1 /* 2 * (C) 2001 Dave Jones, Arjan van de ven. 3 * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> 4 * 5 * Licensed under the terms of the GNU GPL License version 2. 6 * Based upon reverse engineered information, and on Intel documentation 7 * for chipsets ICH2-M and ICH3-M. 8 * 9 * Many thanks to Ducrot Bruno for finding and fixing the last 10 * "missing link" for ICH2-M/ICH3-M support, and to Thomas Winkler 11 * for extensive testing. 12 * 13 * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous* 14 */ 15 16 17 /********************************************************************* 18 * SPEEDSTEP - DEFINITIONS * 19 *********************************************************************/ 20 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 #include <linux/init.h> 24 #include <linux/cpufreq.h> 25 #include <linux/pci.h> 26 #include <linux/sched.h> 27 28 #include <asm/cpu_device_id.h> 29 30 #include "speedstep-lib.h" 31 32 33 /* speedstep_chipset: 34 * It is necessary to know which chipset is used. As accesses to 35 * this device occur at various places in this module, we need a 36 * static struct pci_dev * pointing to that device. 37 */ 38 static struct pci_dev *speedstep_chipset_dev; 39 40 41 /* speedstep_processor 42 */ 43 static enum speedstep_processor speedstep_processor; 44 45 static u32 pmbase; 46 47 /* 48 * There are only two frequency states for each processor. Values 49 * are in kHz for the time being. 50 */ 51 static struct cpufreq_frequency_table speedstep_freqs[] = { 52 {SPEEDSTEP_HIGH, 0}, 53 {SPEEDSTEP_LOW, 0}, 54 {0, CPUFREQ_TABLE_END}, 55 }; 56 57 58 /** 59 * speedstep_find_register - read the PMBASE address 60 * 61 * Returns: -ENODEV if no register could be found 62 */ 63 static int speedstep_find_register(void) 64 { 65 if (!speedstep_chipset_dev) 66 return -ENODEV; 67 68 /* get PMBASE */ 69 pci_read_config_dword(speedstep_chipset_dev, 0x40, &pmbase); 70 if (!(pmbase & 0x01)) { 71 printk(KERN_ERR "speedstep-ich: could not find speedstep register\n"); 72 return -ENODEV; 73 } 74 75 pmbase &= 0xFFFFFFFE; 76 if (!pmbase) { 77 printk(KERN_ERR "speedstep-ich: could not find speedstep register\n"); 78 return -ENODEV; 79 } 80 81 pr_debug("pmbase is 0x%x\n", pmbase); 82 return 0; 83 } 84 85 /** 86 * speedstep_set_state - set the SpeedStep state 87 * @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH) 88 * 89 * Tries to change the SpeedStep state. Can be called from 90 * smp_call_function_single. 91 */ 92 static void speedstep_set_state(unsigned int state) 93 { 94 u8 pm2_blk; 95 u8 value; 96 unsigned long flags; 97 98 if (state > 0x1) 99 return; 100 101 /* Disable IRQs */ 102 local_irq_save(flags); 103 104 /* read state */ 105 value = inb(pmbase + 0x50); 106 107 pr_debug("read at pmbase 0x%x + 0x50 returned 0x%x\n", pmbase, value); 108 109 /* write new state */ 110 value &= 0xFE; 111 value |= state; 112 113 pr_debug("writing 0x%x to pmbase 0x%x + 0x50\n", value, pmbase); 114 115 /* Disable bus master arbitration */ 116 pm2_blk = inb(pmbase + 0x20); 117 pm2_blk |= 0x01; 118 outb(pm2_blk, (pmbase + 0x20)); 119 120 /* Actual transition */ 121 outb(value, (pmbase + 0x50)); 122 123 /* Restore bus master arbitration */ 124 pm2_blk &= 0xfe; 125 outb(pm2_blk, (pmbase + 0x20)); 126 127 /* check if transition was successful */ 128 value = inb(pmbase + 0x50); 129 130 /* Enable IRQs */ 131 local_irq_restore(flags); 132 133 pr_debug("read at pmbase 0x%x + 0x50 returned 0x%x\n", pmbase, value); 134 135 if (state == (value & 0x1)) 136 pr_debug("change to %u MHz succeeded\n", 137 speedstep_get_frequency(speedstep_processor) / 1000); 138 else 139 printk(KERN_ERR "cpufreq: change failed - I/O error\n"); 140 141 return; 142 } 143 144 /* Wrapper for smp_call_function_single. */ 145 static void _speedstep_set_state(void *_state) 146 { 147 speedstep_set_state(*(unsigned int *)_state); 148 } 149 150 /** 151 * speedstep_activate - activate SpeedStep control in the chipset 152 * 153 * Tries to activate the SpeedStep status and control registers. 154 * Returns -EINVAL on an unsupported chipset, and zero on success. 