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/cpu-freq-core.h> 31 32#include <mach/regs-clock.h> 33 34/* note, cpufreq support deals in kHz, no Hz */ 35 36static struct cpufreq_driver s3c24xx_driver; 37static struct s3c_cpufreq_config cpu_cur; 38static struct s3c_iotimings s3c24xx_iotiming; 39static struct cpufreq_frequency_table *pll_reg; 40static unsigned int last_target = ~0; 41static unsigned int ftab_size; 42static struct cpufreq_frequency_table *ftab; 43 44static struct clk *_clk_mpll; 45static struct clk *_clk_xtal; 46static struct clk *clk_fclk; 47static struct clk *clk_hclk; 48static struct clk *clk_pclk; 49static struct clk *clk_arm; 50 51#ifdef CONFIG_ARM_S3C24XX_CPUFREQ_DEBUGFS 52struct s3c_cpufreq_config *s3c_cpufreq_getconfig(void) 53{ 54 return &cpu_cur; 55} 56 57struct s3c_iotimings *s3c_cpufreq_getiotimings(void) 58{ 59 return &s3c24xx_iotiming; 60} 61#endif /* CONFIG_ARM_S3C24XX_CPUFREQ_DEBUGFS */ 62 63static void s3c_cpufreq_getcur(struct s3c_cpufreq_config *cfg) 64{ 65 unsigned long fclk, pclk, hclk, armclk; 66 67 cfg->freq.fclk = fclk = clk_get_rate(clk_fclk); 68 cfg->freq.hclk = hclk = clk_get_rate(clk_hclk); 69 cfg->freq.pclk = pclk = clk_get_rate(clk_pclk); 70 cfg->freq.armclk = armclk = clk_get_rate(clk_arm); 71 72 cfg->pll.driver_data = __raw_readl(S3C2410_MPLLCON); 73 cfg->pll.frequency = fclk; 74 75 cfg->freq.hclk_tns = 1000000000 / (cfg->freq.hclk / 10); 76 77 cfg->divs.h_divisor = fclk / hclk; 78 cfg->divs.p_divisor = fclk / pclk; 79} 80 81static inline void s3c_cpufreq_calc(struct s3c_cpufreq_config *cfg) 82{ 83 unsigned long pll = cfg->pll.frequency; 84 85 cfg->freq.fclk = pll; 86 cfg->freq.hclk = pll / cfg->divs.h_divisor; 87 cfg->freq.pclk = pll / cfg->divs.p_divisor; 88 89 /* convert hclk into 10ths of nanoseconds for io calcs */ 90 cfg->freq.hclk_tns = 1000000000 / (cfg->freq.hclk / 10); 91} 92 93static inline int closer(unsigned int target, unsigned int n, unsigned int c) 94{ 95 int diff_cur = abs(target - c); 96 int diff_new = abs(target - n); 97 98 return (diff_new < diff_cur); 99} 100 101static void s3c_cpufreq_show(const char *pfx, 102 struct s3c_cpufreq_config *cfg) 103{ 104 s3c_freq_dbg("%s: Fvco=%u, F=%lu, A=%lu, H=%lu (%u), P=%lu (%u)\n", 105 pfx, cfg->pll.frequency, cfg->freq.fclk, cfg->freq.armclk, 106 cfg->freq.hclk, cfg->divs.h_divisor, 107 cfg->freq.pclk, cfg->divs.p_divisor); 108} 109 110/* functions to wrapper the driver info calls to do the cpu specific work */ 111 112static void s3c_cpufreq_setio(struct s3c_cpufreq_config *cfg) 113{ 114 if (cfg->info->set_iotiming) 115 (cfg->info->set_iotiming)(cfg, &s3c24xx_iotiming); 116} 117 118static int s3c_cpufreq_calcio(struct s3c_cpufreq_config *cfg) 119{ 120 if (cfg->info->calc_iotiming) 121 return (cfg->info->calc_iotiming)(cfg, &s3c24xx_iotiming); 122 123 return 0; 124} 125 126static void s3c_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg) 127{ 128 (cfg->info->set_refresh)(cfg); 129} 130 131static void s3c_cpufreq_setdivs(struct s3c_cpufreq_config *cfg) 132{ 133 (cfg->info->set_divs)(cfg); 134} 135 136static int s3c_cpufreq_calcdivs(struct s3c_cpufreq_config *cfg) 137{ 138 return (cfg->info->calc_divs)(cfg); 139} 140 141static void s3c_cpufreq_setfvco(struct s3c_cpufreq_config *cfg) 142{ 143 cfg->mpll = _clk_mpll; 144 (cfg->info->set_fvco)(cfg); 145} 146 147static inline void s3c_cpufreq_resume_clocks(void) 148{ 149 cpu_cur.info->resume_clocks(); 150} 151 152static inline void s3c_cpufreq_updateclk(struct clk *clk, 153 unsigned int freq) 154{ 155 clk_set_rate(clk, freq); 156} 157 158static 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_freq_transition_begin(policy, &freqs.freqs); 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_freq_transition_end(policy, &freqs.freqs, 0); 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 280static 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 358struct clk *s3c_cpufreq_clk_get(struct device *dev, const char *name) 359{ 360 struct clk *clk; 361 362 clk = clk_get(dev, name); 363 if (IS_ERR(clk)) 364 printk(KERN_ERR "cpufreq: failed to get clock '%s'\n", name); 365 366 return clk; 367} 368 369static int s3c_cpufreq_init(struct cpufreq_policy *policy) 370{ 371 policy->clk = clk_arm; 372 return cpufreq_generic_init(policy, ftab, cpu_cur.info->latency); 373} 374 375static int __init s3c_cpufreq_initclks(void) 376{ 377 _clk_mpll = s3c_cpufreq_clk_get(NULL, "mpll"); 378 _clk_xtal = s3c_cpufreq_clk_get(NULL, "xtal"); 379 clk_fclk = s3c_cpufreq_clk_get(NULL, "fclk"); 380 clk_hclk = s3c_cpufreq_clk_get(NULL, "hclk"); 381 clk_pclk = s3c_cpufreq_clk_get(NULL, "pclk"); 382 clk_arm = s3c_cpufreq_clk_get(NULL, "armclk"); 383 384 if (IS_ERR(clk_fclk) || IS_ERR(clk_hclk) || IS_ERR(clk_pclk) || 385 IS_ERR(_clk_mpll) || IS_ERR(clk_arm) || IS_ERR(_clk_xtal)) { 386 printk(KERN_ERR "%s: could not get clock(s)\n", __func__); 387 return -ENOENT; 388 } 389 390 printk(KERN_INFO "%s: clocks f=%lu,h=%lu,p=%lu,a=%lu\n", __func__, 391 clk_get_rate(clk_fclk) / 1000, 392 clk_get_rate(clk_hclk) / 1000, 393 clk_get_rate(clk_pclk) / 1000, 394 clk_get_rate(clk_arm) / 1000); 395 396 return 0; 397} 398 399#ifdef CONFIG_PM 400static struct cpufreq_frequency_table suspend_pll; 401static unsigned int suspend_freq; 402 403static int s3c_cpufreq_suspend(struct cpufreq_policy *policy) 404{ 405 suspend_pll.frequency = clk_get_rate(_clk_mpll); 406 suspend_pll.driver_data = __raw_readl(S3C2410_MPLLCON); 407 suspend_freq = clk_get_rate(clk_arm); 408 409 return 0; 410} 411 412static int s3c_cpufreq_resume(struct cpufreq_policy *policy) 413{ 414 int ret; 415 416 s3c_freq_dbg("%s: resuming with policy %p\n", __func__, policy); 417 418 last_target = ~0; /* invalidate last_target setting */ 419 420 /* first, find out what speed we resumed at. */ 421 s3c_cpufreq_resume_clocks(); 422 423 /* whilst we will be called later on, we try and re-set the 424 * cpu frequencies as soon as possible so that we do not end 425 * up resuming devices and then immediately having to re-set 426 * a number of settings once these devices have restarted. 427 * 428 * as a note, it is expected devices are not used until they 429 * have been un-suspended and at that time they should have 430 * used the updated clock settings. 