diff options
Diffstat (limited to 'arch/arm/plat-s3c/clock.c')
-rw-r--r-- | arch/arm/plat-s3c/clock.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/arch/arm/plat-s3c/clock.c b/arch/arm/plat-s3c/clock.c new file mode 100644 index 000000000000..b6be76e2fe51 --- /dev/null +++ b/arch/arm/plat-s3c/clock.c | |||
@@ -0,0 +1,368 @@ | |||
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/io.h> | ||
42 | |||
43 | #include <mach/hardware.h> | ||
44 | #include <asm/irq.h> | ||
45 | |||
46 | #include <plat/cpu-freq.h> | ||
47 | |||
48 | #include <plat/clock.h> | ||
49 | #include <plat/cpu.h> | ||
50 | |||
51 | /* clock information */ | ||
52 | |||
53 | static LIST_HEAD(clocks); | ||
54 | |||
55 | /* We originally used an mutex here, but some contexts (see resume) | ||
56 | * are calling functions such as clk_set_parent() with IRQs disabled | ||
57 | * causing an BUG to be triggered. | ||
58 | */ | ||
59 | DEFINE_SPINLOCK(clocks_lock); | ||
60 | |||
61 | /* enable and disable calls for use with the clk struct */ | ||
62 | |||
63 | static int clk_null_enable(struct clk *clk, int enable) | ||
64 | { | ||
65 | return 0; | ||
66 | } | ||
67 | |||
68 | /* Clock API calls */ | ||
69 | |||
70 | struct clk *clk_get(struct device *dev, const char *id) | ||
71 | { | ||
72 | struct clk *p; | ||
73 | struct clk *clk = ERR_PTR(-ENOENT); | ||
74 | int idno; | ||
75 | |||
76 | if (dev == NULL || dev->bus != &platform_bus_type) | ||
77 | idno = -1; | ||
78 | else | ||
79 | idno = to_platform_device(dev)->id; | ||
80 | |||
81 | spin_lock(&clocks_lock); | ||
82 | |||
83 | list_for_each_entry(p, &clocks, list) { | ||
84 | if (p->id == idno && | ||
85 | strcmp(id, p->name) == 0 && | ||
86 | try_module_get(p->owner)) { | ||
87 | clk = p; | ||
88 | break; | ||
89 | } | ||
90 | } | ||
91 | |||
92 | /* check for the case where a device was supplied, but the | ||
93 | * clock that was being searched for is not device specific */ | ||
94 | |||
95 | if (IS_ERR(clk)) { | ||
96 | list_for_each_entry(p, &clocks, list) { | ||
97 | if (p->id == -1 && strcmp(id, p->name) == 0 && | ||
98 | try_module_get(p->owner)) { | ||
99 | clk = p; | ||
100 | break; | ||
101 | } | ||
102 | } | ||
103 | } | ||
104 | |||
105 | spin_unlock(&clocks_lock); | ||
106 | return clk; | ||
107 | } | ||
108 | |||
109 | void clk_put(struct clk *clk) | ||
110 | { | ||
111 | module_put(clk->owner); | ||
112 | } | ||
113 | |||
114 | int clk_enable(struct clk *clk) | ||
115 | { | ||
116 | if (IS_ERR(clk) || clk == NULL) | ||
117 | return -EINVAL; | ||
118 | |||
119 | clk_enable(clk->parent); | ||
120 | |||
121 | spin_lock(&clocks_lock); | ||
122 | |||
123 | if ((clk->usage++) == 0) | ||
124 | (clk->enable)(clk, 1); | ||
125 | |||
126 | spin_unlock(&clocks_lock); | ||
127 | return 0; | ||
128 | } | ||
129 | |||
130 | void clk_disable(struct clk *clk) | ||
131 | { | ||
132 | if (IS_ERR(clk) || clk == NULL) | ||
133 | return; | ||
134 | |||
135 | spin_lock(&clocks_lock); | ||
136 | |||
137 | if ((--clk->usage) == 0) | ||
138 | (clk->enable)(clk, 0); | ||
139 | |||
140 | spin_unlock(&clocks_lock); | ||
