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1 /*
2  *  linux/arch/arm/plat-omap/clock.c
3  *
4  *  Copyright (C) 2004 - 2008 Nokia corporation
5  *  Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
6  *
7  *  Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com>
8  *
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  */
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/module.h>
16 #include <linux/list.h>
17 #include <linux/errno.h>
18 #include <linux/err.h>
19 #include <linux/string.h>
20 #include <linux/clk.h>
21 #include <linux/mutex.h>
22 #include <linux/platform_device.h>
23 #include <linux/cpufreq.h>
24 #include <linux/debugfs.h>
25 #include <linux/io.h>
26 
27 #include <mach/clock.h>
28 
29 static LIST_HEAD(clocks);
30 static DEFINE_MUTEX(clocks_mutex);
31 static DEFINE_SPINLOCK(clockfw_lock);
32 
33 static struct clk_functions *arch_clock;
34 
35 /*-------------------------------------------------------------------------
36  * Standard clock functions defined in include/linux/clk.h
37  *-------------------------------------------------------------------------*/
38 
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  */
clk_get(struct device * dev,const char * id)43 struct clk * clk_get(struct device *dev, const char *id)
44 {
45 	struct clk *p, *clk = ERR_PTR(-ENOENT);
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;
52 
53 	mutex_lock(&clocks_mutex);
54 
55 	list_for_each_entry(p, &clocks, node) {
56 		if (p->id == idno &&
57 		    strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
58 			clk = p;
59 			goto found;
60 		}
61 	}
62 
63 	list_for_each_entry(p, &clocks, node) {
64 		if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
65 			clk = p;
66 			break;
67 		}
68 	}
69 
70 found:
71 	mutex_unlock(&clocks_mutex);
72 
73 	return clk;
74 }
75 EXPORT_SYMBOL(clk_get);
76 
clk_enable(struct clk * clk)77 int clk_enable(struct clk *clk)
78 {
79 	unsigned long flags;
80 	int ret = 0;
81 
82 	if (clk == NULL || IS_ERR(clk))
83 		return -EINVAL;
84 
85 	spin_lock_irqsave(&clockfw_lock, flags);
86 	if (arch_clock->clk_enable)
87 		ret = arch_clock->clk_enable(clk);
88 	spin_unlock_irqrestore(&clockfw_lock, flags);
89 
90 	return ret;
91 }
92 EXPORT_SYMBOL(clk_enable);
93 
clk_disable(struct clk * clk)94 void clk_disable(struct clk *clk)
95 {
96 	unsigned long flags;
97 
98 	if (clk == NULL || IS_ERR(clk))
99 		return;
100 
101 	spin_lock_irqsave(&clockfw_lock, flags);
102 	if (clk->usecount == 0) {
103 		printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
104 		       clk->name);
105 		WARN_ON(1);
106 		goto out;
107 	}
108 
109 	if (arch_clock->clk_disable)
110 		arch_clock->clk_disable(clk);
111 
112 out:
113 	spin_unlock_irqrestore(&clockfw_lock, flags);
114 }
115 EXPORT_SYMBOL(clk_disable);
116 
clk_get_usecount(struct clk * clk)117 int clk_get_usecount(struct clk *clk)
118 {
119 	unsigned long flags;
120 	int ret = 0;
121 
122 	if (clk == NULL || IS_ERR(clk))
123 		return 0;
124 
125 	spin_lock_irqsave(&clockfw_lock, flags);
126 	ret = clk->usecount;
127 	spin_unlock_irqrestore(&clockfw_lock, flags);
128 
129 	return ret;
130 }
