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 * temperature 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/init.h> 38 #include <linux/kthread.h> 39 #include <linux/of_platform.h> 40 41 #include <asm/machdep.h> 42 #include <asm/io.h> 43 #include <asm/sections.h> 44 #include <asm/macio.h> 45 46 #define LOG_TEMP 0 /* continuously log temperature */ 47 48 static struct { 49 volatile int running; 50 struct task_struct *poll_task; 51 52 struct mutex lock; 53 struct platform_device *of_dev; 54 55 struct i2c_client *thermostat; 56 struct i2c_client *fan; 57 58 int overheat_temp; /* 100% fan at this temp */ 59 int overheat_hyst; 60 int temp; 61 int casetemp; 62 int fan_level; /* active fan_table setting */ 63 64 int downind; 65 int upind; 66 67 int r0, r1, r20, r23, r25; /* saved register */ 68 } x; 69 70 #define T(x,y) (((x)<<8) | (y)*0x100/10 ) 71 72 static struct { 73 int fan_down_setting; 74 int temp; 75 int fan_up_setting; 76 } fan_table[] = { 77 { 11, T(0,0), 11 }, /* min fan */ 78 { 11, T(55,0), 11 }, 79 { 6, T(55,3), 11 }, 80 { 7, T(56,0), 11 }, 81 { 8, T(57,0), 8 }, 82 { 7, T(58,3), 7 }, 83 { 6, T(58,8), 6 }, 84 { 5, T(59,2), 5 }, 85 { 4, T(59,6), 4 }, 86 { 3, T(59,9), 3 }, 87 { 2, T(60,1), 2 }, 88 { 1, 0xfffff, 1 } /* on fire */ 89 }; 90 91 static void 92 print_temp( const char *s, int temp ) 93 { 94 printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 ); 95 } 96 97 static ssize_t 98 show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf ) 99 { 100 return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 ); 101 } 102 103 static ssize_t 104 show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf ) 105 { 106 return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 ); 107 } 108 109 static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL ); 110 static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL ); 111 112 113 114 /************************************************************************/ 115 /* controller thread */ 116 /************************************************************************/ 117 118 static int 119 write_reg( struct i2c_client *cl, int reg, int data, int len ) 120 { 121 u8 tmp[3]; 122 123 if( len < 1 || len > 2 || data < 0 ) 124 return -EINVAL; 125 126 tmp[0] = reg; 127 tmp[1] = (len == 1) ? data : (data >> 8); 128 tmp[2] = data; 129 len++; 130 131 if( i2c_master_send(cl, tmp, len) != len ) 132 return -ENODEV; 133 return 0; 134 } 135 136 static int 137 read_reg( struct i2c_client *cl, int reg, int len ) 138 { 139 u8 buf[2]; 140 141 if( len != 1 && len != 2 ) 142 return -EINVAL; 143 buf[0] = reg; 144 if( i2c_master_send(cl, buf, 1) != 1 ) 145 return -ENODEV; 146 if( i2c_master_recv(cl, buf, len) != len ) 147 return -ENODEV; 148 return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0]; 149 } 150 151 static void 152 tune_fan( int fan_setting ) 153 { 154 int val = (fan_setting << 3) | 7; 155 156 /* write_reg( x.fan, 0x24, val, 1 ); */ 157 write_reg( x.fan, 0x25, val, 1 ); 158 write_reg( x.fan, 0x20, 0, 1 ); 159 print_temp("CPU-temp: ", x.temp ); 160 if( x.casetemp ) 161 print_temp(", Case: ", x.casetemp ); 162 printk(", Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting ); 163 164 x.fan_level = fan_setting; 165 } 166 167 static void 168 poll_temp( void ) 169 { 170 int temp, i, level, casetemp; 171 172 temp = read_reg( x.thermostat, 0, 2 ); 173 174 /* this actually occurs when the computer is loaded */ 175 if( temp < 0 ) 176 return; 177 178 casetemp = read_reg(x.fan, 0x0b, 1) << 8; 179 casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5; 180 181 if( LOG_TEMP && x.temp != temp ) { 182 print_temp("CPU-temp: ", temp ); 183 print_temp(", Case: ", casetemp ); 184 printk(", Fan: %d\n", 11-x.fan_level ); 185 } 186 x.temp = temp; 187 x.casetemp = casetemp; 188 189 level = -1; 190 for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ ) 191 ; 192 if( i < x.downind ) 193 level = fan_table[i].fan_down_setting; 194 x.downind = i; 195 196 for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ ) 197 ; 198 if( x.upind < i ) 199 level = fan_table[i].fan_up_setting; 200 x.upind = i; 201 202 if( level >= 0 ) 203 tune_fan( level ); 204 } 205 206 207 static void 208 setup_hardware( void ) 209 { 210 int val; 211 int err; 212 213 /* save registers (if we unload the module) */ 214 x.r0 = read_reg( x.fan, 0x00, 1 ); 215 x.r1 = read_reg( x.fan, 0x01, 1 ); 216 x.r20 = read_reg( x.fan, 0x20, 1 ); 217 x.r23 = read_reg( x.fan, 0x23, 1 ); 218 x.r25 = read_reg( x.fan, 0x25, 1 ); 219 220 /* improve measurement resolution (convergence time 1.5s) */ 221 if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) { 222 val |= 0x60; 223 if( write_reg( x.thermostat, 1, val, 1 ) ) 224 printk("Failed writing config register\n"); 225 } 226 /* disable interrupts and TAC input */ 227 write_reg( x.fan, 0x01, 0x01, 1 ); 228 /* enable filter */ 229 write_reg( x.fan, 0x23, 0x91, 1 ); 230 /* remote temp. controls fan */ 231 write_reg( x.fan, 0x00, 0x95, 1 ); 232 233 /* The thermostat (which besides measureing temperature controls 234 * has a THERM output which puts the fan on 100%) is usually 235 * set to kick in at 80 C (chip default). We reduce this a bit 236 * to be on the safe side (OSX doesn't)... 237 */ 238 if( x.overheat_temp == (80 << 8) ) { 239 x.overheat_temp = 75 << 8; 240 x.overheat_hyst = 70 << 8; 241 write_reg( x.thermostat, 2, x.overheat_hyst, 2 ); 242 write_reg( x.thermostat, 3, x.overheat_temp, 2 ); 243 244 print_temp("Reducing overheating limit to ", x.overheat_temp ); 245 print_temp(" (Hyst: ", x.overheat_hyst ); 246 printk(")\n"); 247 } 248 249 /* set an initial fan setting */ 250 x.downind = 0xffff; 251 x.upind = -1; 252 /* tune_fan( fan_up_table[x.upind].fan_setting ); */ 253 254 err = device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature ); 255 err |= device_create_file( &x.of_dev->dev, &dev_attr_case_temperature ); 256 if (err) 257 printk(KERN_WARNING 258 "Failed to create temperature attribute file(s).\n"); 259 } 260 261 static void 262 restore_regs( void ) 263 { 264 device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature ); 265 device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature ); 266 267 write_reg( x.fan, 0x01, x.r1, 1 ); 268 write_reg( x.fan, 0x20, x.r20, 1 ); 269 write_reg( x.fan, 0x23, x.r23, 1 ); 270 write_reg( x.fan, 0x25, x.r25, 1 ); 271 write_reg( x.fan, 0x00, x.r0, 1 ); 272 } 273 274 static int control_loop(void *dummy) 275 { 276 mutex_lock(&x.lock); 277 setup_hardware(); 278 mutex_unlock(&x.lock); 279 