linux/arch/powerpc/platforms/powermac/cpufreq_64.c
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   1/*
   2 *  Copyright (C) 2002 - 2005 Benjamin Herrenschmidt <benh@kernel.crashing.org>
   3 *  and                       Markus Demleitner <msdemlei@cl.uni-heidelberg.de>
   4 *
   5 * This program is free software; you can redistribute it and/or modify
   6 * it under the terms of the GNU General Public License version 2 as
   7 * published by the Free Software Foundation.
   8 *
   9 * This driver adds basic cpufreq support for SMU & 970FX based G5 Macs,
  10 * that is iMac G5 and latest single CPU desktop.
  11 */
  12
  13#undef DEBUG
  14
  15#include <linux/module.h>
  16#include <linux/types.h>
  17#include <linux/errno.h>
  18#include <linux/kernel.h>
  19#include <linux/delay.h>
  20#include <linux/sched.h>
  21#include <linux/slab.h>
  22#include <linux/cpufreq.h>
  23#include <linux/init.h>
  24#include <linux/completion.h>
  25#include <linux/mutex.h>
  26#include <asm/prom.h>
  27#include <asm/machdep.h>
  28#include <asm/irq.h>
  29#include <asm/sections.h>
  30#include <asm/cputable.h>
  31#include <asm/time.h>
  32#include <asm/smu.h>
  33#include <asm/pmac_pfunc.h>
  34
  35#define DBG(fmt...) pr_debug(fmt)
  36
  37/* see 970FX user manual */
  38
  39#define SCOM_PCR 0x0aa001                       /* PCR scom addr */
  40
  41#define PCR_HILO_SELECT         0x80000000U     /* 1 = PCR, 0 = PCRH */
  42#define PCR_SPEED_FULL          0x00000000U     /* 1:1 speed value */
  43#define PCR_SPEED_HALF          0x00020000U     /* 1:2 speed value */
  44#define PCR_SPEED_QUARTER       0x00040000U     /* 1:4 speed value */
  45#define PCR_SPEED_MASK          0x000e0000U     /* speed mask */
  46#define PCR_SPEED_SHIFT         17
  47#define PCR_FREQ_REQ_VALID      0x00010000U     /* freq request valid */
  48#define PCR_VOLT_REQ_VALID      0x00008000U     /* volt request valid */
  49#define PCR_TARGET_TIME_MASK    0x00006000U     /* target time */
  50#define PCR_STATLAT_MASK        0x00001f00U     /* STATLAT value */
  51#define PCR_SNOOPLAT_MASK       0x000000f0U     /* SNOOPLAT value */
  52#define PCR_SNOOPACC_MASK       0x0000000fU     /* SNOOPACC value */
  53
  54#define SCOM_PSR 0x408001                       /* PSR scom addr */
  55/* warning: PSR is a 64 bits register */
  56#define PSR_CMD_RECEIVED        0x2000000000000000U   /* command received */
  57#define PSR_CMD_COMPLETED       0x1000000000000000U   /* command completed */
  58#define PSR_CUR_SPEED_MASK      0x0300000000000000U   /* current speed */
  59#define PSR_CUR_SPEED_SHIFT     (56)
  60
  61/*
  62 * The G5 only supports two frequencies (Quarter speed is not supported)
  63 */
  64#define CPUFREQ_HIGH                  0
  65#define CPUFREQ_LOW                   1
  66
  67static struct cpufreq_frequency_table g5_cpu_freqs[] = {
  68        {CPUFREQ_HIGH,          0},
  69        {CPUFREQ_LOW,           0},
  70        {0,                     CPUFREQ_TABLE_END},
  71};
  72
  73static struct freq_attr* g5_cpu_freqs_attr[] = {
  74        &cpufreq_freq_attr_scaling_available_freqs,
  75        NULL,
  76};
  77
  78/* Power mode data is an array of the 32 bits PCR values to use for
  79 * the various frequencies, retrieved from the device-tree
  80 */
  81static int g5_pmode_cur;
  82
  83static void (*g5_switch_volt)(int speed_mode);
  84static int (*g5_switch_freq)(int speed_mode);
  85static int (*g5_query_freq)(void);
  86
  87static DEFINE_MUTEX(g5_switch_mutex);
  88
  89static unsigned long transition_latency;
  90
  91#ifdef CONFIG_PMAC_SMU
  92
  93static const u32 *g5_pmode_data;
  94static int g5_pmode_max;
  95
  96static struct smu_sdbp_fvt *g5_fvt_table;       /* table of op. points */
  97static int g5_fvt_count;                        /* number of op. points */
  98static int g5_fvt_cur;                          /* current op. point */
  99
 100/*
 101 * SMU based voltage switching for Neo2 platforms
 102 */
 103
 104static void g5_smu_switch_volt(int speed_mode)
 105{
 106        struct smu_simple_cmd   cmd;
 107
 108        DECLARE_COMPLETION_ONSTACK(comp);
 109        smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, smu_done_complete,
 110                         &comp, 'V', 'S', 'L', 'E', 'W',
 111                         0xff, g5_fvt_cur+1, speed_mode);
 112        wait_for_completion(&comp);
 113}
 114
 115/*
 116 * Platform function based voltage/vdnap switching for Neo2
 117 */
 118
 119static struct pmf_function *pfunc_set_vdnap0;
 120static struct pmf_function *pfunc_vdnap0_complete;
 121
 122static void g5_vdnap_switch_volt(int speed_mode)
 123{
 124        struct pmf_args args;
 125        u32 slew, done = 0;
 126        unsigned long timeout;
 127
 128        slew = (speed_mode == CPUFREQ_LOW) ? 1 : 0;
 129        args.count = 1;
 130        args.u[0].p = &slew;
 131
 132        pmf_call_one(pfunc_set_vdnap0, &args);
 133
 134        /* It's an irq GPIO so we should be able to just block here,
 135         * I'll do that later after I've properly tested the IRQ code for
 136         * platform functions
 137         */
 138        timeout = jiffies + HZ/10;
 139        while(!time_after(jiffies, timeout)) {
 140                args.count = 1;
 141                args.u[0].p = &done;
 142                pmf_call_one(pfunc_vdnap0_complete, &args);
 143                if (done)
 144                        break;
 145                msleep(1);
 146        }
 147        if (done == 0)
 148                printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n");
 149}
 150
 151
 152/*
 153 * SCOM based frequency switching for 970FX rev3
 154 */
 155static int g5_scom_switch_freq(int speed_mode)
 156{
 157        unsigned long flags;
 158        int to;
 159
 160        /* If frequency is going up, first ramp up the voltage */
 161        if (speed_mode < g5_pmode_cur)
 162                g5_switch_volt(speed_mode);
 163
 164        local_irq_save(flags);
 165
 166        /* Clear PCR high */
 167        scom970_write(SCOM_PCR, 0);
 168        /* Clear PCR low */
 169        scom970_write(SCOM_PCR, PCR_HILO_SELECT | 0);
 170        /* Set PCR low */
 171        scom970_write(SCOM_PCR, PCR_HILO_SELECT |
 172                      g5_pmode_data[speed_mode]);
 173
 174        /* Wait for completion */
 175        for (to = 0; to < 10; to++) {
 176                unsigned long psr = scom970_read(SCOM_PSR);
 177
 178                if ((psr & PSR_CMD_RECEIVED) == 0 &&
 179                    (((psr >> PSR_CUR_SPEED_SHIFT) ^
 180                      (g5_pmode_data[speed_mode] >> PCR_SPEED_SHIFT)) & 0x3)
 181                    == 0)
 182                        break;
 183                if (psr & PSR_CMD_COMPLETED)
 184                        break;
 185                udelay(100);
 186        }
 187
 188        local_irq_restore(flags);
 189
 190        /* If frequency is going down, last ramp the voltage */
 191        if (speed_mode > g5_pmode_cur)
 192                g5_switch_volt(speed_mode);
 193
 194        g5_pmode_cur = speed_mode;
 195        ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
 196
 197        return 0;
 198}
 199
 200static int g5_scom_query_freq(void)
 201{
 202        unsigned long psr = scom970_read(SCOM_PSR);
 203        int i;
 204
 205        for (i = 0; i <= g5_pmode_max; i++)
 206                if ((((psr >> PSR_CUR_SPEED_SHIFT) ^
 207                      (g5_pmode_data[i] >> PCR_SPEED_SHIFT)) & 0x3) == 0)
 208                        break;
 209        return i;
 210}
 211
 212/*
 213 * Fake voltage switching for platforms with missing support
 214 */
 215
 216static void g5_dummy_switch_volt(int speed_mode)
 217{
 218}
 219
 220#endif /* CONFIG_PMAC_SMU */
 221
 222/*
 223 * Platform function based voltage switching for PowerMac7,2 & 7,3
 224 */
 225
 226static struct pmf_function *pfunc_cpu0_volt_high;
 227static struct pmf_function *pfunc_cpu0_volt_low;
 228static struct pmf_function *pfunc_cpu1_volt_high;
 229static struct pmf_function *pfunc_cpu1_volt_low;
 230
 231static void g5_pfunc_switch_volt(int speed_mode)
 232{
 233        if (speed_mode == CPUFREQ_HIGH) {
 234                if (pfunc_cpu0_volt_high)
 235                        pmf_call_one(pfunc_cpu0_volt_high, NULL);
 236                if (pfunc_cpu1_volt_high)
 237                        pmf_call_one(pfunc_cpu1_volt_high, NULL);
 238        } else {
 239                if (pfunc_cpu0_volt_low)
 240                        pmf_call_one(pfunc_cpu0_volt_low, NULL);
 241                if (pfunc_cpu1_volt_low)
 242                        pmf_call_one(pfunc_cpu1_volt_low, NULL);
 243        }
 244        msleep(10); /* should be faster , to fix */
 245}
 246
 247/*
 248 * Platform function based frequency switching for PowerMac7,2 & 7,3
 249 */
 250
 251static struct pmf_function *pfunc_cpu_setfreq_high;
 252static struct pmf_function *pfunc_cpu_setfreq_low;
 253static struct pmf_function *pfunc_cpu_getfreq;
 254static struct pmf_function *pfunc_slewing_done;
 255
 256static int g5_pfunc_switch_freq(int speed_mode)
 257{
 258        struct pmf_args args;
 259        u32 done = 0;
 260        unsigned long timeout;
 261        int rc;
 262
 263        DBG("g5_pfunc_switch_freq(%d)\n", speed_mode);
 264
 265        /* If frequency is going up, first ramp up the voltage */
 266        if (speed_mode < g5_pmode_cur)
 267                g5_switch_volt(speed_mode);
 268
 269        /* Do it */
 270        if (speed_mode == CPUFREQ_HIGH)
 271                rc = pmf_call_one(pfunc_cpu_setfreq_high, NULL);
 272        else
 273                rc = pmf_call_one(pfunc_cpu_setfreq_low, NULL);
 274
 275        if (rc)
 276                printk(KERN_WARNING "cpufreq: pfunc switch error %d\n", rc);
 277
 278        /* It's an irq GPIO so we should be able to just block here,
 279         * I'll do that later after I've properly tested the IRQ code for
 280         * platform functions
 281         */
 282        timeout = jiffies + HZ/10;
 283        while(!time_after(jiffies, timeout)) {
 284                args.count = 1;
 285                args.u[0].p = &done;
 286                pmf_call_one(pfunc_slewing_done, &args);
 287                if (done)
 288                        break;
 289                msleep(1);
 290        }
 291        if (done == 0)
 292                printk(KERN_WARNING "cpufreq: Timeout in clock slewing !\n");
 293
 294        /* If frequency is going down, last ramp the voltage */
 295        if (speed_mode > g5_pmode_cur)
 296                g5_switch_volt(speed_mode);
 297
 298        g5_pmode_cur = speed_mode;
 299        ppc_proc_freq = g5_cpu_freqs[speed_mode].frequency * 1000ul;
 300
 301        return 0;
 302}
 303
 304static int g5_pfunc_query_freq(void)
 305{
 306        struct pmf_args args;
 307        u32 val = 0;
 308
 309        args.count = 1;
 310        args.u[0].p = &val;
 311        pmf_call_one(pfunc_cpu_getfreq, &args);
 312        return val ? CPUFREQ_HIGH : CPUFREQ_LOW;
 313}
 314
 315
 316/*
 317 * Common interface to the cpufreq core
 318 */
 319
 320static int g5_cpufreq_verify(struct cpufreq_policy *policy)
 321{
 322        return cpufreq_frequency_table_verify(policy, g5_cpu_freqs);
 323}
 324
 325static int g5_cpufreq_target(struct cpufreq_policy *policy,
 326        unsigned int target_freq, unsigned int relation)
 327{
 328        unsigned int newstate = 0;
 329        struct cpufreq_freqs freqs;
 330        int rc;
 331
 332        if (cpufreq_frequency_table_target(policy, g5_cpu_freqs,
 333                        target_freq, relation, &newstate))
 334                return -EINVAL;
 335
 336        if (g5_pmode_cur == newstate)
 337                return 0;
 338
 339        mutex_lock(&g5_switch_mutex);
 340
 341        freqs.old = g5_cpu_freqs[g5_pmode_cur].frequency;
 342        freqs.new = g5_cpu_freqs[newstate].frequency;
 343        freqs.cpu = 0;
 344
 345        cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 346        rc = g5_switch_freq(newstate);
 347        cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 348
 349        mutex_unlock(&g5_switch_mutex);
 350
 351        return rc;
 352}
 353
 354static unsigned int g5_cpufreq_get_speed(unsigned int cpu)
 355{
 356        return g5_cpu_freqs[g5_pmode_cur].frequency;
 357}
 358
 359static int g5_cpufreq_cpu_init(struct cpufreq_policy *policy)
 360{
 361        policy->cpuinfo.transition_latency = transition_latency;
 362        policy->cur = g5_cpu_freqs[g5_query_freq()].frequency;
 363        /* secondary CPUs are tied to the primary one by the
 364         * cpufreq core if in the secondary policy we tell it that
 365         * it actually must be one policy together with all others. */
 366        cpumask_copy(policy->cpus, &cpu_online_map);
 367        cpufreq_frequency_table_get_attr(g5_cpu_freqs, policy->cpu);
 368
 369        return cpufreq_frequency_table_cpuinfo(policy,
 370                g5_cpu_freqs);
 371}
 372
 373
 374static struct cpufreq_driver g5_cpufreq_driver = {
 375        .name           = "powermac",
 376        .owner          = THIS_MODULE,
 377        .flags          = CPUFREQ_CONST_LOOPS,
 378        .init           = g5_cpufreq_cpu_init,
 379        .verify         = g5_cpufreq_verify,
 380        .target         = g5_cpufreq_target,
 381        .get            = g5_cpufreq_get_speed,
 382        .attr           = g5_cpu_freqs_attr,
 383};
 384
 385
 386#ifdef CONFIG_PMAC_SMU
 387
 388static int __init g5_neo2_cpufreq_init(struct device_node *cpus)
 389{
 390        struct device_node *cpunode;
 391        unsigned int psize, ssize;
 392        unsigned long max_freq;
 393        char *freq_method, *volt_method;
 394        const u32 *valp;
 395        u32 pvr_hi;
 396        int use_volts_vdnap = 0;
 397        int use_volts_smu = 0;
 398        int rc = -ENODEV;
 399
 400        /* Check supported platforms */
 401        if (machine_is_compatible("PowerMac8,1") ||
 402            machine_is_compatible("PowerMac8,2") ||
 403            machine_is_compatible("PowerMac9,1"))
 404                use_volts_smu = 1;
 405        else if (machine_is_compatible("PowerMac11,2"))
 406                use_volts_vdnap = 1;
 407        else
 408                return -ENODEV;
 409
 410        /* Get first CPU node */
 411        for (cpunode = NULL;
 412             (cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {
 413                const u32 *reg = of_get_property(cpunode, "reg", NULL);
 414                if (reg == NULL || (*reg) != 0)
 415                        continue;
 416                if (!strcmp(cpunode->type, "cpu"))
 417                        break;
 418        }
 419        if (cpunode == NULL) {
 420                printk(KERN_ERR "cpufreq: Can't find any CPU 0 node\n");
 421                return -ENODEV;
 422        }
 423
 424        /* Check 970FX for now */
 425        valp = of_get_property(cpunode, "cpu-version", NULL);
 426        if (!valp) {
 427                DBG("No cpu-version property !\n");
 428                goto bail_noprops;
 429        }
 430        pvr_hi = (*valp) >> 16;
 431        if (pvr_hi != 0x3c && pvr_hi != 0x44) {
 432                printk(KERN_ERR "cpufreq: Unsupported CPU version\n");
 433                goto bail_noprops;
 434        }
 435
 436        /* Look for the powertune data in the device-tree */
 437        g5_pmode_data = of_get_property(cpunode, "power-mode-data",&psize);
 438        if (!g5_pmode_data) {
 439                DBG("No power-mode-data !\n");
 440                goto bail_noprops;
 441        }
 442        g5_pmode_max = psize / sizeof(u32) - 1;
 443
 444        if (use_volts_smu) {
 445                const struct smu_sdbp_header *shdr;
 446
 447                /* Look for the FVT table */
 448                shdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
 449                if (!shdr)
 450                        goto bail_noprops;
 451                g5_fvt_table = (struct smu_sdbp_fvt *)&shdr[1];
 452                ssize = (shdr->len * sizeof(u32)) -
 453                        sizeof(struct smu_sdbp_header);
 454                g5_fvt_count = ssize / sizeof(struct smu_sdbp_fvt);
 455                g5_fvt_cur = 0;
 456
 457                /* Sanity checking */
 458                if (g5_fvt_count < 1 || g5_pmode_max < 1)
 459                        goto bail_noprops;
 460
 461                g5_switch_volt = g5_smu_switch_volt;
 462                volt_method = "SMU";
 463        } else if (use_volts_vdnap) {
 464                struct device_node *root;
 465
 466                root = of_find_node_by_path("/");
 467                if (root == NULL) {
 468                        printk(KERN_ERR "cpufreq: Can't find root of "
 469                               "device tree\n");
 470                        goto bail_noprops;
 471                }
 472                pfunc_set_vdnap0 = pmf_find_function(root, "set-vdnap0");
 473                pfunc_vdnap0_complete =
 474                        pmf_find_function(root, "slewing-done");
 475                if (pfunc_set_vdnap0 == NULL ||
 476                    pfunc_vdnap0_complete == NULL) {
 477                        printk(KERN_ERR "cpufreq: Can't find required "
 478                               "platform function\n");
 479                        goto bail_noprops;
 480                }
 481
 482                g5_switch_volt = g5_vdnap_switch_volt;
 483                volt_method = "GPIO";
 484        } else {
 485                g5_switch_volt = g5_dummy_switch_volt;
 486                volt_method = "none";
 487        }
 488
 489        /*
 490         * From what I see, clock-frequency is always the maximal frequency.
 491         * The current driver can not slew sysclk yet, so we really only deal
 492         * with powertune steps for now. We also only implement full freq and
 493         * half freq in this version. So far, I haven't yet seen a machine
 494         * supporting anything else.
 495         */
 496        valp = of_get_property(cpunode, "clock-frequency", NULL);
 497        if (!valp)
 498                return -ENODEV;
 499        max_freq = (*valp)/1000;
 500        g5_cpu_freqs[0].frequency = max_freq;
 501        g5_cpu_freqs[1].frequency = max_freq/2;
 502
 503        /* Set callbacks */
 504        transition_latency = 12000;
 505        g5_switch_freq = g5_scom_switch_freq;
 506        g5_query_freq = g5_scom_query_freq;
 507        freq_method = "SCOM";
 508
 509        /* Force apply current frequency to make sure everything is in
 510         * sync (voltage is right for example). Firmware may leave us with
 511         * a strange setting ...
 512         */
 513        g5_switch_volt(CPUFREQ_HIGH);
 514        msleep(10);
 515        g5_pmode_cur = -1;
 516        g5_switch_freq(g5_query_freq());
 517
 518        printk(KERN_INFO "Registering G5 CPU frequency driver\n");
 519        printk(KERN_INFO "Frequency method: %s, Voltage method: %s\n",
 520               freq_method, volt_method);
 521        printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
 522                g5_cpu_freqs[1].frequency/1000,
 523                g5_cpu_freqs[0].frequency/1000,
 524                g5_cpu_freqs[g5_pmode_cur].frequency/1000);
 525
 526        rc = cpufreq_register_driver(&g5_cpufreq_driver);
 527
 528        /* We keep the CPU node on hold... hopefully, Apple G5 don't have
 529         * hotplug CPU with a dynamic device-tree ...
 530         */
 531        return rc;
 532
 533 bail_noprops:
 534        of_node_put(cpunode);
 535
 536        return rc;
 537}
 538
 539#endif /* CONFIG_PMAC_SMU */
 540
 541
 542static int __init g5_pm72_cpufreq_init(struct device_node *cpus)
 543{
 544        struct device_node *cpuid = NULL, *hwclock = NULL, *cpunode = NULL;
 545        const u8 *eeprom = NULL;
 546        const u32 *valp;
 547        u64 max_freq, min_freq, ih, il;
 548        int has_volt = 1, rc = 0;
 549
 550        DBG("cpufreq: Initializing for PowerMac7,2, PowerMac7,3 and"
 551            " RackMac3,1...\n");
 552
 553        /* Get first CPU node */
 554        for (cpunode = NULL;
 555             (cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {
 556                if (!strcmp(cpunode->type, "cpu"))
 557                        break;
 558        }
 559        if (cpunode == NULL) {
 560                printk(KERN_ERR "cpufreq: Can't find any CPU node\n");
 561                return -ENODEV;
 562        }
 563
 564        /* Lookup the cpuid eeprom node */
 565        cpuid = of_find_node_by_path("/u3@0,f8000000/i2c@f8001000/cpuid@a0");
 566        if (cpuid != NULL)
 567                eeprom = of_get_property(cpuid, "cpuid", NULL);
 568        if (eeprom == NULL) {
 569                printk(KERN_ERR "cpufreq: Can't find cpuid EEPROM !\n");
 570                rc = -ENODEV;
 571                goto bail;
 572        }
 573
 574        /* Lookup the i2c hwclock */
 575        for (hwclock = NULL;
 576             (hwclock = of_find_node_by_name(hwclock, "i2c-hwclock")) != NULL;){
 577                const char *loc = of_get_property(hwclock,
 578                                "hwctrl-location", NULL);
 579                if (loc == NULL)
 580                        continue;
 581                if (strcmp(loc, "CPU CLOCK"))
 582                        continue;
 583                if (!of_get_property(hwclock, "platform-get-frequency", NULL))
 584                        continue;
 585                break;
 586        }
 587        if (hwclock == NULL) {
 588                printk(KERN_ERR "cpufreq: Can't find i2c clock chip !\n");
 589                rc = -ENODEV;
 590                goto bail;
 591        }
 592
 593        DBG("cpufreq: i2c clock chip found: %s\n", hwclock->full_name);
 594
 595        /* Now get all the platform functions */
 596        pfunc_cpu_getfreq =
 597                pmf_find_function(hwclock, "get-frequency");
 598        pfunc_cpu_setfreq_high =
 599                pmf_find_function(hwclock, "set-frequency-high");
 600        pfunc_cpu_setfreq_low =
 601                pmf_find_function(hwclock, "set-frequency-low");
 602        pfunc_slewing_done =
 603                pmf_find_function(hwclock, "slewing-done");
 604        pfunc_cpu0_volt_high =
 605                pmf_find_function(hwclock, "set-voltage-high-0");
 606        pfunc_cpu0_volt_low =
 607                pmf_find_function(hwclock, "set-voltage-low-0");
 608        pfunc_cpu1_volt_high =
 609                pmf_find_function(hwclock, "set-voltage-high-1");
 610        pfunc_cpu1_volt_low =
 611                pmf_find_function(hwclock, "set-voltage-low-1");
 612
 613        /* Check we have minimum requirements */
 614        if (pfunc_cpu_getfreq == NULL || pfunc_cpu_setfreq_high == NULL ||
 615            pfunc_cpu_setfreq_low == NULL || pfunc_slewing_done == NULL) {
 616                printk(KERN_ERR "cpufreq: Can't find platform functions !\n");
 617                rc = -ENODEV;
 618                goto bail;
 619        }
 620
 621        /* Check that we have complete sets */
 622        if (pfunc_cpu0_volt_high == NULL || pfunc_cpu0_volt_low == NULL) {
 623                pmf_put_function(pfunc_cpu0_volt_high);
 624                pmf_put_function(pfunc_cpu0_volt_low);
 625                pfunc_cpu0_volt_high = pfunc_cpu0_volt_low = NULL;
 626                has_volt = 0;
 627        }
 628        if (!has_volt ||
 629            pfunc_cpu1_volt_high == NULL || pfunc_cpu1_volt_low == NULL) {
 630                pmf_put_function(pfunc_cpu1_volt_high);
 631                pmf_put_function(pfunc_cpu1_volt_low);
 632                pfunc_cpu1_volt_high = pfunc_cpu1_volt_low = NULL;
 633        }
 634
 635        /* Note: The device tree also contains a "platform-set-values"
 636         * function for which I haven't quite figured out the usage. It
 637         * might have to be called on init and/or wakeup, I'm not too sure
 638         * but things seem to work fine without it so far ...
 639         */
 640
 641        /* Get max frequency from device-tree */
 642        valp = of_get_property(cpunode, "clock-frequency", NULL);
 643        if (!valp) {
 644                printk(KERN_ERR "cpufreq: Can't find CPU frequency !\n");
 645                rc = -ENODEV;
 646                goto bail;
 647        }
 648
 649        max_freq = (*valp)/1000;
 650
 651        /* Now calculate reduced frequency by using the cpuid input freq
 652         * ratio. This requires 64 bits math unless we are willing to lose
 653         * some precision
 654         */
 655        ih = *((u32 *)(eeprom + 0x10));
 656        il = *((u32 *)(eeprom + 0x20));
 657
 658        /* Check for machines with no useful settings */
 659        if (il == ih) {
 660                printk(KERN_WARNING "cpufreq: No low frequency mode available"
 661                       " on this model !\n");
 662                rc = -ENODEV;
 663                goto bail;
 664        }
 665
 666        min_freq = 0;
 667        if (ih != 0 && il != 0)
 668                min_freq = (max_freq * il) / ih;
 669
 670        /* Sanity check */
 671        if (min_freq >= max_freq || min_freq < 1000) {
 672                printk(KERN_ERR "cpufreq: Can't calculate low frequency !\n");
 673                rc = -ENXIO;
 674                goto bail;
 675        }
 676        g5_cpu_freqs[0].frequency = max_freq;
 677        g5_cpu_freqs[1].frequency = min_freq;
 678
 679        /* Set callbacks */
 680        transition_latency = CPUFREQ_ETERNAL;
 681        g5_switch_volt = g5_pfunc_switch_volt;
 682        g5_switch_freq = g5_pfunc_switch_freq;
 683        g5_query_freq = g5_pfunc_query_freq;
 684
 685        /* Force apply current frequency to make sure everything is in
 686         * sync (voltage is right for example). Firmware may leave us with
 687         * a strange setting ...
 688         */
 689        g5_switch_volt(CPUFREQ_HIGH);
 690        msleep(10);
 691        g5_pmode_cur = -1;
 692        g5_switch_freq(g5_query_freq());
 693
 694        printk(KERN_INFO "Registering G5 CPU frequency driver\n");
 695        printk(KERN_INFO "Frequency method: i2c/pfunc, "
 696               "Voltage method: %s\n", has_volt ? "i2c/pfunc" : "none");
 697        printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
 698                g5_cpu_freqs[1].frequency/1000,
 699                g5_cpu_freqs[0].frequency/1000,
 700                g5_cpu_freqs[g5_pmode_cur].frequency/1000);
 701
 702        rc = cpufreq_register_driver(&g5_cpufreq_driver);
 703 bail:
 704        if (rc != 0) {
 705                pmf_put_function(pfunc_cpu_getfreq);
 706                pmf_put_function(pfunc_cpu_setfreq_high);
 707                pmf_put_function(pfunc_cpu_setfreq_low);
 708                pmf_put_function(pfunc_slewing_done);
 709                pmf_put_function(pfunc_cpu0_volt_high);
 710                pmf_put_function(pfunc_cpu0_volt_low);
 711                pmf_put_function(pfunc_cpu1_volt_high);
 712                pmf_put_function(pfunc_cpu1_volt_low);
 713        }
 714        of_node_put(hwclock);
 715        of_node_put(cpuid);
 716        of_node_put(cpunode);
 717
 718        return rc;
 719}
 720
 721static int __init g5_cpufreq_init(void)
 722{
 723        struct device_node *cpus;
 724        int rc = 0;
 725
 726        cpus = of_find_node_by_path("/cpus");
 727        if (cpus == NULL) {
 728                DBG("No /cpus node !\n");
 729                return -ENODEV;
 730        }
 731
 732        if (machine_is_compatible("PowerMac7,2") ||
 733            machine_is_compatible("PowerMac7,3") ||
 734            machine_is_compatible("RackMac3,1"))
 735                rc = g5_pm72_cpufreq_init(cpus);
 736#ifdef CONFIG_PMAC_SMU
 737        else
 738                rc = g5_neo2_cpufreq_init(cpus);
 739#endif /* CONFIG_PMAC_SMU */
 740
 741        of_node_put(cpus);
 742        return rc;
 743}
 744
 745module_init(g5_cpufreq_init);
 746
 747
 748MODULE_LICENSE("GPL");
 749