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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/base/power/clock_ops.c - Generic clock manipulation PM callbacks
4 *
5 * Copyright (c) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
6 */
7
8#include <linux/kernel.h>
9#include <linux/device.h>
10#include <linux/io.h>
11#include <linux/pm.h>
12#include <linux/pm_clock.h>
13#include <linux/clk.h>
14#include <linux/clkdev.h>
15#include <linux/of_clk.h>
16#include <linux/slab.h>
17#include <linux/err.h>
18#include <linux/pm_domain.h>
19#include <linux/pm_runtime.h>
20
21#ifdef CONFIG_PM_CLK
22
23enum pce_status {
24 PCE_STATUS_NONE = 0,
25 PCE_STATUS_ACQUIRED,
26 PCE_STATUS_ENABLED,
27 PCE_STATUS_ERROR,
28};
29
30struct pm_clock_entry {
31 struct list_head node;
32 char *con_id;
33 struct clk *clk;
34 enum pce_status status;
35};
36
37/**
38 * pm_clk_enable - Enable a clock, reporting any errors
39 * @dev: The device for the given clock
40 * @ce: PM clock entry corresponding to the clock.
41 */
42static inline void __pm_clk_enable(struct device *dev, struct pm_clock_entry *ce)
43{
44 int ret;
45
46 if (ce->status < PCE_STATUS_ERROR) {
47 ret = clk_enable(ce->clk);
48 if (!ret)
49 ce->status = PCE_STATUS_ENABLED;
50 else
51 dev_err(dev, "%s: failed to enable clk %p, error %d\n",
52 __func__, ce->clk, ret);
53 }
54}
55
56/**
57 * pm_clk_acquire - Acquire a device clock.
58 * @dev: Device whose clock is to be acquired.
59 * @ce: PM clock entry corresponding to the clock.
60 */
61static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
62{
63 if (!ce->clk)
64 ce->clk = clk_get(dev, ce->con_id);
65 if (IS_ERR(ce->clk)) {
66 ce->status = PCE_STATUS_ERROR;
67 } else {
68 if (clk_prepare(ce->clk)) {
69 ce->status = PCE_STATUS_ERROR;
70 dev_err(dev, "clk_prepare() failed\n");
71 } else {
72 ce->status = PCE_STATUS_ACQUIRED;
73 dev_dbg(dev,
74 "Clock %pC con_id %s managed by runtime PM.\n",
75 ce->clk, ce->con_id);
76 }
77 }
78}
79
80static int __pm_clk_add(struct device *dev, const char *con_id,
81 struct clk *clk)
82{
83 struct pm_subsys_data *psd = dev_to_psd(dev);
84 struct pm_clock_entry *ce;
85
86 if (!psd)
87 return -EINVAL;
88
89 ce = kzalloc(sizeof(*ce), GFP_KERNEL);
90 if (!ce)
91 return -ENOMEM;
92
93 if (con_id) {
94 ce->con_id = kstrdup(con_id, GFP_KERNEL);
95 if (!ce->con_id) {
96 kfree(ce);
97 return -ENOMEM;
98 }
99 } else {
100 if (IS_ERR(clk)) {
101 kfree(ce);
102 return -ENOENT;
103 }
104 ce->clk = clk;
105 }
106
107 pm_clk_acquire(dev, ce);
108
109 spin_lock_irq(&psd->lock);
110 list_add_tail(&ce->node, &psd->clock_list);
111 spin_unlock_irq(&psd->lock);
112 return 0;
113}
114
115/**
116 * pm_clk_add - Start using a device clock for power management.
117 * @dev: Device whose clock is going to be used for power management.
118 * @con_id: Connection ID of the clock.
119 *
120 * Add the clock represented by @con_id to the list of clocks used for
121 * the power management of @dev.
122 */
123int pm_clk_add(struct device *dev, const char *con_id)
124{
125 return __pm_clk_add(dev, con_id, NULL);
126}
127EXPORT_SYMBOL_GPL(pm_clk_add);
128
129/**
130 * pm_clk_add_clk - Start using a device clock for power management.
131 * @dev: Device whose clock is going to be used for power management.
132 * @clk: Clock pointer
133 *
134 * Add the clock to the list of clocks used for the power management of @dev.
135 * The power-management code will take control of the clock reference, so
136 * callers should not call clk_put() on @clk after this function sucessfully
137 * returned.
138 */
139int pm_clk_add_clk(struct device *dev, struct clk *clk)
140{
141 return __pm_clk_add(dev, NULL, clk);
142}
143EXPORT_SYMBOL_GPL(pm_clk_add_clk);
144
145
146/**
147 * of_pm_clk_add_clk - Start using a device clock for power management.
148 * @dev: Device whose clock is going to be used for power management.
149 * @name: Name of clock that is going to be used for power management.
