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[] = { 0x49, 0x2c, I2C_CLIENT_END };
  55 static unsigned short           normal_i2c_range[] = { 0x48, 0x4f, 0x2c, 0x2f, I2C_CLIENT_END };
  56
  57 I2C_CLIENT_INSMOD;
  58
  59 static struct {
  60         volatile int            running;
  61         struct completion       completion;
  62         pid_t                   poll_task;
  63
  64         struct semaphore        lock;
  65         struct of_device        *of_dev;
  66
  67         struct i2c_client       *thermostat;
  68         struct i2c_client       *fan;
  69
  70         int                     overheat_temp;          /* 100% fan at this temp */
  71         int                     overheat_hyst;
  72         int                     temp;
  73         int                     casetemp;
  74         int                     fan_level;              /* active fan_table setting */
  75
  76         int                     downind;
  77         int                     upind;
  78
  79         int                     r0, r1, r20, r23, r25;  /* saved register */
  80 } x;
  81
  82 #define T(x,y)                  (((x)<<8) | (y)*0x100/10 )
  83
  84 static struct {
  85         int                     fan_down_setting;
  86         int                     temp;
  87         int                     fan_up_setting;
  88 } fan_table[] = {
  89         { 11, T(0,0),  11 },    /* min fan */
  90         { 11, T(55,0), 11 },
  91         {  6, T(55,3), 11 },
  92         {  7, T(56,0), 11 },
  93         {  8, T(57,0), 8 },
  94         {  7, T(58,3), 7 },
  95         {  6, T(58,8), 6 },
  96         {  5, T(59,2), 5 },
  97         {  4, T(59,6), 4 },
  98         {  3, T(59,9), 3 },
  99         {  2, T(60,1), 2 },
 100         {  1, 0xfffff, 1 }      /* on fire */
 101 };
 102
 103 static void
 104 print_temp( const char *s, int temp )
 105 {
 106         printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
 107 }
 108
 109 static ssize_t
 110 show_cpu_temperature( struct device *dev, char *buf )
 111 {
 112         return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 );
 113 }
 114
 115 static ssize_t
 116 show_case_temperature( struct device *dev, char *buf )
 117 {
 118         return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 );
 119 }
 120
 121 static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );
 122 static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );
 123
 124
 125
 126 /************************************************************************/
 127 /*      controller thread                                               */
 128 /************************************************************************/
 129
 130 static int
 131 write_reg( struct i2c_client *cl, int reg, int data, int len )
 132 {
 133         u8 tmp[3];
 134
 135         if( len < 1 || len > 2 || data < 0 )
 136                 return -EINVAL;
 137
 138         tmp[0] = reg;
 139         tmp[1] = (len == 1) ? data : (data >> 8);
 140         tmp[2] = data;
 141         len++;
 142
 143         if( i2c_master_send(cl, tmp, len) != len )
 144                 return -ENODEV;
 145         return 0;
 146 }
 147
 148 static int
 149 read_reg( struct i2c_client *cl, int reg, int len )
 150 {
 151         u8 buf[2];
 152
 153         if( len != 1 && len != 2 )
 154                 return -EINVAL;
 155         buf[0] = reg;
 156         if( i2c_master_send(cl, buf, 1) != 1 )
 157                 return -ENODEV;
 158         if( i2c_master_recv(cl, buf, len) != len )
 159                 return -ENODEV;
 160         return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0];
 161 }
 162
 163 static void
 164 tune_fan( int fan_setting )
 165 {
 166         int val = (fan_setting << 3) | 7;
 167
 168         /* write_reg( x.fan, 0x24, val, 1 ); */
 169         write_reg( x.fan, 0x25, val, 1 );
 170         write_reg( x.fan, 0x20, 0, 1 );
 171         print_temp("CPU-temp: ", x.temp );
 172         if( x.casetemp )
 173                 print_temp(", Case: ", x.casetemp );
 174         printk(",  Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );
 175
 176         x.fan_level = fan_setting;
 177 }
 178
 179 static void
 180 poll_temp( void )
 181 {
 182         int temp, i, level, casetemp;
 183
 184         temp = read_reg( x.thermostat, 0, 2 );
 185
 186         /* this actually occurs when the computer is loaded */
 187         if( temp < 0 )
 188                 return;
 189
 190         casetemp = read_reg(x.fan, 0x0b, 1) << 8;
 191         casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;
 192
 193         if( LOG_TEMP && x.temp != temp ) {
 194                 print_temp("CPU-temp: ", temp );
 195                 print_temp(", Case: ", casetemp );
 196                 printk(",  Fan: %d\n", 11-x.fan_level );
 197         }
 198         x.temp = temp;
 199         x.casetemp = casetemp;
 200
 201         level = -1;
 202         for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )
 203                 ;
 204         if( i < x.downind )
 205                 level = fan_table[i].fan_down_setting;
 206         x.downind = i;
 207
 208         for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )
 209                 ;
 210         if( x.upind < i )
 211                 level = fan_table[i].fan_up_setting;
 212         x.upind = i;
 213
 214         if( level >= 0 )
 215                 tune_fan( level );
 216 }
 217
 218
 219 static void
 220 setup_hardware( void )
 221 {
 222         int val;
 223
 224         /* save registers (if we unload the module) */
 225         x.r0 = read_reg( x.fan, 0x00, 1 );
 226         x.r1 = read_reg( x.fan, 0x01, 1 );
 227         x.r20 = read_reg( x.fan, 0x20, 1 );
 228         x.r23 = read_reg( x.fan, 0x23, 1 );
 229         x.r25 = read_reg( x.fan, 0x25, 1 );
 230
 231         /* improve measurement resolution (convergence time 1.5s) */
 232         if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) {
 233                 val |= 0x60;
 234                 if( write_reg( x.thermostat, 1, val, 1 ) )
 235                         printk("Failed writing config register\n");
 236         }
 237         /* disable interrupts and TAC input */
 238         write_reg( x.fan, 0x01, 0x01, 1 );
 239         /* enable filter */
 240         write_reg( x.fan, 0x23, 0x91, 1 );
 241         /* remote temp. controls fan */
 242         write_reg( x.fan, 0x00, 0x95, 1 );
 243
 244         /* The thermostat (which besides measureing temperature controls
 245          * has a THERM output which puts the fan on 100%) is usually
 246          * set to kick in at 80 C (chip default). We reduce this a bit
 247          * to be on the safe side (OSX doesn't)...
 248          */
 249         if( x.overheat_temp == (80 << 8) ) {
 250                 x.overheat_temp = 65 << 8;
 251                 x.overheat_hyst = 60 << 8;
 252                 write_reg( x.thermostat, 2, x.overheat_hyst, 2 );
 253                 write_reg( x.thermostat, 3, x.overheat_temp, 2 );
 254
 255                 print_temp("Reducing overheating limit to ", x.overheat_temp );
 256                 print_temp(" (Hyst: ", x.overheat_hyst );
 257                 printk(")\n");
 258         }
 259
 260         /* set an initial fan setting */
 261         x.downind = 0xffff;
 262         x.upind = -1;
 263         /* tune_fan( fan_up_table[x.upind].fan_setting ); */
 264
 265         device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 266         device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
 267 }
 268
 269 static void
 270 restore_regs( void )
 271 {
 272         device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 273         device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );
 274
 275         write_reg( x.fan, 0x01, x.r1, 1 );
 276         write_reg( x.fan, 0x20, x.r20, 1 );
 277         write_reg( x.fan, 0x23, x.r23, 1 );
 278         write_reg( x.fan, 0x25, x.r25, 1 );
 279         write_reg( x.fan, 0x00, x.r0, 1 );
 280 }
 281
 282 static int
 283 control_loop( void *dummy )
 284 {
 285         daemonize("g4fand");
 286
 287         down( &x.lock );
 288         setup_hardware();
 289
 290         while( x.running ) {
 291                 up( &x.lock );
 292
 293                 msleep_interruptible(8000);
 294
 295                 down( &x.lock );
 296                 poll_temp();
 297         }
 298
 299         restore_regs();
 300         up( &x.lock );
 301
 302         complete_and_exit( &x.completion, 0 );
 303 }
 304
 305
 306 /************************************************************************/
 307 /*      i2c probing and setup                                           */
 308 /************************************************************************/
 309
 310 static int
 311 do_attach( struct i2c_adapter *adapter )
 312 {
 313         int ret = 0;
 314
 315         if( strncmp(adapter->name, "uni-n", 5) )
 316                 return 0;
 317
 318         if( !x.running ) {
 319                 ret = i2c_probe( adapter, &addr_data, &do_probe );
 320                 if( x.thermostat && x.fan ) {
 321                         x.running = 1;
 322                         init_completion( &x.completion );
 323                         x.poll_task = kernel_thread( control_loop, NULL, SIGCHLD | CLONE_KERNEL );
 324                 }
 325         }
 326         return ret;
 327 }
 328
 329 static int
 330 do_detach( struct i2c_client *client )
 331 {
 332         int err;
 333
 334         if( (err=i2c_detach_client(client)) )
 335                 printk(KERN_ERR "failed to detach thermostat client\n");
 336         else {
 337                 if( x.running ) {
 338                         x.running = 0;
 339                         wait_for_completion( &x.completion );
 340                 }
 341                 if( client == x.thermostat )
 342                         x.thermostat = NULL;
 343                 else if( client == x.fan )
 344                         x.fan = NULL;
 345                 else {
 346                         printk(KERN_ERR "g4fan: bad client\n");
 347                 }
 348                 kfree( client );
 349         }
 350         return err;
 351 }
 352
 353 static struct i2c_driver g4fan_driver = {
 354         .owner          = THIS_MODULE,
 355         .name           = "therm_windtunnel",
 356         .id             = I2C_DRIVERID_G4FAN,
 357         .flags          = I2C_DF_NOTIFY,
 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=kmalloc(sizeof(*cl), GFP_KERNEL)) )
 432                 return -ENOMEM;
 433         memset( cl, 0, sizeof(struct i2c_client) );
 434
 435         cl->addr = addr;
 436         cl->adapter = adapter;
 437         cl->driver = &g4fan_driver;
 438         cl->flags = 0;
 439
 440         if( addr < 0x48 )
 441                 return attach_fan( cl );
 442         return attach_thermostat( cl );
 443 }
 444
 445
 446 /************************************************************************/
 447 /*      initialization / cleanup                                        */
 448 /************************************************************************/
 449
 450 static int
 451 therm_of_probe( struct of_device *dev, const struct of_match *match )
 452 {
 453         return i2c_add_driver( &g4fan_driver );
 454 }
 455
 456 static int
 457 therm_of_remove( struct of_device *dev )
 458 {
 459         return i2c_del_driver( &g4fan_driver );
 460 }
 461
 462 static struct of_match therm_of_match[] = {{
 463         .name           = "fan",
 464         .type           = OF_ANY_MATCH,
 465         .compatible     = "adm1030"
 466     }, {}
 467 };
 468
 469 static struct of_platform_driver therm_of_driver = {
 470         .name           = "temperature",
 471         .match_table    = therm_of_match,
 472         .probe          = therm_of_probe,
 473         .remove         = therm_of_remove,
 474 };
 475
 476 struct apple_thermal_info {
 477         u8              id;                     /* implementation ID */
 478         u8              fan_count;              /* number of fans */
 479         u8              thermostat_count;       /* number of thermostats */
 480         u8              unused;
 481 };
 482
 483 static int __init
 484 g4fan_init( void )
 485 {
 486         struct apple_thermal_info *info;
 487         struct device_node *np;
 488
 489         init_MUTEX( &x.lock );
 490
 491         if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
 492                 return -ENODEV;
 493         info = (struct apple_thermal_info*)get_property(np, "thermal-info", NULL);
 494         of_node_put(np);
 495
 496         if( !info || !machine_is_compatible("PowerMac3,6") )
 497                 return -ENODEV;
 498
 499         if( info->id != 3 ) {
 500                 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );
 501                 return -ENODEV;
 502         }
 503         if( !(np=of_find_node_by_name(NULL, "fan")) )
 504                 return -ENODEV;
 505         x.of_dev = of_platform_device_create( np, "temperature" );
 506         of_node_put( np );
 507
 508         if( !x.of_dev ) {
 509                 printk(KERN_ERR "Can't register fan controller!\n");
 510                 return -ENODEV;
 511         }
 512
 513         of_register_driver( &therm_of_driver );
 514         return 0;
 515 }
 516
 517 static void __exit
 518 g4fan_exit( void )
 519 {
 520         of_unregister_driver( &therm_of_driver );
 521
 522         if( x.of_dev )
 523                 of_device_unregister( x.of_dev );
 524 }
 525
 526 module_init(g4fan_init);
 527 module_exit(g4fan_exit);
 528
 529 MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
 530 MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
 531 MODULE_LICENSE("GPL");