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Paul Walmsleyd459bfe2008-08-19 11:08:43 +03001/*
2 * OMAP2/3 clockdomain framework functions
3 *
4 * Copyright (C) 2008 Texas Instruments, Inc.
5 * Copyright (C) 2008 Nokia Corporation
6 *
7 * Written by Paul Walmsley and Jouni Högander
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13#ifdef CONFIG_OMAP_DEBUG_CLOCKDOMAIN
14# define DEBUG
15#endif
16
17#include <linux/module.h>
18#include <linux/kernel.h>
19#include <linux/device.h>
20#include <linux/list.h>
21#include <linux/errno.h>
22#include <linux/delay.h>
23#include <linux/clk.h>
24#include <linux/limits.h>
Paul Walmsley5b74c672009-02-03 02:10:03 -070025#include <linux/err.h>
Paul Walmsleyd459bfe2008-08-19 11:08:43 +030026
27#include <linux/io.h>
28
29#include <linux/bitops.h>
30
31#include <mach/clock.h>
32
33#include "prm.h"
34#include "prm-regbits-24xx.h"
35#include "cm.h"
36
37#include <mach/powerdomain.h>
38#include <mach/clockdomain.h>
39
40/* clkdm_list contains all registered struct clockdomains */
41static LIST_HEAD(clkdm_list);
42
43/* clkdm_mutex protects clkdm_list add and del ops */
44static DEFINE_MUTEX(clkdm_mutex);
45
46/* array of powerdomain deps to be added/removed when clkdm in hwsup mode */
47static struct clkdm_pwrdm_autodep *autodeps;
48
49
50/* Private functions */
51
52/*
53 * _autodep_lookup - resolve autodep pwrdm names to pwrdm pointers; store
54 * @autodep: struct clkdm_pwrdm_autodep * to resolve
55 *
56 * Resolve autodep powerdomain names to powerdomain pointers via
57 * pwrdm_lookup() and store the pointers in the autodep structure. An
58 * "autodep" is a powerdomain sleep/wakeup dependency that is
59 * automatically added and removed whenever clocks in the associated
60 * clockdomain are enabled or disabled (respectively) when the
61 * clockdomain is in hardware-supervised mode. Meant to be called
62 * once at clockdomain layer initialization, since these should remain
63 * fixed for a particular architecture. No return value.
64 */
65static void _autodep_lookup(struct clkdm_pwrdm_autodep *autodep)
66{
67 struct powerdomain *pwrdm;
68
69 if (!autodep)
70 return;
71
72 if (!omap_chip_is(autodep->omap_chip))
73 return;
74
Paul Walmsley5b74c672009-02-03 02:10:03 -070075 pwrdm = pwrdm_lookup(autodep->pwrdm.name);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +030076 if (!pwrdm) {
Russell King7aec53a2009-02-22 21:00:55 +000077 pr_err("clockdomain: autodeps: powerdomain %s does not exist\n",
78 autodep->pwrdm.name);
Paul Walmsley5b74c672009-02-03 02:10:03 -070079 pwrdm = ERR_PTR(-ENOENT);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +030080 }
Paul Walmsley5b74c672009-02-03 02:10:03 -070081 autodep->pwrdm.ptr = pwrdm;
Paul Walmsleyd459bfe2008-08-19 11:08:43 +030082}
83
84/*
85 * _clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable
86 * @clkdm: struct clockdomain *
87 *
88 * Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm'
89 * in hardware-supervised mode. Meant to be called from clock framework
90 * when a clock inside clockdomain 'clkdm' is enabled. No return value.
