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 struct {
  52         volatile int            running;
  53         struct task_struct      *poll_task;
  54
  55         struct mutex            lock;
  56         struct of_device        *of_dev;
  57
  58         struct i2c_client       *thermostat;
  59         struct i2c_client       *fan;
  60
  61         int                     overheat_temp;          /* 100% fan at this temp */
  62         int                     overheat_hyst;
  63         int                     temp;
  64         int                     casetemp;
  65         int                     fan_level;              /* active fan_table setting */
  66
  67         int                     downind;
  68         int                     upind;
  69
  70         int                     r0, r1, r20, r23, r25;  /* saved register */
  71 } x;
  72
  73 #define T(x,y)                  (((x)<<8) | (y)*0x100/10 )
  74
  75 static struct {
  76         int                     fan_down_setting;
  77         int                     temp;
  78         int                     fan_up_setting;
  79 } fan_table[] = {
  80         { 11, T(0,0),  11 },    /* min fan */
  81         { 11, T(55,0), 11 },
  82         {  6, T(55,3), 11 },
  83         {  7, T(56,0), 11 },
  84         {  8, T(57,0), 8 },
  85         {  7, T(58,3), 7 },
  86         {  6, T(58,8), 6 },
  87         {  5, T(59,2), 5 },
  88         {  4, T(59,6), 4 },
  89         {  3, T(59,9), 3 },
  90         {  2, T(60,1), 2 },
  91         {  1, 0xfffff, 1 }      /* on fire */
  92 };
  93
  94 static void
  95 print_temp( const char *s, int temp )
  96 {
  97         printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
  98 }
  99
 100 static ssize_t
 101 show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf )
 102 {
 103         return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 );
 104 }
 105
 106 static ssize_t
 107 show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf )
 108 {
 109         return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 );
 110 }
 111
 112 static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );
 113 static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );
 114
 115
 116
 117 /************************************************************************/
 118 /*      controller thread                                               */
 119 /************************************************************************/
 120
 121 static int
 122 write_reg( struct i2c_client *cl, int reg, int data, int len )
 123 {
 124         u8 tmp[3];
 125
 126         if( len < 1 || len > 2 || data < 0 )
 127                 return -EINVAL;
 128
 129         tmp[0] = reg;
 130         tmp[1] = (len == 1) ? data : (data >> 8);
 131         tmp[2] = data;
 132         len++;
 133
 134         if( i2c_master_send(cl, tmp, len) != len )
 135                 return -ENODEV;
 136         return 0;
 137 }
 138
 139 static int
 140 read_reg( struct i2c_client *cl, int reg, int len )
 141 {
 142         u8 buf[2];
 143
 144         if( len != 1 && len != 2 )
 145                 return -EINVAL;
 146         buf[0] = reg;
 147         if( i2c_master_send(cl, buf, 1) != 1 )
 148                 return -ENODEV;
 149         if( i2c_master_recv(cl, buf, len) != len )
 150                 return -ENODEV;
 151         return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0];
 152 }
 153
 154 static void
 155 tune_fan( int fan_setting )
 156 {
 157         int val = (fan_setting << 3) | 7;
 158
 159         /* write_reg( x.fan, 0x24, val, 1 ); */
 160         write_reg( x.fan, 0x25, val, 1 );
 161         write_reg( x.fan, 0x20, 0, 1 );
 162         print_temp("CPU-temp: ", x.temp );
 163         if( x.casetemp )
 164                 print_temp(", Case: ", x.casetemp );
 165         printk(",  Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );
 166
 167         x.fan_level = fan_setting;
 168 }
 169
 170 static void
 171 poll_temp( void )
 172 {
 173         int temp, i, level, casetemp;
 174
 175         temp = read_reg( x.thermostat, 0, 2 );
 176
 177         /* this actually occurs when the computer is loaded */
 178         if( temp < 0 )
 179                 return;
 180
 181         casetemp = read_reg(x.fan, 0x0b, 1) << 8;
 182         casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;
 183
 184         if( LOG_TEMP && x.temp != temp ) {
 185                 print_temp("CPU-temp: ", temp );
 186                 print_temp(", Case: ", casetemp );
 187                 printk(",  Fan: %d\n", 11-x.fan_level );
 188         }
 189         x.temp = temp;
 190         x.casetemp = casetemp;
 191
 192         level = -1;
 193         for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )
 194                 ;
 195         if( i < x.downind )
 196                 level = fan_table[i].fan_down_setting;
 197         x.downind = i;
 198
 199         for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )
 200                 ;
 201         if( x.upind < i )
 202                 level = fan_table[i].fan_up_setting;
 203         x.upind = i;
 204
 205         if( level >= 0 )
 206                 tune_fan( level );
 207 }
 208
 209
 210 static void
 211 setup_hardware( void )
 212 {
 213         int val;
 214         int err;
 215
 216         /* save registers (if we unload the module) */
 217         x.r0 = read_reg( x.fan, 0x00, 1 );
 218         x.r1 = read_reg( x.fan, 0x01, 1 );
 219         x.r20 = read_reg( x.fan, 0x20, 1 );
 220         x.r23 = read_reg( x.fan, 0x23, 1 );
 221         x.r25 = read_reg( x.fan, 0x25, 1 );
 222
 223         /* improve measurement resolution (convergence time 1.5s) */
 224         if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) {
 225                 val |= 0x60;
 226                 if( write_reg( x.thermostat, 1, val, 1 ) )
 227                         printk("Failed writing config register\n");
 228         }
 229         /* disable interrupts and TAC input */
 230         write_reg( x.fan, 0x01, 0x01, 1 );
 231         /* enable filter */
 232         write_reg( x.fan, 0x23, 0x91, 1 );
 233         /* remote temp. controls fan */
 234         write_reg( x.fan, 0x00, 0x95, 1 );
 235
 236         /* The thermostat (which besides measureing temperature controls
 237          * has a THERM output which puts the fan on 100%) is usually
 238          * set to kick in at 80 C (chip default). We reduce this a bit
 239          * to be on the safe side (OSX doesn't)...
