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 115254175ADT7467_pra.pdf and 3686221171167ADT7460_b.pdf
7 * http://www.onsemi.com/PowerSolutions/product.do?id=ADT7467
8 * http://www.onsemi.com/PowerSolutions/product.do?id=ADT7460
9 *
10 */
11
12#include <linux/types.h>
13#include <linux/module.h>
14#include <linux/errno.h>
15#include <linux/kernel.h>
16#include <linux/delay.h>
17#include <linux/sched.h>
18#include <linux/i2c.h>
19#include <linux/slab.h>
20#include <linux/init.h>
21#include <linux/spinlock.h>
22#include <linux/wait.h>
23#include <linux/suspend.h>
24#include <linux/kthread.h>
25#include <linux/moduleparam.h>
26#include <linux/freezer.h>
27#include <linux/of_platform.h>
28
29#include <asm/prom.h>
30#include <asm/machdep.h>
31#include <asm/io.h>
32#include <asm/sections.h>
33
34#undef DEBUG
35
36#define CONFIG_REG   0x40
37#define MANUAL_MASK  0xe0
38#define AUTO_MASK    0x20
39#define INVERT_MASK  0x10
40
41static u8 TEMP_REG[3]    = {0x26, 0x25, 0x27}; /* local, sensor1, sensor2 */
42static u8 LIMIT_REG[3]   = {0x6b, 0x6a, 0x6c}; /* local, sensor1, sensor2 */
43static u8 MANUAL_MODE[2] = {0x5c, 0x5d};
44static u8 REM_CONTROL[2] = {0x00, 0x40};
45static u8 FAN_SPEED[2]   = {0x28, 0x2a};
46static u8 FAN_SPD_SET[2] = {0x30, 0x31};
47
48static u8 default_limits_local[3] = {70, 50, 70};    /* local, sensor1, sensor2 */
49static u8 default_limits_chip[3] = {80, 65, 80};    /* local, sensor1, sensor2 */
50static const char *sensor_location[3] = { "?", "?", "?" };
51
52static int limit_adjust;
53static int fan_speed = -1;
54static bool verbose;
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
69module_param(verbose, bool, 0);
70MODULE_PARM_DESC(verbose,"Verbose log operations "
71		 "(default 0)");
72
73struct thermostat {
74	struct i2c_client	*clt;
75	u8			temps[3];
76	u8			cached_temp[3];
77	u8			initial_limits[3];
78	u8			limits[3];
79	int			last_speed[2];
80	int			last_var[2];
81	int			pwm_inv[2];
82	struct task_struct	*thread;
83	struct platform_device	*pdev;
84	enum {
85		ADT7460,
86		ADT7467
87	}			type;
88};
89
90static void write_both_fan_speed(struct thermostat *th, int speed);
91static void write_fan_speed(struct thermostat *th, int speed, int fan);
92
93static int
94write_reg(struct thermostat* th, int reg, u8 data)
95{
96	u8 tmp[2];
97	int rc;
98
99	tmp[0] = reg;
100	tmp[1] = data;
101	rc = i2c_master_send(th->clt, (const char *)tmp, 2);
102	if (rc < 0)
103		return rc;
104	if (rc != 2)
105		return -ENODEV;
106	return 0;
107}
108
109static int
110read_reg(struct thermostat* th, int reg)
111{
112	u8 reg_addr, data;
113	int rc;
114
115	reg_addr = (u8)reg;
116	rc = i2c_master_send(th->clt, &reg_addr, 1);
117	if (rc < 0)
118		return rc;
119	if (rc != 1)
120		return -ENODEV;
121	rc = i2c_master_recv(th->clt, (char *)&data, 1);
122	if (rc < 0)
123		return rc;
124	return data;
125}
126
127static int read_fan_speed(struct thermostat *th, u8 addr)
128{
129	u8 tmp[2];
130	u16 res;
131
132	/* should start with low byte */
133	tmp[1] = read_reg(th, addr);
134	tmp[0] = read_reg(th, addr + 1);
135
136	res = tmp[1] + (tmp[0] << 8);
137	/* "a value of 0xffff means that the fan has stopped" */
138	return (res == 0xffff ? 0 : (90000*60)/res);
139}
140
141static void write_both_fan_speed(struct thermostat *th, int speed)
142{
143	write_fan_speed(th, speed, 0);
144	if (th->type == ADT7460)
145		write_fan_speed(th, speed, 1);
146}
147
148static void write_fan_speed(struct thermostat *th, int speed, int fan)
149{
150	u8 manual;
151
152	if (speed > 0xff)
153		speed = 0xff;
154	else if (speed < -1)
155		speed = 0;
156
157	if (th->type == ADT7467 && fan == 1)
158		return;
159
160	if (th->last_speed[fan] != speed) {
161		if (verbose) {
162			if (speed == -1)
163				printk(KERN_DEBUG "adt746x: Setting speed to automatic "
164					"for %s fan.\n", sensor_location[fan+1]);
165			else
166				printk(KERN_DEBUG "adt746x: Setting speed to %d "
167					"for %s fan.\n", speed, sensor_location[fan+1]);
168		}
169	} else
170		return;
171
172	if (speed >= 0) {
173		manual = read_reg(th, MANUAL_MODE[fan]);
174		manual &= ~INVERT_MASK;
175		write_reg(th, MANUAL_MODE[fan],
176			manual | MANUAL_MASK | th->pwm_inv[fan]);
177		write_reg(th, FAN_SPD_SET[fan], speed);
178	} else {
179		/* back to automatic */
180		if(th->type == ADT7460) {
181			manual = read_reg(th,
182				MANUAL_MODE[fan]) & (~MANUAL_MASK);
183			manual &= ~INVERT_MASK;
184			manual |= th->pwm_inv[fan];
185			write_reg(th,
186				MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
187		} else {
188			manual = read_reg(th, MANUAL_MODE[fan]);
189			manual &= ~INVERT_MASK;
190			manual |= th->pwm_inv[fan];
191			write_reg(th, MANUAL_MODE[fan], manual&(~AUTO_MASK));
192		}
193	}
194
195	th->last_speed[fan] = speed;
196}
197
198static void read_sensors(struct thermostat *th)
199{
200	int i = 0;
201
202	for (i = 0; i < 3; i++)
203		th->temps[i]  = read_reg(th, TEMP_REG[i]);
204}
205
206#ifdef DEBUG
207static void display_stats(struct thermostat *th)
208{
209	if (th->temps[0] != th->cached_temp[0]
210	||  th->temps[1] != th->cached_temp[1]
211	||  th->temps[2] != th->cached_temp[2]) {
212		printk(KERN_INFO "adt746x: Temperature infos:"
213				 " thermostats: %d,%d,%d;"
214				 " limits: %d,%d,%d;"
215				 " fan speed: %d RPM\n",
216				 th->temps[0], th->temps[1], th->temps[2],
217				 th->limits[0],  th->limits[1],  th->limits[2],
218				 read_fan_speed(th, FAN_SPEED[0]));
219	}
220	th->cached_temp[0] = th->temps[0];
221	th->cached_temp[1] = th->temps[1];
222	th->cached_temp[2] = th->temps[2];
223}
224#endif
225
226static void update_fans_speed (struct thermostat *th)
227{
228	int lastvar = 0; /* last variation, for iBook */
229	int i = 0;
230
231	/* we don't care about local sensor, so we start at sensor 1 */
232	for (i = 1; i < 3; i++) {
233		int started = 0;
234		int fan_number = (th->type == ADT7460 && i == 2);
235		int var = th->temps[i] - th->limits[i];
236
237		if (var > -1) {
238			int step = (255 - fan_speed) / 7;
239			int new_speed = 0;
240
241			/* hysteresis : change fan speed only if variation is
242			 * more than two degrees */
243			if (abs(var - th->last_var[fan_number]) < 2)
244				continue;
245
246			started = 1;
247			new_speed = fan_speed + ((var-1)*step);
248
249			if (new_speed < fan_speed)
250				new_speed = fan_speed;
251			if (new_speed > 255)
252				new_speed = 255;
253
254			if (verbose)
255				printk(KERN_DEBUG "adt746x: Setting fans speed to %d "
256						 "(limit exceeded by %d on %s)\n",
257						new_speed, var,
258						sensor_location[fan_number+1]);
259			write_both_fan_speed(th, new_speed);
260			th->last_var[fan_number] = var;
261		} else if (var < -2) {
262			/* don't stop fan if sensor2 is cold and sensor1 is not
263			 * so cold (lastvar >= -1) */
264			if (i == 2 && lastvar < -1) {
265				if (th->last_speed[fan_number] != 0)
266					if (verbose)
267						printk(KERN_DEBUG "adt746x: Stopping "
268							"fans.\n");
269				write_both_fan_speed(th, 0);
270			}
271		}
272
273		lastvar = var;
274
275		if (started)
276			return; /* we don't want to re-stop the fan
277				* if sensor1 is heating and sensor2 is not */
278	}
279}
280
281static int monitor_task(void *arg)
282{
283	struct thermostat* th = arg;
284
285	set_freezable();
286	while(!kthread_should_stop()) {
287		try_to_freeze();
288		msleep_interruptible(2000);
289
290#ifndef DEBUG
291		if (fan_speed != -1)
292			read_sensors(th);
293#else
294		read_sensors(th);
295#endif
296
297		if (fan_speed != -1)
298			update_fans_speed(th);
299
300#ifdef DEBUG
301		display_stats(th);
302#endif
303
304	}
305
306	return 0;
307}
308
309static void set_limit(struct thermostat *th, int i)
310{
311	/* Set sensor1 limit higher to avoid powerdowns */
312	th->limits[i] = default_limits_chip[i] + limit_adjust;
313	write_reg(th, LIMIT_REG[i], th->limits[i]);
314
315	/* set our limits to normal */
316	th->limits[i] = default_limits_local[i] + limit_adjust;
317}
318
319#define BUILD_SHOW_FUNC_INT(name, data)				\
320static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)	\
321{								\
322	struct thermostat *th = dev_get_drvdata(dev);		\
323	return sprintf(buf, "%d\n", data);			\
324}
325
326#define BUILD_SHOW_FUNC_INT_LITE(name, data)				\
327static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)	\
328{								\
329	return sprintf(buf, "%d\n", data);			\
330}
331
332#define BUILD_SHOW_FUNC_STR(name, data)				\
333static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
334{								\
335	return sprintf(buf, "%s\n", data);			\
336}
337
338#define BUILD_SHOW_FUNC_FAN(name, data)				\
339static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
340{								\
341	struct thermostat *th = dev_get_drvdata(dev);		\
342	return sprintf(buf, "%d (%d rpm)\n", 			\
343		th->last_speed[data],				\
344		read_fan_speed(th, FAN_SPEED[data])		\
345		);						\
346}
347
348#define BUILD_STORE_FUNC_DEG(name, data)			\
349static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
350{								\
351	struct thermostat *th = dev_get_drvdata(dev);		\
352	int val;						\
353	int i;							\
354	val = simple_strtol(buf, NULL, 10);			\
355	printk(KERN_INFO "Adjusting limits by %d degrees\n", val);	\
356	limit_adjust = val;					\
357	for (i=0; i < 3; i++)					\
358		set_limit(th, i);				\
359	return n;						\
360}
361
362#define BUILD_STORE_FUNC_INT(name, data)			\
363static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
364{								\
365	int val;						\
366	val = simple_strtol(buf, NULL, 10);			\
367	if (val < 0 || val > 255)				\
368		return -EINVAL;					\
369	printk(KERN_INFO "Setting specified fan speed to %d\n", val);	\
370	data = val;						\
371	return n;						\
372}
373
374BUILD_SHOW_FUNC_INT(sensor1_temperature,	 (read_reg(th, TEMP_REG[1])))
375BUILD_SHOW_FUNC_INT(sensor2_temperature,	 (read_reg(th, TEMP_REG[2])))
376BUILD_SHOW_FUNC_INT(sensor1_limit,		 th->limits[1])
377BUILD_SHOW_FUNC_INT(sensor2_limit,		 th->limits[2])
378BUILD_SHOW_FUNC_STR(sensor1_location,		 sensor_location[1])
379BUILD_SHOW_FUNC_STR(sensor2_location,		 sensor_location[2])
380
381BUILD_SHOW_FUNC_INT_LITE(specified_fan_speed, fan_speed)
382BUILD_STORE_FUNC_INT(specified_fan_speed,fan_speed)
383
384BUILD_SHOW_FUNC_FAN(sensor1_fan_speed,	 0)
385BUILD_SHOW_FUNC_FAN(sensor2_fan_speed,	 1)
386
387BUILD_SHOW_FUNC_INT_LITE(limit_adjust,	 limit_adjust)
388BUILD_STORE_FUNC_DEG(limit_adjust,	 th)
389
390static DEVICE_ATTR(sensor1_temperature,	S_IRUGO,
391		   show_sensor1_temperature,NULL);
392static DEVICE_ATTR(sensor2_temperature,	S_IRUGO,
393		   show_sensor2_temperature,NULL);
394static DEVICE_ATTR(sensor1_limit, S_IRUGO,
395		   show_sensor1_limit,	NULL);
396static DEVICE_ATTR(sensor2_limit, S_IRUGO,
397		   show_sensor2_limit,	NULL);
398static DEVICE_ATTR(sensor1_location, S_IRUGO,
399		   show_sensor1_location, NULL);
400static DEVICE_ATTR(sensor2_location, S_IRUGO,
401		   show_sensor2_location, NULL);
402
403static DEVICE_ATTR(specified_fan_speed,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
404		   show_specified_fan_speed,store_specified_fan_speed);
405
406static DEVICE_ATTR(sensor1_fan_speed,	S_IRUGO,
407		   show_sensor1_fan_speed,	NULL);
408static DEVICE_ATTR(sensor2_fan_speed,	S_IRUGO,
409		   show_sensor2_fan_speed,	NULL);
410
411static DEVICE_ATTR(limit_adjust,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
412		   show_limit_adjust,	store_limit_adjust);
413
414static void thermostat_create_files(struct thermostat *th)
415{
416	struct device_node *np = th->clt->dev.of_node;
417	struct device *dev;
418	int err;
419
420	/* To maintain ABI compatibility with userspace, create
421	 * the old style platform driver and attach the attributes
422	 * to it here
423	 */
424	th->pdev = of_platform_device_create(np, "temperatures", NULL);
425	if (!th->pdev)
426		return;
427	dev = &th->pdev->dev;
428	dev_set_drvdata(dev, th);
429	err = device_create_file(dev, &dev_attr_sensor1_temperature);
430	err |= device_create_file(dev, &dev_attr_sensor2_temperature);
431	err |= device_create_file(dev, &dev_attr_sensor1_limit);
432	err |= device_create_file(dev, &dev_attr_sensor2_limit);
433	err |= device_create_file(dev, &dev_attr_sensor1_location);
434	err |= device_create_file(dev, &dev_attr_sensor2_location);
435	err |= device_create_file(dev, &dev_attr_limit_adjust);
436	err |= device_create_file(dev, &dev_attr_specified_fan_speed);
437	err |= device_create_file(dev, &dev_attr_sensor1_fan_speed);
438	if(th->type == ADT7460)
439		err |= device_create_file(dev, &dev_attr_sensor2_fan_speed);
440	if (err)
441		printk(KERN_WARNING
442			"Failed to create temperature attribute file(s).\n");
443}
444
445static void thermostat_remove_files(struct thermostat *th)
446{
447	struct device *dev;
448
449	if (!th->pdev)
450		return;
451	dev = &th->pdev->dev;
452	device_remove_file(dev, &dev_attr_sensor1_temperature);
453	device_remove_file(dev, &dev_attr_sensor2_temperature);
454	device_remove_file(dev, &dev_attr_sensor1_limit);
455	device_remove_file(dev, &dev_attr_sensor2_limit);
456	device_remove_file(dev, &dev_attr_sensor1_location);
457	device_remove_file(dev, &dev_attr_sensor2_location);
458	device_remove_file(dev, &dev_attr_limit_adjust);
459	device_remove_file(dev, &dev_attr_specified_fan_speed);
460	device_remove_file(dev, &dev_attr_sensor1_fan_speed);
461	if (th->type == ADT7460)
462		device_remove_file(dev, &dev_attr_sensor2_fan_speed);
463	of_device_unregister(th->pdev);
464
465}
466
467static int probe_thermostat(struct i2c_client *client,
468			    const struct i2c_device_id *id)
469{
470	struct device_node *np = client->dev.of_node;
471	struct thermostat* th;
472	const __be32 *prop;
473	int i, rc, vers, offset = 0;
474
475	if (!np)
476		return -ENXIO;
477	prop = of_get_property(np, "hwsensor-params-version", NULL);
478	if (!prop)
479		return -ENXIO;
480	vers = be32_to_cpup(prop);
481	printk(KERN_INFO "adt746x: version %d (%ssupported)\n",
482	       vers, vers == 1 ? "" : "un");
483	if (vers != 1)
484		return -ENXIO;
485
486	if (of_get_property(np, "hwsensor-location", NULL)) {
487		for (i = 0; i < 3; i++) {
488			sensor_location[i] = of_get_property(np,
489					"hwsensor-location", NULL) + offset;
490
491			if (sensor_location[i] == NULL)
492				sensor_location[i] = "";
493
494			printk(KERN_INFO "sensor %d: %s\n", i, sensor_location[i]);
495			offset += strlen(sensor_location[i]) + 1;
496		}
497	}
498
499	th = kzalloc(sizeof(struct thermostat), GFP_KERNEL);
500	if (!th)
501		return -ENOMEM;
502
503	i2c_set_clientdata(client, th);
504	th->clt = client;
505	th->type = id->driver_data;
506
507	rc = read_reg(th, CONFIG_REG);
508	if (rc < 0) {
509		dev_err(&client->dev, "Thermostat failed to read config!\n");
510		kfree(th);
511		return -ENODEV;
512	}
513
514	/* force manual control to start the fan quieter */
515	if (fan_speed == -1)
516		fan_speed = 64;
517
518	if (th->type == ADT7460) {
519		printk(KERN_INFO "adt746x: ADT7460 initializing\n");
520		/* The 7460 needs to be started explicitly */
521		write_reg(th, CONFIG_REG, 1);
522	} else
523		printk(KERN_INFO "adt746x: ADT7467 initializing\n");
524
525	for (i = 0; i < 3; i++) {
526		th->initial_limits[i] = read_reg(th, LIMIT_REG[i]);
527		set_limit(th, i);
528	}
529
530	printk(KERN_INFO "adt746x: Lowering max temperatures from %d, %d, %d"
531			 " to %d, %d, %d\n",
532			 th->initial_limits[0], th->initial_limits[1],
533			 th->initial_limits[2], th->limits[0], th->limits[1],
534			 th->limits[2]);
535
536	/* record invert bit status because fw can corrupt it after suspend */
537	th->pwm_inv[0] = read_reg(th, MANUAL_MODE[0]) & INVERT_MASK;
538	th->pwm_inv[1] = read_reg(th, MANUAL_MODE[1]) & INVERT_MASK;
539
540	/* be sure to really write fan speed the first time */
541	th->last_speed[0] = -2;
542	th->last_speed[1] = -2;
543	th->last_var[0] = -80;
544	th->last_var[1] = -80;
545
546	if (fan_speed != -1) {
547		/* manual mode, stop fans */
548		write_both_fan_speed(th, 0);
549	} else {
550		/* automatic mode */
551		write_both_fan_speed(th, -1);
552	}
553
554	th->thread = kthread_run(monitor_task, th, "kfand");
555	if (th->thread == ERR_PTR(-ENOMEM)) {
556		printk(KERN_INFO "adt746x: Kthread creation failed\n");
557		th->thread = NULL;
558		return -ENOMEM;
559	}
560
561	thermostat_create_files(th);
562
563	return 0;
564}
565
566static int remove_thermostat(struct i2c_client *client)
567{
568	struct thermostat *th = i2c_get_clientdata(client);
569	int i;
570
571	thermostat_remove_files(th);
572
573	if (th->thread != NULL)
574		kthread_stop(th->thread);
575
576	printk(KERN_INFO "adt746x: Putting max temperatures back from "
577			 "%d, %d, %d to %d, %d, %d\n",
578		th->limits[0], th->limits[1], th->limits[2],
579		th->initial_limits[0], th->initial_limits[1],
580		th->initial_limits[2]);
581
582	for (i = 0; i < 3; i++)
583		write_reg(th, LIMIT_REG[i], th->initial_limits[i]);
584
585	write_both_fan_speed(th, -1);
586
587	kfree(th);
588
589	return 0;
590}
591
592static const struct i2c_device_id therm_adt746x_id[] = {
593	{ "MAC,adt7460", ADT7460 },
594	{ "MAC,adt7467", ADT7467 },
595	{ }
596};
597MODULE_DEVICE_TABLE(i2c, therm_adt746x_id);
598
599static struct i2c_driver thermostat_driver = {
600	.driver = {
601		.name	= "therm_adt746x",
602	},
603	.probe = probe_thermostat,
604	.remove = remove_thermostat,
605	.id_table = therm_adt746x_id,
606};
607
608static int __init thermostat_init(void)
609{
610#ifndef CONFIG_I2C_POWERMAC
611	request_module("i2c-powermac");
612#endif
613
614	return i2c_add_driver(&thermostat_driver);
615}
616
617static void __exit thermostat_exit(void)
618{
619	i2c_del_driver(&thermostat_driver);
620}
621
622module_init(thermostat_init);
623module_exit(thermostat_exit);
624