Merge tag 'edac_for_4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp
[sfrench/cifs-2.6.git] / drivers / cpufreq / s3c24xx-cpufreq.c
1 /*
2  * Copyright (c) 2006-2008 Simtec Electronics
3  *      http://armlinux.simtec.co.uk/
4  *      Ben Dooks <ben@simtec.co.uk>
5  *
6  * S3C24XX CPU Frequency scaling
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11 */
12
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/interrupt.h>
18 #include <linux/ioport.h>
19 #include <linux/cpufreq.h>
20 #include <linux/cpu.h>
21 #include <linux/clk.h>
22 #include <linux/err.h>
23 #include <linux/io.h>
24 #include <linux/device.h>
25 #include <linux/sysfs.h>
26 #include <linux/slab.h>
27
28 #include <asm/mach/arch.h>
29 #include <asm/mach/map.h>
30
31 #include <plat/cpu.h>
32 #include <plat/cpu-freq-core.h>
33
34 #include <mach/regs-clock.h>
35
36 /* note, cpufreq support deals in kHz, no Hz */
37
38 static struct cpufreq_driver s3c24xx_driver;
39 static struct s3c_cpufreq_config cpu_cur;
40 static struct s3c_iotimings s3c24xx_iotiming;
41 static struct cpufreq_frequency_table *pll_reg;
42 static unsigned int last_target = ~0;
43 static unsigned int ftab_size;
44 static struct cpufreq_frequency_table *ftab;
45
46 static struct clk *_clk_mpll;
47 static struct clk *_clk_xtal;
48 static struct clk *clk_fclk;
49 static struct clk *clk_hclk;
50 static struct clk *clk_pclk;
51 static struct clk *clk_arm;
52
53 #ifdef CONFIG_ARM_S3C24XX_CPUFREQ_DEBUGFS
54 struct s3c_cpufreq_config *s3c_cpufreq_getconfig(void)
55 {
56         return &cpu_cur;
57 }
58
59 struct s3c_iotimings *s3c_cpufreq_getiotimings(void)
60 {
61         return &s3c24xx_iotiming;
62 }
63 #endif /* CONFIG_ARM_S3C24XX_CPUFREQ_DEBUGFS */
64
65 static void s3c_cpufreq_getcur(struct s3c_cpufreq_config *cfg)
66 {
67         unsigned long fclk, pclk, hclk, armclk;
68
69         cfg->freq.fclk = fclk = clk_get_rate(clk_fclk);
70         cfg->freq.hclk = hclk = clk_get_rate(clk_hclk);
71         cfg->freq.pclk = pclk = clk_get_rate(clk_pclk);
72         cfg->freq.armclk = armclk = clk_get_rate(clk_arm);
73
74         cfg->pll.driver_data = __raw_readl(S3C2410_MPLLCON);
75         cfg->pll.frequency = fclk;
76
77         cfg->freq.hclk_tns = 1000000000 / (cfg->freq.hclk / 10);
78
79         cfg->divs.h_divisor = fclk / hclk;
80         cfg->divs.p_divisor = fclk / pclk;
81 }
82
83 static inline void s3c_cpufreq_calc(struct s3c_cpufreq_config *cfg)
84 {
85         unsigned long pll = cfg->pll.frequency;
86
87         cfg->freq.fclk = pll;
88         cfg->freq.hclk = pll / cfg->divs.h_divisor;
89         cfg->freq.pclk = pll / cfg->divs.p_divisor;
90
91         /* convert hclk into 10ths of nanoseconds for io calcs */
92         cfg->freq.hclk_tns = 1000000000 / (cfg->freq.hclk / 10);
93 }
94
95 static inline int closer(unsigned int target, unsigned int n, unsigned int c)
96 {
97         int diff_cur = abs(target - c);
98         int diff_new = abs(target - n);
99
100         return (diff_new < diff_cur);
101 }
102
103 static void s3c_cpufreq_show(const char *pfx,
104                                  struct s3c_cpufreq_config *cfg)
105 {
106         s3c_freq_dbg("%s: Fvco=%u, F=%lu, A=%lu, H=%lu (%u), P=%lu (%u)\n",
107                      pfx, cfg->pll.frequency, cfg->freq.fclk, cfg->freq.armclk,
108                      cfg->freq.hclk, cfg->divs.h_divisor,
109                      cfg->freq.pclk, cfg->divs.p_divisor);
110 }
111
112 /* functions to wrapper the driver info calls to do the cpu specific work */
113
