arch/i386/kernel/cpu/cpufreq/acpi.c

   1 /*
   2  * acpi-cpufreq-io.c - ACPI Processor P-States Driver ($Revision: 1.3 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
   7  *
   8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or (at
  13  *  your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful, but
  16  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  *  General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License along
  21  *  with this program; if not, write to the Free Software Foundation, Inc.,
  22  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  23  *
  24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25  */
  26
  27 #include <linux/config.h>
  28 #include <linux/kernel.h>
  29 #include <linux/module.h>
  30 #include <linux/init.h>
  31 #include <linux/cpufreq.h>
  32 #include <linux/proc_fs.h>
  33 #include <linux/seq_file.h>
  34 #include <asm/io.h>
  35 #include <asm/delay.h>
  36 #include <asm/uaccess.h>
  37
  38 #include <linux/acpi.h>
  39 #include <acpi/processor.h>
  40
  41 #define ACPI_PROCESSOR_COMPONENT        0x01000000
  42 #define ACPI_PROCESSOR_CLASS            "processor"
  43 #define ACPI_PROCESSOR_DRIVER_NAME      "ACPI Processor P-States Driver"
  44 #define ACPI_PROCESSOR_DEVICE_NAME      "Processor"
  45
  46 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  47 ACPI_MODULE_NAME                ("acpi_processor_perf")
  48
  49 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
  50 MODULE_DESCRIPTION(ACPI_PROCESSOR_DRIVER_NAME);
  51 MODULE_LICENSE("GPL");
  52
  53
  54 struct cpufreq_acpi_io {
  55         struct acpi_processor_performance       acpi_data;
  56         struct cpufreq_frequency_table          *freq_table;
  57 };
  58
  59 static struct cpufreq_acpi_io   *acpi_io_data[NR_CPUS];
  60
  61
  62 static int
  63 acpi_processor_write_port(
  64         u16     port,
  65         u8      bit_width,
  66         u32     value)
  67 {
  68         if (bit_width <= 8) {
  69                 outb(value, port);
  70         } else if (bit_width <= 16) {
  71                 outw(value, port);
  72         } else if (bit_width <= 32) {
  73                 outl(value, port);
  74         } else {
  75                 return -ENODEV;
  76         }
  77         return 0;
  78 }
  79
  80 static int
  81 acpi_processor_read_port(
  82         u16     port,
  83         u8      bit_width,
  84         u32     *ret)
  85 {
  86         *ret = 0;
  87         if (bit_width <= 8) {
  88                 *ret = inb(port);
  89         } else if (bit_width <= 16) {
  90                 *ret = inw(port);
  91         } else if (bit_width <= 32) {
  92                 *ret = inl(port);
  93         } else {
  94                 return -ENODEV;
  95         }
  96         return 0;
  97 }
  98
  99 static int
 100 acpi_processor_set_performance (
 101         struct cpufreq_acpi_io  *data,
 102         unsigned int            cpu,
 103         int                     state)
 104 {
 105         u16                     port = 0;
 106         u8                      bit_width = 0;
 107         int                     ret = 0;
 108         u32                     value = 0;
 109         int                     i = 0;
 110         struct cpufreq_freqs    cpufreq_freqs;
 111
 112         ACPI_FUNCTION_TRACE("acpi_processor_set_performance");
 113
 114         if (state == data->acpi_data.state) {
 115                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 116                         "Already at target state (P%d)\n", state));
 117                 return_VALUE(0);
 118         }
 119
 120         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Transitioning from P%d to P%d\n",
 121                 data->acpi_data.state, state));
 122
 123         /* cpufreq frequency struct */
 124         cpufreq_freqs.cpu = cpu;
 125         cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
 126         cpufreq_freqs.new = data->freq_table[state].frequency;
 127
 128         /* notify cpufreq */
 129         cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
 130
 131         /*
 132          * First we write the target state's 'control' value to the
 133          * control_register.
 134          */
 135
 136         port = data->acpi_data.control_register.address;
 137         bit_width = data->acpi_data.control_register.bit_width;
 138         value = (u32) data->acpi_data.states[state].control;
 139
 140         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 141                 "Writing 0x%08x to port 0x%04x\n", value, port));
 142
 143         ret = acpi_processor_write_port(port, bit_width, value);
 144         if (ret) {
 145                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 146                         "Invalid port width 0x%04x\n", bit_width));
 147                 return_VALUE(ret);
 148         }
 149
 150         /*
 151          * Then we read the 'status_register' and compare the value with the
 152          * target state's 'status' to make sure the transition was successful.
 153          * Note that we'll poll for up to 1ms (100 cycles of 10us) before
 154          * giving up.
 155          */
 156
 157         port = data->acpi_data.status_register.address;
 158         bit_width = data->acpi_data.status_register.bit_width;
 159
 160         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 161                 "Looking for 0x%08x from port 0x%04x\n",
 162                 (u32) data->acpi_data.states[state].status, port));
 163
 164         for (i=0; i<100; i++) {
 165                 ret = acpi_processor_read_port(port, bit_width, &value);
 166                 if (ret) {
 167                         ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 168                                 "Invalid port width 0x%04x\n", bit_width));
 169                         return_VALUE(ret);
 170                 }
 171                 if (value == (u32) data->acpi_data.states[state].status)
 172                         break;
 173                 udelay(10);
 174         }
 175
 176         /* notify cpufreq */
 177         cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
 178
 179         if (value != (u32) data->acpi_data.states[state].status) {
 180                 unsigned int tmp = cpufreq_freqs.new;
 181                 cpufreq_freqs.new = cpufreq_freqs.old;
 182                 cpufreq_freqs.old = tmp;
 183                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
 184                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
 185                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Transition failed\n"));
 186                 return_VALUE(-ENODEV);
 187         }
 188
 189         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 190                 "Transition successful after %d microseconds\n",
 191                 i * 10));
 192
 193         data->acpi_data.state = state;
 194
 195         return_VALUE(0);
 196 }
 197
 198
 199 static int
 200 acpi_cpufreq_target (
 201         struct cpufreq_policy   *policy,
 202         unsigned int target_freq,
 203         unsigned int relation)
 204 {
 205         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
 206         unsigned int next_state = 0;
 207         unsigned int result = 0;
 208
 209         ACPI_FUNCTION_TRACE("acpi_cpufreq_setpolicy");
 210
 211         result = cpufreq_frequency_table_target(policy,
 212                         data->freq_table,
 213                         target_freq,
 214                         relation,
 215                         &next_state);
 216         if (result)
 217                 return_VALUE(result);
 218
 219         result = acpi_processor_set_performance (data, policy->cpu, next_state);
 220
 221         return_VALUE(result);
 222 }
 223
 224
 225 static int
 226 acpi_cpufreq_verify (
 227         struct cpufreq_policy   *policy)
 228 {
 229         unsigned int result = 0;
 230         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
 231
 232         ACPI_FUNCTION_TRACE("acpi_cpufreq_verify");
 233
 234         result = cpufreq_frequency_table_verify(policy,
 235                         data->freq_table);
 236
 237         return_VALUE(result);
 238 }
 239
 240
 241 static unsigned long
 242 acpi_cpufreq_guess_freq (
 243         struct cpufreq_acpi_io  *data,
 244         unsigned int            cpu)
 245 {
 246         if (cpu_khz) {
 247                 /* search the closest match to cpu_khz */
 248                 unsigned int i;
 249                 unsigned long freq;
 250                 unsigned long freqn = data->acpi_data.states[0].core_frequency * 1000;
 251
 252                 for (i=0; i < (data->acpi_data.state_count - 1); i++) {
 253                         freq = freqn;
 254                         freqn = data->acpi_data.states[i+1].core_frequency * 1000;
 255                         if ((2 * cpu_khz) > (freqn + freq)) {
 256                                 data->acpi_data.state = i;
 257                                 return (freq);
 258                         }
 259                 }
 260                 data->acpi_data.state = data->acpi_data.state_count - 1;
 261                 return (freqn);
 262         } else
 263                 /* assume CPU is at P0... */
 264                 data->acpi_data.state = 0;
 265                 return data->acpi_data.states[0].core_frequency * 1000;
 266
 267 }
 268
 269 static int
 270 acpi_cpufreq_cpu_init (
 271         struct cpufreq_policy   *policy)
 272 {
 273         unsigned int            i;
 274         unsigned int            cpu = policy->cpu;
 275         struct cpufreq_acpi_io  *data;
 276         unsigned int            result = 0;
 277
 278         ACPI_FUNCTION_TRACE("acpi_cpufreq_cpu_init");
 279
 280         data = kmalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
 281         if (!data)
 282                 return_VALUE(-ENOMEM);
 283         memset(data, 0, sizeof(struct cpufreq_acpi_io));
 284
 285         acpi_io_data[cpu] = data;
 286
 287         result = acpi_processor_register_performance(&data->acpi_data, cpu);
 288         if (result)
 289                 goto err_free;
 290
 291         /* capability check */
 292         if (data->acpi_data.state_count <= 1) {
 293                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "No P-States\n"));
 294                 result = -ENODEV;
 295                 goto err_unreg;
 296         }
 297         if ((data->acpi_data.control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) ||
 298             (data->acpi_data.status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
 299                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unsupported address space [%d, %d]\n",
 300                                   (u32) (data->acpi_data.control_register.space_id),
 301                                   (u32) (data->acpi_data.status_register.space_id)));
 302                 result = -ENODEV;
 303                 goto err_unreg;
 304         }
 305
 306         /* alloc freq_table */
 307         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (data->acpi_data.state_count + 1), GFP_KERNEL);
 308         if (!data->freq_table) {
 309                 result = -ENOMEM;
 310                 goto err_unreg;
 311         }
 312
 313         /* detect transition latency */
 314         policy->cpuinfo.transition_latency = 0;
 315         for (i=0; i<data->acpi_data.state_count; i++) {
 316                 if ((data->acpi_data.states[i].transition_latency * 1000) > policy->cpuinfo.transition_latency)
 317                         policy->cpuinfo.transition_latency = data->acpi_data.states[i].transition_latency * 1000;
 318         }
 319         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
 320
 321         /* The current speed is unknown and not detectable by ACPI...  */
 322         policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
 323
 324         /* table init */
 325         for (i=0; i<=data->acpi_data.state_count; i++)
 326         {
 327                 data->freq_table[i].index = i;
 328                 if (i<data->acpi_data.state_count)
 329                         data->freq_table[i].frequency = data->acpi_data.states[i].core_frequency * 1000;
 330                 else
 331                         data->freq_table[i].frequency = CPUFREQ_TABLE_END;
 332         }
 333
 334         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
 335         if (result) {
 336                 goto err_freqfree;
 337         }
 338
 339
 340         printk(KERN_INFO "cpufreq: CPU%u - ACPI performance management activated.\n",
 341                cpu);
 342         for (i = 0; i < data->acpi_data.state_count; i++)
 343                 printk(KERN_INFO "cpufreq: %cP%d: %d MHz, %d mW, %d uS\n",
 344                         (i == data->acpi_data.state?'*':' '), i,
 345                         (u32) data->acpi_data.states[i].core_frequency,
 346                         (u32) data->acpi_data.states[i].power,
 347                         (u32) data->acpi_data.states[i].transition_latency);
 348
 349         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
 350         return_VALUE(result);
 351
 352  err_freqfree:
 353         kfree(data->freq_table);
 354  err_unreg:
 355         acpi_processor_unregister_performance(&data->acpi_data, cpu);
 356  err_free:
 357         kfree(data);
 358         acpi_io_data[cpu] = NULL;
 359
 360         return_VALUE(result);
 361 }
 362
 363
 364 static int
 365 acpi_cpufreq_cpu_exit (
 366         struct cpufreq_policy   *policy)
 367 {
 368         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
 369
 370
 371         ACPI_FUNCTION_TRACE("acpi_cpufreq_cpu_exit");
 372
 373         if (data) {
 374                 cpufreq_frequency_table_put_attr(policy->cpu);
 375                 acpi_io_data[policy->cpu] = NULL;
 376                 acpi_processor_unregister_performance(&data->acpi_data, policy->cpu);
 377                 kfree(data);
 378         }
 379
 380         return_VALUE(0);
 381 }
 382
 383
 384 static struct freq_attr* acpi_cpufreq_attr[] = {
 385         &cpufreq_freq_attr_scaling_available_freqs,
 386         NULL,
 387 };
 388
 389 static struct cpufreq_driver acpi_cpufreq_driver = {
 390         .verify         = acpi_cpufreq_verify,
 391         .target         = acpi_cpufreq_target,
 392         .init           = acpi_cpufreq_cpu_init,
 393         .exit           = acpi_cpufreq_cpu_exit,
 394         .name           = "acpi-cpufreq",
 395         .owner          = THIS_MODULE,
 396         .attr           = acpi_cpufreq_attr,
 397 };
 398
 399
 400 static int __init
 401 acpi_cpufreq_init (void)
 402 {
 403         int                     result = 0;
 404
 405         ACPI_FUNCTION_TRACE("acpi_cpufreq_init");
 406
 407         result = cpufreq_register_driver(&acpi_cpufreq_driver);
 408
 409         return_VALUE(result);
 410 }
 411
 412
 413 static void __exit
 414 acpi_cpufreq_exit (void)
 415 {
 416         ACPI_FUNCTION_TRACE("acpi_cpufreq_exit");
 417
 418         cpufreq_unregister_driver(&acpi_cpufreq_driver);
 419
 420         return_VOID;
 421 }
 422
 423
 424 late_initcall(acpi_cpufreq_init);
 425 module_exit(acpi_cpufreq_exit);