blob: 459ce9da13e0631b41e6cafc5ed9a85523e5e1b7 [file] [log] [blame]
Mike Turquetteb24764902012-03-15 23:11:19 -07001/*
2 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
3 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * Standard functionality for the common clock API. See Documentation/clk.txt
10 */
11
Michael Turquetteb09d6d92015-01-29 14:22:50 -080012#include <linux/clk-provider.h>
Sylwester Nawrocki86be4082014-06-18 17:29:32 +020013#include <linux/clk/clk-conf.h>
Mike Turquetteb24764902012-03-15 23:11:19 -070014#include <linux/module.h>
15#include <linux/mutex.h>
16#include <linux/spinlock.h>
17#include <linux/err.h>
18#include <linux/list.h>
19#include <linux/slab.h>
Grant Likely766e6a42012-04-09 14:50:06 -050020#include <linux/of.h>
Stephen Boyd46c87732012-09-24 13:38:04 -070021#include <linux/device.h>
Prashant Gaikwadf2f6c252013-01-04 12:30:52 +053022#include <linux/init.h>
Mike Turquette533ddeb2013-03-28 13:59:02 -070023#include <linux/sched.h>
Mike Turquetteb24764902012-03-15 23:11:19 -070024
Sylwester Nawrockid6782c22013-08-23 17:03:43 +020025#include "clk.h"
26
Mike Turquetteb24764902012-03-15 23:11:19 -070027static DEFINE_SPINLOCK(enable_lock);
28static DEFINE_MUTEX(prepare_lock);
29
Mike Turquette533ddeb2013-03-28 13:59:02 -070030static struct task_struct *prepare_owner;
31static struct task_struct *enable_owner;
32
33static int prepare_refcnt;
34static int enable_refcnt;
35
Mike Turquetteb24764902012-03-15 23:11:19 -070036static HLIST_HEAD(clk_root_list);
37static HLIST_HEAD(clk_orphan_list);
38static LIST_HEAD(clk_notifier_list);
39
Tomeu Vizoso035a61c2015-01-23 12:03:30 +010040static long clk_core_get_accuracy(struct clk_core *clk);
41static unsigned long clk_core_get_rate(struct clk_core *clk);
42static int clk_core_get_phase(struct clk_core *clk);
43static bool clk_core_is_prepared(struct clk_core *clk);
44static bool clk_core_is_enabled(struct clk_core *clk);
Tomeu Vizoso035a61c2015-01-23 12:03:30 +010045static struct clk_core *clk_core_lookup(const char *name);
46
Michael Turquetteb09d6d92015-01-29 14:22:50 -080047/*** private data structures ***/
48
49struct clk_core {
50 const char *name;
51 const struct clk_ops *ops;
52 struct clk_hw *hw;
53 struct module *owner;
54 struct clk_core *parent;
55 const char **parent_names;
56 struct clk_core **parents;
57 u8 num_parents;
58 u8 new_parent_index;
59 unsigned long rate;
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +010060 unsigned long req_rate;
Michael Turquetteb09d6d92015-01-29 14:22:50 -080061 unsigned long new_rate;
62 struct clk_core *new_parent;
63 struct clk_core *new_child;
64 unsigned long flags;
65 unsigned int enable_count;
66 unsigned int prepare_count;
67 unsigned long accuracy;
68 int phase;
69 struct hlist_head children;
70 struct hlist_node child_node;
71 struct hlist_node debug_node;
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +010072 struct hlist_head clks;
Michael Turquetteb09d6d92015-01-29 14:22:50 -080073 unsigned int notifier_count;
74#ifdef CONFIG_DEBUG_FS
75 struct dentry *dentry;
76#endif
77 struct kref ref;
78};
79
Stephen Boyddfc202e2015-02-02 14:37:41 -080080#define CREATE_TRACE_POINTS
81#include <trace/events/clk.h>
82
Michael Turquetteb09d6d92015-01-29 14:22:50 -080083struct clk {
84 struct clk_core *core;
85 const char *dev_id;
86 const char *con_id;
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +010087 unsigned long min_rate;
88 unsigned long max_rate;
Stephen Boyd50595f82015-02-06 11:42:44 -080089 struct hlist_node clks_node;
Michael Turquetteb09d6d92015-01-29 14:22:50 -080090};
91
Mike Turquetteeab89f62013-03-28 13:59:01 -070092/*** locking ***/
93static void clk_prepare_lock(void)
94{
Mike Turquette533ddeb2013-03-28 13:59:02 -070095 if (!mutex_trylock(&prepare_lock)) {
96 if (prepare_owner == current) {
97 prepare_refcnt++;
98 return;
99 }
100 mutex_lock(&prepare_lock);
101 }
102 WARN_ON_ONCE(prepare_owner != NULL);
103 WARN_ON_ONCE(prepare_refcnt != 0);
104 prepare_owner = current;
105 prepare_refcnt = 1;
Mike Turquetteeab89f62013-03-28 13:59:01 -0700106}
107
108static void clk_prepare_unlock(void)
109{
Mike Turquette533ddeb2013-03-28 13:59:02 -0700110 WARN_ON_ONCE(prepare_owner != current);
111 WARN_ON_ONCE(prepare_refcnt == 0);
112
113 if (--prepare_refcnt)
114 return;
115 prepare_owner = NULL;
Mike Turquetteeab89f62013-03-28 13:59:01 -0700116 mutex_unlock(&prepare_lock);
117}
118
119static unsigned long clk_enable_lock(void)
120{
121 unsigned long flags;
Mike Turquette533ddeb2013-03-28 13:59:02 -0700122
123 if (!spin_trylock_irqsave(&enable_lock, flags)) {
124 if (enable_owner == current) {
125 enable_refcnt++;
126 return flags;
127 }
128 spin_lock_irqsave(&enable_lock, flags);
129 }
130 WARN_ON_ONCE(enable_owner != NULL);
131 WARN_ON_ONCE(enable_refcnt != 0);
132 enable_owner = current;
133 enable_refcnt = 1;
Mike Turquetteeab89f62013-03-28 13:59:01 -0700134 return flags;
135}
136
137static void clk_enable_unlock(unsigned long flags)
138{
Mike Turquette533ddeb2013-03-28 13:59:02 -0700139 WARN_ON_ONCE(enable_owner != current);
140 WARN_ON_ONCE(enable_refcnt == 0);
141
142 if (--enable_refcnt)
143 return;
144 enable_owner = NULL;
Mike Turquetteeab89f62013-03-28 13:59:01 -0700145 spin_unlock_irqrestore(&enable_lock, flags);
146}
147
Mike Turquetteb24764902012-03-15 23:11:19 -0700148/*** debugfs support ***/
149
Mike Turquetteea72dc22013-12-18 21:38:52 -0800150#ifdef CONFIG_DEBUG_FS
Mike Turquetteb24764902012-03-15 23:11:19 -0700151#include <linux/debugfs.h>
152
153static struct dentry *rootdir;
Mike Turquetteb24764902012-03-15 23:11:19 -0700154static int inited = 0;
Stephen Boyd6314b672014-09-04 23:37:49 -0700155static DEFINE_MUTEX(clk_debug_lock);
156static HLIST_HEAD(clk_debug_list);
Mike Turquetteb24764902012-03-15 23:11:19 -0700157
Sachin Kamat6b44c8542014-07-01 11:56:34 +0530158static struct hlist_head *all_lists[] = {
159 &clk_root_list,
160 &clk_orphan_list,
161 NULL,
162};
163
164static struct hlist_head *orphan_list[] = {
165 &clk_orphan_list,
166 NULL,
167};
168
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100169static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
170 int level)
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530171{
172 if (!c)
173 return;
174
Mike Turquettee59c5372014-02-18 21:21:25 -0800175 seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530176 level * 3 + 1, "",
177 30 - level * 3, c->name,
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100178 c->enable_count, c->prepare_count, clk_core_get_rate(c),
179 clk_core_get_accuracy(c), clk_core_get_phase(c));
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530180}
181
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100182static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530183 int level)
184{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100185 struct clk_core *child;
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530186
187 if (!c)
188 return;
189
190 clk_summary_show_one(s, c, level);
191
Sasha Levinb67bfe02013-02-27 17:06:00 -0800192 hlist_for_each_entry(child, &c->children, child_node)
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530193 clk_summary_show_subtree(s, child, level + 1);
194}
195
196static int clk_summary_show(struct seq_file *s, void *data)
197{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100198 struct clk_core *c;
Peter De Schrijver27b8d5f2014-05-30 18:03:57 +0300199 struct hlist_head **lists = (struct hlist_head **)s->private;
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530200
Mike Turquettee59c5372014-02-18 21:21:25 -0800201 seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n");
202 seq_puts(s, "----------------------------------------------------------------------------------------\n");
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530203
Mike Turquetteeab89f62013-03-28 13:59:01 -0700204 clk_prepare_lock();
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530205
Peter De Schrijver27b8d5f2014-05-30 18:03:57 +0300206 for (; *lists; lists++)
207 hlist_for_each_entry(c, *lists, child_node)
208 clk_summary_show_subtree(s, c, 0);
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530209
Mike Turquetteeab89f62013-03-28 13:59:01 -0700210 clk_prepare_unlock();
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530211
212 return 0;
213}
214
215
216static int clk_summary_open(struct inode *inode, struct file *file)
217{
218 return single_open(file, clk_summary_show, inode->i_private);
219}
220
221static const struct file_operations clk_summary_fops = {
222 .open = clk_summary_open,
223 .read = seq_read,
224 .llseek = seq_lseek,
225 .release = single_release,
226};
227
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100228static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530229{
230 if (!c)
231 return;
232
233 seq_printf(s, "\"%s\": { ", c->name);
234 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
235 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100236 seq_printf(s, "\"rate\": %lu", clk_core_get_rate(c));
237 seq_printf(s, "\"accuracy\": %lu", clk_core_get_accuracy(c));
238 seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530239}
240
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100241static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530242{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100243 struct clk_core *child;
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530244
245 if (!c)
246 return;
247
248 clk_dump_one(s, c, level);
249
Sasha Levinb67bfe02013-02-27 17:06:00 -0800250 hlist_for_each_entry(child, &c->children, child_node) {
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530251 seq_printf(s, ",");
252 clk_dump_subtree(s, child, level + 1);
253 }
254
255 seq_printf(s, "}");
256}
257
258static int clk_dump(struct seq_file *s, void *data)
259{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100260 struct clk_core *c;
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530261 bool first_node = true;
Peter De Schrijver27b8d5f2014-05-30 18:03:57 +0300262 struct hlist_head **lists = (struct hlist_head **)s->private;
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530263
264 seq_printf(s, "{");
265
Mike Turquetteeab89f62013-03-28 13:59:01 -0700266 clk_prepare_lock();
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530267
Peter De Schrijver27b8d5f2014-05-30 18:03:57 +0300268 for (; *lists; lists++) {
269 hlist_for_each_entry(c, *lists, child_node) {
270 if (!first_node)
271 seq_puts(s, ",");
272 first_node = false;
273 clk_dump_subtree(s, c, 0);
274 }
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530275 }
276
Mike Turquetteeab89f62013-03-28 13:59:01 -0700277 clk_prepare_unlock();
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530278
279 seq_printf(s, "}");
280 return 0;
281}
282
283
284static int clk_dump_open(struct inode *inode, struct file *file)
285{
286 return single_open(file, clk_dump, inode->i_private);
287}
288
289static const struct file_operations clk_dump_fops = {
290 .open = clk_dump_open,
291 .read = seq_read,
292 .llseek = seq_lseek,
293 .release = single_release,
294};
295
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100296static int clk_debug_create_one(struct clk_core *clk, struct dentry *pdentry)
Mike Turquetteb24764902012-03-15 23:11:19 -0700297{
298 struct dentry *d;
299 int ret = -ENOMEM;
300
301 if (!clk || !pdentry) {
302 ret = -EINVAL;
303 goto out;
304 }
305
306 d = debugfs_create_dir(clk->name, pdentry);
307 if (!d)
308 goto out;
309
310 clk->dentry = d;
311
312 d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry,
313 (u32 *)&clk->rate);
314 if (!d)
315 goto err_out;
316
Boris BREZILLON5279fc42013-12-21 10:34:47 +0100317 d = debugfs_create_u32("clk_accuracy", S_IRUGO, clk->dentry,
318 (u32 *)&clk->accuracy);
319 if (!d)
320 goto err_out;
321
Mike Turquettee59c5372014-02-18 21:21:25 -0800322 d = debugfs_create_u32("clk_phase", S_IRUGO, clk->dentry,
323 (u32 *)&clk->phase);
324 if (!d)
325 goto err_out;
326
Mike Turquetteb24764902012-03-15 23:11:19 -0700327 d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry,
328 (u32 *)&clk->flags);
329 if (!d)
330 goto err_out;
331
332 d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry,
333 (u32 *)&clk->prepare_count);
334 if (!d)
335 goto err_out;
336
337 d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry,
338 (u32 *)&clk->enable_count);
339 if (!d)
340 goto err_out;
341
342 d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry,
343 (u32 *)&clk->notifier_count);
344 if (!d)
345 goto err_out;
346
Chris Brandabeab452014-07-03 14:01:29 -0700347 if (clk->ops->debug_init) {
348 ret = clk->ops->debug_init(clk->hw, clk->dentry);
349 if (ret)
Alex Elderc646cbf2014-03-21 06:43:56 -0500350 goto err_out;
Chris Brandabeab452014-07-03 14:01:29 -0700351 }
Alex Elderc646cbf2014-03-21 06:43:56 -0500352
Mike Turquetteb24764902012-03-15 23:11:19 -0700353 ret = 0;
354 goto out;
355
356err_out:
Alex Elderb5f98e62013-11-27 09:39:49 -0600357 debugfs_remove_recursive(clk->dentry);
358 clk->dentry = NULL;
Mike Turquetteb24764902012-03-15 23:11:19 -0700359out:
360 return ret;
361}
362
Mike Turquetteb24764902012-03-15 23:11:19 -0700363/**
364 * clk_debug_register - add a clk node to the debugfs clk tree
365 * @clk: the clk being added to the debugfs clk tree
366 *
367 * Dynamically adds a clk to the debugfs clk tree if debugfs has been
368 * initialized. Otherwise it bails out early since the debugfs clk tree
369 * will be created lazily by clk_debug_init as part of a late_initcall.
Mike Turquetteb24764902012-03-15 23:11:19 -0700370 */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100371static int clk_debug_register(struct clk_core *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700372{
Mike Turquetteb24764902012-03-15 23:11:19 -0700373 int ret = 0;
374
Stephen Boyd6314b672014-09-04 23:37:49 -0700375 mutex_lock(&clk_debug_lock);
376 hlist_add_head(&clk->debug_node, &clk_debug_list);
377
Mike Turquetteb24764902012-03-15 23:11:19 -0700378 if (!inited)
Stephen Boyd6314b672014-09-04 23:37:49 -0700379 goto unlock;
Mike Turquetteb24764902012-03-15 23:11:19 -0700380
Stephen Boyd6314b672014-09-04 23:37:49 -0700381 ret = clk_debug_create_one(clk, rootdir);
382unlock:
383 mutex_unlock(&clk_debug_lock);
Mike Turquetteb24764902012-03-15 23:11:19 -0700384
Mike Turquetteb24764902012-03-15 23:11:19 -0700385 return ret;
386}
387
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +0200388 /**
389 * clk_debug_unregister - remove a clk node from the debugfs clk tree
390 * @clk: the clk being removed from the debugfs clk tree
391 *
392 * Dynamically removes a clk and all it's children clk nodes from the
393 * debugfs clk tree if clk->dentry points to debugfs created by
394 * clk_debug_register in __clk_init.
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +0200395 */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100396static void clk_debug_unregister(struct clk_core *clk)
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +0200397{
Stephen Boyd6314b672014-09-04 23:37:49 -0700398 mutex_lock(&clk_debug_lock);
Stephen Boyd6314b672014-09-04 23:37:49 -0700399 hlist_del_init(&clk->debug_node);
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +0200400 debugfs_remove_recursive(clk->dentry);
Stephen Boyd6314b672014-09-04 23:37:49 -0700401 clk->dentry = NULL;
Stephen Boyd6314b672014-09-04 23:37:49 -0700402 mutex_unlock(&clk_debug_lock);
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +0200403}
404
Tomeu Vizoso61c7cdd2014-12-02 08:54:21 +0100405struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
Peter De Schrijverfb2b3c92014-06-26 18:00:53 +0300406 void *data, const struct file_operations *fops)
407{
408 struct dentry *d = NULL;
409
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100410 if (hw->core->dentry)
411 d = debugfs_create_file(name, mode, hw->core->dentry, data,
412 fops);
Peter De Schrijverfb2b3c92014-06-26 18:00:53 +0300413
414 return d;
415}
416EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
417
Mike Turquetteb24764902012-03-15 23:11:19 -0700418/**
419 * clk_debug_init - lazily create the debugfs clk tree visualization
420 *
421 * clks are often initialized very early during boot before memory can
422 * be dynamically allocated and well before debugfs is setup.
423 * clk_debug_init walks the clk tree hierarchy while holding
424 * prepare_lock and creates the topology as part of a late_initcall,
425 * thus insuring that clks initialized very early will still be
426 * represented in the debugfs clk tree. This function should only be
427 * called once at boot-time, and all other clks added dynamically will
428 * be done so with clk_debug_register.
