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 int
 304do_attach( struct i2c_adapter *adapter )
 305{
 306        /* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */
 307        static const unsigned short scan_ds1775[] = {
 308                0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
 309                I2C_CLIENT_END
 310        };
 311        static const unsigned short scan_adm1030[] = {
 312                0x2c, 0x2d, 0x2e, 0x2f,
 313                I2C_CLIENT_END
 314        };
 315
 316        if( strncmp(adapter->name, "uni-n", 5) )
 317                return 0;
 318
 319        if( !x.running ) {
 320                struct i2c_board_info info;
 321
 322                memset(&info, 0, sizeof(struct i2c_board_info));
 323                strlcpy(info.type, "therm_ds1775", I2C_NAME_SIZE);
 324                i2c_new_probed_device(adapter, &info, scan_ds1775, NULL);
 325
 326                strlcpy(info.type, "therm_adm1030", I2C_NAME_SIZE);
 327                i2c_new_probed_device(adapter, &info, scan_adm1030, NULL);
 328
 329                if( x.thermostat && x.fan ) {
 330                        x.running = 1;
 331                        x.poll_task = kthread_run(control_loop, NULL, "g4fand");
 332                }
 333        }
 334        return 0;
 335}
 336
 337static int
 338do_remove(struct i2c_client *client)
 339{
 340        if (x.running) {
 341                x.running = 0;
 342                kthread_stop(x.poll_task);
 343                x.poll_task = NULL;
 344        }
 345        if (client == x.thermostat)
 346                x.thermostat = NULL;
 347        else if (client == x.fan)
 348                x.fan = NULL;
 349        else
 350                printk(KERN_ERR "g4fan: bad client\n");
 351
 352        return 0;
 353}
 354
 355static int
 356attach_fan( struct i2c_client *cl )
 357{
 358        if( x.fan )
 359                goto out;
 360
 361        /* check that this is an ADM1030 */
 362        if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 )
 363                goto out;
 364        printk("ADM1030 fan controller [@%02x]\n", cl->addr );
 365
 366        x.fan = cl;
 367 out:
 368        return 0;
 369}
 370
 371static int
 372attach_thermostat( struct i2c_client *cl ) 
 373{
 374        int hyst_temp, os_temp, temp;
 375
 376        if( x.thermostat )
 377                goto out;
 378
 379        if( (temp=read_reg(cl, 0, 2)) < 0 )
 380                goto out;
 381        
 382        /* temperature sanity check */
 383        if( temp < 0x1600 || temp > 0x3c00 )
 384                goto out;
 385        hyst_temp = read_reg(cl, 2, 2);
 386        os_temp = read_reg(cl, 3, 2);
 387        if( hyst_temp < 0 || os_temp < 0 )
 388                goto out;
 389
 390        printk("DS1775 digital thermometer [@%02x]\n", cl->addr );
 391        print_temp("Temp: ", temp );
 392        print_temp("  Hyst: ", hyst_temp );
 393        print_temp("  OS: ", os_temp );
 394        printk("\n");
 395
 396        x.temp = temp;
 397        x.overheat_temp = os_temp;
 398        x.overheat_hyst = hyst_temp;
 399        x.thermostat = cl;
 400out:
 401        return 0;
 402}
 403
 404enum chip { ds1775, adm1030 };
 405
 406static const struct i2c_device_id therm_windtunnel_id[] = {
 407        { "therm_ds1775", ds1775 },
 408        { "therm_adm1030", adm1030 },
 409        { }
 410};
 411
 412static int
 413do_probe(struct i2c_client *cl, const struct i2c_device_id *id)
 414{
 415        struct i2c_adapter *adapter = cl->adapter;
 416
 417        if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
 418                                     | I2C_FUNC_SMBUS_WRITE_BYTE) )
 419                return 0;
 420
 421        switch (id->driver_data) {
 422        case adm1030:
 423                return attach_fan( cl );
 424        case ds1775:
 425                return attach_thermostat(cl);
 426        }
 427        return 0;
 428}
 429
 430static struct i2c_driver g4fan_driver = {
 431        .driver = {
 432                .name   = "therm_windtunnel",
 433        },
 434        .attach_adapter = do_attach,
 435        .probe          = do_probe,
 436        .remove         = do_remove,
 437        .id_table       = therm_windtunnel_id,
 438};
 439
 440
 441/************************************************************************/
 442/*      initialization / cleanup                                        */
 443/************************************************************************/
 444
 445static int therm_of_probe(struct platform_device *dev)
 446{
 447        return i2c_add_driver( &g4fan_driver );
 448}
 449
 450static int
 451therm_of_remove( struct platform_device *dev )
 452{
 453        i2c_del_driver( &g4fan_driver );
 454        return 0;
 455}
 456
 457static const struct of_device_id therm_of_match[] = {{
 458        .name           = "fan",
 459        .compatible     = "adm1030"
 460    }, {}
 461};
 462
 463static struct platform_driver therm_of_driver = {
 464        .driver = {
 465                .name = "temperature",
 466                .owner = THIS_MODULE,
 467                .of_match_table = therm_of_match,
 468        },
 469        .probe          = therm_of_probe,
 470        .remove         = therm_of_remove,
 471};
 472
 473struct apple_thermal_info {
 474        u8              id;                     /* implementation ID */
 475        u8              fan_count;              /* number of fans */
 476        u8              thermostat_count;       /* number of thermostats */
 477        u8              unused;
 478};
 479
 480static int __init
 481g4fan_init( void )
 482{
 483        const struct apple_thermal_info *info;
 484        struct device_node *np;
 485
 486        mutex_init(&x.lock);
 487
 488        if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
 489                return -ENODEV;
 490        info = of_get_property(np, "thermal-info", NULL);
 491        of_node_put(np);
 492
 493        if( !info || !of_machine_is_compatible("PowerMac3,6") )
 494                return -ENODEV;
 495
 496        if( info->id != 3 ) {
 497                printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );
 498                return -ENODEV;
 499        }
 500        if( !(np=of_find_node_by_name(NULL, "fan")) )
 501                return -ENODEV;
 502        x.of_dev = of_platform_device_create(np, "temperature", NULL);
 503        of_node_put( np );
 504
 505        if( !x.of_dev ) {
 506                printk(KERN_ERR "Can't register fan controller!\n");
 507                return -ENODEV;
 508        }
 509
 510        platform_driver_register( &therm_of_driver );
 511        return 0;
 512}
 513
 514static void __exit
 515g4fan_exit( void )
 516{
 517        platform_driver_unregister( &therm_of_driver );
 518
 519        if( x.of_dev )
 520                of_device_unregister( x.of_dev );
 521}
 522
 523module_init(g4fan_init);
 524module_exit(g4fan_exit);
 525
 526MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
 527MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
 528MODULE_LICENSE("GPL");
 529
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