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