therm_adt746x.c revision a33ca23231a37e28d15da9546b1f3e83dc48284b
1/*
2 * Device driver for the i2c thermostat found on the iBook G4, Albook G4
3 *
4 * Copyright (C) 2003, 2004 Colin Leroy, Rasmus Rohde, Benjamin Herrenschmidt
5 *
6 * Documentation from
7 * http://www.analog.com/UploadedFiles/Data_Sheets/115254175ADT7467_pra.pdf
8 * http://www.analog.com/UploadedFiles/Data_Sheets/3686221171167ADT7460_b.pdf
9 *
10 */
11
12#include <linux/config.h>
13#include <linux/types.h>
14#include <linux/module.h>
15#include <linux/errno.h>
16#include <linux/kernel.h>
17#include <linux/delay.h>
18#include <linux/sched.h>
19#include <linux/i2c.h>
20#include <linux/slab.h>
21#include <linux/init.h>
22#include <linux/spinlock.h>
23#include <linux/smp_lock.h>
24#include <linux/wait.h>
25#include <linux/suspend.h>
26#include <linux/kthread.h>
27#include <linux/moduleparam.h>
28
29#include <asm/prom.h>
30#include <asm/machdep.h>
31#include <asm/io.h>
32#include <asm/system.h>
33#include <asm/sections.h>
34#include <asm/of_device.h>
35
36#undef DEBUG
37
38#define CONFIG_REG   0x40
39#define MANUAL_MASK  0xe0
40#define AUTO_MASK    0x20
41
42static u8 TEMP_REG[3]    = {0x26, 0x25, 0x27}; /* local, sensor1, sensor2 */
43static u8 LIMIT_REG[3]   = {0x6b, 0x6a, 0x6c}; /* local, sensor1, sensor2 */
44static u8 MANUAL_MODE[2] = {0x5c, 0x5d};
45static u8 REM_CONTROL[2] = {0x00, 0x40};
46static u8 FAN_SPEED[2]   = {0x28, 0x2a};
47static u8 FAN_SPD_SET[2] = {0x30, 0x31};
48
49static u8 default_limits_local[3] = {70, 50, 70};    /* local, sensor1, sensor2 */
50static u8 default_limits_chip[3] = {80, 65, 80};    /* local, sensor1, sensor2 */
51static char *sensor_location[3] = {NULL, NULL, NULL};
52
53static int limit_adjust = 0;
54static int fan_speed = -1;
55
56MODULE_AUTHOR("Colin Leroy <colin@colino.net>");
57MODULE_DESCRIPTION("Driver for ADT746x thermostat in iBook G4 and "
58		   "Powerbook G4 Alu");
59MODULE_LICENSE("GPL");
60
61module_param(limit_adjust, int, 0644);
62MODULE_PARM_DESC(limit_adjust,"Adjust maximum temperatures (50 sensor1, 70 sensor2) "
63		 "by N degrees.");
64
65module_param(fan_speed, int, 0644);
66MODULE_PARM_DESC(fan_speed,"Specify starting fan speed (0-255) "
67		 "(default 64)");
68
69struct thermostat {
70	struct i2c_client	clt;
71	u8			temps[3];
72	u8			cached_temp[3];
73	u8			initial_limits[3];
74	u8			limits[3];
75	int			last_speed[2];
76	int			last_var[2];
77};
78
79static enum {ADT7460, ADT7467} therm_type;
80static int therm_bus, therm_address;
81static struct of_device * of_dev;
82static struct thermostat* thermostat;
83static struct task_struct *thread_therm = NULL;
84
85static int attach_one_thermostat(struct i2c_adapter *adapter, int addr,
86				 int busno);
87
88static void write_both_fan_speed(struct thermostat *th, int speed);
89static void write_fan_speed(struct thermostat *th, int speed, int fan);
90
91static int
92write_reg(struct thermostat* th, int reg, u8 data)
93{
94	u8 tmp[2];
95	int rc;
96
97	tmp[0] = reg;
98	tmp[1] = data;
99	rc = i2c_master_send(&th->clt, (const char *)tmp, 2);
100	if (rc < 0)
101		return rc;
102	if (rc != 2)
103		return -ENODEV;
104	return 0;
105}
106
107static int
108read_reg(struct thermostat* th, int reg)
109{
110	u8 reg_addr, data;
111	int rc;
112
113	reg_addr = (u8)reg;
114	rc = i2c_master_send(&th->clt, &reg_addr, 1);
115	if (rc < 0)
116		return rc;
117	if (rc != 1)
118		return -ENODEV;
119	rc = i2c_master_recv(&th->clt, (char *)&data, 1);
120	if (rc < 0)
121		return rc;
122	return data;
123}
124
125static int
126attach_thermostat(struct i2c_adapter *adapter)
127{
128	unsigned long bus_no;
129
130	if (strncmp(adapter->name, "uni-n", 5))
131		return -ENODEV;
132	bus_no = simple_strtoul(adapter->name + 6, NULL, 10);
133	if (bus_no != therm_bus)
134		return -ENODEV;
135	return attach_one_thermostat(adapter, therm_address, bus_no);
136}
137
138static int
139detach_thermostat(struct i2c_adapter *adapter)
140{
141	struct thermostat* th;
142	int i;
143
144	if (thermostat == NULL)
145		return 0;
146
147	th = thermostat;
148
149	if (thread_therm != NULL) {
150		kthread_stop(thread_therm);
151	}
152
153	printk(KERN_INFO "adt746x: Putting max temperatures back from "
154			 "%d, %d, %d to %d, %d, %d\n",
155		th->limits[0], th->limits[1], th->limits[2],
156		th->initial_limits[0], th->initial_limits[1],
157		th->initial_limits[2]);
158
159	for (i = 0; i < 3; i++)
160		write_reg(th, LIMIT_REG[i], th->initial_limits[i]);
161
162	write_both_fan_speed(th, -1);
163
164	i2c_detach_client(&th->clt);
165
166	thermostat = NULL;
167
168	kfree(th);
169
170	return 0;
171}
172
173static struct i2c_driver thermostat_driver = {
174	.driver = {
175		.owner	= THIS_MODULE,
176		.name	= "therm_adt746x",
177	},
178	.attach_adapter	= attach_thermostat,
179	.detach_adapter	= detach_thermostat,
180};
181
182static int read_fan_speed(struct thermostat *th, u8 addr)
183{
184	u8 tmp[2];
185	u16 res;
186
187	/* should start with low byte */
188	tmp[1] = read_reg(th, addr);
189	tmp[0] = read_reg(th, addr + 1);
190
191	res = tmp[1] + (tmp[0] << 8);
192	/* "a value of 0xffff means that the fan has stopped" */
193	return (res == 0xffff ? 0 : (90000*60)/res);
194}
195
196static void write_both_fan_speed(struct thermostat *th, int speed)
197{
198	write_fan_speed(th, speed, 0);
199	if (therm_type == ADT7460)
200		write_fan_speed(th, speed, 1);
201}
202
203static void write_fan_speed(struct thermostat *th, int speed, int fan)
204{
205	u8 manual;
206
207	if (speed > 0xff)
208		speed = 0xff;
209	else if (speed < -1)
210		speed = 0;
211
212	if (therm_type == ADT7467 && fan == 1)
213		return;
214
215	if (th->last_speed[fan] != speed) {
216		if (speed == -1)
217			printk(KERN_DEBUG "adt746x: Setting speed to automatic "
218				"for %s fan.\n", sensor_location[fan+1]);
219		else
220			printk(KERN_DEBUG "adt746x: Setting speed to %d "
221				"for %s fan.\n", speed, sensor_location[fan+1]);
222	} else
223		return;
224
225	if (speed >= 0) {
226		manual = read_reg(th, MANUAL_MODE[fan]);
227		write_reg(th, MANUAL_MODE[fan], manual|MANUAL_MASK);
228		write_reg(th, FAN_SPD_SET[fan], speed);
229	} else {
230		/* back to automatic */
231		if(therm_type == ADT7460) {
232			manual = read_reg(th,
233				MANUAL_MODE[fan]) & (~MANUAL_MASK);
234
235			write_reg(th,
236				MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
237		} else {
238			manual = read_reg(th, MANUAL_MODE[fan]);
239			write_reg(th, MANUAL_MODE[fan], manual&(~AUTO_MASK));
240		}
241	}
242
243	th->last_speed[fan] = speed;
244}
245
246static void read_sensors(struct thermostat *th)
247{
248	int i = 0;
249
250	for (i = 0; i < 3; i++)
251		th->temps[i]  = read_reg(th, TEMP_REG[i]);
252}
253
254#ifdef DEBUG
255static void display_stats(struct thermostat *th)
256{
257	if (th->temps[0] != th->cached_temp[0]
258	||  th->temps[1] != th->cached_temp[1]
259	||  th->temps[2] != th->cached_temp[2]) {
260		printk(KERN_INFO "adt746x: Temperature infos:"
261				 " thermostats: %d,%d,%d;"
262				 " limits: %d,%d,%d;"
263				 " fan speed: %d RPM\n",
264				 th->temps[0], th->temps[1], th->temps[2],
265				 th->limits[0],  th->limits[1],  th->limits[2],
266				 read_fan_speed(th, FAN_SPEED[0]));
267	}
268	th->cached_temp[0] = th->temps[0];
269	th->cached_temp[1] = th->temps[1];
270	th->cached_temp[2] = th->temps[2];
271}
272#endif
273
274static void update_fans_speed (struct thermostat *th)
275{
276	int lastvar = 0; /* last variation, for iBook */
277	int i = 0;
278
279	/* we don't care about local sensor, so we start at sensor 1 */
280	for (i = 1; i < 3; i++) {
281		int started = 0;
282		int fan_number = (therm_type == ADT7460 && i == 2);
283		int var = th->temps[i] - th->limits[i];
284
285		if (var > -1) {
286			int step = (255 - fan_speed) / 7;
287			int new_speed = 0;
288
289			/* hysteresis : change fan speed only if variation is
290			 * more than two degrees */
291			if (abs(var - th->last_var[fan_number]) < 2)
292				continue;
293
294			started = 1;
295			new_speed = fan_speed + ((var-1)*step);
296
297			if (new_speed < fan_speed)
298				new_speed = fan_speed;
299			if (new_speed > 255)
300				new_speed = 255;
301
302			printk(KERN_DEBUG "adt746x: setting fans speed to %d "
303					 "(limit exceeded by %d on %s) \n",
304					new_speed, var,
305					sensor_location[fan_number+1]);
306			write_both_fan_speed(th, new_speed);
307			th->last_var[fan_number] = var;
308		} else if (var < -2) {
309			/* don't stop fan if sensor2 is cold and sensor1 is not
310			 * so cold (lastvar >= -1) */
311			if (i == 2 && lastvar < -1) {
312				if (th->last_speed[fan_number] != 0)
313					printk(KERN_DEBUG "adt746x: Stopping "
314						"fans.\n");
315				write_both_fan_speed(th, 0);
316			}
317		}
318
319		lastvar = var;
320
321		if (started)
322			return; /* we don't want to re-stop the fan
323				* if sensor1 is heating and sensor2 is not */
324	}
325}
326
327static int monitor_task(void *arg)
328{
329	struct thermostat* th = arg;
330
331	while(!kthread_should_stop()) {
332		try_to_freeze();
333		msleep_interruptible(2000);
334
335#ifndef DEBUG
336		if (fan_speed != -1)
337			read_sensors(th);
338#else
339		read_sensors(th);
340#endif
341
342		if (fan_speed != -1)
343			update_fans_speed(th);
344
345#ifdef DEBUG
346		display_stats(th);
347#endif
348
349	}
350
351	return 0;
352}
353
354static void set_limit(struct thermostat *th, int i)
355{
356		/* Set sensor1 limit higher to avoid powerdowns */
357		th->limits[i] = default_limits_chip[i] + limit_adjust;
358		write_reg(th, LIMIT_REG[i], th->limits[i]);
359
360		/* set our limits to normal */
361		th->limits[i] = default_limits_local[i] + limit_adjust;
362}
363
364static int attach_one_thermostat(struct i2c_adapter *adapter, int addr,
365				 int busno)
366{
367	struct thermostat* th;
368	int rc;
369	int i;
370
371	if (thermostat)
372		return 0;
373
374	th = (struct thermostat *)
375		kmalloc(sizeof(struct thermostat), GFP_KERNEL);
376
377	if (!th)
378		return -ENOMEM;
379
380	memset(th, 0, sizeof(*th));
381	th->clt.addr = addr;
382	th->clt.adapter = adapter;
383	th->clt.driver = &thermostat_driver;
384	strcpy(th->clt.name, "thermostat");
385
386	rc = read_reg(th, 0);
387	if (rc < 0) {
388		printk(KERN_ERR "adt746x: Thermostat failed to read config "
389				"from bus %d !\n",
390				busno);
391		kfree(th);
392		return -ENODEV;
393	}
394
395	/* force manual control to start the fan quieter */
396	if (fan_speed == -1)
397		fan_speed = 64;
398
399	if(therm_type == ADT7460) {
400		printk(KERN_INFO "adt746x: ADT7460 initializing\n");
401		/* The 7460 needs to be started explicitly */
402		write_reg(th, CONFIG_REG, 1);
403	} else
404		printk(KERN_INFO "adt746x: ADT7467 initializing\n");
405
406	for (i = 0; i < 3; i++) {
407		th->initial_limits[i] = read_reg(th, LIMIT_REG[i]);
408		set_limit(th, i);
409	}
410
411	printk(KERN_INFO "adt746x: Lowering max temperatures from %d, %d, %d"
412			 " to %d, %d, %d\n",
413			 th->initial_limits[0], th->initial_limits[1],
414			 th->initial_limits[2], th->limits[0], th->limits[1],
415			 th->limits[2]);
416
417	thermostat = th;
418
419	if (i2c_attach_client(&th->clt)) {
420		printk(KERN_INFO "adt746x: Thermostat failed to attach "
421				 "client !\n");
422		thermostat = NULL;
423		kfree(th);
424		return -ENODEV;
425	}
426
427	/* be sure to really write fan speed the first time */
428	th->last_speed[0] = -2;
429	th->last_speed[1] = -2;
430	th->last_var[0] = -80;
431	th->last_var[1] = -80;
432
433	if (fan_speed != -1) {
434		/* manual mode, stop fans */
435		write_both_fan_speed(th, 0);
436	} else {
437		/* automatic mode */
438		write_both_fan_speed(th, -1);
439	}
440
441	thread_therm = kthread_run(monitor_task, th, "kfand");
442
443	if (thread_therm == ERR_PTR(-ENOMEM)) {
444		printk(KERN_INFO "adt746x: Kthread creation failed\n");
445		thread_therm = NULL;
446		return -ENOMEM;
447	}
448
449	return 0;
450}
451
452/*
453 * Now, unfortunately, sysfs doesn't give us a nice void * we could
454 * pass around to the attribute functions, so we don't really have
455 * choice but implement a bunch of them...
456 *
457 * FIXME, it does now...
458 */
459#define BUILD_SHOW_FUNC_INT(name, data)				\
460static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)	\
461{								\
462	return sprintf(buf, "%d\n", data);			\
463}
464
465#define BUILD_SHOW_FUNC_STR(name, data)				\
466static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
467{								\
468	return sprintf(buf, "%s\n", data);			\
469}
470
471#define BUILD_SHOW_FUNC_FAN(name, data)				\
472static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
473{								\
474	return sprintf(buf, "%d (%d rpm)\n", 			\
475		thermostat->last_speed[data],			\
476		read_fan_speed(thermostat, FAN_SPEED[data])	\
477		);						\
478}
479
480#define BUILD_STORE_FUNC_DEG(name, data)			\
481static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
482{								\
483	int val;						\
484	int i;							\
485	val = simple_strtol(buf, NULL, 10);			\
486	printk(KERN_INFO "Adjusting limits by %d degrees\n", val);	\
487	limit_adjust = val;					\
488	for (i=0; i < 3; i++)					\
489		set_limit(thermostat, i);			\
490	return n;						\
491}
492
493#define BUILD_STORE_FUNC_INT(name, data)			\
494static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
495{								\
496	u32 val;						\
497	val = simple_strtoul(buf, NULL, 10);			\
498	if (val < 0 || val > 255)				\
499		return -EINVAL;					\
500	printk(KERN_INFO "Setting specified fan speed to %d\n", val);	\
501	data = val;						\
502	return n;						\
503}
504
505BUILD_SHOW_FUNC_INT(sensor1_temperature,	 (read_reg(thermostat, TEMP_REG[1])))
506BUILD_SHOW_FUNC_INT(sensor2_temperature,	 (read_reg(thermostat, TEMP_REG[2])))
507BUILD_SHOW_FUNC_INT(sensor1_limit,		 thermostat->limits[1])
508BUILD_SHOW_FUNC_INT(sensor2_limit,		 thermostat->limits[2])
509BUILD_SHOW_FUNC_STR(sensor1_location,		 sensor_location[1])
510BUILD_SHOW_FUNC_STR(sensor2_location,		 sensor_location[2])
511
512BUILD_SHOW_FUNC_INT(specified_fan_speed, fan_speed)
513BUILD_SHOW_FUNC_FAN(sensor1_fan_speed,	 0)
514BUILD_SHOW_FUNC_FAN(sensor2_fan_speed,	 1)
515
516BUILD_STORE_FUNC_INT(specified_fan_speed,fan_speed)
517BUILD_SHOW_FUNC_INT(limit_adjust,	 limit_adjust)
518BUILD_STORE_FUNC_DEG(limit_adjust,	 thermostat)
519
520static DEVICE_ATTR(sensor1_temperature,	S_IRUGO,
521		   show_sensor1_temperature,NULL);
522static DEVICE_ATTR(sensor2_temperature,	S_IRUGO,
523		   show_sensor2_temperature,NULL);
524static DEVICE_ATTR(sensor1_limit, S_IRUGO,
525		   show_sensor1_limit,	NULL);
526static DEVICE_ATTR(sensor2_limit, S_IRUGO,
527		   show_sensor2_limit,	NULL);
528static DEVICE_ATTR(sensor1_location, S_IRUGO,
529		   show_sensor1_location, NULL);
530static DEVICE_ATTR(sensor2_location, S_IRUGO,
531		   show_sensor2_location, NULL);
532
533static DEVICE_ATTR(specified_fan_speed,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
534		   show_specified_fan_speed,store_specified_fan_speed);
535
536static DEVICE_ATTR(sensor1_fan_speed,	S_IRUGO,
537		   show_sensor1_fan_speed,	NULL);
538static DEVICE_ATTR(sensor2_fan_speed,	S_IRUGO,
539		   show_sensor2_fan_speed,	NULL);
540
541static DEVICE_ATTR(limit_adjust,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
542		   show_limit_adjust,	store_limit_adjust);
543
544
545static int __init
546thermostat_init(void)
547{
548	struct device_node* np;
549	u32 *prop;
550	int i = 0, offset = 0;
551
552	np = of_find_node_by_name(NULL, "fan");
553	if (!np)
554		return -ENODEV;
555	if (device_is_compatible(np, "adt7460"))
556		therm_type = ADT7460;
557	else if (device_is_compatible(np, "adt7467"))
558		therm_type = ADT7467;
559	else
560		return -ENODEV;
561
562	prop = (u32 *)get_property(np, "hwsensor-params-version", NULL);
563	printk(KERN_INFO "adt746x: version %d (%ssupported)\n", *prop,
564			 (*prop == 1)?"":"un");
565	if (*prop != 1)
566		return -ENODEV;
567
568	prop = (u32 *)get_property(np, "reg", NULL);
569	if (!prop)
570		return -ENODEV;
571
572	/* look for bus either by path or using "reg" */
573	if (strstr(np->full_name, "/i2c-bus@") != NULL) {
574		const char *tmp_bus = (strstr(np->full_name, "/i2c-bus@") + 9);
575		therm_bus = tmp_bus[0]-'0';
576	} else {
577		therm_bus = ((*prop) >> 8) & 0x0f;
578	}
579
580	therm_address = ((*prop) & 0xff) >> 1;
581
582	printk(KERN_INFO "adt746x: Thermostat bus: %d, address: 0x%02x, "
583			 "limit_adjust: %d, fan_speed: %d\n",
584			 therm_bus, therm_address, limit_adjust, fan_speed);
585
586	if (get_property(np, "hwsensor-location", NULL)) {
587		for (i = 0; i < 3; i++) {
588			sensor_location[i] = get_property(np,
589					"hwsensor-location", NULL) + offset;
590
591			if (sensor_location[i] == NULL)
592				sensor_location[i] = "";
593
594			printk(KERN_INFO "sensor %d: %s\n", i, sensor_location[i]);
595			offset += strlen(sensor_location[i]) + 1;
596		}
597	} else {
598		sensor_location[0] = "?";
599		sensor_location[1] = "?";
600		sensor_location[2] = "?";
601	}
602
603	of_dev = of_platform_device_create(np, "temperatures", NULL);
604
605	if (of_dev == NULL) {
606		printk(KERN_ERR "Can't register temperatures device !\n");
607		return -ENODEV;
608	}
609
610	device_create_file(&of_dev->dev, &dev_attr_sensor1_temperature);
611	device_create_file(&of_dev->dev, &dev_attr_sensor2_temperature);
612	device_create_file(&of_dev->dev, &dev_attr_sensor1_limit);
613	device_create_file(&of_dev->dev, &dev_attr_sensor2_limit);
614	device_create_file(&of_dev->dev, &dev_attr_sensor1_location);
615	device_create_file(&of_dev->dev, &dev_attr_sensor2_location);
616	device_create_file(&of_dev->dev, &dev_attr_limit_adjust);
617	device_create_file(&of_dev->dev, &dev_attr_specified_fan_speed);
618	device_create_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
619	if(therm_type == ADT7460)
620		device_create_file(&of_dev->dev, &dev_attr_sensor2_fan_speed);
621
622#ifndef CONFIG_I2C_KEYWEST
623	request_module("i2c-keywest");
624#endif
625
626	return i2c_add_driver(&thermostat_driver);
627}
628
629static void __exit
630thermostat_exit(void)
631{
632	if (of_dev) {
633		device_remove_file(&of_dev->dev, &dev_attr_sensor1_temperature);
634		device_remove_file(&of_dev->dev, &dev_attr_sensor2_temperature);
635		device_remove_file(&of_dev->dev, &dev_attr_sensor1_limit);
636		device_remove_file(&of_dev->dev, &dev_attr_sensor2_limit);
637		device_remove_file(&of_dev->dev, &dev_attr_sensor1_location);
638		device_remove_file(&of_dev->dev, &dev_attr_sensor2_location);
639		device_remove_file(&of_dev->dev, &dev_attr_limit_adjust);
640		device_remove_file(&of_dev->dev, &dev_attr_specified_fan_speed);
641		device_remove_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
642
643		if(therm_type == ADT7460)
644			device_remove_file(&of_dev->dev,
645					   &dev_attr_sensor2_fan_speed);
646
647		of_device_unregister(of_dev);
648	}
649	i2c_del_driver(&thermostat_driver);
650}
651
652module_init(thermostat_init);
653module_exit(thermostat_exit);
654