2 * OMAP2/3 clockdomain framework functions
4 * Copyright (C) 2008 Texas Instruments, Inc.
5 * Copyright (C) 2008 Nokia Corporation
7 * Written by Paul Walmsley and Jouni Högander
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.
13 #ifdef CONFIG_OMAP_DEBUG_CLOCKDOMAIN
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>
25 #include <linux/err.h>
29 #include <linux/bitops.h>
31 #include <mach/clock.h>
34 #include "prm-regbits-24xx.h"
37 #include <mach/powerdomain.h>
38 #include <mach/clockdomain.h>
40 /* clkdm_list contains all registered struct clockdomains */
41 static LIST_HEAD(clkdm_list);
43 /* clkdm_mutex protects clkdm_list add and del ops */
44 static DEFINE_MUTEX(clkdm_mutex);
46 /* array of powerdomain deps to be added/removed when clkdm in hwsup mode */
47 static struct clkdm_pwrdm_autodep *autodeps;
50 /* Private functions */
53 * _autodep_lookup - resolve autodep pwrdm names to pwrdm pointers; store
54 * @autodep: struct clkdm_pwrdm_autodep * to resolve
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.
65 static void _autodep_lookup(struct clkdm_pwrdm_autodep *autodep)
67 struct powerdomain *pwrdm;
72 if (!omap_chip_is(autodep->omap_chip))
75 pwrdm = pwrdm_lookup(autodep->pwrdm.name);
77 pr_err("clockdomain: autodeps: powerdomain %s does not exist\n",
79 pwrdm = ERR_PTR(-ENOENT);
81 autodep->pwrdm.ptr = pwrdm;
85 * _clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable
86 * @clkdm: struct clockdomain *
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.
92 static void _clkdm_add_autodeps(struct clockdomain *clkdm)
94 struct clkdm_pwrdm_autodep *autodep;
96 for (autodep = autodeps; autodep->pwrdm.ptr; autodep++) {
97 if (IS_ERR(autodep->pwrdm.ptr))
100 if (!omap_chip_is(autodep->omap_chip))
103 pr_debug("clockdomain: adding %s sleepdep/wkdep for "
104 "pwrdm %s\n", autodep->pwrdm.ptr->name,
105 clkdm->pwrdm.ptr->name);
107 pwrdm_add_sleepdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
108 pwrdm_add_wkdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
113 * _clkdm_add_autodeps - remove auto sleepdeps/wkdeps from clkdm
114 * @clkdm: struct clockdomain *
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.
120 static void _clkdm_del_autodeps(struct clockdomain *clkdm)
122 struct clkdm_pwrdm_autodep *autodep;
124 for (autodep = autodeps; autodep->pwrdm.ptr; autodep++) {
125 if (IS_ERR(autodep->pwrdm.ptr))
128 if (!omap_chip_is(autodep->omap_chip))
131 pr_debug("clockdomain: removing %s sleepdep/wkdep for "
132 "pwrdm %s\n", autodep->pwrdm.ptr->name,
133 clkdm->pwrdm.ptr->name);
135 pwrdm_del_sleepdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
136 pwrdm_del_wkdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
141 static struct clockdomain *_clkdm_lookup(const char *name)
143 struct clockdomain *clkdm, *temp_clkdm;
150 list_for_each_entry(temp_clkdm, &clkdm_list, node) {
151 if (!strcmp(name, temp_clkdm->name)) {
161 /* Public functions */
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
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.
174 void clkdm_init(struct clockdomain **clkdms,
175 struct clkdm_pwrdm_autodep *init_autodeps)
177 struct clockdomain **c = NULL;
178 struct clkdm_pwrdm_autodep *autodep = NULL;
181 for (c = clkdms; *c; c++)
184 autodeps = init_autodeps;
186 for (autodep = autodeps; autodep->pwrdm.ptr; autodep++)
187 _autodep_lookup(autodep);
191 * clkdm_register - register a clockdomain
192 * @clkdm: struct clockdomain * to register
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.
198 int clkdm_register(struct clockdomain *clkdm)
201 struct powerdomain *pwrdm;
203 if (!clkdm || !clkdm->name)
206 if (!omap_chip_is(clkdm->omap_chip))
209 pwrdm = pwrdm_lookup(clkdm->pwrdm.name);
211 pr_err("clockdomain: %s: powerdomain %s does not exist\n",
212 clkdm->name, clkdm->pwrdm.name);
215 clkdm->pwrdm.ptr = pwrdm;
217 mutex_lock(&clkdm_mutex);
218 /* Verify that the clockdomain is not already registered */
219 if (_clkdm_lookup(clkdm->name)) {
224 list_add(&clkdm->node, &clkdm_list);
226 pwrdm_add_clkdm(pwrdm, clkdm);
228 pr_debug("clockdomain: registered %s\n", clkdm->name);
232 mutex_unlock(&clkdm_mutex);
238 * clkdm_unregister - unregister a clockdomain
239 * @clkdm: struct clockdomain * to unregister
241 * Removes a clockdomain from the internal clockdomain list. Returns
242 * -EINVAL if clkdm argument is NULL.
