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[ARM] omap: allow double-registering of clocks
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1da177e4 1/*
b9158556 2 * linux/arch/arm/plat-omap/clock.c
1da177e4 3 *
137b3ee2 4 * Copyright (C) 2004 - 2008 Nokia corporation
1da177e4
LT
5 * Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
6 *
1a8bfa1e
TL
7 * Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com>
8 *
1da177e4
LT
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 */
1da177e4 13#include <linux/kernel.h>
1a8bfa1e
TL
14#include <linux/init.h>
15#include <linux/module.h>
1da177e4
LT
16#include <linux/list.h>
17#include <linux/errno.h>
18#include <linux/err.h>
4e57b681 19#include <linux/string.h>
f8ce2547 20#include <linux/clk.h>
00431707 21#include <linux/mutex.h>
b824efae 22#include <linux/platform_device.h>
b851cb28 23#include <linux/cpufreq.h>
137b3ee2 24#include <linux/debugfs.h>
fced80c7 25#include <linux/io.h>
1da177e4 26
a09e64fb 27#include <mach/clock.h>
1da177e4 28
7df3450e 29static LIST_HEAD(clocks);
00431707 30static DEFINE_MUTEX(clocks_mutex);
7df3450e 31static DEFINE_SPINLOCK(clockfw_lock);
1da177e4 32
1a8bfa1e 33static struct clk_functions *arch_clock;
1da177e4 34
1a8bfa1e 35/*-------------------------------------------------------------------------
f07adc59 36 * Standard clock functions defined in include/linux/clk.h
1a8bfa1e 37 *-------------------------------------------------------------------------*/
1da177e4 38
b824efae
TL
39/*
40 * Returns a clock. Note that we first try to use device id on the bus
41 * and clock name. If this fails, we try to use clock name only.
42 */
1a8bfa1e 43struct clk * clk_get(struct device *dev, const char *id)
1da177e4
LT
44{
45 struct clk *p, *clk = ERR_PTR(-ENOENT);
b824efae
TL
46 int idno;
47
48 if (dev == NULL || dev->bus != &platform_bus_type)
49 idno = -1;
50 else
51 idno = to_platform_device(dev)->id;
1da177e4 52
00431707 53 mutex_lock(&clocks_mutex);
b824efae
TL
54
55 list_for_each_entry(p, &clocks, node) {
eee5b191 56 if (p->id == idno && strcmp(id, p->name) == 0) {
b824efae 57 clk = p;
67d4d835 58 goto found;
b824efae
TL
59 }
60 }
61
1da177e4 62 list_for_each_entry(p, &clocks, node) {
eee5b191 63 if (strcmp(id, p->name) == 0) {
1da177e4
LT
64 clk = p;
65 break;
66 }
67 }
b824efae 68
67d4d835 69found:
00431707 70 mutex_unlock(&clocks_mutex);
1da177e4
LT
71
72 return clk;
73}
74EXPORT_SYMBOL(clk_get);
75
1da177e4
LT
76int clk_enable(struct clk *clk)
77{
78 unsigned long flags;
1a8bfa1e 79 int ret = 0;
1da177e4 80
b824efae
TL
81 if (clk == NULL || IS_ERR(clk))
82 return -EINVAL;
83
1da177e4 84 spin_lock_irqsave(&clockfw_lock, flags);
f07adc59 85 if (arch_clock->clk_enable)
1a8bfa1e 86 ret = arch_clock->clk_enable(clk);
1da177e4 87 spin_unlock_irqrestore(&clockfw_lock, flags);
1a8bfa1e 88
1da177e4
LT
89 return ret;
90}
91EXPORT_SYMBOL(clk_enable);
92
1da177e4
LT
93void clk_disable(struct clk *clk)
94{
95 unsigned long flags;
96
b824efae
TL
97 if (clk == NULL || IS_ERR(clk))
98 return;
99
1da177e4 100 spin_lock_irqsave(&clockfw_lock, flags);
7cf95774
TL
101 if (clk->usecount == 0) {
102 printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
103 clk->name);
104 WARN_ON(1);
105 goto out;
106 }
107
f07adc59 108 if (arch_clock->clk_disable)
1a8bfa1e 109 arch_clock->clk_disable(clk);
7cf95774
TL
110
111out:
1da177e4
LT
112 spin_unlock_irqrestore(&clockfw_lock, flags);
113}
114EXPORT_SYMBOL(clk_disable);
115
1da177e4
LT
116int clk_get_usecount(struct clk *clk)
117{
