git.oblomov.eu Git - linux-2.6/blob - arch/powerpc/platforms/powermac/cpufreq_32.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 #include <linux/module.h>
  17 #include <linux/types.h>
  18 #include <linux/errno.h>
  19 #include <linux/kernel.h>
  20 #include <linux/delay.h>
  21 #include <linux/sched.h>
  22 #include <linux/adb.h>
  23 #include <linux/pmu.h>
  24 #include <linux/slab.h>
  25 #include <linux/cpufreq.h>
  26 #include <linux/init.h>
  27 #include <linux/sysdev.h>
  28 #include <linux/hardirq.h>
  29 #include <asm/prom.h>
  30 #include <asm/machdep.h>
  31 #include <asm/irq.h>
  32 #include <asm/pmac_feature.h>
  33 #include <asm/mmu_context.h>
  34 #include <asm/sections.h>
  35 #include <asm/cputable.h>
  36 #include <asm/time.h>
  37 #include <asm/system.h>
  38 #include <asm/mpic.h>
  39 #include <asm/keylargo.h>
  40
  41 /* WARNING !!! This will cause calibrate_delay() to be called,
  42  * but this is an __init function ! So you MUST go edit
  43  * init/main.c to make it non-init before enabling DEBUG_FREQ
  44  */
  45 #undef DEBUG_FREQ
  46
  47 /*
  48  * There is a problem with the core cpufreq code on SMP kernels,
  49  * it won't recalculate the Bogomips properly
  50  */
  51 #ifdef CONFIG_SMP
  52 #warning "WARNING, CPUFREQ not recommended on SMP kernels"
  53 #endif
  54
  55 extern void low_choose_7447a_dfs(int dfs);
  56 extern void low_choose_750fx_pll(int pll);
  57 extern void low_sleep_handler(void);
  58
  59 /*
  60  * Currently, PowerMac cpufreq supports only high & low frequencies
  61  * that are set by the firmware
  62  */
  63 static unsigned int low_freq;
  64 static unsigned int hi_freq;
  65 static unsigned int cur_freq;
  66 static unsigned int sleep_freq;
  67
  68 /*
  69  * Different models uses different mechanisms to switch the frequency
  70  */
  71 static int (*set_speed_proc)(int low_speed);
  72 static unsigned int (*get_speed_proc)(void);
  73
  74 /*
  75  * Some definitions used by the various speedprocs
  76  */
  77 static u32 voltage_gpio;
  78 static u32 frequency_gpio;
  79 static u32 slew_done_gpio;
  80 static int no_schedule;
  81 static int has_cpu_l2lve;
  82 static int is_pmu_based;
  83
  84 /* There are only two frequency states for each processor. Values
  85  * are in kHz for the time being.
  86  */
  87 #define CPUFREQ_HIGH                  0
  88 #define CPUFREQ_LOW                   1
  89
  90 static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
  91         {CPUFREQ_HIGH,          0},
  92         {CPUFREQ_LOW,           0},
  93         {0,                     CPUFREQ_TABLE_END},
  94 };
  95
  96 static struct freq_attr* pmac_cpu_freqs_attr[] = {
  97         &cpufreq_freq_attr_scaling_available_freqs,
  98         NULL,
  99 };
 100
 101 static inline void local_delay(unsigned long ms)
 102 {
 103         if (no_schedule)
 104                 mdelay(ms);
 105         else
 106                 msleep(ms);
 107 }
 108
 109 #ifdef DEBUG_FREQ
 110 static inline void debug_calc_bogomips(void)
 111 {
 112         /* This will cause a recalc of bogomips and display the
 113          * result. We backup/restore the value to avoid affecting the
 114          * core cpufreq framework's own calculation.
