aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-tegra/clock.c
blob: 03ad578349b98aa55e89f8639ff49663dd0f8d6d (plain) (blame)
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
/*
 *
 * Copyright (C) 2010 Google, Inc.
 *
 * Author:
 *	Colin Cross <ccross@google.com>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/debugfs.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <asm/clkdev.h>

#include "clock.h"

static LIST_HEAD(clocks);

static DEFINE_SPINLOCK(clock_lock);

struct clk *tegra_get_clock_by_name(const char *name)
{
	struct clk *c;
	struct clk *ret = NULL;
	unsigned long flags;
	spin_lock_irqsave(&clock_lock, flags);
	list_for_each_entry(c, &clocks, node) {
		if (strcmp(c->name, name) == 0) {
			ret = c;
			break;
		}
	}
	spin_unlock_irqrestore(&clock_lock, flags);
	return ret;
}

int clk_reparent(struct clk *c, struct clk *parent)
{
	pr_debug("%s: %s\n", __func__, c->name);
	if (c->refcnt && c->parent)
		clk_disable_locked(c->parent);
	c->parent = parent;
	if (c->refcnt && c->parent)
		clk_enable_locked(c->parent);
	list_del(&c->sibling);
	list_add_tail(&c->sibling, &parent->children);
	return 0;
}

static void propagate_rate(struct clk *c)
{
	struct clk *clkp;
	pr_debug("%s: %s\n", __func__, c->name);
	list_for_each_entry(clkp, &c->children, sibling) {
		pr_debug("   %s\n", clkp->name);
		if (clkp->ops->recalculate_rate)
			clkp->ops->recalculate_rate(clkp);
		propagate_rate(clkp);
	}
}

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

	spin_lock_irqsave(&clock_lock, flags);

	INIT_LIST_HEAD(&c->children);
	INIT_LIST_HEAD(&c->sibling);

	if (c->ops && c->ops->init)
		c->ops->init(c);

	list_add(&c->node, &clocks);

	if (c->parent)
		list_add_tail(&c->sibling, &c->parent->children);

	spin_unlock_irqrestore(&clock_lock, flags);
}

int clk_enable_locked(struct clk *c)
{
	int ret;
	pr_debug("%s: %s\n", __func__, c->name);
	if (c->refcnt == 0) {
		if (c->parent) {
			ret = clk_enable_locked(c->parent);
			if (ret)
				return ret;
		}

		if (c->ops && c->ops->enable) {
			ret = c->ops->enable(c);
			if (ret) {
				if (c->parent)
					clk_disable_locked(c->parent);
				return ret;
			}
			c->state = ON;
#ifdef CONFIG_DEBUG_FS
			c->set = 1;
#endif
		}
	}
	c->refcnt++;

	return 0;
}

int clk_enable(struct clk *c)
{
	int ret;
	unsigned long flags;
	spin_lock_irqsave(&clock_lock, flags);
	ret = clk_enable_locked(c);
	spin_unlock_irqrestore(&clock_lock, flags);
	return ret;
}
EXPORT_SYMBOL(clk_enable);

void clk_disable_locked(struct clk *c)
{
	pr_debug("%s: %s\n", __func__, c->name);
	if (c->refcnt == 0) {
		WARN(1, "Attempting to disable clock %s with refcnt 0", c->name);
		return;
	}
	if (c->refcnt == 1) {
		if (c->ops && c->ops->disable)
			c->ops->disable(c);

		if (c->parent)
			clk_disable_locked(c->parent);

		c->state = OFF;
	}
	c->refcnt--;
}

void clk_disable(struct clk *c)
{
	unsigned long flags;
	spin_lock_irqsave(&clock_lock, flags);
	clk_disable_locked(c);
	spin_unlock_irqrestore(&clock_lock, flags);
}
EXPORT_SYMBOL(clk_disable);

int clk_set_parent_locked(struct clk *c, struct clk *parent)
{
	int ret;

	pr_debug("%s: %s\n", __func__, c->name);

	if (!c->ops || !c->ops->set_parent)
		return -ENOSYS;

	ret = c->ops->set_parent(c, parent);

	if (ret)
		return ret;

	propagate_rate(c);

	return 0;
}

int clk_set_parent(struct clk *c, struct clk *parent)
{
	int ret;
	unsigned long flags;
	spin_lock_irqsave(&clock_lock, flags);
	ret = clk_set_parent_locked(c, parent);
	spin_unlock_irqrestore(&clock_lock, flags);
	return ret;
}
EXPORT_SYMBOL(clk_set_parent);

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

int clk_set_rate(struct clk *c, unsigned long rate)
{
	int ret = 0;
	unsigned long flags;

	spin_lock_irqsave(&clock_lock, flags);

	pr_debug("%s: %s\n", __func__, c->name);

	if (c->ops && c->ops->set_rate)
		ret = c->ops->set_rate(c, rate);
	else
		ret = -ENOSYS;

	propagate_rate(c);

	spin_unlock_irqrestore(&clock_lock, flags);

	return ret;
}
EXPORT_SYMBOL(clk_set_rate);

