xref: /openbmc/linux/drivers/hwmon/amc6821.c (revision 5bd8e16d)
1 /*
2  * amc6821.c - Part of lm_sensors, Linux kernel modules for hardware
3  *	       monitoring
4  * Copyright (C) 2009 T. Mertelj <tomaz.mertelj@guest.arnes.si>
5  *
6  * Based on max6650.c:
7  * Copyright (C) 2007 Hans J. Koch <hjk@hansjkoch.de>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22  */
23 
24 
25 #include <linux/kernel.h>	/* Needed for KERN_INFO */
26 #include <linux/module.h>
27 #include <linux/init.h>
28 #include <linux/slab.h>
29 #include <linux/jiffies.h>
30 #include <linux/i2c.h>
31 #include <linux/hwmon.h>
32 #include <linux/hwmon-sysfs.h>
33 #include <linux/err.h>
34 #include <linux/mutex.h>
35 
36 
37 /*
38  * Addresses to scan.
39  */
40 
41 static const unsigned short normal_i2c[] = {0x18, 0x19, 0x1a, 0x2c, 0x2d, 0x2e,
42 	0x4c, 0x4d, 0x4e, I2C_CLIENT_END};
43 
44 
45 
46 /*
47  * Insmod parameters
48  */
49 
50 static int pwminv;	/*Inverted PWM output. */
51 module_param(pwminv, int, S_IRUGO);
52 
53 static int init = 1; /*Power-on initialization.*/
54 module_param(init, int, S_IRUGO);
55 
56 
57 enum chips { amc6821 };
58 
59 #define AMC6821_REG_DEV_ID 0x3D
60 #define AMC6821_REG_COMP_ID 0x3E
61 #define AMC6821_REG_CONF1 0x00
62 #define AMC6821_REG_CONF2 0x01
63 #define AMC6821_REG_CONF3 0x3F
64 #define AMC6821_REG_CONF4 0x04
65 #define AMC6821_REG_STAT1 0x02
66 #define AMC6821_REG_STAT2 0x03
67 #define AMC6821_REG_TDATA_LOW 0x08
68 #define AMC6821_REG_TDATA_HI 0x09
69 #define AMC6821_REG_LTEMP_HI 0x0A
70 #define AMC6821_REG_RTEMP_HI 0x0B
71 #define AMC6821_REG_LTEMP_LIMIT_MIN 0x15
72 #define AMC6821_REG_LTEMP_LIMIT_MAX 0x14
73 #define AMC6821_REG_RTEMP_LIMIT_MIN 0x19
74 #define AMC6821_REG_RTEMP_LIMIT_MAX 0x18
75 #define AMC6821_REG_LTEMP_CRIT 0x1B
76 #define AMC6821_REG_RTEMP_CRIT 0x1D
77 #define AMC6821_REG_PSV_TEMP 0x1C
78 #define AMC6821_REG_DCY 0x22
79 #define AMC6821_REG_LTEMP_FAN_CTRL 0x24
80 #define AMC6821_REG_RTEMP_FAN_CTRL 0x25
81 #define AMC6821_REG_DCY_LOW_TEMP 0x21
82 
83 #define AMC6821_REG_TACH_LLIMITL 0x10
84 #define AMC6821_REG_TACH_LLIMITH 0x11
85 #define AMC6821_REG_TACH_HLIMITL 0x12
86 #define AMC6821_REG_TACH_HLIMITH 0x13
87 
88 #define AMC6821_CONF1_START 0x01
89 #define AMC6821_CONF1_FAN_INT_EN 0x02
90 #define AMC6821_CONF1_FANIE 0x04
91 #define AMC6821_CONF1_PWMINV 0x08
92 #define AMC6821_CONF1_FAN_FAULT_EN 0x10
93 #define AMC6821_CONF1_FDRC0 0x20
94 #define AMC6821_CONF1_FDRC1 0x40
95 #define AMC6821_CONF1_THERMOVIE 0x80
96 
97 #define AMC6821_CONF2_PWM_EN 0x01
98 #define AMC6821_CONF2_TACH_MODE 0x02
99 #define AMC6821_CONF2_TACH_EN 0x04
100 #define AMC6821_CONF2_RTFIE 0x08
101 #define AMC6821_CONF2_LTOIE 0x10
102 #define AMC6821_CONF2_RTOIE 0x20
103 #define AMC6821_CONF2_PSVIE 0x40
104 #define AMC6821_CONF2_RST 0x80
105 
106 #define AMC6821_CONF3_THERM_FAN_EN 0x80
107 #define AMC6821_CONF3_REV_MASK 0x0F
108 
109 #define AMC6821_CONF4_OVREN 0x10
110 #define AMC6821_CONF4_TACH_FAST 0x20
111 #define AMC6821_CONF4_PSPR 0x40
112 #define AMC6821_CONF4_MODE 0x80
113 
114 #define AMC6821_STAT1_RPM_ALARM 0x01
115 #define AMC6821_STAT1_FANS 0x02
116 #define AMC6821_STAT1_RTH 0x04
117 #define AMC6821_STAT1_RTL 0x08
118 #define AMC6821_STAT1_R_THERM 0x10
119 #define AMC6821_STAT1_RTF 0x20
120 #define AMC6821_STAT1_LTH 0x40
121 #define AMC6821_STAT1_LTL 0x80
122 
123 #define AMC6821_STAT2_RTC 0x08
124 #define AMC6821_STAT2_LTC 0x10
125 #define AMC6821_STAT2_LPSV 0x20
126 #define AMC6821_STAT2_L_THERM 0x40
127 #define AMC6821_STAT2_THERM_IN 0x80
128 
129 enum {IDX_TEMP1_INPUT = 0, IDX_TEMP1_MIN, IDX_TEMP1_MAX,
130 	IDX_TEMP1_CRIT, IDX_TEMP2_INPUT, IDX_TEMP2_MIN,
131 	IDX_TEMP2_MAX, IDX_TEMP2_CRIT,
132 	TEMP_IDX_LEN, };
133 
134 static const u8 temp_reg[] = {AMC6821_REG_LTEMP_HI,
135 			AMC6821_REG_LTEMP_LIMIT_MIN,
136 			AMC6821_REG_LTEMP_LIMIT_MAX,
137 			AMC6821_REG_LTEMP_CRIT,
138 			AMC6821_REG_RTEMP_HI,
139 			AMC6821_REG_RTEMP_LIMIT_MIN,
140 			AMC6821_REG_RTEMP_LIMIT_MAX,
141 			AMC6821_REG_RTEMP_CRIT, };
142 
143 enum {IDX_FAN1_INPUT = 0, IDX_FAN1_MIN, IDX_FAN1_MAX,
