arch/arm/plat-s3c24xx/cpu-freq.c

   1 /* linux/arch/arm/plat-s3c24xx/cpu-freq.c
   2  *
   3  * Copyright (c) 2006-2008 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/sysfs.h>
  25 #include <linux/slab.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 #ifdef CONFIG_CPU_FREQ_S3C24XX_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_CPU_FREQ_S3C24XX_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.index = __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->info->set_fvco)(cfg);
 146 }
 147
 148 static inline void s3c_cpufreq_resume_clocks(void)
 149 {
 150         cpu_cur.info->resume_clocks();
 151 }
 152
 153 static inline void s3c_cpufreq_updateclk(struct clk *clk,
 154                                          unsigned int freq)
 155 {
 156         clk_set_rate(clk, freq);
 157 }
 158
 159 static int s3c_cpufreq_settarget(struct cpufreq_policy *policy,
 160                                  unsigned int target_freq,
 161                                  struct cpufreq_frequency_table *pll)
 162 {
 163         struct s3c_cpufreq_freqs freqs;
 164         struct s3c_cpufreq_config cpu_new;
 165         unsigned long flags;
 166
 167         cpu_new = cpu_cur;  /* copy new from current */
 168
 169         s3c_cpufreq_show("cur", &cpu_cur);
 170
 171         /* TODO - check for DMA currently outstanding */
 172
 173         cpu_new.pll = pll ? *pll : cpu_cur.pll;
 174
 175         if (pll)
 176                 freqs.pll_changing = 1;
 177
 178         /* update our frequencies */
 179
 180         cpu_new.freq.armclk = target_freq;
 181         cpu_new.freq.fclk = cpu_new.pll.frequency;
 182
 183         if (s3c_cpufreq_calcdivs(&cpu_new) < 0) {
 184                 printk(KERN_ERR "no divisors for %d\n", target_freq);
 185                 goto err_notpossible;
 186         }
 187
 188         s3c_freq_dbg("%s: got divs\n", __func__);
 189
 190         s3c_cpufreq_calc(&cpu_new);
 191
 192         s3c_freq_dbg("%s: calculated frequencies for new\n", __func__);
 193
 194         if (cpu_new.freq.hclk != cpu_cur.freq.hclk) {
 195                 if (s3c_cpufreq_calcio(&cpu_new) < 0) {
 196                         printk(KERN_ERR "%s: no IO timings\n", __func__);
 197                         goto err_notpossible;
 198                 }
 199         }
 200
 201         s3c_cpufreq_show("new", &cpu_new);
 202
 203         /* setup our cpufreq parameters */
 204
 205         freqs.old = cpu_cur.freq;
 206         freqs.new = cpu_new.freq;
 207
 208         freqs.freqs.cpu = 0;
 209         freqs.freqs.old = cpu_cur.freq.armclk / 1000;
 210         freqs.freqs.new = cpu_new.freq.armclk / 1000;
 211
 212         /* update f/h/p clock settings before we issue the change
 213          * notification, so that drivers do not need to do anything
 214          * special if they want to recalculate on CPUFREQ_PRECHANGE. */
 215
 216         s3c_cpufreq_updateclk(_clk_mpll, cpu_new.pll.frequency);
 217         s3c_cpufreq_updateclk(clk_fclk, cpu_new.freq.fclk);
 218         s3c_cpufreq_updateclk(clk_hclk, cpu_new.freq.hclk);
 219         s3c_cpufreq_updateclk(clk_pclk, cpu_new.freq.pclk);
 220
 221         /* start the frequency change */
 222
 223         if (policy)
 224                 cpufreq_notify_transition(&freqs.freqs, CPUFREQ_PRECHANGE);
 225
 226         /* If hclk is staying the same, then we do not need to
 227          * re-write the IO or the refresh timings whilst we are changing
 228          * speed. */
 229
 230         local_irq_save(flags);
 231
 232         /* is our memory clock slowing down? */
 233         if (cpu_new.freq.hclk < cpu_cur.freq.hclk) {
 234                 s3c_cpufreq_setrefresh(&cpu_new);
 235                 s3c_cpufreq_setio(&cpu_new);
 236         }
 237
 238         if (cpu_new.freq.fclk == cpu_cur.freq.fclk) {
 239                 /* not changing PLL, just set the divisors */
 240
 241                 s3c_cpufreq_setdivs(&cpu_new);
 242         } else {
 243                 if (cpu_new.freq.fclk < cpu_cur.freq.fclk) {
 244                         /* slow the cpu down, then set divisors */
 245
 246                         s3c_cpufreq_setfvco(&cpu_new);
 247                         s3c_cpufreq_setdivs(&cpu_new);
 248                 } else {
 249                         /* set the divisors, then speed up */
 250
 251                         s3c_cpufreq_setdivs(&cpu_new);
 252                         s3c_cpufreq_setfvco(&cpu_new);
 253                 }
 254         }
 255
 256         /* did our memory clock speed up */
 257         if (cpu_new.freq.hclk > cpu_cur.freq.hclk) {
 258                 s3c_cpufreq_setrefresh(&cpu_new);
 259                 s3c_cpufreq_setio(&cpu_new);
 260         }
 261
 262         /* update our current settings */
 263         cpu_cur = cpu_new;
 264
 265         local_irq_restore(flags);
 266
 267         /* notify everyone we've done this */
 268         if (policy)
 269                 cpufreq_notify_transition(&freqs.freqs, CPUFREQ_POSTCHANGE);
 270
 271         s3c_freq_dbg("%s: finished\n", __func__);
 272         return 0;
 273
 274  err_notpossible:
 275         printk(KERN_ERR "no compatible settings for %d\n", target_freq);
 276         return -EINVAL;
 277 }
 278
 279 /* s3c_cpufreq_target
 280  *
 281  * called by the cpufreq core to adjust the frequency that the CPU
 282  * is currently running at.
 283  */
 284
 285 static int s3c_cpufreq_target(struct cpufreq_policy *policy,
 286                               unsigned int target_freq,
 287                               unsigned int relation)
 288 {
 289         struct cpufreq_frequency_table *pll;
 290         unsigned int index;
 291
 292         /* avoid repeated calls which cause a needless amout of duplicated
 293          * logging output (and CPU time as the calculation process is
 294          * done) */
 295         if (target_freq == last_target)
 296                 return 0;
 297
 298         last_target = target_freq;
 299
 300         s3c_freq_dbg("%s: policy %p, target %u, relation %u\n",
 301                      __func__, policy, target_freq, relation);
 302
 303         if (ftab) {
 304                 if (cpufreq_frequency_table_target(policy, ftab,
 305                                                    target_freq, relation,
 306                                                    &index)) {
 307                         s3c_freq_dbg("%s: table failed\n", __func__);
 308                         return -EINVAL;
 309                 }
 310
 311                 s3c_freq_dbg("%s: adjust %d to entry %d (%u)\n", __func__,
 312                              target_freq, index, ftab[index].frequency);
 313                 target_freq = ftab[index].frequency;
 314         }
 315
 316         target_freq *= 1000;  /* convert target to Hz */
 317
 318         /* find the settings for our new frequency */
 319
 320         if (!pll_reg || cpu_cur.lock_pll) {
 321                 /* either we've not got any PLL values, or we've locked
 322                  * to the current one. */
 323                 pll = NULL;
 324         } else {
 325                 struct cpufreq_policy tmp_policy;
 326                 int ret;
 327
 328                 /* we keep the cpu pll table in Hz, to ensure we get an
 329                  * accurate value for the PLL output. */
 330
 331                 tmp_policy.min = policy->min * 1000;
 332                 tmp_policy.max = policy->max * 1000;
 333                 tmp_policy.cpu = policy->cpu;
 334
 335                 /* cpufreq_frequency_table_target uses a pointer to 'index'
 336                  * which is the number of the table entry, not the value of
 337                  * the table entry's index field. */
 338
 339                 ret = cpufreq_frequency_table_target(&tmp_policy, pll_reg,
 340                                                      target_freq, relation,
 341                                                      &index);
 342
 343                 if (ret < 0) {
 344                         printk(KERN_ERR "%s: no PLL available\n", __func__);
 345                         goto err_notpossible;
 346                 }
 347
 348                 pll = pll_reg + index;
 349
