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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/init.h>
10#include <linux/kernel.h>
11#include <linux/io.h>
12#include <linux/pm.h>
13#include <linux/pm_runtime.h>
14#include <linux/clk.h>
15#include <linux/slab.h>
16#include <linux/err.h>
17
18#ifdef CONFIG_PM
19
20struct pm_clk_data {
21 struct list_head clock_list;
22 spinlock_t lock;
23};
24
25enum pce_status {
26 PCE_STATUS_NONE = 0,
27 PCE_STATUS_ACQUIRED,
28 PCE_STATUS_ENABLED,
29 PCE_STATUS_ERROR,
30};
31
32struct pm_clock_entry {
33 struct list_head node;
34 char *con_id;
35 struct clk *clk;
36 enum pce_status status;
37};
38
39static struct pm_clk_data *__to_pcd(struct device *dev)
40{
41 return dev ? dev->power.subsys_data : NULL;
42}
43
44/**
45 * pm_clk_acquire - Acquire a device clock.
46 * @dev: Device whose clock is to be acquired.
47 * @ce: PM clock entry corresponding to the clock.
48 */
49static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
50{
51 ce->clk = clk_get(dev, ce->con_id);
52 if (IS_ERR(ce->clk)) {
53 ce->status = PCE_STATUS_ERROR;
54 } else {
55 ce->status = PCE_STATUS_ACQUIRED;
56 dev_dbg(dev, "Clock %s managed by runtime PM.\n", ce->con_id);
57 }
58}
59
60/**
61 * pm_clk_add - Start using a device clock for power management.
62 * @dev: Device whose clock is going to be used for power management.
63 * @con_id: Connection ID of the clock.
64 *
65 * Add the clock represented by @con_id to the list of clocks used for
66 * the power management of @dev.
67 */
68int pm_clk_add(struct device *dev, const char *con_id)
69{
70 struct pm_clk_data *pcd = __to_pcd(dev);
71 struct pm_clock_entry *ce;
72
73 if (!pcd)
74 return -EINVAL;
75
76 ce = kzalloc(sizeof(*ce), GFP_KERNEL);
77 if (!ce) {
78 dev_err(dev, "Not enough memory for clock entry.\n");
79 return -ENOMEM;
80 }
81
82 if (con_id) {
83 ce->con_id = kstrdup(con_id, GFP_KERNEL);
84 if (!ce->con_id) {
85 dev_err(dev,
86 "Not enough memory for clock connection ID.\n");
87 kfree(ce);
88 return -ENOMEM;
89 }
90 }
91
92 pm_clk_acquire(dev, ce);
93
94 spin_lock_irq(&pcd->lock);
95 list_add_tail(&ce->node, &pcd->clock_list);
96 spin_unlock_irq(&pcd->lock);
97 return 0;
98}
99
100/**
101 * __pm_clk_remove - Destroy PM clock entry.
102 * @ce: PM clock entry to destroy.
103 */
104static void __pm_clk_remove(struct pm_clock_entry *ce)
105{
106 if (!ce)
107 return;
108
109 if (ce->status < PCE_STATUS_ERROR) {
110 if (ce->status == PCE_STATUS_ENABLED)
111 clk_disable(ce->clk);
112
113 if (ce->status >= PCE_STATUS_ACQUIRED)
114 clk_put(ce->clk);
115 }
116
117 if (ce->con_id)
118 kfree(ce->con_id);
119
120 kfree(ce);
121}
122
123/**
124 * pm_clk_remove - Stop using a device clock for power management.
125 * @dev: Device whose clock should not be used for PM any more.
126 * @con_id: Connection ID of the clock.
127 *
128 * Remove the clock represented by @con_id from the list of clocks used for
129 * the power management of @dev.
130 */
131void pm_clk_remove(struct device *dev, const char *con_id)
132{
133 struct pm_clk_data *pcd = __to_pcd(dev);
134 struct pm_clock_entry *ce;
135
136 if (!pcd)
137 return;
138
139 spin_lock_irq(&pcd->lock);
140
141 list_for_each_entry(ce, &pcd->clock_list, node) {
142 if (!con_id && !ce->con_id)
143 goto remove;
144 else if (!con_id || !ce->con_id)
145 continue;
146 else if (!strcmp(con_id, ce->con_id))
147 goto remove;
148 }
149
150 spin_unlock_irq(&pcd->lock);
151 return;
152
153 remove:
154 list_del(&ce->node);
155 spin_unlock_irq(&pcd->lock);
156
157 __pm_clk_remove(ce);
158}
159
160/**
161 * pm_clk_init - Initialize a device's list of power management clocks.
162 * @dev: Device to initialize the list of PM clocks for.
163 *
164 * Allocate a struct pm_clk_data object, initialize its lock member and
165 * make the @dev's power.subsys_data field point to it.
