Merge git://git.kernel.org/pub/scm/linux/kernel/git/kyle/parisc-2.6
[linux-2.6] / arch / arm / plat-omap / clock.c
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  */
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
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
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
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
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
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
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
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
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
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  */
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 */
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 */
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  */
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
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
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
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
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
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
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  */
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
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
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 (IS_ERR(d))
432                 return PTR_ERR(d);
433         c->dent = d;
434
435         d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
436         if (IS_ERR(d)) {
437                 err = PTR_ERR(d);
438                 goto err_out;
439         }
440         d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
441         if (IS_ERR(d)) {
442                 err = PTR_ERR(d);
443                 goto err_out;
444         }
445         d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
446         if (IS_ERR(d)) {
447                 err = PTR_ERR(d);
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
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
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 (IS_ERR(d))
487                 return PTR_ERR(d);
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) */