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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
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#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/slab.h>
38#include <linux/init.h>
39#include <asm/prom.h>
40#include <asm/machdep.h>
41#include <asm/io.h>
42#include <asm/system.h>
43#include <asm/sections.h>
44#include <asm/of_device.h>
Jeff Mahoney5e655772005-07-06 15:44:41 -040045#include <asm/macio.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
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) */
Jean Delvareb3d5496e2005-04-02 20:31:02 +020054static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
55 0x4c, 0x4d, 0x4e, 0x4f,
56 0x2c, 0x2d, 0x2e, 0x2f,
57 I2C_CLIENT_END };
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
59I2C_CLIENT_INSMOD;
60
61static struct {
62 volatile int running;
63 struct completion completion;
64 pid_t poll_task;
65
66 struct semaphore lock;
67 struct of_device *of_dev;
68
69 struct i2c_client *thermostat;
70 struct i2c_client *fan;
71
72 int overheat_temp; /* 100% fan at this temp */
73 int overheat_hyst;
74 int temp;
75 int casetemp;
76 int fan_level; /* active fan_table setting */
77
78 int downind;
79 int upind;
80
81 int r0, r1, r20, r23, r25; /* saved register */
82} x;
83
84#define T(x,y) (((x)<<8) | (y)*0x100/10 )
85
86static struct {
87 int fan_down_setting;
88 int temp;
89 int fan_up_setting;
90} fan_table[] = {
91 { 11, T(0,0), 11 }, /* min fan */
92 { 11, T(55,0), 11 },
93 { 6, T(55,3), 11 },
94 { 7, T(56,0), 11 },
95 { 8, T(57,0), 8 },
96 { 7, T(58,3), 7 },
97 { 6, T(58,8), 6 },
98 { 5, T(59,2), 5 },
99 { 4, T(59,6), 4 },
100 { 3, T(59,9), 3 },
101 { 2, T(60,1), 2 },
102 { 1, 0xfffff, 1 } /* on fire */
103};
104
105static void
106print_temp( const char *s, int temp )
107{
108 printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
109}
110
111static ssize_t
Yani Ioannoue404e272005-05-17 06:42:58 -0400112show_cpu_temperature( struct device *dev, struct device_attribute *attr, char *buf )
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113{
114 return sprintf(buf, "%d.%d\n", x.temp>>8, (x.temp & 255)*10/256 );
115}
116
117static ssize_t
Yani Ioannoue404e272005-05-17 06:42:58 -0400118show_case_temperature( struct device *dev, struct device_attribute *attr, char *buf )
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119{
120 return sprintf(buf, "%d.%d\n", x.casetemp>>8, (x.casetemp & 255)*10/256 );
121}
122
123static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );
124static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );
125
126
127
128/************************************************************************/
129/* controller thread */
130/************************************************************************/
131
132static int
133write_reg( struct i2c_client *cl, int reg, int data, int len )
134{
135 u8 tmp[3];
136
137 if( len < 1 || len > 2 || data < 0 )
138 return -EINVAL;
139
140 tmp[0] = reg;
141 tmp[1] = (len == 1) ? data : (data >> 8);
142 tmp[2] = data;
143 len++;
144
145 if( i2c_master_send(cl, tmp, len) != len )
146 return -ENODEV;
147 return 0;
148}
149
150static int
151read_reg( struct i2c_client *cl, int reg, int len )
152{
153 u8 buf[2];
154
155 if( len != 1 && len != 2 )
156 return -EINVAL;
157 buf[0] = reg;
158 if( i2c_master_send(cl, buf, 1) != 1 )
159 return -ENODEV;
160 if( i2c_master_recv(cl, buf, len) != len )
161 return -ENODEV;
162 return (len == 2)? ((unsigned int)buf[0] << 8) | buf[1] : buf[0];
163}
164
165static void
166tune_fan( int fan_setting )
167{
168 int val = (fan_setting << 3) | 7;
169
170 /* write_reg( x.fan, 0x24, val, 1 ); */
171 write_reg( x.fan, 0x25, val, 1 );
172 write_reg( x.fan, 0x20, 0, 1 );
173 print_temp("CPU-temp: ", x.temp );
174 if( x.casetemp )
175 print_temp(", Case: ", x.casetemp );
176 printk(", Fan: %d (tuned %+d)\n", 11-fan_setting, x.fan_level-fan_setting );
177
178 x.fan_level = fan_setting;
179}
180
181static void
182poll_temp( void )
183{
184 int temp, i, level, casetemp;
185
186 temp = read_reg( x.thermostat, 0, 2 );
187
188 /* this actually occurs when the computer is loaded */
189 if( temp < 0 )
190 return;
191
192 casetemp = read_reg(x.fan, 0x0b, 1) << 8;
193 casetemp |= (read_reg(x.fan, 0x06, 1) & 0x7) << 5;
194
195 if( LOG_TEMP && x.temp != temp ) {
196 print_temp("CPU-temp: ", temp );
197 print_temp(", Case: ", casetemp );
198 printk(", Fan: %d\n", 11-x.fan_level );
199 }
200 x.temp = temp;
201 x.casetemp = casetemp;
202
203 level = -1;
204 for( i=0; (temp & 0xffff) > fan_table[i].temp ; i++ )
205 ;
206 if( i < x.downind )
207 level = fan_table[i].fan_down_setting;
208 x.downind = i;
209
210 for( i=0; (temp & 0xffff) >= fan_table[i+1].temp ; i++ )
211 ;
212 if( x.upind < i )
213 level = fan_table[i].fan_up_setting;
214 x.upind = i;
215
216 if( level >= 0 )
217 tune_fan( level );
218}
219
220
221static void
222setup_hardware( void )
223{
224 int val;
225
226 /* save registers (if we unload the module) */
227 x.r0 = read_reg( x.fan, 0x00, 1 );
228 x.r1 = read_reg( x.fan, 0x01, 1 );
229 x.r20 = read_reg( x.fan, 0x20, 1 );
230 x.r23 = read_reg( x.fan, 0x23, 1 );
231 x.r25 = read_reg( x.fan, 0x25, 1 );
232
233 /* improve measurement resolution (convergence time 1.5s) */
234 if( (val=read_reg(x.thermostat, 1, 1)) >= 0 ) {
235 val |= 0x60;
236 if( write_reg( x.thermostat, 1, val, 1 ) )
237 printk("Failed writing config register\n");
238 }
239 /* disable interrupts and TAC input */
240 write_reg( x.fan, 0x01, 0x01, 1 );
241 /* enable filter */
242 write_reg( x.fan, 0x23, 0x91, 1 );
243 /* remote temp. controls fan */
244 write_reg( x.fan, 0x00, 0x95, 1 );
245
246 /* The thermostat (which besides measureing temperature controls
247 * has a THERM output which puts the fan on 100%) is usually
248 * set to kick in at 80 C (chip default). We reduce this a bit
249 * to be on the safe side (OSX doesn't)...
250 */
251 if( x.overheat_temp == (80 << 8) ) {
252 x.overheat_temp = 65 << 8;
253 x.overheat_hyst = 60 << 8;
254 write_reg( x.thermostat, 2, x.overheat_hyst, 2 );
255 write_reg( x.thermostat, 3, x.overheat_temp, 2 );
256
257 print_temp("Reducing overheating limit to ", x.overheat_temp );
258 print_temp(" (Hyst: ", x.overheat_hyst );
259 printk(")\n");
260 }
261
262 /* set an initial fan setting */
263 x.downind = 0xffff;
264 x.upind = -1;
265 /* tune_fan( fan_up_table[x.upind].fan_setting ); */
266
267 device_create_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
268 device_create_file( &x.of_dev->dev, &dev_attr_case_temperature );
269}
270
271static void
272restore_regs( void )
273{
274 device_remove_file( &x.of_dev->dev, &dev_attr_cpu_temperature );
275 device_remove_file( &x.of_dev->dev, &dev_attr_case_temperature );
276
277 write_reg( x.fan, 0x01, x.r1, 1 );
278 write_reg( x.fan, 0x20, x.r20, 1 );
279 write_reg( x.fan, 0x23, x.r23, 1 );
280 write_reg( x.fan, 0x25, x.r25, 1 );
281 write_reg( x.fan, 0x00, x.r0, 1 );
282}
283
284static int
285control_loop( void *dummy )
286{
287 daemonize("g4fand");
288
289 down( &x.lock );
290 setup_hardware();
291
292 while( x.running ) {
293 up( &x.lock );
294
295 msleep_interruptible(8000);
296
297 down( &x.lock );
298 poll_temp();
299 }
300
301 restore_regs();
302 up( &x.lock );
303
304 complete_and_exit( &x.completion, 0 );
305}
306
307
308/************************************************************************/
309/* i2c probing and setup */
310/************************************************************************/
311
312static int
313do_attach( struct i2c_adapter *adapter )
314{
315 int ret = 0;
316
317 if( strncmp(adapter->name, "uni-n", 5) )
318 return 0;
319
320 if( !x.running ) {
321 ret = i2c_probe( adapter, &addr_data, &do_probe );
322 if( x.thermostat && x.fan ) {
323 x.running = 1;
324 init_completion( &x.completion );
325 x.poll_task = kernel_thread( control_loop, NULL, SIGCHLD | CLONE_KERNEL );
326 }
327 }
328 return ret;
329}
330
331static int
332do_detach( struct i2c_client *client )
333{
334 int err;
335
336 if( (err=i2c_detach_client(client)) )
337 printk(KERN_ERR "failed to detach thermostat client\n");
338 else {
339 if( x.running ) {
340 x.running = 0;
341 wait_for_completion( &x.completion );
342 }
343 if( client == x.thermostat )
344 x.thermostat = NULL;
345 else if( client == x.fan )
346 x.fan = NULL;
347 else {
348 printk(KERN_ERR "g4fan: bad client\n");
349 }
350 kfree( client );
351 }
352 return err;
353}
354
355static struct i2c_driver g4fan_driver = {
Laurent Riffarda33ca232005-11-26 20:40:34 +0100356 .driver = {
Laurent Riffarda33ca232005-11-26 20:40:34 +0100357 .name = "therm_windtunnel",
358 },
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 .id = I2C_DRIVERID_G4FAN,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 .attach_adapter = do_attach,
361 .detach_client = do_detach,
362};
363
364static int
365attach_fan( struct i2c_client *cl )
366{
367 if( x.fan )
368 goto out;
369
370 /* check that this is an ADM1030 */
371 if( read_reg(cl, 0x3d, 1) != 0x30 || read_reg(cl, 0x3e, 1) != 0x41 )
372 goto out;
373 printk("ADM1030 fan controller [@%02x]\n", cl->addr );
374
375 strlcpy( cl->name, "ADM1030 fan controller", sizeof(cl->name) );
376
377 if( !i2c_attach_client(cl) )
378 x.fan = cl;
379 out:
380 if( cl != x.fan )
381 kfree( cl );
382 return 0;
383}
384
385static int
386attach_thermostat( struct i2c_client *cl )
387{
388 int hyst_temp, os_temp, temp;
389
390 if( x.thermostat )
391 goto out;
392
393 if( (temp=read_reg(cl, 0, 2)) < 0 )
394 goto out;
395
396 /* temperature sanity check */
397 if( temp < 0x1600 || temp > 0x3c00 )
398 goto out;
399 hyst_temp = read_reg(cl, 2, 2);
400 os_temp = read_reg(cl, 3, 2);
401 if( hyst_temp < 0 || os_temp < 0 )
402 goto out;
403
404 printk("DS1775 digital thermometer [@%02x]\n", cl->addr );
405 print_temp("Temp: ", temp );
406 print_temp(" Hyst: ", hyst_temp );
407 print_temp(" OS: ", os_temp );
408 printk("\n");
409
410 x.temp = temp;
411 x.overheat_temp = os_temp;
412 x.overheat_hyst = hyst_temp;
413
414 strlcpy( cl->name, "DS1775 thermostat", sizeof(cl->name) );
415
416 if( !i2c_attach_client(cl) )
417 x.thermostat = cl;
418out:
419 if( cl != x.thermostat )
420 kfree( cl );
421 return 0;
422}
423
424static int
425do_probe( struct i2c_adapter *adapter, int addr, int kind )
426{
427 struct i2c_client *cl;
428
429 if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
430 | I2C_FUNC_SMBUS_WRITE_BYTE) )
431 return 0;
432
433 if( !(cl=kmalloc(sizeof(*cl), GFP_KERNEL)) )
434 return -ENOMEM;
435 memset( cl, 0, sizeof(struct i2c_client) );
436
437 cl->addr = addr;
438 cl->adapter = adapter;
439 cl->driver = &g4fan_driver;
440 cl->flags = 0;
441
442 if( addr < 0x48 )
443 return attach_fan( cl );
444 return attach_thermostat( cl );
445}
446
447
448/************************************************************************/
449/* initialization / cleanup */
450/************************************************************************/
451
452static int
Jeff Mahoney5e655772005-07-06 15:44:41 -0400453therm_of_probe( struct of_device *dev, const struct of_device_id *match )
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454{
455 return i2c_add_driver( &g4fan_driver );
456}
457
458static int
459therm_of_remove( struct of_device *dev )
460{
461 return i2c_del_driver( &g4fan_driver );
462}
463
Jeff Mahoney5e655772005-07-06 15:44:41 -0400464static struct of_device_id therm_of_match[] = {{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 .name = "fan",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 .compatible = "adm1030"
467 }, {}
468};
469
470static struct of_platform_driver therm_of_driver = {
471 .name = "temperature",
472 .match_table = therm_of_match,
473 .probe = therm_of_probe,
474 .remove = therm_of_remove,
475};
476
477struct apple_thermal_info {
478 u8 id; /* implementation ID */
479 u8 fan_count; /* number of fans */
480 u8 thermostat_count; /* number of thermostats */
481 u8 unused;
482};
483
484static int __init
485g4fan_init( void )
486{
Jeremy Kerr018a3d12006-07-12 15:40:29 +1000487 const struct apple_thermal_info *info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 struct device_node *np;
489
490 init_MUTEX( &x.lock );
491
492 if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
493 return -ENODEV;
Jeremy Kerr018a3d12006-07-12 15:40:29 +1000494 info = get_property(np, "thermal-info", NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 of_node_put(np);
496
497 if( !info || !machine_is_compatible("PowerMac3,6") )
498 return -ENODEV;
499
500 if( info->id != 3 ) {
501 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );
502 return -ENODEV;
503 }
504 if( !(np=of_find_node_by_name(NULL, "fan")) )
505 return -ENODEV;
Benjamin Herrenschmidt0365ba72005-09-22 21:44:06 -0700506 x.of_dev = of_platform_device_create(np, "temperature", NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 of_node_put( np );
508
509 if( !x.of_dev ) {
510 printk(KERN_ERR "Can't register fan controller!\n");
511 return -ENODEV;
512 }
513
514 of_register_driver( &therm_of_driver );
515 return 0;
516}
517
518static void __exit
519g4fan_exit( void )
520{
521 of_unregister_driver( &therm_of_driver );
522
523 if( x.of_dev )
524 of_device_unregister( x.of_dev );
525}
526
527module_init(g4fan_init);
528module_exit(g4fan_exit);
529
530MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
531MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
532MODULE_LICENSE("GPL");