aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/plat-omap/clock.c
blob: 964704f40bbeecd80ffa646eb4008ce9657b86c8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
/*
 *  linux/arch/arm/plat-omap/clock.c
 *
 *  Copyright (C) 2004 - 2008 Nokia corporation
 *  Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
 *
 *  Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/clk.h>
#include <linux/mutex.h>
#include <linux/cpufreq.h>
#include <linux/debugfs.h>
#include <linux/io.h>

#include <plat/clock.h>

static LIST_HEAD(clocks);
static DEFINE_MUTEX(clocks_mutex);
static DEFINE_SPINLOCK(clockfw_lock);

static struct clk_functions *arch_clock;

/*
 * Standard clock functions defined in include/linux/clk.h
 */

int clk_enable(struct clk *clk)
{
	unsigned long flags;
	int ret;

	if (clk == NULL || IS_ERR(clk))
		return -EINVAL;

	if (!arch_clock || !arch_clock->clk_enable)
		return -EINVAL;

	spin_lock_irqsave(&clockfw_lock, flags);
	ret = arch_clock->clk_enable(clk);
	spin_unlock_irqrestore(&clockfw_lock, flags);

	return ret;
}
EXPORT_SYMBOL(clk_enable);

void clk_disable(struct clk *clk)
{
	unsigned long flags;

	if (clk == NULL || IS_ERR(clk))
		return;

	if (!arch_clock || !arch_clock->clk_disable)
		return;

	spin_lock_irqsave(&clockfw_lock, flags);
	if (clk->usecount == 0) {
		pr_err("Trying disable clock %s with 0 usecount\n",
		       clk->name);
		WARN_ON(1);
		goto out;
	}

	arch_clock->clk_disable(clk);

out:
	spin_unlock_irqrestore(&clockfw_lock, flags);
}
EXPORT_SYMBOL(clk_disable);

unsigned long clk_get_rate(struct clk *clk)
{
	unsigned long flags;
	unsigned long ret;

	if (clk == NULL || IS_ERR(clk))
		return 0;

	spin_lock_irqsave(&clockfw_lock, flags);
	ret = clk->rate;
	spin_unlock_irqrestore(&clockfw_lock, flags);

	return ret;
}
EXPORT_SYMBOL(clk_get_rate);

/*
 * Optional clock functions defined in include/linux/clk.h
 */

long clk_round_rate(struct clk *clk, unsigned long rate)
{
	unsigned long flags;
	long ret;

	if (clk == NULL || IS_ERR(clk))
		return 0;

	if (!arch_clock || !arch_clock->clk_round_rate)
		return 0;

	spin_lock_irqsave(&clockfw_lock, flags);
	ret = arch_clock->clk_round_rate(clk, rate);
	spin_unlock_irqrestore(&clockfw_lock, flags);

	return ret;
}
EXPORT_SYMBOL(clk_round_rate);

int clk_set_rate(struct clk *clk, unsigned long rate)
{
	unsigned long flags;
	int ret = -EINVAL;

	if (clk == NULL || IS_ERR(clk))
		return ret;

	if (!arch_clock || !arch_clock->clk_set_rate)
		return ret;

	spin_lock_irqsave(&clockfw_lock, flags);
	ret = arch_clock->clk_set_rate(clk, rate);
	if (ret == 0)
		propagate_rate(clk);
	spin_unlock_irqrestore(&clockfw_lock, flags);

	return ret;
}
EXPORT_SYMBOL(clk_set_rate);

int clk_set_parent(struct clk *clk, struct clk *parent)
{
	unsigned long flags;
	int ret = -EINVAL;

	if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
		return ret;

	if (!arch_clock || !arch_clock->clk_set_parent)
		return ret;

	spin_lock_irqsave(&clockfw_lock, flags);
	if (clk->usecount == 0) {
		ret = arch_clock->clk_set_parent(clk, parent);
		if (ret == 0)
			propagate_rate(clk);
	} else
		ret = -EBUSY;
	spin_unlock_irqrestore(&clockfw_lock, flags);

	return ret;
}
EXPORT_SYMBOL(clk_set_parent);

struct clk *clk_get_parent(struct clk *clk)
{
	return clk->parent;
}
EXPORT_SYMBOL(clk_get_parent);

/*
 * OMAP specific clock functions shared between omap1 and omap2
 */

int __initdata mpurate;

