1/* 2 * linux/arch/arm/mach-pxa/cpufreq-pxa2xx.c 3 * 4 * Copyright (C) 2002,2003 Intrinsyc Software 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19 * 20 * History: 21 * 31-Jul-2002 : Initial version [FB] 22 * 29-Jan-2003 : added PXA255 support [FB] 23 * 20-Apr-2003 : ported to v2.5 (Dustin McIntire, Sensoria Corp.) 24 * 25 * Note: 26 * This driver may change the memory bus clock rate, but will not do any 27 * platform specific access timing changes... for example if you have flash 28 * memory connected to CS0, you will need to register a platform specific 29 * notifier which will adjust the memory access strobes to maintain a 30 * minimum strobe width. 31 * 32 */ 33 34#include <linux/kernel.h> 35#include <linux/module.h> 36#include <linux/sched.h> 37#include <linux/init.h> 38#include <linux/cpufreq.h> 39#include <linux/err.h> 40#include <linux/regulator/consumer.h> 41 42#include <mach/pxa2xx-regs.h> 43 44#ifdef DEBUG 45static unsigned int freq_debug; 46module_param(freq_debug, uint, 0); 47MODULE_PARM_DESC(freq_debug, "Set the debug messages to on=1/off=0"); 48#else 49#define freq_debug 0 50#endif 51 52static struct regulator *vcc_core; 53 54static unsigned int pxa27x_maxfreq; 55module_param(pxa27x_maxfreq, uint, 0); 56MODULE_PARM_DESC(pxa27x_maxfreq, "Set the pxa27x maxfreq in MHz" 57 "(typically 624=>pxa270, 416=>pxa271, 520=>pxa272)"); 58 59typedef struct { 60 unsigned int khz; 61 unsigned int membus; 62 unsigned int cccr; 63 unsigned int div2; 64 unsigned int cclkcfg; 65 int vmin; 66 int vmax; 67} pxa_freqs_t; 68 69/* Define the refresh period in mSec for the SDRAM and the number of rows */ 70#define SDRAM_TREF 64 /* standard 64ms SDRAM */ 71static unsigned int sdram_rows; 72 73#define CCLKCFG_TURBO 0x1 74#define CCLKCFG_FCS 0x2 75#define CCLKCFG_HALFTURBO 0x4 76#define CCLKCFG_FASTBUS 0x8 77#define MDREFR_DB2_MASK (MDREFR_K2DB2 | MDREFR_K1DB2) 78#define MDREFR_DRI_MASK 0xFFF 79 80#define MDCNFG_DRAC2(mdcnfg) (((mdcnfg) >> 21) & 0x3) 81#define MDCNFG_DRAC0(mdcnfg) (((mdcnfg) >> 5) & 0x3) 82 83/* 84 * PXA255 definitions 85 */ 86/* Use the run mode frequencies for the CPUFREQ_POLICY_PERFORMANCE policy */ 87#define CCLKCFG CCLKCFG_TURBO | CCLKCFG_FCS 88 89static pxa_freqs_t pxa255_run_freqs[] = 90{ 91 /* CPU MEMBUS CCCR DIV2 CCLKCFG run turbo PXbus SDRAM */ 92 { 99500, 99500, 0x121, 1, CCLKCFG, -1, -1}, /* 99, 99, 50, 50 */ 93 {132700, 132700, 0x123, 1, CCLKCFG, -1, -1}, /* 133, 133, 66, 66 */ 94 {199100, 99500, 0x141, 0, CCLKCFG, -1, -1}, /* 199, 199, 99, 99 */ 95 {265400, 132700, 0x143, 1, CCLKCFG, -1, -1}, /* 265, 265, 133, 66 */ 96 {331800, 165900, 0x145, 1, CCLKCFG, -1, -1}, /* 331, 331, 166, 83 */ 97 {398100, 99500, 0x161, 0, CCLKCFG, -1, -1}, /* 398, 398, 196, 99 */ 98}; 99 100/* Use the turbo mode frequencies for the CPUFREQ_POLICY_POWERSAVE policy */ 101static pxa_freqs_t pxa255_turbo_freqs[] = 102{ 103 /* CPU MEMBUS CCCR DIV2 CCLKCFG run turbo PXbus SDRAM */ 104 { 99500, 99500, 0x121, 1, CCLKCFG, -1, -1}, /* 99, 99, 50, 50 */ 105 {199100, 