Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[pandora-kernel.git] / 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 <plat/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 int clk_enable(struct clk *clk)
40 {
41         unsigned long flags;
42         int ret = 0;
43
44         if (clk == NULL || IS_ERR(clk))
45                 return -EINVAL;
46
47         spin_lock_irqsave(&clockfw_lock, flags);
48         if (arch_clock->clk_enable)
49                 ret = arch_clock->clk_enable(clk);
50         spin_unlock_irqrestore(&clockfw_lock, flags);
51
52         return ret;
53 }
54 EXPORT_SYMBOL(clk_enable);
55
56 void clk_disable(struct clk *clk)
57 {
58         unsigned long flags;
59
60         if (clk == NULL || IS_ERR(clk))
61                 return;
62
63         spin_lock_irqsave(&clockfw_lock, flags);
64         if (clk->usecount == 0) {
65                 printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
66                        clk->name);
67                 WARN_ON(1);
68                 goto out;
69         }
70
71         if (arch_clock->clk_disable)
72                 arch_clock->clk_disable(clk);
73
74 out:
75         spin_unlock_irqrestore(&clockfw_lock, flags);
76 }
77 EXPORT_SYMBOL(clk_disable);
78
79 unsigned long clk_get_rate(struct clk *clk)
80 {
81         unsigned long flags;
82         unsigned long ret = 0;
83
84         if (clk == NULL || IS_ERR(clk))
85                 return 0;
86
87         spin_lock_irqsave(&clockfw_lock, flags);
88         ret = clk->rate;
89         spin_unlock_irqrestore(&clockfw_lock, flags);
90
91         return ret;
92 }
93 EXPORT_SYMBOL(clk_get_rate);
94
95 /*-------------------------------------------------------------------------
96  * Optional clock functions defined in include/linux/clk.h
97  *-------------------------------------------------------------------------*/
98
99 long clk_round_rate(struct clk *clk, unsigned long rate)
100 {
101         unsigned long flags;
102         long ret = 0;
103
104         if (clk == NULL || IS_ERR(clk))
105                 return ret;
106
107         spin_lock_irqsave(&clockfw_lock, flags);
108         if (arch_clock->clk_round_rate)
109                 ret = arch_clock->clk_round_rate(clk, rate);
110         spin_unlock_irqrestore(&clockfw_lock, flags);
111
112         return ret;
113 }
114 EXPORT_SYMBOL(clk_round_rate);
115
116 int clk_set_rate(struct clk *clk, unsigned long rate)
117 {
118         unsigned long flags;
119         int ret = -EINVAL;
120
121         if (clk == NULL || IS_ERR(clk))
122                 return ret;
123
124         spin_lock_irqsave(&clockfw_lock, flags);
125         if (arch_clock->clk_set_rate)
126                 ret = arch_clock->clk_set_rate(clk, rate);
127         if (ret == 0) {
128                 if (clk->recalc)
129                         clk->rate = clk->recalc(clk);
130                 propagate_rate(clk);
131         }
132         spin_unlock_irqrestore(&clockfw_lock, flags);
133
134         return ret;
135 }
136 EXPORT_SYMBOL(clk_set_rate);
137
138 int clk_set_parent(struct clk *clk, struct clk *parent)
139 {
140         unsigned long flags;
141         int ret = -EINVAL;
142
143         if (cpu_is_omap44xx())
144         /* OMAP4 clk framework not supported yet */
145                 return 0;
146         if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
147                 return ret;
148
149         spin_lock_irqsave(&clockfw_lock, flags);
150         if (clk->usecount == 0) {
151                 if (arch_clock->clk_set_parent)
152                         ret = arch_clock->clk_set_parent(clk, parent);
153                 if (ret == 0) {
154                         if (clk->recalc)
155                                 clk->rate = clk->recalc(clk);
156                         propagate_rate(clk);
157                 }
158         } else
159                 ret = -EBUSY;
160         spin_unlock_irqrestore(&clockfw_lock, flags);
161
162         return ret;
163 }
164 EXPORT_SYMBOL(clk_set_parent);
165
166 struct clk *clk_get_parent(struct clk *clk)
167 {
168         return clk->parent;
169 }
170 EXPORT_SYMBOL(clk_get_parent);
171
172 /*-------------------------------------------------------------------------
173  * OMAP specific clock functions shared between omap1 and omap2
174  *-------------------------------------------------------------------------*/
175
176 unsigned int __initdata mpurate;
177
178 /*
179  * By default we use the rate set by the bootloader.
