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/config.h>
  17 #include <linux/module.h>
  18 #include <linux/types.h>
  19 #include <linux/errno.h>
  20 #include <linux/kernel.h>
  21 #include <linux/delay.h>
  22 #include <linux/sched.h>
  23 #include <linux/adb.h>
  24 #include <linux/pmu.h>
  25 #include <linux/slab.h>
  26 #include <linux/cpufreq.h>
  27 #include <linux/init.h>
  28 #include <linux/sysdev.h>
  29 #include <linux/i2c.h>
  30 #include <linux/hardirq.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/system.h>
  40 #include <asm/mpic.h>
  41 #include <asm/keylargo.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 /*
  50  * There is a problem with the core cpufreq code on SMP kernels,
  51  * it won't recalculate the Bogomips properly
  52  */
  53 #ifdef CONFIG_SMP
  54 #warning "WARNING, CPUFREQ not recommended on SMP kernels"
  55 #endif
  56
  57 extern void low_choose_7447a_dfs(int dfs);
  58 extern void low_choose_750fx_pll(int pll);
  59 extern void low_sleep_handler(void);
  60
  61 /*
  62  * Currently, PowerMac cpufreq supports only high & low frequencies
  63  * that are set by the firmware
  64  */
  65 static unsigned int low_freq;
  66 static unsigned int hi_freq;
  67 static unsigned int cur_freq;
  68 static unsigned int sleep_freq;
  69
  70 /*
  71  * Different models uses different mecanisms to switch the frequency
  72  */
  73 static int (*set_speed_proc)(int low_speed);
  74 static unsigned int (*get_speed_proc)(void);
  75
  76 /*
  77  * Some definitions used by the various speedprocs
  78  */
  79 static u32 voltage_gpio;
  80 static u32 frequency_gpio;
  81 static u32 slew_done_gpio;
  82 static int no_schedule;
  83 static int has_cpu_l2lve;
  84 static int is_pmu_based;
  85
  86 /* There are only two frequency states for each processor. Values
  87  * are in kHz for the time being.
  88  */
  89 #define CPUFREQ_HIGH                  0
  90 #define CPUFREQ_LOW                   1
  91
  92 static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
  93         {CPUFREQ_HIGH,          0},
  94         {CPUFREQ_LOW,           0},
  95         {0,                     CPUFREQ_TABLE_END},
  96 };
  97
  98 static struct freq_attr* pmac_cpu_freqs_attr[] = {
  99         &cpufreq_freq_attr_scaling_available_freqs,
 100         NULL,
 101 };
 102
 103 static inline void local_delay(unsigned long ms)
 104 {
 105         if (no_schedule)
 106                 mdelay(ms);
 107         else
 108                 msleep(ms);
 109 }
 110
 111 #ifdef DEBUG_FREQ
 112 static inline void debug_calc_bogomips(void)
 113 {
 114         /* This will cause a recalc of bogomips and display the
 115          * result. We backup/restore the value to avoid affecting the
 116          * core cpufreq framework's own calculation.
 117          */
 118         extern void calibrate_delay(void);
 119
 120         unsigned long save_lpj = loops_per_jiffy;
 121         calibrate_delay();
 122         loops_per_jiffy = save_lpj;
 123 }
 124 #endif /* DEBUG_FREQ */
 125
 126 /* Switch CPU speed under 750FX CPU control
 127  */
 128 static int cpu_750fx_cpu_speed(int low_speed)
 129 {
 130         u32 hid2;
 131
 132         if (low_speed == 0) {
 133                 /* ramping up, set voltage first */
 134                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 135                 /* Make sure we sleep for at least 1ms */
 136                 local_delay(10);
 137
 138                 /* tweak L2 for high voltage */
 139                 if (has_cpu_l2lve) {
 140                         hid2 = mfspr(SPRN_HID2);
 141                         hid2 &= ~0x2000;
 142                         mtspr(SPRN_HID2, hid2);
 143                 }
 144         }
 145 #ifdef CONFIG_6xx
 146         low_choose_750fx_pll(low_speed);
 147 #endif
 148         if (low_speed == 1) {
 149                 /* tweak L2 for low voltage */
 150                 if (has_cpu_l2lve) {
 151                         hid2 = mfspr(SPRN_HID2);
 152                         hid2 |= 0x2000;
 153                         mtspr(SPRN_HID2, hid2);
 154                 }
 155
 156                 /* ramping down, set voltage last */
 157                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 158                 local_delay(10);
 159         }
 160
 161         return 0;
 162 }
 163
 164 static unsigned int cpu_750fx_get_cpu_speed(void)
 165 {
 166         if (mfspr(SPRN_HID1) & HID1_PS)
 167                 return low_freq;
 168         else
 169                 return hi_freq;
 170 }
 171
 172 /* Switch CPU speed using DFS */
 173 static int dfs_set_cpu_speed(int low_speed)
 174 {
 175         if (low_speed == 0) {
 176                 /* ramping up, set voltage first */
 177                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 178                 /* Make sure we sleep for at least 1ms */
 179                 local_delay(1);
 180         }
 181
 182         /* set frequency */
 183 #ifdef CONFIG_6xx
 184         low_choose_7447a_dfs(low_speed);
 185 #endif
 186         udelay(100);
 187
 188         if (low_speed == 1) {
 189                 /* ramping down, set voltage last */
 190                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 191                 local_delay(1);
 192         }
 193
 194         return 0;
 195 }
 196
 197 static unsigned int dfs_get_cpu_speed(void)
 198 {
 199         if (mfspr(SPRN_HID1) & HID1_DFS)
 200                 return low_freq;
 201         else
 202                 return hi_freq;
 203 }
 204
 205
 206 /* Switch CPU speed using slewing GPIOs
 207  */
 208 static int gpios_set_cpu_speed(int low_speed)
 209 {
 210         int gpio, timeout = 0;
 211
 212         /* If ramping up, set voltage first */
 213         if (low_speed == 0) {
 214                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 215                 /* Delay is way too big but it's ok, we schedule */
 216                 local_delay(10);
 217         }
 218
 219         /* Set frequency */
 220         gpio =  pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 221         if (low_speed == ((gpio & 0x01) == 0))
 222                 goto skip;
 223
 224         pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
 225                           low_speed ? 0x04 : 0x05);
 226         udelay(200);
 227         do {
 228                 if (++timeout > 100)
 229                         break;
 230                 local_delay(1);
 231                 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
 232         } while((gpio & 0x02) == 0);
 233  skip:
 234         /* If ramping down, set voltage last */
 235         if (low_speed == 1) {
 236                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 237                 /* Delay is way too big but it's ok, we schedule */
 238                 local_delay(10);
 239         }
 240
 241 #ifdef DEBUG_FREQ
 242         debug_calc_bogomips();
 243 #endif
 244
 245         return 0;
 246 }
 247
 248 /* Switch CPU speed under PMU control
 249  */
 250 static int pmu_set_cpu_speed(int low_speed)
 251 {
 252         struct adb_request req;
 253         unsigned long save_l2cr;
 254         unsigned long save_l3cr;
 255         unsigned int pic_prio;
 256         unsigned long flags;
 257
 258         preempt_disable();
 259
 260 #ifdef DEBUG_FREQ
 261         printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
 262 #endif
 263         pmu_suspend();
 264
 265         /* Disable all interrupt sources on openpic */
 266         pic_prio = mpic_cpu_get_priority();
 267         mpic_cpu_set_priority(0xf);
 268
 269         /* Make sure the decrementer won't interrupt us */
 270         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 271         /* Make sure any pending DEC interrupt occuring while we did
 272          * the above didn't re-enable the DEC */
 273         mb();
 274         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 275
 276         /* We can now disable MSR_EE */
 277         local_irq_save(flags);
 278
 279         /* Giveup the FPU & vec */
 280         enable_kernel_fp();
 281
 282 #ifdef CONFIG_ALTIVEC
 283         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 284                 enable_kernel_altivec();
 285 #endif /* CONFIG_ALTIVEC */
 286
 287         /* Save & disable L2 and L3 caches */
 288         save_l3cr = _get_L3CR();        /* (returns -1 if not available) */
 289         save_l2cr = _get_L2CR();        /* (returns -1 if not available) */
 290
 291         /* Send the new speed command. My assumption is that this command
 292          * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
 293          */
 294         pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
 295         while (!req.complete)
 296                 pmu_poll();
 297
 298         /* Prepare the northbridge for the speed transition */
 299         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
 300
 301         /* Call low level code to backup CPU state and recover from
 302          * hardware reset
 303          */
 304         low_sleep_handler();
 305
 306         /* Restore the northbridge */
 307         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
 308
 309         /* Restore L2 cache */
 310         if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
 311                 _set_L2CR(save_l2cr);
 312         /* Restore L3 cache */
 313         if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
 314                 _set_L3CR(save_l3cr);
 315
 316         /* Restore userland MMU context */
 317         set_context(current->active_mm->context.id, current->active_mm->pgd);
 318
 319 #ifdef DEBUG_FREQ
 320         printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
 321 #endif
 322
 323         /* Restore low level PMU operations */
 324         pmu_unlock();
 325
 326         /* Restore decrementer */
 327         wakeup_decrementer();
 328
 329         /* Restore interrupts */
 330         mpic_cpu_set_priority(pic_prio);
 331
 332         /* Let interrupts flow again ... */
 333         local_irq_restore(flags);
 334
 335 #ifdef DEBUG_FREQ
 336         debug_calc_bogomips();
 337 #endif
 338
 339         pmu_resume();
 340
 341         preempt_enable();
 342
 343         return 0;
 344 }
 345
 346 static int do_set_cpu_speed(int speed_mode, int notify)
 347 {
 348         struct cpufreq_freqs freqs;
 349         unsigned long l3cr;
 350         static unsigned long prev_l3cr;
 351
 352         freqs.old = cur_freq;
 353         freqs.new = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
 354         freqs.cpu = smp_processor_id();
 355
 356         if (freqs.old == freqs.new)
 357                 return 0;
 358
 359         if (notify)
 360                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 361         if (speed_mode == CPUFREQ_LOW &&
 362             cpu_has_feature(CPU_FTR_L3CR)) {
 363                 l3cr = _get_L3CR();
 364                 if (l3cr & L3CR_L3E) {
 365                         prev_l3cr = l3cr;
 366                         _set_L3CR(0);
 367                 }
 368         }
 369         set_speed_proc(speed_mode == CPUFREQ_LOW);
 370         if (speed_mode == CPUFREQ_HIGH &&
 371             cpu_has_feature(CPU_FTR_L3CR)) {
 372                 l3cr = _get_L3CR();
 373                 if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
 374                         _set_L3CR(prev_l3cr);
 375         }
 376         if (notify)
 377                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 378         cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
 379
 380         return 0;
 381 }
 382
 383 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
 384 {
 385         return cur_freq;
 386 }
 387
 388 static int pmac_cpufreq_verify(struct cpufreq_policy *policy)
 389 {
 390         return cpufreq_frequency_table_verify(policy, pmac_cpu_freqs);
 391 }
 392
 393 static int pmac_cpufreq_target( struct cpufreq_policy *policy,
 394                                         unsigned int target_freq,
 395                                         unsigned int relation)
 396 {
 397         unsigned int    newstate = 0;
 398         int             rc;
 399
 400         if (cpufreq_frequency_table_target(policy, pmac_cpu_freqs,
 401                         target_freq, relation, &newstate))
 402                 return -EINVAL;
 403
 404         rc = do_set_cpu_speed(newstate, 1);
 405
 406         ppc_proc_freq = cur_freq * 1000ul;
 407         return rc;
 408 }
 409
 410 static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
 411 {
 412         if (policy->cpu != 0)
 413                 return -ENODEV;
 414
 415         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 416         policy->cpuinfo.transition_latency      = CPUFREQ_ETERNAL;
 417         policy->cur = cur_freq;
 418
 419         cpufreq_frequency_table_get_attr(pmac_cpu_freqs, policy->cpu);
 420         return cpufreq_frequency_table_cpuinfo(policy, pmac_cpu_freqs);
 421 }
 422
 423 static u32 read_gpio(struct device_node *np)
 424 {
 425         u32 *reg = (u32 *)get_property(np, "reg", NULL);
 426         u32 offset;
 427
 428         if (reg == NULL)
 429                 return 0;
 430         /* That works for all keylargos but shall be fixed properly
 431          * some day... The problem is that it seems we can't rely
 432          * on the "reg" property of the GPIO nodes, they are either
 433          * relative to the base of KeyLargo or to the base of the
 434          * GPIO space, and the device-tree doesn't help.
 435          */
 436         offset = *reg;
 437         if (offset < KEYLARGO_GPIO_LEVELS0)
 438                 offset += KEYLARGO_GPIO_LEVELS0;
 439         return offset;
 440 }
 441
 442 static int pmac_cpufreq_suspend(struct cpufreq_policy *policy, pm_message_t pmsg)
 443 {
 444         /* Ok, this could be made a bit smarter, but let's be robust for now. We
 445          * always force a speed change to high speed before sleep, to make sure
 446          * we have appropriate voltage and/or bus speed for the wakeup process,
 447          * and to make sure our loops_per_jiffies are "good enough", that is will
 448          * not cause too short delays if we sleep in low speed and wake in high
 449          * speed..
 450          */
 451         no_schedule = 1;
 452         sleep_freq = cur_freq;
 453         if (cur_freq == low_freq && !is_pmu_based)
 454                 do_set_cpu_speed(CPUFREQ_HIGH, 0);
 455         return 0;
 456 }
 457
 458 static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
 459 {
 460         /* If we resume, first check if we have a get() function */
 461         if (get_speed_proc)
 462                 cur_freq = get_speed_proc();
 463         else
 464                 cur_freq = 0;
 465
 466         /* We don't, hrm... we don't really know our speed here, best
 467          * is that we force a switch to whatever it was, which is
 468          * probably high speed due to our suspend() routine
 469          */
 470         do_set_cpu_speed(sleep_freq == low_freq ?
 471                          CPUFREQ_LOW : CPUFREQ_HIGH, 0);
 472
 473         ppc_proc_freq = cur_freq * 1000ul;
 474
 475         no_schedule = 0;
 476         return 0;
 477 }
 478
 479 static struct cpufreq_driver pmac_cpufreq_driver = {
 480         .verify         = pmac_cpufreq_verify,
 481         .target         = pmac_cpufreq_target,
 482         .get            = pmac_cpufreq_get_speed,
 483         .init           = pmac_cpufreq_cpu_init,
 484         .suspend        = pmac_cpufreq_suspend,
 485         .resume         = pmac_cpufreq_resume,
 486         .flags          = CPUFREQ_PM_NO_WARN,
 487         .attr           = pmac_cpu_freqs_attr,
 488         .name           = "powermac",
 489         .owner          = THIS_MODULE,
 490 };
 491
 492
 493 static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
 494 {
 495         struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
 496                                                                 "voltage-gpio");
 497         struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
 498                                                                 "frequency-gpio");
 499         struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
 500                                                                      "slewing-done");
 501         u32 *value;
 502
 503         /*
 504          * Check to see if it's GPIO driven or PMU only
 505          *
 506          * The way we extract the GPIO address is slightly hackish, but it
 507          * works well enough for now. We need to abstract the whole GPIO
 508          * stuff sooner or later anyway
 509          */
 510
 511         if (volt_gpio_np)
 512                 voltage_gpio = read_gpio(volt_gpio_np);
 513         if (freq_gpio_np)
 514                 frequency_gpio = read_gpio(freq_gpio_np);
 515         if (slew_done_gpio_np)
 516                 slew_done_gpio = read_gpio(slew_done_gpio_np);
 517
 518         /* If we use the frequency GPIOs, calculate the min/max speeds based
 519          * on the bus frequencies
 520          */
 521         if (frequency_gpio && slew_done_gpio) {
 522                 int lenp, rc;
 523                 u32 *freqs, *ratio;
 524
 525                 freqs = (u32 *)get_property(cpunode, "bus-frequencies", &lenp);
 526                 lenp /= sizeof(u32);
 527                 if (freqs == NULL || lenp != 2) {
 528                         printk(KERN_ERR "cpufreq: bus-frequencies incorrect or missing\n");
 529                         return 1;
 530                 }
 531                 ratio = (u32 *)get_property(cpunode, "processor-to-bus-ratio*2", NULL);
 532                 if (ratio == NULL) {
 533                         printk(KERN_ERR "cpufreq: processor-to-bus-ratio*2 missing\n");
 534                         return 1;
 535                 }
 536
 537                 /* Get the min/max bus frequencies */
 538                 low_freq = min(freqs[0], freqs[1]);
 539                 hi_freq = max(freqs[0], freqs[1]);
 540
 541                 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
 542                  * frequency, it claims it to be around 84Mhz on some models while
 543                  * it appears to be approx. 101Mhz on all. Let's hack around here...
 544                  * fortunately, we don't need to be too precise
 545                  */
 546                 if (low_freq < 98000000)
 547                         low_freq = 101000000;
 548
 549                 /* Convert those to CPU core clocks */
 550                 low_freq = (low_freq * (*ratio)) / 2000;
 551                 hi_freq = (hi_freq * (*ratio)) / 2000;
 552
 553                 /* Now we get the frequencies, we read the GPIO to see what is out current
 554                  * speed
 555                  */
 556                 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 557                 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
 558
 559                 set_speed_proc = gpios_set_cpu_speed;
 560                 return 1;
 561         }
 562
 563         /* If we use the PMU, look for the min & max frequencies in the
 564          * device-tree
 565          */
 566         value = (u32 *)get_property(cpunode, "min-clock-frequency", NULL);
 567         if (!value)
 568                 return 1;
 569         low_freq = (*value) / 1000;
 570         /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
 571          * here */
 572         if (low_freq < 100000)
 573                 low_freq *= 10;
 574
 575         value = (u32 *)get_property(cpunode, "max-clock-frequency", NULL);
 576         if (!value)
 577                 return 1;
 578         hi_freq = (*value) / 1000;
 579         set_speed_proc = pmu_set_cpu_speed;
 580         is_pmu_based = 1;
 581
 582         return 0;
 583 }
 584
 585 static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
 586 {
 587         struct device_node *volt_gpio_np;
 588
 589         if (get_property(cpunode, "dynamic-power-step", NULL) == NULL)
 590                 return 1;
 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         if (!voltage_gpio){
 596                 printk(KERN_ERR "cpufreq: missing cpu-vcore-select gpio\n");
 597                 return 1;
 598         }
 599
 600         /* OF only reports the high frequency */
 601         hi_freq = cur_freq;
 602         low_freq = cur_freq/2;
 603
 604         /* Read actual frequency from CPU */
 605         cur_freq = dfs_get_cpu_speed();
 606         set_speed_proc = dfs_set_cpu_speed;
 607         get_speed_proc = dfs_get_cpu_speed;
 608
 609         return 0;
 610 }
 611
 612 static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
 613 {
 614         struct device_node *volt_gpio_np;
 615         u32 pvr, *value;
 616
 617         if (get_property(cpunode, "dynamic-power-step", NULL) == NULL)
 618                 return 1;
 619
 620         hi_freq = cur_freq;
 621         value = (u32 *)get_property(cpunode, "reduced-clock-frequency", NULL);
 622         if (!value)
 623                 return 1;
 624         low_freq = (*value) / 1000;
 625
 626         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 627         if (volt_gpio_np)
 628                 voltage_gpio = read_gpio(volt_gpio_np);
 629
 630         pvr = mfspr(SPRN_PVR);
 631         has_cpu_l2lve = !((pvr & 0xf00) == 0x100);
 632
 633         set_speed_proc = cpu_750fx_cpu_speed;
 634         get_speed_proc = cpu_750fx_get_cpu_speed;
 635         cur_freq = cpu_750fx_get_cpu_speed();
 636
 637         return 0;
 638 }
 639
 640 /* Currently, we support the following machines:
 641  *
 642  *  - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
 643  *  - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
 644  *  - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
 645  *  - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
 646  *  - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
 647  *  - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
 648  *  - Recent MacRISC3 laptops
 649  *  - All new machines with 7447A CPUs
 650  */
 651 static int __init pmac_cpufreq_setup(void)
 652 {
 653         struct device_node      *cpunode;
 654         u32                     *value;
 655
 656         if (strstr(cmd_line, "nocpufreq"))
 657                 return 0;
 658
 659         /* Assume only one CPU */
 660         cpunode = find_type_devices("cpu");
 661         if (!cpunode)
 662                 goto out;
 663
 664         /* Get current cpu clock freq */
 665         value = (u32 *)get_property(cpunode, "clock-frequency", NULL);
 666         if (!value)
 667                 goto out;
 668         cur_freq = (*value) / 1000;
 669
 670         /*  Check for 7447A based MacRISC3 */
 671         if (machine_is_compatible("MacRISC3") &&
 672             get_property(cpunode, "dynamic-power-step", NULL) &&
 673             PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
 674                 pmac_cpufreq_init_7447A(cpunode);
 675         /* Check for other MacRISC3 machines */
 676         } else if (machine_is_compatible("PowerBook3,4") ||
 677                    machine_is_compatible("PowerBook3,5") ||
 678                    machine_is_compatible("MacRISC3")) {
 679                 pmac_cpufreq_init_MacRISC3(cpunode);
 680         /* Else check for iBook2 500/600 */
 681         } else if (machine_is_compatible("PowerBook4,1")) {
 682                 hi_freq = cur_freq;
 683                 low_freq = 400000;
 684                 set_speed_proc = pmu_set_cpu_speed;
 685                 is_pmu_based = 1;
 686         }
 687         /* Else check for TiPb 550 */
 688         else if (machine_is_compatible("PowerBook3,3") && cur_freq == 550000) {
 689                 hi_freq = cur_freq;
 690                 low_freq = 500000;
 691                 set_speed_proc = pmu_set_cpu_speed;
 692                 is_pmu_based = 1;
 693         }
 694         /* Else check for TiPb 400 & 500 */
 695         else if (machine_is_compatible("PowerBook3,2")) {
 696                 /* We only know about the 400 MHz and the 500Mhz model
 697                  * they both have 300 MHz as low frequency
 698                  */
 699                 if (cur_freq < 350000 || cur_freq > 550000)
 700                         goto out;
 701                 hi_freq = cur_freq;
 702                 low_freq = 300000;
 703                 set_speed_proc = pmu_set_cpu_speed;
 704                 is_pmu_based = 1;
 705         }
 706         /* Else check for 750FX */
 707         else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
 708                 pmac_cpufreq_init_750FX(cpunode);
 709 out:
 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