99500, 0x221, 0, CCLKCFG, -1, -1}, /* 99, 199, 50, 99 */ 106 {298500, 99500, 0x321, 0, CCLKCFG, -1, -1}, /* 99, 287, 50, 99 */ 107 {298600, 99500, 0x1c1, 0, CCLKCFG, -1, -1}, /* 199, 287, 99, 99 */ 108 {398100, 99500, 0x241, 0, CCLKCFG, -1, -1}, /* 199, 398, 99, 99 */ 109}; 110 111#define NUM_PXA25x_RUN_FREQS ARRAY_SIZE(pxa255_run_freqs) 112#define NUM_PXA25x_TURBO_FREQS ARRAY_SIZE(pxa255_turbo_freqs) 113 114static struct cpufreq_frequency_table 115 pxa255_run_freq_table[NUM_PXA25x_RUN_FREQS+1]; 116static struct cpufreq_frequency_table 117 pxa255_turbo_freq_table[NUM_PXA25x_TURBO_FREQS+1]; 118 119static unsigned int pxa255_turbo_table; 120module_param(pxa255_turbo_table, uint, 0); 121MODULE_PARM_DESC(pxa255_turbo_table, "Selects the frequency table (0 = run table, !0 = turbo table)"); 122 123/* 124 * PXA270 definitions 125 * 126 * For the PXA27x: 127 * Control variables are A, L, 2N for CCCR; B, HT, T for CLKCFG. 128 * 129 * A = 0 => memory controller clock from table 3-7, 130 * A = 1 => memory controller clock = system bus clock 131 * Run mode frequency = 13 MHz * L 132 * Turbo mode frequency = 13 MHz * L * N 133 * System bus frequency = 13 MHz * L / (B + 1) 134 * 135 * In CCCR: 136 * A = 1 137 * L = 16 oscillator to run mode ratio 138 * 2N = 6 2 * (turbo mode to run mode ratio) 139 * 140 * In CCLKCFG: 141 * B = 1 Fast bus mode 142 * HT = 0 Half-Turbo mode 143 * T = 1 Turbo mode 144 * 145 * For now, just support some of the combinations in table 3-7 of 146 * PXA27x Processor Family Developer's Manual to simplify frequency 147 * change sequences. 148 */ 149#define PXA27x_CCCR(A, L, N2) (A << 25 | N2 << 7 | L) 150#define CCLKCFG2(B, HT, T) \ 151 (CCLKCFG_FCS | \ 152 ((B) ? CCLKCFG_FASTBUS : 0) | \ 153 ((HT) ? CCLKCFG_HALFTURBO : 0) | \ 154 ((T) ? CCLKCFG_TURBO : 0)) 155 156static pxa_freqs_t pxa27x_freqs[] = { 157 {104000, 104000, PXA27x_CCCR(1, 8, 2), 0, CCLKCFG2(1, 0, 1), 900000, 1705000 }, 158 {156000, 104000, PXA27x_CCCR(1, 8, 3), 0, CCLKCFG2(1, 0, 1), 1000000, 1705000 }, 159 {208000, 208000, PXA27x_CCCR(0, 16, 2), 1, CCLKCFG2(0, 0, 1), 1180000, 1705000 }, 160 {312000, 208000, PXA27x_CCCR(1, 16, 3), 1, CCLKCFG2(1, 0, 1), 1250000, 1705000 }, 161 {416000, 208000, PXA27x_CCCR(1, 16, 4), 1, CCLKCFG2(1, 0, 1), 1350000, 1705000 }, 162 {520000, 208000, PXA27x_CCCR(1, 16, 5), 1, CCLKCFG2(1, 0, 1), 1450000, 1705000 }, 163 {624000, 208000, PXA27x_CCCR(1, 16, 6), 1, CCLKCFG2(1, 0, 1), 1550000, 1705000 } 164}; 165 166#define NUM_PXA27x_FREQS ARRAY_SIZE(pxa27x_freqs) 167static struct cpufreq_frequency_table 168 pxa27x_freq_table[NUM_PXA27x_FREQS+1]; 169 170extern unsigned get_clk_frequency_khz(int info); 171 172#ifdef CONFIG_REGULATOR 173 174static int pxa_cpufreq_change_voltage(pxa_freqs_t *pxa_freq) 175{ 176 int ret = 0; 177 int vmin, vmax; 178 179 if (!cpu_is_pxa27x()) 180 return 0; 181 182 vmin = pxa_freq->vmin; 183 vmax = pxa_freq->vmax; 184 if ((vmin == -1) || (vmax == -1)) 185 return 0; 186 187 ret = regulator_set_voltage(vcc_core, vmin, vmax); 188 if (ret) 189 pr_err("cpufreq: Failed to set vcc_core in [%dmV..