xref: /openbmc/linux/arch/arm/mach-omap2/clockdomain.c (revision 59fb659b065f52fcc2deed293cfbfc58f890376c)
1 /*
2  * OMAP2/3/4 clockdomain framework functions
3  *
4  * Copyright (C) 2008-2010 Texas Instruments, Inc.
5  * Copyright (C) 2008-2010 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/module.h>
17 #include <linux/kernel.h>
18 #include <linux/device.h>
19 #include <linux/list.h>
20 #include <linux/errno.h>
21 #include <linux/delay.h>
22 #include <linux/clk.h>
23 #include <linux/limits.h>
24 #include <linux/err.h>
25 
26 #include <linux/io.h>
27 
28 #include <linux/bitops.h>
29 
30 #include "prm2xxx_3xxx.h"
31 #include "prm-regbits-24xx.h"
32 #include "cm2xxx_3xxx.h"
33 #include "cm2xxx_3xxx.h"
34 
35 #include <plat/clock.h>
36 #include <plat/powerdomain.h>
37 #include <plat/clockdomain.h>
38 #include <plat/prcm.h>
39 
40 /* clkdm_list contains all registered struct clockdomains */
41 static LIST_HEAD(clkdm_list);
42 
43 /* array of clockdomain deps to be added/removed when clkdm in hwsup mode */
44 static struct clkdm_autodep *autodeps;
45 
46 
47 /* Private functions */
48 
49 static struct clockdomain *_clkdm_lookup(const char *name)
50 {
51 	struct clockdomain *clkdm, *temp_clkdm;
52 
53 	if (!name)
54 		return NULL;
55 
56 	clkdm = NULL;
57 
58 	list_for_each_entry(temp_clkdm, &clkdm_list, node) {
59 		if (!strcmp(name, temp_clkdm->name)) {
60 			clkdm = temp_clkdm;
61 			break;
62 		}
63 	}
64 
65 	return clkdm;
66 }
67 
68 /**
69  * _clkdm_register - register a clockdomain
70  * @clkdm: struct clockdomain * to register
71  *
72  * Adds a clockdomain to the internal clockdomain list.
73  * Returns -EINVAL if given a null pointer, -EEXIST if a clockdomain is
74  * already registered by the provided name, or 0 upon success.
75  */
76 static int _clkdm_register(struct clockdomain *clkdm)
77 {
78 	struct powerdomain *pwrdm;
79 
80 	if (!clkdm || !clkdm->name)
81 		return -EINVAL;
82 
83 	if (!omap_chip_is(clkdm->omap_chip))
84 		return -EINVAL;
85 
86 	pwrdm = pwrdm_lookup(clkdm->pwrdm.name);
87 	if (!pwrdm) {
88 		pr_err("clockdomain: %s: powerdomain %s does not exist\n",
89 			clkdm->name, clkdm->pwrdm.name);
90 		return -EINVAL;
91 	}
92 	clkdm->pwrdm.ptr = pwrdm;
93 
94 	/* Verify that the clockdomain is not already registered */
95 	if (_clkdm_lookup(clkdm->name))
96 		return -EEXIST;
97 
98 	list_add(&clkdm->node, &clkdm_list);
99 
100 	pwrdm_add_clkdm(pwrdm, clkdm);
101 
102 	pr_debug("clockdomain: registered %s\n", clkdm->name);
103 
104 	return 0;
105 }
106 
107 /* _clkdm_deps_lookup - look up the specified clockdomain in a clkdm list */
108 static struct clkdm_dep *_clkdm_deps_lookup(struct clockdomain *clkdm,
109 					    struct clkdm_dep *deps)
110 {
111 	struct clkdm_dep *cd;
112 
113 	if (!clkdm || !deps || !omap_chip_is(clkdm->omap_chip))
114 		return ERR_PTR(-EINVAL);
115 
116 	for (cd = deps; cd->clkdm_name; cd++) {
117 		if (!omap_chip_is(cd->omap_chip))
118 			continue;
119 
120 		if (!cd->clkdm && cd->clkdm_name)
121 			cd->clkdm = _clkdm_lookup(cd->clkdm_name);
122 
123 		if (cd->clkdm == clkdm)
124 			break;
125 	}
126 
127 	if (!cd->clkdm_name)
128 		return ERR_PTR(-ENOENT);
129 
130 	return cd;
131 }
132 
133 /*
134  * _autodep_lookup - resolve autodep clkdm names to clkdm pointers; store
135  * @autodep: struct clkdm_autodep * to resolve
136  *
137  * Resolve autodep clockdomain names to clockdomain pointers via
138  * clkdm_lookup() and store the pointers in the autodep structure.  An
139  * "autodep" is a clockdomain sleep/wakeup dependency that is
140  * automatically added and removed whenever clocks in the associated
141  * clockdomain are enabled or disabled (respectively) when the
142  * clockdomain is in hardware-supervised mode.	Meant to be called
143  * once at clockdomain layer initialization, since these should remain
144  * fixed for a particular architecture.  No return value.
145  */
146 static void _autodep_lookup(struct clkdm_autodep *autodep)
147 {
148 	struct clockdomain *clkdm;
149 
150 	if (!autodep)
151 		return;
152 
153 	if (!omap_chip_is(autodep->omap_chip))
154 		return;
155 
156 	clkdm = clkdm_lookup(autodep->clkdm.name);
157 	if (!clkdm) {
158 		pr_err("clockdomain: autodeps: clockdomain %s does not exist\n",
159 			 autodep->clkdm.name);
160 		clkdm = ERR_PTR(-ENOENT);
161 	}
162 	autodep->clkdm.ptr = clkdm;
163 }
164 
165 /*
166  * _clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable
167  * @clkdm: struct clockdomain *
168  *
169  * Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm'
170  * in hardware-supervised mode.  Meant to be called from clock framework
171  * when a clock inside clockdomain 'clkdm' is enabled.	No return value.
172  */
173 static void _clkdm_add_autodeps(struct clockdomain *clkdm)
174 {
175 	struct clkdm_autodep *autodep;
176 
177 	if (!autodeps)
178 		return;
179 
180 	for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
181 		if (IS_ERR(autodep->clkdm.ptr))
182 			continue;
183 
184 		if (!omap_chip_is(autodep->omap_chip))
185 			continue;
186 
187 		pr_debug("clockdomain: adding %s sleepdep/wkdep for "
188 			 "clkdm %s\n", autodep->clkdm.ptr->name,
189 			 clkdm->name);
190 
191 		clkdm_add_sleepdep(clkdm, autodep->clkdm.ptr);
192 		clkdm_add_wkdep(clkdm, autodep->clkdm.ptr);
193 	}
194 }
195 
196 /*
197  * _clkdm_add_autodeps - remove auto sleepdeps/wkdeps from clkdm
198  * @clkdm: struct clockdomain *
199  *
200  * Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm'
201  * in hardware-supervised mode.  Meant to be called from clock framework
202  * when a clock inside clockdomain 'clkdm' is disabled.  No return value.
203  */
204 static void _clkdm_del_autodeps(struct clockdomain *clkdm)
205 {
206 	struct clkdm_autodep *autodep;
207 
208 	if (!autodeps)
209 		return;
210 
211 	for (autodep = autodeps; autodep->clkdm.ptr; autodep++) {
212 		if (IS_ERR(autodep->clkdm.ptr))
213 			continue;
214 
215 		if (!omap_chip_is(autodep->omap_chip))
216 			continue;
217 
218 		pr_debug("clockdomain: removing %s sleepdep/wkdep for "
219 			 "clkdm %s\n", autodep->clkdm.ptr->name,
220 			 clkdm->name);
221 
222 		clkdm_del_sleepdep(clkdm, autodep->clkdm.ptr);
223 		clkdm_del_wkdep(clkdm, autodep->clkdm.ptr);
224 	}
225 }
226 
227 /*
228  * _omap2_clkdm_set_hwsup - set the hwsup idle transition bit
229  * @clkdm: struct clockdomain *
230  * @enable: int 0 to disable, 1 to enable
231  *
232  * Internal helper for actually switching the bit that controls hwsup
233  * idle transitions for clkdm.
234  */
235 static void _omap2_clkdm_set_hwsup(struct clockdomain *clkdm, int enable)
236 {
237 	u32 bits, v;
238 
239 	if (cpu_is_omap24xx()) {
240 		if (enable)
241 			bits = OMAP24XX_CLKSTCTRL_ENABLE_AUTO;
242 		else
243 			bits = OMAP24XX_CLKSTCTRL_DISABLE_AUTO;
244 	} else if (cpu_is_omap34xx() || cpu_is_omap44xx()) {
245 		if (enable)
246 			bits = OMAP34XX_CLKSTCTRL_ENABLE_AUTO;
247 		else
248 			bits = OMAP34XX_CLKSTCTRL_DISABLE_AUTO;
249 	} else {
250 		BUG();
251 	}
252 
253 	bits = bits << __ffs(clkdm->clktrctrl_mask);
254 
255 	v = __raw_readl(clkdm->clkstctrl_reg);
256 	v &= ~(clkdm->clktrctrl_mask);
257 	v |= bits;
258 	__raw_writel(v, clkdm->clkstctrl_reg);
259 
260 }
261 
262 /* Public functions */
263 
264 /**
265  * clkdm_init - set up the clockdomain layer
266  * @clkdms: optional pointer to an array of clockdomains to register
267  * @init_autodeps: optional pointer to an array of autodeps to register
268  *
269  * Set up internal state.  If a pointer to an array of clockdomains
270  * @clkdms was supplied, loop through the list of clockdomains,
271  * register all that are available on the current platform. Similarly,
272  * if a pointer to an array of clockdomain autodependencies
273  * @init_autodeps was provided, register those.  No return value.
274  */
275 void clkdm_init(struct clockdomain **clkdms,
276 		struct clkdm_autodep *init_autodeps)
277 {
278 	struct clockdomain **c = NULL;
279 	struct clockdomain *clkdm;
280 	struct clkdm_autodep *autodep = NULL;
281 
282 	if (clkdms)
283 		for (c = clkdms; *c; c++)
284 			_clkdm_register(*c);
285 
286 	autodeps = init_autodeps;
287 	if (autodeps)
288 		for (autodep = autodeps; autodep->clkdm.ptr; autodep++)
289 			_autodep_lookup(autodep);
290 
291 	/*
292 	 * Put all clockdomains into software-supervised mode; PM code
293 	 * should later enable hardware-supervised mode as appropriate
294 	 */
295 	list_for_each_entry(clkdm, &clkdm_list, node) {
296 		if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
297 			omap2_clkdm_wakeup(clkdm);
298 		else if (clkdm->flags & CLKDM_CAN_DISABLE_AUTO)
299 			omap2_clkdm_deny_idle(clkdm);
300 
301 		clkdm_clear_all_wkdeps(clkdm);
302 		clkdm_clear_all_sleepdeps(clkdm);
303 	}
304 }
305 
306 /**
307  * clkdm_lookup - look up a clockdomain by name, return a pointer
308  * @name: name of clockdomain
309  *
310  * Find a registered clockdomain by its name @name.  Returns a pointer
311  * to the struct clockdomain if found, or NULL otherwise.
312  */
313 struct clockdomain *clkdm_lookup(const char *name)
314 {
315 	struct clockdomain *clkdm, *temp_clkdm;
316 
317 	if (!name)
318 		return NULL;
319 
320 	clkdm = NULL;
321 
322 	list_for_each_entry(temp_clkdm, &clkdm_list, node) {
323 		if (!strcmp(name, temp_clkdm->name)) {
324 			clkdm = temp_clkdm;
325 			break;
326 		}
327 	}
328 
329 	return clkdm;
330 }
331 
332 /**
333  * clkdm_for_each - call function on each registered clockdomain
334  * @fn: callback function *
335  *
336  * Call the supplied function @fn for each registered clockdomain.
337  * The callback function @fn can return anything but 0 to bail
338  * out early from the iterator.  The callback function is called with
339  * the clkdm_mutex held, so no clockdomain structure manipulation
340  * functions should be called from the callback, although hardware
341  * clockdomain control functions are fine.  Returns the last return
342  * value of the callback function, which should be 0 for success or
343  * anything else to indicate failure; or -EINVAL if the function pointer
344  * is null.
345  */
346 int clkdm_for_each(int (*fn)(struct clockdomain *clkdm, void *user),
347 			void *user)
348 {
349 	struct clockdomain *clkdm;
350 	int ret = 0;
351 
352 	if (!fn)
353 		return -EINVAL;
354 
355 	list_for_each_entry(clkdm, &clkdm_list, node) {
356 		ret = (*fn)(clkdm, user);
357 		if (ret)
358 			break;
359 	}
360 
361 	return ret;
362 }
363 
364 
365 /**
366  * clkdm_get_pwrdm - return a ptr to the pwrdm that this clkdm resides in
367  * @clkdm: struct clockdomain *
368  *
369  * Return a pointer to the struct powerdomain that the specified clockdomain
370  * @clkdm exists in, or returns NULL if @clkdm is NULL.
371  */
372 struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
373 {
374 	if (!clkdm)
375 		return NULL;
376 
377 	return clkdm->pwrdm.ptr;
378 }
379 
380 
381 /* Hardware clockdomain control */
382 
383 /**
384  * clkdm_add_wkdep - add a wakeup dependency from clkdm2 to clkdm1
385  * @clkdm1: wake this struct clockdomain * up (dependent)
386  * @clkdm2: when this struct clockdomain * wakes up (source)
387  *
388  * When the clockdomain represented by @clkdm2 wakes up, wake up
389  * @clkdm1. Implemented in hardware on the OMAP, this feature is
390  * designed to reduce wakeup latency of the dependent clockdomain @clkdm1.
391  * Returns -EINVAL if presented with invalid clockdomain pointers,
392  * -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or 0 upon
393  * success.
