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-rw-r--r--arch/arm/plat-s3c/clock.c359
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diff --git a/arch/arm/plat-s3c/clock.c b/arch/arm/plat-s3c/clock.c
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1/* linux/arch/arm/plat-s3c24xx/clock.c
2 *
3 * Copyright (c) 2004-2005 Simtec Electronics
4 * Ben Dooks <ben@simtec.co.uk>
5 *
6 * S3C24XX Core clock control support
7 *
8 * Based on, and code from linux/arch/arm/mach-versatile/clock.c
9 **
10 ** Copyright (C) 2004 ARM Limited.
11 ** Written by Deep Blue Solutions Limited.
12 *
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
27*/
28
29#include <linux/init.h>
30#include <linux/module.h>
31#include <linux/kernel.h>
32#include <linux/list.h>
33#include <linux/errno.h>
34#include <linux/err.h>
35#include <linux/platform_device.h>
36#include <linux/sysdev.h>
37#include <linux/interrupt.h>
38#include <linux/ioport.h>
39#include <linux/clk.h>
40#include <linux/spinlock.h>
41#include <linux/delay.h>
42#include <linux/io.h>
43
44#include <mach/hardware.h>
45#include <asm/irq.h>
46
47#include <plat/cpu-freq.h>
48
49#include <plat/clock.h>
50#include <plat/cpu.h>
51
52/* clock information */
53
54static LIST_HEAD(clocks);
55
56/* We originally used an mutex here, but some contexts (see resume)
57 * are calling functions such as clk_set_parent() with IRQs disabled
58 * causing an BUG to be triggered.
59 */
60DEFINE_SPINLOCK(clocks_lock);
61
62/* enable and disable calls for use with the clk struct */
63
64static int clk_null_enable(struct clk *clk, int enable)
65{
66 return 0;
67}
68
69/* Clock API calls */
70
71struct clk *clk_get(struct device *dev, const char *id)
72{
73 struct clk *p;
74 struct clk *clk = ERR_PTR(-ENOENT);
75 int idno;
76
77 if (dev == NULL || dev->bus != &platform_bus_type)
78 idno = -1;
79 else
80 idno = to_platform_device(dev)->id;
81
82 spin_lock(&clocks_lock);
83
84 list_for_each_entry(p, &clocks, list) {
85 if (p->id == idno &&
86 strcmp(id, p->name) == 0 &&
87 try_module_get(p->owner)) {
88 clk = p;
89 break;
90 }
91 }
92
93 /* check for the case where a device was supplied, but the
94 * clock that was being searched for is not device specific */
95
96 if (IS_ERR(clk)) {
97 list_for_each_entry(p, &clocks, list) {
98 if (p->id == -1 && strcmp(id, p->name) == 0 &&
99 try_module_get(p->owner)) {
100 clk = p;
101 break;
102 }
103 }
104 }
105
106 spin_unlock(&clocks_lock);
107 return clk;
108}
109
110void clk_put(struct clk *clk)
111{
112 module_put(clk->owner);
113}
114
115int clk_enable(struct clk *clk)
116{
117 if (IS_ERR(clk) || clk == NULL)
118 return -EINVAL;
119
120 clk_enable(clk->parent);
121
122 spin_lock(&clocks_lock);
123
124 if ((clk->usage++) == 0)
125 (clk->enable)(clk, 1);
126
127 spin_unlock(&clocks_lock);
128 return 0;
129}
130
131void clk_disable(struct clk *clk)
132{
133 if (IS_ERR(clk) || clk == NULL)
134 return;
135
136 spin_lock(&clocks_lock);
137
138 if ((--clk->usage) == 0)
139 (clk->enable)(clk, 0);
140
141 spin_unlock(&clocks_lock);
142 clk_disable(clk->parent);
143}
144
145
146unsigned long clk_get_rate(struct clk *clk)
147{
148 if (IS_ERR(clk))
149 return 0;
150
151 if (clk->rate != 0)
152 return clk->rate;
153
154 if (clk->get_rate != NULL)
155 return (clk->get_rate)(clk);
156
157 if (clk->parent != NULL)
158 return clk_get_rate(clk->parent);
159
160 return clk->rate;
161}
162
163long clk_round_rate(struct clk *clk, unsigned long rate)
164{
165 if (!IS_ERR(clk) && clk->round_rate)
166 return (clk->round_rate)(clk, rate);
167
168 return rate;
169}
170
171int clk_set_rate(struct clk *clk, unsigned long rate)
172{
173 int ret;
174
175 if (IS_ERR(clk))
176 return -EINVAL;
177
178 /* We do not default just do a clk->rate = rate as
179 * the clock may have been made this way by choice.