%dmV]\n", 190 vmin, vmax); 191 return ret; 192} 193 194static __init void pxa_cpufreq_init_voltages(void) 195{ 196 vcc_core = regulator_get(NULL, "vcc_core"); 197 if (IS_ERR(vcc_core)) { 198 pr_info("cpufreq: Didn't find vcc_core regulator\n"); 199 vcc_core = NULL; 200 } else { 201 pr_info("cpufreq: Found vcc_core regulator\n"); 202 } 203} 204#else 205static int pxa_cpufreq_change_voltage(pxa_freqs_t *pxa_freq) 206{ 207 return 0; 208} 209 210static __init void pxa_cpufreq_init_voltages(void) { } 211#endif 212 213static void find_freq_tables(struct cpufreq_frequency_table **freq_table, 214 pxa_freqs_t **pxa_freqs) 215{ 216 if (cpu_is_pxa25x()) { 217 if (!pxa255_turbo_table) { 218 *pxa_freqs = pxa255_run_freqs; 219 *freq_table = pxa255_run_freq_table; 220 } else { 221 *pxa_freqs = pxa255_turbo_freqs; 222 *freq_table = pxa255_turbo_freq_table; 223 } 224 } 225 if (cpu_is_pxa27x()) { 226 *pxa_freqs = pxa27x_freqs; 227 *freq_table = pxa27x_freq_table; 228 } 229} 230 231static void pxa27x_guess_max_freq(void) 232{ 233 if (!pxa27x_maxfreq) { 234 pxa27x_maxfreq = 416000; 235 printk(KERN_INFO "PXA CPU 27x max frequency not defined " 236 "(pxa27x_maxfreq), assuming pxa271 with %dkHz maxfreq\n", 237 pxa27x_maxfreq); 238 } else { 239 pxa27x_maxfreq *= 1000; 240 } 241} 242 243static void init_sdram_rows(void) 244{ 245 uint32_t mdcnfg = MDCNFG; 246 unsigned int drac2 = 0, drac0 = 0; 247 248 if (mdcnfg & (MDCNFG_DE2 | MDCNFG_DE3)) 249 drac2 = MDCNFG_DRAC2(mdcnfg); 250 251 if (mdcnfg & (MDCNFG_DE0 | MDCNFG_DE1)) 252 drac0 = MDCNFG_DRAC0(mdcnfg); 253 254 sdram_rows = 1 << (11 + max(drac0, drac2)); 255} 256 257static u32 mdrefr_dri(unsigned int freq) 258{ 259 u32 interval = freq * SDRAM_TREF / sdram_rows; 260 261 return (interval - (cpu_is_pxa27x() ? 31 : 0)) / 32; 262} 263 264/* find a valid frequency point */ 265static int pxa_verify_policy(struct cpufreq_policy *policy) 266{ 267 struct cpufreq_frequency_table *pxa_freqs_table; 268 pxa_freqs_t *pxa_freqs; 269 int ret; 270 271 find_freq_tables(&pxa_freqs_table, &pxa_freqs); 272 ret = cpufreq_frequency_table_verify(policy, pxa_freqs_table); 273 274 if (freq_debug) 275 pr_debug("Verified CPU policy: %dKhz min to %dKhz max\n", 276 policy->min, policy->max); 277 278 return ret; 279} 280 281static unsigned int pxa_cpufreq_get(unsigned int cpu) 282{ 283 return get_clk_frequency_khz(0); 284} 285 286static int pxa_set_target(struct cpufreq_policy *policy, 287 unsigned int target_freq, 288 unsigned int relation) 289{ 290 struct cpufreq_frequency_table *pxa_freqs_table; 291 pxa_freqs_t *pxa_freq_settings; 292 struct cpufreq_freqs freqs; 293 unsigned int idx; 294 unsigned long flags; 295 unsigned int new_freq_cpu, new_freq_mem; 296 unsigned int unused, preset_mdrefr, postset_mdrefr, cclkcfg; 297 int ret = 0; 298 299 /* Get the current policy */ 300 find_freq_tables(&pxa_freqs_table, &pxa_freq_settings); 301 302 /* Lookup the next frequency */ 303 if (cpufreq_frequency_table_target(policy, pxa_freqs_table, 304 target_freq, relation, &idx)) { 305 return -EINVAL; 306 } 307 308 new_freq_cpu = pxa_freq_settings[idx].khz; 309 new_freq_mem = pxa_freq_settings[idx].membus; 310 freqs.old = policy->cur; 311 freqs.new = new_freq_cpu; 312 freqs.cpu = policy->cpu; 313 314 if (freq_debug) 315 pr_debug("Changing CPU frequency to %d Mhz, (SDRAM %d Mhz)\n", 316 freqs.new / 1000, (pxa_freq_settings[idx].div2) ? 