2 * drivers/base/power/clock_ops.c - Generic clock manipulation PM callbacks
4 * Copyright (c) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
6 * This file is released under the GPLv2.
9 #include <linux/kernel.h>
10 #include <linux/device.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>
30 struct pm_clock_entry {
31 struct list_head node;
34 enum pce_status status;
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.
42 static inline void __pm_clk_enable(struct device *dev, struct pm_clock_entry *ce)
46 if (ce->status < PCE_STATUS_ERROR) {
47 ret = clk_enable(ce->clk);
49 ce->status = PCE_STATUS_ENABLED;
51 dev_err(dev, "%s: failed to enable clk %p, error %d\n",
52 __func__, ce->clk, ret);
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.
61 static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
64 ce->clk = clk_get(dev, ce->con_id);
65 if (IS_ERR(ce->clk)) {
66 ce->status = PCE_STATUS_ERROR;
69 ce->status = PCE_STATUS_ACQUIRED;
70 dev_dbg(dev, "Clock %pC con_id %s managed by runtime PM.\n",
75 static int __pm_clk_add(struct device *dev, const char *con_id,
78 struct pm_subsys_data *psd = dev_to_psd(dev);
79 struct pm_clock_entry *ce;
84 ce = kzalloc(sizeof(*ce), GFP_KERNEL);
89 ce->con_id = kstrdup(con_id, GFP_KERNEL);
92 "Not enough memory for clock connection ID.\n");
104 pm_clk_acquire(dev, ce);
106 spin_lock_irq(&psd->lock);
107 list_add_tail(&ce->node, &psd->clock_list);
108 spin_unlock_irq(&psd->lock);
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.
117 * Add the clock represented by @con_id to the list of clocks used for
118 * the power management of @dev.
120 int pm_clk_add(struct device *dev, const char *con_id)
122 return __pm_clk_add(dev, con_id, NULL);
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
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
135 int pm_clk_add_clk(struct device *dev, struct clk *clk)
137 return __pm_clk_add(dev, NULL, clk);
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.
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.
151 int of_pm_clk_add_clks(struct device *dev)
154 unsigned int i, count;
157 if (!dev || !dev->of_node)
160 count = of_count_phandle_with_args(dev->of_node, "clocks",
165 clks = kcalloc(count, sizeof(*clks), GFP_KERNEL);
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]);
176 ret = pm_clk_add_clk(dev, clks[i]);
189 pm_clk_remove_clk(dev, clks[i]);
197 * __pm_clk_remove - Destroy PM clock entry.
198 * @ce: PM clock entry to destroy.
200 static void __pm_clk_remove(struct pm_clock_entry *ce)
205 if (ce->status < PCE_STATUS_ERROR) {
206 if (ce->status == PCE_STATUS_ENABLED)
207 clk_disable(ce->clk);
209 if (ce->status >= PCE_STATUS_ACQUIRED) {
210 clk_unprepare(ce->clk);
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.
224 * Remove the clock represented by @con_id from the list of clocks used for
225 * the power management of @dev.
227 void pm_clk_remove(struct device *dev, const char *con_id)
229 struct pm_subsys_data *psd = dev_to_psd(dev);
230 struct pm_clock_entry *ce;
235 spin_lock_irq(&psd->lock);
237 list_for_each_entry(ce, &psd->clock_list, node) {
238 if (!con_id && !ce->con_id)
240 else if (!con_id || !ce->con_id)
242 else if (!strcmp(con_id, ce->con_id))
246 spin_unlock_irq(&psd->lock);
251 spin_unlock_irq(&psd->lock);
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
261 * Remove the clock pointed to by @clk from the list of clocks used for
262 * the power management of @dev.
264 void pm_clk_remove_clk(struct device *dev, struct clk *clk)
266 struct pm_subsys_data *psd = dev_to_psd(dev);
267 struct pm_clock_entry *ce;
272 spin_lock_irq(&psd->lock);
274 list_for_each_entry(ce, &psd->clock_list, node) {
279 spin_unlock_irq(&psd->lock);
284 spin_unlock_irq(&psd->lock);
290 * pm_clk_init - Initialize a device's list of power management clocks.
291 * @dev: Device to initialize the list of PM clocks for.
293 * Initialize the lock and clock_list members of the device's pm_subsys_data
296 void pm_clk_init(struct device *dev)
298 struct pm_subsys_data *psd = dev_to_psd(dev);
300 INIT_LIST_HEAD(&psd->clock_list);
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.
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.
310 int pm_clk_create(struct device *dev)
312 return dev_pm_get_subsys_data(dev);
316 * pm_clk_destroy - Destroy a device's list of power management clocks.
317 * @dev: Device to destroy the list of PM clocks for.
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
323 void pm_clk_destroy(struct device *dev)
325 struct pm_subsys_data *psd = dev_to_psd(dev);
326 struct pm_clock_entry *ce, *c;
327 struct list_head list;
332 INIT_LIST_HEAD(&list);
334 spin_lock_irq(&psd->lock);
336 list_for_each_entry_safe_reverse(ce, c, &psd->clock_list, node)
337 list_move(&ce->node, &list);
339 spin_unlock_irq(&psd->lock);
341 dev_pm_put_subsys_data(dev);
343 list_for_each_entry_safe_reverse(ce, c, &list, node) {
350 * pm_clk_suspend - Disable clocks in a device's PM clock list.
351 * @dev: Device to disable the clocks for.
353 int pm_clk_suspend(struct device *dev)
355 struct pm_subsys_data *psd = dev_to_psd(dev);
356 struct pm_clock_entry *ce;
359 dev_dbg(dev, "%s()\n", __func__);
364 spin_lock_irqsave(&psd->lock, flags);
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;
374 spin_unlock_irqrestore(&psd->lock, flags);
380 * pm_clk_resume - Enable clocks in a device's PM clock list.
381 * @dev: Device to enable the clocks for.
383 int pm_clk_resume(struct device *dev)
385 struct pm_subsys_data *psd = dev_to_psd(dev);
386 struct pm_clock_entry *ce;
389 dev_dbg(dev, "%s()\n", __func__);
394 spin_lock_irqsave(&psd->lock, flags);
396 list_for_each_entry(ce, &psd->clock_list, node)
397 __pm_clk_enable(dev, ce);
399 spin_unlock_irqrestore(&psd->lock, flags);
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.
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.
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
420 static int pm_clk_notify(struct notifier_block *nb,
421 unsigned long action, void *data)
423 struct pm_clk_notifier_block *clknb;
424 struct device *dev = data;
428 dev_dbg(dev, "%s() %ld\n", __func__, action);
430 clknb = container_of(nb, struct pm_clk_notifier_block, nb);
433 case BUS_NOTIFY_ADD_DEVICE:
437 error = pm_clk_create(dev);
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);
446 pm_clk_add(dev, NULL);
450 case BUS_NOTIFY_DEL_DEVICE:
451 if (dev->pm_domain != clknb->pm_domain)
454 dev_pm_domain_set(dev, NULL);
462 int pm_clk_runtime_suspend(struct device *dev)
466 dev_dbg(dev, "%s\n", __func__);
468 ret = pm_generic_runtime_suspend(dev);
470 dev_err(dev, "failed to suspend device\n");
474 ret = pm_clk_suspend(dev);
476 dev_err(dev, "failed to suspend clock\n");
477 pm_generic_runtime_resume(dev);
484 int pm_clk_runtime_resume(struct device *dev)
488 dev_dbg(dev, "%s\n", __func__);
490 ret = pm_clk_resume(dev);
492 dev_err(dev, "failed to resume clock\n");
496 return pm_generic_runtime_resume(dev);
499 #else /* !CONFIG_PM_CLK */
502 * enable_clock - Enable a device clock.
503 * @dev: Device whose clock is to be enabled.
504 * @con_id: Connection ID of the clock.
506 static void enable_clock(struct device *dev, const char *con_id)
510 clk = clk_get(dev, con_id);
512 clk_prepare_enable(clk);
514 dev_info(dev, "Runtime PM disabled, clock forced on.\n");
519 * disable_clock - Disable a device clock.
520 * @dev: Device whose clock is to be disabled.
521 * @con_id: Connection ID of the clock.
523 static void disable_clock(struct device *dev, const char *con_id)
527 clk = clk_get(dev, con_id);
529 clk_disable_unprepare(clk);
531 dev_info(dev, "Runtime PM disabled, clock forced off.\n");
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.
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.
546 static int pm_clk_notify(struct notifier_block *nb,
547 unsigned long action, void *data)
549 struct pm_clk_notifier_block *clknb;
550 struct device *dev = data;
553 dev_dbg(dev, "%s() %ld\n", __func__, action);
555 clknb = container_of(nb, struct pm_clk_notifier_block, nb);
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);
563 enable_clock(dev, NULL);
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);
572 disable_clock(dev, NULL);
580 #endif /* !CONFIG_PM_CLK */
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.
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
592 void pm_clk_add_notifier(struct bus_type *bus,
593 struct pm_clk_notifier_block *clknb)
598 clknb->nb.notifier_call = pm_clk_notify;
599 bus_register_notifier(bus, &clknb->nb);