 115          */
 116         extern void calibrate_delay(void);
 117
 118         unsigned long save_lpj = loops_per_jiffy;
 119         calibrate_delay();
 120         loops_per_jiffy = save_lpj;
 121 }
 122 #endif /* DEBUG_FREQ */
 123
 124 /* Switch CPU speed under 750FX CPU control
 125  */
 126 static int cpu_750fx_cpu_speed(int low_speed)
 127 {
 128         u32 hid2;
 129
 130         if (low_speed == 0) {
 131                 /* ramping up, set voltage first */
 132                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 133                 /* Make sure we sleep for at least 1ms */
 134                 local_delay(10);
 135
 136                 /* tweak L2 for high voltage */
 137                 if (has_cpu_l2lve) {
 138                         hid2 = mfspr(SPRN_HID2);
 139                         hid2 &= ~0x2000;
 140                         mtspr(SPRN_HID2, hid2);
 141                 }
 142         }
 143 #ifdef CONFIG_6xx
 144         low_choose_750fx_pll(low_speed);
 145 #endif
 146         if (low_speed == 1) {
 147                 /* tweak L2 for low voltage */
 148                 if (has_cpu_l2lve) {
 149                         hid2 = mfspr(SPRN_HID2);
 150                         hid2 |= 0x2000;
 151                         mtspr(SPRN_HID2, hid2);
 152                 }
 153
 154                 /* ramping down, set voltage last */
 155                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 156                 local_delay(10);
 157         }
 158
 159         return 0;
 160 }
 161
 162 static unsigned int cpu_750fx_get_cpu_speed(void)
 163 {
 164         if (mfspr(SPRN_HID1) & HID1_PS)
 165                 return low_freq;
 166         else
 167                 return hi_freq;
 168 }
 169
 170 /* Switch CPU speed using DFS */
 171 static int dfs_set_cpu_speed(int low_speed)
 172 {
 173         if (low_speed == 0) {
 174                 /* ramping up, set voltage first */
 175                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 176                 /* Make sure we sleep for at least 1ms */
 177                 local_delay(1);
 178         }
 179
 180         /* set frequency */
 181 #ifdef CONFIG_6xx
 182         low_choose_7447a_dfs(low_speed);
 183 #endif
 184         udelay(100);
 185
 186         if (low_speed == 1) {
 187                 /* ramping down, set voltage last */
 188                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 189                 local_delay(1);
 190         }
 191
 192         return 0;
 193 }
 194
 195 static unsigned int dfs_get_cpu_speed(void)
 196 {
 197         if (mfspr(SPRN_HID1) & HID1_DFS)
 198                 return low_freq;
 199         else
 200                 return hi_freq;
 201 }
 202
 203
 204 /* Switch CPU speed using slewing GPIOs
 205  */
 206 static int gpios_set_cpu_speed(int low_speed)
 207 {
 208         int gpio, timeout = 0;
 209
 210         /* If ramping up, set voltage first */
 211         if (low_speed == 0) {
 212                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 213                 /* Delay is way too big but it's ok, we schedule */
 214                 local_delay(10);
 215         }
 216
 217         /* Set frequency */
 218         gpio =  pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 219         if (low_speed == ((gpio & 0x01) == 0))
 220                 goto skip;
 221
 222         pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
 223                           low_speed ? 0x04 : 0x05);
 224         udelay(200);
 225         do {
 226                 if (++timeout > 100)
 227                         break;
 228                 local_delay(1);
 229                 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
 230         } while((gpio & 0x02) == 0);
 231  skip:
 232         /* If ramping down, set voltage last */
 233         if (low_speed == 1) {
 234                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 235                 /* Delay is way too big but it's ok, we schedule */
 236                 local_delay(10);
 237         }
 238
 239 #ifdef DEBUG_FREQ
 240         debug_calc_bogomips();
 241 #endif
 242
 243         return 0;
 244 }
 245
 246 /* Switch CPU speed under PMU control
 247  */
 248 static int pmu_set_cpu_speed(int low_speed)
 249 {
 250         struct adb_request req;
 251         unsigned long save_l2cr;
 252         unsigned long save_l3cr;
 253         unsigned int pic_prio;
 254         unsigned long flags;
 255
 256         preempt_disable();
 257
 258 #ifdef DEBUG_FREQ
 259         printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
 260 #endif
 261         pmu_suspend();
 262
 263         /* Disable all interrupt sources on openpic */
 264         pic_prio = mpic_cpu_get_priority();
 265         mpic_cpu_set_priority(0xf);
 266
 267         /* Make sure the decrementer won't interrupt us */
 268         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 269         /* Make sure any pending DEC interrupt occurring while we did
 270          * the above didn't re-enable the DEC */
 271         mb();
 272         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 273
 274         /* We can now disable MSR_EE */
 275         local_irq_save(flags);
 276
 277         /* Giveup the FPU & vec */
 278         enable_kernel_fp();
 279
 280 #ifdef CONFIG_ALTIVEC
 281         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 282                 enable_kernel_altivec();
 283 #endif /* CONFIG_ALTIVEC */
 284
 285         /* Save & disable L2 and L3 caches */
 286         save_l3cr = _get_L3CR();        /* (returns -1 if not available) */
 287         save_l2cr = _get_L2CR();        /* (returns -1 if not available) */
 288
 289         /* Send the new speed command. My assumption is that this command
 290          * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
 291          */
 292         pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
 293         while (!req.complete)
 294                 pmu_poll();
 295
 296         /* Prepare the northbridge for the speed transition */
 297         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
 298
 299         /* Call low level code to backup CPU state and recover from
 300          * hardware reset
 301          */
 302         low_sleep_handler();
 303
 304         /* Restore the northbridge */
 305         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
 306
 307         /* Restore L2 cache */
 308         if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
 309                 _set_L2CR(save_l2cr);
 310         /* Restore L3 cache */
 311         if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
 312                 _set_L3CR(save_l3cr);
 313
 314         /* Restore userland MMU context */
 315         set_context(current->active_mm->context.id, current->active_mm->pgd);
 316
 317 #ifdef DEBUG_FREQ
 318         printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
 319 #endif
 320
 321         /* Restore low level PMU operations */
 322         pmu_unlock();
 323
 324         /* Restore decrementer */
 325         wakeup_decrementer();
 326
 327         /* Restore interrupts */
 328         mpic_cpu_set_priority(pic_prio);
 329
 330         /* Let interrupts flow again ... */
 331         local_irq_restore(flags);
 332
 333 #ifdef DEBUG_FREQ
 334         debug_calc_bogomips();
 335 #endif
 336
 337         pmu_resume();
 338
 339         preempt_enable();
 340
 341         return 0;
 342 }
 343
 344 static int do_set_cpu_speed(int speed_mode, int notify)
 345 {
 346         struct cpufreq_freqs freqs;
 347         unsigned long l3cr;
 348         static unsigned long prev_l3cr;
 349
 350         freqs.old = cur_freq;
 351         freqs.new = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
 352         freqs.cpu = smp_processor_id();
 353
 354         if (freqs.old == freqs.new)
 355                 return 0;
 356
 357         if (notify)
 358                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 359         if (speed_mode == CPUFREQ_LOW &&
 360             cpu_has_feature(CPU_FTR_L3CR)) {
 361                 l3cr = _get_L3CR();
 362                 if (l3cr & L3CR_L3E) {
 363                         prev_l3cr = l3cr;
 364                         _set_L3CR(0);
 365                 }
 366         }
 367         set_speed_proc(speed_mode == CPUFREQ_LOW);
 368         if (speed_mode == CPUFREQ_HIGH &&
 369             cpu_has_feature(CPU_FTR_L3CR)) {
 370                 l3cr = _get_L3CR();
 371                 if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
 372                         _set_L3CR(prev_l3cr);
 373         }
 374         if (notify)
 375                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 376         cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
 377
 378         return 0;
 379 }
 380
 381 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
 382 {
 383         return cur_freq;
 384 }
 385
 386 static int pmac_cpufreq_verify(struct cpufreq_policy *policy)
 387 {
 388         return cpufreq_frequency_table_verify(policy, pmac_cpu_freqs);
