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TOMOYO Linux Cross Reference
Linux/arch/arm/mach-omap2/clockdomain.c

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  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /*
  3  * OMAP2/3/4 clockdomain framework functions
  4  *
  5  * Copyright (C) 2008-2011 Texas Instruments, Inc.
  6  * Copyright (C) 2008-2011 Nokia Corporation
  7  *
  8  * Written by Paul Walmsley and Jouni Högander
  9  * Added OMAP4 specific support by Abhijit Pagare <abhijitpagare@ti.com>
 10  */
 11 #undef DEBUG
 12 
 13 #include <linux/kernel.h>
 14 #include <linux/device.h>
 15 #include <linux/list.h>
 16 #include <linux/errno.h>
 17 #include <linux/string.h>
 18 #include <linux/delay.h>
 19 #include <linux/clk.h>
 20 #include <linux/limits.h>
 21 #include <linux/err.h>
 22 #include <linux/clk-provider.h>
 23 #include <linux/cpu_pm.h>
 24 
 25 #include <linux/io.h>
 26 
 27 #include <linux/bitops.h>
 28 
 29 #include "soc.h"
 30 #include "clock.h"
 31 #include "clockdomain.h"
 32 #include "pm.h"
 33 
 34 /* clkdm_list contains all registered struct clockdomains */
 35 static LIST_HEAD(clkdm_list);
 36 
 37 /* array of clockdomain deps to be added/removed when clkdm in hwsup mode */
 38 static struct clkdm_autodep *autodeps;
 39 
 40 static struct clkdm_ops *arch_clkdm;
 41 void clkdm_save_context(void);
 42 void clkdm_restore_context(void);
 43 
 44 /* Private functions */
 45 
 46 static struct clockdomain *_clkdm_lookup(const char *name)
 47 {
 48         struct clockdomain *clkdm, *temp_clkdm;
 49 
 50         if (!name)
 51                 return NULL;
 52 
 53         clkdm = NULL;
 54 
 55         list_for_each_entry(temp_clkdm, &clkdm_list, node) {
 56                 if (!strcmp(name, temp_clkdm->name)) {
 57                         clkdm = temp_clkdm;
 58                         break;
 59                 }
 60         }
 61 
 62         return clkdm;
 63 }
 64 
 65 /**
 66  * _clkdm_register - register a clockdomain
 67  * @clkdm: struct clockdomain * to register
 68  *
 69  * Adds a clockdomain to the internal clockdomain list.
 70  * Returns -EINVAL if given a null pointer, -EEXIST if a clockdomain is
 71  * already registered by the provided name, or 0 upon success.
 72  */
 73 static int _clkdm_register(struct clockdomain *clkdm)
 74 {
 75         struct powerdomain *pwrdm;
 76 
 77         if (!clkdm || !clkdm->name)
 78                 return -EINVAL;
 79 
 80         pwrdm = pwrdm_lookup(clkdm->pwrdm.name);
 81         if (!pwrdm) {
 82                 pr_err("clockdomain: %s: powerdomain %s does not exist\n",
 83                         clkdm->name, clkdm->pwrdm.name);
 84                 return -EINVAL;
 85         }
 86         clkdm->pwrdm.ptr = pwrdm;
 87 
 88         /* Verify that the clockdomain is not already registered */
 89         if (_clkdm_lookup(clkdm->name))
 90                 return -EEXIST;
 91 
 92         list_add(&clkdm->node, &clkdm_list);
 93 
 94         pwrdm_add_clkdm(pwrdm, clkdm);
 95 
 96         pr_debug("clockdomain: registered %s\n", clkdm->name);
 97 
 98         return 0;
 99 }
100 
101 /* _clkdm_deps_lookup - look up the specified clockdomain in a clkdm list */
102 static struct clkdm_dep *_clkdm_deps_lookup(struct clockdomain *clkdm,
103                                             struct clkdm_dep *deps)
104 {
105         struct clkdm_dep *cd;
106 
107         if (!clkdm || !deps)
108                 return ERR_PTR(-EINVAL);
109 
110         for (cd = deps; cd->clkdm_name; cd++) {
111                 if (!cd->clkdm && cd->clkdm_name)
112                         cd->clkdm = _clkdm_lookup(cd->clkdm_name);
113 
114                 if (cd->clkdm == clkdm)
115                         break;
116         }
117 
118         if (!cd->clkdm_name)
119                 return ERR_PTR(-ENOENT);
120 
121         return cd;
122 }
123 
124 /**
125  * _autodep_lookup - resolve autodep clkdm names to clkdm pointers; store
126  * @autodep: struct clkdm_autodep * to resolve
127  *
128  * Resolve autodep clockdomain names to clockdomain pointers via
129  * clkdm_lookup() and store the pointers in the autodep structure.  An
130  * "autodep" is a clockdomain sleep/wakeup dependency that is
131  * automatically added and removed whenever clocks in the associated
132  * clockdomain are enabled or disabled (respectively) when the
133  * clockdomain is in hardware-supervised mode.  Meant to be called
134  * once at clockdomain layer initialization, since these should remain
135  * fixed for a particular architecture.  No return value.
136  *
137  * XXX autodeps are deprecated and should be removed at the earliest
138  * opportunity
139  */
140 static void _autodep_lookup(struct clkdm_autodep *autodep)
141 {
142         struct clockdomain *clkdm;
143 
144         if (!autodep)
145                 return;
146 
147         clkdm = clkdm_lookup(autodep->clkdm.name);
148         if (!clkdm) {
149                 pr_err("clockdomain: autodeps: clockdomain %s does not exist\n",
150                          autodep->clkdm.name);
151                 clkdm = ERR_PTR(-ENOENT);
152         }
153         autodep->clkdm.ptr = clkdm;
154 }
155 
156 /**
157  * _resolve_clkdm_deps() - resolve clkdm_names in @clkdm_deps to clkdms
158  * @clkdm: clockdomain that we are resolving dependencies for
159  * @clkdm_deps: ptr to array of struct clkdm_deps to resolve
160  *
161  * Iterates through @clkdm_deps, looking up the struct clockdomain named by
162  * clkdm_name and storing the clockdomain pointer in the struct clkdm_dep.
163  * No return value.
164  */
165 static void _resolve_clkdm_deps(struct clockdomain *clkdm,
166                                 struct clkdm_dep *clkdm_deps)
167 {
168         struct clkdm_dep *cd;
169 
170         for (cd = clkdm_deps; cd && cd->clkdm_name; cd++) {
171                 if (cd->clkdm)
172                         continue;
173                 cd->clkdm = _clkdm_lookup(cd->clkdm_name);
174 
175                 WARN(!cd->clkdm, "clockdomain: %s: could not find clkdm %s while resolving dependencies - should never happen",
176                      clkdm->name, cd->clkdm_name);
177         }
178 }
179 
180 /**
181  * _clkdm_add_wkdep - add a wakeup dependency from clkdm2 to clkdm1 (lockless)
182  * @clkdm1: wake this struct clockdomain * up (dependent)
183  * @clkdm2: when this struct clockdomain * wakes up (source)
184  *
185  * When the clockdomain represented by @clkdm2 wakes up, wake up
186  * @clkdm1. Implemented in hardware on the OMAP, this feature is
187  * designed to reduce wakeup latency of the dependent clockdomain @clkdm1.
188  * Returns -EINVAL if presented with invalid clockdomain pointers,
189  * -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 0 upon
190  * success.
191  */
192 static int _clkdm_add_wkdep(struct clockdomain *clkdm1,
193                             struct clockdomain *clkdm2)
194 {
195         struct clkdm_dep *cd;
196         int ret = 0;
197 
198         if (!clkdm1 || !clkdm2)
199                 return -EINVAL;
200 
201         cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
202         if (IS_ERR(cd))
203                 ret = PTR_ERR(cd);
204 
205         if (!arch_clkdm || !arch_clkdm->clkdm_add_wkdep)
206                 ret = -EINVAL;
207 
208         if (ret) {
209                 pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n",
210                          clkdm1->name, clkdm2->name);
211                 return ret;
212         }
213 
214         cd->wkdep_usecount++;
215         if (cd->wkdep_usecount == 1) {
216                 pr_debug("clockdomain: hardware will wake up %s when %s wakes up\n",
217                          clkdm1->name, clkdm2->name);
218 
219                 ret = arch_clkdm->clkdm_add_wkdep(clkdm1, clkdm2);
220         }
221 
222         return ret;
223 }
224 
225 /**
226  * _clkdm_del_wkdep - remove a wakeup dep from clkdm2 to clkdm1 (lockless)
227  * @clkdm1: wake this struct clockdomain * up (dependent)
228  * @clkdm2: when this struct clockdomain * wakes up (source)
229  *
230  * Remove a wakeup dependency causing @clkdm1 to wake up when @clkdm2
231  * wakes up.  Returns -EINVAL if presented with invalid clockdomain
232  * pointers, -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or
233  * 0 upon success.
234  */
235 static int _clkdm_del_wkdep(struct clockdomain *clkdm1,
236                             struct clockdomain *clkdm2)
237 {
238         struct clkdm_dep *cd;
239         int ret = 0;
240 
241         if (!clkdm1 || !clkdm2)
242                 return -EINVAL;
243 
244         cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
245         if (IS_ERR(cd))
246                 ret = PTR_ERR(cd);
247 
248         if (!arch_clkdm || !arch_clkdm->clkdm_del_wkdep)
249                 ret = -EINVAL;
250 
251         if (ret) {
252                 pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n",
253                          clkdm1->name, clkdm2->name);
254                 return ret;
255         }
256 
257         cd->wkdep_usecount--;
258         if (cd->wkdep_usecount == 0) {
259                 pr_debug("clockdomain: hardware will no longer wake up %s after %s wakes up\n",
260                          clkdm1->name, clkdm2->name);
261 
262                 ret = arch_clkdm->clkdm_del_wkdep(clkdm1, clkdm2);
263         }
264 
265         return ret;
266 }
267 
268 /**
269  * _clkdm_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1 (lockless)
270  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
271  * @clkdm2: when this struct clockdomain * is active (source)
272  *
273  * Prevent @clkdm1 from automatically going inactive (and then to
274  * retention or off) if @clkdm2 is active.  Returns -EINVAL if
275  * presented with invalid clockdomain pointers or called on a machine
276  * that does not support software-configurable hardware sleep
277  * dependencies, -ENOENT if the specified dependency cannot be set in
278  * hardware, or 0 upon success.
279  */
280 static int _clkdm_add_sleepdep(struct clockdomain *clkdm1,
281                                struct clockdomain *clkdm2)
282 {
283         struct clkdm_dep *cd;
284         int ret = 0;
285 
286         if (!clkdm1 || !clkdm2)
287                 return -EINVAL;
288 
289         cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
290         if (IS_ERR(cd))
291                 ret = PTR_ERR(cd);
292 
293         if (!arch_clkdm || !arch_clkdm->clkdm_add_sleepdep)
294                 ret = -EINVAL;
295 
296         if (ret) {
297                 pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n",
298                          clkdm1->name, clkdm2->name);
299                 return ret;
300         }
301 
302         cd->sleepdep_usecount++;
303         if (cd->sleepdep_usecount == 1) {
304                 pr_debug("clockdomain: will prevent %s from sleeping if %s is active\n",
305                          clkdm1->name, clkdm2->name);
306 
307                 ret = arch_clkdm->clkdm_add_sleepdep(clkdm1, clkdm2);
308         }
309 
310         return ret;
311 }
312 
313 /**
314  * _clkdm_del_sleepdep - remove a sleep dep from clkdm2 to clkdm1 (lockless)
315  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
316  * @clkdm2: when this struct clockdomain * is active (source)
317  *
318  * Allow @clkdm1 to automatically go inactive (and then to retention or
319  * off), independent of the activity state of @clkdm2.  Returns -EINVAL
320  * if presented with invalid clockdomain pointers or called on a machine
321  * that does not support software-configurable hardware sleep dependencies,
322  * -ENOENT if the specified dependency cannot be cleared in hardware, or
323  * 0 upon success.
324  */
325 static int _clkdm_del_sleepdep(struct clockdomain *clkdm1,
326                                struct clockdomain *clkdm2)
327 {
328         struct clkdm_dep *cd;
329         int ret = 0;
330 
331         if (!clkdm1 || !clkdm2)
332                 return -EINVAL;
333 
334         cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
335         if (IS_ERR(cd))
336                 ret = PTR_ERR(cd);
337 
338         if (!arch_clkdm || !arch_clkdm->clkdm_del_sleepdep)
339                 ret = -EINVAL;
340 
341         if (ret) {
342                 pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n",
343                          clkdm1->name, clkdm2->name);
344                 return ret;
345         }
346 
347         cd->sleepdep_usecount--;
348         if (cd->sleepdep_usecount == 0) {
349                 pr_debug("clockdomain: will no longer prevent %s from sleeping if %s is active\n",
350                          clkdm1->name, clkdm2->name);
351 
352                 ret = arch_clkdm->clkdm_del_sleepdep(clkdm1, clkdm2);
353         }
354 
355         return ret;
356 }
357 
358 /* Public functions */
359 
360 /**
361  * clkdm_register_platform_funcs - register clockdomain implementation fns
362  * @co: func pointers for arch specific implementations
363  *
364  * Register the list of function pointers used to implement the
365  * clockdomain functions on different OMAP SoCs.  Should be called
366  * before any other clkdm_register*() function.  Returns -EINVAL if
367  * @co is null, -EEXIST if platform functions have already been
368  * registered, or 0 upon success.
369  */
370 int clkdm_register_platform_funcs(struct clkdm_ops *co)
371 {
372         if (!co)
373                 return -EINVAL;
374 
375         if (arch_clkdm)
376                 return -EEXIST;
377 
378         arch_clkdm = co;
379 
380         return 0;
381 };
382 
383 /**
384  * clkdm_register_clkdms - register SoC clockdomains
385  * @cs: pointer to an array of struct clockdomain to register
386  *
387  * Register the clockdomains available on a particular OMAP SoC.  Must
388  * be called after clkdm_register_platform_funcs().  May be called
389  * multiple times.  Returns -EACCES if called before
390  * clkdm_register_platform_funcs(); -EINVAL if the argument @cs is
391  * null; or 0 upon success.
392  */
393 int clkdm_register_clkdms(struct clockdomain **cs)
394 {
395         struct clockdomain **c = NULL;
396 
397         if (!arch_clkdm)
398                 return -EACCES;
399 
400         if (!cs)
401                 return -EINVAL;
402 
403         for (c = cs; *c; c++)
404                 _clkdm_register(*c);
405 
406         return 0;
407 }
408 
409 /**
410  * clkdm_register_autodeps - register autodeps (if required)
411  * @ia: pointer to a static array of struct clkdm_autodep to register
412  *
413  * Register clockdomain "automatic dependencies."  These are
414  * clockdomain wakeup and sleep dependencies that are automatically
415  * added whenever the first clock inside a clockdomain is enabled, and
416  * removed whenever the last clock inside a clockdomain is disabled.
417  * These are currently only used on OMAP3 devices, and are deprecated,
418  * since they waste energy.  However, until the OMAP2/3 IP block
419  * enable/disable sequence can be converted to match the OMAP4
420  * sequence, they are needed.
421  *
422  * Must be called only after all of the SoC clockdomains are
423  * registered, since the function will resolve autodep clockdomain
424  * names into clockdomain pointers.
425  *
426  * The struct clkdm_autodep @ia array must be static, as this function
427  * does not copy the array elements.
428  *
429  * Returns -EACCES if called before any clockdomains have been
430  * registered, -EINVAL if called with a null @ia argument, -EEXIST if
431  * autodeps have already been registered, or 0 upon success.
432  */
433 int clkdm_register_autodeps(struct clkdm_autodep *ia)
434 {
435         struct clkdm_autodep *a = NULL;
436 
437         if (list_empty(&clkdm_list))
438                 return -EACCES;
439 
440         if (!ia)
441                 return -EINVAL;
442 
443         if (autodeps)
444                 return -EEXIST;
445 
446         autodeps = ia;
447         for (a = autodeps; a->clkdm.ptr; a++)
448                 _autodep_lookup(a);
449 
450         return 0;
451 }
452 
453 static int cpu_notifier(struct notifier_block *nb, unsigned long cmd, void *v)
454 {
455         switch (cmd) {
456         case CPU_CLUSTER_PM_ENTER:
457                 if (enable_off_mode)
458                         clkdm_save_context();
459                 break;
460         case CPU_CLUSTER_PM_EXIT:
461                 if (enable_off_mode)
462                         clkdm_restore_context();
463                 break;
464         }
465 
466         return NOTIFY_OK;
467 }
468 
469 /**
470  * clkdm_complete_init - set up the clockdomain layer
471  *
472  * Put all clockdomains into software-supervised mode; PM code should
473  * later enable hardware-supervised mode as appropriate.  Must be
474  * called after clkdm_register_clkdms().  Returns -EACCES if called
475  * before clkdm_register_clkdms(), or 0 upon success.
476  */
477 int clkdm_complete_init(void)
478 {
479         struct clockdomain *clkdm;
480         static struct notifier_block nb;
481 
482         if (list_empty(&clkdm_list))
483                 return -EACCES;
484 
485         list_for_each_entry(clkdm, &clkdm_list, node) {
486                 clkdm_deny_idle(clkdm);
487 
488                 _resolve_clkdm_deps(clkdm, clkdm->wkdep_srcs);
489                 clkdm_clear_all_wkdeps(clkdm);
490 
491                 _resolve_clkdm_deps(clkdm, clkdm->sleepdep_srcs);
492                 clkdm_clear_all_sleepdeps(clkdm);
493         }
494 
495         /* Only AM43XX can lose clkdm context during rtc-ddr suspend */
496         if (soc_is_am43xx()) {
497                 nb.notifier_call = cpu_notifier;
498                 cpu_pm_register_notifier(&nb);
499         }
500 
501         return 0;
502 }
503 
504 /**
505  * clkdm_lookup - look up a clockdomain by name, return a pointer
506  * @name: name of clockdomain
507  *
508  * Find a registered clockdomain by its name @name.  Returns a pointer
509  * to the struct clockdomain if found, or NULL otherwise.
