Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[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 <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 /* This functions is moved to arch/arm/common/clkdev.c. For OMAP4 since
40  * clock framework is not up , it is defined here to avoid rework in
41  * every driver. Also dummy prcm reset function is added */
42
43 /* Dummy hooks only for OMAP4.For rest OMAPs, common clkdev is used */
44 #if defined(CONFIG_ARCH_OMAP4)
45 struct clk *clk_get(struct device *dev, const char *id)
46 {
47         return NULL;
48 }
49 EXPORT_SYMBOL(clk_get);
50
51 void clk_put(struct clk *clk)
52 {
53 }
54 EXPORT_SYMBOL(clk_put);
55
56 void omap2_clk_prepare_for_reboot(void)
57 {
58 }
59 EXPORT_SYMBOL(omap2_clk_prepare_for_reboot);
60
61 void omap_prcm_arch_reset(char mode)
62 {
63 }
64 EXPORT_SYMBOL(omap_prcm_arch_reset);
65 #endif
66 int clk_enable(struct clk *clk)
67 {
68         unsigned long flags;
69         int ret = 0;
70         if (cpu_is_omap44xx())
71                 /* OMAP4 clk framework not supported yet */
72                 return 0;
73
74         if (clk == NULL || IS_ERR(clk))
75                 return -EINVAL;
76
77         spin_lock_irqsave(&clockfw_lock, flags);
78         if (arch_clock->clk_enable)
79                 ret = arch_clock->clk_enable(clk);
80         spin_unlock_irqrestore(&clockfw_lock, flags);
81
82         return ret;
83 }
84 EXPORT_SYMBOL(clk_enable);
85
86 void clk_disable(struct clk *clk)
87 {
88         unsigned long flags;
89
90         if (clk == NULL || IS_ERR(clk))
91                 return;
92
93         spin_lock_irqsave(&clockfw_lock, flags);
94         if (clk->usecount == 0) {
95                 printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
96                        clk->name);
97                 WARN_ON(1);
98                 goto out;
99         }
100
101         if (arch_clock->clk_disable)
102                 arch_clock->clk_disable(clk);
103
104 out:
105         spin_unlock_irqrestore(&clockfw_lock, flags);
106 }
107 EXPORT_SYMBOL(clk_disable);
108
109 unsigned long clk_get_rate(struct clk *clk)
110 {
111         unsigned long flags;
112         unsigned long ret = 0;
113
114         if (clk == NULL || IS_ERR(clk))
115                 return 0;
116
117         spin_lock_irqsave(&clockfw_lock, flags);
118         ret = clk->rate;
119         spin_unlock_irqrestore(&clockfw_lock, flags);
120
121         return ret;
122 }
123 EXPORT_SYMBOL(clk_get_rate);
124
125 /*-------------------------------------------------------------------------
126  * Optional clock functions defined in include/linux/clk.h
127  *-------------------------------------------------------------------------*/
128
129 long clk_round_rate(struct clk *clk, unsigned long rate)
130 {
131         unsigned long flags;
132         long ret = 0;
133
134         if (clk == NULL || IS_ERR(clk))
135                 return ret;
136
137         spin_lock_irqsave(&clockfw_lock, flags);
138         if (arch_clock->clk_round_rate)
139                 ret = arch_clock->clk_round_rate(clk, rate);
140         spin_unlock_irqrestore(&clockfw_lock, flags);
141
142         return ret;
143 }
144 EXPORT_SYMBOL(clk_round_rate);
145
146 int clk_set_rate(struct clk *clk, unsigned long rate)
147 {
148         unsigned long flags;
149         int ret = -EINVAL;
150
151         if (clk == NULL || IS_ERR(clk))
152                 return ret;
153
154         spin_lock_irqsave(&clockfw_lock, flags);
155         if (arch_clock->clk_set_rate)
156                 ret = arch_clock->clk_set_rate(clk, rate);
157         if (ret == 0) {
158                 if (clk->recalc)
159                         clk->rate = clk->recalc(clk);
160                 propagate_rate(clk);
161         }
162         spin_unlock_irqrestore(&clockfw_lock, flags);
163
164         return ret;
165 }
166 EXPORT_SYMBOL(clk_set_rate);
167
168 int clk_set_parent(struct clk *clk, struct clk *parent)
169 {
170         unsigned long flags;
171         int ret = -EINVAL;
172
173         if (cpu_is_omap44xx())
174         /* OMAP4 clk framework not supported yet */
175                 return 0;
176         if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
177                 return ret;
178
179         spin_lock_irqsave(&clockfw_lock, flags);
180         if (clk->usecount == 0) {
181                 if (arch_clock->clk_set_parent)
182                         ret = arch_clock->clk_set_parent(clk, parent);
183                 if (ret == 0) {
184                         if (clk->recalc)
185                                 clk->rate = clk->recalc(clk);
186                         propagate_rate(clk);
187                 }
188         } else
189                 ret = -EBUSY;
190         spin_unlock_irqrestore(&clockfw_lock, flags);
191
192         return ret;
193 }
194 EXPORT_SYMBOL(clk_set_parent);
195
196 struct clk *clk_get_parent(struct clk *clk)
197 {
198         return clk->parent;
199 }
200 EXPORT_SYMBOL(clk_get_parent);
201
202 /*-------------------------------------------------------------------------
203  * OMAP specific clock functions shared between omap1 and omap2
204  *-------------------------------------------------------------------------*/
205
206 unsigned int __initdata mpurate;
207
208 /*
209  * By default we use the rate set by the bootloader.
