drivers/cpufreq/pmac32-cpufreq.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
   4  *  Copyright (C) 2004        John Steele Scott <toojays@toojays.net>
   5  *
   6  * TODO: Need a big cleanup here. Basically, we need to have different
   7  * cpufreq_driver structures for the different type of HW instead of the
   8  * current mess. We also need to better deal with the detection of the
   9  * type of machine.
  10  */
  11
  12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/module.h>
  15 #include <linux/types.h>
  16 #include <linux/errno.h>
  17 #include <linux/kernel.h>
  18 #include <linux/delay.h>
  19 #include <linux/sched.h>
  20 #include <linux/adb.h>
  21 #include <linux/pmu.h>
  22 #include <linux/cpufreq.h>
  23 #include <linux/init.h>
  24 #include <linux/device.h>
  25 #include <linux/hardirq.h>
  26 #include <linux/of.h>
  27
  28 #include <asm/machdep.h>
  29 #include <asm/irq.h>
  30 #include <asm/pmac_feature.h>
  31 #include <asm/mmu_context.h>
  32 #include <asm/sections.h>
  33 #include <asm/cputable.h>
  34 #include <asm/time.h>
  35 #include <asm/mpic.h>
  36 #include <asm/keylargo.h>
  37 #include <asm/switch_to.h>
  38
  39 /* WARNING !!! This will cause calibrate_delay() to be called,
  40  * but this is an __init function ! So you MUST go edit
  41  * init/main.c to make it non-init before enabling DEBUG_FREQ
  42  */
  43 #undef DEBUG_FREQ
  44
  45 extern void low_choose_7447a_dfs(int dfs);
  46 extern void low_choose_750fx_pll(int pll);
  47 extern void low_sleep_handler(void);
  48
  49 /*
  50  * Currently, PowerMac cpufreq supports only high & low frequencies
  51  * that are set by the firmware
  52  */
  53 static unsigned int low_freq;
  54 static unsigned int hi_freq;
  55 static unsigned int cur_freq;
  56 static unsigned int sleep_freq;
  57 static unsigned long transition_latency;
  58
  59 /*
  60  * Different models uses different mechanisms to switch the frequency
  61  */
  62 static int (*set_speed_proc)(int low_speed);
  63 static unsigned int (*get_speed_proc)(void);
  64
  65 /*
  66  * Some definitions used by the various speedprocs
  67  */
  68 static u32 voltage_gpio;
  69 static u32 frequency_gpio;
  70 static u32 slew_done_gpio;
  71 static int no_schedule;
  72 static int has_cpu_l2lve;
  73 static int is_pmu_based;
  74
  75 /* There are only two frequency states for each processor. Values
  76  * are in kHz for the time being.
  77  */
  78 #define CPUFREQ_HIGH                  0
  79 #define CPUFREQ_LOW                   1
  80
  81 static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
  82         {0, CPUFREQ_HIGH,       0},
  83         {0, CPUFREQ_LOW,        0},
  84         {0, 0,                  CPUFREQ_TABLE_END},
  85 };
  86
  87 static inline void local_delay(unsigned long ms)
  88 {
  89         if (no_schedule)
  90                 mdelay(ms);
  91         else
  92                 msleep(ms);
  93 }
  94
  95 #ifdef DEBUG_FREQ
  96 static inline void debug_calc_bogomips(void)
  97 {
  98         /* This will cause a recalc of bogomips and display the
  99          * result. We backup/restore the value to avoid affecting the
 100          * core cpufreq framework's own calculation.