114 static void s3c_cpufreq_setio(struct s3c_cpufreq_config *cfg)
115 {
116         if (cfg->info->set_iotiming)
117                 (cfg->info->set_iotiming)(cfg, &s3c24xx_iotiming);
118 }
119
120 static int s3c_cpufreq_calcio(struct s3c_cpufreq_config *cfg)
121 {
122         if (cfg->info->calc_iotiming)
123                 return (cfg->info->calc_iotiming)(cfg, &s3c24xx_iotiming);
124
125         return 0;
126 }
127
128 static void s3c_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg)
129 {
130         (cfg->info->set_refresh)(cfg);
131 }
132
133 static void s3c_cpufreq_setdivs(struct s3c_cpufreq_config *cfg)
134 {
135         (cfg->info->set_divs)(cfg);
136 }
137
138 static int s3c_cpufreq_calcdivs(struct s3c_cpufreq_config *cfg)
139 {
140         return (cfg->info->calc_divs)(cfg);
141 }
142
143 static void s3c_cpufreq_setfvco(struct s3c_cpufreq_config *cfg)
144 {
145         cfg->mpll = _clk_mpll;
146         (cfg->info->set_fvco)(cfg);
147 }
148
149 static inline void s3c_cpufreq_updateclk(struct clk *clk,
150                                          unsigned int freq)
151 {
152         clk_set_rate(clk, freq);
153 }
154
155 static int s3c_cpufreq_settarget(struct cpufreq_policy *policy,
156                                  unsigned int target_freq,
157                                  struct cpufreq_frequency_table *pll)
158 {
159         struct s3c_cpufreq_freqs freqs;
160         struct s3c_cpufreq_config cpu_new;
161         unsigned long flags;
162
163         cpu_new = cpu_cur;  /* copy new from current */
164
165         s3c_cpufreq_show("cur", &cpu_cur);
166
167         /* TODO - check for DMA currently outstanding */
168
169         cpu_new.pll = pll ? *pll : cpu_cur.pll;
170
171         if (pll)
172                 freqs.pll_changing = 1;
173
174         /* update our frequencies */
175
176         cpu_new.freq.armclk = target_freq;
177         cpu_new.freq.fclk = cpu_new.pll.frequency;
178
179         if (s3c_cpufreq_calcdivs(&cpu_new) < 0) {
180                 pr_err("no divisors for %d\n", target_freq);
181                 goto err_notpossible;
182         }
183
184         s3c_freq_dbg("%s: got divs\n", __func__);
185
186         s3c_cpufreq_calc(&cpu_new);
187
188         s3c_freq_dbg("%s: calculated frequencies for new\n", __func__);
189
190         if (cpu_new.freq.hclk != cpu_cur.freq.hclk) {
191                 if (s3c_cpufreq_calcio(&cpu_new) < 0) {
192                         pr_err("%s: no IO timings\n", __func__);
193                         goto err_notpossible;
194                 }
195         }
196
197         s3c_cpufreq_show("new", &cpu_new);
198
199         /* setup our cpufreq parameters */
200
201         freqs.old = cpu_cur.freq;
202         freqs.new = cpu_new.freq;
203
204         freqs.freqs.old = cpu_cur.freq.armclk / 1000;
205         freqs.freqs.new = cpu_new.freq.armclk / 1000;
206
207         /* update f/h/p clock settings before we issue the change
208          * notification, so that drivers do not need to do anything
209          * special if they want to recalculate on CPUFREQ_PRECHANGE. */
210
211         s3c_cpufreq_updateclk(_clk_mpll, cpu_new.pll.frequency);
212         s3c_cpufreq_updateclk(clk_fclk, cpu_new.freq.fclk);
213         s3c_cpufreq_updateclk(clk_hclk, cpu_new.freq.hclk);
214         s3c_cpufreq_updateclk(clk_pclk, cpu_new.freq.pclk);
215
216         /* start the frequency change */
217         cpufreq_freq_transition_begin(policy, &freqs.freqs);
218
219         /* If hclk is staying the same, then we do not need to