210  * You can override this with mpurate= cmdline option.
211  */
212 static int __init omap_clk_setup(char *str)
213 {
214         get_option(&str, &mpurate);
215
216         if (!mpurate)
217                 return 1;
218
219         if (mpurate < 1000)
220                 mpurate *= 1000000;
221
222         return 1;
223 }
224 __setup("mpurate=", omap_clk_setup);
225
226 /* Used for clocks that always have same value as the parent clock */
227 unsigned long followparent_recalc(struct clk *clk)
228 {
229         return clk->parent->rate;
230 }
231
232 void clk_reparent(struct clk *child, struct clk *parent)
233 {
234         list_del_init(&child->sibling);
235         if (parent)
236                 list_add(&child->sibling, &parent->children);
237         child->parent = parent;
238
239         /* now do the debugfs renaming to reattach the child
240            to the proper parent */
241 }
242
243 /* Propagate rate to children */
244 void propagate_rate(struct clk * tclk)
245 {
246         struct clk *clkp;
247
248         list_for_each_entry(clkp, &tclk->children, sibling) {
249                 if (clkp->recalc)
250                         clkp->rate = clkp->recalc(clkp);
251                 propagate_rate(clkp);
252         }
253 }
254
255 static LIST_HEAD(root_clks);
256
257 /**
258  * recalculate_root_clocks - recalculate and propagate all root clocks
259  *
260  * Recalculates all root clocks (clocks with no parent), which if the
261  * clock's .recalc is set correctly, should also propagate their rates.
262  * Called at init.
263  */
264 void recalculate_root_clocks(void)
265 {
266         struct clk *clkp;
267
268         list_for_each_entry(clkp, &root_clks, sibling) {
269                 if (clkp->recalc)
270                         clkp->rate = clkp->recalc(clkp);
271                 propagate_rate(clkp);
272         }
273 }
274
275 /**
276  * clk_preinit - initialize any fields in the struct clk before clk init
277  * @clk: struct clk * to initialize
278  *
279  * Initialize any struct clk fields needed before normal clk initialization
280  * can run.  No return value.
281  */
282 void clk_preinit(struct clk *clk)
283 {
284         INIT_LIST_HEAD(&clk->children);
285 }
286
287 int clk_register(struct clk *clk)
288 {
289         if (clk == NULL || IS_ERR(clk))
290                 return -EINVAL;
291
292         /*
293          * trap out already registered clocks
294          */
295         if (clk->node.next || clk->node.prev)
296                 return 0;
297
298         mutex_lock(&clocks_mutex);
299         if (clk->parent)
300                 list_add(&clk->sibling, &clk->parent->children);
301         else
302                 list_add(&clk->sibling, &root_clks);
303
304         list_add(&clk->node, &clocks);
305         if (clk->init)
306                 clk->init(clk);
307         mutex_unlock(&clocks_mutex);
308
309         return 0;
310 }
311 EXPORT_SYMBOL(clk_register);
312
313 void clk_unregister(struct clk *clk)
314 {
315         if (clk == NULL || IS_ERR(clk))
316                 return;
317
318         mutex_lock(&clocks_mutex);
319         list_del(&clk->sibling);
320         list_del(&clk->node);
321         mutex_unlock(&clocks_mutex);
322 }
323 EXPORT_SYMBOL(clk_unregister);
324
325 void clk_enable_init_clocks(void)
326 {
327         struct clk *clkp;
328
329         list_for_each_entry(clkp, &clocks, node) {
330                 if (clkp->flags & ENABLE_ON_INIT)
331                         clk_enable(clkp);
332         }
333 }
334 EXPORT_SYMBOL(clk_enable_init_clocks);
335
336 /*
337  * Low level helpers
338  */
339 static int clkll_enable_null(struct clk *clk)
340 {
341         return 0;
342 }
343
344 static void clkll_disable_null(struct clk *clk)
345 {
346 }
347
348 const struct clkops clkops_null = {
349         .enable         = clkll_enable_null,
350         .disable        = clkll_disable_null,
351 };
352
353 #ifdef CONFIG_CPU_FREQ
354 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
355 {
356         unsigned long flags;
357
358         spin_lock_irqsave(&clockfw_lock, flags);
