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9#include <linux/init.h>
10#include <linux/kernel.h>
11#include <linux/device.h>
12#include <linux/io.h>
13#include <linux/pm.h>
14#include <linux/pm_clock.h>
15#include <linux/clk.h>
16#include <linux/slab.h>
17#include <linux/err.h>
18
19#ifdef CONFIG_PM
20
21enum pce_status {
22 PCE_STATUS_NONE = 0,
23 PCE_STATUS_ACQUIRED,
24 PCE_STATUS_ENABLED,
25 PCE_STATUS_ERROR,
26};
27
28struct pm_clock_entry {
29 struct list_head node;
30 char *con_id;
31 struct clk *clk;
32 enum pce_status status;
33};
34
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36
37
38
39
40static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
41{
42 ce->clk = clk_get(dev, ce->con_id);
43 if (IS_ERR(ce->clk)) {
44 ce->status = PCE_STATUS_ERROR;
45 } else {
46 ce->status = PCE_STATUS_ACQUIRED;
47 dev_dbg(dev, "Clock %s managed by runtime PM.\n", ce->con_id);
48 }
49}
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58
59int pm_clk_add(struct device *dev, const char *con_id)
60{
61 struct pm_subsys_data *psd = dev_to_psd(dev);
62 struct pm_clock_entry *ce;
63
64 if (!psd)
65 return -EINVAL;
66
67 ce = kzalloc(sizeof(*ce), GFP_KERNEL);
68 if (!ce) {
69 dev_err(dev, "Not enough memory for clock entry.\n");
70 return -ENOMEM;
71 }
72
73 if (con_id) {
74 ce->con_id = kstrdup(con_id, GFP_KERNEL);
75 if (!ce->con_id) {
76 dev_err(dev,
77 "Not enough memory for clock connection ID.\n");
78 kfree(ce);
79 return -ENOMEM;
80 }
81 }
82
83 pm_clk_acquire(dev, ce);
84
85 spin_lock_irq(&psd->lock);
86 list_add_tail(&ce->node, &psd->clock_list);
87 spin_unlock_irq(&psd->lock);
88 return 0;
89}
90
91
92
93
94
95static void __pm_clk_remove(struct pm_clock_entry *ce)
96{
97 if (!ce)
98 return;
99
100 if (ce->status < PCE_STATUS_ERROR) {
101 if (ce->status == PCE_STATUS_ENABLED)
102 clk_disable_unprepare(ce->clk);
103
104 if (ce->status >= PCE_STATUS_ACQUIRED)
105 clk_put(ce->clk);
106 }
107
108 kfree(ce->con_id);
109 kfree(ce);
110}
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118
119
120void pm_clk_remove(struct device *dev, const char *con_id)
121{
122 struct pm_subsys_data *psd = dev_to_psd(dev);
123 struct pm_clock_entry *ce;
124
125 if (!psd)
126 return;
127
128 spin_lock_irq(&psd->lock);
129
130 list_for_each_entry(ce, &psd->clock_list, node) {
131 if (!con_id && !ce->con_id)
132 goto remove;
133 else if (!con_id || !ce->con_id)
134 continue;
135 else if (!strcmp(con_id, ce->con_id))
136 goto remove;
137 }
138
139 spin_unlock_irq(&psd->lock);
140 return;
141
142 remove:
143 list_del(&ce->node);
144 spin_unlock_irq(&psd->lock);
145
146 __pm_clk_remove(ce);
147}
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155
156void pm_clk_init(struct device *dev)
157{
158 struct pm_subsys_data *psd = dev_to_psd(dev);
159 if (psd)
160 INIT_LIST_HEAD(&psd->clock_list);
161}
162
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169
170int pm_clk_create(struct device *dev)
171{
172 return dev_pm_get_subsys_data(dev);
173}
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182
183void pm_clk_destroy(struct device *dev)
184{
185 struct pm_subsys_data *psd = dev_to_psd(dev);
186 struct pm_clock_entry *ce, *c;
187 struct list_head list;
188
189 if (!psd)
190 return;
191
192 INIT_LIST_HEAD(&list);
193
194 spin_lock_irq(&psd->lock);
195
196 list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
197 list_move(&ce->node, &list);
198
199 spin_unlock_irq(&psd->lock);
200
201 dev_pm_put_subsys_data(dev);
202
203 list_for_each_entry_safe_reverse(ce, c, &list, node) {
204 list_del(&ce->node);
205 __pm_clk_remove(ce);
206 }
207}
208
209#endif
210
211#ifdef CONFIG_PM_RUNTIME
212
213
214
215
216
217int pm_clk_suspend(struct device *dev)
218{
219 struct pm_subsys_data *psd = dev_to_psd(dev);
220 struct pm_clock_entry *ce;
221 unsigned long flags;
222
223 dev_dbg(dev, "%s()\n", __func__);
224
225 if (!psd)
226 return 0;
227
228 spin_lock_irqsave(&psd->lock, flags);
229
230 list_for_each_entry_reverse(ce, &psd->clock_list, node) {
231 if (ce->status < PCE_STATUS_ERROR) {
232 if (ce->status == PCE_STATUS_ENABLED)
233 clk_disable(ce->clk);
234 ce->status = PCE_STATUS_ACQUIRED;
235 }
236 }
237
238 spin_unlock_irqrestore(&psd->lock, flags);
239
240 return 0;
241}
242
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245
