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/init.h>
10 #include <linux/kernel.h>
11 #include <linux/device.h>
14 #include <linux/pm_clock.h>
15 #include <linux/clk.h>
16 #include <linux/slab.h>
17 #include <linux/err.h>
28 struct pm_clock_entry
{
29 struct list_head node
;
32 enum pce_status status
;
36 * pm_clk_acquire - Acquire a device clock.
37 * @dev: Device whose clock is to be acquired.
38 * @ce: PM clock entry corresponding to the clock.
40 static void pm_clk_acquire(struct device
*dev
, struct pm_clock_entry
*ce
)
42 ce
->clk
= clk_get(dev
, ce
->con_id
);
43 if (IS_ERR(ce
->clk
)) {
44 ce
->status
= PCE_STATUS_ERROR
;
47 ce
->status
= PCE_STATUS_ACQUIRED
;
48 dev_dbg(dev
, "Clock %s managed by runtime PM.\n", ce
->con_id
);
53 * pm_clk_add - Start using a device clock for power management.
54 * @dev: Device whose clock is going to be used for power management.
55 * @con_id: Connection ID of the clock.
57 * Add the clock represented by @con_id to the list of clocks used for
58 * the power management of @dev.
60 int pm_clk_add(struct device
*dev
, const char *con_id
)
62 struct pm_subsys_data
*psd
= dev_to_psd(dev
);
63 struct pm_clock_entry
*ce
;
68 ce
= kzalloc(sizeof(*ce
), GFP_KERNEL
);
70 dev_err(dev
, "Not enough memory for clock entry.\n");
75 ce
->con_id
= kstrdup(con_id
, GFP_KERNEL
);
78 "Not enough memory for clock connection ID.\n");
84 pm_clk_acquire(dev
, ce
);
86 spin_lock_irq(&psd
->lock
);
87 list_add_tail(&ce
->node
, &psd
->clock_list
);
88 spin_unlock_irq(&psd
->lock
);
93 * __pm_clk_remove - Destroy PM clock entry.
94 * @ce: PM clock entry to destroy.
96 static void __pm_clk_remove(struct pm_clock_entry
*ce
)
101 if (ce
->status
< PCE_STATUS_ERROR
) {
102 if (ce
->status
== PCE_STATUS_ENABLED
)
103 clk_disable(ce
->clk
);
105 if (ce
->status
>= PCE_STATUS_ACQUIRED
) {
106 clk_unprepare(ce
->clk
);
116 * pm_clk_remove - Stop using a device clock for power management.
117 * @dev: Device whose clock should not be used for PM any more.
118 * @con_id: Connection ID of the clock.
120 * Remove the clock represented by @con_id from the list of clocks used for
121 * the power management of @dev.
123 void pm_clk_remove(struct device
*dev
, const char *con_id
)
125 struct pm_subsys_data
*psd
= dev_to_psd(dev
);
126 struct pm_clock_entry
*ce
;
131 spin_lock_irq(&psd
->lock
);
133 list_for_each_entry(ce
, &psd
->clock_list
, node
) {
134 if (!con_id
&& !ce
->con_id
)
136 else if (!con_id
|| !ce
->con_id
)
138 else if (!strcmp(con_id
, ce
->con_id
))
142 spin_unlock_irq(&psd
->lock
);
147 spin_unlock_irq(&psd
->lock
);
153 * pm_clk_init - Initialize a device's list of power management clocks.
154 * @dev: Device to initialize the list of PM clocks for.
156 * Initialize the lock and clock_list members of the device's pm_subsys_data
159 void pm_clk_init(struct device
*dev
)
161 struct pm_subsys_data
*psd
= dev_to_psd(dev
);
163 INIT_LIST_HEAD(&psd
->clock_list
);
167 * pm_clk_create - Create and initialize a device's list of PM clocks.
168 * @dev: Device to create and initialize the list of PM clocks for.
170 * Allocate a struct pm_subsys_data object, initialize its lock and clock_list
171 * members and make the @dev's power.subsys_data field point to it.
173 int pm_clk_create(struct device
*dev
)
175 return dev_pm_get_subsys_data(dev
);
179 * pm_clk_destroy - Destroy a device's list of power management clocks.
180 * @dev: Device to destroy the list of PM clocks for.