280 for (;;) { 281 msleep_interruptible(8000); 282 if (kthread_should_stop()) 283 break; 284 285 mutex_lock(&x.lock); 286 poll_temp(); 287 mutex_unlock(&x.lock); 288 } 289 290 mutex_lock(&x.lock); 291 restore_regs(); 292 mutex_unlock(&x.lock); 293 294 return 0; 295 } 296 297 298 /************************************************************************/ 299 /* i2c probing and setup */ 300 /************************************************************************/ 301 302 static void do_attach(struct i2c_adapter *adapter) 303 { 304 struct i2c_board_info info = { }; 305 struct device_node *np; 306 307 /* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */ 308 static const unsigned short scan_ds1775[] = { 309 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 310 I2C_CLIENT_END 311 }; 312 static const unsigned short scan_adm1030[] = { 313 0x2c, 0x2d, 0x2e, 0x2f, 314 I2C_CLIENT_END 315 }; 316 317 if (x.running || strncmp(adapter->name, "uni-n", 5)) 318 return; 319 320 np = of_find_compatible_node(adapter->dev.of_node, NULL, "MAC,ds1775"); 321 if (np) { 322 of_node_put(np); 323 } else { 324 strscpy(info.type, "MAC,ds1775", I2C_NAME_SIZE); 325 i2c_new_scanned_device(adapter, &info, scan_ds1775, NULL); 326 } 327 328 np = of_find_compatible_node(adapter->dev.of_node, NULL, "MAC,adm1030"); 329 if (np) { 330 of_node_put(np); 331 } else { 332 strscpy(info.type, "MAC,adm1030", I2C_NAME_SIZE); 333 i2c_new_scanned_device(adapter, &info, scan_adm1030, NULL); 334 } 335 } 336 337 static int 338 do_remove(struct i2c_client *client) 339 { 340 if (x.running) { 341 x.running = 0; 342 kthread_stop(x.poll_task); 343 x.poll_task = NULL; 344 } 345 if (client == x.thermostat) 346 x.thermostat = NULL; 347 else if (client == x.fan) 348 x.fan = NULL; 349 else 350 printk(KERN_ERR "g4fan: bad client\n"); 351 352 return 0; 353 } 354 355 static int 356 attach_fan( struct i2c_client *cl ) 357 { 358 if( x.fan ) 359 goto out; 360 361 /* check that this is an ADM1030 */ 362 if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 ) 363 goto out; 364 printk("ADM1030 fan controller [@%02x]\n", cl->addr ); 365 366 x.fan = cl; 367 out: 368 return 0; 369 } 370 371 static int 372 attach_thermostat( struct i2c_client *cl ) 373 { 374 int hyst_temp, os_temp, temp; 375 376 if( x.thermostat ) 377 goto out; 378 379 if( (temp=read_reg(cl, 0, 2)) < 0 ) 380 goto out; 381 382 /* temperature sanity check */ 383 if( temp < 0x1600 || temp > 0x3c00 ) 384 goto out; 385 hyst_temp = read_reg(cl, 2, 2); 386 os_temp = read_reg(cl, 3, 2); 387 if( hyst_temp < 0 || os_temp < 0 ) 388 goto out; 389 390 printk("DS1775 digital thermometer [@%02x]\n", cl->addr ); 391 print_temp("Temp: ", temp ); 392 print_temp(" Hyst: ", hyst_temp ); 393 print_temp(" OS: ", os_temp ); 394 printk("\n"); 395 396 x.temp = temp; 397 x.overheat_temp = os_temp; 398 x.overheat_hyst = hyst_temp; 399 x.thermostat = cl; 400 out: 401 return 0; 402 } 403 404 enum chip { ds1775, adm1030 }; 405 406 static const struct i2c_device_id therm_windtunnel_id[] = { 407 { "MAC,ds1775", ds1775 }, 408 { "MAC,adm1030", adm1030 }, 409 { } 410 }; 411 MODULE_DEVICE_TABLE(i2c, therm_windtunnel_id); 412 413 static int 414 do_probe(struct i2c_client *cl, const struct i2c_device_id *id) 415 { 416 struct i2c_adapter *adapter = cl->adapter; 417 int ret = 0; 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 ret = attach_fan(cl); 426 break; 427 case ds1775: 428 ret = attach_thermostat(cl); 429 break; 430 } 431 432 if (!x.running && x.thermostat && x.fan) { 433 x.running = 1; 434 x.poll_task = kthread_run(control_loop, NULL, "g4fand"); 435 } 436 437 return ret; 438 } 439 440 static struct i2c_driver g4fan_driver = { 441 .driver = { 442 .name = "therm_windtunnel", 443 }, 444 .probe = do_probe, 445 .remove = do_remove, 446 .id_table = therm_windtunnel_id, 447 }; 448 449 450 /************************************************************************/ 451 /* initialization / cleanup */ 452 /************************************************************************/ 453 454 static int therm_of_probe(struct platform_device *dev) 455 { 456 struct i2c_adapter *adap; 457 int ret, i = 0; 458 459 adap = i2c_get_adapter(0); 460 if (!adap) 461 return -EPROBE_DEFER; 462 463 ret = i2c_add_driver(&g4fan_driver); 464 if (ret) { 465 i2c_put_adapter(adap); 466 return ret; 467 } 468 469 /* We assume Macs have consecutive I2C bus numbers starting at 0 */ 470 while (adap) { 471 do_attach(adap); 472 if (x.running) 473 return 0; 474 i2c_put_adapter(adap); 475 adap = i2c_get_adapter(++i); 476 } 477 478 return -ENODEV; 479 } 480 481 static int 482 therm_of_remove( struct platform_device *dev ) 483 { 484 i2c_del_driver( &g4fan_driver ); 485 return 0; 486 } 487 488 static const struct of_device_id therm_of_match[] = {{ 489 .name = "fan", 490 .compatible = "adm1030" 491 }, {} 492 }; 493 MODULE_DEVICE_TABLE(of, therm_of_match); 494 495 static struct platform_driver therm_of_driver = { 496 .driver = { 497 .name = "temperature", 498 .of_match_table = therm_of_match, 499 }, 500 .probe = therm_of_probe, 501 .remove = therm_of_remove, 502 }; 503 504 struct apple_thermal_info { 505 u8 id; /* implementation ID */ 506 u8 fan_count; /* number of fans */ 507 u8 thermostat_count; /* number of thermostats */ 508 u8 unused; 509 }; 510 511 static int __init 512 g4fan_init( void ) 513 { 514 const struct apple_thermal_info *info; 515 struct device_node *np; 516 517 mutex_init(&x.lock); 518 519 if( !(np=of_find_node_by_name(NULL, "power-mgt")) ) 520 return -ENODEV; 521 info = of_get_property(np, "thermal-info", NULL); 522 of_node_put(np); 523 524 if( !info || !of_machine_is_compatible("PowerMac3,6") ) 525 return -ENODEV; 526 527 if( info->id != 3 ) { 528 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id ); 529 return -ENODEV; 530 } 531 if( !(np=of_find_node_by_name(NULL, "fan")) ) 532 return -ENODEV; 533 x.of_dev = of_platform_device_create(np, "temperature", NULL); 534 of_node_put( np ); 535 536 if( !x.of_dev ) { 537 printk(KERN_ERR "Can't register fan controller!\n"); 538 return -ENODEV; 539 } 540 541 platform_driver_register( &therm_of_driver ); 542 return 0; 543 } 544 545 static void __exit 546 g4fan_exit( void ) 547 { 548 platform_driver_unregister( &therm_of_driver ); 549 550 if( x.of_dev ) 551 of_device_unregister( x.of_dev ); 552 } 553 554 module_init(g4fan_init); 555 module_exit(g4fan_exit); 556 557 MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>"); 558 MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller"); 559 MODULE_LICENSE("GPL"); 560