2 * Generic OPP Interface
4 * Copyright (C) 2009-2010 Texas Instruments Incorporated.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16 #include <linux/clk.h>
17 #include <linux/errno.h>
18 #include <linux/err.h>
19 #include <linux/slab.h>
20 #include <linux/device.h>
21 #include <linux/export.h>
22 #include <linux/regulator/consumer.h>
27 * The root of the list of all opp-tables. All opp_table structures branch off
28 * from here, with each opp_table containing the list of opps it supports in
29 * various states of availability.
31 LIST_HEAD(opp_tables
);
32 /* Lock to allow exclusive modification to the device and opp lists */
33 DEFINE_MUTEX(opp_table_lock
);
35 #define opp_rcu_lockdep_assert() \
37 RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \
38 !lockdep_is_held(&opp_table_lock), \
39 "Missing rcu_read_lock() or " \
40 "opp_table_lock protection"); \
43 static struct opp_device
*_find_opp_dev(const struct device
*dev
,
44 struct opp_table
*opp_table
)
46 struct opp_device
*opp_dev
;
48 list_for_each_entry(opp_dev
, &opp_table
->dev_list
, node
)
49 if (opp_dev
->dev
== dev
)
56 * _find_opp_table() - find opp_table struct using device pointer
57 * @dev: device pointer used to lookup OPP table
59 * Search OPP table for one containing matching device. Does a RCU reader
60 * operation to grab the pointer needed.
62 * Return: pointer to 'struct opp_table' if found, otherwise -ENODEV or
63 * -EINVAL based on type of error.
65 * Locking: For readers, this function must be called under rcu_read_lock().
66 * opp_table is a RCU protected pointer, which means that opp_table is valid
67 * as long as we are under RCU lock.
69 * For Writers, this function must be called with opp_table_lock held.
71 struct opp_table
*_find_opp_table(struct device
*dev
)
73 struct opp_table
*opp_table
;
75 opp_rcu_lockdep_assert();
77 if (IS_ERR_OR_NULL(dev
)) {
78 pr_err("%s: Invalid parameters\n", __func__
);
79 return ERR_PTR(-EINVAL
);
82 list_for_each_entry_rcu(opp_table
, &opp_tables
, node
)
83 if (_find_opp_dev(dev
, opp_table
))
86 return ERR_PTR(-ENODEV
);
90 * dev_pm_opp_get_voltage() - Gets the voltage corresponding to an opp
91 * @opp: opp for which voltage has to be returned for
93 * Return: voltage in micro volt corresponding to the opp, else
96 * This is useful only for devices with single power supply.
98 * Locking: This function must be called under rcu_read_lock(). opp is a rcu
99 * protected pointer. This means that opp which could have been fetched by
100 * opp_find_freq_{exact,ceil,floor} functions is valid as long as we are
101 * under RCU lock. The pointer returned by the opp_find_freq family must be
102 * used in the same section as the usage of this function with the pointer
103 * prior to unlocking with rcu_read_unlock() to maintain the integrity of the
106 unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp
*opp
)
108 struct dev_pm_opp
*tmp_opp
;
111 opp_rcu_lockdep_assert();
113 tmp_opp
= rcu_dereference(opp
);
114 if (IS_ERR_OR_NULL(tmp_opp
))
115 pr_err("%s: Invalid parameters\n", __func__
);
117 v
= tmp_opp
->supplies
[0].u_volt
;
121 EXPORT_SYMBOL_GPL(dev_pm_opp_get_voltage
);
124 * dev_pm_opp_get_freq() - Gets the frequency corresponding to an available opp
125 * @opp: opp for which frequency has to be returned for
127 * Return: frequency in hertz corresponding to the opp, else
130 * Locking: This function must be called under rcu_read_lock(). opp is a rcu
131 * protected pointer. This means that opp which could have been fetched by
132 * opp_find_freq_{exact,ceil,floor} functions is valid as long as we are
133 * under RCU lock. The pointer returned by the opp_find_freq family must be
134 * used in the same section as the usage of this function with the pointer
135 * prior to unlocking with rcu_read_unlock() to maintain the integrity of the
138 unsigned long dev_pm_opp_get_freq(struct dev_pm_opp
*opp
)
140 struct dev_pm_opp
*tmp_opp
;
143 opp_rcu_lockdep_assert();
145 tmp_opp
= rcu_dereference(opp
);
146 if (IS_ERR_OR_NULL(tmp_opp
) || !tmp_opp
->available
)
147 pr_err("%s: Invalid parameters\n", __func__
);
153 EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq
);
156 * dev_pm_opp_is_turbo() - Returns if opp is turbo OPP or not
157 * @opp: opp for which turbo mode is being verified
159 * Turbo OPPs are not for normal use, and can be enabled (under certain
160 * conditions) for short duration of times to finish high throughput work
161 * quickly. Running on them for longer times may overheat the chip.
163 * Return: true if opp is turbo opp, else false.
165 * Locking: This function must be called under rcu_read_lock(). opp is a rcu
166 * protected pointer. This means that opp which could have been fetched by
167 * opp_find_freq_{exact,ceil,floor} functions is valid as long as we are
168 * under RCU lock. The pointer returned by the opp_find_freq family must be
169 * used in the same section as the usage of this function with the pointer
170 * prior to unlocking with rcu_read_unlock() to maintain the integrity of the
173 bool dev_pm_opp_is_turbo(struct dev_pm_opp
*opp
)
175 struct dev_pm_opp
*tmp_opp
;
177 opp_rcu_lockdep_assert();
179 tmp_opp
= rcu_dereference(opp
);
180 if (IS_ERR_OR_NULL(tmp_opp
) || !tmp_opp
->available
) {
181 pr_err("%s: Invalid parameters\n", __func__
);
185 return tmp_opp
->turbo
;
187 EXPORT_SYMBOL_GPL(dev_pm_opp_is_turbo
);
190 * dev_pm_opp_get_max_clock_latency() - Get max clock latency in nanoseconds
191 * @dev: device for which we do this operation
193 * Return: This function returns the max clock latency in nanoseconds.
195 * Locking: This function takes rcu_read_lock().
197 unsigned long dev_pm_opp_get_max_clock_latency(struct device
*dev
)
199 struct opp_table
*opp_table
;
200 unsigned long clock_latency_ns
;
204 opp_table
= _find_opp_table(dev
);
205 if (IS_ERR(opp_table
))
206 clock_latency_ns
= 0;
208 clock_latency_ns
= opp_table
->clock_latency_ns_max
;
211 return clock_latency_ns
;
213 EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency
);
215 static int _get_regulator_count(struct device
*dev
)
217 struct opp_table
*opp_table
;
222 opp_table
= _find_opp_table(dev
);
223 if (!IS_ERR(opp_table
))
224 count
= opp_table
->regulator_count
;
234 * dev_pm_opp_get_max_volt_latency() - Get max voltage latency in nanoseconds
235 * @dev: device for which we do this operation
237 * Return: This function returns the max voltage latency in nanoseconds.
239 * Locking: This function takes rcu_read_lock().
241 unsigned long dev_pm_opp_get_max_volt_latency(struct device
*dev
)
243 struct opp_table
*opp_table
;
244 struct dev_pm_opp
*opp
;
245 struct regulator
*reg
, **regulators
;
246 unsigned long latency_ns
= 0;
253 count
= _get_regulator_count(dev
);
255 /* Regulator may not be required for the device */
259 regulators
= kmalloc_array(count
, sizeof(*regulators
), GFP_KERNEL
);
263 uV
= kmalloc_array(count
, sizeof(*uV
), GFP_KERNEL
);
265 goto free_regulators
;
269 opp_table
= _find_opp_table(dev
);
270 if (IS_ERR(opp_table
)) {
275 memcpy(regulators
, opp_table
->regulators
, count
* sizeof(*regulators
));
277 for (i
= 0; i
< count
; i
++) {
281 list_for_each_entry_rcu(opp
, &opp_table
->opp_list
, node
) {
285 if (opp
->supplies
[i
].u_volt_min
< uV
[i
].min
)
286 uV
[i
].min
= opp
->supplies
[i
].u_volt_min
;
287 if (opp
->supplies
[i
].u_volt_max
> uV
[i
].max
)
288 uV
[i
].max
= opp
->supplies
[i
].u_volt_max
;
295 * The caller needs to ensure that opp_table (and hence the regulator)
296 * isn't freed, while we are executing this routine.
298 for (i
= 0; reg
= regulators
[i
], i
< count
; i
++) {
299 ret
= regulator_set_voltage_time(reg
, uV
[i
].min
, uV
[i
].max
);
301 latency_ns
+= ret
* 1000;
311 EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_volt_latency
);
314 * dev_pm_opp_get_max_transition_latency() - Get max transition latency in
316 * @dev: device for which we do this operation
318 * Return: This function returns the max transition latency, in nanoseconds, to
319 * switch from one OPP to other.
321 * Locking: This function takes rcu_read_lock().
323 unsigned long dev_pm_opp_get_max_transition_latency(struct device
*dev
)
325 return dev_pm_opp_get_max_volt_latency(dev
) +
326 dev_pm_opp_get_max_clock_latency(dev
);
328 EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_transition_latency
);
331 * dev_pm_opp_get_suspend_opp() - Get suspend opp
332 * @dev: device for which we do this operation
334 * Return: This function returns pointer to the suspend opp if it is
335 * defined and available, otherwise it returns NULL.
337 * Locking: This function must be called under rcu_read_lock(). opp is a rcu
338 * protected pointer. The reason for the same is that the opp pointer which is
339 * returned will remain valid for use with opp_get_{voltage, freq} only while
340 * under the locked area. The pointer returned must be used prior to unlocking
341 * with rcu_read_unlock() to maintain the integrity of the pointer.
343 struct dev_pm_opp
*dev_pm_opp_get_suspend_opp(struct device
*dev
)
345 struct opp_table
*opp_table
;
347 opp_rcu_lockdep_assert();
349 opp_table
= _find_opp_table(dev
);
350 if (IS_ERR(opp_table
) || !opp_table
->suspend_opp
||
351 !opp_table
->suspend_opp
->available
)
354 return opp_table
->suspend_opp
;
356 EXPORT_SYMBOL_GPL(dev_pm_opp_get_suspend_opp
);
359 * dev_pm_opp_get_opp_count() - Get number of opps available in the opp table
360 * @dev: device for which we do this operation
362 * Return: This function returns the number of available opps if there are any,
363 * else returns 0 if none or the corresponding error value.
365 * Locking: This function takes rcu_read_lock().
367 int dev_pm_opp_get_opp_count(struct device
*dev
)
369 struct opp_table
*opp_table
;
370 struct dev_pm_opp
*temp_opp
;
375 opp_table
= _find_opp_table(dev
);
376 if (IS_ERR(opp_table
)) {
377 count
= PTR_ERR(opp_table
);
378 dev_err(dev
, "%s: OPP table not found (%d)\n",
383 list_for_each_entry_rcu(temp_opp
, &opp_table
->opp_list
, node
) {
384 if (temp_opp
->available
)
392 EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_count
);
395 * dev_pm_opp_find_freq_exact() - search for an exact frequency
396 * @dev: device for which we do this operation
397 * @freq: frequency to search for
398 * @available: true/false - match for available opp
400 * Return: Searches for exact match in the opp table and returns pointer to the
401 * matching opp if found, else returns ERR_PTR in case of error and should
402 * be handled using IS_ERR. Error return values can be:
403 * EINVAL: for bad pointer
404 * ERANGE: no match found for search
405 * ENODEV: if device not found in list of registered devices
407 * Note: available is a modifier for the search. if available=true, then the
408 * match is for exact matching frequency and is available in the stored OPP
409 * table. if false, the match is for exact frequency which is not available.
411 * This provides a mechanism to enable an opp which is not available currently
412 * or the opposite as well.
414 * Locking: This function must be called under rcu_read_lock(). opp is a rcu
415 * protected pointer. The reason for the same is that the opp pointer which is
416 * returned will remain valid for use with opp_get_{voltage, freq} only while
417 * under the locked area. The pointer returned must be used prior to unlocking
418 * with rcu_read_unlock() to maintain the integrity of the pointer.
420 struct dev_pm_opp
*dev_pm_opp_find_freq_exact(struct device
*dev
,
424 struct opp_table
*opp_table
;
425 struct dev_pm_opp
*temp_opp
, *opp
= ERR_PTR(-ERANGE
);
427 opp_rcu_lockdep_assert();
429 opp_table
= _find_opp_table(dev
);
430 if (IS_ERR(opp_table
)) {
431 int r
= PTR_ERR(opp_table
);
433 dev_err(dev
, "%s: OPP table not found (%d)\n", __func__
, r
);
437 list_for_each_entry_rcu(temp_opp
, &opp_table
->opp_list
, node
) {
438 if (temp_opp
->available
== available
&&
439 temp_opp
->rate
== freq
) {
447 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact
);
449 static noinline
struct dev_pm_opp
*_find_freq_ceil(struct opp_table
*opp_table
,
452 struct dev_pm_opp
*temp_opp
, *opp
= ERR_PTR(-ERANGE
);
454 list_for_each_entry_rcu(temp_opp
, &opp_table
->opp_list
, node
) {
455 if (temp_opp
->available
&& temp_opp
->rate
>= *freq
) {
466 * dev_pm_opp_find_freq_ceil() - Search for an rounded ceil freq
467 * @dev: device for which we do this operation
468 * @freq: Start frequency
470 * Search for the matching ceil *available* OPP from a starting freq
473 * Return: matching *opp and refreshes *freq accordingly, else returns
474 * ERR_PTR in case of error and should be handled using IS_ERR. Error return
476 * EINVAL: for bad pointer
477 * ERANGE: no match found for search
478 * ENODEV: if device not found in list of registered devices
480 * Locking: This function must be called under rcu_read_lock(). opp is a rcu
481 * protected pointer. The reason for the same is that the opp pointer which is
482 * returned will remain valid for use with opp_get_{voltage, freq} only while
483 * under the locked area. The pointer returned must be used prior to unlocking
484 * with rcu_read_unlock() to maintain the integrity of the pointer.
