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
write_reg(struct thermostat * th,int reg,u8 data)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
read_reg(struct thermostat * th,int reg)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, ®_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
read_fan_speed(struct thermostat * th,u8 addr)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
write_both_fan_speed(struct thermostat * th,int speed)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
write_fan_speed(struct thermostat * th,int speed,int fan)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
read_sensors(struct thermostat * th)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
display_stats(struct thermostat * th)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
update_fans_speed(struct thermostat * th)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
monitor_task(void * arg)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
set_limit(struct thermostat * th,int i)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
thermostat_create_files(struct thermostat * th)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
thermostat_remove_files(struct thermostat * th)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
probe_thermostat(struct i2c_client * client,const struct i2c_device_id * id)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
remove_thermostat(struct i2c_client * client)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
thermostat_init(void)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
thermostat_exit(void)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