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>
28 #include <linux/bitops.h>
30 #include <asm/arch/clock.h>
33 #include "prm-regbits-24xx.h"
36 #include <asm/arch/powerdomain.h>
37 #include <asm/arch/clockdomain.h>
39 /* clkdm_list contains all registered struct clockdomains */
40 static LIST_HEAD(clkdm_list);
42 /* clkdm_mutex protects clkdm_list add and del ops */
43 static DEFINE_MUTEX(clkdm_mutex);
45 /* array of powerdomain deps to be added/removed when clkdm in hwsup mode */
46 static struct clkdm_pwrdm_autodep *autodeps;
49 /* Private functions */
52 * _autodep_lookup - resolve autodep pwrdm names to pwrdm pointers; store
53 * @autodep: struct clkdm_pwrdm_autodep * to resolve
55 * Resolve autodep powerdomain names to powerdomain pointers via
56 * pwrdm_lookup() and store the pointers in the autodep structure. An
57 * "autodep" is a powerdomain sleep/wakeup dependency that is
58 * automatically added and removed whenever clocks in the associated
59 * clockdomain are enabled or disabled (respectively) when the
60 * clockdomain is in hardware-supervised mode. Meant to be called
61 * once at clockdomain layer initialization, since these should remain
62 * fixed for a particular architecture. No return value.
64 static void _autodep_lookup(struct clkdm_pwrdm_autodep *autodep)
66 struct powerdomain *pwrdm;
71 if (!omap_chip_is(autodep->omap_chip))
74 pwrdm = pwrdm_lookup(autodep->pwrdm_name);
76 pr_debug("clockdomain: _autodep_lookup: powerdomain %s "
77 "does not exist\n", autodep->pwrdm_name);
81 autodep->pwrdm = pwrdm;
87 * _clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable
88 * @clkdm: struct clockdomain *
90 * Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm'
91 * in hardware-supervised mode. Meant to be called from clock framework
92 * when a clock inside clockdomain 'clkdm' is enabled. No return value.
94 static void _clkdm_add_autodeps(struct clockdomain *clkdm)
96 struct clkdm_pwrdm_autodep *autodep;
98 for (autodep = autodeps; autodep->pwrdm_name; autodep++) {
102 pr_debug("clockdomain: adding %s sleepdep/wkdep for "
103 "pwrdm %s\n", autodep->pwrdm_name,
106 pwrdm_add_sleepdep(clkdm->pwrdm, autodep->pwrdm);
107 pwrdm_add_wkdep(clkdm->pwrdm, autodep->pwrdm);
112 * _clkdm_add_autodeps - remove auto sleepdeps/wkdeps from clkdm
113 * @clkdm: struct clockdomain *
115 * Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm'
116 * in hardware-supervised mode. Meant to be called from clock framework
117 * when a clock inside clockdomain 'clkdm' is disabled. No return value.
119 static void _clkdm_del_autodeps(struct clockdomain *clkdm)
121 struct clkdm_pwrdm_autodep *autodep;
123 for (autodep = autodeps; autodep->pwrdm_name; autodep++) {
127 pr_debug("clockdomain: removing %s sleepdep/wkdep for "
128 "pwrdm %s\n", autodep->pwrdm_name,
131 pwrdm_del_sleepdep(clkdm->pwrdm, autodep->pwrdm);
132 pwrdm_del_wkdep(clkdm->pwrdm, autodep->pwrdm);
137 struct clockdomain *_clkdm_lookup(const char *name)
139 struct clockdomain *clkdm, *temp_clkdm;
146 list_for_each_entry(temp_clkdm, &clkdm_list, node) {
147 if (!strcmp(name, temp_clkdm->name)) {
157 /* Public functions */
160 * clkdm_init - set up the clockdomain layer
161 * @clkdms: optional pointer to an array of clockdomains to register
162 * @init_autodeps: optional pointer to an array of autodeps to register
164 * Set up internal state. If a pointer to an array of clockdomains
165 * was supplied, loop through the list of clockdomains, register all
166 * that are available on the current platform. Similarly, if a
167 * pointer to an array of clockdomain-powerdomain autodependencies was
168 * provided, register those. No return value.
170 void clkdm_init(struct clockdomain **clkdms, struct clkdm_pwrdm_autodep *init_autodeps)
172 struct clockdomain **c = NULL;
173 struct clkdm_pwrdm_autodep *autodep = NULL;
176 for (c = clkdms; *c; c++)
179 autodeps = init_autodeps;
181 for (autodep = autodeps; autodep->pwrdm_name; autodep++)
182 _autodep_lookup(autodep);
186 * clkdm_register - register a clockdomain
187 * @clkdm: struct clockdomain * to register
189 * Adds a clockdomain to the internal clockdomain list.
190 * Returns -EINVAL if given a null pointer, -EEXIST if a clockdomain is
191 * already registered by the provided name, or 0 upon success.
193 int clkdm_register(struct clockdomain *clkdm)
196 struct powerdomain *pwrdm;
198 if (!clkdm || !clkdm->name)
201 if (!omap_chip_is(clkdm->omap_chip))
204 pwrdm = pwrdm_lookup(clkdm->pwrdm_name);
206 pr_debug("clockdomain: clkdm_register %s: powerdomain %s "
207 "does not exist\n", clkdm->name, clkdm->pwrdm_name);
210 clkdm->pwrdm = pwrdm;
212 mutex_lock(&clkdm_mutex);
213 /* Verify that the clockdomain is not already registered */
214 if (_clkdm_lookup(clkdm->name)) {
219 list_add(&clkdm->node, &clkdm_list);
221 pwrdm_add_clkdm(pwrdm, clkdm);
223 pr_debug("clockdomain: registered %s\n", clkdm->name);
227 mutex_unlock(&clkdm_mutex);
233 * clkdm_unregister - unregister a clockdomain
234 * @clkdm: struct clockdomain * to unregister
236 * Removes a clockdomain from the internal clockdomain list. Returns
237 * -EINVAL if clkdm argument is NULL.
239 int clkdm_unregister(struct clockdomain *clkdm)
244 pwrdm_del_clkdm(clkdm->pwrdm, clkdm);
246 mutex_lock(&clkdm_mutex);
247 list_del(&clkdm->node);
248 mutex_unlock(&clkdm_mutex);
250 pr_debug("clockdomain: unregistered %s\n", clkdm->name);
256 * clkdm_lookup - look up a clockdomain by name, return a pointer
257 * @name: name of clockdomain
259 * Find a registered clockdomain by its name. Returns a pointer to the
260 * struct clockdomain if found, or NULL otherwise.
262 struct clockdomain *clkdm_lookup(const char *name)
264 struct clockdomain *clkdm, *temp_clkdm;
271 mutex_lock(&clkdm_mutex);
272 list_for_each_entry(temp_clkdm, &clkdm_list, node) {
273 if (!strcmp(name, temp_clkdm->name)) {
278 mutex_unlock(&clkdm_mutex);
284 * clkdm_for_each - call function on each registered clockdomain
285 * @fn: callback function *
287 * Call the supplied function for each registered clockdomain.
288 * The callback function can return anything but 0 to bail
289 * out early from the iterator. The callback function is called with
290 * the clkdm_mutex held, so no clockdomain structure manipulation
291 * functions should be called from the callback, although hardware
292 * clockdomain control functions are fine. Returns the last return
293 * value of the callback function, which should be 0 for success or
294 * anything else to indicate failure; or -EINVAL if the function pointer
297 int clkdm_for_each(int (*fn)(struct clockdomain *clkdm))
299 struct clockdomain *clkdm;
305 mutex_lock(&clkdm_mutex);
306 list_for_each_entry(clkdm, &clkdm_list, node) {
311 mutex_unlock(&clkdm_mutex);
317 /* Hardware clockdomain control */
320 * omap2_clkdm_clktrctrl_read - read the clkdm's current state transition mode
321 * @clk: struct clk * of a clockdomain
323 * Return the clockdomain's current state transition mode from the
324 * corresponding domain CM_CLKSTCTRL register. Returns -EINVAL if clk
325 * is NULL or the current mode upon success.
