arch/ppc/platforms/pmac_cpufreq.c

   1 /*
   2  *  arch/ppc/platforms/pmac_cpufreq.c
   3  *
   4  *  Copyright (C) 2002 - 2004 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  */
  12
  13 #include <linux/config.h>
  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/slab.h>
  23 #include <linux/cpufreq.h>
  24 #include <linux/init.h>
  25 #include <linux/sysdev.h>
  26 #include <linux/i2c.h>
  27 #include <linux/hardirq.h>
  28 #include <asm/prom.h>
  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/system.h>
  37 #include <asm/open_pic.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 /*
  46  * There is a problem with the core cpufreq code on SMP kernels,
  47  * it won't recalculate the Bogomips properly
  48  */
  49 #ifdef CONFIG_SMP
  50 #warning "WARNING, CPUFREQ not recommended on SMP kernels"
  51 #endif
  52
  53 extern void low_choose_7447a_dfs(int dfs);
  54 extern void low_choose_750fx_pll(int pll);
  55 extern void low_sleep_handler(void);
  56
  57 /*
  58  * Currently, PowerMac cpufreq supports only high & low frequencies
  59  * that are set by the firmware
  60  */
  61 static unsigned int low_freq;
  62 static unsigned int hi_freq;
  63 static unsigned int cur_freq;
  64
  65 /*
  66  * Different models uses different mecanisms to switch the frequency
  67  */
  68 static int (*set_speed_proc)(int low_speed);
  69
  70 /*
  71  * Some definitions used by the various speedprocs
  72  */
  73 static u32 voltage_gpio;
  74 static u32 frequency_gpio;
  75 static u32 slew_done_gpio;
  76
  77
  78 #define PMAC_CPU_LOW_SPEED      1
  79 #define PMAC_CPU_HIGH_SPEED     0
  80
  81 /* There are only two frequency states for each processor. Values
  82  * are in kHz for the time being.
  83  */
  84 #define CPUFREQ_HIGH                  PMAC_CPU_HIGH_SPEED
  85 #define CPUFREQ_LOW                   PMAC_CPU_LOW_SPEED
  86
  87 static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
  88         {CPUFREQ_HIGH,          0},
  89         {CPUFREQ_LOW,           0},
  90         {0,                     CPUFREQ_TABLE_END},
  91 };
  92
  93 static inline void wakeup_decrementer(void)
  94 {
  95         set_dec(tb_ticks_per_jiffy);
  96         /* No currently-supported powerbook has a 601,
  97          * so use get_tbl, not native
  98          */
  99         last_jiffy_stamp(0) = tb_last_stamp = get_tbl();
 100 }
 101
 102 #ifdef DEBUG_FREQ
 103 static inline void debug_calc_bogomips(void)
 104 {
 105         /* This will cause a recalc of bogomips and display the
 106          * result. We backup/restore the value to avoid affecting the
 107          * core cpufreq framework's own calculation.
 108          */
 109         extern void calibrate_delay(void);
 110
 111         unsigned long save_lpj = loops_per_jiffy;
 112         calibrate_delay();
 113         loops_per_jiffy = save_lpj;
 114 }
 115 #endif /* DEBUG_FREQ */
 116
 117 /* Switch CPU speed under 750FX CPU control
 118  */
 119 static int __pmac cpu_750fx_cpu_speed(int low_speed)
 120 {
 121 #ifdef DEBUG_FREQ
 122         printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
 123 #endif
 124 #ifdef CONFIG_6xx
 125         low_choose_750fx_pll(low_speed);
 126 #endif
 127 #ifdef DEBUG_FREQ
 128         printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
 129         debug_calc_bogomips();
 130 #endif
 131
 132         return 0;
 133 }
 134
 135 /* Switch CPU speed using DFS */
 136 static int __pmac dfs_set_cpu_speed(int low_speed)
 137 {
 138         if (low_speed == 0) {
 139                 /* ramping up, set voltage first */
 140                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 141                 /* Make sure we sleep for at least 1ms */
 142                 msleep(1);
 143         }
 144
 145         /* set frequency */
 146         low_choose_7447a_dfs(low_speed);
 147
 148         if (low_speed == 1) {
 149                 /* ramping down, set voltage last */
 150                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 151                 msleep(1);
 152         }
 153
 154         return 0;
 155 }
 156
 157
 158 /* Switch CPU speed using slewing GPIOs
 159  */
 160 static int __pmac gpios_set_cpu_speed(int low_speed)
 161 {
 162         int gpio;
 163
 164         /* If ramping up, set voltage first */
 165         if (low_speed == 0) {
 166                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 167                 /* Delay is way too big but it's ok, we schedule */
 168                 msleep(10);
 169         }
 170
 171         /* Set frequency */
 172         pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
 173                           low_speed ? 0x04 : 0x05);
 174         udelay(200);
 175         do {
 176                 set_current_state(TASK_UNINTERRUPTIBLE);
 177                 schedule_timeout(1);
 178                 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
 179         } while((gpio & 0x02) == 0);
 180
 181         /* If ramping down, set voltage last */
 182         if (low_speed == 1) {
 183                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 184                 /* Delay is way too big but it's ok, we schedule */
 185                 msleep(10);
 186         }
 187
 188 #ifdef DEBUG_FREQ
 189         debug_calc_bogomips();
 190 #endif
 191
 192         return 0;
 193 }
 194
 195 /* Switch CPU speed under PMU control
 196  */
 197 static int __pmac pmu_set_cpu_speed(int low_speed)
 198 {
 199         struct adb_request req;
 200         unsigned long save_l2cr;
 201         unsigned long save_l3cr;
 202
 203         preempt_disable();
 204
 205 #ifdef DEBUG_FREQ
 206         printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
 207 #endif
 208         /* Disable all interrupt sources on openpic */
 209         openpic_set_priority(0xf);
 210
 211         /* Make sure the decrementer won't interrupt us */
 212         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 213         /* Make sure any pending DEC interrupt occuring while we did
 214          * the above didn't re-enable the DEC */
 215         mb();
 216         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 217
 218         /* We can now disable MSR_EE */
 219         local_irq_disable();
 220
 221         /* Giveup the FPU & vec */
 222         enable_kernel_fp();
 223
 224 #ifdef CONFIG_ALTIVEC
 225         if (cur_cpu_spec[0]->cpu_features & CPU_FTR_ALTIVEC)
 226                 enable_kernel_altivec();
 227 #endif /* CONFIG_ALTIVEC */
 228
 229         /* Save & disable L2 and L3 caches */
 230         save_l3cr = _get_L3CR();        /* (returns -1 if not available) */
 231         save_l2cr = _get_L2CR();        /* (returns -1 if not available) */
 232         if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
 233                 _set_L3CR(save_l3cr & 0x7fffffff);
 234         if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
 235                 _set_L2CR(save_l2cr & 0x7fffffff);
 236
 237         /* Send the new speed command. My assumption is that this command
 238          * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
 239          */
 240         pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
 241         while (!req.complete)
 242                 pmu_poll();
 243
 244         /* Prepare the northbridge for the speed transition */
 245         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
 246
 247         /* Call low level code to backup CPU state and recover from
 248          * hardware reset
 249          */
 250         low_sleep_handler();
 251
 252         /* Restore the northbridge */
 253         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
 254
 255         /* Restore L2 cache */
 256         if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
 257                 _set_L2CR(save_l2cr);
 258         /* Restore L3 cache */
 259         if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
 260                 _set_L3CR(save_l3cr);
 261
 262         /* Restore userland MMU context */
 263         set_context(current->active_mm->context, current->active_mm->pgd);
 264
 265 #ifdef DEBUG_FREQ
 266         printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
 267 #endif
 268
 269         /* Restore low level PMU operations */
 270         pmu_unlock();
 271
 272         /* Restore decrementer */
 273         wakeup_decrementer();
 274
 275         /* Restore interrupts */
 276         openpic_set_priority(0);
 277
 278         /* Let interrupts flow again ... */
 279         local_irq_enable();
 280
 281 #ifdef DEBUG_FREQ
 282         debug_calc_bogomips();
 283 #endif
 284
 285         preempt_enable();
 286
 287         return 0;
 288 }
 289
 290 static int __pmac do_set_cpu_speed(int speed_mode)
 291 {
 292         struct cpufreq_freqs freqs;
 293
 294         freqs.old = cur_freq;
 295         freqs.new = (speed_mode == PMAC_CPU_HIGH_SPEED) ? hi_freq : low_freq;
 296         freqs.cpu = smp_processor_id();
 297
 298         if (freqs.old == freqs.new)
 299                 return 0;
 300
 301         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 302         set_speed_proc(speed_mode == PMAC_CPU_LOW_SPEED);
 303         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 304         cur_freq = (speed_mode == PMAC_CPU_HIGH_SPEED) ? hi_freq : low_freq;
 305
 306         return 0;
 307 }
 308
 309 static int __pmac pmac_cpufreq_verify(struct cpufreq_policy *policy)
 310 {
 311         return cpufreq_frequency_table_verify(policy, pmac_cpu_freqs);
 312 }
 313
 314 static int __pmac pmac_cpufreq_target(  struct cpufreq_policy *policy,
 315                                         unsigned int target_freq,
 316                                         unsigned int relation)
 317 {
 318         unsigned int    newstate = 0;
 319
 320         if (cpufreq_frequency_table_target(policy, pmac_cpu_freqs,
 321                         target_freq, relation, &newstate))
 322                 return -EINVAL;
 323
 324         return do_set_cpu_speed(newstate);
 325 }
 326
 327 unsigned int __pmac pmac_get_one_cpufreq(int i)
 328 {
 329         /* Supports only one CPU for now */
 330         return (i == 0) ? cur_freq : 0;
 331 }
 332
 333 static int __pmac pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
 334 {
 335         if (policy->cpu != 0)
 336                 return -ENODEV;
 337
 338         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 339         policy->cpuinfo.transition_latency      = CPUFREQ_ETERNAL;
 340         policy->cur = cur_freq;
 341
 342         return cpufreq_frequency_table_cpuinfo(policy, &pmac_cpu_freqs[0]);
 343 }
 344
 345 static u32 __pmac read_gpio(struct device_node *np)
 346 {
 347         u32 *reg = (u32 *)get_property(np, "reg", NULL);
 348
 349         if (reg == NULL)
 350                 return 0;
 351         /* That works for all keylargos but shall be fixed properly
 352          * some day...
 353          */
 354         return 0x50 + (*reg);
 355 }
 356
 357 static struct cpufreq_driver pmac_cpufreq_driver = {
 358         .verify         = pmac_cpufreq_verify,
 359         .target         = pmac_cpufreq_target,
 360         .init           = pmac_cpufreq_cpu_init,
 361         .name           = "powermac",
 362         .owner          = THIS_MODULE,
 363 };
 364
 365
 366 static int __pmac pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
 367 {
 368         struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
 369                                                                 "voltage-gpio");
 370         struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
 371                                                                 "frequency-gpio");
 372         struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
 373                                                                      "slewing-done");
 374         u32 *value;
 375
 376         /*
 377          * Check to see if it's GPIO driven or PMU only
 378          *
 379          * The way we extract the GPIO address is slightly hackish, but it
 380          * works well enough for now. We need to abstract the whole GPIO
 381          * stuff sooner or later anyway
 382          */
 383
 384         if (volt_gpio_np)
 385                 voltage_gpio = read_gpio(volt_gpio_np);
 386         if (freq_gpio_np)
 387                 frequency_gpio = read_gpio(freq_gpio_np);
 388         if (slew_done_gpio_np)
 389                 slew_done_gpio = read_gpio(slew_done_gpio_np);
 390
 391         /* If we use the frequency GPIOs, calculate the min/max speeds based
 392          * on the bus frequencies
 393          */
 394         if (frequency_gpio && slew_done_gpio) {
 395                 int lenp, rc;
 396                 u32 *freqs, *ratio;
 397
 398                 freqs = (u32 *)get_property(cpunode, "bus-frequencies", &lenp);
 399                 lenp /= sizeof(u32);
 400                 if (freqs == NULL || lenp != 2) {
 401                         printk(KERN_ERR "cpufreq: bus-frequencies incorrect or missing\n");
 402                         return 1;
 403                 }
 404                 ratio = (u32 *)get_property(cpunode, "processor-to-bus-ratio*2", NULL);
 405                 if (ratio == NULL) {
 406                         printk(KERN_ERR "cpufreq: processor-to-bus-ratio*2 missing\n");
 407                         return 1;
 408                 }
 409
 410                 /* Get the min/max bus frequencies */
 411                 low_freq = min(freqs[0], freqs[1]);
 412                 hi_freq = max(freqs[0], freqs[1]);
 413
 414                 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
 415                  * frequency, it claims it to be around 84Mhz on some models while
 416                  * it appears to be approx. 101Mhz on all. Let's hack around here...
 417                  * fortunately, we don't need to be too precise
 418                  */
 419                 if (low_freq < 98000000)
 420                         low_freq = 101000000;
 421
 422                 /* Convert those to CPU core clocks */
 423                 low_freq = (low_freq * (*ratio)) / 2000;
 424                 hi_freq = (hi_freq * (*ratio)) / 2000;
 425
 426                 /* Now we get the frequencies, we read the GPIO to see what is out current
 427                  * speed
 428                  */
 429                 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 430                 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
 431
 432                 set_speed_proc = gpios_set_cpu_speed;
 433                 return 1;
 434         }
 435
 436         /* If we use the PMU, look for the min & max frequencies in the
 437          * device-tree
 438          */
 439         value = (u32 *)get_property(cpunode, "min-clock-frequency", NULL);
 440         if (!value)
 441                 return 1;
 442         low_freq = (*value) / 1000;
 443         /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
 444          * here */
 445         if (low_freq < 100000)
 446                 low_freq *= 10;
 447
 448         value = (u32 *)get_property(cpunode, "max-clock-frequency", NULL);
 449         if (!value)
 450                 return 1;
 451         hi_freq = (*value) / 1000;
 452         set_speed_proc = pmu_set_cpu_speed;
 453
 454         return 0;
 455 }
 456
 457 static int __pmac pmac_cpufreq_init_7447A(struct device_node *cpunode)
 458 {
 459         struct device_node *volt_gpio_np;
 460         u32 *reg;
 461
 462         /* OF only reports the high frequency */
 463         hi_freq = cur_freq;
 464         low_freq = cur_freq/2;
 465         if (mfspr(HID1) & HID1_DFS)
 466                 cur_freq = low_freq;
 467         else
 468                 cur_freq = hi_freq;
 469
 470         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 471         if (!volt_gpio_np){
 472                 printk(KERN_ERR "cpufreq: missing cpu-vcore-select gpio\n");
 473                 return 1;
 474         }
 475
 476         reg = (u32 *)get_property(volt_gpio_np, "reg", NULL);
 477         voltage_gpio = *reg;
 478         set_speed_proc = dfs_set_cpu_speed;
 479
 480         return 0;
 481 }
 482
 483 /* Currently, we support the following machines:
 484  *
 485  *  - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
 486  *  - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
 487  *  - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
 488  *  - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
 489  *  - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
 490  *  - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
 491  *  - Recent MacRISC3 laptops
 492  *  - iBook G4s and PowerBook G4s with 7447A CPUs
 493  */
 494 static int __init pmac_cpufreq_setup(void)
 495 {
 496         struct device_node      *cpunode;
 497         u32                     *value;
 498
 499         if (strstr(cmd_line, "nocpufreq"))
 500                 return 0;
 501
 502         /* Assume only one CPU */
 503         cpunode = find_type_devices("cpu");
 504         if (!cpunode)
 505                 goto out;
 506
 507         /* Get current cpu clock freq */
 508         value = (u32 *)get_property(cpunode, "clock-frequency", NULL);
 509         if (!value)
 510                 goto out;
 511         cur_freq = (*value) / 1000;
 512
 513         /*  Check for 7447A based iBook G4 or PowerBook */
 514         if (machine_is_compatible("PowerBook6,5") ||
 515             machine_is_compatible("PowerBook6,4") ||
 516             machine_is_compatible("PowerBook5,5") ||
 517             machine_is_compatible("PowerBook5,4")) {
 518                 pmac_cpufreq_init_7447A(cpunode);
 519         /* Check for other MacRISC3 machines */
 520         } else if (machine_is_compatible("PowerBook3,4") ||
 521                    machine_is_compatible("PowerBook3,5") ||
 522                    machine_is_compatible("MacRISC3")) {
 523                 pmac_cpufreq_init_MacRISC3(cpunode);
 524         /* Else check for iBook2 500/600 */
 525         } else if (machine_is_compatible("PowerBook4,1")) {
 526                 hi_freq = cur_freq;
 527                 low_freq = 400000;
 528                 set_speed_proc = pmu_set_cpu_speed;
 529         }
 530         /* Else check for TiPb 400 & 500 */
 531         else if (machine_is_compatible("PowerBook3,2")) {
 532                 /* We only know about the 400 MHz and the 500Mhz model
 533                  * they both have 300 MHz as low frequency
 534                  */
 535                 if (cur_freq < 350000 || cur_freq > 550000)
 536                         goto out;
 537                 hi_freq = cur_freq;
 538                 low_freq = 300000;
 539                 set_speed_proc = pmu_set_cpu_speed;
 540         }
 541         /* Else check for 750FX */
 542         else if (PVR_VER(mfspr(PVR)) == 0x7000) {
 543                 if (get_property(cpunode, "dynamic-power-step", NULL) == NULL)
 544                         goto out;
 545                 hi_freq = cur_freq;
 546                 value = (u32 *)get_property(cpunode, "reduced-clock-frequency", NULL);
 547                 if (!value)
 548                         goto out;
 549                 low_freq = (*value) / 1000;
 550                 set_speed_proc = cpu_750fx_cpu_speed;
 551         }
 552 out:
 553         if (set_speed_proc == NULL)
 554                 return -ENODEV;
 555
 556         pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
 557         pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
 558
 559         printk(KERN_INFO "Registering PowerMac CPU frequency driver\n");
 560         printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
 561                low_freq/1000, hi_freq/1000, cur_freq/1000);
 562
 563         return cpufreq_register_driver(&pmac_cpufreq_driver);
 564 }
 565
 566 module_init(pmac_cpufreq_setup);
 567