180  * You can override this with mpurate= cmdline option.
181  */
182 static int __init omap_clk_setup(char *str)
183 {
184         get_option(&str, &mpurate);
185
186         if (!mpurate)
187                 return 1;
188
189         if (mpurate < 1000)
190                 mpurate *= 1000000;
191
192         return 1;
193 }
194 __setup("mpurate=", omap_clk_setup);
195
196 /* Used for clocks that always have same value as the parent clock */
197 unsigned long followparent_recalc(struct clk *clk)
198 {
199         return clk->parent->rate;
200 }
201
202 void clk_reparent(struct clk *child, struct clk *parent)
203 {
204         list_del_init(&child->sibling);
205         if (parent)
206                 list_add(&child->sibling, &parent->children);
207         child->parent = parent;
208
209         /* now do the debugfs renaming to reattach the child
210            to the proper parent */
211 }
212
213 /* Propagate rate to children */
214 void propagate_rate(struct clk * tclk)
215 {
216         struct clk *clkp;
217
218         list_for_each_entry(clkp, &tclk->children, sibling) {
219                 if (clkp->recalc)
220                         clkp->rate = clkp->recalc(clkp);
221                 propagate_rate(clkp);
222         }
223 }
224
225 static LIST_HEAD(root_clks);
226
227 /**
228  * recalculate_root_clocks - recalculate and propagate all root clocks
229  *
230  * Recalculates all root clocks (clocks with no parent), which if the
231  * clock's .recalc is set correctly, should also propagate their rates.
232  * Called at init.
233  */
234 void recalculate_root_clocks(void)
235 {
236         struct clk *clkp;
237
238         list_for_each_entry(clkp, &root_clks, sibling) {
239                 if (clkp->recalc)
240                         clkp->rate = clkp->recalc(clkp);
241                 propagate_rate(clkp);
242         }
243 }
244
245 /**
246  * clk_preinit - initialize any fields in the struct clk before clk init
247  * @clk: struct clk * to initialize
248  *
249  * Initialize any struct clk fields needed before normal clk initialization
250  * can run.  No return value.
251  */
252 void clk_preinit(struct clk *clk)
253 {
254         INIT_LIST_HEAD(&clk->children);
255 }
256
257 int clk_register(struct clk *clk)
258 {
259         if (clk == NULL || IS_ERR(clk))
260                 return -EINVAL;
261
262         /*
263          * trap out already registered clocks
264          */
265         if (clk->node.next || clk->node.prev)
266                 return 0;
267
268         mutex_lock(&clocks_mutex);
269         if (clk->parent)
270                 list_add(&clk->sibling, &clk->parent->children);
271         else
272                 list_add(&clk->sibling, &root_clks);
273
274         list_add(&clk->node, &clocks);
275         if (clk->init)
276                 clk->init(clk);
277         mutex_unlock(&clocks_mutex);
278
279         return 0;
280 }
281 EXPORT_SYMBOL(clk_register);
282
283 void clk_unregister(struct clk *clk)
284 {
285         if (clk == NULL || IS_ERR(clk))
286                 return;
287
288         mutex_lock(&clocks_mutex);
289         list_del(&clk->sibling);
290         list_del(&clk->node);
291         mutex_unlock(&clocks_mutex);
292 }
293 EXPORT_SYMBOL(clk_unregister);
294
295 void clk_enable_init_clocks(void)
296 {
297         struct clk *clkp;
298
299         list_for_each_entry(clkp, &clocks, node) {
300                 if (clkp->flags & ENABLE_ON_INIT)
301                         clk_enable(clkp);
302         }
303 }
304
305 /*
306  * Low level helpers
307  */
308 static int clkll_enable_null(struct clk *clk)
309 {
310         return 0;
311 }
312
313 static void clkll_disable_null(struct clk *clk)
314 {
315 }
316
317 const struct clkops clkops_null = {
318         .enable         = clkll_enable_null,
319         .disable        = clkll_disable_null,
320 };
321
322 #ifdef CONFIG_CPU_FREQ
323 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
324 {
325         unsigned long flags;
326
327         spin_lock_irqsave(&clockfw_lock, flags);
328         if (arch_clock->clk_init_cpufreq_table)
329                 arch_clock->clk_init_cpufreq_table(table);
330         spin_unlock_irqrestore(&clockfw_lock, flags);
