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.h>
40 #include <linux/of_platform.h>
41 #include <linux/platform_device.h>
42
43 #include <asm/machdep.h>
44 #include <asm/io.h>
45 #include <asm/sections.h>
46 #include <asm/macio.h>
47
48 #define LOG_TEMP 0 /* continuously log temperature */
49
50 static struct {
51 volatile int running;
52 struct task_struct *poll_task;
53
54 struct mutex lock;
55 struct platform_device *of_dev;
56
57 struct i2c_client *thermostat;
58 struct i2c_client *fan;
59
60 int overheat_temp; /* 100% fan at this temp */
61 int overheat_hyst;
62 int temp;
63 int casetemp;
64 int fan_level; /* active fan_table setting */
65
66 int downind;
67 int upind;
68
69 int r0, r1, r20, r23, r25; /* saved register */
70 } x;
71
72 #define T(x,y) (((x)<<8) | (y)*0x100/10 )
73
74 static struct {
75 int fan_down_setting;
76 int temp;
77 int fan_up_setting;
78 } fan_table[] = {
79 { 11, T(0,0), 11 }, /* min fan */
80 { 11, T(55,0), 11 },
81 { 6, T(55,3), 11 },
82 { 7, T(56,0), 11 },
83 { 8, T(57,0), 8 },
84 { 7, T(58,3), 7 },
85 { 6, T(58,8), 6 },
86 { 5, T(59,2), 5 },
87 { 4, T(59,6), 4 },
88 { 3, T(59,9), 3 },
89 { 2, T(60,1), 2 },
90 { 1, 0xfffff, 1 } /* on fire */
91 };
92
93 static void
print_temp(const char * s,int temp)94 print_temp( const char *s, int temp )
95 {
96 printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
97 }
98
99 static ssize_t
show_cpu_temperature(struct device * dev,struct device_attribute * attr,char * buf)100 show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf )
101 {
102 return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 );
103 }
104
105 static ssize_t
show_case_temperature(struct device * dev,struct device_attribute * attr,char * buf)106 show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf )
107 {
108 return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 );
109 }
110
111 static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );
112 static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );
113
114
115
116 /************************************************************************/
117 /* controller thread */
118 /************************************************************************/
119
120 static int
write_reg(struct i2c_client * cl,int reg,int data,int len)121 write_reg( struct i2c_client *cl, int reg, int data, int len )
122 {
123 u8 tmp[3];
124
125 if( len < 1 || len > 2 || data < 0 )
126 return -EINVAL;
127
128 tmp[0] = reg;
129 tmp[1] = (len == 1) ? data : (data >> 8);
130 tmp[2] = data;
131 len++;
132
133 if( i2c_master_send(cl, tmp, len) != len )
134 return -ENODEV;
135 return 0;
136 }
137
138 static int
read_reg(struct i2c_client * cl,int reg,int len)139 read_reg( struct i2c_client *cl, int reg, int len )
140 {
141 u8 buf[2];
142
143 if( len != 1 && len != 2 )
144 return -EINVAL;
145 buf[0] = reg;
146 if( i2c_master_send(cl, buf, 1) != 1 )
147 return -ENODEV;
148 if( i2c_master_recv(cl, buf, len) != len )
149 return -ENODEV;
150 return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0];
151 }
152
153 static void
tune_fan(int fan_setting)154 tune_fan( int fan_setting )
155 {
156 int val = (fan_setting << 3) | 7;
157
158 /* write_reg( x.fan, 0x24, val, 1 ); */
159 write_reg( x.fan, 0x25, val, 1 );
160 write_reg( x.fan, 0x20, 0, 1 );
161 print_temp("CPU-temp: ", x.temp );
162 if( x.casetemp )
163 print_temp(", Case: ", x.casetemp );
164 printk(", Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );
165
166 x.fan_level = fan_setting;
167 }
168
169 static void
poll_temp(void)170 poll_temp( void )
171 {
172 int temp, i, level, casetemp;
173
174 temp = read_reg( x.thermostat, 0, 2 );
175
176 /* this actually occurs when the computer is loaded */
177 if( temp < 0 )
178 return;
179
180 casetemp = read_reg(x.fan, 0x0b, 1) << 8;
181 casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;
182
183 if( LOG_TEMP && x.temp != temp ) {
184 print_temp("CPU-temp: ", temp );
185 print_temp(", Case: ", casetemp );
186 printk(", Fan: %d\n", 11-x.fan_level );
187 }
188 x.temp = temp;
189 x.casetemp = casetemp;
190
191 level = -1;
192 for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )
193 ;
194 if( i < x.downind )
195 level = fan_table[i].fan_down_setting;
196 x.downind = i;
197
198 for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )
199 ;
200 if( x.upind < i )
201 level = fan_table[i].fan_up_setting;
202 x.upind = i;
203
204 if( level >= 0 )
205 tune_fan( level );
206 }
207
208
209 static void
setup_hardware(void)210 setup_hardware( void )
211 {
212 int val;
213 int err;
214
215 /* save registers (if we unload the module) */
216 x.r0 = read_reg( x.fan, 0x00, 1 );
217 x.r1 = read_reg( x.fan, 0x01, 1 );
218 x.r20 = read_reg( x.fan, 0x20, 1 );
219 x.r23 = read_reg( x.fan, 0x23, 1 );
220 x.r25 = read_reg( x.fan, 0x25, 1 );
221
222 /* improve measurement resolution (convergence time 1.5s) */
223 if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) {
224 val |= 0x60;
225 if( write_reg( x.thermostat, 1, val, 1 ) )
226 printk("Failed writing config register\n");
227 }
228 /* disable interrupts and TAC input */
229 write_reg( x.fan, 0x01, 0x01, 1 );
230 /* enable filter */
231 write_reg( x.fan, 0x23, 0x91, 1 );
232 /* remote temp. controls fan */
233 write_reg( x.fan, 0x00, 0x95, 1 );
234
235 /* The thermostat (which besides measureing temperature controls
236 * has a THERM output which puts the fan on 100%) is usually
237 * set to kick in at 80 C (chip default). We reduce this a bit
238 * to be on the safe side (OSX doesn't)...