486 struct dev_pm_opp
*dev_pm_opp_find_freq_ceil(struct device
*dev
,
489 struct opp_table
*opp_table
;
491 opp_rcu_lockdep_assert();
494 dev_err(dev
, "%s: Invalid argument freq=%p\n", __func__
, freq
);
495 return ERR_PTR(-EINVAL
);
498 opp_table
= _find_opp_table(dev
);
499 if (IS_ERR(opp_table
))
500 return ERR_CAST(opp_table
);
502 return _find_freq_ceil(opp_table
, freq
);
504 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil
);
507 * dev_pm_opp_find_freq_floor() - Search for a rounded floor freq
508 * @dev: device for which we do this operation
509 * @freq: Start frequency
511 * Search for the matching floor *available* OPP from a starting freq
514 * Return: matching *opp and refreshes *freq accordingly, else returns
515 * ERR_PTR in case of error and should be handled using IS_ERR. Error return
517 * EINVAL: for bad pointer
518 * ERANGE: no match found for search
519 * ENODEV: if device not found in list of registered devices
521 * Locking: This function must be called under rcu_read_lock(). opp is a rcu
522 * protected pointer. The reason for the same is that the opp pointer which is
523 * returned will remain valid for use with opp_get_{voltage, freq} only while
524 * under the locked area. The pointer returned must be used prior to unlocking
525 * with rcu_read_unlock() to maintain the integrity of the pointer.
527 struct dev_pm_opp
*dev_pm_opp_find_freq_floor(struct device
*dev
,
530 struct opp_table
*opp_table
;
531 struct dev_pm_opp
*temp_opp
, *opp
= ERR_PTR(-ERANGE
);
533 opp_rcu_lockdep_assert();
536 dev_err(dev
, "%s: Invalid argument freq=%p\n", __func__
, freq
);
537 return ERR_PTR(-EINVAL
);
540 opp_table
= _find_opp_table(dev
);
541 if (IS_ERR(opp_table
))
542 return ERR_CAST(opp_table
);
544 list_for_each_entry_rcu(temp_opp
, &opp_table
->opp_list
, node
) {
545 if (temp_opp
->available
) {
546 /* go to the next node, before choosing prev */
547 if (temp_opp
->rate
> *freq
)
558 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor
);
561 * The caller needs to ensure that opp_table (and hence the clk) isn't freed,
562 * while clk returned here is used.
564 static struct clk
*_get_opp_clk(struct device
*dev
)
566 struct opp_table
*opp_table
;
571 opp_table
= _find_opp_table(dev
);
572 if (IS_ERR(opp_table
)) {
573 dev_err(dev
, "%s: device opp doesn't exist\n", __func__
);
574 clk
= ERR_CAST(opp_table
);
578 clk
= opp_table
->clk
;
580 dev_err(dev
, "%s: No clock available for the device\n",
588 static int _set_opp_voltage(struct device
*dev
, struct regulator
*reg
,
589 struct dev_pm_opp_supply
*supply
)
593 /* Regulator not available for device */
595 dev_dbg(dev
, "%s: regulator not available: %ld\n", __func__
,
600 dev_dbg(dev
, "%s: voltages (mV): %lu %lu %lu\n", __func__
,
601 supply
->u_volt_min
, supply
->u_volt
, supply
->u_volt_max
);
603 ret
= regulator_set_voltage_triplet(reg
, supply
->u_volt_min
,
604 supply
->u_volt
, supply
->u_volt_max
);
606 dev_err(dev
, "%s: failed to set voltage (%lu %lu %lu mV): %d\n",
607 __func__
, supply
->u_volt_min
, supply
->u_volt
,
608 supply
->u_volt_max
, ret
);
614 * dev_pm_opp_set_rate() - Configure new OPP based on frequency
615 * @dev: device for which we do this operation
616 * @target_freq: frequency to achieve
618 * This configures the power-supplies and clock source to the levels specified
619 * by the OPP corresponding to the target_freq.
621 * Locking: This function takes rcu_read_lock().
623 int dev_pm_opp_set_rate(struct device
*dev
, unsigned long target_freq
)
625 struct opp_table
*opp_table
;
626 struct dev_pm_opp
*old_opp
, *opp
;
627 struct regulator
*reg
= ERR_PTR(-ENXIO
);
629 unsigned long freq
, old_freq
;
630 struct dev_pm_opp_supply old_supply
, new_supply
;
633 if (unlikely(!target_freq
)) {
634 dev_err(dev
, "%s: Invalid target frequency %lu\n", __func__
,
639 clk
= _get_opp_clk(dev
);
643 freq
= clk_round_rate(clk
, target_freq
);
647 old_freq
= clk_get_rate(clk
);
649 /* Return early if nothing to do */
650 if (old_freq
== freq
) {
651 dev_dbg(dev
, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n",
658 opp_table
= _find_opp_table(dev
);
659 if (IS_ERR(opp_table
)) {
660 dev_err(dev
, "%s: device opp doesn't exist\n", __func__
);
662 return PTR_ERR(opp_table
);
665 old_opp
= _find_freq_ceil(opp_table
, &old_freq
);
666 if (IS_ERR(old_opp
)) {
667 dev_err(dev
, "%s: failed to find current OPP for freq %lu (%ld)\n",
668 __func__
, old_freq
, PTR_ERR(old_opp
));
671 opp
= _find_freq_ceil(opp_table
, &freq
);
674 dev_err(dev
, "%s: failed to find OPP for freq %lu (%d)\n",
675 __func__
, freq
, ret
);
680 if (opp_table
->regulators
) {
681 /* This function only supports single regulator per device */
682 if (WARN_ON(opp_table
->regulator_count
> 1)) {
683 dev_err(dev
, "multiple regulators not supported\n");
688 reg
= opp_table
->regulators
[0];
692 old_supply
.u_volt
= 0;
694 memcpy(&old_supply
, old_opp
->supplies
, sizeof(old_supply
));
696 memcpy(&new_supply
, opp
->supplies
, sizeof(new_supply
));
700 /* Scaling up? Scale voltage before frequency */
701 if (freq
> old_freq
) {
702 ret
= _set_opp_voltage(dev
, reg
, &new_supply
);
704 goto restore_voltage
;
707 /* Change frequency */
709 dev_dbg(dev
, "%s: switching OPP: %lu Hz --> %lu Hz\n",
710 __func__
, old_freq
, freq
);
712 ret
= clk_set_rate(clk
, freq
);
714 dev_err(dev
, "%s: failed to set clock rate: %d\n", __func__
,
716 goto restore_voltage
;
719 /* Scaling down? Scale voltage after frequency */
720 if (freq
< old_freq
) {
721 ret
= _set_opp_voltage(dev
, reg
, &new_supply
);
729 if (clk_set_rate(clk
, old_freq
))
730 dev_err(dev
, "%s: failed to restore old-freq (%lu Hz)\n",
733 /* This shouldn't harm even if the voltages weren't updated earlier */
734 if (old_supply
.u_volt
)
735 _set_opp_voltage(dev
, reg
, &old_supply
);
739 EXPORT_SYMBOL_GPL(dev_pm_opp_set_rate
);
741 /* OPP-dev Helpers */
742 static void _kfree_opp_dev_rcu(struct rcu_head
*head
)
744 struct opp_device
*opp_dev
;
746 opp_dev
= container_of(head
, struct opp_device
, rcu_head
);
747 kfree_rcu(opp_dev
, rcu_head
);
750 static void _remove_opp_dev(struct opp_device
*opp_dev
,
751 struct opp_table
*opp_table
)
753 opp_debug_unregister(opp_dev
, opp_table
);
754 list_del(&opp_dev
->node
);
755 call_srcu(&opp_table
->srcu_head
.srcu
, &opp_dev
->rcu_head
,
759 struct opp_device
*_add_opp_dev(const struct device
*dev
,
760 struct opp_table
*opp_table
)
762 struct opp_device
*opp_dev
;
765 opp_dev
= kzalloc(sizeof(*opp_dev
), GFP_KERNEL
);
769 /* Initialize opp-dev */
771 list_add_rcu(&opp_dev
->node
, &opp_table
->dev_list
);
773 /* Create debugfs entries for the opp_table */
774 ret
= opp_debug_register(opp_dev
, opp_table
);
776 dev_err(dev
, "%s: Failed to register opp debugfs (%d)\n",
783 * _add_opp_table() - Find OPP table or allocate a new one
784 * @dev: device for which we do this operation
786 * It tries to find an existing table first, if it couldn't find one, it
787 * allocates a new OPP table and returns that.
789 * Return: valid opp_table pointer if success, else NULL.
791 static struct opp_table
*_add_opp_table(struct device
*dev
)
793 struct opp_table
*opp_table
;
794 struct opp_device
*opp_dev
;
797 /* Check for existing table for 'dev' first */
798 opp_table
= _find_opp_table(dev
);
799 if (!IS_ERR(opp_table
))
803 * Allocate a new OPP table. In the infrequent case where a new
804 * device is needed to be added, we pay this penalty.
806 opp_table
= kzalloc(sizeof(*opp_table
), GFP_KERNEL
);
810 INIT_LIST_HEAD(&opp_table
->dev_list
);
812 opp_dev
= _add_opp_dev(dev
, opp_table
);
818 _of_init_opp_table(opp_table
, dev
);
820 /* Find clk for the device */
821 opp_table
->clk
= clk_get(dev
, NULL
);
822 if (IS_ERR(opp_table
->clk
)) {
823 ret
= PTR_ERR(opp_table
->clk
);
824 if (ret
!= -EPROBE_DEFER
)
825 dev_dbg(dev
, "%s: Couldn't find clock: %d\n", __func__
,
829 srcu_init_notifier_head(&opp_table
->srcu_head
);
830 INIT_LIST_HEAD(&opp_table
->opp_list
);
832 /* Secure the device table modification */
833 list_add_rcu(&opp_table
->node
, &opp_tables
);
838 * _kfree_device_rcu() - Free opp_table RCU handler
841 static void _kfree_device_rcu(struct rcu_head
*head
)
843 struct opp_table
*opp_table
= container_of(head
, struct opp_table
,
846 kfree_rcu(opp_table
, rcu_head
);
850 * _remove_opp_table() - Removes a OPP table
851 * @opp_table: OPP table to be removed.
853 * Removes/frees OPP table if it doesn't contain any OPPs.
855 static void _remove_opp_table(struct opp_table
*opp_table
)
857 struct opp_device
*opp_dev
;
859 if (!list_empty(&opp_table
->opp_list
))
862 if (opp_table
->supported_hw
)
865 if (opp_table
->prop_name
)
868 if (opp_table
->regulators
)
872 if (!IS_ERR(opp_table
->clk
))
873 clk_put(opp_table
->clk
);
875 opp_dev
= list_first_entry(&opp_table
->dev_list
, struct opp_device
,
878 _remove_opp_dev(opp_dev
, opp_table
);
880 /* dev_list must be empty now */
881 WARN_ON(!list_empty(&opp_table
->dev_list
));
883 list_del_rcu(&opp_table
->node
);
884 call_srcu(&opp_table
->srcu_head
.srcu
, &opp_table
->rcu_head
,
889 * _kfree_opp_rcu() - Free OPP RCU handler
892 static void _kfree_opp_rcu(struct rcu_head
*head
)
894 struct dev_pm_opp
*opp
= container_of(head
, struct dev_pm_opp
, rcu_head
);
896 kfree_rcu(opp
, rcu_head
);
900 * _opp_remove() - Remove an OPP from a table definition
901 * @opp_table: points back to the opp_table struct this opp belongs to
902 * @opp: pointer to the OPP to remove
903 * @notify: OPP_EVENT_REMOVE notification should be sent or not
905 * This function removes an opp definition from the opp table.
907 * Locking: The internal opp_table and opp structures are RCU protected.
908 * It is assumed that the caller holds required mutex for an RCU updater
911 void _opp_remove(struct opp_table
*opp_table
, struct dev_pm_opp
*opp
,
915 * Notify the changes in the availability of the operable
916 * frequency/voltage list.
919 srcu_notifier_call_chain(&opp_table
->srcu_head
,
920 OPP_EVENT_REMOVE
, opp
);
921 opp_debug_remove_one(opp
);
922 list_del_rcu(&opp
->node
);
923 call_srcu(&opp_table
->srcu_head
.srcu
, &opp
->rcu_head
, _kfree_opp_rcu
);
925 _remove_opp_table(opp_table
);
929 * dev_pm_opp_remove() - Remove an OPP from OPP table
930 * @dev: device for which we do this operation
931 * @freq: OPP to remove with matching 'freq'
933 * This function removes an opp from the opp table.
