git.oblomov.eu Git - linux-2.6/blob - arch/powerpc/platforms/powermac/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/mpic.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 #ifdef DEBUG_FREQ
 114 static inline void debug_calc_bogomips(void)
 115 {
 116         /* This will cause a recalc of bogomips and display the
 117          * result. We backup/restore the value to avoid affecting the
 118          * core cpufreq framework's own calculation.
 119          */
 120         extern void calibrate_delay(void);
 121
 122         unsigned long save_lpj = loops_per_jiffy;
 123         calibrate_delay();
 124         loops_per_jiffy = save_lpj;
 125 }
 126 #endif /* DEBUG_FREQ */
 127
 128 /* Switch CPU speed under 750FX CPU control
 129  */
 130 static int cpu_750fx_cpu_speed(int low_speed)
 131 {
 132         u32 hid2;
 133
 134         if (low_speed == 0) {
 135                 /* ramping up, set voltage first */
 136                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 137                 /* Make sure we sleep for at least 1ms */
 138                 local_delay(10);
 139
 140                 /* tweak L2 for high voltage */
 141                 if (has_cpu_l2lve) {
 142                         hid2 = mfspr(SPRN_HID2);
 143                         hid2 &= ~0x2000;
 144                         mtspr(SPRN_HID2, hid2);
 145                 }
 146         }
 147 #ifdef CONFIG_6xx
 148         low_choose_750fx_pll(low_speed);
 149 #endif
 150         if (low_speed == 1) {
 151                 /* tweak L2 for low voltage */
 152                 if (has_cpu_l2lve) {
 153                         hid2 = mfspr(SPRN_HID2);
 154                         hid2 |= 0x2000;
 155                         mtspr(SPRN_HID2, hid2);
 156                 }
 157
 158                 /* ramping down, set voltage last */
 159                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 160                 local_delay(10);
 161         }
 162
 163         return 0;
 164 }
 165
 166 static unsigned int cpu_750fx_get_cpu_speed(void)
 167 {
 168         if (mfspr(SPRN_HID1) & HID1_PS)
 169                 return low_freq;
 170         else
 171                 return hi_freq;
 172 }
 173
 174 /* Switch CPU speed using DFS */
 175 static int dfs_set_cpu_speed(int low_speed)
 176 {
 177         if (low_speed == 0) {
 178                 /* ramping up, set voltage first */
 179                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 180                 /* Make sure we sleep for at least 1ms */
 181                 local_delay(1);
 182         }
 183
 184         /* set frequency */
 185 #ifdef CONFIG_6xx
 186         low_choose_7447a_dfs(low_speed);
 187 #endif
 188         udelay(100);
 189
 190         if (low_speed == 1) {
 191                 /* ramping down, set voltage last */
 192                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 193                 local_delay(1);
 194         }
 195
 196         return 0;
 197 }
 198
 199 static unsigned int dfs_get_cpu_speed(void)
 200 {
 201         if (mfspr(SPRN_HID1) & HID1_DFS)
 202                 return low_freq;
 203         else
 204                 return hi_freq;
 205 }
 206
 207
 208 /* Switch CPU speed using slewing GPIOs
 209  */
 210 static int gpios_set_cpu_speed(int low_speed)
 211 {
 212         int gpio, timeout = 0;
 213
 214         /* If ramping up, set voltage first */
 215         if (low_speed == 0) {
 216                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 217                 /* Delay is way too big but it's ok, we schedule */
 218                 local_delay(10);
 219         }
 220
 221         /* Set frequency */
 222         gpio =  pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 223         if (low_speed == ((gpio & 0x01) == 0))
 224                 goto skip;
 225
 226         pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
 227                           low_speed ? 0x04 : 0x05);
 228         udelay(200);
 229         do {
 230                 if (++timeout > 100)
 231                         break;
 232                 local_delay(1);
 233                 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
 234         } while((gpio & 0x02) == 0);
 235  skip:
 236         /* If ramping down, set voltage last */
 237         if (low_speed == 1) {
 238                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 239                 /* Delay is way too big but it's ok, we schedule */
 240                 local_delay(10);
 241         }
 242
 243 #ifdef DEBUG_FREQ
 244         debug_calc_bogomips();
 245 #endif
 246
 247         return 0;
 248 }
 249
 250 /* Switch CPU speed under PMU control
 251  */
 252 static int pmu_set_cpu_speed(int low_speed)
 253 {
 254         struct adb_request req;
 255         unsigned long save_l2cr;
 256         unsigned long save_l3cr;
 257         unsigned int pic_prio;
 258         unsigned long flags;
 259
 260         preempt_disable();
 261
 262 #ifdef DEBUG_FREQ
 263         printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
 264 #endif
 265         pmu_suspend();
 266
 267         /* Disable all interrupt sources on openpic */
 268         pic_prio = mpic_cpu_get_priority();
 269         mpic_cpu_set_priority(0xf);
 270
 271         /* Make sure the decrementer won't interrupt us */
 272         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 273         /* Make sure any pending DEC interrupt occuring while we did
 274          * the above didn't re-enable the DEC */
 275         mb();
 276         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 277
 278         /* We can now disable MSR_EE */
 279         local_irq_save(flags);
 280
 281         /* Giveup the FPU & vec */
 282         enable_kernel_fp();
 283
 284 #ifdef CONFIG_ALTIVEC
 285         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 286                 enable_kernel_altivec();
 287 #endif /* CONFIG_ALTIVEC */
 288
 289         /* Save & disable L2 and L3 caches */
 290         save_l3cr = _get_L3CR();        /* (returns -1 if not available) */
 291         save_l2cr = _get_L2CR();        /* (returns -1 if not available) */
 292
 293         /* Send the new speed command. My assumption is that this command
 294          * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
 295          */
 296         pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
 297         while (!req.complete)
 298                 pmu_poll();
 299
 300         /* Prepare the northbridge for the speed transition */
 301         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
 302
 303         /* Call low level code to backup CPU state and recover from
 304          * hardware reset
 305          */
 306         low_sleep_handler();
 307
 308         /* Restore the northbridge */
 309         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
 310
 311         /* Restore L2 cache */
 312         if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
 313                 _set_L2CR(save_l2cr);
 314         /* Restore L3 cache */
 315         if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
 316                 _set_L3CR(save_l3cr);
 317
 318         /* Restore userland MMU context */
 319         set_context(current->active_mm->context, current->active_mm->pgd);
 320
 321 #ifdef DEBUG_FREQ
 322         printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
 323 #endif
 324
 325         /* Restore low level PMU operations */
 326         pmu_unlock();
 327
 328         /* Restore decrementer */
 329         wakeup_decrementer();
 330
 331         /* Restore interrupts */
 332         mpic_cpu_set_priority(pic_prio);
 333
 334         /* Let interrupts flow again ... */
 335         local_irq_restore(flags);
 336
 337 #ifdef DEBUG_FREQ
 338         debug_calc_bogomips();
 339 #endif
 340
 341         pmu_resume();
 342
 343         preempt_enable();
 344
 345         return 0;
 346 }
 347
 348 static int do_set_cpu_speed(int speed_mode, int notify)
 349 {
 350         struct cpufreq_freqs freqs;
 351         unsigned long l3cr;
 352         static unsigned long prev_l3cr;
 353
 354         freqs.old = cur_freq;
 355         freqs.new = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
 356         freqs.cpu = smp_processor_id();
 357
 358         if (freqs.old == freqs.new)
 359                 return 0;
 360
 361         if (notify)
 362                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 363         if (speed_mode == CPUFREQ_LOW &&
 364             cpu_has_feature(CPU_FTR_L3CR)) {
 365                 l3cr = _get_L3CR();
 366                 if (l3cr & L3CR_L3E) {
 367                         prev_l3cr = l3cr;
 368                         _set_L3CR(0);
 369                 }
 370         }
 371         set_speed_proc(speed_mode == CPUFREQ_LOW);
 372         if (speed_mode == CPUFREQ_HIGH &&
 373             cpu_has_feature(CPU_FTR_L3CR)) {
 374                 l3cr = _get_L3CR();
 375                 if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
 376                         _set_L3CR(prev_l3cr);
 377         }
 378         if (notify)
 379                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 380         cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
 381
 382         return 0;
 383 }
 384
 385 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
 386 {
 387         return cur_freq;
 388 }
 389
 390 static int pmac_cpufreq_verify(struct cpufreq_policy *policy)
 391 {
 392         return cpufreq_frequency_table_verify(policy, pmac_cpu_freqs);
 393 }
 394
 395 static int pmac_cpufreq_target( struct cpufreq_policy *policy,
 396                                         unsigned int target_freq,
 397                                         unsigned int relation)
 398 {
 399         unsigned int    newstate = 0;
 400
 401         if (cpufreq_frequency_table_target(policy, pmac_cpu_freqs,
 402                         target_freq, relation, &newstate))
 403                 return -EINVAL;
 404
 405         return do_set_cpu_speed(newstate, 1);
 406 }
 407
 408 unsigned int pmac_get_one_cpufreq(int i)
 409 {
 410         /* Supports only one CPU for now */
 411         return (i == 0) ? cur_freq : 0;
 412 }
 413
 414 static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
 415 {
 416         if (policy->cpu != 0)
 417                 return -ENODEV;
 418
 419         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 420         policy->cpuinfo.transition_latency      = CPUFREQ_ETERNAL;
 421         policy->cur = cur_freq;
 422
 423         cpufreq_frequency_table_get_attr(pmac_cpu_freqs, policy->cpu);
 424         return cpufreq_frequency_table_cpuinfo(policy, pmac_cpu_freqs);
 425 }
 426
 427 static u32 read_gpio(struct device_node *np)
 428 {
 429         u32 *reg = (u32 *)get_property(np, "reg", NULL);
 430         u32 offset;
 431
 432         if (reg == NULL)
 433                 return 0;
 434         /* That works for all keylargos but shall be fixed properly
 435          * some day... The problem is that it seems we can't rely
 436          * on the "reg" property of the GPIO nodes, they are either
 437          * relative to the base of KeyLargo or to the base of the
 438          * GPIO space, and the device-tree doesn't help.
 439          */
 440         offset = *reg;
 441         if (offset < KEYLARGO_GPIO_LEVELS0)
 442                 offset += KEYLARGO_GPIO_LEVELS0;
 443         return offset;
 444 }
 445
 446 static int pmac_cpufreq_suspend(struct cpufreq_policy *policy, pm_message_t pmsg)
 447 {
 448         /* Ok, this could be made a bit smarter, but let's be robust for now. We
 449          * always force a speed change to high speed before sleep, to make sure
 450          * we have appropriate voltage and/or bus speed for the wakeup process,
 451          * and to make sure our loops_per_jiffies are "good enough", that is will
 452          * not cause too short delays if we sleep in low speed and wake in high
 453          * speed..
 454          */
 455         no_schedule = 1;
 456         sleep_freq = cur_freq;
 457         if (cur_freq == low_freq && !is_pmu_based)
 458                 do_set_cpu_speed(CPUFREQ_HIGH, 0);
 459         return 0;
 460 }
 461
 462 static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
 463 {
 464         /* If we resume, first check if we have a get() function */
 465         if (get_speed_proc)
 466                 cur_freq = get_speed_proc();
 467         else
 468                 cur_freq = 0;
 469
 470         /* We don't, hrm... we don't really know our speed here, best
 471          * is that we force a switch to whatever it was, which is
 472          * probably high speed due to our suspend() routine
 473          */
 474         do_set_cpu_speed(sleep_freq == low_freq ?
 475                          CPUFREQ_LOW : CPUFREQ_HIGH, 0);
 476
 477         no_schedule = 0;
 478         return 0;
 479 }
 480
 481 static struct cpufreq_driver pmac_cpufreq_driver = {
 482         .verify         = pmac_cpufreq_verify,
 483         .target         = pmac_cpufreq_target,
 484         .get            = pmac_cpufreq_get_speed,
 485         .init           = pmac_cpufreq_cpu_init,
 486         .suspend        = pmac_cpufreq_suspend,
 487         .resume         = pmac_cpufreq_resume,
 488         .flags          = CPUFREQ_PM_NO_WARN,
 489         .attr           = pmac_cpu_freqs_attr,
 490         .name           = "powermac",
 491         .owner          = THIS_MODULE,
 492 };
 493
 494
 495 static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
 496 {
 497         struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
 498                                                                 "voltage-gpio");
 499         struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
 500                                                                 "frequency-gpio");
 501         struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
 502                                                                      "slewing-done");
 503         u32 *value;
 504
 505         /*
 506          * Check to see if it's GPIO driven or PMU only
 507          *
 508          * The way we extract the GPIO address is slightly hackish, but it
 509          * works well enough for now. We need to abstract the whole GPIO
 510          * stuff sooner or later anyway
 511          */
 512
 513         if (volt_gpio_np)
 514                 voltage_gpio = read_gpio(volt_gpio_np);
 515         if (freq_gpio_np)
 516                 frequency_gpio = read_gpio(freq_gpio_np);
 517         if (slew_done_gpio_np)
 518                 slew_done_gpio = read_gpio(slew_done_gpio_np);
 519
 520         /* If we use the frequency GPIOs, calculate the min/max speeds based
 521          * on the bus frequencies
 522          */
 523         if (frequency_gpio && slew_done_gpio) {
 524                 int lenp, rc;
 525                 u32 *freqs, *ratio;
 526
 527                 freqs = (u32 *)get_property(cpunode, "bus-frequencies", &lenp);
 528                 lenp /= sizeof(u32);
 529                 if (freqs == NULL || lenp != 2) {
 530                         printk(KERN_ERR "cpufreq: bus-frequencies incorrect or missing\n");
 531                         return 1;
 532                 }
 533                 ratio = (u32 *)get_property(cpunode, "processor-to-bus-ratio*2", NULL);
 534                 if (ratio == NULL) {
 535                         printk(KERN_ERR "cpufreq: processor-to-bus-ratio*2 missing\n");
 536                         return 1;
 537                 }
 538
 539                 /* Get the min/max bus frequencies */
 540                 low_freq = min(freqs[0], freqs[1]);
 541                 hi_freq = max(freqs[0], freqs[1]);
 542
 543                 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
 544                  * frequency, it claims it to be around 84Mhz on some models while
 545                  * it appears to be approx. 101Mhz on all. Let's hack around here...
 546                  * fortunately, we don't need to be too precise
 547                  */
 548                 if (low_freq < 98000000)
 549                         low_freq = 101000000;
 550
 551                 /* Convert those to CPU core clocks */
 552                 low_freq = (low_freq * (*ratio)) / 2000;
 553                 hi_freq = (hi_freq * (*ratio)) / 2000;
 554
 555                 /* Now we get the frequencies, we read the GPIO to see what is out current
 556                  * speed
 557                  */
 558                 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 559                 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
 560
 561                 set_speed_proc = gpios_set_cpu_speed;
 562                 return 1;
 563         }
 564
 565         /* If we use the PMU, look for the min & max frequencies in the
 566          * device-tree
 567          */
 568         value = (u32 *)get_property(cpunode, "min-clock-frequency", NULL);
 569         if (!value)
 570                 return 1;
 571         low_freq = (*value) / 1000;
 572         /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
 573          * here */
 574         if (low_freq < 100000)
 575                 low_freq *= 10;
 576
 577         value = (u32 *)get_property(cpunode, "max-clock-frequency", NULL);
 578         if (!value)
 579                 return 1;
 580         hi_freq = (*value) / 1000;
 581         set_speed_proc = pmu_set_cpu_speed;
 582         is_pmu_based = 1;
 583
 584         return 0;
 585 }
 586
 587 static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
 588 {
 589         struct device_node *volt_gpio_np;
 590
 591         if (get_property(cpunode, "dynamic-power-step", NULL) == NULL)
 592                 return 1;
 593
 594         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 595         if (volt_gpio_np)
 596                 voltage_gpio = read_gpio(volt_gpio_np);
 597         if (!voltage_gpio){
 598                 printk(KERN_ERR "cpufreq: missing cpu-vcore-select gpio\n");
 599                 return 1;
 600         }
 601
 602         /* OF only reports the high frequency */
 603         hi_freq = cur_freq;
 604         low_freq = cur_freq/2;
 605
 606         /* Read actual frequency from CPU */
 607         cur_freq = dfs_get_cpu_speed();
 608         set_speed_proc = dfs_set_cpu_speed;
 609         get_speed_proc = dfs_get_cpu_speed;
 610
 611         return 0;
 612 }
 613
 614 static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
 615 {
 616         struct device_node *volt_gpio_np;
 617         u32 pvr, *value;
 618
 619         if (get_property(cpunode, "dynamic-power-step", NULL) == NULL)
 620                 return 1;
 621
 622         hi_freq = cur_freq;
 623         value = (u32 *)get_property(cpunode, "reduced-clock-frequency", NULL);
 624         if (!value)
 625                 return 1;
 626         low_freq = (*value) / 1000;
 627
 628         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 629         if (volt_gpio_np)
 630                 voltage_gpio = read_gpio(volt_gpio_np);
 631
 632         pvr = mfspr(SPRN_PVR);
 633         has_cpu_l2lve = !((pvr & 0xf00) == 0x100);
 634
 635         set_speed_proc = cpu_750fx_cpu_speed;
 636         get_speed_proc = cpu_750fx_get_cpu_speed;
 637         cur_freq = cpu_750fx_get_cpu_speed();
 638
 639         return 0;
 640 }
 641
 642 /* Currently, we support the following machines:
 643  *
 644  *  - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
 645  *  - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
 646  *  - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
 647  *  - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
 648  *  - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
 649  *  - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
 650  *  - Recent MacRISC3 laptops
 651  *  - All new machines with 7447A CPUs
 652  */
 653 static int __init pmac_cpufreq_setup(void)
 654 {
 655         struct device_node      *cpunode;
 656         u32                     *value;
 657
 658         if (strstr(cmd_line, "nocpufreq"))
 659                 return 0;
 660
 661         /* Assume only one CPU */
 662         cpunode = find_type_devices("cpu");
 663         if (!cpunode)
 664                 goto out;
 665
 666         /* Get current cpu clock freq */
 667         value = (u32 *)get_property(cpunode, "clock-frequency", NULL);
 668         if (!value)
 669                 goto out;
 670         cur_freq = (*value) / 1000;
 671
 672         /*  Check for 7447A based MacRISC3 */
 673         if (machine_is_compatible("MacRISC3") &&
 674             get_property(cpunode, "dynamic-power-step", NULL) &&
 675             PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
 676                 pmac_cpufreq_init_7447A(cpunode);
 677         /* Check for other MacRISC3 machines */
 678         } else if (machine_is_compatible("PowerBook3,4") ||
 679                    machine_is_compatible("PowerBook3,5") ||
 680                    machine_is_compatible("MacRISC3")) {
 681                 pmac_cpufreq_init_MacRISC3(cpunode);
 682         /* Else check for iBook2 500/600 */
 683         } else if (machine_is_compatible("PowerBook4,1")) {
 684                 hi_freq = cur_freq;
 685                 low_freq = 400000;
 686                 set_speed_proc = pmu_set_cpu_speed;
 687                 is_pmu_based = 1;
 688         }
 689         /* Else check for TiPb 550 */
 690         else if (machine_is_compatible("PowerBook3,3") && cur_freq == 550000) {
 691                 hi_freq = cur_freq;
 692                 low_freq = 500000;
 693                 set_speed_proc = pmu_set_cpu_speed;
 694                 is_pmu_based = 1;
 695         }
 696         /* Else check for TiPb 400 & 500 */
 697         else if (machine_is_compatible("PowerBook3,2")) {
 698                 /* We only know about the 400 MHz and the 500Mhz model
 699                  * they both have 300 MHz as low frequency
 700                  */
 701                 if (cur_freq < 350000 || cur_freq > 550000)
 702                         goto out;
 703                 hi_freq = cur_freq;
 704                 low_freq = 300000;
 705                 set_speed_proc = pmu_set_cpu_speed;
 706                 is_pmu_based = 1;
 707         }
 708         /* Else check for 750FX */
 709         else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
 710                 pmac_cpufreq_init_750FX(cpunode);
 711 out:
 712         if (set_speed_proc == NULL)
 713                 return -ENODEV;
 714
 715         pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
 716         pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
 717
 718         printk(KERN_INFO "Registering PowerMac CPU frequency driver\n");
 719         printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
 720                low_freq/1000, hi_freq/1000, cur_freq/1000);
 721
 722         return cpufreq_register_driver(&pmac_cpufreq_driver);
 723 }
 724
 725 module_init(pmac_cpufreq_setup);
 726