034         int ret;
1035
1036         genpd = dev_to_genpd(dev);
1037         if (IS_ERR(genpd))
1038                 return -EINVAL;
1039
1040         if (dev->power.wakeup_path && genpd_is_active_wakeup(genpd))
1041                 return 0;
1042
1043         if (poweroff)
1044                 ret = pm_generic_poweroff_noirq(dev);
1045         else
1046                 ret = pm_generic_suspend_noirq(dev);
1047         if (ret)
1048                 return ret;
1049
1050         if (genpd->dev_ops.stop && genpd->dev_ops.start) {
1051                 ret = pm_runtime_force_suspend(dev);
1052                 if (ret)
1053                         return ret;
1054         }
1055
1056         genpd_lock(genpd);
1057         genpd->suspended_count++;
1058         genpd_sync_power_off(genpd, true, 0);
1059         genpd_unlock(genpd);
1060
1061         return 0;
1062 }
1063
1064 /**
1065  * genpd_suspend_noirq - Completion of suspend of device in an I/O PM domain.
1066  * @dev: Device to suspend.
1067  *
1068  * Stop the device and remove power from the domain if all devices in it have
1069  * been stopped.
1070  */
1071 static int genpd_suspend_noirq(struct device *dev)
1072 {
1073         dev_dbg(dev, "%s()\n", __func__);
1074
1075         return genpd_finish_suspend(dev, false);
1076 }
1077
1078 /**
1079  * genpd_resume_noirq - Start of resume of device in an I/O PM domain.
1080  * @dev: Device to resume.
1081  *
1082  * Restore power to the device's PM domain, if necessary, and start the device.
1083  */
1084 static int genpd_resume_noirq(struct device *dev)
1085 {
1086         struct generic_pm_domain *genpd;
1087         int ret = 0;
1088
1089         dev_dbg(dev, "%s()\n", __func__);
1090
1091         genpd = dev_to_genpd(dev);
1092         if (IS_ERR(genpd))
1093                 return -EINVAL;
1094
1095         if (dev->power.wakeup_path && genpd_is_active_wakeup(genpd))
1096                 return 0;
1097
1098         genpd_lock(genpd);
1099         genpd_sync_power_on(genpd, true, 0);
1100         genpd->suspended_count--;
1101         genpd_unlock(genpd);
1102
1103         if (genpd->dev_ops.stop && genpd->dev_ops.start)
1104                 ret = pm_runtime_force_resume(dev);
1105
1106         ret = pm_generic_resume_noirq(dev);
1107         if (ret)
1108                 return ret;
1109
1110         return ret;
1111 }
1112
1113 /**
1114  * genpd_freeze_noirq - Completion of freezing a device in an I/O PM domain.
1115  * @dev: Device to freeze.
1116  *
1117  * Carry out a late freeze of a device under the assumption that its
1118  * pm_domain field points to the domain member of an object of type
1119  * struct generic_pm_domain representing a power domain consisting of I/O
1120  * devices.
1121  */
1122 static int genpd_freeze_noirq(struct device *dev)
1123 {
1124         const struct generic_pm_domain *genpd;
1125         int ret = 0;
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         ret = pm_generic_freeze_noirq(dev);
1134         if (ret)
1135                 return ret;
1136
1137         if (genpd->dev_ops.stop && genpd->dev_ops.start)
1138                 ret = pm_runtime_force_suspend(dev);
1139
1140         return ret;
1141 }
1142
1143 /**
1144  * genpd_thaw_noirq - Early thaw of device in an I/O PM domain.
1145  * @dev: Device to thaw.
1146  *
1147  * Start the device, unless power has been removed from the domain already
1148  * before the system transition.
1149  */
1150 static int genpd_thaw_noirq(struct device *dev)
1151 {
1152         const struct generic_pm_domain *genpd;
1153         int ret = 0;
1154
1155         dev_dbg(dev, "%s()\n", __func__);
1156
1157         genpd = dev_to_genpd(dev);
1158         if (IS_ERR(genpd))
1159                 return -EINVAL;
1160
1161         if (genpd->dev_ops.stop && genpd->dev_ops.start) {
1162                 ret = pm_runtime_force_resume(dev);
1163                 if (ret)
1164                         return ret;
1165         }
1166
1167         return pm_generic_thaw_noirq(dev);
1168 }
1169
1170 /**
1171  * genpd_poweroff_noirq - Completion of hibernation of device in an
1172  *   I/O PM domain.
1173  * @dev: Device to poweroff.
1174  *
1175  * Stop the device and remove power from the domain if all devices in it have
1176  * been stopped.
1177  */
1178 static int genpd_poweroff_noirq(struct device *dev)
1179 {
1180         dev_dbg(dev, "%s()\n", __func__);
1181
1182         return genpd_finish_suspend(dev, true);
1183 }
1184
1185 /**
1186  * genpd_restore_noirq - Start of restore of device in an I/O PM domain.
1187  * @dev: Device to resume.
1188  *
1189  * Make sure the domain will be in the same power state as before the
1190  * hibernation the system is resuming from and start the device if necessary.
1191  */
1192 static int genpd_restore_noirq(struct device *dev)
1193 {
1194         struct generic_pm_domain *genpd;
1195         int ret = 0;
1196
1197         dev_dbg(dev, "%s()\n", __func__);
1198
1199         genpd = dev_to_genpd(dev);
1200         if (IS_ERR(genpd))
1201                 return -EINVAL;
1202
1203         /*
1204          * At this point suspended_count == 0 means we are being run for the
1205          * first time for the given domain in the present cycle.
1206          */
1207         genpd_lock(genpd);
1208         if (genpd->suspended_count++ == 0)
1209                 /*
1210                  * The boot kernel might put the domain into arbitrary state,
1211                  * so make it appear as powered off to genpd_sync_power_on(),
1212                  * so that it tries to power it on in case it was really off.
1213                  */
1214                 genpd->status = GPD_STATE_POWER_OFF;
1215
1216         genpd_sync_power_on(genpd, true, 0);
1217         genpd_unlock(genpd);
1218
1219         if (genpd->dev_ops.stop && genpd->dev_ops.start) {
1220                 ret = pm_runtime_force_resume(dev);
1221                 if (ret)
1222                         return ret;
1223         }
1224
1225         return pm_generic_restore_noirq(dev);
1226 }
1227
1228 /**
1229  * genpd_complete - Complete power transition of a device in a power domain.
1230  * @dev: Device to complete the transition of.
1231  *
1232  * Complete a power transition of a device (during a system-wide power
1233  * transition) under the assumption that its pm_domain field points to the
1234  * domain member of an object of type struct generic_pm_domain representing
1235  * a power domain consisting of I/O devices.
1236  */
1237 static void genpd_complete(struct device *dev)
1238 {
1239         struct generic_pm_domain *genpd;
1240
1241         dev_dbg(dev, "%s()\n", __func__);
1242
1243         genpd = dev_to_genpd(dev);
1244         if (IS_ERR(genpd))
1245                 return;
1246
1247         pm_generic_complete(dev);
1248
1249         genpd_lock(genpd);
1250
1251         genpd->prepared_count--;
1252         if (!genpd->prepared_count)
1253                 genpd_queue_power_off_work(genpd);
1254
1255         genpd_unlock(genpd);
1256 }
1257
1258 /**
1259  * genpd_syscore_switch - Switch power during system core suspend or resume.
