arch/arm/mach-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 #include <linux/init.h>
  14 #include <linux/module.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/ioport.h>
  17 #include <linux/cpufreq.h>
  18 #include <linux/cpu.h>
  19 #include <linux/clk.h>
  20 #include <linux/err.h>
  21 #include <linux/io.h>
  22 #include <linux/device.h>
  23 #include <linux/sysfs.h>
  24 #include <linux/slab.h>
  25
  26 #include <asm/mach/arch.h>
  27 #include <asm/mach/map.h>
  28
  29 #include <plat/cpu.h>
  30 #include <plat/clock.h>
  31 #include <plat/cpu-freq-core.h>
  32
  33 #include <mach/regs-clock.h>
  34
  35 /* note, cpufreq support deals in kHz, no Hz */
  36
  37 static struct cpufreq_driver s3c24xx_driver;
  38 static struct s3c_cpufreq_config cpu_cur;
  39 static struct s3c_iotimings s3c24xx_iotiming;
  40 static struct cpufreq_frequency_table *pll_reg;
  41 static unsigned int last_target = ~0;
  42 static unsigned int ftab_size;
  43 static struct cpufreq_frequency_table *ftab;
  44
  45 static struct clk *_clk_mpll;
  46 static struct clk *_clk_xtal;
  47 static struct clk *clk_fclk;
  48 static struct clk *clk_hclk;
  49 static struct clk *clk_pclk;
  50 static struct clk *clk_arm;
  51
  52 #ifdef CONFIG_CPU_FREQ_S3C24XX_DEBUGFS
  53 struct s3c_cpufreq_config *s3c_cpufreq_getconfig(void)
  54 {
  55         return &cpu_cur;
  56 }
  57
  58 struct s3c_iotimings *s3c_cpufreq_getiotimings(void)
  59 {
  60         return &s3c24xx_iotiming;
  61 }
  62 #endif /* CONFIG_CPU_FREQ_S3C24XX_DEBUGFS */
  63
  64 static void s3c_cpufreq_getcur(struct s3c_cpufreq_config *cfg)
  65 {
  66         unsigned long fclk, pclk, hclk, armclk;
  67
  68         cfg->freq.fclk = fclk = clk_get_rate(clk_fclk);
  69         cfg->freq.hclk = hclk = clk_get_rate(clk_hclk);
  70         cfg->freq.pclk = pclk = clk_get_rate(clk_pclk);
  71         cfg->freq.armclk = armclk = clk_get_rate(clk_arm);
  72
  73         cfg->pll.index = __raw_readl(S3C2410_MPLLCON);
  74         cfg->pll.frequency = fclk;
  75
  76         cfg->freq.hclk_tns = 1000000000 / (cfg->freq.hclk / 10);
  77
  78         cfg->divs.h_divisor = fclk / hclk;
  79         cfg->divs.p_divisor = fclk / pclk;
  80 }
  81
  82 static inline void s3c_cpufreq_calc(struct s3c_cpufreq_config *cfg)
  83 {
  84         unsigned long pll = cfg->pll.frequency;
  85
  86         cfg->freq.fclk = pll;
  87         cfg->freq.hclk = pll / cfg->divs.h_divisor;
  88         cfg->freq.pclk = pll / cfg->divs.p_divisor;
  89
  90         /* convert hclk into 10ths of nanoseconds for io calcs */
  91         cfg->freq.hclk_tns = 1000000000 / (cfg->freq.hclk / 10);
  92 }
  93
  94 static inline int closer(unsigned int target, unsigned int n, unsigned int c)
  95 {
  96         int diff_cur = abs(target - c);
  97         int diff_new = abs(target - n);
  98
  99         return (diff_new < diff_cur);
 100 }
 101
 102 static void s3c_cpufreq_show(const char *pfx,
 103                                  struct s3c_cpufreq_config *cfg)
 104 {
