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[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / arch / arm / plat-s3c24xx / cpu-freq.c
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1 /* linux/arch/arm/plat-s3c24xx/cpu-freq.c
3 * Copyright (c) 2006-2008 Simtec Electronics
4 * http://armlinux.simtec.co.uk/
5 * Ben Dooks <ben@simtec.co.uk>
7 * S3C24XX CPU Frequency scaling
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/init.h>
15 #include <linux/module.h>
16 #include <linux/interrupt.h>
17 #include <linux/ioport.h>
18 #include <linux/cpufreq.h>
19 #include <linux/cpu.h>
20 #include <linux/clk.h>
21 #include <linux/err.h>
22 #include <linux/io.h>
23 #include <linux/sysdev.h>
24 #include <linux/kobject.h>
25 #include <linux/sysfs.h>
26 #include <linux/slab.h>
28 #include <asm/mach/arch.h>
29 #include <asm/mach/map.h>
31 #include <plat/cpu.h>
32 #include <plat/clock.h>
33 #include <plat/cpu-freq-core.h>
35 #include <mach/regs-clock.h>
37 /* note, cpufreq support deals in kHz, no Hz */
39 static struct cpufreq_driver s3c24xx_driver;
40 static struct s3c_cpufreq_config cpu_cur;
41 static struct s3c_iotimings s3c24xx_iotiming;
42 static struct cpufreq_frequency_table *pll_reg;
43 static unsigned int last_target = ~0;
44 static unsigned int ftab_size;
45 static struct cpufreq_frequency_table *ftab;
47 static struct clk *_clk_mpll;
48 static struct clk *_clk_xtal;
49 static struct clk *clk_fclk;
50 static struct clk *clk_hclk;
51 static struct clk *clk_pclk;
52 static struct clk *clk_arm;
54 #ifdef CONFIG_CPU_FREQ_S3C24XX_DEBUGFS
55 struct s3c_cpufreq_config *s3c_cpufreq_getconfig(void)
57 return &cpu_cur;
60 struct s3c_iotimings *s3c_cpufreq_getiotimings(void)
62 return &s3c24xx_iotiming;
64 #endif /* CONFIG_CPU_FREQ_S3C24XX_DEBUGFS */
66 static void s3c_cpufreq_getcur(struct s3c_cpufreq_config *cfg)
68 unsigned long fclk, pclk, hclk, armclk;
70 cfg->freq.fclk = fclk = clk_get_rate(clk_fclk);
71 cfg->freq.hclk = hclk = clk_get_rate(clk_hclk);
72 cfg->freq.pclk = pclk = clk_get_rate(clk_pclk);
73 cfg->freq.armclk = armclk = clk_get_rate(clk_arm);
75 cfg->pll.index = __raw_readl(S3C2410_MPLLCON);
76 cfg->pll.frequency = fclk;
78 cfg->freq.hclk_tns = 1000000000 / (cfg->freq.hclk / 10);
80 cfg->divs.h_divisor = fclk / hclk;
81 cfg->divs.p_divisor = fclk / pclk;
84 static inline void s3c_cpufreq_calc(struct s3c_cpufreq_config *cfg)
86 unsigned long pll = cfg->pll.frequency;
88 cfg->freq.fclk = pll;
89 cfg->freq.hclk = pll / cfg->divs.h_divisor;
90 cfg->freq.pclk = pll / cfg->divs.p_divisor;
92 /* convert hclk into 10ths of nanoseconds for io calcs */
93 cfg->freq.hclk_tns = 1000000000 / (cfg->freq.hclk / 10);
96 static inline int closer(unsigned int target, unsigned int n, unsigned int c)
98 int diff_cur = abs(target - c);
99 int diff_new = abs(target - n);
101 return (diff_new < diff_cur);
104 static void s3c_cpufreq_show(const char *pfx,
105 struct s3c_cpufreq_config *cfg)
107 s3c_freq_dbg("%s: Fvco=%u, F=%lu, A=%lu, H=%lu (%u), P=%lu (%u)\n",
108 pfx, cfg->pll.frequency, cfg->freq.fclk, cfg->freq.armclk,