317 (new_freq_mem / 2000) : (new_freq_mem / 1000)); 318 319 if (vcc_core && freqs.new > freqs.old) 320 ret = pxa_cpufreq_change_voltage(&pxa_freq_settings[idx]); 321 if (ret) 322 return ret; 323 /* 324 * Tell everyone what we're about to do... 325 * you should add a notify client with any platform specific 326 * Vcc changing capability 327 */ 328 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); 329 330 /* Calculate the next MDREFR. If we're slowing down the SDRAM clock 331 * we need to preset the smaller DRI before the change. If we're 332 * speeding up we need to set the larger DRI value after the change. 333 */ 334 preset_mdrefr = postset_mdrefr = MDREFR; 335 if ((MDREFR & MDREFR_DRI_MASK) > mdrefr_dri(new_freq_mem)) { 336 preset_mdrefr = (preset_mdrefr & ~MDREFR_DRI_MASK); 337 preset_mdrefr |= mdrefr_dri(new_freq_mem); 338 } 339 postset_mdrefr = 340 (postset_mdrefr & ~MDREFR_DRI_MASK) | mdrefr_dri(new_freq_mem); 341 342 /* If we're dividing the memory clock by two for the SDRAM clock, this 343 * must be set prior to the change. Clearing the divide must be done 344 * after the change. 345 */ 346 if (pxa_freq_settings[idx].div2) { 347 preset_mdrefr |= MDREFR_DB2_MASK; 348 postset_mdrefr |= MDREFR_DB2_MASK; 349 } else { 350 postset_mdrefr &= ~MDREFR_DB2_MASK; 351 } 352 353 local_irq_save(flags); 354 355 /* Set new the CCCR and prepare CCLKCFG */ 356 CCCR = pxa_freq_settings[idx].cccr; 357 cclkcfg = pxa_freq_settings[idx].cclkcfg; 358 359 asm volatile(" \n\ 360 ldr r4, [%1] /* load MDREFR */ \n\ 361 b 2f \n\ 362 .align 5 \n\ 3631: \n\ 364 str %3, [%1] /* preset the MDREFR */ \n\ 365 mcr p14, 0, %2, c6, c0, 0 /* set CCLKCFG[FCS] */ \n\ 366 str %4, [%1] /* postset the MDREFR */ \n\ 367 \n\ 368 b 3f \n\ 3692: b 1b \n\ 3703: nop \n\ 371 " 372 : "=&r" (unused) 373 : "r" (&MDREFR), "r" (cclkcfg), 374 "r" (preset_mdrefr), "r" (postset_mdrefr) 375 : "r4", "r5"); 376 local_irq_restore(flags); 377 378 /* 379 * Tell everyone what we've just done... 380 * you should add a notify client with any platform specific 381 * SDRAM refresh timer adjustments 382 */ 383 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); 384 385 /* 386 * Even if voltage setting fails, we don't report it, as the frequency 387 * change succeeded. The voltage reduction is not a critical failure, 388 * only power savings will suffer from this. 389 * 390 * Note: if the voltage change fails, and a return value is returned, a 391 * bug is triggered (seems a deadlock). Should anybody find out where, 392 * the "return 0" should become a "return ret". 393 */ 394 if (vcc_core && freqs.new < freqs.old) 395 ret = pxa_cpufreq_change_voltage(&pxa_freq_settings[idx]); 396 397 return 0; 398} 399 400static int pxa_cpufreq_init(struct cpufreq_policy *policy) 401{ 402 int i; 403 unsigned int freq; 404 struct cpufreq_frequency_table *pxa255_freq_table; 405 pxa_freqs_t *pxa255_freqs; 406 407 /* try to guess pxa27x cpu */ 408 if (cpu_is_pxa27x()) 409 pxa27x_guess_max_freq(); 410 411 pxa_cpufreq_init_voltages(); 412 413 init_sdram_rows(); 414 415 /* set default policy and cpuinfo */ 416 policy->cpuinfo.transition_latency = 1000; 417 policy->cur = get_clk_frequency_khz(0); /* current freq */ 418 policy->min = policy->max = policy->cur; 419 420 /* Generate pxa25x the run cpufreq_frequency_table struct */ 421 for (i = 0; i < NUM_PXA25x_RUN_FREQS; i++) { 422 pxa255_run_freq_table[i].frequency = pxa255_run_freqs[i].khz; 423 pxa255_run_freq_table[i].index = i; 424 } 425 pxa255_run_freq_table[i].frequency = CPUFREQ_TABLE_END; 426 427 /* Generate pxa25x the turbo cpufreq_frequency_table struct */ 428 for (i = 0; i < NUM_PXA25x_TURBO_FREQS; i++) { 429 pxa255_turbo_freq_table[i].frequency = 430 pxa255_turbo_freqs[i].khz; 431 pxa255_turbo_freq_table[i].index = i; 432 } 433 pxa255_turbo_freq_table[i].frequency = CPUFREQ_TABLE_END; 434 435 pxa255_turbo_table = !!pxa255_turbo_table; 436 437 /* Generate the pxa27x cpufreq_frequency_table struct */ 438 for (i = 0; i < NUM_PXA27x_FREQS; i++) { 439 freq = pxa27x_freqs[i].khz; 440 if (freq > pxa27x_maxfreq) 441 break; 442 pxa27x_freq_table[i].frequency = freq; 443 pxa27x_freq_table[i].index = i; 444 } 445 pxa27x_freq_table[i].index = i; 446 pxa27x_freq_table[i].frequency = CPUFREQ_TABLE_END; 447 448 /* 449 * Set the policy's minimum and maximum frequencies from the tables 450 * just constructed. This sets cpuinfo.mxx_freq, min and max. 451 */ 452 if (cpu_is_pxa25x()) { 453 find_freq_tables(&pxa255_freq_table, &pxa255_freqs); 454 pr_info("PXA255 cpufreq using %s frequency table\n", 455 pxa255_turbo_table ? "turbo" : "run"); 456 cpufreq_frequency_table_cpuinfo(policy, pxa255_freq_table); 457 } 458 else if (cpu_is_pxa27x()) 459 cpufreq_frequency_table_cpuinfo(policy, pxa27x_freq_table); 460 461 printk(KERN_INFO "PXA CPU frequency change support initialized\n"); 462 463 return 0; 464} 465 466static struct cpufreq_driver pxa_cpufreq_driver = { 467 .verify = pxa_verify_policy, 468 .target = pxa_set_target, 469 .init = pxa_cpufreq_init, 470 .get = pxa_cpufreq_get, 471 .name = "PXA2xx", 472}; 473 474static int __init pxa_cpu_init(void) 475{ 476 int ret = -ENODEV; 477 if (cpu_is_pxa25x() || cpu_is_pxa27x()) 478 ret = cpufreq_register_driver(&pxa_cpufreq_driver); 479 return ret; 480} 481 482static void __exit pxa_cpu_exit(void) 483{ 484 cpufreq_unregister_driver(&pxa_cpufreq_driver); 485} 486 487 488MODULE_AUTHOR("Intrinsyc Software Inc."); 489MODULE_DESCRIPTION("CPU frequency changing driver for the PXA architecture"); 490MODULE_LICENSE("GPL"); 491module_init(pxa_cpu_init); 492module_exit(pxa_cpu_exit); 493