131 EXPORT_SYMBOL(clk_get_usecount);
132 
clk_get_rate(struct clk * clk)133 unsigned long clk_get_rate(struct clk *clk)
134 {
135 	unsigned long flags;
136 	unsigned long ret = 0;
137 
138 	if (clk == NULL || IS_ERR(clk))
139 		return 0;
140 
141 	spin_lock_irqsave(&clockfw_lock, flags);
142 	ret = clk->rate;
143 	spin_unlock_irqrestore(&clockfw_lock, flags);
144 
145 	return ret;
146 }
147 EXPORT_SYMBOL(clk_get_rate);
148 
clk_put(struct clk * clk)149 void clk_put(struct clk *clk)
150 {
151 	if (clk && !IS_ERR(clk))
152 		module_put(clk->owner);
153 }
154 EXPORT_SYMBOL(clk_put);
155 
156 /*-------------------------------------------------------------------------
157  * Optional clock functions defined in include/linux/clk.h
158  *-------------------------------------------------------------------------*/
159 
clk_round_rate(struct clk * clk,unsigned long rate)160 long clk_round_rate(struct clk *clk, unsigned long rate)
161 {
162 	unsigned long flags;
163 	long ret = 0;
164 
165 	if (clk == NULL || IS_ERR(clk))
166 		return ret;
167 
168 	spin_lock_irqsave(&clockfw_lock, flags);
169 	if (arch_clock->clk_round_rate)
170 		ret = arch_clock->clk_round_rate(clk, rate);
171 	spin_unlock_irqrestore(&clockfw_lock, flags);
172 
173 	return ret;
174 }
175 EXPORT_SYMBOL(clk_round_rate);
176 
clk_set_rate(struct clk * clk,unsigned long rate)177 int clk_set_rate(struct clk *clk, unsigned long rate)
178 {
179 	unsigned long flags;
180 	int ret = -EINVAL;
181 
182 	if (clk == NULL || IS_ERR(clk))
183 		return ret;
184 
185 	spin_lock_irqsave(&clockfw_lock, flags);
186 	if (arch_clock->clk_set_rate)
187 		ret = arch_clock->clk_set_rate(clk, rate);
188 	spin_unlock_irqrestore(&clockfw_lock, flags);
189 
190 	return ret;
191 }
192 EXPORT_SYMBOL(clk_set_rate);
193 
clk_set_parent(struct clk * clk,struct clk * parent)194 int clk_set_parent(struct clk *clk, struct clk *parent)
195 {
196 	unsigned long flags;
197 	int ret = -EINVAL;
198 
199 	if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
200 		return ret;
201 
202 	spin_lock_irqsave(&clockfw_lock, flags);
203 	if (arch_clock->clk_set_parent)
204 		ret =  arch_clock->clk_set_parent(clk, parent);
205 	spin_unlock_irqrestore(&clockfw_lock, flags);
206 
207 	return ret;
208 }
209 EXPORT_SYMBOL(clk_set_parent);
210 
clk_get_parent(struct clk * clk)211 struct clk *clk_get_parent(struct clk *clk)
212 {
213 	unsigned long flags;
214 	struct clk * ret = NULL;
215 
216 	if (clk == NULL || IS_ERR(clk))
217 		return ret;
218 
219 	spin_lock_irqsave(&clockfw_lock, flags);
220 	if (arch_clock->clk_get_parent)
221 		ret = arch_clock->clk_get_parent(clk);
222 	spin_unlock_irqrestore(&clockfw_lock, flags);
223 
224 	return ret;
225 }
226 EXPORT_SYMBOL(clk_get_parent);
227 
228 /*-------------------------------------------------------------------------
229  * OMAP specific clock functions shared between omap1 and omap2
230  *-------------------------------------------------------------------------*/
231 
232 unsigned int __initdata mpurate;
233 
234 /*
235  * By default we use the rate set by the bootloader.
236  * You can override this with mpurate= cmdline option.
237  */
omap_clk_setup(char * str)238 static int __init omap_clk_setup(char *str)
239 {
240 	get_option(&str, &mpurate);
241 
242 	if (!mpurate)
243 		return 1;
244 
245 	if (mpurate < 1000)
246 		mpurate *= 1000000;
247 
248 	return 1;
249 }
250 __setup("mpurate=", omap_clk_setup);
251 
252 /* Used for clocks that always have same value as the parent clock */
followparent_recalc(struct clk * clk)253 void followparent_recalc(struct clk *clk)
254 {
255 	if (clk == NULL || IS_ERR(clk))
256 		return;
257 
258 	clk->rate = clk->parent->rate;
259 	if (unlikely(clk->flags & RATE_PROPAGATES))
260 		propagate_rate(clk);
261 }
262 
263 /* Propagate rate to children */
propagate_rate(struct clk * tclk)264 void propagate_rate(struct clk * tclk)
265 {
266 	struct clk *clkp;
267 
268 	if (tclk == NULL || IS_ERR(tclk))
269 		return;
270 
271 	list_for_each_entry(clkp, &clocks, node) {
272 		if (likely(clkp->parent != tclk))
273 			continue;
274 		if (likely((u32)clkp->recalc))
275 			clkp->recalc(clkp);
276 	}
277 }
278 
279 /**
280  * recalculate_root_clocks - recalculate and propagate all root clocks
281  *
282  * Recalculates all root clocks (clocks with no parent), which if the
283  * clock's .recalc is set correctly, should also propagate their rates.
284  * Called at init.
285  */
recalculate_root_clocks(void)286 void recalculate_root_clocks(void)
287 {
288 	struct clk *clkp;
289 
290 	list_for_each_entry(clkp, &clocks, node) {
291 		if (unlikely(!clkp->parent) && likely((u32)clkp->recalc))
292 			clkp->recalc(clkp);
293 	}
294 }
295 
clk_register(struct clk * clk)296 int clk_register(struct clk *clk)
297 {
298 	if (clk == NULL || IS_ERR(clk))
299 		return -EINVAL;
300 
301 	mutex_lock(&clocks_mutex);
302 	list_add(&clk->node, &clocks);
303 	if (clk->init)
304 		clk->init(clk);
305 	mutex_unlock(&clocks_mutex);
306 
307 	return 0;
308 }
309 EXPORT_SYMBOL(clk_register);
310 
clk_unregister(struct clk * clk)311 void clk_unregister(struct clk *clk)
312 {
313 	if (clk == NULL || IS_ERR(clk))
314 		return;
315 
316 	mutex_lock(&clocks_mutex);
317 	list_del(&clk->node);
318 	mutex_unlock(&clocks_mutex);
319 }
320 EXPORT_SYMBOL(clk_unregister);
321 
clk_deny_idle(struct clk * clk)322 void clk_deny_idle(struct clk *clk)
323 {
324 	unsigned long flags;
325 
326 	if (clk == NULL || IS_ERR(clk))
327 		return;
328 
329 	spin_lock_irqsave(&clockfw_lock, flags);
330 	if (arch_clock->clk_deny_idle)
331 		arch_clock->clk_deny_idle(clk);
332 	spin_unlock_irqrestore(&clockfw_lock, flags);
333 }
334 EXPORT_SYMBOL(clk_deny_idle);
335 
clk_allow_idle(struct clk * clk)336 void clk_allow_idle(struct clk *clk)
337 {
338 	unsigned long flags;
339 
340 	if (clk == NULL || IS_ERR(clk))
341 		return;
342 
343 	spin_lock_irqsave(&clockfw_lock, flags);
344 	if (arch_clock->clk_allow_idle)
345 		arch_clock->clk_allow_idle(clk);
346 	spin_unlock_irqrestore(&clockfw_lock, flags);
347 }
348 EXPORT_SYMBOL(clk_allow_idle);
349 
clk_enable_init_clocks(void)350 void clk_enable_init_clocks(void)
351 {
352 	struct clk *clkp;
353 
354 	list_for_each_entry(clkp, &clocks, node) {
355 		if (clkp->flags & ENABLE_ON_INIT)
356 			clk_enable(clkp);
357 	}
358 }
359 EXPORT_SYMBOL(clk_enable_init_clocks);
360 
361 #ifdef CONFIG_CPU_FREQ
clk_init_cpufreq_table(struct cpufreq_frequency_table ** table)362 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
363 {
364 	unsigned long flags;
365 
366 	spin_lock_irqsave(&clockfw_lock, flags);