510  */
511 struct clockdomain *clkdm_lookup(const char *name)
512 {
513         struct clockdomain *clkdm, *temp_clkdm;
514 
515         if (!name)
516                 return NULL;
517 
518         clkdm = NULL;
519 
520         list_for_each_entry(temp_clkdm, &clkdm_list, node) {
521                 if (!strcmp(name, temp_clkdm->name)) {
522                         clkdm = temp_clkdm;
523                         break;
524                 }
525         }
526 
527         return clkdm;
528 }
529 
530 /**
531  * clkdm_for_each - call function on each registered clockdomain
532  * @fn: callback function *
533  *
534  * Call the supplied function @fn for each registered clockdomain.
535  * The callback function @fn can return anything but 0 to bail
536  * out early from the iterator.  The callback function is called with
537  * the clkdm_mutex held, so no clockdomain structure manipulation
538  * functions should be called from the callback, although hardware
539  * clockdomain control functions are fine.  Returns the last return
540  * value of the callback function, which should be 0 for success or
541  * anything else to indicate failure; or -EINVAL if the function pointer
542  * is null.
543  */
544 int clkdm_for_each(int (*fn)(struct clockdomain *clkdm, void *user),
545                         void *user)
546 {
547         struct clockdomain *clkdm;
548         int ret = 0;
549 
550         if (!fn)
551                 return -EINVAL;
552 
553         list_for_each_entry(clkdm, &clkdm_list, node) {
554                 ret = (*fn)(clkdm, user);
555                 if (ret)
556                         break;
557         }
558 
559         return ret;
560 }
561 
562 
563 /**
564  * clkdm_get_pwrdm - return a ptr to the pwrdm that this clkdm resides in
565  * @clkdm: struct clockdomain *
566  *
567  * Return a pointer to the struct powerdomain that the specified clockdomain
568  * @clkdm exists in, or returns NULL if @clkdm is NULL.
569  */
570 struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
571 {
572         if (!clkdm)
573                 return NULL;
574 
575         return clkdm->pwrdm.ptr;
576 }
577 
578 
579 /* Hardware clockdomain control */
580 
581 /**
582  * clkdm_add_wkdep - add a wakeup dependency from clkdm2 to clkdm1
583  * @clkdm1: wake this struct clockdomain * up (dependent)
584  * @clkdm2: when this struct clockdomain * wakes up (source)
585  *
586  * When the clockdomain represented by @clkdm2 wakes up, wake up
587  * @clkdm1. Implemented in hardware on the OMAP, this feature is
588  * designed to reduce wakeup latency of the dependent clockdomain @clkdm1.
589  * Returns -EINVAL if presented with invalid clockdomain pointers,
590  * -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 0 upon
591  * success.
592  */
593 int clkdm_add_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
594 {
595         struct clkdm_dep *cd;
596         int ret;
597 
598         if (!clkdm1 || !clkdm2)
599                 return -EINVAL;
600 
601         cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
602         if (IS_ERR(cd))
603                 return PTR_ERR(cd);
604 
605         pwrdm_lock(cd->clkdm->pwrdm.ptr);
606         ret = _clkdm_add_wkdep(clkdm1, clkdm2);
607         pwrdm_unlock(cd->clkdm->pwrdm.ptr);
608 
609         return ret;
610 }
611 
612 /**
613  * clkdm_del_wkdep - remove a wakeup dependency from clkdm2 to clkdm1
614  * @clkdm1: wake this struct clockdomain * up (dependent)
615  * @clkdm2: when this struct clockdomain * wakes up (source)
616  *
617  * Remove a wakeup dependency causing @clkdm1 to wake up when @clkdm2
618  * wakes up.  Returns -EINVAL if presented with invalid clockdomain
619  * pointers, -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or
620  * 0 upon success.
621  */
622 int clkdm_del_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
623 {
624         struct clkdm_dep *cd;
625         int ret;
626 
627         if (!clkdm1 || !clkdm2)
628                 return -EINVAL;
629 
630         cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
631         if (IS_ERR(cd))
632                 return PTR_ERR(cd);
633 
634         pwrdm_lock(cd->clkdm->pwrdm.ptr);
635         ret = _clkdm_del_wkdep(clkdm1, clkdm2);
636         pwrdm_unlock(cd->clkdm->pwrdm.ptr);
637 
638         return ret;
639 }
640 
641 /**
642  * clkdm_read_wkdep - read wakeup dependency state from clkdm2 to clkdm1
643  * @clkdm1: wake this struct clockdomain * up (dependent)
644  * @clkdm2: when this struct clockdomain * wakes up (source)
645  *
646  * Return 1 if a hardware wakeup dependency exists wherein @clkdm1 will be
647  * awoken when @clkdm2 wakes up; 0 if dependency is not set; -EINVAL
648  * if either clockdomain pointer is invalid; or -ENOENT if the hardware
649  * is incapable.
650  *
651  * REVISIT: Currently this function only represents software-controllable
652  * wakeup dependencies.  Wakeup dependencies fixed in hardware are not
653  * yet handled here.
654  */
655 int clkdm_read_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
656 {
657         struct clkdm_dep *cd;
658         int ret = 0;
659 
660         if (!clkdm1 || !clkdm2)
661                 return -EINVAL;
662 
663         cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
664         if (IS_ERR(cd))
665                 ret = PTR_ERR(cd);
666 
667         if (!arch_clkdm || !arch_clkdm->clkdm_read_wkdep)
668                 ret = -EINVAL;
669 
670         if (ret) {
671                 pr_debug("clockdomain: hardware cannot set/clear wake up of %s when %s wakes up\n",
672                          clkdm1->name, clkdm2->name);
673                 return ret;
674         }
675 
676         /* XXX It's faster to return the wkdep_usecount */
677         return arch_clkdm->clkdm_read_wkdep(clkdm1, clkdm2);
678 }
679 
680 /**
681  * clkdm_clear_all_wkdeps - remove all wakeup dependencies from target clkdm
682  * @clkdm: struct clockdomain * to remove all wakeup dependencies from
683  *
684  * Remove all inter-clockdomain wakeup dependencies that could cause
685  * @clkdm to wake.  Intended to be used during boot to initialize the
686  * PRCM to a known state, after all clockdomains are put into swsup idle
687  * and woken up.  Returns -EINVAL if @clkdm pointer is invalid, or
688  * 0 upon success.
689  */
690 int clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
691 {
692         if (!clkdm)
693                 return -EINVAL;
694 
695         if (!arch_clkdm || !arch_clkdm->clkdm_clear_all_wkdeps)
696                 return -EINVAL;
697 
698         return arch_clkdm->clkdm_clear_all_wkdeps(clkdm);
699 }
700 
701 /**
702  * clkdm_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1
703  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
704  * @clkdm2: when this struct clockdomain * is active (source)
705  *
706  * Prevent @clkdm1 from automatically going inactive (and then to
707  * retention or off) if @clkdm2 is active.  Returns -EINVAL if
708  * presented with invalid clockdomain pointers or called on a machine
709  * that does not support software-configurable hardware sleep
710  * dependencies, -ENOENT if the specified dependency cannot be set in
711  * hardware, or 0 upon success.
712  */
713 int clkdm_add_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
714 {
715         struct clkdm_dep *cd;
716         int ret;
717 
718         if (!clkdm1 || !clkdm2)
719                 return -EINVAL;
720 
721         cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
722         if (IS_ERR(cd))
723                 return PTR_ERR(cd);
724 
725         pwrdm_lock(cd->clkdm->pwrdm.ptr);
726         ret = _clkdm_add_sleepdep(clkdm1, clkdm2);
727         pwrdm_unlock(cd->clkdm->pwrdm.ptr);
728 
729         return ret;
730 }
731 
732 /**
733  * clkdm_del_sleepdep - remove a sleep dependency from clkdm2 to clkdm1
734  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
735  * @clkdm2: when this struct clockdomain * is active (source)
736  *
737  * Allow @clkdm1 to automatically go inactive (and then to retention or
738  * off), independent of the activity state of @clkdm2.  Returns -EINVAL
739  * if presented with invalid clockdomain pointers or called on a machine
740  * that does not support software-configurable hardware sleep dependencies,
741  * -ENOENT if the specified dependency cannot be cleared in hardware, or
742  * 0 upon success.
743  */
744 int clkdm_del_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
745 {
746         struct clkdm_dep *cd;
747         int ret;
748 
749         if (!clkdm1 || !clkdm2)
750                 return -EINVAL;
751 
752         cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
753         if (IS_ERR(cd))
754                 return PTR_ERR(cd);
755 
756         pwrdm_lock(cd->clkdm->pwrdm.ptr);
757         ret = _clkdm_del_sleepdep(clkdm1, clkdm2);
758         pwrdm_unlock(cd->clkdm->pwrdm.ptr);
759 
760         return ret;
761 }
762 
763 /**
764  * clkdm_read_sleepdep - read sleep dependency state from clkdm2 to clkdm1
765  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
766  * @clkdm2: when this struct clockdomain * is active (source)
767  *
768  * Return 1 if a hardware sleep dependency exists wherein @clkdm1 will
769  * not be allowed to automatically go inactive if @clkdm2 is active;
770  * 0 if @clkdm1's automatic power state inactivity transition is independent
771  * of @clkdm2's; -EINVAL if either clockdomain pointer is invalid or called
772  * on a machine that does not support software-configurable hardware sleep
773  * dependencies; or -ENOENT if the hardware is incapable.
774  *
775  * REVISIT: Currently this function only represents software-controllable
776  * sleep dependencies.  Sleep dependencies fixed in hardware are not
777  * yet handled here.
778  */
779 int clkdm_read_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
780 {
781         struct clkdm_dep *cd;
782         int ret = 0;
783 
784         if (!clkdm1 || !clkdm2)
785                 return -EINVAL;
786 
787         cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
788         if (IS_ERR(cd))
789                 ret = PTR_ERR(cd);
790 
791         if (!arch_clkdm || !arch_clkdm->clkdm_read_sleepdep)
792                 ret = -EINVAL;
793 
794         if (ret) {
795                 pr_debug("clockdomain: hardware cannot set/clear sleep dependency affecting %s from %s\n",
796                          clkdm1->name, clkdm2->name);
797                 return ret;
798         }
799 
800         /* XXX It's faster to return the sleepdep_usecount */
801         return arch_clkdm->clkdm_read_sleepdep(clkdm1, clkdm2);
802 }
803 
804 /**
805  * clkdm_clear_all_sleepdeps - remove all sleep dependencies from target clkdm
806  * @clkdm: struct clockdomain * to remove all sleep dependencies from
807  *
808  * Remove all inter-clockdomain sleep dependencies that could prevent
809  * @clkdm from idling.  Intended to be used during boot to initialize the
810  * PRCM to a known state, after all clockdomains are put into swsup idle
811  * and woken up.  Returns -EINVAL if @clkdm pointer is invalid, or
812  * 0 upon success.
813  */
814 int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm)
815 {
816         if (!clkdm)
817                 return -EINVAL;
818 
819         if (!arch_clkdm || !arch_clkdm->clkdm_clear_all_sleepdeps)
820                 return -EINVAL;
821 
822         return arch_clkdm->clkdm_clear_all_sleepdeps(clkdm);
823 }
824 
825 /**
826  * clkdm_sleep_nolock - force clockdomain sleep transition (lockless)
827  * @clkdm: struct clockdomain *
828  *
829  * Instruct the CM to force a sleep transition on the specified
830  * clockdomain @clkdm.  Only for use by the powerdomain code.  Returns
831  * -EINVAL if @clkdm is NULL or if clockdomain does not support
832  * software-initiated sleep; 0 upon success.
