SAFE public projects git trees. - safe/jmp/linux-2.6/blob - arch/arm/plat-s3c24xx/cpu-freq.c

   1 /* linux/arch/arm/plat-s3c24xx/cpu-freq.c
   2  *
   3  * Copyright (c) 2006,2007,2008 Simtec Electronics
   4  *      http://armlinux.simtec.co.uk/
   5  *      Ben Dooks <ben@simtec.co.uk>
   6  *
   7  * S3C24XX CPU Frequency scaling
   8  *
   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.
  12 */
  13
  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
  27 #include <asm/mach/arch.h>
  28 #include <asm/mach/map.h>
  29
  30 #include <plat/cpu.h>
  31 #include <plat/clock.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 static void s3c_cpufreq_getcur(struct s3c_cpufreq_config *cfg)
  54 {
  55         unsigned long fclk, pclk, hclk, armclk;
  56
  57         cfg->freq.fclk = fclk = clk_get_rate(clk_fclk);
  58         cfg->freq.hclk = hclk = clk_get_rate(clk_hclk);
  59         cfg->freq.pclk = pclk = clk_get_rate(clk_pclk);
  60         cfg->freq.armclk = armclk = clk_get_rate(clk_arm);
  61
  62         cfg->pll.index = __raw_readl(S3C2410_MPLLCON);
  63         cfg->pll.frequency = fclk;
  64
  65         cfg->freq.hclk_tns = 1000000000 / (cfg->freq.hclk / 10);
  66
  67         cfg->divs.h_divisor = fclk / hclk;
  68         cfg->divs.p_divisor = fclk / pclk;
  69 }
  70
  71 static inline void s3c_cpufreq_calc(struct s3c_cpufreq_config *cfg)
  72 {
  73         unsigned long pll = cfg->pll.frequency;
  74
  75         cfg->freq.fclk = pll;
  76         cfg->freq.hclk = pll / cfg->divs.h_divisor;
  77         cfg->freq.pclk = pll / cfg->divs.p_divisor;
  78
  79         /* convert hclk into 10ths of nanoseconds for io calcs */
  80         cfg->freq.hclk_tns = 1000000000 / (cfg->freq.hclk / 10);
  81 }
  82
  83 static inline int closer(unsigned int target, unsigned int n, unsigned int c)
  84 {
  85         int diff_cur = abs(target - c);
  86         int diff_new = abs(target - n);
  87
  88         return (diff_new < diff_cur);
  89 }
  90
  91 static void s3c_cpufreq_show(const char *pfx,
  92                                  struct s3c_cpufreq_config *cfg)
  93 {
  94         s3c_freq_dbg("%s: Fvco=%u, F=%lu, A=%lu, H=%lu (%u), P=%lu (%u)\n",
  95                      pfx, cfg->pll.frequency, cfg->freq.fclk, cfg->freq.armclk,
  96                      cfg->freq.hclk, cfg->divs.h_divisor,
  97                      cfg->freq.pclk, cfg->divs.p_divisor);
  98 }
  99
 100 /* functions to wrapper the driver info calls to do the cpu specific work */
 101
 102 static void s3c_cpufreq_setio(struct s3c_cpufreq_config *cfg)
 103 {
 104         if (cfg->info->set_iotiming)
 105                 (cfg->info->set_iotiming)(cfg, &s3c24xx_iotiming);
 106 }
 107
 108 static int s3c_cpufreq_calcio(struct s3c_cpufreq_config *cfg)
 109 {
 110         if (cfg->info->calc_iotiming)
 111                 return (cfg->info->calc_iotiming)(cfg, &s3c24xx_iotiming);
 112
 113         return 0;
 114 }
 115
 116 static void s3c_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg)
 117 {
 118         (cfg->info->set_refresh)(cfg);
 119 }
 120
 121 static void s3c_cpufreq_setdivs(struct s3c_cpufreq_config *cfg)
 122 {
 123         (cfg->info->set_divs)(cfg);
 124 }
 125
 126 static int s3c_cpufreq_calcdivs(struct s3c_cpufreq_config *cfg)
 127 {
 128         return (cfg->info->calc_divs)(cfg);
 129 }
 130
 131 static void s3c_cpufreq_setfvco(struct s3c_cpufreq_config *cfg)
 132 {
 133         (cfg->info->set_fvco)(cfg);
 134 }
 135
 136 static inline void s3c_cpufreq_resume_clocks(void)
 137 {
 138         cpu_cur.info->resume_clocks();
 139 }
 140
 141 static inline void s3c_cpufreq_updateclk(struct clk *clk,
 142                                          unsigned int freq)
 143 {
 144         clk_set_rate(clk, freq);
 145 }
 146
 147 static int s3c_cpufreq_settarget(struct cpufreq_policy *policy,
 148                                  unsigned int target_freq,
 149                                  struct cpufreq_frequency_table *pll)
 150 {
 151         struct s3c_cpufreq_freqs freqs;
 152         struct s3c_cpufreq_config cpu_new;
 153         unsigned long flags;
 154
 155         cpu_new = cpu_cur;  /* copy new from current */
 156
 157         s3c_cpufreq_show("cur", &cpu_cur);
 158
 159         /* TODO - check for DMA currently outstanding */
 160
 161         cpu_new.pll = pll ? *pll : cpu_cur.pll;
 162
 163         if (pll)
 164                 freqs.pll_changing = 1;
 165
 166         /* update our frequencies */
 167
 168         cpu_new.freq.armclk = target_freq;
 169         cpu_new.freq.fclk = cpu_new.pll.frequency;
 170
 171         if (s3c_cpufreq_calcdivs(&cpu_new) < 0) {
 172                 printk(KERN_ERR "no divisors for %d\n", target_freq);
 173                 goto err_notpossible;
 174         }
 175
 176         s3c_freq_dbg("%s: got divs\n", __func__);
 177
 178         s3c_cpufreq_calc(&cpu_new);
 179
 180         s3c_freq_dbg("%s: calculated frequencies for new\n", __func__);
 181
 182         if (cpu_new.freq.hclk != cpu_cur.freq.hclk) {
 183                 if (s3c_cpufreq_calcio(&cpu_new) < 0) {
 184                         printk(KERN_ERR "%s: no IO timings\n", __func__);
 185                         goto err_notpossible;
 186                 }
 187         }
 188
 189         s3c_cpufreq_show("new", &cpu_new);
 190
 191         /* setup our cpufreq parameters */
 192
 193         freqs.old = cpu_cur.freq;
 194         freqs.new = cpu_new.freq;
 195
 196         freqs.freqs.cpu = 0;
 197         freqs.freqs.old = cpu_cur.freq.armclk / 1000;
 198         freqs.freqs.new = cpu_new.freq.armclk / 1000;
 199
 200         /* update f/h/p clock settings before we issue the change
 201          * notification, so that drivers do not need to do anything
 202          * special if they want to recalculate on CPUFREQ_PRECHANGE. */
 203
 204         s3c_cpufreq_updateclk(_clk_mpll, cpu_new.pll.frequency);
 205         s3c_cpufreq_updateclk(clk_fclk, cpu_new.freq.fclk);
 206         s3c_cpufreq_updateclk(clk_hclk, cpu_new.freq.hclk);
 207         s3c_cpufreq_updateclk(clk_pclk, cpu_new.freq.pclk);
 208
 209         /* start the frequency change */
 210
 211         if (policy)
 212                 cpufreq_notify_transition(&freqs.freqs, CPUFREQ_PRECHANGE);
 213
 214         /* If hclk is staying the same, then we do not need to
 215          * re-write the IO or the refresh timings whilst we are changing
 216          * speed. */
 217
 218         local_irq_save(flags);
 219
 220         /* is our memory clock slowing down? */
 221         if (cpu_new.freq.hclk < cpu_cur.freq.hclk) {
 222                 s3c_cpufreq_setrefresh(&cpu_new);
 223                 s3c_cpufreq_setio(&cpu_new);
 224         }
 225
 226         if (cpu_new.freq.fclk == cpu_cur.freq.fclk) {
 227                 /* not changing PLL, just set the divisors */
 228
 229                 s3c_cpufreq_setdivs(&cpu_new);
 230         } else {
 231                 if (cpu_new.freq.fclk < cpu_cur.freq.fclk) {
 232                         /* slow the cpu down, then set divisors */
 233
 234                         s3c_cpufreq_setfvco(&cpu_new);
 235                         s3c_cpufreq_setdivs(&cpu_new);
 236                 } else {
 237                         /* set the divisors, then speed up */
 238
 239                         s3c_cpufreq_setdivs(&cpu_new);
 240                         s3c_cpufreq_setfvco(&cpu_new);
 241                 }
 242         }
 243
 244         /* did our memory clock speed up */
 245         if (cpu_new.freq.hclk > cpu_cur.freq.hclk) {
 246                 s3c_cpufreq_setrefresh(&cpu_new);
 247                 s3c_cpufreq_setio(&cpu_new);
 248         }
 249
 250         /* update our current settings */
 251         cpu_cur = cpu_new;
 252
 253         local_irq_restore(flags);
 254
 255         /* notify everyone we've done this */
 256         if (policy)
 257                 cpufreq_notify_transition(&freqs.freqs, CPUFREQ_POSTCHANGE);
 258
 259         s3c_freq_dbg("%s: finished\n", __func__);
 260         return 0;
 261
 262  err_notpossible:
 263         printk(KERN_ERR "no compatible settings for %d\n", target_freq);
 264         return -EINVAL;
 265 }
 266
 267 /* s3c_cpufreq_target
 268  *
 269  * called by the cpufreq core to adjust the frequency that the CPU
 270  * is currently running at.