 389 }
 390
 391 static int pmac_cpufreq_target( struct cpufreq_policy *policy,
 392                                         unsigned int target_freq,
 393                                         unsigned int relation)
 394 {
 395         unsigned int    newstate = 0;
 396         int             rc;
 397
 398         if (cpufreq_frequency_table_target(policy, pmac_cpu_freqs,
 399                         target_freq, relation, &newstate))
 400                 return -EINVAL;
 401
 402         rc = do_set_cpu_speed(newstate, 1);
 403
 404         ppc_proc_freq = cur_freq * 1000ul;
 405         return rc;
 406 }
 407
 408 static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
 409 {
 410         if (policy->cpu != 0)
 411                 return -ENODEV;
 412
 413         policy->cpuinfo.transition_latency      = CPUFREQ_ETERNAL;
 414         policy->cur = cur_freq;
 415
 416         cpufreq_frequency_table_get_attr(pmac_cpu_freqs, policy->cpu);
 417         return cpufreq_frequency_table_cpuinfo(policy, pmac_cpu_freqs);
 418 }
 419
 420 static u32 read_gpio(struct device_node *np)
 421 {
 422         const u32 *reg = of_get_property(np, "reg", NULL);
 423         u32 offset;
 424
 425         if (reg == NULL)
 426                 return 0;
 427         /* That works for all keylargos but shall be fixed properly
 428          * some day... The problem is that it seems we can't rely
 429          * on the "reg" property of the GPIO nodes, they are either
 430          * relative to the base of KeyLargo or to the base of the
 431          * GPIO space, and the device-tree doesn't help.
 432          */
 433         offset = *reg;
 434         if (offset < KEYLARGO_GPIO_LEVELS0)
 435                 offset += KEYLARGO_GPIO_LEVELS0;
 436         return offset;
 437 }
 438
 439 static int pmac_cpufreq_suspend(struct cpufreq_policy *policy, pm_message_t pmsg)
 440 {
 441         /* Ok, this could be made a bit smarter, but let's be robust for now. We
 442          * always force a speed change to high speed before sleep, to make sure
 443          * we have appropriate voltage and/or bus speed for the wakeup process,
 444          * and to make sure our loops_per_jiffies are "good enough", that is will
 445          * not cause too short delays if we sleep in low speed and wake in high
 446          * speed..
 447          */
 448         no_schedule = 1;
 449         sleep_freq = cur_freq;
 450         if (cur_freq == low_freq && !is_pmu_based)
 451                 do_set_cpu_speed(CPUFREQ_HIGH, 0);
 452         return 0;
 453 }
 454
 455 static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
 456 {
 457         /* If we resume, first check if we have a get() function */
 458         if (get_speed_proc)
 459                 cur_freq = get_speed_proc();
 460         else
 461                 cur_freq = 0;
 462
 463         /* We don't, hrm... we don't really know our speed here, best
 464          * is that we force a switch to whatever it was, which is
 465          * probably high speed due to our suspend() routine
 466          */
 467         do_set_cpu_speed(sleep_freq == low_freq ?
 468                          CPUFREQ_LOW : CPUFREQ_HIGH, 0);
 469
 470         ppc_proc_freq = cur_freq * 1000ul;
 471
 472         no_schedule = 0;
 473         return 0;
 474 }
 475
 476 static struct cpufreq_driver pmac_cpufreq_driver = {
 477         .verify         = pmac_cpufreq_verify,
 478         .target         = pmac_cpufreq_target,
 479         .get            = pmac_cpufreq_get_speed,
 480         .init           = pmac_cpufreq_cpu_init,
 481         .suspend        = pmac_cpufreq_suspend,
 482         .resume         = pmac_cpufreq_resume,
 483         .flags          = CPUFREQ_PM_NO_WARN,
 484         .attr           = pmac_cpu_freqs_attr,
 485         .name           = "powermac",
 486         .owner          = THIS_MODULE,
 487 };
 488
 489
 490 static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
 491 {
 492         struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
 493                                                                 "voltage-gpio");
 494         struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
 495                                                                 "frequency-gpio");
 496         struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
 497                                                                      "slewing-done");
 498         const u32 *value;
 499
 500         /*
 501          * Check to see if it's GPIO driven or PMU only
 502          *
 503          * The way we extract the GPIO address is slightly hackish, but it
 504          * works well enough for now. We need to abstract the whole GPIO
 505          * stuff sooner or later anyway
 506          */
 507
 508         if (volt_gpio_np)
 509                 voltage_gpio = read_gpio(volt_gpio_np);
 510         if (freq_gpio_np)
 511                 frequency_gpio = read_gpio(freq_gpio_np);
 512         if (slew_done_gpio_np)
 513                 slew_done_gpio = read_gpio(slew_done_gpio_np);
 514
 515         /* If we use the frequency GPIOs, calculate the min/max speeds based
 516          * on the bus frequencies
 517          */
 518         if (frequency_gpio && slew_done_gpio) {
 519                 int lenp, rc;
 520                 const u32 *freqs, *ratio;
 521
 522                 freqs = of_get_property(cpunode, "bus-frequencies", &lenp);
 523                 lenp /= sizeof(u32);
 524                 if (freqs == NULL || lenp != 2) {
 525                         printk(KERN_ERR "cpufreq: bus-frequencies incorrect or missing\n");
 526                         return 1;
 527                 }
 528                 ratio = of_get_property(cpunode, "processor-to-bus-ratio*2",
 529                                                 NULL);
 530                 if (ratio == NULL) {
 531                         printk(KERN_ERR "cpufreq: processor-to-bus-ratio*2 missing\n");
 532                         return 1;
 533                 }
 534
 535                 /* Get the min/max bus frequencies */
 536                 low_freq = min(freqs[0], freqs[1]);
 537                 hi_freq = max(freqs[0], freqs[1]);
 538
 539                 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
 540                  * frequency, it claims it to be around 84Mhz on some models while
 541                  * it appears to be approx. 101Mhz on all. Let's hack around here...
 542                  * fortunately, we don't need to be too precise
 543                  */
 544                 if (low_freq < 98000000)
 545                         low_freq = 101000000;
 546
 547                 /* Convert those to CPU core clocks */
 548                 low_freq = (low_freq * (*ratio)) / 2000;
 549                 hi_freq = (hi_freq * (*ratio)) / 2000;
 550
 551                 /* Now we get the frequencies, we read the GPIO to see what is out current
 552                  * speed
 553                  */
 554                 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 555                 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
 556
 557                 set_speed_proc = gpios_set_cpu_speed;
 558                 return 1;
 559         }
 560
 561         /* If we use the PMU, look for the min & max frequencies in the
 562          * device-tree
 563          */
 564         value = of_get_property(cpunode, "min-clock-frequency", NULL);
 565         if (!value)
 566                 return 1;
 567         low_freq = (*value) / 1000;
 568         /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
 569          * here */
 570         if (low_freq < 100000)
 571                 low_freq *= 10;
 572
 573         value = of_get_property(cpunode, "max-clock-frequency", NULL);
 574         if (!value)
 575                 return 1;
 576         hi_freq = (*value) / 1000;
 577         set_speed_proc = pmu_set_cpu_speed;
 578         is_pmu_based = 1;
 579
 580         return 0;
 581 }
 582
 583 static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
 584 {
 585         struct device_node *volt_gpio_np;
 586
 587         if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
 588                 return 1;
 589
 590         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 591         if (volt_gpio_np)
 592                 voltage_gpio = read_gpio(volt_gpio_np);
 593         if (!voltage_gpio){
 594                 printk(KERN_ERR "cpufreq: missing cpu-vcore-select gpio\n");
 595                 return 1;
 596         }
 597
 598         /* OF only reports the high frequency */
 599         hi_freq = cur_freq;
 600         low_freq = cur_freq/2;
 601
 602         /* Read actual frequency from CPU */
 603         cur_freq = dfs_get_cpu_speed();
 604         set_speed_proc = dfs_set_cpu_speed;
 605         get_speed_proc = dfs_get_cpu_speed;
 606
 607         return 0;
 608 }
 609
 610 static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
 611 {
 612         struct device_node *volt_gpio_np;
 613         u32 pvr;