327 static int omap2_clkdm_clktrctrl_read(struct clockdomain *clkdm)
334 v = cm_read_mod_reg(clkdm->pwrdm->prcm_offs, CM_CLKSTCTRL);
335 v &= clkdm->clktrctrl_mask;
336 v >>= __ffs(clkdm->clktrctrl_mask);
342 * omap2_clkdm_sleep - force clockdomain sleep transition
343 * @clkdm: struct clockdomain *
345 * Instruct the CM to force a sleep transition on the specified
346 * clockdomain 'clkdm'. Returns -EINVAL if clk is NULL or if
347 * clockdomain does not support software-initiated sleep; 0 upon
350 int omap2_clkdm_sleep(struct clockdomain *clkdm)
355 if (!(clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) {
356 pr_debug("clockdomain: %s does not support forcing "
357 "sleep via software\n", clkdm->name);
361 pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name);
363 if (cpu_is_omap24xx()) {
365 cm_set_mod_reg_bits(OMAP24XX_FORCESTATE,
366 clkdm->pwrdm->prcm_offs, PM_PWSTCTRL);
368 } else if (cpu_is_omap34xx()) {
370 u32 v = (OMAP34XX_CLKSTCTRL_FORCE_SLEEP <<
371 __ffs(clkdm->clktrctrl_mask));
373 cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask, v,
374 clkdm->pwrdm->prcm_offs, CM_CLKSTCTRL);
384 * omap2_clkdm_wakeup - force clockdomain wakeup transition
385 * @clkdm: struct clockdomain *
387 * Instruct the CM to force a wakeup transition on the specified
388 * clockdomain 'clkdm'. Returns -EINVAL if clkdm is NULL or if the
389 * clockdomain does not support software-controlled wakeup; 0 upon
392 int omap2_clkdm_wakeup(struct clockdomain *clkdm)
397 if (!(clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)) {
398 pr_debug("clockdomain: %s does not support forcing "
399 "wakeup via software\n", clkdm->name);
403 pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name);
405 if (cpu_is_omap24xx()) {
407 cm_clear_mod_reg_bits(OMAP24XX_FORCESTATE,
408 clkdm->pwrdm->prcm_offs, PM_PWSTCTRL);
410 } else if (cpu_is_omap34xx()) {
412 u32 v = (OMAP34XX_CLKSTCTRL_FORCE_WAKEUP <<
413 __ffs(clkdm->clktrctrl_mask));
415 cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask, v,
416 clkdm->pwrdm->prcm_offs, CM_CLKSTCTRL);
426 * omap2_clkdm_allow_idle - enable hwsup idle transitions for clkdm
427 * @clkdm: struct clockdomain *
429 * Allow the hardware to automatically switch the clockdomain into
430 * active or idle states, as needed by downstream clocks. If the
431 * clockdomain has any downstream clocks enabled in the clock
432 * framework, wkdep/sleepdep autodependencies are added; this is so
433 * device drivers can read and write to the device. No return value.
435 void omap2_clkdm_allow_idle(struct clockdomain *clkdm)
442 if (!(clkdm->flags & CLKDM_CAN_ENABLE_AUTO)) {
443 pr_debug("clock: automatic idle transitions cannot be enabled "
444 "on clockdomain %s\n", clkdm->name);
448 pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
451 if (atomic_read(&clkdm->usecount) > 0)
452 _clkdm_add_autodeps(clkdm);
454 if (cpu_is_omap24xx())
455 v = OMAP24XX_CLKSTCTRL_ENABLE_AUTO;
456 else if (cpu_is_omap34xx())
457 v = OMAP34XX_CLKSTCTRL_ENABLE_AUTO;
462 cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask,
463 v << __ffs(clkdm->clktrctrl_mask),
464 clkdm->pwrdm->prcm_offs,
469 * omap2_clkdm_deny_idle - disable hwsup idle transitions for clkdm
470 * @clkdm: struct clockdomain *
472 * Prevent the hardware from automatically switching the clockdomain
473 * into inactive or idle states. If the clockdomain has downstream
474 * clocks enabled in the clock framework, wkdep/sleepdep
475 * autodependencies are removed. No return value.
