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
))
304 struct clockdomain
*clkdm
;
310 mutex_lock(&clkdm_mutex
);
311 list_for_each_entry(clkdm
, &clkdm_list
, node
) {
316 mutex_unlock(&clkdm_mutex
);
323 * clkdm_get_pwrdm - return a ptr to the pwrdm that this clkdm resides in
324 * @clkdm: struct clockdomain *
326 * Return a pointer to the struct powerdomain that the specified clockdomain
327 * 'clkdm' exists in, or returns NULL if clkdm argument is NULL.
329 struct powerdomain
*clkdm_get_pwrdm(struct clockdomain
*clkdm
)
334 return clkdm
->pwrdm
.ptr
;
338 /* Hardware clockdomain control */
341 * omap2_clkdm_clktrctrl_read - read the clkdm's current state transition mode
342 * @clk: struct clk * of a clockdomain
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.
348 static int omap2_clkdm_clktrctrl_read(struct clockdomain
*clkdm
)
355 v
= cm_read_mod_reg(clkdm
->pwrdm
.ptr
->prcm_offs
, CM_CLKSTCTRL
);
356 v
&= clkdm
->clktrctrl_mask
;
357 v
>>= __ffs(clkdm
->clktrctrl_mask
);
363 * omap2_clkdm_sleep - force clockdomain sleep transition
364 * @clkdm: struct clockdomain *
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
371 int omap2_clkdm_sleep(struct clockdomain
*clkdm
)
376 if (!(clkdm
->flags
& CLKDM_CAN_FORCE_SLEEP
)) {
377 pr_debug("clockdomain: %s does not support forcing "
378 "sleep via software\n", clkdm
->name
);
382 pr_debug("clockdomain: forcing sleep on %s\n", clkdm
->name
);
384 if (cpu_is_omap24xx()) {
386 cm_set_mod_reg_bits(OMAP24XX_FORCESTATE
,
387 clkdm
->pwrdm
.ptr
->prcm_offs
, PM_PWSTCTRL
);
389 } else if (cpu_is_omap34xx()) {
391 u32 v
= (OMAP34XX_CLKSTCTRL_FORCE_SLEEP
<<
392 __ffs(clkdm
->clktrctrl_mask
));
394 cm_rmw_mod_reg_bits(clkdm
->clktrctrl_mask
, v
,
395 clkdm
->pwrdm
.ptr
->prcm_offs
, CM_CLKSTCTRL
);
405 * omap2_clkdm_wakeup - force clockdomain wakeup transition
406 * @clkdm: struct clockdomain *
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
413 int omap2_clkdm_wakeup(struct clockdomain
*clkdm
)
418 if (!(clkdm
->flags
& CLKDM_CAN_FORCE_WAKEUP
)) {
419 pr_debug("clockdomain: %s does not support forcing "
420 "wakeup via software\n", clkdm
->name
);
424 pr_debug("clockdomain: forcing wakeup on %s\n", clkdm
->name
);
426 if (cpu_is_omap24xx()) {
428 cm_clear_mod_reg_bits(OMAP24XX_FORCESTATE
,
429 clkdm
->pwrdm
.ptr
->prcm_offs
, PM_PWSTCTRL
);
431 } else if (cpu_is_omap34xx()) {
433 u32 v
= (OMAP34XX_CLKSTCTRL_FORCE_WAKEUP
<<
434 __ffs(clkdm
->clktrctrl_mask
));
436 cm_rmw_mod_reg_bits(clkdm
->clktrctrl_mask
, v
,
437 clkdm
->pwrdm
.ptr
->prcm_offs
, CM_CLKSTCTRL
);
447 * omap2_clkdm_allow_idle - enable hwsup idle transitions for clkdm
448 * @clkdm: struct clockdomain *
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.
456 void omap2_clkdm_allow_idle(struct clockdomain
*clkdm
)
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
);
469 pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
472 if (atomic_read(&clkdm
->usecount
) > 0)
473 _clkdm_add_autodeps(clkdm
);
475 if (cpu_is_omap24xx())
476 v
= OMAP24XX_CLKSTCTRL_ENABLE_AUTO
;
477 else if (cpu_is_omap34xx())
478 v
= OMAP34XX_CLKSTCTRL_ENABLE_AUTO
;
483 cm_rmw_mod_reg_bits(clkdm
->clktrctrl_mask
,
484 v
<< __ffs(clkdm
->clktrctrl_mask
),
485 clkdm
->pwrdm
.ptr
->prcm_offs
,
490 * omap2_clkdm_deny_idle - disable hwsup idle transitions for clkdm
491 * @clkdm: struct clockdomain *
493 * Prevent the hardware from automatically switching the clockdomain
494 * into inactive or idle states. If the clockdomain has downstream
495 * clocks enabled in the clock framework, wkdep/sleepdep
496 * autodependencies are removed. No return value.