 350                 s3c_freq_dbg("%s: target %u => %u\n",
 351                              __func__, target_freq, pll->frequency);
 352
 353                 target_freq = pll->frequency;
 354         }
 355
 356         return s3c_cpufreq_settarget(policy, target_freq, pll);
 357
 358  err_notpossible:
 359         printk(KERN_ERR "no compatible settings for %d\n", target_freq);
 360         return -EINVAL;
 361 }
 362
 363 static unsigned int s3c_cpufreq_get(unsigned int cpu)
 364 {
 365         return clk_get_rate(clk_arm) / 1000;
 366 }
 367
 368 struct clk *s3c_cpufreq_clk_get(struct device *dev, const char *name)
 369 {
 370         struct clk *clk;
 371
 372         clk = clk_get(dev, name);
 373         if (IS_ERR(clk))
 374                 printk(KERN_ERR "cpufreq: failed to get clock '%s'\n", name);
 375
 376         return clk;
 377 }
 378
 379 static int s3c_cpufreq_init(struct cpufreq_policy *policy)
 380 {
 381         printk(KERN_INFO "%s: initialising policy %p\n", __func__, policy);
 382
 383         if (policy->cpu != 0)
 384                 return -EINVAL;
 385
 386         policy->cur = s3c_cpufreq_get(0);
 387         policy->min = policy->cpuinfo.min_freq = 0;
 388         policy->max = policy->cpuinfo.max_freq = cpu_cur.info->max.fclk / 1000;
 389         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 390
 391         /* feed the latency information from the cpu driver */
 392         policy->cpuinfo.transition_latency = cpu_cur.info->latency;
 393
 394         if (ftab)
 395                 cpufreq_frequency_table_cpuinfo(policy, ftab);
 396
 397         return 0;
 398 }
 399
 400 static __init int s3c_cpufreq_initclks(void)
 401 {
 402         _clk_mpll = s3c_cpufreq_clk_get(NULL, "mpll");
 403         _clk_xtal = s3c_cpufreq_clk_get(NULL, "xtal");
 404         clk_fclk = s3c_cpufreq_clk_get(NULL, "fclk");
 405         clk_hclk = s3c_cpufreq_clk_get(NULL, "hclk");
 406         clk_pclk = s3c_cpufreq_clk_get(NULL, "pclk");
 407         clk_arm = s3c_cpufreq_clk_get(NULL, "armclk");
 408
 409         if (IS_ERR(clk_fclk) || IS_ERR(clk_hclk) || IS_ERR(clk_pclk) ||
 410             IS_ERR(_clk_mpll) || IS_ERR(clk_arm) || IS_ERR(_clk_xtal)) {
 411                 printk(KERN_ERR "%s: could not get clock(s)\n", __func__);
 412                 return -ENOENT;
 413         }
 414
 415         printk(KERN_INFO "%s: clocks f=%lu,h=%lu,p=%lu,a=%lu\n", __func__,
 416                clk_get_rate(clk_fclk) / 1000,
 417                clk_get_rate(clk_hclk) / 1000,
 418                clk_get_rate(clk_pclk) / 1000,
 419                clk_get_rate(clk_arm) / 1000);
 420
 421         return 0;
 422 }
 423
 424 static int s3c_cpufreq_verify(struct cpufreq_policy *policy)
 425 {
 426         if (policy->cpu != 0)
 427                 return -EINVAL;
 428
 429         return 0;
 430 }
 431
 432 #ifdef CONFIG_PM
 433 static struct cpufreq_frequency_table suspend_pll;
 434 static unsigned int suspend_freq;
 435
 436 static int s3c_cpufreq_suspend(struct cpufreq_policy *policy)
 437 {
 438         suspend_pll.frequency = clk_get_rate(_clk_mpll);
 439         suspend_pll.index = __raw_readl(S3C2410_MPLLCON);
 440         suspend_freq = s3c_cpufreq_get(0) * 1000;
 441
 442         return 0;
 443 }
 444
 445 static int s3c_cpufreq_resume(struct cpufreq_policy *policy)
 446 {
 447         int ret;
 448
 449         s3c_freq_dbg("%s: resuming with policy %p\n", __func__, policy);
 450
 451         last_target = ~0;       /* invalidate last_target setting */
 452
 453         /* first, find out what speed we resumed at. */
 454         s3c_cpufreq_resume_clocks();
 455
 456         /* whilst we will be called later on, we try and re-set the
 457          * cpu frequencies as soon as possible so that we do not end
 458          * up resuming devices and then immediately having to re-set
 459          * a number of settings once these devices have restarted.
 460          *
 461          * as a note, it is expected devices are not used until they
 462          * have been un-suspended and at that time they should have
 463          * used the updated clock settings.