150 *
151 * Add the clock described in the 'clocks' device-tree node that matches
152 * with the 'name' provided, to the list of clocks used for the power
153 * management of @dev. On success, returns 0. Returns a negative error
154 * code if the clock is not found or cannot be added.
155 */
156int of_pm_clk_add_clk(struct device *dev, const char *name)
157{
158 struct clk *clk;
159 int ret;
160
161 if (!dev || !dev->of_node || !name)
162 return -EINVAL;
163
164 clk = of_clk_get_by_name(dev->of_node, name);
165 if (IS_ERR(clk))
166 return PTR_ERR(clk);
167
168 ret = pm_clk_add_clk(dev, clk);
169 if (ret) {
170 clk_put(clk);
171 return ret;
172 }
173
174 return 0;
175}
176EXPORT_SYMBOL_GPL(of_pm_clk_add_clk);
177
178/**
179 * of_pm_clk_add_clks - Start using device clock(s) for power management.
180 * @dev: Device whose clock(s) is going to be used for power management.
181 *
182 * Add a series of clocks described in the 'clocks' device-tree node for
183 * a device to the list of clocks used for the power management of @dev.
184 * On success, returns the number of clocks added. Returns a negative
185 * error code if there are no clocks in the device node for the device
186 * or if adding a clock fails.
187 */
188int of_pm_clk_add_clks(struct device *dev)
189{
190 struct clk **clks;
191 int i, count;
192 int ret;
193
194 if (!dev || !dev->of_node)
195 return -EINVAL;
196
197 count = of_clk_get_parent_count(dev->of_node);
198 if (count <= 0)
199 return -ENODEV;
200
201 clks = kcalloc(count, sizeof(*clks), GFP_KERNEL);
202 if (!clks)
203 return -ENOMEM;
204
205 for (i = 0; i < count; i++) {
206 clks[i] = of_clk_get(dev->of_node, i);
207 if (IS_ERR(clks[i])) {
208 ret = PTR_ERR(clks[i]);
209 goto error;
210 }
211
212 ret = pm_clk_add_clk(dev, clks[i]);
213 if (ret) {
214 clk_put(clks[i]);
215 goto error;
216 }
217 }
218
219 kfree(clks);
220
221 return i;
222
223error:
224 while (i--)
225 pm_clk_remove_clk(dev, clks[i]);
226
227 kfree(clks);
228
229 return ret;
230}
231EXPORT_SYMBOL_GPL(of_pm_clk_add_clks);
232
233/**
234 * __pm_clk_remove - Destroy PM clock entry.
235 * @ce: PM clock entry to destroy.
236 */
237static void __pm_clk_remove(struct pm_clock_entry *ce)
238{
239 if (!ce)
240 return;
241
242 if (ce->status < PCE_STATUS_ERROR) {
243 if (ce->status == PCE_STATUS_ENABLED)
244 clk_disable(ce->clk);
245
246 if (ce->status >= PCE_STATUS_ACQUIRED) {
247 clk_unprepare(ce->clk);
248 clk_put(ce->clk);
249 }
250 }
251
252 kfree(ce->con_id);
253 kfree(ce);
254}
255
256/**
257 * pm_clk_remove - Stop using a device clock for power management.
258 * @dev: Device whose clock should not be used for PM any more.
259 * @con_id: Connection ID of the clock.
260 *
261 * Remove the clock represented by @con_id from the list of clocks used for
262 * the power management of @dev.
263 */
264void pm_clk_remove(struct device *dev, const char *con_id)
265{
266 struct pm_subsys_data *psd = dev_to_psd(dev);
267 struct pm_clock_entry *ce;
268
269 if (!psd)
270 return;
271
272 spin_lock_irq(&psd->lock);
273
274 list_for_each_entry(ce, &psd->clock_list, node) {
275 if (!con_id && !ce->con_id)
276 goto remove;
277 else if (!con_id || !ce->con_id)
278 continue;
279 else if (!strcmp(con_id, ce->con_id))
280 goto remove;
281 }
282
283 spin_unlock_irq(&psd->lock);
284 return;
285
286 remove:
287 list_del(&ce->node);
288 spin_unlock_irq(&psd->lock);
289
290 __pm_clk_remove(ce);
291}
292EXPORT_SYMBOL_GPL(pm_clk_remove);
293
294/**
295 * pm_clk_remove_clk - Stop using a device clock for power management.
296 * @dev: Device whose clock should not be used for PM any more.
297 * @clk: Clock pointer
298 *
299 * Remove the clock pointed to by @clk from the list of clocks used for
300 * the power management of @dev.
301 */
302void pm_clk_remove_clk(struct device *dev, struct clk *clk)
303{
304 struct pm_subsys_data *psd = dev_to_psd(dev);
305 struct pm_clock_entry *ce;
306
307 if (!psd || !clk)
308 return;
309
310 spin_lock_irq(&psd->lock);
311
312 list_for_each_entry(ce, &psd->clock_list, node) {
313 if (clk == ce->clk)
314 goto remove;
315 }
316
317 spin_unlock_irq(&psd->lock);
318 return;
319
320 remove:
321 list_del(&ce->node);
322 spin_unlock_irq(&psd->lock);
323
324 __pm_clk_remove(ce);
325}
326EXPORT_SYMBOL_GPL(pm_clk_remove_clk);
327
328/**
329 * pm_clk_init - Initialize a device's list of power management clocks.
330 * @dev: Device to initialize the list of PM clocks for.
331 *
332 * Initialize the lock and clock_list members of the device's pm_subsys_data
333 * object.
334 */
335void pm_clk_init(struct device *dev)
336{
337 struct pm_subsys_data *psd = dev_to_psd(dev);
338 if (psd)
339 INIT_LIST_HEAD(&psd->clock_list);
340}
341EXPORT_SYMBOL_GPL(pm_clk_init);
342
343/**
344 * pm_clk_create - Create and initialize a device's list of PM clocks.
345 * @dev: Device to create and initialize the list of PM clocks for.
346 *
347 * Allocate a struct pm_subsys_data object, initialize its lock and clock_list
348 * members and make the @dev's power.subsys_data field point to it.
349 */
350int pm_clk_create(struct device *dev)
351{
352 return dev_pm_get_subsys_data(dev);
353}
354EXPORT_SYMBOL_GPL(pm_clk_create);
355
356/**
357 * pm_clk_destroy - Destroy a device's list of power management clocks.
358 * @dev: Device to destroy the list of PM clocks for.
359 *
360 * Clear the @dev's power.subsys_data field, remove the list of clock entries
361 * from the struct pm_subsys_data object pointed to by it before and free
362 * that object.
363 */
364void pm_clk_destroy(struct device *dev)
365{
366 struct pm_subsys_data *psd = dev_to_psd(dev);
367 struct pm_clock_entry *ce, *c;
368 struct list_head list;
369
370 if (!psd)
371 return;
372
373 INIT_LIST_HEAD(&list);
374
375 spin_lock_irq(&psd->lock);
376
377 list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
378 list_move(&ce->node, &list);
379
380 spin_unlock_irq(&psd->lock);
381
382 dev_pm_put_subsys_data(dev);
383
384 list_for_each_entry_safe_reverse(ce, c, &list, node) {
385 list_del(&ce->node);
386 __pm_clk_remove(ce);
387 }
388}
389EXPORT_SYMBOL_GPL(pm_clk_destroy);
390
391/**
392 * pm_clk_suspend - Disable clocks in a device's PM clock list.
393 * @dev: Device to disable the clocks for.
394 */
395int pm_clk_suspend(struct device *dev)
396{
397 struct pm_subsys_data *psd = dev_to_psd(dev);
398 struct pm_clock_entry *ce;
399 unsigned long flags;
400
401 dev_dbg(dev, "%s()\n", __func__);
402
403 if (!psd)
404 return 0;
405
406 spin_lock_irqsave(&psd->lock, flags);
407
408 list_for_each_entry_reverse(ce, &psd->clock_list, node) {
409 if (ce->status < PCE_STATUS_ERROR) {
410 if (ce->status == PCE_STATUS_ENABLED)
411 clk_disable(ce->clk);
412 ce->status = PCE_STATUS_ACQUIRED;
413 }
414 }
415
416 spin_unlock_irqrestore(&psd->lock, flags);
417
418 return 0;
419}
420EXPORT_SYMBOL_GPL(pm_clk_suspend);
421
422/**
423 * pm_clk_resume - Enable clocks in a device's PM clock list.
424 * @dev: Device to enable the clocks for.
425 */
426int pm_clk_resume(struct device *dev)
427{
428 struct pm_subsys_data *psd = dev_to_psd(dev);
429 struct pm_clock_entry *ce;
430 unsigned long flags;
431
432 dev_dbg(dev, "%s()\n", __func__);
433
434 if (!psd)
435 return 0;
436
437 spin_lock_irqsave(&psd->lock, flags);
438
439 list_for_each_entry(ce, &psd->clock_list, node)
440 __pm_clk_enable(dev, ce);
441
442 spin_unlock_irqrestore(&psd->lock, flags);
443
444 return 0;
445}
446EXPORT_SYMBOL_GPL(pm_clk_resume);
447
448/**
449 * pm_clk_notify - Notify routine for device addition and removal.
450 * @nb: Notifier block object this function is a member of.
451 * @action: Operation being carried out by the caller.
452 * @data: Device the routine is being run for.
453 *
454 * For this function to work, @nb must be a member of an object of type
455 * struct pm_clk_notifier_block containing all of the requisite data.
456 * Specifically, the pm_domain member of that object is copied to the device's
457 * pm_domain field and its con_ids member is used to populate the device's list
458 * of PM clocks, depending on @action.
459 *
460 * If the device's pm_domain field is already populated with a value different
461 * from the one stored in the struct pm_clk_notifier_block object, the function
462 * does nothing.
463 */
464static int pm_clk_notify(struct notifier_block *nb,
465 unsigned long action, void *data)
466{
467 struct pm_clk_notifier_block *clknb;
468 struct device *dev = data;
469 char **con_id;
470 int error;
471
472 dev_dbg(dev, "%s() %ld\n", __func__, action);
473
474 clknb = container_of(nb, struct pm_clk_notifier_block, nb);
475
476 switch (action) {
477 case BUS_NOTIFY_ADD_DEVICE:
478 if (dev->pm_domain)
479 break;
480
481 error = pm_clk_create(dev);
482 if (error)
483 break;
484
485 dev_pm_domain_set(dev, clknb->pm_domain);
486 if (clknb->con_ids[0]) {
487 for (con_id = clknb->con_ids; *con_id; con_id++)
488 pm_clk_add(dev, *con_id);
489 } else {
490 pm_clk_add(dev, NULL);
491 }
492
493 break;
494 case BUS_NOTIFY_DEL_DEVICE:
495 if (dev->pm_domain != clknb->pm_domain)
496 break;
497
498 dev_pm_domain_set(dev, NULL);
499 pm_clk_destroy(dev);
500 break;
501 }
502
503 return 0;
504}
505
506int pm_clk_runtime_suspend(struct device *dev)
507{
508 int ret;
509
510 dev_dbg(dev, "%s\n", __func__);
511
512 ret = pm_generic_runtime_suspend(dev);
513 if (ret) {
514 dev_err(dev, "failed to suspend device\n");
515 return ret;
516 }
517
518 ret = pm_clk_suspend(dev);
519 if (ret) {
520 dev_err(dev, "failed to suspend clock\n");
521 pm_generic_runtime_resume(dev);
522 return ret;
523 }
524
525 return 0;
526}
527EXPORT_SYMBOL_GPL(pm_clk_runtime_suspend);
528
529int pm_clk_runtime_resume(struct device *dev)
530{
531 int ret;
532
533 dev_dbg(dev, "%s\n", __func__);
534
535 ret = pm_clk_resume(dev);
536 if (ret) {
537 dev_err(dev, "failed to resume clock\n");
538 return ret;
539 }
540
541 return pm_generic_runtime_resume(dev);
542}
543EXPORT_SYMBOL_GPL(pm_clk_runtime_resume);
544
545#else /* !CONFIG_PM_CLK */
546
547/**
548 * enable_clock - Enable a device clock.
549 * @dev: Device whose clock is to be enabled.
550 * @con_id: Connection ID of the clock.
551 */
552static void enable_clock(struct device *dev, const char *con_id)
553{
554 struct clk *clk;
555
556 clk = clk_get(dev, con_id);
557 if (!IS_ERR(clk)) {
558 clk_prepare_enable(clk);
559 clk_put(clk);
560 dev_info(dev, "Runtime PM disabled, clock forced on.\n");
561 }
562}
563
564/**
565 * disable_clock - Disable a device clock.
566 * @dev: Device whose clock is to be disabled.
567 * @con_id: Connection ID of the clock.
568 */
569static void disable_clock(struct device *dev, const char *con_id)
570{
571 struct clk *clk;
572
573 clk = clk_get(dev, con_id);
574 if (!IS_ERR(clk)) {
575 clk_disable_unprepare(clk);
576 clk_put(clk);
577 dev_info(dev, "Runtime PM disabled, clock forced off.\n");
578 }
579}
580
581/**
582 * pm_clk_notify - Notify routine for device addition and removal.
583 * @nb: Notifier block object this function is a member of.
584 * @action: Operation being carried out by the caller.
585 * @data: Device the routine is being run for.
586 *
587 * For this function to work, @nb must be a member of an object of type
588 * struct pm_clk_notifier_block containing all of the requisite data.
589 * Specifically, the con_ids member of that object is used to enable or disable
590 * the device's clocks, depending on @action.
591 */
592static int pm_clk_notify(struct notifier_block *nb,
593 unsigned long action, void *data)
594{
595 struct pm_clk_notifier_block *clknb;
596 struct device *dev = data;
597 char **con_id;
598
599 dev_dbg(dev, "%s() %ld\n", __func__, action);
600
601 clknb = container_of(nb, struct pm_clk_notifier_block, nb);
602
603 switch (action) {
604 case BUS_NOTIFY_BIND_DRIVER:
605 if (clknb->con_ids[0]) {
606 for (con_id = clknb->con_ids; *con_id; con_id++)
607 enable_clock(dev, *con_id);
608 } else {
609 enable_clock(dev, NULL);
610 }
611 break;
612 case BUS_NOTIFY_DRIVER_NOT_BOUND:
613 case BUS_NOTIFY_UNBOUND_DRIVER:
614 if (clknb->con_ids[0]) {
615 for (con_id = clknb->con_ids; *con_id; con_id++)
616 disable_clock(dev, *con_id);
617 } else {
618 disable_clock(dev, NULL);
619 }
620 break;
621 }
622
623 return 0;
624}
625
626#endif /* !CONFIG_PM_CLK */
627
628/**
629 * pm_clk_add_notifier - Add bus type notifier for power management clocks.
630 * @bus: Bus type to add the notifier to.
631 * @clknb: Notifier to be added to the given bus type.
632 *
633 * The nb member of @clknb is not expected to be initialized and its
634 * notifier_call member will be replaced with pm_clk_notify(). However,
635 * the remaining members of @clknb should be populated prior to calling this
636 * routine.
637 */
638void pm_clk_add_notifier(struct bus_type *bus,
639 struct pm_clk_notifier_block *clknb)
640{
641 if (!bus || !clknb)
642 return;
643
644 clknb->nb.notifier_call = pm_clk_notify;
645 bus_register_notifier(bus, &clknb->nb);
646}
647EXPORT_SYMBOL_GPL(pm_clk_add_notifier);
1/*
2 * drivers/base/power/clock_ops.c - Generic clock manipulation PM callbacks
3 *
4 * Copyright (c) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
5 *
6 * This file is released under the GPLv2.
7 */
8
9#include <linux/kernel.h>
10#include <linux/device.h>
11#include <linux/io.h>
12#include <linux/pm.h>
13#include <linux/pm_clock.h>
14#include <linux/clk.h>
15#include <linux/clkdev.h>
16#include <linux/slab.h>
17#include <linux/err.h>
18#include <linux/pm_domain.h>
19#include <linux/pm_runtime.h>
20
21#ifdef CONFIG_PM_CLK
22
23enum pce_status {
24 PCE_STATUS_NONE = 0,
25 PCE_STATUS_ACQUIRED,
26 PCE_STATUS_ENABLED,
27 PCE_STATUS_ERROR,
28};
29
30struct pm_clock_entry {
31 struct list_head node;
32 char *con_id;
33 struct clk *clk;
34 enum pce_status status;
35};
36
37/**
38 * pm_clk_enable - Enable a clock, reporting any errors
39 * @dev: The device for the given clock
40 * @ce: PM clock entry corresponding to the clock.
41 */
42static inline void __pm_clk_enable(struct device *dev, struct pm_clock_entry *ce)
43{
44 int ret;
45
46 if (ce->status < PCE_STATUS_ERROR) {
47 ret = clk_enable(ce->clk);
48 if (!ret)
49 ce->status = PCE_STATUS_ENABLED;
50 else
51 dev_err(dev, "%s: failed to enable clk %p, error %d\n",
52 __func__, ce->clk, ret);
53 }
54}
55
56/**
57 * pm_clk_acquire - Acquire a device clock.
58 * @dev: Device whose clock is to be acquired.
59 * @ce: PM clock entry corresponding to the clock.
60 */
61static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
62{
63 if (!ce->clk)
64 ce->clk = clk_get(dev, ce->con_id);
65 if (IS_ERR(ce->clk)) {
66 ce->status = PCE_STATUS_ERROR;
67 } else {
68 clk_prepare(ce->clk);
69 ce->status = PCE_STATUS_ACQUIRED;
70 dev_dbg(dev, "Clock %pC con_id %s managed by runtime PM.\n",
71 ce->clk, ce->con_id);
72 }
73}
74
75static int __pm_clk_add(struct device *dev, const char *con_id,
76 struct clk *clk)
77{
78 struct pm_subsys_data *psd = dev_to_psd(dev);
79 struct pm_clock_entry *ce;
80
81 if (!psd)
82 return -EINVAL;
83
84 ce = kzalloc(sizeof(*ce), GFP_KERNEL);
85 if (!ce)
86 return -ENOMEM;
87
88 if (con_id) {
89 ce->con_id = kstrdup(con_id, GFP_KERNEL);
90 if (!ce->con_id) {
91 dev_err(dev,
92 "Not enough memory for clock connection ID.\n");
93 kfree(ce);
94 return -ENOMEM;
95 }
96 } else {
97 if (IS_ERR(clk)) {
98 kfree(ce);
99 return -ENOENT;
100 }
101 ce->clk = clk;
102 }
103
104 pm_clk_acquire(dev, ce);
105
106 spin_lock_irq(&psd->lock);
107 list_add_tail(&ce->node, &psd->clock_list);
108 spin_unlock_irq(&psd->lock);
109 return 0;
110}
111
112/**
113 * pm_clk_add - Start using a device clock for power management.
114 * @dev: Device whose clock is going to be used for power management.
115 * @con_id: Connection ID of the clock.
116 *
117 * Add the clock represented by @con_id to the list of clocks used for
118 * the power management of @dev.
119 */
120int pm_clk_add(struct device *dev, const char *con_id)
121{
122 return __pm_clk_add(dev, con_id, NULL);
123}
124
125/**
126 * pm_clk_add_clk - Start using a device clock for power management.