144 	FAN1_IDX_LEN, };
145 
146 static const u8 fan_reg_low[] = {AMC6821_REG_TDATA_LOW,
147 			AMC6821_REG_TACH_LLIMITL,
148 			AMC6821_REG_TACH_HLIMITL, };
149 
150 
151 static const u8 fan_reg_hi[] = {AMC6821_REG_TDATA_HI,
152 			AMC6821_REG_TACH_LLIMITH,
153 			AMC6821_REG_TACH_HLIMITH, };
154 
155 static int amc6821_probe(
156 		struct i2c_client *client,
157 		const struct i2c_device_id *id);
158 static int amc6821_detect(
159 		struct i2c_client *client,
160 		struct i2c_board_info *info);
161 static int amc6821_init_client(struct i2c_client *client);
162 static int amc6821_remove(struct i2c_client *client);
163 static struct amc6821_data *amc6821_update_device(struct device *dev);
164 
165 /*
166  * Driver data (common to all clients)
167  */
168 
169 static const struct i2c_device_id amc6821_id[] = {
170 	{ "amc6821", amc6821 },
171 	{ }
172 };
173 
174 MODULE_DEVICE_TABLE(i2c, amc6821_id);
175 
176 static struct i2c_driver amc6821_driver = {
177 	.class = I2C_CLASS_HWMON,
178 	.driver = {
179 		.name	= "amc6821",
180 	},
181 	.probe = amc6821_probe,
182 	.remove = amc6821_remove,
183 	.id_table = amc6821_id,
184 	.detect = amc6821_detect,
185 	.address_list = normal_i2c,
186 };
187 
188 
189 /*
190  * Client data (each client gets its own)
191  */
192 
193 struct amc6821_data {
194 	struct device *hwmon_dev;
195 	struct mutex update_lock;
196 	char valid; /* zero until following fields are valid */
197 	unsigned long last_updated; /* in jiffies */
198 
199 	/* register values */
200 	int temp[TEMP_IDX_LEN];
201 
202 	u16 fan[FAN1_IDX_LEN];
203 	u8 fan1_div;
204 
205 	u8 pwm1;
206 	u8 temp1_auto_point_temp[3];
207 	u8 temp2_auto_point_temp[3];
208 	u8 pwm1_auto_point_pwm[3];
209 	u8 pwm1_enable;
210 	u8 pwm1_auto_channels_temp;
211 
212 	u8 stat1;
213 	u8 stat2;
214 };
215 
216 
217 static ssize_t get_temp(
218 		struct device *dev,
219 		struct device_attribute *devattr,
220 		char *buf)
221 {
222 	struct amc6821_data *data = amc6821_update_device(dev);
223 	int ix = to_sensor_dev_attr(devattr)->index;
224 
225 	return sprintf(buf, "%d\n", data->temp[ix] * 1000);
226 }
227 
228 
229 
230 static ssize_t set_temp(
231 		struct device *dev,
232 		struct device_attribute *attr,
233 		const char *buf,
234 		size_t count)
235 {
236 	struct i2c_client *client = to_i2c_client(dev);
237 	struct amc6821_data *data = i2c_get_clientdata(client);
238 	int ix = to_sensor_dev_attr(attr)->index;
239 	long val;
240 
241 	int ret = kstrtol(buf, 10, &val);
242 	if (ret)
243 		return ret;
244 	val = clamp_val(val / 1000, -128, 127);
245 
246 	mutex_lock(&data->update_lock);
247 	data->temp[ix] = val;
248 	if (i2c_smbus_write_byte_data(client, temp_reg[ix], data->temp[ix])) {
249 		dev_err(&client->dev, "Register write error, aborting.\n");
250 		count = -EIO;
251 	}
252 	mutex_unlock(&data->update_lock);
253 	return count;
254 }
255 
256 
257 
258 
259 static ssize_t get_temp_alarm(
260 	struct device *dev,
261 	struct device_attribute *devattr,
262 	char *buf)
263 {
264 	struct amc6821_data *data = amc6821_update_device(dev);
265 	int ix = to_sensor_dev_attr(devattr)->index;
266 	u8 flag;
267 
268 	switch (ix) {
269 	case IDX_TEMP1_MIN:
270 		flag = data->stat1 & AMC6821_STAT1_LTL;
271 		break;
272 	case IDX_TEMP1_MAX:
273 		flag = data->stat1 & AMC6821_STAT1_LTH;
274 		break;
275 	case IDX_TEMP1_CRIT:
276 		flag = data->stat2 & AMC6821_STAT2_LTC;
277 		break;
278 	case IDX_TEMP2_MIN:
279 		flag = data->stat1 & AMC6821_STAT1_RTL;
280 		break;
281 	case IDX_TEMP2_MAX:
282 		flag = data->stat1 & AMC6821_STAT1_RTH;
283 		break;
284 	case IDX_TEMP2_CRIT:
285 		flag = data->stat2 & AMC6821_STAT2_RTC;
286 		break;
287 	default:
288 		dev_dbg(dev, "Unknown attr->index (%d).\n", ix);
289 		return -EINVAL;
290 	}
291 	if (flag)
292 		return sprintf(buf, "1");
293 	else
294 		return sprintf(buf, "0");
295 }
296 
297 
298 
299 
300 static ssize_t get_temp2_fault(
301 		struct device *dev,
302 		struct device_attribute *devattr,
303 		char *buf)
304 {
305 	struct amc6821_data *data = amc6821_update_device(dev);