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

	spin_lock_irqsave(&clock_lock, flags);

	pr_debug("%s: %s\n", __func__, c->name);

	ret = c->rate;

	spin_unlock_irqrestore(&clock_lock, flags);
	return ret;
}
EXPORT_SYMBOL(clk_get_rate);

static int tegra_clk_init_one_from_table(struct tegra_clk_init_table *table)
{
	struct clk *c;
	struct clk *p;

	int ret = 0;

	c = tegra_get_clock_by_name(table->name);

	if (!c) {
		pr_warning("Unable to initialize clock %s\n",
			table->name);
		return -ENODEV;
	}

	if (table->parent) {
		p = tegra_get_clock_by_name(table->parent);
		if (!p) {
			pr_warning("Unable to find parent %s of clock %s\n",
				table->parent, table->name);
			return -ENODEV;
		}

		if (c->parent != p) {
			ret = clk_set_parent(c, p);
			if (ret) {
				pr_warning("Unable to set parent %s of clock %s: %d\n",
					table->parent, table->name, ret);
				return -EINVAL;
			}
		}
	}

	if (table->rate && table->rate != clk_get_rate(c)) {
		ret = clk_set_rate(c, table->rate);
		if (ret) {
			pr_warning("Unable to set clock %s to rate %lu: %d\n",
				table->name, table->rate, ret);
			return -EINVAL;
		}
	}

	if (table->enabled) {
		ret = clk_enable(c);
		if (ret) {
			pr_warning("Unable to enable clock %s: %d\n",
				table->name, ret);
			return -EINVAL;
		}
	}

	return 0;
}

void tegra_clk_init_from_table(struct tegra_clk_init_table *table)
{
	for (; table->name; table++)
		tegra_clk_init_one_from_table(table);
}
EXPORT_SYMBOL(tegra_clk_init_from_table);

void tegra_periph_reset_deassert(struct clk *c)
{
	tegra2_periph_reset_deassert(c);
}
EXPORT_SYMBOL(tegra_periph_reset_deassert);

void tegra_periph_reset_assert(struct clk *c)
{
	tegra2_periph_reset_assert(c);
}
EXPORT_SYMBOL(tegra_periph_reset_assert);

int __init tegra_init_clock(void)
{
	tegra2_init_clocks();

	return 0;
}

#ifdef CONFIG_DEBUG_FS
static struct dentry *clk_debugfs_root;


static void clock_tree_show_one(struct seq_file *s, struct clk *c, int level)
{
	struct clk *child;
	struct clk *safe;
	const char *state = "uninit";
	char div[5] = {0};

	if (c->state == ON)
		state = "on";
	else if (c->state == OFF)
		state = "off";

	if (c->mul != 0 && c->div != 0) {
		BUG_ON(c->mul > 2);
		if (c->mul > c->div)
			snprintf(div, sizeof(div), "x%d", c->mul / c->div);
		else
			snprintf(div, sizeof(div), "%d%s", c->div / c->mul,
				(c->div % c->mul) ? ".5" : "");
	}

	seq_printf(s, "%*s%-*s %-6s %-3d %-5s %-10lu\n",
		level * 3 + 1, c->set ? "" : "*",
		30 - level * 3, c->name,
		state, c->refcnt, div, c->rate);
	list_for_each_entry_safe(child, safe, &c->children, sibling) {
		clock_tree_show_one(s, child, level + 1);
	}
}

static int clock_tree_show(struct seq_file *s, void *data)
{
	struct clk *c;
	unsigned long flags;
	seq_printf(s, " clock                          state  ref div   rate      \n");
	seq_printf(s, "-----------------------------------------------------------\n");
	spin_lock_irqsave(&clock_lock, flags);
	list_for_each_entry(c, &clocks, node)
		if (c->parent == NULL)
			clock_tree_show_one(s, c, 0);
	spin_unlock_irqrestore(&clock_lock, flags);
	return 0;
}

static int clock_tree_open(struct inode *inode, struct file *file)
{
	return single_open(file, clock_tree_show, inode->i_private);
}

static const struct file_operations clock_tree_fops = {
	.open		= clock_tree_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int possible_parents_show(struct seq_file *s, void *data)
{
	struct clk *c = s->private;
	int i;

	for (i = 0; c->inputs[i].input; i++) {
		char *first = (i == 0) ? "" : " ";
		seq_printf(s, "%s%s", first, c->inputs[i].input->name);
	}
	seq_printf(s, "\n");
	return 0;
}

static int possible_parents_open(struct inode *inode, struct file *file)
{
	return single_open(file, possible_parents_show, inode->i_private);
}

static const struct file_operations possible_parents_fops = {
	.open		= possible_parents_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int clk_debugfs_register_one(struct clk *c)
{
	struct dentry *d, *child, *child_tmp;

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

	d = debugfs_create_u8("refcnt", S_IRUGO, c->dent, (u8 *)&c->refcnt);
	if (!d)
		goto err_out;

	d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
	if (!d)
		goto err_out;

	d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
	if (!d)
		goto err_out;

	if (c->inputs) {
		d = debugfs_create_file("possible_parents", S_IRUGO, c->dent,
			c, &possible_parents_fops);
		if (!d)
			goto err_out;
	}

	return 0;

err_out:
	d = c->dent;
	list_for_each_entry_safe(child, child_tmp, &d->d_subdirs, d_u.d_child)
		debugfs_remove(child);
	debugfs_remove(c->dent);
	return -ENOMEM;
}

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 = -ENOMEM;

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

	d = debugfs_create_file("clock_tree", S_IRUGO, clk_debugfs_root, NULL,
		&clock_tree_fops);
	if (!d)
		goto err_out;

	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