935 * Locking: The internal opp_table and opp structures are RCU protected.
936 * Hence this function internally uses RCU updater strategy with mutex locks
937 * to keep the integrity of the internal data structures. Callers should ensure
938 * that this function is *NOT* called under RCU protection or in contexts where
939 * mutex cannot be locked.
941 void dev_pm_opp_remove(struct device
*dev
, unsigned long freq
)
943 struct dev_pm_opp
*opp
;
944 struct opp_table
*opp_table
;
947 /* Hold our table modification lock here */
948 mutex_lock(&opp_table_lock
);
950 opp_table
= _find_opp_table(dev
);
951 if (IS_ERR(opp_table
))
954 list_for_each_entry(opp
, &opp_table
->opp_list
, node
) {
955 if (opp
->rate
== freq
) {
962 dev_warn(dev
, "%s: Couldn't find OPP with freq: %lu\n",
967 _opp_remove(opp_table
, opp
, true);
969 mutex_unlock(&opp_table_lock
);
971 EXPORT_SYMBOL_GPL(dev_pm_opp_remove
);
973 struct dev_pm_opp
*_allocate_opp(struct device
*dev
,
974 struct opp_table
**opp_table
)
976 struct dev_pm_opp
*opp
;
977 int count
, supply_size
;
978 struct opp_table
*table
;
980 table
= _add_opp_table(dev
);
984 /* Allocate space for at least one supply */
985 count
= table
->regulator_count
? table
->regulator_count
: 1;
986 supply_size
= sizeof(*opp
->supplies
) * count
;
988 /* allocate new OPP node and supplies structures */
989 opp
= kzalloc(sizeof(*opp
) + supply_size
, GFP_KERNEL
);
995 /* Put the supplies at the end of the OPP structure as an empty array */
996 opp
->supplies
= (struct dev_pm_opp_supply
*)(opp
+ 1);
997 INIT_LIST_HEAD(&opp
->node
);
1004 static bool _opp_supported_by_regulators(struct dev_pm_opp
*opp
,
1005 struct opp_table
*opp_table
)
1007 struct regulator
*reg
;
1010 for (i
= 0; i
< opp_table
->regulator_count
; i
++) {
1011 reg
= opp_table
->regulators
[i
];
1013 if (!regulator_is_supported_voltage(reg
,
1014 opp
->supplies
[i
].u_volt_min
,
1015 opp
->supplies
[i
].u_volt_max
)) {
1016 pr_warn("%s: OPP minuV: %lu maxuV: %lu, not supported by regulator\n",
1017 __func__
, opp
->supplies
[i
].u_volt_min
,
1018 opp
->supplies
[i
].u_volt_max
);
1026 int _opp_add(struct device
*dev
, struct dev_pm_opp
*new_opp
,
1027 struct opp_table
*opp_table
)
1029 struct dev_pm_opp
*opp
;
1030 struct list_head
*head
= &opp_table
->opp_list
;
1034 * Insert new OPP in order of increasing frequency and discard if
1037 * Need to use &opp_table->opp_list in the condition part of the 'for'
1038 * loop, don't replace it with head otherwise it will become an infinite
1041 list_for_each_entry_rcu(opp
, &opp_table
->opp_list
, node
) {
1042 if (new_opp
->rate
> opp
->rate
) {
1047 if (new_opp
->rate
< opp
->rate
)
1050 /* Duplicate OPPs */
1051 dev_warn(dev
, "%s: duplicate OPPs detected. Existing: freq: %lu, volt: %lu, enabled: %d. New: freq: %lu, volt: %lu, enabled: %d\n",
1052 __func__
, opp
->rate
, opp
->supplies
[0].u_volt
,
1053 opp
->available
, new_opp
->rate
,
1054 new_opp
->supplies
[0].u_volt
, new_opp
->available
);
1056 /* Should we compare voltages for all regulators here ? */
1057 return opp
->available
&&
1058 new_opp
->supplies
[0].u_volt
== opp
->supplies
[0].u_volt
? 0 : -EEXIST
;
1061 new_opp
->opp_table
= opp_table
;
1062 list_add_rcu(&new_opp
->node
, head
);
1064 ret
= opp_debug_create_one(new_opp
, opp_table
);
1066 dev_err(dev
, "%s: Failed to register opp to debugfs (%d)\n",
1069 if (!_opp_supported_by_regulators(new_opp
, opp_table
)) {
1070 new_opp
->available
= false;
1071 dev_warn(dev
, "%s: OPP not supported by regulators (%lu)\n",
1072 __func__
, new_opp
->rate
);
1079 * _opp_add_v1() - Allocate a OPP based on v1 bindings.
1080 * @dev: device for which we do this operation
1081 * @freq: Frequency in Hz for this OPP
1082 * @u_volt: Voltage in uVolts for this OPP
1083 * @dynamic: Dynamically added OPPs.
1085 * This function adds an opp definition to the opp table and returns status.
1086 * The opp is made available by default and it can be controlled using
1087 * dev_pm_opp_enable/disable functions and may be removed by dev_pm_opp_remove.
1089 * NOTE: "dynamic" parameter impacts OPPs added by the dev_pm_opp_of_add_table
1090 * and freed by dev_pm_opp_of_remove_table.
1092 * Locking: The internal opp_table and opp structures are RCU protected.
1093 * Hence this function internally uses RCU updater strategy with mutex locks
1094 * to keep the integrity of the internal data structures. Callers should ensure
1095 * that this function is *NOT* called under RCU protection or in contexts where
1096 * mutex cannot be locked.
1100 * Duplicate OPPs (both freq and volt are same) and opp->available
1101 * -EEXIST Freq are same and volt are different OR
1102 * Duplicate OPPs (both freq and volt are same) and !opp->available
1103 * -ENOMEM Memory allocation failure
1105 int _opp_add_v1(struct device
*dev
, unsigned long freq
, long u_volt
,
1108 struct opp_table
*opp_table
;
1109 struct dev_pm_opp
*new_opp
;
1113 /* Hold our table modification lock here */
1114 mutex_lock(&opp_table_lock
);
1116 new_opp
= _allocate_opp(dev
, &opp_table
);
1122 /* populate the opp table */
1123 new_opp
->rate
= freq
;
1124 tol
= u_volt
* opp_table
->voltage_tolerance_v1
/ 100;
1125 new_opp
->supplies
[0].u_volt
= u_volt
;
1126 new_opp
->supplies
[0].u_volt_min
= u_volt
- tol
;
1127 new_opp
->supplies
[0].u_volt_max
= u_volt
+ tol
;
1128 new_opp
->available
= true;
1129 new_opp
->dynamic
= dynamic
;
1131 ret
= _opp_add(dev
, new_opp
, opp_table
);
1135 mutex_unlock(&opp_table_lock
);
1138 * Notify the changes in the availability of the operable
1139 * frequency/voltage list.