331 }
332
333 void clk_exit_cpufreq_table(struct cpufreq_frequency_table **table)
334 {
335         unsigned long flags;
336
337         spin_lock_irqsave(&clockfw_lock, flags);
338         if (arch_clock->clk_exit_cpufreq_table)
339                 arch_clock->clk_exit_cpufreq_table(table);
340         spin_unlock_irqrestore(&clockfw_lock, flags);
341 }
342 #endif
343
344 /*-------------------------------------------------------------------------*/
345
346 #ifdef CONFIG_OMAP_RESET_CLOCKS
347 /*
348  * Disable any unused clocks left on by the bootloader
349  */
350 static int __init clk_disable_unused(void)
351 {
352         struct clk *ck;
353         unsigned long flags;
354
355         list_for_each_entry(ck, &clocks, node) {
356                 if (ck->ops == &clkops_null)
357                         continue;
358
359                 if (ck->usecount > 0 || ck->enable_reg == 0)
360                         continue;
361
362                 spin_lock_irqsave(&clockfw_lock, flags);
363                 if (arch_clock->clk_disable_unused)
364                         arch_clock->clk_disable_unused(ck);
365                 spin_unlock_irqrestore(&clockfw_lock, flags);
366         }
367
368         return 0;
369 }
370 late_initcall(clk_disable_unused);
371 #endif
372
373 int __init clk_init(struct clk_functions * custom_clocks)
374 {
375         if (!custom_clocks) {
376                 printk(KERN_ERR "No custom clock functions registered\n");
377                 BUG();
378         }
379
380         arch_clock = custom_clocks;
381
382         return 0;
383 }
384
385 #if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
386 /*
387  *      debugfs support to trace clock tree hierarchy and attributes
388  */
389 static struct dentry *clk_debugfs_root;
390
391 static int clk_debugfs_register_one(struct clk *c)
392 {
393         int err;
394         struct dentry *d, *child;
395         struct clk *pa = c->parent;
396         char s[255];
397         char *p = s;
398
399         p += sprintf(p, "%s", c->name);
400         if (c->id != 0)
401                 sprintf(p, ":%d", c->id);
402         d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root);
403         if (!d)
404                 return -ENOMEM;
405         c->dent = d;
406
407         d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
408         if (!d) {
409                 err = -ENOMEM;
410                 goto err_out;
411         }
412         d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
413         if (!d) {
414                 err = -ENOMEM;
415                 goto err_out;
416         }
417         d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
418         if (!d) {
419                 err = -ENOMEM;
420                 goto err_out;
421         }
422         return 0;
423
424 err_out:
425         d = c->dent;
426         list_for_each_entry(child, &d->d_subdirs, d_u.d_child)
427                 debugfs_remove(child);
428         debugfs_remove(c->dent);
429         return err;
430 }
431
432 static int clk_debugfs_register(struct clk *c)
433 {
434         int err;
435         struct clk *pa = c->parent;
436
437         if (pa && !pa->dent) {
438                 err = clk_debugfs_register(pa);
439                 if (err)
440                         return err;
441         }
442
443         if (!c->dent) {
444                 err = clk_debugfs_register_one(c);
445                 if (err)
446                         return err;
447         }
448         return 0;
449 }
450
451 static int __init clk_debugfs_init(void)
452 {
453         struct clk *c;
454         struct dentry *d;
455         int err;
456
457         d = debugfs_create_dir("clock", NULL);
458         if (!d)
459                 return -ENOMEM;
460         clk_debugfs_root = d;
461
462         list_for_each_entry(c, &clocks, node) {
463                 err = clk_debugfs_register(c);
464                 if (err)
465                         goto err_out;
466         }
467         return 0;
468 err_out:
469         debugfs_remove_recursive(clk_debugfs_root);
470         return err;
471 }
472 late_initcall(clk_debugfs_init);
473
474 #endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */