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 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 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 - 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 /**
1047 * clkdm_in_hwsup - is clockdomain @clkdm have hardware-supervised idle enabled?
1048 * @clkdm: struct clockdomain *
1049 *
1050 * Returns true if clockdomain @clkdm currently has
1051 * hardware-supervised idle enabled, or false if it does not or if
1052 * @clkdm is NULL. It is only valid to call this function after
1053 * clkdm_init() has been called. This function does not actually read
1054 * bits from the hardware; it instead tests an in-memory flag that is
1055 * changed whenever the clockdomain code changes the auto-idle mode.
1056 */
1057 bool clkdm_in_hwsup(struct clockdomain *clkdm)
1058 {
1059 bool ret;
1060
1061 if (!clkdm)
1062 return false;
1063
1064 ret = (clkdm->_flags & _CLKDM_FLAG_HWSUP_ENABLED) ? true : false;
1065
1066 return ret;
1067 }
1068
1069 /**
1070 * clkdm_missing_idle_reporting - can @clkdm enter autoidle even if in use?
1071 * @clkdm: struct clockdomain *
1072 *
1073 * Returns true if clockdomain @clkdm has the
1074 * CLKDM_MISSING_IDLE_REPORTING flag set, or false if not or @clkdm is
1075 * null. More information is available in the documentation for the
1076 * CLKDM_MISSING_IDLE_REPORTING macro.
1077 */
1078 bool clkdm_missing_idle_reporting(struct clockdomain *clkdm)
1079 {
1080 if (!clkdm)
1081 return false;
1082
1083 return (clkdm->flags & CLKDM_MISSING_IDLE_REPORTING) ? true : false;
1084 }
1085
1086 /* Public autodep handling functions (deprecated) */
1087
1088 /**
1089 * clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable
1090 * @clkdm: struct clockdomain *
1091 *
1092 * Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm'
1093 * in hardware-supervised mode. Meant to be called from clock framework
1094 * when a clock inside clockdomain 'clkdm' is enabled. No return value.
1095 *
1096 * XXX autodeps are deprecated and should be removed at the earliest
1097 * opportunity
1098 */
1099 void clkdm_add_autodeps(struct clockdomain *clkdm)
1100 {
1101 struct clkdm_autodep *autodep;
1102
1103 if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
1104 return;
1105
1106 for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
1107 if (IS_ERR(autodep->clkdm.ptr))
1108 continue;
1109
1110 pr_debug("clockdomain: %s: adding %s sleepdep/wkdep\n",
1111 clkdm->name, autodep->clkdm.ptr->name);
1112
1113 _clkdm_add_sleepdep(clkdm, autodep->clkdm.ptr);
1114 _clkdm_add_wkdep(clkdm, autodep->clkdm.ptr);
1115 }
1116 }
1117
1118 /**
1119 * clkdm_del_autodeps - remove auto sleepdeps/wkdeps from clkdm
1120 * @clkdm: struct clockdomain *
1121 *
1122 * Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm'
1123 * in hardware-supervised mode. Meant to be called from clock framework
1124 * when a clock inside clockdomain 'clkdm' is disabled. No return value.
1125 *
1126 * XXX autodeps are deprecated and should be removed at the earliest
1127 * opportunity
1128 */
1129 void clkdm_del_autodeps(struct clockdomain *clkdm)
1130 {
1131 struct clkdm_autodep *autodep;
1132
1133 if (!autodeps || clkdm->flags & CLKDM_NO_AUTODEPS)
1134 return;
1135
1136 for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
1137 if (IS_ERR(autodep->clkdm.ptr))
1138 continue;
1139
1140 pr_debug("clockdomain: %s: removing %s sleepdep/wkdep\n",
1141 clkdm->name, autodep->clkdm.ptr->name);
1142
1143 _clkdm_del_sleepdep(clkdm, autodep->clkdm.ptr);
1144 _clkdm_del_wkdep(clkdm, autodep->clkdm.ptr);
1145 }
1146 }
1147
1148 /* Clockdomain-to-clock/hwmod framework interface code */
1149
1150 static int _clkdm_clk_hwmod_enable(struct clockdomain *clkdm)
1151 {
1152 if (!clkdm || !arch_clkdm || !arch_clkdm->clkdm_clk_enable)
1153 return -EINVAL;
1154
1155 pwrdm_lock(clkdm->pwrdm.ptr);
1156
1157 /*
1158 * For arch's with no autodeps, clkcm_clk_enable
1159 * should be called for every clock instance or hwmod that is
1160 * enabled, so the clkdm can be force woken up.
