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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/slab.h>
16#include <linux/err.h>
17
18#ifdef CONFIG_PM
19
20enum pce_status {
21 PCE_STATUS_NONE = 0,
22 PCE_STATUS_ACQUIRED,
23 PCE_STATUS_ENABLED,
24 PCE_STATUS_ERROR,
25};
26
27struct pm_clock_entry {
28 struct list_head node;
29 char *con_id;
30 struct clk *clk;
31 enum pce_status status;
32};
33
34/**
35 * pm_clk_enable - Enable a clock, reporting any errors
36 * @dev: The device for the given clock
37 * @clk: The clock being enabled.
38 */
39static inline int __pm_clk_enable(struct device *dev, struct clk *clk)
40{
41 int ret = clk_enable(clk);
42 if (ret)
43 dev_err(dev, "%s: failed to enable clk %p, error %d\n",
44 __func__, clk, ret);
45
46 return ret;
47}
48
49/**
50 * pm_clk_acquire - Acquire a device clock.
51 * @dev: Device whose clock is to be acquired.
52 * @ce: PM clock entry corresponding to the clock.
53 */
54static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
55{
56 ce->clk = clk_get(dev, ce->con_id);
57 if (IS_ERR(ce->clk)) {
58 ce->status = PCE_STATUS_ERROR;
59 } else {
60 clk_prepare(ce->clk);
61 ce->status = PCE_STATUS_ACQUIRED;
62 dev_dbg(dev, "Clock %s managed by runtime PM.\n", ce->con_id);
63 }
64}
65
66/**
67 * pm_clk_add - Start using a device clock for power management.
68 * @dev: Device whose clock is going to be used for power management.
69 * @con_id: Connection ID of the clock.
70 *
71 * Add the clock represented by @con_id to the list of clocks used for
72 * the power management of @dev.
73 */
74int pm_clk_add(struct device *dev, const char *con_id)
75{
76 struct pm_subsys_data *psd = dev_to_psd(dev);
77 struct pm_clock_entry *ce;
78
79 if (!psd)
80 return -EINVAL;
81
82 ce = kzalloc(sizeof(*ce), GFP_KERNEL);
83 if (!ce) {
84 dev_err(dev, "Not enough memory for clock entry.\n");
85 return -ENOMEM;
86 }
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 }
97
98 pm_clk_acquire(dev, ce);
99
100 spin_lock_irq(&psd->lock);
101 list_add_tail(&ce->node, &psd->clock_list);
102 spin_unlock_irq(&psd->lock);
103 return 0;
104}
105
106/**
107 * __pm_clk_remove - Destroy PM clock entry.
108 * @ce: PM clock entry to destroy.
109 */
110static void __pm_clk_remove(struct pm_clock_entry *ce)
111{
112 if (!ce)
113 return;
114
115 if (ce->status < PCE_STATUS_ERROR) {
116 if (ce->status == PCE_STATUS_ENABLED)
117 clk_disable(ce->clk);
118
119 if (ce->status >= PCE_STATUS_ACQUIRED) {
120 clk_unprepare(ce->clk);
121 clk_put(ce->clk);
122 }
123 }
124
125 kfree(ce->con_id);
126 kfree(ce);
127}
128
129/**
130 * pm_clk_remove - Stop using a device clock for power management.
131 * @dev: Device whose clock should not be used for PM any more.
132 * @con_id: Connection ID of the clock.
133 *
134 * Remove the clock represented by @con_id from the list of clocks used for
135 * the power management of @dev.
136 */
137void pm_clk_remove(struct device *dev, const char *con_id)
138{
139 struct pm_subsys_data *psd = dev_to_psd(dev);
140 struct pm_clock_entry *ce;
141
142 if (!psd)
143 return;
144
145 spin_lock_irq(&psd->lock);
146
147 list_for_each_entry(ce, &psd->clock_list, node) {
148 if (!con_id && !ce->con_id)
149 goto remove;
150 else if (!con_id || !ce->con_id)
151 continue;
152 else if (!strcmp(con_id, ce->con_id))
153 goto remove;
154 }
155
156 spin_unlock_irq(&psd->lock);
157 return;
158
159 remove:
160 list_del(&ce->node);
161 spin_unlock_irq(&psd->lock);
162
163 __pm_clk_remove(ce);
164}
165
166/**
167 * pm_clk_init - Initialize a device's list of power management clocks.
168 * @dev: Device to initialize the list of PM clocks for.
169 *
170 * Initialize the lock and clock_list members of the device's pm_subsys_data
171 * object.
172 */
173void pm_clk_init(struct device *dev)
174{
175 struct pm_subsys_data *psd = dev_to_psd(dev);
176 if (psd)
177 INIT_LIST_HEAD(&psd->clock_list);
178}
179
180/**
181 * pm_clk_create - Create and initialize a device's list of PM clocks.
182 * @dev: Device to create and initialize the list of PM clocks for.
183 *
184 * Allocate a struct pm_subsys_data object, initialize its lock and clock_list
185 * members and make the @dev's power.subsys_data field point to it.
186 */
187int pm_clk_create(struct device *dev)
188{
189 return dev_pm_get_subsys_data(dev);
190}
191
192/**
193 * pm_clk_destroy - Destroy a device's list of power management clocks.
194 * @dev: Device to destroy the list of PM clocks for.
195 *
196 * Clear the @dev's power.subsys_data field, remove the list of clock entries
197 * from the struct pm_subsys_data object pointed to by it before and free
198 * that object.
199 */
200void pm_clk_destroy(struct device *dev)
201{
202 struct pm_subsys_data *psd = dev_to_psd(dev);
203 struct pm_clock_entry *ce, *c;
204 struct list_head list;
205
206 if (!psd)
207 return;
208
209 INIT_LIST_HEAD(&list);
210
211 spin_lock_irq(&psd->lock);
212
213 list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
214 list_move(&ce->node, &list);
215
216 spin_unlock_irq(&psd->lock);
217
218 dev_pm_put_subsys_data(dev);
219
220 list_for_each_entry_safe_reverse(ce, c, &list, node) {
221 list_del(&ce->node);
222 __pm_clk_remove(ce);
223 }
224}
225
226#endif /* CONFIG_PM */
227
228#ifdef CONFIG_PM_RUNTIME
229
230/**
231 * pm_clk_suspend - Disable clocks in a device's PM clock list.
232 * @dev: Device to disable the clocks for.
233 */
234int pm_clk_suspend(struct device *dev)
235{
236 struct pm_subsys_data *psd = dev_to_psd(dev);
237 struct pm_clock_entry *ce;
238 unsigned long flags;
239
240 dev_dbg(dev, "%s()\n", __func__);
241
242 if (!psd)
243 return 0;
244
245 spin_lock_irqsave(&psd->lock, flags);
246
247 list_for_each_entry_reverse(ce, &psd->clock_list, node) {
248 if (ce->status < PCE_STATUS_ERROR) {
249 if (ce->status == PCE_STATUS_ENABLED)
250 clk_disable(ce->clk);
251 ce->status = PCE_STATUS_ACQUIRED;
252 }
253 }
254
255 spin_unlock_irqrestore(&psd->lock, flags);
256
257 return 0;
258}
259
260/**
261 * pm_clk_resume - Enable clocks in a device's PM clock list.
262 * @dev: Device to enable the clocks for.
263 */
264int pm_clk_resume(struct device *dev)
265{
266 struct pm_subsys_data *psd = dev_to_psd(dev);
267 struct pm_clock_entry *ce;
268 unsigned long flags;
269 int ret;
270
271 dev_dbg(dev, "%s()\n", __func__);
272
273 if (!psd)
274 return 0;
275
276 spin_lock_irqsave(&psd->lock, flags);
277
278 list_for_each_entry(ce, &psd->clock_list, node) {
279 if (ce->status < PCE_STATUS_ERROR) {
280 ret = __pm_clk_enable(dev, ce->clk);
281 if (!ret)
282 ce->status = PCE_STATUS_ENABLED;
283 }
284 }
285
286 spin_unlock_irqrestore(&psd->lock, flags);
287
288 return 0;
289}
290
291/**
292 * pm_clk_notify - Notify routine for device addition and removal.
293 * @nb: Notifier block object this function is a member of.
294 * @action: Operation being carried out by the caller.
295 * @data: Device the routine is being run for.
296 *
297 * For this function to work, @nb must be a member of an object of type
298 * struct pm_clk_notifier_block containing all of the requisite data.
299 * Specifically, the pm_domain member of that object is copied to the device's
300 * pm_domain field and its con_ids member is used to populate the device's list
301 * of PM clocks, depending on @action.
302 *
303 * If the device's pm_domain field is already populated with a value different
304 * from the one stored in the struct pm_clk_notifier_block object, the function
305 * does nothing.
306 */
307static int pm_clk_notify(struct notifier_block *nb,
308 unsigned long action, void *data)
309{
310 struct pm_clk_notifier_block *clknb;
311 struct device *dev = data;
312 char **con_id;
313 int error;
314
315 dev_dbg(dev, "%s() %ld\n", __func__, action);
316
317 clknb = container_of(nb, struct pm_clk_notifier_block, nb);
318
319 switch (action) {
320 case BUS_NOTIFY_ADD_DEVICE:
321 if (dev->pm_domain)
322 break;
323
324 error = pm_clk_create(dev);
325 if (error)
326 break;
327
328 dev->pm_domain = clknb->pm_domain;
329 if (clknb->con_ids[0]) {
330 for (con_id = clknb->con_ids; *con_id; con_id++)
331 pm_clk_add(dev, *con_id);
332 } else {
333 pm_clk_add(dev, NULL);
334 }
335
336 break;
337 case BUS_NOTIFY_DEL_DEVICE:
338 if (dev->pm_domain != clknb->pm_domain)
339 break;
340
341 dev->pm_domain = NULL;
342 pm_clk_destroy(dev);
343 break;
344 }
345
346 return 0;
347}
348
349#else /* !CONFIG_PM_RUNTIME */
350
351#ifdef CONFIG_PM
352
353/**
354 * pm_clk_suspend - Disable clocks in a device's PM clock list.