306 	if (data->stat1 & AMC6821_STAT1_RTF)
307 		return sprintf(buf, "1");
308 	else
309 		return sprintf(buf, "0");
310 }
311 
312 static ssize_t get_pwm1(
313 		struct device *dev,
314 		struct device_attribute *devattr,
315 		char *buf)
316 {
317 	struct amc6821_data *data = amc6821_update_device(dev);
318 	return sprintf(buf, "%d\n", data->pwm1);
319 }
320 
321 static ssize_t set_pwm1(
322 		struct device *dev,
323 		struct device_attribute *devattr,
324 		const char *buf,
325 		size_t count)
326 {
327 	struct i2c_client *client = to_i2c_client(dev);
328 	struct amc6821_data *data = i2c_get_clientdata(client);
329 	long val;
330 	int ret = kstrtol(buf, 10, &val);
331 	if (ret)
332 		return ret;
333 
334 	mutex_lock(&data->update_lock);
335 	data->pwm1 = clamp_val(val , 0, 255);
336 	i2c_smbus_write_byte_data(client, AMC6821_REG_DCY, data->pwm1);
337 	mutex_unlock(&data->update_lock);
338 	return count;
339 }
340 
341 static ssize_t get_pwm1_enable(
342 		struct device *dev,
343 		struct device_attribute *devattr,
344 		char *buf)
345 {
346 	struct amc6821_data *data = amc6821_update_device(dev);
347 	return sprintf(buf, "%d\n", data->pwm1_enable);
348 }
349 
350 static ssize_t set_pwm1_enable(
351 		struct device *dev,
352 		struct device_attribute *attr,
353 		const char *buf,
354 		size_t count)
355 {
356 	struct i2c_client *client = to_i2c_client(dev);
357 	struct amc6821_data *data = i2c_get_clientdata(client);
358 	long val;
359 	int config = kstrtol(buf, 10, &val);
360 	if (config)
361 		return config;
362 
363 	config = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF1);
364 	if (config < 0) {
365 			dev_err(&client->dev,
366 			"Error reading configuration register, aborting.\n");
367 			return config;
368 	}
369 
370 	switch (val) {
371 	case 1:
372 		config &= ~AMC6821_CONF1_FDRC0;
373 		config &= ~AMC6821_CONF1_FDRC1;
374 		break;
375 	case 2:
376 		config &= ~AMC6821_CONF1_FDRC0;
377 		config |= AMC6821_CONF1_FDRC1;
378 		break;
379 	case 3:
380 		config |= AMC6821_CONF1_FDRC0;
381 		config |= AMC6821_CONF1_FDRC1;
382 		break;
383 	default:
384 		return -EINVAL;
385 	}
386 	mutex_lock(&data->update_lock);
387 	if (i2c_smbus_write_byte_data(client, AMC6821_REG_CONF1, config)) {
388 			dev_err(&client->dev,
389 			"Configuration register write error, aborting.\n");
390 			count = -EIO;
391 	}
392 	mutex_unlock(&data->update_lock);
393 	return count;
394 }
395 
396 
397 static ssize_t get_pwm1_auto_channels_temp(
398 		struct device *dev,
399 		struct device_attribute *devattr,
400 		char *buf)
401 {
402 	struct amc6821_data *data = amc6821_update_device(dev);
403 	return sprintf(buf, "%d\n", data->pwm1_auto_channels_temp);
404 }
405 
406 
407 static ssize_t get_temp_auto_point_temp(
408 		struct device *dev,
409 		struct device_attribute *devattr,
410 		char *buf)
411 {
412 	int ix = to_sensor_dev_attr_2(devattr)->index;
413 	int nr = to_sensor_dev_attr_2(devattr)->nr;
414 	struct amc6821_data *data = amc6821_update_device(dev);
415 	switch (nr) {
416 	case 1:
417 		return sprintf(buf, "%d\n",
418 			data->temp1_auto_point_temp[ix] * 1000);
419 	case 2:
420 		return sprintf(buf, "%d\n",
421 			data->temp2_auto_point_temp[ix] * 1000);
422 	default:
423 		dev_dbg(dev, "Unknown attr->nr (%d).\n", nr);
424 		return -EINVAL;
425 	}
426 }
427 
428 
429 static ssize_t get_pwm1_auto_point_pwm(
430 		struct device *dev,
431 		struct device_attribute *devattr,
432 		char *buf)
433 {
434 	int ix = to_sensor_dev_attr(devattr)->index;
435 	struct amc6821_data *data = amc6821_update_device(dev);
436 	return sprintf(buf, "%d\n", data->pwm1_auto_point_pwm[ix]);
437 }
438 
439 
440 static inline ssize_t set_slope_register(struct i2c_client *client,
441 		u8 reg,
442 		u8 dpwm,
443 		u8 *ptemp)
444 {
445 	int dt;
446 	u8 tmp;
447 
448 	dt = ptemp[2]-ptemp[1];
449 	for (tmp = 4; tmp > 0; tmp--) {
450 		if (dt * (0x20 >> tmp) >= dpwm)
451 			break;
452 	}
453 	tmp |= (ptemp[1] & 0x7C) << 1;
454 	if (i2c_smbus_write_byte_data(client,
455 			reg, tmp)) {
456 		dev_err(&client->dev, "Register write error, aborting.\n");