1260  * @dev: Device that normally is marked as "always on" to switch power for.
1261  *
1262  * This routine may only be called during the system core (syscore) suspend or
1263  * resume phase for devices whose "always on" flags are set.
1264  */
1265 static void genpd_syscore_switch(struct device *dev, bool suspend)
1266 {
1267         struct generic_pm_domain *genpd;
1268
1269         genpd = dev_to_genpd(dev);
1270         if (!genpd_present(genpd))
1271                 return;
1272
1273         if (suspend) {
1274                 genpd->suspended_count++;
1275                 genpd_sync_power_off(genpd, false, 0);
1276         } else {
1277                 genpd_sync_power_on(genpd, false, 0);
1278                 genpd->suspended_count--;
1279         }
1280 }
1281
1282 void pm_genpd_syscore_poweroff(struct device *dev)
1283 {
1284         genpd_syscore_switch(dev, true);
1285 }
1286 EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweroff);
1287
1288 void pm_genpd_syscore_poweron(struct device *dev)
1289 {
1290         genpd_syscore_switch(dev, false);
1291 }
1292 EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweron);
1293
1294 #else /* !CONFIG_PM_SLEEP */
1295
1296 #define genpd_prepare           NULL
1297 #define genpd_suspend_noirq     NULL
1298 #define genpd_resume_noirq      NULL
1299 #define genpd_freeze_noirq      NULL
1300 #define genpd_thaw_noirq        NULL
1301 #define genpd_poweroff_noirq    NULL
1302 #define genpd_restore_noirq     NULL
1303 #define genpd_complete          NULL
1304
1305 #endif /* CONFIG_PM_SLEEP */
1306
1307 static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
1308                                         struct generic_pm_domain *genpd,
1309                                         struct gpd_timing_data *td)
1310 {
1311         struct generic_pm_domain_data *gpd_data;
1312         int ret;
1313
1314         ret = dev_pm_get_subsys_data(dev);
1315         if (ret)
1316                 return ERR_PTR(ret);
1317
1318         gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL);
1319         if (!gpd_data) {
1320                 ret = -ENOMEM;
1321                 goto err_put;
1322         }
1323
1324         if (td)
1325                 gpd_data->td = *td;
1326
1327         gpd_data->base.dev = dev;
1328         gpd_data->td.constraint_changed = true;
1329         gpd_data->td.effective_constraint_ns = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS;
1330         gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
1331
1332         spin_lock_irq(&dev->power.lock);
1333
1334         if (dev->power.subsys_data->domain_data) {
1335                 ret = -EINVAL;
1336                 goto err_free;
1337         }
1338
1339         dev->power.subsys_data->domain_data = &gpd_data->base;
1340
1341         spin_unlock_irq(&dev->power.lock);
1342
1343         return gpd_data;
1344
1345  err_free:
1346         spin_unlock_irq(&dev->power.lock);
1347         kfree(gpd_data);
1348  err_put:
1349         dev_pm_put_subsys_data(dev);
1350         return ERR_PTR(ret);
1351 }
1352
1353 static void genpd_free_dev_data(struct device *dev,
1354                                 struct generic_pm_domain_data *gpd_data)
1355 {
1356         spin_lock_irq(&dev->power.lock);
1357
1358         dev->power.subsys_data->domain_data = NULL;
1359
1360         spin_unlock_irq(&dev->power.lock);
1361
1362         kfree(gpd_data);
1363         dev_pm_put_subsys_data(dev);
1364 }
1365
1366 static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
1367                             struct gpd_timing_data *td)
1368 {
1369         struct generic_pm_domain_data *gpd_data;
1370         int ret = 0;
1371
1372         dev_dbg(dev, "%s()\n", __func__);
1373
1374         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
1375                 return -EINVAL;
1376
1377         gpd_data = genpd_alloc_dev_data(dev, genpd, td);
1378         if (IS_ERR(gpd_data))
1379                 return PTR_ERR(gpd_data);
1380
1381         genpd_lock(genpd);
1382
1383         if (genpd->prepared_count > 0) {
1384                 ret = -EAGAIN;
1385                 goto out;
1386         }
1387
1388         ret = genpd->attach_dev ? genpd->attach_dev(genpd, dev) : 0;
1389         if (ret)
1390                 goto out;
1391
1392         dev_pm_domain_set(dev, &genpd->domain);
1393
1394         genpd->device_count++;
1395         genpd->max_off_time_changed = true;
1396
1397         list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
1398
1399  out:
1400         genpd_unlock(genpd);
1401
1402         if (ret)
1403                 genpd_free_dev_data(dev, gpd_data);
1404         else
1405                 dev_pm_qos_add_notifier(dev, &gpd_data->nb);
1406
1407         return ret;
1408 }
1409
1410 /**
1411  * __pm_genpd_add_device - Add a device to an I/O PM domain.
1412  * @genpd: PM domain to add the device to.
1413  * @dev: Device to be added.
1414  * @td: Set of PM QoS timing parameters to attach to the device.
1415  */
1416 int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
1417                           struct gpd_timing_data *td)
1418 {
1419         int ret;
1420
1421         mutex_lock(&gpd_list_lock);
1422         ret = genpd_add_device(genpd, dev, td);
1423         mutex_unlock(&gpd_list_lock);
1424
1425         return ret;
1426 }
1427 EXPORT_SYMBOL_GPL(__pm_genpd_add_device);
1428
1429 static int genpd_remove_device(struct generic_pm_domain *genpd,
1430                                struct device *dev)
1431 {
1432         struct generic_pm_domain_data *gpd_data;
1433         struct pm_domain_data *pdd;
1434         int ret = 0;
1435
1436         dev_dbg(dev, "%s()\n", __func__);
1437
1438         pdd = dev->power.subsys_data->domain_data;
1439         gpd_data = to_gpd_data(pdd);
1440         dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
1441
1442         genpd_lock(genpd);
1443
1444         if (genpd->prepared_count > 0) {
1445                 ret = -EAGAIN;
1446                 goto out;
1447         }
1448
1449         genpd->device_count--;
1450         genpd->max_off_time_changed = true;
1451
1452         if (genpd->detach_dev)
1453                 genpd->detach_dev(genpd, dev);
1454
1455         dev_pm_domain_set(dev, NULL);
1456
1457         list_del_init(&pdd->list_node);
1458
1459         genpd_unlock(genpd);
1460
1461         genpd_free_dev_data(dev, gpd_data);
1462
1463         return 0;
1464
1465  out:
1466         genpd_unlock(genpd);
1467         dev_pm_qos_add_notifier(dev, &gpd_data->nb);
1468
1469         return ret;
1470 }
1471
1472 /**
1473  * pm_genpd_remove_device - Remove a device from an I/O PM domain.
1474  * @genpd: PM domain to remove the device from.
1475  * @dev: Device to be removed.
1476  */
1477 int pm_genpd_remove_device(struct generic_pm_domain *genpd,
1478                            struct device *dev)
1479 {
1480         if (!genpd || genpd != genpd_lookup_dev(dev))
1481                 return -EINVAL;
1482
1483         return genpd_remove_device(genpd, dev);
1484 }
1485 EXPORT_SYMBOL_GPL(pm_genpd_remove_device);
1486
1487 static int genpd_add_subdomain(struct generic_pm_domain *genpd,
1488                                struct generic_pm_domain *subdomain)
1489 {
1490         struct gpd_link *link, *itr;
1491         int ret = 0;
1492
1493         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)
1494             || genpd == subdomain)
1495                 return -EINVAL;
1496
1497         /*
1498          * If the domain can be powered on/off in an IRQ safe
1499          * context, ensure that the subdomain can also be
1500          * powered on/off in that context.