 271  */
 272
 273 static int s3c_cpufreq_target(struct cpufreq_policy *policy,
 274                               unsigned int target_freq,
 275                               unsigned int relation)
 276 {
 277         struct cpufreq_frequency_table *pll;
 278         unsigned int index;
 279
 280         /* avoid repeated calls which cause a needless amout of duplicated
 281          * logging output (and CPU time as the calculation process is
 282          * done) */
 283         if (target_freq == last_target)
 284                 return 0;
 285
 286         last_target = target_freq;
 287
 288         s3c_freq_dbg("%s: policy %p, target %u, relation %u\n",
 289                      __func__, policy, target_freq, relation);
 290
 291         if (ftab) {
 292                 if (cpufreq_frequency_table_target(policy, ftab,
 293                                                    target_freq, relation,
 294                                                    &index)) {
 295                         s3c_freq_dbg("%s: table failed\n", __func__);
 296                         return -EINVAL;
 297                 }
 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                 int ret;
 315
 316                 /* we keep the cpu pll table in Hz, to ensure we get an
 317                  * accurate value for the PLL output. */
 318
 319                 tmp_policy.min = policy->min * 1000;
 320                 tmp_policy.max = policy->max * 1000;
 321                 tmp_policy.cpu = policy->cpu;
 322
 323                 /* cpufreq_frequency_table_target uses a pointer to 'index'
 324                  * which is the number of the table entry, not the value of
 325                  * the table entry's index field. */
 326
 327                 ret = cpufreq_frequency_table_target(&tmp_policy, pll_reg,
 328                                                      target_freq, relation,
 329                                                      &index);
 330
 331                 if (ret < 0) {
 332                         printk(KERN_ERR "%s: no PLL available\n", __func__);
 333                         goto err_notpossible;
 334                 }
 335
 336                 pll = pll_reg + index;
 337
 338                 s3c_freq_dbg("%s: target %u => %u\n",
 339                              __func__, target_freq, pll->frequency);
 340
 341                 target_freq = pll->frequency;
 342         }
 343
 344         return s3c_cpufreq_settarget(policy, target_freq, pll);
 345
 346  err_notpossible:
 347         printk(KERN_ERR "no compatible settings for %d\n", target_freq);
 348         return -EINVAL;
 349 }
 350
 351 static unsigned int s3c_cpufreq_get(unsigned int cpu)
 352 {
 353         return clk_get_rate(clk_arm) / 1000;
 354 }
 355
 356 struct clk *s3c_cpufreq_clk_get(struct device *dev, const char *name)
 357 {
 358         struct clk *clk;
 359
 360         clk = clk_get(dev, name);
 361         if (IS_ERR(clk))
 362                 printk(KERN_ERR "cpufreq: failed to get clock '%s'\n", name);
 363
 364         return clk;
 365 }
 366
 367 static int s3c_cpufreq_init(struct cpufreq_policy *policy)
 368 {