 464          */
 465
 466         ret = s3c_cpufreq_settarget(NULL, suspend_freq, &suspend_pll);
 467         if (ret) {
 468                 printk(KERN_ERR "%s: failed to reset pll/freq\n", __func__);
 469                 return ret;
 470         }
 471
 472         return 0;
 473 }
 474 #else
 475 #define s3c_cpufreq_resume NULL
 476 #define s3c_cpufreq_suspend NULL
 477 #endif
 478
 479 static struct cpufreq_driver s3c24xx_driver = {
 480         .flags          = CPUFREQ_STICKY,
 481         .verify         = s3c_cpufreq_verify,
 482         .target         = s3c_cpufreq_target,
 483         .get            = s3c_cpufreq_get,
 484         .init           = s3c_cpufreq_init,
 485         .suspend        = s3c_cpufreq_suspend,
 486         .resume         = s3c_cpufreq_resume,
 487         .name           = "s3c24xx",
 488 };
 489
 490
 491 int __init s3c_cpufreq_register(struct s3c_cpufreq_info *info)
 492 {
 493         if (!info || !info->name) {
 494                 printk(KERN_ERR "%s: failed to pass valid information\n",
 495                        __func__);
 496                 return -EINVAL;
 497         }
 498
 499         printk(KERN_INFO "S3C24XX CPU Frequency driver, %s cpu support\n",
 500                info->name);
 501
 502         /* check our driver info has valid data */
 503
 504         BUG_ON(info->set_refresh == NULL);
 505         BUG_ON(info->set_divs == NULL);
 506         BUG_ON(info->calc_divs == NULL);
 507
 508         /* info->set_fvco is optional, depending on whether there
 509          * is a need to set the clock code. */
 510
 511         cpu_cur.info = info;
 512
 513         /* Note, driver registering should probably update locktime */
 514
 515         return 0;
 516 }
 517
 518 int __init s3c_cpufreq_setboard(struct s3c_cpufreq_board *board)
 519 {
 520         struct s3c_cpufreq_board *ours;
 521
 522         if (!board) {
 523                 printk(KERN_INFO "%s: no board data\n", __func__);
 524                 return -EINVAL;
 525         }
 526
 527         /* Copy the board information so that each board can make this
 528          * initdata. */
 529
 530         ours = kzalloc(sizeof(struct s3c_cpufreq_board), GFP_KERNEL);
 531         if (ours == NULL) {
 532                 printk(KERN_ERR "%s: no memory\n", __func__);
 533                 return -ENOMEM;
 534         }
 535
 536         *ours = *board;
 537         cpu_cur.board = ours;
 538
 539         return 0;
 540 }
 541
 542 int __init s3c_cpufreq_auto_io(void)
 543 {
 544         int ret;
 545
 546         if (!cpu_cur.info->get_iotiming) {
 547                 printk(KERN_ERR "%s: get_iotiming undefined\n", __func__);
 548                 return -ENOENT;
 549         }
 550
 551         printk(KERN_INFO "%s: working out IO settings\n", __func__);
 552
 553         ret = (cpu_cur.info->get_iotiming)(&cpu_cur, &s3c24xx_iotiming);
 554         if (ret)
 555                 printk(KERN_ERR "%s: failed to get timings\n", __func__);
 556
 557         return ret;
 558 }
 559
 560 /* if one or is zero, then return the other, otherwise return the min */
 561 #define do_min(_a, _b) ((_a) == 0 ? (_b) : (_b) == 0 ? (_a) : min(_a, _b))
 562
 563 /**
 564  * s3c_cpufreq_freq_min - find the minimum settings for the given freq.
 565  * @dst: The destination structure
 566  * @a: One argument.
 567  * @b: The other argument.
 568  *
 569  * Create a minimum of each frequency entry in the 'struct s3c_freq',
 570  * unless the entry is zero when it is ignored and the non-zero argument
 571  * used.