1161 */
1162 clkdm->usecount++;
1163 if (clkdm->usecount > 1 && autodeps) {
1164 pwrdm_unlock(clkdm->pwrdm.ptr);
1165 return 0;
1166 }
1167
1168 arch_clkdm->clkdm_clk_enable(clkdm);
1169 pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
1170 pwrdm_unlock(clkdm->pwrdm.ptr);
1171
1172 pr_debug("clockdomain: %s: enabled\n", clkdm->name);
1173
1174 return 0;
1175 }
1176
1177 /**
1178 * clkdm_clk_enable - add an enabled downstream clock to this clkdm
1179 * @clkdm: struct clockdomain *
1180 * @clk: struct clk * of the enabled downstream clock
1181 *
1182 * Increment the usecount of the clockdomain @clkdm and ensure that it
1183 * is awake before @clk is enabled. Intended to be called by
1184 * clk_enable() code. If the clockdomain is in software-supervised
1185 * idle mode, force the clockdomain to wake. If the clockdomain is in
1186 * hardware-supervised idle mode, add clkdm-pwrdm autodependencies, to
1187 * ensure that devices in the clockdomain can be read from/written to
1188 * by on-chip processors. Returns -EINVAL if passed null pointers;
1189 * returns 0 upon success or if the clockdomain is in hwsup idle mode.
1190 */
1191 int clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
1192 {
1193 /*
1194 * XXX Rewrite this code to maintain a list of enabled
1195 * downstream clocks for debugging purposes?
1196 */
1197
1198 if (!clk)
1199 return -EINVAL;
1200
1201 return _clkdm_clk_hwmod_enable(clkdm);
1202 }
1203
1204 /**
1205 * clkdm_clk_disable - remove an enabled downstream clock from this clkdm
1206 * @clkdm: struct clockdomain *
1207 * @clk: struct clk * of the disabled downstream clock
1208 *
1209 * Decrement the usecount of this clockdomain @clkdm when @clk is
1210 * disabled. Intended to be called by clk_disable() code. If the
1211 * clockdomain usecount goes to 0, put the clockdomain to sleep
1212 * (software-supervised mode) or remove the clkdm autodependencies
1213 * (hardware-supervised mode). Returns -EINVAL if passed null
1214 * pointers; -ERANGE if the @clkdm usecount underflows; or returns 0
1215 * upon success or if the clockdomain is in hwsup idle mode.
1216 */
1217 int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
1218 {
1219 if (!clkdm || !clk || !arch_clkdm || !arch_clkdm->clkdm_clk_disable)
1220 return -EINVAL;
1221
1222 pwrdm_lock(clkdm->pwrdm.ptr);
1223
1224 /* corner case: disabling unused clocks */
1225 if ((__clk_get_enable_count(clk) == 0) && clkdm->usecount == 0)
1226 goto ccd_exit;
1227
1228 if (clkdm->usecount == 0) {
1229 pwrdm_unlock(clkdm->pwrdm.ptr);
1230 WARN_ON(1); /* underflow */
1231 return -ERANGE;
1232 }
1233
1234 clkdm->usecount--;
1235 if (clkdm->usecount > 0) {
1236 pwrdm_unlock(clkdm->pwrdm.ptr);
1237 return 0;
1238 }
1239
1240 arch_clkdm->clkdm_clk_disable(clkdm);
1241 pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
1242
1243 pr_debug("clockdomain: %s: disabled\n", clkdm->name);
1244
1245 ccd_exit:
1246 pwrdm_unlock(clkdm->pwrdm.ptr);
1247
1248 return 0;
1249 }
1250
1251 /**
1252 * clkdm_hwmod_enable - add an enabled downstream hwmod to this clkdm
1253 * @clkdm: struct clockdomain *
1254 * @oh: struct omap_hwmod * of the enabled downstream hwmod
1255 *
1256 * Increment the usecount of the clockdomain @clkdm and ensure that it
1257 * is awake before @oh is enabled. Intended to be called by
1258 * module_enable() code.
1259 * If the clockdomain is in software-supervised idle mode, force the
1260 * clockdomain to wake. If the clockdomain is in hardware-supervised idle
1261 * mode, add clkdm-pwrdm autodependencies, to ensure that devices in the
1262 * clockdomain can be read from/written to by on-chip processors.
1263 * Returns -EINVAL if passed null pointers;
1264 * returns 0 upon success or if the clockdomain is in hwsup idle mode.
1265 */
1266 int clkdm_hwmod_enable(struct clockdomain *clkdm, struct omap_hwmod *oh)
1267 {
1268 /* The clkdm attribute does not exist yet prior OMAP4 */
1269 if (cpu_is_omap24xx() || cpu_is_omap34xx())
1270 return 0;
1271
1272 /*
1273 * XXX Rewrite this code to maintain a list of enabled
1274 * downstream hwmods for debugging purposes?
1275 */
1276
1277 if (!oh)
1278 return -EINVAL;
1279
1280 return _clkdm_clk_hwmod_enable(clkdm);
1281 }
1282
1283 /**
1284 * clkdm_hwmod_disable - remove an enabled downstream hwmod from this clkdm
1285 * @clkdm: struct clockdomain *
1286 * @oh: struct omap_hwmod * of the disabled downstream hwmod
1287 *
1288 * Decrement the usecount of this clockdomain @clkdm when @oh is
1289 * disabled. Intended to be called by module_disable() code.
1290 * If the clockdomain usecount goes to 0, put the clockdomain to sleep
1291 * (software-supervised mode) or remove the clkdm autodependencies
1292 * (hardware-supervised mode).
1293 * Returns -EINVAL if passed null pointers; -ERANGE if the @clkdm usecount
1294 * underflows; or returns 0 upon success or if the clockdomain is in hwsup
1295 * idle mode.
1296 */
1297 int clkdm_hwmod_disable(struct clockdomain *clkdm, struct omap_hwmod *oh)
1298 {
1299 /* The clkdm attribute does not exist yet prior OMAP4 */
1300 if (cpu_is_omap24xx() || cpu_is_omap34xx())
1301 return 0;
1302
1303 /*
1304 * XXX Rewrite this code to maintain a list of enabled
1305 * downstream hwmods for debugging purposes?
1306 */
1307
1308 if (!clkdm || !oh || !arch_clkdm || !arch_clkdm->clkdm_clk_disable)
1309 return -EINVAL;
1310
1311 pwrdm_lock(clkdm->pwrdm.ptr);
1312
1313 if (clkdm->usecount == 0) {
1314 pwrdm_unlock(clkdm->pwrdm.ptr);
1315 WARN_ON(1); /* underflow */
1316 return -ERANGE;
1317 }
1318
1319 clkdm->usecount--;
1320 if (clkdm->usecount > 0) {
1321 pwrdm_unlock(clkdm->pwrdm.ptr);
1322 return 0;
1323 }
1324
1325 arch_clkdm->clkdm_clk_disable(clkdm);
1326 pwrdm_state_switch_nolock(clkdm->pwrdm.ptr);
1327 pwrdm_unlock(clkdm->pwrdm.ptr);
1328
1329 pr_debug("clockdomain: %s: disabled\n", clkdm->name);
1330
1331 return 0;
1332 }
1333
1334 /**
1335 * _clkdm_save_context - save the context for the control of this clkdm
1336 *
1337 * Due to a suspend or hibernation operation, the state of the registers
1338 * controlling this clkdm will be lost, save their context.
1339 */
1340 static int _clkdm_save_context(struct clockdomain *clkdm, void *ununsed)
1341 {
1342 if (!arch_clkdm || !arch_clkdm->clkdm_save_context)
1343 return -EINVAL;
1344
1345 return arch_clkdm->clkdm_save_context(clkdm);
1346 }
1347
1348 /**
1349 * _clkdm_restore_context - restore context for control of this clkdm
1350 *
1351 * Restore the register values for this clockdomain.
1352 */
1353 static int _clkdm_restore_context(struct clockdomain *clkdm, void *ununsed)
1354 {
1355 if (!arch_clkdm || !arch_clkdm->clkdm_restore_context)
1356 return -EINVAL;
1357
1358 return arch_clkdm->clkdm_restore_context(clkdm);
1359 }
1360
1361 /**
1362 * clkdm_save_context - Saves the context for each registered clkdm
1363 *
1364 * Save the context for each registered clockdomain.
1365 */
1366 void clkdm_save_context(void)
1367 {
1368 clkdm_for_each(_clkdm_save_context, NULL);
1369 }
1370
1371 /**
1372 * clkdm_restore_context - Restores the context for each registered clkdm
1373 *
1374 * Restore the context for each registered clockdomain.
1375 */
1376 void clkdm_restore_context(void)
1377 {
1378 clkdm_for_each(_clkdm_restore_context, NULL);
1379 }