91 */
92static void _clkdm_add_autodeps(struct clockdomain *clkdm)
93{
94 struct clkdm_pwrdm_autodep *autodep;
95
Paul Walmsley5b74c672009-02-03 02:10:03 -070096 for (autodep = autodeps; autodep->pwrdm.ptr; autodep++) {
97 if (IS_ERR(autodep->pwrdm.ptr))
Paul Walmsleyd459bfe2008-08-19 11:08:43 +030098 continue;
99
Paul Walmsleyd96df002009-01-27 19:44:35 -0700100 if (!omap_chip_is(autodep->omap_chip))
101 continue;
102
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300103 pr_debug("clockdomain: adding %s sleepdep/wkdep for "
Paul Walmsley5b74c672009-02-03 02:10:03 -0700104 "pwrdm %s\n", autodep->pwrdm.ptr->name,
105 clkdm->pwrdm.ptr->name);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300106
Paul Walmsley5b74c672009-02-03 02:10:03 -0700107 pwrdm_add_sleepdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
108 pwrdm_add_wkdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300109 }
110}
111
112/*
113 * _clkdm_add_autodeps - remove auto sleepdeps/wkdeps from clkdm
114 * @clkdm: struct clockdomain *
115 *
116 * Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm'
117 * in hardware-supervised mode. Meant to be called from clock framework
118 * when a clock inside clockdomain 'clkdm' is disabled. No return value.
119 */
120static void _clkdm_del_autodeps(struct clockdomain *clkdm)
121{
122 struct clkdm_pwrdm_autodep *autodep;
123
Paul Walmsley5b74c672009-02-03 02:10:03 -0700124 for (autodep = autodeps; autodep->pwrdm.ptr; autodep++) {
125 if (IS_ERR(autodep->pwrdm.ptr))
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300126 continue;
127
Paul Walmsleyd96df002009-01-27 19:44:35 -0700128 if (!omap_chip_is(autodep->omap_chip))
129 continue;
130
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300131 pr_debug("clockdomain: removing %s sleepdep/wkdep for "
Paul Walmsley5b74c672009-02-03 02:10:03 -0700132 "pwrdm %s\n", autodep->pwrdm.ptr->name,
133 clkdm->pwrdm.ptr->name);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300134
Paul Walmsley5b74c672009-02-03 02:10:03 -0700135 pwrdm_del_sleepdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
136 pwrdm_del_wkdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300137 }
138}
139
140
141static struct clockdomain *_clkdm_lookup(const char *name)
142{
143 struct clockdomain *clkdm, *temp_clkdm;
144
145 if (!name)
146 return NULL;
147
148 clkdm = NULL;
149
150 list_for_each_entry(temp_clkdm, &clkdm_list, node) {
151 if (!strcmp(name, temp_clkdm->name)) {
152 clkdm = temp_clkdm;
153 break;
154 }
155 }
156
157 return clkdm;
158}
159
160
161/* Public functions */
162
163/**
164 * clkdm_init - set up the clockdomain layer
165 * @clkdms: optional pointer to an array of clockdomains to register
166 * @init_autodeps: optional pointer to an array of autodeps to register
167 *
168 * Set up internal state. If a pointer to an array of clockdomains
169 * was supplied, loop through the list of clockdomains, register all
170 * that are available on the current platform. Similarly, if a
171 * pointer to an array of clockdomain-powerdomain autodependencies was
172 * provided, register those. No return value.
173 */
174void clkdm_init(struct clockdomain **clkdms,
175 struct clkdm_pwrdm_autodep *init_autodeps)
176{
177 struct clockdomain **c = NULL;
178 struct clkdm_pwrdm_autodep *autodep = NULL;
179
180 if (clkdms)
181 for (c = clkdms; *c; c++)
182 clkdm_register(*c);
183
184 autodeps = init_autodeps;
185 if (autodeps)
Paul Walmsley5b74c672009-02-03 02:10:03 -0700186 for (autodep = autodeps; autodep->pwrdm.ptr; autodep++)
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300187 _autodep_lookup(autodep);
188}
189
190/**
191 * clkdm_register - register a clockdomain
192 * @clkdm: struct clockdomain * to register
193 *
194 * Adds a clockdomain to the internal clockdomain list.
195 * Returns -EINVAL if given a null pointer, -EEXIST if a clockdomain is
196 * already registered by the provided name, or 0 upon success.