 105         s3c_freq_dbg("%s: Fvco=%u, F=%lu, A=%lu, H=%lu (%u), P=%lu (%u)\n",
 106                      pfx, cfg->pll.frequency, cfg->freq.fclk, cfg->freq.armclk,
 107                      cfg->freq.hclk, cfg->divs.h_divisor,
 108                      cfg->freq.pclk, cfg->divs.p_divisor);
 109 }
 110
 111 /* functions to wrapper the driver info calls to do the cpu specific work */
 112
 113 static void s3c_cpufreq_setio(struct s3c_cpufreq_config *cfg)
 114 {
 115         if (cfg->info->set_iotiming)
 116                 (cfg->info->set_iotiming)(cfg, &s3c24xx_iotiming);
 117 }
 118
 119 static int s3c_cpufreq_calcio(struct s3c_cpufreq_config *cfg)
 120 {
 121         if (cfg->info->calc_iotiming)
 122                 return (cfg->info->calc_iotiming)(cfg, &s3c24xx_iotiming);
 123
 124         return 0;
 125 }
 126
 127 static void s3c_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg)
 128 {
 129         (cfg->info->set_refresh)(cfg);
 130 }
 131
 132 static void s3c_cpufreq_setdivs(struct s3c_cpufreq_config *cfg)
 133 {
 134         (cfg->info->set_divs)(cfg);
 135 }
 136
 137 static int s3c_cpufreq_calcdivs(struct s3c_cpufreq_config *cfg)
 138 {
 139         return (cfg->info->calc_divs)(cfg);
 140 }
 141
 142 static void s3c_cpufreq_setfvco(struct s3c_cpufreq_config *cfg)
 143 {
 144         (cfg->info->set_fvco)(cfg);
 145 }
 146
 147 static inline void s3c_cpufreq_resume_clocks(void)
 148 {
 149         cpu_cur.info->resume_clocks();
 150 }
 151
 152 static inline void s3c_cpufreq_updateclk(struct clk *clk,
 153                                          unsigned int freq)
 154 {
 155         clk_set_rate(clk, freq);
 156 }
 157
 158 static int s3c_cpufreq_settarget(struct cpufreq_policy *policy,
 159                                  unsigned int target_freq,
 160                                  struct cpufreq_frequency_table *pll)
 161 {
 162         struct s3c_cpufreq_freqs freqs;
 163         struct s3c_cpufreq_config cpu_new;
 164         unsigned long flags;
 165
 166         cpu_new = cpu_cur;  /* copy new from current */
 167
 168         s3c_cpufreq_show("cur", &cpu_cur);
 169
 170         /* TODO - check for DMA currently outstanding */
 171
 172         cpu_new.pll = pll ? *pll : cpu_cur.pll;
 173
 174         if (pll)
 175                 freqs.pll_changing = 1;
 176
 177         /* update our frequencies */
 178
 179         cpu_new.freq.armclk = target_freq;
 180         cpu_new.freq.fclk = cpu_new.pll.frequency;
 181
 182         if (s3c_cpufreq_calcdivs(&cpu_new) < 0) {
 183                 printk(KERN_ERR "no divisors for %d\n", target_freq);
 184                 goto err_notpossible;
 185         }
 186
 187         s3c_freq_dbg("%s: got divs\n", __func__);
 188
 189         s3c_cpufreq_calc(&cpu_new);
 190
 191         s3c_freq_dbg("%s: calculated frequencies for new\n", __func__);
 192
 193         if (cpu_new.freq.hclk != cpu_cur.freq.hclk) {
 194                 if (s3c_cpufreq_calcio(&cpu_new) < 0) {
 195                         printk(KERN_ERR "%s: no IO timings\n", __func__);
