1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Device driver for the i2c thermostat found on the iBook G4, Albook G4
4  *
5  * Copyright (C) 2003, 2004 Colin Leroy, Rasmus Rohde, Benjamin Herrenschmidt
6  *
7  * Documentation from 115254175ADT7467_pra.pdf and 3686221171167ADT7460_b.pdf
8  * http://www.onsemi.com/PowerSolutions/product.do?id=ADT7467
9  * http://www.onsemi.com/PowerSolutions/product.do?id=ADT7460
10  *
11  */
12 
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/wait.h>
24 #include <linux/suspend.h>
25 #include <linux/kthread.h>
26 #include <linux/moduleparam.h>
27 #include <linux/freezer.h>
28 #include <linux/of_platform.h>
29 
30 #include <asm/prom.h>
31 #include <asm/machdep.h>
32 #include <asm/io.h>
33 #include <asm/sections.h>
34 
35 #undef DEBUG
36 
37 #define CONFIG_REG   0x40
38 #define MANUAL_MASK  0xe0
39 #define AUTO_MASK    0x20
40 #define INVERT_MASK  0x10
41 
42 static u8 TEMP_REG[3]    = {0x26, 0x25, 0x27}; /* local, sensor1, sensor2 */
43 static u8 LIMIT_REG[3]   = {0x6b, 0x6a, 0x6c}; /* local, sensor1, sensor2 */
44 static u8 MANUAL_MODE[2] = {0x5c, 0x5d};
45 static u8 REM_CONTROL[2] = {0x00, 0x40};
46 static u8 FAN_SPEED[2]   = {0x28, 0x2a};
47 static u8 FAN_SPD_SET[2] = {0x30, 0x31};
48 
49 static u8 default_limits_local[3] = {70, 50, 70};    /* local, sensor1, sensor2 */
50 static u8 default_limits_chip[3] = {80, 65, 80};    /* local, sensor1, sensor2 */
51 static const char *sensor_location[3] = { "?", "?", "?" };
52 
53 static int limit_adjust;
54 static int fan_speed = -1;
55 static bool verbose;
56 
57 MODULE_AUTHOR("Colin Leroy <colin@colino.net>");
58 MODULE_DESCRIPTION("Driver for ADT746x thermostat in iBook G4 and "
59 		   "Powerbook G4 Alu");
60 MODULE_LICENSE("GPL");
61 
62 module_param(limit_adjust, int, 0644);
63 MODULE_PARM_DESC(limit_adjust,"Adjust maximum temperatures (50 sensor1, 70 sensor2) "
64 		 "by N degrees.");
65 
66 module_param(fan_speed, int, 0644);
67 MODULE_PARM_DESC(fan_speed,"Specify starting fan speed (0-255) "
68 		 "(default 64)");
69 
70 module_param(verbose, bool, 0);
71 MODULE_PARM_DESC(verbose,"Verbose log operations "
72 		 "(default 0)");
73 
74 struct thermostat {
75 	struct i2c_client	*clt;
76 	u8			temps[3];
77 	u8			cached_temp[3];
78 	u8			initial_limits[3];
79 	u8			limits[3];
80 	int			last_speed[2];
81 	int			last_var[2];
82 	int			pwm_inv[2];
83 	struct task_struct	*thread;
84 	struct platform_device	*pdev;
85 	enum {
86 		ADT7460,
87 		ADT7467
88 	}			type;
89 };
90 
91 static void write_both_fan_speed(struct thermostat *th, int speed);
92 static void write_fan_speed(struct thermostat *th, int speed, int fan);
93 
94 static int
95 write_reg(struct thermostat* th, int reg, u8 data)
96 {
97 	u8 tmp[2];
98 	int rc;
99 
100 	tmp[0] = reg;
101 	tmp[1] = data;
102 	rc = i2c_master_send(th->clt, (const char *)tmp, 2);
103 	if (rc < 0)
104 		return rc;
105 	if (rc != 2)
106 		return -ENODEV;
107 	return 0;
108 }
109 
110 static int
111 read_reg(struct thermostat* th, int reg)
112 {
113 	u8 reg_addr, data;
114 	int rc;
115 
116 	reg_addr = (u8)reg;
117 	rc = i2c_master_send(th->clt, &reg_addr, 1);
118 	if (rc < 0)
119 		return rc;
120 	if (rc != 1)
121 		return -ENODEV;
122 	rc = i2c_master_recv(th->clt, (char *)&data, 1);
123 	if (rc < 0)
124 		return rc;
125 	return data;
126 }
127 
128 static int read_fan_speed(struct thermostat *th, u8 addr)
129 {
130 	u8 tmp[2];
131 	u16 res;
132 
133 	/* should start with low byte */
134 	tmp[1] = read_reg(th, addr);
135 	tmp[0] = read_reg(th, addr + 1);
136 
137 	res = tmp[1] + (tmp[0] << 8);
138 	/* "a value of 0xffff means that the fan has stopped" */
139 	return (res == 0xffff ? 0 : (90000*60)/res);
140 }
141 
142 static void write_both_fan_speed(struct thermostat *th, int speed)
143 {
144 	write_fan_speed(th, speed, 0);
145 	if (th->type == ADT7460)
146 		write_fan_speed(th, speed, 1);
147 }
148 
149 static void write_fan_speed(struct thermostat *th, int speed, int fan)
150 {
151 	u8 manual;
152 
153 	if (speed > 0xff)
154 		speed = 0xff;
155 	else if (speed < -1)
156 		speed = 0;
157 
158 	if (th->type == ADT7467 && fan == 1)
159 		return;
160 
161 	if (th->last_speed[fan] != speed) {
162 		if (verbose) {
163 			if (speed == -1)
164 				printk(KERN_DEBUG "adt746x: Setting speed to automatic "
165 					"for %s fan.\n", sensor_location[fan+1]);
166 			else
167 				printk(KERN_DEBUG "adt746x: Setting speed to %d "
168 					"for %s fan.\n", speed, sensor_location[fan+1]);
169 		}
170 	} else
171 		return;
172 
173 	if (speed >= 0) {
174 		manual = read_reg(th, MANUAL_MODE[fan]);
175 		manual &= ~INVERT_MASK;
176 		write_reg(th, MANUAL_MODE[fan],
177 			manual | MANUAL_MASK | th->pwm_inv[fan]);
178 		write_reg(th, FAN_SPD_SET[fan], speed);
179 	} else {
180 		/* back to automatic */
181 		if(th->type == ADT7460) {
182 			manual = read_reg(th,
183 				MANUAL_MODE[fan]) & (~MANUAL_MASK);
184 			manual &= ~INVERT_MASK;
185 			manual |= th->pwm_inv[fan];
186 			write_reg(th,
187 				MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
188 		} else {
189 			manual = read_reg(th, MANUAL_MODE[fan]);
190 			manual &= ~INVERT_MASK;
191 			manual |= th->pwm_inv[fan];
192 			write_reg(th, MANUAL_MODE[fan], manual&(~AUTO_MASK));
193 		}
194 	}
195 
196 	th->last_speed[fan] = speed;
197 }
198 
199 static void read_sensors(struct thermostat *th)
200 {
201 	int i = 0;
202 
203 	for (i = 0; i < 3; i++)
204 		th->temps[i]  = read_reg(th, TEMP_REG[i]);
205 }
206 
207 #ifdef DEBUG
208 static void display_stats(struct thermostat *th)
209 {
210 	if (th->temps[0] != th->cached_temp[0]
211 	||  th->temps[1] != th->cached_temp[1]
212 	||  th->temps[2] != th->cached_temp[2]) {
213 		printk(KERN_INFO "adt746x: Temperature infos:"
214 				 " thermostats: %d,%d,%d;"
215 				 " limits: %d,%d,%d;"
216 				 " fan speed: %d RPM\n",
217 				 th->temps[0], th->temps[1], th->temps[2],
218 				 th->limits[0],  th->limits[1],  th->limits[2],
219 				 read_fan_speed(th, FAN_SPEED[0]));
220 	}
221 	th->cached_temp[0] = th->temps[0];
222 	th->cached_temp[1] = th->temps[1];
223 	th->cached_temp[2] = th->temps[2];
224 }
225 #endif
226 
227 static void update_fans_speed (struct thermostat *th)
228 {
229 	int lastvar = 0; /* last variation, for iBook */
230 	int i = 0;
231 
232 	/* we don't care about local sensor, so we start at sensor 1 */
233 	for (i = 1; i < 3; i++) {
234 		bool started = false;
235 		int fan_number = (th->type == ADT7460 && i == 2);
236 		int var = th->temps[i] - th->limits[i];
237 
238 		if (var > -1) {
239 			int step = (255 - fan_speed) / 7;
240 			int new_speed = 0;
241 
242 			/* hysteresis : change fan speed only if variation is
243 			 * more than two degrees */
244 			if (abs(var - th->last_var[fan_number]) < 2)
245 				continue;
246 
247 			started = true;
248 			new_speed = fan_speed + ((var-1)*step);
249 
250 			if (new_speed < fan_speed)
251 				new_speed = fan_speed;
252 			if (new_speed > 255)
253 				new_speed = 255;
254 
255 			if (verbose)
256 				printk(KERN_DEBUG "adt746x: Setting fans speed to %d "
257 						 "(limit exceeded by %d on %s)\n",
258 						new_speed, var,
259 						sensor_location[fan_number+1]);
260 			write_both_fan_speed(th, new_speed);
261 			th->last_var[fan_number] = var;
262 		} else if (var < -2) {
263 			/* don't stop fan if sensor2 is cold and sensor1 is not
264 			 * so cold (lastvar >= -1) */
265 			if (i == 2 && lastvar < -1) {
266 				if (th->last_speed[fan_number] != 0)
267 					if (verbose)
268 						printk(KERN_DEBUG "adt746x: Stopping "
269 							"fans.\n");
270 				write_both_fan_speed(th, 0);
271 			}
272 		}
273 
274 		lastvar = var;
275 
276 		if (started)
277 			return; /* we don't want to re-stop the fan
278 				* if sensor1 is heating and sensor2 is not */
279 	}
280 }
281 
282 static int monitor_task(void *arg)
283 {
284 	struct thermostat* th = arg;
285 
286 	set_freezable();
287 	while(!kthread_should_stop()) {
288 		try_to_freeze();
289 		msleep_interruptible(2000);
290 
291 #ifndef DEBUG
292 		if (fan_speed != -1)
293 			read_sensors(th);
294 #else
295 		read_sensors(th);
296 #endif
297 
298 		if (fan_speed != -1)
299 			update_fans_speed(th);
300 
301 #ifdef DEBUG
302 		display_stats(th);
303 #endif
304 
305 	}
306 
307 	return 0;
308 }
309 
310 static void set_limit(struct thermostat *th, int i)
311 {
312 	/* Set sensor1 limit higher to avoid powerdowns */
313 	th->limits[i] = default_limits_chip[i] + limit_adjust;
314 	write_reg(th, LIMIT_REG[i], th->limits[i]);
315 
316 	/* set our limits to normal */
317 	th->limits[i] = default_limits_local[i] + limit_adjust;
318 }
319 
320 #define BUILD_SHOW_FUNC_INT(name, data)				\
321 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)	\
322 {								\
323 	struct thermostat *th = dev_get_drvdata(dev);		\
324 	return sprintf(buf, "%d\n", data);			\
325 }
326 
327 #define BUILD_SHOW_FUNC_INT_LITE(name, data)				\
328 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)	\
329 {								\
330 	return sprintf(buf, "%d\n", data);			\
331 }
332 
333 #define BUILD_SHOW_FUNC_STR(name, data)				\
334 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
335 {								\
336 	return sprintf(buf, "%s\n", data);			\
337 }
338 
339 #define BUILD_SHOW_FUNC_FAN(name, data)				\
340 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
341 {								\
342 	struct thermostat *th = dev_get_drvdata(dev);		\
343 	return sprintf(buf, "%d (%d rpm)\n", 			\
344 		th->last_speed[data],				\
345 		read_fan_speed(th, FAN_SPEED[data])		\
346 		);						\
347 }
348 
349 #define BUILD_STORE_FUNC_DEG(name, data)			\
350 static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
351 {								\
352 	struct thermostat *th = dev_get_drvdata(dev);		\
353 	int val;						\
354 	int i;							\
355 	val = simple_strtol(buf, NULL, 10);			\
356 	printk(KERN_INFO "Adjusting limits by %d degrees\n", val);	\
357 	limit_adjust = val;					\
358 	for (i=0; i < 3; i++)					\
359 		set_limit(th, i);				\
360 	return n;						\
361 }
362 
363 #define BUILD_STORE_FUNC_INT(name, data)			\
364 static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
365 {								\
366 	int val;						\
367 	val = simple_strtol(buf, NULL, 10);			\
368 	if (val < 0 || val > 255)				\
369 		return -EINVAL;					\
370 	printk(KERN_INFO "Setting specified fan speed to %d\n", val);	\
371 	data = val;						\
372 	return n;						\
373 }
374 
375 BUILD_SHOW_FUNC_INT(sensor1_temperature,	 (read_reg(th, TEMP_REG[1])))
376 BUILD_SHOW_FUNC_INT(sensor2_temperature,	 (read_reg(th, TEMP_REG[2])))
377 BUILD_SHOW_FUNC_INT(sensor1_limit,		 th->limits[1])
378 BUILD_SHOW_FUNC_INT(sensor2_limit,		 th->limits[2])
379 BUILD_SHOW_FUNC_STR(sensor1_location,		 sensor_location[1])
380 BUILD_SHOW_FUNC_STR(sensor2_location,		 sensor_location[2])
381 
382 BUILD_SHOW_FUNC_INT_LITE(specified_fan_speed, fan_speed)
383 BUILD_STORE_FUNC_INT(specified_fan_speed,fan_speed)
384 
385 BUILD_SHOW_FUNC_FAN(sensor1_fan_speed,	 0)
386 BUILD_SHOW_FUNC_FAN(sensor2_fan_speed,	 1)
387 
388 BUILD_SHOW_FUNC_INT_LITE(limit_adjust,	 limit_adjust)
389 BUILD_STORE_FUNC_DEG(limit_adjust,	 th)
390 
391 static DEVICE_ATTR(sensor1_temperature,	S_IRUGO,
392 		   show_sensor1_temperature,NULL);
393 static DEVICE_ATTR(sensor2_temperature,	S_IRUGO,
394 		   show_sensor2_temperature,NULL);
395 static DEVICE_ATTR(sensor1_limit, S_IRUGO,
396 		   show_sensor1_limit,	NULL);
397 static DEVICE_ATTR(sensor2_limit, S_IRUGO,
398 		   show_sensor2_limit,	NULL);
399 static DEVICE_ATTR(sensor1_location, S_IRUGO,
400 		   show_sensor1_location, NULL);
401 static DEVICE_ATTR(sensor2_location, S_IRUGO,
402 		   show_sensor2_location, NULL);
403 
404 static DEVICE_ATTR(specified_fan_speed,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
405 		   show_specified_fan_speed,store_specified_fan_speed);
406 
407 static DEVICE_ATTR(sensor1_fan_speed,	S_IRUGO,
408 		   show_sensor1_fan_speed,	NULL);
409 static DEVICE_ATTR(sensor2_fan_speed,	S_IRUGO,
410 		   show_sensor2_fan_speed,	NULL);
411 
412 static DEVICE_ATTR(limit_adjust,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
413 		   show_limit_adjust,	store_limit_adjust);
414 
415 static void thermostat_create_files(struct thermostat *th)
416 {
417 	struct device_node *np = th->clt->dev.of_node;
418 	struct device *dev;
419 	int err;
420 
421 	/* To maintain ABI compatibility with userspace, create
422 	 * the old style platform driver and attach the attributes
423 	 * to it here
424 	 */
425 	th->pdev = of_platform_device_create(np, "temperatures", NULL);
426 	if (!th->pdev)
427 		return;
428 	dev = &th->pdev->dev;
429 	dev_set_drvdata(dev, th);
430 	err = device_create_file(dev, &dev_attr_sensor1_temperature);
431 	err |= device_create_file(dev, &dev_attr_sensor2_temperature);
432 	err |= device_create_file(dev, &dev_attr_sensor1_limit);
433 	err |= device_create_file(dev, &dev_attr_sensor2_limit);
434 	err |= device_create_file(dev, &dev_attr_sensor1_location);
435 	err |= device_create_file(dev, &dev_attr_sensor2_location);
436 	err |= device_create_file(dev, &dev_attr_limit_adjust);
437 	err |= device_create_file(dev, &dev_attr_specified_fan_speed);
438 	err |= device_create_file(dev, &dev_attr_sensor1_fan_speed);
439 	if(th->type == ADT7460)
440 		err |= device_create_file(dev, &dev_attr_sensor2_fan_speed);
441 	if (err)
442 		printk(KERN_WARNING
443 			"Failed to create temperature attribute file(s).\n");
444 }
445 
446 static void thermostat_remove_files(struct thermostat *th)
447 {
448 	struct device *dev;
449 
450 	if (!th->pdev)
451 		return;
452 	dev = &th->pdev->dev;
453 	device_remove_file(dev, &dev_attr_sensor1_temperature);
454 	device_remove_file(dev, &dev_attr_sensor2_temperature);
455 	device_remove_file(dev, &dev_attr_sensor1_limit);
456 	device_remove_file(dev, &dev_attr_sensor2_limit);
457 	device_remove_file(dev, &dev_attr_sensor1_location);
458 	device_remove_file(dev, &dev_attr_sensor2_location);
459 	device_remove_file(dev, &dev_attr_limit_adjust);
460 	device_remove_file(dev, &dev_attr_specified_fan_speed);
461 	device_remove_file(dev, &dev_attr_sensor1_fan_speed);
462 	if (th->type == ADT7460)
463 		device_remove_file(dev, &dev_attr_sensor2_fan_speed);
464 	of_device_unregister(th->pdev);
465 
466 }
467 
468 static int probe_thermostat(struct i2c_client *client,
469 			    const struct i2c_device_id *id)
470 {
471 	struct device_node *np = client->dev.of_node;
472 	struct thermostat* th;
473 	const __be32 *prop;
474 	int i, rc, vers, offset = 0;
475 
476 	if (!np)
477 		return -ENXIO;
478 	prop = of_get_property(np, "hwsensor-params-version", NULL);
479 	if (!prop)
480 		return -ENXIO;
481 	vers = be32_to_cpup(prop);
482 	printk(KERN_INFO "adt746x: version %d (%ssupported)\n",
483 	       vers, vers == 1 ? "" : "un");
484 	if (vers != 1)
485 		return -ENXIO;
486 
487 	if (of_get_property(np, "hwsensor-location", NULL)) {
488 		for (i = 0; i < 3; i++) {
489 			sensor_location[i] = of_get_property(np,
490 					"hwsensor-location", NULL) + offset;
491 
492 			if (sensor_location[i] == NULL)
493 				sensor_location[i] = "";
494 
495 			printk(KERN_INFO "sensor %d: %s\n", i, sensor_location[i]);
496 			offset += strlen(sensor_location[i]) + 1;
497 		}
498 	}
499 
500 	th = kzalloc(sizeof(struct thermostat), GFP_KERNEL);
501 	if (!th)
502 		return -ENOMEM;
503 
504 	i2c_set_clientdata(client, th);
505 	th->clt = client;
506 	th->type = id->driver_data;
507 
508 	rc = read_reg(th, CONFIG_REG);
509 	if (rc < 0) {
510 		dev_err(&client->dev, "Thermostat failed to read config!\n");
511 		kfree(th);
512 		return -ENODEV;
513 	}
514 
515 	/* force manual control to start the fan quieter */
516 	if (fan_speed == -1)
517 		fan_speed = 64;
518 
519 	if (th->type == ADT7460) {
520 		printk(KERN_INFO "adt746x: ADT7460 initializing\n");
521 		/* The 7460 needs to be started explicitly */
522 		write_reg(th, CONFIG_REG, 1);
523 	} else
524 		printk(KERN_INFO "adt746x: ADT7467 initializing\n");
525 
526 	for (i = 0; i < 3; i++) {
527 		th->initial_limits[i] = read_reg(th, LIMIT_REG[i]);
528 		set_limit(th, i);
529 	}
530 
531 	printk(KERN_INFO "adt746x: Lowering max temperatures from %d, %d, %d"
532 			 " to %d, %d, %d\n",
533 			 th->initial_limits[0], th->initial_limits[1],
534 			 th->initial_limits[2], th->limits[0], th->limits[1],
535 			 th->limits[2]);
536 
537 	/* record invert bit status because fw can corrupt it after suspend */
538 	th->pwm_inv[0] = read_reg(th, MANUAL_MODE[0]) & INVERT_MASK;
539 	th->pwm_inv[1] = read_reg(th, MANUAL_MODE[1]) & INVERT_MASK;
540 
541 	/* be sure to really write fan speed the first time */
542 	th->last_speed[0] = -2;
543 	th->last_speed[1] = -2;
544 	th->last_var[0] = -80;
545 	th->last_var[1] = -80;
546 
547 	if (fan_speed != -1) {
548 		/* manual mode, stop fans */
549 		write_both_fan_speed(th, 0);
550 	} else {
551 		/* automatic mode */
552 		write_both_fan_speed(th, -1);
553 	}
554 
555 	th->thread = kthread_run(monitor_task, th, "kfand");
556 	if (th->thread == ERR_PTR(-ENOMEM)) {
557 		printk(KERN_INFO "adt746x: Kthread creation failed\n");
558 		th->thread = NULL;
559 		return -ENOMEM;
560 	}
561 
562 	thermostat_create_files(th);
563 
564 	return 0;
565 }
566 
567 static int remove_thermostat(struct i2c_client *client)
568 {
569 	struct thermostat *th = i2c_get_clientdata(client);
570 	int i;
571 
572 	thermostat_remove_files(th);
573 
574 	if (th->thread != NULL)
575 		kthread_stop(th->thread);
576 
577 	printk(KERN_INFO "adt746x: Putting max temperatures back from "
578 			 "%d, %d, %d to %d, %d, %d\n",
579 		th->limits[0], th->limits[1], th->limits[2],
580 		th->initial_limits[0], th->initial_limits[1],
581 		th->initial_limits[2]);
582 
583 	for (i = 0; i < 3; i++)
584 		write_reg(th, LIMIT_REG[i], th->initial_limits[i]);
585 
586 	write_both_fan_speed(th, -1);
587 
588 	kfree(th);
589 
590 	return 0;
591 }
592 
593 static const struct i2c_device_id therm_adt746x_id[] = {
594 	{ "MAC,adt7460", ADT7460 },
595 	{ "MAC,adt7467", ADT7467 },
596 	{ }
597 };
598 MODULE_DEVICE_TABLE(i2c, therm_adt746x_id);
599 
600 static struct i2c_driver thermostat_driver = {
601 	.driver = {
602 		.name	= "therm_adt746x",
603 	},
604 	.probe = probe_thermostat,
605 	.remove = remove_thermostat,
606 	.id_table = therm_adt746x_id,
607 };
608 
609 static int __init thermostat_init(void)
610 {
611 #ifndef CONFIG_I2C_POWERMAC
612 	request_module("i2c-powermac");
613 #endif
614 
615 	return i2c_add_driver(&thermostat_driver);
616 }
617 
618 static void __exit thermostat_exit(void)
619 {
620 	i2c_del_driver(&thermostat_driver);
621 }
622 
623 module_init(thermostat_init);
624 module_exit(thermostat_exit);
625