drivers/cpufreq/pmac32-cpufreq.c

   1 /*
   2  *  Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
   3  *  Copyright (C) 2004        John Steele Scott <toojays@toojays.net>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * TODO: Need a big cleanup here. Basically, we need to have different
  10  * cpufreq_driver structures for the different type of HW instead of the
  11  * current mess. We also need to better deal with the detection of the
  12  * type of machine.
  13  *
  14  */
  15
  16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17
  18 #include <linux/module.h>
  19 #include <linux/types.h>
  20 #include <linux/errno.h>
  21 #include <linux/kernel.h>
  22 #include <linux/delay.h>
  23 #include <linux/sched.h>
  24 #include <linux/adb.h>
  25 #include <linux/pmu.h>
  26 #include <linux/cpufreq.h>
  27 #include <linux/init.h>
  28 #include <linux/device.h>
  29 #include <linux/hardirq.h>
  30 #include <linux/of_device.h>
  31 #include <asm/prom.h>
  32 #include <asm/machdep.h>
  33 #include <asm/irq.h>
  34 #include <asm/pmac_feature.h>
  35 #include <asm/mmu_context.h>
  36 #include <asm/sections.h>
  37 #include <asm/cputable.h>
  38 #include <asm/time.h>
  39 #include <asm/mpic.h>
  40 #include <asm/keylargo.h>
  41 #include <asm/switch_to.h>
  42
  43 /* WARNING !!! This will cause calibrate_delay() to be called,
  44  * but this is an __init function ! So you MUST go edit
  45  * init/main.c to make it non-init before enabling DEBUG_FREQ
  46  */
  47 #undef DEBUG_FREQ
  48
  49 extern void low_choose_7447a_dfs(int dfs);
  50 extern void low_choose_750fx_pll(int pll);
  51 extern void low_sleep_handler(void);
  52
  53 /*
  54  * Currently, PowerMac cpufreq supports only high & low frequencies
  55  * that are set by the firmware
  56  */
  57 static unsigned int low_freq;
  58 static unsigned int hi_freq;
  59 static unsigned int cur_freq;
  60 static unsigned int sleep_freq;
  61 static unsigned long transition_latency;
  62
  63 /*
  64  * Different models uses different mechanisms to switch the frequency
  65  */
  66 static int (*set_speed_proc)(int low_speed);
  67 static unsigned int (*get_speed_proc)(void);
  68
  69 /*
  70  * Some definitions used by the various speedprocs
  71  */
  72 static u32 voltage_gpio;
  73 static u32 frequency_gpio;
  74 static u32 slew_done_gpio;
  75 static int no_schedule;
  76 static int has_cpu_l2lve;
  77 static int is_pmu_based;
  78
  79 /* There are only two frequency states for each processor. Values
  80  * are in kHz for the time being.
  81  */
  82 #define CPUFREQ_HIGH                  0
  83 #define CPUFREQ_LOW                   1
  84
  85 static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
  86         {0, CPUFREQ_HIGH,       0},
  87         {0, CPUFREQ_LOW,        0},
  88         {0, 0,                  CPUFREQ_TABLE_END},
  89 };
  90
  91 static inline void local_delay(unsigned long ms)
  92 {
  93         if (no_schedule)
  94                 mdelay(ms);
  95         else
  96                 msleep(ms);
  97 }
  98
  99 #ifdef DEBUG_FREQ
 100 static inline void debug_calc_bogomips(void)
 101 {
 102         /* This will cause a recalc of bogomips and display the
 103          * result. We backup/restore the value to avoid affecting the
 104          * core cpufreq framework's own calculation.
 105          */
 106         unsigned long save_lpj = loops_per_jiffy;
 107         calibrate_delay();
 108         loops_per_jiffy = save_lpj;
 109 }
 110 #endif /* DEBUG_FREQ */
 111
 112 /* Switch CPU speed under 750FX CPU control
 113  */
 114 static int cpu_750fx_cpu_speed(int low_speed)
 115 {
 116         u32 hid2;
 117
 118         if (low_speed == 0) {
 119                 /* ramping up, set voltage first */
 120                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 121                 /* Make sure we sleep for at least 1ms */
 122                 local_delay(10);
 123
 124                 /* tweak L2 for high voltage */
 125                 if (has_cpu_l2lve) {
 126                         hid2 = mfspr(SPRN_HID2);
 127                         hid2 &= ~0x2000;
 128                         mtspr(SPRN_HID2, hid2);
 129                 }
 130         }
 131 #ifdef CONFIG_6xx
 132         low_choose_750fx_pll(low_speed);
 133 #endif
 134         if (low_speed == 1) {
 135                 /* tweak L2 for low voltage */
 136                 if (has_cpu_l2lve) {
 137                         hid2 = mfspr(SPRN_HID2);
 138                         hid2 |= 0x2000;
 139                         mtspr(SPRN_HID2, hid2);
 140                 }
 141
 142                 /* ramping down, set voltage last */
 143                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 144                 local_delay(10);
 145         }
 146
 147         return 0;
 148 }
 149
 150 static unsigned int cpu_750fx_get_cpu_speed(void)
 151 {
 152         if (mfspr(SPRN_HID1) & HID1_PS)
 153                 return low_freq;
 154         else
 155                 return hi_freq;
 156 }
 157
 158 /* Switch CPU speed using DFS */
 159 static int dfs_set_cpu_speed(int low_speed)
 160 {
 161         if (low_speed == 0) {
 162                 /* ramping up, set voltage first */
 163                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 164                 /* Make sure we sleep for at least 1ms */
 165                 local_delay(1);
 166         }
 167
 168         /* set frequency */
 169 #ifdef CONFIG_6xx
 170         low_choose_7447a_dfs(low_speed);
 171 #endif
 172         udelay(100);
 173
 174         if (low_speed == 1) {
 175                 /* ramping down, set voltage last */
 176                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 177                 local_delay(1);
 178         }
 179
 180         return 0;
 181 }
 182
 183 static unsigned int dfs_get_cpu_speed(void)
 184 {
 185         if (mfspr(SPRN_HID1) & HID1_DFS)
 186                 return low_freq;
 187         else
 188                 return hi_freq;
 189 }
 190
 191
 192 /* Switch CPU speed using slewing GPIOs
 193  */
 194 static int gpios_set_cpu_speed(int low_speed)
 195 {
 196         int gpio, timeout = 0;
 197
 198         /* If ramping up, set voltage first */
 199         if (low_speed == 0) {
 200                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 201                 /* Delay is way too big but it's ok, we schedule */
 202                 local_delay(10);
 203         }
 204
 205         /* Set frequency */
 206         gpio =  pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 207         if (low_speed == ((gpio & 0x01) == 0))
 208                 goto skip;
 209
 210         pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
 211                           low_speed ? 0x04 : 0x05);
 212         udelay(200);
 213         do {
 214                 if (++timeout > 100)
 215                         break;
 216                 local_delay(1);
 217                 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
 218         } while((gpio & 0x02) == 0);
 219  skip:
 220         /* If ramping down, set voltage last */
 221         if (low_speed == 1) {
 222                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 223                 /* Delay is way too big but it's ok, we schedule */
 224                 local_delay(10);
 225         }
 226
 227 #ifdef DEBUG_FREQ
 228         debug_calc_bogomips();
 229 #endif
 230
 231         return 0;
 232 }
 233
 234 /* Switch CPU speed under PMU control
 235  */
 236 static int pmu_set_cpu_speed(int low_speed)
 237 {
 238         struct adb_request req;
 239         unsigned long save_l2cr;
 240         unsigned long save_l3cr;
 241         unsigned int pic_prio;
 242         unsigned long flags;
 243
 244         preempt_disable();
 245
 246 #ifdef DEBUG_FREQ
 247         printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
 248 #endif
 249         pmu_suspend();
 250
 251         /* Disable all interrupt sources on openpic */
 252         pic_prio = mpic_cpu_get_priority();
 253         mpic_cpu_set_priority(0xf);
 254
 255         /* Make sure the decrementer won't interrupt us */
 256         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 257         /* Make sure any pending DEC interrupt occurring while we did
 258          * the above didn't re-enable the DEC */
 259         mb();
 260         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 261
 262         /* We can now disable MSR_EE */
 263         local_irq_save(flags);
 264
 265         /* Giveup the FPU & vec */
 266         enable_kernel_fp();
 267
 268 #ifdef CONFIG_ALTIVEC
 269         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 270                 enable_kernel_altivec();
 271 #endif /* CONFIG_ALTIVEC */
 272
 273         /* Save & disable L2 and L3 caches */
 274         save_l3cr = _get_L3CR();        /* (returns -1 if not available) */
 275         save_l2cr = _get_L2CR();        /* (returns -1 if not available) */
 276
 277         /* Send the new speed command. My assumption is that this command
 278          * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
 279          */
 280         pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
 281         while (!req.complete)
 282                 pmu_poll();
 283
 284         /* Prepare the northbridge for the speed transition */
 285         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
 286
 287         /* Call low level code to backup CPU state and recover from
 288          * hardware reset
 289          */
 290         low_sleep_handler();
 291
 292         /* Restore the northbridge */
 293         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
 294
 295         /* Restore L2 cache */
 296         if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
 297                 _set_L2CR(save_l2cr);
 298         /* Restore L3 cache */
 299         if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
 300                 _set_L3CR(save_l3cr);
 301
 302         /* Restore userland MMU context */
 303         switch_mmu_context(NULL, current->active_mm, NULL);
 304
 305 #ifdef DEBUG_FREQ
 306         printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
 307 #endif
 308
 309         /* Restore low level PMU operations */
 310         pmu_unlock();
 311
 312         /*
 313          * Restore decrementer; we'll take a decrementer interrupt
 314          * as soon as interrupts are re-enabled and the generic
 315          * clockevents code will reprogram it with the right value.
 316          */
 317         set_dec(1);
 318
 319         /* Restore interrupts */
 320         mpic_cpu_set_priority(pic_prio);
 321
 322         /* Let interrupts flow again ... */
 323         local_irq_restore(flags);
 324
 325 #ifdef DEBUG_FREQ
 326         debug_calc_bogomips();
 327 #endif
 328
 329         pmu_resume();
 330
 331         preempt_enable();
 332
 333         return 0;
 334 }
 335
 336 static int do_set_cpu_speed(struct cpufreq_policy *policy, int speed_mode)
 337 {
 338         unsigned long l3cr;
 339         static unsigned long prev_l3cr;
 340
 341         if (speed_mode == CPUFREQ_LOW &&
 342             cpu_has_feature(CPU_FTR_L3CR)) {
 343                 l3cr = _get_L3CR();
 344                 if (l3cr & L3CR_L3E) {
 345                         prev_l3cr = l3cr;
 346                         _set_L3CR(0);
 347                 }
 348         }
 349         set_speed_proc(speed_mode == CPUFREQ_LOW);
 350         if (speed_mode == CPUFREQ_HIGH &&
 351             cpu_has_feature(CPU_FTR_L3CR)) {
 352                 l3cr = _get_L3CR();
 353                 if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
 354                         _set_L3CR(prev_l3cr);
 355         }
 356         cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
 357
 358         return 0;
 359 }
 360
 361 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
 362 {
 363         return cur_freq;
 364 }
 365
 366 static int pmac_cpufreq_target( struct cpufreq_policy *policy,
 367                                         unsigned int index)
 368 {
 369         int             rc;
 370
 371         rc = do_set_cpu_speed(policy, index);
 372
 373         ppc_proc_freq = cur_freq * 1000ul;
 374         return rc;
 375 }
 376
 377 static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
 378 {
 379         return cpufreq_generic_init(policy, pmac_cpu_freqs, transition_latency);
 380 }
 381
 382 static u32 read_gpio(struct device_node *np)
 383 {
 384         const u32 *reg = of_get_property(np, "reg", NULL);
 385         u32 offset;
 386
 387         if (reg == NULL)
 388                 return 0;
 389         /* That works for all keylargos but shall be fixed properly
 390          * some day... The problem is that it seems we can't rely
 391          * on the "reg" property of the GPIO nodes, they are either
 392          * relative to the base of KeyLargo or to the base of the
 393          * GPIO space, and the device-tree doesn't help.
 394          */
 395         offset = *reg;
 396         if (offset < KEYLARGO_GPIO_LEVELS0)
 397                 offset += KEYLARGO_GPIO_LEVELS0;
 398         return offset;
 399 }
 400
 401 static int pmac_cpufreq_suspend(struct cpufreq_policy *policy)
 402 {
 403         /* Ok, this could be made a bit smarter, but let's be robust for now. We
 404          * always force a speed change to high speed before sleep, to make sure
 405          * we have appropriate voltage and/or bus speed for the wakeup process,
 406          * and to make sure our loops_per_jiffies are "good enough", that is will
 407          * not cause too short delays if we sleep in low speed and wake in high
 408          * speed..
 409          */
 410         no_schedule = 1;
 411         sleep_freq = cur_freq;
 412         if (cur_freq == low_freq && !is_pmu_based)
 413                 do_set_cpu_speed(policy, CPUFREQ_HIGH);
 414         return 0;
 415 }
 416
 417 static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
 418 {
 419         /* If we resume, first check if we have a get() function */
 420         if (get_speed_proc)
 421                 cur_freq = get_speed_proc();
 422         else
 423                 cur_freq = 0;
 424
 425         /* We don't, hrm... we don't really know our speed here, best
 426          * is that we force a switch to whatever it was, which is
 427          * probably high speed due to our suspend() routine
 428          */
 429         do_set_cpu_speed(policy, sleep_freq == low_freq ?
 430                          CPUFREQ_LOW : CPUFREQ_HIGH);
 431
 432         ppc_proc_freq = cur_freq * 1000ul;
 433
 434         no_schedule = 0;
 435         return 0;
 436 }
 437
 438 static struct cpufreq_driver pmac_cpufreq_driver = {
 439         .verify         = cpufreq_generic_frequency_table_verify,
 440         .target_index   = pmac_cpufreq_target,
 441         .get            = pmac_cpufreq_get_speed,
 442         .init           = pmac_cpufreq_cpu_init,
 443         .suspend        = pmac_cpufreq_suspend,
 444         .resume         = pmac_cpufreq_resume,
 445         .flags          = CPUFREQ_PM_NO_WARN |
 446                           CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
 447         .attr           = cpufreq_generic_attr,
 448         .name           = "powermac",
 449 };
 450
 451
 452 static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
 453 {
 454         struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
 455                                                                 "voltage-gpio");
 456         struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
 457                                                                 "frequency-gpio");
 458         struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
 459                                                                      "slewing-done");
 460         const u32 *value;
 461
 462         /*
 463          * Check to see if it's GPIO driven or PMU only
 464          *
 465          * The way we extract the GPIO address is slightly hackish, but it
 466          * works well enough for now. We need to abstract the whole GPIO
 467          * stuff sooner or later anyway
 468          */
 469
 470         if (volt_gpio_np)
 471                 voltage_gpio = read_gpio(volt_gpio_np);
 472         if (freq_gpio_np)
 473                 frequency_gpio = read_gpio(freq_gpio_np);
 474         if (slew_done_gpio_np)
 475                 slew_done_gpio = read_gpio(slew_done_gpio_np);
 476
 477         of_node_put(volt_gpio_np);
 478         of_node_put(freq_gpio_np);
 479         of_node_put(slew_done_gpio_np);
 480
 481         /* If we use the frequency GPIOs, calculate the min/max speeds based
 482          * on the bus frequencies
 483          */
 484         if (frequency_gpio && slew_done_gpio) {
 485                 int lenp, rc;
 486                 const u32 *freqs, *ratio;
 487
 488                 freqs = of_get_property(cpunode, "bus-frequencies", &lenp);
 489                 lenp /= sizeof(u32);
 490                 if (freqs == NULL || lenp != 2) {
 491                         pr_err("bus-frequencies incorrect or missing\n");
 492                         return 1;
 493                 }
 494                 ratio = of_get_property(cpunode, "processor-to-bus-ratio*2",
 495                                                 NULL);
 496                 if (ratio == NULL) {
 497                         pr_err("processor-to-bus-ratio*2 missing\n");
 498                         return 1;
 499                 }
 500
 501                 /* Get the min/max bus frequencies */
 502                 low_freq = min(freqs[0], freqs[1]);
 503                 hi_freq = max(freqs[0], freqs[1]);
 504
 505                 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
 506                  * frequency, it claims it to be around 84Mhz on some models while
 507                  * it appears to be approx. 101Mhz on all. Let's hack around here...
 508                  * fortunately, we don't need to be too precise
 509                  */
 510                 if (low_freq < 98000000)
 511                         low_freq = 101000000;
 512
 513                 /* Convert those to CPU core clocks */
 514                 low_freq = (low_freq * (*ratio)) / 2000;
 515                 hi_freq = (hi_freq * (*ratio)) / 2000;
 516
 517                 /* Now we get the frequencies, we read the GPIO to see what is out current
 518                  * speed
 519                  */
 520                 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 521                 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
 522
 523                 set_speed_proc = gpios_set_cpu_speed;
 524                 return 1;
 525         }
 526
 527         /* If we use the PMU, look for the min & max frequencies in the
 528          * device-tree
 529          */
 530         value = of_get_property(cpunode, "min-clock-frequency", NULL);
 531         if (!value)
 532                 return 1;
 533         low_freq = (*value) / 1000;
 534         /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
 535          * here */
 536         if (low_freq < 100000)
 537                 low_freq *= 10;
 538
 539         value = of_get_property(cpunode, "max-clock-frequency", NULL);
 540         if (!value)
 541                 return 1;
 542         hi_freq = (*value) / 1000;
 543         set_speed_proc = pmu_set_cpu_speed;
 544         is_pmu_based = 1;
 545
 546         return 0;
 547 }
 548
 549 static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
 550 {
 551         struct device_node *volt_gpio_np;
 552
 553         if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
 554                 return 1;
 555
 556         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 557         if (volt_gpio_np)
 558                 voltage_gpio = read_gpio(volt_gpio_np);
 559         of_node_put(volt_gpio_np);
 560         if (!voltage_gpio){
 561                 pr_err("missing cpu-vcore-select gpio\n");
 562                 return 1;
 563         }
 564
 565         /* OF only reports the high frequency */
 566         hi_freq = cur_freq;
 567         low_freq = cur_freq/2;
 568
 569         /* Read actual frequency from CPU */
 570         cur_freq = dfs_get_cpu_speed();
 571         set_speed_proc = dfs_set_cpu_speed;
 572         get_speed_proc = dfs_get_cpu_speed;
 573
 574         return 0;
 575 }
 576
 577 static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
 578 {
 579         struct device_node *volt_gpio_np;
 580         u32 pvr;
 581         const u32 *value;
 582
 583         if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
 584                 return 1;
 585
 586         hi_freq = cur_freq;
 587         value = of_get_property(cpunode, "reduced-clock-frequency", NULL);
 588         if (!value)
 589                 return 1;
 590         low_freq = (*value) / 1000;
 591
 592         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 593         if (volt_gpio_np)
 594                 voltage_gpio = read_gpio(volt_gpio_np);
 595
 596         of_node_put(volt_gpio_np);
 597         pvr = mfspr(SPRN_PVR);
 598         has_cpu_l2lve = !((pvr & 0xf00) == 0x100);
 599
 600         set_speed_proc = cpu_750fx_cpu_speed;
 601         get_speed_proc = cpu_750fx_get_cpu_speed;
 602         cur_freq = cpu_750fx_get_cpu_speed();
 603
 604         return 0;
 605 }
 606
 607 /* Currently, we support the following machines:
 608  *
 609  *  - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
 610  *  - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
 611  *  - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
 612  *  - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
 613  *  - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
 614  *  - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
 615  *  - Recent MacRISC3 laptops
 616  *  - All new machines with 7447A CPUs
 617  */
 618 static int __init pmac_cpufreq_setup(void)
 619 {
 620         struct device_node      *cpunode;
 621         const u32               *value;
 622
 623         if (strstr(boot_command_line, "nocpufreq"))
 624                 return 0;
 625
 626         /* Get first CPU node */
 627         cpunode = of_cpu_device_node_get(0);
 628         if (!cpunode)
 629                 goto out;
 630
 631         /* Get current cpu clock freq */
 632         value = of_get_property(cpunode, "clock-frequency", NULL);
 633         if (!value)
 634                 goto out;
 635         cur_freq = (*value) / 1000;
 636
 637         /*  Check for 7447A based MacRISC3 */
 638         if (of_machine_is_compatible("MacRISC3") &&
 639             of_get_property(cpunode, "dynamic-power-step", NULL) &&
 640             PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
 641                 pmac_cpufreq_init_7447A(cpunode);
 642
 643                 /* Allow dynamic switching */
 644                 transition_latency = 8000000;
 645                 pmac_cpufreq_driver.flags &= ~CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING;
 646         /* Check for other MacRISC3 machines */
 647         } else if (of_machine_is_compatible("PowerBook3,4") ||
 648                    of_machine_is_compatible("PowerBook3,5") ||
 649                    of_machine_is_compatible("MacRISC3")) {
 650                 pmac_cpufreq_init_MacRISC3(cpunode);
 651         /* Else check for iBook2 500/600 */
 652         } else if (of_machine_is_compatible("PowerBook4,1")) {
 653                 hi_freq = cur_freq;
 654                 low_freq = 400000;
 655                 set_speed_proc = pmu_set_cpu_speed;
 656                 is_pmu_based = 1;
 657         }
 658         /* Else check for TiPb 550 */
 659         else if (of_machine_is_compatible("PowerBook3,3") && cur_freq == 550000) {
 660                 hi_freq = cur_freq;
 661                 low_freq = 500000;
 662                 set_speed_proc = pmu_set_cpu_speed;
 663                 is_pmu_based = 1;
 664         }
 665         /* Else check for TiPb 400 & 500 */
 666         else if (of_machine_is_compatible("PowerBook3,2")) {
 667                 /* We only know about the 400 MHz and the 500Mhz model
 668                  * they both have 300 MHz as low frequency
 669                  */
 670                 if (cur_freq < 350000 || cur_freq > 550000)
 671                         goto out;
 672                 hi_freq = cur_freq;
 673                 low_freq = 300000;
 674                 set_speed_proc = pmu_set_cpu_speed;
 675                 is_pmu_based = 1;
 676         }
 677         /* Else check for 750FX */
 678         else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
 679                 pmac_cpufreq_init_750FX(cpunode);
 680 out:
 681         of_node_put(cpunode);
 682         if (set_speed_proc == NULL)
 683                 return -ENODEV;
 684
 685         pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
 686         pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
 687         ppc_proc_freq = cur_freq * 1000ul;
 688
 689         pr_info("Registering PowerMac CPU frequency driver\n");
 690         pr_info("Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
 691                 low_freq/1000, hi_freq/1000, cur_freq/1000);
 692
 693         return cpufreq_register_driver(&pmac_cpufreq_driver);
 694 }
 695
 696 module_init(pmac_cpufreq_setup);
 697