429 */
430static int __init clk_debug_init(void)
431{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100432 struct clk_core *clk;
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530433 struct dentry *d;
Mike Turquetteb24764902012-03-15 23:11:19 -0700434
435 rootdir = debugfs_create_dir("clk", NULL);
436
437 if (!rootdir)
438 return -ENOMEM;
439
Peter De Schrijver27b8d5f2014-05-30 18:03:57 +0300440 d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530441 &clk_summary_fops);
442 if (!d)
443 return -ENOMEM;
444
Peter De Schrijver27b8d5f2014-05-30 18:03:57 +0300445 d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530446 &clk_dump_fops);
447 if (!d)
448 return -ENOMEM;
449
Peter De Schrijver27b8d5f2014-05-30 18:03:57 +0300450 d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
451 &orphan_list, &clk_summary_fops);
452 if (!d)
453 return -ENOMEM;
Mike Turquetteb24764902012-03-15 23:11:19 -0700454
Peter De Schrijver27b8d5f2014-05-30 18:03:57 +0300455 d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
456 &orphan_list, &clk_dump_fops);
457 if (!d)
Mike Turquetteb24764902012-03-15 23:11:19 -0700458 return -ENOMEM;
459
Stephen Boyd6314b672014-09-04 23:37:49 -0700460 mutex_lock(&clk_debug_lock);
461 hlist_for_each_entry(clk, &clk_debug_list, debug_node)
462 clk_debug_create_one(clk, rootdir);
Mike Turquetteb24764902012-03-15 23:11:19 -0700463
464 inited = 1;
Stephen Boyd6314b672014-09-04 23:37:49 -0700465 mutex_unlock(&clk_debug_lock);
Mike Turquetteb24764902012-03-15 23:11:19 -0700466
467 return 0;
468}
469late_initcall(clk_debug_init);
470#else
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100471static inline int clk_debug_register(struct clk_core *clk) { return 0; }
472static inline void clk_debug_reparent(struct clk_core *clk,
473 struct clk_core *new_parent)
Ulf Hanssonb33d2122013-04-02 23:09:37 +0200474{
475}
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100476static inline void clk_debug_unregister(struct clk_core *clk)
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +0200477{
478}
Mike Turquette70d347e2012-03-26 11:53:47 -0700479#endif
Mike Turquetteb24764902012-03-15 23:11:19 -0700480
Mike Turquetteb24764902012-03-15 23:11:19 -0700481/* caller must hold prepare_lock */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100482static void clk_unprepare_unused_subtree(struct clk_core *clk)
Ulf Hansson1c155b32013-03-12 20:26:03 +0100483{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100484 struct clk_core *child;
Ulf Hansson1c155b32013-03-12 20:26:03 +0100485
Krzysztof Kozlowski496eadf2015-01-09 09:28:10 +0100486 lockdep_assert_held(&prepare_lock);
487
Ulf Hansson1c155b32013-03-12 20:26:03 +0100488 hlist_for_each_entry(child, &clk->children, child_node)
489 clk_unprepare_unused_subtree(child);
490
491 if (clk->prepare_count)
492 return;
493
494 if (clk->flags & CLK_IGNORE_UNUSED)
495 return;
496
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100497 if (clk_core_is_prepared(clk)) {
Stephen Boyddfc202e2015-02-02 14:37:41 -0800498 trace_clk_unprepare(clk);
Ulf Hansson3cc82472013-03-12 20:26:04 +0100499 if (clk->ops->unprepare_unused)
500 clk->ops->unprepare_unused(clk->hw);
501 else if (clk->ops->unprepare)
Ulf Hansson1c155b32013-03-12 20:26:03 +0100502 clk->ops->unprepare(clk->hw);
Stephen Boyddfc202e2015-02-02 14:37:41 -0800503 trace_clk_unprepare_complete(clk);
Ulf Hansson3cc82472013-03-12 20:26:04 +0100504 }
Ulf Hansson1c155b32013-03-12 20:26:03 +0100505}
506
507/* caller must hold prepare_lock */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100508static void clk_disable_unused_subtree(struct clk_core *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700509{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100510 struct clk_core *child;
Mike Turquetteb24764902012-03-15 23:11:19 -0700511 unsigned long flags;
512
Krzysztof Kozlowski496eadf2015-01-09 09:28:10 +0100513 lockdep_assert_held(&prepare_lock);
514
Sasha Levinb67bfe02013-02-27 17:06:00 -0800515 hlist_for_each_entry(child, &clk->children, child_node)
Mike Turquetteb24764902012-03-15 23:11:19 -0700516 clk_disable_unused_subtree(child);
517
Mike Turquetteeab89f62013-03-28 13:59:01 -0700518 flags = clk_enable_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700519
520 if (clk->enable_count)
521 goto unlock_out;
522
523 if (clk->flags & CLK_IGNORE_UNUSED)
524 goto unlock_out;
525
Mike Turquette7c045a52012-12-04 11:00:35 -0800526 /*
527 * some gate clocks have special needs during the disable-unused
528 * sequence. call .disable_unused if available, otherwise fall
529 * back to .disable
530 */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100531 if (clk_core_is_enabled(clk)) {
Stephen Boyddfc202e2015-02-02 14:37:41 -0800532 trace_clk_disable(clk);
Mike Turquette7c045a52012-12-04 11:00:35 -0800533 if (clk->ops->disable_unused)
534 clk->ops->disable_unused(clk->hw);
535 else if (clk->ops->disable)
536 clk->ops->disable(clk->hw);
Stephen Boyddfc202e2015-02-02 14:37:41 -0800537 trace_clk_disable_complete(clk);
Mike Turquette7c045a52012-12-04 11:00:35 -0800538 }
Mike Turquetteb24764902012-03-15 23:11:19 -0700539
540unlock_out:
Mike Turquetteeab89f62013-03-28 13:59:01 -0700541 clk_enable_unlock(flags);
Mike Turquetteb24764902012-03-15 23:11:19 -0700542}
543
Olof Johansson1e435252013-04-27 14:10:18 -0700544static bool clk_ignore_unused;
545static int __init clk_ignore_unused_setup(char *__unused)
546{
547 clk_ignore_unused = true;
548 return 1;
549}
550__setup("clk_ignore_unused", clk_ignore_unused_setup);
551
Mike Turquetteb24764902012-03-15 23:11:19 -0700552static int clk_disable_unused(void)
553{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100554 struct clk_core *clk;
Mike Turquetteb24764902012-03-15 23:11:19 -0700555
Olof Johansson1e435252013-04-27 14:10:18 -0700556 if (clk_ignore_unused) {
557 pr_warn("clk: Not disabling unused clocks\n");
558 return 0;
559 }
560
Mike Turquetteeab89f62013-03-28 13:59:01 -0700561 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700562
Sasha Levinb67bfe02013-02-27 17:06:00 -0800563 hlist_for_each_entry(clk, &clk_root_list, child_node)
Mike Turquetteb24764902012-03-15 23:11:19 -0700564 clk_disable_unused_subtree(clk);
565
Sasha Levinb67bfe02013-02-27 17:06:00 -0800566 hlist_for_each_entry(clk, &clk_orphan_list, child_node)
Mike Turquetteb24764902012-03-15 23:11:19 -0700567 clk_disable_unused_subtree(clk);
568
Ulf Hansson1c155b32013-03-12 20:26:03 +0100569 hlist_for_each_entry(clk, &clk_root_list, child_node)
570 clk_unprepare_unused_subtree(clk);
571
572 hlist_for_each_entry(clk, &clk_orphan_list, child_node)
573 clk_unprepare_unused_subtree(clk);
574
Mike Turquetteeab89f62013-03-28 13:59:01 -0700575 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700576
577 return 0;
578}
Saravana Kannand41d5802013-05-09 11:35:01 -0700579late_initcall_sync(clk_disable_unused);
Mike Turquetteb24764902012-03-15 23:11:19 -0700580
581/*** helper functions ***/
582
Russ Dill65800b22012-11-26 11:20:09 -0800583const char *__clk_get_name(struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700584{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100585 return !clk ? NULL : clk->core->name;
Mike Turquetteb24764902012-03-15 23:11:19 -0700586}
Niels de Vos48950842012-12-13 13:12:25 +0100587EXPORT_SYMBOL_GPL(__clk_get_name);
Mike Turquetteb24764902012-03-15 23:11:19 -0700588
Russ Dill65800b22012-11-26 11:20:09 -0800589struct clk_hw *__clk_get_hw(struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700590{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100591 return !clk ? NULL : clk->core->hw;
Mike Turquetteb24764902012-03-15 23:11:19 -0700592}
Stephen Boyd0b7f04b2014-01-17 19:47:17 -0800593EXPORT_SYMBOL_GPL(__clk_get_hw);
Mike Turquetteb24764902012-03-15 23:11:19 -0700594
Russ Dill65800b22012-11-26 11:20:09 -0800595u8 __clk_get_num_parents(struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700596{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100597 return !clk ? 0 : clk->core->num_parents;
Mike Turquetteb24764902012-03-15 23:11:19 -0700598}
Stephen Boyd0b7f04b2014-01-17 19:47:17 -0800599EXPORT_SYMBOL_GPL(__clk_get_num_parents);
Mike Turquetteb24764902012-03-15 23:11:19 -0700600
Russ Dill65800b22012-11-26 11:20:09 -0800601struct clk *__clk_get_parent(struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700602{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100603 if (!clk)
604 return NULL;
605
606 /* TODO: Create a per-user clk and change callers to call clk_put */
607 return !clk->core->parent ? NULL : clk->core->parent->hw->clk;
Mike Turquetteb24764902012-03-15 23:11:19 -0700608}
Stephen Boyd0b7f04b2014-01-17 19:47:17 -0800609EXPORT_SYMBOL_GPL(__clk_get_parent);
Mike Turquetteb24764902012-03-15 23:11:19 -0700610
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100611static struct clk_core *clk_core_get_parent_by_index(struct clk_core *clk,
612 u8 index)
James Hogan7ef3dcc2013-07-29 12:24:58 +0100613{
614 if (!clk || index >= clk->num_parents)
615 return NULL;
616 else if (!clk->parents)
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100617 return clk_core_lookup(clk->parent_names[index]);
James Hogan7ef3dcc2013-07-29 12:24:58 +0100618 else if (!clk->parents[index])
619 return clk->parents[index] =
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100620 clk_core_lookup(clk->parent_names[index]);
James Hogan7ef3dcc2013-07-29 12:24:58 +0100621 else
622 return clk->parents[index];
623}
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100624
625struct clk *clk_get_parent_by_index(struct clk *clk, u8 index)
626{
627 struct clk_core *parent;
628
629 if (!clk)
630 return NULL;
631
632 parent = clk_core_get_parent_by_index(clk->core, index);
633
634 return !parent ? NULL : parent->hw->clk;
635}
Stephen Boyd0b7f04b2014-01-17 19:47:17 -0800636EXPORT_SYMBOL_GPL(clk_get_parent_by_index);
James Hogan7ef3dcc2013-07-29 12:24:58 +0100637
Russ Dill65800b22012-11-26 11:20:09 -0800638unsigned int __clk_get_enable_count(struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700639{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100640 return !clk ? 0 : clk->core->enable_count;
Mike Turquetteb24764902012-03-15 23:11:19 -0700641}
642
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100643static unsigned long clk_core_get_rate_nolock(struct clk_core *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700644{
645 unsigned long ret;
646
647 if (!clk) {
Rajendra Nayak34e44fe2012-03-26 19:01:48 +0530648 ret = 0;
Mike Turquetteb24764902012-03-15 23:11:19 -0700649 goto out;
650 }
651
652 ret = clk->rate;
653
654 if (clk->flags & CLK_IS_ROOT)
655 goto out;
656
657 if (!clk->parent)
Rajendra Nayak34e44fe2012-03-26 19:01:48 +0530658 ret = 0;
Mike Turquetteb24764902012-03-15 23:11:19 -0700659
660out:
661 return ret;
662}
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100663
664unsigned long __clk_get_rate(struct clk *clk)
665{
666 if (!clk)
667 return 0;
668
669 return clk_core_get_rate_nolock(clk->core);
670}
Stephen Boyd0b7f04b2014-01-17 19:47:17 -0800671EXPORT_SYMBOL_GPL(__clk_get_rate);
Mike Turquetteb24764902012-03-15 23:11:19 -0700672
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100673static unsigned long __clk_get_accuracy(struct clk_core *clk)
Boris BREZILLON5279fc42013-12-21 10:34:47 +0100674{
675 if (!clk)
676 return 0;
677
678 return clk->accuracy;
679}
680
Russ Dill65800b22012-11-26 11:20:09 -0800681unsigned long __clk_get_flags(struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700682{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100683 return !clk ? 0 : clk->core->flags;
Mike Turquetteb24764902012-03-15 23:11:19 -0700684}
Thierry Redingb05c6832013-09-03 09:43:51 +0200685EXPORT_SYMBOL_GPL(__clk_get_flags);
Mike Turquetteb24764902012-03-15 23:11:19 -0700686
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100687static bool clk_core_is_prepared(struct clk_core *clk)
Ulf Hansson3d6ee282013-03-12 20:26:02 +0100688{
689 int ret;
690
691 if (!clk)
692 return false;
693
694 /*
695 * .is_prepared is optional for clocks that can prepare
696 * fall back to software usage counter if it is missing
697 */
698 if (!clk->ops->is_prepared) {
699 ret = clk->prepare_count ? 1 : 0;
700 goto out;
701 }
702
703 ret = clk->ops->is_prepared(clk->hw);
704out:
705 return !!ret;
706}
707
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100708bool __clk_is_prepared(struct clk *clk)
709{
710 if (!clk)
711 return false;
712
713 return clk_core_is_prepared(clk->core);
714}
715
716static bool clk_core_is_enabled(struct clk_core *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700717{
718 int ret;
719
720 if (!clk)
Stephen Boyd2ac6b1f2012-10-03 23:38:55 -0700721 return false;
Mike Turquetteb24764902012-03-15 23:11:19 -0700722
723 /*
724 * .is_enabled is only mandatory for clocks that gate
725 * fall back to software usage counter if .is_enabled is missing
726 */
727 if (!clk->ops->is_enabled) {
728 ret = clk->enable_count ? 1 : 0;
729 goto out;
730 }
731
732 ret = clk->ops->is_enabled(clk->hw);
733out:
Stephen Boyd2ac6b1f2012-10-03 23:38:55 -0700734 return !!ret;
Mike Turquetteb24764902012-03-15 23:11:19 -0700735}
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100736
737bool __clk_is_enabled(struct clk *clk)
738{
739 if (!clk)
740 return false;
741
742 return clk_core_is_enabled(clk->core);
743}
Stephen Boyd0b7f04b2014-01-17 19:47:17 -0800744EXPORT_SYMBOL_GPL(__clk_is_enabled);
Mike Turquetteb24764902012-03-15 23:11:19 -0700745
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100746static struct clk_core *__clk_lookup_subtree(const char *name,
747 struct clk_core *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700748{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100749 struct clk_core *child;
750 struct clk_core *ret;
Mike Turquetteb24764902012-03-15 23:11:19 -0700751
752 if (!strcmp(clk->name, name))
753 return clk;
754
Sasha Levinb67bfe02013-02-27 17:06:00 -0800755 hlist_for_each_entry(child, &clk->children, child_node) {
Mike Turquetteb24764902012-03-15 23:11:19 -0700756 ret = __clk_lookup_subtree(name, child);
757 if (ret)
758 return ret;
759 }
760
761 return NULL;
762}
763
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100764static struct clk_core *clk_core_lookup(const char *name)
Mike Turquetteb24764902012-03-15 23:11:19 -0700765{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100766 struct clk_core *root_clk;
767 struct clk_core *ret;
Mike Turquetteb24764902012-03-15 23:11:19 -0700768
769 if (!name)
770 return NULL;
771
772 /* search the 'proper' clk tree first */
Sasha Levinb67bfe02013-02-27 17:06:00 -0800773 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
Mike Turquetteb24764902012-03-15 23:11:19 -0700774 ret = __clk_lookup_subtree(name, root_clk);
775 if (ret)
776 return ret;
777 }
778
779 /* if not found, then search the orphan tree */
Sasha Levinb67bfe02013-02-27 17:06:00 -0800780 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
Mike Turquetteb24764902012-03-15 23:11:19 -0700781 ret = __clk_lookup_subtree(name, root_clk);
782 if (ret)
783 return ret;
784 }
785
786 return NULL;
787}
788
Stephen Boyd15a02c12015-01-19 18:05:28 -0800789static bool mux_is_better_rate(unsigned long rate, unsigned long now,
790 unsigned long best, unsigned long flags)
James Hogane366fdd2013-07-29 12:25:02 +0100791{
Stephen Boyd15a02c12015-01-19 18:05:28 -0800792 if (flags & CLK_MUX_ROUND_CLOSEST)
793 return abs(now - rate) < abs(best - rate);
794
795 return now <= rate && now > best;
796}
797
798static long
799clk_mux_determine_rate_flags(struct clk_hw *hw, unsigned long rate,
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +0100800 unsigned long min_rate,
801 unsigned long max_rate,
Stephen Boyd15a02c12015-01-19 18:05:28 -0800802 unsigned long *best_parent_rate,
803 struct clk_hw **best_parent_p,
804 unsigned long flags)
James Hogane366fdd2013-07-29 12:25:02 +0100805{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100806 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
James Hogane366fdd2013-07-29 12:25:02 +0100807 int i, num_parents;
808 unsigned long parent_rate, best = 0;
809
810 /* if NO_REPARENT flag set, pass through to current parent */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100811 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
812 parent = core->parent;
813 if (core->flags & CLK_SET_RATE_PARENT)
Javier Martinez Canillas9e0ad7d2015-02-12 14:58:28 +0100814 best = __clk_determine_rate(parent ? parent->hw : NULL,
815 rate, min_rate, max_rate);
James Hogane366fdd2013-07-29 12:25:02 +0100816 else if (parent)
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100817 best = clk_core_get_rate_nolock(parent);
James Hogane366fdd2013-07-29 12:25:02 +0100818 else
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100819 best = clk_core_get_rate_nolock(core);
James Hogane366fdd2013-07-29 12:25:02 +0100820 goto out;
821 }
822
823 /* find the parent that can provide the fastest rate <= rate */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100824 num_parents = core->num_parents;
James Hogane366fdd2013-07-29 12:25:02 +0100825 for (i = 0; i < num_parents; i++) {
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100826 parent = clk_core_get_parent_by_index(core, i);
James Hogane366fdd2013-07-29 12:25:02 +0100827 if (!parent)
828 continue;
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100829 if (core->flags & CLK_SET_RATE_PARENT)
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +0100830 parent_rate = __clk_determine_rate(parent->hw, rate,
831 min_rate,
832 max_rate);
James Hogane366fdd2013-07-29 12:25:02 +0100833 else
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100834 parent_rate = clk_core_get_rate_nolock(parent);
Stephen Boyd15a02c12015-01-19 18:05:28 -0800835 if (mux_is_better_rate(rate, parent_rate, best, flags)) {
James Hogane366fdd2013-07-29 12:25:02 +0100836 best_parent = parent;
837 best = parent_rate;
838 }
839 }
840
841out:
842 if (best_parent)
Tomeu Vizoso646cafc2014-12-02 08:54:22 +0100843 *best_parent_p = best_parent->hw;
James Hogane366fdd2013-07-29 12:25:02 +0100844 *best_parent_rate = best;
845
846 return best;
847}
Stephen Boyd15a02c12015-01-19 18:05:28 -0800848
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100849struct clk *__clk_lookup(const char *name)
850{
851 struct clk_core *core = clk_core_lookup(name);
852
853 return !core ? NULL : core->hw->clk;
854}
855
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +0100856static void clk_core_get_boundaries(struct clk_core *clk,
857 unsigned long *min_rate,
858 unsigned long *max_rate)
859{
860 struct clk *clk_user;
861
862 *min_rate = 0;
863 *max_rate = ULONG_MAX;
864
Stephen Boyd50595f82015-02-06 11:42:44 -0800865 hlist_for_each_entry(clk_user, &clk->clks, clks_node)
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +0100866 *min_rate = max(*min_rate, clk_user->min_rate);
867
Stephen Boyd50595f82015-02-06 11:42:44 -0800868 hlist_for_each_entry(clk_user, &clk->clks, clks_node)
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +0100869 *max_rate = min(*max_rate, clk_user->max_rate);
870}
871
Stephen Boyd15a02c12015-01-19 18:05:28 -0800872/*
873 * Helper for finding best parent to provide a given frequency. This can be used
874 * directly as a determine_rate callback (e.g. for a mux), or from a more
875 * complex clock that may combine a mux with other operations.