1a8bfa1e
TL
118 unsigned long flags;
119 int ret = 0;
1da177e4 120
b824efae
TL
121 if (clk == NULL || IS_ERR(clk))
122 return 0;
123
1a8bfa1e
TL
124 spin_lock_irqsave(&clockfw_lock, flags);
125 ret = clk->usecount;
126 spin_unlock_irqrestore(&clockfw_lock, flags);
1da177e4 127
1a8bfa1e 128 return ret;
1da177e4 129}
1a8bfa1e 130EXPORT_SYMBOL(clk_get_usecount);
1da177e4 131
1a8bfa1e 132unsigned long clk_get_rate(struct clk *clk)
1da177e4 133{
1a8bfa1e
TL
134 unsigned long flags;
135 unsigned long ret = 0;
1da177e4 136
b824efae
TL
137 if (clk == NULL || IS_ERR(clk))
138 return 0;
139
1a8bfa1e
TL
140 spin_lock_irqsave(&clockfw_lock, flags);
141 ret = clk->rate;
142 spin_unlock_irqrestore(&clockfw_lock, flags);
1da177e4 143
1a8bfa1e 144 return ret;
1da177e4 145}
1a8bfa1e 146EXPORT_SYMBOL(clk_get_rate);
1da177e4 147
1a8bfa1e 148void clk_put(struct clk *clk)
bb13b5fd 149{
bb13b5fd 150}
1a8bfa1e 151EXPORT_SYMBOL(clk_put);
bb13b5fd 152
1a8bfa1e 153/*-------------------------------------------------------------------------
f07adc59 154 * Optional clock functions defined in include/linux/clk.h
1a8bfa1e 155 *-------------------------------------------------------------------------*/
bb13b5fd 156
1da177e4
LT
157long clk_round_rate(struct clk *clk, unsigned long rate)
158{
1a8bfa1e
TL
159 unsigned long flags;
160 long ret = 0;
1da177e4 161
b824efae
TL
162 if (clk == NULL || IS_ERR(clk))
163 return ret;
164
1a8bfa1e
TL
165 spin_lock_irqsave(&clockfw_lock, flags);
166 if (arch_clock->clk_round_rate)
167 ret = arch_clock->clk_round_rate(clk, rate);
168 spin_unlock_irqrestore(&clockfw_lock, flags);
1da177e4 169
1a8bfa1e 170 return ret;
1da177e4
LT
171}
172EXPORT_SYMBOL(clk_round_rate);
173
1a8bfa1e 174int clk_set_rate(struct clk *clk, unsigned long rate)
1da177e4 175{
1a8bfa1e 176 unsigned long flags;
b824efae
TL
177 int ret = -EINVAL;
178
179 if (clk == NULL || IS_ERR(clk))
180 return ret;
bb13b5fd 181
1a8bfa1e
TL
182 spin_lock_irqsave(&clockfw_lock, flags);
183 if (arch_clock->clk_set_rate)
184 ret = arch_clock->clk_set_rate(clk, rate);
c6af4508
RK
185 if (ret == 0 && (clk->flags & RATE_PROPAGATES))
186 propagate_rate(clk);
1a8bfa1e 187 spin_unlock_irqrestore(&clockfw_lock, flags);
1da177e4 188
1a8bfa1e 189 return ret;
1da177e4 190}
1a8bfa1e 191EXPORT_SYMBOL(clk_set_rate);
1da177e4 192
1a8bfa1e 193int clk_set_parent(struct clk *clk, struct clk *parent)
1da177e4 194{
1a8bfa1e 195 unsigned long flags;
b824efae
TL
196 int ret = -EINVAL;
197
198 if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
199 return ret;
1da177e4 200
1a8bfa1e
TL
201 spin_lock_irqsave(&clockfw_lock, flags);
202 if (arch_clock->clk_set_parent)
c6af4508
RK
203 ret = arch_clock->clk_set_parent(clk, parent);
204 if (ret == 0 && (clk->flags & RATE_PROPAGATES))
205 propagate_rate(clk);
1a8bfa1e 206 spin_unlock_irqrestore(&clockfw_lock, flags);
1da177e4 207
1a8bfa1e 208 return ret;
1da177e4 209}
1a8bfa1e 210EXPORT_SYMBOL(clk_set_parent);
1da177e4 211
1a8bfa1e 212struct clk *clk_get_parent(struct clk *clk)
1da177e4 213{
2e777bf1 214 return clk->parent;
1da177e4 215}
1a8bfa1e 216EXPORT_SYMBOL(clk_get_parent);
1da177e4 217
1a8bfa1e
TL
218/*-------------------------------------------------------------------------
219 * OMAP specific clock functions shared between omap1 and omap2
220 *-------------------------------------------------------------------------*/
1da177e4 221
1a8bfa1e 222unsigned int __initdata mpurate;
1da177e4 223
1a8bfa1e
TL
224/*
225 * By default we use the rate set by the bootloader.