 572  */
 573 static void s3c_cpufreq_freq_min(struct s3c_freq *dst,
 574                                  struct s3c_freq *a, struct s3c_freq *b)
 575 {
 576         dst->fclk = do_min(a->fclk, b->fclk);
 577         dst->hclk = do_min(a->hclk, b->hclk);
 578         dst->pclk = do_min(a->pclk, b->pclk);
 579         dst->armclk = do_min(a->armclk, b->armclk);
 580 }
 581
 582 static inline u32 calc_locktime(u32 freq, u32 time_us)
 583 {
 584         u32 result;
 585
 586         result = freq * time_us;
 587         result = DIV_ROUND_UP(result, 1000 * 1000);
 588
 589         return result;
 590 }
 591
 592 static void s3c_cpufreq_update_loctkime(void)
 593 {
 594         unsigned int bits = cpu_cur.info->locktime_bits;
 595         u32 rate = (u32)clk_get_rate(_clk_xtal);
 596         u32 val;
 597
 598         if (bits == 0) {
 599                 WARN_ON(1);
 600                 return;
 601         }
 602
 603         val = calc_locktime(rate, cpu_cur.info->locktime_u) << bits;
 604         val |= calc_locktime(rate, cpu_cur.info->locktime_m);
 605
 606         printk(KERN_INFO "%s: new locktime is 0x%08x\n", __func__, val);
 607         __raw_writel(val, S3C2410_LOCKTIME);
 608 }
 609
 610 static int s3c_cpufreq_build_freq(void)
 611 {
 612         int size, ret;
 613
 614         if (!cpu_cur.info->calc_freqtable)
 615                 return -EINVAL;
 616
 617         kfree(ftab);
 618         ftab = NULL;
 619
 620         size = cpu_cur.info->calc_freqtable(&cpu_cur, NULL, 0);
 621         size++;
 622
 623         ftab = kmalloc(sizeof(struct cpufreq_frequency_table) * size, GFP_KERNEL);
 624         if (!ftab) {
 625                 printk(KERN_ERR "%s: no memory for tables\n", __func__);
 626                 return -ENOMEM;
 627         }
 628
 629         ftab_size = size;
 630
 631         ret = cpu_cur.info->calc_freqtable(&cpu_cur, ftab, size);
 632         s3c_cpufreq_addfreq(ftab, ret, size, CPUFREQ_TABLE_END);
 633
 634         return 0;
 635 }
 636
 637 static int __init s3c_cpufreq_initcall(void)
 638 {
 639         int ret = 0;
 640
 641         if (cpu_cur.info && cpu_cur.board) {
 642                 ret = s3c_cpufreq_initclks();
 643                 if (ret)
 644                         goto out;
 645
 646                 /* get current settings */
 647                 s3c_cpufreq_getcur(&cpu_cur);
 648                 s3c_cpufreq_show("cur", &cpu_cur);
 649
 650                 if (cpu_cur.board->auto_io) {
 651                         ret = s3c_cpufreq_auto_io();
 652                         if (ret) {
 653                                 printk(KERN_ERR "%s: failed to get io timing\n",
 654                                        __func__);
 655                                 goto out;
 656                         }
 657                 }
 658
 659                 if (cpu_cur.board->need_io && !cpu_cur.info->set_iotiming) {
 660                         printk(KERN_ERR "%s: no IO support registered\n",
 661                                __func__);
 662                         ret = -EINVAL;
 663                         goto out;
 664                 }
 665
 666                 if (!cpu_cur.info->need_pll)
 667                         cpu_cur.lock_pll = 1;
 668
 669                 s3c_cpufreq_update_loctkime();
 670
 671                 s3c_cpufreq_freq_min(&cpu_cur.max, &cpu_cur.board->max,
 672                                      &cpu_cur.info->max);
 673
 674                 if (cpu_cur.info->calc_freqtable)
 675                         s3c_cpufreq_build_freq();
 676
 677                 ret = cpufreq_register_driver(&s3c24xx_driver);
 678         }
 679
 680  out:
 681         return ret;
 682 }
 683
 684 late_initcall(s3c_cpufreq_initcall);
 685
 686 /**
 687  * s3c_plltab_register - register CPU PLL table.
 688  * @plls: The list of PLL entries.
 689  * @plls_no: The size of the PLL entries @plls.
 690  *
 691  * Register the given set of PLLs with the system.
 692  */
 693 int __init s3c_plltab_register(struct cpufreq_frequency_table *plls,
 694                                unsigned int plls_no)
 695 {
 696         struct cpufreq_frequency_table *vals;
 697         unsigned int size;
 698
 699         size = sizeof(struct cpufreq_frequency_table) * (plls_no + 1);
 700
 701         vals = kmalloc(size, GFP_KERNEL);
 702         if (vals) {
 703                 memcpy(vals, plls, size);
 704                 pll_reg = vals;
 705
 706                 /* write a terminating entry, we don't store it in the
 707                  * table that is stored in the kernel */
 708                 vals += plls_no;
 709                 vals->frequency = CPUFREQ_TABLE_END;
 710
 711                 printk(KERN_INFO "cpufreq: %d PLL entries\n", plls_no);
 712         } else
 713                 printk(KERN_ERR "cpufreq: no memory for PLL tables\n");
 714
 715         return vals ? 0 : -ENOMEM;
 716 }