therm_windtunnel.c 12 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528
/* 
 *   Creation Date: <2003/03/14 20:54:13 samuel>
 *   Time-stamp: <2004/03/20 14:20:59 samuel>
 *   
 *	<therm_windtunnel.c>
 *	
 *	The G4 "windtunnel" has a single fan controlled by an
 *	ADM1030 fan controller and a DS1775 thermostat.
 *
 *	The fan controller is equipped with a temperature sensor
 *	which measures the case temperature. The DS1775 sensor
 *	measures the CPU temperature. This driver tunes the
 *	behavior of the fan. It is based upon empirical observations
 *	of the 'AppleFan' driver under Mac OS X.
 *
 *	WARNING: This driver has only been testen on Apple's
 *	1.25 MHz Dual G4 (March 03). It is tuned for a CPU
 *	temperature around 57 C.
 *
 *   Copyright (C) 2003, 2004 Samuel Rydh (samuel@ibrium.se)
 *
 *   Loosely based upon 'thermostat.c' written by Benjamin Herrenschmidt
 *   
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation
 *   
 */

#include <linux/types.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kthread.h>
#include <linux/of_platform.h>

#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/sections.h>
#include <asm/macio.h>

#define LOG_TEMP		0			/* continuously log temperature */

static struct {
	volatile int		running;
	struct task_struct	*poll_task;
	
	struct mutex	 	lock;
	struct platform_device	*of_dev;
	
	struct i2c_client	*thermostat;
	struct i2c_client	*fan;

	int			overheat_temp;		/* 100% fan at this temp */
	int			overheat_hyst;
	int			temp;
	int			casetemp;
	int			fan_level;		/* active fan_table setting */

	int			downind;
	int			upind;

	int			r0, r1, r20, r23, r25;	/* saved register */
} x;

#define T(x,y)			(((x)<<8) | (y)*0x100/10 )

static struct {
	int			fan_down_setting;
	int			temp;
	int			fan_up_setting;
} fan_table[] = {
	{ 11, T(0,0),  11 },	/* min fan */
	{ 11, T(55,0), 11 },
	{  6, T(55,3), 11 },
	{  7, T(56,0), 11 },
	{  8, T(57,0), 8 },
	{  7, T(58,3), 7 },
	{  6, T(58,8), 6 },
	{  5, T(59,2), 5 },
	{  4, T(59,6), 4 },
	{  3, T(59,9), 3 },
	{  2, T(60,1), 2 },
	{  1, 0xfffff, 1 }	/* on fire */
};

static void
print_temp( const char *s, int temp )
{
	printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
}

static ssize_t
show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf )
{
	return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 );
}

static ssize_t
show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf )
{
	return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 );
}

static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );
static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );



/************************************************************************/
/*	controller thread						*/
/************************************************************************/

static int
write_reg( struct i2c_client *cl, int reg, int data, int len )
{
	u8 tmp[3];

	if( len < 1 || len > 2 || data < 0 )
		return -EINVAL;

	tmp[0] = reg;
	tmp[1] = (len == 1) ? data : (data >> 8);
	tmp[2] = data;
	len++;
	
	if( i2c_master_send(cl, tmp, len) != len )
		return -ENODEV;
	return 0;
}

static int
read_reg( struct i2c_client *cl, int reg, int len )
{
	u8 buf[2];

	if( len != 1 && len != 2 )
		return -EINVAL;
	buf[0] = reg;
	if( i2c_master_send(cl, buf, 1) != 1 )
		return -ENODEV;
	if( i2c_master_recv(cl, buf, len) != len )
		return -ENODEV;
	return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0];
}

static void
tune_fan( int fan_setting )
{
	int val = (fan_setting << 3) | 7;

	/* write_reg( x.fan, 0x24, val, 1 ); */
	write_reg( x.fan, 0x25, val, 1 );
	write_reg( x.fan, 0x20, 0, 1 );
	print_temp("CPU-temp: ", x.temp );
	if( x.casetemp )
		print_temp(", Case: ", x.casetemp );
	printk(",  Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );

	x.fan_level = fan_setting;
}

static void
poll_temp( void )
{
	int temp, i, level, casetemp;

	temp = read_reg( x.thermostat, 0, 2 );

	/* this actually occurs when the computer is loaded */
	if( temp < 0 )
		return;

	casetemp = read_reg(x.fan, 0x0b, 1) << 8;
	casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;

	if( LOG_TEMP && x.temp != temp ) {
		print_temp("CPU-temp: ", temp );
		print_temp(", Case: ", casetemp );
		printk(",  Fan: %d\n", 11-x.fan_level );
	}
	x.temp = temp;
	x.casetemp = casetemp;

	level = -1;
	for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )
		;
	if( i < x.downind )
		level = fan_table[i].fan_down_setting;
	x.downind = i;

	for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )
		;
	if( x.upind < i )
		level = fan_table[i].fan_up_setting;
	x.upind = i;

	if( level >= 0 )
		tune_fan( level );
}


static void
setup_hardware( void )
{
	int val;
	int err;

	/* save registers (if we unload the module) */
	x.r0 = read_reg( x.fan, 0x00, 1 );
	x.r1 = read_reg( x.fan, 0x01, 1 );
	x.r20 = read_reg( x.fan, 0x20, 1 );
	x.r23 = read_reg( x.fan, 0x23, 1 );
	x.r25 = read_reg( x.fan, 0x25, 1 );

	/* improve measurement resolution (convergence time 1.5s) */
	if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) {
		val |= 0x60;
		if( write_reg( x.thermostat, 1, val, 1 ) )
			printk("Failed writing config register\n");
	}
	/* disable interrupts and TAC input */
	write_reg( x.fan, 0x01, 0x01, 1 );
	/* enable filter */
	write_reg( x.fan, 0x23, 0x91, 1 );
	/* remote temp. controls fan */
	write_reg( x.fan, 0x00, 0x95, 1 );

	/* The thermostat (which besides measureing temperature controls
	 * has a THERM output which puts the fan on 100%) is usually
	 * set to kick in at 80 C (chip default). We reduce this a bit
	 * to be on the safe side (OSX doesn't)...
	 */
	if( x.overheat_temp == (80 << 8) ) {
		x.overheat_temp = 75 << 8;
		x.overheat_hyst = 70 << 8;
		write_reg( x.thermostat, 2, x.overheat_hyst, 2 );
		write_reg( x.thermostat, 3, x.overheat_temp, 2 );

		print_temp("Reducing overheating limit to ", x.overheat_temp );
		print_temp(" (Hyst: ", x.overheat_hyst );
		printk(")\n");
	}

	/* set an initial fan setting */
	x.downind = 0xffff;
	x.upind = -1;
	/* tune_fan( fan_up_table[x.upind].fan_setting ); */

	err = device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
	err |= device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
	if (err)
		printk(KERN_WARNING
			"Failed to create temperature attribute file(s).\n");
}

static void
restore_regs( void )
{
	device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
	device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );

	write_reg( x.fan, 0x01, x.r1, 1 );
	write_reg( x.fan, 0x20, x.r20, 1 );
	write_reg( x.fan, 0x23, x.r23, 1 );
	write_reg( x.fan, 0x25, x.r25, 1 );
	write_reg( x.fan, 0x00, x.r0, 1 );
}

static int control_loop(void *dummy)
{
	mutex_lock(&x.lock);
	setup_hardware();
	mutex_unlock(&x.lock);

	for (;;) {
		msleep_interruptible(8000);
		if (kthread_should_stop())
			break;

		mutex_lock(&x.lock);
		poll_temp();
		mutex_unlock(&x.lock);
	}

	mutex_lock(&x.lock);
	restore_regs();
	mutex_unlock(&x.lock);

	return 0;
}


/************************************************************************/
/*	i2c probing and setup						*/
/************************************************************************/

static int
do_attach( struct i2c_adapter *adapter )
{
	/* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */
	static const unsigned short scan_ds1775[] = {
		0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
		I2C_CLIENT_END
	};
	static const unsigned short scan_adm1030[] = {
		0x2c, 0x2d, 0x2e, 0x2f,
		I2C_CLIENT_END
	};

	if( strncmp(adapter->name, "uni-n", 5) )
		return 0;

	if( !x.running ) {
		struct i2c_board_info info;

		memset(&info, 0, sizeof(struct i2c_board_info));
		strlcpy(info.type, "therm_ds1775", I2C_NAME_SIZE);
		i2c_new_probed_device(adapter, &info, scan_ds1775, NULL);

		strlcpy(info.type, "therm_adm1030", I2C_NAME_SIZE);
		i2c_new_probed_device(adapter, &info, scan_adm1030, NULL);

		if( x.thermostat && x.fan ) {
			x.running = 1;
			x.poll_task = kthread_run(control_loop, NULL, "g4fand");
		}
	}
	return 0;
}

static int
do_remove(struct i2c_client *client)
{
	if (x.running) {
		x.running = 0;
		kthread_stop(x.poll_task);
		x.poll_task = NULL;
	}
	if (client == x.thermostat)
		x.thermostat = NULL;
	else if (client == x.fan)
		x.fan = NULL;
	else
		printk(KERN_ERR "g4fan: bad client\n");

	return 0;
}

static int
attach_fan( struct i2c_client *cl )
{
	if( x.fan )
		goto out;

	/* check that this is an ADM1030 */
	if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 )
		goto out;
	printk("ADM1030 fan controller [@%02x]\n", cl->addr );

	x.fan = cl;
 out:
	return 0;
}

static int
attach_thermostat( struct i2c_client *cl ) 
{
	int hyst_temp, os_temp, temp;

	if( x.thermostat )
		goto out;

	if( (temp=read_reg(cl, 0, 2)) < 0 )
		goto out;
	
	/* temperature sanity check */
	if( temp < 0x1600 || temp > 0x3c00 )
		goto out;
	hyst_temp = read_reg(cl, 2, 2);
	os_temp = read_reg(cl, 3, 2);
	if( hyst_temp < 0 || os_temp < 0 )
		goto out;

	printk("DS1775 digital thermometer [@%02x]\n", cl->addr );
	print_temp("Temp: ", temp );
	print_temp("  Hyst: ", hyst_temp );
	print_temp("  OS: ", os_temp );
	printk("\n");

	x.temp = temp;
	x.overheat_temp = os_temp;
	x.overheat_hyst = hyst_temp;
	x.thermostat = cl;
out:
	return 0;
}

enum chip { ds1775, adm1030 };

static const struct i2c_device_id therm_windtunnel_id[] = {
	{ "therm_ds1775", ds1775 },
	{ "therm_adm1030", adm1030 },
	{ }
};

static int
do_probe(struct i2c_client *cl, const struct i2c_device_id *id)
{
	struct i2c_adapter *adapter = cl->adapter;

	if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
				     | I2C_FUNC_SMBUS_WRITE_BYTE) )
		return 0;

	switch (id->driver_data) {
	case adm1030:
		return attach_fan( cl );
	case ds1775:
		return attach_thermostat(cl);
	}
	return 0;
}

static struct i2c_driver g4fan_driver = {
	.driver = {
		.name	= "therm_windtunnel",
	},
	.attach_adapter = do_attach,
	.probe		= do_probe,
	.remove		= do_remove,
	.id_table	= therm_windtunnel_id,
};


/************************************************************************/
/*	initialization / cleanup					*/
/************************************************************************/

static int therm_of_probe(struct platform_device *dev)
{
	return i2c_add_driver( &g4fan_driver );
}

static int
therm_of_remove( struct platform_device *dev )
{
	i2c_del_driver( &g4fan_driver );
	return 0;
}

static const struct of_device_id therm_of_match[] = {{
	.name		= "fan",
	.compatible	= "adm1030"
    }, {}
};

static struct platform_driver therm_of_driver = {
	.driver = {
		.name = "temperature",
		.owner = THIS_MODULE,
		.of_match_table = therm_of_match,
	},
	.probe		= therm_of_probe,
	.remove		= therm_of_remove,
};

struct apple_thermal_info {
	u8		id;			/* implementation ID */
	u8		fan_count;		/* number of fans */
	u8		thermostat_count;	/* number of thermostats */
	u8		unused;
};

static int __init
g4fan_init( void )
{
	const struct apple_thermal_info *info;
	struct device_node *np;

	mutex_init(&x.lock);

	if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
		return -ENODEV;
	info = of_get_property(np, "thermal-info", NULL);
	of_node_put(np);

	if( !info || !of_machine_is_compatible("PowerMac3,6") )
		return -ENODEV;

	if( info->id != 3 ) {
		printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );
		return -ENODEV;
	}
	if( !(np=of_find_node_by_name(NULL, "fan")) )
		return -ENODEV;
	x.of_dev = of_platform_device_create(np, "temperature", NULL);
	of_node_put( np );

	if( !x.of_dev ) {
		printk(KERN_ERR "Can't register fan controller!\n");
		return -ENODEV;
	}

	platform_driver_register( &therm_of_driver );
	return 0;
}

static void __exit
g4fan_exit( void )
{
	platform_driver_unregister( &therm_of_driver );

	if( x.of_dev )
		of_device_unregister( x.of_dev );
}

module_init(g4fan_init);
module_exit(g4fan_exit);

MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
MODULE_LICENSE("GPL");