linux/include/linux/clk.h
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   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 *  linux/include/linux/clk.h
   4 *
   5 *  Copyright (C) 2004 ARM Limited.
   6 *  Written by Deep Blue Solutions Limited.
   7 *  Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
   8 */
   9#ifndef __LINUX_CLK_H
  10#define __LINUX_CLK_H
  11
  12#include <linux/err.h>
  13#include <linux/kernel.h>
  14#include <linux/notifier.h>
  15
  16struct device;
  17struct clk;
  18struct device_node;
  19struct of_phandle_args;
  20
  21/**
  22 * DOC: clk notifier callback types
  23 *
  24 * PRE_RATE_CHANGE - called immediately before the clk rate is changed,
  25 *     to indicate that the rate change will proceed.  Drivers must
  26 *     immediately terminate any operations that will be affected by the
  27 *     rate change.  Callbacks may either return NOTIFY_DONE, NOTIFY_OK,
  28 *     NOTIFY_STOP or NOTIFY_BAD.
  29 *
  30 * ABORT_RATE_CHANGE: called if the rate change failed for some reason
  31 *     after PRE_RATE_CHANGE.  In this case, all registered notifiers on
  32 *     the clk will be called with ABORT_RATE_CHANGE. Callbacks must
  33 *     always return NOTIFY_DONE or NOTIFY_OK.
  34 *
  35 * POST_RATE_CHANGE - called after the clk rate change has successfully
  36 *     completed.  Callbacks must always return NOTIFY_DONE or NOTIFY_OK.
  37 *
  38 */
  39#define PRE_RATE_CHANGE                 BIT(0)
  40#define POST_RATE_CHANGE                BIT(1)
  41#define ABORT_RATE_CHANGE               BIT(2)
  42
  43/**
  44 * struct clk_notifier - associate a clk with a notifier
  45 * @clk: struct clk * to associate the notifier with
  46 * @notifier_head: a blocking_notifier_head for this clk
  47 * @node: linked list pointers
  48 *
  49 * A list of struct clk_notifier is maintained by the notifier code.
  50 * An entry is created whenever code registers the first notifier on a
  51 * particular @clk.  Future notifiers on that @clk are added to the
  52 * @notifier_head.
  53 */
  54struct clk_notifier {
  55        struct clk                      *clk;
  56        struct srcu_notifier_head       notifier_head;
  57        struct list_head                node;
  58};
  59
  60/**
  61 * struct clk_notifier_data - rate data to pass to the notifier callback
  62 * @clk: struct clk * being changed
  63 * @old_rate: previous rate of this clk
  64 * @new_rate: new rate of this clk
  65 *
  66 * For a pre-notifier, old_rate is the clk's rate before this rate
  67 * change, and new_rate is what the rate will be in the future.  For a
  68 * post-notifier, old_rate and new_rate are both set to the clk's
  69 * current rate (this was done to optimize the implementation).
  70 */
  71struct clk_notifier_data {
  72        struct clk              *clk;
  73        unsigned long           old_rate;
  74        unsigned long           new_rate;
  75};
  76
  77/**
  78 * struct clk_bulk_data - Data used for bulk clk operations.
  79 *
  80 * @id: clock consumer ID
  81 * @clk: struct clk * to store the associated clock
  82 *
  83 * The CLK APIs provide a series of clk_bulk_() API calls as
  84 * a convenience to consumers which require multiple clks.  This
  85 * structure is used to manage data for these calls.
  86 */
  87struct clk_bulk_data {
  88        const char              *id;
  89        struct clk              *clk;
  90};
  91
  92#ifdef CONFIG_COMMON_CLK
  93
  94/**
  95 * clk_notifier_register: register a clock rate-change notifier callback
  96 * @clk: clock whose rate we are interested in
  97 * @nb: notifier block with callback function pointer
  98 *
  99 * ProTip: debugging across notifier chains can be frustrating. Make sure that
 100 * your notifier callback function prints a nice big warning in case of
 101 * failure.
 102 */
 103int clk_notifier_register(struct clk *clk, struct notifier_block *nb);
 104
 105/**
 106 * clk_notifier_unregister: unregister a clock rate-change notifier callback
 107 * @clk: clock whose rate we are no longer interested in
 108 * @nb: notifier block which will be unregistered
 109 */
 110int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb);
 111
 112/**
 113 * clk_get_accuracy - obtain the clock accuracy in ppb (parts per billion)
 114 *                    for a clock source.
