linux/drivers/macintosh/therm_windtunnel.c
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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 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 *      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 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/init.h>
  38#include <linux/kthread.h>
  39#include <linux/of_platform.h>
  40
  41#include <asm/prom.h>
  42#include <asm/machdep.h>
  43#include <asm/io.h>
  44#include <asm/sections.h>
  45#include <asm/macio.h>
  46
  47#define LOG_TEMP                0                       /* continuously log temperature */
  48
  49static struct {
  50        volatile int            running;
  51        struct task_struct      *poll_task;
  52        
  53        struct mutex            lock;
  54        struct platform_device  *of_dev;
  55        
  56        struct i2c_client       *thermostat;
  57        struct i2c_client       *fan;
  58
  59        int                     overheat_temp;          /* 100% fan at this temp */
  60        int                     overheat_hyst;
  61        int                     temp;
  62        int                     casetemp;
  63        int                     fan_level;              /* active fan_table setting */
  64
  65        int                     downind;
  66        int                     upind;
  67
  68        int                     r0, r1, r20, r23, r25;  /* saved register */
  69} x;
  70
  71#define T(x,y)                  (((x)<<8) | (y)*0x100/10 )
  72
  73static struct {
  74        int                     fan_down_setting;
  75        int                     temp;
  76        int                     fan_up_setting;
  77} fan_table[] = {
  78        { 11, T(0,0),  11 },    /* min fan */
  79        { 11, T(55,0), 11 },
  80        {  6, T(55,3), 11 },
  81        {  7, T(56,0), 11 },
  82        {  8, T(57,0), 8 },
  83        {  7, T(58,3), 7 },
  84        {  6, T(58,8), 6 },
  85        {  5, T(59,2), 5 },
  86        {  4, T(59,6), 4 },
  87        {  3, T(59,9), 3 },
  88        {  2, T(60,1), 2 },
  89        {  1, 0xfffff, 1 }      /* on fire */
  90};
  91
  92static void
  93print_temp( const char *s, int temp )
  94{
  95        printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
  96}
  97
  98static ssize_t
  99show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf )
 100{
 101        return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 );
 102}
 103
 104static ssize_t
 105show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf )
 106{
 107        return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 );
 108}
 109
 110static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );
 111static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );
 112
 113
 114
 115/************************************************************************/
 116/*      controller thread                                               */
 117/************************************************************************/
 118
 119static int
 120write_reg( struct i2c_client *cl, int reg, int data, int len )
 121{
 122        u8 tmp[3];
 123
 124        if( len < 1 || len > 2 || data < 0 )
 125                return -EINVAL;
 126
 127        tmp[0] = reg;
 128        tmp[1] = (len == 1) ? data : (data >> 8);
 129        tmp[2] = data;
 130        len++;
 131        
 132        if( i2c_master_send(cl, tmp, len) != len )
 133                return -ENODEV;
 134        return 0;
 135}
 136
 137static int
 138read_reg( struct i2c_client *cl, int reg, int len )
 139{
 140        u8 buf[2];
 141
 142        if( len != 1 && len != 2 )
 143                return -EINVAL;
 144        buf[0] = reg;
 145        if( i2c_master_send(cl, buf, 1) != 1 )
 146                return -ENODEV;
 147        if( i2c_master_recv(cl, buf, len) != len )
 148                return -ENODEV;
 149        return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0];
 150}
 151
 152static void
 153tune_fan( int fan_setting )
 154{
 155        int val = (fan_setting << 3) | 7;
 156
 157        /* write_reg( x.fan, 0x24, val, 1 ); */
 158        write_reg( x.fan, 0x25, val, 1 );
 159        write_reg( x.fan, 0x20, 0, 1 );
 160        print_temp("CPU-temp: ", x.temp );
 161        if( x.casetemp )
 162                print_temp(", Case: ", x.casetemp );
 163        printk(",  Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );
 164
 165        x.fan_level = fan_setting;
 166}
 167
 168static void
 169poll_temp( void )
 170{
 171        int temp, i, level, casetemp;
 172
 173        temp = read_reg( x.thermostat, 0, 2 );
 174
 175        /* this actually occurs when the computer is loaded */
 176        if( temp < 0 )
 177                return;
 178
 179        casetemp = read_reg(x.fan, 0x0b, 1) << 8;
 180        casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;
 181
 182        if( LOG_TEMP && x.temp != temp ) {
 183                print_temp("CPU-temp: ", temp );
 184                print_temp(", Case: ", casetemp );
 185                printk(",  Fan: %d\n", 11-x.fan_level );
 186        }
 187        x.temp = temp;
 188        x.casetemp = casetemp;
 189
 190        level = -1;
 191        for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )
 192                ;
 193        if( i < x.downind )
 194                level = fan_table[i].fan_down_setting;
 195        x.downind = i;
 196
 197        for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )
 198                ;
 199        if( x.upind < i )
 200                level = fan_table[i].fan_up_setting;
 201        x.upind = i;
 202
 203        if( level >= 0 )
 204                tune_fan( level );
 205}
 206
 207
 208static void
 209setup_hardware( void )
 210{
 211        int val;
 212        int err;
 213
 214        /* save registers (if we unload the module) */
 215        x.r0 = read_reg( x.fan, 0x00, 1 );
 216        x.r1 = read_reg( x.fan, 0x01, 1 );
 217        x.r20 = read_reg( x.fan, 0x20, 1 );
 218        x.r23 = read_reg( x.fan, 0x23, 1 );
 219        x.r25 = read_reg( x.fan, 0x25, 1 );
 220
 221        /* improve measurement resolution (convergence time 1.5s) */
 222        if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) {
 223                val |= 0x60;
 224                if( write_reg( x.thermostat, 1, val, 1 ) )
 225                        printk("Failed writing config register\n");
 226        }
 227        /* disable interrupts and TAC input */
 228        write_reg( x.fan, 0x01, 0x01, 1 );
 229        /* enable filter */
 230        write_reg( x.fan, 0x23, 0x91, 1 );
 231        /* remote temp. controls fan */
 232        write_reg( x.fan, 0x00, 0x95, 1 );
 233
 234        /* The thermostat (which besides measureing temperature controls
 235         * has a THERM output which puts the fan on 100%) is usually
 236         * set to kick in at 80 C (chip default). We reduce this a bit
 237         * to be on the safe side (OSX doesn't)...
 238         */
 239        if( x.overheat_temp == (80 << 8) ) {
 240                x.overheat_temp = 75 << 8;
 241                x.overheat_hyst = 70 << 8;
 242                write_reg( x.thermostat, 2, x.overheat_hyst, 2 );
 243                write_reg( x.thermostat, 3, x.overheat_temp, 2 );
 244
 245                print_temp("Reducing overheating limit to ", x.overheat_temp );
 246                print_temp(" (Hyst: ", x.overheat_hyst );
 247                printk(")\n");
 248        }
 249
 250        /* set an initial fan setting */
 251        x.downind = 0xffff;
 252        x.upind = -1;
 253        /* tune_fan( fan_up_table[x.upind].fan_setting ); */
 254
 255        err = device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 256        err |= device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
 257        if (err)
 258                printk(KERN_WARNING
 259                        "Failed to create temperature attribute file(s).\n");
 260}
 261
 262static void
 263restore_regs( void )
 264{
 265        device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
 266        device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );
 267
 268        write_reg( x.fan, 0x01, x.r1, 1 );
 269        write_reg( x.fan, 0x20, x.r20, 1 );
 270        write_reg( x.fan, 0x23, x.r23, 1 );
 271        write_reg( x.fan, 0x25, x.r25, 1 );
 272        write_reg( x.fan, 0x00, x.r0, 1 );
 273}
 274
 275static int control_loop(void *dummy)
 276{
 277        mutex_lock(&x.lock);
 278        setup_hardware();
 279        mutex_unlock(&x.lock);
 280
 281        for (;;) {
 282                msleep_interruptible(8000);
 283                if (kthread_should_stop())
 284                        break;
 285
 286                mutex_lock(&x.lock);
 287                poll_temp();
 288                mutex_unlock(&x.lock);
 289        }
 290
 291        mutex_lock(&x.lock);
 292        restore_regs();
 293        mutex_unlock(&x.lock);
 294
 295        return 0;
 296}
 297
 298
 299/************************************************************************/
 300/*      i2c probing and setup                                           */
 301/************************************************************************/
 302
 303static void do_attach(struct i2c_adapter *adapter)
 304{
 305        struct i2c_board_info info = { };
 306        struct device_node *np;
 307
 308        /* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */
 309        static const unsigned short scan_ds1775[] = {
 310                0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
 311                I2C_CLIENT_END
 312        };
 313        static const unsigned short scan_adm1030[] = {
 314                0x2c, 0x2d, 0x2e, 0x2f,
 315                I2C_CLIENT_END
 316        };
 317
 318        if (x.running || strncmp(adapter->name, "uni-n", 5))
 319                return;
 320
 321        np = of_find_compatible_node(adapter->dev.of_node, NULL, "MAC,ds1775");
 322        if (np) {
 323                of_node_put(np);
 324        } else {
 325                strlcpy(info.type, "MAC,ds1775", I2C_NAME_SIZE);
 326                i2c_new_scanned_device(adapter, &info, scan_ds1775, NULL);
 327        }
 328
 329        np = of_find_compatible_node(adapter->dev.of_node, NULL, "MAC,adm1030");
 330        if (np) {
 331                of_node_put(np);
 332        } else {
 333                strlcpy(info.type, "MAC,adm1030", I2C_NAME_SIZE);
 334                i2c_new_scanned_device(adapter, &info, scan_adm1030, NULL);
 335        }
 336}
 337
 338static int
 339do_remove(struct i2c_client *client)
 340{
 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        return 0;
 354}
 355
 356static int
 357attach_fan( struct i2c_client *cl )
 358{
 359        if( x.fan )
 360                goto out;
 361
 362        /* check that this is an ADM1030 */
 363        if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 )
 364                goto out;
 365        printk("ADM1030 fan controller [@%02x]\n", cl->addr );
 366
 367        x.fan = cl;
 368 out:
 369        return 0;
 370}
 371
 372static int
 373attach_thermostat( struct i2c_client *cl ) 
 374{
 375        int hyst_temp, os_temp, temp;
 376
 377        if( x.thermostat )
 378                goto out;
 379
 380        if( (temp=read_reg(cl, 0, 2)) < 0 )
 381                goto out;
 382        
 383        /* temperature sanity check */
 384        if( temp < 0x1600 || temp > 0x3c00 )
 385                goto out;
 386        hyst_temp = read_reg(cl, 2, 2);
 387        os_temp = read_reg(cl, 3, 2);
 388        if( hyst_temp < 0 || os_temp < 0 )
 389                goto out;
 390
 391        printk("DS1775 digital thermometer [@%02x]\n", cl->addr );
 392        print_temp("Temp: ", temp );
 393        print_temp("  Hyst: ", hyst_temp );
 394        print_temp("  OS: ", os_temp );
 395        printk("\n");
 396
 397        x.temp = temp;
 398        x.overheat_temp = os_temp;
 399        x.overheat_hyst = hyst_temp;
 400        x.thermostat = cl;
 401out:
 402        return 0;
 403}
 404
 405enum chip { ds1775, adm1030 };
 406
 407static const struct i2c_device_id therm_windtunnel_id[] = {
 408        { "MAC,ds1775", ds1775 },
 409        { "MAC,adm1030", adm1030 },
 410        { }
 411};
 412MODULE_DEVICE_TABLE(i2c, therm_windtunnel_id);
 413
 414static int
 415do_probe(struct i2c_client *cl, const struct i2c_device_id *id)
 416{
 417        struct i2c_adapter *adapter = cl->adapter;
 418        int ret = 0;
 419
 420        if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
 421                                     | I2C_FUNC_SMBUS_WRITE_BYTE) )
 422                return 0;
 423
 424        switch (id->driver_data) {
 425        case adm1030:
 426                ret = attach_fan(cl);
 427                break;
 428        case ds1775:
 429                ret = attach_thermostat(cl);
 430                break;
 431        }
 432
 433        if (!x.running && x.thermostat && x.fan) {
 434                x.running = 1;
 435                x.poll_task = kthread_run(control_loop, NULL, "g4fand");
 436        }
 437
 438        return ret;
 439}
 440
 441static struct i2c_driver g4fan_driver = {
 442        .driver = {
 443                .name   = "therm_windtunnel",
 444        },
 445        .probe          = do_probe,
 446        .remove         = do_remove,
 447        .id_table       = therm_windtunnel_id,
 448};
 449
 450
 451/************************************************************************/
 452/*      initialization / cleanup                                        */
 453/************************************************************************/
 454
 455static int therm_of_probe(struct platform_device *dev)
 456{
 457        struct i2c_adapter *adap;
 458        int ret, i = 0;
 459
 460        adap = i2c_get_adapter(0);
 461        if (!adap)
 462                return -EPROBE_DEFER;
 463
 464        ret = i2c_add_driver(&g4fan_driver);
 465        if (ret) {
 466                i2c_put_adapter(adap);
 467                return ret;
 468        }
 469
 470        /* We assume Macs have consecutive I2C bus numbers starting at 0 */
 471        while (adap) {
 472                do_attach(adap);
 473                if (x.running)
 474                        return 0;
 475                i2c_put_adapter(adap);
 476                adap = i2c_get_adapter(++i);
 477        }
 478
 479        return -ENODEV;
 480}
 481
 482static int
 483therm_of_remove( struct platform_device *dev )
 484{
 485        i2c_del_driver( &g4fan_driver );
 486        return 0;
 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         = 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 __init
 513g4fan_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 __exit
 547g4fan_exit( void )
 548{
 549        platform_driver_unregister( &therm_of_driver );
 550
 551        if( x.of_dev )
 552                of_device_unregister( x.of_dev );
 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