166 */
167int pm_clk_init(struct device *dev)
168{
169 struct pm_clk_data *pcd;
170
171 pcd = kzalloc(sizeof(*pcd), GFP_KERNEL);
172 if (!pcd) {
173 dev_err(dev, "Not enough memory for PM clock data.\n");
174 return -ENOMEM;
175 }
176
177 INIT_LIST_HEAD(&pcd->clock_list);
178 spin_lock_init(&pcd->lock);
179 dev->power.subsys_data = pcd;
180 return 0;
181}
182
183/**
184 * pm_clk_destroy - Destroy a device's list of power management clocks.
185 * @dev: Device to destroy the list of PM clocks for.
186 *
187 * Clear the @dev's power.subsys_data field, remove the list of clock entries
188 * from the struct pm_clk_data object pointed to by it before and free
189 * that object.
190 */
191void pm_clk_destroy(struct device *dev)
192{
193 struct pm_clk_data *pcd = __to_pcd(dev);
194 struct pm_clock_entry *ce, *c;
195 struct list_head list;
196
197 if (!pcd)
198 return;
199
200 dev->power.subsys_data = NULL;
201 INIT_LIST_HEAD(&list);
202
203 spin_lock_irq(&pcd->lock);
204
205 list_for_each_entry_safe_reverse(ce, c, &pcd->clock_list, node)
206 list_move(&ce->node, &list);
207
208 spin_unlock_irq(&pcd->lock);
209
210 kfree(pcd);
211
212 list_for_each_entry_safe_reverse(ce, c, &list, node) {
213 list_del(&ce->node);
214 __pm_clk_remove(ce);
215 }
216}
217
218#endif /* CONFIG_PM */
219
220#ifdef CONFIG_PM_RUNTIME
221
222/**
223 * pm_clk_suspend - Disable clocks in a device's PM clock list.
224 * @dev: Device to disable the clocks for.
225 */
226int pm_clk_suspend(struct device *dev)
227{
228 struct pm_clk_data *pcd = __to_pcd(dev);
229 struct pm_clock_entry *ce;
230 unsigned long flags;
231
232 dev_dbg(dev, "%s()\n", __func__);
233
234 if (!pcd)
235 return 0;
236
237 spin_lock_irqsave(&pcd->lock, flags);
238
239 list_for_each_entry_reverse(ce, &pcd->clock_list, node) {
240 if (ce->status < PCE_STATUS_ERROR) {
241 clk_disable(ce->clk);
242 ce->status = PCE_STATUS_ACQUIRED;
243 }
244 }
245
246 spin_unlock_irqrestore(&pcd->lock, flags);
247
248 return 0;
249}
250
251/**
252 * pm_clk_resume - Enable clocks in a device's PM clock list.
253 * @dev: Device to enable the clocks for.
254 */
255int pm_clk_resume(struct device *dev)
256{
257 struct pm_clk_data *pcd = __to_pcd(dev);
258 struct pm_clock_entry *ce;
259 unsigned long flags;
260
261 dev_dbg(dev, "%s()\n", __func__);
262
263 if (!pcd)
264 return 0;
265
266 spin_lock_irqsave(&pcd->lock, flags);
267
268 list_for_each_entry(ce, &pcd->clock_list, node) {
269 if (ce->status < PCE_STATUS_ERROR) {
270 clk_enable(ce->clk);
271 ce->status = PCE_STATUS_ENABLED;
272 }
273 }
274
275 spin_unlock_irqrestore(&pcd->lock, flags);
276
277 return 0;
278}
279
280/**
281 * pm_clk_notify - Notify routine for device addition and removal.
282 * @nb: Notifier block object this function is a member of.
283 * @action: Operation being carried out by the caller.
284 * @data: Device the routine is being run for.
285 *
286 * For this function to work, @nb must be a member of an object of type
287 * struct pm_clk_notifier_block containing all of the requisite data.
288 * Specifically, the pm_domain member of that object is copied to the device's
289 * pm_domain field and its con_ids member is used to populate the device's list
290 * of PM clocks, depending on @action.
291 *
292 * If the device's pm_domain field is already populated with a value different
293 * from the one stored in the struct pm_clk_notifier_block object, the function
294 * does nothing.
295 */
296static int pm_clk_notify(struct notifier_block *nb,
297 unsigned long action, void *data)
298{
299 struct pm_clk_notifier_block *clknb;
300 struct device *dev = data;
301 char **con_id;
302 int error;
303
304 dev_dbg(dev, "%s() %ld\n", __func__, action);
305
306 clknb = container_of(nb, struct pm_clk_notifier_block, nb);
307
308 switch (action) {
309 case BUS_NOTIFY_ADD_DEVICE:
310 if (dev->pm_domain)
311 break;
312
313 error = pm_clk_init(dev);
314 if (error)
315 break;
316
317 dev->pm_domain = clknb->pm_domain;
318 if (clknb->con_ids[0]) {
319 for (con_id = clknb->con_ids; *con_id; con_id++)
320 pm_clk_add(dev, *con_id);
321 } else {
322 pm_clk_add(dev, NULL);
323 }
324
325 break;
326 case BUS_NOTIFY_DEL_DEVICE:
327 if (dev->pm_domain != clknb->pm_domain)
328 break;
329
330 dev->pm_domain = NULL;
331 pm_clk_destroy(dev);
332 break;
333 }
334
335 return 0;
336}
337
338#else /* !CONFIG_PM_RUNTIME */
339
340#ifdef CONFIG_PM
341
342/**
343 * pm_clk_suspend - Disable clocks in a device's PM clock list.