457 		return -EIO;
458 	}
459 	return 0;
460 }
461 
462 
463 
464 static ssize_t set_temp_auto_point_temp(
465 		struct device *dev,
466 		struct device_attribute *attr,
467 		const char *buf,
468 		size_t count)
469 {
470 	struct i2c_client *client = to_i2c_client(dev);
471 	struct amc6821_data *data = amc6821_update_device(dev);
472 	int ix = to_sensor_dev_attr_2(attr)->index;
473 	int nr = to_sensor_dev_attr_2(attr)->nr;
474 	u8 *ptemp;
475 	u8 reg;
476 	int dpwm;
477 	long val;
478 	int ret = kstrtol(buf, 10, &val);
479 	if (ret)
480 		return ret;
481 
482 	switch (nr) {
483 	case 1:
484 		ptemp = data->temp1_auto_point_temp;
485 		reg = AMC6821_REG_LTEMP_FAN_CTRL;
486 		break;
487 	case 2:
488 		ptemp = data->temp2_auto_point_temp;
489 		reg = AMC6821_REG_RTEMP_FAN_CTRL;
490 		break;
491 	default:
492 		dev_dbg(dev, "Unknown attr->nr (%d).\n", nr);
493 		return -EINVAL;
494 	}
495 
496 	data->valid = 0;
497 	mutex_lock(&data->update_lock);
498 	switch (ix) {
499 	case 0:
500 		ptemp[0] = clamp_val(val / 1000, 0,
501 				     data->temp1_auto_point_temp[1]);
502 		ptemp[0] = clamp_val(ptemp[0], 0,
503 				     data->temp2_auto_point_temp[1]);
504 		ptemp[0] = clamp_val(ptemp[0], 0, 63);
505 		if (i2c_smbus_write_byte_data(
506 					client,
507 					AMC6821_REG_PSV_TEMP,
508 					ptemp[0])) {
509 				dev_err(&client->dev,
510 					"Register write error, aborting.\n");
511 				count = -EIO;
512 		}
513 		goto EXIT;
514 	case 1:
515 		ptemp[1] = clamp_val(val / 1000, (ptemp[0] & 0x7C) + 4, 124);
516 		ptemp[1] &= 0x7C;
517 		ptemp[2] = clamp_val(ptemp[2], ptemp[1] + 1, 255);
518 		break;
519 	case 2:
520 		ptemp[2] = clamp_val(val / 1000, ptemp[1]+1, 255);
521 		break;
522 	default:
523 		dev_dbg(dev, "Unknown attr->index (%d).\n", ix);
524 		count = -EINVAL;
525 		goto EXIT;
526 	}
527 	dpwm = data->pwm1_auto_point_pwm[2] - data->pwm1_auto_point_pwm[1];
528 	if (set_slope_register(client, reg, dpwm, ptemp))
529 		count = -EIO;
530 
531 EXIT:
532 	mutex_unlock(&data->update_lock);
533 	return count;
534 }
535 
536 
537 
538 static ssize_t set_pwm1_auto_point_pwm(
539 		struct device *dev,
540 		struct device_attribute *attr,
541 		const char *buf,
542 		size_t count)
543 {
544 	struct i2c_client *client = to_i2c_client(dev);
545 	struct amc6821_data *data = i2c_get_clientdata(client);
546 	int dpwm;
547 	long val;
548 	int ret = kstrtol(buf, 10, &val);
549 	if (ret)
550 		return ret;
551 
552 	mutex_lock(&data->update_lock);
553 	data->pwm1_auto_point_pwm[1] = clamp_val(val, 0, 254);
554 	if (i2c_smbus_write_byte_data(client, AMC6821_REG_DCY_LOW_TEMP,
555 			data->pwm1_auto_point_pwm[1])) {
556 		dev_err(&client->dev, "Register write error, aborting.\n");
557 		count = -EIO;
558 		goto EXIT;
559 	}
560 	dpwm = data->pwm1_auto_point_pwm[2] - data->pwm1_auto_point_pwm[1];
561 	if (set_slope_register(client, AMC6821_REG_LTEMP_FAN_CTRL, dpwm,
562 			data->temp1_auto_point_temp)) {
563 		count = -EIO;
564 		goto EXIT;
565 	}
566 	if (set_slope_register(client, AMC6821_REG_RTEMP_FAN_CTRL, dpwm,
567 			data->temp2_auto_point_temp)) {
568 		count = -EIO;
569 		goto EXIT;
570 	}
571 
572 EXIT:
573 	data->valid = 0;
574 	mutex_unlock(&data->update_lock);
575 	return count;
576 }
577 
578 static ssize_t get_fan(
579 		struct device *dev,
580 		struct device_attribute *devattr,
581 		char *buf)
582 {
583 	struct amc6821_data *data = amc6821_update_device(dev);
584 	int ix = to_sensor_dev_attr(devattr)->index;
585 	if (0 == data->fan[ix])
586 		return sprintf(buf, "0");
587 	return sprintf(buf, "%d\n", (int)(6000000 / data->fan[ix]));
588 }
589 
590 
591 
592 static ssize_t get_fan1_fault(
593 		struct device *dev,
594 		struct device_attribute *devattr,
595 		char *buf)
596 {
597 	struct amc6821_data *data = amc6821_update_device(dev);
598 	if (data->stat1 & AMC6821_STAT1_FANS)
599 		return sprintf(buf, "1");
600 	else
601 		return sprintf(buf, "0");
602 }
603 
604 
605 
606 static ssize_t set_fan(
607 		struct device *dev,
608 		struct device_attribute *attr,
609 		const char *buf, size_t count)