 369         printk(KERN_INFO "%s: initialising policy %p\n", __func__, policy);
 370
 371         if (policy->cpu != 0)
 372                 return -EINVAL;
 373
 374         policy->cur = s3c_cpufreq_get(0);
 375         policy->min = policy->cpuinfo.min_freq = 0;
 376         policy->max = policy->cpuinfo.max_freq = cpu_cur.info->max.fclk / 1000;
 377         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 378
 379         /* feed the latency information from the cpu driver */
 380         policy->cpuinfo.transition_latency = cpu_cur.info->latency;
 381
 382         if (ftab)
 383                 cpufreq_frequency_table_cpuinfo(policy, ftab);
 384
 385         return 0;
 386 }
 387
 388 static __init int s3c_cpufreq_initclks(void)
 389 {
 390         _clk_mpll = s3c_cpufreq_clk_get(NULL, "mpll");
 391         _clk_xtal = s3c_cpufreq_clk_get(NULL, "xtal");
 392         clk_fclk = s3c_cpufreq_clk_get(NULL, "fclk");
 393         clk_hclk = s3c_cpufreq_clk_get(NULL, "hclk");
 394         clk_pclk = s3c_cpufreq_clk_get(NULL, "pclk");
 395         clk_arm = s3c_cpufreq_clk_get(NULL, "armclk");
 396
 397         if (IS_ERR(clk_fclk) || IS_ERR(clk_hclk) || IS_ERR(clk_pclk) ||
 398             IS_ERR(_clk_mpll) || IS_ERR(clk_arm) || IS_ERR(_clk_xtal)) {
 399                 printk(KERN_ERR "%s: could not get clock(s)\n", __func__);
 400                 return -ENOENT;
 401         }
 402
 403         printk(KERN_INFO "%s: clocks f=%lu,h=%lu,p=%lu,a=%lu\n", __func__,
 404                clk_get_rate(clk_fclk) / 1000,
 405                clk_get_rate(clk_hclk) / 1000,
 406                clk_get_rate(clk_pclk) / 1000,
 407                clk_get_rate(clk_arm) / 1000);
 408
 409         return 0;
 410 }
 411
 412 static int s3c_cpufreq_verify(struct cpufreq_policy *policy)
 413 {
 414         if (policy->cpu != 0)
 415                 return -EINVAL;
 416
 417         return 0;
 418 }
 419
 420 #ifdef CONFIG_PM
 421 static struct cpufreq_frequency_table suspend_pll;
 422 static unsigned int suspend_freq;
 423
 424 static int s3c_cpufreq_suspend(struct cpufreq_policy *policy, pm_message_t pmsg)
 425 {
 426         suspend_pll.frequency = clk_get_rate(_clk_mpll);
 427         suspend_pll.index = __raw_readl(S3C2410_MPLLCON);
 428         suspend_freq = s3c_cpufreq_get(0) * 1000;
 429
 430         return 0;
 431 }
 432
 433 static int s3c_cpufreq_resume(struct cpufreq_policy *policy)
 434 {
 435         int ret;
 436
 437         s3c_freq_dbg("%s: resuming with policy %p\n", __func__, policy);
 438
 439         last_target = ~0;       /* invalidate last_target setting */
 440
 441         /* first, find out what speed we resumed at. */
 442         s3c_cpufreq_resume_clocks();
 443
 444         /* whilst we will be called later on, we try and re-set the
 445          * cpu frequencies as soon as possible so that we do not end
 446          * up resuming devices and then immediatley having to re-set
 447          * a number of settings once these devices have restarted.
 448          *
 449          * as a note, it is expected devices are not used until they
 450          * have been un-suspended and at that time they should have
 451          * used the updated clock settings.
 452          */
 453
 454         ret = s3c_cpufreq_settarget(NULL, suspend_freq, &suspend_pll);
 455         if (ret) {
 456                 printk(KERN_ERR "%s: failed to reset pll/freq\n", __func__);
 457                 return ret;
 458         }
 459
 460         return 0;
 461 }
 462 #else
 463 #define s3c_cpufreq_resume NULL
 464 #define s3c_cpufreq_suspend NULL
 465 #endif
 466
 467 static struct cpufreq_driver s3c24xx_driver = {
 468         .flags          = CPUFREQ_STICKY,
 469         .verify         = s3c_cpufreq_verify,
 470         .target         = s3c_cpufreq_target,
 471         .get            = s3c_cpufreq_get,
 472         .init           = s3c_cpufreq_init,
 473         .suspend        = s3c_cpufreq_suspend,
 474         .resume         = s3c_cpufreq_resume,
 475         .name           = "s3c24xx",
 476 };
 477
 478
 479 int __init s3c_cpufreq_register(struct s3c_cpufreq_info *info)
 480 {
 481         if (!info || !info->name) {
 482                 printk(KERN_ERR "%s: failed to pass valid information\n",
 483                        __func__);
 484                 return -EINVAL;
 485         }
 486
 487         printk(KERN_INFO "S3C24XX CPU Frequency driver, %s cpu support\n",
 488                info->name);
 489
 490         /* check our driver info has valid data */
 491
 492         BUG_ON(info->set_refresh == NULL);
 493         BUG_ON(info->set_divs == NULL);
 494         BUG_ON(info->calc_divs == NULL);
 495
 496         /* info->set_fvco is optional, depending on whether there
 497          * is a need to set the clock code. */
 498
 499         cpu_cur.info = info;
 500
 501         /* Note, driver registering should probably update locktime */
 502
 503         return 0;
 504 }
 505
 506 int __init s3c_cpufreq_setboard(struct s3c_cpufreq_board *board)
 507 {
 508         struct s3c_cpufreq_board *ours;
 509
 510         if (!board) {
 511                 printk(KERN_INFO "%s: no board data\n", __func__);
 512                 return -EINVAL;
 513         }
 514
 515         /* Copy the board information so that each board can make this
 516          * initdata. */
 517
 518         ours = kzalloc(sizeof(struct s3c_cpufreq_board), GFP_KERNEL);
 519         if (ours == NULL) {
 520                 printk(KERN_ERR "%s: no memory\n", __func__);
 521                 return -ENOMEM;
 522         }
 523
 524         *ours = *board;
 525         cpu_cur.board = ours;
 526
 527         return 0;
 528 }
 529
 530 int __init s3c_cpufreq_auto_io(void)
 531 {
 532         int ret;
 533
 534         if (!cpu_cur.info->get_iotiming) {
 535                 printk(KERN_ERR "%s: get_iotiming undefined\n", __func__);
 536                 return -ENOENT;
 537         }
 538
 539         printk(KERN_INFO "%s: working out IO settings\n", __func__);
 540
 541         ret = (cpu_cur.info->get_iotiming)(&cpu_cur, &s3c24xx_iotiming);
 542         if (ret)
 543                 printk(KERN_ERR "%s: failed to get timings\n", __func__);
 544
 545         return ret;
 546 }
 547
 548 /* if one or is zero, then return the other, otherwise return the min */
 549 #define do_min(_a, _b) ((_a) == 0 ? (_b) : (_b) == 0 ? (_a) : min(_a, _b))
 550
 551 /**
 552  * s3c_cpufreq_freq_min - find the minimum settings for the given freq.
 553  * @dst: The destination structure
 554  * @a: One argument.
 555  * @b: The other argument.
 556  *
 557  * Create a minimum of each frequency entry in the 'struct s3c_freq',
 558  * unless the entry is zero when it is ignored and the non-zero argument
 559  * used.