 240          */
 241         if( x.overheat_temp == (80 << 8) ) {
 242                 x.overheat_temp = 75 << 8;
 243                 x.overheat_hyst = 70 << 8;
 244                 write_reg( x.thermostat, 2, x.overheat_hyst, 2 );
 245                 write_reg( x.thermostat, 3, x.overheat_temp, 2 );
 246
 247                 print_temp("Reducing overheating limit to ", x.overheat_temp );
 248                 print_temp(" (Hyst: ", x.overheat_hyst );
 249                 printk(")\n");
 250         }
 251
 252         /* set an initial fan setting */
 253         x.downind = 0xffff;
 254         x.upind = -1;
 255         /* tune_fan( fan_up_table[x.upind].fan_setting ); */
 256
 257         err = device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 258         err |= device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
 259         if (err)
 260                 printk(KERN_WARNING
 261                         "Failed to create temperature attribute file(s).\n");
 262 }
 263
 264 static void
 265 restore_regs( void )
 266 {
 267         device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 268         device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );
 269
 270         write_reg( x.fan, 0x01, x.r1, 1 );
 271         write_reg( x.fan, 0x20, x.r20, 1 );
 272         write_reg( x.fan, 0x23, x.r23, 1 );
 273         write_reg( x.fan, 0x25, x.r25, 1 );
 274         write_reg( x.fan, 0x00, x.r0, 1 );
 275 }
 276
 277 static int control_loop(void *dummy)
 278 {
 279         mutex_lock(&x.lock);
 280         setup_hardware();
 281         mutex_unlock(&x.lock);
 282
 283         for (;;) {
 284                 msleep_interruptible(8000);
 285                 if (kthread_should_stop())
 286                         break;
 287
 288                 mutex_lock(&x.lock);
 289                 poll_temp();
 290                 mutex_unlock(&x.lock);
 291         }
 292
 293         mutex_lock(&x.lock);
 294         restore_regs();
 295         mutex_unlock(&x.lock);
 296
 297         return 0;
 298 }
 299
 300
 301 /************************************************************************/
 302 /*      i2c probing and setup                                           */
 303 /************************************************************************/
 304
 305 static int
 306 do_attach( struct i2c_adapter *adapter )
 307 {
 308         /* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */
 309         static const unsigned short scan_ds1775[] = {
 310                 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
 311                 I2C_CLIENT_END
 312         };
 313         static const unsigned short scan_adm1030[] = {
 314                 0x2c, 0x2d, 0x2e, 0x2f,
 315                 I2C_CLIENT_END
 316         };
 317
 318         if( strncmp(adapter->name, "uni-n", 5) )
 319                 return 0;
 320
 321         if( !x.running ) {
 322                 struct i2c_board_info info;
 323
 324                 memset(&info, 0, sizeof(struct i2c_board_info));
 325                 strlcpy(info.type, "therm_ds1775", I2C_NAME_SIZE);
 326                 i2c_new_probed_device(adapter, &info, scan_ds1775);
 327
 328                 strlcpy(info.type, "therm_adm1030", I2C_NAME_SIZE);
 329                 i2c_new_probed_device(adapter, &info, scan_adm1030);
 330
 331                 if( x.thermostat && x.fan ) {
 332                         x.running = 1;
 333                         x.poll_task = kthread_run(control_loop, NULL, "g4fand");
 334                 }
 335         }
 336         return 0;
 337 }
 338
 339 static int
 340 do_remove(struct i2c_client *client)
 341 {
 342         if (x.running) {
 343                 x.running = 0;
 344                 kthread_stop(x.poll_task);
 345                 x.poll_task = NULL;
 346         }
 347         if (client == x.thermostat)
 348                 x.thermostat = NULL;
 349         else if (client == x.fan)
 350                 x.fan = NULL;
 351         else
 352                 printk(KERN_ERR "g4fan: bad client\n");
 353
 354         return 0;
 355 }
 356
 357 static int
 358 attach_fan( struct i2c_client *cl )
 359 {
 360         if( x.fan )
 361                 goto out;
 362
 363         /* check that this is an ADM1030 */
 364         if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 )
 365                 goto out;
 366         printk("ADM1030 fan controller [@%02x]\n", cl->addr );
 367
 368         x.fan = cl;
 369  out:
 370         return 0;
 371 }
 372
 373 static int
 374 attach_thermostat( struct i2c_client *cl )
 375 {
 376         int hyst_temp, os_temp, temp;
 377
 378         if( x.thermostat )
 379                 goto out;
 380
 381         if( (temp=read_reg(cl, 0, 2)) < 0 )
