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