1141 srcu_notifier_call_chain(&opp_table
->srcu_head
, OPP_EVENT_ADD
, new_opp
);
1145 _opp_remove(opp_table
, new_opp
, false);
1147 mutex_unlock(&opp_table_lock
);
1152 * dev_pm_opp_set_supported_hw() - Set supported platforms
1153 * @dev: Device for which supported-hw has to be set.
1154 * @versions: Array of hierarchy of versions to match.
1155 * @count: Number of elements in the array.
1157 * This is required only for the V2 bindings, and it enables a platform to
1158 * specify the hierarchy of versions it supports. OPP layer will then enable
1159 * OPPs, which are available for those versions, based on its 'opp-supported-hw'
1162 * Locking: The internal opp_table and opp structures are RCU protected.
1163 * Hence this function internally uses RCU updater strategy with mutex locks
1164 * to keep the integrity of the internal data structures. Callers should ensure
1165 * that this function is *NOT* called under RCU protection or in contexts where
1166 * mutex cannot be locked.
1168 int dev_pm_opp_set_supported_hw(struct device
*dev
, const u32
*versions
,
1171 struct opp_table
*opp_table
;
1174 /* Hold our table modification lock here */
1175 mutex_lock(&opp_table_lock
);
1177 opp_table
= _add_opp_table(dev
);
1183 /* Make sure there are no concurrent readers while updating opp_table */
1184 WARN_ON(!list_empty(&opp_table
->opp_list
));
1186 /* Do we already have a version hierarchy associated with opp_table? */
1187 if (opp_table
->supported_hw
) {
1188 dev_err(dev
, "%s: Already have supported hardware list\n",
1194 opp_table
->supported_hw
= kmemdup(versions
, count
* sizeof(*versions
),
1196 if (!opp_table
->supported_hw
) {
1201 opp_table
->supported_hw_count
= count
;
1202 mutex_unlock(&opp_table_lock
);
1206 _remove_opp_table(opp_table
);
1208 mutex_unlock(&opp_table_lock
);
1212 EXPORT_SYMBOL_GPL(dev_pm_opp_set_supported_hw
);
1215 * dev_pm_opp_put_supported_hw() - Releases resources blocked for supported hw
1216 * @dev: Device for which supported-hw has to be put.
1218 * This is required only for the V2 bindings, and is called for a matching
1219 * dev_pm_opp_set_supported_hw(). Until this is called, the opp_table structure
1220 * will not be freed.
1222 * Locking: The internal opp_table and opp structures are RCU protected.
1223 * Hence this function internally uses RCU updater strategy with mutex locks
1224 * to keep the integrity of the internal data structures. Callers should ensure
1225 * that this function is *NOT* called under RCU protection or in contexts where
1226 * mutex cannot be locked.
1228 void dev_pm_opp_put_supported_hw(struct device
*dev
)
1230 struct opp_table
*opp_table
;
1232 /* Hold our table modification lock here */
1233 mutex_lock(&opp_table_lock
);
1235 /* Check for existing table for 'dev' first */
1236 opp_table
= _find_opp_table(dev
);
1237 if (IS_ERR(opp_table
)) {
1238 dev_err(dev
, "Failed to find opp_table: %ld\n",
1239 PTR_ERR(opp_table
));
1243 /* Make sure there are no concurrent readers while updating opp_table */
1244 WARN_ON(!list_empty(&opp_table
->opp_list
));
1246 if (!opp_table
->supported_hw
) {
1247 dev_err(dev
, "%s: Doesn't have supported hardware list\n",
1252 kfree(opp_table
->supported_hw
);
1253 opp_table
->supported_hw
= NULL
;
1254 opp_table
->supported_hw_count
= 0;
1256 /* Try freeing opp_table if this was the last blocking resource */
1257 _remove_opp_table(opp_table
);
1260 mutex_unlock(&opp_table_lock
);
1262 EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw
);
1265 * dev_pm_opp_set_prop_name() - Set prop-extn name
1266 * @dev: Device for which the prop-name has to be set.
1267 * @name: name to postfix to properties.
1269 * This is required only for the V2 bindings, and it enables a platform to
1270 * specify the extn to be used for certain property names. The properties to
1271 * which the extension will apply are opp-microvolt and opp-microamp. OPP core
1272 * should postfix the property name with -<name> while looking for them.
1274 * Locking: The internal opp_table and opp structures are RCU protected.
1275 * Hence this function internally uses RCU updater strategy with mutex locks
1276 * to keep the integrity of the internal data structures. Callers should ensure
1277 * that this function is *NOT* called under RCU protection or in contexts where
1278 * mutex cannot be locked.
1280 int dev_pm_opp_set_prop_name(struct device
*dev
, const char *name
)
1282 struct opp_table
*opp_table
;
1285 /* Hold our table modification lock here */
1286 mutex_lock(&opp_table_lock
);
1288 opp_table
= _add_opp_table(dev
);
1294 /* Make sure there are no concurrent readers while updating opp_table */
1295 WARN_ON(!list_empty(&opp_table
->opp_list
));
1297 /* Do we already have a prop-name associated with opp_table? */
1298 if (opp_table
->prop_name
) {
1299 dev_err(dev
, "%s: Already have prop-name %s\n", __func__
,
1300 opp_table
->prop_name
);
1305 opp_table
->prop_name
= kstrdup(name
, GFP_KERNEL
);
1306 if (!opp_table
->prop_name
) {
1311 mutex_unlock(&opp_table_lock
);
1315 _remove_opp_table(opp_table
);
1317 mutex_unlock(&opp_table_lock
);
1321 EXPORT_SYMBOL_GPL(dev_pm_opp_set_prop_name
);
1324 * dev_pm_opp_put_prop_name() - Releases resources blocked for prop-name
1325 * @dev: Device for which the prop-name has to be put.
1327 * This is required only for the V2 bindings, and is called for a matching
1328 * dev_pm_opp_set_prop_name(). Until this is called, the opp_table structure
1329 * will not be freed.
1331 * Locking: The internal opp_table and opp structures are RCU protected.
1332 * Hence this function internally uses RCU updater strategy with mutex locks
1333 * to keep the integrity of the internal data structures. Callers should ensure
1334 * that this function is *NOT* called under RCU protection or in contexts where
1335 * mutex cannot be locked.
1337 void dev_pm_opp_put_prop_name(struct device
*dev
)
1339 struct opp_table
*opp_table
;
1341 /* Hold our table modification lock here */
1342 mutex_lock(&opp_table_lock
);
1344 /* Check for existing table for 'dev' first */
1345 opp_table
= _find_opp_table(dev
);
1346 if (IS_ERR(opp_table
)) {
1347 dev_err(dev
, "Failed to find opp_table: %ld\n",
1348 PTR_ERR(opp_table
));
1352 /* Make sure there are no concurrent readers while updating opp_table */
1353 WARN_ON(!list_empty(&opp_table
->opp_list
));
1355 if (!opp_table
->prop_name
) {
1356 dev_err(dev
, "%s: Doesn't have a prop-name\n", __func__
);
1360 kfree(opp_table
->prop_name
);
1361 opp_table
->prop_name
= NULL
;
1363 /* Try freeing opp_table if this was the last blocking resource */
1364 _remove_opp_table(opp_table
);
1367 mutex_unlock(&opp_table_lock
);
1369 EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name
);
1372 * dev_pm_opp_set_regulators() - Set regulator names for the device
1373 * @dev: Device for which regulator name is being set.
1374 * @names: Array of pointers to the names of the regulator.
1375 * @count: Number of regulators.
1377 * In order to support OPP switching, OPP layer needs to know the name of the
1378 * device's regulators, as the core would be required to switch voltages as
1381 * This must be called before any OPPs are initialized for the device.
1383 * Locking: The internal opp_table and opp structures are RCU protected.
1384 * Hence this function internally uses RCU updater strategy with mutex locks
1385 * to keep the integrity of the internal data structures. Callers should ensure
1386 * that this function is *NOT* called under RCU protection or in contexts where
1387 * mutex cannot be locked.
1389 struct opp_table
*dev_pm_opp_set_regulators(struct device
*dev
,
1390 const char * const names
[],
1393 struct opp_table
*opp_table
;
1394 struct regulator
*reg
;
1397 mutex_lock(&opp_table_lock
);
1399 opp_table
= _add_opp_table(dev
);
1405 /* This should be called before OPPs are initialized */
1406 if (WARN_ON(!list_empty(&opp_table
->opp_list
))) {
1411 /* Already have regulators set */
1412 if (WARN_ON(opp_table
->regulators
)) {
1417 opp_table
->regulators
= kmalloc_array(count
,
1418 sizeof(*opp_table
->regulators
),
1420 if (!opp_table
->regulators
) {
1425 for (i
= 0; i
< count
; i
++) {
1426 reg
= regulator_get_optional(dev
, names
[i
]);
1429 if (ret
!= -EPROBE_DEFER
)
1430 dev_err(dev
, "%s: no regulator (%s) found: %d\n",
1431 __func__
, names
[i
], ret
);
1432 goto free_regulators
;
1435 opp_table
->regulators
[i
] = reg
;
1438 opp_table
->regulator_count
= count
;
1440 mutex_unlock(&opp_table_lock
);
1445 regulator_put(opp_table
->regulators
[--i
]);
1447 kfree(opp_table
->regulators
);
1448 opp_table
->regulators
= NULL
;
1450 _remove_opp_table(opp_table
);
1452 mutex_unlock(&opp_table_lock
);
1454 return ERR_PTR(ret
);
1456 EXPORT_SYMBOL_GPL(dev_pm_opp_set_regulators
);
1459 * dev_pm_opp_put_regulators() - Releases resources blocked for regulator
1460 * @opp_table: OPP table returned from dev_pm_opp_set_regulators().
1462 * Locking: The internal opp_table and opp structures are RCU protected.
1463 * Hence this function internally uses RCU updater strategy with mutex locks
1464 * to keep the integrity of the internal data structures. Callers should ensure
1465 * that this function is *NOT* called under RCU protection or in contexts where
1466 * mutex cannot be locked.
1468 void dev_pm_opp_put_regulators(struct opp_table
*opp_table
)
1472 mutex_lock(&opp_table_lock
);
1474 if (!opp_table
->regulators
) {
1475 pr_err("%s: Doesn't have regulators set\n", __func__
);
1479 /* Make sure there are no concurrent readers while updating opp_table */
1480 WARN_ON(!list_empty(&opp_table
->opp_list
));
1482 for (i
= opp_table
->regulator_count
- 1; i
>= 0; i
--)
1483 regulator_put(opp_table
->regulators
[i
]);
1485 kfree(opp_table
->regulators
);
1486 opp_table
->regulators
= NULL
;
1487 opp_table
->regulator_count
= 0;
1489 /* Try freeing opp_table if this was the last blocking resource */
1490 _remove_opp_table(opp_table
);
1493 mutex_unlock(&opp_table_lock
);
1495 EXPORT_SYMBOL_GPL(dev_pm_opp_put_regulators
);
1498 * dev_pm_opp_add() - Add an OPP table from a table definitions
1499 * @dev: device for which we do this operation
1500 * @freq: Frequency in Hz for this OPP
1501 * @u_volt: Voltage in uVolts for this OPP
1503 * This function adds an opp definition to the opp table and returns status.
1504 * The opp is made available by default and it can be controlled using
1505 * dev_pm_opp_enable/disable functions.
1507 * Locking: The internal opp_table and opp structures are RCU protected.
1508 * Hence this function internally uses RCU updater strategy with mutex locks
1509 * to keep the integrity of the internal data structures. Callers should ensure
1510 * that this function is *NOT* called under RCU protection or in contexts where
1511 * mutex cannot be locked.
1515 * Duplicate OPPs (both freq and volt are same) and opp->available
1516 * -EEXIST Freq are same and volt are different OR
1517 * Duplicate OPPs (both freq and volt are same) and !opp->available
1518 * -ENOMEM Memory allocation failure
1520 int dev_pm_opp_add(struct device
*dev
, unsigned long freq
, unsigned long u_volt
)
1522 return _opp_add_v1(dev
, freq
, u_volt
, true);
1524 EXPORT_SYMBOL_GPL(dev_pm_opp_add
);
1527 * _opp_set_availability() - helper to set the availability of an opp
1528 * @dev: device for which we do this operation
1529 * @freq: OPP frequency to modify availability
1530 * @availability_req: availability status requested for this opp
1532 * Set the availability of an OPP with an RCU operation, opp_{enable,disable}
1533 * share a common logic which is isolated here.
1535 * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
1536 * copy operation, returns 0 if no modification was done OR modification was
1539 * Locking: The internal opp_table and opp structures are RCU protected.
1540 * Hence this function internally uses RCU updater strategy with mutex locks to
1541 * keep the integrity of the internal data structures. Callers should ensure
1542 * that this function is *NOT* called under RCU protection or in contexts where
1543 * mutex locking or synchronize_rcu() blocking calls cannot be used.
1545 static int _opp_set_availability(struct device
*dev
, unsigned long freq
,
1546 bool availability_req
)
1548 struct opp_table
*opp_table
;
1549 struct dev_pm_opp
*new_opp
, *tmp_opp
, *opp
= ERR_PTR(-ENODEV
);
1552 /* keep the node allocated */
1553 new_opp
= kmalloc(sizeof(*new_opp
), GFP_KERNEL
);
1557 mutex_lock(&opp_table_lock
);
1559 /* Find the opp_table */
1560 opp_table
= _find_opp_table(dev
);
1561 if (IS_ERR(opp_table
)) {
1562 r
= PTR_ERR(opp_table
);
1563 dev_warn(dev
, "%s: Device OPP not found (%d)\n", __func__
, r
);
1567 /* Do we have the frequency? */
1568 list_for_each_entry(tmp_opp
, &opp_table
->opp_list
, node
) {
1569 if (tmp_opp
->rate
== freq
) {
1579 /* Is update really needed? */
1580 if (opp
->available
== availability_req
)
1582 /* copy the old data over */
1585 /* plug in new node */
1586 new_opp
->available
= availability_req
;
1588 list_replace_rcu(&opp
->node
, &new_opp
->node
);
1589 mutex_unlock(&opp_table_lock
);
1590 call_srcu(&opp_table
->srcu_head
.srcu
, &opp
->rcu_head
, _kfree_opp_rcu
);
1592 /* Notify the change of the OPP availability */
1593 if (availability_req
)
1594 srcu_notifier_call_chain(&opp_table
->srcu_head
,
1595 OPP_EVENT_ENABLE
, new_opp
);
1597 srcu_notifier_call_chain(&opp_table
->srcu_head
,
1598 OPP_EVENT_DISABLE
, new_opp
);
1603 mutex_unlock(&opp_table_lock
);
1609 * dev_pm_opp_enable() - Enable a specific OPP
1610 * @dev: device for which we do this operation
1611 * @freq: OPP frequency to enable
1613 * Enables a provided opp. If the operation is valid, this returns 0, else the
1614 * corresponding error value. It is meant to be used for users an OPP available
1615 * after being temporarily made unavailable with dev_pm_opp_disable.
1617 * Locking: The internal opp_table and opp structures are RCU protected.
1618 * Hence this function indirectly uses RCU and mutex locks to keep the
1619 * integrity of the internal data structures. Callers should ensure that
1620 * this function is *NOT* called under RCU protection or in contexts where
1621 * mutex locking or synchronize_rcu() blocking calls cannot be used.
1623 * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
1624 * copy operation, returns 0 if no modification was done OR modification was
1627 int dev_pm_opp_enable(struct device
*dev
, unsigned long freq
)
1629 return _opp_set_availability(dev
, freq
, true);
1631 EXPORT_SYMBOL_GPL(dev_pm_opp_enable
);
1634 * dev_pm_opp_disable() - Disable a specific OPP
1635 * @dev: device for which we do this operation
1636 * @freq: OPP frequency to disable
1638 * Disables a provided opp. If the operation is valid, this returns
1639 * 0, else the corresponding error value. It is meant to be a temporary
1640 * control by users to make this OPP not available until the circumstances are
1641 * right to make it available again (with a call to dev_pm_opp_enable).
1643 * Locking: The internal opp_table and opp structures are RCU protected.
1644 * Hence this function indirectly uses RCU and mutex locks to keep the
1645 * integrity of the internal data structures. Callers should ensure that
1646 * this function is *NOT* called under RCU protection or in contexts where
1647 * mutex locking or synchronize_rcu() blocking calls cannot be used.
1649 * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the
1650 * copy operation, returns 0 if no modification was done OR modification was
1653 int dev_pm_opp_disable(struct device
*dev
, unsigned long freq
)
1655 return _opp_set_availability(dev
, freq
, false);
1657 EXPORT_SYMBOL_GPL(dev_pm_opp_disable
);
1660 * dev_pm_opp_get_notifier() - find notifier_head of the device with opp
1661 * @dev: device pointer used to lookup OPP table.
1663 * Return: pointer to notifier head if found, otherwise -ENODEV or
1664 * -EINVAL based on type of error casted as pointer. value must be checked
1665 * with IS_ERR to determine valid pointer or error result.
1667 * Locking: This function must be called under rcu_read_lock(). opp_table is a
1668 * RCU protected pointer. The reason for the same is that the opp pointer which
1669 * is returned will remain valid for use with opp_get_{voltage, freq} only while
1670 * under the locked area. The pointer returned must be used prior to unlocking
1671 * with rcu_read_unlock() to maintain the integrity of the pointer.
1673 struct srcu_notifier_head
*dev_pm_opp_get_notifier(struct device
*dev
)
1675 struct opp_table
*opp_table
= _find_opp_table(dev
);
1677 if (IS_ERR(opp_table
))
1678 return ERR_CAST(opp_table
); /* matching type */
1680 return &opp_table
->srcu_head
;
1682 EXPORT_SYMBOL_GPL(dev_pm_opp_get_notifier
);
1685 * Free OPPs either created using static entries present in DT or even the
1686 * dynamically added entries based on remove_all param.
1688 void _dev_pm_opp_remove_table(struct device
*dev
, bool remove_all
)
1690 struct opp_table
*opp_table
;
1691 struct dev_pm_opp
*opp
, *tmp
;
1693 /* Hold our table modification lock here */
1694 mutex_lock(&opp_table_lock
);
1696 /* Check for existing table for 'dev' */
1697 opp_table
= _find_opp_table(dev
);
1698 if (IS_ERR(opp_table
)) {
1699 int error
= PTR_ERR(opp_table
);
1701 if (error
!= -ENODEV
)
1702 WARN(1, "%s: opp_table: %d\n",
1703 IS_ERR_OR_NULL(dev
) ?
1704 "Invalid device" : dev_name(dev
),
1709 /* Find if opp_table manages a single device */
1710 if (list_is_singular(&opp_table
->dev_list
)) {
1711 /* Free static OPPs */
1712 list_for_each_entry_safe(opp
, tmp
, &opp_table
->opp_list
, node
) {
1713 if (remove_all
|| !opp
->dynamic
)
1714 _opp_remove(opp_table
, opp
, true);
1717 _remove_opp_dev(_find_opp_dev(dev
, opp_table
), opp_table
);
1721 mutex_unlock(&opp_table_lock
);
1725 * dev_pm_opp_remove_table() - Free all OPPs associated with the device
1726 * @dev: device pointer used to lookup OPP table.
1728 * Free both OPPs created using static entries present in DT and the
1729 * dynamically added entries.
1731 * Locking: The internal opp_table and opp structures are RCU protected.
1732 * Hence this function indirectly uses RCU updater strategy with mutex locks
1733 * to keep the integrity of the internal data structures. Callers should ensure
1734 * that this function is *NOT* called under RCU protection or in contexts where
1735 * mutex cannot be locked.
1737 void dev_pm_opp_remove_table(struct device
*dev
)
1739 _dev_pm_opp_remove_table(dev
, true);
1741 EXPORT_SYMBOL_GPL(dev_pm_opp_remove_table
);