833  */
834 static int clkdm_sleep_nolock(struct clockdomain *clkdm)
835 {
836         int ret;
837 
838         if (!clkdm)
839                 return -EINVAL;
840 
841         if (!(clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) {
842                 pr_debug("clockdomain: %s does not support forcing sleep via software\n",
843                          clkdm->name);
844                 return -EINVAL;
845         }
846 
847         if (!arch_clkdm || !arch_clkdm->clkdm_sleep)
848                 return -EINVAL;
849 
850         pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name);
851 
852         clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
853         ret = arch_clkdm->clkdm_sleep(clkdm);
854         ret |= pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
855 
856         return ret;
857 }
858 
859 /**
860  * clkdm_sleep - force clockdomain sleep transition
861  * @clkdm: struct clockdomain *
862  *
863  * Instruct the CM to force a sleep transition on the specified
864  * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if
865  * clockdomain does not support software-initiated sleep; 0 upon
866  * success.
867  */
868 int clkdm_sleep(struct clockdomain *clkdm)
869 {
870         int ret;
871 
872         pwrdm_lock(clkdm->pwrdm.ptr);
873         ret = clkdm_sleep_nolock(clkdm);
874         pwrdm_unlock(clkdm->pwrdm.ptr);
875 
876         return ret;
877 }
878 
879 /**
880  * clkdm_wakeup_nolock - force clockdomain wakeup transition (lockless)
881  * @clkdm: struct clockdomain *
882  *
883  * Instruct the CM to force a wakeup transition on the specified
884  * clockdomain @clkdm.  Only for use by the powerdomain code.  Returns
885  * -EINVAL if @clkdm is NULL or if the clockdomain does not support
886  * software-controlled wakeup; 0 upon success.
887  */
888 static int clkdm_wakeup_nolock(struct clockdomain *clkdm)
889 {
890         int ret;
891 
892         if (!clkdm)
893                 return -EINVAL;
894 
895         if (!(clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)) {
896                 pr_debug("clockdomain: %s does not support forcing wakeup via software\n",
897                          clkdm->name);
898                 return -EINVAL;
899         }
900 
901         if (!arch_clkdm || !arch_clkdm->clkdm_wakeup)
902                 return -EINVAL;
903 
904         pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name);
905 
906         clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
907         ret = arch_clkdm->clkdm_wakeup(clkdm);
908         ret |= pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
909 
910         return ret;
911 }
912 
913 /**
914  * clkdm_wakeup - force clockdomain wakeup transition
915  * @clkdm: struct clockdomain *
916  *
917  * Instruct the CM to force a wakeup transition on the specified
918  * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if the
919  * clockdomain does not support software-controlled wakeup; 0 upon
920  * success.
921  */
922 int clkdm_wakeup(struct clockdomain *clkdm)
923 {
924         int ret;
925 
926         pwrdm_lock(clkdm->pwrdm.ptr);
927         ret = clkdm_wakeup_nolock(clkdm);
928         pwrdm_unlock(clkdm->pwrdm.ptr);
929 
930         return ret;
931 }
932 
933 /**
934  * clkdm_allow_idle_nolock - enable hwsup idle transitions for clkdm
935  * @clkdm: struct clockdomain *
936  *
937  * Allow the hardware to automatically switch the clockdomain @clkdm
938  * into active or idle states, as needed by downstream clocks.  If the
939  * clockdomain has any downstream clocks enabled in the clock
940  * framework, wkdep/sleepdep autodependencies are added; this is so
941  * device drivers can read and write to the device.  Only for use by
942  * the powerdomain code.  No return value.
943  */
944 void clkdm_allow_idle_nolock(struct clockdomain *clkdm)
945 {
946         if (!clkdm)
947                 return;
948 
949         if (!WARN_ON(!clkdm->forcewake_count))
950                 clkdm->forcewake_count--;
951 
952         if (clkdm->forcewake_count)
953                 return;
954 
955         if (!clkdm->usecount && (clkdm->flags & CLKDM_CAN_FORCE_SLEEP))
956                 clkdm_sleep_nolock(clkdm);
957 
958         if (!(clkdm->flags & CLKDM_CAN_ENABLE_AUTO))
959                 return;
960 
961         if (clkdm->flags & CLKDM_MISSING_IDLE_REPORTING)
962                 return;
963 
964         if (!arch_clkdm || !arch_clkdm->clkdm_allow_idle)
965                 return;
966 
967         pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
968                  clkdm->name);
969 
970         clkdm->_flags |= _CLKDM_FLAG_HWSUP_ENABLED;
971         arch_clkdm->clkdm_allow_idle(clkdm);
972         pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
973 }
974 
975 /**
976  * clkdm_allow_idle - enable hwsup idle transitions for clkdm
977  * @clkdm: struct clockdomain *
978  *
979  * Allow the hardware to automatically switch the clockdomain @clkdm into
980  * active or idle states, as needed by downstream clocks.  If the
981  * clockdomain has any downstream clocks enabled in the clock
982  * framework, wkdep/sleepdep autodependencies are added; this is so
983  * device drivers can read and write to the device.  No return value.
984  */
985 void clkdm_allow_idle(struct clockdomain *clkdm)
986 {
987         pwrdm_lock(clkdm->pwrdm.ptr);
988         clkdm_allow_idle_nolock(clkdm);
989         pwrdm_unlock(clkdm->pwrdm.ptr);
990 }
991 
992 /**
993  * clkdm_deny_idle_nolock - disable hwsup idle transitions for clkdm
994  * @clkdm: struct clockdomain *
995  *
996  * Prevent the hardware from automatically switching the clockdomain
997  * @clkdm into inactive or idle states.  If the clockdomain has
998  * downstream clocks enabled in the clock framework, wkdep/sleepdep
999  * autodependencies are removed.  Only for use by the powerdomain
1000  * code.  No return value.