1501          */
1502         if (!genpd_is_irq_safe(genpd) && genpd_is_irq_safe(subdomain)) {
1503                 WARN(1, "Parent %s of subdomain %s must be IRQ safe\n",
1504                                 genpd->name, subdomain->name);
1505                 return -EINVAL;
1506         }
1507
1508         link = kzalloc(sizeof(*link), GFP_KERNEL);
1509         if (!link)
1510                 return -ENOMEM;
1511
1512         genpd_lock(subdomain);
1513         genpd_lock_nested(genpd, SINGLE_DEPTH_NESTING);
1514
1515         if (!genpd_status_on(genpd) && genpd_status_on(subdomain)) {
1516                 ret = -EINVAL;
1517                 goto out;
1518         }
1519
1520         list_for_each_entry(itr, &genpd->master_links, master_node) {
1521                 if (itr->slave == subdomain && itr->master == genpd) {
1522                         ret = -EINVAL;
1523                         goto out;
1524                 }
1525         }
1526
1527         link->master = genpd;
1528         list_add_tail(&link->master_node, &genpd->master_links);
1529         link->slave = subdomain;
1530         list_add_tail(&link->slave_node, &subdomain->slave_links);
1531         if (genpd_status_on(subdomain))
1532                 genpd_sd_counter_inc(genpd);
1533
1534  out:
1535         genpd_unlock(genpd);
1536         genpd_unlock(subdomain);
1537         if (ret)
1538                 kfree(link);
1539         return ret;
1540 }
1541
1542 /**
1543  * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
1544  * @genpd: Master PM domain to add the subdomain to.
1545  * @subdomain: Subdomain to be added.
1546  */
1547 int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
1548                            struct generic_pm_domain *subdomain)
1549 {
1550         int ret;
1551
1552         mutex_lock(&gpd_list_lock);
1553         ret = genpd_add_subdomain(genpd, subdomain);
1554         mutex_unlock(&gpd_list_lock);
1555
1556         return ret;
1557 }
1558 EXPORT_SYMBOL_GPL(pm_genpd_add_subdomain);
1559
1560 /**
1561  * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain.
1562  * @genpd: Master PM domain to remove the subdomain from.
1563  * @subdomain: Subdomain to be removed.
1564  */
1565 int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
1566                               struct generic_pm_domain *subdomain)
1567 {
1568         struct gpd_link *l, *link;
1569         int ret = -EINVAL;
1570
1571         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain))
1572                 return -EINVAL;
1573
1574         genpd_lock(subdomain);
1575         genpd_lock_nested(genpd, SINGLE_DEPTH_NESTING);
1576
1577         if (!list_empty(&subdomain->master_links) || subdomain->device_count) {
1578                 pr_warn("%s: unable to remove subdomain %s\n", genpd->name,
1579                         subdomain->name);
1580                 ret = -EBUSY;
1581                 goto out;
1582         }
1583
1584         list_for_each_entry_safe(link, l, &genpd->master_links, master_node) {
1585                 if (link->slave != subdomain)
1586                         continue;
1587
1588                 list_del(&link->master_node);
1589                 list_del(&link->slave_node);
1590                 kfree(link);
1591                 if (genpd_status_on(subdomain))
1592                         genpd_sd_counter_dec(genpd);
1593
1594                 ret = 0;
1595                 break;
1596         }
1597
1598 out:
1599         genpd_unlock(genpd);
1600         genpd_unlock(subdomain);
1601
1602         return ret;
1603 }
1604 EXPORT_SYMBOL_GPL(pm_genpd_remove_subdomain);
1605
1606 static int genpd_set_default_power_state(struct generic_pm_domain *genpd)
1607 {
1608         struct genpd_power_state *state;
1609
1610         state = kzalloc(sizeof(*state), GFP_KERNEL);
1611         if (!state)
1612                 return -ENOMEM;
1613
1614         genpd->states = state;
1615         genpd->state_count = 1;
1616         genpd->free = state;
1617
1618         return 0;
1619 }
1620
1621 static void genpd_lock_init(struct generic_pm_domain *genpd)
1622 {
1623         if (genpd->flags & GENPD_FLAG_IRQ_SAFE) {
1624                 spin_lock_init(&genpd->slock);
1625                 genpd->lock_ops = &genpd_spin_ops;
1626         } else {
1627                 mutex_init(&genpd->mlock);
1628                 genpd->lock_ops = &genpd_mtx_ops;
1629         }
1630 }
1631
1632 /**
1633  * pm_genpd_init - Initialize a generic I/O PM domain object.
1634  * @genpd: PM domain object to initialize.
1635  * @gov: PM domain governor to associate with the domain (may be NULL).
1636  * @is_off: Initial value of the domain's power_is_off field.
1637  *
1638  * Returns 0 on successful initialization, else a negative error code.
1639  */
1640 int pm_genpd_init(struct generic_pm_domain *genpd,
1641                   struct dev_power_governor *gov, bool is_off)
1642 {
1643         int ret;
1644
1645         if (IS_ERR_OR_NULL(genpd))
1646                 return -EINVAL;
1647
1648         INIT_LIST_HEAD(&genpd->master_links);
1649         INIT_LIST_HEAD(&genpd->slave_links);
1650         INIT_LIST_HEAD(&genpd->dev_list);
1651         genpd_lock_init(genpd);
1652         genpd->gov = gov;
1653         INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
1654         atomic_set(&genpd->sd_count, 0);
1655         genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE;
1656         genpd->device_count = 0;
1657         genpd->max_off_time_ns = -1;
1658         genpd->max_off_time_changed = true;
1659         genpd->provider = NULL;
1660         genpd->has_provider = false;
1661         genpd->accounting_time = ktime_get();
1662         genpd->domain.ops.runtime_suspend = genpd_runtime_suspend;
1663         genpd->domain.ops.runtime_resume = genpd_runtime_resume;
1664         genpd->domain.ops.prepare = genpd_prepare;
1665         genpd->domain.ops.suspend_noirq = genpd_suspend_noirq;
1666         genpd->domain.ops.resume_noirq = genpd_resume_noirq;
1667         genpd->domain.ops.freeze_noirq = genpd_freeze_noirq;
1668         genpd->domain.ops.thaw_noirq = genpd_thaw_noirq;
1669         genpd->domain.ops.poweroff_noirq = genpd_poweroff_noirq;
1670         genpd->domain.ops.restore_noirq = genpd_restore_noirq;
1671         genpd->domain.ops.complete = genpd_complete;
1672
1673         if (genpd->flags & GENPD_FLAG_PM_CLK) {
1674                 genpd->dev_ops.stop = pm_clk_suspend;
1675                 genpd->dev_ops.start = pm_clk_resume;
1676         }
1677
1678         /* Always-on domains must be powered on at initialization. */
1679         if (genpd_is_always_on(genpd) && !genpd_status_on(genpd))
1680                 return -EINVAL;
1681
1682         /* Use only one "off" state if there were no states declared */
1683         if (genpd->state_count == 0) {
1684                 ret = genpd_set_default_power_state(genpd);
1685                 if (ret)
1686                         return ret;
1687         }
1688
1689         mutex_lock(&gpd_list_lock);
1690         list_add(&genpd->gpd_list_node, &gpd_list);
1691         mutex_unlock(&gpd_list_lock);
1692
1693         return 0;
1694 }
1695 EXPORT_SYMBOL_GPL(pm_genpd_init);
1696
1697 static int genpd_remove(struct generic_pm_domain *genpd)
1698 {
1699         struct gpd_link *l, *link;
1700
1701         if (IS_ERR_OR_NULL(genpd))
1702                 return -EINVAL;
1703
1704         genpd_lock(genpd);
1705
1706         if (genpd->has_provider) {
1707                 genpd_unlock(genpd);
1708                 pr_err("Provider present, unable to remove %s\n", genpd->name);
1709                 return -EBUSY;
1710         }
1711
1712         if (!list_empty(&genpd->master_links) || genpd->device_count) {
1713                 genpd_unlock(genpd);
1714                 pr_err("%s: unable to remove %s\n", __func__, genpd->name);
1715                 return -EBUSY;
1716         }
1717
1718         list_for_each_entry_safe(link, l, &genpd->slave_links, slave_node) {
1719                 list_del(&link->master_node);
1720                 list_del(&link->slave_node);
1721                 kfree(link);
1722         }
1723
1724         list_del(&genpd->gpd_list_node);
1725         genpd_unlock(genpd);
1726         cancel_work_sync(&genpd->power_off_work);
1727         kfree(genpd->free);
1728         pr_debug("%s: removed %s\n", __func__, genpd->name);
1729
1730         return 0;
1731 }
1732
1733 /**
1734  * pm_genpd_remove - Remove a generic I/O PM domain
1735  * @genpd: Pointer to PM domain that is to be removed.
1736  *
1737  * To remove the PM domain, this function:
1738  *  - Removes the PM domain as a subdomain to any parent domains,
1739  *    if it was added.
1740  *  - Removes the PM domain from the list of registered PM domains.
1741  *
1742  * The PM domain will only be removed, if the associated provider has
1743  * been removed, it is not a parent to any other PM domain and has no
1744  * devices associated with it.
1745  */
1746 int pm_genpd_remove(struct generic_pm_domain *genpd)
1747 {
1748         int ret;
1749
1750         mutex_lock(&gpd_list_lock);
1751         ret = genpd_remove(genpd);
1752         mutex_unlock(&gpd_list_lock);
1753
1754         return ret;
1755 }
1756 EXPORT_SYMBOL_GPL(pm_genpd_remove);
1757
1758 #ifdef CONFIG_PM_GENERIC_DOMAINS_OF
1759
1760 /*
1761  * Device Tree based PM domain providers.
1762  *
1763  * The code below implements generic device tree based PM domain providers that
1764  * bind device tree nodes with generic PM domains registered in the system.
1765  *
1766  * Any driver that registers generic PM domains and needs to support binding of
1767  * devices to these domains is supposed to register a PM domain provider, which
1768  * maps a PM domain specifier retrieved from the device tree to a PM domain.
1769  *
1770  * Two simple mapping functions have been provided for convenience:
1771  *  - genpd_xlate_simple() for 1:1 device tree node to PM domain mapping.
1772  *  - genpd_xlate_onecell() for mapping of multiple PM domains per node by
1773  *    index.
1774  */
1775
1776 /**
1777  * struct of_genpd_provider - PM domain provider registration structure
1778  * @link: Entry in global list of PM domain providers
1779  * @node: Pointer to device tree node of PM domain provider
1780  * @xlate: Provider-specific xlate callback mapping a set of specifier cells
1781  *         into a PM domain.
1782  * @data: context pointer to be passed into @xlate callback
1783  */
1784 struct of_genpd_provider {
1785         struct list_head link;
1786         struct device_node *node;
1787         genpd_xlate_t xlate;
1788         void *data;
1789 };
1790
1791 /* List of registered PM domain providers. */
1792 static LIST_HEAD(of_genpd_providers);
1793 /* Mutex to protect the list above. */
1794 static DEFINE_MUTEX(of_genpd_mutex);
1795
1796 /**
1797  * genpd_xlate_simple() - Xlate function for direct node-domain mapping
1798  * @genpdspec: OF phandle args to map into a PM domain
1799  * @data: xlate function private data - pointer to struct generic_pm_domain
1800  *
1801  * This is a generic xlate function that can be used to model PM domains that
1802  * have their own device tree nodes. The private data of xlate function needs
1803  * to be a valid pointer to struct generic_pm_domain.
1804  */
1805 static struct generic_pm_domain *genpd_xlate_simple(
1806                                         struct of_phandle_args *genpdspec,
1807                                         void *data)
1808 {
1809         return data;
1810 }
1811
1812 /**
1813  * genpd_xlate_onecell() - Xlate function using a single index.
1814  * @genpdspec: OF phandle args to map into a PM domain
1815  * @data: xlate function private data - pointer to struct genpd_onecell_data
1816  *
1817  * This is a generic xlate function that can be used to model simple PM domain
1818  * controllers that have one device tree node and provide multiple PM domains.
1819  * A single cell is used as an index into an array of PM domains specified in
1820  * the genpd_onecell_data struct when registering the provider.
1821  */
1822 static struct generic_pm_domain *genpd_xlate_onecell(
1823                                         struct of_phandle_args *genpdspec,
1824                                         void *data)
1825 {
1826         struct genpd_onecell_data *genpd_data = data;
1827         unsigned int idx = genpdspec->args[0];
1828
1829         if (genpdspec->args_count != 1)
1830                 return ERR_PTR(-EINVAL);
1831
1832         if (idx >= genpd_data->num_domains) {
1833                 pr_err("%s: invalid domain index %u\n", __func__, idx);
1834                 return ERR_PTR(-EINVAL);
1835         }
1836
1837         if (!genpd_data->domains[idx])
1838                 return ERR_PTR(-ENOENT);
1839
1840         return genpd_data->domains[idx];
1841 }
1842
1843 /**
1844  * genpd_add_provider() - Register a PM domain provider for a node
1845  * @np: Device node pointer associated with the PM domain provider.
1846  * @xlate: Callback for decoding PM domain from phandle arguments.
1847  * @data: Context pointer for @xlate callback.
1848  */
1849 static int genpd_add_provider(struct device_node *np, genpd_xlate_t xlate,
1850                               void *data)
1851 {
1852         struct of_genpd_provider *cp;
1853
1854         cp = kzalloc(sizeof(*cp), GFP_KERNEL);
1855         if (!cp)
1856                 return -ENOMEM;
1857
1858         cp->node = of_node_get(np);
1859         cp->data = data;
1860         cp->xlate = xlate;
1861
1862         mutex_lock(&of_genpd_mutex);
1863         list_add(&cp->link, &of_genpd_providers);
1864         mutex_unlock(&of_genpd_mutex);
1865         pr_debug("Added domain provider from %pOF\n", np);
1866
1867         return 0;
1868 }
1869
1870 /**
1871  * of_genpd_add_provider_simple() - Register a simple PM domain provider
1872  * @np: Device node pointer associated with the PM domain provider.
1873  * @genpd: Pointer to PM domain associated with the PM domain provider.
