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