1001  */
1002 void clkdm_deny_idle_nolock(struct clockdomain *clkdm)
1003 {
1004         if (!clkdm)
1005                 return;
1006 
1007         if (clkdm->forcewake_count++)
1008                 return;
1009 
1010         if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
1011                 clkdm_wakeup_nolock(clkdm);
1012 
1013         if (!(clkdm->flags & CLKDM_CAN_DISABLE_AUTO))
1014                 return;
1015 
1016         if (clkdm->flags & CLKDM_MISSING_IDLE_REPORTING)
1017                 return;
1018 
1019         if (!arch_clkdm || !arch_clkdm->clkdm_deny_idle)
1020                 return;
1021 
1022         pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
1023                  clkdm->name);
1024 
1025         clkdm->_flags &= ~_CLKDM_FLAG_HWSUP_ENABLED;
1026         arch_clkdm->clkdm_deny_idle(clkdm);
1027         pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
1028 }
1029 
1030 /**
1031  * clkdm_deny_idle - disable hwsup idle transitions for clkdm
1032  * @clkdm: struct clockdomain *
1033  *
1034  * Prevent the hardware from automatically switching the clockdomain
1035  * @clkdm into inactive or idle states.  If the clockdomain has
1036  * downstream clocks enabled in the clock framework, wkdep/sleepdep
1037  * autodependencies are removed.  No return value.
1038  */
1039 void clkdm_deny_idle(struct clockdomain *clkdm)
1040 {
1041         pwrdm_lock(clkdm->pwrdm.ptr);
1042         clkdm_deny_idle_nolock(clkdm);
1043         pwrdm_unlock(clkdm->pwrdm.ptr);
1044 }
1045 
1046 /* Public autodep handling functions (deprecated) */
1047 
1048 /**
1049  * clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable
1050  * @clkdm: struct clockdomain *
1051  *
1052  * Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm'
1053  * in hardware-supervised mode.  Meant to be called from clock framework
1054  * when a clock inside clockdomain 'clkdm' is enabled.  No return value.
1055  *
1056  * XXX autodeps are deprecated and should be removed at the earliest
1057  * opportunity
1058  */
1059 void clkdm_add_autodeps(struct clockdomain *clkdm)
1060 {
1061         struct clkdm_autodep *autodep;
1062 
1063         if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
1064                 return;
1065 
1066         for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
1067                 if (IS_ERR(autodep->clkdm.ptr))
1068                         continue;
1069 
1070                 pr_debug("clockdomain: %s: adding %s sleepdep/wkdep\n",
1071                          clkdm->name, autodep->clkdm.ptr->name);
1072 
1073                 _clkdm_add_sleepdep(clkdm, autodep->clkdm.ptr);
1074                 _clkdm_add_wkdep(clkdm, autodep->clkdm.ptr);
1075         }
1076 }
1077 
1078 /**
1079  * clkdm_del_autodeps - remove auto sleepdeps/wkdeps from clkdm
1080  * @clkdm: struct clockdomain *
1081  *
1082  * Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm'
1083  * in hardware-supervised mode.  Meant to be called from clock framework
1084  * when a clock inside clockdomain 'clkdm' is disabled.  No return value.
1085  *
1086  * XXX autodeps are deprecated and should be removed at the earliest
1087  * opportunity
1088  */
1089 void clkdm_del_autodeps(struct clockdomain *clkdm)
1090 {
1091         struct clkdm_autodep *autodep;
1092 
1093         if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
1094                 return;
1095 
1096         for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
1097                 if (IS_ERR(autodep->clkdm.ptr))
1098                         continue;
1099 
1100                 pr_debug("clockdomain: %s: removing %s sleepdep/wkdep\n",
1101                          clkdm->name, autodep->clkdm.ptr->name);
1102 
1103                 _clkdm_del_sleepdep(clkdm, autodep->clkdm.ptr);
1104                 _clkdm_del_wkdep(clkdm, autodep->clkdm.ptr);
1105         }
1106 }
1107 
1108 /* Clockdomain-to-clock/hwmod framework interface code */
1109 
1110 /**
1111  * clkdm_clk_enable - add an enabled downstream clock to this clkdm
1112  * @clkdm: struct clockdomain *
1113  * @unused: struct clk * of the enabled downstream clock
1114  *
1115  * Increment the usecount of the clockdomain @clkdm and ensure that it
1116  * is awake before @clk is enabled.  Intended to be called by
1117  * clk_enable() code.  If the clockdomain is in software-supervised
1118  * idle mode, force the clockdomain to wake.  If the clockdomain is in
1119  * hardware-supervised idle mode, add clkdm-pwrdm autodependencies, to
1120  * ensure that devices in the clockdomain can be read from/written to
1121  * by on-chip processors.  Returns -EINVAL if passed null pointers;
1122  * returns 0 upon success or if the clockdomain is in hwsup idle mode.
1123  */
1124 int clkdm_clk_enable(struct clockdomain *clkdm, struct clk *unused)
1125 {
1126         if (!clkdm || !arch_clkdm || !arch_clkdm->clkdm_clk_enable)
1127                 return -EINVAL;
1128 
1129         pwrdm_lock(clkdm->pwrdm.ptr);
1130 
1131         /*
1132          * For arch's with no autodeps, clkcm_clk_enable
1133          * should be called for every clock instance or hwmod that is
1134          * enabled, so the clkdm can be force woken up.
1135          */
1136         clkdm->usecount++;
1137         if (clkdm->usecount > 1 && autodeps) {
1138                 pwrdm_unlock(clkdm->pwrdm.ptr);
1139                 return 0;
1140         }
1141 
1142         arch_clkdm->clkdm_clk_enable(clkdm);
1143         pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
1144         pwrdm_unlock(clkdm->pwrdm.ptr);
1145 
1146         pr_debug("clockdomain: %s: enabled\n", clkdm->name);
1147 
1148         return 0;
1149 }
1150 
1151 /**
1152  * clkdm_clk_disable - remove an enabled downstream clock from this clkdm
1153  * @clkdm: struct clockdomain *
1154  * @clk: struct clk * of the disabled downstream clock
1155  *
1156  * Decrement the usecount of this clockdomain @clkdm when @clk is
1157  * disabled.  Intended to be called by clk_disable() code.  If the
1158  * clockdomain usecount goes to 0, put the clockdomain to sleep
1159  * (software-supervised mode) or remove the clkdm autodependencies
1160  * (hardware-supervised mode).  Returns -EINVAL if passed null
1161  * pointers; -ERANGE if the @clkdm usecount underflows; or returns 0
1162  * upon success or if the clockdomain is in hwsup idle mode.
