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/i2c.h>
  29 #include <linux/hardirq.h>
  30 #include <asm/prom.h>
  31 #include <asm/machdep.h>
  32 #include <asm/irq.h>
  33 #include <asm/pmac_feature.h>
  34 #include <asm/mmu_context.h>
  35 #include <asm/sections.h>
  36 #include <asm/cputable.h>
  37 #include <asm/time.h>
  38 #include <asm/system.h>
  39 #include <asm/mpic.h>
  40 #include <asm/keylargo.h>
  41
  42 /* WARNING !!! This will cause calibrate_delay() to be called,
  43  * but this is an __init function ! So you MUST go edit
  44  * init/main.c to make it non-init before enabling DEBUG_FREQ
  45  */
  46 #undef DEBUG_FREQ
  47
  48 /*
  49  * There is a problem with the core cpufreq code on SMP kernels,
  50  * it won't recalculate the Bogomips properly
  51  */
  52 #ifdef CONFIG_SMP
  53 #warning "WARNING, CPUFREQ not recommended on SMP kernels"
  54 #endif
  55
  56 extern void low_choose_7447a_dfs(int dfs);
  57 extern void low_choose_750fx_pll(int pll);
  58 extern void low_sleep_handler(void);
  59
  60 /*
  61  * Currently, PowerMac cpufreq supports only high & low frequencies
  62  * that are set by the firmware
  63  */
  64 static unsigned int low_freq;
  65 static unsigned int hi_freq;
  66 static unsigned int cur_freq;
  67 static unsigned int sleep_freq;
  68
  69 /*
  70  * Different models uses different mechanisms to switch the frequency
  71  */
  72 static int (*set_speed_proc)(int low_speed);
  73 static unsigned int (*get_speed_proc)(void);
  74
  75 /*
  76  * Some definitions used by the various speedprocs
  77  */
  78 static u32 voltage_gpio;
  79 static u32 frequency_gpio;
  80 static u32 slew_done_gpio;
  81 static int no_schedule;
  82 static int has_cpu_l2lve;
  83 static int is_pmu_based;
  84
  85 /* There are only two frequency states for each processor. Values
  86  * are in kHz for the time being.
  87  */
  88 #define CPUFREQ_HIGH                  0
  89 #define CPUFREQ_LOW                   1
  90
  91 static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
  92         {CPUFREQ_HIGH,          0},
  93         {CPUFREQ_LOW,           0},
  94         {0,                     CPUFREQ_TABLE_END},
  95 };
  96
  97 static struct freq_attr* pmac_cpu_freqs_attr[] = {
  98         &cpufreq_freq_attr_scaling_available_freqs,
  99         NULL,
 100 };
 101
 102 static inline void local_delay(unsigned long ms)
 103 {
 104         if (no_schedule)
 105                 mdelay(ms);
 106         else
 107                 msleep(ms);
 108 }
 109
 110 #ifdef DEBUG_FREQ
 111 static inline void debug_calc_bogomips(void)
 112 {
 113         /* This will cause a recalc of bogomips and display the
 114          * result. We backup/restore the value to avoid affecting the
 115          * core cpufreq framework's own calculation.
 116          */
 117         extern void calibrate_delay(void);
 118
 119         unsigned long save_lpj = loops_per_jiffy;
 120         calibrate_delay();
 121         loops_per_jiffy = save_lpj;
 122 }
 123 #endif /* DEBUG_FREQ */
 124
 125 /* Switch CPU speed under 750FX CPU control
 126  */
 127 static int cpu_750fx_cpu_speed(int low_speed)
 128 {
 129         u32 hid2;
 130
 131         if (low_speed == 0) {
 132                 /* ramping up, set voltage first */
 133                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 134                 /* Make sure we sleep for at least 1ms */
 135                 local_delay(10);
 136
 137                 /* tweak L2 for high voltage */
 138                 if (has_cpu_l2lve) {
 139                         hid2 = mfspr(SPRN_HID2);
 140                         hid2 &= ~0x2000;
 141                         mtspr(SPRN_HID2, hid2);
 142                 }
 143         }
 144 #ifdef CONFIG_6xx
 145         low_choose_750fx_pll(low_speed);
 146 #endif
 147         if (low_speed == 1) {
 148                 /* tweak L2 for low voltage */
 149                 if (has_cpu_l2lve) {
 150                         hid2 = mfspr(SPRN_HID2);
 151                         hid2 |= 0x2000;
 152                         mtspr(SPRN_HID2, hid2);
 153                 }
 154
 155                 /* ramping down, set voltage last */
 156                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 157                 local_delay(10);
 158         }
 159
 160         return 0;
 161 }
 162
 163 static unsigned int cpu_750fx_get_cpu_speed(void)
 164 {
 165         if (mfspr(SPRN_HID1) & HID1_PS)
 166                 return low_freq;
 167         else
 168                 return hi_freq;
 169 }
 170
 171 /* Switch CPU speed using DFS */
 172 static int dfs_set_cpu_speed(int low_speed)
 173 {
 174         if (low_speed == 0) {
 175                 /* ramping up, set voltage first */
 176                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 177                 /* Make sure we sleep for at least 1ms */
 178                 local_delay(1);
 179         }
 180
 181         /* set frequency */
 182 #ifdef CONFIG_6xx
 183         low_choose_7447a_dfs(low_speed);
 184 #endif
 185         udelay(100);
 186
 187         if (low_speed == 1) {
 188                 /* ramping down, set voltage last */
 189                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 190                 local_delay(1);
 191         }
 192
 193         return 0;
 194 }
 195
 196 static unsigned int dfs_get_cpu_speed(void)
 197 {
 198         if (mfspr(SPRN_HID1) & HID1_DFS)
 199                 return low_freq;
 200         else
 201                 return hi_freq;
 202 }
 203
 204
 205 /* Switch CPU speed using slewing GPIOs
 206  */
 207 static int gpios_set_cpu_speed(int low_speed)
 208 {
 209         int gpio, timeout = 0;
 210
 211         /* If ramping up, set voltage first */
 212         if (low_speed == 0) {
 213                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 214                 /* Delay is way too big but it's ok, we schedule */
 215                 local_delay(10);
 216         }
 217
 218         /* Set frequency */
 219         gpio =  pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 220         if (low_speed == ((gpio & 0x01) == 0))
 221                 goto skip;
 222
 223         pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
 224                           low_speed ? 0x04 : 0x05);
 225         udelay(200);
 226         do {
 227                 if (++timeout > 100)
 228                         break;
 229                 local_delay(1);
 230                 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
 231         } while((gpio & 0x02) == 0);
 232  skip:
 233         /* If ramping down, set voltage last */
 234         if (low_speed == 1) {
 235                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 236                 /* Delay is way too big but it's ok, we schedule */
 237                 local_delay(10);
 238         }
 239
 240 #ifdef DEBUG_FREQ
 241         debug_calc_bogomips();
 242 #endif
 243
 244         return 0;
 245 }
 246
 247 /* Switch CPU speed under PMU control
 248  */
 249 static int pmu_set_cpu_speed(int low_speed)
 250 {
 251         struct adb_request req;
 252         unsigned long save_l2cr;
 253         unsigned long save_l3cr;
 254         unsigned int pic_prio;
 255         unsigned long flags;
 256
 257         preempt_disable();
 258
 259 #ifdef DEBUG_FREQ
 260         printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
 261 #endif
 262         pmu_suspend();
 263
 264         /* Disable all interrupt sources on openpic */
 265         pic_prio = mpic_cpu_get_priority();
 266         mpic_cpu_set_priority(0xf);
 267
 268         /* Make sure the decrementer won't interrupt us */
 269         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 270         /* Make sure any pending DEC interrupt occurring while we did
 271          * the above didn't re-enable the DEC */
 272         mb();
 273         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 274
 275         /* We can now disable MSR_EE */
 276         local_irq_save(flags);
 277
 278         /* Giveup the FPU & vec */
 279         enable_kernel_fp();
 280
 281 #ifdef CONFIG_ALTIVEC
 282         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 283                 enable_kernel_altivec();
 284 #endif /* CONFIG_ALTIVEC */
 285
 286         /* Save & disable L2 and L3 caches */
 287         save_l3cr = _get_L3CR();        /* (returns -1 if not available) */
 288         save_l2cr = _get_L2CR();        /* (returns -1 if not available) */
 289
 290         /* Send the new speed command. My assumption is that this command
 291          * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
 292          */
 293         pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
 294         while (!req.complete)
 295                 pmu_poll();
 296
 297         /* Prepare the northbridge for the speed transition */
 298         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
 299
 300         /* Call low level code to backup CPU state and recover from
 301          * hardware reset
 302          */
 303         low_sleep_handler();
 304
 305         /* Restore the northbridge */
 306         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
 307
 308         /* Restore L2 cache */
 309         if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
 310                 _set_L2CR(save_l2cr);
 311         /* Restore L3 cache */
 312         if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
 313                 _set_L3CR(save_l3cr);
 314
 315         /* Restore userland MMU context */
 316         set_context(current->active_mm->context.id, current->active_mm->pgd);
 317
 318 #ifdef DEBUG_FREQ
 319         printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
 320 #endif
 321
 322         /* Restore low level PMU operations */
 323         pmu_unlock();
 324
 325         /* Restore decrementer */
 326         wakeup_decrementer();
 327
 328         /* Restore interrupts */
 329         mpic_cpu_set_priority(pic_prio);
 330
 331         /* Let interrupts flow again ... */
 332         local_irq_restore(flags);
 333
 334 #ifdef DEBUG_FREQ
 335         debug_calc_bogomips();
 336 #endif
 337
 338         pmu_resume();
 339
 340         preempt_enable();
 341
 342         return 0;
 343 }
 344
 345 static int do_set_cpu_speed(int speed_mode, int notify)
 346 {
 347         struct cpufreq_freqs freqs;
 348         unsigned long l3cr;
 349         static unsigned long prev_l3cr;
 350
 351         freqs.old = cur_freq;
 352         freqs.new = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
 353         freqs.cpu = smp_processor_id();
 354
 355         if (freqs.old == freqs.new)
 356                 return 0;
 357
 358         if (notify)
 359                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 360         if (speed_mode == CPUFREQ_LOW &&
 361             cpu_has_feature(CPU_FTR_L3CR)) {
 362                 l3cr = _get_L3CR();
 363                 if (l3cr & L3CR_L3E) {
 364                         prev_l3cr = l3cr;
 365                         _set_L3CR(0);
 366                 }
 367         }
 368         set_speed_proc(speed_mode == CPUFREQ_LOW);
 369         if (speed_mode == CPUFREQ_HIGH &&
 370             cpu_has_feature(CPU_FTR_L3CR)) {
 371                 l3cr = _get_L3CR();
 372                 if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
 373                         _set_L3CR(prev_l3cr);
 374         }
 375         if (notify)
 376                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 377         cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
 378
 379         return 0;
 380 }
 381
 382 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
 383 {
 384         return cur_freq;
 385 }
 386
 387 static int pmac_cpufreq_verify(struct cpufreq_policy *policy)
 388 {
 389         return cpufreq_frequency_table_verify(policy, pmac_cpu_freqs);
 390 }
 391
 392 static int pmac_cpufreq_target( struct cpufreq_policy *policy,
 393                                         unsigned int target_freq,
 394                                         unsigned int relation)
 395 {
 396         unsigned int    newstate = 0;
 397         int             rc;
 398
 399         if (cpufreq_frequency_table_target(policy, pmac_cpu_freqs,
 400                         target_freq, relation, &newstate))
 401                 return -EINVAL;
 402
 403         rc = do_set_cpu_speed(newstate, 1);
 404
 405         ppc_proc_freq = cur_freq * 1000ul;
 406         return rc;
 407 }
 408
 409 static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
 410 {
 411         if (policy->cpu != 0)
 412                 return -ENODEV;
 413
 414         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 415         policy->cpuinfo.transition_latency      = CPUFREQ_ETERNAL;
 416         policy->cur = cur_freq;
 417
 418         cpufreq_frequency_table_get_attr(pmac_cpu_freqs, policy->cpu);
 419         return cpufreq_frequency_table_cpuinfo(policy, pmac_cpu_freqs);
 420 }
 421
 422 static u32 read_gpio(struct device_node *np)
 423 {
 424         const u32 *reg = get_property(np, "reg", NULL);
 425         u32 offset;
 426
 427         if (reg == NULL)
 428                 return 0;
 429         /* That works for all keylargos but shall be fixed properly
 430          * some day... The problem is that it seems we can't rely
 431          * on the "reg" property of the GPIO nodes, they are either
 432          * relative to the base of KeyLargo or to the base of the
 433          * GPIO space, and the device-tree doesn't help.
 434          */
 435         offset = *reg;
 436         if (offset < KEYLARGO_GPIO_LEVELS0)
 437                 offset += KEYLARGO_GPIO_LEVELS0;
 438         return offset;
 439 }
 440
 441 static int pmac_cpufreq_suspend(struct cpufreq_policy *policy, pm_message_t pmsg)
 442 {
 443         /* Ok, this could be made a bit smarter, but let's be robust for now. We
 444          * always force a speed change to high speed before sleep, to make sure
 445          * we have appropriate voltage and/or bus speed for the wakeup process,
 446          * and to make sure our loops_per_jiffies are "good enough", that is will
 447          * not cause too short delays if we sleep in low speed and wake in high
 448          * speed..
 449          */
 450         no_schedule = 1;
 451         sleep_freq = cur_freq;
 452         if (cur_freq == low_freq && !is_pmu_based)
 453                 do_set_cpu_speed(CPUFREQ_HIGH, 0);
 454         return 0;
 455 }
 456
 457 static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
 458 {
 459         /* If we resume, first check if we have a get() function */
 460         if (get_speed_proc)
 461                 cur_freq = get_speed_proc();
 462         else
 463                 cur_freq = 0;
 464
 465         /* We don't, hrm... we don't really know our speed here, best
 466          * is that we force a switch to whatever it was, which is
 467          * probably high speed due to our suspend() routine
 468          */
 469         do_set_cpu_speed(sleep_freq == low_freq ?
 470                          CPUFREQ_LOW : CPUFREQ_HIGH, 0);
 471
 472         ppc_proc_freq = cur_freq * 1000ul;
 473
 474         no_schedule = 0;
 475         return 0;
 476 }
 477
 478 static struct cpufreq_driver pmac_cpufreq_driver = {
 479         .verify         = pmac_cpufreq_verify,
 480         .target         = pmac_cpufreq_target,
 481         .get            = pmac_cpufreq_get_speed,
 482         .init           = pmac_cpufreq_cpu_init,
 483         .suspend        = pmac_cpufreq_suspend,
 484         .resume         = pmac_cpufreq_resume,
 485         .flags          = CPUFREQ_PM_NO_WARN,
 486         .attr           = pmac_cpu_freqs_attr,
 487         .name           = "powermac",
 488         .owner          = THIS_MODULE,
 489 };
 490
 491
 492 static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
 493 {
 494         struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
 495                                                                 "voltage-gpio");
 496         struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
 497                                                                 "frequency-gpio");
 498         struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
 499                                                                      "slewing-done");
 500         const u32 *value;
 501
 502         /*
 503          * Check to see if it's GPIO driven or PMU only
 504          *
 505          * The way we extract the GPIO address is slightly hackish, but it
 506          * works well enough for now. We need to abstract the whole GPIO
 507          * stuff sooner or later anyway
 508          */
 509
 510         if (volt_gpio_np)
 511                 voltage_gpio = read_gpio(volt_gpio_np);
 512         if (freq_gpio_np)
 513                 frequency_gpio = read_gpio(freq_gpio_np);
 514         if (slew_done_gpio_np)
 515                 slew_done_gpio = read_gpio(slew_done_gpio_np);
 516
 517         /* If we use the frequency GPIOs, calculate the min/max speeds based
 518          * on the bus frequencies
 519          */
 520         if (frequency_gpio && slew_done_gpio) {
 521                 int lenp, rc;
 522                 const u32 *freqs, *ratio;
 523
 524                 freqs = get_property(cpunode, "bus-frequencies", &lenp);
 525                 lenp /= sizeof(u32);
 526                 if (freqs == NULL || lenp != 2) {
 527                         printk(KERN_ERR "cpufreq: bus-frequencies incorrect or missing\n");
 528                         return 1;
 529                 }
 530                 ratio = get_property(cpunode, "processor-to-bus-ratio*2", NULL);
 531                 if (ratio == NULL) {
 532                         printk(KERN_ERR "cpufreq: processor-to-bus-ratio*2 missing\n");
 533                         return 1;
 534                 }
 535
 536                 /* Get the min/max bus frequencies */
 537                 low_freq = min(freqs[0], freqs[1]);
 538                 hi_freq = max(freqs[0], freqs[1]);
 539
 540                 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
 541                  * frequency, it claims it to be around 84Mhz on some models while
 542                  * it appears to be approx. 101Mhz on all. Let's hack around here...
 543                  * fortunately, we don't need to be too precise
 544                  */
 545                 if (low_freq < 98000000)
 546                         low_freq = 101000000;
 547
 548                 /* Convert those to CPU core clocks */
 549                 low_freq = (low_freq * (*ratio)) / 2000;
 550                 hi_freq = (hi_freq * (*ratio)) / 2000;
 551
 552                 /* Now we get the frequencies, we read the GPIO to see what is out current
 553                  * speed
 554                  */
 555                 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 556                 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
 557
 558                 set_speed_proc = gpios_set_cpu_speed;
 559                 return 1;
 560         }
 561
 562         /* If we use the PMU, look for the min & max frequencies in the
 563          * device-tree
 564          */
 565         value = get_property(cpunode, "min-clock-frequency", NULL);
 566         if (!value)
 567                 return 1;
 568         low_freq = (*value) / 1000;
 569         /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
 570          * here */
 571         if (low_freq < 100000)
 572                 low_freq *= 10;
 573
 574         value = get_property(cpunode, "max-clock-frequency", NULL);
 575         if (!value)
 576                 return 1;
 577         hi_freq = (*value) / 1000;
 578         set_speed_proc = pmu_set_cpu_speed;
 579         is_pmu_based = 1;
 580
 581         return 0;
 582 }
 583
 584 static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
 585 {
 586         struct device_node *volt_gpio_np;
 587
 588         if (get_property(cpunode, "dynamic-power-step", NULL) == NULL)
 589                 return 1;
 590
 591         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 592         if (volt_gpio_np)
 593                 voltage_gpio = read_gpio(volt_gpio_np);
 594         if (!voltage_gpio){
 595                 printk(KERN_ERR "cpufreq: missing cpu-vcore-select gpio\n");
 596                 return 1;
 597         }
 598
 599         /* OF only reports the high frequency */
 600         hi_freq = cur_freq;
 601         low_freq = cur_freq/2;
 602
 603         /* Read actual frequency from CPU */
 604         cur_freq = dfs_get_cpu_speed();
 605         set_speed_proc = dfs_set_cpu_speed;
 606         get_speed_proc = dfs_get_cpu_speed;
 607
 608         return 0;
 609 }
 610
 611 static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
 612 {
 613         struct device_node *volt_gpio_np;
 614         u32 pvr;
 615         const u32 *value;
 616
 617         if (get_property(cpunode, "dynamic-power-step", NULL) == NULL)
 618                 return 1;
 619
 620         hi_freq = cur_freq;
 621         value = 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         const 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 = 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