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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};
411MODULE_DEVICE_TABLE(i2c, therm_windtunnel_id);
412
413static int
414do_probe(struct i2c_client *cl, const struct i2c_device_id *id)
415{
416 struct i2c_adapter *adapter = cl->adapter;
417
418 if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
419 | I2C_FUNC_SMBUS_WRITE_BYTE) )
420 return 0;
421
422 switch (id->driver_data) {
423 case adm1030:
424 return attach_fan( cl );
425 case ds1775:
426 return attach_thermostat(cl);
427 }
428 return 0;
429}
430
431static struct i2c_driver g4fan_driver = {
432 .driver = {
433 .name = "therm_windtunnel",
434 },
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 struct i2c_adapter *adap;
448 int ret, i = 0;
449
450 adap = i2c_get_adapter(0);
451 if (!adap)
452 return -EPROBE_DEFER;
453
454 ret = i2c_add_driver(&g4fan_driver);
455 if (ret) {
456 i2c_put_adapter(adap);
457 return ret;
458 }
459
460 /* We assume Macs have consecutive I2C bus numbers starting at 0 */
461 while (adap) {
462 do_attach(adap);
463 if (x.running)
464 return 0;
465 i2c_put_adapter(adap);
466 adap = i2c_get_adapter(++i);
467 }
468
469 return -ENODEV;
470}
471
472static int
473therm_of_remove( struct platform_device *dev )
474{
475 i2c_del_driver( &g4fan_driver );
476 return 0;
477}
478
479static const struct of_device_id therm_of_match[] = {{
480 .name = "fan",
481 .compatible = "adm1030"
482 }, {}
483};
484MODULE_DEVICE_TABLE(of, therm_of_match);
485
486static struct platform_driver therm_of_driver = {
487 .driver = {
488 .name = "temperature",
489 .of_match_table = therm_of_match,
490 },
491 .probe = therm_of_probe,
492 .remove = therm_of_remove,
493};
494
495struct apple_thermal_info {
496 u8 id; /* implementation ID */
497 u8 fan_count; /* number of fans */
498 u8 thermostat_count; /* number of thermostats */
499 u8 unused;
500};
501
502static int __init
503g4fan_init( void )
504{
505 const struct apple_thermal_info *info;
506 struct device_node *np;
507
508 mutex_init(&x.lock);
509
510 if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
511 return -ENODEV;
512 info = of_get_property(np, "thermal-info", NULL);
513 of_node_put(np);
514
515 if( !info || !of_machine_is_compatible("PowerMac3,6") )
516 return -ENODEV;
517
518 if( info->id != 3 ) {
519 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );
520 return -ENODEV;
521 }
522 if( !(np=of_find_node_by_name(NULL, "fan")) )
523 return -ENODEV;
524 x.of_dev = of_platform_device_create(np, "temperature", NULL);
525 of_node_put( np );
526
527 if( !x.of_dev ) {
528 printk(KERN_ERR "Can't register fan controller!\n");
529 return -ENODEV;
530 }
531
532 platform_driver_register( &therm_of_driver );
533 return 0;
534}
535
536static void __exit
537g4fan_exit( void )
538{
539 platform_driver_unregister( &therm_of_driver );
540
541 if( x.of_dev )
542 of_device_unregister( x.of_dev );
543}
544
545module_init(g4fan_init);
546module_exit(g4fan_exit);
547
548MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
549MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
550MODULE_LICENSE("GPL");
551

Warning: That file was not part of the compilation database. It may have many parsing errors.