 196                         goto err_notpossible;
 197                 }
 198         }
 199
 200         s3c_cpufreq_show("new", &cpu_new);
 201
 202         /* setup our cpufreq parameters */
 203
 204         freqs.old = cpu_cur.freq;
 205         freqs.new = cpu_new.freq;
 206
 207         freqs.freqs.old = cpu_cur.freq.armclk / 1000;
 208         freqs.freqs.new = cpu_new.freq.armclk / 1000;
 209
 210         /* update f/h/p clock settings before we issue the change
 211          * notification, so that drivers do not need to do anything
 212          * special if they want to recalculate on CPUFREQ_PRECHANGE. */
 213
 214         s3c_cpufreq_updateclk(_clk_mpll, cpu_new.pll.frequency);
 215         s3c_cpufreq_updateclk(clk_fclk, cpu_new.freq.fclk);
 216         s3c_cpufreq_updateclk(clk_hclk, cpu_new.freq.hclk);
 217         s3c_cpufreq_updateclk(clk_pclk, cpu_new.freq.pclk);
 218
 219         /* start the frequency change */
 220         cpufreq_notify_transition(policy, &freqs.freqs, CPUFREQ_PRECHANGE);
 221
 222         /* If hclk is staying the same, then we do not need to
 223          * re-write the IO or the refresh timings whilst we are changing
 224          * speed. */
 225
 226         local_irq_save(flags);
 227
 228         /* is our memory clock slowing down? */
 229         if (cpu_new.freq.hclk < cpu_cur.freq.hclk) {
 230                 s3c_cpufreq_setrefresh(&cpu_new);
 231                 s3c_cpufreq_setio(&cpu_new);
 232         }
 233
 234         if (cpu_new.freq.fclk == cpu_cur.freq.fclk) {
 235                 /* not changing PLL, just set the divisors */
 236
 237                 s3c_cpufreq_setdivs(&cpu_new);
 238         } else {
 239                 if (cpu_new.freq.fclk < cpu_cur.freq.fclk) {
 240                         /* slow the cpu down, then set divisors */
 241
 242                         s3c_cpufreq_setfvco(&cpu_new);
 243                         s3c_cpufreq_setdivs(&cpu_new);
 244                 } else {
 245                         /* set the divisors, then speed up */
 246
 247                         s3c_cpufreq_setdivs(&cpu_new);
 248                         s3c_cpufreq_setfvco(&cpu_new);
 249                 }
 250         }
 251
 252         /* did our memory clock speed up */
 253         if (cpu_new.freq.hclk > cpu_cur.freq.hclk) {
 254                 s3c_cpufreq_setrefresh(&cpu_new);
 255                 s3c_cpufreq_setio(&cpu_new);
 256         }
 257
 258         /* update our current settings */
 259         cpu_cur = cpu_new;
 260
 261         local_irq_restore(flags);
 262
 263         /* notify everyone we've done this */
 264         cpufreq_notify_transition(policy, &freqs.freqs, CPUFREQ_POSTCHANGE);
 265
 266         s3c_freq_dbg("%s: finished\n", __func__);
 267         return 0;
 268
 269  err_notpossible:
 270         printk(KERN_ERR "no compatible settings for %d\n", target_freq);
 271         return -EINVAL;
 272 }
 273
 274 /* s3c_cpufreq_target
 275  *
 276  * called by the cpufreq core to adjust the frequency that the CPU
 277  * is currently running at.