155 */ 156 static int speedstep_activate(void) 157 { 158 u16 value = 0; 159 160 if (!speedstep_chipset_dev) 161 return -EINVAL; 162 163 pci_read_config_word(speedstep_chipset_dev, 0x00A0, &value); 164 if (!(value & 0x08)) { 165 value |= 0x08; 166 pr_debug("activating SpeedStep (TM) registers\n"); 167 pci_write_config_word(speedstep_chipset_dev, 0x00A0, value); 168 } 169 170 return 0; 171 } 172 173 174 /** 175 * speedstep_detect_chipset - detect the Southbridge which contains SpeedStep logic 176 * 177 * Detects ICH2-M, ICH3-M and ICH4-M so far. The pci_dev points to 178 * the LPC bridge / PM module which contains all power-management 179 * functions. Returns the SPEEDSTEP_CHIPSET_-number for the detected 180 * chipset, or zero on failure. 181 */ 182 static unsigned int speedstep_detect_chipset(void) 183 { 184 speedstep_chipset_dev = pci_get_subsys(PCI_VENDOR_ID_INTEL, 185 PCI_DEVICE_ID_INTEL_82801DB_12, 186 PCI_ANY_ID, PCI_ANY_ID, 187 NULL); 188 if (speedstep_chipset_dev) 189 return 4; /* 4-M */ 190 191 speedstep_chipset_dev = pci_get_subsys(PCI_VENDOR_ID_INTEL, 192 PCI_DEVICE_ID_INTEL_82801CA_12, 193 PCI_ANY_ID, PCI_ANY_ID, 194 NULL); 195 if (speedstep_chipset_dev) 196 return 3; /* 3-M */ 197 198 199 speedstep_chipset_dev = pci_get_subsys(PCI_VENDOR_ID_INTEL, 200 PCI_DEVICE_ID_INTEL_82801BA_10, 201 PCI_ANY_ID, PCI_ANY_ID, 202 NULL); 203 if (speedstep_chipset_dev) { 204 /* speedstep.c causes lockups on Dell Inspirons 8000 and 205 * 8100 which use a pretty old revision of the 82815 206 * host brige. Abort on these systems. 207 */ 208 static struct pci_dev *hostbridge; 209 210 hostbridge = pci_get_subsys(PCI_VENDOR_ID_INTEL, 211 PCI_DEVICE_ID_INTEL_82815_MC, 212 PCI_ANY_ID, PCI_ANY_ID, 213 NULL); 214 215 if (!hostbridge) 216 return 2; /* 2-M */ 217 218 if (hostbridge->revision < 5) { 219 pr_debug("hostbridge does not support speedstep\n"); 220 speedstep_chipset_dev = NULL; 221 pci_dev_put(hostbridge); 222 return 0; 223 } 224 225 pci_dev_put(hostbridge); 226 return 2; /* 2-M */ 227 } 228 229 return 0; 230 } 231 232 static void get_freq_data(void *_speed) 233 { 234 unsigned int *speed = _speed; 235 236 *speed = speedstep_get_frequency(speedstep_processor); 237 } 238 239 static unsigned int speedstep_get(unsigned int cpu) 240 { 241 unsigned int speed; 242 243 /* You're supposed to ensure CPU is online. */ 244 if (smp_call_function_single(cpu, get_freq_data, &speed, 1) != 0) 245 BUG(); 246 247 pr_debug("detected %u kHz as current frequency\n", speed); 248 return speed; 249 } 250 251 /** 252 * speedstep_target - set a new CPUFreq policy 253 * @policy: new policy 254 * @target_freq: the target frequency 255 * @relation: how that frequency relates to achieved frequency 256 * (CPUFREQ_RELATION_L or CPUFREQ_RELATION_H) 257 * 258 * Sets a new CPUFreq policy. 259 */ 260 static int speedstep_target(struct cpufreq_policy *policy, 261 unsigned int target_freq, 262 unsigned int relation) 263 { 264 unsigned int newstate = 0, policy_cpu; 265 struct cpufreq_freqs freqs; 266 int i; 267 268 if (cpufreq_frequency_table_target(policy, &speedstep_freqs[0], 269 target_freq, relation, &newstate)) 270 return -EINVAL; 271 272 policy_cpu = cpumask_any_and(policy->cpus, cpu_online_mask); 273 freqs.old = speedstep_get(policy_cpu); 274 freqs.new = speedstep_freqs[newstate].frequency; 275 freqs.cpu = policy->cpu; 276 277 pr_debug("transiting from %u to %u kHz\n", freqs.old, freqs.new); 278 279 /* no transition necessary */ 280 if (freqs.old == freqs.new) 281 return 0; 282 283 for_each_cpu(i, policy->cpus) { 284 freqs.cpu = i; 285 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); 286 } 287 288 smp_call_function_single(policy_cpu, _speedstep_set_state, &newstate, 289 true); 290 291 for_each_cpu(i, policy->cpus) { 292 freqs.cpu = i; 293 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); 294 } 295 296 return 0; 297 } 298 299 300 /** 301 * speedstep_verify - verifies a new CPUFreq policy 302 * @policy: new policy 303 * 304 * Limit must be within speedstep_low_freq and speedstep_high_freq, with 305 * at least one border included. 306 */ 307 static int speedstep_verify(struct cpufreq_policy *policy) 308 { 309 return cpufreq_frequency_table_verify(policy, &speedstep_freqs[0]); 310 } 311 312 struct get_freqs { 313 struct cpufreq_policy *policy; 314 int ret; 315 }; 316 317 static void get_freqs_on_cpu(void *_get_freqs) 318 { 319 struct get_freqs *get_freqs = _get_freqs; 320 321 get_freqs->ret = 322 speedstep_get_freqs(speedstep_processor, 323 &speedstep_freqs[SPEEDSTEP_LOW].frequency, 324 &speedstep_freqs[SPEEDSTEP_HIGH].frequency, 325 &get_freqs->policy->cpuinfo.transition_latency, 326 &speedstep_set_state); 327 } 328 329 static int speedstep_cpu_init(struct cpufreq_policy *policy) 330 { 331 int result; 332 unsigned int policy_cpu, speed; 333 struct get_freqs gf; 334 335 /* only run on CPU to be set, or on its sibling */ 336 #ifdef CONFIG_SMP 337 cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu)); 338 #endif 339 policy_cpu = cpumask_any_and(policy->cpus, cpu_online_mask); 340 341 /* detect low and high frequency and transition latency */ 342 gf.policy = policy; 343 smp_call_function_single(policy_cpu, get_freqs_on_cpu, &gf, 1); 344 if (gf.ret) 345 return gf.ret; 346 347 /* get current speed setting */ 348 speed = speedstep_get(policy_cpu); 349 if (!speed) 350 return -EIO; 351 352 pr_debug("currently at %s speed setting - %i MHz\n", 353 (speed == speedstep_freqs[SPEEDSTEP_LOW].frequency) 354 ? "low" : "high", 355 (speed / 1000)); 356 357 /* cpuinfo and default policy values */ 358 policy->cur = speed; 359 360 result = cpufreq_frequency_table_cpuinfo(policy, speedstep_freqs); 361 if (result) 362 return result; 363 364 cpufreq_frequency_table_get_attr(speedstep_freqs, policy->cpu); 365 366 return 0; 367 } 368 369 370 static int speedstep_cpu_exit(struct cpufreq_policy *policy) 371 { 372 cpufreq_frequency_table_put_attr(policy->cpu); 373 return 0; 374 } 375 376 static struct freq_attr *speedstep_attr[] = { 377 &cpufreq_freq_attr_scaling_available_freqs, 378 NULL, 379 }; 380 381 382 static struct cpufreq_driver speedstep_driver = { 383 .name = "speedstep-ich", 384 .verify = speedstep_verify, 385 .target = speedstep_target, 386 .init = speedstep_cpu_init, 387 .exit = speedstep_cpu_exit, 388 .get = speedstep_get, 389 .owner = THIS_MODULE, 390 .attr = speedstep_attr, 391 }; 392 393 static const struct x86_cpu_id ss_smi_ids[] = { 394 { X86_VENDOR_INTEL, 6, 0xb, }, 395 { X86_VENDOR_INTEL, 6, 0x8, }, 396 { X86_VENDOR_INTEL, 15, 2 }, 397 {} 398 }; 399 #if 0 400 /* Autoload or not? Do not for now. */ 401 MODULE_DEVICE_TABLE(x86cpu, ss_smi_ids); 402 #endif 403 404 /** 405 * speedstep_init - initializes the SpeedStep CPUFreq driver 406 * 407 * Initializes the SpeedStep support. Returns -ENODEV on unsupported 408 * devices, -EINVAL on problems during initiatization, and zero on 409 * success. 410 */ 411 static int __init speedstep_init(void) 412 { 413 if (!x86_match_cpu(ss_smi_ids)) 414 return -ENODEV; 415 416 /* detect processor */ 417 speedstep_processor = speedstep_detect_processor(); 418 if (!speedstep_processor) { 419 pr_debug("Intel(R) SpeedStep(TM) capable processor " 420 "not found\n"); 421 return -ENODEV; 422 } 423 424 /* detect chipset */ 425 if (!speedstep_detect_chipset()) { 426 pr_debug("Intel(R) SpeedStep(TM) for this chipset not " 427 "(yet) available.\n"); 428 return -ENODEV; 429 } 430 431 /* activate speedstep support */ 432 if (speedstep_activate()) { 433 pci_dev_put(speedstep_chipset_dev); 434 return -EINVAL; 435 } 436 437 if (speedstep_find_register()) 438 return -ENODEV; 439 440 return cpufreq_register_driver(&speedstep_driver); 441 } 442 443 444 /** 445 * speedstep_exit - unregisters SpeedStep support 446 * 447 * Unregisters SpeedStep support. 448 */ 449 static void __exit speedstep_exit(void) 450 { 451 pci_dev_put(speedstep_chipset_dev); 452 cpufreq_unregister_driver(&speedstep_driver); 453 } 454 455 456 MODULE_AUTHOR("Dave Jones <davej@redhat.com>, " 457 "Dominik Brodowski <linux@brodo.de>"); 458 MODULE_DESCRIPTION("Speedstep driver for Intel mobile processors on chipsets " 459 "with ICH-M southbridges."); 460 MODULE_LICENSE("GPL"); 461 462 module_init(speedstep_init); 463 module_exit(speedstep_exit); 464