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 40 #include <asm/prom.h> 41 #include <asm/machdep.h> 42 #include <asm/io.h> 43 #include <asm/system.h> 44 #include <asm/sections.h> 45 #include <asm/of_platform.h> 46 #include <asm/macio.h> 47 48 #define LOG_TEMP 0 /* continously log temperature */ 49 50 #define I2C_DRIVERID_G4FAN 0x9001 /* fixme */ 51 52 static int do_probe( struct i2c_adapter *adapter, int addr, int kind); 53 54 /* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */ 55 static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 56 0x4c, 0x4d, 0x4e, 0x4f, 57 0x2c, 0x2d, 0x2e, 0x2f, 58 I2C_CLIENT_END }; 59 60 I2C_CLIENT_INSMOD; 61 62 static struct { 63 volatile int running; 64 struct completion completion; 65 pid_t poll_task; 66 67 struct semaphore lock; 68 struct of_device *of_dev; 69 70 struct i2c_client *thermostat; 71 struct i2c_client *fan; 72 73 int overheat_temp; /* 100% fan at this temp */ 74 int overheat_hyst; 75 int temp; 76 int casetemp; 77 int fan_level; /* active fan_table setting */ 78 79 int downind; 80 int upind; 81 82 int r0, r1, r20, r23, r25; /* saved register */ 83 } x; 84 85 #define T(x,y) (((x)<<8) | (y)*0x100/10 ) 86 87 static struct { 88 int fan_down_setting; 89 int temp; 90 int fan_up_setting; 91 } fan_table[] = { 92 { 11, T(0,0), 11 }, /* min fan */ 93 { 11, T(55,0), 11 }, 94 { 6, T(55,3), 11 }, 95 { 7, T(56,0), 11 }, 96 { 8, T(57,0), 8 }, 97 { 7, T(58,3), 7 }, 98 { 6, T(58,8), 6 }, 99 { 5, T(59,2), 5 }, 100 { 4, T(59,6), 4 }, 101 { 3, T(59,9), 3 }, 102 { 2, T(60,1), 2 }, 103 { 1, 0xfffff, 1 } /* on fire */ 104 }; 105 106 static void 107 print_temp( const char *s, int temp ) 108 { 109 printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 ); 110 } 111 112 static ssize_t 113 show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf ) 114 { 115 return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 ); 116 } 117 118 static ssize_t 119 show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf ) 120 { 121 return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 ); 122 } 123 124 static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL ); 125 static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL ); 126 127 128 129 /************************************************************************/ 130 /* controller thread */ 131 /************************************************************************/ 132 133 static int 134 write_reg( struct i2c_client *cl, int reg, int data, int len ) 135 { 136 u8 tmp[3]; 137 138 if( len < 1 || len > 2 || data < 0 ) 139 return -EINVAL; 140 141 tmp[0] = reg; 142 tmp[1] = (len == 1) ? data : (data >> 8); 143 tmp[2] = data; 144 len++; 145 146 if( i2c_master_send(cl, tmp, len) != len ) 147 return -ENODEV; 148 return 0; 149 } 150 151 static int 152 read_reg( struct i2c_client *cl, int reg, int len ) 153 { 154 u8 buf[2]; 155 156 if( len != 1 && len != 2 ) 157 return -EINVAL; 158 buf[0] = reg; 159 if( i2c_master_send(cl, buf, 1) != 1 ) 160 return -ENODEV; 161 if( i2c_master_recv(cl, buf, len) != len ) 162 return -ENODEV; 163 return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0]; 164 } 165 166 static void 167 tune_fan( int fan_setting ) 168 { 169 int val = (fan_setting << 3) | 7; 170 171 /* write_reg( x.fan, 0x24, val, 1 ); */ 172 write_reg( x.fan, 0x25, val, 1 ); 173 write_reg( x.fan, 0x20, 0, 1 ); 174 print_temp("CPU-temp: ", x.temp ); 175 if( x.casetemp ) 176 print_temp(", Case: ", x.casetemp ); 177 printk(", Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting ); 178 179 x.fan_level = fan_setting; 180 } 181 182 static void 183 poll_temp( void ) 184 { 185 int temp, i, level, casetemp; 186 187 temp = read_reg( x.thermostat, 0, 2 ); 188 189 /* this actually occurs when the computer is loaded */ 190 if( temp < 0 ) 191 return; 192 193 casetemp = read_reg(x.fan, 0x0b, 1) << 8; 194 casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5; 195 196 if( LOG_TEMP && x.temp != temp ) { 197 print_temp("CPU-temp: ", temp ); 198 print_temp(", Case: ", casetemp ); 199 printk(", Fan: %d\n", 11-x.fan_level ); 200 } 201 x.temp = temp; 202 x.casetemp = casetemp; 203 204 level = -1; 205 for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ ) 206 ; 207 if( i < x.downind ) 208 level = fan_table[i].fan_down_setting; 209 x.downind = i; 210 211 for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ ) 212 ; 213 if( x.upind < i ) 214 level = fan_table[i].fan_up_setting; 215 x.upind = i; 216 217 if( level >= 0 ) 218 tune_fan( level ); 219 } 220 221 222 static void 223 setup_hardware( void ) 224 { 225 int val; 226 227 /* save registers (if we unload the module) */ 228 x.r0 = read_reg( x.fan, 0x00, 1 ); 229 x.r1 = read_reg( x.fan, 0x01, 1 ); 230 x.r20 = read_reg( x.fan, 0x20, 1 ); 231 x.r23 = read_reg( x.fan, 0x23, 1 ); 232 x.r25 = read_reg( x.fan, 0x25, 1 ); 233 234 /* improve measurement resolution (convergence time 1.5s) */ 235 if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) { 236 val |= 0x60; 237 if( write_reg( x.thermostat, 1, val, 1 ) ) 238 printk("Failed writing config register\n"); 239 } 240 /* disable interrupts and TAC input */ 241 write_reg( x.fan, 0x01, 0x01, 1 ); 242 /* enable filter */ 243 write_reg( x.fan, 0x23, 0x91, 1 ); 244 /* remote temp. controls fan */ 245 write_reg( x.fan, 0x00, 0x95, 1 ); 246 247 /* The thermostat (which besides measureing temperature controls 248 * has a THERM output which puts the fan on 100%) is usually 249 * set to kick in at 80 C (chip default). We reduce this a bit 250 * to be on the safe side (OSX doesn't)... 251 */ 252 if( x.overheat_temp == (80 << 8) ) { 253 x.overheat_temp = 65 << 8; 254 x.overheat_hyst = 60 << 8; 255 write_reg( x.thermostat, 2, x.overheat_hyst, 2 ); 256 write_reg( x.thermostat, 3, x.overheat_temp, 2 ); 257 258 print_temp("Reducing overheating limit to ", x.overheat_temp ); 259 print_temp(" (Hyst: ", x.overheat_hyst ); 260 printk(")\n"); 261 } 262 263 /* set an initial fan setting */ 264 x.downind = 0xffff; 265 x.upind = -1; 266 /* tune_fan( fan_up_table[x.upind].fan_setting ); */ 267 268 device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature ); 269 device_create_file( &x.of_dev->dev, &dev_attr_case_temperature ); 270 } 271 272 static void 273 restore_regs( void ) 274 { 275 device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature ); 276 device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature ); 277 278 write_reg( x.fan, 0x01, x.r1, 1 ); 279 write_reg( x.fan, 0x20, x.r20, 1 ); 280 write_reg( x.fan, 0x23, x.r23, 1 ); 281 write_reg( x.fan, 0x25, x.r25, 1 ); 282 write_reg( x.fan, 0x00, x.r0, 1 ); 283 } 284 285 static int 286 control_loop( void *dummy ) 287 { 288 daemonize("g4fand"); 289 290 down( &x.lock ); 291 setup_hardware(); 292 293 while( x.running ) { 294 up( &x.lock ); 295 296 msleep_interruptible(8000); 297 298 down( &x.lock ); 299 poll_temp(); 300 } 301 302 restore_regs(); 303 up( &x.lock ); 304 305 complete_and_exit( &x.completion, 0 ); 306 } 307 308 309 /************************************************************************/ 310 /* i2c probing and setup */ 311 /************************************************************************/ 312 313 static int 314 do_attach( struct i2c_adapter *adapter ) 315 { 316 int ret = 0; 317 318 if( strncmp(adapter->name, "uni-n", 5) ) 319 return 0; 320 321 if( !x.running ) { 322 ret = i2c_probe( adapter, &addr_data, &do_probe ); 323 if( x.thermostat && x.fan ) { 324 x.running = 1; 325 init_completion( &x.completion ); 326 x.poll_task = kernel_thread( control_loop, NULL, SIGCHLD | CLONE_KERNEL ); 327 } 328 } 329 return ret; 330 } 331 332 static int 333 do_detach( struct i2c_client *client ) 334 { 335 int err; 336 337 if( (err=i2c_detach_client(client)) ) 338 printk(KERN_ERR "failed to detach thermostat client\n"); 339 else { 340 if( x.running ) { 341 x.running = 0; 342 wait_for_completion( &x.completion ); 343 } 344 if( client == x.thermostat ) 345 x.thermostat = NULL; 346 else if( client == x.fan ) 347 x.fan = NULL; 348 else { 349 printk(KERN_ERR "g4fan: bad client\n"); 350 } 351 kfree( client ); 352 } 353 return err; 354 } 355 356 static struct i2c_driver g4fan_driver = { 357 .driver = { 358 .name = "therm_windtunnel", 359 }, 360 .id = I2C_DRIVERID_G4FAN, 361 .attach_adapter = do_attach, 362 .detach_client = do_detach, 363 }; 364 365 static int 366 attach_fan( struct i2c_client *cl ) 367 { 368 if( x.fan ) 369 goto out; 370 371 /* check that this is an ADM1030 */ 372 if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 ) 373 goto out; 374 printk("ADM1030 fan controller [@%02x]\n", cl->addr ); 375 376 strlcpy( cl->name, "ADM1030 fan controller", sizeof(cl->name) ); 377 378 if( !i2c_attach_client(cl) ) 379 x.fan = cl; 380 out: 381 if( cl != x.fan ) 382 kfree( cl ); 383 return 0; 384 } 385 386 static int 387 attach_thermostat( struct i2c_client *cl ) 388 { 389 int hyst_temp, os_temp, temp; 390 391 if( x.thermostat ) 392 goto out; 393 394 if( (temp=read_reg(cl, 0, 2)) < 0 ) 395 goto out; 396 397 /* temperature sanity check */ 398 if( temp < 0x1600 || temp > 0x3c00 ) 399 goto out; 400 hyst_temp = read_reg(cl, 2, 2); 401 os_temp = read_reg(cl, 3, 2); 402 if( hyst_temp < 0 || os_temp < 0 ) 403 goto out; 404 405 printk("DS1775 digital thermometer [@%02x]\n", cl->addr ); 406 print_temp("Temp: ", temp ); 407 print_temp(" Hyst: ", hyst_temp ); 408 print_temp(" OS: ", os_temp ); 409 printk("\n"); 410 411 x.temp = temp; 412 x.overheat_temp = os_temp; 413 x.overheat_hyst = hyst_temp; 414 415 strlcpy( cl->name, "DS1775 thermostat", sizeof(cl->name) ); 416 417 if( !i2c_attach_client(cl) ) 418 x.thermostat = cl; 419 out: 420 if( cl != x.thermostat ) 421 kfree( cl ); 422 return 0; 423 } 424 425 static int 426 do_probe( struct i2c_adapter *adapter, int addr, int kind ) 427 { 428 struct i2c_client *cl; 429 430 if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA 431 | I2C_FUNC_SMBUS_WRITE_BYTE) ) 432 return 0; 433 434 if( !(cl=kmalloc(sizeof(*cl), GFP_KERNEL)) ) 435 return -ENOMEM; 436 memset( cl, 0, sizeof(struct i2c_client) ); 437 438 cl->addr = addr; 439 cl->adapter = adapter; 440 cl->driver = &g4fan_driver; 441 cl->flags = 0; 442 443 if( addr < 0x48 ) 444 return attach_fan( cl ); 445 return attach_thermostat( cl ); 446 } 447 448 449 /************************************************************************/ 450 /* initialization / cleanup */ 451 /************************************************************************/ 452 453 static int 454 therm_of_probe( struct of_device *dev, const struct of_device_id *match ) 455 { 456 return i2c_add_driver( &g4fan_driver ); 457 } 458 459 static int 460 therm_of_remove( struct of_device *dev ) 461 { 462 i2c_del_driver( &g4fan_driver ); 463 return 0; 464 } 465 466 static struct of_device_id therm_of_match[] = {{ 467 .name = "fan", 468 .compatible = "adm1030" 469 }, {} 470 }; 471 472 static struct of_platform_driver therm_of_driver = { 473 .name = "temperature", 474 .match_table = therm_of_match, 475 .probe = therm_of_probe, 476 .remove = therm_of_remove, 477 }; 478 479 struct apple_thermal_info { 480 u8 id; /* implementation ID */ 481 u8 fan_count; /* number of fans */ 482 u8 thermostat_count; /* number of thermostats */ 483 u8 unused; 484 }; 485 486 static int __init 487 g4fan_init( void ) 488 { 489 const struct apple_thermal_info *info; 490 struct device_node *np; 491 492 init_MUTEX( &x.lock ); 493 494 if( !(np=of_find_node_by_name(NULL, "power-mgt")) ) 495 return -ENODEV; 496 info = of_get_property(np, "thermal-info", NULL); 497 of_node_put(np); 498 499 if( !info || !machine_is_compatible("PowerMac3,6") ) 500 return -ENODEV; 501 502 if( info->id != 3 ) { 503 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id ); 504 return -ENODEV; 505 } 506 if( !(np=of_find_node_by_name(NULL, "fan")) ) 507 return -ENODEV; 508 x.of_dev = of_platform_device_create(np, "temperature", NULL); 509 of_node_put( np ); 510 511 if( !x.of_dev ) { 512 printk(KERN_ERR "Can't register fan controller!\n"); 513 return -ENODEV; 514 } 515 516 of_register_platform_driver( &therm_of_driver ); 517 return 0; 518 } 519 520 static void __exit 521 g4fan_exit( void ) 522 { 523 of_unregister_platform_driver( &therm_of_driver ); 524 525 if( x.of_dev ) 526 of_device_unregister( x.of_dev ); 527 } 528 529 module_init(g4fan_init); 530 module_exit(g4fan_exit); 531 532 MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>"); 533 MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller"); 534 MODULE_LICENSE("GPL"); 535