 278  */
 279
 280 static int s3c_cpufreq_target(struct cpufreq_policy *policy,
 281                               unsigned int target_freq,
 282                               unsigned int relation)
 283 {
 284         struct cpufreq_frequency_table *pll;
 285         unsigned int index;
 286
 287         /* avoid repeated calls which cause a needless amout of duplicated
 288          * logging output (and CPU time as the calculation process is
 289          * done) */
 290         if (target_freq == last_target)
 291                 return 0;
 292
 293         last_target = target_freq;
 294
 295         s3c_freq_dbg("%s: policy %p, target %u, relation %u\n",
 296                      __func__, policy, target_freq, relation);
 297
 298         if (ftab) {
 299                 if (cpufreq_frequency_table_target(policy, ftab,
 300                                                    target_freq, relation,
 301                                                    &index)) {
 302                         s3c_freq_dbg("%s: table failed\n", __func__);
 303                         return -EINVAL;
 304                 }
 305
 306                 s3c_freq_dbg("%s: adjust %d to entry %d (%u)\n", __func__,
 307                              target_freq, index, ftab[index].frequency);
 308                 target_freq = ftab[index].frequency;
 309         }
 310
 311         target_freq *= 1000;  /* convert target to Hz */
 312
 313         /* find the settings for our new frequency */
 314
 315         if (!pll_reg || cpu_cur.lock_pll) {
 316                 /* either we've not got any PLL values, or we've locked
 317                  * to the current one. */
 318                 pll = NULL;
 319         } else {
 320                 struct cpufreq_policy tmp_policy;
 321                 int ret;
 322
 323                 /* we keep the cpu pll table in Hz, to ensure we get an
 324                  * accurate value for the PLL output. */
 325
 326                 tmp_policy.min = policy->min * 1000;
 327                 tmp_policy.max = policy->max * 1000;
 328                 tmp_policy.cpu = policy->cpu;
 329
 330                 /* cpufreq_frequency_table_target uses a pointer to 'index'
 331                  * which is the number of the table entry, not the value of
 332                  * the table entry's index field. */
 333
 334                 ret = cpufreq_frequency_table_target(&tmp_policy, pll_reg,
 335                                                      target_freq, relation,
 336                                                      &index);
 337
 338                 if (ret < 0) {
 339                         printk(KERN_ERR "%s: no PLL available\n", __func__);
 340                         goto err_notpossible;
 341                 }
 342
 343                 pll = pll_reg + index;
 344
 345                 s3c_freq_dbg("%s: target %u => %u\n",
 346                              __func__, target_freq, pll->frequency);
 347
 348                 target_freq = pll->frequency;
 349         }
 350
 351         return s3c_cpufreq_settarget(policy, target_freq, pll);
 352
 353  err_notpossible:
 354         printk(KERN_ERR "no compatible settings for %d\n", target_freq);
 355         return -EINVAL;
 356 }
 357
 358 static unsigned int s3c_cpufreq_get(unsigned int cpu)
 359 {
 360         return clk_get_rate(clk_arm) / 1000;
 361 }
 362
 363 struct clk *s3c_cpufreq_clk_get(struct device *dev, const char *name)
 364 {
 365         struct clk *clk;
 366
 367         clk = clk_get(dev, name);
 368         if (IS_ERR(clk))
 369                 printk(KERN_ERR "cpufreq: failed to get clock '%s'\n", name);
 370
 371         return clk;
 372 }
 373
 374 static int s3c_cpufreq_init(struct cpufreq_policy *policy)
 375 {
 376         printk(KERN_INFO "%s: initialising policy %p\n", __func__, policy);
 377