182 * Clear the @dev's power.subsys_data field, remove the list of clock entries
183 * from the struct pm_subsys_data object pointed to by it before and free
186 void pm_clk_destroy(struct device
*dev
)
188 struct pm_subsys_data
*psd
= dev_to_psd(dev
);
189 struct pm_clock_entry
*ce
, *c
;
190 struct list_head list
;
195 INIT_LIST_HEAD(&list
);
197 spin_lock_irq(&psd
->lock
);
199 list_for_each_entry_safe_reverse(ce
, c
, &psd
->clock_list
, node
)
200 list_move(&ce
->node
, &list
);
202 spin_unlock_irq(&psd
->lock
);
204 dev_pm_put_subsys_data(dev
);
206 list_for_each_entry_safe_reverse(ce
, c
, &list
, node
) {
212 #endif /* CONFIG_PM */
214 #ifdef CONFIG_PM_RUNTIME
217 * pm_clk_suspend - Disable clocks in a device's PM clock list.
218 * @dev: Device to disable the clocks for.
220 int pm_clk_suspend(struct device
*dev
)
222 struct pm_subsys_data
*psd
= dev_to_psd(dev
);
223 struct pm_clock_entry
*ce
;
226 dev_dbg(dev
, "%s()\n", __func__
);
231 spin_lock_irqsave(&psd
->lock
, flags
);
233 list_for_each_entry_reverse(ce
, &psd
->clock_list
, node
) {
234 if (ce
->status
< PCE_STATUS_ERROR
) {
235 if (ce
->status
== PCE_STATUS_ENABLED
)
236 clk_disable(ce
->clk
);
237 ce
->status
= PCE_STATUS_ACQUIRED
;
241 spin_unlock_irqrestore(&psd
->lock
, flags
);
247 * pm_clk_resume - Enable clocks in a device's PM clock list.
248 * @dev: Device to enable the clocks for.
250 int pm_clk_resume(struct device
*dev
)
252 struct pm_subsys_data
*psd
= dev_to_psd(dev
);
253 struct pm_clock_entry
*ce
;
257 dev_dbg(dev
, "%s()\n", __func__
);
262 spin_lock_irqsave(&psd
->lock
, flags
);
264 list_for_each_entry(ce
, &psd
->clock_list
, node
) {
265 if (ce
->status
< PCE_STATUS_ERROR
) {
266 ret
= clk_enable(ce
->clk
);
268 ce
->status
= PCE_STATUS_ENABLED
;
272 spin_unlock_irqrestore(&psd
->lock
, flags
);
278 * pm_clk_notify - Notify routine for device addition and removal.
279 * @nb: Notifier block object this function is a member of.
280 * @action: Operation being carried out by the caller.
281 * @data: Device the routine is being run for.
283 * For this function to work, @nb must be a member of an object of type
284 * struct pm_clk_notifier_block containing all of the requisite data.
285 * Specifically, the pm_domain member of that object is copied to the device's
286 * pm_domain field and its con_ids member is used to populate the device's list
287 * of PM clocks, depending on @action.
289 * If the device's pm_domain field is already populated with a value different
290 * from the one stored in the struct pm_clk_notifier_block object, the function
293 static int pm_clk_notify(struct notifier_block
*nb
,
294 unsigned long action
, void *data
)
296 struct pm_clk_notifier_block
*clknb
;
297 struct device
*dev
= data
;
301 dev_dbg(dev
, "%s() %ld\n", __func__
, action
);
303 clknb
= container_of(nb
, struct pm_clk_notifier_block
, nb
);
306 case BUS_NOTIFY_ADD_DEVICE
:
310 error
= pm_clk_create(dev
);
314 dev
->pm_domain
= clknb
->pm_domain
;
315 if (clknb
->con_ids
[0]) {
316 for (con_id
= clknb
->con_ids
; *con_id
; con_id
++)
317 pm_clk_add(dev
, *con_id
);
319 pm_clk_add(dev
, NULL
);
323 case BUS_NOTIFY_DEL_DEVICE
:
324 if (dev
->pm_domain
!= clknb
->pm_domain
)
327 dev
->pm_domain
= NULL
;
335 #else /* !CONFIG_PM_RUNTIME */
340 * pm_clk_suspend - Disable clocks in a device's PM clock list.
341 * @dev: Device to disable the clocks for.
343 int pm_clk_suspend(struct device
*dev
)
345 struct pm_subsys_data
*psd
= dev_to_psd(dev
);
346 struct pm_clock_entry
*ce
;
349 dev_dbg(dev
, "%s()\n", __func__
);
351 /* If there is no driver, the clocks are already disabled. */
352 if (!psd
|| !dev
->driver
)
355 spin_lock_irqsave(&psd
->lock
, flags
);
357 list_for_each_entry_reverse(ce
, &psd
->clock_list
, node
)
358 clk_disable(ce
->clk
);
360 spin_unlock_irqrestore(&psd
->lock
, flags
);
366 * pm_clk_resume - Enable clocks in a device's PM clock list.
367 * @dev: Device to enable the clocks for.
369 int pm_clk_resume(struct device
*dev
)
371 struct pm_subsys_data
*psd
= dev_to_psd(dev
);
372 struct pm_clock_entry
*ce
;
375 dev_dbg(dev
, "%s()\n", __func__
);
377 /* If there is no driver, the clocks should remain disabled. */
378 if (!psd
|| !dev
->driver
)
381 spin_lock_irqsave(&psd
->lock
, flags
);
383 list_for_each_entry(ce
, &psd
->clock_list
, node
)
386 spin_unlock_irqrestore(&psd
->lock
, flags
);
391 #endif /* CONFIG_PM */
394 * enable_clock - Enable a device clock.
395 * @dev: Device whose clock is to be enabled.
396 * @con_id: Connection ID of the clock.
398 static void enable_clock(struct device
*dev
, const char *con_id
)
402 clk
= clk_get(dev
, con_id
);
404 clk_prepare_enable(clk
);
406 dev_info(dev
, "Runtime PM disabled, clock forced on.\n");
411 * disable_clock - Disable a device clock.
412 * @dev: Device whose clock is to be disabled.
413 * @con_id: Connection ID of the clock.
415 static void disable_clock(struct device
*dev
, const char *con_id
)
419 clk
= clk_get(dev
, con_id
);
421 clk_disable_unprepare(clk
);
423 dev_info(dev
, "Runtime PM disabled, clock forced off.\n");
428 * pm_clk_notify - Notify routine for device addition and removal.
429 * @nb: Notifier block object this function is a member of.
430 * @action: Operation being carried out by the caller.
431 * @data: Device the routine is being run for.
433 * For this function to work, @nb must be a member of an object of type
434 * struct pm_clk_notifier_block containing all of the requisite data.
435 * Specifically, the con_ids member of that object is used to enable or disable
436 * the device's clocks, depending on @action.
438 static int pm_clk_notify(struct notifier_block
*nb
,
439 unsigned long action
, void *data
)
441 struct pm_clk_notifier_block
*clknb
;
442 struct device
*dev
= data
;
445 dev_dbg(dev
, "%s() %ld\n", __func__
, action
);
447 clknb
= container_of(nb
, struct pm_clk_notifier_block
, nb
);
450 case BUS_NOTIFY_BIND_DRIVER
:
451 if (clknb
->con_ids
[0]) {
452 for (con_id
= clknb
->con_ids
; *con_id
; con_id
++)
453 enable_clock(dev
, *con_id
);
455 enable_clock(dev
, NULL
);
458 case BUS_NOTIFY_UNBOUND_DRIVER
:
459 if (clknb
->con_ids
[0]) {
460 for (con_id
= clknb
->con_ids
; *con_id
; con_id
++)
461 disable_clock(dev
, *con_id
);
463 disable_clock(dev
, NULL
);
471 #endif /* !CONFIG_PM_RUNTIME */
474 * pm_clk_add_notifier - Add bus type notifier for power management clocks.
475 * @bus: Bus type to add the notifier to.
476 * @clknb: Notifier to be added to the given bus type.
478 * The nb member of @clknb is not expected to be initialized and its
479 * notifier_call member will be replaced with pm_clk_notify(). However,
480 * the remaining members of @clknb should be populated prior to calling this
483 void pm_clk_add_notifier(struct bus_type
*bus
,
484 struct pm_clk_notifier_block
*clknb
)
489 clknb
->nb
.notifier_call
= pm_clk_notify
;
490 bus_register_notifier(bus
, &clknb
->nb
);