431 */ 432 433 ret = s3c_cpufreq_settarget(NULL, suspend_freq, &suspend_pll); 434 if (ret) { 435 printk(KERN_ERR "%s: failed to reset pll/freq\n", __func__); 436 return ret; 437 } 438 439 return 0; 440} 441#else 442#define s3c_cpufreq_resume NULL 443#define s3c_cpufreq_suspend NULL 444#endif 445 446static struct cpufreq_driver s3c24xx_driver = { 447 .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK, 448 .target = s3c_cpufreq_target, 449 .get = cpufreq_generic_get, 450 .init = s3c_cpufreq_init, 451 .suspend = s3c_cpufreq_suspend, 452 .resume = s3c_cpufreq_resume, 453 .name = "s3c24xx", 454}; 455 456 457int __init s3c_cpufreq_register(struct s3c_cpufreq_info *info) 458{ 459 if (!info || !info->name) { 460 printk(KERN_ERR "%s: failed to pass valid information\n", 461 __func__); 462 return -EINVAL; 463 } 464 465 printk(KERN_INFO "S3C24XX CPU Frequency driver, %s cpu support\n", 466 info->name); 467 468 /* check our driver info has valid data */ 469 470 BUG_ON(info->set_refresh == NULL); 471 BUG_ON(info->set_divs == NULL); 472 BUG_ON(info->calc_divs == NULL); 473 474 /* info->set_fvco is optional, depending on whether there 475 * is a need to set the clock code. */ 476 477 cpu_cur.info = info; 478 479 /* Note, driver registering should probably update locktime */ 480 481 return 0; 482} 483 484int __init s3c_cpufreq_setboard(struct s3c_cpufreq_board *board) 485{ 486 struct s3c_cpufreq_board *ours; 487 488 if (!board) { 489 printk(KERN_INFO "%s: no board data\n", __func__); 490 return -EINVAL; 491 } 492 493 /* Copy the board information so that each board can make this 494 * initdata. */ 495 496 ours = kzalloc(sizeof(*ours), GFP_KERNEL); 497 if (ours == NULL) { 498 printk(KERN_ERR "%s: no memory\n", __func__); 499 return -ENOMEM; 500 } 501 502 *ours = *board; 503 cpu_cur.board = ours; 504 505 return 0; 506} 507 508static int __init s3c_cpufreq_auto_io(void) 509{ 510 int ret; 511 512 if (!cpu_cur.info->get_iotiming) { 513 printk(KERN_ERR "%s: get_iotiming undefined\n", __func__); 514 return -ENOENT; 515 } 516 517 printk(KERN_INFO "%s: working out IO settings\n", __func__); 518 519 ret = (cpu_cur.info->get_iotiming)(&cpu_cur, &s3c24xx_iotiming); 520 if (ret) 521 printk(KERN_ERR "%s: failed to get timings\n", __func__); 522 523 return ret; 524} 525 526/* if one or is zero, then return the other, otherwise return the min */ 527#define do_min(_a, _b) ((_a) == 0 ? (_b) : (_b) == 0 ? (_a) : min(_a, _b)) 528 529/** 530 * s3c_cpufreq_freq_min - find the minimum settings for the given freq. 531 * @dst: The destination structure 532 * @a: One argument. 533 * @b: The other argument. 534 * 535 * Create a minimum of each frequency entry in the 'struct s3c_freq', 536 * unless the entry is zero when it is ignored and the non-zero argument 537 * used. 538 */ 539static void s3c_cpufreq_freq_min(struct s3c_freq *dst, 540 struct s3c_freq *a, struct s3c_freq *b) 541{ 542 dst->fclk = do_min(a->fclk, b->fclk); 543 dst->hclk = do_min(a->hclk, b->hclk); 544 dst->pclk = do_min(a->pclk, b->pclk); 545 dst->armclk = do_min(a->armclk, b->armclk); 546} 547 548static inline u32 calc_locktime(u32 freq, u32 time_us) 