 378         if (policy->cpu != 0)
 379                 return -EINVAL;
 380
 381         policy->cur = s3c_cpufreq_get(0);
 382         policy->min = policy->cpuinfo.min_freq = 0;
 383         policy->max = policy->cpuinfo.max_freq = cpu_cur.info->max.fclk / 1000;
 384         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 385
 386         /* feed the latency information from the cpu driver */
 387         policy->cpuinfo.transition_latency = cpu_cur.info->latency;
 388
 389         if (ftab)
 390                 cpufreq_frequency_table_cpuinfo(policy, ftab);
 391
 392         return 0;
 393 }
 394
 395 static __init int s3c_cpufreq_initclks(void)
 396 {
 397         _clk_mpll = s3c_cpufreq_clk_get(NULL, "mpll");
 398         _clk_xtal = s3c_cpufreq_clk_get(NULL, "xtal");
 399         clk_fclk = s3c_cpufreq_clk_get(NULL, "fclk");
 400         clk_hclk = s3c_cpufreq_clk_get(NULL, "hclk");
 401         clk_pclk = s3c_cpufreq_clk_get(NULL, "pclk");
 402         clk_arm = s3c_cpufreq_clk_get(NULL, "armclk");
 403
 404         if (IS_ERR(clk_fclk) || IS_ERR(clk_hclk) || IS_ERR(clk_pclk) ||
 405             IS_ERR(_clk_mpll) || IS_ERR(clk_arm) || IS_ERR(_clk_xtal)) {
 406                 printk(KERN_ERR "%s: could not get clock(s)\n", __func__);
 407                 return -ENOENT;
 408         }
 409
 410         printk(KERN_INFO "%s: clocks f=%lu,h=%lu,p=%lu,a=%lu\n", __func__,
 411                clk_get_rate(clk_fclk) / 1000,
 412                clk_get_rate(clk_hclk) / 1000,
 413                clk_get_rate(clk_pclk) / 1000,
 414                clk_get_rate(clk_arm) / 1000);
 415
 416         return 0;
 417 }
 418
 419 static int s3c_cpufreq_verify(struct cpufreq_policy *policy)
 420 {
 421         if (policy->cpu != 0)
 422                 return -EINVAL;
 423
 424         return 0;
 425 }
 426
 427 #ifdef CONFIG_PM
 428 static struct cpufreq_frequency_table suspend_pll;
 429 static unsigned int suspend_freq;
 430
 431 static int s3c_cpufreq_suspend(struct cpufreq_policy *policy)
 432 {
 433         suspend_pll.frequency = clk_get_rate(_clk_mpll);
 434         suspend_pll.index = __raw_readl(S3C2410_MPLLCON);
 435         suspend_freq = s3c_cpufreq_get(0) * 1000;
 436
 437         return 0;
 438 }
 439
 440 static int s3c_cpufreq_resume(struct cpufreq_policy *policy)
 441 {
 442         int ret;
 443
 444         s3c_freq_dbg("%s: resuming with policy %p\n", __func__, policy);
 445
 446         last_target = ~0;       /* invalidate last_target setting */
 447
 448         /* first, find out what speed we resumed at. */
 449         s3c_cpufreq_resume_clocks();
 450
 451         /* whilst we will be called later on, we try and re-set the
 452          * cpu frequencies as soon as possible so that we do not end
 453          * up resuming devices and then immediately having to re-set
 454          * a number of settings once these devices have restarted.
 455          *
 456          * as a note, it is expected devices are not used until they
 457          * have been un-suspended and at that time they should have
 458          * used the updated clock settings.
 459          */
 460
 461         ret = s3c_cpufreq_settarget(NULL, suspend_freq, &suspend_pll);
 462         if (ret) {
 463                 printk(KERN_ERR "%s: failed to reset pll/freq\n", __func__);
 464                 return ret;
 465         }
 466
 467         return 0;
 468 }
 469 #else
 470 #define s3c_cpufreq_resume NULL
 471 #define s3c_cpufreq_suspend NULL
 472 #endif
 473
 474 static struct cpufreq_driver s3c24xx_driver = {
 475         .flags          = CPUFREQ_STICKY,
 476         .verify         = s3c_cpufreq_verify,
 477         .target         = s3c_cpufreq_target,
 478         .get            = s3c_cpufreq_get,
 479         .init           = s3c_cpufreq_init,
 480         .suspend        = s3c_cpufreq_suspend,