610 {
611 	struct i2c_client *client = to_i2c_client(dev);
612 	struct amc6821_data *data = i2c_get_clientdata(client);
613 	long val;
614 	int ix = to_sensor_dev_attr(attr)->index;
615 	int ret = kstrtol(buf, 10, &val);
616 	if (ret)
617 		return ret;
618 	val = 1 > val ? 0xFFFF : 6000000/val;
619 
620 	mutex_lock(&data->update_lock);
621 	data->fan[ix] = (u16) clamp_val(val, 1, 0xFFFF);
622 	if (i2c_smbus_write_byte_data(client, fan_reg_low[ix],
623 			data->fan[ix] & 0xFF)) {
624 		dev_err(&client->dev, "Register write error, aborting.\n");
625 		count = -EIO;
626 		goto EXIT;
627 	}
628 	if (i2c_smbus_write_byte_data(client,
629 			fan_reg_hi[ix], data->fan[ix] >> 8)) {
630 		dev_err(&client->dev, "Register write error, aborting.\n");
631 		count = -EIO;
632 	}
633 EXIT:
634 	mutex_unlock(&data->update_lock);
635 	return count;
636 }
637 
638 
639 
640 static ssize_t get_fan1_div(
641 		struct device *dev,
642 		struct device_attribute *devattr,
643 		char *buf)
644 {
645 	struct amc6821_data *data = amc6821_update_device(dev);
646 	return sprintf(buf, "%d\n", data->fan1_div);
647 }
648 
649 static ssize_t set_fan1_div(
650 		struct device *dev,
651 		struct device_attribute *attr,
652 		const char *buf, size_t count)
653 {
654 	struct i2c_client *client = to_i2c_client(dev);
655 	struct amc6821_data *data = i2c_get_clientdata(client);
656 	long val;
657 	int config = kstrtol(buf, 10, &val);
658 	if (config)
659 		return config;
660 
661 	config = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF4);
662 	if (config < 0) {
663 		dev_err(&client->dev,
664 			"Error reading configuration register, aborting.\n");
665 		return config;
666 	}
667 	mutex_lock(&data->update_lock);
668 	switch (val) {
669 	case 2:
670 		config &= ~AMC6821_CONF4_PSPR;
671 		data->fan1_div = 2;
672 		break;
673 	case 4:
674 		config |= AMC6821_CONF4_PSPR;
675 		data->fan1_div = 4;
676 		break;
677 	default:
678 		count = -EINVAL;
679 		goto EXIT;
680 	}
681 	if (i2c_smbus_write_byte_data(client, AMC6821_REG_CONF4, config)) {
682 		dev_err(&client->dev,
683 			"Configuration register write error, aborting.\n");
684 		count = -EIO;
685 	}
686 EXIT:
687 	mutex_unlock(&data->update_lock);
688 	return count;
689 }
690 
691 
692 
693 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
694 	get_temp, NULL, IDX_TEMP1_INPUT);
695 static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR, get_temp,
696 	set_temp, IDX_TEMP1_MIN);
697 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR, get_temp,
698 	set_temp, IDX_TEMP1_MAX);
699 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO | S_IWUSR, get_temp,
700 	set_temp, IDX_TEMP1_CRIT);
701 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO,
702 	get_temp_alarm, NULL, IDX_TEMP1_MIN);
703 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO,
704 	get_temp_alarm, NULL, IDX_TEMP1_MAX);
705 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO,
706 	get_temp_alarm, NULL, IDX_TEMP1_CRIT);
707 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO | S_IWUSR,
708 	get_temp, NULL, IDX_TEMP2_INPUT);
709 static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR, get_temp,
710 	set_temp, IDX_TEMP2_MIN);
711 static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO | S_IWUSR, get_temp,
712 	set_temp, IDX_TEMP2_MAX);
713 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO | S_IWUSR, get_temp,
714 	set_temp, IDX_TEMP2_CRIT);
715 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO,
716 	get_temp2_fault, NULL, 0);
717 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO,
718 	get_temp_alarm, NULL, IDX_TEMP2_MIN);
719 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO,
720 	get_temp_alarm, NULL, IDX_TEMP2_MAX);
721 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO,
722 	get_temp_alarm, NULL, IDX_TEMP2_CRIT);
723 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, get_fan, NULL, IDX_FAN1_INPUT);
724 static SENSOR_DEVICE_ATTR(fan1_min, S_IRUGO | S_IWUSR,
725 	get_fan, set_fan, IDX_FAN1_MIN);
726 static SENSOR_DEVICE_ATTR(fan1_max, S_IRUGO | S_IWUSR,
727 	get_fan, set_fan, IDX_FAN1_MAX);
728 static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, get_fan1_fault, NULL, 0);
729 static SENSOR_DEVICE_ATTR(fan1_div, S_IRUGO | S_IWUSR,
730 	get_fan1_div, set_fan1_div, 0);
731 
732 static SENSOR_DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm1, set_pwm1, 0);
733 static SENSOR_DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO,
734 	get_pwm1_enable, set_pwm1_enable, 0);
735 static SENSOR_DEVICE_ATTR(pwm1_auto_point1_pwm, S_IRUGO,
736 	get_pwm1_auto_point_pwm, NULL, 0);
737 static SENSOR_DEVICE_ATTR(pwm1_auto_point2_pwm, S_IWUSR | S_IRUGO,
738 	get_pwm1_auto_point_pwm, set_pwm1_auto_point_pwm, 1);
739 static SENSOR_DEVICE_ATTR(pwm1_auto_point3_pwm, S_IRUGO,
740 	get_pwm1_auto_point_pwm, NULL, 2);
741 static SENSOR_DEVICE_ATTR(pwm1_auto_channels_temp, S_IRUGO,
742 	get_pwm1_auto_channels_temp, NULL, 0);
743 static SENSOR_DEVICE_ATTR_2(temp1_auto_point1_temp, S_IRUGO,
744 	get_temp_auto_point_temp, NULL, 1, 0);
745 static SENSOR_DEVICE_ATTR_2(temp1_auto_point2_temp, S_IWUSR | S_IRUGO,
746 	get_temp_auto_point_temp, set_temp_auto_point_temp, 1, 1);
747 static SENSOR_DEVICE_ATTR_2(temp1_auto_point3_temp, S_IWUSR | S_IRUGO,
748 	get_temp_auto_point_temp, set_temp_auto_point_temp, 1, 2);
749 
750 static SENSOR_DEVICE_ATTR_2(temp2_auto_point1_temp, S_IWUSR | S_IRUGO,
751 	get_temp_auto_point_temp, set_temp_auto_point_temp, 2, 0);
752 static SENSOR_DEVICE_ATTR_2(temp2_auto_point2_temp, S_IWUSR | S_IRUGO,
753 	get_temp_auto_point_temp, set_temp_auto_point_temp, 2, 1);
754 static SENSOR_DEVICE_ATTR_2(temp2_auto_point3_temp, S_IWUSR | S_IRUGO,
755 	get_temp_auto_point_temp, set_temp_auto_point_temp, 2, 2);
756 
757 
758 
759 static struct attribute *amc6821_attrs[] = {
760 	&sensor_dev_attr_temp1_input.dev_attr.attr,
761 	&sensor_dev_attr_temp1_min.dev_attr.attr,
762 	&sensor_dev_attr_temp1_max.dev_attr.attr,
763 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
764 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
765 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
766 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
767 	&sensor_dev_attr_temp2_input.dev_attr.attr,
768 	&sensor_dev_attr_temp2_min.dev_attr.attr,
769 	&sensor_dev_attr_temp2_max.dev_attr.attr,
770 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
771 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
772 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
773 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
774 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
775 	&sensor_dev_attr_fan1_input.dev_attr.attr,
776 	&sensor_dev_attr_fan1_min.dev_attr.attr,
777 	&sensor_dev_attr_fan1_max.dev_attr.attr,
778 	&sensor_dev_attr_fan1_fault.dev_attr.attr,
779 	&sensor_dev_attr_fan1_div.dev_attr.attr,
780 	&sensor_dev_attr_pwm1.dev_attr.attr,
781 	&sensor_dev_attr_pwm1_enable.dev_attr.attr,
782 	&sensor_dev_attr_pwm1_auto_channels_temp.dev_attr.attr,
783 	&sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
784 	&sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
785 	&sensor_dev_attr_pwm1_auto_point3_pwm.dev_attr.attr,
786 	&sensor_dev_attr_temp1_auto_point1_temp.dev_attr.attr,
787 	&sensor_dev_attr_temp1_auto_point2_temp.dev_attr.attr,
788 	&sensor_dev_attr_temp1_auto_point3_temp.dev_attr.attr,
789 	&sensor_dev_attr_temp2_auto_point1_temp.dev_attr.attr,
790 	&sensor_dev_attr_temp2_auto_point2_temp.dev_attr.attr,
791 	&sensor_dev_attr_temp2_auto_point3_temp.dev_attr.attr,
792 	NULL
793 };
794 
795 static struct attribute_group amc6821_attr_grp = {
796 	.attrs = amc6821_attrs,
797 };
798 
799 
800 
801 /* Return 0 if detection is successful, -ENODEV otherwise */
802 static int amc6821_detect(
803 		struct i2c_client *client,
804 		struct i2c_board_info *info)
805 {
806 	struct i2c_adapter *adapter = client->adapter;
807 	int address = client->addr;
808 	int dev_id, comp_id;
809 
810 	dev_dbg(&adapter->dev, "amc6821_detect called.\n");
811 
812 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
813 		dev_dbg(&adapter->dev,
814 			"amc6821: I2C bus doesn't support byte mode, "
815 			"skipping.\n");
816 		return -ENODEV;
817 	}
818 
819 	dev_id = i2c_smbus_read_byte_data(client, AMC6821_REG_DEV_ID);
820 	comp_id = i2c_smbus_read_byte_data(client, AMC6821_REG_COMP_ID);
821 	if (dev_id != 0x21 || comp_id != 0x49) {
822 		dev_dbg(&adapter->dev,
823 			"amc6821: detection failed at 0x%02x.\n",
824 			address);
825 		return -ENODEV;
826 	}
827 
828 	/*
829 	 * Bit 7 of the address register is ignored, so we can check the
830 	 * ID registers again
831 	 */
832 	dev_id = i2c_smbus_read_byte_data(client, 0x80 | AMC6821_REG_DEV_ID);
833 	comp_id = i2c_smbus_read_byte_data(client, 0x80 | AMC6821_REG_COMP_ID);
834 	if (dev_id != 0x21 || comp_id != 0x49) {
835 		dev_dbg(&adapter->dev,
836 			"amc6821: detection failed at 0x%02x.\n",
837 			address);
838 		return -ENODEV;
839 	}
840 
841 	dev_info(&adapter->dev, "amc6821: chip found at 0x%02x.\n", address);
842 	strlcpy(info->type, "amc6821", I2C_NAME_SIZE);
843 
844 	return 0;
845 }
846 
847 static int amc6821_probe(
848 	struct i2c_client *client,
849 	const struct i2c_device_id *id)
850 {
851 	struct amc6821_data *data;
852 	int err;
853 
854 	data = devm_kzalloc(&client->dev, sizeof(struct amc6821_data),
855 			    GFP_KERNEL);
856 	if (!data)
857 		return -ENOMEM;
858 
859 	i2c_set_clientdata(client, data);
860 	mutex_init(&data->update_lock);
861 
862 	/*
863 	 * Initialize the amc6821 chip
864 	 */
865 	err = amc6821_init_client(client);
866 	if (err)
867 		return err;
868 
869 	err = sysfs_create_group(&client->dev.kobj, &amc6821_attr_grp);
870 	if (err)
871 		return err;
872 
873 	data->hwmon_dev = hwmon_device_register(&client->dev);
874 	if (!IS_ERR(data->hwmon_dev))
875 		return 0;
876 
877 	err = PTR_ERR(data->hwmon_dev);
878 	dev_err(&client->dev, "error registering hwmon device.\n");
879 	sysfs_remove_group(&client->dev.kobj, &amc6821_attr_grp);
880 	return err;
881 }
882 
883 static int amc6821_remove(struct i2c_client *client)
884 {
885 	struct amc6821_data *data = i2c_get_clientdata(client);
886 
887 	hwmon_device_unregister(data->hwmon_dev);
888 	sysfs_remove_group(&client->dev.kobj, &amc6821_attr_grp);
889 
890 	return 0;
891 }
892 
893 
894 static int amc6821_init_client(struct i2c_client *client)
895 {
896 	int config;
897 	int err = -EIO;
898 
899 	if (init) {
900 		config = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF4);
901 
902 		if (config < 0) {
903 				dev_err(&client->dev,
904 			"Error reading configuration register, aborting.\n");
905 				return err;
906 		}
907 
908 		config |= AMC6821_CONF4_MODE;
909 
910 		if (i2c_smbus_write_byte_data(client, AMC6821_REG_CONF4,
911 				config)) {
912 			dev_err(&client->dev,
913 			"Configuration register write error, aborting.\n");
914 			return err;
915 		}
916 
917 		config = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF3);
918 
919 		if (config < 0) {
920 			dev_err(&client->dev,
921 			"Error reading configuration register, aborting.\n");
922 			return err;
923 		}
924 
925 		dev_info(&client->dev, "Revision %d\n", config & 0x0f);
926 
927 		config &= ~AMC6821_CONF3_THERM_FAN_EN;
928 
929 		if (i2c_smbus_write_byte_data(client, AMC6821_REG_CONF3,
930 				config)) {
931 			dev_err(&client->dev,
932 			"Configuration register write error, aborting.\n");
933 			return err;
934 		}
935 
936 		config = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF2);
937 
938 		if (config < 0) {
939 			dev_err(&client->dev,
940 			"Error reading configuration register, aborting.\n");
941 			return err;
942 		}
943 
944 		config &= ~AMC6821_CONF2_RTFIE;
945 		config &= ~AMC6821_CONF2_LTOIE;
946 		config &= ~AMC6821_CONF2_RTOIE;
947 		if (i2c_smbus_write_byte_data(client,
948 				AMC6821_REG_CONF2, config)) {
949 			dev_err(&client->dev,
950 			"Configuration register write error, aborting.\n");
951 			return err;
952 		}
953 
954 		config = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF1);
955 
956 		if (config < 0) {
957 			dev_err(&client->dev,
958 			"Error reading configuration register, aborting.\n");
