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 <linux/kthread.h> 40 41 #include <asm/prom.h> 42 #include <asm/machdep.h> 43 #include <asm/io.h> 44 #include <asm/system.h> 45 #include <asm/sections.h> 46 #include <asm/of_platform.h> 47 #include <asm/macio.h> 48 49 #define LOG_TEMP 0 /* continously log temperature */ 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 const 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 task_struct *poll_task; 64 65 struct semaphore lock; 66 struct of_device *of_dev; 67 68 struct i2c_client *thermostat; 69 struct i2c_client *fan; 70 71 int overheat_temp; /* 100% fan at this temp */ 72 int overheat_hyst; 73 int temp; 74 int casetemp; 75 int fan_level; /* active fan_table setting */ 76 77 int downind; 78 int upind; 79 80 int r0, r1, r20, r23, r25; /* saved register */ 81 } x; 82 83 #define T(x,y) (((x)<<8) | (y)*0x100/10 ) 84 85 static struct { 86 int fan_down_setting; 87 int temp; 88 int fan_up_setting; 89 } fan_table[] = { 90 { 11, T(0,0), 11 }, /* min fan */ 91 { 11, T(55,0), 11 }, 92 { 6, T(55,3), 11 }, 93 { 7, T(56,0), 11 }, 94 { 8, T(57,0), 8 }, 95 { 7, T(58,3), 7 }, 96 { 6, T(58,8), 6 }, 97 { 5, T(59,2), 5 }, 98 { 4, T(59,6), 4 }, 99 { 3, T(59,9), 3 }, 100 { 2, T(60,1), 2 }, 101 { 1, 0xfffff, 1 } /* on fire */ 102 }; 103 104 static void 105 print_temp( const char *s, int temp ) 106 { 107 printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 ); 108 } 109 110 static ssize_t 111 show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf ) 112 { 113 return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 ); 114 } 115 116 static ssize_t 117 show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf ) 118 { 119 return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 ); 120 } 121 122 static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL ); 123 static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL ); 124 125 126 127 /************************************************************************/ 128 /* controller thread */ 129 /************************************************************************/ 130 131 static int 132 write_reg( struct i2c_client *cl, int reg, int data, int len ) 133 { 134 u8 tmp[3]; 135 136 if( len < 1 || len > 2 || data < 0 ) 137 return -EINVAL; 138 139 tmp[0] = reg; 140 tmp[1] = (len == 1) ? data : (data >> 8); 141 tmp[2] = data; 142 len++; 143 144 if( i2c_master_send(cl, tmp, len) != len ) 145 return -ENODEV; 146 return 0; 147 } 148 149 static int 150 read_reg( struct i2c_client *cl, int reg, int len ) 151 { 152 u8 buf[2]; 153 154 if( len != 1 && len != 2 ) 155 return -EINVAL; 156 buf[0] = reg; 157 if( i2c_master_send(cl, buf, 1) != 1 ) 158 return -ENODEV; 159 if( i2c_master_recv(cl, buf, len) != len ) 160 return -ENODEV; 161 return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0]; 162 } 163 164 static void 165 tune_fan( int fan_setting ) 166 { 167 int val = (fan_setting << 3) | 7; 168 169 /* write_reg( x.fan, 0x24, val, 1 ); */ 170 write_reg( x.fan, 0x25, val, 1 ); 171 write_reg( x.fan, 0x20, 0, 1 ); 172 print_temp("CPU-temp: ", x.temp ); 173 if( x.casetemp ) 174 print_temp(", Case: ", x.casetemp ); 175 printk(", Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting ); 176 177 x.fan_level = fan_setting; 178 } 179 180 static void 181 poll_temp( void ) 182 { 183 int temp, i, level, casetemp; 184 185 temp = read_reg( x.thermostat, 0, 2 ); 186 187 /* this actually occurs when the computer is loaded */ 188 if( temp < 0 ) 189 return; 190 191 casetemp = read_reg(x.fan, 0x0b, 1) << 8; 192 casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5; 193 194 if( LOG_TEMP && x.temp != temp ) { 195 print_temp("CPU-temp: ", temp ); 196 print_temp(", Case: ", casetemp ); 197 printk(", Fan: %d\n", 11-x.fan_level ); 198 } 199 x.temp = temp; 200 x.casetemp = casetemp; 201 202 level = -1; 203 for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ ) 204 ; 205 if( i < x.downind ) 206 level = fan_table[i].fan_down_setting; 207 x.downind = i; 208 209 for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ ) 210 ; 211 if( x.upind < i ) 212 level = fan_table[i].fan_up_setting; 213 x.upind = i; 214 215 if( level >= 0 ) 216 tune_fan( level ); 217 } 218 219 220 static void 221 setup_hardware( void ) 222 { 223 int val; 224 int err; 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 err = device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature ); 268 err |= device_create_file( &x.of_dev->dev, &dev_attr_case_temperature ); 269 if (err) 270 printk(KERN_WARNING 271 "Failed to create temperature attribute file(s).\n"); 272 } 273 274 static void 275 restore_regs( void ) 276 { 277 device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature ); 278 device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature ); 279 280 write_reg( x.fan, 0x01, x.r1, 1 ); 281 write_reg( x.fan, 0x20, x.r20, 1 ); 282 write_reg( x.fan, 0x23, x.r23, 1 ); 283 write_reg( x.fan, 0x25, x.r25, 1 ); 284 write_reg( x.fan, 0x00, x.r0, 1 ); 285 } 286 287 static int control_loop(void *dummy) 288 { 289 down(&x.lock); 290 setup_hardware(); 291 up(&x.lock); 292 293 for (;;) { 294 msleep_interruptible(8000); 295 if (kthread_should_stop()) 296 break; 297 298 down(&x.lock); 299 poll_temp(); 300 up(&x.lock); 301 } 302 303 down(&x.lock); 304 restore_regs(); 305 up(&x.lock); 306 307 return 0; 308 } 309 310 311 /************************************************************************/ 312 /* i2c probing and setup */ 313 /************************************************************************/ 314 315 static int 316 do_attach( struct i2c_adapter *adapter ) 317 { 318 int ret = 0; 319 320 if( strncmp(adapter->name, "uni-n", 5) ) 321 return 0; 322 323 if( !x.running ) { 324 ret = i2c_probe( adapter, &addr_data, &do_probe ); 325 if( x.thermostat && x.fan ) { 326 x.running = 1; 327 x.poll_task = kthread_run(control_loop, NULL, "g4fand"); 328 } 329 } 330 return ret; 331 } 332 333 static int 334 do_detach( struct i2c_client *client ) 335 { 336 int err; 337 338 if( (err=i2c_detach_client(client)) ) 339 printk(KERN_ERR "failed to detach thermostat client\n"); 340 else { 341 if( x.running ) { 342 x.running = 0; 343 kthread_stop(x.poll_task); 344 x.poll_task = NULL; 345 } 346 if( client == x.thermostat ) 347 x.thermostat = NULL; 348 else if( client == x.fan ) 349 x.fan = NULL; 350 else { 351 printk(KERN_ERR "g4fan: bad client\n"); 352 } 353 kfree( client ); 354 } 355 return err; 356 } 357 358 static struct i2c_driver g4fan_driver = { 359 .driver = { 360 .name = "therm_windtunnel", 361 }, 362 .attach_adapter = do_attach, 363 .detach_client = do_detach, 364 }; 365 366 static int 367 attach_fan( struct i2c_client *cl ) 368 { 369 if( x.fan ) 370 goto out; 371 372 /* check that this is an ADM1030 */ 373 if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 ) 374 goto out; 375 printk("ADM1030 fan controller [@%02x]\n", cl->addr ); 376 377 strlcpy( cl->name, "ADM1030 fan controller", sizeof(cl->name) ); 378 379 if( !i2c_attach_client(cl) ) 380 x.fan = cl; 381 out: 382 if( cl != x.fan ) 383 kfree( cl ); 384 return 0; 385 } 386 387 static int 388 attach_thermostat( struct i2c_client *cl ) 389 { 390 int hyst_temp, os_temp, temp; 391 392 if( x.thermostat ) 393 goto out; 394 395 if( (temp=read_reg(cl, 0, 2)) < 0 ) 396 goto out; 397 398 /* temperature sanity check */ 399 if( temp < 0x1600 || temp > 0x3c00 ) 400 goto out; 401 hyst_temp = read_reg(cl, 2, 2); 402 os_temp = read_reg(cl, 3, 2); 403 if( hyst_temp < 0 || os_temp < 0 ) 404 goto out; 405 406 printk("DS1775 digital thermometer [@%02x]\n", cl->addr ); 407 print_temp("Temp: ", temp ); 408 print_temp(" Hyst: ", hyst_temp ); 409 print_temp(" OS: ", os_temp ); 410 printk("\n"); 411 412 x.temp = temp; 413 x.overheat_temp = os_temp; 414 x.overheat_hyst = hyst_temp; 415 416 strlcpy( cl->name, "DS1775 thermostat", sizeof(cl->name) ); 417 418 if( !i2c_attach_client(cl) ) 419 x.thermostat = cl; 420 out: 421 if( cl != x.thermostat ) 422 kfree( cl ); 423 return 0; 424 } 425 426 static int 427 do_probe( struct i2c_adapter *adapter, int addr, int kind ) 428 { 429 struct i2c_client *cl; 430 431 if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA 432 | I2C_FUNC_SMBUS_WRITE_BYTE) ) 433 return 0; 434 435 if( !(cl=kzalloc(sizeof(*cl), GFP_KERNEL)) ) 436 return -ENOMEM; 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