109 cfg->freq.hclk, cfg->divs.h_divisor,
110 cfg->freq.pclk, cfg->divs.p_divisor);
113 /* functions to wrapper the driver info calls to do the cpu specific work */
115 static void s3c_cpufreq_setio(struct s3c_cpufreq_config *cfg)
117 if (cfg->info->set_iotiming)
118 (cfg->info->set_iotiming)(cfg, &s3c24xx_iotiming);
121 static int s3c_cpufreq_calcio(struct s3c_cpufreq_config *cfg)
123 if (cfg->info->calc_iotiming)
124 return (cfg->info->calc_iotiming)(cfg, &s3c24xx_iotiming);
126 return 0;
129 static void s3c_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg)
131 (cfg->info->set_refresh)(cfg);
134 static void s3c_cpufreq_setdivs(struct s3c_cpufreq_config *cfg)
136 (cfg->info->set_divs)(cfg);
139 static int s3c_cpufreq_calcdivs(struct s3c_cpufreq_config *cfg)
141 return (cfg->info->calc_divs)(cfg);
144 static void s3c_cpufreq_setfvco(struct s3c_cpufreq_config *cfg)
146 (cfg->info->set_fvco)(cfg);
149 static inline void s3c_cpufreq_resume_clocks(void)
151 cpu_cur.info->resume_clocks();
154 static inline void s3c_cpufreq_updateclk(struct clk *clk,
155 unsigned int freq)
157 clk_set_rate(clk, freq);
160 static int s3c_cpufreq_settarget(struct cpufreq_policy *policy,
161 unsigned int target_freq,
162 struct cpufreq_frequency_table *pll)
164 struct s3c_cpufreq_freqs freqs;
165 struct s3c_cpufreq_config cpu_new;
166 unsigned long flags;
168 cpu_new = cpu_cur; /* copy new from current */
170 s3c_cpufreq_show("cur", &cpu_cur);
172 /* TODO - check for DMA currently outstanding */
174 cpu_new.pll = pll ? *pll : cpu_cur.pll;
176 if (pll)
177 freqs.pll_changing = 1;
179 /* update our frequencies */
181 cpu_new.freq.armclk = target_freq;
182 cpu_new.freq.fclk = cpu_new.pll.frequency;
184 if (s3c_cpufreq_calcdivs(&cpu_new) < 0) {
185 printk(KERN_ERR "no divisors for %d\n", target_freq);
186 goto err_notpossible;
189 s3c_freq_dbg("%s: got divs\n", __func__);
191 s3c_cpufreq_calc(&cpu_new);
193 s3c_freq_dbg("%s: calculated frequencies for new\n", __func__);
195 if (cpu_new.freq.hclk != cpu_cur.freq.hclk) {
196 if (s3c_cpufreq_calcio(&cpu_new) < 0) {
197 printk(KERN_ERR "%s: no IO timings\n", __func__);
198 goto err_notpossible;
202 s3c_cpufreq_show("new", &cpu_new);
204 /* setup our cpufreq parameters */
206 freqs.old = cpu_cur.freq;
207 freqs.new = cpu_new.freq;
209 freqs.freqs.cpu = 0;
210 freqs.freqs.old = cpu_cur.freq.armclk / 1000;
211 freqs.freqs.new = cpu_new.freq.armclk / 1000;
213 /* update f/h/p clock settings before we issue the change
214 * notification, so that drivers do not need to do anything
215 * special if they want to recalculate on CPUFREQ_PRECHANGE. */
217 s3c_cpufreq_updateclk(_clk_mpll, cpu_new.pll.frequency);
218 s3c_cpufreq_updateclk(clk_fclk, cpu_new.freq.fclk);
219 s3c_cpufreq_updateclk(clk_hclk, cpu_new.freq.hclk);
220 s3c_cpufreq_updateclk(clk_pclk, cpu_new.freq.pclk);
222 /* start the frequency change */
224 if (policy)
225 cpufreq_notify_transition(&freqs.freqs, CPUFREQ_PRECHANGE);
227 /* If hclk is staying the same, then we do not need to
228 * re-write the IO or the refresh timings whilst we are changing
229 * speed. */
231 local_irq_save(flags);
233 /* is our memory clock slowing down? */
234 if (cpu_new.freq.hclk < cpu_cur.freq.hclk) {
235 s3c_cpufreq_setrefresh(&cpu_new);
236 s3c_cpufreq_setio(&cpu_new);
239 if (cpu_new.freq.fclk == cpu_cur.freq.fclk) {
240 /* not changing PLL, just set the divisors */
242 s3c_cpufreq_setdivs(&cpu_new);
243 } else {
244 if (cpu_new.freq.fclk < cpu_cur.freq.fclk) {
245 /* slow the cpu down, then set divisors */
247 s3c_cpufreq_setfvco(&cpu_new);
248 s3c_cpufreq_setdivs(&cpu_new);
249 } else {
250 /* set the divisors, then speed up */
252 s3c_cpufreq_setdivs(&cpu_new);
253 s3c_cpufreq_setfvco(&cpu_new);
257 /* did our memory clock speed up */
258 if (cpu_new.freq.hclk > cpu_cur.freq.hclk) {
259 s3c_cpufreq_setrefresh(&cpu_new);
260 s3c_cpufreq_setio(&cpu_new);
263 /* update our current settings */
264 cpu_cur = cpu_new;
266 local_irq_restore(flags);
268 /* notify everyone we've done this */
269 if (policy)
270 cpufreq_notify_transition(&freqs.freqs, CPUFREQ_POSTCHANGE);
272 s3c_freq_dbg("%s: finished\n", __func__);
273 return 0;
275 err_notpossible:
276 printk(KERN_ERR "no compatible settings for %d\n", target_freq);
277 return -EINVAL;
280 /* s3c_cpufreq_target
282 * called by the cpufreq core to adjust the frequency that the CPU
283 * is currently running at.
286 static int s3c_cpufreq_target(struct cpufreq_policy *policy,
287 unsigned int target_freq,
288 unsigned int relation)
290 struct cpufreq_frequency_table *pll;
291 unsigned int index;
293 /* avoid repeated calls which cause a needless amout of duplicated
294 * logging output (and CPU time as the calculation process is
295 * done) */
296 if (target_freq == last_target)
297 return 0;
299 last_target = target_freq;
301 s3c_freq_dbg("%s: policy %p, target %u, relation %u\n",
302 __func__, policy, target_freq, relation);
304 if (ftab) {
305 if (cpufreq_frequency_table_target(policy, ftab,
306 target_freq, relation,
307 &index)) {
308 s3c_freq_dbg("%s: table failed\n", __func__);
309 return -EINVAL;
312 s3c_freq_dbg("%s: adjust %d to entry %d (%u)\n", __func__,
313 target_freq, index, ftab[index].frequency);
314 target_freq = ftab[index].frequency;
317 target_freq *= 1000; /* convert target to Hz */
319 /* find the settings for our new frequency */
321 if (!pll_reg || cpu_cur.lock_pll) {
322 /* either we've not got any PLL values, or we've locked
323 * to the current one. */
324 pll = NULL;
325 } else {
326 struct cpufreq_policy tmp_policy;
327 int ret;
329 /* we keep the cpu pll table in Hz, to ensure we get an
330 * accurate value for the PLL output. */
332 tmp_policy.min = policy->min * 1000;
333 tmp_policy.max = policy->max * 1000;
334 tmp_policy.cpu = policy->cpu;
336 /* cpufreq_frequency_table_target uses a pointer to 'index'
337 * which is the number of the table entry, not the value of
338 * the table entry's index field. */
340 ret = cpufreq_frequency_table_target(&tmp_policy, pll_reg,
341 target_freq, relation,
342 &index);
344 if (ret < 0) {
345 printk(KERN_ERR "%s: no PLL available\n", __func__);
346 goto err_notpossible;
349 pll = pll_reg + index;
351 s3c_freq_dbg("%s: target %u => %u\n",
352 __func__, target_freq, pll->frequency);
354 target_freq = pll->frequency;
357 return s3c_cpufreq_settarget(policy, target_freq, pll);
359 err_notpossible:
360 printk(KERN_ERR "no compatible settings for %d\n", target_freq);
361 return -EINVAL;
364 static unsigned int s3c_cpufreq_get(unsigned int cpu)
366 return clk_get_rate(clk_arm) / 1000;
369 struct clk *s3c_cpufreq_clk_get(struct device *dev, const char *name)
371 struct clk *clk;
373 clk = clk_get(dev, name);
374 if (IS_ERR(clk))
375 printk(KERN_ERR "cpufreq: failed to get clock '%s'\n", name);
377 return clk;
380 static int s3c_cpufreq_init(struct cpufreq_policy *policy)
382 printk(KERN_INFO "%s: initialising policy %p\n", __func__, policy);
384 if (policy->cpu != 0)
385 return -EINVAL;
387 policy->cur = s3c_cpufreq_get(0);
388 policy->min = policy->cpuinfo.min_freq = 0;
389 policy->max = policy->cpuinfo.max_freq = cpu_cur.info->max.fclk / 1000;
390 policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
392 /* feed the latency information from the cpu driver */
393 policy->cpuinfo.transition_latency = cpu_cur.info->latency;
395 if (ftab)
396 cpufreq_frequency_table_cpuinfo(policy, ftab);
398 return 0;
401 static __init int s3c_cpufreq_initclks(void)
403 _clk_mpll = s3c_cpufreq_clk_get(NULL, "mpll");
404 _clk_xtal = s3c_cpufreq_clk_get(NULL, "xtal");
405 clk_fclk = s3c_cpufreq_clk_get(NULL, "fclk");
406 clk_hclk = s3c_cpufreq_clk_get(NULL, "hclk");
407 clk_pclk = s3c_cpufreq_clk_get(NULL, "pclk");
408 clk_arm = s3c_cpufreq_clk_get(NULL, "armclk");
410 if (IS_ERR(clk_fclk) || IS_ERR(clk_hclk) || IS_ERR(clk_pclk) ||
411 IS_ERR(_clk_mpll) || IS_ERR(clk_arm) || IS_ERR(_clk_xtal)) {
412 printk(KERN_ERR "%s: could not get clock(s)\n", __func__);
413 return -ENOENT;
416 printk(KERN_INFO "%s: clocks f=%lu,h=%lu,p=%lu,a=%lu\n", __func__,
417 clk_get_rate(clk_fclk) / 1000,
418 clk_get_rate(clk_hclk) / 1000,
419 clk_get_rate(clk_pclk) / 1000,
420 clk_get_rate(clk_arm) / 1000);
422 return 0;
425 static int s3c_cpufreq_verify(struct cpufreq_policy *policy)
427 if (policy->cpu != 0)
428 return -EINVAL;
430 return 0;
433 #ifdef CONFIG_PM
434 static struct cpufreq_frequency_table suspend_pll;
435 static unsigned int suspend_freq;
437 static int s3c_cpufreq_suspend(struct cpufreq_policy *policy, pm_message_t pmsg)
439 suspend_pll.frequency = clk_get_rate(_clk_mpll);
440 suspend_pll.index = __raw_readl(S3C2410_MPLLCON);
441 suspend_freq = s3c_cpufreq_get(0) * 1000;
443 return 0;
446 static int s3c_cpufreq_resume(struct cpufreq_policy *policy)
448 int ret;
450 s3c_freq_dbg("%s: resuming with policy %p\n", __func__, policy);
452 last_target = ~0; /* invalidate last_target setting */
454 /* first, find out what speed we resumed at. */
455 s3c_cpufreq_resume_clocks();
457 /* whilst we will be called later on, we try and re-set the
458 * cpu frequencies as soon as possible so that we do not end
459 * up resuming devices and then immediatley having to re-set
460 * a number of settings once these devices have restarted.