 481         .resume         = s3c_cpufreq_resume,
 482         .name           = "s3c24xx",
 483 };
 484
 485
 486 int __init s3c_cpufreq_register(struct s3c_cpufreq_info *info)
 487 {
 488         if (!info || !info->name) {
 489                 printk(KERN_ERR "%s: failed to pass valid information\n",
 490                        __func__);
 491                 return -EINVAL;
 492         }
 493
 494         printk(KERN_INFO "S3C24XX CPU Frequency driver, %s cpu support\n",
 495                info->name);
 496
 497         /* check our driver info has valid data */
 498
 499         BUG_ON(info->set_refresh == NULL);
 500         BUG_ON(info->set_divs == NULL);
 501         BUG_ON(info->calc_divs == NULL);
 502
 503         /* info->set_fvco is optional, depending on whether there
 504          * is a need to set the clock code. */
 505
 506         cpu_cur.info = info;
 507
 508         /* Note, driver registering should probably update locktime */
 509
 510         return 0;
 511 }
 512
 513 int __init s3c_cpufreq_setboard(struct s3c_cpufreq_board *board)
 514 {
 515         struct s3c_cpufreq_board *ours;
 516
 517         if (!board) {
 518                 printk(KERN_INFO "%s: no board data\n", __func__);
 519                 return -EINVAL;
 520         }
 521
 522         /* Copy the board information so that each board can make this
 523          * initdata. */
 524
 525         ours = kzalloc(sizeof(struct s3c_cpufreq_board), GFP_KERNEL);
 526         if (ours == NULL) {
 527                 printk(KERN_ERR "%s: no memory\n", __func__);
 528                 return -ENOMEM;
 529         }
 530
 531         *ours = *board;
 532         cpu_cur.board = ours;
 533
 534         return 0;
 535 }
 536
 537 int __init s3c_cpufreq_auto_io(void)
 538 {
 539         int ret;
 540
 541         if (!cpu_cur.info->get_iotiming) {
 542                 printk(KERN_ERR "%s: get_iotiming undefined\n", __func__);
 543                 return -ENOENT;
 544         }
 545
 546         printk(KERN_INFO "%s: working out IO settings\n", __func__);
 547
 548         ret = (cpu_cur.info->get_iotiming)(&cpu_cur, &s3c24xx_iotiming);
 549         if (ret)
 550                 printk(KERN_ERR "%s: failed to get timings\n", __func__);
 551
 552         return ret;
 553 }
 554
 555 /* if one or is zero, then return the other, otherwise return the min */
 556 #define do_min(_a, _b) ((_a) == 0 ? (_b) : (_b) == 0 ? (_a) : min(_a, _b))
 557
 558 /**
 559  * s3c_cpufreq_freq_min - find the minimum settings for the given freq.
 560  * @dst: The destination structure
 561  * @a: One argument.
 562  * @b: The other argument.
 563  *
 564  * Create a minimum of each frequency entry in the 'struct s3c_freq',
 565  * unless the entry is zero when it is ignored and the non-zero argument
 566  * used.
 567  */
 568 static void s3c_cpufreq_freq_min(struct s3c_freq *dst,
 569                                  struct s3c_freq *a, struct s3c_freq *b)
 570 {
 571         dst->fclk = do_min(a->fclk, b->fclk);
 572         dst->hclk = do_min(a->hclk, b->hclk);
 573         dst->pclk = do_min(a->pclk, b->pclk);
 574         dst->armclk = do_min(a->armclk, b->armclk);
 575 }
 576
 577 static inline u32 calc_locktime(u32 freq, u32 time_us)
 578 {
 579         u32 result;
 580
 581         result = freq * time_us;
 582         result = DIV_ROUND_UP(result, 1000 * 1000);
 583
 584         return result;
 585 }
 586
 587 static void s3c_cpufreq_update_loctkime(void)
 588 {
 589         unsigned int bits = cpu_cur.info->locktime_bits;
 590         u32 rate = (u32)clk_get_rate(_clk_xtal);
 591         u32 val;
 592
 593         if (bits == 0) {
 594                 WARN_ON(1);
 595                 return;
 596         }
 597
 598         val = calc_locktime(rate, cpu_cur.info->locktime_u) << bits;
 599         val |= calc_locktime(rate, cpu_cur.info->locktime_m);
 600
 601         printk(KERN_INFO "%s: new locktime is 0x%08x\n", __func__, val);
 602         __raw_writel(val, S3C2410_LOCKTIME);
 603 }
 604
 605 static int s3c_cpufreq_build_freq(void)
 606 {
 607         int size, ret;
 608
 609         if (!cpu_cur.info->calc_freqtable)
 610                 return -EINVAL;
 611
 612         kfree(ftab);
 613         ftab = NULL;
 614
 615         size = cpu_cur.info->calc_freqtable(&cpu_cur, NULL, 0);
 616         size++;
 617
 618         ftab = kmalloc(sizeof(struct cpufreq_frequency_table) * size, GFP_KERNEL);
 619         if (!ftab) {
 620                 printk(KERN_ERR "%s: no memory for tables\n", __func__);
 621                 return -ENOMEM;
 622         }
 623
 624         ftab_size = size;
 625
 626         ret = cpu_cur.info->calc_freqtable(&cpu_cur, ftab, size);
 627         s3c_cpufreq_addfreq(ftab, ret, size, CPUFREQ_TABLE_END);
 628
 629         return 0;
 630 }
 631
 632 static int __init s3c_cpufreq_initcall(void)
 633 {
 634         int ret = 0;
 635
 636         if (cpu_cur.info && cpu_cur.board) {
 637                 ret = s3c_cpufreq_initclks();
 638                 if (ret)
 639                         goto out;
 640
 641                 /* get current settings */
 642                 s3c_cpufreq_getcur(&cpu_cur);
 643                 s3c_cpufreq_show("cur", &cpu_cur);
 644
 645                 if (cpu_cur.board->auto_io) {
 646                         ret = s3c_cpufreq_auto_io();
 647                         if (ret) {
 648                                 printk(KERN_ERR "%s: failed to get io timing\n",
 649                                        __func__);
 650                                 goto out;
 651                         }
 652                 }
 653
 654                 if (cpu_cur.board->need_io && !cpu_cur.info->set_iotiming) {
 655                         printk(KERN_ERR "%s: no IO support registered\n",
 656                                __func__);
 657                         ret = -EINVAL;
 658                         goto out;
 659                 }
 660
 661                 if (!cpu_cur.info->need_pll)
 662                         cpu_cur.lock_pll = 1;
 663
 664                 s3c_cpufreq_update_loctkime();
 665
 666                 s3c_cpufreq_freq_min(&cpu_cur.max, &cpu_cur.board->max,
 667                                      &cpu_cur.info->max);
 668
 669                 if (cpu_cur.info->calc_freqtable)
 670                         s3c_cpufreq_build_freq();
 671
 672                 ret = cpufreq_register_driver(&s3c24xx_driver);
 673         }
 674
 675  out:
 676         return ret;
 677 }
 678
 679 late_initcall(s3c_cpufreq_initcall);
 680
 681 /**
 682  * s3c_plltab_register - register CPU PLL table.
 683  * @plls: The list of PLL entries.
 684  * @plls_no: The size of the PLL entries @plls.
 685  *
 686  * Register the given set of PLLs with the system.
 687  */
 688 int __init s3c_plltab_register(struct cpufreq_frequency_table *plls,
 689                                unsigned int plls_no)
 690 {
 691         struct cpufreq_frequency_table *vals;
 692         unsigned int size;
 693
 694         size = sizeof(struct cpufreq_frequency_table) * (plls_no + 1);
 695
 696         vals = kmalloc(size, GFP_KERNEL);
 697         if (vals) {
 698                 memcpy(vals, plls, size);
 699                 pll_reg = vals;
 700
 701                 /* write a terminating entry, we don't store it in the
 702                  * table that is stored in the kernel */
 703                 vals += plls_no;
 704                 vals->frequency = CPUFREQ_TABLE_END;
 705
 706                 printk(KERN_INFO "cpufreq: %d PLL entries\n", plls_no);
 707         } else
 708                 printk(KERN_ERR "cpufreq: no memory for PLL tables\n");
 709
 710         return vals ? 0 : -ENOMEM;
 711 }