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