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  *      temperatur 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/config.h>
  31 #include <linux/types.h>
  32 #include <linux/module.h>
  33 #include <linux/errno.h>
  34 #include <linux/kernel.h>
  35 #include <linux/delay.h>
  36 #include <linux/sched.h>
  37 #include <linux/i2c.h>
  38 #include <linux/slab.h>
  39 #include <linux/init.h>
  40 #include <asm/prom.h>
  41 #include <asm/machdep.h>
  42 #include <asm/io.h>
  43 #include <asm/system.h>
  44 #include <asm/sections.h>
  45 #include <asm/of_device.h>
  46
  47 #define LOG_TEMP                0                       /* continously log temperature */
  48
  49 #define I2C_DRIVERID_G4FAN      0x9001                  /* fixme */
  50
  51 static int                      do_probe( struct i2c_adapter *adapter, int addr, int kind);
  52
  53 /* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */
  54 static unsigned short           normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
  55                                                  0x4c, 0x4d, 0x4e, 0x4f,
  56                                                  0x2c, 0x2d, 0x2e, 0x2f,
  57                                                  I2C_CLIENT_END };
  58
  59 I2C_CLIENT_INSMOD;
  60
  61 static struct {
  62         volatile int            running;
  63         struct completion       completion;
  64         pid_t                   poll_task;
  65
  66         struct semaphore        lock;
  67         struct of_device        *of_dev;
  68
  69         struct i2c_client       *thermostat;
  70         struct i2c_client       *fan;
  71
  72         int                     overheat_temp;          /* 100% fan at this temp */
  73         int                     overheat_hyst;
  74         int                     temp;
  75         int                     casetemp;
  76         int                     fan_level;              /* active fan_table setting */
  77
  78         int                     downind;
  79         int                     upind;
  80
  81         int                     r0, r1, r20, r23, r25;  /* saved register */
  82 } x;
  83
  84 #define T(x,y)                  (((x)<<8) | (y)*0x100/10 )
  85
  86 static struct {
  87         int                     fan_down_setting;
  88         int                     temp;
  89         int                     fan_up_setting;
  90 } fan_table[] = {
  91         { 11, T(0,0),  11 },    /* min fan */
  92         { 11, T(55,0), 11 },
  93         {  6, T(55,3), 11 },
  94         {  7, T(56,0), 11 },
  95         {  8, T(57,0), 8 },
  96         {  7, T(58,3), 7 },
  97         {  6, T(58,8), 6 },
  98         {  5, T(59,2), 5 },
  99         {  4, T(59,6), 4 },
 100         {  3, T(59,9), 3 },
 101         {  2, T(60,1), 2 },
 102         {  1, 0xfffff, 1 }      /* on fire */
 103 };
 104
 105 static void
 106 print_temp( const char *s, int temp )
 107 {
 108         printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
 109 }
 110
 111 static ssize_t
 112 show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf )
 113 {
 114         return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 );
 115 }
 116
 117 static ssize_t
 118 show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf )
 119 {
 120         return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 );
 121 }
 122
 123 static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );
 124 static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );
 125
 126
 127
 128 /************************************************************************/
 129 /*      controller thread                                               */
 130 /************************************************************************/
 131
 132 static int
 133 write_reg( struct i2c_client *cl, int reg, int data, int len )
 134 {
 135         u8 tmp[3];
 136
 137         if( len < 1 || len > 2 || data < 0 )
 138                 return -EINVAL;
 139
 140         tmp[0] = reg;
 141         tmp[1] = (len == 1) ? data : (data >> 8);
 142         tmp[2] = data;
 143         len++;
 144
 145         if( i2c_master_send(cl, tmp, len) != len )
 146                 return -ENODEV;
 147         return 0;
 148 }
 149
 150 static int
 151 read_reg( struct i2c_client *cl, int reg, int len )
 152 {
 153         u8 buf[2];
 154
 155         if( len != 1 && len != 2 )
 156                 return -EINVAL;
 157         buf[0] = reg;
 158         if( i2c_master_send(cl, buf, 1) != 1 )
 159                 return -ENODEV;
 160         if( i2c_master_recv(cl, buf, len) != len )
 161                 return -ENODEV;
 162         return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0];
 163 }
 164
 165 static void
 166 tune_fan( int fan_setting )
 167 {
 168         int val = (fan_setting << 3) | 7;
 169
 170         /* write_reg( x.fan, 0x24, val, 1 ); */
 171         write_reg( x.fan, 0x25, val, 1 );
 172         write_reg( x.fan, 0x20, 0, 1 );
 173         print_temp("CPU-temp: ", x.temp );
 174         if( x.casetemp )
 175                 print_temp(", Case: ", x.casetemp );
 176         printk(",  Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );
 177
 178         x.fan_level = fan_setting;
 179 }
 180
 181 static void
 182 poll_temp( void )
 183 {
 184         int temp, i, level, casetemp;
 185
 186         temp = read_reg( x.thermostat, 0, 2 );
 187
 188         /* this actually occurs when the computer is loaded */
 189         if( temp < 0 )
 190                 return;
 191
 192         casetemp = read_reg(x.fan, 0x0b, 1) << 8;
 193         casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;
 194
 195         if( LOG_TEMP && x.temp != temp ) {
 196                 print_temp("CPU-temp: ", temp );
 197                 print_temp(", Case: ", casetemp );
 198                 printk(",  Fan: %d\n", 11-x.fan_level );
 199         }
 200         x.temp = temp;
 201         x.casetemp = casetemp;
 202
 203         level = -1;
 204         for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )
 205                 ;
 206         if( i < x.downind )
 207                 level = fan_table[i].fan_down_setting;
 208         x.downind = i;
 209
 210         for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )
 211                 ;
 212         if( x.upind < i )
 213                 level = fan_table[i].fan_up_setting;
 214         x.upind = i;
 215
 216         if( level >= 0 )
 217                 tune_fan( level );
 218 }
 219
 220
 221 static void
 222 setup_hardware( void )
 223 {
 224         int val;
 225
 226         /* save registers (if we unload the module) */
 227         x.r0 = read_reg( x.fan, 0x00, 1 );
 228         x.r1 = read_reg( x.fan, 0x01, 1 );
 229         x.r20 = read_reg( x.fan, 0x20, 1 );
 230         x.r23 = read_reg( x.fan, 0x23, 1 );
 231         x.r25 = read_reg( x.fan, 0x25, 1 );
 232
 233         /* improve measurement resolution (convergence time 1.5s) */
 234         if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) {
 235                 val |= 0x60;
 236                 if( write_reg( x.thermostat, 1, val, 1 ) )
 237                         printk("Failed writing config register\n");
 238         }
 239         /* disable interrupts and TAC input */
 240         write_reg( x.fan, 0x01, 0x01, 1 );
 241         /* enable filter */
 242         write_reg( x.fan, 0x23, 0x91, 1 );
 243         /* remote temp. controls fan */
 244         write_reg( x.fan, 0x00, 0x95, 1 );
 245
 246         /* The thermostat (which besides measureing temperature controls
 247          * has a THERM output which puts the fan on 100%) is usually
 248          * set to kick in at 80 C (chip default). We reduce this a bit
 249          * to be on the safe side (OSX doesn't)...
 250          */
 251         if( x.overheat_temp == (80 << 8) ) {
 252                 x.overheat_temp = 65 << 8;
 253                 x.overheat_hyst = 60 << 8;
 254                 write_reg( x.thermostat, 2, x.overheat_hyst, 2 );
 255                 write_reg( x.thermostat, 3, x.overheat_temp, 2 );
 256
 257                 print_temp("Reducing overheating limit to ", x.overheat_temp );
 258                 print_temp(" (Hyst: ", x.overheat_hyst );
 259                 printk(")\n");
 260         }
 261
 262         /* set an initial fan setting */
 263         x.downind = 0xffff;
 264         x.upind = -1;
 265         /* tune_fan( fan_up_table[x.upind].fan_setting ); */
 266
 267         device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 268         device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
 269 }
 270
 271 static void
 272 restore_regs( void )
 273 {
 274         device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 275         device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );
 276
 277         write_reg( x.fan, 0x01, x.r1, 1 );
 278         write_reg( x.fan, 0x20, x.r20, 1 );
 279         write_reg( x.fan, 0x23, x.r23, 1 );
 280         write_reg( x.fan, 0x25, x.r25, 1 );
 281         write_reg( x.fan, 0x00, x.r0, 1 );
 282 }
 283
 284 static int
 285 control_loop( void *dummy )
 286 {
 287         daemonize("g4fand");
 288
 289         down( &x.lock );
 290         setup_hardware();
 291
 292         while( x.running ) {
 293                 up( &x.lock );
 294
 295                 msleep_interruptible(8000);
 296
 297                 down( &x.lock );
 298                 poll_temp();
 299         }
 300
 301         restore_regs();
 302         up( &x.lock );
 303
 304         complete_and_exit( &x.completion, 0 );
 305 }
 306
 307
 308 /************************************************************************/
 309 /*      i2c probing and setup                                           */
 310 /************************************************************************/
 311
 312 static int
 313 do_attach( struct i2c_adapter *adapter )
 314 {
 315         int ret = 0;
 316
 317         if( strncmp(adapter->name, "uni-n", 5) )
 318                 return 0;
 319
 320         if( !x.running ) {
 321                 ret = i2c_probe( adapter, &addr_data, &do_probe );
 322                 if( x.thermostat && x.fan ) {
 323                         x.running = 1;
 324                         init_completion( &x.completion );
 325                         x.poll_task = kernel_thread( control_loop, NULL, SIGCHLD | CLONE_KERNEL );
 326                 }
 327         }
 328         return ret;
 329 }
 330
 331 static int
 332 do_detach( struct i2c_client *client )
 333 {
 334         int err;
 335
 336         if( (err=i2c_detach_client(client)) )
 337                 printk(KERN_ERR "failed to detach thermostat client\n");
 338         else {
 339                 if( x.running ) {
 340                         x.running = 0;
 341                         wait_for_completion( &x.completion );
 342                 }
 343                 if( client == x.thermostat )
 344                         x.thermostat = NULL;
 345                 else if( client == x.fan )
 346                         x.fan = NULL;
 347                 else {
 348                         printk(KERN_ERR "g4fan: bad client\n");
 349                 }
 350                 kfree( client );
 351         }
 352         return err;
 353 }
 354
 355 static struct i2c_driver g4fan_driver = {
 356         .owner          = THIS_MODULE,
 357         .name           = "therm_windtunnel",
 358         .id             = I2C_DRIVERID_G4FAN,
 359         .flags          = I2C_DF_NOTIFY,
 360         .attach_adapter = do_attach,
 361         .detach_client  = do_detach,
 362 };
 363
 364 static int
 365 attach_fan( struct i2c_client *cl )
 366 {
 367         if( x.fan )
 368                 goto out;
 369
 370         /* check that this is an ADM1030 */
 371         if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 )
 372                 goto out;
 373         printk("ADM1030 fan controller [@%02x]\n", cl->addr );
 374
 375         strlcpy( cl->name, "ADM1030 fan controller", sizeof(cl->name) );
 376
 377         if( !i2c_attach_client(cl) )
 378                 x.fan = cl;
 379  out:
 380         if( cl != x.fan )
 381                 kfree( cl );
 382         return 0;
 383 }
 384
 385 static int
 386 attach_thermostat( struct i2c_client *cl )
 387 {
 388         int hyst_temp, os_temp, temp;
 389
 390         if( x.thermostat )
 391                 goto out;
 392
 393         if( (temp=read_reg(cl, 0, 2)) < 0 )
 394                 goto out;
 395
 396         /* temperature sanity check */
 397         if( temp < 0x1600 || temp > 0x3c00 )
 398                 goto out;
 399         hyst_temp = read_reg(cl, 2, 2);
 400         os_temp = read_reg(cl, 3, 2);
 401         if( hyst_temp < 0 || os_temp < 0 )
 402                 goto out;
 403
 404         printk("DS1775 digital thermometer [@%02x]\n", cl->addr );
 405         print_temp("Temp: ", temp );
 406         print_temp("  Hyst: ", hyst_temp );
 407         print_temp("  OS: ", os_temp );
 408         printk("\n");
 409
 410         x.temp = temp;
 411         x.overheat_temp = os_temp;
 412         x.overheat_hyst = hyst_temp;
 413
 414         strlcpy( cl->name, "DS1775 thermostat", sizeof(cl->name) );
 415
 416         if( !i2c_attach_client(cl) )
 417                 x.thermostat = cl;
 418 out:
 419         if( cl != x.thermostat )
 420                 kfree( cl );
 421         return 0;
 422 }
 423
 424 static int
 425 do_probe( struct i2c_adapter *adapter, int addr, int kind )
 426 {
 427         struct i2c_client *cl;
 428
 429         if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
 430                                      | I2C_FUNC_SMBUS_WRITE_BYTE) )
 431                 return 0;
 432
 433         if( !(cl=kmalloc(sizeof(*cl), GFP_KERNEL)) )
 434                 return -ENOMEM;
 435         memset( cl, 0, sizeof(struct i2c_client) );
 436
 437         cl->addr = addr;
 438         cl->adapter = adapter;
 439         cl->driver = &g4fan_driver;
 440         cl->flags = 0;
 441
 442         if( addr < 0x48 )
 443                 return attach_fan( cl );
 444         return attach_thermostat( cl );
 445 }
 446
 447
 448 /************************************************************************/
 449 /*      initialization / cleanup                                        */
 450 /************************************************************************/
 451
 452 static int
 453 therm_of_probe( struct of_device *dev, const struct of_match *match )
 454 {
 455         return i2c_add_driver( &g4fan_driver );
 456 }
 457
 458 static int
 459 therm_of_remove( struct of_device *dev )
 460 {
 461         return i2c_del_driver( &g4fan_driver );
 462 }
 463
 464 static struct of_match therm_of_match[] = {{
 465         .name           = "fan",
 466         .type           = OF_ANY_MATCH,
 467         .compatible     = "adm1030"
 468     }, {}
 469 };
 470
 471 static struct of_platform_driver therm_of_driver = {
 472         .name           = "temperature",
 473         .match_table    = therm_of_match,
 474         .probe          = therm_of_probe,
 475         .remove         = therm_of_remove,
 476 };
 477
 478 struct apple_thermal_info {
 479         u8              id;                     /* implementation ID */
 480         u8              fan_count;              /* number of fans */
 481         u8              thermostat_count;       /* number of thermostats */
 482         u8              unused;
 483 };
 484
 485 static int __init
 486 g4fan_init( void )
 487 {
 488         struct apple_thermal_info *info;
 489         struct device_node *np;
 490
 491         init_MUTEX( &x.lock );
 492
 493         if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
 494                 return -ENODEV;
 495         info = (struct apple_thermal_info*)get_property(np, "thermal-info", NULL);
 496         of_node_put(np);
 497
 498         if( !info || !machine_is_compatible("PowerMac3,6") )
 499                 return -ENODEV;
 500
 501         if( info->id != 3 ) {
 502                 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );
 503                 return -ENODEV;
 504         }
 505         if( !(np=of_find_node_by_name(NULL, "fan")) )
 506                 return -ENODEV;
 507         x.of_dev = of_platform_device_create( np, "temperature" );
 508         of_node_put( np );
 509
 510         if( !x.of_dev ) {
 511                 printk(KERN_ERR "Can't register fan controller!\n");
 512                 return -ENODEV;
 513         }
 514
 515         of_register_driver( &therm_of_driver );
 516         return 0;
 517 }
 518
 519 static void __exit
 520 g4fan_exit( void )
 521 {
 522         of_unregister_driver( &therm_of_driver );
 523
 524         if( x.of_dev )
 525                 of_device_unregister( x.of_dev );
 526 }
 527
 528 module_init(g4fan_init);
 529 module_exit(g4fan_exit);
 530
 531 MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
 532 MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
 533 MODULE_LICENSE("GPL");