 101          */
 102         unsigned long save_lpj = loops_per_jiffy;
 103         calibrate_delay();
 104         loops_per_jiffy = save_lpj;
 105 }
 106 #endif /* DEBUG_FREQ */
 107
 108 /* Switch CPU speed under 750FX CPU control
 109  */
 110 static int cpu_750fx_cpu_speed(int low_speed)
 111 {
 112         u32 hid2;
 113
 114         if (low_speed == 0) {
 115                 /* ramping up, set voltage first */
 116                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 117                 /* Make sure we sleep for at least 1ms */
 118                 local_delay(10);
 119
 120                 /* tweak L2 for high voltage */
 121                 if (has_cpu_l2lve) {
 122                         hid2 = mfspr(SPRN_HID2);
 123                         hid2 &= ~0x2000;
 124                         mtspr(SPRN_HID2, hid2);
 125                 }
 126         }
 127 #ifdef CONFIG_PPC_BOOK3S_32
 128         low_choose_750fx_pll(low_speed);
 129 #endif
 130         if (low_speed == 1) {
 131                 /* tweak L2 for low voltage */
 132                 if (has_cpu_l2lve) {
 133                         hid2 = mfspr(SPRN_HID2);
 134                         hid2 |= 0x2000;
 135                         mtspr(SPRN_HID2, hid2);
 136                 }
 137
 138                 /* ramping down, set voltage last */
 139                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 140                 local_delay(10);
 141         }
 142
 143         return 0;
 144 }
 145
 146 static unsigned int cpu_750fx_get_cpu_speed(void)
 147 {
 148         if (mfspr(SPRN_HID1) & HID1_PS)
 149                 return low_freq;
 150         else
 151                 return hi_freq;
 152 }
 153
 154 /* Switch CPU speed using DFS */
 155 static int dfs_set_cpu_speed(int low_speed)
 156 {
 157         if (low_speed == 0) {
 158                 /* ramping up, set voltage first */
 159                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 160                 /* Make sure we sleep for at least 1ms */
 161                 local_delay(1);
 162         }
 163
 164         /* set frequency */
 165 #ifdef CONFIG_PPC_BOOK3S_32
 166         low_choose_7447a_dfs(low_speed);
 167 #endif
 168         udelay(100);
 169
 170         if (low_speed == 1) {
 171                 /* ramping down, set voltage last */
 172                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 173                 local_delay(1);
 174         }
 175
 176         return 0;
 177 }
 178
 179 static unsigned int dfs_get_cpu_speed(void)
 180 {
 181         if (mfspr(SPRN_HID1) & HID1_DFS)
 182                 return low_freq;
 183         else
 184                 return hi_freq;
 185 }
 186
 187
 188 /* Switch CPU speed using slewing GPIOs
 189  */
 190 static int gpios_set_cpu_speed(int low_speed)
 191 {
 192         int gpio, timeout = 0;
 193
 194         /* If ramping up, set voltage first */
 195         if (low_speed == 0) {
 196                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 197                 /* Delay is way too big but it's ok, we schedule */
 198                 local_delay(10);
 199         }
 200
 201         /* Set frequency */
 202         gpio =  pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 203         if (low_speed == ((gpio & 0x01) == 0))
 204                 goto skip;
 205
 206         pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
 207                           low_speed ? 0x04 : 0x05);
 208         udelay(200);
 209         do {
 210                 if (++timeout > 100)
 211                         break;
 212                 local_delay(1);
 213                 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
 214         } while((gpio & 0x02) == 0);
 215  skip:
 216         /* If ramping down, set voltage last */
 217         if (low_speed == 1) {
 218                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 219                 /* Delay is way too big but it's ok, we schedule */
 220                 local_delay(10);
 221         }
 222
 223 #ifdef DEBUG_FREQ
 224         debug_calc_bogomips();
 225 #endif
 226
 227         return 0;
 228 }
 229
 230 /* Switch CPU speed under PMU control
 231  */
 232 static int pmu_set_cpu_speed(int low_speed)
 233 {
 234         struct adb_request req;
 235         unsigned long save_l2cr;
 236         unsigned long save_l3cr;
 237         unsigned int pic_prio;
 238         unsigned long flags;
 239
 240         preempt_disable();
 241
 242 #ifdef DEBUG_FREQ
 243         printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
 244 #endif
 245         pmu_suspend();
 246
 247         /* Disable all interrupt sources on openpic */
 248         pic_prio = mpic_cpu_get_priority();
 249         mpic_cpu_set_priority(0xf);
 250
 251         /* Make sure the decrementer won't interrupt us */
 252         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 253         /* Make sure any pending DEC interrupt occurring while we did
 254          * the above didn't re-enable the DEC */
 255         mb();
 256         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 257
 258         /* We can now disable MSR_EE */
 259         local_irq_save(flags);
 260
 261         /* Giveup the FPU & vec */
 262         enable_kernel_fp();
 263
 264 #ifdef CONFIG_ALTIVEC
 265         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 266                 enable_kernel_altivec();
 267 #endif /* CONFIG_ALTIVEC */
 268
 269         /* Save & disable L2 and L3 caches */
 270         save_l3cr = _get_L3CR();        /* (returns -1 if not available) */
 271         save_l2cr = _get_L2CR();        /* (returns -1 if not available) */
 272
 273         /* Send the new speed command. My assumption is that this command
 274          * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
 275          */
 276         pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
 277         while (!req.complete)
 278                 pmu_poll();
 279
 280         /* Prepare the northbridge for the speed transition */
 281         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
 282
 283         /* Call low level code to backup CPU state and recover from
 284          * hardware reset
 285          */
 286         low_sleep_handler();
 287
 288         /* Restore the northbridge */
 289         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
 290
 291         /* Restore L2 cache */
 292         if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
 293                 _set_L2CR(save_l2cr);
 294         /* Restore L3 cache */
 295         if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
 296                 _set_L3CR(save_l3cr);
 297
 298         /* Restore userland MMU context */
 299         switch_mmu_context(NULL, current->active_mm, NULL);
 300
 301 #ifdef DEBUG_FREQ
 302         printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
 303 #endif
 304
 305         /* Restore low level PMU operations */
 306         pmu_unlock();
 307
 308         /*
 309          * Restore decrementer; we'll take a decrementer interrupt
 310          * as soon as interrupts are re-enabled and the generic
 311          * clockevents code will reprogram it with the right value.
 312          */
 313         set_dec(1);
 314
 315         /* Restore interrupts */
 316         mpic_cpu_set_priority(pic_prio);
 317
 318         /* Let interrupts flow again ... */
 319         local_irq_restore(flags);
 320
 321 #ifdef DEBUG_FREQ
 322         debug_calc_bogomips();
 323 #endif
 324
 325         pmu_resume();
 326
 327         preempt_enable();
 328
 329         return 0;
 330 }
 331
 332 static int do_set_cpu_speed(struct cpufreq_policy *policy, int speed_mode)
 333 {
 334         unsigned long l3cr;
 335         static unsigned long prev_l3cr;
 336
 337         if (speed_mode == CPUFREQ_LOW &&
 338             cpu_has_feature(CPU_FTR_L3CR)) {
 339                 l3cr = _get_L3CR();
 340                 if (l3cr & L3CR_L3E) {
 341                         prev_l3cr = l3cr;
 342                         _set_L3CR(0);
 343                 }
 344         }
 345         set_speed_proc(speed_mode == CPUFREQ_LOW);
 346         if (speed_mode == CPUFREQ_HIGH &&
 347             cpu_has_feature(CPU_FTR_L3CR)) {
 348                 l3cr = _get_L3CR();
 349                 if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
 350                         _set_L3CR(prev_l3cr);
 351         }
 352         cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
 353
 354         return 0;
 355 }
 356
 357 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
 358 {
 359         return cur_freq;
 360 }
 361
 362 static int pmac_cpufreq_target( struct cpufreq_policy *policy,
 363                                         unsigned int index)
 364 {
 365         int             rc;
 366
 367         rc = do_set_cpu_speed(policy, index);
 368
 369         ppc_proc_freq = cur_freq * 1000ul;
 370         return rc;
 371 }
 372
 373 static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
 374 {
 375         cpufreq_generic_init(policy, pmac_cpu_freqs, transition_latency);
 376         return 0;
 377 }
 378
 379 static u32 read_gpio(struct device_node *np)
 380 {
 381         const u32 *reg = of_get_property(np, "reg", NULL);
 382         u32 offset;
 383
 384         if (reg == NULL)
 385                 return 0;
 386         /* That works for all keylargos but shall be fixed properly
 387          * some day... The problem is that it seems we can't rely
 388          * on the "reg" property of the GPIO nodes, they are either
 389          * relative to the base of KeyLargo or to the base of the
 390          * GPIO space, and the device-tree doesn't help.
