git.oblomov.eu Git - linux-2.6/blob - arch/ppc/platforms/pmac_cpufreq.c

   1 /*
   2  *  arch/ppc/platforms/pmac_cpufreq.c
   3  *
   4  *  Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
   5  *  Copyright (C) 2004        John Steele Scott <toojays@toojays.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * TODO: Need a big cleanup here. Basically, we need to have different
  12  * cpufreq_driver structures for the different type of HW instead of the
  13  * current mess. We also need to better deal with the detection of the
  14  * type of machine.
  15  *
  16  */
  17
  18 #include <linux/config.h>
  19 #include <linux/module.h>
  20 #include <linux/types.h>
  21 #include <linux/errno.h>
  22 #include <linux/kernel.h>
  23 #include <linux/delay.h>
  24 #include <linux/sched.h>
  25 #include <linux/adb.h>
  26 #include <linux/pmu.h>
  27 #include <linux/slab.h>
  28 #include <linux/cpufreq.h>
  29 #include <linux/init.h>
  30 #include <linux/sysdev.h>
  31 #include <linux/i2c.h>
  32 #include <linux/hardirq.h>
  33 #include <asm/prom.h>
  34 #include <asm/machdep.h>
  35 #include <asm/irq.h>
  36 #include <asm/pmac_feature.h>
  37 #include <asm/mmu_context.h>
  38 #include <asm/sections.h>
  39 #include <asm/cputable.h>
  40 #include <asm/time.h>
  41 #include <asm/system.h>
  42 #include <asm/open_pic.h>
  43 #include <asm/keylargo.h>
  44
  45 /* WARNING !!! This will cause calibrate_delay() to be called,
  46  * but this is an __init function ! So you MUST go edit
  47  * init/main.c to make it non-init before enabling DEBUG_FREQ
  48  */
  49 #undef DEBUG_FREQ
  50
  51 /*
  52  * There is a problem with the core cpufreq code on SMP kernels,
  53  * it won't recalculate the Bogomips properly
  54  */
  55 #ifdef CONFIG_SMP
  56 #warning "WARNING, CPUFREQ not recommended on SMP kernels"
  57 #endif
  58
  59 extern void low_choose_7447a_dfs(int dfs);
  60 extern void low_choose_750fx_pll(int pll);
  61 extern void low_sleep_handler(void);
  62
  63 /*
  64  * Currently, PowerMac cpufreq supports only high & low frequencies
  65  * that are set by the firmware
  66  */
  67 static unsigned int low_freq;
  68 static unsigned int hi_freq;
  69 static unsigned int cur_freq;
  70 static unsigned int sleep_freq;
  71
  72 /*
  73  * Different models uses different mecanisms to switch the frequency
  74  */
  75 static int (*set_speed_proc)(int low_speed);
  76 static unsigned int (*get_speed_proc)(void);
  77
  78 /*
  79  * Some definitions used by the various speedprocs
  80  */
  81 static u32 voltage_gpio;
  82 static u32 frequency_gpio;
  83 static u32 slew_done_gpio;
  84 static int no_schedule;
  85 static int has_cpu_l2lve;
  86 static int is_pmu_based;
  87
  88 /* There are only two frequency states for each processor. Values
  89  * are in kHz for the time being.
  90  */
  91 #define CPUFREQ_HIGH                  0
  92 #define CPUFREQ_LOW                   1
  93
  94 static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
  95         {CPUFREQ_HIGH,          0},
  96         {CPUFREQ_LOW,           0},
  97         {0,                     CPUFREQ_TABLE_END},
  98 };
  99
 100 static struct freq_attr* pmac_cpu_freqs_attr[] = {
 101         &cpufreq_freq_attr_scaling_available_freqs,
 102         NULL,
 103 };
 104
 105 static inline void local_delay(unsigned long ms)
 106 {
 107         if (no_schedule)
 108                 mdelay(ms);
 109         else
 110                 msleep(ms);
 111 }
 112
 113 static inline void wakeup_decrementer(void)
 114 {
 115         set_dec(tb_ticks_per_jiffy);
 116         /* No currently-supported powerbook has a 601,
 117          * so use get_tbl, not native
 118          */
 119         last_jiffy_stamp(0) = tb_last_stamp = get_tbl();
 120 }
 121
 122 #ifdef DEBUG_FREQ
 123 static inline void debug_calc_bogomips(void)
 124 {
 125         /* This will cause a recalc of bogomips and display the
 126          * result. We backup/restore the value to avoid affecting the
 127          * core cpufreq framework's own calculation.
 128          */
 129         extern void calibrate_delay(void);
 130
 131         unsigned long save_lpj = loops_per_jiffy;
 132         calibrate_delay();
 133         loops_per_jiffy = save_lpj;
 134 }
 135 #endif /* DEBUG_FREQ */
 136
 137 /* Switch CPU speed under 750FX CPU control
 138  */
 139 static int cpu_750fx_cpu_speed(int low_speed)
 140 {
 141         u32 hid2;
 142
 143         if (low_speed == 0) {
 144                 /* ramping up, set voltage first */
 145                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 146                 /* Make sure we sleep for at least 1ms */
 147                 local_delay(10);
 148
 149                 /* tweak L2 for high voltage */
 150                 if (has_cpu_l2lve) {
 151                         hid2 = mfspr(SPRN_HID2);
 152                         hid2 &= ~0x2000;
 153                         mtspr(SPRN_HID2, hid2);
 154                 }
 155         }
 156 #ifdef CONFIG_6xx
 157         low_choose_750fx_pll(low_speed);
 158 #endif
 159         if (low_speed == 1) {
 160                 /* tweak L2 for low voltage */
 161                 if (has_cpu_l2lve) {
 162                         hid2 = mfspr(SPRN_HID2);
 163                         hid2 |= 0x2000;
 164                         mtspr(SPRN_HID2, hid2);
 165                 }
 166
 167                 /* ramping down, set voltage last */
 168                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 169                 local_delay(10);
 170         }
 171
 172         return 0;
 173 }
 174
 175 static unsigned int cpu_750fx_get_cpu_speed(void)
 176 {
 177         if (mfspr(SPRN_HID1) & HID1_PS)
 178                 return low_freq;
 179         else
 180                 return hi_freq;
 181 }
 182
 183 /* Switch CPU speed using DFS */
 184 static int dfs_set_cpu_speed(int low_speed)
 185 {
 186         if (low_speed == 0) {
 187                 /* ramping up, set voltage first */
 188                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 189                 /* Make sure we sleep for at least 1ms */
 190                 local_delay(1);
 191         }
 192
 193         /* set frequency */
 194 #ifdef CONFIG_6xx
 195         low_choose_7447a_dfs(low_speed);
 196 #endif
 197         udelay(100);
 198
 199         if (low_speed == 1) {
 200                 /* ramping down, set voltage last */
 201                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 202                 local_delay(1);
 203         }
 204
 205         return 0;
 206 }
 207
 208 static unsigned int dfs_get_cpu_speed(void)
 209 {
 210         if (mfspr(SPRN_HID1) & HID1_DFS)
 211                 return low_freq;
 212         else
 213                 return hi_freq;
 214 }
 215
 216
 217 /* Switch CPU speed using slewing GPIOs
 218  */
 219 static int gpios_set_cpu_speed(int low_speed)
 220 {
 221         int gpio, timeout = 0;
 222
 223         /* If ramping up, set voltage first */
 224         if (low_speed == 0) {
 225                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 226                 /* Delay is way too big but it's ok, we schedule */
 227                 local_delay(10);
 228         }
 229
 230         /* Set frequency */
 231         gpio =  pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 232         if (low_speed == ((gpio & 0x01) == 0))
 233                 goto skip;
 234
 235         pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
 236                           low_speed ? 0x04 : 0x05);
 237         udelay(200);
 238         do {
 239                 if (++timeout > 100)
 240                         break;
 241                 local_delay(1);
 242                 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
 243         } while((gpio & 0x02) == 0);
 244  skip:
 245         /* If ramping down, set voltage last */
 246         if (low_speed == 1) {
 247                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 248                 /* Delay is way too big but it's ok, we schedule */
 249                 local_delay(10);
 250         }
 251
 252 #ifdef DEBUG_FREQ
 253         debug_calc_bogomips();
 254 #endif
 255
 256         return 0;
 257 }
 258
 259 /* Switch CPU speed under PMU control
 260  */
 261 static int pmu_set_cpu_speed(int low_speed)
 262 {
 263         struct adb_request req;
 264         unsigned long save_l2cr;
 265         unsigned long save_l3cr;
 266         unsigned int pic_prio;
 267         unsigned long flags;
 268
 269         preempt_disable();
 270
 271 #ifdef DEBUG_FREQ
 272         printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
 273 #endif
 274         pmu_suspend();
 275
 276         /* Disable all interrupt sources on openpic */
 277         pic_prio = openpic_get_priority();
 278         openpic_set_priority(0xf);
 279
 280         /* Make sure the decrementer won't interrupt us */
 281         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 282         /* Make sure any pending DEC interrupt occuring while we did
 283          * the above didn't re-enable the DEC */
 284         mb();
 285         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 286
 287         /* We can now disable MSR_EE */
 288         local_irq_save(flags);
 289
 290         /* Giveup the FPU & vec */
 291         enable_kernel_fp();
 292
 293 #ifdef CONFIG_ALTIVEC
 294         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 295                 enable_kernel_altivec();
 296 #endif /* CONFIG_ALTIVEC */
 297
 298         /* Save & disable L2 and L3 caches */
 299         save_l3cr = _get_L3CR();        /* (returns -1 if not available) */
 300         save_l2cr = _get_L2CR();        /* (returns -1 if not available) */
 301
 302         /* Send the new speed command. My assumption is that this command
 303          * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
 304          */
 305         pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
 306         while (!req.complete)
 307                 pmu_poll();
 308
 309         /* Prepare the northbridge for the speed transition */
 310         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
 311
 312         /* Call low level code to backup CPU state and recover from
 313          * hardware reset
 314          */
 315         low_sleep_handler();
 316
 317         /* Restore the northbridge */
 318         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
 319
 320         /* Restore L2 cache */
 321         if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
 322                 _set_L2CR(save_l2cr);
 323         /* Restore L3 cache */
 324         if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
 325                 _set_L3CR(save_l3cr);
 326
 327         /* Restore userland MMU context */
 328         set_context(current->active_mm->context, current->active_mm->pgd);
 329
 330 #ifdef DEBUG_FREQ
 331         printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
 332 #endif
 333
 334         /* Restore low level PMU operations */
 335         pmu_unlock();
 336
 337         /* Restore decrementer */
 338         wakeup_decrementer();
 339
 340         /* Restore interrupts */
 341         openpic_set_priority(pic_prio);
 342
 343         /* Let interrupts flow again ... */
 344         local_irq_restore(flags);
 345
 346 #ifdef DEBUG_FREQ
 347         debug_calc_bogomips();
 348 #endif
 349
 350         pmu_resume();
 351
 352         preempt_enable();
 353
 354         return 0;
 355 }
 356
 357 static int do_set_cpu_speed(int speed_mode, int notify)
 358 {
 359         struct cpufreq_freqs freqs;
 360         unsigned long l3cr;
 361         static unsigned long prev_l3cr;
 362
 363         freqs.old = cur_freq;
 364         freqs.new = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
 365         freqs.cpu = smp_processor_id();
 366
 367         if (freqs.old == freqs.new)
 368                 return 0;
 369
 370         if (notify)
 371                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 372         if (speed_mode == CPUFREQ_LOW &&
 373             cpu_has_feature(CPU_FTR_L3CR)) {
 374                 l3cr = _get_L3CR();
 375                 if (l3cr & L3CR_L3E) {
 376                         prev_l3cr = l3cr;
 377                         _set_L3CR(0);
 378                 }
 379         }
 380         set_speed_proc(speed_mode == CPUFREQ_LOW);
 381         if (speed_mode == CPUFREQ_HIGH &&
 382             cpu_has_feature(CPU_FTR_L3CR)) {
 383                 l3cr = _get_L3CR();
 384                 if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
 385                         _set_L3CR(prev_l3cr);
 386         }
 387         if (notify)
 388                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 389         cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
 390
 391         return 0;
 392 }
 393
 394 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
 395 {
 396         return cur_freq;
 397 }
 398
 399 static int pmac_cpufreq_verify(struct cpufreq_policy *policy)
 400 {
 401         return cpufreq_frequency_table_verify(policy, pmac_cpu_freqs);
 402 }
 403
 404 static int pmac_cpufreq_target( struct cpufreq_policy *policy,
 405                                         unsigned int target_freq,
 406                                         unsigned int relation)
 407 {
 408         unsigned int    newstate = 0;
 409
 410         if (cpufreq_frequency_table_target(policy, pmac_cpu_freqs,
 411                         target_freq, relation, &newstate))
 412                 return -EINVAL;
 413
 414         return do_set_cpu_speed(newstate, 1);
 415 }
 416
 417 unsigned int pmac_get_one_cpufreq(int i)
 418 {
 419         /* Supports only one CPU for now */
 420         return (i == 0) ? cur_freq : 0;
 421 }
 422
 423 static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
 424 {
 425         if (policy->cpu != 0)
 426                 return -ENODEV;
 427
 428         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 429         policy->cpuinfo.transition_latency      = CPUFREQ_ETERNAL;
 430         policy->cur = cur_freq;
 431
 432         cpufreq_frequency_table_get_attr(pmac_cpu_freqs, policy->cpu);
 433         return cpufreq_frequency_table_cpuinfo(policy, pmac_cpu_freqs);
 434 }
 435
 436 static u32 read_gpio(struct device_node *np)
 437 {
 438         u32 *reg = (u32 *)get_property(np, "reg", NULL);
 439         u32 offset;
 440
 441         if (reg == NULL)
 442                 return 0;
 443         /* That works for all keylargos but shall be fixed properly
 444          * some day... The problem is that it seems we can't rely
 445          * on the "reg" property of the GPIO nodes, they are either
 446          * relative to the base of KeyLargo or to the base of the
 447          * GPIO space, and the device-tree doesn't help.
 448          */
 449         offset = *reg;
 450         if (offset < KEYLARGO_GPIO_LEVELS0)
 451                 offset += KEYLARGO_GPIO_LEVELS0;
 452         return offset;
 453 }
 454
 455 static int pmac_cpufreq_suspend(struct cpufreq_policy *policy, pm_message_t pmsg)
 456 {
 457         /* Ok, this could be made a bit smarter, but let's be robust for now. We
 458          * always force a speed change to high speed before sleep, to make sure
 459          * we have appropriate voltage and/or bus speed for the wakeup process,
 460          * and to make sure our loops_per_jiffies are "good enough", that is will
 461          * not cause too short delays if we sleep in low speed and wake in high
 462          * speed..
 463          */
 464         no_schedule = 1;
 465         sleep_freq = cur_freq;
 466         if (cur_freq == low_freq && !is_pmu_based)
 467                 do_set_cpu_speed(CPUFREQ_HIGH, 0);
 468         return 0;
 469 }
 470
 471 static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
 472 {
 473         /* If we resume, first check if we have a get() function */
 474         if (get_speed_proc)
 475                 cur_freq = get_speed_proc();
 476         else
 477                 cur_freq = 0;
 478
 479         /* We don't, hrm... we don't really know our speed here, best
 480          * is that we force a switch to whatever it was, which is
 481          * probably high speed due to our suspend() routine
 482          */
 483         do_set_cpu_speed(sleep_freq == low_freq ?
 484                          CPUFREQ_LOW : CPUFREQ_HIGH, 0);
 485
 486         no_schedule = 0;
 487         return 0;
 488 }
 489
 490 static struct cpufreq_driver pmac_cpufreq_driver = {
 491         .verify         = pmac_cpufreq_verify,
 492         .target         = pmac_cpufreq_target,
 493         .get            = pmac_cpufreq_get_speed,
 494         .init           = pmac_cpufreq_cpu_init,
 495         .suspend        = pmac_cpufreq_suspend,
 496         .resume         = pmac_cpufreq_resume,
 497         .flags          = CPUFREQ_PM_NO_WARN,
 498         .attr           = pmac_cpu_freqs_attr,
 499         .name           = "powermac",
 500         .owner          = THIS_MODULE,
 501 };
 502
 503
 504 static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
 505 {
 506         struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
 507                                                                 "voltage-gpio");
 508         struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
 509                                                                 "frequency-gpio");
 510         struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
 511                                                                      "slewing-done");
 512         u32 *value;
 513
 514         /*
 515          * Check to see if it's GPIO driven or PMU only
 516          *
 517          * The way we extract the GPIO address is slightly hackish, but it
 518          * works well enough for now. We need to abstract the whole GPIO
 519          * stuff sooner or later anyway
 520          */
 521
 522         if (volt_gpio_np)
 523                 voltage_gpio = read_gpio(volt_gpio_np);
 524         if (freq_gpio_np)
 525                 frequency_gpio = read_gpio(freq_gpio_np);
 526         if (slew_done_gpio_np)
 527                 slew_done_gpio = read_gpio(slew_done_gpio_np);
 528
 529         /* If we use the frequency GPIOs, calculate the min/max speeds based
 530          * on the bus frequencies
 531          */
 532         if (frequency_gpio && slew_done_gpio) {
 533                 int lenp, rc;
 534                 u32 *freqs, *ratio;
 535
 536                 freqs = (u32 *)get_property(cpunode, "bus-frequencies", &lenp);
 537                 lenp /= sizeof(u32);
 538                 if (freqs == NULL || lenp != 2) {
 539                         printk(KERN_ERR "cpufreq: bus-frequencies incorrect or missing\n");
 540                         return 1;
 541                 }
 542                 ratio = (u32 *)get_property(cpunode, "processor-to-bus-ratio*2", NULL);
 543                 if (ratio == NULL) {
 544                         printk(KERN_ERR "cpufreq: processor-to-bus-ratio*2 missing\n");
 545                         return 1;
 546                 }
 547
 548                 /* Get the min/max bus frequencies */
 549                 low_freq = min(freqs[0], freqs[1]);
 550                 hi_freq = max(freqs[0], freqs[1]);
 551
 552                 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
 553                  * frequency, it claims it to be around 84Mhz on some models while
 554                  * it appears to be approx. 101Mhz on all. Let's hack around here...
 555                  * fortunately, we don't need to be too precise
 556                  */
 557                 if (low_freq < 98000000)
 558                         low_freq = 101000000;
 559
 560                 /* Convert those to CPU core clocks */
 561                 low_freq = (low_freq * (*ratio)) / 2000;
 562                 hi_freq = (hi_freq * (*ratio)) / 2000;
 563
 564                 /* Now we get the frequencies, we read the GPIO to see what is out current
 565                  * speed
 566                  */
 567                 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 568                 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
 569
 570                 set_speed_proc = gpios_set_cpu_speed;
 571                 return 1;
 572         }
 573
 574         /* If we use the PMU, look for the min & max frequencies in the
 575          * device-tree
 576          */
 577         value = (u32 *)get_property(cpunode, "min-clock-frequency", NULL);
 578         if (!value)
 579                 return 1;
 580         low_freq = (*value) / 1000;
 581         /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
 582          * here */
 583         if (low_freq < 100000)
 584                 low_freq *= 10;
 585
 586         value = (u32 *)get_property(cpunode, "max-clock-frequency", NULL);
 587         if (!value)
 588                 return 1;
 589         hi_freq = (*value) / 1000;
 590         set_speed_proc = pmu_set_cpu_speed;
 591         is_pmu_based = 1;
 592
 593         return 0;
 594 }
 595
 596 static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
 597 {
 598         struct device_node *volt_gpio_np;
 599
 600         if (get_property(cpunode, "dynamic-power-step", NULL) == NULL)
 601                 return 1;
 602
 603         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 604         if (volt_gpio_np)
 605                 voltage_gpio = read_gpio(volt_gpio_np);
 606         if (!voltage_gpio){
 607                 printk(KERN_ERR "cpufreq: missing cpu-vcore-select gpio\n");
 608                 return 1;
 609         }
 610
 611         /* OF only reports the high frequency */
 612         hi_freq = cur_freq;
 613         low_freq = cur_freq/2;
 614
 615         /* Read actual frequency from CPU */
 616         cur_freq = dfs_get_cpu_speed();
 617         set_speed_proc = dfs_set_cpu_speed;
 618         get_speed_proc = dfs_get_cpu_speed;
 619
 620         return 0;
 621 }
 622
 623 static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
 624 {
 625         struct device_node *volt_gpio_np;
 626         u32 pvr, *value;
 627
 628         if (get_property(cpunode, "dynamic-power-step", NULL) == NULL)
 629                 return 1;
 630
 631         hi_freq = cur_freq;
 632         value = (u32 *)get_property(cpunode, "reduced-clock-frequency", NULL);
 633         if (!value)
 634                 return 1;
 635         low_freq = (*value) / 1000;
 636
 637         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 638         if (volt_gpio_np)
 639                 voltage_gpio = read_gpio(volt_gpio_np);
 640
 641         pvr = mfspr(SPRN_PVR);
 642         has_cpu_l2lve = !((pvr & 0xf00) == 0x100);
 643
 644         set_speed_proc = cpu_750fx_cpu_speed;
 645         get_speed_proc = cpu_750fx_get_cpu_speed;
 646         cur_freq = cpu_750fx_get_cpu_speed();
 647
 648         return 0;
 649 }
 650
 651 /* Currently, we support the following machines:
 652  *
 653  *  - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
 654  *  - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
 655  *  - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
 656  *  - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
 657  *  - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
 658  *  - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
 659  *  - Recent MacRISC3 laptops
 660  *  - All new machines with 7447A CPUs
 661  */
 662 static int __init pmac_cpufreq_setup(void)
 663 {
 664         struct device_node      *cpunode;
 665         u32                     *value;
 666
 667         if (strstr(cmd_line, "nocpufreq"))
 668                 return 0;
 669
 670         /* Assume only one CPU */
 671         cpunode = find_type_devices("cpu");
 672         if (!cpunode)
 673                 goto out;
 674
 675         /* Get current cpu clock freq */
 676         value = (u32 *)get_property(cpunode, "clock-frequency", NULL);
 677         if (!value)
 678                 goto out;
 679         cur_freq = (*value) / 1000;
 680
 681         /*  Check for 7447A based MacRISC3 */
 682         if (machine_is_compatible("MacRISC3") &&
 683             get_property(cpunode, "dynamic-power-step", NULL) &&
 684             PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
 685                 pmac_cpufreq_init_7447A(cpunode);
 686         /* Check for other MacRISC3 machines */
 687         } else if (machine_is_compatible("PowerBook3,4") ||
 688                    machine_is_compatible("PowerBook3,5") ||
 689                    machine_is_compatible("MacRISC3")) {
 690                 pmac_cpufreq_init_MacRISC3(cpunode);
 691         /* Else check for iBook2 500/600 */
 692         } else if (machine_is_compatible("PowerBook4,1")) {
 693                 hi_freq = cur_freq;
 694                 low_freq = 400000;
 695                 set_speed_proc = pmu_set_cpu_speed;
 696                 is_pmu_based = 1;
 697         }
 698         /* Else check for TiPb 400 & 500 */
 699         else if (machine_is_compatible("PowerBook3,2")) {
 700                 /* We only know about the 400 MHz and the 500Mhz model
 701                  * they both have 300 MHz as low frequency
 702                  */
 703                 if (cur_freq < 350000 || cur_freq > 550000)
 704                         goto out;
 705                 hi_freq = cur_freq;
 706                 low_freq = 300000;
 707                 set_speed_proc = pmu_set_cpu_speed;
 708                 is_pmu_based = 1;
 709         }
 710         /* Else check for 750FX */
 711         else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
 712                 pmac_cpufreq_init_750FX(cpunode);
 713 out:
 714         if (set_speed_proc == NULL)
 715                 return -ENODEV;
 716
 717         pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
 718         pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
 719
 720         printk(KERN_INFO "Registering PowerMac CPU frequency driver\n");
 721         printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
 722                low_freq/1000, hi_freq/1000, cur_freq/1000);
 723
 724         return cpufreq_register_driver(&pmac_cpufreq_driver);
 725 }
 726
 727 module_init(pmac_cpufreq_setup);
 728