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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> | |
adbefaa5 BD |
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 | ||
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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 | ||
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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 | { | |
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309 | if (clk->enable == NULL) |
310 | clk->enable = clk_null_enable; | |
311 | ||
312 | /* add to the list of available clocks */ | |
313 | ||
cec444b7 BD |
314 | /* Quick check to see if this clock has already been registered. */ |
315 | BUG_ON(clk->list.prev != clk->list.next); | |
316 | ||
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317 | spin_lock(&clocks_lock); |
318 | list_add(&clk->list, &clocks); | |
319 | spin_unlock(&clocks_lock); | |
320 | ||
321 | return 0; | |
322 | } | |
323 | ||
324 | int s3c24xx_register_clocks(struct clk **clks, int nr_clks) | |
325 | { | |
326 | int fails = 0; | |
327 | ||
328 | for (; nr_clks > 0; nr_clks--, clks++) { | |
329 | if (s3c24xx_register_clock(*clks) < 0) | |
330 | fails++; | |
331 | } | |
332 | ||
333 | return fails; | |
334 | } | |
335 | ||
336 | /* initalise all the clocks */ | |
337 | ||
338 | int __init s3c24xx_register_baseclocks(unsigned long xtal) | |
339 | { | |
340 | printk(KERN_INFO "S3C24XX Clocks, (c) 2004 Simtec Electronics\n"); | |
341 | ||
342 | clk_xtal.rate = xtal; | |
343 | ||
344 | /* register our clocks */ | |
345 | ||
346 | if (s3c24xx_register_clock(&clk_xtal) < 0) | |
347 | printk(KERN_ERR "failed to register master xtal\n"); | |
348 | ||
349 | if (s3c24xx_register_clock(&clk_mpll) < 0) | |
350 | printk(KERN_ERR "failed to register mpll clock\n"); | |
351 | ||
352 | if (s3c24xx_register_clock(&clk_upll) < 0) | |
353 | printk(KERN_ERR "failed to register upll clock\n"); | |
354 | ||
355 | if (s3c24xx_register_clock(&clk_f) < 0) | |
356 | printk(KERN_ERR "failed to register cpu fclk\n"); | |
357 | ||
358 | if (s3c24xx_register_clock(&clk_h) < 0) | |
359 | printk(KERN_ERR "failed to register cpu hclk\n"); | |
360 | ||
361 | if (s3c24xx_register_clock(&clk_p) < 0) | |
362 | printk(KERN_ERR "failed to register cpu pclk\n"); | |
363 | ||
364 | return 0; | |
365 | } | |
366 |