394  */
395 int clkdm_add_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
396 {
397 	struct clkdm_dep *cd;
398 
399 	if (!clkdm1 || !clkdm2)
400 		return -EINVAL;
401 
402 	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
403 	if (IS_ERR(cd)) {
404 		pr_debug("clockdomain: hardware cannot set/clear wake up of "
405 			 "%s when %s wakes up\n", clkdm1->name, clkdm2->name);
406 		return PTR_ERR(cd);
407 	}
408 
409 	if (atomic_inc_return(&cd->wkdep_usecount) == 1) {
410 		pr_debug("clockdomain: hardware will wake up %s when %s wakes "
411 			 "up\n", clkdm1->name, clkdm2->name);
412 
413 		prm_set_mod_reg_bits((1 << clkdm2->dep_bit),
414 				     clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP);
415 	}
416 
417 	return 0;
418 }
419 
420 /**
421  * clkdm_del_wkdep - remove a wakeup dependency from clkdm2 to clkdm1
422  * @clkdm1: wake this struct clockdomain * up (dependent)
423  * @clkdm2: when this struct clockdomain * wakes up (source)
424  *
425  * Remove a wakeup dependency causing @clkdm1 to wake up when @clkdm2
426  * wakes up.  Returns -EINVAL if presented with invalid clockdomain
427  * pointers, -ENOENT if @clkdm2 cannot wake up clkdm1 in hardware, or
428  * 0 upon success.
429  */
430 int clkdm_del_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
431 {
432 	struct clkdm_dep *cd;
433 
434 	if (!clkdm1 || !clkdm2)
435 		return -EINVAL;
436 
437 	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
438 	if (IS_ERR(cd)) {
439 		pr_debug("clockdomain: hardware cannot set/clear wake up of "
440 			 "%s when %s wakes up\n", clkdm1->name, clkdm2->name);
441 		return PTR_ERR(cd);
442 	}
443 
444 	if (atomic_dec_return(&cd->wkdep_usecount) == 0) {
445 		pr_debug("clockdomain: hardware will no longer wake up %s "
446 			 "after %s wakes up\n", clkdm1->name, clkdm2->name);
447 
448 		prm_clear_mod_reg_bits((1 << clkdm2->dep_bit),
449 				       clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP);
450 	}
451 
452 	return 0;
453 }
454 
455 /**
456  * clkdm_read_wkdep - read wakeup dependency state from clkdm2 to clkdm1
457  * @clkdm1: wake this struct clockdomain * up (dependent)
458  * @clkdm2: when this struct clockdomain * wakes up (source)
459  *
460  * Return 1 if a hardware wakeup dependency exists wherein @clkdm1 will be
461  * awoken when @clkdm2 wakes up; 0 if dependency is not set; -EINVAL
462  * if either clockdomain pointer is invalid; or -ENOENT if the hardware
463  * is incapable.
464  *
465  * REVISIT: Currently this function only represents software-controllable
466  * wakeup dependencies.  Wakeup dependencies fixed in hardware are not
467  * yet handled here.
468  */
469 int clkdm_read_wkdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
470 {
471 	struct clkdm_dep *cd;
472 
473 	if (!clkdm1 || !clkdm2)
474 		return -EINVAL;
475 
476 	cd = _clkdm_deps_lookup(clkdm2, clkdm1->wkdep_srcs);
477 	if (IS_ERR(cd)) {
478 		pr_debug("clockdomain: hardware cannot set/clear wake up of "
479 			 "%s when %s wakes up\n", clkdm1->name, clkdm2->name);
480 		return PTR_ERR(cd);
481 	}
482 
483 	/* XXX It's faster to return the atomic wkdep_usecount */
484 	return prm_read_mod_bits_shift(clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP,
485 				       (1 << clkdm2->dep_bit));
486 }
487 
488 /**
489  * clkdm_clear_all_wkdeps - remove all wakeup dependencies from target clkdm
490  * @clkdm: struct clockdomain * to remove all wakeup dependencies from
491  *
492  * Remove all inter-clockdomain wakeup dependencies that could cause
493  * @clkdm to wake.  Intended to be used during boot to initialize the
494  * PRCM to a known state, after all clockdomains are put into swsup idle
495  * and woken up.  Returns -EINVAL if @clkdm pointer is invalid, or
496  * 0 upon success.