 391          */
 392         offset = *reg;
 393         if (offset < KEYLARGO_GPIO_LEVELS0)
 394                 offset += KEYLARGO_GPIO_LEVELS0;
 395         return offset;
 396 }
 397
 398 static int pmac_cpufreq_suspend(struct cpufreq_policy *policy)
 399 {
 400         /* Ok, this could be made a bit smarter, but let's be robust for now. We
 401          * always force a speed change to high speed before sleep, to make sure
 402          * we have appropriate voltage and/or bus speed for the wakeup process,
 403          * and to make sure our loops_per_jiffies are "good enough", that is will
 404          * not cause too short delays if we sleep in low speed and wake in high
 405          * speed..
 406          */
 407         no_schedule = 1;
 408         sleep_freq = cur_freq;
 409         if (cur_freq == low_freq && !is_pmu_based)
 410                 do_set_cpu_speed(policy, CPUFREQ_HIGH);
 411         return 0;
 412 }
 413
 414 static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
 415 {
 416         /* If we resume, first check if we have a get() function */
 417         if (get_speed_proc)
 418                 cur_freq = get_speed_proc();
 419         else
 420                 cur_freq = 0;
 421
 422         /* We don't, hrm... we don't really know our speed here, best
 423          * is that we force a switch to whatever it was, which is
 424          * probably high speed due to our suspend() routine
 425          */
 426         do_set_cpu_speed(policy, sleep_freq == low_freq ?
 427                          CPUFREQ_LOW : CPUFREQ_HIGH);
 428
 429         ppc_proc_freq = cur_freq * 1000ul;
 430
 431         no_schedule = 0;
 432         return 0;
 433 }
 434
 435 static struct cpufreq_driver pmac_cpufreq_driver = {
 436         .verify         = cpufreq_generic_frequency_table_verify,
 437         .target_index   = pmac_cpufreq_target,
 438         .get            = pmac_cpufreq_get_speed,
 439         .init           = pmac_cpufreq_cpu_init,
 440         .suspend        = pmac_cpufreq_suspend,
 441         .resume         = pmac_cpufreq_resume,
 442         .flags          = CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
 443         .attr           = cpufreq_generic_attr,
 444         .name           = "powermac",
 445 };
 446
 447
 448 static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
 449 {
 450         struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
 451                                                                 "voltage-gpio");
 452         struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
 453                                                                 "frequency-gpio");
 454         struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
 455                                                                      "slewing-done");
 456         const u32 *value;
 457
 458         /*
 459          * Check to see if it's GPIO driven or PMU only
 460          *
 461          * The way we extract the GPIO address is slightly hackish, but it
 462          * works well enough for now. We need to abstract the whole GPIO
 463          * stuff sooner or later anyway
 464          */
 465
 466         if (volt_gpio_np)
 467                 voltage_gpio = read_gpio(volt_gpio_np);
 468         if (freq_gpio_np)
 469                 frequency_gpio = read_gpio(freq_gpio_np);
 470         if (slew_done_gpio_np)
 471                 slew_done_gpio = read_gpio(slew_done_gpio_np);
 472
 473         of_node_put(volt_gpio_np);
 474         of_node_put(freq_gpio_np);
 475         of_node_put(slew_done_gpio_np);
 476
 477         /* If we use the frequency GPIOs, calculate the min/max speeds based
 478          * on the bus frequencies
 479          */
 480         if (frequency_gpio && slew_done_gpio) {
 481                 int lenp, rc;
 482                 const u32 *freqs, *ratio;
 483
 484                 freqs = of_get_property(cpunode, "bus-frequencies", &lenp);
 485                 lenp /= sizeof(u32);
 486                 if (freqs == NULL || lenp != 2) {
 487                         pr_err("bus-frequencies incorrect or missing\n");
 488                         return 1;
 489                 }
 490                 ratio = of_get_property(cpunode, "processor-to-bus-ratio*2",
 491                                                 NULL);
 492                 if (ratio == NULL) {
 493                         pr_err("processor-to-bus-ratio*2 missing\n");
 494                         return 1;
 495                 }
 496
 497                 /* Get the min/max bus frequencies */
 498                 low_freq = min(freqs[0], freqs[1]);
 499                 hi_freq = max(freqs[0], freqs[1]);
 500
 501                 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
 502                  * frequency, it claims it to be around 84Mhz on some models while
 503                  * it appears to be approx. 101Mhz on all. Let's hack around here...
 504                  * fortunately, we don't need to be too precise
 505                  */
 506                 if (low_freq < 98000000)
 507                         low_freq = 101000000;
 508
 509                 /* Convert those to CPU core clocks */
 510                 low_freq = (low_freq * (*ratio)) / 2000;
 511                 hi_freq = (hi_freq * (*ratio)) / 2000;
 512
 513                 /* Now we get the frequencies, we read the GPIO to see what is out current
 514                  * speed
 515                  */
 516                 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 517                 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
 518
 519                 set_speed_proc = gpios_set_cpu_speed;
 520                 return 1;
 521         }
 522
 523         /* If we use the PMU, look for the min & max frequencies in the
 524          * device-tree
 525          */
 526         value = of_get_property(cpunode, "min-clock-frequency", NULL);
 527         if (!value)
 528                 return 1;
 529         low_freq = (*value) / 1000;
 530         /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
 531          * here */
 532         if (low_freq < 100000)
 533                 low_freq *= 10;
 534
 535         value = of_get_property(cpunode, "max-clock-frequency", NULL);
 536         if (!value)
 537                 return 1;
 538         hi_freq = (*value) / 1000;
 539         set_speed_proc = pmu_set_cpu_speed;
 540         is_pmu_based = 1;
 541
 542         return 0;
 543 }
 544
 545 static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
 546 {
 547         struct device_node *volt_gpio_np;
 548
 549         if (!of_property_read_bool(cpunode, "dynamic-power-step"))
 550                 return 1;
 551
 552         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 553         if (volt_gpio_np)
 554                 voltage_gpio = read_gpio(volt_gpio_np);
 555         of_node_put(volt_gpio_np);
 556         if (!voltage_gpio){
 557                 pr_err("missing cpu-vcore-select gpio\n");
 558                 return 1;
 559         }
 560
 561         /* OF only reports the high frequency */
 562         hi_freq = cur_freq;
 563         low_freq = cur_freq/2;
 564
 565         /* Read actual frequency from CPU */
 566         cur_freq = dfs_get_cpu_speed();
 567         set_speed_proc = dfs_set_cpu_speed;
 568         get_speed_proc = dfs_get_cpu_speed;
 569
 570         return 0;
 571 }
 572
 573 static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
 574 {
 575         struct device_node *volt_gpio_np;
 576         u32 pvr;
 577         const u32 *value;
 578
 579         if (!of_property_read_bool(cpunode, "dynamic-power-step"))
 580                 return 1;
 581
 582         hi_freq = cur_freq;
 583         value = of_get_property(cpunode, "reduced-clock-frequency", NULL);
 584         if (!value)
 585                 return 1;
 586         low_freq = (*value) / 1000;
 587
 588         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 589         if (volt_gpio_np)
 590                 voltage_gpio = read_gpio(volt_gpio_np);
 591
 592         of_node_put(volt_gpio_np);
 593         pvr = mfspr(SPRN_PVR);
 594         has_cpu_l2lve = !((pvr & 0xf00) == 0x100);
 595
 596         set_speed_proc = cpu_750fx_cpu_speed;
 597         get_speed_proc = cpu_750fx_get_cpu_speed;
 598         cur_freq = cpu_750fx_get_cpu_speed();
 599
 600         return 0;
 601 }
 602
 603 /* Currently, we support the following machines:
 604  *
 605  *  - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
 606  *  - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
 607  *  - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