239 */
240 if( x.overheat_temp == (80 << 8) ) {
241 x.overheat_temp = 75 << 8;
242 x.overheat_hyst = 70 << 8;
243 write_reg( x.thermostat, 2, x.overheat_hyst, 2 );
244 write_reg( x.thermostat, 3, x.overheat_temp, 2 );
245
246 print_temp("Reducing overheating limit to ", x.overheat_temp );
247 print_temp(" (Hyst: ", x.overheat_hyst );
248 printk(")\n");
249 }
250
251 /* set an initial fan setting */
252 x.downind = 0xffff;
253 x.upind = -1;
254 /* tune_fan( fan_up_table[x.upind].fan_setting ); */
255
256 err = device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
257 err |= device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
258 if (err)
259 printk(KERN_WARNING
260 "Failed to create temperature attribute file(s).\n");
261 }
262
263 static void
restore_regs(void)264 restore_regs( void )
265 {
266 device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
267 device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );
268
269 write_reg( x.fan, 0x01, x.r1, 1 );
270 write_reg( x.fan, 0x20, x.r20, 1 );
271 write_reg( x.fan, 0x23, x.r23, 1 );
272 write_reg( x.fan, 0x25, x.r25, 1 );
273 write_reg( x.fan, 0x00, x.r0, 1 );
274 }
275
control_loop(void * dummy)276 static int control_loop(void *dummy)
277 {
278 mutex_lock(&x.lock);
279 setup_hardware();
280 mutex_unlock(&x.lock);
281
282 for (;;) {
283 msleep_interruptible(8000);
284 if (kthread_should_stop())
285 break;
286
287 mutex_lock(&x.lock);
288 poll_temp();
289 mutex_unlock(&x.lock);
290 }
291
292 mutex_lock(&x.lock);
293 restore_regs();
294 mutex_unlock(&x.lock);
295
296 return 0;
297 }
298
299
300 /************************************************************************/
301 /* i2c probing and setup */
302 /************************************************************************/
303
do_attach(struct i2c_adapter * adapter)304 static void do_attach(struct i2c_adapter *adapter)
305 {
306 struct i2c_board_info info = { };
307 struct device_node *np;
308
309 /* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */
310 static const unsigned short scan_ds1775[] = {
311 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
312 I2C_CLIENT_END
313 };
314 static const unsigned short scan_adm1030[] = {
315 0x2c, 0x2d, 0x2e, 0x2f,
316 I2C_CLIENT_END
317 };
318
319 if (x.running || strncmp(adapter->name, "uni-n", 5))
320 return;
321
322 of_node_get(adapter->dev.of_node);
323 np = of_find_compatible_node(adapter->dev.of_node, NULL, "MAC,ds1775");
324 if (np) {
325 of_node_put(np);
326 } else {
327 strscpy(info.type, "MAC,ds1775", I2C_NAME_SIZE);
328 i2c_new_scanned_device(adapter, &info, scan_ds1775, NULL);
329 }
330
331 of_node_get(adapter->dev.of_node);
332 np = of_find_compatible_node(adapter->dev.of_node, NULL, "MAC,adm1030");
333 if (np) {
334 of_node_put(np);
335 } else {
336 strscpy(info.type, "MAC,adm1030", I2C_NAME_SIZE);
337 i2c_new_scanned_device(adapter, &info, scan_adm1030, NULL);
338 }
339 }
340
341 static void
do_remove(struct i2c_client * client)342 do_remove(struct i2c_client *client)
343 {
344 if (x.running) {
345 x.running = 0;
346 kthread_stop(x.poll_task);
347 x.poll_task = NULL;
348 }
349 if (client == x.thermostat)
350 x.thermostat = NULL;
351 else if (client == x.fan)
352 x.fan = NULL;
353 else
354 printk(KERN_ERR "g4fan: bad client\n");
355 }
356
357 static int
attach_fan(struct i2c_client * cl)358 attach_fan( struct i2c_client *cl )
359 {
360 if( x.fan )
361 goto out;
362
363 /* check that this is an ADM1030 */
364 if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 )
365 goto out;
366 printk("ADM1030 fan controller [@%02x]\n", cl->addr );
367
368 x.fan = cl;
369 out:
370 return 0;
371 }
372
373 static int
attach_thermostat(struct i2c_client * cl)374 attach_thermostat( struct i2c_client *cl )
375 {
376 int hyst_temp, os_temp, temp;
377
378 if( x.thermostat )
379 goto out;
380
381 if( (temp=read_reg(cl, 0, 2)) < 0 )
382 goto out;
383
384 /* temperature sanity check */
385 if( temp < 0x1600 || temp > 0x3c00 )
386 goto out;
387 hyst_temp = read_reg(cl, 2, 2);
388 os_temp = read_reg(cl, 3, 2);
389 if( hyst_temp < 0 || os_temp < 0 )
390 goto out;
391
392 printk("DS1775 digital thermometer [@%02x]\n", cl->addr );
393 print_temp("Temp: ", temp );
394 print_temp(" Hyst: ", hyst_temp );
395 print_temp(" OS: ", os_temp );
396 printk("\n");
397
398 x.temp = temp;
399 x.overheat_temp = os_temp;
400 x.overheat_hyst = hyst_temp;
401 x.thermostat = cl;
402 out:
403 return 0;
404 }
405
406 enum chip { ds1775, adm1030 };
407
408 static const struct i2c_device_id therm_windtunnel_id[] = {
409 { "MAC,ds1775", ds1775 },
410 { "MAC,adm1030", adm1030 },
411 { }
412 };
413 MODULE_DEVICE_TABLE(i2c, therm_windtunnel_id);
414
415 static int
do_probe(struct i2c_client * cl)416 do_probe(struct i2c_client *cl)
417 {
418 const struct i2c_device_id *id = i2c_client_get_device_id(cl);
419 struct i2c_adapter *adapter = cl->adapter;
420 int ret = 0;
421
422 if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
423 | I2C_FUNC_SMBUS_WRITE_BYTE) )
424 return 0;
425
426 switch (id->driver_data) {
427 case adm1030:
428 ret = attach_fan(cl);
429 break;
430 case ds1775:
431 ret = attach_thermostat(cl);
432 break;
433 }
434
435 if (!x.running && x.thermostat && x.fan) {
436 x.running = 1;
437 x.poll_task = kthread_run(control_loop, NULL, "g4fand");
438 }
439
440 return ret;
441 }
442
443 static struct i2c_driver g4fan_driver = {
444 .driver = {
445 .name = "therm_windtunnel",
446 },
447 .probe = do_probe,
448 .remove = do_remove,
449 .id_table = therm_windtunnel_id,
450 };
451
452
453 /************************************************************************/
454 /* initialization / cleanup */
455 /************************************************************************/
456
therm_of_probe(struct platform_device * dev)457 static int therm_of_probe(struct platform_device *dev)
458 {
459 struct i2c_adapter *adap;
460 int ret, i = 0;
461
462 adap = i2c_get_adapter(0);
463 if (!adap)
464 return -EPROBE_DEFER;
465
466 ret = i2c_add_driver(&g4fan_driver);
467 if (ret) {
468 i2c_put_adapter(adap);
469 return ret;
470 }
471
472 /* We assume Macs have consecutive I2C bus numbers starting at 0 */
473 while (adap) {
474 do_attach(adap);
475 if (x.running)
476 return 0;
477 i2c_put_adapter(adap);
478 adap = i2c_get_adapter(++i);
479 }
480
481 return -ENODEV;
482 }
483
therm_of_remove(struct platform_device * dev)484 static void therm_of_remove(struct platform_device *dev)
485 {
486 i2c_del_driver( &g4fan_driver );
487 }
488
489 static const struct of_device_id therm_of_match[] = {{
490 .name = "fan",
491 .compatible = "adm1030"
492 }, {}
493 };
494 MODULE_DEVICE_TABLE(of, therm_of_match);
495
496 static 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
505 struct 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
512 static int __init
g4fan_init(void)513 g4fan_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
546 static void __exit
g4fan_exit(void)547 g4fan_exit( void )
548 {
549 platform_driver_unregister( &therm_of_driver );
550
551 if( x.of_dev )
552 of_platform_device_destroy(&x.of_dev->dev, NULL);
553 }
554
555 module_init(g4fan_init);
556 module_exit(g4fan_exit);
557
558 MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
559 MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
560 MODULE_LICENSE("GPL");
561