959 			return err;
960 		}
961 
962 		config &= ~AMC6821_CONF1_THERMOVIE;
963 		config &= ~AMC6821_CONF1_FANIE;
964 		config |= AMC6821_CONF1_START;
965 		if (pwminv)
966 			config |= AMC6821_CONF1_PWMINV;
967 		else
968 			config &= ~AMC6821_CONF1_PWMINV;
969 
970 		if (i2c_smbus_write_byte_data(
971 				client, AMC6821_REG_CONF1, config)) {
972 			dev_err(&client->dev,
973 			"Configuration register write error, aborting.\n");
974 			return err;
975 		}
976 	}
977 	return 0;
978 }
979 
980 
981 static struct amc6821_data *amc6821_update_device(struct device *dev)
982 {
983 	struct i2c_client *client = to_i2c_client(dev);
984 	struct amc6821_data *data = i2c_get_clientdata(client);
985 	int timeout = HZ;
986 	u8 reg;
987 	int i;
988 
989 	mutex_lock(&data->update_lock);
990 
991 	if (time_after(jiffies, data->last_updated + timeout) ||
992 			!data->valid) {
993 
994 		for (i = 0; i < TEMP_IDX_LEN; i++)
995 			data->temp[i] = i2c_smbus_read_byte_data(client,
996 				temp_reg[i]);
997 
998 		data->stat1 = i2c_smbus_read_byte_data(client,
999 			AMC6821_REG_STAT1);
1000 		data->stat2 = i2c_smbus_read_byte_data(client,
1001 			AMC6821_REG_STAT2);
1002 
1003 		data->pwm1 = i2c_smbus_read_byte_data(client,
1004 			AMC6821_REG_DCY);
1005 		for (i = 0; i < FAN1_IDX_LEN; i++) {
1006 			data->fan[i] = i2c_smbus_read_byte_data(
1007 					client,
1008 					fan_reg_low[i]);
1009 			data->fan[i] += i2c_smbus_read_byte_data(
1010 					client,
1011 					fan_reg_hi[i]) << 8;
1012 		}
1013 		data->fan1_div = i2c_smbus_read_byte_data(client,
1014 			AMC6821_REG_CONF4);
1015 		data->fan1_div = data->fan1_div & AMC6821_CONF4_PSPR ? 4 : 2;
1016 
1017 		data->pwm1_auto_point_pwm[0] = 0;
1018 		data->pwm1_auto_point_pwm[2] = 255;
1019 		data->pwm1_auto_point_pwm[1] = i2c_smbus_read_byte_data(client,
1020 			AMC6821_REG_DCY_LOW_TEMP);
1021 
1022 		data->temp1_auto_point_temp[0] =
1023 			i2c_smbus_read_byte_data(client,
1024 					AMC6821_REG_PSV_TEMP);
1025 		data->temp2_auto_point_temp[0] =
1026 				data->temp1_auto_point_temp[0];
1027 		reg = i2c_smbus_read_byte_data(client,
1028 			AMC6821_REG_LTEMP_FAN_CTRL);
1029 		data->temp1_auto_point_temp[1] = (reg & 0xF8) >> 1;
1030 		reg &= 0x07;
1031 		reg = 0x20 >> reg;
1032 		if (reg > 0)
1033 			data->temp1_auto_point_temp[2] =
1034 				data->temp1_auto_point_temp[1] +
1035 				(data->pwm1_auto_point_pwm[2] -
1036 				data->pwm1_auto_point_pwm[1]) / reg;
1037 		else
1038 			data->temp1_auto_point_temp[2] = 255;
1039 
1040 		reg = i2c_smbus_read_byte_data(client,
1041 			AMC6821_REG_RTEMP_FAN_CTRL);
1042 		data->temp2_auto_point_temp[1] = (reg & 0xF8) >> 1;
1043 		reg &= 0x07;
1044 		reg = 0x20 >> reg;
1045 		if (reg > 0)
1046 			data->temp2_auto_point_temp[2] =
1047 				data->temp2_auto_point_temp[1] +
1048 				(data->pwm1_auto_point_pwm[2] -
1049 				data->pwm1_auto_point_pwm[1]) / reg;
1050 		else
1051 			data->temp2_auto_point_temp[2] = 255;
1052 
1053 		reg = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF1);
1054 		reg = (reg >> 5) & 0x3;
1055 		switch (reg) {
1056 		case 0: /*open loop: software sets pwm1*/
1057 			data->pwm1_auto_channels_temp = 0;
1058 			data->pwm1_enable = 1;
1059 			break;
1060 		case 2: /*closed loop: remote T (temp2)*/
1061 			data->pwm1_auto_channels_temp = 2;
1062 			data->pwm1_enable = 2;
1063 			break;
1064 		case 3: /*closed loop: local and remote T (temp2)*/
1065 			data->pwm1_auto_channels_temp = 3;
1066 			data->pwm1_enable = 3;
1067 			break;
1068 		case 1: /*
1069 			 * semi-open loop: software sets rpm, chip controls
1070 			 * pwm1, currently not implemented
1071 			 */
1072 			data->pwm1_auto_channels_temp = 0;
1073 			data->pwm1_enable = 0;
1074 			break;
1075 		}
1076 
1077 		data->last_updated = jiffies;
1078 		data->valid = 1;
1079 	}
1080 	mutex_unlock(&data->update_lock);
1081 	return data;
1082 }
1083 
1084 module_i2c_driver(amc6821_driver);
1085 
1086 MODULE_LICENSE("GPL");
1087 MODULE_AUTHOR("T. Mertelj <tomaz.mertelj@guest.arnes.si>");
1088 MODULE_DESCRIPTION("Texas Instruments amc6821 hwmon driver");
1089