220          * re-write the IO or the refresh timings whilst we are changing
221          * speed. */
222
223         local_irq_save(flags);
224
225         /* is our memory clock slowing down? */
226         if (cpu_new.freq.hclk < cpu_cur.freq.hclk) {
227                 s3c_cpufreq_setrefresh(&cpu_new);
228                 s3c_cpufreq_setio(&cpu_new);
229         }
230
231         if (cpu_new.freq.fclk == cpu_cur.freq.fclk) {
232                 /* not changing PLL, just set the divisors */
233
234                 s3c_cpufreq_setdivs(&cpu_new);
235         } else {
236                 if (cpu_new.freq.fclk < cpu_cur.freq.fclk) {
237                         /* slow the cpu down, then set divisors */
238
239                         s3c_cpufreq_setfvco(&cpu_new);
240                         s3c_cpufreq_setdivs(&cpu_new);
241                 } else {
242                         /* set the divisors, then speed up */
243
244                         s3c_cpufreq_setdivs(&cpu_new);
245                         s3c_cpufreq_setfvco(&cpu_new);
246                 }
247         }
248
249         /* did our memory clock speed up */
250         if (cpu_new.freq.hclk > cpu_cur.freq.hclk) {
251                 s3c_cpufreq_setrefresh(&cpu_new);
252                 s3c_cpufreq_setio(&cpu_new);
253         }
254
255         /* update our current settings */
256         cpu_cur = cpu_new;
257
258         local_irq_restore(flags);
259
260         /* notify everyone we've done this */
261         cpufreq_freq_transition_end(policy, &freqs.freqs, 0);
262
263         s3c_freq_dbg("%s: finished\n", __func__);
264         return 0;
265
266  err_notpossible:
267         pr_err("no compatible settings for %d\n", target_freq);
268         return -EINVAL;
269 }
270
271 /* s3c_cpufreq_target
272  *
273  * called by the cpufreq core to adjust the frequency that the CPU
274  * is currently running at.
275  */
276
277 static int s3c_cpufreq_target(struct cpufreq_policy *policy,
278                               unsigned int target_freq,
279                               unsigned int relation)
280 {
281         struct cpufreq_frequency_table *pll;
282         unsigned int index;
283
284         /* avoid repeated calls which cause a needless amout of duplicated
285          * logging output (and CPU time as the calculation process is
286          * done) */
287         if (target_freq == last_target)
288                 return 0;
289
290         last_target = target_freq;
291
292         s3c_freq_dbg("%s: policy %p, target %u, relation %u\n",
293                      __func__, policy, target_freq, relation);
294
295         if (ftab) {
296                 index = cpufreq_frequency_table_target(policy, target_freq,
297                                                        relation);
298
299                 s3c_freq_dbg("%s: adjust %d to entry %d (%u)\n", __func__,
300                              target_freq, index, ftab[index].frequency);
301                 target_freq = ftab[index].frequency;
302         }
303
304         target_freq *= 1000;  /* convert target to Hz */
305
306         /* find the settings for our new frequency */
307
308         if (!pll_reg || cpu_cur.lock_pll) {
309                 /* either we've not got any PLL values, or we've locked
310                  * to the current one. */
311                 pll = NULL;
312         } else {
313                 struct cpufreq_policy tmp_policy;
314
315                 /* we keep the cpu pll table in Hz, to ensure we get an
316                  * accurate value for the PLL output. */