359         if (arch_clock->clk_init_cpufreq_table)
360                 arch_clock->clk_init_cpufreq_table(table);
361         spin_unlock_irqrestore(&clockfw_lock, flags);
362 }
363 EXPORT_SYMBOL(clk_init_cpufreq_table);
364 #endif
365
366 /*-------------------------------------------------------------------------*/
367
368 #ifdef CONFIG_OMAP_RESET_CLOCKS
369 /*
370  * Disable any unused clocks left on by the bootloader
371  */
372 static int __init clk_disable_unused(void)
373 {
374         struct clk *ck;
375         unsigned long flags;
376
377         list_for_each_entry(ck, &clocks, node) {
378                 if (ck->ops == &clkops_null)
379                         continue;
380
381                 if (ck->usecount > 0 || ck->enable_reg == 0)
382                         continue;
383
384                 spin_lock_irqsave(&clockfw_lock, flags);
385                 if (arch_clock->clk_disable_unused)
386                         arch_clock->clk_disable_unused(ck);
387                 spin_unlock_irqrestore(&clockfw_lock, flags);
388         }
389
390         return 0;
391 }
392 late_initcall(clk_disable_unused);
393 #endif
394
395 int __init clk_init(struct clk_functions * custom_clocks)
396 {
397         if (!custom_clocks) {
398                 printk(KERN_ERR "No custom clock functions registered\n");
399                 BUG();
400         }
401
402         arch_clock = custom_clocks;
403
404         return 0;
405 }
406
407 #if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
408 /*
409  *      debugfs support to trace clock tree hierarchy and attributes
410  */
411 static struct dentry *clk_debugfs_root;
412
413 static int clk_debugfs_register_one(struct clk *c)
414 {
415         int err;
416         struct dentry *d, *child;
417         struct clk *pa = c->parent;
418         char s[255];
419         char *p = s;
420
421         p += sprintf(p, "%s", c->name);
422         if (c->id != 0)
423                 sprintf(p, ":%d", c->id);
424         d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root);
425         if (!d)
426                 return -ENOMEM;
427         c->dent = d;
428
429         d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
430         if (!d) {
431                 err = -ENOMEM;
432                 goto err_out;
433         }
434         d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
435         if (!d) {
436                 err = -ENOMEM;
437                 goto err_out;
438         }
439         d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
440         if (!d) {
441                 err = -ENOMEM;
442                 goto err_out;
443         }
444         return 0;
445
446 err_out:
447         d = c->dent;
448         list_for_each_entry(child, &d->d_subdirs, d_u.d_child)
449                 debugfs_remove(child);
450         debugfs_remove(c->dent);
451         return err;
452 }
453
454 static int clk_debugfs_register(struct clk *c)
455 {
456         int err;
457         struct clk *pa = c->parent;
458
459         if (pa && !pa->dent) {
460                 err = clk_debugfs_register(pa);
461                 if (err)
462                         return err;
463         }
464
465         if (!c->dent) {
466                 err = clk_debugfs_register_one(c);
467                 if (err)
468                         return err;
469         }
470         return 0;
471 }
472
473 static int __init clk_debugfs_init(void)
474 {
475         struct clk *c;
476         struct dentry *d;
477         int err;
478
479         d = debugfs_create_dir("clock", NULL);
480         if (!d)
481                 return -ENOMEM;
482         clk_debugfs_root = d;
483
484         list_for_each_entry(c, &clocks, node) {
485                 err = clk_debugfs_register(c);
486                 if (err)
487                         goto err_out;
488         }
489         return 0;
490 err_out:
491         debugfs_remove(clk_debugfs_root); /* REVISIT: Cleanup correctly */
492         return err;
493 }
494 late_initcall(clk_debugfs_init);
495
496 #endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */