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-rw-r--r--arch/arm/plat-s3c24xx/pwm-clock.c437
1 files changed, 437 insertions, 0 deletions
diff --git a/arch/arm/plat-s3c24xx/pwm-clock.c b/arch/arm/plat-s3c24xx/pwm-clock.c
new file mode 100644
index 000000000000..2cda3e3c6786
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+++ b/arch/arm/plat-s3c24xx/pwm-clock.c
@@ -0,0 +1,437 @@
1/* linux/arch/arm/plat-s3c24xx/pwm-clock.c
2 *
3 * Copyright (c) 2007 Simtec Electronics
4 * Copyright (c) 2007, 2008 Ben Dooks
5 * Ben Dooks <ben-linux@fluff.org>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License.
10*/
11
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/kernel.h>
15#include <linux/list.h>
16#include <linux/errno.h>
17#include <linux/clk.h>
18#include <linux/err.h>
19#include <linux/io.h>
20
21#include <asm/hardware.h>
22#include <asm/irq.h>
23
24#include <asm/arch/regs-clock.h>
25#include <asm/arch/regs-gpio.h>
26
27#include <asm/plat-s3c24xx/clock.h>
28#include <asm/plat-s3c24xx/cpu.h>
29
30#include <asm/plat-s3c/regs-timer.h>
31
32/* Each of the timers 0 through 5 go through the following
33 * clock tree, with the inputs depending on the timers.
34 *
35 * pclk ---- [ prescaler 0 ] -+---> timer 0
36 * +---> timer 1
37 *
38 * pclk ---- [ prescaler 1 ] -+---> timer 2
39 * +---> timer 3
40 * \---> timer 4
41 *
42 * Which are fed into the timers as so:
43 *
44 * prescaled 0 ---- [ div 2,4,8,16 ] ---\
45 * [mux] -> timer 0
46 * tclk 0 ------------------------------/
47 *
48 * prescaled 0 ---- [ div 2,4,8,16 ] ---\
49 * [mux] -> timer 1
50 * tclk 0 ------------------------------/
51 *
52 *
53 * prescaled 1 ---- [ div 2,4,8,16 ] ---\
54 * [mux] -> timer 2
55 * tclk 1 ------------------------------/
56 *
57 * prescaled 1 ---- [ div 2,4,8,16 ] ---\
58 * [mux] -> timer 3
59 * tclk 1 ------------------------------/
60 *
61 * prescaled 1 ---- [ div 2,4,8, 16 ] --\
62 * [mux] -> timer 4
63 * tclk 1 ------------------------------/
64 *
65 * Since the mux and the divider are tied together in the
66 * same register space, it is impossible to set the parent
67 * and the rate at the same time. To avoid this, we add an
68 * intermediate 'prescaled-and-divided' clock to select
69 * as the parent for the timer input clock called tdiv.
70 *
71 * prescaled clk --> pwm-tdiv ---\
72 * [ mux ] --> timer X
73 * tclk -------------------------/
74*/
75
76static unsigned long clk_pwm_scaler_getrate(struct clk *clk)
77{
78 unsigned long tcfg0 = __raw_readl(S3C2410_TCFG0);
79
80 if (clk->id == 1) {
81 tcfg0 &= S3C2410_TCFG_PRESCALER1_MASK;
82 tcfg0 >>= S3C2410_TCFG_PRESCALER1_SHIFT;
83 } else {
84 tcfg0 &= S3C2410_TCFG_PRESCALER0_MASK;
85 }
86
87 return clk_get_rate(clk->parent) / (tcfg0 + 1);
88}
89
90/* TODO - add set rate calls. */
91
92struct clk clk_timer_scaler[] = {
93 [0] = {
94 .name = "pwm-scaler0",
95 .id = -1,
96 .get_rate = clk_pwm_scaler_getrate,
97 },
98 [1] = {
99 .name = "pwm-scaler1",
100 .id = -1,
101 .get_rate = clk_pwm_scaler_getrate,
102 },
103};
104
105struct clk clk_timer_tclk[] = {
106 [0] = {
107 .name = "pwm-tclk0",
108 .id = -1,
109 },
110 [1] = {
111 .name = "pwm-tclk1",
112 .id = -1,
113 },
114};
115
116struct pwm_tdiv_clk {
117 struct clk clk;
118 unsigned int divisor;
119};
120
121static inline struct pwm_tdiv_clk *to_tdiv(struct clk *clk)
122{
123 return container_of(clk, struct pwm_tdiv_clk, clk);
124}
125
126static inline unsigned long tcfg_to_divisor(unsigned long tcfg1)
127{
128 return 1 << (1 + tcfg1);
129}
130
131static unsigned long clk_pwm_tdiv_get_rate(struct clk *clk)
132{
133 unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