141 | clk_disable(clk->parent); | ||
142 | } | ||
143 | |||
144 | |||
145 | unsigned long clk_get_rate(struct clk *clk) | ||
146 | { | ||
147 | if (IS_ERR(clk)) | ||
148 | return 0; | ||
149 | |||
150 | if (clk->rate != 0) | ||
151 | return clk->rate; | ||
152 | |||
153 | if (clk->get_rate != NULL) | ||
154 | return (clk->get_rate)(clk); | ||
155 | |||
156 | if (clk->parent != NULL) | ||
157 | return clk_get_rate(clk->parent); | ||
158 | |||
159 | return clk->rate; | ||
160 | } | ||
161 | |||
162 | long clk_round_rate(struct clk *clk, unsigned long rate) | ||
163 | { | ||
164 | if (!IS_ERR(clk) && clk->round_rate) | ||
165 | return (clk->round_rate)(clk, rate); | ||
166 | |||
167 | return rate; | ||
168 | } | ||
169 | |||
170 | int clk_set_rate(struct clk *clk, unsigned long rate) | ||
171 | { | ||
172 | int ret; | ||
173 | |||
174 | if (IS_ERR(clk)) | ||
175 | return -EINVAL; | ||
176 | |||
177 | /* We do not default just do a clk->rate = rate as | ||
178 | * the clock may have been made this way by choice. | ||
179 | */ | ||
180 | |||
181 | WARN_ON(clk->set_rate == NULL); | ||
182 | |||
183 | if (clk->set_rate == NULL) | ||
184 | return -EINVAL; | ||
185 | |||
186 | spin_lock(&clocks_lock); | ||
187 | ret = (clk->set_rate)(clk, rate); | ||
188 | spin_unlock(&clocks_lock); | ||
189 | |||
190 | return ret; | ||
191 | } | ||
192 | |||
193 | struct clk *clk_get_parent(struct clk *clk) | ||
194 | { | ||
195 | return clk->parent; | ||
196 | } | ||
197 | |||
198 | int clk_set_parent(struct clk *clk, struct clk *parent) | ||
199 | { | ||
200 | int ret = 0; | ||
201 | |||
202 | if (IS_ERR(clk)) | ||
203 | return -EINVAL; | ||
204 | |||
205 | spin_lock(&clocks_lock); | ||
206 | |||
207 | if (clk->set_parent) | ||
208 | ret = (clk->set_parent)(clk, parent); | ||
209 | |||
210 | spin_unlock(&clocks_lock); | ||
211 | |||
212 | return ret; | ||
213 | } | ||
214 | |||
215 | EXPORT_SYMBOL(clk_get); | ||
216 | EXPORT_SYMBOL(clk_put); | ||
217 | EXPORT_SYMBOL(clk_enable); | ||
218 | EXPORT_SYMBOL(clk_disable); | ||
219 | EXPORT_SYMBOL(clk_get_rate); | ||
220 | EXPORT_SYMBOL(clk_round_rate); | ||
221 | EXPORT_SYMBOL(clk_set_rate); | ||
222 | EXPORT_SYMBOL(clk_get_parent); | ||
223 | EXPORT_SYMBOL(clk_set_parent); | ||
224 | |||
225 | /* base clocks */ | ||
226 | |||
227 | static int clk_default_setrate(struct clk *clk, unsigned long rate) | ||
228 | { | ||
229 | clk->rate = rate; | ||
230 | return 0; | ||
231 | } | ||
232 | |||
233 | struct clk clk_xtal = { | ||
234 | .name = "xtal", | ||
235 | .id = -1, | ||
236 | .rate = 0, | ||
237 | .parent = NULL, | ||
238 | .ctrlbit = 0, | ||
239 | }; | ||
240 | |||
241 | struct clk clk_ext = { | ||
242 | .name = "ext", | ||
243 | .id = -1, | ||
244 | }; | ||
245 | |||
246 | struct clk clk_epll = { | ||
247 | .name = "epll", | ||
248 | .id = -1, | ||
249 | }; | ||
250 | |||
251 | struct clk clk_mpll = { | ||
252 | .name = "mpll", | ||
253 | .id = -1, | ||
254 | .set_rate = clk_default_setrate, | ||
255 | }; | ||
256 | |||
257 | struct clk clk_upll = { | ||
258 | .name = "upll", | ||
259 | .id = -1, | ||