355 * @dev: Device to disable the clocks for.
356 */
357int pm_clk_suspend(struct device *dev)
358{
359 struct pm_subsys_data *psd = dev_to_psd(dev);
360 struct pm_clock_entry *ce;
361 unsigned long flags;
362
363 dev_dbg(dev, "%s()\n", __func__);
364
365 /* If there is no driver, the clocks are already disabled. */
366 if (!psd || !dev->driver)
367 return 0;
368
369 spin_lock_irqsave(&psd->lock, flags);
370
371 list_for_each_entry_reverse(ce, &psd->clock_list, node)
372 clk_disable(ce->clk);
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 there is no driver, the clocks should remain disabled. */
392 if (!psd || !dev->driver)
393 return 0;
394
395 spin_lock_irqsave(&psd->lock, flags);
396
397 list_for_each_entry(ce, &psd->clock_list, node)
398 __pm_clk_enable(dev, ce->clk);
399
400 spin_unlock_irqrestore(&psd->lock, flags);
401
402 return 0;
403}
404
405#endif /* CONFIG_PM */
406
407/**
408 * enable_clock - Enable a device clock.
409 * @dev: Device whose clock is to be enabled.
410 * @con_id: Connection ID of the clock.
411 */
412static void enable_clock(struct device *dev, const char *con_id)
413{
414 struct clk *clk;
415
416 clk = clk_get(dev, con_id);
417 if (!IS_ERR(clk)) {
418 clk_prepare_enable(clk);
419 clk_put(clk);
420 dev_info(dev, "Runtime PM disabled, clock forced on.\n");
421 }
422}
423
424/**
425 * disable_clock - Disable a device clock.
426 * @dev: Device whose clock is to be disabled.
427 * @con_id: Connection ID of the clock.
428 */
429static void disable_clock(struct device *dev, const char *con_id)
430{
431 struct clk *clk;
432
433 clk = clk_get(dev, con_id);
434 if (!IS_ERR(clk)) {
435 clk_disable_unprepare(clk);
436 clk_put(clk);
437 dev_info(dev, "Runtime PM disabled, clock forced off.\n");
438 }
439}
440
441/**
442 * pm_clk_notify - Notify routine for device addition and removal.
443 * @nb: Notifier block object this function is a member of.
444 * @action: Operation being carried out by the caller.
445 * @data: Device the routine is being run for.
446 *
447 * For this function to work, @nb must be a member of an object of type
448 * struct pm_clk_notifier_block containing all of the requisite data.
449 * Specifically, the con_ids member of that object is used to enable or disable
450 * the device's clocks, depending on @action.
451 */
452static int pm_clk_notify(struct notifier_block *nb,
453 unsigned long action, void *data)
454{
455 struct pm_clk_notifier_block *clknb;
456 struct device *dev = data;
457 char **con_id;
458
459 dev_dbg(dev, "%s() %ld\n", __func__, action);
460
461 clknb = container_of(nb, struct pm_clk_notifier_block, nb);
462
463 switch (action) {
464 case BUS_NOTIFY_BIND_DRIVER:
465 if (clknb->con_ids[0]) {
466 for (con_id = clknb->con_ids; *con_id; con_id++)
467 enable_clock(dev, *con_id);
468 } else {
469 enable_clock(dev, NULL);
470 }
471 break;
472 case BUS_NOTIFY_UNBOUND_DRIVER:
473 if (clknb->con_ids[0]) {
474 for (con_id = clknb->con_ids; *con_id; con_id++)
475 disable_clock(dev, *con_id);
476 } else {
477 disable_clock(dev, NULL);
478 }
479 break;
480 }
481
482 return 0;
483}
484
485#endif /* !CONFIG_PM_RUNTIME */
486
487/**
488 * pm_clk_add_notifier - Add bus type notifier for power management clocks.
489 * @bus: Bus type to add the notifier to.
490 * @clknb: Notifier to be added to the given bus type.
491 *
492 * The nb member of @clknb is not expected to be initialized and its
493 * notifier_call member will be replaced with pm_clk_notify(). However,
494 * the remaining members of @clknb should be populated prior to calling this
495 * routine.
496 */
497void pm_clk_add_notifier(struct bus_type *bus,
498 struct pm_clk_notifier_block *clknb)
499{
500 if (!bus || !clknb)
501 return;
502
503 clknb->nb.notifier_call = pm_clk_notify;
504 bus_register_notifier(bus, &clknb->nb);
505}
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);