477 void omap2_clkdm_deny_idle(struct clockdomain *clkdm)
484 if (!(clkdm->flags & CLKDM_CAN_DISABLE_AUTO)) {
485 pr_debug("clockdomain: automatic idle transitions cannot be "
486 "disabled on %s\n", clkdm->name);
490 pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
493 if (cpu_is_omap24xx())
494 v = OMAP24XX_CLKSTCTRL_DISABLE_AUTO;
495 else if (cpu_is_omap34xx())
496 v = OMAP34XX_CLKSTCTRL_DISABLE_AUTO;
500 cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask,
501 v << __ffs(clkdm->clktrctrl_mask),
502 clkdm->pwrdm->prcm_offs, CM_CLKSTCTRL);
504 if (atomic_read(&clkdm->usecount) > 0)
505 _clkdm_del_autodeps(clkdm);
509 /* Clockdomain-to-clock framework interface code */
512 * omap2_clkdm_clk_enable - add an enabled downstream clock to this clkdm
513 * @clkdm: struct clockdomain *
514 * @clk: struct clk * of the enabled downstream clock
516 * Increment the usecount of this clockdomain 'clkdm' and ensure that
517 * it is awake. Intended to be called by clk_enable() code. If the
518 * clockdomain is in software-supervised idle mode, force the
519 * clockdomain to wake. If the clockdomain is in hardware-supervised
520 * idle mode, add clkdm-pwrdm autodependencies, to ensure that devices
521 * in the clockdomain can be read from/written to by on-chip processors.
522 * Returns -EINVAL if passed null pointers; returns 0 upon success or
523 * if the clockdomain is in hwsup idle mode.
525 int omap2_clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
530 * XXX Rewrite this code to maintain a list of enabled
531 * downstream clocks for debugging purposes?
537 if (atomic_inc_return(&clkdm->usecount) > 1)
540 /* Clockdomain now has one enabled downstream clock */
542 pr_debug("clockdomain: clkdm %s: clk %s now enabled\n", clkdm->name,
545 v = omap2_clkdm_clktrctrl_read(clkdm);
547 if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ||
548 (cpu_is_omap24xx() && v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO))
549 _clkdm_add_autodeps(clkdm);
551 omap2_clkdm_wakeup(clkdm);
557 * omap2_clkdm_clk_disable - remove an enabled downstream clock from this clkdm
558 * @clkdm: struct clockdomain *
559 * @clk: struct clk * of the disabled downstream clock
561 * Decrement the usecount of this clockdomain 'clkdm'. Intended to be
562 * called by clk_disable() code. If the usecount goes to 0, put the
563 * clockdomain to sleep (software-supervised mode) or remove the
564 * clkdm-pwrdm autodependencies (hardware-supervised mode). Returns
565 * -EINVAL if passed null pointers; -ERANGE if the clkdm usecount
566 * underflows and debugging is enabled; or returns 0 upon success or
567 * if the clockdomain is in hwsup idle mode.
569 int omap2_clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
574 * XXX Rewrite this code to maintain a list of enabled
575 * downstream clocks for debugging purposes?
582 if (atomic_read(&clkdm->usecount) == 0) {
583 WARN_ON(1); /* underflow */
588 if (atomic_dec_return(&clkdm->usecount) > 0)
591 /* All downstream clocks of this clockdomain are now disabled */
593 pr_debug("clockdomain: clkdm %s: clk %s now disabled\n", clkdm->name,
596 v = omap2_clkdm_clktrctrl_read(clkdm);
598 if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ||
599 (cpu_is_omap24xx() && v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO))
600 _clkdm_del_autodeps(clkdm);
602 omap2_clkdm_sleep(clkdm);