 614         const u32 *value;
 615
 616         if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
 617                 return 1;
 618
 619         hi_freq = cur_freq;
 620         value = of_get_property(cpunode, "reduced-clock-frequency", NULL);
 621         if (!value)
 622                 return 1;
 623         low_freq = (*value) / 1000;
 624
 625         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 626         if (volt_gpio_np)
 627                 voltage_gpio = read_gpio(volt_gpio_np);
 628
 629         pvr = mfspr(SPRN_PVR);
 630         has_cpu_l2lve = !((pvr & 0xf00) == 0x100);
 631
 632         set_speed_proc = cpu_750fx_cpu_speed;
 633         get_speed_proc = cpu_750fx_get_cpu_speed;
 634         cur_freq = cpu_750fx_get_cpu_speed();
 635
 636         return 0;
 637 }
 638
 639 /* Currently, we support the following machines:
 640  *
 641  *  - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
 642  *  - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
 643  *  - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
 644  *  - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
 645  *  - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
 646  *  - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
 647  *  - Recent MacRISC3 laptops
 648  *  - All new machines with 7447A CPUs
 649  */
 650 static int __init pmac_cpufreq_setup(void)
 651 {
 652         struct device_node      *cpunode;
 653         const u32               *value;
 654
 655         if (strstr(cmd_line, "nocpufreq"))
 656                 return 0;
 657
 658         /* Assume only one CPU */
 659         cpunode = of_find_node_by_type(NULL, "cpu");
 660         if (!cpunode)
 661                 goto out;
 662
 663         /* Get current cpu clock freq */
 664         value = of_get_property(cpunode, "clock-frequency", NULL);
 665         if (!value)
 666                 goto out;
 667         cur_freq = (*value) / 1000;
 668
 669         /*  Check for 7447A based MacRISC3 */
 670         if (machine_is_compatible("MacRISC3") &&
 671             of_get_property(cpunode, "dynamic-power-step", NULL) &&
 672             PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
 673                 pmac_cpufreq_init_7447A(cpunode);
 674         /* Check for other MacRISC3 machines */
 675         } else if (machine_is_compatible("PowerBook3,4") ||
 676                    machine_is_compatible("PowerBook3,5") ||
 677                    machine_is_compatible("MacRISC3")) {
 678                 pmac_cpufreq_init_MacRISC3(cpunode);
 679         /* Else check for iBook2 500/600 */
 680         } else if (machine_is_compatible("PowerBook4,1")) {
 681                 hi_freq = cur_freq;
 682                 low_freq = 400000;
 683                 set_speed_proc = pmu_set_cpu_speed;
 684                 is_pmu_based = 1;
 685         }
 686         /* Else check for TiPb 550 */
 687         else if (machine_is_compatible("PowerBook3,3") && cur_freq == 550000) {
 688                 hi_freq = cur_freq;
 689                 low_freq = 500000;
 690                 set_speed_proc = pmu_set_cpu_speed;
 691                 is_pmu_based = 1;
 692         }
 693         /* Else check for TiPb 400 & 500 */
 694         else if (machine_is_compatible("PowerBook3,2")) {
 695                 /* We only know about the 400 MHz and the 500Mhz model
 696                  * they both have 300 MHz as low frequency
 697                  */
 698                 if (cur_freq < 350000 || cur_freq > 550000)
 699                         goto out;
 700                 hi_freq = cur_freq;
 701                 low_freq = 300000;
 702                 set_speed_proc = pmu_set_cpu_speed;
 703                 is_pmu_based = 1;
 704         }
 705         /* Else check for 750FX */
 706         else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
 707                 pmac_cpufreq_init_750FX(cpunode);
 708 out:
 709         of_node_put(cpunode);
 710         if (set_speed_proc == NULL)
 711                 return -ENODEV;
 712
 713         pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
 714         pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
 715         ppc_proc_freq = cur_freq * 1000ul;
 716
 717         printk(KERN_INFO "Registering PowerMac CPU frequency driver\n");
 718         printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
 719                low_freq/1000, hi_freq/1000, cur_freq/1000);
 720
 721         return cpufreq_register_driver(&pmac_cpufreq_driver);
 722 }
 723
 724 module_init(pmac_cpufreq_setup);
 725