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 #include <linux/of_address.h>
  28
  29 #include <asm/machdep.h>
  30 #include <asm/irq.h>
  31 #include <asm/pmac_feature.h>
  32 #include <asm/mmu_context.h>
  33 #include <asm/sections.h>
  34 #include <asm/cputable.h>
  35 #include <asm/time.h>
  36 #include <asm/mpic.h>
  37 #include <asm/keylargo.h>
  38 #include <asm/switch_to.h>
  39
  40 /* WARNING !!! This will cause calibrate_delay() to be called,
  41  * but this is an __init function ! So you MUST go edit
  42  * init/main.c to make it non-init before enabling DEBUG_FREQ
  43  */
  44 #undef DEBUG_FREQ
  45
  46 extern void low_choose_7447a_dfs(int dfs);
  47 extern void low_choose_750fx_pll(int pll);
  48 extern void low_sleep_handler(void);
  49
  50 /*
  51  * Currently, PowerMac cpufreq supports only high & low frequencies
  52  * that are set by the firmware
  53  */
  54 static unsigned int low_freq;
  55 static unsigned int hi_freq;
  56 static unsigned int cur_freq;
  57 static unsigned int sleep_freq;
  58 static unsigned long transition_latency;
  59
  60 /*
  61  * Different models uses different mechanisms to switch the frequency
  62  */
  63 static int (*set_speed_proc)(int low_speed);
  64 static unsigned int (*get_speed_proc)(void);
  65
  66 /*
  67  * Some definitions used by the various speedprocs
  68  */
  69 static u32 voltage_gpio;
  70 static u32 frequency_gpio;
  71 static u32 slew_done_gpio;
  72 static int no_schedule;
  73 static int has_cpu_l2lve;
  74 static int is_pmu_based;
  75
  76 /* There are only two frequency states for each processor. Values
  77  * are in kHz for the time being.
  78  */
  79 #define CPUFREQ_HIGH                  0
  80 #define CPUFREQ_LOW                   1
  81
  82 static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
  83         {0, CPUFREQ_HIGH,       0},
  84         {0, CPUFREQ_LOW,        0},
  85         {0, 0,                  CPUFREQ_TABLE_END},
  86 };
  87
  88 static inline void local_delay(unsigned long ms)
  89 {
  90         if (no_schedule)
  91                 mdelay(ms);
  92         else
  93                 msleep(ms);
  94 }
  95
  96 #ifdef DEBUG_FREQ
  97 static inline void debug_calc_bogomips(void)
  98 {
  99         /* This will cause a recalc of bogomips and display the
 100          * result. We backup/restore the value to avoid affecting the
 101          * core cpufreq framework's own calculation.
 102          */
 103         unsigned long save_lpj = loops_per_jiffy;
 104         calibrate_delay();
 105         loops_per_jiffy = save_lpj;
 106 }
 107 #endif /* DEBUG_FREQ */
 108
 109 /* Switch CPU speed under 750FX CPU control
 110  */
 111 static int cpu_750fx_cpu_speed(int low_speed)
 112 {
 113         u32 hid2;
 114
 115         if (low_speed == 0) {
 116                 /* ramping up, set voltage first */
 117                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 118                 /* Make sure we sleep for at least 1ms */
 119                 local_delay(10);
 120
 121                 /* tweak L2 for high voltage */
 122                 if (has_cpu_l2lve) {
 123                         hid2 = mfspr(SPRN_HID2);
 124                         hid2 &= ~0x2000;
 125                         mtspr(SPRN_HID2, hid2);
 126                 }
 127         }
 128 #ifdef CONFIG_PPC_BOOK3S_32
 129         low_choose_750fx_pll(low_speed);
 130 #endif
 131         if (low_speed == 1) {
 132                 /* tweak L2 for low voltage */
 133                 if (has_cpu_l2lve) {
 134                         hid2 = mfspr(SPRN_HID2);
 135                         hid2 |= 0x2000;
 136                         mtspr(SPRN_HID2, hid2);
 137                 }
 138
 139                 /* ramping down, set voltage last */
 140                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 141                 local_delay(10);
 142         }
 143
 144         return 0;
 145 }
 146
 147 static unsigned int cpu_750fx_get_cpu_speed(void)
 148 {
 149         if (mfspr(SPRN_HID1) & HID1_PS)
 150                 return low_freq;
 151         else
 152                 return hi_freq;
 153 }
 154
 155 /* Switch CPU speed using DFS */
 156 static int dfs_set_cpu_speed(int low_speed)
 157 {
 158         if (low_speed == 0) {
 159                 /* ramping up, set voltage first */
 160                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 161                 /* Make sure we sleep for at least 1ms */
 162                 local_delay(1);
 163         }
 164
 165         /* set frequency */
 166 #ifdef CONFIG_PPC_BOOK3S_32
 167         low_choose_7447a_dfs(low_speed);
 168 #endif
 169         udelay(100);
 170
 171         if (low_speed == 1) {
 172                 /* ramping down, set voltage last */
 173                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 174                 local_delay(1);