497  */
498 int clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
499 {
500 	struct clkdm_dep *cd;
501 	u32 mask = 0;
502 
503 	if (!clkdm)
504 		return -EINVAL;
505 
506 	for (cd = clkdm->wkdep_srcs; cd && cd->clkdm_name; cd++) {
507 		if (!omap_chip_is(cd->omap_chip))
508 			continue;
509 
510 		if (!cd->clkdm && cd->clkdm_name)
511 			cd->clkdm = _clkdm_lookup(cd->clkdm_name);
512 
513 		/* PRM accesses are slow, so minimize them */
514 		mask |= 1 << cd->clkdm->dep_bit;
515 		atomic_set(&cd->wkdep_usecount, 0);
516 	}
517 
518 	prm_clear_mod_reg_bits(mask, clkdm->pwrdm.ptr->prcm_offs, PM_WKDEP);
519 
520 	return 0;
521 }
522 
523 /**
524  * clkdm_add_sleepdep - add a sleep dependency from clkdm2 to clkdm1
525  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
526  * @clkdm2: when this struct clockdomain * is active (source)
527  *
528  * Prevent @clkdm1 from automatically going inactive (and then to
529  * retention or off) if @clkdm2 is active.  Returns -EINVAL if
530  * presented with invalid clockdomain pointers or called on a machine
531  * that does not support software-configurable hardware sleep
532  * dependencies, -ENOENT if the specified dependency cannot be set in
533  * hardware, or 0 upon success.
534  */
535 int clkdm_add_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
536 {
537 	struct clkdm_dep *cd;
538 
539 	if (!cpu_is_omap34xx())
540 		return -EINVAL;
541 
542 	if (!clkdm1 || !clkdm2)
543 		return -EINVAL;
544 
545 	cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
546 	if (IS_ERR(cd)) {
547 		pr_debug("clockdomain: hardware cannot set/clear sleep "
548 			 "dependency affecting %s from %s\n", clkdm1->name,
549 			 clkdm2->name);
550 		return PTR_ERR(cd);
551 	}
552 
553 	if (atomic_inc_return(&cd->sleepdep_usecount) == 1) {
554 		pr_debug("clockdomain: will prevent %s from sleeping if %s "
555 			 "is active\n", clkdm1->name, clkdm2->name);
556 
557 		cm_set_mod_reg_bits((1 << clkdm2->dep_bit),
558 				    clkdm1->pwrdm.ptr->prcm_offs,
559 				    OMAP3430_CM_SLEEPDEP);
560 	}
561 
562 	return 0;
563 }
564 
565 /**
566  * clkdm_del_sleepdep - remove a sleep dependency from clkdm2 to clkdm1
567  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
568  * @clkdm2: when this struct clockdomain * is active (source)
569  *
570  * Allow @clkdm1 to automatically go inactive (and then to retention or
571  * off), independent of the activity state of @clkdm2.  Returns -EINVAL
572  * if presented with invalid clockdomain pointers or called on a machine
573  * that does not support software-configurable hardware sleep dependencies,
574  * -ENOENT if the specified dependency cannot be cleared in hardware, or
575  * 0 upon success.
576  */
577 int clkdm_del_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
578 {
579 	struct clkdm_dep *cd;
580 
581 	if (!cpu_is_omap34xx())
582 		return -EINVAL;
583 
584 	if (!clkdm1 || !clkdm2)
585 		return -EINVAL;
586 
587 	cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
588 	if (IS_ERR(cd)) {
589 		pr_debug("clockdomain: hardware cannot set/clear sleep "
590 			 "dependency affecting %s from %s\n", clkdm1->name,
591 			 clkdm2->name);
592 		return PTR_ERR(cd);
593 	}
594 
595 	if (atomic_dec_return(&cd->sleepdep_usecount) == 0) {
596 		pr_debug("clockdomain: will no longer prevent %s from "
597 			 "sleeping if %s is active\n", clkdm1->name,
598 			 clkdm2->name);
599 
600 		cm_clear_mod_reg_bits((1 << clkdm2->dep_bit),
601 				      clkdm1->pwrdm.ptr->prcm_offs,
602 				      OMAP3430_CM_SLEEPDEP);
603 	}
604 
605 	return 0;
606 }
607 
608 /**
609  * clkdm_read_sleepdep - read sleep dependency state from clkdm2 to clkdm1
610  * @clkdm1: prevent this struct clockdomain * from sleeping (dependent)
611  * @clkdm2: when this struct clockdomain * is active (source)
612  *
613  * Return 1 if a hardware sleep dependency exists wherein @clkdm1 will
614  * not be allowed to automatically go inactive if @clkdm2 is active;
615  * 0 if @clkdm1's automatic power state inactivity transition is independent
616  * of @clkdm2's; -EINVAL if either clockdomain pointer is invalid or called
617  * on a machine that does not support software-configurable hardware sleep
618  * dependencies; or -ENOENT if the hardware is incapable.
619  *
620  * REVISIT: Currently this function only represents software-controllable
621  * sleep dependencies.	Sleep dependencies fixed in hardware are not
622  * yet handled here.
