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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 an8 * ADM1030 fan controller and a DS1775 thermostat.9 *10 * The fan controller is equipped with a temperature sensor11 * which measures the case temperature. The DS1775 sensor12 * measures the CPU temperature. This driver tunes the13 * behavior of the fan. It is based upon empirical observations14 * of the 'AppleFan' driver under Mac OS X.15 *16 * WARNING: This driver has only been testen on Apple's17 * 1.25 MHz Dual G4 (March 03). It is tuned for a CPU18 * 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 Herrenschmidt23 * 24 * This program is free software; you can redistribute it and/or25 * modify it under the terms of the GNU General Public License26 * as published by the Free Software Foundation27 * 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/init.h>38#include <linux/kthread.h>39#include <linux/of.h>40#include <linux/of_platform.h>41#include <linux/platform_device.h>42 43#include <asm/machdep.h>44#include <asm/io.h>45#include <asm/sections.h>46#include <asm/macio.h>47 48#define LOG_TEMP 0 /* continuously log temperature */49 50static struct {51 volatile int running;52 struct task_struct *poll_task;53 54 struct mutex lock;55 struct platform_device *of_dev;56 57 struct i2c_client *thermostat;58 struct i2c_client *fan;59 60 int overheat_temp; /* 100% fan at this temp */61 int overheat_hyst;62 int temp;63 int casetemp;64 int fan_level; /* active fan_table setting */65 66 int downind;67 int upind;68 69 int r0, r1, r20, r23, r25; /* saved register */70} x;71 72#define T(x,y) (((x)<<8) | (y)*0x100/10 )73 74static struct {75 int fan_down_setting;76 int temp;77 int fan_up_setting;78} fan_table[] = {79 { 11, T(0,0), 11 }, /* min fan */80 { 11, T(55,0), 11 },81 { 6, T(55,3), 11 },82 { 7, T(56,0), 11 },83 { 8, T(57,0), 8 },84 { 7, T(58,3), 7 },85 { 6, T(58,8), 6 },86 { 5, T(59,2), 5 },87 { 4, T(59,6), 4 },88 { 3, T(59,9), 3 },89 { 2, T(60,1), 2 },90 { 1, 0xfffff, 1 } /* on fire */91};92 93static void94print_temp( const char *s, int temp )95{96 printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );97}98 99static ssize_t100show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf )101{102 return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 );103}104 105static ssize_t106show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf )107{108 return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 );109}110 111static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );112static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );113 114 115 116/************************************************************************/117/* controller thread */118/************************************************************************/119 120static int121write_reg( struct i2c_client *cl, int reg, int data, int len )122{123 u8 tmp[3];124 125 if( len < 1 || len > 2 || data < 0 )126 return -EINVAL;127 128 tmp[0] = reg;129 tmp[1] = (len == 1) ? data : (data >> 8);130 tmp[2] = data;131 len++;132 133 if( i2c_master_send(cl, tmp, len) != len )134 return -ENODEV;135 return 0;136}137 138static int139read_reg( struct i2c_client *cl, int reg, int len )140{141 u8 buf[2];142 143 if( len != 1 && len != 2 )144 return -EINVAL;145 buf[0] = reg;146 if( i2c_master_send(cl, buf, 1) != 1 )147 return -ENODEV;148 if( i2c_master_recv(cl, buf, len) != len )149 return -ENODEV;150 return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0];151}152 153static void154tune_fan( int fan_setting )155{156 int val = (fan_setting << 3) | 7;157 158 /* write_reg( x.fan, 0x24, val, 1 ); */159 write_reg( x.fan, 0x25, val, 1 );160 write_reg( x.fan, 0x20, 0, 1 );161 print_temp("CPU-temp: ", x.temp );162 if( x.casetemp )163 print_temp(", Case: ", x.casetemp );164 printk(", Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );165 166 x.fan_level = fan_setting;167}168 169static void170poll_temp( void )171{172 int temp, i, level, casetemp;173 174 temp = read_reg( x.thermostat, 0, 2 );175 176 /* this actually occurs when the computer is loaded */177 if( temp < 0 )178 return;179 180 casetemp = read_reg(x.fan, 0x0b, 1) << 8;181 casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;182 183 if( LOG_TEMP && x.temp != temp ) {184 print_temp("CPU-temp: ", temp );185 print_temp(", Case: ", casetemp );186 printk(", Fan: %d\n", 11-x.fan_level );187 }188 x.temp = temp;189 x.casetemp = casetemp;190 191 level = -1;192 for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )193 ;194 if( i < x.downind )195 level = fan_table[i].fan_down_setting;196 x.downind = i;197 198 for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )199 ;200 if( x.upind < i )201 level = fan_table[i].fan_up_setting;202 x.upind = i;203 204 if( level >= 0 )205 tune_fan( level );206}207 208 209static void210setup_hardware( void )211{212 int val;213 int err;214 215 /* save registers (if we unload the module) */216 x.r0 = read_reg( x.fan, 0x00, 1 );217 x.r1 = read_reg( x.fan, 0x01, 1 );218 x.r20 = read_reg( x.fan, 0x20, 1 );219 x.r23 = read_reg( x.fan, 0x23, 1 );220 x.r25 = read_reg( x.fan, 0x25, 1 );221 222 /* improve measurement resolution (convergence time 1.5s) */223 if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) {224 val |= 0x60;225 if( write_reg( x.thermostat, 1, val, 1 ) )226 printk("Failed writing config register\n");227 }228 /* disable interrupts and TAC input */229 write_reg( x.fan, 0x01, 0x01, 1 );230 /* enable filter */231 write_reg( x.fan, 0x23, 0x91, 1 );232 /* remote temp. controls fan */233 write_reg( x.fan, 0x00, 0x95, 1 );234 235 /* The thermostat (which besides measureing temperature controls236 * has a THERM output which puts the fan on 100%) is usually237 * set to kick in at 80 C (chip default). We reduce this a bit238 * to be on the safe side (OSX doesn't)...239 */240 if( x.overheat_temp == (80 << 8) ) {241 x.overheat_temp = 75 << 8;242 x.overheat_hyst = 70 << 8;243 write_reg( x.thermostat, 2, x.overheat_hyst, 2 );244 write_reg( x.thermostat, 3, x.overheat_temp, 2 );245 246 print_temp("Reducing overheating limit to ", x.overheat_temp );247 print_temp(" (Hyst: ", x.overheat_hyst );248 printk(")\n");249 }250 251 /* set an initial fan setting */252 x.downind = 0xffff;253 x.upind = -1;254 /* tune_fan( fan_up_table[x.upind].fan_setting ); */255 256 err = device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );257 err |= device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );258 if (err)259 printk(KERN_WARNING260 "Failed to create temperature attribute file(s).\n");261}262 263static void264restore_regs( void )265{266 device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );267 device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );268 269 write_reg( x.fan, 0x01, x.r1, 1 );270 write_reg( x.fan, 0x20, x.r20, 1 );271 write_reg( x.fan, 0x23, x.r23, 1 );272 write_reg( x.fan, 0x25, x.r25, 1 );273 write_reg( x.fan, 0x00, x.r0, 1 );274}275 276static int control_loop(void *dummy)277{278 mutex_lock(&x.lock);279 setup_hardware();280 mutex_unlock(&x.lock);281 282 for (;;) {283 msleep_interruptible(8000);284 if (kthread_should_stop())285 break;286 287 mutex_lock(&x.lock);288 poll_temp();289 mutex_unlock(&x.lock);290 }291 292 mutex_lock(&x.lock);293 restore_regs();294 mutex_unlock(&x.lock);295 296 return 0;297}298 299 300/************************************************************************/301/* i2c probing and setup */302/************************************************************************/303 304static void do_attach(struct i2c_adapter *adapter)305{306 struct i2c_board_info info = { };307 struct device_node *np;308 309 /* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */310 static const unsigned short scan_ds1775[] = {311 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,312 I2C_CLIENT_END313 };314 static const unsigned short scan_adm1030[] = {315 0x2c, 0x2d, 0x2e, 0x2f,316 I2C_CLIENT_END317 };318 319 if (x.running || strncmp(adapter->name, "uni-n", 5))320 return;321 322 of_node_get(adapter->dev.of_node);323 np = of_find_compatible_node(adapter->dev.of_node, NULL, "MAC,ds1775");324 if (np) {325 of_node_put(np);326 } else {327 strscpy(info.type, "MAC,ds1775", I2C_NAME_SIZE);328 i2c_new_scanned_device(adapter, &info, scan_ds1775, NULL);329 }330 331 of_node_get(adapter->dev.of_node);332 np = of_find_compatible_node(adapter->dev.of_node, NULL, "MAC,adm1030");333 if (np) {334 of_node_put(np);335 } else {336 strscpy(info.type, "MAC,adm1030", I2C_NAME_SIZE);337 i2c_new_scanned_device(adapter, &info, scan_adm1030, NULL);338 }339}340 341static void342do_remove(struct i2c_client *client)343{344 if (x.running) {345 x.running = 0;346 kthread_stop(x.poll_task);347 x.poll_task = NULL;348 }349 if (client == x.thermostat)350 x.thermostat = NULL;351 else if (client == x.fan)352 x.fan = NULL;353 else354 printk(KERN_ERR "g4fan: bad client\n");355}356 357static int358attach_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 373static int374attach_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;402out:403 return 0;404}405 406enum chip { ds1775, adm1030 };407 408static const struct i2c_device_id therm_windtunnel_id[] = {409 { "MAC,ds1775", ds1775 },410 { "MAC,adm1030", adm1030 },411 { }412};413MODULE_DEVICE_TABLE(i2c, therm_windtunnel_id);414 415static int416do_probe(struct i2c_client *cl)417{418 const struct i2c_device_id *id = i2c_client_get_device_id(cl);419 struct i2c_adapter *adapter = cl->adapter;420 int ret = 0;421 422 if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA423 | I2C_FUNC_SMBUS_WRITE_BYTE) )424 return 0;425 426 switch (id->driver_data) {427 case adm1030:428 ret = attach_fan(cl);429 break;430 case ds1775:431 ret = attach_thermostat(cl);432 break;433 }434 435 if (!x.running && x.thermostat && x.fan) {436 x.running = 1;437 x.poll_task = kthread_run(control_loop, NULL, "g4fand");438 }439 440 return ret;441}442 443static struct i2c_driver g4fan_driver = {444 .driver = {445 .name = "therm_windtunnel",446 },447 .probe = do_probe,448 .remove = do_remove,449 .id_table = therm_windtunnel_id,450};451 452 453/************************************************************************/454/* initialization / cleanup */455/************************************************************************/456 457static int therm_of_probe(struct platform_device *dev)458{459 struct i2c_adapter *adap;460 int ret, i = 0;461 462 adap = i2c_get_adapter(0);463 if (!adap)464 return -EPROBE_DEFER;465 466 ret = i2c_add_driver(&g4fan_driver);467 if (ret) {468 i2c_put_adapter(adap);469 return ret;470 }471 472 /* We assume Macs have consecutive I2C bus numbers starting at 0 */473 while (adap) {474 do_attach(adap);475 if (x.running)476 return 0;477 i2c_put_adapter(adap);478 adap = i2c_get_adapter(++i);479 }480 481 return -ENODEV;482}483 484static void therm_of_remove(struct platform_device *dev)485{486 i2c_del_driver( &g4fan_driver );487}488 489static const struct of_device_id therm_of_match[] = {{490 .name = "fan",491 .compatible = "adm1030"492 }, {}493};494MODULE_DEVICE_TABLE(of, therm_of_match);495 496static struct platform_driver therm_of_driver = {497 .driver = {498 .name = "temperature",499 .of_match_table = therm_of_match,500 },501 .probe = therm_of_probe,502 .remove_new = therm_of_remove,503};504 505struct apple_thermal_info {506 u8 id; /* implementation ID */507 u8 fan_count; /* number of fans */508 u8 thermostat_count; /* number of thermostats */509 u8 unused;510};511 512static int __init513g4fan_init( void )514{515 const struct apple_thermal_info *info;516 struct device_node *np;517 518 mutex_init(&x.lock);519 520 if( !(np=of_find_node_by_name(NULL, "power-mgt")) )521 return -ENODEV;522 info = of_get_property(np, "thermal-info", NULL);523 of_node_put(np);524 525 if( !info || !of_machine_is_compatible("PowerMac3,6") )526 return -ENODEV;527 528 if( info->id != 3 ) {529 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );530 return -ENODEV;531 }532 if( !(np=of_find_node_by_name(NULL, "fan")) )533 return -ENODEV;534 x.of_dev = of_platform_device_create(np, "temperature", NULL);535 of_node_put( np );536 537 if( !x.of_dev ) {538 printk(KERN_ERR "Can't register fan controller!\n");539 return -ENODEV;540 }541 542 platform_driver_register( &therm_of_driver );543 return 0;544}545 546static void __exit547g4fan_exit( void )548{549 platform_driver_unregister( &therm_of_driver );550 551 if( x.of_dev )552 of_platform_device_destroy(&x.of_dev->dev, NULL);553}554 555module_init(g4fan_init);556module_exit(g4fan_exit);557 558MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");559MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");560MODULE_LICENSE("GPL");561