462 * as a note, it is expected devices are not used until they
463 * have been un-suspended and at that time they should have
464 * used the updated clock settings.
467 ret = s3c_cpufreq_settarget(NULL, suspend_freq, &suspend_pll);
468 if (ret) {
469 printk(KERN_ERR "%s: failed to reset pll/freq\n", __func__);
470 return ret;
473 return 0;
475 #else
476 #define s3c_cpufreq_resume NULL
477 #define s3c_cpufreq_suspend NULL
478 #endif
480 static struct cpufreq_driver s3c24xx_driver = {
481 .flags = CPUFREQ_STICKY,
482 .verify = s3c_cpufreq_verify,
483 .target = s3c_cpufreq_target,
484 .get = s3c_cpufreq_get,
485 .init = s3c_cpufreq_init,
486 .suspend = s3c_cpufreq_suspend,
487 .resume = s3c_cpufreq_resume,
488 .name = "s3c24xx",
492 int __init s3c_cpufreq_register(struct s3c_cpufreq_info *info)
494 if (!info || !info->name) {
495 printk(KERN_ERR "%s: failed to pass valid information\n",
496 __func__);
497 return -EINVAL;
500 printk(KERN_INFO "S3C24XX CPU Frequency driver, %s cpu support\n",
501 info->name);
503 /* check our driver info has valid data */
505 BUG_ON(info->set_refresh == NULL);
506 BUG_ON(info->set_divs == NULL);
507 BUG_ON(info->calc_divs == NULL);
509 /* info->set_fvco is optional, depending on whether there
510 * is a need to set the clock code. */
512 cpu_cur.info = info;
514 /* Note, driver registering should probably update locktime */
516 return 0;
519 int __init s3c_cpufreq_setboard(struct s3c_cpufreq_board *board)
521 struct s3c_cpufreq_board *ours;
523 if (!board) {
524 printk(KERN_INFO "%s: no board data\n", __func__);
525 return -EINVAL;
528 /* Copy the board information so that each board can make this
529 * initdata. */
531 ours = kzalloc(sizeof(struct s3c_cpufreq_board), GFP_KERNEL);
532 if (ours == NULL) {
533 printk(KERN_ERR "%s: no memory\n", __func__);
534 return -ENOMEM;
537 *ours = *board;
538 cpu_cur.board = ours;
540 return 0;
543 int __init s3c_cpufreq_auto_io(void)
545 int ret;
547 if (!cpu_cur.info->get_iotiming) {
548 printk(KERN_ERR "%s: get_iotiming undefined\n", __func__);
549 return -ENOENT;
552 printk(KERN_INFO "%s: working out IO settings\n", __func__);
554 ret = (cpu_cur.info->get_iotiming)(&cpu_cur, &s3c24xx_iotiming);
555 if (ret)
556 printk(KERN_ERR "%s: failed to get timings\n", __func__);
558 return ret;
561 /* if one or is zero, then return the other, otherwise return the min */
562 #define do_min(_a, _b) ((_a) == 0 ? (_b) : (_b) == 0 ? (_a) : min(_a, _b))
565 * s3c_cpufreq_freq_min - find the minimum settings for the given freq.
566 * @dst: The destination structure
567 * @a: One argument.
568 * @b: The other argument.
570 * Create a minimum of each frequency entry in the 'struct s3c_freq',
571 * unless the entry is zero when it is ignored and the non-zero argument
572 * used.
