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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 * https://www.onsemi.com/PowerSolutions/product.do?id=ADT7467
9 * https://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.h>
29#include <linux/of_platform.h>
30#include <linux/platform_device.h>
31
32#include <asm/machdep.h>
33#include <asm/io.h>
34#include <asm/sections.h>
35
36#undef DEBUG
37
38#define CONFIG_REG 0x40
39#define MANUAL_MASK 0xe0
40#define AUTO_MASK 0x20
41#define INVERT_MASK 0x10
42
43static u8 TEMP_REG[3] = {0x26, 0x25, 0x27}; /* local, sensor1, sensor2 */
44static u8 LIMIT_REG[3] = {0x6b, 0x6a, 0x6c}; /* local, sensor1, sensor2 */
45static u8 MANUAL_MODE[2] = {0x5c, 0x5d};
46static u8 REM_CONTROL[2] = {0x00, 0x40};
47static u8 FAN_SPEED[2] = {0x28, 0x2a};
48static u8 FAN_SPD_SET[2] = {0x30, 0x31};
49
50static u8 default_limits_local[3] = {70, 50, 70}; /* local, sensor1, sensor2 */
51static u8 default_limits_chip[3] = {80, 65, 80}; /* local, sensor1, sensor2 */
52static const char *sensor_location[3] = { "?", "?", "?" };
53
54static int limit_adjust;
55static int fan_speed = -1;
56static bool verbose;
57
58MODULE_AUTHOR("Colin Leroy <[email protected]>");
59MODULE_DESCRIPTION("Driver for ADT746x thermostat in iBook G4 and "
60 "Powerbook G4 Alu");
61MODULE_LICENSE("GPL");
62
63module_param(limit_adjust, int, 0644);
64MODULE_PARM_DESC(limit_adjust,"Adjust maximum temperatures (50 sensor1, 70 sensor2) "
65 "by N degrees.");
66
67module_param(fan_speed, int, 0644);
68MODULE_PARM_DESC(fan_speed,"Specify starting fan speed (0-255) "
69 "(default 64)");
70
71module_param(verbose, bool, 0);
72MODULE_PARM_DESC(verbose,"Verbose log operations "
73 "(default 0)");
74
75struct thermostat {
76 struct i2c_client *clt;
77 u8 temps[3];
78 u8 cached_temp[3];
79 u8 initial_limits[3];
80 u8 limits[3];
81 int last_speed[2];
82 int last_var[2];
83 int pwm_inv[2];
84 struct task_struct *thread;
85 struct platform_device *pdev;
86 enum {
87 ADT7460,
88 ADT7467
89 } type;
90};
91
92static void write_both_fan_speed(struct thermostat *th, int speed);
93static void write_fan_speed(struct thermostat *th, int speed, int fan);
94
95static int
96write_reg(struct thermostat* th, int reg, u8 data)
97{
98 u8 tmp[2];
99 int rc;
100
101 tmp[0] = reg;
102 tmp[1] = data;
103 rc = i2c_master_send(th->clt, (const char *)tmp, 2);
104 if (rc < 0)
105 return rc;
106 if (rc != 2)
107 return -ENODEV;
108 return 0;
109}
110
111static int
112read_reg(struct thermostat* th, int reg)
113{
114 u8 reg_addr, data;
115 int rc;
116
117 reg_addr = (u8)reg;
118 rc = i2c_master_send(th->clt, &reg_addr, 1);
119 if (rc < 0)
120 return rc;
121 if (rc != 1)
122 return -ENODEV;
123 rc = i2c_master_recv(th->clt, (char *)&data, 1);
124 if (rc < 0)
125 return rc;
126 return data;
127}
128
129static int read_fan_speed(struct thermostat *th, u8 addr)
130{
131 u8 tmp[2];
132 u16 res;
133
134 /* should start with low byte */
135 tmp[1] = read_reg(th, addr);
136 tmp[0] = read_reg(th, addr + 1);
137
138 res = tmp[1] + (tmp[0] << 8);
139 /* "a value of 0xffff means that the fan has stopped" */
140 return (res == 0xffff ? 0 : (90000*60)/res);
141}
142
143static void write_both_fan_speed(struct thermostat *th, int speed)
144{
145 write_fan_speed(th, speed, 0);
146 if (th->type == ADT7460)
147 write_fan_speed(th, speed, 1);
148}
149
150static void write_fan_speed(struct thermostat *th, int speed, int fan)
151{
152 u8 manual;
153
154 if (speed > 0xff)
155 speed = 0xff;
156 else if (speed < -1)
157 speed = 0;
158
159 if (th->type == ADT7467 && fan == 1)
160 return;
161
162 if (th->last_speed[fan] != speed) {
163 if (verbose) {
164 if (speed == -1)
165 printk(KERN_DEBUG "adt746x: Setting speed to automatic "
166 "for %s fan.\n", sensor_location[fan+1]);
167 else
168 printk(KERN_DEBUG "adt746x: Setting speed to %d "
169 "for %s fan.\n", speed, sensor_location[fan+1]);
170 }
171 } else
172 return;
173
174 if (speed >= 0) {
175 manual = read_reg(th, MANUAL_MODE[fan]);
176 manual &= ~INVERT_MASK;
177 write_reg(th, MANUAL_MODE[fan],
178 manual | MANUAL_MASK | th->pwm_inv[fan]);
179 write_reg(th, FAN_SPD_SET[fan], speed);
180 } else {
181 /* back to automatic */
182 if(th->type == ADT7460) {
183 manual = read_reg(th,
184 MANUAL_MODE[fan]) & (~MANUAL_MASK);
185 manual &= ~INVERT_MASK;
186 manual |= th->pwm_inv[fan];
187 write_reg(th,
188 MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
189 } else {
190 manual = read_reg(th, MANUAL_MODE[fan]);
191 manual &= ~INVERT_MASK;
192 manual |= th->pwm_inv[fan];
193 write_reg(th, MANUAL_MODE[fan], manual&(~AUTO_MASK));
194 }
195 }
196
197 th->last_speed[fan] = speed;
198}
199
200static void read_sensors(struct thermostat *th)
201{
202 int i = 0;
203
204 for (i = 0; i < 3; i++)
205 th->temps[i] = read_reg(th, TEMP_REG[i]);
206}
207
208#ifdef DEBUG
209static void display_stats(struct thermostat *th)
210{
211 if (th->temps[0] != th->cached_temp[0]
212 || th->temps[1] != th->cached_temp[1]
213 || th->temps[2] != th->cached_temp[2]) {
214 printk(KERN_INFO "adt746x: Temperature infos:"
215 " thermostats: %d,%d,%d;"
216 " limits: %d,%d,%d;"
217 " fan speed: %d RPM\n",
218 th->temps[0], th->temps[1], th->temps[2],
219 th->limits[0], th->limits[1], th->limits[2],
220 read_fan_speed(th, FAN_SPEED[0]));
221 }
222 th->cached_temp[0] = th->temps[0];
223 th->cached_temp[1] = th->temps[1];
224 th->cached_temp[2] = th->temps[2];
225}
226#endif
227
228static void update_fans_speed (struct thermostat *th)
229{
230 int lastvar = 0; /* last variation, for iBook */
231 int i = 0;
232
233 /* we don't care about local sensor, so we start at sensor 1 */
234 for (i = 1; i < 3; i++) {
235 bool started = false;
236 int fan_number = (th->type == ADT7460 && i == 2);
237 int var = th->temps[i] - th->limits[i];
238
239 if (var > -1) {
240 int step = (255 - fan_speed) / 7;
241 int new_speed = 0;
242
243 /* hysteresis : change fan speed only if variation is
244 * more than two degrees */
245 if (abs(var - th->last_var[fan_number]) < 2)
246 continue;
247
248 started = true;
249 new_speed = fan_speed + ((var-1)*step);
250
251 if (new_speed < fan_speed)
252 new_speed = fan_speed;
253 if (new_speed > 255)
254 new_speed = 255;
255
256 if (verbose)
257 printk(KERN_DEBUG "adt746x: Setting fans speed to %d "
258 "(limit exceeded by %d on %s)\n",
259 new_speed, var,
260 sensor_location[fan_number+1]);
261 write_both_fan_speed(th, new_speed);
262 th->last_var[fan_number] = var;
263 } else if (var < -2) {
264 /* don't stop fan if sensor2 is cold and sensor1 is not
265 * so cold (lastvar >= -1) */
266 if (i == 2 && lastvar < -1) {
267 if (th->last_speed[fan_number] != 0)
268 if (verbose)
269 printk(KERN_DEBUG "adt746x: Stopping "
270 "fans.\n");
271 write_both_fan_speed(th, 0);
272 }
273 }
274
275 lastvar = var;
276
277 if (started)
278 return; /* we don't want to re-stop the fan
279 * if sensor1 is heating and sensor2 is not */
280 }
281}
282
283static int monitor_task(void *arg)
284{
285 struct thermostat* th = arg;
286
287 set_freezable();
288 while(!kthread_should_stop()) {
289 try_to_freeze();
290 msleep_interruptible(2000);
291
292#ifndef DEBUG
293 if (fan_speed != -1)
294 read_sensors(th);
295#else
296 read_sensors(th);
297#endif
298
299 if (fan_speed != -1)
300 update_fans_speed(th);
301
302#ifdef DEBUG
303 display_stats(th);
304#endif
305
306 }
307
308 return 0;
309}
310
311static void set_limit(struct thermostat *th, int i)
312{
313 /* Set sensor1 limit higher to avoid powerdowns */
314 th->limits[i] = default_limits_chip[i] + limit_adjust;
315 write_reg(th, LIMIT_REG[i], th->limits[i]);
316
317 /* set our limits to normal */
318 th->limits[i] = default_limits_local[i] + limit_adjust;
319}
320
321#define BUILD_SHOW_FUNC_INT(name, data) \
322static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf) \
323{ \
324 struct thermostat *th = dev_get_drvdata(dev); \
325 return sprintf(buf, "%d\n", data); \
326}
327
328#define BUILD_SHOW_FUNC_INT_LITE(name, data) \
329static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf) \
330{ \
331 return sprintf(buf, "%d\n", data); \
332}
333
334#define BUILD_SHOW_FUNC_STR(name, data) \
335static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf) \
336{ \
337 return sprintf(buf, "%s\n", data); \
338}
339
340#define BUILD_SHOW_FUNC_FAN(name, data) \
341static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf) \
342{ \
343 struct thermostat *th = dev_get_drvdata(dev); \
344 return sprintf(buf, "%d (%d rpm)\n", \
345 th->last_speed[data], \
346 read_fan_speed(th, FAN_SPEED[data]) \
347 ); \
348}
349
350#define BUILD_STORE_FUNC_DEG(name, data) \
351static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
352{ \
353 struct thermostat *th = dev_get_drvdata(dev); \
354 int val; \
355 int i; \
356 val = simple_strtol(buf, NULL, 10); \
357 printk(KERN_INFO "Adjusting limits by %d degrees\n", val); \
358 limit_adjust = val; \
359 for (i=0; i < 3; i++) \
360 set_limit(th, i); \
361 return n; \
362}
363
364#define BUILD_STORE_FUNC_INT(name, data) \
365static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
366{ \
367 int val; \
368 val = simple_strtol(buf, NULL, 10); \
369 if (val < 0 || val > 255) \
370 return -EINVAL; \
371 printk(KERN_INFO "Setting specified fan speed to %d\n", val); \
372 data = val; \
373 return n; \
374}
375
376BUILD_SHOW_FUNC_INT(sensor1_temperature, (read_reg(th, TEMP_REG[1])))
377BUILD_SHOW_FUNC_INT(sensor2_temperature, (read_reg(th, TEMP_REG[2])))
378BUILD_SHOW_FUNC_INT(sensor1_limit, th->limits[1])
379BUILD_SHOW_FUNC_INT(sensor2_limit, th->limits[2])
380BUILD_SHOW_FUNC_STR(sensor1_location, sensor_location[1])
381BUILD_SHOW_FUNC_STR(sensor2_location, sensor_location[2])
382
383BUILD_SHOW_FUNC_INT_LITE(specified_fan_speed, fan_speed)
384BUILD_STORE_FUNC_INT(specified_fan_speed,fan_speed)
385
386BUILD_SHOW_FUNC_FAN(sensor1_fan_speed, 0)
387BUILD_SHOW_FUNC_FAN(sensor2_fan_speed, 1)
388
389BUILD_SHOW_FUNC_INT_LITE(limit_adjust, limit_adjust)
390BUILD_STORE_FUNC_DEG(limit_adjust, th)
391
392static DEVICE_ATTR(sensor1_temperature, S_IRUGO,
393 show_sensor1_temperature,NULL);
394static DEVICE_ATTR(sensor2_temperature, S_IRUGO,
395 show_sensor2_temperature,NULL);
396static DEVICE_ATTR(sensor1_limit, S_IRUGO,
397 show_sensor1_limit, NULL);
398static DEVICE_ATTR(sensor2_limit, S_IRUGO,
399 show_sensor2_limit, NULL);
400static DEVICE_ATTR(sensor1_location, S_IRUGO,
401 show_sensor1_location, NULL);
402static DEVICE_ATTR(sensor2_location, S_IRUGO,
403 show_sensor2_location, NULL);
404
405static DEVICE_ATTR(specified_fan_speed, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
406 show_specified_fan_speed,store_specified_fan_speed);
407
408static DEVICE_ATTR(sensor1_fan_speed, S_IRUGO,
409 show_sensor1_fan_speed, NULL);
410static DEVICE_ATTR(sensor2_fan_speed, S_IRUGO,
411 show_sensor2_fan_speed, NULL);
412
413static DEVICE_ATTR(limit_adjust, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
414 show_limit_adjust, store_limit_adjust);
415
416static void thermostat_create_files(struct thermostat *th)
417{
418 struct device_node *np = th->clt->dev.of_node;
419 struct device *dev;
420 int err;
421
422 /* To maintain ABI compatibility with userspace, create
423 * the old style platform driver and attach the attributes
424 * to it here
425 */
426 th->pdev = of_platform_device_create(np, "temperatures", NULL);
427 if (!th->pdev)
428 return;
429 dev = &th->pdev->dev;
430 dev_set_drvdata(dev, th);
431 err = device_create_file(dev, &dev_attr_sensor1_temperature);
432 err |= device_create_file(dev, &dev_attr_sensor2_temperature);
433 err |= device_create_file(dev, &dev_attr_sensor1_limit);
434 err |= device_create_file(dev, &dev_attr_sensor2_limit);
435 err |= device_create_file(dev, &dev_attr_sensor1_location);
436 err |= device_create_file(dev, &dev_attr_sensor2_location);
437 err |= device_create_file(dev, &dev_attr_limit_adjust);
438 err |= device_create_file(dev, &dev_attr_specified_fan_speed);
439 err |= device_create_file(dev, &dev_attr_sensor1_fan_speed);
440 if(th->type == ADT7460)
441 err |= device_create_file(dev, &dev_attr_sensor2_fan_speed);
442 if (err)
443 printk(KERN_WARNING
444 "Failed to create temperature attribute file(s).\n");
445}
446
447static void thermostat_remove_files(struct thermostat *th)
448{
449 struct device *dev;
450
451 if (!th->pdev)
452 return;
453 dev = &th->pdev->dev;
454 device_remove_file(dev, &dev_attr_sensor1_temperature);
455 device_remove_file(dev, &dev_attr_sensor2_temperature);
456 device_remove_file(dev, &dev_attr_sensor1_limit);
457 device_remove_file(dev, &dev_attr_sensor2_limit);
458 device_remove_file(dev, &dev_attr_sensor1_location);
459 device_remove_file(dev, &dev_attr_sensor2_location);
460 device_remove_file(dev, &dev_attr_limit_adjust);
461 device_remove_file(dev, &dev_attr_specified_fan_speed);
462 device_remove_file(dev, &dev_attr_sensor1_fan_speed);
463 if (th->type == ADT7460)
464 device_remove_file(dev, &dev_attr_sensor2_fan_speed);
465 of_device_unregister(th->pdev);
466
467}
468
469static int probe_thermostat(struct i2c_client *client)
470{
471 const struct i2c_device_id *id = i2c_client_get_device_id(client);
472 struct device_node *np = client->dev.of_node;
473 struct thermostat* th;
474 const __be32 *prop;
475 int i, rc, vers, offset = 0;
476
477 if (!np)
478 return -ENXIO;
479 prop = of_get_property(np, "hwsensor-params-version", NULL);
480 if (!prop)
481 return -ENXIO;
482 vers = be32_to_cpup(prop);
483 printk(KERN_INFO "adt746x: version %d (%ssupported)\n",
484 vers, vers == 1 ? "" : "un");
485 if (vers != 1)
486 return -ENXIO;
487
488 if (of_property_present(np, "hwsensor-location")) {
489 for (i = 0; i < 3; i++) {
490 sensor_location[i] = of_get_property(np,
491 "hwsensor-location", NULL) + offset;
492
493 if (sensor_location[i] == NULL)
494 sensor_location[i] = "";
495
496 printk(KERN_INFO "sensor %d: %s\n", i, sensor_location[i]);
497 offset += strlen(sensor_location[i]) + 1;
498 }
499 }
500
501 th = kzalloc_obj(struct thermostat);
502 if (!th)
503 return -ENOMEM;
504
505 i2c_set_clientdata(client, th);
506 th->clt = client;
507 th->type = id->driver_data;
508
509 rc = read_reg(th, CONFIG_REG);
510 if (rc < 0) {
511 dev_err(&client->dev, "Thermostat failed to read config!\n");
512 kfree(th);
513 return -ENODEV;
514 }
515
516 /* force manual control to start the fan quieter */
517 if (fan_speed == -1)
518 fan_speed = 64;
519
520 if (th->type == ADT7460) {
521 printk(KERN_INFO "adt746x: ADT7460 initializing\n");
522 /* The 7460 needs to be started explicitly */
523 write_reg(th, CONFIG_REG, 1);
524 } else
525 printk(KERN_INFO "adt746x: ADT7467 initializing\n");
526
527 for (i = 0; i < 3; i++) {
528 th->initial_limits[i] = read_reg(th, LIMIT_REG[i]);
529 set_limit(th, i);
530 }
531
532 printk(KERN_INFO "adt746x: Lowering max temperatures from %d, %d, %d"
533 " to %d, %d, %d\n",
534 th->initial_limits[0], th->initial_limits[1],
535 th->initial_limits[2], th->limits[0], th->limits[1],
536 th->limits[2]);
537
538 /* record invert bit status because fw can corrupt it after suspend */
539 th->pwm_inv[0] = read_reg(th, MANUAL_MODE[0]) & INVERT_MASK;
540 th->pwm_inv[1] = read_reg(th, MANUAL_MODE[1]) & INVERT_MASK;
541
542 /* be sure to really write fan speed the first time */
543 th->last_speed[0] = -2;
544 th->last_speed[1] = -2;
545 th->last_var[0] = -80;
546 th->last_var[1] = -80;
547
548 if (fan_speed != -1) {
549 /* manual mode, stop fans */
550 write_both_fan_speed(th, 0);
551 } else {
552 /* automatic mode */
553 write_both_fan_speed(th, -1);
554 }
555
556 th->thread = kthread_run(monitor_task, th, "kfand");
557 if (th->thread == ERR_PTR(-ENOMEM)) {
558 printk(KERN_INFO "adt746x: Kthread creation failed\n");
559 th->thread = NULL;
560 return -ENOMEM;
561 }
562
563 thermostat_create_files(th);
564
565 return 0;
566}
567
568static void remove_thermostat(struct i2c_client *client)
569{
570 struct thermostat *th = i2c_get_clientdata(client);
571 int i;
572
573 thermostat_remove_files(th);
574
575 if (th->thread != NULL)
576 kthread_stop(th->thread);
577
578 printk(KERN_INFO "adt746x: Putting max temperatures back from "
579 "%d, %d, %d to %d, %d, %d\n",
580 th->limits[0], th->limits[1], th->limits[2],
581 th->initial_limits[0], th->initial_limits[1],
582 th->initial_limits[2]);
583
584 for (i = 0; i < 3; i++)
585 write_reg(th, LIMIT_REG[i], th->initial_limits[i]);
586
587 write_both_fan_speed(th, -1);
588
589 kfree(th);
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);