134 unsigned int divisor;
135
136 tcfg1 >>= S3C2410_TCFG1_SHIFT(clk->id);
137 tcfg1 &= S3C2410_TCFG1_MUX_MASK;
138
139 if (tcfg1 == S3C2410_TCFG1_MUX_TCLK)
140 divisor = to_tdiv(clk)->divisor;
141 else
142 divisor = tcfg_to_divisor(tcfg1);
143
144 return clk_get_rate(clk->parent) / divisor;
145}
146
147static unsigned long clk_pwm_tdiv_round_rate(struct clk *clk,
148 unsigned long rate)
149{
150 unsigned long parent_rate;
151 unsigned long divisor;
152
153 parent_rate = clk_get_rate(clk->parent);
154 divisor = parent_rate / rate;
155
156 if (divisor <= 2)
157 divisor = 2;
158 else if (divisor <= 4)
159 divisor = 4;
160 else if (divisor <= 8)
161 divisor = 8;
162 else
163 divisor = 16;
164
165 return parent_rate / divisor;
166}
167
168static unsigned long clk_pwm_tdiv_bits(struct pwm_tdiv_clk *divclk)
169{
170 unsigned long bits;
171
172 switch (divclk->divisor) {
173 case 2:
174 bits = S3C2410_TCFG1_MUX_DIV2;
175 break;
176 case 4:
177 bits = S3C2410_TCFG1_MUX_DIV4;
178 break;
179 case 8:
180 bits = S3C2410_TCFG1_MUX_DIV8;
181 break;
182 case 16:
183 default:
184 bits = S3C2410_TCFG1_MUX_DIV16;
185 break;
186 }
187
188 return bits;
189}
190
191static void clk_pwm_tdiv_update(struct pwm_tdiv_clk *divclk)
192{
193 unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
194 unsigned long bits = clk_pwm_tdiv_bits(divclk);
195 unsigned long flags;
196 unsigned long shift = S3C2410_TCFG1_SHIFT(divclk->clk.id);
197
198 local_irq_save(flags);
199
200 tcfg1 = __raw_readl(S3C2410_TCFG1);
201 tcfg1 &= ~(S3C2410_TCFG1_MUX_MASK << shift);
202 tcfg1 |= bits << shift;
203 __raw_writel(tcfg1, S3C2410_TCFG1);
204
205 local_irq_restore(flags);
206}
207
208static int clk_pwm_tdiv_set_rate(struct clk *clk, unsigned long rate)
209{
210 struct pwm_tdiv_clk *divclk = to_tdiv(clk);
211 unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
212 unsigned long parent_rate = clk_get_rate(clk->parent);
213 unsigned long divisor;
214
215 tcfg1 >>= S3C2410_TCFG1_SHIFT(clk->id);
216 tcfg1 &= S3C2410_TCFG1_MUX_MASK;
217
218 rate = clk_round_rate(clk, rate);
219 divisor = parent_rate / rate;
220
221 if (divisor > 16)
222 return -EINVAL;
223
224 divclk->divisor = divisor;
225
226 /* Update the current MUX settings if we are currently
227 * selected as the clock source for this clock. */
228
229 if (tcfg1 != S3C2410_TCFG1_MUX_TCLK)
230 clk_pwm_tdiv_update(divclk);
231
232 return 0;
233}
234
235struct pwm_tdiv_clk clk_timer_tdiv[] = {
236 [0] = {
237 .clk = {
238 .name = "pwm-tdiv",
239 .parent = &clk_timer_scaler[0],
240 .get_rate = clk_pwm_tdiv_get_rate,
241 .set_rate = clk_pwm_tdiv_set_rate,
242 .round_rate = clk_pwm_tdiv_round_rate,
243 },
244 },
245 [1] = {
246 .clk = {
247 .name = "pwm-tdiv",
248 .parent = &clk_timer_scaler[0],
249 .get_rate = clk_pwm_tdiv_get_rate,
250 .set_rate = clk_pwm_tdiv_set_rate,
251 .round_rate = clk_pwm_tdiv_round_rate,
252 }
253 },
254 [2] = {
255 .clk = {
256 .name = "pwm-tdiv",
257 .parent = &clk_timer_scaler[1],
258 .get_rate = clk_pwm_tdiv_get_rate,
259 .set_rate = clk_pwm_tdiv_set_rate,
260 .round_rate = clk_pwm_tdiv_round_rate,
261 },
262 },
263 [3] = {
264 .clk = {
265 .name = "pwm-tdiv",
266 .parent = &clk_timer_scaler[1],
267 .get_rate = clk_pwm_tdiv_get_rate,
268 .set_rate = clk_pwm_tdiv_set_rate,
269 .round_rate = clk_pwm_tdiv_round_rate,
270 },
271 },
272 [4] = {
273 .clk = {
274 .name = "pwm-tdiv",
275 .parent = &clk_timer_scaler[1],
276 .get_rate = clk_pwm_tdiv_get_rate,
277 .set_rate = clk_pwm_tdiv_set_rate,
278 .round_rate = clk_pwm_tdiv_round_rate,
279 },
280 },
281};
282
283static int __init clk_pwm_tdiv_register(unsigned int id)
284{
285 struct pwm_tdiv_clk *divclk = &clk_timer_tdiv[id];
286 unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
287
288 tcfg1 >>= S3C2410_TCFG1_SHIFT(id);
289 tcfg1 &= S3C2410_TCFG1_MUX_MASK;
290
291 divclk->clk.id = id;
292 divclk->divisor = tcfg_to_divisor(tcfg1);
293
294 return s3c24xx_register_clock(&divclk->clk);
295}
296
297static inline struct clk *s3c24xx_pwmclk_tclk(unsigned int id)
298{
299 return (id >= 2) ? &clk_timer_tclk[1] : &clk_timer_tclk[0];
300}
301
302static inline struct clk *s3c24xx_pwmclk_tdiv(unsigned int id)
303{
304 return &clk_timer_tdiv[id].clk;
305}
306
307static int clk_pwm_tin_set_parent(struct clk *clk, struct clk *parent)
308{
309 unsigned int id = clk->id;
310 unsigned long tcfg1;
311 unsigned long flags;
312 unsigned long bits;
313 unsigned long shift = S3C2410_TCFG1_SHIFT(id);
314
315 if (parent == s3c24xx_pwmclk_tclk(id))
316 bits = S3C2410_TCFG1_MUX_TCLK << shift;
317 else if (parent == s3c24xx_pwmclk_tdiv(id))
318 bits = clk_pwm_tdiv_bits(to_tdiv(clk)) << shift;
319 else
320 return -EINVAL;
321
322 clk->parent = parent;
323
324 local_irq_save(flags);
325
326 tcfg1 = __raw_readl(S3C2410_TCFG1);
327 tcfg1 &= ~(S3C2410_TCFG1_MUX_MASK << shift);
328 __raw_writel(tcfg1 | bits, S3C2410_TCFG1);
329
330 local_irq_restore(flags);
331
332 return 0;
333}
334
335static struct clk clk_tin[] = {
336 [0] = {
337 .name = "pwm-tin",
338 .id = 0,
339 .set_parent = clk_pwm_tin_set_parent,
340 },
341 [1] = {
342 .name = "pwm-tin",
343 .id = 1,
344 .set_parent = clk_pwm_tin_set_parent,
345 },
346 [2] = {
347 .name = "pwm-tin",
348 .id = 2,
349 .set_parent = clk_pwm_tin_set_parent,
350 },
351 [3] = {
352 .name = "pwm-tin",
353 .id = 3,
354 .set_parent = clk_pwm_tin_set_parent,
355 },
356 [4] = {
357 .name = "pwm-tin",
358 .id = 4,
359 .set_parent = clk_pwm_tin_set_parent,
360 },
361};
362
363static __init int clk_pwm_tin_register(struct clk *pwm)
364{
365 unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
366 unsigned int id = pwm->id;
367
368 struct clk *parent;
369 int ret;
370
371 ret = s3c24xx_register_clock(pwm);
372 if (ret < 0)
373 return ret;
374
375 tcfg1 >>= S3C2410_TCFG1_SHIFT(id);
376 tcfg1 &= S3C2410_TCFG1_MUX_MASK;
377
378 if (tcfg1 == S3C2410_TCFG1_MUX_TCLK)
379 parent = s3c24xx_pwmclk_tclk(id);
380 else
381 parent = s3c24xx_pwmclk_tdiv(id);
382
383 return clk_set_parent(pwm, parent);
384}
385
386static __init int s3c24xx_pwmclk_init(void)
387{
388 struct clk *clk_timers;
389 unsigned int clk;
390 int ret;
391
392 clk_timers = clk_get(NULL, "timers");
393 if (IS_ERR(clk_timers)) {
394 printk(KERN_ERR "%s: no parent clock\n", __func__);
395 return -EINVAL;
396 }
397
398 for (clk = 0; clk < ARRAY_SIZE(clk_timer_scaler); clk++) {
399 clk_timer_scaler[clk].parent = clk_timers;
400 ret = s3c24xx_register_clock(&clk_timer_scaler[clk]);
401 if (ret < 0) {
402 printk(KERN_ERR "error adding pwm scaler%d clock\n", clk);
403 goto err;
404 }
405 }
406
407 for (clk = 0; clk < ARRAY_SIZE(clk_timer_tclk); clk++) {
408 ret = s3c24xx_register_clock(&clk_timer_tclk[clk]);
409 if (ret < 0) {
410 printk(KERN_ERR "error adding pww tclk%d\n", clk);
411 goto err;
412 }
413 }
414
415 for (clk = 0; clk < ARRAY_SIZE(clk_timer_tdiv); clk++) {
416 ret = clk_pwm_tdiv_register(clk);
417 if (ret < 0) {
418 printk(KERN_ERR "error adding pwm%d tdiv clock\n", clk);
419 goto err;
420 }
421 }
422
423 for (clk = 0; clk < ARRAY_SIZE(clk_tin); clk++) {
424 ret = clk_pwm_tin_register(&clk_tin[clk]);
425 if (ret < 0) {
426 printk(KERN_ERR "error adding pwm%d tin clock\n", clk);
427 goto err;
428 }
429 }
430
431 return 0;
432
433 err:
434 return ret;
435}
436
437arch_initcall(s3c24xx_pwmclk_init);