180 */
181
182 WARN_ON(clk->set_rate == NULL);
183
184 if (clk->set_rate == NULL)
185 return -EINVAL;
186
187 spin_lock(&clocks_lock);
188 ret = (clk->set_rate)(clk, rate);
189 spin_unlock(&clocks_lock);
190
191 return ret;
192}
193
194struct clk *clk_get_parent(struct clk *clk)
195{
196 return clk->parent;
197}
198
199int clk_set_parent(struct clk *clk, struct clk *parent)
200{
201 int ret = 0;
202
203 if (IS_ERR(clk))
204 return -EINVAL;
205
206 spin_lock(&clocks_lock);
207
208 if (clk->set_parent)
209 ret = (clk->set_parent)(clk, parent);
210
211 spin_unlock(&clocks_lock);
212
213 return ret;
214}
215
216EXPORT_SYMBOL(clk_get);
217EXPORT_SYMBOL(clk_put);
218EXPORT_SYMBOL(clk_enable);
219EXPORT_SYMBOL(clk_disable);
220EXPORT_SYMBOL(clk_get_rate);
221EXPORT_SYMBOL(clk_round_rate);
222EXPORT_SYMBOL(clk_set_rate);
223EXPORT_SYMBOL(clk_get_parent);
224EXPORT_SYMBOL(clk_set_parent);
225
226/* base clocks */
227
228static int clk_default_setrate(struct clk *clk, unsigned long rate)
229{
230 clk->rate = rate;
231 return 0;
232}
233
234struct clk clk_xtal = {
235 .name = "xtal",
236 .id = -1,
237 .rate = 0,
238 .parent = NULL,
239 .ctrlbit = 0,
240};
241
242struct clk clk_mpll = {
243 .name = "mpll",
244 .id = -1,
245 .set_rate = clk_default_setrate,
246};
247
248struct clk clk_upll = {
249 .name = "upll",
250 .id = -1,
251 .parent = NULL,
252 .ctrlbit = 0,
253};
254
255struct clk clk_f = {
256 .name = "fclk",
257 .id = -1,
258 .rate = 0,
259 .parent = &clk_mpll,
260 .ctrlbit = 0,
261 .set_rate = clk_default_setrate,
262};
263
264struct clk clk_h = {
265 .name = "hclk",
266 .id = -1,
267 .rate = 0,
268 .parent = NULL,
269 .ctrlbit = 0,
270 .set_rate = clk_default_setrate,
271};
272
273struct clk clk_p = {
274 .name = "pclk",
275 .id = -1,
276 .rate = 0,
277 .parent = NULL,
278 .ctrlbit = 0,
279 .set_rate = clk_default_setrate,
280};
281
282struct clk clk_usb_bus = {
283 .name = "usb-bus",
284 .id = -1,
285 .rate = 0,
286 .parent = &clk_upll,
287};
288
289
290
291struct clk s3c24xx_uclk = {
292 .name = "uclk",
293 .id = -1,
294};
295
296/* initialise the clock system */
297
298int s3c24xx_register_clock(struct clk *clk)
299{
300 clk->owner = THIS_MODULE;
301
302 if (clk->enable == NULL)
303 clk->enable = clk_null_enable;
304
305 /* add to the list of available clocks */
306
307 /* Quick check to see if this clock has already been registered. */
308 BUG_ON(clk->list.prev != clk->list.next);
309
310 spin_lock(&clocks_lock);
311 list_add(&clk->list, &clocks);
312 spin_unlock(&clocks_lock);
313
314 return 0;
315}
316
317int s3c24xx_register_clocks(struct clk **clks, int nr_clks)
318{
319 int fails = 0;
320
321 for (; nr_clks > 0; nr_clks--, clks++) {
322 if (s3c24xx_register_clock(*clks) < 0)
323 fails++;
324 }
325
326 return fails;
327}
328
329/* initalise all the clocks */
330
331int __init s3c24xx_register_baseclocks(unsigned long xtal)
332{
333 printk(KERN_INFO "S3C24XX Clocks, (c) 2004 Simtec Electronics\n");
334
335 clk_xtal.rate = xtal;
336
337 /* register our clocks */
338
339 if (s3c24xx_register_clock(&clk_xtal) < 0)
340 printk(KERN_ERR "failed to register master xtal\n");
341
342 if (s3c24xx_register_clock(&clk_mpll) < 0)
343 printk(KERN_ERR "failed to register mpll clock\n");
344
345 if (s3c24xx_register_clock(&clk_upll) < 0)
346 printk(KERN_ERR "failed to register upll clock\n");
347
348 if (s3c24xx_register_clock(&clk_f) < 0)
349 printk(KERN_ERR "failed to register cpu fclk\n");
350
351 if (s3c24xx_register_clock(&clk_h) < 0)
352 printk(KERN_ERR "failed to register cpu hclk\n");
353
354 if (s3c24xx_register_clock(&clk_p) < 0)
355 printk(KERN_ERR "failed to register cpu pclk\n");
356
357 return 0;
358}
359