876 */
877long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate,
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +0100878 unsigned long min_rate,
879 unsigned long max_rate,
Stephen Boyd15a02c12015-01-19 18:05:28 -0800880 unsigned long *best_parent_rate,
881 struct clk_hw **best_parent_p)
882{
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +0100883 return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
884 best_parent_rate,
Stephen Boyd15a02c12015-01-19 18:05:28 -0800885 best_parent_p, 0);
886}
Stephen Boyd0b7f04b2014-01-17 19:47:17 -0800887EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
James Hogane366fdd2013-07-29 12:25:02 +0100888
Stephen Boyd15a02c12015-01-19 18:05:28 -0800889long __clk_mux_determine_rate_closest(struct clk_hw *hw, unsigned long rate,
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +0100890 unsigned long min_rate,
891 unsigned long max_rate,
Stephen Boyd15a02c12015-01-19 18:05:28 -0800892 unsigned long *best_parent_rate,
893 struct clk_hw **best_parent_p)
894{
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +0100895 return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
896 best_parent_rate,
Stephen Boyd15a02c12015-01-19 18:05:28 -0800897 best_parent_p,
898 CLK_MUX_ROUND_CLOSEST);
899}
900EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
901
Mike Turquetteb24764902012-03-15 23:11:19 -0700902/*** clk api ***/
903
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100904static void clk_core_unprepare(struct clk_core *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700905{
906 if (!clk)
907 return;
908
909 if (WARN_ON(clk->prepare_count == 0))
910 return;
911
912 if (--clk->prepare_count > 0)
913 return;
914
915 WARN_ON(clk->enable_count > 0);
916
Stephen Boyddfc202e2015-02-02 14:37:41 -0800917 trace_clk_unprepare(clk);
918
Mike Turquetteb24764902012-03-15 23:11:19 -0700919 if (clk->ops->unprepare)
920 clk->ops->unprepare(clk->hw);
921
Stephen Boyddfc202e2015-02-02 14:37:41 -0800922 trace_clk_unprepare_complete(clk);
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100923 clk_core_unprepare(clk->parent);
Mike Turquetteb24764902012-03-15 23:11:19 -0700924}
925
926/**
927 * clk_unprepare - undo preparation of a clock source
Peter Meerwald24ee1a02013-06-29 15:14:19 +0200928 * @clk: the clk being unprepared
Mike Turquetteb24764902012-03-15 23:11:19 -0700929 *
930 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
931 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
932 * if the operation may sleep. One example is a clk which is accessed over
933 * I2c. In the complex case a clk gate operation may require a fast and a slow
934 * part. It is this reason that clk_unprepare and clk_disable are not mutually
935 * exclusive. In fact clk_disable must be called before clk_unprepare.
936 */
937void clk_unprepare(struct clk *clk)
938{
Stephen Boyd63589e92014-03-26 16:06:37 -0700939 if (IS_ERR_OR_NULL(clk))
940 return;
941
Mike Turquetteeab89f62013-03-28 13:59:01 -0700942 clk_prepare_lock();
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100943 clk_core_unprepare(clk->core);
Mike Turquetteeab89f62013-03-28 13:59:01 -0700944 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700945}
946EXPORT_SYMBOL_GPL(clk_unprepare);
947
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100948static int clk_core_prepare(struct clk_core *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700949{
950 int ret = 0;
951
952 if (!clk)
953 return 0;
954
955 if (clk->prepare_count == 0) {
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100956 ret = clk_core_prepare(clk->parent);
Mike Turquetteb24764902012-03-15 23:11:19 -0700957 if (ret)
958 return ret;
959
Stephen Boyddfc202e2015-02-02 14:37:41 -0800960 trace_clk_prepare(clk);
961
962 if (clk->ops->prepare)
Mike Turquetteb24764902012-03-15 23:11:19 -0700963 ret = clk->ops->prepare(clk->hw);
Stephen Boyddfc202e2015-02-02 14:37:41 -0800964
965 trace_clk_prepare_complete(clk);
966
967 if (ret) {
968 clk_core_unprepare(clk->parent);
969 return ret;
Mike Turquetteb24764902012-03-15 23:11:19 -0700970 }
971 }
972
973 clk->prepare_count++;
974
975 return 0;
976}
977
978/**
979 * clk_prepare - prepare a clock source
980 * @clk: the clk being prepared
981 *
982 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
983 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
984 * operation may sleep. One example is a clk which is accessed over I2c. In
985 * the complex case a clk ungate operation may require a fast and a slow part.
986 * It is this reason that clk_prepare and clk_enable are not mutually
987 * exclusive. In fact clk_prepare must be called before clk_enable.
988 * Returns 0 on success, -EERROR otherwise.
989 */
990int clk_prepare(struct clk *clk)
991{
992 int ret;
993
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100994 if (!clk)
995 return 0;
996
Mike Turquetteeab89f62013-03-28 13:59:01 -0700997 clk_prepare_lock();
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100998 ret = clk_core_prepare(clk->core);
Mike Turquetteeab89f62013-03-28 13:59:01 -0700999 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001000
1001 return ret;
1002}
1003EXPORT_SYMBOL_GPL(clk_prepare);
1004
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001005static void clk_core_disable(struct clk_core *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -07001006{
1007 if (!clk)
1008 return;
1009
1010 if (WARN_ON(clk->enable_count == 0))
1011 return;
1012
1013 if (--clk->enable_count > 0)
1014 return;
1015
Stephen Boyddfc202e2015-02-02 14:37:41 -08001016 trace_clk_disable(clk);
1017
Mike Turquetteb24764902012-03-15 23:11:19 -07001018 if (clk->ops->disable)
1019 clk->ops->disable(clk->hw);
1020
Stephen Boyddfc202e2015-02-02 14:37:41 -08001021 trace_clk_disable_complete(clk);
1022
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001023 clk_core_disable(clk->parent);
1024}
1025
1026static void __clk_disable(struct clk *clk)
1027{
1028 if (!clk)
1029 return;
1030
1031 clk_core_disable(clk->core);
Mike Turquetteb24764902012-03-15 23:11:19 -07001032}
1033
1034/**
1035 * clk_disable - gate a clock
1036 * @clk: the clk being gated
1037 *
1038 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
1039 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
1040 * clk if the operation is fast and will never sleep. One example is a
1041 * SoC-internal clk which is controlled via simple register writes. In the
1042 * complex case a clk gate operation may require a fast and a slow part. It is
1043 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
1044 * In fact clk_disable must be called before clk_unprepare.
1045 */
1046void clk_disable(struct clk *clk)
1047{
1048 unsigned long flags;
1049
Stephen Boyd63589e92014-03-26 16:06:37 -07001050 if (IS_ERR_OR_NULL(clk))
1051 return;
1052
Mike Turquetteeab89f62013-03-28 13:59:01 -07001053 flags = clk_enable_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001054 __clk_disable(clk);
Mike Turquetteeab89f62013-03-28 13:59:01 -07001055 clk_enable_unlock(flags);
Mike Turquetteb24764902012-03-15 23:11:19 -07001056}
1057EXPORT_SYMBOL_GPL(clk_disable);
1058
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001059static int clk_core_enable(struct clk_core *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -07001060{
1061 int ret = 0;
1062
1063 if (!clk)
1064 return 0;
1065
1066 if (WARN_ON(clk->prepare_count == 0))
1067 return -ESHUTDOWN;
1068
1069 if (clk->enable_count == 0) {
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001070 ret = clk_core_enable(clk->parent);
Mike Turquetteb24764902012-03-15 23:11:19 -07001071
1072 if (ret)
1073 return ret;
1074
Stephen Boyddfc202e2015-02-02 14:37:41 -08001075 trace_clk_enable(clk);
1076
1077 if (clk->ops->enable)
Mike Turquetteb24764902012-03-15 23:11:19 -07001078 ret = clk->ops->enable(clk->hw);
Stephen Boyddfc202e2015-02-02 14:37:41 -08001079
1080 trace_clk_enable_complete(clk);
1081
1082 if (ret) {
1083 clk_core_disable(clk->parent);
1084 return ret;
Mike Turquetteb24764902012-03-15 23:11:19 -07001085 }
1086 }
1087
1088 clk->enable_count++;
1089 return 0;
1090}
1091
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001092static int __clk_enable(struct clk *clk)
1093{
1094 if (!clk)
1095 return 0;
1096
1097 return clk_core_enable(clk->core);
1098}
1099
Mike Turquetteb24764902012-03-15 23:11:19 -07001100/**
1101 * clk_enable - ungate a clock
1102 * @clk: the clk being ungated
1103 *
1104 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
1105 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1106 * if the operation will never sleep. One example is a SoC-internal clk which
1107 * is controlled via simple register writes. In the complex case a clk ungate
1108 * operation may require a fast and a slow part. It is this reason that
1109 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
1110 * must be called before clk_enable. Returns 0 on success, -EERROR
1111 * otherwise.
1112 */
1113int clk_enable(struct clk *clk)
1114{
1115 unsigned long flags;
1116 int ret;
1117
Mike Turquetteeab89f62013-03-28 13:59:01 -07001118 flags = clk_enable_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001119 ret = __clk_enable(clk);
Mike Turquetteeab89f62013-03-28 13:59:01 -07001120 clk_enable_unlock(flags);
Mike Turquetteb24764902012-03-15 23:11:19 -07001121
1122 return ret;
1123}
1124EXPORT_SYMBOL_GPL(clk_enable);
1125
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001126static unsigned long clk_core_round_rate_nolock(struct clk_core *clk,
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01001127 unsigned long rate,
1128 unsigned long min_rate,
1129 unsigned long max_rate)
Mike Turquetteb24764902012-03-15 23:11:19 -07001130{
Shawn Guo81536e02012-04-12 20:50:17 +08001131 unsigned long parent_rate = 0;
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001132 struct clk_core *parent;
Tomeu Vizoso646cafc2014-12-02 08:54:22 +01001133 struct clk_hw *parent_hw;
Mike Turquetteb24764902012-03-15 23:11:19 -07001134
Krzysztof Kozlowski496eadf2015-01-09 09:28:10 +01001135 lockdep_assert_held(&prepare_lock);
1136
Mike Turquetteb24764902012-03-15 23:11:19 -07001137 if (!clk)
Stephen Boyd2ac6b1f2012-10-03 23:38:55 -07001138 return 0;
Mike Turquetteb24764902012-03-15 23:11:19 -07001139
James Hogan71472c02013-07-29 12:25:00 +01001140 parent = clk->parent;
1141 if (parent)
1142 parent_rate = parent->rate;
Mike Turquetteb24764902012-03-15 23:11:19 -07001143
Tomeu Vizoso646cafc2014-12-02 08:54:22 +01001144 if (clk->ops->determine_rate) {
1145 parent_hw = parent ? parent->hw : NULL;
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01001146 return clk->ops->determine_rate(clk->hw, rate,
1147 min_rate, max_rate,
1148 &parent_rate, &parent_hw);
Tomeu Vizoso646cafc2014-12-02 08:54:22 +01001149 } else if (clk->ops->round_rate)
James Hogan71472c02013-07-29 12:25:00 +01001150 return clk->ops->round_rate(clk->hw, rate, &parent_rate);
1151 else if (clk->flags & CLK_SET_RATE_PARENT)
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01001152 return clk_core_round_rate_nolock(clk->parent, rate, min_rate,
1153 max_rate);
James Hogan71472c02013-07-29 12:25:00 +01001154 else
1155 return clk->rate;
Mike Turquetteb24764902012-03-15 23:11:19 -07001156}
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001157
1158/**
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01001159 * __clk_determine_rate - get the closest rate actually supported by a clock
1160 * @hw: determine the rate of this clock
1161 * @rate: target rate
1162 * @min_rate: returned rate must be greater than this rate
1163 * @max_rate: returned rate must be less than this rate
1164 *
1165 * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate and
1166 * .determine_rate.
1167 */
1168unsigned long __clk_determine_rate(struct clk_hw *hw,
1169 unsigned long rate,
1170 unsigned long min_rate,
1171 unsigned long max_rate)
1172{
1173 if (!hw)
1174 return 0;
1175
1176 return clk_core_round_rate_nolock(hw->core, rate, min_rate, max_rate);
1177}
1178EXPORT_SYMBOL_GPL(__clk_determine_rate);
1179
1180/**
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001181 * __clk_round_rate - round the given rate for a clk
1182 * @clk: round the rate of this clock
1183 * @rate: the rate which is to be rounded
1184 *
1185 * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate
1186 */
1187unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
1188{
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01001189 unsigned long min_rate;
1190 unsigned long max_rate;
1191
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001192 if (!clk)
1193 return 0;
1194
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01001195 clk_core_get_boundaries(clk->core, &min_rate, &max_rate);
1196
1197 return clk_core_round_rate_nolock(clk->core, rate, min_rate, max_rate);
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001198}
Arnd Bergmann1cdf8ee2014-06-03 11:40:14 +02001199EXPORT_SYMBOL_GPL(__clk_round_rate);
Mike Turquetteb24764902012-03-15 23:11:19 -07001200
1201/**
1202 * clk_round_rate - round the given rate for a clk
1203 * @clk: the clk for which we are rounding a rate
1204 * @rate: the rate which is to be rounded
1205 *
1206 * Takes in a rate as input and rounds it to a rate that the clk can actually
1207 * use which is then returned. If clk doesn't support round_rate operation
1208 * then the parent rate is returned.
1209 */
1210long clk_round_rate(struct clk *clk, unsigned long rate)
1211{
1212 unsigned long ret;
1213
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001214 if (!clk)
1215 return 0;
1216
Mike Turquetteeab89f62013-03-28 13:59:01 -07001217 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001218 ret = __clk_round_rate(clk, rate);
Mike Turquetteeab89f62013-03-28 13:59:01 -07001219 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001220
1221 return ret;
1222}
1223EXPORT_SYMBOL_GPL(clk_round_rate);
1224
1225/**
1226 * __clk_notify - call clk notifier chain
1227 * @clk: struct clk * that is changing rate
1228 * @msg: clk notifier type (see include/linux/clk.h)
1229 * @old_rate: old clk rate
1230 * @new_rate: new clk rate
1231 *
1232 * Triggers a notifier call chain on the clk rate-change notification
1233 * for 'clk'. Passes a pointer to the struct clk and the previous
1234 * and current rates to the notifier callback. Intended to be called by
1235 * internal clock code only. Returns NOTIFY_DONE from the last driver
1236 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1237 * a driver returns that.
1238 */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001239static int __clk_notify(struct clk_core *clk, unsigned long msg,
Mike Turquetteb24764902012-03-15 23:11:19 -07001240 unsigned long old_rate, unsigned long new_rate)
1241{
1242 struct clk_notifier *cn;
1243 struct clk_notifier_data cnd;
1244 int ret = NOTIFY_DONE;
1245
Mike Turquetteb24764902012-03-15 23:11:19 -07001246 cnd.old_rate = old_rate;
1247 cnd.new_rate = new_rate;
1248
1249 list_for_each_entry(cn, &clk_notifier_list, node) {
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001250 if (cn->clk->core == clk) {
1251 cnd.clk = cn->clk;
Mike Turquetteb24764902012-03-15 23:11:19 -07001252 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1253 &cnd);
Mike Turquetteb24764902012-03-15 23:11:19 -07001254 }
1255 }
1256
1257 return ret;
1258}
1259
1260/**
Boris BREZILLON5279fc42013-12-21 10:34:47 +01001261 * __clk_recalc_accuracies
1262 * @clk: first clk in the subtree
1263 *
1264 * Walks the subtree of clks starting with clk and recalculates accuracies as
1265 * it goes. Note that if a clk does not implement the .recalc_accuracy
1266 * callback then it is assumed that the clock will take on the accuracy of it's
1267 * parent.
1268 *
1269 * Caller must hold prepare_lock.
1270 */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001271static void __clk_recalc_accuracies(struct clk_core *clk)
Boris BREZILLON5279fc42013-12-21 10:34:47 +01001272{
1273 unsigned long parent_accuracy = 0;
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001274 struct clk_core *child;
Boris BREZILLON5279fc42013-12-21 10:34:47 +01001275
Krzysztof Kozlowski496eadf2015-01-09 09:28:10 +01001276 lockdep_assert_held(&prepare_lock);
1277
Boris BREZILLON5279fc42013-12-21 10:34:47 +01001278 if (clk->parent)
1279 parent_accuracy = clk->parent->accuracy;
1280
1281 if (clk->ops->recalc_accuracy)
1282 clk->accuracy = clk->ops->recalc_accuracy(clk->hw,
1283 parent_accuracy);
1284 else
1285 clk->accuracy = parent_accuracy;
1286
1287 hlist_for_each_entry(child, &clk->children, child_node)
1288 __clk_recalc_accuracies(child);
1289}
1290
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001291static long clk_core_get_accuracy(struct clk_core *clk)
Boris BREZILLON5279fc42013-12-21 10:34:47 +01001292{
1293 unsigned long accuracy;
1294
1295 clk_prepare_lock();
1296 if (clk && (clk->flags & CLK_GET_ACCURACY_NOCACHE))
1297 __clk_recalc_accuracies(clk);
1298
1299 accuracy = __clk_get_accuracy(clk);
1300 clk_prepare_unlock();
1301
1302 return accuracy;
1303}
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001304
1305/**
1306 * clk_get_accuracy - return the accuracy of clk
1307 * @clk: the clk whose accuracy is being returned
1308 *
1309 * Simply returns the cached accuracy of the clk, unless
1310 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1311 * issued.
1312 * If clk is NULL then returns 0.
1313 */
1314long clk_get_accuracy(struct clk *clk)
1315{
1316 if (!clk)
1317 return 0;
1318
1319 return clk_core_get_accuracy(clk->core);
1320}
Boris BREZILLON5279fc42013-12-21 10:34:47 +01001321EXPORT_SYMBOL_GPL(clk_get_accuracy);
1322
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001323static unsigned long clk_recalc(struct clk_core *clk,
1324 unsigned long parent_rate)
Stephen Boyd8f2c2db2014-03-26 16:06:36 -07001325{
1326 if (clk->ops->recalc_rate)
1327 return clk->ops->recalc_rate(clk->hw, parent_rate);
1328 return parent_rate;
1329}
1330
Boris BREZILLON5279fc42013-12-21 10:34:47 +01001331/**
Mike Turquetteb24764902012-03-15 23:11:19 -07001332 * __clk_recalc_rates
1333 * @clk: first clk in the subtree
1334 * @msg: notification type (see include/linux/clk.h)
1335 *
1336 * Walks the subtree of clks starting with clk and recalculates rates as it
1337 * goes. Note that if a clk does not implement the .recalc_rate callback then
Peter Meerwald24ee1a02013-06-29 15:14:19 +02001338 * it is assumed that the clock will take on the rate of its parent.
Mike Turquetteb24764902012-03-15 23:11:19 -07001339 *
1340 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1341 * if necessary.
1342 *
1343 * Caller must hold prepare_lock.
1344 */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001345static void __clk_recalc_rates(struct clk_core *clk, unsigned long msg)
Mike Turquetteb24764902012-03-15 23:11:19 -07001346{
1347 unsigned long old_rate;
1348 unsigned long parent_rate = 0;
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001349 struct clk_core *child;
Mike Turquetteb24764902012-03-15 23:11:19 -07001350
Krzysztof Kozlowski496eadf2015-01-09 09:28:10 +01001351 lockdep_assert_held(&prepare_lock);
1352
Mike Turquetteb24764902012-03-15 23:11:19 -07001353 old_rate = clk->rate;
1354
1355 if (clk->parent)
1356 parent_rate = clk->parent->rate;
1357
Stephen Boyd8f2c2db2014-03-26 16:06:36 -07001358 clk->rate = clk_recalc(clk, parent_rate);
Mike Turquetteb24764902012-03-15 23:11:19 -07001359
1360 /*
1361 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1362 * & ABORT_RATE_CHANGE notifiers
1363 */
1364 if (clk->notifier_count && msg)
1365 __clk_notify(clk, msg, old_rate, clk->rate);
1366
Sasha Levinb67bfe02013-02-27 17:06:00 -08001367 hlist_for_each_entry(child, &clk->children, child_node)
Mike Turquetteb24764902012-03-15 23:11:19 -07001368 __clk_recalc_rates(child, msg);
1369}
1370
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001371static unsigned long clk_core_get_rate(struct clk_core *clk)
1372{
1373 unsigned long rate;
1374
1375 clk_prepare_lock();
1376
1377 if (clk && (clk->flags & CLK_GET_RATE_NOCACHE))
1378 __clk_recalc_rates(clk, 0);
1379
1380 rate = clk_core_get_rate_nolock(clk);
1381 clk_prepare_unlock();
1382
1383 return rate;
1384}
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001385
Mike Turquetteb24764902012-03-15 23:11:19 -07001386/**
Ulf Hanssona093bde2012-08-31 14:21:28 +02001387 * clk_get_rate - return the rate of clk
1388 * @clk: the clk whose rate is being returned
1389 *
1390 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1391 * is set, which means a recalc_rate will be issued.
1392 * If clk is NULL then returns 0.
1393 */
1394unsigned long clk_get_rate(struct clk *clk)
1395{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001396 if (!clk)
1397 return 0;
Ulf Hanssona093bde2012-08-31 14:21:28 +02001398
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001399 return clk_core_get_rate(clk->core);
Ulf Hanssona093bde2012-08-31 14:21:28 +02001400}
1401EXPORT_SYMBOL_GPL(clk_get_rate);
1402
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001403static int clk_fetch_parent_index(struct clk_core *clk,
1404 struct clk_core *parent)
James Hogan4935b222013-07-29 12:24:59 +01001405{
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001406 int i;
James Hogan4935b222013-07-29 12:24:59 +01001407
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001408 if (!clk->parents) {
Tomasz Figa96a7ed92013-09-29 02:37:15 +02001409 clk->parents = kcalloc(clk->num_parents,
1410 sizeof(struct clk *), GFP_KERNEL);
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001411 if (!clk->parents)
1412 return -ENOMEM;
1413 }
James Hogan4935b222013-07-29 12:24:59 +01001414
1415 /*
1416 * find index of new parent clock using cached parent ptrs,
1417 * or if not yet cached, use string name comparison and cache
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001418 * them now to avoid future calls to clk_core_lookup.
James Hogan4935b222013-07-29 12:24:59 +01001419 */
1420 for (i = 0; i < clk->num_parents; i++) {
Tomasz Figada0f0b22013-09-29 02:37:16 +02001421 if (clk->parents[i] == parent)
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001422 return i;
Tomasz Figada0f0b22013-09-29 02:37:16 +02001423
1424 if (clk->parents[i])
1425 continue;
1426
1427 if (!strcmp(clk->parent_names[i], parent->name)) {
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001428 clk->parents[i] = clk_core_lookup(parent->name);
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001429 return i;
James Hogan4935b222013-07-29 12:24:59 +01001430 }
1431 }
1432
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001433 return -EINVAL;
James Hogan4935b222013-07-29 12:24:59 +01001434}
1435
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001436static void clk_reparent(struct clk_core *clk, struct clk_core *new_parent)
James Hogan4935b222013-07-29 12:24:59 +01001437{
1438 hlist_del(&clk->child_node);
1439
James Hogan903efc52013-08-29 12:10:51 +01001440 if (new_parent) {
1441 /* avoid duplicate POST_RATE_CHANGE notifications */
1442 if (new_parent->new_child == clk)
1443 new_parent->new_child = NULL;
1444
James Hogan4935b222013-07-29 12:24:59 +01001445 hlist_add_head(&clk->child_node, &new_parent->children);
James Hogan903efc52013-08-29 12:10:51 +01001446 } else {
James Hogan4935b222013-07-29 12:24:59 +01001447 hlist_add_head(&clk->child_node, &clk_orphan_list);
James Hogan903efc52013-08-29 12:10:51 +01001448 }
James Hogan4935b222013-07-29 12:24:59 +01001449
1450 clk->parent = new_parent;
1451}
1452
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001453static struct clk_core *__clk_set_parent_before(struct clk_core *clk,
1454 struct clk_core *parent)
James Hogan4935b222013-07-29 12:24:59 +01001455{
1456 unsigned long flags;
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001457 struct clk_core *old_parent = clk->parent;
James Hogan4935b222013-07-29 12:24:59 +01001458
1459 /*
1460 * Migrate prepare state between parents and prevent race with
1461 * clk_enable().
1462 *
1463 * If the clock is not prepared, then a race with
1464 * clk_enable/disable() is impossible since we already have the
1465 * prepare lock (future calls to clk_enable() need to be preceded by
1466 * a clk_prepare()).
1467 *
1468 * If the clock is prepared, migrate the prepared state to the new
1469 * parent and also protect against a race with clk_enable() by
1470 * forcing the clock and the new parent on. This ensures that all
1471 * future calls to clk_enable() are practically NOPs with respect to
1472 * hardware and software states.
1473 *
1474 * See also: Comment for clk_set_parent() below.
1475 */
1476 if (clk->prepare_count) {
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001477 clk_core_prepare(parent);
1478 clk_core_enable(parent);
1479 clk_core_enable(clk);
James Hogan4935b222013-07-29 12:24:59 +01001480 }
1481
1482 /* update the clk tree topology */
1483 flags = clk_enable_lock();
1484 clk_reparent(clk, parent);
1485 clk_enable_unlock(flags);
1486
Stephen Boyd3fa22522014-01-15 10:47:22 -08001487 return old_parent;
1488}
1489
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001490static void __clk_set_parent_after(struct clk_core *core,
1491 struct clk_core *parent,
1492 struct clk_core *old_parent)
Stephen Boyd3fa22522014-01-15 10:47:22 -08001493{
1494 /*
1495 * Finish the migration of prepare state and undo the changes done
1496 * for preventing a race with clk_enable().
1497 */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001498 if (core->prepare_count) {
1499 clk_core_disable(core);
1500 clk_core_disable(old_parent);
1501 clk_core_unprepare(old_parent);
Stephen Boyd3fa22522014-01-15 10:47:22 -08001502 }
Stephen Boyd3fa22522014-01-15 10:47:22 -08001503}
1504
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001505static int __clk_set_parent(struct clk_core *clk, struct clk_core *parent,
1506 u8 p_index)
Stephen Boyd3fa22522014-01-15 10:47:22 -08001507{
1508 unsigned long flags;
1509 int ret = 0;
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001510 struct clk_core *old_parent;
Stephen Boyd3fa22522014-01-15 10:47:22 -08001511
1512 old_parent = __clk_set_parent_before(clk, parent);
1513
Stephen Boyddfc202e2015-02-02 14:37:41 -08001514 trace_clk_set_parent(clk, parent);
1515
James Hogan4935b222013-07-29 12:24:59 +01001516 /* change clock input source */
1517 if (parent && clk->ops->set_parent)
1518 ret = clk->ops->set_parent(clk->hw, p_index);
1519
Stephen Boyddfc202e2015-02-02 14:37:41 -08001520 trace_clk_set_parent_complete(clk, parent);
1521
James Hogan4935b222013-07-29 12:24:59 +01001522 if (ret) {
1523 flags = clk_enable_lock();
1524 clk_reparent(clk, old_parent);
1525 clk_enable_unlock(flags);
1526
1527 if (clk->prepare_count) {
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001528 clk_core_disable(clk);
1529 clk_core_disable(parent);
1530 clk_core_unprepare(parent);
James Hogan4935b222013-07-29 12:24:59 +01001531 }
1532 return ret;
1533 }
1534
Stephen Boyd3fa22522014-01-15 10:47:22 -08001535 __clk_set_parent_after(clk, parent, old_parent);
James Hogan4935b222013-07-29 12:24:59 +01001536
James Hogan4935b222013-07-29 12:24:59 +01001537 return 0;
1538}
1539
Ulf Hanssona093bde2012-08-31 14:21:28 +02001540/**
Mike Turquetteb24764902012-03-15 23:11:19 -07001541 * __clk_speculate_rates
1542 * @clk: first clk in the subtree
1543 * @parent_rate: the "future" rate of clk's parent
1544 *
1545 * Walks the subtree of clks starting with clk, speculating rates as it
1546 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1547 *
1548 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1549 * pre-rate change notifications and returns early if no clks in the
1550 * subtree have subscribed to the notifications. Note that if a clk does not
1551 * implement the .recalc_rate callback then it is assumed that the clock will
Peter Meerwald24ee1a02013-06-29 15:14:19 +02001552 * take on the rate of its parent.
Mike Turquetteb24764902012-03-15 23:11:19 -07001553 *
1554 * Caller must hold prepare_lock.
1555 */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001556static int __clk_speculate_rates(struct clk_core *clk,
1557 unsigned long parent_rate)
Mike Turquetteb24764902012-03-15 23:11:19 -07001558{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001559 struct clk_core *child;
Mike Turquetteb24764902012-03-15 23:11:19 -07001560 unsigned long new_rate;
1561 int ret = NOTIFY_DONE;
1562
Krzysztof Kozlowski496eadf2015-01-09 09:28:10 +01001563 lockdep_assert_held(&prepare_lock);
1564
Stephen Boyd8f2c2db2014-03-26 16:06:36 -07001565 new_rate = clk_recalc(clk, parent_rate);
Mike Turquetteb24764902012-03-15 23:11:19 -07001566
Soren Brinkmannfb72a052013-04-03 12:17:12 -07001567 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
Mike Turquetteb24764902012-03-15 23:11:19 -07001568 if (clk->notifier_count)
1569 ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate);
1570
Mike Turquette86bcfa22014-02-24 16:08:41 -08001571 if (ret & NOTIFY_STOP_MASK) {
1572 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1573 __func__, clk->name, ret);
Mike Turquetteb24764902012-03-15 23:11:19 -07001574 goto out;
Mike Turquette86bcfa22014-02-24 16:08:41 -08001575 }
Mike Turquetteb24764902012-03-15 23:11:19 -07001576
Sasha Levinb67bfe02013-02-27 17:06:00 -08001577 hlist_for_each_entry(child, &clk->children, child_node) {
Mike Turquetteb24764902012-03-15 23:11:19 -07001578 ret = __clk_speculate_rates(child, new_rate);
Soren Brinkmannfb72a052013-04-03 12:17:12 -07001579 if (ret & NOTIFY_STOP_MASK)
Mike Turquetteb24764902012-03-15 23:11:19 -07001580 break;
1581 }
1582
1583out:
1584 return ret;
1585}
1586
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001587static void clk_calc_subtree(struct clk_core *clk, unsigned long new_rate,
1588 struct clk_core *new_parent, u8 p_index)
Mike Turquetteb24764902012-03-15 23:11:19 -07001589{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001590 struct clk_core *child;
Mike Turquetteb24764902012-03-15 23:11:19 -07001591
1592 clk->new_rate = new_rate;
James Hogan71472c02013-07-29 12:25:00 +01001593 clk->new_parent = new_parent;
1594 clk->new_parent_index = p_index;
1595 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1596 clk->new_child = NULL;
1597 if (new_parent && new_parent != clk->parent)
1598 new_parent->new_child = clk;
Mike Turquetteb24764902012-03-15 23:11:19 -07001599
Sasha Levinb67bfe02013-02-27 17:06:00 -08001600 hlist_for_each_entry(child, &clk->children, child_node) {
Stephen Boyd8f2c2db2014-03-26 16:06:36 -07001601 child->new_rate = clk_recalc(child, new_rate);
James Hogan71472c02013-07-29 12:25:00 +01001602 clk_calc_subtree(child, child->new_rate, NULL, 0);
Mike Turquetteb24764902012-03-15 23:11:19 -07001603 }
1604}
1605
1606/*
1607 * calculate the new rates returning the topmost clock that has to be
1608 * changed.
1609 */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001610static struct clk_core *clk_calc_new_rates(struct clk_core *clk,
1611 unsigned long rate)
Mike Turquetteb24764902012-03-15 23:11:19 -07001612{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001613 struct clk_core *top = clk;
1614 struct clk_core *old_parent, *parent;
Tomeu Vizoso646cafc2014-12-02 08:54:22 +01001615 struct clk_hw *parent_hw;
Shawn Guo81536e02012-04-12 20:50:17 +08001616 unsigned long best_parent_rate = 0;
Mike Turquetteb24764902012-03-15 23:11:19 -07001617 unsigned long new_rate;
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01001618 unsigned long min_rate;
1619 unsigned long max_rate;
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001620 int p_index = 0;
Boris Brezillon03bc10a2015-03-29 03:48:48 +02001621 long ret;
Mike Turquetteb24764902012-03-15 23:11:19 -07001622
Mike Turquette7452b212012-03-26 14:45:36 -07001623 /* sanity */
1624 if (IS_ERR_OR_NULL(clk))
1625 return NULL;
1626
Mike Turquette63f5c3b2012-05-02 16:23:43 -07001627 /* save parent rate, if it exists */
James Hogan71472c02013-07-29 12:25:00 +01001628 parent = old_parent = clk->parent;
1629 if (parent)
1630 best_parent_rate = parent->rate;
Mike Turquette63f5c3b2012-05-02 16:23:43 -07001631
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01001632 clk_core_get_boundaries(clk, &min_rate, &max_rate);
1633
James Hogan71472c02013-07-29 12:25:00 +01001634 /* find the closest rate and parent clk/rate */
1635 if (clk->ops->determine_rate) {
Tomeu Vizoso646cafc2014-12-02 08:54:22 +01001636 parent_hw = parent ? parent->hw : NULL;
Boris Brezillon03bc10a2015-03-29 03:48:48 +02001637 ret = clk->ops->determine_rate(clk->hw, rate,
1638 min_rate,
1639 max_rate,
1640 &best_parent_rate,
1641 &parent_hw);
1642 if (ret < 0)
1643 return NULL;
1644
1645 new_rate = ret;
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001646 parent = parent_hw ? parent_hw->core : NULL;
James Hogan71472c02013-07-29 12:25:00 +01001647 } else if (clk->ops->round_rate) {
Boris Brezillon03bc10a2015-03-29 03:48:48 +02001648 ret = clk->ops->round_rate(clk->hw, rate,
1649 &best_parent_rate);
1650 if (ret < 0)
1651 return NULL;
1652
1653 new_rate = ret;
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01001654 if (new_rate < min_rate || new_rate > max_rate)
1655 return NULL;
James Hogan71472c02013-07-29 12:25:00 +01001656 } else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) {
1657 /* pass-through clock without adjustable parent */
1658 clk->new_rate = clk->rate;
1659 return NULL;
1660 } else {
1661 /* pass-through clock with adjustable parent */
1662 top = clk_calc_new_rates(parent, rate);
1663 new_rate = parent->new_rate;
Mike Turquette63f5c3b2012-05-02 16:23:43 -07001664 goto out;
Mike Turquette7452b212012-03-26 14:45:36 -07001665 }
1666
James Hogan71472c02013-07-29 12:25:00 +01001667 /* some clocks must be gated to change parent */
1668 if (parent != old_parent &&
1669 (clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) {
1670 pr_debug("%s: %s not gated but wants to reparent\n",
1671 __func__, clk->name);
Mike Turquetteb24764902012-03-15 23:11:19 -07001672 return NULL;
1673 }
1674
James Hogan71472c02013-07-29 12:25:00 +01001675 /* try finding the new parent index */
Stephen Boyd4526e7b2014-12-22 11:26:42 -08001676 if (parent && clk->num_parents > 1) {
James Hogan71472c02013-07-29 12:25:00 +01001677 p_index = clk_fetch_parent_index(clk, parent);
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001678 if (p_index < 0) {
James Hogan71472c02013-07-29 12:25:00 +01001679 pr_debug("%s: clk %s can not be parent of clk %s\n",
1680 __func__, parent->name, clk->name);
1681 return NULL;
1682 }
Mike Turquetteb24764902012-03-15 23:11:19 -07001683 }
1684
James Hogan71472c02013-07-29 12:25:00 +01001685 if ((clk->flags & CLK_SET_RATE_PARENT) && parent &&
1686 best_parent_rate != parent->rate)
1687 top = clk_calc_new_rates(parent, best_parent_rate);
Mike Turquetteb24764902012-03-15 23:11:19 -07001688
1689out:
James Hogan71472c02013-07-29 12:25:00 +01001690 clk_calc_subtree(clk, new_rate, parent, p_index);
Mike Turquetteb24764902012-03-15 23:11:19 -07001691
1692 return top;
1693}
1694
1695/*
1696 * Notify about rate changes in a subtree. Always walk down the whole tree
1697 * so that in case of an error we can walk down the whole tree again and
1698 * abort the change.
1699 */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001700static struct clk_core *clk_propagate_rate_change(struct clk_core *clk,
1701 unsigned long event)
Mike Turquetteb24764902012-03-15 23:11:19 -07001702{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001703 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
Mike Turquetteb24764902012-03-15 23:11:19 -07001704 int ret = NOTIFY_DONE;
1705
1706 if (clk->rate == clk->new_rate)
Sachin Kamat5fda6852013-03-13 15:17:49 +05301707 return NULL;
Mike Turquetteb24764902012-03-15 23:11:19 -07001708
1709 if (clk->notifier_count) {
1710 ret = __clk_notify(clk, event, clk->rate, clk->new_rate);
Soren Brinkmannfb72a052013-04-03 12:17:12 -07001711 if (ret & NOTIFY_STOP_MASK)
Mike Turquetteb24764902012-03-15 23:11:19 -07001712 fail_clk = clk;
1713 }
1714
Sasha Levinb67bfe02013-02-27 17:06:00 -08001715 hlist_for_each_entry(child, &clk->children, child_node) {
James Hogan71472c02013-07-29 12:25:00 +01001716 /* Skip children who will be reparented to another clock */
1717 if (child->new_parent && child->new_parent != clk)
1718 continue;
1719 tmp_clk = clk_propagate_rate_change(child, event);
1720 if (tmp_clk)
1721 fail_clk = tmp_clk;
1722 }
1723
1724 /* handle the new child who might not be in clk->children yet */
1725 if (clk->new_child) {
1726 tmp_clk = clk_propagate_rate_change(clk->new_child, event);
1727 if (tmp_clk)
1728 fail_clk = tmp_clk;
Mike Turquetteb24764902012-03-15 23:11:19 -07001729 }
1730
1731 return fail_clk;
1732}
1733
1734/*
1735 * walk down a subtree and set the new rates notifying the rate
1736 * change on the way
1737 */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001738static void clk_change_rate(struct clk_core *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -07001739{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001740 struct clk_core *child;
Tero Kristo067bb172014-08-21 16:47:45 +03001741 struct hlist_node *tmp;
Mike Turquetteb24764902012-03-15 23:11:19 -07001742 unsigned long old_rate;
Pawel Mollbf47b4f2012-06-08 14:04:06 +01001743 unsigned long best_parent_rate = 0;
Stephen Boyd3fa22522014-01-15 10:47:22 -08001744 bool skip_set_rate = false;
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001745 struct clk_core *old_parent;
Mike Turquetteb24764902012-03-15 23:11:19 -07001746
1747 old_rate = clk->rate;
1748
Stephen Boyd3fa22522014-01-15 10:47:22 -08001749 if (clk->new_parent)
1750 best_parent_rate = clk->new_parent->rate;
1751 else if (clk->parent)
Pawel Mollbf47b4f2012-06-08 14:04:06 +01001752 best_parent_rate = clk->parent->rate;
1753
Stephen Boyd3fa22522014-01-15 10:47:22 -08001754 if (clk->new_parent && clk->new_parent != clk->parent) {
1755 old_parent = __clk_set_parent_before(clk, clk->new_parent);
Stephen Boyddfc202e2015-02-02 14:37:41 -08001756 trace_clk_set_parent(clk, clk->new_parent);
Stephen Boyd3fa22522014-01-15 10:47:22 -08001757
1758 if (clk->ops->set_rate_and_parent) {
1759 skip_set_rate = true;
1760 clk->ops->set_rate_and_parent(clk->hw, clk->new_rate,
1761 best_parent_rate,
1762 clk->new_parent_index);
1763 } else if (clk->ops->set_parent) {
1764 clk->ops->set_parent(clk->hw, clk->new_parent_index);
1765 }
1766
Stephen Boyddfc202e2015-02-02 14:37:41 -08001767 trace_clk_set_parent_complete(clk, clk->new_parent);
Stephen Boyd3fa22522014-01-15 10:47:22 -08001768 __clk_set_parent_after(clk, clk->new_parent, old_parent);
1769 }
1770
Stephen Boyddfc202e2015-02-02 14:37:41 -08001771 trace_clk_set_rate(clk, clk->new_rate);
1772
Stephen Boyd3fa22522014-01-15 10:47:22 -08001773 if (!skip_set_rate && clk->ops->set_rate)
Pawel Mollbf47b4f2012-06-08 14:04:06 +01001774 clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate);
Mike Turquetteb24764902012-03-15 23:11:19 -07001775
Stephen Boyddfc202e2015-02-02 14:37:41 -08001776 trace_clk_set_rate_complete(clk, clk->new_rate);
1777
Stephen Boyd8f2c2db2014-03-26 16:06:36 -07001778 clk->rate = clk_recalc(clk, best_parent_rate);
Mike Turquetteb24764902012-03-15 23:11:19 -07001779
1780 if (clk->notifier_count && old_rate != clk->rate)
1781 __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);
1782
Tero Kristo067bb172014-08-21 16:47:45 +03001783 /*
1784 * Use safe iteration, as change_rate can actually swap parents
1785 * for certain clock types.
1786 */
1787 hlist_for_each_entry_safe(child, tmp, &clk->children, child_node) {
James Hogan71472c02013-07-29 12:25:00 +01001788 /* Skip children who will be reparented to another clock */
1789 if (child->new_parent && child->new_parent != clk)
1790 continue;
Mike Turquetteb24764902012-03-15 23:11:19 -07001791 clk_change_rate(child);
James Hogan71472c02013-07-29 12:25:00 +01001792 }
1793
1794 /* handle the new child who might not be in clk->children yet */
1795 if (clk->new_child)
1796 clk_change_rate(clk->new_child);
Mike Turquetteb24764902012-03-15 23:11:19 -07001797}
1798
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01001799static int clk_core_set_rate_nolock(struct clk_core *clk,
1800 unsigned long req_rate)
1801{
1802 struct clk_core *top, *fail_clk;
1803 unsigned long rate = req_rate;
1804 int ret = 0;
1805
1806 if (!clk)
1807 return 0;
1808
1809 /* bail early if nothing to do */
1810 if (rate == clk_core_get_rate_nolock(clk))
1811 return 0;
1812
1813 if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count)
1814 return -EBUSY;
1815
1816 /* calculate new rates and get the topmost changed clock */
1817 top = clk_calc_new_rates(clk, rate);
1818 if (!top)
1819 return -EINVAL;
1820
1821 /* notify that we are about to change rates */
1822 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1823 if (fail_clk) {
1824 pr_debug("%s: failed to set %s rate\n", __func__,
1825 fail_clk->name);
1826 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1827 return -EBUSY;
1828 }
1829
1830 /* change the rates */
1831 clk_change_rate(top);
1832
1833 clk->req_rate = req_rate;
1834
1835 return ret;
1836}
1837
Mike Turquetteb24764902012-03-15 23:11:19 -07001838/**
1839 * clk_set_rate - specify a new rate for clk
1840 * @clk: the clk whose rate is being changed
1841 * @rate: the new rate for clk
1842 *
Mike Turquette5654dc92012-03-26 11:51:34 -07001843 * In the simplest case clk_set_rate will only adjust the rate of clk.
Mike Turquetteb24764902012-03-15 23:11:19 -07001844 *
Mike Turquette5654dc92012-03-26 11:51:34 -07001845 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1846 * propagate up to clk's parent; whether or not this happens depends on the
1847 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1848 * after calling .round_rate then upstream parent propagation is ignored. If
1849 * *parent_rate comes back with a new rate for clk's parent then we propagate
Peter Meerwald24ee1a02013-06-29 15:14:19 +02001850 * up to clk's parent and set its rate. Upward propagation will continue
Mike Turquette5654dc92012-03-26 11:51:34 -07001851 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1852 * .round_rate stops requesting changes to clk's parent_rate.
Mike Turquetteb24764902012-03-15 23:11:19 -07001853 *
Mike Turquette5654dc92012-03-26 11:51:34 -07001854 * Rate changes are accomplished via tree traversal that also recalculates the
1855 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
Mike Turquetteb24764902012-03-15 23:11:19 -07001856 *
1857 * Returns 0 on success, -EERROR otherwise.
1858 */
1859int clk_set_rate(struct clk *clk, unsigned long rate)
1860{
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01001861 int ret;
Mike Turquetteb24764902012-03-15 23:11:19 -07001862
Mike Turquette89ac8d72013-08-21 23:58:09 -07001863 if (!clk)
1864 return 0;
1865
Mike Turquetteb24764902012-03-15 23:11:19 -07001866 /* prevent racing with updates to the clock topology */
Mike Turquetteeab89f62013-03-28 13:59:01 -07001867 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001868
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01001869 ret = clk_core_set_rate_nolock(clk->core, rate);
Mike Turquetteb24764902012-03-15 23:11:19 -07001870
Mike Turquetteeab89f62013-03-28 13:59:01 -07001871 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001872
1873 return ret;
1874}
1875EXPORT_SYMBOL_GPL(clk_set_rate);
1876
1877/**
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01001878 * clk_set_rate_range - set a rate range for a clock source
1879 * @clk: clock source
1880 * @min: desired minimum clock rate in Hz, inclusive
1881 * @max: desired maximum clock rate in Hz, inclusive
1882 *
1883 * Returns success (0) or negative errno.
1884 */
1885int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
1886{
1887 int ret = 0;
1888
1889 if (!clk)
1890 return 0;
1891
1892 if (min > max) {
1893 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
1894 __func__, clk->core->name, clk->dev_id, clk->con_id,
1895 min, max);
1896 return -EINVAL;
1897 }
1898
1899 clk_prepare_lock();
1900
1901 if (min != clk->min_rate || max != clk->max_rate) {
1902 clk->min_rate = min;
1903 clk->max_rate = max;
1904 ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
1905 }
1906
1907 clk_prepare_unlock();
1908
1909 return ret;
1910}
1911EXPORT_SYMBOL_GPL(clk_set_rate_range);
1912
1913/**
1914 * clk_set_min_rate - set a minimum clock rate for a clock source
1915 * @clk: clock source
1916 * @rate: desired minimum clock rate in Hz, inclusive
1917 *
1918 * Returns success (0) or negative errno.
1919 */
1920int clk_set_min_rate(struct clk *clk, unsigned long rate)
1921{
1922 if (!clk)
1923 return 0;
1924
1925 return clk_set_rate_range(clk, rate, clk->max_rate);
1926}
1927EXPORT_SYMBOL_GPL(clk_set_min_rate);
1928
1929/**
1930 * clk_set_max_rate - set a maximum clock rate for a clock source
1931 * @clk: clock source
1932 * @rate: desired maximum clock rate in Hz, inclusive
1933 *
1934 * Returns success (0) or negative errno.
1935 */
1936int clk_set_max_rate(struct clk *clk, unsigned long rate)
1937{
1938 if (!clk)
1939 return 0;
1940
1941 return clk_set_rate_range(clk, clk->min_rate, rate);
1942}
1943EXPORT_SYMBOL_GPL(clk_set_max_rate);
1944
1945/**
Mike Turquetteb24764902012-03-15 23:11:19 -07001946 * clk_get_parent - return the parent of a clk
1947 * @clk: the clk whose parent gets returned
1948 *
1949 * Simply returns clk->parent. Returns NULL if clk is NULL.
1950 */
1951struct clk *clk_get_parent(struct clk *clk)
1952{
1953 struct clk *parent;
1954
Mike Turquetteeab89f62013-03-28 13:59:01 -07001955 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001956 parent = __clk_get_parent(clk);
Mike Turquetteeab89f62013-03-28 13:59:01 -07001957 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001958
1959 return parent;
1960}
1961EXPORT_SYMBOL_GPL(clk_get_parent);
1962
1963/*
1964 * .get_parent is mandatory for clocks with multiple possible parents. It is
1965 * optional for single-parent clocks. Always call .get_parent if it is
1966 * available and WARN if it is missing for multi-parent clocks.
1967 *
1968 * For single-parent clocks without .get_parent, first check to see if the
1969 * .parents array exists, and if so use it to avoid an expensive tree
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001970 * traversal. If .parents does not exist then walk the tree.
Mike Turquetteb24764902012-03-15 23:11:19 -07001971 */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001972static struct clk_core *__clk_init_parent(struct clk_core *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -07001973{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001974 struct clk_core *ret = NULL;
Mike Turquetteb24764902012-03-15 23:11:19 -07001975 u8 index;
1976
1977 /* handle the trivial cases */
1978
1979 if (!clk->num_parents)
1980 goto out;
1981
1982 if (clk->num_parents == 1) {
1983 if (IS_ERR_OR_NULL(clk->parent))
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001984 clk->parent = clk_core_lookup(clk->parent_names[0]);
Mike Turquetteb24764902012-03-15 23:11:19 -07001985 ret = clk->parent;
1986 goto out;
1987 }
1988
1989 if (!clk->ops->get_parent) {
1990 WARN(!clk->ops->get_parent,
1991 "%s: multi-parent clocks must implement .get_parent\n",
1992 __func__);
1993 goto out;
1994 };
1995
1996 /*
1997 * Do our best to cache parent clocks in clk->parents. This prevents
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01001998 * unnecessary and expensive lookups. We don't set clk->parent here;
1999 * that is done by the calling function.
Mike Turquetteb24764902012-03-15 23:11:19 -07002000 */
2001
2002 index = clk->ops->get_parent(clk->hw);
2003
2004 if (!clk->parents)
2005 clk->parents =
Tomasz Figa96a7ed92013-09-29 02:37:15 +02002006 kcalloc(clk->num_parents, sizeof(struct clk *),
Mike Turquetteb24764902012-03-15 23:11:19 -07002007 GFP_KERNEL);
2008
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002009 ret = clk_core_get_parent_by_index(clk, index);
Mike Turquetteb24764902012-03-15 23:11:19 -07002010
2011out:
2012 return ret;
2013}
2014
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002015static void clk_core_reparent(struct clk_core *clk,
2016 struct clk_core *new_parent)
Ulf Hanssonb33d2122013-04-02 23:09:37 +02002017{
2018 clk_reparent(clk, new_parent);
Boris BREZILLON5279fc42013-12-21 10:34:47 +01002019 __clk_recalc_accuracies(clk);
Mike Turquetteb24764902012-03-15 23:11:19 -07002020 __clk_recalc_rates(clk, POST_RATE_CHANGE);
2021}
2022
Mike Turquetteb24764902012-03-15 23:11:19 -07002023/**
Thierry Reding4e88f3d2015-01-21 17:13:00 +01002024 * clk_has_parent - check if a clock is a possible parent for another
2025 * @clk: clock source
2026 * @parent: parent clock source
Mike Turquetteb24764902012-03-15 23:11:19 -07002027 *
Thierry Reding4e88f3d2015-01-21 17:13:00 +01002028 * This function can be used in drivers that need to check that a clock can be
2029 * the parent of another without actually changing the parent.
Saravana Kannanf8aa0bd2013-05-15 21:07:24 -07002030 *
Thierry Reding4e88f3d2015-01-21 17:13:00 +01002031 * Returns true if @parent is a possible parent for @clk, false otherwise.
Mike Turquetteb24764902012-03-15 23:11:19 -07002032 */
Thierry Reding4e88f3d2015-01-21 17:13:00 +01002033bool clk_has_parent(struct clk *clk, struct clk *parent)
2034{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002035 struct clk_core *core, *parent_core;
Thierry Reding4e88f3d2015-01-21 17:13:00 +01002036 unsigned int i;
2037
2038 /* NULL clocks should be nops, so return success if either is NULL. */
2039 if (!clk || !parent)
2040 return true;
2041
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002042 core = clk->core;
2043 parent_core = parent->core;
2044
Thierry Reding4e88f3d2015-01-21 17:13:00 +01002045 /* Optimize for the case where the parent is already the parent. */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002046 if (core->parent == parent_core)
Thierry Reding4e88f3d2015-01-21 17:13:00 +01002047 return true;
2048
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002049 for (i = 0; i < core->num_parents; i++)
2050 if (strcmp(core->parent_names[i], parent_core->name) == 0)
Thierry Reding4e88f3d2015-01-21 17:13:00 +01002051 return true;
2052
2053 return false;
2054}
2055EXPORT_SYMBOL_GPL(clk_has_parent);
2056
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002057static int clk_core_set_parent(struct clk_core *clk, struct clk_core *parent)
Mike Turquetteb24764902012-03-15 23:11:19 -07002058{
2059 int ret = 0;
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02002060 int p_index = 0;
Ulf Hansson031dcc92013-04-02 23:09:38 +02002061 unsigned long p_rate = 0;
Mike Turquetteb24764902012-03-15 23:11:19 -07002062
Mike Turquette89ac8d72013-08-21 23:58:09 -07002063 if (!clk)
2064 return 0;
2065
Mike Turquetteb24764902012-03-15 23:11:19 -07002066 /* prevent racing with updates to the clock topology */
Mike Turquetteeab89f62013-03-28 13:59:01 -07002067 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07002068
2069 if (clk->parent == parent)
2070 goto out;
2071
Stephen Boydb61c43c2015-02-02 14:11:25 -08002072 /* verify ops for for multi-parent clks */
2073 if ((clk->num_parents > 1) && (!clk->ops->set_parent)) {
2074 ret = -ENOSYS;
2075 goto out;
2076 }
2077
Ulf Hansson031dcc92013-04-02 23:09:38 +02002078 /* check that we are allowed to re-parent if the clock is in use */
2079 if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) {
2080 ret = -EBUSY;
2081 goto out;
2082 }
2083
2084 /* try finding the new parent index */
2085 if (parent) {
2086 p_index = clk_fetch_parent_index(clk, parent);
2087 p_rate = parent->rate;
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02002088 if (p_index < 0) {
Ulf Hansson031dcc92013-04-02 23:09:38 +02002089 pr_debug("%s: clk %s can not be parent of clk %s\n",
2090 __func__, parent->name, clk->name);
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02002091 ret = p_index;
Ulf Hansson031dcc92013-04-02 23:09:38 +02002092 goto out;
2093 }
2094 }
2095
Mike Turquetteb24764902012-03-15 23:11:19 -07002096 /* propagate PRE_RATE_CHANGE notifications */
Soren Brinkmannf3aab5d2013-04-16 10:06:50 -07002097 ret = __clk_speculate_rates(clk, p_rate);
Mike Turquetteb24764902012-03-15 23:11:19 -07002098
2099 /* abort if a driver objects */
Soren Brinkmannfb72a052013-04-03 12:17:12 -07002100 if (ret & NOTIFY_STOP_MASK)
Mike Turquetteb24764902012-03-15 23:11:19 -07002101 goto out;
2102
Ulf Hansson031dcc92013-04-02 23:09:38 +02002103 /* do the re-parent */
2104 ret = __clk_set_parent(clk, parent, p_index);
Mike Turquetteb24764902012-03-15 23:11:19 -07002105
Boris BREZILLON5279fc42013-12-21 10:34:47 +01002106 /* propagate rate an accuracy recalculation accordingly */
2107 if (ret) {
Mike Turquetteb24764902012-03-15 23:11:19 -07002108 __clk_recalc_rates(clk, ABORT_RATE_CHANGE);
Boris BREZILLON5279fc42013-12-21 10:34:47 +01002109 } else {
Ulf Hanssona68de8e2013-04-02 23:09:39 +02002110 __clk_recalc_rates(clk, POST_RATE_CHANGE);
Boris BREZILLON5279fc42013-12-21 10:34:47 +01002111 __clk_recalc_accuracies(clk);
2112 }
Mike Turquetteb24764902012-03-15 23:11:19 -07002113
2114out:
Mike Turquetteeab89f62013-03-28 13:59:01 -07002115 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07002116
2117 return ret;
2118}
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002119
2120/**
2121 * clk_set_parent - switch the parent of a mux clk
2122 * @clk: the mux clk whose input we are switching
2123 * @parent: the new input to clk
2124 *
2125 * Re-parent clk to use parent as its new input source. If clk is in
2126 * prepared state, the clk will get enabled for the duration of this call. If
2127 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2128 * that, the reparenting is glitchy in hardware, etc), use the
2129 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2130 *
2131 * After successfully changing clk's parent clk_set_parent will update the
2132 * clk topology, sysfs topology and propagate rate recalculation via
2133 * __clk_recalc_rates.
2134 *
2135 * Returns 0 on success, -EERROR otherwise.
2136 */
2137int clk_set_parent(struct clk *clk, struct clk *parent)
2138{
2139 if (!clk)
2140 return 0;
2141
2142 return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
2143}
Mike Turquetteb24764902012-03-15 23:11:19 -07002144EXPORT_SYMBOL_GPL(clk_set_parent);
2145
2146/**
Mike Turquettee59c5372014-02-18 21:21:25 -08002147 * clk_set_phase - adjust the phase shift of a clock signal
2148 * @clk: clock signal source
2149 * @degrees: number of degrees the signal is shifted
2150 *
2151 * Shifts the phase of a clock signal by the specified
2152 * degrees. Returns 0 on success, -EERROR otherwise.
2153 *
2154 * This function makes no distinction about the input or reference
2155 * signal that we adjust the clock signal phase against. For example
2156 * phase locked-loop clock signal generators we may shift phase with
2157 * respect to feedback clock signal input, but for other cases the
2158 * clock phase may be shifted with respect to some other, unspecified
2159 * signal.
2160 *
2161 * Additionally the concept of phase shift does not propagate through
2162 * the clock tree hierarchy, which sets it apart from clock rates and
2163 * clock accuracy. A parent clock phase attribute does not have an
2164 * impact on the phase attribute of a child clock.
2165 */
2166int clk_set_phase(struct clk *clk, int degrees)
2167{
Stephen Boyd08b95752015-02-02 14:09:43 -08002168 int ret = -EINVAL;
Mike Turquettee59c5372014-02-18 21:21:25 -08002169
2170 if (!clk)
Stephen Boyd08b95752015-02-02 14:09:43 -08002171 return 0;
Mike Turquettee59c5372014-02-18 21:21:25 -08002172
2173 /* sanity check degrees */
2174 degrees %= 360;
2175 if (degrees < 0)
2176 degrees += 360;
2177
2178 clk_prepare_lock();
2179
Stephen Boyddfc202e2015-02-02 14:37:41 -08002180 trace_clk_set_phase(clk->core, degrees);
2181
Stephen Boyd08b95752015-02-02 14:09:43 -08002182 if (clk->core->ops->set_phase)
2183 ret = clk->core->ops->set_phase(clk->core->hw, degrees);
Mike Turquettee59c5372014-02-18 21:21:25 -08002184
Stephen Boyddfc202e2015-02-02 14:37:41 -08002185 trace_clk_set_phase_complete(clk->core, degrees);
2186
Mike Turquettee59c5372014-02-18 21:21:25 -08002187 if (!ret)
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002188 clk->core->phase = degrees;
Mike Turquettee59c5372014-02-18 21:21:25 -08002189
Mike Turquettee59c5372014-02-18 21:21:25 -08002190 clk_prepare_unlock();
2191
Mike Turquettee59c5372014-02-18 21:21:25 -08002192 return ret;
2193}
Maxime Ripard9767b042015-01-20 22:23:43 +01002194EXPORT_SYMBOL_GPL(clk_set_phase);
Mike Turquettee59c5372014-02-18 21:21:25 -08002195
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002196static int clk_core_get_phase(struct clk_core *clk)
Mike Turquettee59c5372014-02-18 21:21:25 -08002197{
2198 int ret = 0;
2199
2200 if (!clk)
2201 goto out;
2202
2203 clk_prepare_lock();
2204 ret = clk->phase;
2205 clk_prepare_unlock();
2206
2207out:
2208 return ret;
2209}
Maxime Ripard9767b042015-01-20 22:23:43 +01002210EXPORT_SYMBOL_GPL(clk_get_phase);
Mike Turquettee59c5372014-02-18 21:21:25 -08002211
2212/**
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002213 * clk_get_phase - return the phase shift of a clock signal
2214 * @clk: clock signal source
2215 *
2216 * Returns the phase shift of a clock node in degrees, otherwise returns
2217 * -EERROR.
2218 */
2219int clk_get_phase(struct clk *clk)
2220{
2221 if (!clk)
2222 return 0;
2223
2224 return clk_core_get_phase(clk->core);
2225}
Mike Turquetteb24764902012-03-15 23:11:19 -07002226
2227/**
Michael Turquette3d3801e2015-02-25 09:11:01 -08002228 * clk_is_match - check if two clk's point to the same hardware clock
2229 * @p: clk compared against q
2230 * @q: clk compared against p
2231 *
2232 * Returns true if the two struct clk pointers both point to the same hardware
2233 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2234 * share the same struct clk_core object.
2235 *
2236 * Returns false otherwise. Note that two NULL clks are treated as matching.
2237 */
2238bool clk_is_match(const struct clk *p, const struct clk *q)
2239{
2240 /* trivial case: identical struct clk's or both NULL */
2241 if (p == q)
2242 return true;
2243
2244 /* true if clk->core pointers match. Avoid derefing garbage */
2245 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
2246 if (p->core == q->core)
2247 return true;
2248
2249 return false;
2250}
2251EXPORT_SYMBOL_GPL(clk_is_match);
2252
2253/**
Mike Turquetteb24764902012-03-15 23:11:19 -07002254 * __clk_init - initialize the data structures in a struct clk
2255 * @dev: device initializing this clk, placeholder for now
2256 * @clk: clk being initialized
2257 *
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002258 * Initializes the lists in struct clk_core, queries the hardware for the
Mike Turquetteb24764902012-03-15 23:11:19 -07002259 * parent and rate and sets them both.
Mike Turquetteb24764902012-03-15 23:11:19 -07002260 */
Michael Turquetteb09d6d92015-01-29 14:22:50 -08002261static int __clk_init(struct device *dev, struct clk *clk_user)
Mike Turquetteb24764902012-03-15 23:11:19 -07002262{
Mike Turquetted1302a32012-03-29 14:30:40 -07002263 int i, ret = 0;
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002264 struct clk_core *orphan;
Sasha Levinb67bfe02013-02-27 17:06:00 -08002265 struct hlist_node *tmp2;
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002266 struct clk_core *clk;
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01002267 unsigned long rate;
Mike Turquetteb24764902012-03-15 23:11:19 -07002268
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002269 if (!clk_user)
Mike Turquetted1302a32012-03-29 14:30:40 -07002270 return -EINVAL;
Mike Turquetteb24764902012-03-15 23:11:19 -07002271
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002272 clk = clk_user->core;
2273
Mike Turquetteeab89f62013-03-28 13:59:01 -07002274 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07002275
2276 /* check to see if a clock with this name is already registered */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002277 if (clk_core_lookup(clk->name)) {
Mike Turquetted1302a32012-03-29 14:30:40 -07002278 pr_debug("%s: clk %s already initialized\n",
2279 __func__, clk->name);
2280 ret = -EEXIST;
Mike Turquetteb24764902012-03-15 23:11:19 -07002281 goto out;
Mike Turquetted1302a32012-03-29 14:30:40 -07002282 }
Mike Turquetteb24764902012-03-15 23:11:19 -07002283
Mike Turquetted4d7e3d2012-03-26 16:15:52 -07002284 /* check that clk_ops are sane. See Documentation/clk.txt */
2285 if (clk->ops->set_rate &&
James Hogan71472c02013-07-29 12:25:00 +01002286 !((clk->ops->round_rate || clk->ops->determine_rate) &&
2287 clk->ops->recalc_rate)) {
2288 pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
Mike Turquetted4d7e3d2012-03-26 16:15:52 -07002289 __func__, clk->name);
Mike Turquetted1302a32012-03-29 14:30:40 -07002290 ret = -EINVAL;
Mike Turquetted4d7e3d2012-03-26 16:15:52 -07002291 goto out;
2292 }
2293
2294 if (clk->ops->set_parent && !clk->ops->get_parent) {
2295 pr_warning("%s: %s must implement .get_parent & .set_parent\n",
2296 __func__, clk->name);
Mike Turquetted1302a32012-03-29 14:30:40 -07002297 ret = -EINVAL;
Mike Turquetted4d7e3d2012-03-26 16:15:52 -07002298 goto out;
2299 }
2300
Stephen Boyd3fa22522014-01-15 10:47:22 -08002301 if (clk->ops->set_rate_and_parent &&
2302 !(clk->ops->set_parent && clk->ops->set_rate)) {
2303 pr_warn("%s: %s must implement .set_parent & .set_rate\n",
2304 __func__, clk->name);
2305 ret = -EINVAL;
2306 goto out;
2307 }
2308
Mike Turquetteb24764902012-03-15 23:11:19 -07002309 /* throw a WARN if any entries in parent_names are NULL */
2310 for (i = 0; i < clk->num_parents; i++)
2311 WARN(!clk->parent_names[i],
2312 "%s: invalid NULL in %s's .parent_names\n",
2313 __func__, clk->name);
2314
2315 /*
2316 * Allocate an array of struct clk *'s to avoid unnecessary string
2317 * look-ups of clk's possible parents. This can fail for clocks passed
2318 * in to clk_init during early boot; thus any access to clk->parents[]
2319 * must always check for a NULL pointer and try to populate it if
2320 * necessary.
2321 *
2322 * If clk->parents is not NULL we skip this entire block. This allows
2323 * for clock drivers to statically initialize clk->parents.
2324 */
Rajendra Nayak9ca1c5a2012-06-06 14:41:30 +05302325 if (clk->num_parents > 1 && !clk->parents) {
Tomasz Figa96a7ed92013-09-29 02:37:15 +02002326 clk->parents = kcalloc(clk->num_parents, sizeof(struct clk *),
2327 GFP_KERNEL);
Mike Turquetteb24764902012-03-15 23:11:19 -07002328 /*
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002329 * clk_core_lookup returns NULL for parents that have not been
Mike Turquetteb24764902012-03-15 23:11:19 -07002330 * clk_init'd; thus any access to clk->parents[] must check
2331 * for a NULL pointer. We can always perform lazy lookups for
2332 * missing parents later on.
2333 */
2334 if (clk->parents)
2335 for (i = 0; i < clk->num_parents; i++)
2336 clk->parents[i] =
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002337 clk_core_lookup(clk->parent_names[i]);
Mike Turquetteb24764902012-03-15 23:11:19 -07002338 }
2339
2340 clk->parent = __clk_init_parent(clk);
2341
2342 /*
2343 * Populate clk->parent if parent has already been __clk_init'd. If
2344 * parent has not yet been __clk_init'd then place clk in the orphan
2345 * list. If clk has set the CLK_IS_ROOT flag then place it in the root
2346 * clk list.
2347 *
2348 * Every time a new clk is clk_init'd then we walk the list of orphan
2349 * clocks and re-parent any that are children of the clock currently
2350 * being clk_init'd.
2351 */
2352 if (clk->parent)
2353 hlist_add_head(&clk->child_node,
2354 &clk->parent->children);
2355 else if (clk->flags & CLK_IS_ROOT)
2356 hlist_add_head(&clk->child_node, &clk_root_list);
2357 else
2358 hlist_add_head(&clk->child_node, &clk_orphan_list);
2359
2360 /*
Boris BREZILLON5279fc42013-12-21 10:34:47 +01002361 * Set clk's accuracy. The preferred method is to use
2362 * .recalc_accuracy. For simple clocks and lazy developers the default
2363 * fallback is to use the parent's accuracy. If a clock doesn't have a
2364 * parent (or is orphaned) then accuracy is set to zero (perfect
2365 * clock).
2366 */
2367 if (clk->ops->recalc_accuracy)
2368 clk->accuracy = clk->ops->recalc_accuracy(clk->hw,
2369 __clk_get_accuracy(clk->parent));
2370 else if (clk->parent)
2371 clk->accuracy = clk->parent->accuracy;
2372 else
2373 clk->accuracy = 0;
2374
2375 /*
Maxime Ripard9824cf72014-07-14 13:53:27 +02002376 * Set clk's phase.
2377 * Since a phase is by definition relative to its parent, just
2378 * query the current clock phase, or just assume it's in phase.
2379 */
2380 if (clk->ops->get_phase)
2381 clk->phase = clk->ops->get_phase(clk->hw);
2382 else
2383 clk->phase = 0;
2384
2385 /*
Mike Turquetteb24764902012-03-15 23:11:19 -07002386 * Set clk's rate. The preferred method is to use .recalc_rate. For
2387 * simple clocks and lazy developers the default fallback is to use the
2388 * parent's rate. If a clock doesn't have a parent (or is orphaned)
2389 * then rate is set to zero.
2390 */
2391 if (clk->ops->recalc_rate)
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01002392 rate = clk->ops->recalc_rate(clk->hw,
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002393 clk_core_get_rate_nolock(clk->parent));
Mike Turquetteb24764902012-03-15 23:11:19 -07002394 else if (clk->parent)
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01002395 rate = clk->parent->rate;
Mike Turquetteb24764902012-03-15 23:11:19 -07002396 else
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01002397 rate = 0;
2398 clk->rate = clk->req_rate = rate;
Mike Turquetteb24764902012-03-15 23:11:19 -07002399
2400 /*
2401 * walk the list of orphan clocks and reparent any that are children of
2402 * this clock
2403 */
Sasha Levinb67bfe02013-02-27 17:06:00 -08002404 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
Alex Elder12d298862013-09-05 08:33:24 -05002405 if (orphan->num_parents && orphan->ops->get_parent) {
Martin Fuzzey1f61e5f2012-11-22 20:15:05 +01002406 i = orphan->ops->get_parent(orphan->hw);
2407 if (!strcmp(clk->name, orphan->parent_names[i]))
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002408 clk_core_reparent(orphan, clk);
Martin Fuzzey1f61e5f2012-11-22 20:15:05 +01002409 continue;
2410 }
2411
Mike Turquetteb24764902012-03-15 23:11:19 -07002412 for (i = 0; i < orphan->num_parents; i++)
2413 if (!strcmp(clk->name, orphan->parent_names[i])) {
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002414 clk_core_reparent(orphan, clk);
Mike Turquetteb24764902012-03-15 23:11:19 -07002415 break;
2416 }
Martin Fuzzey1f61e5f2012-11-22 20:15:05 +01002417 }
Mike Turquetteb24764902012-03-15 23:11:19 -07002418
2419 /*
2420 * optional platform-specific magic
2421 *
2422 * The .init callback is not used by any of the basic clock types, but
2423 * exists for weird hardware that must perform initialization magic.
2424 * Please consider other ways of solving initialization problems before
Peter Meerwald24ee1a02013-06-29 15:14:19 +02002425 * using this callback, as its use is discouraged.
Mike Turquetteb24764902012-03-15 23:11:19 -07002426 */
2427 if (clk->ops->init)
2428 clk->ops->init(clk->hw);
2429
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002430 kref_init(&clk->ref);
Mike Turquetteb24764902012-03-15 23:11:19 -07002431out:
Mike Turquetteeab89f62013-03-28 13:59:01 -07002432 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07002433
Stephen Boyd89f7e9d2014-12-12 15:04:16 -08002434 if (!ret)
2435 clk_debug_register(clk);
2436
Mike Turquetted1302a32012-03-29 14:30:40 -07002437 return ret;
Mike Turquetteb24764902012-03-15 23:11:19 -07002438}
2439
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002440struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
2441 const char *con_id)
Saravana Kannan0197b3e2012-04-25 22:58:56 -07002442{
Saravana Kannan0197b3e2012-04-25 22:58:56 -07002443 struct clk *clk;
2444
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002445 /* This is to allow this function to be chained to others */
2446 if (!hw || IS_ERR(hw))
2447 return (struct clk *) hw;
Saravana Kannan0197b3e2012-04-25 22:58:56 -07002448
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002449 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
2450 if (!clk)
2451 return ERR_PTR(-ENOMEM);
2452
2453 clk->core = hw->core;
2454 clk->dev_id = dev_id;
2455 clk->con_id = con_id;
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01002456 clk->max_rate = ULONG_MAX;
2457
2458 clk_prepare_lock();
Stephen Boyd50595f82015-02-06 11:42:44 -08002459 hlist_add_head(&clk->clks_node, &hw->core->clks);
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01002460 clk_prepare_unlock();
Saravana Kannan0197b3e2012-04-25 22:58:56 -07002461
2462 return clk;
2463}
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002464
Stephen Boyd73e0e492015-02-06 11:42:43 -08002465void __clk_free_clk(struct clk *clk)
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01002466{
2467 clk_prepare_lock();
Stephen Boyd50595f82015-02-06 11:42:44 -08002468 hlist_del(&clk->clks_node);
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01002469 clk_prepare_unlock();
2470
2471 kfree(clk);
2472}
Saravana Kannan0197b3e2012-04-25 22:58:56 -07002473
Stephen Boyd293ba3b2014-04-18 16:29:42 -07002474/**
2475 * clk_register - allocate a new clock, register it and return an opaque cookie
2476 * @dev: device that is registering this clock
2477 * @hw: link to hardware-specific clock data
2478 *
2479 * clk_register is the primary interface for populating the clock tree with new
2480 * clock nodes. It returns a pointer to the newly allocated struct clk which
2481 * cannot be dereferenced by driver code but may be used in conjuction with the
2482 * rest of the clock API. In the event of an error clk_register will return an
2483 * error code; drivers must test for an error code after calling clk_register.
2484 */
2485struct clk *clk_register(struct device *dev, struct clk_hw *hw)
Mike Turquetteb24764902012-03-15 23:11:19 -07002486{
Mike Turquetted1302a32012-03-29 14:30:40 -07002487 int i, ret;
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002488 struct clk_core *clk;
Stephen Boyd293ba3b2014-04-18 16:29:42 -07002489
2490 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
2491 if (!clk) {
2492 pr_err("%s: could not allocate clk\n", __func__);
2493 ret = -ENOMEM;
2494 goto fail_out;
2495 }
Mike Turquetteb24764902012-03-15 23:11:19 -07002496
Andrzej Hajda612936f2015-02-13 14:36:33 -08002497 clk->name = kstrdup_const(hw->init->name, GFP_KERNEL);
Saravana Kannan0197b3e2012-04-25 22:58:56 -07002498 if (!clk->name) {
2499 pr_err("%s: could not allocate clk->name\n", __func__);
2500 ret = -ENOMEM;
2501 goto fail_name;
2502 }
2503 clk->ops = hw->init->ops;
Sylwester Nawrockiac2df522013-08-24 20:10:41 +02002504 if (dev && dev->driver)
2505 clk->owner = dev->driver->owner;
Mike Turquetteb24764902012-03-15 23:11:19 -07002506 clk->hw = hw;
Saravana Kannan0197b3e2012-04-25 22:58:56 -07002507 clk->flags = hw->init->flags;
2508 clk->num_parents = hw->init->num_parents;
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002509 hw->core = clk;
Mike Turquetteb24764902012-03-15 23:11:19 -07002510
Mike Turquetted1302a32012-03-29 14:30:40 -07002511 /* allocate local copy in case parent_names is __initdata */
Tomasz Figa96a7ed92013-09-29 02:37:15 +02002512 clk->parent_names = kcalloc(clk->num_parents, sizeof(char *),
2513 GFP_KERNEL);
Mike Turquetteb24764902012-03-15 23:11:19 -07002514
Mike Turquetted1302a32012-03-29 14:30:40 -07002515 if (!clk->parent_names) {
2516 pr_err("%s: could not allocate clk->parent_names\n", __func__);
2517 ret = -ENOMEM;
2518 goto fail_parent_names;
2519 }
2520
2521
2522 /* copy each string name in case parent_names is __initdata */
Saravana Kannan0197b3e2012-04-25 22:58:56 -07002523 for (i = 0; i < clk->num_parents; i++) {
Andrzej Hajda612936f2015-02-13 14:36:33 -08002524 clk->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
Saravana Kannan0197b3e2012-04-25 22:58:56 -07002525 GFP_KERNEL);
Mike Turquetted1302a32012-03-29 14:30:40 -07002526 if (!clk->parent_names[i]) {
2527 pr_err("%s: could not copy parent_names\n", __func__);
2528 ret = -ENOMEM;
2529 goto fail_parent_names_copy;
2530 }
2531 }
2532
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01002533 INIT_HLIST_HEAD(&clk->clks);
2534
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002535 hw->clk = __clk_create_clk(hw, NULL, NULL);
2536 if (IS_ERR(hw->clk)) {
2537 pr_err("%s: could not allocate per-user clk\n", __func__);
2538 ret = PTR_ERR(hw->clk);
2539 goto fail_parent_names_copy;
2540 }
Mike Turquetted1302a32012-03-29 14:30:40 -07002541
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002542 ret = __clk_init(dev, hw->clk);
Mike Turquetted1302a32012-03-29 14:30:40 -07002543 if (!ret)
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002544 return hw->clk;
2545
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01002546 __clk_free_clk(hw->clk);
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002547 hw->clk = NULL;
Mike Turquetted1302a32012-03-29 14:30:40 -07002548
2549fail_parent_names_copy:
2550 while (--i >= 0)
Andrzej Hajda612936f2015-02-13 14:36:33 -08002551 kfree_const(clk->parent_names[i]);
Mike Turquetted1302a32012-03-29 14:30:40 -07002552 kfree(clk->parent_names);
2553fail_parent_names:
Andrzej Hajda612936f2015-02-13 14:36:33 -08002554 kfree_const(clk->name);
Saravana Kannan0197b3e2012-04-25 22:58:56 -07002555fail_name:
Mike Turquetted1302a32012-03-29 14:30:40 -07002556 kfree(clk);
2557fail_out:
2558 return ERR_PTR(ret);
Mike Turquetteb24764902012-03-15 23:11:19 -07002559}
2560EXPORT_SYMBOL_GPL(clk_register);
2561
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002562/*
2563 * Free memory allocated for a clock.
2564 * Caller must hold prepare_lock.
2565 */
2566static void __clk_release(struct kref *ref)
2567{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002568 struct clk_core *clk = container_of(ref, struct clk_core, ref);
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002569 int i = clk->num_parents;
2570
Krzysztof Kozlowski496eadf2015-01-09 09:28:10 +01002571 lockdep_assert_held(&prepare_lock);
2572
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002573 kfree(clk->parents);
2574 while (--i >= 0)
Andrzej Hajda612936f2015-02-13 14:36:33 -08002575 kfree_const(clk->parent_names[i]);
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002576
2577 kfree(clk->parent_names);
Andrzej Hajda612936f2015-02-13 14:36:33 -08002578 kfree_const(clk->name);
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002579 kfree(clk);
2580}
2581
2582/*
2583 * Empty clk_ops for unregistered clocks. These are used temporarily
2584 * after clk_unregister() was called on a clock and until last clock
2585 * consumer calls clk_put() and the struct clk object is freed.
2586 */
2587static int clk_nodrv_prepare_enable(struct clk_hw *hw)
2588{
2589 return -ENXIO;
2590}
2591
2592static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
2593{
2594 WARN_ON_ONCE(1);
2595}
2596
2597static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
2598 unsigned long parent_rate)
2599{
2600 return -ENXIO;
2601}
2602
2603static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
2604{
2605 return -ENXIO;
2606}
2607
2608static const struct clk_ops clk_nodrv_ops = {
2609 .enable = clk_nodrv_prepare_enable,
2610 .disable = clk_nodrv_disable_unprepare,
2611 .prepare = clk_nodrv_prepare_enable,
2612 .unprepare = clk_nodrv_disable_unprepare,
2613 .set_rate = clk_nodrv_set_rate,
2614 .set_parent = clk_nodrv_set_parent,
2615};
2616
Mark Brown1df5c932012-04-18 09:07:12 +01002617/**
2618 * clk_unregister - unregister a currently registered clock
2619 * @clk: clock to unregister
Mark Brown1df5c932012-04-18 09:07:12 +01002620 */
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002621void clk_unregister(struct clk *clk)
2622{
2623 unsigned long flags;
2624
Stephen Boyd6314b672014-09-04 23:37:49 -07002625 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2626 return;
2627
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002628 clk_debug_unregister(clk->core);
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002629
2630 clk_prepare_lock();
2631
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002632 if (clk->core->ops == &clk_nodrv_ops) {
2633 pr_err("%s: unregistered clock: %s\n", __func__,
2634 clk->core->name);
Stephen Boyd6314b672014-09-04 23:37:49 -07002635 return;
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002636 }
2637 /*
2638 * Assign empty clock ops for consumers that might still hold
2639 * a reference to this clock.
2640 */
2641 flags = clk_enable_lock();
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002642 clk->core->ops = &clk_nodrv_ops;
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002643 clk_enable_unlock(flags);
2644
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002645 if (!hlist_empty(&clk->core->children)) {
2646 struct clk_core *child;
Stephen Boyd874f2242014-04-18 16:29:43 -07002647 struct hlist_node *t;
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002648
2649 /* Reparent all children to the orphan list. */
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002650 hlist_for_each_entry_safe(child, t, &clk->core->children,
2651 child_node)
2652 clk_core_set_parent(child, NULL);
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002653 }
2654
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002655 hlist_del_init(&clk->core->child_node);
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002656
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002657 if (clk->core->prepare_count)
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002658 pr_warn("%s: unregistering prepared clock: %s\n",
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002659 __func__, clk->core->name);
2660 kref_put(&clk->core->ref, __clk_release);
Stephen Boyd6314b672014-09-04 23:37:49 -07002661
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002662 clk_prepare_unlock();
2663}
Mark Brown1df5c932012-04-18 09:07:12 +01002664EXPORT_SYMBOL_GPL(clk_unregister);
2665
Stephen Boyd46c87732012-09-24 13:38:04 -07002666static void devm_clk_release(struct device *dev, void *res)
2667{
Stephen Boyd293ba3b2014-04-18 16:29:42 -07002668 clk_unregister(*(struct clk **)res);
Stephen Boyd46c87732012-09-24 13:38:04 -07002669}
2670
2671/**
2672 * devm_clk_register - resource managed clk_register()
2673 * @dev: device that is registering this clock
2674 * @hw: link to hardware-specific clock data
2675 *
2676 * Managed clk_register(). Clocks returned from this function are
2677 * automatically clk_unregister()ed on driver detach. See clk_register() for
2678 * more information.
2679 */
2680struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
2681{
2682 struct clk *clk;
Stephen Boyd293ba3b2014-04-18 16:29:42 -07002683 struct clk **clkp;
Stephen Boyd46c87732012-09-24 13:38:04 -07002684
Stephen Boyd293ba3b2014-04-18 16:29:42 -07002685 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
2686 if (!clkp)
Stephen Boyd46c87732012-09-24 13:38:04 -07002687 return ERR_PTR(-ENOMEM);
2688
Stephen Boyd293ba3b2014-04-18 16:29:42 -07002689 clk = clk_register(dev, hw);
2690 if (!IS_ERR(clk)) {
2691 *clkp = clk;
2692 devres_add(dev, clkp);
Stephen Boyd46c87732012-09-24 13:38:04 -07002693 } else {
Stephen Boyd293ba3b2014-04-18 16:29:42 -07002694 devres_free(clkp);
Stephen Boyd46c87732012-09-24 13:38:04 -07002695 }
2696
2697 return clk;
2698}
2699EXPORT_SYMBOL_GPL(devm_clk_register);
2700
2701static int devm_clk_match(struct device *dev, void *res, void *data)
2702{
2703 struct clk *c = res;
2704 if (WARN_ON(!c))
2705 return 0;
2706 return c == data;
2707}
2708
2709/**
2710 * devm_clk_unregister - resource managed clk_unregister()
2711 * @clk: clock to unregister
2712 *
2713 * Deallocate a clock allocated with devm_clk_register(). Normally
2714 * this function will not need to be called and the resource management
2715 * code will ensure that the resource is freed.
2716 */
2717void devm_clk_unregister(struct device *dev, struct clk *clk)
2718{
2719 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
2720}
2721EXPORT_SYMBOL_GPL(devm_clk_unregister);
2722
Sylwester Nawrockiac2df522013-08-24 20:10:41 +02002723/*
2724 * clkdev helpers
2725 */
2726int __clk_get(struct clk *clk)
2727{
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002728 struct clk_core *core = !clk ? NULL : clk->core;
2729
2730 if (core) {
2731 if (!try_module_get(core->owner))
Sylwester Nawrocki00efcb12014-01-07 13:03:43 +01002732 return 0;
Sylwester Nawrockiac2df522013-08-24 20:10:41 +02002733
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002734 kref_get(&core->ref);
Sylwester Nawrocki00efcb12014-01-07 13:03:43 +01002735 }
Sylwester Nawrockiac2df522013-08-24 20:10:41 +02002736 return 1;
2737}
2738
2739void __clk_put(struct clk *clk)
2740{
Tomeu Vizoso10cdfe52014-12-02 08:54:19 +01002741 struct module *owner;
2742
Sylwester Nawrocki00efcb12014-01-07 13:03:43 +01002743 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
Sylwester Nawrockiac2df522013-08-24 20:10:41 +02002744 return;
2745
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002746 clk_prepare_lock();
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01002747
Stephen Boyd50595f82015-02-06 11:42:44 -08002748 hlist_del(&clk->clks_node);
Tomeu Vizosoec02ace2015-02-06 15:13:01 +01002749 if (clk->min_rate > clk->core->req_rate ||
2750 clk->max_rate < clk->core->req_rate)
2751 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
2752
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01002753 owner = clk->core->owner;
2754 kref_put(&clk->core->ref, __clk_release);
2755
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002756 clk_prepare_unlock();
2757
Tomeu Vizoso10cdfe52014-12-02 08:54:19 +01002758 module_put(owner);
Tomeu Vizoso1c8e6002015-01-23 12:03:31 +01002759
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002760 kfree(clk);
Sylwester Nawrockiac2df522013-08-24 20:10:41 +02002761}
2762
Mike Turquetteb24764902012-03-15 23:11:19 -07002763/*** clk rate change notifiers ***/
2764
2765/**
2766 * clk_notifier_register - add a clk rate change notifier
2767 * @clk: struct clk * to watch
2768 * @nb: struct notifier_block * with callback info
2769 *
2770 * Request notification when clk's rate changes. This uses an SRCU
2771 * notifier because we want it to block and notifier unregistrations are
2772 * uncommon. The callbacks associated with the notifier must not
2773 * re-enter into the clk framework by calling any top-level clk APIs;
2774 * this will cause a nested prepare_lock mutex.
2775 *
Soren Brinkmann5324fda2014-01-22 11:48:37 -08002776 * In all notification cases cases (pre, post and abort rate change) the
2777 * original clock rate is passed to the callback via struct
2778 * clk_notifier_data.old_rate and the new frequency is passed via struct
Mike Turquetteb24764902012-03-15 23:11:19 -07002779 * clk_notifier_data.new_rate.
2780 *
Mike Turquetteb24764902012-03-15 23:11:19 -07002781 * clk_notifier_register() must be called from non-atomic context.
2782 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2783 * allocation failure; otherwise, passes along the return value of
2784 * srcu_notifier_chain_register().
2785 */
2786int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
2787{
2788 struct clk_notifier *cn;
2789 int ret = -ENOMEM;
2790
2791 if (!clk || !nb)
2792 return -EINVAL;
2793
Mike Turquetteeab89f62013-03-28 13:59:01 -07002794 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07002795
2796 /* search the list of notifiers for this clk */
2797 list_for_each_entry(cn, &clk_notifier_list, node)
2798 if (cn->clk == clk)
2799 break;
2800
2801 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2802 if (cn->clk != clk) {
2803 cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
2804 if (!cn)
2805 goto out;
2806
2807 cn->clk = clk;
2808 srcu_init_notifier_head(&cn->notifier_head);
2809
2810 list_add(&cn->node, &clk_notifier_list);
2811 }
2812
2813 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
2814
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002815 clk->core->notifier_count++;
Mike Turquetteb24764902012-03-15 23:11:19 -07002816
2817out:
Mike Turquetteeab89f62013-03-28 13:59:01 -07002818 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07002819
2820 return ret;
2821}
2822EXPORT_SYMBOL_GPL(clk_notifier_register);
2823
2824/**
2825 * clk_notifier_unregister - remove a clk rate change notifier
2826 * @clk: struct clk *
2827 * @nb: struct notifier_block * with callback info
2828 *
2829 * Request no further notification for changes to 'clk' and frees memory
2830 * allocated in clk_notifier_register.
2831 *
2832 * Returns -EINVAL if called with null arguments; otherwise, passes
2833 * along the return value of srcu_notifier_chain_unregister().
2834 */
2835int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
2836{
2837 struct clk_notifier *cn = NULL;
2838 int ret = -EINVAL;
2839
2840 if (!clk || !nb)
2841 return -EINVAL;
2842
Mike Turquetteeab89f62013-03-28 13:59:01 -07002843 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07002844
2845 list_for_each_entry(cn, &clk_notifier_list, node)
2846 if (cn->clk == clk)
2847 break;
2848
2849 if (cn->clk == clk) {
2850 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
2851
Tomeu Vizoso035a61c2015-01-23 12:03:30 +01002852 clk->core->notifier_count--;
Mike Turquetteb24764902012-03-15 23:11:19 -07002853
2854 /* XXX the notifier code should handle this better */
2855 if (!cn->notifier_head.head) {
2856 srcu_cleanup_notifier_head(&cn->notifier_head);
Lai Jiangshan72b53222013-06-03 17:17:15 +08002857 list_del(&cn->node);
Mike Turquetteb24764902012-03-15 23:11:19 -07002858 kfree(cn);
2859 }
2860
2861 } else {
2862 ret = -ENOENT;
2863 }
2864
Mike Turquetteeab89f62013-03-28 13:59:01 -07002865 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07002866
2867 return ret;
2868}
2869EXPORT_SYMBOL_GPL(clk_notifier_unregister);
Grant Likely766e6a42012-04-09 14:50:06 -05002870
2871#ifdef CONFIG_OF
2872/**
2873 * struct of_clk_provider - Clock provider registration structure
2874 * @link: Entry in global list of clock providers
2875 * @node: Pointer to device tree node of clock provider
2876 * @get: Get clock callback. Returns NULL or a struct clk for the
2877 * given clock specifier
2878 * @data: context pointer to be passed into @get callback
2879 */
2880struct of_clk_provider {
2881 struct list_head link;
2882
2883 struct device_node *node;
2884 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
2885 void *data;
2886};
2887
Prashant Gaikwadf2f6c252013-01-04 12:30:52 +05302888static const struct of_device_id __clk_of_table_sentinel
2889 __used __section(__clk_of_table_end);
2890
Grant Likely766e6a42012-04-09 14:50:06 -05002891static LIST_HEAD(of_clk_providers);
Sylwester Nawrockid6782c22013-08-23 17:03:43 +02002892static DEFINE_MUTEX(of_clk_mutex);
2893
Grant Likely766e6a42012-04-09 14:50:06 -05002894struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
2895 void *data)
2896{
2897 return data;
2898}
2899EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
2900
Shawn Guo494bfec2012-08-22 21:36:27 +08002901struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
2902{
2903 struct clk_onecell_data *clk_data = data;
2904 unsigned int idx = clkspec->args[0];
2905
2906 if (idx >= clk_data->clk_num) {
2907 pr_err("%s: invalid clock index %d\n", __func__, idx);
2908 return ERR_PTR(-EINVAL);
2909 }
2910
2911 return clk_data->clks[idx];
2912}
2913EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
2914
Grant Likely766e6a42012-04-09 14:50:06 -05002915/**
2916 * of_clk_add_provider() - Register a clock provider for a node
2917 * @np: Device node pointer associated with clock provider
2918 * @clk_src_get: callback for decoding clock
2919 * @data: context pointer for @clk_src_get callback.
2920 */
2921int of_clk_add_provider(struct device_node *np,
2922 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
2923 void *data),
2924 void *data)
2925{
2926 struct of_clk_provider *cp;
Sylwester Nawrocki86be4082014-06-18 17:29:32 +02002927 int ret;
Grant Likely766e6a42012-04-09 14:50:06 -05002928
2929 cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
2930 if (!cp)
2931 return -ENOMEM;
2932
2933 cp->node = of_node_get(np);
2934 cp->data = data;
2935 cp->get = clk_src_get;
2936
Sylwester Nawrockid6782c22013-08-23 17:03:43 +02002937 mutex_lock(&of_clk_mutex);
Grant Likely766e6a42012-04-09 14:50:06 -05002938 list_add(&cp->link, &of_clk_providers);
Sylwester Nawrockid6782c22013-08-23 17:03:43 +02002939 mutex_unlock(&of_clk_mutex);
Grant Likely766e6a42012-04-09 14:50:06 -05002940 pr_debug("Added clock from %s\n", np->full_name);
2941
Sylwester Nawrocki86be4082014-06-18 17:29:32 +02002942 ret = of_clk_set_defaults(np, true);
2943 if (ret < 0)
2944 of_clk_del_provider(np);
2945
2946 return ret;
Grant Likely766e6a42012-04-09 14:50:06 -05002947}
2948EXPORT_SYMBOL_GPL(of_clk_add_provider);
2949
2950/**
2951 * of_clk_del_provider() - Remove a previously registered clock provider
2952 * @np: Device node pointer associated with clock provider
2953 */
2954void of_clk_del_provider(struct device_node *np)
2955{
2956 struct of_clk_provider *cp;
2957
Sylwester Nawrockid6782c22013-08-23 17:03:43 +02002958 mutex_lock(&of_clk_mutex);
Grant Likely766e6a42012-04-09 14:50:06 -05002959 list_for_each_entry(cp, &of_clk_providers, link) {
2960 if (cp->node == np) {
2961 list_del(&cp->link);
2962 of_node_put(cp->node);
2963 kfree(cp);
2964 break;
2965 }
2966 }
Sylwester Nawrockid6782c22013-08-23 17:03:43 +02002967 mutex_unlock(&of_clk_mutex);
Grant Likely766e6a42012-04-09 14:50:06 -05002968}
2969EXPORT_SYMBOL_GPL(of_clk_del_provider);
2970
Stephen Boyd73e0e492015-02-06 11:42:43 -08002971struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
2972 const char *dev_id, const char *con_id)
Grant Likely766e6a42012-04-09 14:50:06 -05002973{
2974 struct of_clk_provider *provider;
Jean-Francois Moinea34cd462013-11-25 19:47:04 +01002975 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
Grant Likely766e6a42012-04-09 14:50:06 -05002976
Stephen Boyd306c3422015-02-05 15:39:11 -08002977 if (!clkspec)
2978 return ERR_PTR(-EINVAL);
2979
Grant Likely766e6a42012-04-09 14:50:06 -05002980 /* Check if we have such a provider in our array */
Stephen Boyd306c3422015-02-05 15:39:11 -08002981 mutex_lock(&of_clk_mutex);
Grant Likely766e6a42012-04-09 14:50:06 -05002982 list_for_each_entry(provider, &of_clk_providers, link) {
2983 if (provider->node == clkspec->np)
2984 clk = provider->get(clkspec, provider->data);
Stephen Boyd73e0e492015-02-06 11:42:43 -08002985 if (!IS_ERR(clk)) {
2986 clk = __clk_create_clk(__clk_get_hw(clk), dev_id,
2987 con_id);
2988
2989 if (!IS_ERR(clk) && !__clk_get(clk)) {
2990 __clk_free_clk(clk);
2991 clk = ERR_PTR(-ENOENT);
2992 }
2993
Grant Likely766e6a42012-04-09 14:50:06 -05002994 break;
Stephen Boyd73e0e492015-02-06 11:42:43 -08002995 }
Grant Likely766e6a42012-04-09 14:50:06 -05002996 }
Stephen Boyd306c3422015-02-05 15:39:11 -08002997 mutex_unlock(&of_clk_mutex);
Sylwester Nawrockid6782c22013-08-23 17:03:43 +02002998
2999 return clk;
3000}
3001
Stephen Boyd306c3422015-02-05 15:39:11 -08003002/**
3003 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3004 * @clkspec: pointer to a clock specifier data structure
3005 *
3006 * This function looks up a struct clk from the registered list of clock
3007 * providers, an input is a clock specifier data structure as returned
3008 * from the of_parse_phandle_with_args() function call.
3009 */
Sylwester Nawrockid6782c22013-08-23 17:03:43 +02003010struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
3011{
Stephen Boyd306c3422015-02-05 15:39:11 -08003012 return __of_clk_get_from_provider(clkspec, NULL, __func__);
Grant Likely766e6a42012-04-09 14:50:06 -05003013}
3014
Mike Turquettef6102742013-10-07 23:12:13 -07003015int of_clk_get_parent_count(struct device_node *np)
3016{
3017 return of_count_phandle_with_args(np, "clocks", "#clock-cells");
3018}
3019EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
3020
Grant Likely766e6a42012-04-09 14:50:06 -05003021const char *of_clk_get_parent_name(struct device_node *np, int index)
3022{
3023 struct of_phandle_args clkspec;
Ben Dooks7a0fc1a2014-02-13 18:02:49 +00003024 struct property *prop;
Grant Likely766e6a42012-04-09 14:50:06 -05003025 const char *clk_name;
Ben Dooks7a0fc1a2014-02-13 18:02:49 +00003026 const __be32 *vp;
3027 u32 pv;
Grant Likely766e6a42012-04-09 14:50:06 -05003028 int rc;
Ben Dooks7a0fc1a2014-02-13 18:02:49 +00003029 int count;
Grant Likely766e6a42012-04-09 14:50:06 -05003030
3031 if (index < 0)
3032 return NULL;
3033
3034 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
3035 &clkspec);
3036 if (rc)
3037 return NULL;
3038
Ben Dooks7a0fc1a2014-02-13 18:02:49 +00003039 index = clkspec.args_count ? clkspec.args[0] : 0;
3040 count = 0;
3041
3042 /* if there is an indices property, use it to transfer the index
3043 * specified into an array offset for the clock-output-names property.
3044 */
3045 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
3046 if (index == pv) {
3047 index = count;
3048 break;
3049 }
3050 count++;
3051 }
3052
Grant Likely766e6a42012-04-09 14:50:06 -05003053 if (of_property_read_string_index(clkspec.np, "clock-output-names",
Ben Dooks7a0fc1a2014-02-13 18:02:49 +00003054 index,
Grant Likely766e6a42012-04-09 14:50:06 -05003055 &clk_name) < 0)
3056 clk_name = clkspec.np->name;
3057
3058 of_node_put(clkspec.np);
3059 return clk_name;
3060}
3061EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
3062
Gregory CLEMENT1771b102014-02-24 19:10:13 +01003063struct clock_provider {
3064 of_clk_init_cb_t clk_init_cb;
3065 struct device_node *np;
3066 struct list_head node;
3067};
3068
3069static LIST_HEAD(clk_provider_list);
3070
3071/*
3072 * This function looks for a parent clock. If there is one, then it
3073 * checks that the provider for this parent clock was initialized, in
3074 * this case the parent clock will be ready.
3075 */
3076static int parent_ready(struct device_node *np)
3077{
3078 int i = 0;
3079
3080 while (true) {
3081 struct clk *clk = of_clk_get(np, i);
3082
3083 /* this parent is ready we can check the next one */
3084 if (!IS_ERR(clk)) {
3085 clk_put(clk);
3086 i++;
3087 continue;
3088 }
3089
3090 /* at least one parent is not ready, we exit now */
3091 if (PTR_ERR(clk) == -EPROBE_DEFER)
3092 return 0;
3093
3094 /*
3095 * Here we make assumption that the device tree is
3096 * written correctly. So an error means that there is
3097 * no more parent. As we didn't exit yet, then the
3098 * previous parent are ready. If there is no clock
3099 * parent, no need to wait for them, then we can
3100 * consider their absence as being ready
3101 */
3102 return 1;
3103 }
3104}
3105
Grant Likely766e6a42012-04-09 14:50:06 -05003106/**
3107 * of_clk_init() - Scan and init clock providers from the DT
3108 * @matches: array of compatible values and init functions for providers.
3109 *
Gregory CLEMENT1771b102014-02-24 19:10:13 +01003110 * This function scans the device tree for matching clock providers
Sylwester Nawrockie5ca8fb2014-03-27 12:08:36 +01003111 * and calls their initialization functions. It also does it by trying
Gregory CLEMENT1771b102014-02-24 19:10:13 +01003112 * to follow the dependencies.
Grant Likely766e6a42012-04-09 14:50:06 -05003113 */
3114void __init of_clk_init(const struct of_device_id *matches)
3115{
Alex Elder7f7ed582013-08-22 11:31:31 -05003116 const struct of_device_id *match;
Grant Likely766e6a42012-04-09 14:50:06 -05003117 struct device_node *np;
Gregory CLEMENT1771b102014-02-24 19:10:13 +01003118 struct clock_provider *clk_provider, *next;
3119 bool is_init_done;
3120 bool force = false;
Grant Likely766e6a42012-04-09 14:50:06 -05003121
Prashant Gaikwadf2f6c252013-01-04 12:30:52 +05303122 if (!matches)
Tero Kristo819b4862013-10-22 11:39:36 +03003123 matches = &__clk_of_table;
Prashant Gaikwadf2f6c252013-01-04 12:30:52 +05303124
Gregory CLEMENT1771b102014-02-24 19:10:13 +01003125 /* First prepare the list of the clocks providers */
Alex Elder7f7ed582013-08-22 11:31:31 -05003126 for_each_matching_node_and_match(np, matches, &match) {
Gregory CLEMENT1771b102014-02-24 19:10:13 +01003127 struct clock_provider *parent =
3128 kzalloc(sizeof(struct clock_provider), GFP_KERNEL);
3129
3130 parent->clk_init_cb = match->data;
3131 parent->np = np;
Sylwester Nawrocki3f6d4392014-03-27 11:43:32 +01003132 list_add_tail(&parent->node, &clk_provider_list);
Gregory CLEMENT1771b102014-02-24 19:10:13 +01003133 }
3134
3135 while (!list_empty(&clk_provider_list)) {
3136 is_init_done = false;
3137 list_for_each_entry_safe(clk_provider, next,
3138 &clk_provider_list, node) {
3139 if (force || parent_ready(clk_provider->np)) {
Sylwester Nawrocki86be4082014-06-18 17:29:32 +02003140
Gregory CLEMENT1771b102014-02-24 19:10:13 +01003141 clk_provider->clk_init_cb(clk_provider->np);
Sylwester Nawrocki86be4082014-06-18 17:29:32 +02003142 of_clk_set_defaults(clk_provider->np, true);
3143
Gregory CLEMENT1771b102014-02-24 19:10:13 +01003144 list_del(&clk_provider->node);
3145 kfree(clk_provider);
3146 is_init_done = true;
3147 }
3148 }
3149
3150 /*
Sylwester Nawrockie5ca8fb2014-03-27 12:08:36 +01003151 * We didn't manage to initialize any of the
Gregory CLEMENT1771b102014-02-24 19:10:13 +01003152 * remaining providers during the last loop, so now we
3153 * initialize all the remaining ones unconditionally
3154 * in case the clock parent was not mandatory
3155 */
3156 if (!is_init_done)
3157 force = true;
Grant Likely766e6a42012-04-09 14:50:06 -05003158 }
3159}
3160#endif