623  */
624 int clkdm_read_sleepdep(struct clockdomain *clkdm1, struct clockdomain *clkdm2)
625 {
626 	struct clkdm_dep *cd;
627 
628 	if (!cpu_is_omap34xx())
629 		return -EINVAL;
630 
631 	if (!clkdm1 || !clkdm2)
632 		return -EINVAL;
633 
634 	cd = _clkdm_deps_lookup(clkdm2, clkdm1->sleepdep_srcs);
635 	if (IS_ERR(cd)) {
636 		pr_debug("clockdomain: hardware cannot set/clear sleep "
637 			 "dependency affecting %s from %s\n", clkdm1->name,
638 			 clkdm2->name);
639 		return PTR_ERR(cd);
640 	}
641 
642 	/* XXX It's faster to return the atomic sleepdep_usecount */
643 	return prm_read_mod_bits_shift(clkdm1->pwrdm.ptr->prcm_offs,
644 				       OMAP3430_CM_SLEEPDEP,
645 				       (1 << clkdm2->dep_bit));
646 }
647 
648 /**
649  * clkdm_clear_all_sleepdeps - remove all sleep dependencies from target clkdm
650  * @clkdm: struct clockdomain * to remove all sleep dependencies from
651  *
652  * Remove all inter-clockdomain sleep dependencies that could prevent
653  * @clkdm from idling.  Intended to be used during boot to initialize the
654  * PRCM to a known state, after all clockdomains are put into swsup idle
655  * and woken up.  Returns -EINVAL if @clkdm pointer is invalid, or
656  * 0 upon success.
657  */
658 int clkdm_clear_all_sleepdeps(struct clockdomain *clkdm)
659 {
660 	struct clkdm_dep *cd;
661 	u32 mask = 0;
662 
663 	if (!cpu_is_omap34xx())
664 		return -EINVAL;
665 
666 	if (!clkdm)
667 		return -EINVAL;
668 
669 	for (cd = clkdm->sleepdep_srcs; cd && cd->clkdm_name; cd++) {
670 		if (!omap_chip_is(cd->omap_chip))
671 			continue;
672 
673 		if (!cd->clkdm && cd->clkdm_name)
674 			cd->clkdm = _clkdm_lookup(cd->clkdm_name);
675 
676 		/* PRM accesses are slow, so minimize them */
677 		mask |= 1 << cd->clkdm->dep_bit;
678 		atomic_set(&cd->sleepdep_usecount, 0);
679 	}
680 
681 	prm_clear_mod_reg_bits(mask, clkdm->pwrdm.ptr->prcm_offs,
682 			       OMAP3430_CM_SLEEPDEP);
683 
684 	return 0;
685 }
686 
687 /**
688  * omap2_clkdm_clktrctrl_read - read the clkdm's current state transition mode
689  * @clkdm: struct clkdm * of a clockdomain
690  *
691  * Return the clockdomain @clkdm current state transition mode from the
692  * corresponding domain CM_CLKSTCTRL register.	Returns -EINVAL if @clkdm
693  * is NULL or the current mode upon success.
694  */
695 static int omap2_clkdm_clktrctrl_read(struct clockdomain *clkdm)
696 {
697 	u32 v;
698 
699 	if (!clkdm)
700 		return -EINVAL;
701 
702 	v = __raw_readl(clkdm->clkstctrl_reg);
703 	v &= clkdm->clktrctrl_mask;
704 	v >>= __ffs(clkdm->clktrctrl_mask);
705 
706 	return v;
707 }
708 
709 /**
710  * omap2_clkdm_sleep - force clockdomain sleep transition
711  * @clkdm: struct clockdomain *
712  *
713  * Instruct the CM to force a sleep transition on the specified
714  * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if
715  * clockdomain does not support software-initiated sleep; 0 upon
716  * success.
717  */
718 int omap2_clkdm_sleep(struct clockdomain *clkdm)
719 {
720 	if (!clkdm)
721 		return -EINVAL;
722 
723 	if (!(clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) {
724 		pr_debug("clockdomain: %s does not support forcing "
725 			 "sleep via software\n", clkdm->name);
726 		return -EINVAL;
727 	}
728 
729 	pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name);
730 
731 	if (cpu_is_omap24xx()) {
732 
733 		cm_set_mod_reg_bits(OMAP24XX_FORCESTATE_MASK,
734 			    clkdm->pwrdm.ptr->prcm_offs, OMAP2_PM_PWSTCTRL);
735 
736 	} else if (cpu_is_omap34xx() || cpu_is_omap44xx()) {
737 
738 		u32 bits = (OMAP34XX_CLKSTCTRL_FORCE_SLEEP <<
739 			 __ffs(clkdm->clktrctrl_mask));
740 
741 		u32 v = __raw_readl(clkdm->clkstctrl_reg);
742 		v &= ~(clkdm->clktrctrl_mask);
743 		v |= bits;
744 		__raw_writel(v, clkdm->clkstctrl_reg);
745 
746 	} else {
747 		BUG();
748 	};
749 
750 	return 0;
751 }
752 
753 /**
754  * omap2_clkdm_wakeup - force clockdomain wakeup transition
755  * @clkdm: struct clockdomain *
756  *
757  * Instruct the CM to force a wakeup transition on the specified
758  * clockdomain @clkdm.  Returns -EINVAL if @clkdm is NULL or if the
759  * clockdomain does not support software-controlled wakeup; 0 upon
760  * success.
761  */
762 int omap2_clkdm_wakeup(struct clockdomain *clkdm)
763 {
764 	if (!clkdm)
765 		return -EINVAL;
766 
767 	if (!(clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)) {
768 		pr_debug("clockdomain: %s does not support forcing "
769 			 "wakeup via software\n", clkdm->name);
770 		return -EINVAL;
771 	}
772 
773 	pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name);
774 
775 	if (cpu_is_omap24xx()) {
776 
777 		cm_clear_mod_reg_bits(OMAP24XX_FORCESTATE_MASK,
778 			      clkdm->pwrdm.ptr->prcm_offs, OMAP2_PM_PWSTCTRL);
779 
780 	} else if (cpu_is_omap34xx() || cpu_is_omap44xx()) {
781 
782 		u32 bits = (OMAP34XX_CLKSTCTRL_FORCE_WAKEUP <<
783 			 __ffs(clkdm->clktrctrl_mask));
784 
785 		u32 v = __raw_readl(clkdm->clkstctrl_reg);
786 		v &= ~(clkdm->clktrctrl_mask);
787 		v |= bits;
788 		__raw_writel(v, clkdm->clkstctrl_reg);
789 
790 	} else {
791 		BUG();
792 	};
793 
794 	return 0;
795 }
796 
797 /**
798  * omap2_clkdm_allow_idle - enable hwsup idle transitions for clkdm
799  * @clkdm: struct clockdomain *
800  *
801  * Allow the hardware to automatically switch the clockdomain @clkdm into
802  * active or idle states, as needed by downstream clocks.  If the
803  * clockdomain has any downstream clocks enabled in the clock
804  * framework, wkdep/sleepdep autodependencies are added; this is so
805  * device drivers can read and write to the device.  No return value.
806  */
807 void omap2_clkdm_allow_idle(struct clockdomain *clkdm)
808 {
809 	if (!clkdm)
810 		return;
811 
812 	if (!(clkdm->flags & CLKDM_CAN_ENABLE_AUTO)) {
813 		pr_debug("clock: automatic idle transitions cannot be enabled "
814 			 "on clockdomain %s\n", clkdm->name);
815 		return;
816 	}
817 
818 	pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
819 		 clkdm->name);
820 
821 	/*
822 	 * XXX This should be removed once TI adds wakeup/sleep
823 	 * dependency code and data for OMAP4.
824 	 */
825 	if (cpu_is_omap44xx()) {
826 		WARN_ONCE(1, "clockdomain: OMAP4 wakeup/sleep dependency "
827 			  "support is not yet implemented\n");
828 	} else {
829 		if (atomic_read(&clkdm->usecount) > 0)
830 			_clkdm_add_autodeps(clkdm);
831 	}
832 
833 	_omap2_clkdm_set_hwsup(clkdm, 1);
834 
835 	pwrdm_clkdm_state_switch(clkdm);
836 }
837 
838 /**
839  * omap2_clkdm_deny_idle - disable hwsup idle transitions for clkdm
840  * @clkdm: struct clockdomain *
841  *
842  * Prevent the hardware from automatically switching the clockdomain
843  * @clkdm into inactive or idle states.  If the clockdomain has
844  * downstream clocks enabled in the clock framework, wkdep/sleepdep
845  * autodependencies are removed.  No return value.
846  */
847 void omap2_clkdm_deny_idle(struct clockdomain *clkdm)
848 {
849 	if (!clkdm)
850 		return;
851 
852 	if (!(clkdm->flags & CLKDM_CAN_DISABLE_AUTO)) {
853 		pr_debug("clockdomain: automatic idle transitions cannot be "
854 			 "disabled on %s\n", clkdm->name);
855 		return;
856 	}
857 
858 	pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
859 		 clkdm->name);
860 
861 	_omap2_clkdm_set_hwsup(clkdm, 0);
862 
863 	/*
864 	 * XXX This should be removed once TI adds wakeup/sleep
865 	 * dependency code and data for OMAP4.
866 	 */
867 	if (cpu_is_omap44xx()) {
868 		WARN_ONCE(1, "clockdomain: OMAP4 wakeup/sleep dependency "
869 			  "support is not yet implemented\n");
870 	} else {
871 		if (atomic_read(&clkdm->usecount) > 0)
872 			_clkdm_del_autodeps(clkdm);
873 	}
874 }
875 
876 
877 /* Clockdomain-to-clock framework interface code */
878 
879 /**
880  * omap2_clkdm_clk_enable - add an enabled downstream clock to this clkdm
881  * @clkdm: struct clockdomain *
882  * @clk: struct clk * of the enabled downstream clock
883  *
884  * Increment the usecount of the clockdomain @clkdm and ensure that it
885  * is awake before @clk is enabled.  Intended to be called by
886  * clk_enable() code.  If the clockdomain is in software-supervised
887  * idle mode, force the clockdomain to wake.  If the clockdomain is in
888  * hardware-supervised idle mode, add clkdm-pwrdm autodependencies, to
889  * ensure that devices in the clockdomain can be read from/written to
890  * by on-chip processors.  Returns -EINVAL if passed null pointers;
891  * returns 0 upon success or if the clockdomain is in hwsup idle mode.
892  */
893 int omap2_clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
894 {
895 	int v;
896 
897 	/*
898 	 * XXX Rewrite this code to maintain a list of enabled
899 	 * downstream clocks for debugging purposes?
900 	 */
901 
902 	if (!clkdm || !clk)
903 		return -EINVAL;
904 
905 	if (atomic_inc_return(&clkdm->usecount) > 1)
906 		return 0;
907 
908 	/* Clockdomain now has one enabled downstream clock */
909 
910 	pr_debug("clockdomain: clkdm %s: clk %s now enabled\n", clkdm->name,
911 		 clk->name);
912 
913 	if (!clkdm->clkstctrl_reg)
914 		return 0;
915 
916 	v = omap2_clkdm_clktrctrl_read(clkdm);
917 
918 	if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ||
919 	    (cpu_is_omap24xx() && v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO)) {
920 		/* Disable HW transitions when we are changing deps */
921 		_omap2_clkdm_set_hwsup(clkdm, 0);
922 		_clkdm_add_autodeps(clkdm);
923 		_omap2_clkdm_set_hwsup(clkdm, 1);
924 	} else {
925 		omap2_clkdm_wakeup(clkdm);
926 	}
927 
928 	pwrdm_wait_transition(clkdm->pwrdm.ptr);
929 	pwrdm_clkdm_state_switch(clkdm);
930 
931 	return 0;
932 }
933 
934 /**
935  * omap2_clkdm_clk_disable - remove an enabled downstream clock from this clkdm
936  * @clkdm: struct clockdomain *
937  * @clk: struct clk * of the disabled downstream clock
938  *
939  * Decrement the usecount of this clockdomain @clkdm when @clk is
940  * disabled.  Intended to be called by clk_disable() code.  If the
941  * clockdomain usecount goes to 0, put the clockdomain to sleep
942  * (software-supervised mode) or remove the clkdm autodependencies
943  * (hardware-supervised mode).  Returns -EINVAL if passed null
944  * pointers; -ERANGE if the @clkdm usecount underflows and debugging
945  * is enabled; or returns 0 upon success or if the clockdomain is in
946  * hwsup idle mode.
947  */
948 int omap2_clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
949 {
950 	int v;
951 
952 	/*
953 	 * XXX Rewrite this code to maintain a list of enabled
954 	 * downstream clocks for debugging purposes?
955 	 */
956 
957 	if (!clkdm || !clk)
958 		return -EINVAL;
959 
960 #ifdef DEBUG
961 	if (atomic_read(&clkdm->usecount) == 0) {
962 		WARN_ON(1); /* underflow */
963 		return -ERANGE;
964 	}
965 #endif
966 
967 	if (atomic_dec_return(&clkdm->usecount) > 0)
968 		return 0;
969 
970 	/* All downstream clocks of this clockdomain are now disabled */
971 
972 	pr_debug("clockdomain: clkdm %s: clk %s now disabled\n", clkdm->name,
973 		 clk->name);
974 
975 	if (!clkdm->clkstctrl_reg)
976 		return 0;
977 
978 	v = omap2_clkdm_clktrctrl_read(clkdm);
979 
980 	if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ||
981 	    (cpu_is_omap24xx() && v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO)) {
982 		/* Disable HW transitions when we are changing deps */
983 		_omap2_clkdm_set_hwsup(clkdm, 0);
984 		_clkdm_del_autodeps(clkdm);
985 		_omap2_clkdm_set_hwsup(clkdm, 1);
986 	} else {
987 		omap2_clkdm_sleep(clkdm);
988 	}
989 
990 	pwrdm_clkdm_state_switch(clkdm);
991 
992 	return 0;
993 }
994 
995