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
  37 /* WARNING !!! This will cause calibrate_delay() to be called,
  38  * but this is an __init function ! So you MUST go edit
  39  * init/main.c to make it non-init before enabling DEBUG_FREQ
  40  */
  41 #undef DEBUG_FREQ
  42
  43 /*
  44  * There is a problem with the core cpufreq code on SMP kernels,
  45  * it won't recalculate the Bogomips properly
  46  */
  47 #ifdef CONFIG_SMP
  48 #warning "WARNING, CPUFREQ not recommended on SMP kernels"
  49 #endif
  50
  51 extern void low_choose_7447a_dfs(int dfs);
  52 extern void low_choose_750fx_pll(int pll);
  53 extern void low_sleep_handler(void);
  54 extern void openpic_suspend(struct sys_device *sysdev, u32 state);
  55 extern void openpic_resume(struct sys_device *sysdev);
  56 extern void enable_kernel_altivec(void);
  57 extern void enable_kernel_fp(void);
  58
  59 /*
  60  * Currently, PowerMac cpufreq supports only high & low frequencies
  61  * that are set by the firmware
  62  */
  63 static unsigned int low_freq;
  64 static unsigned int hi_freq;
  65 static unsigned int cur_freq;
  66
  67 /*
  68  * Different models uses different mecanisms to switch the frequency
  69  */
  70 static int (*set_speed_proc)(int low_speed);
  71
  72 /*
  73  * Some definitions used by the various speedprocs
  74  */
  75 static u32 voltage_gpio;
  76 static u32 frequency_gpio;
  77 static u32 slew_done_gpio;
  78
  79
  80 #define PMAC_CPU_LOW_SPEED      1
  81 #define PMAC_CPU_HIGH_SPEED     0
  82
  83 /* There are only two frequency states for each processor. Values
  84  * are in kHz for the time being.
  85  */
  86 #define CPUFREQ_HIGH                  PMAC_CPU_HIGH_SPEED
  87 #define CPUFREQ_LOW                   PMAC_CPU_LOW_SPEED
  88
  89 static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
  90         {CPUFREQ_HIGH,          0},
  91         {CPUFREQ_LOW,           0},
  92         {0,                     CPUFREQ_TABLE_END},
  93 };
  94
  95 static inline void wakeup_decrementer(void)
  96 {
  97         set_dec(tb_ticks_per_jiffy);
  98         /* No currently-supported powerbook has a 601,
  99          * so use get_tbl, not native
 100          */
 101         last_jiffy_stamp(0) = tb_last_stamp = get_tbl();
 102 }
 103
 104 #ifdef DEBUG_FREQ
 105 static inline void debug_calc_bogomips(void)
 106 {
 107         /* This will cause a recalc of bogomips and display the
 108          * result. We backup/restore the value to avoid affecting the
 109          * core cpufreq framework's own calculation.
 110          */
 111         extern void calibrate_delay(void);
 112
 113         unsigned long save_lpj = loops_per_jiffy;
 114         calibrate_delay();
 115         loops_per_jiffy = save_lpj;
 116 }
 117 #endif /* DEBUG_FREQ */
 118
 119 /* Switch CPU speed under 750FX CPU control
 120  */
 121 static int __pmac cpu_750fx_cpu_speed(int low_speed)
 122 {
 123 #ifdef DEBUG_FREQ
 124         printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
 125 #endif
 126 #ifdef CONFIG_6xx
 127         low_choose_750fx_pll(low_speed);
 128 #endif
 129 #ifdef DEBUG_FREQ
 130         printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
 131         debug_calc_bogomips();
 132 #endif
 133
 134         return 0;
 135 }
 136
 137 /* Switch CPU speed using DFS */
 138 static int __pmac dfs_set_cpu_speed(int low_speed)
 139 {
 140         if (low_speed == 0) {
 141                 /* ramping up, set voltage first */
 142                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 143                 set_current_state(TASK_UNINTERRUPTIBLE);
 144                 schedule_timeout(HZ/1000);
 145         } else {
 146                 /* ramping down, enable aack delay first */
 147                 pmac_call_feature(PMAC_FTR_AACK_DELAY_ENABLE, NULL, 1, 0);
 148         }
 149
 150         /* set frequency */
 151         low_choose_7447a_dfs(low_speed);
 152
 153         if (low_speed == 1) {
 154                 /* ramping down, set voltage last */
 155                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 156                 set_current_state(TASK_UNINTERRUPTIBLE);
 157                 schedule_timeout(HZ/1000);
 158         } else {
 159                 /* ramping up, disable aack delay last */
 160                 pmac_call_feature(PMAC_FTR_AACK_DELAY_ENABLE, NULL, 0, 0);
 161         }
 162
 163         return 0;
 164 }
 165
 166
 167 /* Switch CPU speed using slewing GPIOs
 168  */
 169 static int __pmac gpios_set_cpu_speed(int low_speed)
 170 {
 171         int gpio;
 172
 173         /* If ramping up, set voltage first */
 174         if (low_speed == 0) {
 175                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
 176                 /* Delay is way too big but it's ok, we schedule */
 177                 set_current_state(TASK_UNINTERRUPTIBLE);
 178                 schedule_timeout(HZ/100);
 179         }
 180
 181         /* Set frequency */
 182         pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
 183                           low_speed ? 0x04 : 0x05);
 184         udelay(200);
 185         do {
 186                 set_current_state(TASK_UNINTERRUPTIBLE);
 187                 schedule_timeout(1);
 188                 gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
 189         } while((gpio & 0x02) == 0);
 190
 191         /* If ramping down, set voltage last */
 192         if (low_speed == 1) {
 193                 pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
 194                 /* Delay is way too big but it's ok, we schedule */
 195                 set_current_state(TASK_UNINTERRUPTIBLE);
 196                 schedule_timeout(HZ/100);
 197         }
 198
 199 #ifdef DEBUG_FREQ
 200         debug_calc_bogomips();
 201 #endif
 202
 203         return 0;
 204 }
 205
 206 /* Switch CPU speed under PMU control
 207  */
 208 static int __pmac pmu_set_cpu_speed(int low_speed)
 209 {
 210         struct adb_request req;
 211         unsigned long save_l2cr;
 212         unsigned long save_l3cr;
 213
 214         preempt_disable();
 215
 216 #ifdef DEBUG_FREQ
 217         printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
 218 #endif
 219         /* Disable all interrupt sources on openpic */
 220         openpic_suspend(NULL, 1);
 221
 222         /* Make sure the decrementer won't interrupt us */
 223         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 224         /* Make sure any pending DEC interrupt occuring while we did
 225          * the above didn't re-enable the DEC */
 226         mb();
 227         asm volatile("mtdec %0" : : "r" (0x7fffffff));
 228
 229         /* We can now disable MSR_EE */
 230         local_irq_disable();
 231
 232         /* Giveup the FPU & vec */
 233         enable_kernel_fp();
 234
 235 #ifdef CONFIG_ALTIVEC
 236         if (cur_cpu_spec[0]->cpu_features & CPU_FTR_ALTIVEC)
 237                 enable_kernel_altivec();
 238 #endif /* CONFIG_ALTIVEC */
 239
 240         /* Save & disable L2 and L3 caches */
 241         save_l3cr = _get_L3CR();        /* (returns -1 if not available) */
 242         save_l2cr = _get_L2CR();        /* (returns -1 if not available) */
 243         if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
 244                 _set_L3CR(save_l3cr & 0x7fffffff);
 245         if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
 246                 _set_L2CR(save_l2cr & 0x7fffffff);
 247
 248         /* Send the new speed command. My assumption is that this command
 249          * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
 250          */
 251         pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
 252         while (!req.complete)
 253                 pmu_poll();
 254
 255         /* Prepare the northbridge for the speed transition */
 256         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
 257
 258         /* Call low level code to backup CPU state and recover from
 259          * hardware reset
 260          */
 261         low_sleep_handler();
 262
 263         /* Restore the northbridge */
 264         pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
 265
 266         /* Restore L2 cache */
 267         if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
 268                 _set_L2CR(save_l2cr);
 269         /* Restore L3 cache */
 270         if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
 271                 _set_L3CR(save_l3cr);
 272
 273         /* Restore userland MMU context */
 274         set_context(current->active_mm->context, current->active_mm->pgd);
 275
 276 #ifdef DEBUG_FREQ
 277         printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
 278 #endif
 279
 280         /* Restore low level PMU operations */
 281         pmu_unlock();
 282
 283         /* Restore decrementer */
 284         wakeup_decrementer();
 285
 286         /* Restore interrupts */
 287         openpic_resume(NULL);
 288
 289         /* Let interrupts flow again ... */
 290         local_irq_enable();
 291
 292 #ifdef DEBUG_FREQ
 293         debug_calc_bogomips();
 294 #endif
 295
 296         preempt_enable();
 297
 298         return 0;
 299 }
 300
 301 static int __pmac do_set_cpu_speed(int speed_mode)
 302 {
 303         struct cpufreq_freqs freqs;
 304
 305         freqs.old = cur_freq;
 306         freqs.new = (speed_mode == PMAC_CPU_HIGH_SPEED) ? hi_freq : low_freq;
 307         freqs.cpu = smp_processor_id();
 308
 309         if (freqs.old == freqs.new)
 310                 return 0;
 311
 312         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 313         set_speed_proc(speed_mode == PMAC_CPU_LOW_SPEED);
 314         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 315         cur_freq = (speed_mode == PMAC_CPU_HIGH_SPEED) ? hi_freq : low_freq;
 316
 317         return 0;
 318 }
 319
 320 static int __pmac pmac_cpufreq_verify(struct cpufreq_policy *policy)
 321 {
 322         return cpufreq_frequency_table_verify(policy, pmac_cpu_freqs);
 323 }
 324
 325 static int __pmac pmac_cpufreq_target(  struct cpufreq_policy *policy,
 326                                         unsigned int target_freq,
 327                                         unsigned int relation)
 328 {
 329         unsigned int    newstate = 0;
 330
 331         if (cpufreq_frequency_table_target(policy, pmac_cpu_freqs,
 332                         target_freq, relation, &newstate))
 333                 return -EINVAL;
 334
 335         return do_set_cpu_speed(newstate);
 336 }
 337
 338 unsigned int __pmac pmac_get_one_cpufreq(int i)
 339 {
 340         /* Supports only one CPU for now */
 341         return (i == 0) ? cur_freq : 0;
 342 }
 343
 344 static int __pmac pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
 345 {
 346         if (policy->cpu != 0)
 347                 return -ENODEV;
 348
 349         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 350         policy->cpuinfo.transition_latency      = CPUFREQ_ETERNAL;
 351         policy->cur = cur_freq;
 352
 353         return cpufreq_frequency_table_cpuinfo(policy, &pmac_cpu_freqs[0]);
 354 }
 355
 356 static u32 __pmac read_gpio(struct device_node *np)
 357 {
 358         u32 *reg = (u32 *)get_property(np, "reg", NULL);
 359
 360         if (reg == NULL)
 361                 return 0;
 362         /* That works for all keylargos but shall be fixed properly
 363          * some day...
 364          */
 365         return 0x50 + (*reg);
 366 }
 367
 368 static struct cpufreq_driver pmac_cpufreq_driver = {
 369         .verify         = pmac_cpufreq_verify,
 370         .target         = pmac_cpufreq_target,
 371         .init           = pmac_cpufreq_cpu_init,
 372         .name           = "powermac",
 373         .owner          = THIS_MODULE,
 374 };
 375
 376
 377 static int __pmac pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
 378 {
 379         struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
 380                                                                 "voltage-gpio");
 381         struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
 382                                                                 "frequency-gpio");
 383         struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
 384                                                                      "slewing-done");
 385         u32 *value;
 386
 387         /*
 388          * Check to see if it's GPIO driven or PMU only
 389          *
 390          * The way we extract the GPIO address is slightly hackish, but it
 391          * works well enough for now. We need to abstract the whole GPIO
 392          * stuff sooner or later anyway
 393          */
 394
 395         if (volt_gpio_np)
 396                 voltage_gpio = read_gpio(volt_gpio_np);
 397         if (freq_gpio_np)
 398                 frequency_gpio = read_gpio(freq_gpio_np);
 399         if (slew_done_gpio_np)
 400                 slew_done_gpio = read_gpio(slew_done_gpio_np);
 401
 402         /* If we use the frequency GPIOs, calculate the min/max speeds based
 403          * on the bus frequencies
 404          */
 405         if (frequency_gpio && slew_done_gpio) {
 406                 int lenp, rc;
 407                 u32 *freqs, *ratio;
 408
 409                 freqs = (u32 *)get_property(cpunode, "bus-frequencies", &lenp);
 410                 lenp /= sizeof(u32);
 411                 if (freqs == NULL || lenp != 2) {
 412                         printk(KERN_ERR "cpufreq: bus-frequencies incorrect or missing\n");
 413                         return 1;
 414                 }
 415                 ratio = (u32 *)get_property(cpunode, "processor-to-bus-ratio*2", NULL);
 416                 if (ratio == NULL) {
 417                         printk(KERN_ERR "cpufreq: processor-to-bus-ratio*2 missing\n");
 418                         return 1;
 419                 }
 420
 421                 /* Get the min/max bus frequencies */
 422                 low_freq = min(freqs[0], freqs[1]);
 423                 hi_freq = max(freqs[0], freqs[1]);
 424
 425                 /* Grrrr.. It _seems_ that the device-tree is lying on the low bus
 426                  * frequency, it claims it to be around 84Mhz on some models while
 427                  * it appears to be approx. 101Mhz on all. Let's hack around here...
 428                  * fortunately, we don't need to be too precise
 429                  */
 430                 if (low_freq < 98000000)
 431                         low_freq = 101000000;
 432
 433                 /* Convert those to CPU core clocks */
 434                 low_freq = (low_freq * (*ratio)) / 2000;
 435                 hi_freq = (hi_freq * (*ratio)) / 2000;
 436
 437                 /* Now we get the frequencies, we read the GPIO to see what is out current
 438                  * speed
 439                  */
 440                 rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
 441                 cur_freq = (rc & 0x01) ? hi_freq : low_freq;
 442
 443                 set_speed_proc = gpios_set_cpu_speed;
 444                 return 1;
 445         }
 446
 447         /* If we use the PMU, look for the min & max frequencies in the
 448          * device-tree
 449          */
 450         value = (u32 *)get_property(cpunode, "min-clock-frequency", NULL);
 451         if (!value)
 452                 return 1;
 453         low_freq = (*value) / 1000;
 454         /* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
 455          * here */
 456         if (low_freq < 100000)
 457                 low_freq *= 10;
 458
 459         value = (u32 *)get_property(cpunode, "max-clock-frequency", NULL);
 460         if (!value)
 461                 return 1;
 462         hi_freq = (*value) / 1000;
 463         set_speed_proc = pmu_set_cpu_speed;
 464
 465         return 0;
 466 }
 467
 468 static int __pmac pmac_cpufreq_init_7447A(struct device_node *cpunode)
 469 {
 470         struct device_node *volt_gpio_np;
 471         u32 *reg;
 472
 473         /* OF only reports the high frequency */
 474         hi_freq = cur_freq;
 475         low_freq = cur_freq/2;
 476         if (mfspr(HID1) & HID1_DFS)
 477                 cur_freq = low_freq;
 478         else
 479                 cur_freq = hi_freq;
 480
 481         volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
 482         if (!volt_gpio_np){
 483                 printk(KERN_ERR "cpufreq: missing cpu-vcore-select gpio\n");
 484                 return 1;
 485         }
 486
 487         reg = (u32 *)get_property(volt_gpio_np, "reg", NULL);
 488         voltage_gpio = *reg;
 489         set_speed_proc = dfs_set_cpu_speed;
 490
 491         return 0;
 492 }
 493
 494 /* Currently, we support the following machines:
 495  *
 496  *  - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
 497  *  - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
 498  *  - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
 499  *  - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
 500  *  - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
 501  *  - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
 502  *  - Recent MacRISC3 laptops
 503  *  - iBook G4s and PowerBook G4s with 7447A CPUs
 504  */
 505 static int __init pmac_cpufreq_setup(void)
 506 {
 507         struct device_node      *cpunode;
 508         u32                     *value;
 509
 510         if (strstr(cmd_line, "nocpufreq"))
 511                 return 0;
 512
 513         /* Assume only one CPU */
 514         cpunode = find_type_devices("cpu");
 515         if (!cpunode)
 516                 goto out;
 517
 518         /* Get current cpu clock freq */
 519         value = (u32 *)get_property(cpunode, "clock-frequency", NULL);
 520         if (!value)
 521                 goto out;
 522         cur_freq = (*value) / 1000;
 523
 524         /*  Check for 7447A based iBook G4 or PowerBook */
 525         if (machine_is_compatible("PowerBook6,5") ||
 526             machine_is_compatible("PowerBook6,4") ||
 527             machine_is_compatible("PowerBook5,5") ||
 528             machine_is_compatible("PowerBook5,4")) {
 529                 pmac_cpufreq_init_7447A(cpunode);
 530         /* Check for other MacRISC3 machines */
 531         } else if (machine_is_compatible("PowerBook3,4") ||
 532                    machine_is_compatible("PowerBook3,5") ||
 533                    machine_is_compatible("MacRISC3")) {
 534                 pmac_cpufreq_init_MacRISC3(cpunode);
 535         /* Else check for iBook2 500/600 */
 536         } else if (machine_is_compatible("PowerBook4,1")) {
 537                 hi_freq = cur_freq;
 538                 low_freq = 400000;
 539                 set_speed_proc = pmu_set_cpu_speed;
 540         }
 541         /* Else check for TiPb 400 & 500 */
 542         else if (machine_is_compatible("PowerBook3,2")) {
 543                 /* We only know about the 400 MHz and the 500Mhz model
 544                  * they both have 300 MHz as low frequency
 545                  */
 546                 if (cur_freq < 350000 || cur_freq > 550000)
 547                         goto out;
 548                 hi_freq = cur_freq;
 549                 low_freq = 300000;
 550                 set_speed_proc = pmu_set_cpu_speed;
 551         }
 552         /* Else check for 750FX */
 553         else if (PVR_VER(mfspr(PVR)) == 0x7000) {
 554                 if (get_property(cpunode, "dynamic-power-step", NULL) == NULL)
 555                         goto out;
 556                 hi_freq = cur_freq;
 557                 value = (u32 *)get_property(cpunode, "reduced-clock-frequency", NULL);
 558                 if (!value)
 559                         goto out;
 560                 low_freq = (*value) / 1000;
 561                 set_speed_proc = cpu_750fx_cpu_speed;
 562         }
 563 out:
 564         if (set_speed_proc == NULL)
 565                 return -ENODEV;
 566
 567         pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
 568         pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
 569
 570         printk(KERN_INFO "Registering PowerMac CPU frequency driver\n");
 571         printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
 572                low_freq/1000, hi_freq/1000, cur_freq/1000);
 573
 574         return cpufreq_register_driver(&pmac_cpufreq_driver);
 575 }
 576
 577 module_init(pmac_cpufreq_setup);
 578