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 #define I2C_DRIVERID_G4FAN      0x9001                  /* fixme */
  51
  52 static int                      do_probe( struct i2c_adapter *adapter, int addr, int kind);
  53
  54 /* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */
  55 static unsigned short           normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
  56                                                  0x4c, 0x4d, 0x4e, 0x4f,
  57                                                  0x2c, 0x2d, 0x2e, 0x2f,
  58                                                  I2C_CLIENT_END };
  59
  60 I2C_CLIENT_INSMOD;
  61
  62 static struct {
  63         volatile int            running;
  64         struct completion       completion;
  65         pid_t                   poll_task;
  66
  67         struct semaphore        lock;
  68         struct of_device        *of_dev;
  69
  70         struct i2c_client       *thermostat;
  71         struct i2c_client       *fan;
  72
  73         int                     overheat_temp;          /* 100% fan at this temp */
  74         int                     overheat_hyst;
  75         int                     temp;
  76         int                     casetemp;
  77         int                     fan_level;              /* active fan_table setting */
  78
  79         int                     downind;
  80         int                     upind;
  81
  82         int                     r0, r1, r20, r23, r25;  /* saved register */
  83 } x;
  84
  85 #define T(x,y)                  (((x)<<8) | (y)*0x100/10 )
  86
  87 static struct {
  88         int                     fan_down_setting;
  89         int                     temp;
  90         int                     fan_up_setting;
  91 } fan_table[] = {
  92         { 11, T(0,0),  11 },    /* min fan */
  93         { 11, T(55,0), 11 },
  94         {  6, T(55,3), 11 },
  95         {  7, T(56,0), 11 },
  96         {  8, T(57,0), 8 },
  97         {  7, T(58,3), 7 },
  98         {  6, T(58,8), 6 },
  99         {  5, T(59,2), 5 },
 100         {  4, T(59,6), 4 },
 101         {  3, T(59,9), 3 },
 102         {  2, T(60,1), 2 },
 103         {  1, 0xfffff, 1 }      /* on fire */
 104 };
 105
 106 static void
 107 print_temp( const char *s, int temp )
 108 {
 109         printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
 110 }
 111
 112 static ssize_t
 113 show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf )
 114 {
 115         return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 );
 116 }
 117
 118 static ssize_t
 119 show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf )
 120 {
 121         return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 );
 122 }
 123
 124 static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );
 125 static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );
 126
 127
 128
 129 /************************************************************************/
 130 /*      controller thread                                               */
 131 /************************************************************************/
 132
 133 static int
 134 write_reg( struct i2c_client *cl, int reg, int data, int len )
 135 {
 136         u8 tmp[3];
 137
 138         if( len < 1 || len > 2 || data < 0 )
 139                 return -EINVAL;
 140
 141         tmp[0] = reg;
 142         tmp[1] = (len == 1) ? data : (data >> 8);
 143         tmp[2] = data;
 144         len++;
 145
 146         if( i2c_master_send(cl, tmp, len) != len )
 147                 return -ENODEV;
 148         return 0;
 149 }
 150
 151 static int
 152 read_reg( struct i2c_client *cl, int reg, int len )
 153 {
 154         u8 buf[2];
 155
 156         if( len != 1 && len != 2 )
 157                 return -EINVAL;
 158         buf[0] = reg;
 159         if( i2c_master_send(cl, buf, 1) != 1 )
 160                 return -ENODEV;
 161         if( i2c_master_recv(cl, buf, len) != len )
 162                 return -ENODEV;
 163         return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0];
 164 }
 165
 166 static void
 167 tune_fan( int fan_setting )
 168 {
 169         int val = (fan_setting << 3) | 7;
 170
 171         /* write_reg( x.fan, 0x24, val, 1 ); */
 172         write_reg( x.fan, 0x25, val, 1 );
 173         write_reg( x.fan, 0x20, 0, 1 );
 174         print_temp("CPU-temp: ", x.temp );
 175         if( x.casetemp )
 176                 print_temp(", Case: ", x.casetemp );
 177         printk(",  Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );
 178
 179         x.fan_level = fan_setting;
 180 }
 181
 182 static void
 183 poll_temp( void )
 184 {
 185         int temp, i, level, casetemp;
 186
 187         temp = read_reg( x.thermostat, 0, 2 );
 188
 189         /* this actually occurs when the computer is loaded */
 190         if( temp < 0 )
 191                 return;
 192
 193         casetemp = read_reg(x.fan, 0x0b, 1) << 8;
 194         casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;
 195
 196         if( LOG_TEMP && x.temp != temp ) {
 197                 print_temp("CPU-temp: ", temp );
 198                 print_temp(", Case: ", casetemp );
 199                 printk(",  Fan: %d\n", 11-x.fan_level );
 200         }
 201         x.temp = temp;
 202         x.casetemp = casetemp;
 203
 204         level = -1;
 205         for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )
 206                 ;
 207         if( i < x.downind )
 208                 level = fan_table[i].fan_down_setting;
 209         x.downind = i;
 210
 211         for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )
 212                 ;
 213         if( x.upind < i )
 214                 level = fan_table[i].fan_up_setting;
 215         x.upind = i;
 216
 217         if( level >= 0 )
 218                 tune_fan( level );
 219 }
 220
 221
 222 static void
 223 setup_hardware( void )
 224 {
 225         int val;
 226
 227         /* save registers (if we unload the module) */
 228         x.r0 = read_reg( x.fan, 0x00, 1 );
 229         x.r1 = read_reg( x.fan, 0x01, 1 );
 230         x.r20 = read_reg( x.fan, 0x20, 1 );
 231         x.r23 = read_reg( x.fan, 0x23, 1 );
 232         x.r25 = read_reg( x.fan, 0x25, 1 );
 233
 234         /* improve measurement resolution (convergence time 1.5s) */
 235         if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) {
 236                 val |= 0x60;
 237                 if( write_reg( x.thermostat, 1, val, 1 ) )
 238                         printk("Failed writing config register\n");
 239         }
 240         /* disable interrupts and TAC input */
 241         write_reg( x.fan, 0x01, 0x01, 1 );
 242         /* enable filter */
 243         write_reg( x.fan, 0x23, 0x91, 1 );
 244         /* remote temp. controls fan */
 245         write_reg( x.fan, 0x00, 0x95, 1 );
 246
 247         /* The thermostat (which besides measureing temperature controls
 248          * has a THERM output which puts the fan on 100%) is usually
 249          * set to kick in at 80 C (chip default). We reduce this a bit
 250          * to be on the safe side (OSX doesn't)...
 251          */
 252         if( x.overheat_temp == (80 << 8) ) {
 253                 x.overheat_temp = 65 << 8;
 254                 x.overheat_hyst = 60 << 8;
 255                 write_reg( x.thermostat, 2, x.overheat_hyst, 2 );
 256                 write_reg( x.thermostat, 3, x.overheat_temp, 2 );
 257
 258                 print_temp("Reducing overheating limit to ", x.overheat_temp );
 259                 print_temp(" (Hyst: ", x.overheat_hyst );
 260                 printk(")\n");
 261         }
 262
 263         /* set an initial fan setting */
 264         x.downind = 0xffff;
 265         x.upind = -1;
 266         /* tune_fan( fan_up_table[x.upind].fan_setting ); */
 267
 268         device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 269         device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
 270 }
 271
 272 static void
 273 restore_regs( void )
 274 {
 275         device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 276         device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );
 277
 278         write_reg( x.fan, 0x01, x.r1, 1 );
 279         write_reg( x.fan, 0x20, x.r20, 1 );
 280         write_reg( x.fan, 0x23, x.r23, 1 );
 281         write_reg( x.fan, 0x25, x.r25, 1 );
 282         write_reg( x.fan, 0x00, x.r0, 1 );
 283 }
 284
 285 static int
 286 control_loop( void *dummy )
 287 {
 288         daemonize("g4fand");
 289
 290         down( &x.lock );
 291         setup_hardware();
 292
 293         while( x.running ) {
 294                 up( &x.lock );
 295
 296                 msleep_interruptible(8000);
 297
 298                 down( &x.lock );
 299                 poll_temp();
 300         }
 301
 302         restore_regs();
 303         up( &x.lock );
 304
 305         complete_and_exit( &x.completion, 0 );
 306 }
 307
 308
 309 /************************************************************************/
 310 /*      i2c probing and setup                                           */
 311 /************************************************************************/
 312
 313 static int
 314 do_attach( struct i2c_adapter *adapter )
 315 {
 316         int ret = 0;
 317
 318         if( strncmp(adapter->name, "uni-n", 5) )
 319                 return 0;
 320
 321         if( !x.running ) {
 322                 ret = i2c_probe( adapter, &addr_data, &do_probe );
 323                 if( x.thermostat && x.fan ) {
 324                         x.running = 1;
 325                         init_completion( &x.completion );
 326                         x.poll_task = kernel_thread( control_loop, NULL, SIGCHLD | CLONE_KERNEL );
 327                 }
 328         }
 329         return ret;
 330 }
 331
 332 static int
 333 do_detach( struct i2c_client *client )
 334 {
 335         int err;
 336
 337         if( (err=i2c_detach_client(client)) )
 338                 printk(KERN_ERR "failed to detach thermostat client\n");
 339         else {
 340                 if( x.running ) {
 341                         x.running = 0;
 342                         wait_for_completion( &x.completion );
 343                 }
 344                 if( client == x.thermostat )
 345                         x.thermostat = NULL;
 346                 else if( client == x.fan )
 347                         x.fan = NULL;
 348                 else {
 349                         printk(KERN_ERR "g4fan: bad client\n");
 350                 }
 351                 kfree( client );
 352         }
 353         return err;
 354 }
 355
 356 static struct i2c_driver g4fan_driver = {
 357         .driver = {
 358                 .name   = "therm_windtunnel",
 359         },
 360         .id             = I2C_DRIVERID_G4FAN,
 361         .attach_adapter = do_attach,
 362         .detach_client  = do_detach,
 363 };
 364
 365 static int
 366 attach_fan( struct i2c_client *cl )
 367 {
 368         if( x.fan )
 369                 goto out;
 370
 371         /* check that this is an ADM1030 */
 372         if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 )
 373                 goto out;
 374         printk("ADM1030 fan controller [@%02x]\n", cl->addr );
 375
 376         strlcpy( cl->name, "ADM1030 fan controller", sizeof(cl->name) );
 377
 378         if( !i2c_attach_client(cl) )
 379                 x.fan = cl;
 380  out:
 381         if( cl != x.fan )
 382                 kfree( cl );
 383         return 0;
 384 }
 385
 386 static int
 387 attach_thermostat( struct i2c_client *cl )
 388 {
 389         int hyst_temp, os_temp, temp;
 390
 391         if( x.thermostat )
 392                 goto out;
 393
 394         if( (temp=read_reg(cl, 0, 2)) < 0 )
 395                 goto out;
 396
 397         /* temperature sanity check */
 398         if( temp < 0x1600 || temp > 0x3c00 )
 399                 goto out;
 400         hyst_temp = read_reg(cl, 2, 2);
 401         os_temp = read_reg(cl, 3, 2);
 402         if( hyst_temp < 0 || os_temp < 0 )
 403                 goto out;
 404
 405         printk("DS1775 digital thermometer [@%02x]\n", cl->addr );
 406         print_temp("Temp: ", temp );
 407         print_temp("  Hyst: ", hyst_temp );
 408         print_temp("  OS: ", os_temp );
 409         printk("\n");
 410
 411         x.temp = temp;
 412         x.overheat_temp = os_temp;
 413         x.overheat_hyst = hyst_temp;
 414
 415         strlcpy( cl->name, "DS1775 thermostat", sizeof(cl->name) );
 416
 417         if( !i2c_attach_client(cl) )
 418                 x.thermostat = cl;
 419 out:
 420         if( cl != x.thermostat )
 421                 kfree( cl );
 422         return 0;
 423 }
 424
 425 static int
 426 do_probe( struct i2c_adapter *adapter, int addr, int kind )
 427 {
 428         struct i2c_client *cl;
 429
 430         if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
 431                                      | I2C_FUNC_SMBUS_WRITE_BYTE) )
 432                 return 0;
 433
 434         if( !(cl=kzalloc(sizeof(*cl), GFP_KERNEL)) )
 435                 return -ENOMEM;
 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_device_id *match )
 454 {
 455         return i2c_add_driver( &g4fan_driver );
 456 }
 457
 458 static int
 459 therm_of_remove( struct of_device *dev )
 460 {
 461         i2c_del_driver( &g4fan_driver );
 462         return 0;
 463 }
 464
 465 static struct of_device_id therm_of_match[] = {{
 466         .name           = "fan",
 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         const 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 = of_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", NULL);
 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_platform_driver( &therm_of_driver );
 516         return 0;
 517 }
 518
 519 static void __exit
 520 g4fan_exit( void )
 521 {
 522         of_unregister_platform_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");