drivers/macintosh/therm_windtunnel.c

   1 /*
   2  *   Creation Date: <2003/03/14 20:54:13 samuel>
   3  *   Time-stamp: <2004/03/20 14:20:59 samuel>
   4  *
   5  *      <therm_windtunnel.c>
   6  *
   7  *      The G4 "windtunnel" has a single fan controlled by an
   8  *      ADM1030 fan controller and a DS1775 thermostat.
   9  *
  10  *      The fan controller is equipped with a temperature sensor
  11  *      which measures the case temperature. The DS1775 sensor
  12  *      measures the CPU temperature. This driver tunes the
  13  *      behavior of the fan. It is based upon empirical observations
  14  *      of the 'AppleFan' driver under Mac OS X.
  15  *
  16  *      WARNING: This driver has only been testen on Apple's
  17  *      1.25 MHz Dual G4 (March 03). It is tuned for a CPU
  18  *      temperature around 57 C.
  19  *
  20  *   Copyright (C) 2003, 2004 Samuel Rydh (samuel@ibrium.se)
  21  *
  22  *   Loosely based upon 'thermostat.c' written by Benjamin Herrenschmidt
  23  *
  24  *   This program is free software; you can redistribute it and/or
  25  *   modify it under the terms of the GNU General Public License
  26  *   as published by the Free Software Foundation
  27  *
  28  */
  29
  30 #include <linux/types.h>
  31 #include <linux/module.h>
  32 #include <linux/errno.h>
  33 #include <linux/kernel.h>
  34 #include <linux/delay.h>
  35 #include <linux/sched.h>
  36 #include <linux/i2c.h>
  37 #include <linux/init.h>
  38 #include <linux/kthread.h>
  39 #include <linux/of.h>
  40 #include <linux/of_platform.h>
  41 #include <linux/platform_device.h>
  42
  43 #include <asm/machdep.h>
  44 #include <asm/io.h>
  45 #include <asm/sections.h>
  46 #include <asm/macio.h>
  47
  48 #define LOG_TEMP                0                       /* continuously log temperature */
  49
  50 static struct {
  51         volatile int            running;
  52         struct task_struct      *poll_task;
  53
  54         struct mutex            lock;
  55         struct platform_device  *of_dev;
  56
  57         struct i2c_client       *thermostat;
  58         struct i2c_client       *fan;
  59
  60         int                     overheat_temp;          /* 100% fan at this temp */
  61         int                     overheat_hyst;
  62         int                     temp;
  63         int                     casetemp;
  64         int                     fan_level;              /* active fan_table setting */
  65
  66         int                     downind;
  67         int                     upind;
  68
  69         int                     r0, r1, r20, r23, r25;  /* saved register */
  70 } x;
  71
  72 #define T(x,y)                  (((x)<<8) | (y)*0x100/10 )
  73
  74 static struct {
  75         int                     fan_down_setting;
  76         int                     temp;
  77         int                     fan_up_setting;
  78 } fan_table[] = {
  79         { 11, T(0,0),  11 },    /* min fan */
  80         { 11, T(55,0), 11 },
  81         {  6, T(55,3), 11 },
  82         {  7, T(56,0), 11 },
  83         {  8, T(57,0), 8 },
  84         {  7, T(58,3), 7 },
  85         {  6, T(58,8), 6 },
  86         {  5, T(59,2), 5 },
  87         {  4, T(59,6), 4 },
  88         {  3, T(59,9), 3 },
  89         {  2, T(60,1), 2 },
  90         {  1, 0xfffff, 1 }      /* on fire */
  91 };
  92
  93 static void
  94 print_temp( const char *s, int temp )
  95 {
  96         printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
  97 }
  98
  99 static ssize_t
 100 show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf )
 101 {
 102         return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 );
 103 }
 104
 105 static ssize_t
 106 show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf )
 107 {
 108         return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 );
 109 }
 110
 111 static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );
 112 static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );
 113
 114
 115
 116 /************************************************************************/
 117 /*      controller thread                                               */
 118 /************************************************************************/
 119
 120 static int
 121 write_reg( struct i2c_client *cl, int reg, int data, int len )
 122 {
 123         u8 tmp[3];
 124
 125         if( len < 1 || len > 2 || data < 0 )
 126                 return -EINVAL;
 127
 128         tmp[0] = reg;
 129         tmp[1] = (len == 1) ? data : (data >> 8);
 130         tmp[2] = data;
 131         len++;
 132
 133         if( i2c_master_send(cl, tmp, len) != len )
 134                 return -ENODEV;
 135         return 0;
 136 }
 137
 138 static int
 139 read_reg( struct i2c_client *cl, int reg, int len )
 140 {
 141         u8 buf[2];
 142
 143         if( len != 1 && len != 2 )
 144                 return -EINVAL;
 145         buf[0] = reg;
 146         if( i2c_master_send(cl, buf, 1) != 1 )
 147                 return -ENODEV;
 148         if( i2c_master_recv(cl, buf, len) != len )
 149                 return -ENODEV;
 150         return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0];
 151 }
 152
 153 static void
 154 tune_fan( int fan_setting )
 155 {
 156         int val = (fan_setting << 3) | 7;
 157
 158         /* write_reg( x.fan, 0x24, val, 1 ); */
 159         write_reg( x.fan, 0x25, val, 1 );
 160         write_reg( x.fan, 0x20, 0, 1 );
 161         print_temp("CPU-temp: ", x.temp );
 162         if( x.casetemp )
 163                 print_temp(", Case: ", x.casetemp );
 164         printk(",  Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );
 165
 166         x.fan_level = fan_setting;
 167 }
 168
 169 static void
 170 poll_temp( void )
 171 {
 172         int temp, i, level, casetemp;
 173
 174         temp = read_reg( x.thermostat, 0, 2 );
 175
 176         /* this actually occurs when the computer is loaded */
 177         if( temp < 0 )
 178                 return;
 179
 180         casetemp = read_reg(x.fan, 0x0b, 1) << 8;
 181         casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;
 182
 183         if( LOG_TEMP && x.temp != temp ) {
 184                 print_temp("CPU-temp: ", temp );
 185                 print_temp(", Case: ", casetemp );
 186                 printk(",  Fan: %d\n", 11-x.fan_level );
 187         }
 188         x.temp = temp;
 189         x.casetemp = casetemp;
 190
 191         level = -1;
 192         for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )
 193                 ;
 194         if( i < x.downind )
 195                 level = fan_table[i].fan_down_setting;
 196         x.downind = i;
 197
 198         for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )
 199                 ;
 200         if( x.upind < i )
 201                 level = fan_table[i].fan_up_setting;
 202         x.upind = i;
 203
 204         if( level >= 0 )
 205                 tune_fan( level );
 206 }
 207
 208
 209 static void
 210 setup_hardware( void )
 211 {
 212         int val;
 213         int err;
 214
 215         /* save registers (if we unload the module) */
 216         x.r0 = read_reg( x.fan, 0x00, 1 );
 217         x.r1 = read_reg( x.fan, 0x01, 1 );
 218         x.r20 = read_reg( x.fan, 0x20, 1 );
 219         x.r23 = read_reg( x.fan, 0x23, 1 );
 220         x.r25 = read_reg( x.fan, 0x25, 1 );
 221
 222         /* improve measurement resolution (convergence time 1.5s) */
 223         if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) {
 224                 val |= 0x60;
 225                 if( write_reg( x.thermostat, 1, val, 1 ) )
 226                         printk("Failed writing config register\n");
 227         }
 228         /* disable interrupts and TAC input */
 229         write_reg( x.fan, 0x01, 0x01, 1 );
 230         /* enable filter */
 231         write_reg( x.fan, 0x23, 0x91, 1 );
 232         /* remote temp. controls fan */
 233         write_reg( x.fan, 0x00, 0x95, 1 );
 234
 235         /* The thermostat (which besides measureing temperature controls
 236          * has a THERM output which puts the fan on 100%) is usually
 237          * set to kick in at 80 C (chip default). We reduce this a bit
 238          * to be on the safe side (OSX doesn't)...
 239          */
 240         if( x.overheat_temp == (80 << 8) ) {
 241                 x.overheat_temp = 75 << 8;
 242                 x.overheat_hyst = 70 << 8;
 243                 write_reg( x.thermostat, 2, x.overheat_hyst, 2 );
 244                 write_reg( x.thermostat, 3, x.overheat_temp, 2 );
 245
 246                 print_temp("Reducing overheating limit to ", x.overheat_temp );
 247                 print_temp(" (Hyst: ", x.overheat_hyst );
 248                 printk(")\n");
 249         }
 250
 251         /* set an initial fan setting */
 252         x.downind = 0xffff;
 253         x.upind = -1;
 254         /* tune_fan( fan_up_table[x.upind].fan_setting ); */
 255
 256         err = device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 257         err |= device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
 258         if (err)
 259                 printk(KERN_WARNING
 260                         "Failed to create temperature attribute file(s).\n");
 261 }
 262
 263 static void
 264 restore_regs( void )
 265 {
 266         device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 267         device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );
 268
 269         write_reg( x.fan, 0x01, x.r1, 1 );
 270         write_reg( x.fan, 0x20, x.r20, 1 );
 271         write_reg( x.fan, 0x23, x.r23, 1 );
 272         write_reg( x.fan, 0x25, x.r25, 1 );
 273         write_reg( x.fan, 0x00, x.r0, 1 );
 274 }
 275
 276 static int control_loop(void *dummy)
 277 {
 278         mutex_lock(&x.lock);
 279         setup_hardware();
 280         mutex_unlock(&x.lock);
 281
 282         for (;;) {
 283                 msleep_interruptible(8000);
 284                 if (kthread_should_stop())
 285                         break;
 286
 287                 mutex_lock(&x.lock);
 288                 poll_temp();
 289                 mutex_unlock(&x.lock);
 290         }
 291
 292         mutex_lock(&x.lock);
 293         restore_regs();
 294         mutex_unlock(&x.lock);
 295
 296         return 0;
 297 }
 298
 299
 300 /************************************************************************/
 301 /*      i2c probing and setup                                           */
 302 /************************************************************************/
 303
 304 static void do_attach(struct i2c_adapter *adapter)
 305 {
 306         struct i2c_board_info info = { };
 307         struct device_node *np;
 308
 309         /* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */
 310         static const unsigned short scan_ds1775[] = {
 311                 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
 312                 I2C_CLIENT_END
 313         };
 314         static const unsigned short scan_adm1030[] = {
 315                 0x2c, 0x2d, 0x2e, 0x2f,
 316                 I2C_CLIENT_END
 317         };
 318
 319         if (x.running || strncmp(adapter->name, "uni-n", 5))
 320                 return;
 321
 322         of_node_get(adapter->dev.of_node);
 323         np = of_find_compatible_node(adapter->dev.of_node, NULL, "MAC,ds1775");
 324         if (np) {
 325                 of_node_put(np);
 326         } else {
 327                 strscpy(info.type, "MAC,ds1775", I2C_NAME_SIZE);
 328                 i2c_new_scanned_device(adapter, &info, scan_ds1775, NULL);
 329         }
 330
 331         of_node_get(adapter->dev.of_node);
 332         np = of_find_compatible_node(adapter->dev.of_node, NULL, "MAC,adm1030");
 333         if (np) {
 334                 of_node_put(np);
 335         } else {
 336                 strscpy(info.type, "MAC,adm1030", I2C_NAME_SIZE);
 337                 i2c_new_scanned_device(adapter, &info, scan_adm1030, NULL);
 338         }
 339 }
 340
 341 static void
 342 do_remove(struct i2c_client *client)
 343 {
 344         if (x.running) {
 345                 x.running = 0;
 346                 kthread_stop(x.poll_task);
 347                 x.poll_task = NULL;
 348         }
 349         if (client == x.thermostat)
 350                 x.thermostat = NULL;
 351         else if (client == x.fan)
 352                 x.fan = NULL;
 353         else
 354                 printk(KERN_ERR "g4fan: bad client\n");
 355 }
 356
 357 static int
 358 attach_fan( struct i2c_client *cl )
 359 {
 360         if( x.fan )
 361                 goto out;
 362
 363         /* check that this is an ADM1030 */
 364         if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 )
 365                 goto out;
 366         printk("ADM1030 fan controller [@%02x]\n", cl->addr );
 367
 368         x.fan = cl;
 369  out:
 370         return 0;
 371 }
 372
 373 static int
 374 attach_thermostat( struct i2c_client *cl )
 375 {
 376         int hyst_temp, os_temp, temp;
 377
 378         if( x.thermostat )
 379                 goto out;
 380
 381         if( (temp=read_reg(cl, 0, 2)) < 0 )
 382                 goto out;
 383
 384         /* temperature sanity check */
 385         if( temp < 0x1600 || temp > 0x3c00 )
 386                 goto out;
 387         hyst_temp = read_reg(cl, 2, 2);
 388         os_temp = read_reg(cl, 3, 2);
 389         if( hyst_temp < 0 || os_temp < 0 )
 390                 goto out;
 391
 392         printk("DS1775 digital thermometer [@%02x]\n", cl->addr );
 393         print_temp("Temp: ", temp );
 394         print_temp("  Hyst: ", hyst_temp );
 395         print_temp("  OS: ", os_temp );
 396         printk("\n");
 397
 398         x.temp = temp;
 399         x.overheat_temp = os_temp;
 400         x.overheat_hyst = hyst_temp;
 401         x.thermostat = cl;
 402 out:
 403         return 0;
 404 }
 405
 406 enum chip { ds1775, adm1030 };
 407
 408 static const struct i2c_device_id therm_windtunnel_id[] = {
 409         { "MAC,ds1775", ds1775 },
 410         { "MAC,adm1030", adm1030 },
 411         { }
 412 };
 413 MODULE_DEVICE_TABLE(i2c, therm_windtunnel_id);
 414
 415 static int
 416 do_probe(struct i2c_client *cl)
 417 {
 418         const struct i2c_device_id *id = i2c_client_get_device_id(cl);
 419         struct i2c_adapter *adapter = cl->adapter;
 420         int ret = 0;
 421
 422         if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
 423                                      | I2C_FUNC_SMBUS_WRITE_BYTE) )
 424                 return 0;
 425
 426         switch (id->driver_data) {
 427         case adm1030:
 428                 ret = attach_fan(cl);
 429                 break;
 430         case ds1775:
 431                 ret = attach_thermostat(cl);
 432                 break;
 433         }
 434
 435         if (!x.running && x.thermostat && x.fan) {
 436                 x.running = 1;
 437                 x.poll_task = kthread_run(control_loop, NULL, "g4fand");
 438         }
 439
 440         return ret;
 441 }
 442
 443 static struct i2c_driver g4fan_driver = {
 444         .driver = {
 445                 .name   = "therm_windtunnel",
 446         },
 447         .probe          = do_probe,
 448         .remove         = do_remove,
 449         .id_table       = therm_windtunnel_id,
 450 };
 451
 452
 453 /************************************************************************/
 454 /*      initialization / cleanup                                        */
 455 /************************************************************************/
 456
 457 static int therm_of_probe(struct platform_device *dev)
 458 {
 459         struct i2c_adapter *adap;
 460         int ret, i = 0;
 461
 462         adap = i2c_get_adapter(0);
 463         if (!adap)
 464                 return -EPROBE_DEFER;
 465
 466         ret = i2c_add_driver(&g4fan_driver);
 467         if (ret) {
 468                 i2c_put_adapter(adap);
 469                 return ret;
 470         }
 471
 472         /* We assume Macs have consecutive I2C bus numbers starting at 0 */
 473         while (adap) {
 474                 do_attach(adap);
 475                 if (x.running)
 476                         return 0;
 477                 i2c_put_adapter(adap);
 478                 adap = i2c_get_adapter(++i);
 479         }
 480
 481         return -ENODEV;
 482 }
 483
 484 static void therm_of_remove(struct platform_device *dev)
 485 {
 486         i2c_del_driver( &g4fan_driver );
 487 }
 488
 489 static const struct of_device_id therm_of_match[] = {{
 490         .name           = "fan",
 491         .compatible     = "adm1030"
 492     }, {}
 493 };
 494 MODULE_DEVICE_TABLE(of, therm_of_match);
 495
 496 static struct platform_driver therm_of_driver = {
 497         .driver = {
 498                 .name = "temperature",
 499                 .of_match_table = therm_of_match,
 500         },
 501         .probe          = therm_of_probe,
 502         .remove         = therm_of_remove,
 503 };
 504
 505 struct apple_thermal_info {
 506         u8              id;                     /* implementation ID */
 507         u8              fan_count;              /* number of fans */
 508         u8              thermostat_count;       /* number of thermostats */
 509         u8              unused;
 510 };
 511
 512 static int __init
 513 g4fan_init( void )
 514 {
 515         const struct apple_thermal_info *info;
 516         struct device_node *np;
 517
 518         mutex_init(&x.lock);
 519
 520         if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
 521                 return -ENODEV;
 522         info = of_get_property(np, "thermal-info", NULL);
 523         of_node_put(np);
 524
 525         if( !info || !of_machine_is_compatible("PowerMac3,6") )
 526                 return -ENODEV;
 527
 528         if( info->id != 3 ) {
 529                 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );
 530                 return -ENODEV;
 531         }
 532         if( !(np=of_find_node_by_name(NULL, "fan")) )
 533                 return -ENODEV;
 534         x.of_dev = of_platform_device_create(np, "temperature", NULL);
 535         of_node_put( np );
 536
 537         if( !x.of_dev ) {
 538                 printk(KERN_ERR "Can't register fan controller!\n");
 539                 return -ENODEV;
 540         }
 541
 542         platform_driver_register( &therm_of_driver );
 543         return 0;
 544 }
 545
 546 static void __exit
 547 g4fan_exit( void )
 548 {
 549         platform_driver_unregister( &therm_of_driver );
 550
 551         if( x.of_dev )
 552                 of_platform_device_destroy(&x.of_dev->dev, NULL);
 553 }
 554
 555 module_init(g4fan_init);
 556 module_exit(g4fan_exit);
 557
 558 MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
 559 MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
 560 MODULE_LICENSE("GPL");