 382                 goto out;
 383
 384         /* temperature sanity check */
 385         if( temp < 0x1600 || temp > 0x3c00 )
 386                 goto out;
 387         hyst_temp = read_reg(cl, 2, 2);
 388         os_temp = read_reg(cl, 3, 2);
 389         if( hyst_temp < 0 || os_temp < 0 )
 390                 goto out;
 391
 392         printk("DS1775 digital thermometer [@%02x]\n", cl->addr );
 393         print_temp("Temp: ", temp );
 394         print_temp("  Hyst: ", hyst_temp );
 395         print_temp("  OS: ", os_temp );
 396         printk("\n");
 397
 398         x.temp = temp;
 399         x.overheat_temp = os_temp;
 400         x.overheat_hyst = hyst_temp;
 401         x.thermostat = cl;
 402 out:
 403         return 0;
 404 }
 405
 406 enum chip { ds1775, adm1030 };
 407
 408 static const struct i2c_device_id therm_windtunnel_id[] = {
 409         { "therm_ds1775", ds1775 },
 410         { "therm_adm1030", adm1030 },
 411         { }
 412 };
 413
 414 static int
 415 do_probe(struct i2c_client *cl, const struct i2c_device_id *id)
 416 {
 417         struct i2c_adapter *adapter = cl->adapter;
 418
 419         if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
 420                                      | I2C_FUNC_SMBUS_WRITE_BYTE) )
 421                 return 0;
 422
 423         switch (id->driver_data) {
 424         case adm1030:
 425                 return attach_fan( cl );
 426         case ds1775:
 427                 return attach_thermostat(cl);
 428         }
 429         return 0;
 430 }
 431
 432 static struct i2c_driver g4fan_driver = {
 433         .driver = {
 434                 .name   = "therm_windtunnel",
 435         },
 436         .attach_adapter = do_attach,
 437         .probe          = do_probe,
 438         .remove         = do_remove,
 439         .id_table       = therm_windtunnel_id,
 440 };
 441
 442
 443 /************************************************************************/
 444 /*      initialization / cleanup                                        */
 445 /************************************************************************/
 446
 447 static int
 448 therm_of_probe( struct of_device *dev, const struct of_device_id *match )
 449 {
 450         return i2c_add_driver( &g4fan_driver );
 451 }
 452
 453 static int
 454 therm_of_remove( struct of_device *dev )
 455 {
 456         i2c_del_driver( &g4fan_driver );
 457         return 0;
 458 }
 459
 460 static struct of_device_id therm_of_match[] = {{
 461         .name           = "fan",
 462         .compatible     = "adm1030"
 463     }, {}
 464 };
 465
 466 static struct of_platform_driver therm_of_driver = {
 467         .name           = "temperature",
 468         .match_table    = therm_of_match,
 469         .probe          = therm_of_probe,
 470         .remove         = therm_of_remove,
 471 };
 472
 473 struct apple_thermal_info {
 474         u8              id;                     /* implementation ID */
 475         u8              fan_count;              /* number of fans */
 476         u8              thermostat_count;       /* number of thermostats */
 477         u8              unused;
 478 };
 479
 480 static int __init
 481 g4fan_init( void )
 482 {
 483         const struct apple_thermal_info *info;
 484         struct device_node *np;
 485
 486         mutex_init(&x.lock);
 487
 488         if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
 489                 return -ENODEV;
 490         info = of_get_property(np, "thermal-info", NULL);
 491         of_node_put(np);
 492
 493         if( !info || !machine_is_compatible("PowerMac3,6") )
 494                 return -ENODEV;
 495
 496         if( info->id != 3 ) {
 497                 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );
 498                 return -ENODEV;
 499         }
 500         if( !(np=of_find_node_by_name(NULL, "fan")) )
 501                 return -ENODEV;
 502         x.of_dev = of_platform_device_create(np, "temperature", NULL);
 503         of_node_put( np );
 504
 505         if( !x.of_dev ) {
 506                 printk(KERN_ERR "Can't register fan controller!\n");
 507                 return -ENODEV;
 508         }
 509
 510         of_register_platform_driver( &therm_of_driver );
 511         return 0;
 512 }
 513
 514 static void __exit
 515 g4fan_exit( void )
 516 {
 517         of_unregister_platform_driver( &therm_of_driver );
 518
 519         if( x.of_dev )
 520                 of_device_unregister( x.of_dev );
 521 }
 522
 523 module_init(g4fan_init);
 524 module_exit(g4fan_exit);
 525
 526 MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
 527 MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
 528 MODULE_LICENSE("GPL");