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/config.h> 31 #include <linux/types.h> 32 #include <linux/module.h> 33 #include <linux/errno.h> 34 #include <linux/kernel.h> 35 #include <linux/delay.h> 36 #include <linux/sched.h> 37 #include <linux/i2c.h> 38 #include <linux/slab.h> 39 #include <linux/init.h> 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_device.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[] = { 0x49, 0x2c, I2C_CLIENT_END }; 55 static unsigned short normal_i2c_range[] = { 0x48, 0x4f, 0x2c, 0x2f, I2C_CLIENT_END }; 56 57 I2C_CLIENT_INSMOD; 58 59 static struct { 60 volatile int running; 61 struct completion completion; 62 pid_t poll_task; 63 64 struct semaphore lock; 65 struct of_device *of_dev; 66 67 struct i2c_client *thermostat; 68 struct i2c_client *fan; 69 70 int overheat_temp; /* 100% fan at this temp */ 71 int overheat_hyst; 72 int temp; 73 int casetemp; 74 int fan_level; /* active fan_table setting */ 75 76 int downind; 77 int upind; 78 79 int r0, r1, r20, r23, r25; /* saved register */ 80 } x; 81 82 #define T(x,y) (((x)<<8) | (y)*0x100/10 ) 83 84 static struct { 85 int fan_down_setting; 86 int temp; 87 int fan_up_setting; 88 } fan_table[] = { 89 { 11, T(0,0), 11 }, /* min fan */ 90 { 11, T(55,0), 11 }, 91 { 6, T(55,3), 11 }, 92 { 7, T(56,0), 11 }, 93 { 8, T(57,0), 8 }, 94 { 7, T(58,3), 7 }, 95 { 6, T(58,8), 6 }, 96 { 5, T(59,2), 5 }, 97 { 4, T(59,6), 4 }, 98 { 3, T(59,9), 3 }, 99 { 2, T(60,1), 2 }, 100 { 1, 0xfffff, 1 } /* on fire */ 101 }; 102 103 static void 104 print_temp( const char *s, int temp ) 105 { 106 printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 ); 107 } 108 109 static ssize_t 110 show_cpu_temperature( struct device *dev, char *buf ) 111 { 112 return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 ); 113 } 114 115 static ssize_t 116 show_case_temperature( struct device *dev, char *buf ) 117 { 118 return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 ); 119 } 120 121 static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL ); 122 static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL ); 123 124 125 126 /************************************************************************/ 127 /* controller thread */ 128 /************************************************************************/ 129 130 static int 131 write_reg( struct i2c_client *cl, int reg, int data, int len ) 132 { 133 u8 tmp[3]; 134 135 if( len < 1 || len > 2 || data < 0 ) 136 return -EINVAL; 137 138 tmp[0] = reg; 139 tmp[1] = (len == 1) ? data : (data >> 8); 140 tmp[2] = data; 141 len++; 142 143 if( i2c_master_send(cl, tmp, len) != len ) 144 return -ENODEV; 145 return 0; 146 } 147 148 static int 149 read_reg( struct i2c_client *cl, int reg, int len ) 150 { 151 u8 buf[2]; 152 153 if( len != 1 && len != 2 ) 154 return -EINVAL; 155 buf[0] = reg; 156 if( i2c_master_send(cl, buf, 1) != 1 ) 157 return -ENODEV; 158 if( i2c_master_recv(cl, buf, len) != len ) 159 return -ENODEV; 160 return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0]; 161 } 162 163 static void 164 tune_fan( int fan_setting ) 165 { 166 int val = (fan_setting << 3) | 7; 167 168 /* write_reg( x.fan, 0x24, val, 1 ); */ 169 write_reg( x.fan, 0x25, val, 1 ); 170 write_reg( x.fan, 0x20, 0, 1 ); 171 print_temp("CPU-temp: ", x.temp ); 172 if( x.casetemp ) 173 print_temp(", Case: ", x.casetemp ); 174 printk(", Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting ); 175 176 x.fan_level = fan_setting; 177 } 178 179 static void 180 poll_temp( void ) 181 { 182 int temp, i, level, casetemp; 183 184 temp = read_reg( x.thermostat, 0, 2 ); 185 186 /* this actually occurs when the computer is loaded */ 187 if( temp < 0 ) 188 return; 189 190 casetemp = read_reg(x.fan, 0x0b, 1) << 8; 191 casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5; 192 193 if( LOG_TEMP && x.temp != temp ) { 194 print_temp("CPU-temp: ", temp ); 195 print_temp(", Case: ", casetemp ); 196 printk(", Fan: %d\n", 11-x.fan_level ); 197 } 198 x.temp = temp; 199 x.casetemp = casetemp; 200 201 level = -1; 202 for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ ) 203 ; 204 if( i < x.downind ) 205 level = fan_table[i].fan_down_setting; 206 x.downind = i; 207 208 for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ ) 209 ; 210 if( x.upind < i ) 211 level = fan_table[i].fan_up_setting; 212 x.upind = i; 213 214 if( level >= 0 ) 215 tune_fan( level ); 216 } 217 218 219 static void 220 setup_hardware( void ) 221 { 222 int val; 223 224 /* save registers (if we unload the module) */ 225 x.r0 = read_reg( x.fan, 0x00, 1 ); 226 x.r1 = read_reg( x.fan, 0x01, 1 ); 227 x.r20 = read_reg( x.fan, 0x20, 1 ); 228 x.r23 = read_reg( x.fan, 0x23, 1 ); 229 x.r25 = read_reg( x.fan, 0x25, 1 ); 230 231 /* improve measurement resolution (convergence time 1.5s) */ 232 if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) { 233 val |= 0x60; 234 if( write_reg( x.thermostat, 1, val, 1 ) ) 235 printk("Failed writing config register\n"); 236 } 237 /* disable interrupts and TAC input */ 238 write_reg( x.fan, 0x01, 0x01, 1 ); 239 /* enable filter */ 240 write_reg( x.fan, 0x23, 0x91, 1 ); 241 /* remote temp. controls fan */ 242 write_reg( x.fan, 0x00, 0x95, 1 ); 243 244 /* The thermostat (which besides measureing temperature controls 245 * has a THERM output which puts the fan on 100%) is usually 246 * set to kick in at 80 C (chip default). We reduce this a bit 247 * to be on the safe side (OSX doesn't)... 248 */ 249 if( x.overheat_temp == (80 << 8) ) { 250 x.overheat_temp = 65 << 8; 251 x.overheat_hyst = 60 << 8; 252 write_reg( x.thermostat, 2, x.overheat_hyst, 2 ); 253 write_reg( x.thermostat, 3, x.overheat_temp, 2 ); 254 255 print_temp("Reducing overheating limit to ", x.overheat_temp ); 256 print_temp(" (Hyst: ", x.overheat_hyst ); 257 printk(")\n"); 258 } 259 260 /* set an initial fan setting */ 261 x.downind = 0xffff; 262 x.upind = -1; 263 /* tune_fan( fan_up_table[x.upind].fan_setting ); */ 264 265 device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature ); 266 device_create_file( &x.of_dev->dev, &dev_attr_case_temperature ); 267 } 268 269 static void 270 restore_regs( void ) 271 { 272 device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature ); 273 device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature ); 274 275 write_reg( x.fan, 0x01, x.r1, 1 ); 276 write_reg( x.fan, 0x20, x.r20, 1 ); 277 write_reg( x.fan, 0x23, x.r23, 1 ); 278 write_reg( x.fan, 0x25, x.r25, 1 ); 279 write_reg( x.fan, 0x00, x.r0, 1 ); 280 } 281 282 static int 283 control_loop( void *dummy ) 284 { 285 daemonize("g4fand"); 286 287 down( &x.lock ); 288 setup_hardware(); 289 290 while( x.running ) { 291 up( &x.lock ); 292 293 msleep_interruptible(8000); 294 295 down( &x.lock ); 296 poll_temp(); 297 } 298 299 restore_regs(); 300 up( &x.lock ); 301 302 complete_and_exit( &x.completion, 0 ); 303 } 304 305 306 /************************************************************************/ 307 /* i2c probing and setup */ 308 /************************************************************************/ 309 310 static int 311 do_attach( struct i2c_adapter *adapter ) 312 { 313 int ret = 0; 314 315 if( strncmp(adapter->name, "uni-n", 5) ) 316 return 0; 317 318 if( !x.running ) { 319 ret = i2c_probe( adapter, &addr_data, &do_probe ); 320 if( x.thermostat && x.fan ) { 321 x.running = 1; 322 init_completion( &x.completion ); 323 x.poll_task = kernel_thread( control_loop, NULL, SIGCHLD | CLONE_KERNEL ); 324 } 325 } 326 return ret; 327 } 328 329 static int 330 do_detach( struct i2c_client *client ) 331 { 332 int err; 333 334 if( (err=i2c_detach_client(client)) ) 335 printk(KERN_ERR "failed to detach thermostat client\n"); 336 else { 337 if( x.running ) { 338 x.running = 0; 339 wait_for_completion( &x.completion ); 340 } 341 if( client == x.thermostat ) 342 x.thermostat = NULL; 343 else if( client == x.fan ) 344 x.fan = NULL; 345 else { 346 printk(KERN_ERR "g4fan: bad client\n"); 347 } 348 kfree( client ); 349 } 350 return err; 351 } 352 353 static struct i2c_driver g4fan_driver = { 354 .owner = THIS_MODULE, 355 .name = "therm_windtunnel", 356 .id = I2C_DRIVERID_G4FAN, 357 .flags = I2C_DF_NOTIFY, 358 .attach_adapter = do_attach, 359 .detach_client = do_detach, 360 }; 361 362 static int 363 attach_fan( struct i2c_client *cl ) 364 { 365 if( x.fan ) 366 goto out; 367 368 /* check that this is an ADM1030 */ 369 if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 ) 370 goto out; 371 printk("ADM1030 fan controller [@%02x]\n", cl->addr ); 372 373 strlcpy( cl->name, "ADM1030 fan controller", sizeof(cl->name) ); 374 375 if( !i2c_attach_client(cl) ) 376 x.fan = cl; 377 out: 378 if( cl != x.fan ) 379 kfree( cl ); 380 return 0; 381 } 382 383 static int 384 attach_thermostat( struct i2c_client *cl ) 385 { 386 int hyst_temp, os_temp, temp; 387 388 if( x.thermostat ) 389 goto out; 390 391 if( (temp=read_reg(cl, 0, 2)) < 0 ) 392 goto out; 393 394 /* temperature sanity check */ 395 if( temp < 0x1600 || temp > 0x3c00 ) 396 goto out; 397 hyst_temp = read_reg(cl, 2, 2); 398 os_temp = read_reg(cl, 3, 2); 399 if( hyst_temp < 0 || os_temp < 0 ) 400 goto out; 401 402 printk("DS1775 digital thermometer [@%02x]\n", cl->addr ); 403 print_temp("Temp: ", temp ); 404 print_temp(" Hyst: ", hyst_temp ); 405 print_temp(" OS: ", os_temp ); 406 printk("\n"); 407 408 x.temp = temp; 409 x.overheat_temp = os_temp; 410 x.overheat_hyst = hyst_temp; 411 412 strlcpy( cl->name, "DS1775 thermostat", sizeof(cl->name) ); 413 414 if( !i2c_attach_client(cl) ) 415 x.thermostat = cl; 416 out: 417 if( cl != x.thermostat ) 418 kfree( cl ); 419 return 0; 420 } 421 422 static int 423 do_probe( struct i2c_adapter *adapter, int addr, int kind ) 424 { 425 struct i2c_client *cl; 426 427 if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA 428 | I2C_FUNC_SMBUS_WRITE_BYTE) ) 429 return 0; 430 431 if( !(cl=kmalloc(sizeof(*cl), GFP_KERNEL)) ) 432 return -ENOMEM; 433 memset( cl, 0, sizeof(struct i2c_client) ); 434 435 cl->addr = addr; 436 cl->adapter = adapter; 437 cl->driver = &g4fan_driver; 438 cl->flags = 0; 439 440 if( addr < 0x48 ) 441 return attach_fan( cl ); 442 return attach_thermostat( cl ); 443 } 444 445 446 /************************************************************************/ 447 /* initialization / cleanup */ 448 /************************************************************************/ 449 450 static int 451 therm_of_probe( struct of_device *dev, const struct of_match *match ) 452 { 453 return i2c_add_driver( &g4fan_driver ); 454 } 455 456 static int 457 therm_of_remove( struct of_device *dev ) 458 { 459 return i2c_del_driver( &g4fan_driver ); 460 } 461 462 static struct of_match therm_of_match[] = {{ 463 .name = "fan", 464 .type = OF_ANY_MATCH, 465 .compatible = "adm1030" 466 }, {} 467 }; 468 469 static struct of_platform_driver therm_of_driver = { 470 .name = "temperature", 471 .match_table = therm_of_match, 472 .probe = therm_of_probe, 473 .remove = therm_of_remove, 474 }; 475 476 struct apple_thermal_info { 477 u8 id; /* implementation ID */ 478 u8 fan_count; /* number of fans */ 479 u8 thermostat_count; /* number of thermostats */ 480 u8 unused; 481 }; 482 483 static int __init 484 g4fan_init( void ) 485 { 486 struct apple_thermal_info *info; 487 struct device_node *np; 488 489 init_MUTEX( &x.lock ); 490 491 if( !(np=of_find_node_by_name(NULL, "power-mgt")) ) 492 return -ENODEV; 493 info = (struct apple_thermal_info*)get_property(np, "thermal-info", NULL); 494 of_node_put(np); 495 496 if( !info || !machine_is_compatible("PowerMac3,6") ) 497 return -ENODEV; 498 499 if( info->id != 3 ) { 500 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id ); 501 return -ENODEV; 502 } 503 if( !(np=of_find_node_by_name(NULL, "fan")) ) 504 return -ENODEV; 505 x.of_dev = of_platform_device_create( np, "temperature" ); 506 of_node_put( np ); 507 508 if( !x.of_dev ) { 509 printk(KERN_ERR "Can't register fan controller!\n"); 510 return -ENODEV; 511 } 512 513 of_register_driver( &therm_of_driver ); 514 return 0; 515 } 516 517 static void __exit 518 g4fan_exit( void ) 519 { 520 of_unregister_driver( &therm_of_driver ); 521 522 if( x.of_dev ) 523 of_device_unregister( x.of_dev ); 524 } 525 526 module_init(g4fan_init); 527 module_exit(g4fan_exit); 528 529 MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>"); 530 MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller"); 531 MODULE_LICENSE("GPL"); 532