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_platform.h>
  40
  41 #include <asm/prom.h>
  42 #include <asm/machdep.h>
  43 #include <asm/io.h>
  44 #include <asm/sections.h>
  45 #include <asm/macio.h>
  46
  47 #define LOG_TEMP                0                       /* continuously log temperature */
  48
  49 static struct {
  50         volatile int            running;
  51         struct task_struct      *poll_task;
  52
  53         struct mutex            lock;
  54         struct platform_device  *of_dev;
  55
  56         struct i2c_client       *thermostat;
  57         struct i2c_client       *fan;
  58
  59         int                     overheat_temp;          /* 100% fan at this temp */
  60         int                     overheat_hyst;
  61         int                     temp;
  62         int                     casetemp;
  63         int                     fan_level;              /* active fan_table setting */
  64
  65         int                     downind;
  66         int                     upind;
  67
  68         int                     r0, r1, r20, r23, r25;  /* saved register */
  69 } x;
  70
  71 #define T(x,y)                  (((x)<<8) | (y)*0x100/10 )
  72
  73 static struct {
  74         int                     fan_down_setting;
  75         int                     temp;
  76         int                     fan_up_setting;
  77 } fan_table[] = {
  78         { 11, T(0,0),  11 },    /* min fan */
  79         { 11, T(55,0), 11 },
  80         {  6, T(55,3), 11 },
  81         {  7, T(56,0), 11 },
  82         {  8, T(57,0), 8 },
  83         {  7, T(58,3), 7 },
  84         {  6, T(58,8), 6 },
  85         {  5, T(59,2), 5 },
  86         {  4, T(59,6), 4 },
  87         {  3, T(59,9), 3 },
  88         {  2, T(60,1), 2 },
  89         {  1, 0xfffff, 1 }      /* on fire */
  90 };
  91
  92 static void
  93 print_temp( const char *s, int temp )
  94 {
  95         printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
  96 }
  97
  98 static ssize_t
  99 show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf )
 100 {
 101         return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 );
 102 }
 103
 104 static ssize_t
 105 show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf )
 106 {
 107         return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 );
 108 }
 109
 110 static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );
 111 static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );
 112
 113
 114
 115 /************************************************************************/
 116 /*      controller thread                                               */
 117 /************************************************************************/
 118
 119 static int
 120 write_reg( struct i2c_client *cl, int reg, int data, int len )
 121 {
 122         u8 tmp[3];
 123
 124         if( len < 1 || len > 2 || data < 0 )
 125                 return -EINVAL;
 126
 127         tmp[0] = reg;
 128         tmp[1] = (len == 1) ? data : (data >> 8);
 129         tmp[2] = data;
 130         len++;
 131
 132         if( i2c_master_send(cl, tmp, len) != len )
 133                 return -ENODEV;
 134         return 0;
 135 }
 136
 137 static int
 138 read_reg( struct i2c_client *cl, int reg, int len )
 139 {
 140         u8 buf[2];
 141
 142         if( len != 1 && len != 2 )
 143                 return -EINVAL;
 144         buf[0] = reg;
 145         if( i2c_master_send(cl, buf, 1) != 1 )
 146                 return -ENODEV;
 147         if( i2c_master_recv(cl, buf, len) != len )
 148                 return -ENODEV;
 149         return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0];
 150 }
 151
 152 static void
 153 tune_fan( int fan_setting )
 154 {
 155         int val = (fan_setting << 3) | 7;
 156
 157         /* write_reg( x.fan, 0x24, val, 1 ); */
 158         write_reg( x.fan, 0x25, val, 1 );
 159         write_reg( x.fan, 0x20, 0, 1 );
 160         print_temp("CPU-temp: ", x.temp );
 161         if( x.casetemp )
 162                 print_temp(", Case: ", x.casetemp );
 163         printk(",  Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );
 164
 165         x.fan_level = fan_setting;
 166 }
 167
 168 static void
 169 poll_temp( void )
 170 {
 171         int temp, i, level, casetemp;
 172
 173         temp = read_reg( x.thermostat, 0, 2 );
 174
 175         /* this actually occurs when the computer is loaded */
 176         if( temp < 0 )
 177                 return;
 178
 179         casetemp = read_reg(x.fan, 0x0b, 1) << 8;
 180         casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;
 181
 182         if( LOG_TEMP && x.temp != temp ) {
 183                 print_temp("CPU-temp: ", temp );
 184                 print_temp(", Case: ", casetemp );
 185                 printk(",  Fan: %d\n", 11-x.fan_level );
 186         }
 187         x.temp = temp;
 188         x.casetemp = casetemp;
 189
 190         level = -1;
 191         for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )
 192                 ;
 193         if( i < x.downind )
 194                 level = fan_table[i].fan_down_setting;
 195         x.downind = i;
 196
 197         for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )
 198                 ;
 199         if( x.upind < i )
 200                 level = fan_table[i].fan_up_setting;
 201         x.upind = i;
 202
 203         if( level >= 0 )
 204                 tune_fan( level );
 205 }
 206
 207
 208 static void
 209 setup_hardware( void )
 210 {
 211         int val;
 212         int err;
 213
 214         /* save registers (if we unload the module) */
 215         x.r0 = read_reg( x.fan, 0x00, 1 );
 216         x.r1 = read_reg( x.fan, 0x01, 1 );
 217         x.r20 = read_reg( x.fan, 0x20, 1 );
 218         x.r23 = read_reg( x.fan, 0x23, 1 );
 219         x.r25 = read_reg( x.fan, 0x25, 1 );
 220
 221         /* improve measurement resolution (convergence time 1.5s) */
 222         if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) {
 223                 val |= 0x60;
 224                 if( write_reg( x.thermostat, 1, val, 1 ) )
 225                         printk("Failed writing config register\n");
 226         }
 227         /* disable interrupts and TAC input */
 228         write_reg( x.fan, 0x01, 0x01, 1 );
 229         /* enable filter */
 230         write_reg( x.fan, 0x23, 0x91, 1 );
 231         /* remote temp. controls fan */
 232         write_reg( x.fan, 0x00, 0x95, 1 );
 233
 234         /* The thermostat (which besides measureing temperature controls
 235          * has a THERM output which puts the fan on 100%) is usually
 236          * set to kick in at 80 C (chip default). We reduce this a bit
 237          * to be on the safe side (OSX doesn't)...
 238          */
 239         if( x.overheat_temp == (80 << 8) ) {
 240                 x.overheat_temp = 75 << 8;
 241                 x.overheat_hyst = 70 << 8;
 242                 write_reg( x.thermostat, 2, x.overheat_hyst, 2 );
 243                 write_reg( x.thermostat, 3, x.overheat_temp, 2 );
 244
 245                 print_temp("Reducing overheating limit to ", x.overheat_temp );
 246                 print_temp(" (Hyst: ", x.overheat_hyst );
 247                 printk(")\n");
 248         }
 249
 250         /* set an initial fan setting */
 251         x.downind = 0xffff;
 252         x.upind = -1;
 253         /* tune_fan( fan_up_table[x.upind].fan_setting ); */
 254
 255         err = device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 256         err |= device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
 257         if (err)
 258                 printk(KERN_WARNING
 259                         "Failed to create temperature attribute file(s).\n");
 260 }
 261
 262 static void
 263 restore_regs( void )
 264 {
 265         device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 266         device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );
 267
 268         write_reg( x.fan, 0x01, x.r1, 1 );
 269         write_reg( x.fan, 0x20, x.r20, 1 );
 270         write_reg( x.fan, 0x23, x.r23, 1 );
 271         write_reg( x.fan, 0x25, x.r25, 1 );
 272         write_reg( x.fan, 0x00, x.r0, 1 );
 273 }
 274
 275 static int control_loop(void *dummy)
 276 {
 277         mutex_lock(&x.lock);
 278         setup_hardware();
 279         mutex_unlock(&x.lock);
 280
 281         for (;;) {
 282                 msleep_interruptible(8000);
 283                 if (kthread_should_stop())
 284                         break;
 285
 286                 mutex_lock(&x.lock);
 287                 poll_temp();
 288                 mutex_unlock(&x.lock);
 289         }
 290
 291         mutex_lock(&x.lock);
 292         restore_regs();
 293         mutex_unlock(&x.lock);
 294
 295         return 0;
 296 }
 297
 298
 299 /************************************************************************/
 300 /*      i2c probing and setup                                           */
 301 /************************************************************************/
 302
 303 static void do_attach(struct i2c_adapter *adapter)
 304 {
 305         struct i2c_board_info info = { };
 306         struct device_node *np;
 307
 308         /* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */
 309         static const unsigned short scan_ds1775[] = {
 310                 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
 311                 I2C_CLIENT_END
 312         };
 313         static const unsigned short scan_adm1030[] = {
 314                 0x2c, 0x2d, 0x2e, 0x2f,
 315                 I2C_CLIENT_END
 316         };
 317
 318         if (x.running || strncmp(adapter->name, "uni-n", 5))
 319                 return;
 320
 321         np = of_find_compatible_node(adapter->dev.of_node, NULL, "MAC,ds1775");
 322         if (np) {
 323                 of_node_put(np);
 324         } else {
 325                 strlcpy(info.type, "MAC,ds1775", I2C_NAME_SIZE);
 326                 i2c_new_probed_device(adapter, &info, scan_ds1775, NULL);
 327         }
 328
 329         np = of_find_compatible_node(adapter->dev.of_node, NULL, "MAC,adm1030");
 330         if (np) {
 331                 of_node_put(np);
 332         } else {
 333                 strlcpy(info.type, "MAC,adm1030", I2C_NAME_SIZE);
 334                 i2c_new_probed_device(adapter, &info, scan_adm1030, NULL);
 335         }
 336 }
 337
 338 static int
 339 do_remove(struct i2c_client *client)
 340 {
 341         if (x.running) {
 342                 x.running = 0;
 343                 kthread_stop(x.poll_task);
 344                 x.poll_task = NULL;
 345         }
 346         if (client == x.thermostat)
 347                 x.thermostat = NULL;
 348         else if (client == x.fan)
 349                 x.fan = NULL;
 350         else
 351                 printk(KERN_ERR "g4fan: bad client\n");
 352
 353         return 0;
 354 }
 355
 356 static int
 357 attach_fan( struct i2c_client *cl )
 358 {
 359         if( x.fan )
 360                 goto out;
 361
 362         /* check that this is an ADM1030 */
 363         if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 )
 364                 goto out;
 365         printk("ADM1030 fan controller [@%02x]\n", cl->addr );
 366
 367         x.fan = cl;
 368  out:
 369         return 0;
 370 }
 371
 372 static int
 373 attach_thermostat( struct i2c_client *cl )
 374 {
 375         int hyst_temp, os_temp, temp;
 376
 377         if( x.thermostat )
 378                 goto out;
 379
 380         if( (temp=read_reg(cl, 0, 2)) < 0 )
 381                 goto out;
 382
 383         /* temperature sanity check */
 384         if( temp < 0x1600 || temp > 0x3c00 )
 385                 goto out;
 386         hyst_temp = read_reg(cl, 2, 2);
 387         os_temp = read_reg(cl, 3, 2);
 388         if( hyst_temp < 0 || os_temp < 0 )
 389                 goto out;
 390
 391         printk("DS1775 digital thermometer [@%02x]\n", cl->addr );
 392         print_temp("Temp: ", temp );
 393         print_temp("  Hyst: ", hyst_temp );
 394         print_temp("  OS: ", os_temp );
 395         printk("\n");
 396
 397         x.temp = temp;
 398         x.overheat_temp = os_temp;
 399         x.overheat_hyst = hyst_temp;
 400         x.thermostat = cl;
 401 out:
 402         return 0;
 403 }
 404
 405 enum chip { ds1775, adm1030 };
 406
 407 static const struct i2c_device_id therm_windtunnel_id[] = {
 408         { "MAC,ds1775", ds1775 },
 409         { "MAC,adm1030", adm1030 },
 410         { }
 411 };
 412 MODULE_DEVICE_TABLE(i2c, therm_windtunnel_id);
 413
 414 static int
 415 do_probe(struct i2c_client *cl, const struct i2c_device_id *id)
 416 {
 417         struct i2c_adapter *adapter = cl->adapter;
 418         int ret = 0;
 419
 420         if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
 421                                      | I2C_FUNC_SMBUS_WRITE_BYTE) )
 422                 return 0;
 423
 424         switch (id->driver_data) {
 425         case adm1030:
 426                 ret = attach_fan(cl);
 427                 break;
 428         case ds1775:
 429                 ret = attach_thermostat(cl);
 430                 break;
 431         }
 432
 433         if (!x.running && x.thermostat && x.fan) {
 434                 x.running = 1;
 435                 x.poll_task = kthread_run(control_loop, NULL, "g4fand");
 436         }
 437
 438         return ret;
 439 }
 440
 441 static struct i2c_driver g4fan_driver = {
 442         .driver = {
 443                 .name   = "therm_windtunnel",
 444         },
 445         .probe          = do_probe,
 446         .remove         = do_remove,
 447         .id_table       = therm_windtunnel_id,
 448 };
 449
 450
 451 /************************************************************************/
 452 /*      initialization / cleanup                                        */
 453 /************************************************************************/
 454
 455 static int therm_of_probe(struct platform_device *dev)
 456 {
 457         struct i2c_adapter *adap;
 458         int ret, i = 0;
 459
 460         adap = i2c_get_adapter(0);
 461         if (!adap)
 462                 return -EPROBE_DEFER;
 463
 464         ret = i2c_add_driver(&g4fan_driver);
 465         if (ret) {
 466                 i2c_put_adapter(adap);
 467                 return ret;
 468         }
 469
 470         /* We assume Macs have consecutive I2C bus numbers starting at 0 */
 471         while (adap) {
 472                 do_attach(adap);
 473                 if (x.running)
 474                         return 0;
 475                 i2c_put_adapter(adap);
 476                 adap = i2c_get_adapter(++i);
 477         }
 478
 479         return -ENODEV;
 480 }
 481
 482 static int
 483 therm_of_remove( struct platform_device *dev )
 484 {
 485         i2c_del_driver( &g4fan_driver );
 486         return 0;
 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_device_unregister( x.of_dev );
 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");