127 * @dev: Device whose clock is going to be used for power management.
128 * @clk: Clock pointer
129 *
130 * Add the clock to the list of clocks used for the power management of @dev.
131 * The power-management code will take control of the clock reference, so
132 * callers should not call clk_put() on @clk after this function sucessfully
133 * returned.
134 */
135int pm_clk_add_clk(struct device *dev, struct clk *clk)
136{
137 return __pm_clk_add(dev, NULL, clk);
138}
139
140
141/**
142 * of_pm_clk_add_clks - Start using device clock(s) for power management.
143 * @dev: Device whose clock(s) is going to be used for power management.
144 *
145 * Add a series of clocks described in the 'clocks' device-tree node for
146 * a device to the list of clocks used for the power management of @dev.
147 * On success, returns the number of clocks added. Returns a negative
148 * error code if there are no clocks in the device node for the device
149 * or if adding a clock fails.
150 */
151int of_pm_clk_add_clks(struct device *dev)
152{
153 struct clk **clks;
154 unsigned int i, count;
155 int ret;
156
157 if (!dev || !dev->of_node)
158 return -EINVAL;
159
160 count = of_count_phandle_with_args(dev->of_node, "clocks",
161 "#clock-cells");
162 if (count == 0)
163 return -ENODEV;
164
165 clks = kcalloc(count, sizeof(*clks), GFP_KERNEL);
166 if (!clks)
167 return -ENOMEM;
168
169 for (i = 0; i < count; i++) {
170 clks[i] = of_clk_get(dev->of_node, i);
171 if (IS_ERR(clks[i])) {
172 ret = PTR_ERR(clks[i]);
173 goto error;
174 }
175
176 ret = pm_clk_add_clk(dev, clks[i]);
177 if (ret) {
178 clk_put(clks[i]);
179 goto error;
180 }
181 }
182
183 kfree(clks);
184
185 return i;
186
187error:
188 while (i--)
189 pm_clk_remove_clk(dev, clks[i]);
190
191 kfree(clks);
192
193 return ret;
194}
195
196/**
197 * __pm_clk_remove - Destroy PM clock entry.
198 * @ce: PM clock entry to destroy.
199 */
200static void __pm_clk_remove(struct pm_clock_entry *ce)
201{
202 if (!ce)
203 return;
204
205 if (ce->status < PCE_STATUS_ERROR) {
206 if (ce->status == PCE_STATUS_ENABLED)
207 clk_disable(ce->clk);
208
209 if (ce->status >= PCE_STATUS_ACQUIRED) {
210 clk_unprepare(ce->clk);
211 clk_put(ce->clk);
212 }
213 }
214
215 kfree(ce->con_id);
216 kfree(ce);
217}
218
219/**
220 * pm_clk_remove - Stop using a device clock for power management.
221 * @dev: Device whose clock should not be used for PM any more.
222 * @con_id: Connection ID of the clock.
223 *
224 * Remove the clock represented by @con_id from the list of clocks used for
225 * the power management of @dev.
226 */
227void pm_clk_remove(struct device *dev, const char *con_id)
228{
229 struct pm_subsys_data *psd = dev_to_psd(dev);
230 struct pm_clock_entry *ce;
231
232 if (!psd)
233 return;
234
235 spin_lock_irq(&psd->lock);
236
237 list_for_each_entry(ce, &psd->clock_list, node) {
238 if (!con_id && !ce->con_id)
239 goto remove;
240 else if (!con_id || !ce->con_id)
241 continue;
242 else if (!strcmp(con_id, ce->con_id))
243 goto remove;
244 }
245
246 spin_unlock_irq(&psd->lock);
247 return;
248
249 remove:
250 list_del(&ce->node);
251 spin_unlock_irq(&psd->lock);
252
253 __pm_clk_remove(ce);
254}
255
256/**
257 * pm_clk_remove_clk - Stop using a device clock for power management.
258 * @dev: Device whose clock should not be used for PM any more.
259 * @clk: Clock pointer
260 *
261 * Remove the clock pointed to by @clk from the list of clocks used for
262 * the power management of @dev.
263 */
264void pm_clk_remove_clk(struct device *dev, struct clk *clk)
265{
266 struct pm_subsys_data *psd = dev_to_psd(dev);
267 struct pm_clock_entry *ce;
268
269 if (!psd || !clk)
270 return;
271
272 spin_lock_irq(&psd->lock);
273
274 list_for_each_entry(ce, &psd->clock_list, node) {
275 if (clk == ce->clk)
276 goto remove;
277 }
278
279 spin_unlock_irq(&psd->lock);
280 return;
281
282 remove:
283 list_del(&ce->node);
284 spin_unlock_irq(&psd->lock);
285
286 __pm_clk_remove(ce);
287}
288
289/**
290 * pm_clk_init - Initialize a device's list of power management clocks.