/*
 * By default we use the rate set by the bootloader.
 * You can override this with mpurate= cmdline option.
 */
static int __init omap_clk_setup(char *str)
{
	get_option(&str, &mpurate);

	if (!mpurate)
		return 1;

	if (mpurate < 1000)
		mpurate *= 1000000;

	return 1;
}
__setup("mpurate=", omap_clk_setup);

/* Used for clocks that always have same value as the parent clock */
unsigned long followparent_recalc(struct clk *clk)
{
	return clk->parent->rate;
}

/*
 * Used for clocks that have the same value as the parent clock,
 * divided by some factor
 */
unsigned long omap_fixed_divisor_recalc(struct clk *clk)
{
	WARN_ON(!clk->fixed_div);

	return clk->parent->rate / clk->fixed_div;
}

void clk_reparent(struct clk *child, struct clk *parent)
{
	list_del_init(&child->sibling);
	if (parent)
		list_add(&child->sibling, &parent->children);
	child->parent = parent;

	/* now do the debugfs renaming to reattach the child
	   to the proper parent */
}

/* Propagate rate to children */
void propagate_rate(struct clk *tclk)
{
	struct clk *clkp;

	list_for_each_entry(clkp, &tclk->children, sibling) {
		if (clkp->recalc)
			clkp->rate = clkp->recalc(clkp);
		propagate_rate(clkp);
	}
}

static LIST_HEAD(root_clks);

/**
 * recalculate_root_clocks - recalculate and propagate all root clocks
 *
 * Recalculates all root clocks (clocks with no parent), which if the
 * clock's .recalc is set correctly, should also propagate their rates.
 * Called at init.
 */
void recalculate_root_clocks(void)
{
	struct clk *clkp;

	list_for_each_entry(clkp, &root_clks, sibling) {
		if (clkp->recalc)
			clkp->rate = clkp->recalc(clkp);
		propagate_rate(clkp);
	}
}

/**
 * clk_preinit - initialize any fields in the struct clk before clk init
 * @clk: struct clk * to initialize
 *
 * Initialize any struct clk fields needed before normal clk initialization
 * can run.  No return value.
 */
void clk_preinit(struct clk *clk)
{
	INIT_LIST_HEAD(&clk->children);
}

int clk_register(struct clk *clk)
{
	if (clk == NULL || IS_ERR(clk))
		return -EINVAL;

	/*
	 * trap out already registered clocks
	 */
	if (clk->node.next || clk->node.prev)
		return 0;

	mutex_lock(&clocks_mutex);
	if (clk->parent)
		list_add(&clk->sibling, &clk->parent->children);
	else
		list_add(&clk->sibling, &root_clks);

	list_add(&clk->node, &clocks);
	if (clk->init)
		clk->init(clk);
	mutex_unlock(&clocks_mutex);

	return 0;
}
EXPORT_SYMBOL(clk_register);

void clk_unregister(struct clk *clk)
{
	if (clk == NULL || IS_ERR(clk))
		return;

	mutex_lock(&clocks_mutex);
	list_del(&clk->sibling);
	list_del(&clk->node);
	mutex_unlock(&clocks_mutex);
}
EXPORT_SYMBOL(clk_unregister);

void clk_enable_init_clocks(void)
{
	struct clk *clkp;

	list_for_each_entry(clkp, &clocks, node) {
		if (clkp->flags & ENABLE_ON_INIT)
			clk_enable(clkp);
	}
}

/**
 * omap_clk_get_by_name - locate OMAP struct clk by its name
 * @name: name of the struct clk to locate
 *
 * Locate an OMAP struct clk by its name.  Assumes that struct clk
 * names are unique.  Returns NULL if not found or a pointer to the
 * struct clk if found.
 */
struct clk *omap_clk_get_by_name(const char *name)
{
	struct clk *c;
	struct clk *ret = NULL;

	mutex_lock(&clocks_mutex);

	list_for_each_entry(c, &clocks, node) {
		if (!strcmp(c->name, name)) {
			ret = c;
			break;
		}
	}

	mutex_unlock(&clocks_mutex);

	return ret;
}

int omap_clk_enable_autoidle_all(void)
{
	struct clk *c;
	unsigned long flags;

	spin_lock_irqsave(&clockfw_lock, flags);

	list_for_each_entry(c, &clocks, node)
		if (c->ops->allow_idle)
			c->ops->allow_idle(c);

	spin_unlock_irqrestore(&clockfw_lock, flags);

	return 0;
}

int omap_clk_disable_autoidle_all(void)
{
	struct clk *c;
	unsigned long flags;

	spin_lock_irqsave(&clockfw_lock, flags);

	list_for_each_entry(c, &clocks, node)
		if (c->ops->deny_idle)
			c->ops->deny_idle(c);

	spin_unlock_irqrestore(&clockfw_lock, flags);

	return 0;
}

/*
 * Low level helpers
 */
static int clkll_enable_null(struct clk *clk)
{
	return 0;
}

static void clkll_disable_null(struct clk *clk)
{
}

const struct clkops clkops_null = {
	.enable		= clkll_enable_null,
	.disable	= clkll_disable_null,
};

/*
 * Dummy clock
 *
 * Used for clock aliases that are needed on some OMAPs, but not others
 */
struct clk dummy_ck = {
	.name	= "dummy",
	.ops	= &clkops_null,
};

#ifdef CONFIG_CPU_FREQ
void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
{
	unsigned long flags;

	if (!arch_clock || !arch_clock->clk_init_cpufreq_table)
		return;

	spin_lock_irqsave(&clockfw_lock, flags);
	arch_clock->clk_init_cpufreq_table(table);
	spin_unlock_irqrestore(&clockfw_lock, flags);
}

void clk_exit_cpufreq_table(struct cpufreq_frequency_table **table)
{
	unsigned long flags;

	if (!arch_clock || !arch_clock->clk_exit_cpufreq_table)
		return;

	spin_lock_irqsave(&clockfw_lock, flags);
	arch_clock->clk_exit_cpufreq_table(table);
	spin_unlock_irqrestore(&clockfw_lock, flags);
}
#endif

/*
 *
 */

#ifdef CONFIG_OMAP_RESET_CLOCKS
/*
 * Disable any unused clocks left on by the bootloader
 */
static int __init clk_disable_unused(void)
{
	struct clk *ck;
	unsigned long flags;

	if (!arch_clock || !arch_clock->clk_disable_unused)
		return 0;

	pr_info("clock: disabling unused clocks to save power\n");
	list_for_each_entry(ck, &clocks, node) {
		if (ck->ops == &clkops_null)
			continue;

		if (ck->usecount > 0 || !ck->enable_reg)
			continue;

		spin_lock_irqsave(&clockfw_lock, flags);
		arch_clock->clk_disable_unused(ck);
		spin_unlock_irqrestore(&clockfw_lock, flags);
	}

	return 0;
}
late_initcall(clk_disable_unused);
late_initcall(omap_clk_enable_autoidle_all);
#endif

int __init clk_init(struct clk_functions * custom_clocks)
{
	if (!custom_clocks) {
		pr_err("No custom clock functions registered\n");
		BUG();
	}

	arch_clock = custom_clocks;

	return 0;
}

#if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
/*
 *	debugfs support to trace clock tree hierarchy and attributes
 */
static struct dentry *clk_debugfs_root;

static int clk_debugfs_register_one(struct clk *c)
{
	int err;
	struct dentry *d;
	struct clk *pa = c->parent;

	d = debugfs_create_dir(c->name, pa ? pa->dent : clk_debugfs_root);
	if (!d)
		return -ENOMEM;
	c->dent = d;

	d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
	if (!d) {
		err = -ENOMEM;
		goto err_out;
	}
	d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
	if (!d) {
		err = -ENOMEM;
		goto err_out;
	}
	d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
	if (!d) {
		err = -ENOMEM;
		goto err_out;
	}
	return 0;

err_out:
	debugfs_remove_recursive(c->dent);
	return err;
}

static int clk_debugfs_register(struct clk *c)
{
	int err;
	struct clk *pa = c->parent;

	if (pa && !pa->dent) {
		err = clk_debugfs_register(pa);
		if (err)
			return err;
	}

	if (!c->dent) {
		err = clk_debugfs_register_one(c);
		if (err)
			return err;
	}
	return 0;
}

static int __init clk_debugfs_init(void)
{
	struct clk *c;
	struct dentry *d;
	int err;

	d = debugfs_create_dir("clock", NULL);
	if (!d)
		return -ENOMEM;
	clk_debugfs_root = d;

	list_for_each_entry(c, &clocks, node) {
		err = clk_debugfs_register(c);
		if (err)
			goto err_out;
	}
	return 0;
err_out:
	debugfs_remove_recursive(clk_debugfs_root);
	return err;
}
late_initcall(clk_debugfs_init);

#endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */