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Paul Mundt36ddf312006-01-16 22:14:17 -08001/*
2 * arch/sh/kernel/cpu/clock.c - SuperH clock framework
3 *
Paul Mundtdb62e5b2007-04-26 12:17:20 +09004 * Copyright (C) 2005, 2006, 2007 Paul Mundt
Paul Mundt36ddf312006-01-16 22:14:17 -08005 *
6 * This clock framework is derived from the OMAP version by:
7 *
Paul Mundt1d118562006-12-01 13:15:14 +09008 * Copyright (C) 2004 - 2005 Nokia Corporation
Paul Mundt36ddf312006-01-16 22:14:17 -08009 * Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
10 *
Paul Mundt1d118562006-12-01 13:15:14 +090011 * Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com>
12 *
Paul Mundt36ddf312006-01-16 22:14:17 -080013 * This file is subject to the terms and conditions of the GNU General Public
14 * License. See the file "COPYING" in the main directory of this archive
15 * for more details.
16 */
17#include <linux/kernel.h>
18#include <linux/init.h>
19#include <linux/module.h>
Paul Mundt237b98f2006-09-27 17:28:20 +090020#include <linux/mutex.h>
Paul Mundt36ddf312006-01-16 22:14:17 -080021#include <linux/list.h>
22#include <linux/kref.h>
23#include <linux/seq_file.h>
24#include <linux/err.h>
Paul Mundt1d118562006-12-01 13:15:14 +090025#include <linux/platform_device.h>
Paul Mundtdb62e5b2007-04-26 12:17:20 +090026#include <linux/proc_fs.h>
Paul Mundt36ddf312006-01-16 22:14:17 -080027#include <asm/clock.h>
28#include <asm/timer.h>
29
30static LIST_HEAD(clock_list);
31static DEFINE_SPINLOCK(clock_lock);
Paul Mundt237b98f2006-09-27 17:28:20 +090032static DEFINE_MUTEX(clock_list_sem);
Paul Mundt36ddf312006-01-16 22:14:17 -080033
34/*
35 * Each subtype is expected to define the init routines for these clocks,
36 * as each subtype (or processor family) will have these clocks at the
37 * very least. These are all provided through the CPG, which even some of
38 * the more quirky parts (such as ST40, SH4-202, etc.) still have.
39 *
40 * The processor-specific code is expected to register any additional
41 * clock sources that are of interest.
42 */
43static struct clk master_clk = {
44 .name = "master_clk",
45 .flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES,
Paul Mundt36ddf312006-01-16 22:14:17 -080046 .rate = CONFIG_SH_PCLK_FREQ,
Paul Mundt36ddf312006-01-16 22:14:17 -080047};
48
49static struct clk module_clk = {
50 .name = "module_clk",
51 .parent = &master_clk,
52 .flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES,
53};
54
55static struct clk bus_clk = {
56 .name = "bus_clk",
57 .parent = &master_clk,
58 .flags = CLK_ALWAYS_ENABLED | CLK_RATE_PROPAGATES,
59};
60
61static struct clk cpu_clk = {
62 .name = "cpu_clk",
63 .parent = &master_clk,
64 .flags = CLK_ALWAYS_ENABLED,
65};
66
67/*
68 * The ordering of these clocks matters, do not change it.
69 */
70static struct clk *onchip_clocks[] = {
71 &master_clk,
72 &module_clk,
73 &bus_clk,
74 &cpu_clk,
75};
76
77static void propagate_rate(struct clk *clk)
78{
79 struct clk *clkp;
80
81 list_for_each_entry(clkp, &clock_list, node) {
82 if (likely(clkp->parent != clk))
83 continue;
84 if (likely(clkp->ops && clkp->ops->recalc))
85 clkp->ops->recalc(clkp);
Stuart Menefy24eb17e2007-09-28 11:51:52 +090086 if (unlikely(clkp->flags & CLK_RATE_PROPAGATES))
87 propagate_rate(clkp);
Paul Mundt36ddf312006-01-16 22:14:17 -080088 }
89}
90
91int __clk_enable(struct clk *clk)
92{
93 /*
94 * See if this is the first time we're enabling the clock, some
95 * clocks that are always enabled still require "special"
96 * initialization. This is especially true if the clock mode
97 * changes and the clock needs to hunt for the proper set of
98 * divisors to use before it can effectively recalc.
99 */
100 if (unlikely(atomic_read(&clk->kref.refcount) == 1))
101 if (clk->ops && clk->ops->init)
102 clk->ops->init(clk);
103
dmitry pervushin1929cb32007-04-24 13:39:09 +0900104 kref_get(&clk->kref);
105
Paul Mundt36ddf312006-01-16 22:14:17 -0800106 if (clk->flags & CLK_ALWAYS_ENABLED)
107 return 0;
108
109 if (likely(clk->ops && clk->ops->enable))
110 clk->ops->enable(clk);
111
Paul Mundt36ddf312006-01-16 22:14:17 -0800112 return 0;
113}
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900114EXPORT_SYMBOL_GPL(__clk_enable);
Paul Mundt36ddf312006-01-16 22:14:17 -0800115
116int clk_enable(struct clk *clk)
117{
118 unsigned long flags;
119 int ret;
120
121 spin_lock_irqsave(&clock_lock, flags);
122 ret = __clk_enable(clk);
123 spin_unlock_irqrestore(&clock_lock, flags);
124
125 return ret;
126}
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900127EXPORT_SYMBOL_GPL(clk_enable);
Paul Mundt36ddf312006-01-16 22:14:17 -0800128
129static void clk_kref_release(struct kref *kref)
130{
131 /* Nothing to do */
132}
133
134void __clk_disable(struct clk *clk)
135{
dmitry pervushin1929cb32007-04-24 13:39:09 +0900136 int count = kref_put(&clk->kref, clk_kref_release);
137
Paul Mundt36ddf312006-01-16 22:14:17 -0800138 if (clk->flags & CLK_ALWAYS_ENABLED)
139 return;
140
dmitry pervushin1929cb32007-04-24 13:39:09 +0900141 if (!count) { /* count reaches zero, disable the clock */
142 if (likely(clk->ops && clk->ops->disable))
143 clk->ops->disable(clk);
144 }
Paul Mundt36ddf312006-01-16 22:14:17 -0800145}
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900146EXPORT_SYMBOL_GPL(__clk_disable);
Paul Mundt36ddf312006-01-16 22:14:17 -0800147
148void clk_disable(struct clk *clk)
149{
150 unsigned long flags;
151
152 spin_lock_irqsave(&clock_lock, flags);
153 __clk_disable(clk);
154 spin_unlock_irqrestore(&clock_lock, flags);
155}
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900156EXPORT_SYMBOL_GPL(clk_disable);
Paul Mundt36ddf312006-01-16 22:14:17 -0800157
158int clk_register(struct clk *clk)
159{
Paul Mundt237b98f2006-09-27 17:28:20 +0900160 mutex_lock(&clock_list_sem);
Paul Mundt36ddf312006-01-16 22:14:17 -0800161
162 list_add(&clk->node, &clock_list);
163 kref_init(&clk->kref);
164
Paul Mundt237b98f2006-09-27 17:28:20 +0900165 mutex_unlock(&clock_list_sem);
Paul Mundt36ddf312006-01-16 22:14:17 -0800166
dmitry pervushin1929cb32007-04-24 13:39:09 +0900167 if (clk->flags & CLK_ALWAYS_ENABLED) {
168 pr_debug( "Clock '%s' is ALWAYS_ENABLED\n", clk->name);
169 if (clk->ops && clk->ops->init)
170 clk->ops->init(clk);
171 if (clk->ops && clk->ops->enable)
172 clk->ops->enable(clk);
173 pr_debug( "Enabled.");
174 }
175
Paul Mundt36ddf312006-01-16 22:14:17 -0800176 return 0;
177}
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900178EXPORT_SYMBOL_GPL(clk_register);
Paul Mundt36ddf312006-01-16 22:14:17 -0800179
180void clk_unregister(struct clk *clk)
181{
Paul Mundt237b98f2006-09-27 17:28:20 +0900182 mutex_lock(&clock_list_sem);
Paul Mundt36ddf312006-01-16 22:14:17 -0800183 list_del(&clk->node);
Paul Mundt237b98f2006-09-27 17:28:20 +0900184 mutex_unlock(&clock_list_sem);
Paul Mundt36ddf312006-01-16 22:14:17 -0800185}
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900186EXPORT_SYMBOL_GPL(clk_unregister);
Paul Mundt36ddf312006-01-16 22:14:17 -0800187
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900188unsigned long clk_get_rate(struct clk *clk)
Paul Mundt36ddf312006-01-16 22:14:17 -0800189{
190 return clk->rate;
191}
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900192EXPORT_SYMBOL_GPL(clk_get_rate);
Paul Mundt36ddf312006-01-16 22:14:17 -0800193
194int clk_set_rate(struct clk *clk, unsigned long rate)
195{
dmitry pervushin1929cb32007-04-24 13:39:09 +0900196 return clk_set_rate_ex(clk, rate, 0);
197}
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900198EXPORT_SYMBOL_GPL(clk_set_rate);
dmitry pervushin1929cb32007-04-24 13:39:09 +0900199
200int clk_set_rate_ex(struct clk *clk, unsigned long rate, int algo_id)
201{
Paul Mundt36ddf312006-01-16 22:14:17 -0800202 int ret = -EOPNOTSUPP;
203
204 if (likely(clk->ops && clk->ops->set_rate)) {
205 unsigned long flags;
206
207 spin_lock_irqsave(&clock_lock, flags);
dmitry pervushin1929cb32007-04-24 13:39:09 +0900208 ret = clk->ops->set_rate(clk, rate, algo_id);
Paul Mundt36ddf312006-01-16 22:14:17 -0800209 spin_unlock_irqrestore(&clock_lock, flags);
210 }
211
212 if (unlikely(clk->flags & CLK_RATE_PROPAGATES))
213 propagate_rate(clk);
214
215 return ret;
216}
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900217EXPORT_SYMBOL_GPL(clk_set_rate_ex);
Paul Mundt36ddf312006-01-16 22:14:17 -0800218
219void clk_recalc_rate(struct clk *clk)
220{
221 if (likely(clk->ops && clk->ops->recalc)) {
222 unsigned long flags;
223
224 spin_lock_irqsave(&clock_lock, flags);
225 clk->ops->recalc(clk);
226 spin_unlock_irqrestore(&clock_lock, flags);
227 }
228
229 if (unlikely(clk->flags & CLK_RATE_PROPAGATES))
230 propagate_rate(clk);
231}
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900232EXPORT_SYMBOL_GPL(clk_recalc_rate);
Paul Mundt36ddf312006-01-16 22:14:17 -0800233
Paul Mundtf6991b02007-07-20 13:29:09 +0900234long clk_round_rate(struct clk *clk, unsigned long rate)
235{
236 if (likely(clk->ops && clk->ops->round_rate)) {
237 unsigned long flags, rounded;
238
239 spin_lock_irqsave(&clock_lock, flags);
240 rounded = clk->ops->round_rate(clk, rate);
241 spin_unlock_irqrestore(&clock_lock, flags);
242
243 return rounded;
244 }
245
246 return clk_get_rate(clk);
247}
248EXPORT_SYMBOL_GPL(clk_round_rate);
249
Paul Mundt1d118562006-12-01 13:15:14 +0900250/*
251 * Returns a clock. Note that we first try to use device id on the bus
252 * and clock name. If this fails, we try to use clock name only.
253 */
254struct clk *clk_get(struct device *dev, const char *id)
Paul Mundt36ddf312006-01-16 22:14:17 -0800255{
256 struct clk *p, *clk = ERR_PTR(-ENOENT);
Paul Mundt1d118562006-12-01 13:15:14 +0900257 int idno;
258
259 if (dev == NULL || dev->bus != &platform_bus_type)
260 idno = -1;
261 else
262 idno = to_platform_device(dev)->id;
Paul Mundt36ddf312006-01-16 22:14:17 -0800263
Paul Mundt237b98f2006-09-27 17:28:20 +0900264 mutex_lock(&clock_list_sem);
Paul Mundt36ddf312006-01-16 22:14:17 -0800265 list_for_each_entry(p, &clock_list, node) {
Paul Mundt1d118562006-12-01 13:15:14 +0900266 if (p->id == idno &&
267 strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
268 clk = p;
269 goto found;
270 }
271 }
272
273 list_for_each_entry(p, &clock_list, node) {
Paul Mundt36ddf312006-01-16 22:14:17 -0800274 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
275 clk = p;
276 break;
277 }
278 }
Paul Mundt1d118562006-12-01 13:15:14 +0900279
280found:
Paul Mundt237b98f2006-09-27 17:28:20 +0900281 mutex_unlock(&clock_list_sem);
Paul Mundt36ddf312006-01-16 22:14:17 -0800282
283 return clk;
284}
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900285EXPORT_SYMBOL_GPL(clk_get);
Paul Mundt36ddf312006-01-16 22:14:17 -0800286
287void clk_put(struct clk *clk)
288{
289 if (clk && !IS_ERR(clk))
290 module_put(clk->owner);
291}
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900292EXPORT_SYMBOL_GPL(clk_put);
Paul Mundt36ddf312006-01-16 22:14:17 -0800293
294void __init __attribute__ ((weak))
295arch_init_clk_ops(struct clk_ops **ops, int type)
296{
297}
298
dmitry pervushindfbbbe92007-05-15 08:42:22 +0900299void __init __attribute__ ((weak))
300arch_clk_init(void)
301{
302}
303
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900304static int show_clocks(char *buf, char **start, off_t off,
305 int len, int *eof, void *data)
306{
307 struct clk *clk;
308 char *p = buf;
309
310 list_for_each_entry_reverse(clk, &clock_list, node) {
311 unsigned long rate = clk_get_rate(clk);
312
313 /*
314 * Don't bother listing dummy clocks with no ancestry
315 * that only support enable and disable ops.
316 */
317 if (unlikely(!rate && !clk->parent))
318 continue;
319
320 p += sprintf(p, "%-12s\t: %ld.%02ldMHz\n", clk->name,
321 rate / 1000000, (rate % 1000000) / 10000);
322 }
323
324 return p - buf;
325}
326
Paul Mundt36ddf312006-01-16 22:14:17 -0800327int __init clk_init(void)
328{
329 int i, ret = 0;
330
Paul Mundte4c2cfe2006-09-27 12:31:01 +0900331 BUG_ON(!master_clk.rate);
Paul Mundt36ddf312006-01-16 22:14:17 -0800332
333 for (i = 0; i < ARRAY_SIZE(onchip_clocks); i++) {
334 struct clk *clk = onchip_clocks[i];
335
336 arch_init_clk_ops(&clk->ops, i);
337 ret |= clk_register(clk);
Paul Mundt36ddf312006-01-16 22:14:17 -0800338 }
339
dmitry pervushindfbbbe92007-05-15 08:42:22 +0900340 arch_clk_init();
341
Paul Mundt36ddf312006-01-16 22:14:17 -0800342 /* Kick the child clocks.. */
343 propagate_rate(&master_clk);
344 propagate_rate(&bus_clk);
345
346 return ret;
347}
348
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900349static int __init clk_proc_init(void)
Paul Mundt36ddf312006-01-16 22:14:17 -0800350{
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900351 struct proc_dir_entry *p;
352 p = create_proc_read_entry("clocks", S_IRUSR, NULL,
353 show_clocks, NULL);
354 if (unlikely(!p))
355 return -EINVAL;
Paul Mundt36ddf312006-01-16 22:14:17 -0800356
357 return 0;
358}
Paul Mundtdb62e5b2007-04-26 12:17:20 +0900359subsys_initcall(clk_proc_init);