summaryrefslogtreecommitdiffstats
path: root/arch/arm/plat-omap/clock.c
blob: 0a603242f36712e1060542f6c14c97efd3100a76 (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
/*
 *  linux/arch/arm/plat-omap/clock.c
 *
 *  Copyright (C) 2004 - 2005 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/version.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.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/platform_device.h>

#include <asm/io.h>
#include <asm/semaphore.h>

#include <asm/arch/clock.h>

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

static struct clk_functions *arch_clock;

#ifdef CONFIG_PM_DEBUG

static void print_parents(struct clk *clk)
{
	struct clk *p;
	int printed = 0;

	list_for_each_entry(p, &clocks, node) {
		if (p->parent == clk && p->usecount) {
			if (!clk->usecount && !printed) {
				printk("MISMATCH: %s\n", clk->name);
				printed = 1;
			}
			printk("\t%-15s\n", p->name);
		}
	}
}

void clk_print_usecounts(void)
{
	unsigned long flags;
	struct clk *p;

	spin_lock_irqsave(&clockfw_lock, flags);
	list_for_each_entry(p, &clocks, node) {
		if (p->usecount)
			printk("%-15s: %d\n", p->name, p->usecount);
		print_parents(p);

	}
	spin_unlock_irqrestore(&clockfw_lock, flags);
}

#endif

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

/*
 * Returns a clock. Note that we first try to use device id on the bus
 * and clock name. If this fails, we try to use clock name only.
 */
struct clk * clk_get(struct device *dev, const char *id)
{
	struct clk *p, *clk = ERR_PTR(-ENOENT);
	int idno;

	if (dev == NULL || dev->bus != &platform_bus_type)
		idno = -1;
	else
		idno = to_platform_device(dev)->id;

	mutex_lock(&clocks_mutex);

	list_for_each_entry(p, &clocks, node) {
		if (p->id == idno &&
		    strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
			clk = p;
			goto found;
		}
	}

	list_for_each_entry(p, &clocks, node) {
		if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
			clk = p;
			break;
		}
	}

found:
	mutex_unlock(&clocks_mutex);

	return clk;
}
EXPORT_SYMBOL(clk_get);

int clk_enable(struct clk *clk)
{
	unsigned long flags;
	int ret = 0;

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

	spin_lock_irqsave(&clockfw_lock, flags);
	if (arch_clock->clk_enable)
		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;

	spin_lock_irqsave(&clockfw_lock, flags);
	BUG_ON(clk->usecount == 0);
	if (arch_clock->clk_disable)
		arch_clock->clk_disable(clk);
	spin_unlock_irqrestore(&clockfw_lock, flags);
}
EXPORT_SYMBOL(clk_disable);

int clk_get_usecount(struct clk *clk)
{
	unsigned long flags;
	int ret = 0;

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

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

	return ret;
}
EXPORT_SYMBOL(clk_get_usecount);

unsigned long clk_get_rate(struct clk *clk)
{
	unsigned long flags;
	unsigned long ret = 0;

	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);

void clk_put(struct clk *clk)
{
	if (clk && !IS_ERR(clk))
		module_put(clk->owner);
}
EXPORT_SYMBOL(clk_put);

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

long clk_round_rate(struct clk *clk, unsigned long rate)
{
	unsigned long flags;
	long ret = 0;

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

	spin_lock_irqsave(&clockfw_lock, flags);
	if (arch_clock->clk_round_rate)
		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;

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

	spin_lock_irqsave(&clockfw_lock, flags);
	if (arch_clock->clk_set_parent)
		ret =  arch_clock->clk_set_parent(clk, parent);
	spin_unlock_irqrestore(&clockfw_lock, flags);

	return ret;
}
EXPORT_SYMBOL(clk_set_parent);

struct clk *clk_get_parent(struct clk *clk)
{
	unsigned long flags;
	struct clk * ret = NULL;

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

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

	return ret;
}
EXPORT_SYMBOL(clk_get_parent);

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

unsigned 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 */
void followparent_recalc(struct clk *clk)
{
	if (clk == NULL || IS_ERR(clk))
		return;

	clk->rate = clk->parent->rate;
	if (unlikely(clk->flags & RATE_PROPAGATES))
		propagate_rate(clk);
}

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

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

	list_for_each_entry(clkp, &clocks, node) {
		if (likely(clkp->parent != tclk))
			continue;
		if (likely((u32)clkp->recalc))
			clkp->recalc(clkp);
	}
}

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

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

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

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

	spin_lock_irqsave(&clockfw_lock, flags);
	if (arch_clock->clk_deny_idle)
		arch_clock->clk_deny_idle(clk);
	spin_unlock_irqrestore(&clockfw_lock, flags);
}
EXPORT_SYMBOL(clk_deny_idle);

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

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

	spin_lock_irqsave(&clockfw_lock, flags);
	if (arch_clock->clk_allow_idle)
		arch_clock->clk_allow_idle(clk);
	spin_unlock_irqrestore(&clockfw_lock, flags);
}
EXPORT_SYMBOL(clk_allow_idle);

/*-------------------------------------------------------------------------*/

#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;

	list_for_each_entry(ck, &clocks, node) {
		if (ck->usecount > 0 || (ck->flags & ALWAYS_ENABLED) ||
			ck->enable_reg == 0)
			continue;

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

	return 0;
}
late_initcall(clk_disable_unused);
#endif

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

	arch_clock = custom_clocks;

	return 0;
}
OpenPOWER on IntegriCloud