197 */
198int clkdm_register(struct clockdomain *clkdm)
199{
200 int ret = -EINVAL;
201 struct powerdomain *pwrdm;
202
203 if (!clkdm || !clkdm->name)
204 return -EINVAL;
205
206 if (!omap_chip_is(clkdm->omap_chip))
207 return -EINVAL;
208
Paul Walmsley5b74c672009-02-03 02:10:03 -0700209 pwrdm = pwrdm_lookup(clkdm->pwrdm.name);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300210 if (!pwrdm) {
Russell King7aec53a2009-02-22 21:00:55 +0000211 pr_err("clockdomain: %s: powerdomain %s does not exist\n",
212 clkdm->name, clkdm->pwrdm.name);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300213 return -EINVAL;
214 }
Paul Walmsley5b74c672009-02-03 02:10:03 -0700215 clkdm->pwrdm.ptr = pwrdm;
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300216
217 mutex_lock(&clkdm_mutex);
218 /* Verify that the clockdomain is not already registered */
219 if (_clkdm_lookup(clkdm->name)) {
220 ret = -EEXIST;
221 goto cr_unlock;
Russell King7aec53a2009-02-22 21:00:55 +0000222 }
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300223
224 list_add(&clkdm->node, &clkdm_list);
225
Paul Walmsley8420bb12008-08-19 11:08:44 +0300226 pwrdm_add_clkdm(pwrdm, clkdm);
227
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300228 pr_debug("clockdomain: registered %s\n", clkdm->name);
229 ret = 0;
230
231cr_unlock:
232 mutex_unlock(&clkdm_mutex);
233
234 return ret;
235}
236
237/**
238 * clkdm_unregister - unregister a clockdomain
239 * @clkdm: struct clockdomain * to unregister
240 *
241 * Removes a clockdomain from the internal clockdomain list. Returns
242 * -EINVAL if clkdm argument is NULL.
243 */
244int clkdm_unregister(struct clockdomain *clkdm)
245{
246 if (!clkdm)
247 return -EINVAL;
248
Paul Walmsley5b74c672009-02-03 02:10:03 -0700249 pwrdm_del_clkdm(clkdm->pwrdm.ptr, clkdm);
Paul Walmsley8420bb12008-08-19 11:08:44 +0300250
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300251 mutex_lock(&clkdm_mutex);
252 list_del(&clkdm->node);
253 mutex_unlock(&clkdm_mutex);
254
255 pr_debug("clockdomain: unregistered %s\n", clkdm->name);
256
257 return 0;
258}
259
260/**
261 * clkdm_lookup - look up a clockdomain by name, return a pointer
262 * @name: name of clockdomain
263 *
264 * Find a registered clockdomain by its name. Returns a pointer to the
265 * struct clockdomain if found, or NULL otherwise.
266 */
267struct clockdomain *clkdm_lookup(const char *name)
268{
269 struct clockdomain *clkdm, *temp_clkdm;
270
271 if (!name)
272 return NULL;
273
274 clkdm = NULL;
275
276 mutex_lock(&clkdm_mutex);
277 list_for_each_entry(temp_clkdm, &clkdm_list, node) {
278 if (!strcmp(name, temp_clkdm->name)) {
279 clkdm = temp_clkdm;
280 break;
281 }
282 }
283 mutex_unlock(&clkdm_mutex);
284
285 return clkdm;
286}
287
288/**
289 * clkdm_for_each - call function on each registered clockdomain
290 * @fn: callback function *
291 *
292 * Call the supplied function for each registered clockdomain.
293 * The callback function can return anything but 0 to bail
294 * out early from the iterator. The callback function is called with
295 * the clkdm_mutex held, so no clockdomain structure manipulation
296 * functions should be called from the callback, although hardware
297 * clockdomain control functions are fine. Returns the last return
298 * value of the callback function, which should be 0 for success or
299 * anything else to indicate failure; or -EINVAL if the function pointer
300 * is null.
301 */
302int clkdm_for_each(int (*fn)(struct clockdomain *clkdm))
303{
304 struct clockdomain *clkdm;
305 int ret = 0;
306
307 if (!fn)
308 return -EINVAL;
309
310 mutex_lock(&clkdm_mutex);
311 list_for_each_entry(clkdm, &clkdm_list, node) {
312 ret = (*fn)(clkdm);
313 if (ret)
314 break;
315 }
316 mutex_unlock(&clkdm_mutex);
317
318 return ret;
319}
320
321
Paul Walmsleye89087c2008-05-20 18:41:35 -0600322/**
323 * clkdm_get_pwrdm - return a ptr to the pwrdm that this clkdm resides in
324 * @clkdm: struct clockdomain *
325 *
326 * Return a pointer to the struct powerdomain that the specified clockdomain
327 * 'clkdm' exists in, or returns NULL if clkdm argument is NULL.
328 */
329struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
330{
331 if (!clkdm)
332 return NULL;
333
Paul Walmsley5b74c672009-02-03 02:10:03 -0700334 return clkdm->pwrdm.ptr;
Paul Walmsleye89087c2008-05-20 18:41:35 -0600335}
336
337
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300338/* Hardware clockdomain control */
339
340/**
341 * omap2_clkdm_clktrctrl_read - read the clkdm's current state transition mode
342 * @clk: struct clk * of a clockdomain
343 *
344 * Return the clockdomain's current state transition mode from the
345 * corresponding domain CM_CLKSTCTRL register. Returns -EINVAL if clk
346 * is NULL or the current mode upon success.
347 */
348static int omap2_clkdm_clktrctrl_read(struct clockdomain *clkdm)
349{
350 u32 v;
351
352 if (!clkdm)
353 return -EINVAL;
354
Paul Walmsley5b74c672009-02-03 02:10:03 -0700355 v = cm_read_mod_reg(clkdm->pwrdm.ptr->prcm_offs, CM_CLKSTCTRL);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300356 v &= clkdm->clktrctrl_mask;
357 v >>= __ffs(clkdm->clktrctrl_mask);
358
359 return v;
360}
361
362/**
363 * omap2_clkdm_sleep - force clockdomain sleep transition
364 * @clkdm: struct clockdomain *
365 *
366 * Instruct the CM to force a sleep transition on the specified
367 * clockdomain 'clkdm'. Returns -EINVAL if clk is NULL or if
368 * clockdomain does not support software-initiated sleep; 0 upon
369 * success.
370 */
371int omap2_clkdm_sleep(struct clockdomain *clkdm)
372{
373 if (!clkdm)
374 return -EINVAL;
375
376 if (!(clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) {
377 pr_debug("clockdomain: %s does not support forcing "
378 "sleep via software\n", clkdm->name);
379 return -EINVAL;
380 }
381
382 pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name);
383
384 if (cpu_is_omap24xx()) {
385
386 cm_set_mod_reg_bits(OMAP24XX_FORCESTATE,
Paul Walmsley5b74c672009-02-03 02:10:03 -0700387 clkdm->pwrdm.ptr->prcm_offs, PM_PWSTCTRL);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300388
389 } else if (cpu_is_omap34xx()) {
390
391 u32 v = (OMAP34XX_CLKSTCTRL_FORCE_SLEEP <<
392 __ffs(clkdm->clktrctrl_mask));
393
394 cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask, v,
Paul Walmsley5b74c672009-02-03 02:10:03 -0700395 clkdm->pwrdm.ptr->prcm_offs, CM_CLKSTCTRL);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300396
397 } else {
398 BUG();
399 };
400
401 return 0;
402}
403
404/**
405 * omap2_clkdm_wakeup - force clockdomain wakeup transition
406 * @clkdm: struct clockdomain *
407 *
408 * Instruct the CM to force a wakeup transition on the specified
409 * clockdomain 'clkdm'. Returns -EINVAL if clkdm is NULL or if the
410 * clockdomain does not support software-controlled wakeup; 0 upon
411 * success.
412 */
413int omap2_clkdm_wakeup(struct clockdomain *clkdm)
414{
415 if (!clkdm)
416 return -EINVAL;
417
418 if (!(clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)) {
419 pr_debug("clockdomain: %s does not support forcing "
420 "wakeup via software\n", clkdm->name);
421 return -EINVAL;
422 }
423
424 pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name);
425
426 if (cpu_is_omap24xx()) {
427
428 cm_clear_mod_reg_bits(OMAP24XX_FORCESTATE,
Paul Walmsley5b74c672009-02-03 02:10:03 -0700429 clkdm->pwrdm.ptr->prcm_offs, PM_PWSTCTRL);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300430
431 } else if (cpu_is_omap34xx()) {
432
433 u32 v = (OMAP34XX_CLKSTCTRL_FORCE_WAKEUP <<
434 __ffs(clkdm->clktrctrl_mask));
435
436 cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask, v,
Paul Walmsley5b74c672009-02-03 02:10:03 -0700437 clkdm->pwrdm.ptr->prcm_offs, CM_CLKSTCTRL);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300438
439 } else {
440 BUG();
441 };
442
443 return 0;
444}
445
446/**
447 * omap2_clkdm_allow_idle - enable hwsup idle transitions for clkdm
448 * @clkdm: struct clockdomain *
449 *
450 * Allow the hardware to automatically switch the clockdomain into
451 * active or idle states, as needed by downstream clocks. If the
452 * clockdomain has any downstream clocks enabled in the clock
453 * framework, wkdep/sleepdep autodependencies are added; this is so
454 * device drivers can read and write to the device. No return value.
455 */
456void omap2_clkdm_allow_idle(struct clockdomain *clkdm)
457{
458 u32 v;
459
460 if (!clkdm)
461 return;
462
463 if (!(clkdm->flags & CLKDM_CAN_ENABLE_AUTO)) {
464 pr_debug("clock: automatic idle transitions cannot be enabled "
465 "on clockdomain %s\n", clkdm->name);
466 return;
467 }
468
469 pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
470 clkdm->name);
471
472 if (atomic_read(&clkdm->usecount) > 0)
473 _clkdm_add_autodeps(clkdm);
474
475 if (cpu_is_omap24xx())
476 v = OMAP24XX_CLKSTCTRL_ENABLE_AUTO;
477 else if (cpu_is_omap34xx())
478 v = OMAP34XX_CLKSTCTRL_ENABLE_AUTO;
479 else
480 BUG();
481
482
483 cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask,
484 v << __ffs(clkdm->clktrctrl_mask),
Paul Walmsley5b74c672009-02-03 02:10:03 -0700485 clkdm->pwrdm.ptr->prcm_offs,
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300486 CM_CLKSTCTRL);
Peter 'p2' De Schrijverba20bb12008-10-15 17:48:43 +0300487
488 pwrdm_clkdm_state_switch(clkdm);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300489}
490
491/**
492 * omap2_clkdm_deny_idle - disable hwsup idle transitions for clkdm
493 * @clkdm: struct clockdomain *
494 *
495 * Prevent the hardware from automatically switching the clockdomain
496 * into inactive or idle states. If the clockdomain has downstream
497 * clocks enabled in the clock framework, wkdep/sleepdep
498 * autodependencies are removed. No return value.
499 */
500void omap2_clkdm_deny_idle(struct clockdomain *clkdm)
501{
502 u32 v;
503
504 if (!clkdm)
505 return;
506
507 if (!(clkdm->flags & CLKDM_CAN_DISABLE_AUTO)) {
508 pr_debug("clockdomain: automatic idle transitions cannot be "
509 "disabled on %s\n", clkdm->name);
510 return;
511 }
512
513 pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
514 clkdm->name);
515
516 if (cpu_is_omap24xx())
517 v = OMAP24XX_CLKSTCTRL_DISABLE_AUTO;
518 else if (cpu_is_omap34xx())
519 v = OMAP34XX_CLKSTCTRL_DISABLE_AUTO;
520 else
521 BUG();
522
523 cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask,
524 v << __ffs(clkdm->clktrctrl_mask),
Paul Walmsley5b74c672009-02-03 02:10:03 -0700525 clkdm->pwrdm.ptr->prcm_offs, CM_CLKSTCTRL);
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300526
527 if (atomic_read(&clkdm->usecount) > 0)
528 _clkdm_del_autodeps(clkdm);
529}
530
531
532/* Clockdomain-to-clock framework interface code */
533
534/**
535 * omap2_clkdm_clk_enable - add an enabled downstream clock to this clkdm
536 * @clkdm: struct clockdomain *
537 * @clk: struct clk * of the enabled downstream clock
538 *
539 * Increment the usecount of this clockdomain 'clkdm' and ensure that
540 * it is awake. Intended to be called by clk_enable() code. If the
541 * clockdomain is in software-supervised idle mode, force the
542 * clockdomain to wake. If the clockdomain is in hardware-supervised
543 * idle mode, add clkdm-pwrdm autodependencies, to ensure that devices
544 * in the clockdomain can be read from/written to by on-chip processors.
545 * Returns -EINVAL if passed null pointers; returns 0 upon success or
546 * if the clockdomain is in hwsup idle mode.
547 */
548int omap2_clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
549{
550 int v;
551
552 /*
553 * XXX Rewrite this code to maintain a list of enabled
554 * downstream clocks for debugging purposes?
555 */
556
557 if (!clkdm || !clk)
558 return -EINVAL;
559
560 if (atomic_inc_return(&clkdm->usecount) > 1)
561 return 0;
562
563 /* Clockdomain now has one enabled downstream clock */
564
565 pr_debug("clockdomain: clkdm %s: clk %s now enabled\n", clkdm->name,
566 clk->name);
567
568 v = omap2_clkdm_clktrctrl_read(clkdm);
569
570 if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ||
571 (cpu_is_omap24xx() && v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO))
572 _clkdm_add_autodeps(clkdm);
573 else
574 omap2_clkdm_wakeup(clkdm);
575
Tomi Valkeinen054ce502009-01-27 19:44:31 -0700576 pwrdm_wait_transition(clkdm->pwrdm.ptr);
Peter 'p2' De Schrijverfe617af2008-10-15 17:48:44 +0300577 pwrdm_clkdm_state_switch(clkdm);
Tomi Valkeinen054ce502009-01-27 19:44:31 -0700578
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300579 return 0;
580}
581
582/**
583 * omap2_clkdm_clk_disable - remove an enabled downstream clock from this clkdm
584 * @clkdm: struct clockdomain *
585 * @clk: struct clk * of the disabled downstream clock
586 *
587 * Decrement the usecount of this clockdomain 'clkdm'. Intended to be
588 * called by clk_disable() code. If the usecount goes to 0, put the
589 * clockdomain to sleep (software-supervised mode) or remove the
590 * clkdm-pwrdm autodependencies (hardware-supervised mode). Returns
591 * -EINVAL if passed null pointers; -ERANGE if the clkdm usecount
592 * underflows and debugging is enabled; or returns 0 upon success or
593 * if the clockdomain is in hwsup idle mode.
594 */
595int omap2_clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
596{
597 int v;
598
599 /*
600 * XXX Rewrite this code to maintain a list of enabled
601 * downstream clocks for debugging purposes?
602 */
603
604 if (!clkdm || !clk)
605 return -EINVAL;
606
607#ifdef DEBUG
608 if (atomic_read(&clkdm->usecount) == 0) {
609 WARN_ON(1); /* underflow */
610 return -ERANGE;
611 }
612#endif
613
614 if (atomic_dec_return(&clkdm->usecount) > 0)
615 return 0;
616
617 /* All downstream clocks of this clockdomain are now disabled */
618
619 pr_debug("clockdomain: clkdm %s: clk %s now disabled\n", clkdm->name,
620 clk->name);
621
622 v = omap2_clkdm_clktrctrl_read(clkdm);
623
624 if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ||
625 (cpu_is_omap24xx() && v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO))
626 _clkdm_del_autodeps(clkdm);
627 else
628 omap2_clkdm_sleep(clkdm);
629
Peter 'p2' De Schrijverfe617af2008-10-15 17:48:44 +0300630 pwrdm_clkdm_state_switch(clkdm);
631
Paul Walmsleyd459bfe2008-08-19 11:08:43 +0300632 return 0;
633}
634