 115 * @clk: clock source
 116 *
 117 * This gets the clock source accuracy expressed in ppb.
 118 * A perfect clock returns 0.
 119 */
 120long clk_get_accuracy(struct clk *clk);
 121
 122/**
 123 * clk_set_phase - adjust the phase shift of a clock signal
 124 * @clk: clock signal source
 125 * @degrees: number of degrees the signal is shifted
 126 *
 127 * Shifts the phase of a clock signal by the specified degrees. Returns 0 on
 128 * success, -EERROR otherwise.
 129 */
 130int clk_set_phase(struct clk *clk, int degrees);
 131
 132/**
 133 * clk_get_phase - return the phase shift of a clock signal
 134 * @clk: clock signal source
 135 *
 136 * Returns the phase shift of a clock node in degrees, otherwise returns
 137 * -EERROR.
 138 */
 139int clk_get_phase(struct clk *clk);
 140
 141/**
 142 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
 143 * @clk: clock signal source
 144 * @num: numerator of the duty cycle ratio to be applied
 145 * @den: denominator of the duty cycle ratio to be applied
 146 *
 147 * Adjust the duty cycle of a clock signal by the specified ratio. Returns 0 on
 148 * success, -EERROR otherwise.
 149 */
 150int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den);
 151
 152/**
 153 * clk_get_duty_cycle - return the duty cycle ratio of a clock signal
 154 * @clk: clock signal source
 155 * @scale: scaling factor to be applied to represent the ratio as an integer
 156 *
 157 * Returns the duty cycle ratio multiplied by the scale provided, otherwise
 158 * returns -EERROR.
 159 */
 160int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale);
 161
 162/**
 163 * clk_is_match - check if two clk's point to the same hardware clock
 164 * @p: clk compared against q
 165 * @q: clk compared against p
 166 *
 167 * Returns true if the two struct clk pointers both point to the same hardware
 168 * clock node. Put differently, returns true if @p and @q
 169 * share the same &struct clk_core object.
 170 *
 171 * Returns false otherwise. Note that two NULL clks are treated as matching.
 172 */
 173bool clk_is_match(const struct clk *p, const struct clk *q);
 174
 175#else
 176
 177static inline int clk_notifier_register(struct clk *clk,
 178                                        struct notifier_block *nb)
 179{
 180        return -ENOTSUPP;
 181}
 182
 183static inline int clk_notifier_unregister(struct clk *clk,
 184                                          struct notifier_block *nb)
 185{
 186        return -ENOTSUPP;
 187}
 188
 189static inline long clk_get_accuracy(struct clk *clk)
 190{
 191        return -ENOTSUPP;
 192}
 193
 194static inline long clk_set_phase(struct clk *clk, int phase)
 195{
 196        return -ENOTSUPP;
 197}
 198
 199static inline long clk_get_phase(struct clk *clk)
 200{
 201        return -ENOTSUPP;
 202}
 203
 204static inline int clk_set_duty_cycle(struct clk *clk, unsigned int num,
 205                                     unsigned int den)
 206{
 207        return -ENOTSUPP;
 208}
 209
 210static inline unsigned int clk_get_scaled_duty_cycle(struct clk *clk,
 211                                                     unsigned int scale)
 212{
 213        return 0;
 214}
 215
 216static inline bool clk_is_match(const struct clk *p, const struct clk *q)
 217{
 218        return p == q;
 219}
 220
 221#endif
 222
 223/**
 224 * clk_prepare - prepare a clock source
 225 * @clk: clock source
 226 *
 227 * This prepares the clock source for use.
 228 *
 229 * Must not be called from within atomic context.
 230 */
 231#ifdef CONFIG_HAVE_CLK_PREPARE
 232int clk_prepare(struct clk *clk);
 233int __must_check clk_bulk_prepare(int num_clks,
 234                                  const struct clk_bulk_data *clks);
 235#else
 236static inline int clk_prepare(struct clk *clk)
 237{
 238        might_sleep();
 239        return 0;
 240}
 241
 242static inline int __must_check
 243clk_bulk_prepare(int num_clks, const struct clk_bulk_data *clks)
 244{
 245        might_sleep();
 246        return 0;
 247}
 248#endif
 249
 250/**
 251 * clk_unprepare - undo preparation of a clock source
 252 * @clk: clock source
 253 *
 254 * This undoes a previously prepared clock.  The caller must balance
 255 * the number of prepare and unprepare calls.