246
247int pm_clk_resume(struct device *dev)
248{
249 struct pm_subsys_data *psd = dev_to_psd(dev);
250 struct pm_clock_entry *ce;
251 unsigned long flags;
252
253 dev_dbg(dev, "%s()\n", __func__);
254
255 if (!psd)
256 return 0;
257
258 spin_lock_irqsave(&psd->lock, flags);
259
260 list_for_each_entry(ce, &psd->clock_list, node) {
261 if (ce->status < PCE_STATUS_ERROR) {
262 clk_enable(ce->clk);
263 ce->status = PCE_STATUS_ENABLED;
264 }
265 }
266
267 spin_unlock_irqrestore(&psd->lock, flags);
268
269 return 0;
270}
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287
288static int pm_clk_notify(struct notifier_block *nb,
289 unsigned long action, void *data)
290{
291 struct pm_clk_notifier_block *clknb;
292 struct device *dev = data;
293 char **con_id;
294 int error;
295
296 dev_dbg(dev, "%s() %ld\n", __func__, action);
297
298 clknb = container_of(nb, struct pm_clk_notifier_block, nb);
299
300 switch (action) {
301 case BUS_NOTIFY_ADD_DEVICE:
302 if (dev->pm_domain)
303 break;
304
305 error = pm_clk_create(dev);
306 if (error)
307 break;
308
309 dev->pm_domain = clknb->pm_domain;
310 if (clknb->con_ids[0]) {
311 for (con_id = clknb->con_ids; *con_id; con_id++)
312 pm_clk_add(dev, *con_id);
313 } else {
314 pm_clk_add(dev, NULL);
315 }
316
317 break;
318 case BUS_NOTIFY_DEL_DEVICE:
319 if (dev->pm_domain != clknb->pm_domain)
320 break;
321
322 dev->pm_domain = NULL;
323 pm_clk_destroy(dev);
324 break;
325 }
326
327 return 0;
328}
329
330#else
331
332#ifdef CONFIG_PM
333
334
335
336
337
338int pm_clk_suspend(struct device *dev)
339{
340 struct pm_subsys_data *psd = dev_to_psd(dev);
341 struct pm_clock_entry *ce;
342 unsigned long flags;
343
344 dev_dbg(dev, "%s()\n", __func__);
345
346
347 if (!psd || !dev->driver)
348 return 0;
349
350 spin_lock_irqsave(&psd->lock, flags);
351
352 list_for_each_entry_reverse(ce, &psd->clock_list, node)
353 clk_disable(ce->clk);
354
355 spin_unlock_irqrestore(&psd->lock, flags);
356
357 return 0;
358}
359
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363
364int pm_clk_resume(struct device *dev)
365{
366 struct pm_subsys_data *psd = dev_to_psd(dev);
367 struct pm_clock_entry *ce;
368 unsigned long flags;
369
370 dev_dbg(dev, "%s()\n", __func__);
371
372
373 if (!psd || !dev->driver)
374 return 0;
375
376 spin_lock_irqsave(&psd->lock, flags);
377
378 list_for_each_entry(ce, &psd->clock_list, node)
379 clk_enable(ce->clk);
380
381 spin_unlock_irqrestore(&psd->lock, flags);
382
383 return 0;
384}
385
386#endif
387
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392
393static void enable_clock(struct device *dev, const char *con_id)
394{
395 struct clk *clk;
396
397 clk = clk_get(dev, con_id);
398 if (!IS_ERR(clk)) {
399 clk_prepare_enable(clk);
400 clk_put(clk);
401 dev_info(dev, "Runtime PM disabled, clock forced on.\n");
402 }
403}
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410static void disable_clock(struct device *dev, const char *con_id)
411{
412 struct clk *clk;
413
414 clk = clk_get(dev, con_id);
415 if (!IS_ERR(clk)) {
416 clk_disable_unprepare(clk);
417 clk_put(clk);
418 dev_info(dev, "Runtime PM disabled, clock forced off.\n");
419 }
420}
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433static int pm_clk_notify(struct notifier_block *nb,
434 unsigned long action, void *data)
435{
436 struct pm_clk_notifier_block *clknb;
437 struct device *dev = data;
438 char **con_id;
439
440 dev_dbg(dev, "%s() %ld\n", __func__, action);
441
442 clknb = container_of(nb, struct pm_clk_notifier_block, nb);
443
444 switch (action) {
445 case BUS_NOTIFY_BIND_DRIVER:
446 if (clknb->con_ids[0]) {
447 for (con_id = clknb->con_ids; *con_id; con_id++)
448 enable_clock(dev, *con_id);
449 } else {
450 enable_clock(dev, NULL);
451 }
452 break;
453 case BUS_NOTIFY_UNBOUND_DRIVER:
454 if (clknb->con_ids[0]) {
455 for (con_id = clknb->con_ids; *con_id; con_id++)
456 disable_clock(dev, *con_id);
457 } else {
458 disable_clock(dev, NULL);
459 }
460 break;
461 }
462
463 return 0;
464}
465
466#endif
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477
478void pm_clk_add_notifier(struct bus_type *bus,
479 struct pm_clk_notifier_block *clknb)
480{
481 if (!bus || !clknb)
482 return;
483
484 clknb->nb.notifier_call = pm_clk_notify;
485 bus_register_notifier(bus, &clknb->nb);
486}
487