 560  */
 561 static void s3c_cpufreq_freq_min(struct s3c_freq *dst,
 562                                  struct s3c_freq *a, struct s3c_freq *b)
 563 {
 564         dst->fclk = do_min(a->fclk, b->fclk);
 565         dst->hclk = do_min(a->hclk, b->hclk);
 566         dst->pclk = do_min(a->pclk, b->pclk);
 567         dst->armclk = do_min(a->armclk, b->armclk);
 568 }
 569
 570 static inline u32 calc_locktime(u32 freq, u32 time_us)
 571 {
 572         u32 result;
 573
 574         result = freq * time_us;
 575         result = DIV_ROUND_UP(result, 1000 * 1000);
 576
 577         return result;
 578 }
 579
 580 static void s3c_cpufreq_update_loctkime(void)
 581 {
 582         unsigned int bits = cpu_cur.info->locktime_bits;
 583         u32 rate = (u32)clk_get_rate(_clk_xtal);
 584         u32 val;
 585
 586         if (bits == 0) {
 587                 WARN_ON(1);
 588                 return;
 589         }
 590
 591         val = calc_locktime(rate, cpu_cur.info->locktime_u) << bits;
 592         val |= calc_locktime(rate, cpu_cur.info->locktime_m);
 593
 594         printk(KERN_INFO "%s: new locktime is 0x%08x\n", __func__, val);
 595         __raw_writel(val, S3C2410_LOCKTIME);
 596 }
 597
 598 static int s3c_cpufreq_build_freq(void)
 599 {
 600         int size, ret;
 601
 602         if (!cpu_cur.info->calc_freqtable)
 603                 return -EINVAL;
 604
 605         kfree(ftab);
 606         ftab = NULL;
 607
 608         size = cpu_cur.info->calc_freqtable(&cpu_cur, NULL, 0);
 609         size++;
 610
 611         ftab = kmalloc(sizeof(struct cpufreq_frequency_table) * size, GFP_KERNEL);
 612         if (!ftab) {
 613                 printk(KERN_ERR "%s: no memory for tables\n", __func__);
 614                 return -ENOMEM;
 615         }
 616
 617         ftab_size = size;
 618
 619         ret = cpu_cur.info->calc_freqtable(&cpu_cur, ftab, size);
 620         s3c_cpufreq_addfreq(ftab, ret, size, CPUFREQ_TABLE_END);
 621
 622         return 0;
 623 }
 624
 625 static int __init s3c_cpufreq_initcall(void)
 626 {
 627         int ret = 0;
 628
 629         if (cpu_cur.info && cpu_cur.board) {
 630                 ret = s3c_cpufreq_initclks();
 631                 if (ret)
 632                         goto out;
 633
 634                 /* get current settings */
 635                 s3c_cpufreq_getcur(&cpu_cur);
 636                 s3c_cpufreq_show("cur", &cpu_cur);
 637
 638                 if (cpu_cur.board->auto_io) {
 639                         ret = s3c_cpufreq_auto_io();
 640                         if (ret) {
 641                                 printk(KERN_ERR "%s: failed to get io timing\n",
 642                                        __func__);
 643                                 goto out;
 644                         }
 645                 }
 646
 647                 if (cpu_cur.board->need_io && !cpu_cur.info->set_iotiming) {
 648                         printk(KERN_ERR "%s: no IO support registered\n",
 649                                __func__);
 650                         ret = -EINVAL;
 651                         goto out;
 652                 }
 653
 654                 if (!cpu_cur.info->need_pll)
 655                         cpu_cur.lock_pll = 1;
 656
 657                 s3c_cpufreq_update_loctkime();
 658
 659                 s3c_cpufreq_freq_min(&cpu_cur.max, &cpu_cur.board->max,
 660                                      &cpu_cur.info->max);
 661
 662                 if (cpu_cur.info->calc_freqtable)
 663                         s3c_cpufreq_build_freq();
 664
 665                 ret = cpufreq_register_driver(&s3c24xx_driver);
 666         }
 667
 668  out:
 669         return ret;
 670 }
 671
 672 late_initcall(s3c_cpufreq_initcall);
 673
 674 /**
 675  * s3c_plltab_register - register CPU PLL table.
 676  * @plls: The list of PLL entries.
 677  * @plls_no: The size of the PLL entries @plls.
 678  *
 679  * Register the given set of PLLs with the system.
 680  */
 681 int __init s3c_plltab_register(struct cpufreq_frequency_table *plls,
 682                                unsigned int plls_no)
 683 {
 684         struct cpufreq_frequency_table *vals;
 685         unsigned int size;
 686
 687         size = sizeof(struct cpufreq_frequency_table) * (plls_no + 1);
 688
 689         vals = kmalloc(size, GFP_KERNEL);
 690         if (vals) {
 691                 memcpy(vals, plls, size);
 692                 pll_reg = vals;
 693
 694                 /* write a terminating entry, we don't store it in the
 695                  * table that is stored in the kernel */
 696                 vals += plls_no;
 697                 vals->frequency = CPUFREQ_TABLE_END;
 698
 699                 printk(KERN_INFO "cpufreq: %d PLL entries\n", plls_no);
 700         } else
 701                 printk(KERN_ERR "cpufreq: no memory for PLL tables\n");
 702
 703         return vals ? 0 : -ENOMEM;
 704 }