244 int clkdm_unregister(struct clockdomain *clkdm)
249 pwrdm_del_clkdm(clkdm->pwrdm.ptr, clkdm);
251 mutex_lock(&clkdm_mutex);
252 list_del(&clkdm->node);
253 mutex_unlock(&clkdm_mutex);
255 pr_debug("clockdomain: unregistered %s\n", clkdm->name);
261 * clkdm_lookup - look up a clockdomain by name, return a pointer
262 * @name: name of clockdomain
264 * Find a registered clockdomain by its name. Returns a pointer to the
265 * struct clockdomain if found, or NULL otherwise.
267 struct clockdomain *clkdm_lookup(const char *name)
269 struct clockdomain *clkdm, *temp_clkdm;
276 mutex_lock(&clkdm_mutex);
277 list_for_each_entry(temp_clkdm, &clkdm_list, node) {
278 if (!strcmp(name, temp_clkdm->name)) {
283 mutex_unlock(&clkdm_mutex);
289 * clkdm_for_each - call function on each registered clockdomain
290 * @fn: callback function *
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
302 int clkdm_for_each(int (*fn)(struct clockdomain *clkdm, void *user),
305 struct clockdomain *clkdm;
311 mutex_lock(&clkdm_mutex);
312 list_for_each_entry(clkdm, &clkdm_list, node) {
313 ret = (*fn)(clkdm, user);
317 mutex_unlock(&clkdm_mutex);
324 * clkdm_get_pwrdm - return a ptr to the pwrdm that this clkdm resides in
325 * @clkdm: struct clockdomain *
327 * Return a pointer to the struct powerdomain that the specified clockdomain
328 * 'clkdm' exists in, or returns NULL if clkdm argument is NULL.
330 struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
335 return clkdm->pwrdm.ptr;
339 /* Hardware clockdomain control */
342 * omap2_clkdm_clktrctrl_read - read the clkdm's current state transition mode
343 * @clk: struct clk * of a clockdomain
345 * Return the clockdomain's current state transition mode from the
346 * corresponding domain CM_CLKSTCTRL register. Returns -EINVAL if clk
347 * is NULL or the current mode upon success.
349 static int omap2_clkdm_clktrctrl_read(struct clockdomain *clkdm)
356 v = cm_read_mod_reg(clkdm->pwrdm.ptr->prcm_offs, CM_CLKSTCTRL);
357 v &= clkdm->clktrctrl_mask;
358 v >>= __ffs(clkdm->clktrctrl_mask);
364 * omap2_clkdm_sleep - force clockdomain sleep transition
365 * @clkdm: struct clockdomain *
367 * Instruct the CM to force a sleep transition on the specified
368 * clockdomain 'clkdm'. Returns -EINVAL if clk is NULL or if
369 * clockdomain does not support software-initiated sleep; 0 upon
372 int omap2_clkdm_sleep(struct clockdomain *clkdm)
377 if (!(clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) {
378 pr_debug("clockdomain: %s does not support forcing "
379 "sleep via software\n", clkdm->name);
383 pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name);
385 if (cpu_is_omap24xx()) {
387 cm_set_mod_reg_bits(OMAP24XX_FORCESTATE,
388 clkdm->pwrdm.ptr->prcm_offs, PM_PWSTCTRL);
390 } else if (cpu_is_omap34xx()) {
392 u32 v = (OMAP34XX_CLKSTCTRL_FORCE_SLEEP <<
393 __ffs(clkdm->clktrctrl_mask));
395 cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask, v,
396 clkdm->pwrdm.ptr->prcm_offs, CM_CLKSTCTRL);
406 * omap2_clkdm_wakeup - force clockdomain wakeup transition
407 * @clkdm: struct clockdomain *
409 * Instruct the CM to force a wakeup transition on the specified
410 * clockdomain 'clkdm'. Returns -EINVAL if clkdm is NULL or if the
411 * clockdomain does not support software-controlled wakeup; 0 upon
414 int omap2_clkdm_wakeup(struct clockdomain *clkdm)
419 if (!(clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)) {
420 pr_debug("clockdomain: %s does not support forcing "
421 "wakeup via software\n", clkdm->name);
425 pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name);
427 if (cpu_is_omap24xx()) {
429 cm_clear_mod_reg_bits(OMAP24XX_FORCESTATE,
430 clkdm->pwrdm.ptr->prcm_offs, PM_PWSTCTRL);
432 } else if (cpu_is_omap34xx()) {
434 u32 v = (OMAP34XX_CLKSTCTRL_FORCE_WAKEUP <<
435 __ffs(clkdm->clktrctrl_mask));
437 cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask, v,
438 clkdm->pwrdm.ptr->prcm_offs, CM_CLKSTCTRL);
448 * omap2_clkdm_allow_idle - enable hwsup idle transitions for clkdm
449 * @clkdm: struct clockdomain *
451 * Allow the hardware to automatically switch the clockdomain into
452 * active or idle states, as needed by downstream clocks. If the
453 * clockdomain has any downstream clocks enabled in the clock
454 * framework, wkdep/sleepdep autodependencies are added; this is so
455 * device drivers can read and write to the device. No return value.
457 void omap2_clkdm_allow_idle(struct clockdomain *clkdm)
464 if (!(clkdm->flags & CLKDM_CAN_ENABLE_AUTO)) {
465 pr_debug("clock: automatic idle transitions cannot be enabled "
466 "on clockdomain %s\n", clkdm->name);
470 pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
473 if (atomic_read(&clkdm->usecount) > 0)
474 _clkdm_add_autodeps(clkdm);
476 if (cpu_is_omap24xx())
477 v = OMAP24XX_CLKSTCTRL_ENABLE_AUTO;
478 else if (cpu_is_omap34xx())
479 v = OMAP34XX_CLKSTCTRL_ENABLE_AUTO;
484 cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask,
485 v << __ffs(clkdm->clktrctrl_mask),
486 clkdm->pwrdm.ptr->prcm_offs,
489 pwrdm_clkdm_state_switch(clkdm);
493 * omap2_clkdm_deny_idle - disable hwsup idle transitions for clkdm
494 * @clkdm: struct clockdomain *
496 * Prevent the hardware from automatically switching the clockdomain
497 * into inactive or idle states. If the clockdomain has downstream
498 * clocks enabled in the clock framework, wkdep/sleepdep
499 * autodependencies are removed. No return value.
501 void omap2_clkdm_deny_idle(struct clockdomain *clkdm)
508 if (!(clkdm->flags & CLKDM_CAN_DISABLE_AUTO)) {
509 pr_debug("clockdomain: automatic idle transitions cannot be "
510 "disabled on %s\n", clkdm->name);
514 pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
517 if (cpu_is_omap24xx())
518 v = OMAP24XX_CLKSTCTRL_DISABLE_AUTO;
519 else if (cpu_is_omap34xx())
520 v = OMAP34XX_CLKSTCTRL_DISABLE_AUTO;
524 cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask,
525 v << __ffs(clkdm->clktrctrl_mask),
526 clkdm->pwrdm.ptr->prcm_offs, CM_CLKSTCTRL);
528 if (atomic_read(&clkdm->usecount) > 0)
529 _clkdm_del_autodeps(clkdm);
533 /* Clockdomain-to-clock framework interface code */
536 * omap2_clkdm_clk_enable - add an enabled downstream clock to this clkdm
537 * @clkdm: struct clockdomain *
538 * @clk: struct clk * of the enabled downstream clock
540 * Increment the usecount of this clockdomain 'clkdm' and ensure that
541 * it is awake. Intended to be called by clk_enable() code. If the
542 * clockdomain is in software-supervised idle mode, force the
543 * clockdomain to wake. If the clockdomain is in hardware-supervised
544 * idle mode, add clkdm-pwrdm autodependencies, to ensure that devices
545 * in the clockdomain can be read from/written to by on-chip processors.
546 * Returns -EINVAL if passed null pointers; returns 0 upon success or
547 * if the clockdomain is in hwsup idle mode.
549 int omap2_clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
554 * XXX Rewrite this code to maintain a list of enabled
555 * downstream clocks for debugging purposes?
561 if (atomic_inc_return(&clkdm->usecount) > 1)
564 /* Clockdomain now has one enabled downstream clock */
566 pr_debug("clockdomain: clkdm %s: clk %s now enabled\n", clkdm->name,
569 v = omap2_clkdm_clktrctrl_read(clkdm);
571 if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ||
572 (cpu_is_omap24xx() && v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO))
573 _clkdm_add_autodeps(clkdm);
575 omap2_clkdm_wakeup(clkdm);
577 pwrdm_wait_transition(clkdm->pwrdm.ptr);
578 pwrdm_clkdm_state_switch(clkdm);
584 * omap2_clkdm_clk_disable - remove an enabled downstream clock from this clkdm
585 * @clkdm: struct clockdomain *
586 * @clk: struct clk * of the disabled downstream clock
588 * Decrement the usecount of this clockdomain 'clkdm'. Intended to be
589 * called by clk_disable() code. If the usecount goes to 0, put the
590 * clockdomain to sleep (software-supervised mode) or remove the
591 * clkdm-pwrdm autodependencies (hardware-supervised mode). Returns
592 * -EINVAL if passed null pointers; -ERANGE if the clkdm usecount
593 * underflows and debugging is enabled; or returns 0 upon success or
594 * if the clockdomain is in hwsup idle mode.
596 int omap2_clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
601 * XXX Rewrite this code to maintain a list of enabled
602 * downstream clocks for debugging purposes?
609 if (atomic_read(&clkdm->usecount) == 0) {
610 WARN_ON(1); /* underflow */
615 if (atomic_dec_return(&clkdm->usecount) > 0)
618 /* All downstream clocks of this clockdomain are now disabled */
620 pr_debug("clockdomain: clkdm %s: clk %s now disabled\n", clkdm->name,
623 v = omap2_clkdm_clktrctrl_read(clkdm);
625 if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ||
626 (cpu_is_omap24xx() && v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO))
627 _clkdm_del_autodeps(clkdm);
629 omap2_clkdm_sleep(clkdm);
631 pwrdm_clkdm_state_switch(clkdm);