err.no Git - linux-2.6/blob - arch/ppc/platforms/pmac_cpufreq.c

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