344 * @dev: Device to disable the clocks for.
345 */
346int pm_clk_suspend(struct device *dev)
347{
348 struct pm_clk_data *pcd = __to_pcd(dev);
349 struct pm_clock_entry *ce;
350 unsigned long flags;
351
352 dev_dbg(dev, "%s()\n", __func__);
353
354 /* If there is no driver, the clocks are already disabled. */
355 if (!pcd || !dev->driver)
356 return 0;
357
358 spin_lock_irqsave(&pcd->lock, flags);
359
360 list_for_each_entry_reverse(ce, &pcd->clock_list, node)
361 clk_disable(ce->clk);
362
363 spin_unlock_irqrestore(&pcd->lock, flags);
364
365 return 0;
366}
367
368/**
369 * pm_clk_resume - Enable clocks in a device's PM clock list.
370 * @dev: Device to enable the clocks for.
371 */
372int pm_clk_resume(struct device *dev)
373{
374 struct pm_clk_data *pcd = __to_pcd(dev);
375 struct pm_clock_entry *ce;
376 unsigned long flags;
377
378 dev_dbg(dev, "%s()\n", __func__);
379
380 /* If there is no driver, the clocks should remain disabled. */
381 if (!pcd || !dev->driver)
382 return 0;
383
384 spin_lock_irqsave(&pcd->lock, flags);
385
386 list_for_each_entry(ce, &pcd->clock_list, node)
387 clk_enable(ce->clk);
388
389 spin_unlock_irqrestore(&pcd->lock, flags);
390
391 return 0;
392}
393
394#endif /* CONFIG_PM */
395
396/**
397 * enable_clock - Enable a device clock.
398 * @dev: Device whose clock is to be enabled.
399 * @con_id: Connection ID of the clock.
400 */
401static void enable_clock(struct device *dev, const char *con_id)
402{
403 struct clk *clk;
404
405 clk = clk_get(dev, con_id);
406 if (!IS_ERR(clk)) {
407 clk_enable(clk);
408 clk_put(clk);
409 dev_info(dev, "Runtime PM disabled, clock forced on.\n");
410 }
411}
412
413/**
414 * disable_clock - Disable a device clock.
415 * @dev: Device whose clock is to be disabled.
416 * @con_id: Connection ID of the clock.
417 */
418static void disable_clock(struct device *dev, const char *con_id)
419{
420 struct clk *clk;
421
422 clk = clk_get(dev, con_id);
423 if (!IS_ERR(clk)) {
424 clk_disable(clk);
425 clk_put(clk);
426 dev_info(dev, "Runtime PM disabled, clock forced off.\n");
427 }
428}
429
430/**
431 * pm_clk_notify - Notify routine for device addition and removal.
432 * @nb: Notifier block object this function is a member of.
433 * @action: Operation being carried out by the caller.
434 * @data: Device the routine is being run for.
435 *
436 * For this function to work, @nb must be a member of an object of type
437 * struct pm_clk_notifier_block containing all of the requisite data.
438 * Specifically, the con_ids member of that object is used to enable or disable
439 * the device's clocks, depending on @action.
440 */
441static int pm_clk_notify(struct notifier_block *nb,
442 unsigned long action, void *data)
443{
444 struct pm_clk_notifier_block *clknb;
445 struct device *dev = data;
446 char **con_id;
447
448 dev_dbg(dev, "%s() %ld\n", __func__, action);
449
450 clknb = container_of(nb, struct pm_clk_notifier_block, nb);
451
452 switch (action) {
453 case BUS_NOTIFY_BIND_DRIVER:
454 if (clknb->con_ids[0]) {
455 for (con_id = clknb->con_ids; *con_id; con_id++)
456 enable_clock(dev, *con_id);
457 } else {
458 enable_clock(dev, NULL);
459 }
460 break;
461 case BUS_NOTIFY_UNBOUND_DRIVER:
462 if (clknb->con_ids[0]) {
463 for (con_id = clknb->con_ids; *con_id; con_id++)
464 disable_clock(dev, *con_id);
465 } else {
466 disable_clock(dev, NULL);
467 }
468 break;
469 }
470
471 return 0;
472}
473
474#endif /* !CONFIG_PM_RUNTIME */
475
476/**
477 * pm_clk_add_notifier - Add bus type notifier for power management clocks.
478 * @bus: Bus type to add the notifier to.
479 * @clknb: Notifier to be added to the given bus type.
480 *
481 * The nb member of @clknb is not expected to be initialized and its
482 * notifier_call member will be replaced with pm_clk_notify(). However,
483 * the remaining members of @clknb should be populated prior to calling this
484 * routine.
485 */
486void pm_clk_add_notifier(struct bus_type *bus,
487 struct pm_clk_notifier_block *clknb)
488{
489 if (!bus || !clknb)
490 return;
491
492 clknb->nb.notifier_call = pm_clk_notify;
493 bus_register_notifier(bus, &clknb->nb);
494}