1163  */
1164 int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
1165 {
1166         if (!clkdm || !arch_clkdm || !arch_clkdm->clkdm_clk_disable)
1167                 return -EINVAL;
1168 
1169         pwrdm_lock(clkdm->pwrdm.ptr);
1170 
1171         /* corner case: disabling unused clocks */
1172         if (clk && (__clk_get_enable_count(clk) == 0) && clkdm->usecount == 0)
1173                 goto ccd_exit;
1174 
1175         if (clkdm->usecount == 0) {
1176                 pwrdm_unlock(clkdm->pwrdm.ptr);
1177                 WARN_ON(1); /* underflow */
1178                 return -ERANGE;
1179         }
1180 
1181         clkdm->usecount--;
1182         if (clkdm->usecount > 0) {
1183                 pwrdm_unlock(clkdm->pwrdm.ptr);
1184                 return 0;
1185         }
1186 
1187         arch_clkdm->clkdm_clk_disable(clkdm);
1188         pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
1189 
1190         pr_debug("clockdomain: %s: disabled\n", clkdm->name);
1191 
1192 ccd_exit:
1193         pwrdm_unlock(clkdm->pwrdm.ptr);
1194 
1195         return 0;
1196 }
1197 
1198 /**
1199  * clkdm_hwmod_enable - add an enabled downstream hwmod to this clkdm
1200  * @clkdm: struct clockdomain *
1201  * @oh: struct omap_hwmod * of the enabled downstream hwmod
1202  *
1203  * Increment the usecount of the clockdomain @clkdm and ensure that it
1204  * is awake before @oh is enabled. Intended to be called by
1205  * module_enable() code.
1206  * If the clockdomain is in software-supervised idle mode, force the
1207  * clockdomain to wake.  If the clockdomain is in hardware-supervised idle
1208  * mode, add clkdm-pwrdm autodependencies, to ensure that devices in the
1209  * clockdomain can be read from/written to by on-chip processors.
1210  * Returns -EINVAL if passed null pointers;
1211  * returns 0 upon success or if the clockdomain is in hwsup idle mode.
1212  */
1213 int clkdm_hwmod_enable(struct clockdomain *clkdm, struct omap_hwmod *oh)
1214 {
1215         /* The clkdm attribute does not exist yet prior OMAP4 */
1216         if (cpu_is_omap24xx() || cpu_is_omap34xx())
1217                 return 0;
1218 
1219         /*
1220          * XXX Rewrite this code to maintain a list of enabled
1221          * downstream hwmods for debugging purposes?
1222          */
1223 
1224         if (!oh)
1225                 return -EINVAL;
1226 
1227         return clkdm_clk_enable(clkdm, NULL);
1228 }
1229 
1230 /**
1231  * clkdm_hwmod_disable - remove an enabled downstream hwmod from this clkdm
1232  * @clkdm: struct clockdomain *
1233  * @oh: struct omap_hwmod * of the disabled downstream hwmod
1234  *
1235  * Decrement the usecount of this clockdomain @clkdm when @oh is
1236  * disabled. Intended to be called by module_disable() code.
1237  * If the clockdomain usecount goes to 0, put the clockdomain to sleep
1238  * (software-supervised mode) or remove the clkdm autodependencies
1239  * (hardware-supervised mode).
1240  * Returns -EINVAL if passed null pointers; -ERANGE if the @clkdm usecount
1241  * underflows; or returns 0 upon success or if the clockdomain is in hwsup
1242  * idle mode.
1243  */
1244 int clkdm_hwmod_disable(struct clockdomain *clkdm, struct omap_hwmod *oh)
1245 {
1246         /* The clkdm attribute does not exist yet prior OMAP4 */
1247         if (cpu_is_omap24xx() || cpu_is_omap34xx())
1248                 return 0;
1249 
1250         if (!oh)
1251                 return -EINVAL;
1252 
1253         return clkdm_clk_disable(clkdm, NULL);
1254 }
1255 
1256 /**
1257  * _clkdm_save_context - save the context for the control of this clkdm
1258  *
1259  * Due to a suspend or hibernation operation, the state of the registers
1260  * controlling this clkdm will be lost, save their context.
1261  */
1262 static int _clkdm_save_context(struct clockdomain *clkdm, void *unused)
1263 {
1264         if (!arch_clkdm || !arch_clkdm->clkdm_save_context)
1265                 return -EINVAL;
1266 
1267         return arch_clkdm->clkdm_save_context(clkdm);
1268 }
1269 
1270 /**
1271  * _clkdm_restore_context - restore context for control of this clkdm
1272  *
1273  * Restore the register values for this clockdomain.
1274  */
1275 static int _clkdm_restore_context(struct clockdomain *clkdm, void *unused)
1276 {
1277         if (!arch_clkdm || !arch_clkdm->clkdm_restore_context)
1278                 return -EINVAL;
1279 
1280         return arch_clkdm->clkdm_restore_context(clkdm);
1281 }
1282 
1283 /**
1284  * clkdm_save_context - Saves the context for each registered clkdm
1285  *
1286  * Save the context for each registered clockdomain.
1287  */
1288 void clkdm_save_context(void)
1289 {
1290         clkdm_for_each(_clkdm_save_context, NULL);
1291 }
1292 
1293 /**
1294  * clkdm_restore_context - Restores the context for each registered clkdm
1295  *
1296  * Restore the context for each registered clockdomain.
1297  */
1298 void clkdm_restore_context(void)
1299 {
1300         clkdm_for_each(_clkdm_restore_context, NULL);
1301 }
1302 

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