260 | .parent = NULL, | ||
261 | .ctrlbit = 0, | ||
262 | }; | ||
263 | |||
264 | struct clk clk_f = { | ||
265 | .name = "fclk", | ||
266 | .id = -1, | ||
267 | .rate = 0, | ||
268 | .parent = &clk_mpll, | ||
269 | .ctrlbit = 0, | ||
270 | .set_rate = clk_default_setrate, | ||
271 | }; | ||
272 | |||
273 | struct clk clk_h = { | ||
274 | .name = "hclk", | ||
275 | .id = -1, | ||
276 | .rate = 0, | ||
277 | .parent = NULL, | ||
278 | .ctrlbit = 0, | ||
279 | .set_rate = clk_default_setrate, | ||
280 | }; | ||
281 | |||
282 | struct clk clk_p = { | ||
283 | .name = "pclk", | ||
284 | .id = -1, | ||
285 | .rate = 0, | ||
286 | .parent = NULL, | ||
287 | .ctrlbit = 0, | ||
288 | .set_rate = clk_default_setrate, | ||
289 | }; | ||
290 | |||
291 | struct clk clk_usb_bus = { | ||
292 | .name = "usb-bus", | ||
293 | .id = -1, | ||
294 | .rate = 0, | ||
295 | .parent = &clk_upll, | ||
296 | }; | ||
297 | |||
298 | |||
299 | |||
300 | struct clk s3c24xx_uclk = { | ||
301 | .name = "uclk", | ||
302 | .id = -1, | ||
303 | }; | ||
304 | |||
305 | /* initialise the clock system */ | ||
306 | |||
307 | int s3c24xx_register_clock(struct clk *clk) | ||
308 | { | ||
309 | clk->owner = THIS_MODULE; | ||
310 | |||
311 | if (clk->enable == NULL) | ||
312 | clk->enable = clk_null_enable; | ||
313 | |||
314 | /* add to the list of available clocks */ | ||
315 | |||
316 | /* Quick check to see if this clock has already been registered. */ | ||
317 | BUG_ON(clk->list.prev != clk->list.next); | ||
318 | |||
319 | spin_lock(&clocks_lock); | ||
320 | list_add(&clk->list, &clocks); | ||
321 | spin_unlock(&clocks_lock); | ||
322 | |||
323 | return 0; | ||
324 | } | ||
325 | |||
326 | int s3c24xx_register_clocks(struct clk **clks, int nr_clks) | ||
327 | { | ||
328 | int fails = 0; | ||
329 | |||
330 | for (; nr_clks > 0; nr_clks--, clks++) { | ||
331 | if (s3c24xx_register_clock(*clks) < 0) | ||
332 | fails++; | ||
333 | } | ||
334 | |||
335 | return fails; | ||
336 | } | ||
337 | |||
338 | /* initalise all the clocks */ | ||
339 | |||
340 | int __init s3c24xx_register_baseclocks(unsigned long xtal) | ||
341 | { | ||
342 | printk(KERN_INFO "S3C24XX Clocks, (c) 2004 Simtec Electronics\n"); | ||
343 | |||
344 | clk_xtal.rate = xtal; | ||
345 | |||
346 | /* register our clocks */ | ||
347 | |||
348 | if (s3c24xx_register_clock(&clk_xtal) < 0) | ||
349 | printk(KERN_ERR "failed to register master xtal\n"); | ||
350 | |||
351 | if (s3c24xx_register_clock(&clk_mpll) < 0) | ||
352 | printk(KERN_ERR "failed to register mpll clock\n"); | ||
353 | |||
354 | if (s3c24xx_register_clock(&clk_upll) < 0) | ||
355 | printk(KERN_ERR "failed to register upll clock\n"); | ||
356 | |||
357 | if (s3c24xx_register_clock(&clk_f) < 0) | ||
358 | printk(KERN_ERR "failed to register cpu fclk\n"); | ||
359 | |||
360 | if (s3c24xx_register_clock(&clk_h) < 0) | ||
361 | printk(KERN_ERR "failed to register cpu hclk\n"); | ||
362 | |||
363 | if (s3c24xx_register_clock(&clk_p) < 0) | ||
364 | printk(KERN_ERR "failed to register cpu pclk\n"); | ||
365 | |||
366 | return 0; | ||
367 | } | ||
368 | |||