498 void omap2_clkdm_deny_idle(struct clockdomain
*clkdm
)
505 if (!(clkdm
->flags
& CLKDM_CAN_DISABLE_AUTO
)) {
506 pr_debug("clockdomain: automatic idle transitions cannot be "
507 "disabled on %s\n", clkdm
->name
);
511 pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
514 if (cpu_is_omap24xx())
515 v
= OMAP24XX_CLKSTCTRL_DISABLE_AUTO
;
516 else if (cpu_is_omap34xx())
517 v
= OMAP34XX_CLKSTCTRL_DISABLE_AUTO
;
521 cm_rmw_mod_reg_bits(clkdm
->clktrctrl_mask
,
522 v
<< __ffs(clkdm
->clktrctrl_mask
),
523 clkdm
->pwrdm
.ptr
->prcm_offs
, CM_CLKSTCTRL
);
525 if (atomic_read(&clkdm
->usecount
) > 0)
526 _clkdm_del_autodeps(clkdm
);
530 /* Clockdomain-to-clock framework interface code */
533 * omap2_clkdm_clk_enable - add an enabled downstream clock to this clkdm
534 * @clkdm: struct clockdomain *
535 * @clk: struct clk * of the enabled downstream clock
537 * Increment the usecount of this clockdomain 'clkdm' and ensure that
538 * it is awake. Intended to be called by clk_enable() code. If the
539 * clockdomain is in software-supervised idle mode, force the
540 * clockdomain to wake. If the clockdomain is in hardware-supervised
541 * idle mode, add clkdm-pwrdm autodependencies, to ensure that devices
542 * in the clockdomain can be read from/written to by on-chip processors.
543 * Returns -EINVAL if passed null pointers; returns 0 upon success or
544 * if the clockdomain is in hwsup idle mode.
546 int omap2_clkdm_clk_enable(struct clockdomain
*clkdm
, struct clk
*clk
)
551 * XXX Rewrite this code to maintain a list of enabled
552 * downstream clocks for debugging purposes?
558 if (atomic_inc_return(&clkdm
->usecount
) > 1)
561 /* Clockdomain now has one enabled downstream clock */
563 pr_debug("clockdomain: clkdm %s: clk %s now enabled\n", clkdm
->name
,
566 v
= omap2_clkdm_clktrctrl_read(clkdm
);
568 if ((cpu_is_omap34xx() && v
== OMAP34XX_CLKSTCTRL_ENABLE_AUTO
) ||
569 (cpu_is_omap24xx() && v
== OMAP24XX_CLKSTCTRL_ENABLE_AUTO
))
570 _clkdm_add_autodeps(clkdm
);
572 omap2_clkdm_wakeup(clkdm
);
574 pwrdm_wait_transition(clkdm
->pwrdm
.ptr
);
580 * omap2_clkdm_clk_disable - remove an enabled downstream clock from this clkdm
581 * @clkdm: struct clockdomain *
582 * @clk: struct clk * of the disabled downstream clock
584 * Decrement the usecount of this clockdomain 'clkdm'. Intended to be
585 * called by clk_disable() code. If the usecount goes to 0, put the
586 * clockdomain to sleep (software-supervised mode) or remove the
587 * clkdm-pwrdm autodependencies (hardware-supervised mode). Returns
588 * -EINVAL if passed null pointers; -ERANGE if the clkdm usecount
589 * underflows and debugging is enabled; or returns 0 upon success or
590 * if the clockdomain is in hwsup idle mode.
592 int omap2_clkdm_clk_disable(struct clockdomain
*clkdm
, struct clk
*clk
)
597 * XXX Rewrite this code to maintain a list of enabled
598 * downstream clocks for debugging purposes?
605 if (atomic_read(&clkdm
->usecount
) == 0) {
606 WARN_ON(1); /* underflow */
611 if (atomic_dec_return(&clkdm
->usecount
) > 0)
614 /* All downstream clocks of this clockdomain are now disabled */
616 pr_debug("clockdomain: clkdm %s: clk %s now disabled\n", clkdm
->name
,
619 v
= omap2_clkdm_clktrctrl_read(clkdm
);
621 if ((cpu_is_omap34xx() && v
== OMAP34XX_CLKSTCTRL_ENABLE_AUTO
) ||
622 (cpu_is_omap24xx() && v
== OMAP24XX_CLKSTCTRL_ENABLE_AUTO
))
623 _clkdm_del_autodeps(clkdm
);
625 omap2_clkdm_sleep(clkdm
);