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.h> 40 #include <linux/of_platform.h> 41 #include <linux/platform_device.h> 42 43 #include <asm/machdep.h> 44 #include <asm/io.h> 45 #include <asm/sections.h> 46 #include <asm/macio.h> 47 48 #define LOG_TEMP 0 /* continuously log temperature */ 49 50 static struct { 51 volatile int running; 52 struct task_struct *poll_task; 53 54 struct mutex lock; 55 struct platform_device *of_dev; 56 57 struct i2c_client *thermostat; 58 struct i2c_client *fan; 59 60 int overheat_temp; /* 100% fan at this temp */ 61 int overheat_hyst; 62 int temp; 63 int casetemp; 64 int fan_level; /* active fan_table setting */ 65 66 int downind; 67 int upind; 68 69 int r0, r1, r20, r23, r25; /* saved register */ 70 } x; 71 72 #define T(x,y) (((x)<<8) | (y)*0x100/10 ) 73 74 static struct { 75 int fan_down_setting; 76 int temp; 77 int fan_up_setting; 78 } fan_table[] = { 79 { 11, T(0,0), 11 }, /* min fan */ 80 { 11, T(55,0), 11 }, 81 { 6, T(55,3), 11 }, 82 { 7, T(56,0), 11 }, 83 { 8, T(57,0), 8 }, 84 { 7, T(58,3), 7 }, 85 { 6, T(58,8), 6 }, 86 { 5, T(59,2), 5 }, 87 { 4, T(59,6), 4 }, 88 { 3, T(59,9), 3 }, 89 { 2, T(60,1), 2 }, 90 { 1, 0xfffff, 1 } /* on fire */ 91 }; 92 93 static void 94 print_temp( const char *s, int temp ) 95 { 96 printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 ); 97 } 98 99 static ssize_t 100 show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf ) 101 { 102 return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 ); 103 } 104 105 static ssize_t 106 show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf ) 107 { 108 return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 ); 109 } 110 111 static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL ); 112 static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL ); 113 114 115 116 /************************************************************************/ 117 /* controller thread */ 118 /************************************************************************/ 119 120 static int 121 write_reg( struct i2c_client *cl, int reg, int data, int len ) 122 { 123 u8 tmp[3]; 124 125 if( len < 1 || len > 2 || data < 0 ) 126 return -EINVAL; 127 128 tmp[0] = reg; 129 tmp[1] = (len == 1) ? data : (data >> 8); 130 tmp[2] = data; 131 len++; 132 133 if( i2c_master_send(cl, tmp, len) != len ) 134 return -ENODEV; 135 return 0; 136 } 137 138 static int 139 read_reg( struct i2c_client *cl, int reg, int len ) 140 { 141 u8 buf[2]; 142 143 if( len != 1 && len != 2 ) 144 return -EINVAL; 145 buf[0] = reg; 146 if( i2c_master_send(cl, buf, 1) != 1 ) 147 return -ENODEV; 148 if( i2c_master_recv(cl, buf, len) != len ) 149 return -ENODEV; 150 return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0]; 151 } 152 153 static void 154 tune_fan( int fan_setting ) 155 { 156 int val = (fan_setting << 3) | 7; 157 158 /* write_reg( x.fan, 0x24, val, 1 ); */ 159 write_reg( x.fan, 0x25, val, 1 ); 160 write_reg( x.fan, 0x20, 0, 1 ); 161 print_temp("CPU-temp: ", x.temp ); 162 if( x.casetemp ) 163 print_temp(", Case: ", x.casetemp ); 164 printk(", Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting ); 165 166 x.fan_level = fan_setting; 167 } 168 169 static void 170 poll_temp( void ) 171 { 172 int temp, i, level, casetemp; 173 174 temp = read_reg( x.thermostat, 0, 2 ); 175 176 /* this actually occurs when the computer is loaded */ 177 if( temp < 0 ) 178 return; 179 180 casetemp = read_reg(x.fan, 0x0b, 1) << 8; 181 casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5; 182 183 if( LOG_TEMP && x.temp != temp ) { 184 print_temp("CPU-temp: ", temp ); 185 print_temp(", Case: ", casetemp ); 186 printk(", Fan: %d\n", 11-x.fan_level ); 187 } 188 x.temp = temp; 189 x.casetemp = casetemp; 190 191 level = -1; 192 for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ ) 193 ; 194 if( i < x.downind ) 195 level = fan_table[i].fan_down_setting; 196 x.downind = i; 197 198 for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ ) 199 ; 200 if( x.upind < i ) 201 level = fan_table[i].fan_up_setting; 202 x.upind = i; 203 204 if( level >= 0 ) 205 tune_fan( level ); 206 } 207 208 209 static void 210 setup_hardware( void ) 211 { 212 int val; 213 int err; 214 215 /* save registers (if we unload the module) */ 216 x.r0 = read_reg( x.fan, 0x00, 1 ); 217 x.r1 = read_reg( x.fan, 0x01, 1 ); 218 x.r20 = read_reg( x.fan, 0x20, 1 ); 219 x.r23 = read_reg( x.fan, 0x23, 1 ); 220 x.r25 = read_reg( x.fan, 0x25, 1 ); 221 222 /* improve measurement resolution (convergence time 1.5s) */ 223 if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) { 224 val |= 0x60; 225 if( write_reg( x.thermostat, 1, val, 1 ) ) 226 printk("Failed writing config register\n"); 227 } 228 /* disable interrupts and TAC input */ 229 write_reg( x.fan, 0x01, 0x01, 1 ); 230 /* enable filter */ 231 write_reg( x.fan, 0x23, 0x91, 1 ); 232 /* remote temp. controls fan */ 233 write_reg( x.fan, 0x00, 0x95, 1 ); 234 235 /* The thermostat (which besides measureing temperature controls 236 * has a THERM output which puts the fan on 100%) is usually 237 * set to kick in at 80 C (chip default). We reduce this a bit 238 * to be on the safe side (OSX doesn't)... 239 */ 240 if( x.overheat_temp == (80 << 8) ) { 241 x.overheat_temp = 75 << 8; 242 x.overheat_hyst = 70 << 8; 243 write_reg( x.thermostat, 2, x.overheat_hyst, 2 ); 244 write_reg( x.thermostat, 3, x.overheat_temp, 2 ); 245 246 print_temp("Reducing overheating limit to ", x.overheat_temp ); 247 print_temp(" (Hyst: ", x.overheat_hyst ); 248 printk(")\n"); 249 } 250 251 /* set an initial fan setting */ 252 x.downind = 0xffff; 253 x.upind = -1; 254 /* tune_fan( fan_up_table[x.upind].fan_setting ); */ 255 256 err = device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature ); 257 err |= device_create_file( &x.of_dev->dev, &dev_attr_case_temperature ); 258 if (err) 259 printk(KERN_WARNING 260 "Failed to create temperature attribute file(s).\n"); 261 } 262 263 static void 264 restore_regs( void ) 265 { 266 device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature ); 267 device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature ); 268 269 write_reg( x.fan, 0x01, x.r1, 1 ); 270 write_reg( x.fan, 0x20, x.r20, 1 ); 271 write_reg( x.fan, 0x23, x.r23, 1 ); 272 write_reg( x.fan, 0x25, x.r25, 1 ); 273 write_reg( x.fan, 0x00, x.r0, 1 ); 274 } 275 276 static int control_loop(void *dummy) 277 { 278 mutex_lock(&x.lock); 279 setup_hardware(); 280 mutex_unlock(&x.lock); 281 282 for (;;) { 283 msleep_interruptible(8000); 284 if (kthread_should_stop()) 285 break; 286 287 mutex_lock(&x.lock); 288 poll_temp(); 289 mutex_unlock(&x.lock); 290 } 291 292 mutex_lock(&x.lock); 293 restore_regs(); 294 mutex_unlock(&x.lock); 295 296 return 0; 297 } 298 299 300 /************************************************************************/ 301 /* i2c probing and setup */ 302 /************************************************************************/ 303 304 static void do_attach(struct i2c_adapter *adapter) 305 { 306 struct i2c_board_info info = { }; 307 struct device_node *np; 308 309 /* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */ 310 static const unsigned short scan_ds1775[] = { 311 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 312 I2C_CLIENT_END 313 }; 314 static const unsigned short scan_adm1030[] = { 315 0x2c, 0x2d, 0x2e, 0x2f, 316 I2C_CLIENT_END 317 }; 318 319 if (x.running || strncmp(adapter->name, "uni-n", 5)) 320 return; 321 322 of_node_get(adapter->dev.of_node); 323 np = of_find_compatible_node(adapter->dev.of_node, NULL, "MAC,ds1775"); 324 if (np) { 325 of_node_put(np); 326 } else { 327 strscpy(info.type, "MAC,ds1775", I2C_NAME_SIZE); 328 i2c_new_scanned_device(adapter, &info, scan_ds1775, NULL); 329 } 330 331 of_node_get(adapter->dev.of_node); 332 np = of_find_compatible_node(adapter->dev.of_node, NULL, "MAC,adm1030"); 333 if (np) { 334 of_node_put(np); 335 } else { 336 strscpy(info.type, "MAC,adm1030", I2C_NAME_SIZE); 337 i2c_new_scanned_device(adapter, &info, scan_adm1030, NULL); 338 } 339 } 340 341 static void 342 do_remove(struct i2c_client *client) 343 { 344 if (x.running) { 345 x.running = 0; 346 kthread_stop(x.poll_task); 347 x.poll_task = NULL; 348 } 349 if (client == x.thermostat) 350 x.thermostat = NULL; 351 else if (client == x.fan) 352 x.fan = NULL; 353 else 354 printk(KERN_ERR "g4fan: bad client\n"); 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 { "MAC,ds1775", ds1775 }, 410 { "MAC,adm1030", adm1030 }, 411 { } 412 }; 413 MODULE_DEVICE_TABLE(i2c, therm_windtunnel_id); 414 415 static int 416 do_probe(struct i2c_client *cl) 417 { 418 const struct i2c_device_id *id = i2c_client_get_device_id(cl); 419 struct i2c_adapter *adapter = cl->adapter; 420 int ret = 0; 421 422 if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA 423 | I2C_FUNC_SMBUS_WRITE_BYTE) ) 424 return 0; 425 426 switch (id->driver_data) { 427 case adm1030: 428 ret = attach_fan(cl); 429 break; 430 case ds1775: 431 ret = attach_thermostat(cl); 432 break; 433 } 434 435 if (!x.running && x.thermostat && x.fan) { 436 x.running = 1; 437 x.poll_task = kthread_run(control_loop, NULL, "g4fand"); 438 } 439 440 return ret; 441 } 442 443 static struct i2c_driver g4fan_driver = { 444 .driver = { 445 .name = "therm_windtunnel", 446 }, 447 .probe = do_probe, 448 .remove = do_remove, 449 .id_table = therm_windtunnel_id, 450 }; 451 452 453 /************************************************************************/ 454 /* initialization / cleanup */ 455 /************************************************************************/ 456 457 static int therm_of_probe(struct platform_device *dev) 458 { 459 struct i2c_adapter *adap; 460 int ret, i = 0; 461 462 adap = i2c_get_adapter(0); 463 if (!adap) 464 return -EPROBE_DEFER; 465 466 ret = i2c_add_driver(&g4fan_driver); 467 if (ret) { 468 i2c_put_adapter(adap); 469 return ret; 470 } 471 472 /* We assume Macs have consecutive I2C bus numbers starting at 0 */ 473 while (adap) { 474 do_attach(adap); 475 if (x.running) 476 return 0; 477 i2c_put_adapter(adap); 478 adap = i2c_get_adapter(++i); 479 } 480 481 return -ENODEV; 482 } 483 484 static int 485 therm_of_remove( struct platform_device *dev ) 486 { 487 i2c_del_driver( &g4fan_driver ); 488 return 0; 489 } 490 491 static const struct of_device_id therm_of_match[] = {{ 492 .name = "fan", 493 .compatible = "adm1030" 494 }, {} 495 }; 496 MODULE_DEVICE_TABLE(of, therm_of_match); 497 498 static struct platform_driver therm_of_driver = { 499 .driver = { 500 .name = "temperature", 501 .of_match_table = therm_of_match, 502 }, 503 .probe = therm_of_probe, 504 .remove = therm_of_remove, 505 }; 506 507 struct apple_thermal_info { 508 u8 id; /* implementation ID */ 509 u8 fan_count; /* number of fans */ 510 u8 thermostat_count; /* number of thermostats */ 511 u8 unused; 512 }; 513 514 static int __init 515 g4fan_init( void ) 516 { 517 const struct apple_thermal_info *info; 518 struct device_node *np; 519 520 mutex_init(&x.lock); 521 522 if( !(np=of_find_node_by_name(NULL, "power-mgt")) ) 523 return -ENODEV; 524 info = of_get_property(np, "thermal-info", NULL); 525 of_node_put(np); 526 527 if( !info || !of_machine_is_compatible("PowerMac3,6") ) 528 return -ENODEV; 529 530 if( info->id != 3 ) { 531 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id ); 532 return -ENODEV; 533 } 534 if( !(np=of_find_node_by_name(NULL, "fan")) ) 535 return -ENODEV; 536 x.of_dev = of_platform_device_create(np, "temperature", NULL); 537 of_node_put( np ); 538 539 if( !x.of_dev ) { 540 printk(KERN_ERR "Can't register fan controller!\n"); 541 return -ENODEV; 542 } 543 544 platform_driver_register( &therm_of_driver ); 545 return 0; 546 } 547 548 static void __exit 549 g4fan_exit( void ) 550 { 551 platform_driver_unregister( &therm_of_driver ); 552 553 if( x.of_dev ) 554 of_device_unregister( x.of_dev ); 555 } 556 557 module_init(g4fan_init); 558 module_exit(g4fan_exit); 559 560 MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>"); 561 MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller"); 562 MODULE_LICENSE("GPL"); 563