291 * @dev: Device to initialize the list of PM clocks for.
292 *
293 * Initialize the lock and clock_list members of the device's pm_subsys_data
294 * object.
295 */
296void pm_clk_init(struct device *dev)
297{
298 struct pm_subsys_data *psd = dev_to_psd(dev);
299 if (psd)
300 INIT_LIST_HEAD(&psd->clock_list);
301}
302
303/**
304 * pm_clk_create - Create and initialize a device's list of PM clocks.
305 * @dev: Device to create and initialize the list of PM clocks for.
306 *
307 * Allocate a struct pm_subsys_data object, initialize its lock and clock_list
308 * members and make the @dev's power.subsys_data field point to it.
309 */
310int pm_clk_create(struct device *dev)
311{
312 return dev_pm_get_subsys_data(dev);
313}
314
315/**
316 * pm_clk_destroy - Destroy a device's list of power management clocks.
317 * @dev: Device to destroy the list of PM clocks for.
318 *
319 * Clear the @dev's power.subsys_data field, remove the list of clock entries
320 * from the struct pm_subsys_data object pointed to by it before and free
321 * that object.
322 */
323void pm_clk_destroy(struct device *dev)
324{
325 struct pm_subsys_data *psd = dev_to_psd(dev);
326 struct pm_clock_entry *ce, *c;
327 struct list_head list;
328
329 if (!psd)
330 return;
331
332 INIT_LIST_HEAD(&list);
333
334 spin_lock_irq(&psd->lock);
335
336 list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
337 list_move(&ce->node, &list);
338
339 spin_unlock_irq(&psd->lock);
340
341 dev_pm_put_subsys_data(dev);
342
343 list_for_each_entry_safe_reverse(ce, c, &list, node) {
344 list_del(&ce->node);
345 __pm_clk_remove(ce);
346 }
347}
348
349/**
350 * pm_clk_suspend - Disable clocks in a device's PM clock list.
351 * @dev: Device to disable the clocks for.
352 */
353int pm_clk_suspend(struct device *dev)
354{
355 struct pm_subsys_data *psd = dev_to_psd(dev);
356 struct pm_clock_entry *ce;
357 unsigned long flags;
358
359 dev_dbg(dev, "%s()\n", __func__);
360
361 if (!psd)
362 return 0;
363
364 spin_lock_irqsave(&psd->lock, flags);
365
366 list_for_each_entry_reverse(ce, &psd->clock_list, node) {
367 if (ce->status < PCE_STATUS_ERROR) {
368 if (ce->status == PCE_STATUS_ENABLED)
369 clk_disable(ce->clk);
370 ce->status = PCE_STATUS_ACQUIRED;
371 }
372 }
373
374 spin_unlock_irqrestore(&psd->lock, flags);
375
376 return 0;
377}
378
379/**
380 * pm_clk_resume - Enable clocks in a device's PM clock list.
381 * @dev: Device to enable the clocks for.
382 */
383int pm_clk_resume(struct device *dev)
384{
385 struct pm_subsys_data *psd = dev_to_psd(dev);
386 struct pm_clock_entry *ce;
387 unsigned long flags;
388
389 dev_dbg(dev, "%s()\n", __func__);
390
391 if (!psd)
392 return 0;
393
394 spin_lock_irqsave(&psd->lock, flags);
395
396 list_for_each_entry(ce, &psd->clock_list, node)
397 __pm_clk_enable(dev, ce);
398
399 spin_unlock_irqrestore(&psd->lock, flags);
400
401 return 0;
402}
403
404/**
405 * pm_clk_notify - Notify routine for device addition and removal.
406 * @nb: Notifier block object this function is a member of.
407 * @action: Operation being carried out by the caller.
408 * @data: Device the routine is being run for.
409 *
410 * For this function to work, @nb must be a member of an object of type
411 * struct pm_clk_notifier_block containing all of the requisite data.
412 * Specifically, the pm_domain member of that object is copied to the device's
413 * pm_domain field and its con_ids member is used to populate the device's list
414 * of PM clocks, depending on @action.
415 *
416 * If the device's pm_domain field is already populated with a value different
417 * from the one stored in the struct pm_clk_notifier_block object, the function
418 * does nothing.
419 */
420static int pm_clk_notify(struct notifier_block *nb,
421 unsigned long action, void *data)
422{
423 struct pm_clk_notifier_block *clknb;
424 struct device *dev = data;
425 char **con_id;
426 int error;
427
428 dev_dbg(dev, "%s() %ld\n", __func__, action);
429
430 clknb = container_of(nb, struct pm_clk_notifier_block, nb);
431
432 switch (action) {
433 case BUS_NOTIFY_ADD_DEVICE:
434 if (dev->pm_domain)
435 break;
436
437 error = pm_clk_create(dev);
438 if (error)
439 break;
440
441 dev_pm_domain_set(dev, clknb->pm_domain);
442 if (clknb->con_ids[0]) {
443 for (con_id = clknb->con_ids; *con_id; con_id++)
444 pm_clk_add(dev, *con_id);
445 } else {
446 pm_clk_add(dev, NULL);
447 }
448
449 break;
450 case BUS_NOTIFY_DEL_DEVICE:
451 if (dev->pm_domain != clknb->pm_domain)
452 break;
453
454 dev_pm_domain_set(dev, NULL);
455 pm_clk_destroy(dev);
456 break;
457 }
458
459 return 0;
460}
461
462int pm_clk_runtime_suspend(struct device *dev)
463{
464 int ret;
465
466 dev_dbg(dev, "%s\n", __func__);
467
468 ret = pm_generic_runtime_suspend(dev);
469 if (ret) {
470 dev_err(dev, "failed to suspend device\n");
471 return ret;
472 }
473
474 ret = pm_clk_suspend(dev);
475 if (ret) {
476 dev_err(dev, "failed to suspend clock\n");
477 pm_generic_runtime_resume(dev);
478 return ret;
479 }
480
481 return 0;
482}
483
484int pm_clk_runtime_resume(struct device *dev)
485{
486 int ret;
487
488 dev_dbg(dev, "%s\n", __func__);
489
490 ret = pm_clk_resume(dev);
491 if (ret) {
492 dev_err(dev, "failed to resume clock\n");
493 return ret;
494 }
495
496 return pm_generic_runtime_resume(dev);
497}
498
499#else /* !CONFIG_PM_CLK */
500
501/**
502 * enable_clock - Enable a device clock.
503 * @dev: Device whose clock is to be enabled.
504 * @con_id: Connection ID of the clock.
505 */
506static void enable_clock(struct device *dev, const char *con_id)
507{
508 struct clk *clk;
509
510 clk = clk_get(dev, con_id);
511 if (!IS_ERR(clk)) {
512 clk_prepare_enable(clk);
513 clk_put(clk);
514 dev_info(dev, "Runtime PM disabled, clock forced on.\n");
515 }
516}
517
518/**
519 * disable_clock - Disable a device clock.
520 * @dev: Device whose clock is to be disabled.
521 * @con_id: Connection ID of the clock.
522 */
523static void disable_clock(struct device *dev, const char *con_id)
524{
525 struct clk *clk;
526
527 clk = clk_get(dev, con_id);
528 if (!IS_ERR(clk)) {
529 clk_disable_unprepare(clk);
530 clk_put(clk);
531 dev_info(dev, "Runtime PM disabled, clock forced off.\n");
532 }
533}
534
535/**
536 * pm_clk_notify - Notify routine for device addition and removal.
537 * @nb: Notifier block object this function is a member of.
538 * @action: Operation being carried out by the caller.
539 * @data: Device the routine is being run for.
540 *
541 * For this function to work, @nb must be a member of an object of type
542 * struct pm_clk_notifier_block containing all of the requisite data.
543 * Specifically, the con_ids member of that object is used to enable or disable
544 * the device's clocks, depending on @action.
545 */
546static int pm_clk_notify(struct notifier_block *nb,
547 unsigned long action, void *data)
548{
549 struct pm_clk_notifier_block *clknb;
550 struct device *dev = data;
551 char **con_id;
552
553 dev_dbg(dev, "%s() %ld\n", __func__, action);
554
555 clknb = container_of(nb, struct pm_clk_notifier_block, nb);
556
557 switch (action) {
558 case BUS_NOTIFY_BIND_DRIVER:
559 if (clknb->con_ids[0]) {
560 for (con_id = clknb->con_ids; *con_id; con_id++)
561 enable_clock(dev, *con_id);
562 } else {
563 enable_clock(dev, NULL);
564 }
565 break;
566 case BUS_NOTIFY_DRIVER_NOT_BOUND:
567 case BUS_NOTIFY_UNBOUND_DRIVER:
568 if (clknb->con_ids[0]) {
569 for (con_id = clknb->con_ids; *con_id; con_id++)
570 disable_clock(dev, *con_id);
571 } else {
572 disable_clock(dev, NULL);
573 }
574 break;
575 }
576
577 return 0;
578}
579
580#endif /* !CONFIG_PM_CLK */
581
582/**
583 * pm_clk_add_notifier - Add bus type notifier for power management clocks.
584 * @bus: Bus type to add the notifier to.
585 * @clknb: Notifier to be added to the given bus type.
586 *
587 * The nb member of @clknb is not expected to be initialized and its
588 * notifier_call member will be replaced with pm_clk_notify(). However,
589 * the remaining members of @clknb should be populated prior to calling this
590 * routine.
591 */
592void pm_clk_add_notifier(struct bus_type *bus,
593 struct pm_clk_notifier_block *clknb)
594{
595 if (!bus || !clknb)
596 return;
597
598 clknb->nb.notifier_call = pm_clk_notify;
599 bus_register_notifier(bus, &clknb->nb);
600}