574 static void s3c_cpufreq_freq_min(struct s3c_freq *dst,
575 struct s3c_freq *a, struct s3c_freq *b)
577 dst->fclk = do_min(a->fclk, b->fclk);
578 dst->hclk = do_min(a->hclk, b->hclk);
579 dst->pclk = do_min(a->pclk, b->pclk);
580 dst->armclk = do_min(a->armclk, b->armclk);
583 static inline u32 calc_locktime(u32 freq, u32 time_us)
585 u32 result;
587 result = freq * time_us;
588 result = DIV_ROUND_UP(result, 1000 * 1000);
590 return result;
593 static void s3c_cpufreq_update_loctkime(void)
595 unsigned int bits = cpu_cur.info->locktime_bits;
596 u32 rate = (u32)clk_get_rate(_clk_xtal);
597 u32 val;
599 if (bits == 0) {
600 WARN_ON(1);
601 return;
604 val = calc_locktime(rate, cpu_cur.info->locktime_u) << bits;
605 val |= calc_locktime(rate, cpu_cur.info->locktime_m);
607 printk(KERN_INFO "%s: new locktime is 0x%08x\n", __func__, val);
608 __raw_writel(val, S3C2410_LOCKTIME);
611 static int s3c_cpufreq_build_freq(void)
613 int size, ret;
615 if (!cpu_cur.info->calc_freqtable)
616 return -EINVAL;
618 kfree(ftab);
619 ftab = NULL;
621 size = cpu_cur.info->calc_freqtable(&cpu_cur, NULL, 0);
622 size++;
624 ftab = kmalloc(sizeof(struct cpufreq_frequency_table) * size, GFP_KERNEL);
625 if (!ftab) {
626 printk(KERN_ERR "%s: no memory for tables\n", __func__);
627 return -ENOMEM;
630 ftab_size = size;
632 ret = cpu_cur.info->calc_freqtable(&cpu_cur, ftab, size);
633 s3c_cpufreq_addfreq(ftab, ret, size, CPUFREQ_TABLE_END);
635 return 0;
638 static int __init s3c_cpufreq_initcall(void)
640 int ret = 0;
642 if (cpu_cur.info && cpu_cur.board) {
643 ret = s3c_cpufreq_initclks();
644 if (ret)
645 goto out;
647 /* get current settings */
648 s3c_cpufreq_getcur(&cpu_cur);
649 s3c_cpufreq_show("cur", &cpu_cur);
651 if (cpu_cur.board->auto_io) {
652 ret = s3c_cpufreq_auto_io();
653 if (ret) {
654 printk(KERN_ERR "%s: failed to get io timing\n",
655 __func__);
656 goto out;
660 if (cpu_cur.board->need_io && !cpu_cur.info->set_iotiming) {
661 printk(KERN_ERR "%s: no IO support registered\n",
662 __func__);
663 ret = -EINVAL;
664 goto out;
667 if (!cpu_cur.info->need_pll)
668 cpu_cur.lock_pll = 1;
670 s3c_cpufreq_update_loctkime();
672 s3c_cpufreq_freq_min(&cpu_cur.max, &cpu_cur.board->max,
673 &cpu_cur.info->max);
675 if (cpu_cur.info->calc_freqtable)
676 s3c_cpufreq_build_freq();
678 ret = cpufreq_register_driver(&s3c24xx_driver);
681 out:
682 return ret;
685 late_initcall(s3c_cpufreq_initcall);
688 * s3c_plltab_register - register CPU PLL table.
689 * @plls: The list of PLL entries.
690 * @plls_no: The size of the PLL entries @plls.
692 * Register the given set of PLLs with the system.
694 int __init s3c_plltab_register(struct cpufreq_frequency_table *plls,
695 unsigned int plls_no)
697 struct cpufreq_frequency_table *vals;
698 unsigned int size;
700 size = sizeof(struct cpufreq_frequency_table) * (plls_no + 1);
702 vals = kmalloc(size, GFP_KERNEL);
703 if (vals) {
704 memcpy(vals, plls, size);
705 pll_reg = vals;
707 /* write a terminating entry, we don't store it in the
708 * table that is stored in the kernel */
709 vals += plls_no;
710 vals->frequency = CPUFREQ_TABLE_END;
712 printk(KERN_INFO "cpufreq: %d PLL entries\n", plls_no);
713 } else
714 printk(KERN_ERR "cpufreq: no memory for PLL tables\n");
716 return vals ? 0 : -ENOMEM;