549{ 550 u32 result; 551 552 result = freq * time_us; 553 result = DIV_ROUND_UP(result, 1000 * 1000); 554 555 return result; 556} 557 558static void s3c_cpufreq_update_loctkime(void) 559{ 560 unsigned int bits = cpu_cur.info->locktime_bits; 561 u32 rate = (u32)clk_get_rate(_clk_xtal); 562 u32 val; 563 564 if (bits == 0) { 565 WARN_ON(1); 566 return; 567 } 568 569 val = calc_locktime(rate, cpu_cur.info->locktime_u) << bits; 570 val |= calc_locktime(rate, cpu_cur.info->locktime_m); 571 572 printk(KERN_INFO "%s: new locktime is 0x%08x\n", __func__, val); 573 __raw_writel(val, S3C2410_LOCKTIME); 574} 575 576static int s3c_cpufreq_build_freq(void) 577{ 578 int size, ret; 579 580 if (!cpu_cur.info->calc_freqtable) 581 return -EINVAL; 582 583 kfree(ftab); 584 ftab = NULL; 585 586 size = cpu_cur.info->calc_freqtable(&cpu_cur, NULL, 0); 587 size++; 588 589 ftab = kzalloc(sizeof(*ftab) * size, GFP_KERNEL); 590 if (!ftab) { 591 printk(KERN_ERR "%s: no memory for tables\n", __func__); 592 return -ENOMEM; 593 } 594 595 ftab_size = size; 596 597 ret = cpu_cur.info->calc_freqtable(&cpu_cur, ftab, size); 598 s3c_cpufreq_addfreq(ftab, ret, size, CPUFREQ_TABLE_END); 599 600 return 0; 601} 602 603static int __init s3c_cpufreq_initcall(void) 604{ 605 int ret = 0; 606 607 if (cpu_cur.info && cpu_cur.board) { 608 ret = s3c_cpufreq_initclks(); 609 if (ret) 610 goto out; 611 612 /* get current settings */ 613 s3c_cpufreq_getcur(&cpu_cur); 614 s3c_cpufreq_show("cur", &cpu_cur); 615 616 if (cpu_cur.board->auto_io) { 617 ret = s3c_cpufreq_auto_io(); 618 if (ret) { 619 printk(KERN_ERR "%s: failed to get io timing\n", 620 __func__); 621 goto out; 622 } 623 } 624 625 if (cpu_cur.board->need_io && !cpu_cur.info->set_iotiming) { 626 printk(KERN_ERR "%s: no IO support registered\n", 627 __func__); 628 ret = -EINVAL; 629 goto out; 630 } 631 632 if (!cpu_cur.info->need_pll) 633 cpu_cur.lock_pll = 1; 634 635 s3c_cpufreq_update_loctkime(); 636 637 s3c_cpufreq_freq_min(&cpu_cur.max, &cpu_cur.board->max, 638 &cpu_cur.info->max); 639 640 if (cpu_cur.info->calc_freqtable) 641 s3c_cpufreq_build_freq(); 642 643 ret = cpufreq_register_driver(&s3c24xx_driver); 644 } 645 646 out: 647 return ret; 648} 649 650late_initcall(s3c_cpufreq_initcall); 651 652/** 653 * s3c_plltab_register - register CPU PLL table. 654 * @plls: The list of PLL entries. 655 * @plls_no: The size of the PLL entries @plls. 656 * 657 * Register the given set of PLLs with the system. 658 */ 659int __init s3c_plltab_register(struct cpufreq_frequency_table *plls, 660 unsigned int plls_no) 661{ 662 struct cpufreq_frequency_table *vals; 663 unsigned int size; 664 665 size = sizeof(*vals) * (plls_no + 1); 666 667 vals = kzalloc(size, GFP_KERNEL); 668 if (vals) { 669 memcpy(vals, plls, size); 670 pll_reg = vals; 671 672 /* write a terminating entry, we don't store it in the 673 * table that is stored in the kernel */ 674 vals += plls_no; 675 vals->frequency = CPUFREQ_TABLE_END; 676 677 printk(KERN_INFO "cpufreq: %d PLL entries\n", plls_no); 678 } else 679 printk(KERN_ERR "cpufreq: no memory for PLL tables\n"); 680 681 return vals ? 0 : -ENOMEM; 682} 683