 608  *  - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
 609  *  - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
 610  *  - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
 611  *  - Recent MacRISC3 laptops
 612  *  - All new machines with 7447A CPUs
 613  */
 614 static int __init pmac_cpufreq_setup(void)
 615 {
 616         struct device_node      *cpunode;
 617         const u32               *value;
 618
 619         if (strstr(boot_command_line, "nocpufreq"))
 620                 return 0;
 621
 622         /* Get first CPU node */
 623         cpunode = of_cpu_device_node_get(0);
 624         if (!cpunode)
 625                 goto out;
 626
 627         /* Get current cpu clock freq */
 628         value = of_get_property(cpunode, "clock-frequency", NULL);
 629         if (!value)
 630                 goto out;
 631         cur_freq = (*value) / 1000;
 632
 633         /*  Check for 7447A based MacRISC3 */
 634         if (of_machine_is_compatible("MacRISC3") &&
 635             of_property_read_bool(cpunode, "dynamic-power-step") &&
 636             PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
 637                 pmac_cpufreq_init_7447A(cpunode);
 638
 639                 /* Allow dynamic switching */
 640                 transition_latency = 8000000;
 641                 pmac_cpufreq_driver.flags &= ~CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING;
 642         /* Check for other MacRISC3 machines */
 643         } else if (of_machine_is_compatible("PowerBook3,4") ||
 644                    of_machine_is_compatible("PowerBook3,5") ||
 645                    of_machine_is_compatible("MacRISC3")) {
 646                 pmac_cpufreq_init_MacRISC3(cpunode);
 647         /* Else check for iBook2 500/600 */
 648         } else if (of_machine_is_compatible("PowerBook4,1")) {
 649                 hi_freq = cur_freq;
 650                 low_freq = 400000;
 651                 set_speed_proc = pmu_set_cpu_speed;
 652                 is_pmu_based = 1;
 653         }
 654         /* Else check for TiPb 550 */
 655         else if (of_machine_is_compatible("PowerBook3,3") && cur_freq == 550000) {
 656                 hi_freq = cur_freq;
 657                 low_freq = 500000;
 658                 set_speed_proc = pmu_set_cpu_speed;
 659                 is_pmu_based = 1;
 660         }
 661         /* Else check for TiPb 400 & 500 */
 662         else if (of_machine_is_compatible("PowerBook3,2")) {
 663                 /* We only know about the 400 MHz and the 500Mhz model
 664                  * they both have 300 MHz as low frequency
 665                  */
 666                 if (cur_freq < 350000 || cur_freq > 550000)
 667                         goto out;
 668                 hi_freq = cur_freq;
 669                 low_freq = 300000;
 670                 set_speed_proc = pmu_set_cpu_speed;
 671                 is_pmu_based = 1;
 672         }
 673         /* Else check for 750FX */
 674         else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
 675                 pmac_cpufreq_init_750FX(cpunode);
 676 out:
 677         of_node_put(cpunode);
 678         if (set_speed_proc == NULL)
 679                 return -ENODEV;
 680
 681         pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
 682         pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
 683         ppc_proc_freq = cur_freq * 1000ul;
 684
 685         pr_info("Registering PowerMac CPU frequency driver\n");
 686         pr_info("Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
 687                 low_freq/1000, hi_freq/1000, cur_freq/1000);
 688
 689         return cpufreq_register_driver(&pmac_cpufreq_driver);
 690 }
 691
 692 module_init(pmac_cpufreq_setup);
 693