 256 *
 257 * Must not be called from within atomic context.
 258 */
 259#ifdef CONFIG_HAVE_CLK_PREPARE
 260void clk_unprepare(struct clk *clk);
 261void clk_bulk_unprepare(int num_clks, const struct clk_bulk_data *clks);
 262#else
 263static inline void clk_unprepare(struct clk *clk)
 264{
 265        might_sleep();
 266}
 267static inline void clk_bulk_unprepare(int num_clks,
 268                                      const struct clk_bulk_data *clks)
 269{
 270        might_sleep();
 271}
 272#endif
 273
 274#ifdef CONFIG_HAVE_CLK
 275/**
 276 * clk_get - lookup and obtain a reference to a clock producer.
 277 * @dev: device for clock "consumer"
 278 * @id: clock consumer ID
 279 *
 280 * Returns a struct clk corresponding to the clock producer, or
 281 * valid IS_ERR() condition containing errno.  The implementation
 282 * uses @dev and @id to determine the clock consumer, and thereby
 283 * the clock producer.  (IOW, @id may be identical strings, but
 284 * clk_get may return different clock producers depending on @dev.)
 285 *
 286 * Drivers must assume that the clock source is not enabled.
 287 *
 288 * clk_get should not be called from within interrupt context.
 289 */
 290struct clk *clk_get(struct device *dev, const char *id);
 291
 292/**
 293 * clk_bulk_get - lookup and obtain a number of references to clock producer.
 294 * @dev: device for clock "consumer"
 295 * @num_clks: the number of clk_bulk_data
 296 * @clks: the clk_bulk_data table of consumer
 297 *
 298 * This helper function allows drivers to get several clk consumers in one
 299 * operation. If any of the clk cannot be acquired then any clks
 300 * that were obtained will be freed before returning to the caller.
 301 *
 302 * Returns 0 if all clocks specified in clk_bulk_data table are obtained
 303 * successfully, or valid IS_ERR() condition containing errno.
 304 * The implementation uses @dev and @clk_bulk_data.id to determine the
 305 * clock consumer, and thereby the clock producer.
 306 * The clock returned is stored in each @clk_bulk_data.clk field.
 307 *
 308 * Drivers must assume that the clock source is not enabled.
 309 *
 310 * clk_bulk_get should not be called from within interrupt context.
 311 */
 312int __must_check clk_bulk_get(struct device *dev, int num_clks,
 313                              struct clk_bulk_data *clks);
 314/**
 315 * clk_bulk_get_all - lookup and obtain all available references to clock
 316 *                    producer.
 317 * @dev: device for clock "consumer"
 318 * @clks: pointer to the clk_bulk_data table of consumer
 319 *
 320 * This helper function allows drivers to get all clk consumers in one
 321 * operation. If any of the clk cannot be acquired then any clks
 322 * that were obtained will be freed before returning to the caller.
 323 *
 324 * Returns a positive value for the number of clocks obtained while the
 325 * clock references are stored in the clk_bulk_data table in @clks field.
 326 * Returns 0 if there're none and a negative value if something failed.
 327 *
 328 * Drivers must assume that the clock source is not enabled.
 329 *
 330 * clk_bulk_get should not be called from within interrupt context.
 331 */
 332int __must_check clk_bulk_get_all(struct device *dev,
 333                                  struct clk_bulk_data **clks);
 334
 335/**
 336 * clk_bulk_get_optional - lookup and obtain a number of references to clock producer
 337 * @dev: device for clock "consumer"
 338 * @num_clks: the number of clk_bulk_data
 339 * @clks: the clk_bulk_data table of consumer
 340 *
 341 * Behaves the same as clk_bulk_get() except where there is no clock producer.
 342 * In this case, instead of returning -ENOENT, the function returns 0 and
 343 * NULL for a clk for which a clock producer could not be determined.
 344 */
 345int __must_check clk_bulk_get_optional(struct device *dev, int num_clks,
 346                                       struct clk_bulk_data *clks);
 347/**
 348 * devm_clk_bulk_get - managed get multiple clk consumers
 349 * @dev: device for clock "consumer"
 350 * @num_clks: the number of clk_bulk_data
 351 * @clks: the clk_bulk_data table of consumer
 352 *
 353 * Return 0 on success, an errno on failure.
