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