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/prom.h> 42 #include <asm/machdep.h> 43 #include <asm/io.h> 44 #include <asm/sections.h> 45 #include <asm/macio.h> 46 47 #define LOG_TEMP 0 /* continuously log temperature */ 48 49 static struct { 50 volatile int running; 51 struct task_struct *poll_task; 52 53 struct mutex lock; 54 struct platform_device *of_dev; 55 56 struct i2c_client *thermostat; 57 struct i2c_client *fan; 58 59 int overheat_temp; /* 100% fan at this temp */ 60 int overheat_hyst; 61 int temp; 62 int casetemp; 63 int fan_level; /* active fan_table setting */ 64 65 int downind; 66 int upind; 67 68 int r0, r1, r20, r23, r25; /* saved register */ 69 } x; 70 71 #define T(x,y) (((x)<<8) | (y)*0x100/10 ) 72 73 static struct { 74 int fan_down_setting; 75 int temp; 76 int fan_up_setting; 77 } fan_table[] = { 78 { 11, T(0,0), 11 }, /* min fan */ 79 { 11, T(55,0), 11 }, 80 { 6, T(55,3), 11 }, 81 { 7, T(56,0), 11 }, 82 { 8, T(57,0), 8 }, 83 { 7, T(58,3), 7 }, 84 { 6, T(58,8), 6 }, 85 { 5, T(59,2), 5 }, 86 { 4, T(59,6), 4 }, 87 { 3, T(59,9), 3 }, 88 { 2, T(60,1), 2 }, 89 { 1, 0xfffff, 1 } /* on fire */ 90 }; 91 92 static void 93 print_temp( const char *s, int temp ) 94 { 95 printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 ); 96 } 97 98 static ssize_t 99 show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf ) 100 { 101 return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 ); 102 } 103 104 static ssize_t 105 show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf ) 106 { 107 return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 ); 108 } 109 110 static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL ); 111 static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL ); 112 113 114 115 /************************************************************************/ 116 /* controller thread */ 117 /************************************************************************/ 118 119 static int 120 write_reg( struct i2c_client *cl, int reg, int data, int len ) 121 { 122 u8 tmp[3]; 123 124 if( len < 1 || len > 2 || data < 0 ) 125 return -EINVAL; 126 127 tmp[0] = reg; 128 tmp[1] = (len == 1) ? data : (data >> 8); 129 tmp[2] = data; 130 len++; 131 132 if( i2c_master_send(cl, tmp, len) != len ) 133 return -ENODEV; 134 return 0; 135 } 136 137 static int 138 read_reg( struct i2c_client *cl, int reg, int len ) 139 { 140 u8 buf[2]; 141 142 if( len != 1 && len != 2 ) 143 return -EINVAL; 144 buf[0] = reg; 145 if( i2c_master_send(cl, buf, 1) != 1 ) 146 return -ENODEV; 147 if( i2c_master_recv(cl, buf, len) != len ) 148 return -ENODEV; 149 return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0]; 150 } 151 152 static void 153 tune_fan( int fan_setting ) 154 { 155 int val = (fan_setting << 3) | 7; 156 157 /* write_reg( x.fan, 0x24, val, 1 ); */ 158 write_reg( x.fan, 0x25, val, 1 ); 159 write_reg( x.fan, 0x20, 0, 1 ); 160 print_temp("CPU-temp: ", x.temp ); 161 if( x.casetemp ) 162 print_temp(", Case: ", x.casetemp ); 163 printk(", Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting ); 164 165 x.fan_level = fan_setting; 166 } 167 168 static void 169 poll_temp( void ) 170 { 171 int temp, i, level, casetemp; 172 173 temp = read_reg( x.thermostat, 0, 2 ); 174 175 /* this actually occurs when the computer is loaded */ 176 if( temp < 0 ) 177 return; 178 179 casetemp = read_reg(x.fan, 0x0b, 1) << 8; 180 casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5; 181 182 if( LOG_TEMP && x.temp != temp ) { 183 print_temp("CPU-temp: ", temp ); 184 print_temp(", Case: ", casetemp ); 185 printk(", Fan: %d\n", 11-x.fan_level ); 186 } 187 x.temp = temp; 188 x.casetemp = casetemp; 189 190 level = -1; 191 for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ ) 192 ; 193 if( i < x.downind ) 194 level = fan_table[i].fan_down_setting; 195 x.downind = i; 196 197 for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ ) 198 ; 199 if( x.upind < i ) 200 level = fan_table[i].fan_up_setting; 201 x.upind = i; 202 203 if( level >= 0 ) 204 tune_fan( level ); 205 } 206 207 208 static void 209 setup_hardware( void ) 210 { 211 int val; 212 int err; 213 214 /* save registers (if we unload the module) */ 215 x.r0 = read_reg( x.fan, 0x00, 1 ); 216 x.r1 = read_reg( x.fan, 0x01, 1 ); 217 x.r20 = read_reg( x.fan, 0x20, 1 ); 218 x.r23 = read_reg( x.fan, 0x23, 1 ); 219 x.r25 = read_reg( x.fan, 0x25, 1 ); 220 221 /* improve measurement resolution (convergence time 1.5s) */ 222 if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) { 223 val |= 0x60; 224 if( write_reg( x.thermostat, 1, val, 1 ) ) 225 printk("Failed writing config register\n"); 226 } 227 /* disable interrupts and TAC input */ 228 write_reg( x.fan, 0x01, 0x01, 1 ); 229 /* enable filter */ 230 write_reg( x.fan, 0x23, 0x91, 1 ); 231 /* remote temp. controls fan */ 232 write_reg( x.fan, 0x00, 0x95, 1 ); 233 234 /* The thermostat (which besides measureing temperature controls 235 * has a THERM output which puts the fan on 100%) is usually 236 * set to kick in at 80 C (chip default). We reduce this a bit 237 * to be on the safe side (OSX doesn't)... 238 */ 239 if( x.overheat_temp == (80 << 8) ) { 240 x.overheat_temp = 75 << 8; 241 x.overheat_hyst = 70 << 8; 242 write_reg( x.thermostat, 2, x.overheat_hyst, 2 ); 243 write_reg( x.thermostat, 3, x.overheat_temp, 2 ); 244 245 print_temp("Reducing overheating limit to ", x.overheat_temp ); 246 print_temp(" (Hyst: ", x.overheat_hyst ); 247 printk(")\n"); 248 } 249 250 /* set an initial fan setting */ 251 x.downind = 0xffff; 252 x.upind = -1; 253 /* tune_fan( fan_up_table[x.upind].fan_setting ); */ 254 255 err = device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature ); 256 err |= device_create_file( &x.of_dev->dev, &dev_attr_case_temperature ); 257 if (err) 258 printk(KERN_WARNING 259 "Failed to create temperature attribute file(s).\n"); 260 } 261 262 static void 263 restore_regs( void ) 264 { 265 device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature ); 266 device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature ); 267 268 write_reg( x.fan, 0x01, x.r1, 1 ); 269 write_reg( x.fan, 0x20, x.r20, 1 ); 270 write_reg( x.fan, 0x23, x.r23, 1 ); 271 write_reg( x.fan, 0x25, x.r25, 1 ); 272 write_reg( x.fan, 0x00, x.r0, 1 ); 273 } 274 275 static int control_loop(void *dummy) 276 { 277 mutex_lock(&x.lock); 278 setup_hardware(); 279 mutex_unlock(&x.lock); 280 281 for (;;) { 282 msleep_interruptible(8000); 283 if (kthread_should_stop()) 284 break; 285 286 mutex_lock(&x.lock); 287 poll_temp(); 288 mutex_unlock(&x.lock); 289 } 290 291 mutex_lock(&x.lock); 292 restore_regs(); 293 mutex_unlock(&x.lock); 294 295 return 0; 296 } 297 298 299 /************************************************************************/ 300 /* i2c probing and setup */ 301 /************************************************************************/ 302 303 static int 304 do_attach( struct i2c_adapter *adapter ) 305 { 306 /* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */ 307 static const unsigned short scan_ds1775[] = { 308 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 309 I2C_CLIENT_END 310 }; 311 static const unsigned short scan_adm1030[] = { 312 0x2c, 0x2d, 0x2e, 0x2f, 313 I2C_CLIENT_END 314 }; 315 316 if( strncmp(adapter->name, "uni-n", 5) ) 317 return 0; 318 319 if( !x.running ) { 320 struct i2c_board_info info; 321 322 memset(&info, 0, sizeof(struct i2c_board_info)); 323 strlcpy(info.type, "therm_ds1775", I2C_NAME_SIZE); 324 i2c_new_probed_device(adapter, &info, scan_ds1775, NULL); 325 326 strlcpy(info.type, "therm_adm1030", I2C_NAME_SIZE); 327 i2c_new_probed_device(adapter, &info, scan_adm1030, NULL); 328 329 if( x.thermostat && x.fan ) { 330 x.running = 1; 331 x.poll_task = kthread_run(control_loop, NULL, "g4fand"); 332 } 333 } 334 return 0; 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 { "therm_ds1775", ds1775 }, 408 { "therm_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; 417 418 if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA 419 | I2C_FUNC_SMBUS_WRITE_BYTE) ) 420 return 0; 421 422 switch (id->driver_data) { 423 case adm1030: 424 return attach_fan( cl ); 425 case ds1775: 426 return attach_thermostat(cl); 427 } 428 return 0; 429 } 430 431 static struct i2c_driver g4fan_driver = { 432 .driver = { 433 .name = "therm_windtunnel", 434 }, 435 .attach_adapter = do_attach, 436 .probe = do_probe, 437 .remove = do_remove, 438 .id_table = therm_windtunnel_id, 439 }; 440 441 442 /************************************************************************/ 443 /* initialization / cleanup */ 444 /************************************************************************/ 445 446 static int therm_of_probe(struct platform_device *dev) 447 { 448 return i2c_add_driver( &g4fan_driver ); 449 } 450 451 static int 452 therm_of_remove( struct platform_device *dev ) 453 { 454 i2c_del_driver( &g4fan_driver ); 455 return 0; 456 } 457 458 static const struct of_device_id therm_of_match[] = {{ 459 .name = "fan", 460 .compatible = "adm1030" 461 }, {} 462 }; 463 MODULE_DEVICE_TABLE(of, therm_of_match); 464 465 static struct platform_driver therm_of_driver = { 466 .driver = { 467 .name = "temperature", 468 .of_match_table = therm_of_match, 469 }, 470 .probe = therm_of_probe, 471 .remove = therm_of_remove, 472 }; 473 474 struct apple_thermal_info { 475 u8 id; /* implementation ID */ 476 u8 fan_count; /* number of fans */ 477 u8 thermostat_count; /* number of thermostats */ 478 u8 unused; 479 }; 480 481 static int __init 482 g4fan_init( void ) 483 { 484 const struct apple_thermal_info *info; 485 struct device_node *np; 486 487 mutex_init(&x.lock); 488 489 if( !(np=of_find_node_by_name(NULL, "power-mgt")) ) 490 return -ENODEV; 491 info = of_get_property(np, "thermal-info", NULL); 492 of_node_put(np); 493 494 if( !info || !of_machine_is_compatible("PowerMac3,6") ) 495 return -ENODEV; 496 497 if( info->id != 3 ) { 498 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id ); 499 return -ENODEV; 500 } 501 if( !(np=of_find_node_by_name(NULL, "fan")) ) 502 return -ENODEV; 503 x.of_dev = of_platform_device_create(np, "temperature", NULL); 504 of_node_put( np ); 505 506 if( !x.of_dev ) { 507 printk(KERN_ERR "Can't register fan controller!\n"); 508 return -ENODEV; 509 } 510 511 platform_driver_register( &therm_of_driver ); 512 return 0; 513 } 514 515 static void __exit 516 g4fan_exit( void ) 517 { 518 platform_driver_unregister( &therm_of_driver ); 519 520 if( x.of_dev ) 521 of_device_unregister( x.of_dev ); 522 } 523 524 module_init(g4fan_init); 525 module_exit(g4fan_exit); 526 527 MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>"); 528 MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller"); 529 MODULE_LICENSE("GPL"); 530