blob: c153699d0f842bed724ae6aaab09bf9e35cfad97 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 * temperatur 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/config.h>
31#include <linux/types.h>
32#include <linux/module.h>
33#include <linux/errno.h>
34#include <linux/kernel.h>
35#include <linux/delay.h>
36#include <linux/sched.h>
37#include <linux/i2c.h>
38#include <linux/slab.h>
39#include <linux/init.h>
40#include <asm/prom.h>
41#include <asm/machdep.h>
42#include <asm/io.h>
43#include <asm/system.h>
44#include <asm/sections.h>
45#include <asm/of_device.h>
46
47#define LOG_TEMP 0 /* continously log temperature */
48
49#define I2C_DRIVERID_G4FAN 0x9001 /* fixme */
50
51static int do_probe( struct i2c_adapter *adapter, int addr, int kind);
52
53/* scan 0x48-0x4f (DS1775) and 0x2c-2x2f (ADM1030) */
54static unsigned short normal_i2c[] = { 0x49, 0x2c, I2C_CLIENT_END };
55static unsigned short normal_i2c_range[] = { 0x48, 0x4f, 0x2c, 0x2f, I2C_CLIENT_END };
56
57I2C_CLIENT_INSMOD;
58
59static struct {
60 volatile int running;
61 struct completion completion;
62 pid_t poll_task;
63
64 struct semaphore lock;
65 struct of_device *of_dev;
66
67 struct i2c_client *thermostat;
68 struct i2c_client *fan;
69
70 int overheat_temp; /* 100% fan at this temp */
71 int overheat_hyst;
72 int temp;
73 int casetemp;
74 int fan_level; /* active fan_table setting */
75
76 int downind;
77 int upind;
78
79 int r0, r1, r20, r23, r25; /* saved register */
80} x;
81
82#define T(x,y) (((x)<<8) | (y)*0x100/10 )
83
84static struct {
85 int fan_down_setting;
86 int temp;
87 int fan_up_setting;
88} fan_table[] = {
89 { 11, T(0,0), 11 }, /* min fan */
90 { 11, T(55,0), 11 },
91 { 6, T(55,3), 11 },
92 { 7, T(56,0), 11 },
93 { 8, T(57,0), 8 },
94 { 7, T(58,3), 7 },
95 { 6, T(58,8), 6 },
96 { 5, T(59,2), 5 },
97 { 4, T(59,6), 4 },
98 { 3, T(59,9), 3 },
99 { 2, T(60,1), 2 },
100 { 1, 0xfffff, 1 } /* on fire */
101};
102
103static void
104print_temp( const char *s, int temp )
105{
106 printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
107}
108
109static ssize_t
110show_cpu_temperature( struct device *dev, char *buf )
111{
112 return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 );
113}
114
115static ssize_t
116show_case_temperature( struct device *dev, char *buf )
117{
118 return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 );
119}
120
121static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );
122static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );
123
124
125
126/************************************************************************/
127/* controller thread */
128/************************************************************************/
129
130static int
131write_reg( struct i2c_client *cl, int reg, int data, int len )
132{
133 u8 tmp[3];
134
135 if( len < 1 || len > 2 || data < 0 )
136 return -EINVAL;
137
138 tmp[0] = reg;
139 tmp[1] = (len == 1) ? data : (data >> 8);
140 tmp[2] = data;
141 len++;
142
143 if( i2c_master_send(cl, tmp, len) != len )
144 return -ENODEV;
145 return 0;
146}
147
148static int
149read_reg( struct i2c_client *cl, int reg, int len )
150{
151 u8 buf[2];
152
153 if( len != 1 && len != 2 )
154 return -EINVAL;
155 buf[0] = reg;
156 if( i2c_master_send(cl, buf, 1) != 1 )
157 return -ENODEV;
158 if( i2c_master_recv(cl, buf, len) != len )
159 return -ENODEV;
160 return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0];
161}
162
163static void
164tune_fan( int fan_setting )
165{
166 int val = (fan_setting << 3) | 7;
167
168 /* write_reg( x.fan, 0x24, val, 1 ); */
169 write_reg( x.fan, 0x25, val, 1 );
170 write_reg( x.fan, 0x20, 0, 1 );
171 print_temp("CPU-temp: ", x.temp );
172 if( x.casetemp )
173 print_temp(", Case: ", x.casetemp );
174 printk(", Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );
175
176 x.fan_level = fan_setting;
177}
178
179static void
180poll_temp( void )
181{
182 int temp, i, level, casetemp;
183
184 temp = read_reg( x.thermostat, 0, 2 );
185
186 /* this actually occurs when the computer is loaded */
187 if( temp < 0 )
188 return;
189
190 casetemp = read_reg(x.fan, 0x0b, 1) << 8;
191 casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;
192
193 if( LOG_TEMP && x.temp != temp ) {
194 print_temp("CPU-temp: ", temp );
195 print_temp(", Case: ", casetemp );
196 printk(", Fan: %d\n", 11-x.fan_level );
197 }
198 x.temp = temp;
199 x.casetemp = casetemp;
200
201 level = -1;
202 for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )
203 ;
204 if( i < x.downind )
205 level = fan_table[i].fan_down_setting;
206 x.downind = i;
207
208 for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )
209 ;
210 if( x.upind < i )
211 level = fan_table[i].fan_up_setting;
212 x.upind = i;
213
214 if( level >= 0 )
215 tune_fan( level );
216}
217
218
219static void
220setup_hardware( void )
221{
222 int val;
223
224 /* save registers (if we unload the module) */
225 x.r0 = read_reg( x.fan, 0x00, 1 );
226 x.r1 = read_reg( x.fan, 0x01, 1 );
227 x.r20 = read_reg( x.fan, 0x20, 1 );
228 x.r23 = read_reg( x.fan, 0x23, 1 );
229 x.r25 = read_reg( x.fan, 0x25, 1 );
230
231 /* improve measurement resolution (convergence time 1.5s) */
232 if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) {
233 val |= 0x60;
234 if( write_reg( x.thermostat, 1, val, 1 ) )
235 printk("Failed writing config register\n");
236 }
237 /* disable interrupts and TAC input */
238 write_reg( x.fan, 0x01, 0x01, 1 );
239 /* enable filter */
240 write_reg( x.fan, 0x23, 0x91, 1 );
241 /* remote temp. controls fan */
242 write_reg( x.fan, 0x00, 0x95, 1 );
243
244 /* The thermostat (which besides measureing temperature controls
245 * has a THERM output which puts the fan on 100%) is usually
246 * set to kick in at 80 C (chip default). We reduce this a bit
247 * to be on the safe side (OSX doesn't)...
248 */
249 if( x.overheat_temp == (80 << 8) ) {
250 x.overheat_temp = 65 << 8;
251 x.overheat_hyst = 60 << 8;
252 write_reg( x.thermostat, 2, x.overheat_hyst, 2 );
253 write_reg( x.thermostat, 3, x.overheat_temp, 2 );
254
255 print_temp("Reducing overheating limit to ", x.overheat_temp );
256 print_temp(" (Hyst: ", x.overheat_hyst );
257 printk(")\n");
258 }
259
260 /* set an initial fan setting */
261 x.downind = 0xffff;
262 x.upind = -1;
263 /* tune_fan( fan_up_table[x.upind].fan_setting ); */
264
265 device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
266 device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
267}
268
269static void
270restore_regs( void )
271{
272 device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
273 device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );
274
275 write_reg( x.fan, 0x01, x.r1, 1 );
276 write_reg( x.fan, 0x20, x.r20, 1 );
277 write_reg( x.fan, 0x23, x.r23, 1 );
278 write_reg( x.fan, 0x25, x.r25, 1 );
279 write_reg( x.fan, 0x00, x.r0, 1 );
280}
281
282static int
283control_loop( void *dummy )
284{
285 daemonize("g4fand");
286
287 down( &x.lock );
288 setup_hardware();
289
290 while( x.running ) {
291 up( &x.lock );
292
293 msleep_interruptible(8000);
294
295 down( &x.lock );
296 poll_temp();
297 }
298
299 restore_regs();
300 up( &x.lock );
301
302 complete_and_exit( &x.completion, 0 );
303}
304
305
306/************************************************************************/
307/* i2c probing and setup */
308/************************************************************************/
309
310static int
311do_attach( struct i2c_adapter *adapter )
312{
313 int ret = 0;
314
315 if( strncmp(adapter->name, "uni-n", 5) )
316 return 0;
317
318 if( !x.running ) {
319 ret = i2c_probe( adapter, &addr_data, &do_probe );
320 if( x.thermostat && x.fan ) {
321 x.running = 1;
322 init_completion( &x.completion );
323 x.poll_task = kernel_thread( control_loop, NULL, SIGCHLD | CLONE_KERNEL );
324 }
325 }
326 return ret;
327}
328
329static int
330do_detach( struct i2c_client *client )
331{
332 int err;
333
334 if( (err=i2c_detach_client(client)) )
335 printk(KERN_ERR "failed to detach thermostat client\n");
336 else {
337 if( x.running ) {
338 x.running = 0;
339 wait_for_completion( &x.completion );
340 }
341 if( client == x.thermostat )
342 x.thermostat = NULL;
343 else if( client == x.fan )
344 x.fan = NULL;
345 else {
346 printk(KERN_ERR "g4fan: bad client\n");
347 }
348 kfree( client );
349 }
350 return err;
351}
352
353static struct i2c_driver g4fan_driver = {
354 .owner = THIS_MODULE,
355 .name = "therm_windtunnel",
356 .id = I2C_DRIVERID_G4FAN,
357 .flags = I2C_DF_NOTIFY,
358 .attach_adapter = do_attach,
359 .detach_client = do_detach,
360};
361
362static int
363attach_fan( struct i2c_client *cl )
364{
365 if( x.fan )
366 goto out;
367
368 /* check that this is an ADM1030 */
369 if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 )
370 goto out;
371 printk("ADM1030 fan controller [@%02x]\n", cl->addr );
372
373 strlcpy( cl->name, "ADM1030 fan controller", sizeof(cl->name) );
374
375 if( !i2c_attach_client(cl) )
376 x.fan = cl;
377 out:
378 if( cl != x.fan )
379 kfree( cl );
380 return 0;
381}
382
383static int
384attach_thermostat( struct i2c_client *cl )
385{
386 int hyst_temp, os_temp, temp;
387
388 if( x.thermostat )
389 goto out;
390
391 if( (temp=read_reg(cl, 0, 2)) < 0 )
392 goto out;
393
394 /* temperature sanity check */
395 if( temp < 0x1600 || temp > 0x3c00 )
396 goto out;
397 hyst_temp = read_reg(cl, 2, 2);
398 os_temp = read_reg(cl, 3, 2);
399 if( hyst_temp < 0 || os_temp < 0 )
400 goto out;
401
402 printk("DS1775 digital thermometer [@%02x]\n", cl->addr );
403 print_temp("Temp: ", temp );
404 print_temp(" Hyst: ", hyst_temp );
405 print_temp(" OS: ", os_temp );
406 printk("\n");
407
408 x.temp = temp;
409 x.overheat_temp = os_temp;
410 x.overheat_hyst = hyst_temp;
411
412 strlcpy( cl->name, "DS1775 thermostat", sizeof(cl->name) );
413
414 if( !i2c_attach_client(cl) )
415 x.thermostat = cl;
416out:
417 if( cl != x.thermostat )
418 kfree( cl );
419 return 0;
420}
421
422static int
423do_probe( struct i2c_adapter *adapter, int addr, int kind )
424{
425 struct i2c_client *cl;
426
427 if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
428 | I2C_FUNC_SMBUS_WRITE_BYTE) )
429 return 0;
430
431 if( !(cl=kmalloc(sizeof(*cl), GFP_KERNEL)) )
432 return -ENOMEM;
433 memset( cl, 0, sizeof(struct i2c_client) );
434
435 cl->addr = addr;
436 cl->adapter = adapter;
437 cl->driver = &g4fan_driver;
438 cl->flags = 0;
439
440 if( addr < 0x48 )
441 return attach_fan( cl );
442 return attach_thermostat( cl );
443}
444
445
446/************************************************************************/
447/* initialization / cleanup */
448/************************************************************************/
449
450static int
451therm_of_probe( struct of_device *dev, const struct of_match *match )
452{
453 return i2c_add_driver( &g4fan_driver );
454}
455
456static int
457therm_of_remove( struct of_device *dev )
458{
459 return i2c_del_driver( &g4fan_driver );
460}
461
462static struct of_match therm_of_match[] = {{
463 .name = "fan",
464 .type = OF_ANY_MATCH,
465 .compatible = "adm1030"
466 }, {}
467};
468
469static struct of_platform_driver therm_of_driver = {
470 .name = "temperature",
471 .match_table = therm_of_match,
472 .probe = therm_of_probe,
473 .remove = therm_of_remove,
474};
475
476struct apple_thermal_info {
477 u8 id; /* implementation ID */
478 u8 fan_count; /* number of fans */
479 u8 thermostat_count; /* number of thermostats */
480 u8 unused;
481};
482
483static int __init
484g4fan_init( void )
485{
486 struct apple_thermal_info *info;
487 struct device_node *np;
488
489 init_MUTEX( &x.lock );
490
491 if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
492 return -ENODEV;
493 info = (struct apple_thermal_info*)get_property(np, "thermal-info", NULL);
494 of_node_put(np);
495
496 if( !info || !machine_is_compatible("PowerMac3,6") )
497 return -ENODEV;
498
499 if( info->id != 3 ) {
500 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );
501 return -ENODEV;
502 }
503 if( !(np=of_find_node_by_name(NULL, "fan")) )
504 return -ENODEV;
505 x.of_dev = of_platform_device_create( np, "temperature" );
506 of_node_put( np );
507
508 if( !x.of_dev ) {
509 printk(KERN_ERR "Can't register fan controller!\n");
510 return -ENODEV;
511 }
512
513 of_register_driver( &therm_of_driver );
514 return 0;
515}
516
517static void __exit
518g4fan_exit( void )
519{
520 of_unregister_driver( &therm_of_driver );
521
522 if( x.of_dev )
523 of_device_unregister( x.of_dev );
524}
525
526module_init(g4fan_init);
527module_exit(g4fan_exit);
528
529MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
530MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
531MODULE_LICENSE("GPL");