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/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 const 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 || !of_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"); 529