aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/macintosh/therm_windtunnel.c
blob: 8b9364434aa0bbd21995c9b299c021075fabfb30 (plain)
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
 *	temperatur 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/slab.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/system.h>
#include <asm/sections.h>
#include <asm/macio.h>

#define LOG_TEMP		0			/* continously log temperature */

static struct {
	volatile int		running;
	struct task_struct	*poll_task;
	
	struct mutex	 	lock;
	struct of_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);

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

		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 of_device *dev, const struct of_device_id *match )
{
	return i2c_add_driver( &g4fan_driver );
}

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

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

static struct of_platform_driver therm_of_driver = {
	.name		= "temperature",
	.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 || !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;
	}

	of_register_platform_driver( &therm_of_driver );
	return 0;
}

static void __exit
g4fan_exit( void )
{
	of_unregister_platform_driver( &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");