317
318                 tmp_policy.min = policy->min * 1000;
319                 tmp_policy.max = policy->max * 1000;
320                 tmp_policy.cpu = policy->cpu;
321                 tmp_policy.freq_table = pll_reg;
322
323                 /* cpufreq_frequency_table_target returns the index
324                  * of the table entry, not the value of
325                  * the table entry's index field. */
326
327                 index = cpufreq_frequency_table_target(&tmp_policy, target_freq,
328                                                        relation);
329                 pll = pll_reg + index;
330
331                 s3c_freq_dbg("%s: target %u => %u\n",
332                              __func__, target_freq, pll->frequency);
333
334                 target_freq = pll->frequency;
335         }
336
337         return s3c_cpufreq_settarget(policy, target_freq, pll);
338 }
339
340 struct clk *s3c_cpufreq_clk_get(struct device *dev, const char *name)
341 {
342         struct clk *clk;
343
344         clk = clk_get(dev, name);
345         if (IS_ERR(clk))
346                 pr_err("failed to get clock '%s'\n", name);
347
348         return clk;
349 }
350
351 static int s3c_cpufreq_init(struct cpufreq_policy *policy)
352 {
353         policy->clk = clk_arm;
354         return cpufreq_generic_init(policy, ftab, cpu_cur.info->latency);
355 }
356
357 static int __init s3c_cpufreq_initclks(void)
358 {
359         _clk_mpll = s3c_cpufreq_clk_get(NULL, "mpll");
360         _clk_xtal = s3c_cpufreq_clk_get(NULL, "xtal");
361         clk_fclk = s3c_cpufreq_clk_get(NULL, "fclk");
362         clk_hclk = s3c_cpufreq_clk_get(NULL, "hclk");
363         clk_pclk = s3c_cpufreq_clk_get(NULL, "pclk");
364         clk_arm = s3c_cpufreq_clk_get(NULL, "armclk");
365
366         if (IS_ERR(clk_fclk) || IS_ERR(clk_hclk) || IS_ERR(clk_pclk) ||
367             IS_ERR(_clk_mpll) || IS_ERR(clk_arm) || IS_ERR(_clk_xtal)) {
368                 pr_err("%s: could not get clock(s)\n", __func__);
369                 return -ENOENT;
370         }
371
372         pr_info("%s: clocks f=%lu,h=%lu,p=%lu,a=%lu\n",
373                 __func__,
374                 clk_get_rate(clk_fclk) / 1000,
375                 clk_get_rate(clk_hclk) / 1000,
376                 clk_get_rate(clk_pclk) / 1000,
377                 clk_get_rate(clk_arm) / 1000);
378
379         return 0;
380 }
381
382 #ifdef CONFIG_PM
383 static struct cpufreq_frequency_table suspend_pll;
384 static unsigned int suspend_freq;
385
386 static int s3c_cpufreq_suspend(struct cpufreq_policy *policy)
387 {
388         suspend_pll.frequency = clk_get_rate(_clk_mpll);
389         suspend_pll.driver_data = __raw_readl(S3C2410_MPLLCON);
390         suspend_freq = clk_get_rate(clk_arm);
391
392         return 0;
393 }
394
395 static int s3c_cpufreq_resume(struct cpufreq_policy *policy)
396 {
397         int ret;
398
399         s3c_freq_dbg("%s: resuming with policy %p\n", __func__, policy);
400
401         last_target = ~0;       /* invalidate last_target setting */
402
403         /* whilst we will be called later on, we try and re-set the
404          * cpu frequencies as soon as possible so that we do not end
405          * up resuming devices and then immediately having to re-set
406          * a number of settings once these devices have restarted.
407          *
408          * as a note, it is expected devices are not used until they
409          * have been un-suspended and at that time they should have
410          * used the updated clock settings.
411          */
412
413         ret = s3c_cpufreq_settarget(NULL, suspend_freq, &suspend_pll);
414         if (ret) {
415                 pr_err("%s: failed to reset pll/freq\n", __func__);
416                 return ret;
417         }
418
419         return 0;
420 }
421 #else
422 #define s3c_cpufreq_resume NULL
423 #define s3c_cpufreq_suspend NULL
424 #endif
425
426 static struct cpufreq_driver s3c24xx_driver = {
427         .flags          = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
428         .target         = s3c_cpufreq_target,
429         .get            = cpufreq_generic_get,
430         .init           = s3c_cpufreq_init,
431         .suspend        = s3c_cpufreq_suspend,
432         .resume         = s3c_cpufreq_resume,
433         .name           = "s3c24xx",
434 };
435
436
437 int s3c_cpufreq_register(struct s3c_cpufreq_info *info)
438 {
439         if (!info || !info->name) {
440                 pr_err("%s: failed to pass valid information\n", __func__);
441                 return -EINVAL;
442         }
443
444         pr_info("S3C24XX CPU Frequency driver, %s cpu support\n",
445                 info->name);
446
447         /* check our driver info has valid data */
448
449         BUG_ON(info->set_refresh == NULL);
450         BUG_ON(info->set_divs == NULL);
451         BUG_ON(info->calc_divs == NULL);
452
453         /* info->set_fvco is optional, depending on whether there
454          * is a need to set the clock code. */
455
456         cpu_cur.info = info;
457
458         /* Note, driver registering should probably update locktime */
459
460         return 0;
461 }
462
463 int __init s3c_cpufreq_setboard(struct s3c_cpufreq_board *board)
464 {
465         struct s3c_cpufreq_board *ours;
466
467         if (!board) {
468                 pr_info("%s: no board data\n", __func__);
469                 return -EINVAL;
470         }
471
472         /* Copy the board information so that each board can make this
473          * initdata. */
474
475         ours = kzalloc(sizeof(*ours), GFP_KERNEL);
476         if (ours == NULL) {
477                 pr_err("%s: no memory\n", __func__);
478                 return -ENOMEM;
479         }
480
481         *ours = *board;
482         cpu_cur.board = ours;
483
484         return 0;
485 }
486
487 static int __init s3c_cpufreq_auto_io(void)
488 {
489         int ret;
490
491         if (!cpu_cur.info->get_iotiming) {
492                 pr_err("%s: get_iotiming undefined\n", __func__);
493                 return -ENOENT;
494         }
495
496         pr_info("%s: working out IO settings\n", __func__);
497
498         ret = (cpu_cur.info->get_iotiming)(&cpu_cur, &s3c24xx_iotiming);
499         if (ret)
500                 pr_err("%s: failed to get timings\n", __func__);
501
502         return ret;
503 }
504
505 /* if one or is zero, then return the other, otherwise return the min */
506 #define do_min(_a, _b) ((_a) == 0 ? (_b) : (_b) == 0 ? (_a) : min(_a, _b))
507
508 /**
509  * s3c_cpufreq_freq_min - find the minimum settings for the given freq.
510  * @dst: The destination structure
511  * @a: One argument.
512  * @b: The other argument.
513  *
514  * Create a minimum of each frequency entry in the 'struct s3c_freq',
515  * unless the entry is zero when it is ignored and the non-zero argument
516  * used.