367 	if (arch_clock->clk_init_cpufreq_table)
368 		arch_clock->clk_init_cpufreq_table(table);
369 	spin_unlock_irqrestore(&clockfw_lock, flags);
370 }
371 EXPORT_SYMBOL(clk_init_cpufreq_table);
372 #endif
373 
374 /*-------------------------------------------------------------------------*/
375 
376 #ifdef CONFIG_OMAP_RESET_CLOCKS
377 /*
378  * Disable any unused clocks left on by the bootloader
379  */
clk_disable_unused(void)380 static int __init clk_disable_unused(void)
381 {
382 	struct clk *ck;
383 	unsigned long flags;
384 
385 	list_for_each_entry(ck, &clocks, node) {
386 		if (ck->usecount > 0 || (ck->flags & ALWAYS_ENABLED) ||
387 			ck->enable_reg == 0)
388 			continue;
389 
390 		spin_lock_irqsave(&clockfw_lock, flags);
391 		if (arch_clock->clk_disable_unused)
392 			arch_clock->clk_disable_unused(ck);
393 		spin_unlock_irqrestore(&clockfw_lock, flags);
394 	}
395 
396 	return 0;
397 }
398 late_initcall(clk_disable_unused);
399 #endif
400 
clk_init(struct clk_functions * custom_clocks)401 int __init clk_init(struct clk_functions * custom_clocks)
402 {
403 	if (!custom_clocks) {
404 		printk(KERN_ERR "No custom clock functions registered\n");
405 		BUG();
406 	}
407 
408 	arch_clock = custom_clocks;
409 
410 	return 0;
411 }
412 
413 #if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
414 /*
415  *	debugfs support to trace clock tree hierarchy and attributes
416  */
417 static struct dentry *clk_debugfs_root;
418 
clk_debugfs_register_one(struct clk * c)419 static int clk_debugfs_register_one(struct clk *c)
420 {
421 	int err;
422 	struct dentry *d, *child;
423 	struct clk *pa = c->parent;
424 	char s[255];
425 	char *p = s;
426 
427 	p += sprintf(p, "%s", c->name);
428 	if (c->id != 0)
429 		sprintf(p, ":%d", c->id);
430 	d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root);
431 	if (!d)
432 		return -ENOMEM;
433 	c->dent = d;
434 
435 	d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
436 	if (!d) {
437 		err = -ENOMEM;
438 		goto err_out;
439 	}
440 	d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
441 	if (!d) {
442 		err = -ENOMEM;
443 		goto err_out;
444 	}
445 	d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
446 	if (!d) {
447 		err = -ENOMEM;
448 		goto err_out;
449 	}
450 	return 0;
451 
452 err_out:
453 	d = c->dent;
454 	list_for_each_entry(child, &d->d_subdirs, d_u.d_child)
455 		debugfs_remove(child);
456 	debugfs_remove(c->dent);
457 	return err;
458 }
459 
clk_debugfs_register(struct clk * c)460 static int clk_debugfs_register(struct clk *c)
461 {
462 	int err;
463 	struct clk *pa = c->parent;
464 
465 	if (pa && !pa->dent) {
466 		err = clk_debugfs_register(pa);
467 		if (err)
468 			return err;
469 	}
470 
471 	if (!c->dent) {
472 		err = clk_debugfs_register_one(c);
473 		if (err)
474 			return err;
475 	}
476 	return 0;
477 }
478 
clk_debugfs_init(void)479 static int __init clk_debugfs_init(void)
480 {
481 	struct clk *c;
482 	struct dentry *d;
483 	int err;
484 
485 	d = debugfs_create_dir("clock", NULL);
486 	if (!d)
487 		return -ENOMEM;
488 	clk_debugfs_root = d;
489 
490 	list_for_each_entry(c, &clocks, node) {
491 		err = clk_debugfs_register(c);
492 		if (err)
493 			goto err_out;
494 	}
495 	return 0;
496 err_out:
497 	debugfs_remove(clk_debugfs_root); /* REVISIT: Cleanup correctly */
498 	return err;
499 }
500 late_initcall(clk_debugfs_init);
501 
502 #endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */
503