 354 *
 355 * This helper function allows drivers to get several clk
 356 * consumers in one operation with management, the clks will
 357 * automatically be freed when the device is unbound.
 358 */
 359int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
 360                                   struct clk_bulk_data *clks);
 361/**
 362 * devm_clk_bulk_get_optional - managed get multiple optional consumer clocks
 363 * @dev: device for clock "consumer"
 364 * @num_clks: the number of clk_bulk_data
 365 * @clks: pointer to the clk_bulk_data table of consumer
 366 *
 367 * Behaves the same as devm_clk_bulk_get() except where there is no clock
 368 * producer.  In this case, instead of returning -ENOENT, the function returns
 369 * NULL for given clk. It is assumed all clocks in clk_bulk_data are optional.
 370 *
 371 * Returns 0 if all clocks specified in clk_bulk_data table are obtained
 372 * successfully or for any clk there was no clk provider available, otherwise
 373 * returns valid IS_ERR() condition containing errno.
 374 * The implementation uses @dev and @clk_bulk_data.id to determine the
 375 * clock consumer, and thereby the clock producer.
 376 * The clock returned is stored in each @clk_bulk_data.clk field.
 377 *
 378 * Drivers must assume that the clock source is not enabled.
 379 *
 380 * clk_bulk_get should not be called from within interrupt context.
 381 */
 382int __must_check devm_clk_bulk_get_optional(struct device *dev, int num_clks,
 383                                            struct clk_bulk_data *clks);
 384/**
 385 * devm_clk_bulk_get_all - managed get multiple clk consumers
 386 * @dev: device for clock "consumer"
 387 * @clks: pointer to the clk_bulk_data table of consumer
 388 *
 389 * Returns a positive value for the number of clocks obtained while the
 390 * clock references are stored in the clk_bulk_data table in @clks field.
 391 * Returns 0 if there're none and a negative value if something failed.
 392 *
 393 * This helper function allows drivers to get several clk
 394 * consumers in one operation with management, the clks will
 395 * automatically be freed when the device is unbound.
 396 */
 397
 398int __must_check devm_clk_bulk_get_all(struct device *dev,
 399                                       struct clk_bulk_data **clks);
 400
 401/**
 402 * devm_clk_get - lookup and obtain a managed reference to a clock producer.
 403 * @dev: device for clock "consumer"
 404 * @id: clock consumer ID
 405 *
 406 * Returns a struct clk corresponding to the clock producer, or
 407 * valid IS_ERR() condition containing errno.  The implementation
 408 * uses @dev and @id to determine the clock consumer, and thereby
 409 * the clock producer.  (IOW, @id may be identical strings, but
 410 * clk_get may return different clock producers depending on @dev.)
 411 *
 412 * Drivers must assume that the clock source is not enabled.
 413 *
 414 * devm_clk_get should not be called from within interrupt context.
 415 *
 416 * The clock will automatically be freed when the device is unbound
 417 * from the bus.
 418 */
 419struct clk *devm_clk_get(struct device *dev, const char *id);
 420
 421/**
 422 * devm_clk_get_optional - lookup and obtain a managed reference to an optional
 423 *                         clock producer.
 424 * @dev: device for clock "consumer"
 425 * @id: clock consumer ID
 426 *
 427 * Behaves the same as devm_clk_get() except where there is no clock producer.
 428 * In this case, instead of returning -ENOENT, the function returns NULL.
 429 */
 430struct clk *devm_clk_get_optional(struct device *dev, const char *id);
 431
 432/**
 433 * devm_get_clk_from_child - lookup and obtain a managed reference to a
 434 *                           clock producer from child node.
 435 * @dev: device for clock "consumer"
 436 * @np: pointer to clock consumer node
 437 * @con_id: clock consumer ID
 438 *
 439 * This function parses the clocks, and uses them to look up the
 440 * struct clk from the registered list of clock providers by using
 441 * @np and @con_id
 442 *
 443 * The clock will automatically be freed when the device is unbound
 444 * from the bus.
 445 */
 446struct clk *devm_get_clk_from_child(struct device *dev,
 447                                    struct device_node *np, const char *con_id);
 448/**
 449 * clk_rate_exclusive_get - get exclusivity over the rate control of a
 450 *                          producer
 451 * @clk: clock source
 452 *
 453 * This function allows drivers to get exclusive control over the rate of a
 454 * provider. It prevents any other consumer to execute, even indirectly,
 455 * opereation which could alter the rate of the provider or cause glitches
 456 *
 457 * If exlusivity is claimed more than once on clock, even by the same driver,
 458 * the rate effectively gets locked as exclusivity can't be preempted.
 459 *
 460 * Must not be called from within atomic context.
 461 *
 462 * Returns success (0) or negative errno.
 463 */
 464int clk_rate_exclusive_get(struct clk *clk);
 465
 466/**
 467 * clk_rate_exclusive_put - release exclusivity over the rate control of a
 468 *                          producer
 469 * @clk: clock source
 470 *
 471 * This function allows drivers to release the exclusivity it previously got
 472 * from clk_rate_exclusive_get()
 473 *
 474 * The caller must balance the number of clk_rate_exclusive_get() and
 475 * clk_rate_exclusive_put() calls.
 476 *
 477 * Must not be called from within atomic context.
 478 */
 479void clk_rate_exclusive_put(struct clk *clk);
 480
 481/**
 482 * clk_enable - inform the system when the clock source should be running.
 483 * @clk: clock source
 484 *
 485 * If the clock can not be enabled/disabled, this should return success.
 486 *
 487 * May be called from atomic contexts.
 488 *
 489 * Returns success (0) or negative errno.
 490 */
 491int clk_enable(struct clk *clk);
 492
 493/**
 494 * clk_bulk_enable - inform the system when the set of clks should be running.
 495 * @num_clks: the number of clk_bulk_data
 496 * @clks: the clk_bulk_data table of consumer
 497 *
 498 * May be called from atomic contexts.
 499 *
 500 * Returns success (0) or negative errno.
 501 */
 502int __must_check clk_bulk_enable(int num_clks,
 503                                 const struct clk_bulk_data *clks);
 504
 505/**
 506 * clk_disable - inform the system when the clock source is no longer required.
 507 * @clk: clock source
 508 *
 509 * Inform the system that a clock source is no longer required by
 510 * a driver and may be shut down.
 511 *
 512 * May be called from atomic contexts.
 513 *
 514 * Implementation detail: if the clock source is shared between
 515 * multiple drivers, clk_enable() calls must be balanced by the
 516 * same number of clk_disable() calls for the clock source to be
 517 * disabled.
 518 */
 519void clk_disable(struct clk *clk);
 520
 521/**
 522 * clk_bulk_disable - inform the system when the set of clks is no
 523 *                    longer required.
 524 * @num_clks: the number of clk_bulk_data
 525 * @clks: the clk_bulk_data table of consumer
 526 *
 527 * Inform the system that a set of clks is no longer required by
 528 * a driver and may be shut down.
 529 *
 530 * May be called from atomic contexts.
 531 *
 532 * Implementation detail: if the set of clks is shared between
 533 * multiple drivers, clk_bulk_enable() calls must be balanced by the
 534 * same number of clk_bulk_disable() calls for the clock source to be
 535 * disabled.
 536 */
 537void clk_bulk_disable(int num_clks, const struct clk_bulk_data *clks);
 538
 539/**
 540 * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
 541 *                This is only valid once the clock source has been enabled.
 542 * @clk: clock source
 543 */
 544unsigned long clk_get_rate(struct clk *clk);
 545
 546/**
 547 * clk_put      - "free" the clock source
 548 * @clk: clock source
 549 *
 550 * Note: drivers must ensure that all clk_enable calls made on this
 551 * clock source are balanced by clk_disable calls prior to calling
 552 * this function.
 553 *
 554 * clk_put should not be called from within interrupt context.
 555 */
 556void clk_put(struct clk *clk);
 557
 558/**
 559 * clk_bulk_put - "free" the clock source
 560 * @num_clks: the number of clk_bulk_data
 561 * @clks: the clk_bulk_data table of consumer
 562 *
 563 * Note: drivers must ensure that all clk_bulk_enable calls made on this
 564 * clock source are balanced by clk_bulk_disable calls prior to calling
 565 * this function.
 566 *
 567 * clk_bulk_put should not be called from within interrupt context.
 568 */
 569void clk_bulk_put(int num_clks, struct clk_bulk_data *clks);
 570
 571/**
 572 * clk_bulk_put_all - "free" all the clock source
 573 * @num_clks: the number of clk_bulk_data
 574 * @clks: the clk_bulk_data table of consumer
 575 *
 576 * Note: drivers must ensure that all clk_bulk_enable calls made on this
 577 * clock source are balanced by clk_bulk_disable calls prior to calling
 578 * this function.
 579 *
 580 * clk_bulk_put_all should not be called from within interrupt context.
 581 */
 582void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks);
 583
 584/**
 585 * devm_clk_put - "free" a managed clock source
 586 * @dev: device used to acquire the clock
 587 * @clk: clock source acquired with devm_clk_get()
 588 *
 589 * Note: drivers must ensure that all clk_enable calls made on this
 590 * clock source are balanced by clk_disable calls prior to calling
 591 * this function.
 592 *
 593 * clk_put should not be called from within interrupt context.
 594 */
 595void devm_clk_put(struct device *dev, struct clk *clk);
 596
 597/*
 598 * The remaining APIs are optional for machine class support.
 599 */
 600
 601
 602/**
 603 * clk_round_rate - adjust a rate to the exact rate a clock can provide
 604 * @clk: clock source
 605 * @rate: desired clock rate in Hz
 606 *
 607 * This answers the question "if I were to pass @rate to clk_set_rate(),
 608 * what clock rate would I end up with?" without changing the hardware
 609 * in any way.  In other words:
 610 *
 611 *   rate = clk_round_rate(clk, r);
 612 *
 613 * and:
 614 *
 615 *   clk_set_rate(clk, r);
 616 *   rate = clk_get_rate(clk);
 617 *
 618 * are equivalent except the former does not modify the clock hardware
 619 * in any way.
 620 *
 621 * Returns rounded clock rate in Hz, or negative errno.
 622 */
 623long clk_round_rate(struct clk *clk, unsigned long rate);
 624
 625/**
 626 * clk_set_rate - set the clock rate for a clock source
 627 * @clk: clock source
 628 * @rate: desired clock rate in Hz
 629 *
 630 * Updating the rate starts at the top-most affected clock and then
 631 * walks the tree down to the bottom-most clock that needs updating.
 632 *
 633 * Returns success (0) or negative errno.
 634 */
 635int clk_set_rate(struct clk *clk, unsigned long rate);
 636
 637/**
 638 * clk_set_rate_exclusive- set the clock rate and claim exclusivity over
 639 *                         clock source
 640 * @clk: clock source
 641 * @rate: desired clock rate in Hz
 642 *
 643 * This helper function allows drivers to atomically set the rate of a producer
 644 * and claim exclusivity over the rate control of the producer.
 645 *
 646 * It is essentially a combination of clk_set_rate() and
 647 * clk_rate_exclusite_get(). Caller must balance this call with a call to
 648 * clk_rate_exclusive_put()
 649 *
 650 * Returns success (0) or negative errno.
 651 */
 652int clk_set_rate_exclusive(struct clk *clk, unsigned long rate);
 653
 654/**
 655 * clk_has_parent - check if a clock is a possible parent for another
 656 * @clk: clock source
 657 * @parent: parent clock source
 658 *
 659 * This function can be used in drivers that need to check that a clock can be
 660 * the parent of another without actually changing the parent.
 661 *
 662 * Returns true if @parent is a possible parent for @clk, false otherwise.
 663 */
 664bool clk_has_parent(struct clk *clk, struct clk *parent);
 665
 666/**
 667 * clk_set_rate_range - set a rate range for a clock source
 668 * @clk: clock source
 669 * @min: desired minimum clock rate in Hz, inclusive
 670 * @max: desired maximum clock rate in Hz, inclusive
 671 *
 672 * Returns success (0) or negative errno.
 673 */
 674int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max);
 675
 676/**
 677 * clk_set_min_rate - set a minimum clock rate for a clock source
 678 * @clk: clock source
 679 * @rate: desired minimum clock rate in Hz, inclusive
 680 *
 681 * Returns success (0) or negative errno.
 682 */
 683int clk_set_min_rate(struct clk *clk, unsigned long rate);
 684
 685/**
 686 * clk_set_max_rate - set a maximum clock rate for a clock source
 687 * @clk: clock source
 688 * @rate: desired maximum clock rate in Hz, inclusive
 689 *
 690 * Returns success (0) or negative errno.
 691 */
 692int clk_set_max_rate(struct clk *clk, unsigned long rate);
 693
 694/**
 695 * clk_set_parent - set the parent clock source for this clock
 696 * @clk: clock source
 697 * @parent: parent clock source
 698 *
 699 * Returns success (0) or negative errno.
 700 */
 701int clk_set_parent(struct clk *clk, struct clk *parent);
 702
 703/**
 704 * clk_get_parent - get the parent clock source for this clock
 705 * @clk: clock source
 706 *
 707 * Returns struct clk corresponding to parent clock source, or
 708 * valid IS_ERR() condition containing errno.
 709 */
 710struct clk *clk_get_parent(struct clk *clk);
 711
 712/**
 713 * clk_get_sys - get a clock based upon the device name
 714 * @dev_id: device name
 715 * @con_id: connection ID
 716 *
 717 * Returns a struct clk corresponding to the clock producer, or
 718 * valid IS_ERR() condition containing errno.  The implementation
 719 * uses @dev_id and @con_id to determine the clock consumer, and
 720 * thereby the clock producer. In contrast to clk_get() this function
 721 * takes the device name instead of the device itself for identification.
 722 *
 723 * Drivers must assume that the clock source is not enabled.
 724 *
 725 * clk_get_sys should not be called from within interrupt context.
 726 */
 727struct clk *clk_get_sys(const char *dev_id, const char *con_id);
 728
 729/**
 730 * clk_save_context - save clock context for poweroff
 731 *
 732 * Saves the context of the clock register for powerstates in which the
 733 * contents of the registers will be lost. Occurs deep within the suspend
 734 * code so locking is not necessary.
 735 */
 736int clk_save_context(void);
 737
 738/**
 739 * clk_restore_context - restore clock context after poweroff
 740 *
 741 * This occurs with all clocks enabled. Occurs deep within the resume code
 742 * so locking is not necessary.
 743 */
 744void clk_restore_context(void);
 745
 746#else /* !CONFIG_HAVE_CLK */
 747
 748static inline struct clk *clk_get(struct device *dev, const char *id)
 749{
 750        return NULL;
 751}
 752
 753static inline int __must_check clk_bulk_get(struct device *dev, int num_clks,
 754                                            struct clk_bulk_data *clks)
 755{
 756        return 0;
 757}
 758
 759static inline int __must_check clk_bulk_get_optional(struct device *dev,
 760                                int num_clks, struct clk_bulk_data *clks)
 761{
 762        return 0;
 763}
 764
 765static inline int __must_check clk_bulk_get_all(struct device *dev,
 766                                         struct clk_bulk_data **clks)
 767{
 768        return 0;
 769}
 770
 771static inline struct clk *devm_clk_get(struct device *dev, const char *id)
 772{
 773        return NULL;
 774}
 775
 776static inline struct clk *devm_clk_get_optional(struct device *dev,
 777                                                const char *id)
 778{
 779        return NULL;
 780}
 781
 782static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,
 783                                                 struct clk_bulk_data *clks)
 784{
 785        return 0;
 786}
 787
 788static inline int __must_check devm_clk_bulk_get_optional(struct device *dev,
 789                                int num_clks, struct clk_bulk_data *clks)
 790{
 791        return 0;
 792}
 793
 794static inline int __must_check devm_clk_bulk_get_all(struct device *dev,
 795                                                     struct clk_bulk_data **clks)
 796{
 797
 798        return 0;
 799}
 800
 801static inline struct clk *devm_get_clk_from_child(struct device *dev,
 802                                struct device_node *np, const char *con_id)
 803{
 804        return NULL;
 805}
 806
 807static inline void clk_put(struct clk *clk) {}
 808
 809static inline void clk_bulk_put(int num_clks, struct clk_bulk_data *clks) {}
 810
 811static inline void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks) {}
 812
 813static inline void devm_clk_put(struct device *dev, struct clk *clk) {}
 814
 815
 816static inline int clk_rate_exclusive_get(struct clk *clk)
 817{
 818        return 0;
 819}
 820
 821static inline void clk_rate_exclusive_put(struct clk *clk) {}
 822
 823static inline int clk_enable(struct clk *clk)
 824{
 825        return 0;
 826}
 827
 828static inline int __must_check clk_bulk_enable(int num_clks,