 175         }
 176
 177         return 0;
 178 }
 179
 180 static unsigned int dfs_get_cpu_speed(void)
 181 {
 182         if (mfspr(SPRN_HID1) & HID1_DFS)
 183                 return low_freq;
 184         else
 185                 return hi_freq;
 186 }
 187
 188
 189 /* Switch CPU speed using slewing GPIOs
 190  */
 191 static int gpios_set_cpu_speed(int low_speed)
 192 {
 193         int gpio, timeout = 0;
 194
 195         /* If ramping up, set voltage first */
 196         if (low_speed == 0) {
 197                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 198                 /* Delay is way too big but it's ok, we schedule */
 199                 local_delay(10);
 200         }
 201
 202         /* Set frequency */
 203         gpio =  pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 204         if (low_speed == ((gpio & 0x01) == 0))
 205                 goto skip;
 206
 207         pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
 208                           low_speed ? 0x04 : 0x05);
 209         udelay(200);
 210         do {
 211                 if (++timeout > 100)
 212                         break;
 213                 local_delay(1);
 214                 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
 215         } while((gpio & 0x02) == 0);
 216  skip:
 217         /* If ramping down, set voltage last */
 218         if (low_speed == 1) {
 219                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 220                 /* Delay is way too big but it's ok, we schedule */
 221                 local_delay(10);
 222         }
 223
 224 #ifdef DEBUG_FREQ
 225         debug_calc_bogomips();
 226 #endif
 227
 228         return 0;
 229 }
 230
 231 /* Switch CPU speed under PMU control
 232  */
 233 static int pmu_set_cpu_speed(int low_speed)
 234 {
 235         struct adb_request req;
 236         unsigned long save_l2cr;
 237         unsigned long save_l3cr;
 238         unsigned int pic_prio;
 239         unsigned long flags;
 240
 241         preempt_disable();
 242
 243 #ifdef DEBUG_FREQ
 244         printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
 245 #endif
 246         pmu_suspend();
 247
 248         /* Disable all interrupt sources on openpic */
 249         pic_prio = mpic_cpu_get_priority();
 250         mpic_cpu_set_priority(0xf);
 251
 252         /* Make sure the decrementer won't interrupt us */
 253         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 254         /* Make sure any pending DEC interrupt occurring while we did
 255          * the above didn't re-enable the DEC */
 256         mb();
 257         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 258
 259         /* We can now disable MSR_EE */
 260         local_irq_save(flags);
 261
 262         /* Giveup the FPU & vec */
 263         enable_kernel_fp();
 264
 265 #ifdef CONFIG_ALTIVEC
 266         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 267                 enable_kernel_altivec();
 268 #endif /* CONFIG_ALTIVEC */
 269
 270         /* Save & disable L2 and L3 caches */
 271         save_l3cr = _get_L3CR();        /* (returns -1 if not available) */
 272         save_l2cr = _get_L2CR();        /* (returns -1 if not available) */
 273
 274         /* Send the new speed command. My assumption is that this command
 275          * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
 276          */
 277         pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
 278         while (!req.complete)
 279                 pmu_poll();
 280
 281         /* Prepare the northbridge for the speed transition */
 282         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
 283
 284         /* Call low level code to backup CPU state and recover from
 285          * hardware reset
 286          */
 287         low_sleep_handler();
 288
 289         /* Restore the northbridge */
 290         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
 291
 292         /* Restore L2 cache */
 293         if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
 294                 _set_L2CR(save_l2cr);
 295         /* Restore L3 cache */
 296         if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
 297                 _set_L3CR(save_l3cr);
 298
 299         /* Restore userland MMU context */
 300         switch_mmu_context(NULL, current->active_mm, NULL);
 301
 302 #ifdef DEBUG_FREQ
 303         printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
 304 #endif
 305
 306         /* Restore low level PMU operations */
 307         pmu_unlock();
 308
 309         /*
 310          * Restore decrementer; we'll take a decrementer interrupt
 311          * as soon as interrupts are re-enabled and the generic
 312          * clockevents code will reprogram it with the right value.
 313          */
 314         set_dec(1);
 315
 316         /* Restore interrupts */
 317         mpic_cpu_set_priority(pic_prio);
 318
 319         /* Let interrupts flow again ... */
 320         local_irq_restore(flags);
 321
 322 #ifdef DEBUG_FREQ
 323         debug_calc_bogomips();
 324 #endif
 325
 326         pmu_resume();
 327
 328         preempt_enable();
 329
 330         return 0;
 331 }
 332
 333 static int do_set_cpu_speed(struct cpufreq_policy *policy, int speed_mode)
 334 {
 335         unsigned long l3cr;
 336         static unsigned long prev_l3cr;
 337
 338         if (speed_mode == CPUFREQ_LOW &&
 339             cpu_has_feature(CPU_FTR_L3CR)) {
 340                 l3cr = _get_L3CR();
 341                 if (l3cr & L3CR_L3E) {
 342                         prev_l3cr = l3cr;
 343                         _set_L3CR(0);
 344                 }
 345         }
 346         set_speed_proc(speed_mode == CPUFREQ_LOW);
 347         if (speed_mode == CPUFREQ_HIGH &&
 348             cpu_has_feature(CPU_FTR_L3CR)) {
 349                 l3cr = _get_L3CR();
 350                 if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
 351                         _set_L3CR(prev_l3cr);
 352         }
 353         cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;
 354
 355         return 0;
 356 }
 357
 358 static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
 359 {
 360         return cur_freq;
 361 }
 362
 363 static int pmac_cpufreq_target( struct cpufreq_policy *policy,
 364                                         unsigned int index)
 365 {
 366         int             rc;
 367
 368         rc = do_set_cpu_speed(policy, index);
 369
 370         ppc_proc_freq = cur_freq * 1000ul;
 371         return rc;
 372 }
 373
 374 static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
 375 {
 376         cpufreq_generic_init(policy, pmac_cpu_freqs, transition_latency);
 377         return 0;
 378 }
 379
 380 static u32 read_gpio(struct device_node *np)
 381 {
 382         u64 offset;
 383
 384         if (of_property_read_reg(np, 0, &offset, NULL) < 0)
 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         if (offset < KEYLARGO_GPIO_LEVELS0)
 393                 offset += KEYLARGO_GPIO_LEVELS0;
 394         return offset;
 395 }
 396
 397 static int pmac_cpufreq_suspend(struct cpufreq_policy *policy)
 398 {
 399         /* Ok, this could be made a bit smarter, but let's be robust for now. We
 400          * always force a speed change to high speed before sleep, to make sure
 401          * we have appropriate voltage and/or bus speed for the wakeup process,
 402          * and to make sure our loops_per_jiffies are "good enough", that is will
 403          * not cause too short delays if we sleep in low speed and wake in high
 404          * speed..
 405          */
 406         no_schedule = 1;
 407         sleep_freq = cur_freq;
 408         if (cur_freq == low_freq && !is_pmu_based)
 409                 do_set_cpu_speed(policy, CPUFREQ_HIGH);
 410         return 0;
 411 }
 412
 413 static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
 414 {
 415         /* If we resume, first check if we have a get() function */
 416         if (get_speed_proc)
 417                 cur_freq = get_speed_proc();
 418         else
 419                 cur_freq = 0;
 420
 421         /* We don't, hrm... we don't really know our speed here, best
 422          * is that we force a switch to whatever it was, which is
 423          * probably high speed due to our suspend() routine
 424          */
 425         do_set_cpu_speed(policy, sleep_freq == low_freq ?
 426                          CPUFREQ_LOW : CPUFREQ_HIGH);
 427
 428         ppc_proc_freq = cur_freq * 1000ul;
 429
 430         no_schedule = 0;
 431         return 0;
 432 }
 433
 434 static struct cpufreq_driver pmac_cpufreq_driver = {
 435         .verify         = cpufreq_generic_frequency_table_verify,
 436         .target_index   = pmac_cpufreq_target,
 437         .get            = pmac_cpufreq_get_speed,
 438         .init           = pmac_cpufreq_cpu_init,
 439         .suspend        = pmac_cpufreq_suspend,
 440         .resume         = pmac_cpufreq_resume,
 441         .flags          = CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING,
 442         .attr           = cpufreq_generic_attr,
 443         .name           = "powermac",
 444 };
 445
 446
 447 static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
 448 {
 449         struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
 450                                                                 "voltage-gpio");
 451         struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
 452                                                                 "frequency-gpio");
 453         struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
 454                                                                      "slewing-done");
 455         const u32 *value;
 456
 457         /*
 458          * Check to see if it's GPIO driven or PMU only
 459          *
 460          * The way we extract the GPIO address is slightly hackish, but it
 461          * works well enough for now. We need to abstract the whole GPIO
 462          * stuff sooner or later anyway
 463          */
 464
 465         if (volt_gpio_np)
 466                 voltage_gpio = read_gpio(volt_gpio_np);
 467         if (freq_gpio_np)
 468                 frequency_gpio = read_gpio(freq_gpio_np);
 469         if (slew_done_gpio_np)
 470                 slew_done_gpio = read_gpio(slew_done_gpio_np);
 471
 472         of_node_put(volt_gpio_np);
 473         of_node_put(freq_gpio_np);
 474         of_node_put(slew_done_gpio_np);
 475
 476         /* If we use the frequency GPIOs, calculate the min/max speeds based
 477          * on the bus frequencies
 478          */
 479         if (frequency_gpio && slew_done_gpio) {
 480                 int lenp, rc;
 481                 const u32 *freqs, *ratio;
 482
 483                 freqs = of_get_property(cpunode, "bus-frequencies", &lenp);
 484                 lenp /= sizeof(u32);
 485                 if (freqs == NULL || lenp != 2) {
 486                         pr_err("bus-frequencies incorrect or missing\n");
 487                         return 1;
 488                 }
 489                 ratio = of_get_property(cpunode, "processor-to-bus-ratio*2",
 490                                                 NULL);
 491                 if (ratio == NULL) {
 492                         pr_err("processor-to-bus-ratio*2 missing\n");
 493                         return 1;
 494                 }
 495
 496                 /* Get the min/max bus frequencies */
 497                 low_freq = min(freqs[0], freqs[1]);
 498                 hi_freq = max(freqs[0], freqs[1]);
 499
 500                 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
 501                  * frequency, it claims it to be around 84Mhz on some models while
 502                  * it appears to be approx. 101Mhz on all. Let's hack around here...
 503                  * fortunately, we don't need to be too precise
 504                  */
 505                 if (low_freq < 98000000)
 506                         low_freq = 101000000;
 507
 508                 /* Convert those to CPU core clocks */
 509                 low_freq = (low_freq * (*ratio)) / 2000;
 510                 hi_freq = (hi_freq * (*ratio)) / 2000;
 511
 512                 /* Now we get the frequencies, we read the GPIO to see what is out current
 513                  * speed
 514                  */
 515                 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 516                 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
 517
 518                 set_speed_proc = gpios_set_cpu_speed;
 519                 return 1;
 520         }
 521
 522         /* If we use the PMU, look for the min & max frequencies in the
 523          * device-tree
 524          */
 525         value = of_get_property(cpunode, "min-clock-frequency", NULL);
 526         if (!value)
 527                 return 1;
 528         low_freq = (*value) / 1000;
 529         /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
 530          * here */
 531         if (low_freq < 100000)
 532                 low_freq *= 10;
 533
 534         value = of_get_property(cpunode, "max-clock-frequency", NULL);
 535         if (!value)
 536                 return 1;
 537         hi_freq = (*value) / 1000;
 538         set_speed_proc = pmu_set_cpu_speed;
 539         is_pmu_based = 1;
 540
 541         return 0;
 542 }
 543
 544 static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
 545 {
 546         struct device_node *volt_gpio_np;
 547
 548         if (!of_property_read_bool(cpunode, "dynamic-power-step"))
 549                 return 1;
 550
 551         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 552         if (volt_gpio_np)
 553                 voltage_gpio = read_gpio(volt_gpio_np);
 554         of_node_put(volt_gpio_np);
 555         if (!voltage_gpio){
 556                 pr_err("missing cpu-vcore-select gpio\n");
 557                 return 1;
 558         }
 559
 560         /* OF only reports the high frequency */
 561         hi_freq = cur_freq;
 562         low_freq = cur_freq/2;
 563
 564         /* Read actual frequency from CPU */
 565         cur_freq = dfs_get_cpu_speed();
 566         set_speed_proc = dfs_set_cpu_speed;
 567         get_speed_proc = dfs_get_cpu_speed;
 568
 569         return 0;
 570 }
 571
 572 static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
 573 {
 574         struct device_node *volt_gpio_np;
 575         u32 pvr;
 576         const u32 *value;
 577
 578         if (!of_property_read_bool(cpunode, "dynamic-power-step"))
 579                 return 1;
 580
 581         hi_freq = cur_freq;
 582         value = of_get_property(cpunode, "reduced-clock-frequency", NULL);
 583         if (!value)
 584                 return 1;
 585         low_freq = (*value) / 1000;
 586
 587         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 588         if (volt_gpio_np)
 589                 voltage_gpio = read_gpio(volt_gpio_np);
 590
 591         of_node_put(volt_gpio_np);
 592         pvr = mfspr(SPRN_PVR);
 593         has_cpu_l2lve = !((pvr & 0xf00) == 0x100);
 594
 595         set_speed_proc = cpu_750fx_cpu_speed;
 596         get_speed_proc = cpu_750fx_get_cpu_speed;
 597         cur_freq = cpu_750fx_get_cpu_speed();
 598
 599         return 0;
 600 }
 601
 602 /* Currently, we support the following machines:
 603  *
 604  *  - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
 605  *  - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
 606  *  - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
 607  *  - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
 608  *  - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
 609  *  - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
 610  *  - Recent MacRISC3 laptops
 611  *  - All new machines with 7447A CPUs
 612  */
 613 static int __init pmac_cpufreq_setup(void)
 614 {
 615         struct device_node      *cpunode;
 616         const u32               *value;
 617
 618         if (strstr(boot_command_line, "nocpufreq"))
 619                 return 0;
 620
 621         /* Get first CPU node */
 622         cpunode = of_cpu_device_node_get(0);
 623         if (!cpunode)
 624                 goto out;
 625
 626         /* Get current cpu clock freq */
 627         value = of_get_property(cpunode, "clock-frequency", NULL);
 628         if (!value)
 629                 goto out;
 630         cur_freq = (*value) / 1000;
 631
 632         /*  Check for 7447A based MacRISC3 */
 633         if (of_machine_is_compatible("MacRISC3") &&
 634             of_property_read_bool(cpunode, "dynamic-power-step") &&
 635             PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
 636                 pmac_cpufreq_init_7447A(cpunode);
 637
 638                 /* Allow dynamic switching */
 639                 transition_latency = 8000000;
 640                 pmac_cpufreq_driver.flags &= ~CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING;
 641         /* Check for other MacRISC3 machines */
 642         } else if (of_machine_is_compatible("PowerBook3,4") ||
 643                    of_machine_is_compatible("PowerBook3,5") ||
 644                    of_machine_is_compatible("MacRISC3")) {
 645                 pmac_cpufreq_init_MacRISC3(cpunode);
 646         /* Else check for iBook2 500/600 */
 647         } else if (of_machine_is_compatible("PowerBook4,1")) {
 648                 hi_freq = cur_freq;
 649                 low_freq = 400000;
 650                 set_speed_proc = pmu_set_cpu_speed;
 651                 is_pmu_based = 1;
 652         }
 653         /* Else check for TiPb 550 */
 654         else if (of_machine_is_compatible("PowerBook3,3") && cur_freq == 550000) {
 655                 hi_freq = cur_freq;
 656                 low_freq = 500000;
 657                 set_speed_proc = pmu_set_cpu_speed;
 658                 is_pmu_based = 1;
 659         }
 660         /* Else check for TiPb 400 & 500 */
 661         else if (of_machine_is_compatible("PowerBook3,2")) {
 662                 /* We only know about the 400 MHz and the 500Mhz model
 663                  * they both have 300 MHz as low frequency
 664                  */
 665                 if (cur_freq < 350000 || cur_freq > 550000)
 666                         goto out;
 667                 hi_freq = cur_freq;
 668                 low_freq = 300000;
 669                 set_speed_proc = pmu_set_cpu_speed;
 670                 is_pmu_based = 1;
 671         }
 672         /* Else check for 750FX */
 673         else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
 674                 pmac_cpufreq_init_750FX(cpunode);
 675 out:
 676         of_node_put(cpunode);
 677         if (set_speed_proc == NULL)
 678                 return -ENODEV;
 679
 680         pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
 681         pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
 682         ppc_proc_freq = cur_freq * 1000ul;
 683
 684         pr_info("Registering PowerMac CPU frequency driver\n");
 685         pr_info("Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
 686                 low_freq/1000, hi_freq/1000, cur_freq/1000);
 687
 688         return cpufreq_register_driver(&pmac_cpufreq_driver);
 689 }
 690
 691 module_init(pmac_cpufreq_setup);
 692