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Linux/drivers/macintosh/therm_windtunnel.c

  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 
 49 static 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 
 73 static 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 
 92 static void
 93 print_temp( const char *s, int temp )
 94 {
 95         printk("%s%d.%d C", s ? s : "", temp>>8, (temp & 255)*10/256 );
 96 }
 97 
 98 static ssize_t
 99 show_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 
104 static ssize_t
105 show_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 
110 static DEVICE_ATTR(cpu_temperature, S_IRUGO, show_cpu_temperature, NULL );
111 static DEVICE_ATTR(case_temperature, S_IRUGO, show_case_temperature, NULL );
112 
113 
114 
115 /************************************************************************/
116 /*      controller thread                                               */
117 /************************************************************************/
118 
119 static int
120 write_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 
137 static int
138 read_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 
152 static void
153 tune_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 
168 static void
169 poll_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 
208 static void
209 setup_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 
262 static void
263 restore_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 
275 static 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 
303 static int
304 do_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 
337 static int
338 do_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 
355 static int
356 attach_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 
371 static int
372 attach_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;
400 out:
401         return 0;
402 }
403 
404 enum chip { ds1775, adm1030 };
405 
406 static const struct i2c_device_id therm_windtunnel_id[] = {
407         { "therm_ds1775", ds1775 },
408         { "therm_adm1030", adm1030 },
409         { }
410 };
411 
412 static int
413 do_probe(struct i2c_client *cl, const struct i2c_device_id *id)
414 {
415         struct i2c_adapter *adapter = cl->adapter;
416 
417         if( !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA
418                                      | I2C_FUNC_SMBUS_WRITE_BYTE) )
419                 return 0;
420 
421         switch (id->driver_data) {
422         case adm1030:
423                 return attach_fan( cl );
424         case ds1775:
425                 return attach_thermostat(cl);
426         }
427         return 0;
428 }
429 
430 static struct i2c_driver g4fan_driver = {
431         .driver = {
432                 .name   = "therm_windtunnel",
433         },
434         .attach_adapter = do_attach,
435         .probe          = do_probe,
436         .remove         = do_remove,
437         .id_table       = therm_windtunnel_id,
438 };
439 
440 
441 /************************************************************************/
442 /*      initialization / cleanup                                        */
443 /************************************************************************/
444 
445 static int therm_of_probe(struct platform_device *dev)
446 {
447         return i2c_add_driver( &g4fan_driver );
448 }
449 
450 static int
451 therm_of_remove( struct platform_device *dev )
452 {
453         i2c_del_driver( &g4fan_driver );
454         return 0;
455 }
456 
457 static const struct of_device_id therm_of_match[] = {{
458         .name           = "fan",
459         .compatible     = "adm1030"
460     }, {}
461 };
462 
463 static struct platform_driver therm_of_driver = {
464         .driver = {
465                 .name = "temperature",
466                 .owner = THIS_MODULE,
467                 .of_match_table = therm_of_match,
468         },
469         .probe          = therm_of_probe,
470         .remove         = therm_of_remove,
471 };
472 
473 struct apple_thermal_info {
474         u8              id;                     /* implementation ID */
475         u8              fan_count;              /* number of fans */
476         u8              thermostat_count;       /* number of thermostats */
477         u8              unused;
478 };
479 
480 static int __init
481 g4fan_init( void )
482 {
483         const struct apple_thermal_info *info;
484         struct device_node *np;
485 
486         mutex_init(&x.lock);
487 
488         if( !(np=of_find_node_by_name(NULL, "power-mgt")) )
489                 return -ENODEV;
490         info = of_get_property(np, "thermal-info", NULL);
491         of_node_put(np);
492 
493         if( !info || !of_machine_is_compatible("PowerMac3,6") )
494                 return -ENODEV;
495 
496         if( info->id != 3 ) {
497                 printk(KERN_ERR "therm_windtunnel: unsupported thermal design %d\n", info->id );
498                 return -ENODEV;
499         }
500         if( !(np=of_find_node_by_name(NULL, "fan")) )
501                 return -ENODEV;
502         x.of_dev = of_platform_device_create(np, "temperature", NULL);
503         of_node_put( np );
504 
505         if( !x.of_dev ) {
506                 printk(KERN_ERR "Can't register fan controller!\n");
507                 return -ENODEV;
508         }
509 
510         platform_driver_register( &therm_of_driver );
511         return 0;
512 }
513 
514 static void __exit
515 g4fan_exit( void )
516 {
517         platform_driver_unregister( &therm_of_driver );
518 
519         if( x.of_dev )
520                 of_device_unregister( x.of_dev );
521 }
522 
523 module_init(g4fan_init);
524 module_exit(g4fan_exit);
525 
526 MODULE_AUTHOR("Samuel Rydh <samuel@ibrium.se>");
527 MODULE_DESCRIPTION("Apple G4 (windtunnel) fan controller");
528 MODULE_LICENSE("GPL");
529 

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