226 * You can override this with mpurate= cmdline option.
227 */
228static int __init omap_clk_setup(char *str)
1da177e4 229{
1a8bfa1e 230 get_option(&str, &mpurate);
1da177e4 231
1a8bfa1e
TL
232 if (!mpurate)
233 return 1;
1da177e4 234
1a8bfa1e
TL
235 if (mpurate < 1000)
236 mpurate *= 1000000;
1da177e4 237
1a8bfa1e 238 return 1;
1da177e4 239}
1a8bfa1e 240__setup("mpurate=", omap_clk_setup);
1da177e4 241
1a8bfa1e
TL
242/* Used for clocks that always have same value as the parent clock */
243void followparent_recalc(struct clk *clk)
1da177e4 244{
b824efae
TL
245 if (clk == NULL || IS_ERR(clk))
246 return;
247
1a8bfa1e 248 clk->rate = clk->parent->rate;
1da177e4
LT
249}
250
1a8bfa1e
TL
251/* Propagate rate to children */
252void propagate_rate(struct clk * tclk)
1da177e4 253{
1a8bfa1e 254 struct clk *clkp;
1da177e4 255
b824efae
TL
256 if (tclk == NULL || IS_ERR(tclk))
257 return;
258
1a8bfa1e
TL
259 list_for_each_entry(clkp, &clocks, node) {
260 if (likely(clkp->parent != tclk))
261 continue;
9a5fedac 262 if (clkp->recalc)
1a8bfa1e 263 clkp->recalc(clkp);
9a5fedac
RK
264 if (clkp->flags & RATE_PROPAGATES)
265 propagate_rate(clkp);
1a8bfa1e 266 }
1da177e4
LT
267}
268
6b8858a9
PW
269/**
270 * recalculate_root_clocks - recalculate and propagate all root clocks
271 *
272 * Recalculates all root clocks (clocks with no parent), which if the
273 * clock's .recalc is set correctly, should also propagate their rates.
274 * Called at init.
275 */
276void recalculate_root_clocks(void)
277{
278 struct clk *clkp;
279
280 list_for_each_entry(clkp, &clocks, node) {
9a5fedac
RK
281 if (!clkp->parent) {
282 if (clkp->recalc)
283 clkp->recalc(clkp);
284 if (clkp->flags & RATE_PROPAGATES)
285 propagate_rate(clkp);
286 }
6b8858a9
PW
287 }
288}
289
1da177e4
LT
290int clk_register(struct clk *clk)
291{
b824efae
TL
292 if (clk == NULL || IS_ERR(clk))
293 return -EINVAL;
294
dbb674d5
RK
295 /*
296 * trap out already registered clocks
297 */
298 if (clk->node.next || clk->node.prev)
299 return 0;
300
00431707 301 mutex_lock(&clocks_mutex);
1da177e4
LT
302 list_add(&clk->node, &clocks);
303 if (clk->init)
304 clk->init(clk);
00431707 305 mutex_unlock(&clocks_mutex);
1a8bfa1e 306
1da177e4
LT
307 return 0;
308}
309EXPORT_SYMBOL(clk_register);
310
311void clk_unregister(struct clk *clk)
312{
b824efae
TL
313 if (clk == NULL || IS_ERR(clk))
314 return;
315
00431707 316 mutex_lock(&clocks_mutex);
1da177e4 317 list_del(&clk->node);
00431707 318 mutex_unlock(&clocks_mutex);
1da177e4
LT
319}
320EXPORT_SYMBOL(clk_unregister);
321
6b8858a9
PW
322void clk_enable_init_clocks(void)
323{
324 struct clk *clkp;
325
326 list_for_each_entry(clkp, &clocks, node) {
327 if (clkp->flags & ENABLE_ON_INIT)
328 clk_enable(clkp);
329 }
330}
331EXPORT_SYMBOL(clk_enable_init_clocks);
332
897dcded
RK
333/*
334 * Low level helpers
335 */
336static int clkll_enable_null(struct clk *clk)
337{
338 return 0;
339}
340
341static void clkll_disable_null(struct clk *clk)
342{
343}
344
345const struct clkops clkops_null = {
346 .enable = clkll_enable_null,
347 .disable = clkll_disable_null,
348};
349
6b8858a9
PW
350#ifdef CONFIG_CPU_FREQ
351void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
352{
353 unsigned long flags;
354
355 spin_lock_irqsave(&clockfw_lock, flags);
356 if (arch_clock->clk_init_cpufreq_table)
357 arch_clock->clk_init_cpufreq_table(table);
358 spin_unlock_irqrestore(&clockfw_lock, flags);
359}
360EXPORT_SYMBOL(clk_init_cpufreq_table);
361#endif
362
1a8bfa1e 363/*-------------------------------------------------------------------------*/
bb13b5fd 364
90afd5cb
TL
365#ifdef CONFIG_OMAP_RESET_CLOCKS
366/*
367 * Disable any unused clocks left on by the bootloader
368 */
369static int __init clk_disable_unused(void)
370{
371 struct clk *ck;
372 unsigned long flags;
373
374 list_for_each_entry(ck, &clocks, node) {
897dcded
RK
375 if (ck->ops == &clkops_null)
376 continue;
377
378 if (ck->usecount > 0 || ck->enable_reg == 0)
90afd5cb
TL
379 continue;
380
381 spin_lock_irqsave(&clockfw_lock, flags);
382 if (arch_clock->clk_disable_unused)
383 arch_clock->clk_disable_unused(ck);
384 spin_unlock_irqrestore(&clockfw_lock, flags);
385 }
386
387 return 0;
388}
389late_initcall(clk_disable_unused);
390#endif
391
1a8bfa1e 392int __init clk_init(struct clk_functions * custom_clocks)
bb13b5fd 393{
1a8bfa1e
TL
394 if (!custom_clocks) {
395 printk(KERN_ERR "No custom clock functions registered\n");
396 BUG();
bb13b5fd
TL
397 }
398
1a8bfa1e
TL
399 arch_clock = custom_clocks;
400
bb13b5fd
TL
401 return 0;
402}
6b8858a9 403
137b3ee2
HD
404#if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
405/*
406 * debugfs support to trace clock tree hierarchy and attributes
407 */
408static struct dentry *clk_debugfs_root;
409
410static int clk_debugfs_register_one(struct clk *c)
411{
412 int err;
413 struct dentry *d, *child;
414 struct clk *pa = c->parent;
415 char s[255];
416 char *p = s;
417
418 p += sprintf(p, "%s", c->name);
419 if (c->id != 0)
420 sprintf(p, ":%d", c->id);
421 d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root);
e621f266
Z
422 if (!d)
423 return -ENOMEM;
137b3ee2
HD
424 c->dent = d;
425
426 d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
e621f266
Z
427 if (!d) {
428 err = -ENOMEM;
137b3ee2
HD
429 goto err_out;
430 }
431 d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
e621f266
Z
432 if (!d) {
433 err = -ENOMEM;
137b3ee2
HD
434 goto err_out;
435 }
436 d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
e621f266
Z
437 if (!d) {
438 err = -ENOMEM;
137b3ee2
HD
439 goto err_out;
440 }
441 return 0;
442
443err_out:
444 d = c->dent;
445 list_for_each_entry(child, &d->d_subdirs, d_u.d_child)
446 debugfs_remove(child);
447 debugfs_remove(c->dent);
448 return err;
449}
450
451static int clk_debugfs_register(struct clk *c)
452{
453 int err;
454 struct clk *pa = c->parent;
455
456 if (pa && !pa->dent) {
457 err = clk_debugfs_register(pa);
458 if (err)
459 return err;
460 }
461
462 if (!c->dent) {
463 err = clk_debugfs_register_one(c);
464 if (err)
465 return err;
466 }
467 return 0;
468}
469
470static int __init clk_debugfs_init(void)
471{
472 struct clk *c;
473 struct dentry *d;
474 int err;
475
476 d = debugfs_create_dir("clock", NULL);
e621f266
Z
477 if (!d)
478 return -ENOMEM;
137b3ee2
HD
479 clk_debugfs_root = d;
480
481 list_for_each_entry(c, &clocks, node) {
482 err = clk_debugfs_register(c);
483 if (err)
484 goto err_out;
485 }
486 return 0;
487err_out:
488 debugfs_remove(clk_debugfs_root); /* REVISIT: Cleanup correctly */
489 return err;
490}
491late_initcall(clk_debugfs_init);
492
493#endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */