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 #include <linux/kthread.h>
  40 #include <linux/of_platform.h>
  41
  42 #include <asm/prom.h>
  43 #include <asm/machdep.h>
  44 #include <asm/io.h>
  45 #include <asm/system.h>
  46 #include <asm/sections.h>
  47 #include <asm/macio.h>
  48
  49 #define LOG_TEMP                0                       /* continously log temperature */
  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 const 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 task_struct      *poll_task;
  64
  65         struct mutex            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         int err;
 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         err = device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 268         err |= device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
 269         if (err)
 270                 printk(KERN_WARNING
 271                         "Failed to create temperature attribute file(s).\n");
 272 }
 273
 274 static void
 275 restore_regs( void )
 276 {
 277         device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 278         device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );
 279
 280         write_reg( x.fan, 0x01, x.r1, 1 );
 281         write_reg( x.fan, 0x20, x.r20, 1 );
 282         write_reg( x.fan, 0x23, x.r23, 1 );
 283         write_reg( x.fan, 0x25, x.r25, 1 );
 284         write_reg( x.fan, 0x00, x.r0, 1 );
 285 }
 286
 287 static int control_loop(void *dummy)
 288 {
 289         mutex_lock(&x.lock);
 290         setup_hardware();
 291         mutex_unlock(&x.lock);
 292
 293         for (;;) {
 294                 msleep_interruptible(8000);
 295                 if (kthread_should_stop())
 296                         break;
 297
 298                 mutex_lock(&x.lock);
 299                 poll_temp();
 300                 mutex_unlock(&x.lock);
 301         }
 302
 303         mutex_lock(&x.lock);
 304         restore_regs();
 305         mutex_unlock(&x.lock);
 306
 307         return 0;
 308 }
 309
 310
 311 /************************************************************************/
 312 /*      i2c probing and setup                                           */
 313 /************************************************************************/
 314
 315 static int
 316 do_attach( struct i2c_adapter *adapter )
 317 {
 318         int ret = 0;
 319
 320         if( strncmp(adapter->name, "uni-n", 5) )
 321                 return 0;
 322
 323         if( !x.running ) {
 324                 ret = i2c_probe( adapter, &addr_data, &do_probe );
 325                 if( x.thermostat && x.fan ) {
 326                         x.running = 1;
 327                         x.poll_task = kthread_run(control_loop, NULL, "g4fand");
 328                 }
 329         }
 330         return ret;
 331 }
 332
 333 static int
 334 do_detach( struct i2c_client *client )
 335 {
 336         int err;
 337
 338         if( (err=i2c_detach_client(client)) )
 339                 printk(KERN_ERR "failed to detach thermostat client\n");
 340         else {
 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                 kfree( client );
 354         }
 355         return err;
 356 }
 357
 358 static struct i2c_driver g4fan_driver = {
 359         .driver = {
 360                 .name   = "therm_windtunnel",
 361         },
 362         .attach_adapter = do_attach,
 363         .detach_client  = do_detach,
 364 };
 365
 366 static int
 367 attach_fan( struct i2c_client *cl )
 368 {
 369         if( x.fan )
 370                 goto out;
 371
 372         /* check that this is an ADM1030 */
 373         if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 )
 374                 goto out;
 375         printk("ADM1030 fan controller [@%02x]\n", cl->addr );
 376
 377         strlcpy( cl->name, "ADM1030 fan controller", sizeof(cl->name) );
 378
 379         if( !i2c_attach_client(cl) )
 380                 x.fan = cl;
 381  out:
 382         if( cl != x.fan )
 383                 kfree( cl );
 384         return 0;
 385 }
 386
 387 static int
 388 attach_thermostat( struct i2c_client *cl )
 389 {
 390         int hyst_temp, os_temp, temp;
 391
 392         if( x.thermostat )
 393                 goto out;
 394
 395         if( (temp=read_reg(cl, 0, 2)) < 0 )
 396                 goto out;
 397
 398         /* temperature sanity check */
 399         if( temp < 0x1600 || temp > 0x3c00 )
 400                 goto out;
 401         hyst_temp = read_reg(cl, 2, 2);
 402         os_temp = read_reg(cl, 3, 2);
 403         if( hyst_temp < 0 || os_temp < 0 )
 404                 goto out;
 405
 406         printk("DS1775 digital thermometer [@%02x]\n", cl->addr );
 407         print_temp("Temp: ", temp );
 408         print_temp("  Hyst: ", hyst_temp );
 409         print_temp("  OS: ", os_temp );
 410         printk("\n");
 411
 412         x.temp = temp;
 413         x.overheat_temp = os_temp;
 414         x.overheat_hyst = hyst_temp;
 415
 416         strlcpy( cl->name, "DS1775 thermostat", sizeof(cl->name) );
 417
 418         if( !i2c_attach_client(cl) )
 419                 x.thermostat = cl;
 420 out:
 421         if( cl != x.thermostat )
 422                 kfree( cl );
 423         return 0;
 424 }
 425
 426 static int
 427 do_probe( struct i2c_adapter *adapter, int addr, int kind )
 428 {
 429         struct i2c_client *cl;
 430
 431         if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
 432                                      | I2C_FUNC_SMBUS_WRITE_BYTE) )
 433                 return 0;
 434
 435         if( !(cl=kzalloc(sizeof(*cl), GFP_KERNEL)) )
 436                 return -ENOMEM;
 437
 438         cl->addr = addr;
 439         cl->adapter = adapter;
 440         cl->driver = &g4fan_driver;
 441         cl->flags = 0;
 442
 443         if( addr < 0x48 )
 444                 return attach_fan( cl );
 445         return attach_thermostat( cl );
 446 }
 447
 448
 449 /************************************************************************/
 450 /*      initialization / cleanup                                        */
 451 /************************************************************************/
 452
 453 static int
 454 therm_of_probe( struct of_device *dev, const struct of_device_id *match )
 455 {
 456         return i2c_add_driver( &g4fan_driver );
 457 }
 458
 459 static int
 460 therm_of_remove( struct of_device *dev )
 461 {
 462         i2c_del_driver( &g4fan_driver );
 463         return 0;
 464 }
 465
 466 static struct of_device_id therm_of_match[] = {{
 467         .name           = "fan",
 468         .compatible     = "adm1030"
 469     }, {}
 470 };
 471
 472 static struct of_platform_driver therm_of_driver = {
 473         .name           = "temperature",
 474         .match_table    = therm_of_match,
 475         .probe          = therm_of_probe,
 476         .remove         = therm_of_remove,
 477 };
 478
 479 struct apple_thermal_info {
 480         u8              id;                     /* implementation ID */
 481         u8              fan_count;              /* number of fans */
 482         u8              thermostat_count;       /* number of thermostats */
 483         u8              unused;
 484 };
 485
 486 static int __init
 487 g4fan_init( void )
 488 {
 489         const struct apple_thermal_info *info;
 490         struct device_node *np;
 491
 492         mutex_init(&x.lock);
 493
 494         if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
 495                 return -ENODEV;
 496         info = of_get_property(np, "thermal-info", NULL);
 497         of_node_put(np);
 498
 499         if( !info || !machine_is_compatible("PowerMac3,6") )
 500                 return -ENODEV;
 501
 502         if( info->id != 3 ) {
 503                 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );
 504                 return -ENODEV;
 505         }
 506         if( !(np=of_find_node_by_name(NULL, "fan")) )
 507                 return -ENODEV;
 508         x.of_dev = of_platform_device_create(np, "temperature", NULL);
 509         of_node_put( np );
 510
 511         if( !x.of_dev ) {
 512                 printk(KERN_ERR "Can't register fan controller!\n");
 513                 return -ENODEV;
 514         }
 515
 516         of_register_platform_driver( &therm_of_driver );
 517         return 0;
 518 }
 519
 520 static void __exit
 521 g4fan_exit( void )
 522 {
 523         of_unregister_platform_driver( &therm_of_driver );
 524
 525         if( x.of_dev )
 526                 of_device_unregister( x.of_dev );
 527 }
 528
 529 module_init(g4fan_init);
 530 module_exit(g4fan_exit);
 531
 532 MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
 533 MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
 534 MODULE_LICENSE("GPL");