 829                                               const struct clk_bulk_data *clks)
 830{
 831        return 0;
 832}
 833
 834static inline void clk_disable(struct clk *clk) {}
 835
 836
 837static inline void clk_bulk_disable(int num_clks,
 838                                    const struct clk_bulk_data *clks) {}
 839
 840static inline unsigned long clk_get_rate(struct clk *clk)
 841{
 842        return 0;
 843}
 844
 845static inline int clk_set_rate(struct clk *clk, unsigned long rate)
 846{
 847        return 0;
 848}
 849
 850static inline int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
 851{
 852        return 0;
 853}
 854
 855static inline long clk_round_rate(struct clk *clk, unsigned long rate)
 856{
 857        return 0;
 858}
 859
 860static inline bool clk_has_parent(struct clk *clk, struct clk *parent)
 861{
 862        return true;
 863}
 864
 865static inline int clk_set_rate_range(struct clk *clk, unsigned long min,
 866                                     unsigned long max)
 867{
 868        return 0;
 869}
 870
 871static inline int clk_set_min_rate(struct clk *clk, unsigned long rate)
 872{
 873        return 0;
 874}
 875
 876static inline int clk_set_max_rate(struct clk *clk, unsigned long rate)
 877{
 878        return 0;
 879}
 880
 881static inline int clk_set_parent(struct clk *clk, struct clk *parent)
 882{
 883        return 0;
 884}
 885
 886static inline struct clk *clk_get_parent(struct clk *clk)
 887{
 888        return NULL;
 889}
 890
 891static inline struct clk *clk_get_sys(const char *dev_id, const char *con_id)
 892{
 893        return NULL;
 894}
 895
 896static inline int clk_save_context(void)
 897{
 898        return 0;
 899}
 900
 901static inline void clk_restore_context(void) {}
 902
 903#endif
 904
 905/* clk_prepare_enable helps cases using clk_enable in non-atomic context. */
 906static inline int clk_prepare_enable(struct clk *clk)
 907{
 908        int ret;
 909
 910        ret = clk_prepare(clk);
 911        if (ret)
 912                return ret;
 913        ret = clk_enable(clk);
 914        if (ret)
 915                clk_unprepare(clk);
 916
 917        return ret;
 918}
 919
 920/* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */
 921static inline void clk_disable_unprepare(struct clk *clk)
 922{
 923        clk_disable(clk);
 924        clk_unprepare(clk);
 925}
 926
 927static inline int __must_check
 928clk_bulk_prepare_enable(int num_clks, const struct clk_bulk_data *clks)
 929{
 930        int ret;
 931
 932        ret = clk_bulk_prepare(num_clks, clks);
 933        if (ret)
 934                return ret;
 935        ret = clk_bulk_enable(num_clks, clks);
 936        if (ret)
 937                clk_bulk_unprepare(num_clks, clks);
 938
 939        return ret;
 940}
 941
 942static inline void clk_bulk_disable_unprepare(int num_clks,
 943                                              const struct clk_bulk_data *clks)
 944{
 945        clk_bulk_disable(num_clks, clks);
 946        clk_bulk_unprepare(num_clks, clks);
 947}
 948
 949/**
 950 * clk_get_optional - lookup and obtain a reference to an optional clock
 951 *                    producer.
 952 * @dev: device for clock "consumer"
 953 * @id: clock consumer ID
 954 *
 955 * Behaves the same as clk_get() except where there is no clock producer. In
 956 * this case, instead of returning -ENOENT, the function returns NULL.
 957 */
 958static inline struct clk *clk_get_optional(struct device *dev, const char *id)
 959{
 960        struct clk *clk = clk_get(dev, id);
 961
 962        if (clk == ERR_PTR(-ENOENT))
 963                return NULL;
 964
 965        return clk;
 966}
 967
 968#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
 969struct clk *of_clk_get(struct device_node *np, int index);
 970struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
 971struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
 972#else
 973static inline struct clk *of_clk_get(struct device_node *np, int index)
 974{
 975        return ERR_PTR(-ENOENT);
 976}
 977static inline struct clk *of_clk_get_by_name(struct device_node *np,
 978                                             const char *name)
 979{
 980        return ERR_PTR(-ENOENT);
 981}
 982static inline struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
 983{
 984        return ERR_PTR(-ENOENT);
 985}
 986#endif
 987
 988#endif
 989