diff options
Diffstat (limited to 'arch/arm/plat-s3c/clock.c')
-rw-r--r-- | arch/arm/plat-s3c/clock.c | 359 |
1 files changed, 359 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..da7ac07c7a0b --- /dev/null +++ b/arch/arm/plat-s3c/clock.c | |||
@@ -0,0 +1,359 @@ | |||
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 | |||
54 | static 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 | */ | ||
60 | DEFINE_SPINLOCK(clocks_lock); | ||
61 | |||
62 | /* enable and disable calls for use with the clk struct */ | ||
63 | |||
64 | static int clk_null_enable(struct clk *clk, int enable) | ||
65 | { | ||
66 | return 0; | ||
67 | } | ||
68 | |||
69 | /* Clock API calls */ | ||
70 | |||
71 | struct 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 | |||
110 | void clk_put(struct clk *clk) | ||
111 | { | ||
112 | module_put(clk->owner); | ||
113 | } | ||
114 | |||
115 | int 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 | |||
131 | void 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 | |||
146 | unsigned 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 | |||
163 | long 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 | |||
171 | int 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 | |||
194 | struct clk *clk_get_parent(struct clk *clk) | ||
195 | { | ||
196 | return clk->parent; | ||
197 | } | ||
198 | |||
199 | int 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 | |||
216 | EXPORT_SYMBOL(clk_get); | ||
217 | EXPORT_SYMBOL(clk_put); | ||
218 | EXPORT_SYMBOL(clk_enable); | ||
219 | EXPORT_SYMBOL(clk_disable); | ||
220 | EXPORT_SYMBOL(clk_get_rate); | ||
221 | EXPORT_SYMBOL(clk_round_rate); | ||
222 | EXPORT_SYMBOL(clk_set_rate); | ||
223 | EXPORT_SYMBOL(clk_get_parent); | ||
224 | EXPORT_SYMBOL(clk_set_parent); | ||
225 | |||
226 | /* base clocks */ | ||
227 | |||
228 | static int clk_default_setrate(struct clk *clk, unsigned long rate) | ||
229 | { | ||
230 | clk->rate = rate; | ||
231 | return 0; | ||
232 | } | ||
233 | |||
234 | struct clk clk_xtal = { | ||
235 | .name = "xtal", | ||
236 | .id = -1, | ||
237 | .rate = 0, | ||
238 | .parent = NULL, | ||
239 | .ctrlbit = 0, | ||
240 | }; | ||
241 | |||
242 | struct clk clk_mpll = { | ||
243 | .name = "mpll", | ||
244 | .id = -1, | ||
245 | .set_rate = clk_default_setrate, | ||
246 | }; | ||
247 | |||
248 | struct clk clk_upll = { | ||
249 | .name = "upll", | ||
250 | .id = -1, | ||
251 | .parent = NULL, | ||
252 | .ctrlbit = 0, | ||
253 | }; | ||
254 | |||
255 | struct 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 | |||
264 | struct 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 | |||
273 | struct 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 | |||
282 | struct clk clk_usb_bus = { | ||
283 | .name = "usb-bus", | ||
284 | .id = -1, | ||
285 | .rate = 0, | ||
286 | .parent = &clk_upll, | ||
287 | }; | ||
288 | |||
289 | |||
290 | |||
291 | struct clk s3c24xx_uclk = { | ||
292 | .name = "uclk", | ||
293 | .id = -1, | ||
294 | }; | ||
295 | |||
296 | /* initialise the clock system */ | ||
297 | |||
298 | int 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 | |||
317 | int 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 | |||
331 | int __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 | |||