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