517  */
518 static void s3c_cpufreq_freq_min(struct s3c_freq *dst,
519                                  struct s3c_freq *a, struct s3c_freq *b)
520 {
521         dst->fclk = do_min(a->fclk, b->fclk);
522         dst->hclk = do_min(a->hclk, b->hclk);
523         dst->pclk = do_min(a->pclk, b->pclk);
524         dst->armclk = do_min(a->armclk, b->armclk);
525 }
526
527 static inline u32 calc_locktime(u32 freq, u32 time_us)
528 {
529         u32 result;
530
531         result = freq * time_us;
532         result = DIV_ROUND_UP(result, 1000 * 1000);
533
534         return result;
535 }
536
537 static void s3c_cpufreq_update_loctkime(void)
538 {
539         unsigned int bits = cpu_cur.info->locktime_bits;
540         u32 rate = (u32)clk_get_rate(_clk_xtal);
541         u32 val;
542
543         if (bits == 0) {
544                 WARN_ON(1);
545                 return;
546         }
547
548         val = calc_locktime(rate, cpu_cur.info->locktime_u) << bits;
549         val |= calc_locktime(rate, cpu_cur.info->locktime_m);
550
551         pr_info("%s: new locktime is 0x%08x\n", __func__, val);
552         __raw_writel(val, S3C2410_LOCKTIME);
553 }
554
555 static int s3c_cpufreq_build_freq(void)
556 {
557         int size, ret;
558
559         kfree(ftab);
560
561         size = cpu_cur.info->calc_freqtable(&cpu_cur, NULL, 0);
562         size++;
563
564         ftab = kzalloc(sizeof(*ftab) * size, GFP_KERNEL);
565         if (!ftab) {
566                 pr_err("%s: no memory for tables\n", __func__);
567                 return -ENOMEM;
568         }
569
570         ftab_size = size;
571
572         ret = cpu_cur.info->calc_freqtable(&cpu_cur, ftab, size);
573         s3c_cpufreq_addfreq(ftab, ret, size, CPUFREQ_TABLE_END);
574
575         return 0;
576 }
577
578 static int __init s3c_cpufreq_initcall(void)
579 {
580         int ret = 0;
581
582         if (cpu_cur.info && cpu_cur.board) {
583                 ret = s3c_cpufreq_initclks();
584                 if (ret)
585                         goto out;
586
587                 /* get current settings */
588                 s3c_cpufreq_getcur(&cpu_cur);
589                 s3c_cpufreq_show("cur", &cpu_cur);
590
591                 if (cpu_cur.board->auto_io) {
592                         ret = s3c_cpufreq_auto_io();
593                         if (ret) {
594                                 pr_err("%s: failed to get io timing\n",
595                                        __func__);
596                                 goto out;
597                         }
598                 }
599
600                 if (cpu_cur.board->need_io && !cpu_cur.info->set_iotiming) {
601                         pr_err("%s: no IO support registered\n", __func__);
602                         ret = -EINVAL;
603                         goto out;
604                 }
605
606                 if (!cpu_cur.info->need_pll)
607                         cpu_cur.lock_pll = 1;
608
609                 s3c_cpufreq_update_loctkime();
610
611                 s3c_cpufreq_freq_min(&cpu_cur.max, &cpu_cur.board->max,
612                                      &cpu_cur.info->max);
613
614                 if (cpu_cur.info->calc_freqtable)
615                         s3c_cpufreq_build_freq();
616
617                 ret = cpufreq_register_driver(&s3c24xx_driver);
618         }
619
620  out:
621         return ret;
622 }
623
624 late_initcall(s3c_cpufreq_initcall);
625
626 /**
627  * s3c_plltab_register - register CPU PLL table.
628  * @plls: The list of PLL entries.
629  * @plls_no: The size of the PLL entries @plls.
630  *
631  * Register the given set of PLLs with the system.
632  */
633 int s3c_plltab_register(struct cpufreq_frequency_table *plls,
634                                unsigned int plls_no)
635 {
636         struct cpufreq_frequency_table *vals;
637         unsigned int size;
638
639         size = sizeof(*vals) * (plls_no + 1);
640
641         vals = kzalloc(size, GFP_KERNEL);
642         if (vals) {
643                 memcpy(vals, plls, size);
644                 pll_reg = vals;
645
646                 /* write a terminating entry, we don't store it in the
647                  * table that is stored in the kernel */
648                 vals += plls_no;
649                 vals->frequency = CPUFREQ_TABLE_END;
650
651                 pr_info("%d PLL entries\n", plls_no);
652         } else
653                 pr_err("no memory for PLL tables\n");
654
655         return vals ? 0 : -ENOMEM;
656 }