1874  */
1875 int of_genpd_add_provider_simple(struct device_node *np,
1876                                  struct generic_pm_domain *genpd)
1877 {
1878         int ret = -EINVAL;
1879
1880         if (!np || !genpd)
1881                 return -EINVAL;
1882
1883         mutex_lock(&gpd_list_lock);
1884
1885         if (genpd_present(genpd)) {
1886                 ret = genpd_add_provider(np, genpd_xlate_simple, genpd);
1887                 if (!ret) {
1888                         genpd->provider = &np->fwnode;
1889                         genpd->has_provider = true;
1890                 }
1891         }
1892
1893         mutex_unlock(&gpd_list_lock);
1894
1895         return ret;
1896 }
1897 EXPORT_SYMBOL_GPL(of_genpd_add_provider_simple);
1898
1899 /**
1900  * of_genpd_add_provider_onecell() - Register a onecell PM domain provider
1901  * @np: Device node pointer associated with the PM domain provider.
1902  * @data: Pointer to the data associated with the PM domain provider.
1903  */
1904 int of_genpd_add_provider_onecell(struct device_node *np,
1905                                   struct genpd_onecell_data *data)
1906 {
1907         unsigned int i;
1908         int ret = -EINVAL;
1909
1910         if (!np || !data)
1911                 return -EINVAL;
1912
1913         mutex_lock(&gpd_list_lock);
1914
1915         if (!data->xlate)
1916                 data->xlate = genpd_xlate_onecell;
1917
1918         for (i = 0; i < data->num_domains; i++) {
1919                 if (!data->domains[i])
1920                         continue;
1921                 if (!genpd_present(data->domains[i]))
1922                         goto error;
1923
1924                 data->domains[i]->provider = &np->fwnode;
1925                 data->domains[i]->has_provider = true;
1926         }
1927
1928         ret = genpd_add_provider(np, data->xlate, data);
1929         if (ret < 0)
1930                 goto error;
1931
1932         mutex_unlock(&gpd_list_lock);
1933
1934         return 0;
1935
1936 error:
1937         while (i--) {
1938                 if (!data->domains[i])
1939                         continue;
1940                 data->domains[i]->provider = NULL;
1941                 data->domains[i]->has_provider = false;
1942         }
1943
1944         mutex_unlock(&gpd_list_lock);
1945
1946         return ret;
1947 }
1948 EXPORT_SYMBOL_GPL(of_genpd_add_provider_onecell);
1949
1950 /**
1951  * of_genpd_del_provider() - Remove a previously registered PM domain provider
1952  * @np: Device node pointer associated with the PM domain provider
1953  */
1954 void of_genpd_del_provider(struct device_node *np)
1955 {
1956         struct of_genpd_provider *cp, *tmp;
1957         struct generic_pm_domain *gpd;
1958
1959         mutex_lock(&gpd_list_lock);
1960         mutex_lock(&of_genpd_mutex);
1961         list_for_each_entry_safe(cp, tmp, &of_genpd_providers, link) {
1962                 if (cp->node == np) {
1963                         /*
1964                          * For each PM domain associated with the
1965                          * provider, set the 'has_provider' to false
1966                          * so that the PM domain can be safely removed.
1967                          */
1968                         list_for_each_entry(gpd, &gpd_list, gpd_list_node)
1969                                 if (gpd->provider == &np->fwnode)
1970                                         gpd->has_provider = false;
1971
1972                         list_del(&cp->link);
1973                         of_node_put(cp->node);
1974                         kfree(cp);
1975                         break;
1976                 }
1977         }
1978         mutex_unlock(&of_genpd_mutex);
1979         mutex_unlock(&gpd_list_lock);
1980 }
1981 EXPORT_SYMBOL_GPL(of_genpd_del_provider);
1982
1983 /**
1984  * genpd_get_from_provider() - Look-up PM domain
1985  * @genpdspec: OF phandle args to use for look-up
1986  *
1987  * Looks for a PM domain provider under the node specified by @genpdspec and if
1988  * found, uses xlate function of the provider to map phandle args to a PM
1989  * domain.
1990  *
1991  * Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR()
1992  * on failure.
1993  */
1994 static struct generic_pm_domain *genpd_get_from_provider(
1995                                         struct of_phandle_args *genpdspec)
1996 {
1997         struct generic_pm_domain *genpd = ERR_PTR(-ENOENT);
1998         struct of_genpd_provider *provider;
1999
2000         if (!genpdspec)
2001                 return ERR_PTR(-EINVAL);
2002
2003         mutex_lock(&of_genpd_mutex);
2004
2005         /* Check if we have such a provider in our array */
2006         list_for_each_entry(provider, &of_genpd_providers, link) {
2007                 if (provider->node == genpdspec->np)
2008                         genpd = provider->xlate(genpdspec, provider->data);
2009                 if (!IS_ERR(genpd))
2010                         break;
2011         }
2012
2013         mutex_unlock(&of_genpd_mutex);
2014
2015         return genpd;
2016 }
2017
2018 /**
2019  * of_genpd_add_device() - Add a device to an I/O PM domain
2020  * @genpdspec: OF phandle args to use for look-up PM domain
2021  * @dev: Device to be added.
2022  *
2023  * Looks-up an I/O PM domain based upon phandle args provided and adds
2024  * the device to the PM domain. Returns a negative error code on failure.
2025  */
2026 int of_genpd_add_device(struct of_phandle_args *genpdspec, struct device *dev)
2027 {
2028         struct generic_pm_domain *genpd;
2029         int ret;
2030
2031         mutex_lock(&gpd_list_lock);
2032
2033         genpd = genpd_get_from_provider(genpdspec);
2034         if (IS_ERR(genpd)) {
2035                 ret = PTR_ERR(genpd);
2036                 goto out;
2037         }
2038
2039         ret = genpd_add_device(genpd, dev, NULL);
2040
2041 out:
2042         mutex_unlock(&gpd_list_lock);
2043
2044         return ret;
2045 }
2046 EXPORT_SYMBOL_GPL(of_genpd_add_device);
2047
2048 /**
2049  * of_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
2050  * @parent_spec: OF phandle args to use for parent PM domain look-up
2051  * @subdomain_spec: OF phandle args to use for subdomain look-up
2052  *
2053  * Looks-up a parent PM domain and subdomain based upon phandle args
2054  * provided and adds the subdomain to the parent PM domain. Returns a
2055  * negative error code on failure.
2056  */
2057 int of_genpd_add_subdomain(struct of_phandle_args *parent_spec,
2058                            struct of_phandle_args *subdomain_spec)
2059 {
2060         struct generic_pm_domain *parent, *subdomain;
2061         int ret;
2062
2063         mutex_lock(&gpd_list_lock);
2064
2065         parent = genpd_get_from_provider(parent_spec);
2066         if (IS_ERR(parent)) {
2067                 ret = PTR_ERR(parent);
2068                 goto out;
2069         }
2070
2071         subdomain = genpd_get_from_provider(subdomain_spec);
2072         if (IS_ERR(subdomain)) {
2073                 ret = PTR_ERR(subdomain);
2074                 goto out;
2075         }
2076
2077         ret = genpd_add_subdomain(parent, subdomain);
2078
2079 out:
2080         mutex_unlock(&gpd_list_lock);
2081
2082         return ret;
2083 }
2084 EXPORT_SYMBOL_GPL(of_genpd_add_subdomain);
2085
2086 /**
2087  * of_genpd_remove_last - Remove the last PM domain registered for a provider
2088  * @provider: Pointer to device structure associated with provider
2089  *
2090  * Find the last PM domain that was added by a particular provider and
2091  * remove this PM domain from the list of PM domains. The provider is
2092  * identified by the 'provider' device structure that is passed. The PM
2093  * domain will only be removed, if the provider associated with domain
2094  * has been removed.
2095  *
2096  * Returns a valid pointer to struct generic_pm_domain on success or
2097  * ERR_PTR() on failure.
2098  */
2099 struct generic_pm_domain *of_genpd_remove_last(struct device_node *np)
2100 {
2101         struct generic_pm_domain *gpd, *tmp, *genpd = ERR_PTR(-ENOENT);
2102         int ret;
2103
2104         if (IS_ERR_OR_NULL(np))
2105                 return ERR_PTR(-EINVAL);
2106
2107         mutex_lock(&gpd_list_lock);
2108         list_for_each_entry_safe(gpd, tmp, &gpd_list, gpd_list_node) {
2109                 if (gpd->provider == &np->fwnode) {
2110                         ret = genpd_remove(gpd);
2111                         genpd = ret ? ERR_PTR(ret) : gpd;
2112                         break;
2113                 }
2114         }
2115         mutex_unlock(&gpd_list_lock);
2116
2117         return genpd;
2118 }
2119 EXPORT_SYMBOL_GPL(of_genpd_remove_last);
2120
2121 /**
2122  * genpd_dev_pm_detach - Detach a device from its PM domain.
2123  * @dev: Device to detach.
2124  * @power_off: Currently not used
2125  *
2126  * Try to locate a corresponding generic PM domain, which the device was
2127  * attached to previously. If such is found, the device is detached from it.
2128  */
2129 static void genpd_dev_pm_detach(struct device *dev, bool power_off)
2130 {
2131         struct generic_pm_domain *pd;
2132         unsigned int i;
2133         int ret = 0;
2134
2135         pd = dev_to_genpd(dev);
2136         if (IS_ERR(pd))
2137                 return;
2138
2139         dev_dbg(dev, "removing from PM domain %s\n", pd->name);
2140
2141         for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
2142                 ret = genpd_remove_device(pd, dev);
2143                 if (ret != -EAGAIN)
2144                         break;
2145
2146                 mdelay(i);
2147                 cond_resched();
2148         }
2149
2150         if (ret < 0) {
2151                 dev_err(dev, "failed to remove from PM domain %s: %d",
2152                         pd->name, ret);
2153                 return;
2154         }
2155
2156         /* Check if PM domain can be powered off after removing this device. */
2157         genpd_queue_power_off_work(pd);
2158 }
2159
2160 static void genpd_dev_pm_sync(struct device *dev)
2161 {
2162         struct generic_pm_domain *pd;
2163
2164         pd = dev_to_genpd(dev);
2165         if (IS_ERR(pd))
2166                 return;
2167
2168         genpd_queue_power_off_work(pd);
2169 }
2170
2171 /**
2172  * genpd_dev_pm_attach - Attach a device to its PM domain using DT.
2173  * @dev: Device to attach.
2174  *
2175  * Parse device's OF node to find a PM domain specifier. If such is found,
2176  * attaches the device to retrieved pm_domain ops.
2177  *
2178  * Both generic and legacy Samsung-specific DT bindings are supported to keep
2179  * backwards compatibility with existing DTBs.
2180  *
2181  * Returns 0 on successfully attached PM domain or negative error code. Note
2182  * that if a power-domain exists for the device, but it cannot be found or
2183  * turned on, then return -EPROBE_DEFER to ensure that the device is not
2184  * probed and to re-try again later.
2185  */
2186 int genpd_dev_pm_attach(struct device *dev)
2187 {
2188         struct of_phandle_args pd_args;
2189         struct generic_pm_domain *pd;
2190         unsigned int i;
2191         int ret;
2192
2193         if (!dev->of_node)
2194                 return -ENODEV;
2195
2196         if (dev->pm_domain)
2197                 return -EEXIST;
2198
2199         ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
2200                                         "#power-domain-cells", 0, &pd_args);
2201         if (ret < 0) {
2202                 if (ret != -ENOENT)
2203                         return ret;
2204
2205                 /*
2206                  * Try legacy Samsung-specific bindings
2207                  * (for backwards compatibility of DT ABI)
2208                  */
2209                 pd_args.args_count = 0;
2210                 pd_args.np = of_parse_phandle(dev->of_node,
2211                                                 "samsung,power-domain", 0);
2212                 if (!pd_args.np)
2213                         return -ENOENT;
2214         }
2215
2216         mutex_lock(&gpd_list_lock);
2217         pd = genpd_get_from_provider(&pd_args);
2218         of_node_put(pd_args.np);
2219         if (IS_ERR(pd)) {
2220                 mutex_unlock(&gpd_list_lock);
2221                 dev_dbg(dev, "%s() failed to find PM domain: %ld\n",
2222                         __func__, PTR_ERR(pd));
2223                 return -EPROBE_DEFER;
2224         }
2225
2226         dev_dbg(dev, "adding to PM domain %s\n", pd->name);
2227
2228         for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
2229                 ret = genpd_add_device(pd, dev, NULL);
2230                 if (ret != -EAGAIN)
2231                         break;
2232
2233                 mdelay(i);
2234                 cond_resched();
2235         }
2236         mutex_unlock(&gpd_list_lock);
2237
2238         if (ret < 0) {
2239                 if (ret != -EPROBE_DEFER)
2240                         dev_err(dev, "failed to add to PM domain %s: %d",
2241                                 pd->name, ret);
2242                 goto out;
2243         }
2244
2245         dev->pm_domain->detach = genpd_dev_pm_detach;
2246         dev->pm_domain->sync = genpd_dev_pm_sync;
2247
2248         genpd_lock(pd);
2249         ret = genpd_power_on(pd, 0);
2250         genpd_unlock(pd);
2251 out:
2252         return ret ? -EPROBE_DEFER : 0;
2253 }
2254 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
2255
2256 static const struct of_device_id idle_state_match[] = {
2257         { .compatible = "domain-idle-state", },
2258         { }
2259 };
2260
2261 static int genpd_parse_state(struct genpd_power_state *genpd_state,
2262                                     struct device_node *state_node)
2263 {
2264         int err;
2265         u32 residency;
2266         u32 entry_latency, exit_latency;
2267
2268         err = of_property_read_u32(state_node, "entry-latency-us",
2269                                                 &entry_latency);
2270         if (err) {
2271                 pr_debug(" * %pOF missing entry-latency-us property\n",
2272                                                 state_node);
2273                 return -EINVAL;
2274         }
2275
2276         err = of_property_read_u32(state_node, "exit-latency-us",
2277                                                 &exit_latency);
2278         if (err) {
2279                 pr_debug(" * %pOF missing exit-latency-us property\n",
2280                                                 state_node);
2281                 return -EINVAL;
2282         }
2283
2284         err = of_property_read_u32(state_node, "min-residency-us", &residency);
2285         if (!err)
2286                 genpd_state->residency_ns = 1000 * residency;
2287
2288         genpd_state->power_on_latency_ns = 1000 * exit_latency;
2289         genpd_state->power_off_latency_ns = 1000 * entry_latency;
2290         genpd_state->fwnode = &state_node->fwnode;
2291
2292         return 0;
2293 }
2294
2295 /**
2296  * of_genpd_parse_idle_states: Return array of idle states for the genpd.
2297  *
2298  * @dn: The genpd device node
2299  * @states: The pointer to which the state array will be saved.
2300  * @n: The count of elements in the array returned from this function.
2301  *
2302  * Returns the device states parsed from the OF node. The memory for the states
2303  * is allocated by this function and is the responsibility of the caller to
2304  * free the memory after use.
2305  */
2306 int of_genpd_parse_idle_states(struct device_node *dn,
2307                         struct genpd_power_state **states, int *n)
2308 {
2309         struct genpd_power_state *st;
2310         struct device_node *np;
2311         int i = 0;
2312         int err, ret;
2313         int count;
2314         struct of_phandle_iterator it;
2315         const struct of_device_id *match_id;
2316
2317         count = of_count_phandle_with_args(dn, "domain-idle-states", NULL);
2318         if (count <= 0)
2319                 return -EINVAL;
2320
2321         st = kcalloc(count, sizeof(*st), GFP_KERNEL);
2322         if (!st)
2323                 return -ENOMEM;
2324
2325         /* Loop over the phandles until all the requested entry is found */
2326         of_for_each_phandle(&it, err, dn, "domain-idle-states", NULL, 0) {
2327                 np = it.node;
2328                 match_id = of_match_node(idle_state_match, np);
2329                 if (!match_id)
2330                         continue;
2331                 ret = genpd_parse_state(&st[i++], np);
2332                 if (ret) {
2333                         pr_err
2334                         ("Parsing idle state node %pOF failed with err %d\n",
2335                                                         np, ret);
2336                         of_node_put(np);
2337                         kfree(st);
2338                         return ret;
2339                 }
2340         }
2341
2342         *n = i;
2343         if (!i)
2344                 kfree(st);
2345         else
2346                 *states = st;
2347
2348         return 0;
2349 }
2350 EXPORT_SYMBOL_GPL(of_genpd_parse_idle_states);
2351
2352 #endif /* CONFIG_PM_GENERIC_DOMAINS_OF */
2353
2354
2355 /***        debugfs support        ***/
2356
2357 #ifdef CONFIG_DEBUG_FS
2358 #include <linux/pm.h>
2359 #include <linux/device.h>
2360 #include <linux/debugfs.h>
2361 #include <linux/seq_file.h>
2362 #include <linux/init.h>
2363 #include <linux/kobject.h>
2364 static struct dentry *genpd_debugfs_dir;
2365
2366 /*
2367  * TODO: This function is a slightly modified version of rtpm_status_show
2368  * from sysfs.c, so generalize it.
2369  */
2370 static void rtpm_status_str(struct seq_file *s, struct device *dev)
2371 {
2372         static const char * const status_lookup[] = {
2373                 [RPM_ACTIVE] = "active",
2374                 [RPM_RESUMING] = "resuming",
2375                 [RPM_SUSPENDED] = "suspended",
2376                 [RPM_SUSPENDING] = "suspending"
2377         };
2378         const char *p = "";
2379
2380         if (dev->power.runtime_error)
2381                 p = "error";
2382         else if (dev->power.disable_depth)
2383                 p = "unsupported";
2384         else if (dev->power.runtime_status < ARRAY_SIZE(status_lookup))
2385                 p = status_lookup[dev->power.runtime_status];
2386         else
2387                 WARN_ON(1);
2388
2389         seq_puts(s, p);
2390 }
2391
2392 static int genpd_summary_one(struct seq_file *s,
2393                         struct generic_pm_domain *genpd)
2394 {
2395         static const char * const status_lookup[] = {
2396                 [GPD_STATE_ACTIVE] = "on",
2397                 [GPD_STATE_POWER_OFF] = "off"
2398         };
2399         struct pm_domain_data *pm_data;
2400         const char *kobj_path;
2401         struct gpd_link *link;
2402         char state[16];
2403         int ret;
2404
2405         ret = genpd_lock_interruptible(genpd);
2406         if (ret)
2407                 return -ERESTARTSYS;
2408
2409         if (WARN_ON(genpd->status >= ARRAY_SIZE(status_lookup)))
2410                 goto exit;
2411         if (!genpd_status_on(genpd))
2412                 snprintf(state, sizeof(state), "%s-%u",
2413                          status_lookup[genpd->status], genpd->state_idx);
2414         else
2415                 snprintf(state, sizeof(state), "%s",
2416                          status_lookup[genpd->status]);
2417         seq_printf(s, "%-30s  %-15s ", genpd->name, state);
2418
2419         /*
2420          * Modifications on the list require holding locks on both
2421          * master and slave, so we are safe.
2422          * Also genpd->name is immutable.
2423          */
2424         list_for_each_entry(link, &genpd->master_links, master_node) {
2425                 seq_printf(s, "%s", link->slave->name);
2426                 if (!list_is_last(&link->master_node, &genpd->master_links))
2427                         seq_puts(s, ", ");
2428         }
2429
2430         list_for_each_entry(pm_data, &genpd->dev_list, list_node) {
2431                 kobj_path = kobject_get_path(&pm_data->dev->kobj,
2432                                 genpd_is_irq_safe(genpd) ?
2433                                 GFP_ATOMIC : GFP_KERNEL);
2434                 if (kobj_path == NULL)
2435                         continue;
2436
2437                 seq_printf(s, "\n    %-50s  ", kobj_path);
2438                 rtpm_status_str(s, pm_data->dev);
2439                 kfree(kobj_path);
2440         }
2441
2442         seq_puts(s, "\n");
2443 exit:
2444         genpd_unlock(genpd);
2445
2446         return 0;
2447 }
2448
2449 static int genpd_summary_show(struct seq_file *s, void *data)
2450 {
2451         struct generic_pm_domain *genpd;
2452         int ret = 0;
2453
2454         seq_puts(s, "domain                          status          slaves\n");
2455         seq_puts(s, "    /device                                             runtime status\n");
2456         seq_puts(s, "----------------------------------------------------------------------\n");
2457
2458         ret = mutex_lock_interruptible(&gpd_list_lock);
2459         if (ret)
2460                 return -ERESTARTSYS;
2461
2462         list_for_each_entry(genpd, &gpd_list, gpd_list_node) {
2463                 ret = genpd_summary_one(s, genpd);
2464                 if (ret)
2465                         break;
2466         }
2467         mutex_unlock(&gpd_list_lock);
2468
2469         return ret;
2470 }
2471
2472 static int genpd_status_show(struct seq_file *s, void *data)
2473 {
2474         static const char * const status_lookup[] = {
2475                 [GPD_STATE_ACTIVE] = "on",
2476                 [GPD_STATE_POWER_OFF] = "off"
2477         };
2478
2479         struct generic_pm_domain *genpd = s->private;
2480         int ret = 0;
2481
2482         ret = genpd_lock_interruptible(genpd);
2483         if (ret)
2484                 return -ERESTARTSYS;
2485
2486         if (WARN_ON_ONCE(genpd->status >= ARRAY_SIZE(status_lookup)))
2487                 goto exit;
2488
2489         if (genpd->status == GPD_STATE_POWER_OFF)
2490                 seq_printf(s, "%s-%u\n", status_lookup[genpd->status],
2491                         genpd->state_idx);
2492         else
2493                 seq_printf(s, "%s\n", status_lookup[genpd->status]);
2494 exit:
2495         genpd_unlock(genpd);
2496         return ret;
2497 }
2498
2499 static int genpd_sub_domains_show(struct seq_file *s, void *data)
2500 {
2501         struct generic_pm_domain *genpd = s->private;
2502         struct gpd_link *link;
2503         int ret = 0;
2504
2505         ret = genpd_lock_interruptible(genpd);
2506         if (ret)
2507                 return -ERESTARTSYS;
2508
2509         list_for_each_entry(link, &genpd->master_links, master_node)
2510                 seq_printf(s, "%s\n", link->slave->name);
2511
2512         genpd_unlock(genpd);
2513         return ret;
2514 }
2515
2516 static int genpd_idle_states_show(struct seq_file *s, void *data)
2517 {
2518         struct generic_pm_domain *genpd = s->private;
2519         unsigned int i;
2520         int ret = 0;
2521
2522         ret = genpd_lock_interruptible(genpd);
2523         if (ret)
2524                 return -ERESTARTSYS;
2525
2526         seq_puts(s, "State          Time Spent(ms)\n");
2527
2528         for (i = 0; i < genpd->state_count; i++) {
2529                 ktime_t delta = 0;
2530                 s64 msecs;
2531
2532                 if ((genpd->status == GPD_STATE_POWER_OFF) &&
2533                                 (genpd->state_idx == i))
2534                         delta = ktime_sub(ktime_get(), genpd->accounting_time);
2535
2536                 msecs = ktime_to_ms(
2537                         ktime_add(genpd->states[i].idle_time, delta));
2538                 seq_printf(s, "S%-13i %lld\n", i, msecs);
2539         }
2540
2541         genpd_unlock(genpd);
2542         return ret;
2543 }
2544
2545 static int genpd_active_time_show(struct seq_file *s, void *data)
2546 {
2547         struct generic_pm_domain *genpd = s->private;
2548         ktime_t delta = 0;
2549         int ret = 0;
2550
2551         ret = genpd_lock_interruptible(genpd);
2552         if (ret)
2553                 return -ERESTARTSYS;
2554
2555         if (genpd->status == GPD_STATE_ACTIVE)
2556                 delta = ktime_sub(ktime_get(), genpd->accounting_time);
2557
2558         seq_printf(s, "%lld ms\n", ktime_to_ms(
2559                                 ktime_add(genpd->on_time, delta)));
2560
2561         genpd_unlock(genpd);
2562         return ret;
2563 }
2564
2565 static int genpd_total_idle_time_show(struct seq_file *s, void *data)
2566 {
2567         struct generic_pm_domain *genpd = s->private;
2568         ktime_t delta = 0, total = 0;
2569         unsigned int i;
2570         int ret = 0;
2571
2572         ret = genpd_lock_interruptible(genpd);
2573         if (ret)
2574                 return -ERESTARTSYS;
2575
2576         for (i = 0; i < genpd->state_count; i++) {
2577
2578                 if ((genpd->status == GPD_STATE_POWER_OFF) &&
2579                                 (genpd->state_idx == i))
2580                         delta = ktime_sub(ktime_get(), genpd->accounting_time);
2581
2582                 total = ktime_add(total, genpd->states[i].idle_time);
2583         }
2584         total = ktime_add(total, delta);
2585
2586         seq_printf(s, "%lld ms\n", ktime_to_ms(total));
2587
2588         genpd_unlock(genpd);
2589         return ret;
2590 }
2591
2592
2593 static int genpd_devices_show(struct seq_file *s, void *data)
2594 {
2595         struct generic_pm_domain *genpd = s->private;
2596         struct pm_domain_data *pm_data;
2597         const char *kobj_path;
2598         int ret = 0;
2599
2600         ret = genpd_lock_interruptible(genpd);
2601         if (ret)
2602                 return -ERESTARTSYS;
2603
2604         list_for_each_entry(pm_data, &genpd->dev_list, list_node) {
2605                 kobj_path = kobject_get_path(&pm_data->dev->kobj,
2606                                 genpd_is_irq_safe(genpd) ?
2607                                 GFP_ATOMIC : GFP_KERNEL);
2608                 if (kobj_path == NULL)
2609                         continue;
2610
2611                 seq_printf(s, "%s\n", kobj_path);
2612                 kfree(kobj_path);
2613         }
2614
2615         genpd_unlock(genpd);
2616         return ret;
2617 }
2618
2619 #define define_genpd_open_function(name) \
2620 static int genpd_##name##_open(struct inode *inode, struct file *file) \
2621 { \
2622         return single_open(file, genpd_##name##_show, inode->i_private); \
2623 }
2624
2625 define_genpd_open_function(summary);
2626 define_genpd_open_function(status);
2627 define_genpd_open_function(sub_domains);
2628 define_genpd_open_function(idle_states);
2629 define_genpd_open_function(active_time);
2630 define_genpd_open_function(total_idle_time);
2631 define_genpd_open_function(devices);
2632
2633 #define define_genpd_debugfs_fops(name) \
2634 static const struct file_operations genpd_##name##_fops = { \
2635         .open = genpd_##name##_open, \
2636         .read = seq_read, \
2637         .llseek = seq_lseek, \
2638         .release = single_release, \
2639 }
2640
2641 define_genpd_debugfs_fops(summary);
2642 define_genpd_debugfs_fops(status);
2643 define_genpd_debugfs_fops(sub_domains);
2644 define_genpd_debugfs_fops(idle_states);
2645 define_genpd_debugfs_fops(active_time);
2646 define_genpd_debugfs_fops(total_idle_time);
2647 define_genpd_debugfs_fops(devices);
2648
2649 static int __init genpd_debug_init(void)
2650 {
2651         struct dentry *d;
2652         struct generic_pm_domain *genpd;
2653
2654         genpd_debugfs_dir = debugfs_create_dir("pm_genpd", NULL);
2655
2656         if (!genpd_debugfs_dir)
2657                 return -ENOMEM;
2658
2659         d = debugfs_create_file("pm_genpd_summary", S_IRUGO,
2660                         genpd_debugfs_dir, NULL, &genpd_summary_fops);
2661         if (!d)
2662                 return -ENOMEM;
2663
2664         list_for_each_entry(genpd, &gpd_list, gpd_list_node) {
2665                 d = debugfs_create_dir(genpd->name, genpd_debugfs_dir);
2666                 if (!d)
2667                         return -ENOMEM;
2668
2669                 debugfs_create_file("current_state", 0444,
2670                                 d, genpd, &genpd_status_fops);
2671                 debugfs_create_file("sub_domains", 0444,
2672                                 d, genpd, &genpd_sub_domains_fops);
2673                 debugfs_create_file("idle_states", 0444,
2674                                 d, genpd, &genpd_idle_states_fops);
2675                 debugfs_create_file("active_time", 0444,
2676                                 d, genpd, &genpd_active_time_fops);
2677                 debugfs_create_file("total_idle_time", 0444,
2678                                 d, genpd, &genpd_total_idle_time_fops);
2679                 debugfs_create_file("devices", 0444,
2680                                 d, genpd, &genpd_devices_fops);
2681         }
2682
2683         return 0;
2684 }
2685 late_initcall(genpd_debug_init);
2686
2687 static void __exit genpd_debug_exit(void)
2688 {
2689         debugfs_remove_recursive(genpd_debugfs_dir);
2690 }
2691 __exitcall(genpd_debug_exit);
2692 #endif /* CONFIG_DEBUG_FS */