xref: /linux/drivers/hwmon/amc6821.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * amc6821.c - Part of lm_sensors, Linux kernel modules for hardware
4  *	       monitoring
5  * Copyright (C) 2009 T. Mertelj <tomaz.mertelj@guest.arnes.si>
6  *
7  * Based on max6650.c:
8  * Copyright (C) 2007 Hans J. Koch <hjk@hansjkoch.de>
9  *
10  * Conversion to regmap and with_info API:
11  * Copyright (C) 2024 Guenter Roeck <linux@roeck-us.net>
12  */
13 
14 #include <linux/bitfield.h>
15 #include <linux/bitops.h>
16 #include <linux/bits.h>
17 #include <linux/err.h>
18 #include <linux/hwmon.h>
19 #include <linux/hwmon-sysfs.h>
20 #include <linux/i2c.h>
21 #include <linux/init.h>
22 #include <linux/minmax.h>
23 #include <linux/module.h>
24 #include <linux/mutex.h>
25 #include <linux/regmap.h>
26 #include <linux/slab.h>
27 
28 /*
29  * Addresses to scan.
30  */
31 
32 static const unsigned short normal_i2c[] = {0x18, 0x19, 0x1a, 0x2c, 0x2d, 0x2e,
33 	0x4c, 0x4d, 0x4e, I2C_CLIENT_END};
34 
35 /*
36  * Insmod parameters
37  */
38 
39 static int pwminv;	/*Inverted PWM output. */
40 module_param(pwminv, int, 0444);
41 
42 static int init = 1; /*Power-on initialization.*/
43 module_param(init, int, 0444);
44 
45 #define AMC6821_REG_DEV_ID		0x3D
46 #define AMC6821_REG_COMP_ID		0x3E
47 #define AMC6821_REG_CONF1		0x00
48 #define AMC6821_REG_CONF2		0x01
49 #define AMC6821_REG_CONF3		0x3F
50 #define AMC6821_REG_CONF4		0x04
51 #define AMC6821_REG_STAT1		0x02
52 #define AMC6821_REG_STAT2		0x03
53 #define AMC6821_REG_TEMP_LO		0x06
54 #define AMC6821_REG_TDATA_LOW		0x08
55 #define AMC6821_REG_TDATA_HI		0x09
56 #define AMC6821_REG_LTEMP_HI		0x0A
57 #define AMC6821_REG_RTEMP_HI		0x0B
58 #define AMC6821_REG_LTEMP_LIMIT_MIN	0x15
59 #define AMC6821_REG_LTEMP_LIMIT_MAX	0x14
60 #define AMC6821_REG_RTEMP_LIMIT_MIN	0x19
61 #define AMC6821_REG_RTEMP_LIMIT_MAX	0x18
62 #define AMC6821_REG_LTEMP_CRIT		0x1B
63 #define AMC6821_REG_RTEMP_CRIT		0x1D
64 #define AMC6821_REG_PSV_TEMP		0x1C
65 #define AMC6821_REG_DCY			0x22
66 #define AMC6821_REG_LTEMP_FAN_CTRL	0x24
67 #define AMC6821_REG_RTEMP_FAN_CTRL	0x25
68 #define AMC6821_REG_DCY_LOW_TEMP	0x21
69 
70 #define AMC6821_REG_TACH_LLIMITL	0x10
71 #define AMC6821_REG_TACH_HLIMITL	0x12
72 #define AMC6821_REG_TACH_SETTINGL	0x1e
73 
74 #define AMC6821_CONF1_START		BIT(0)
75 #define AMC6821_CONF1_FAN_INT_EN	BIT(1)
76 #define AMC6821_CONF1_FANIE		BIT(2)
77 #define AMC6821_CONF1_PWMINV		BIT(3)
78 #define AMC6821_CONF1_FAN_FAULT_EN	BIT(4)
79 #define AMC6821_CONF1_FDRC0		BIT(5)
80 #define AMC6821_CONF1_FDRC1		BIT(6)
81 #define AMC6821_CONF1_THERMOVIE		BIT(7)
82 
83 #define AMC6821_CONF2_PWM_EN		BIT(0)
84 #define AMC6821_CONF2_TACH_MODE		BIT(1)
85 #define AMC6821_CONF2_TACH_EN		BIT(2)
86 #define AMC6821_CONF2_RTFIE		BIT(3)
87 #define AMC6821_CONF2_LTOIE		BIT(4)
88 #define AMC6821_CONF2_RTOIE		BIT(5)
89 #define AMC6821_CONF2_PSVIE		BIT(6)
90 #define AMC6821_CONF2_RST		BIT(7)
91 
92 #define AMC6821_CONF3_THERM_FAN_EN	BIT(7)
93 #define AMC6821_CONF3_REV_MASK		GENMASK(3, 0)
94 
95 #define AMC6821_CONF4_OVREN		BIT(4)
96 #define AMC6821_CONF4_TACH_FAST		BIT(5)
97 #define AMC6821_CONF4_PSPR		BIT(6)
98 #define AMC6821_CONF4_MODE		BIT(7)
99 
100 #define AMC6821_STAT1_RPM_ALARM		BIT(0)
101 #define AMC6821_STAT1_FANS		BIT(1)
102 #define AMC6821_STAT1_RTH		BIT(2)
103 #define AMC6821_STAT1_RTL		BIT(3)
104 #define AMC6821_STAT1_R_THERM		BIT(4)
105 #define AMC6821_STAT1_RTF		BIT(5)
106 #define AMC6821_STAT1_LTH		BIT(6)
107 #define AMC6821_STAT1_LTL		BIT(7)
108 
109 #define AMC6821_STAT2_RTC		BIT(3)
110 #define AMC6821_STAT2_LTC		BIT(4)
111 #define AMC6821_STAT2_LPSV		BIT(5)
112 #define AMC6821_STAT2_L_THERM		BIT(6)
113 #define AMC6821_STAT2_THERM_IN		BIT(7)
114 
115 #define AMC6821_TEMP_SLOPE_MASK		GENMASK(2, 0)
116 #define AMC6821_TEMP_LIMIT_MASK		GENMASK(7, 3)
117 
118 /*
119  * Client data (each client gets its own)
120  */
121 
122 struct amc6821_data {
123 	struct regmap *regmap;
124 	struct mutex update_lock;
125 };
126 
127 /*
128  * Return 0 on success or negative error code.
129  *
130  * temps returns set of three temperatures, in °C:
131  * temps[0]: Passive cooling temperature, applies to both channels
132  * temps[1]: Low temperature, start slope calculations
133  * temps[2]: High temperature
134  *
135  * Channel 0: local, channel 1: remote.
136  */
137 static int amc6821_get_auto_point_temps(struct regmap *regmap, int channel, u8 *temps)
138 {
139 	u32 regs[] = {
140 		AMC6821_REG_DCY_LOW_TEMP,
141 		AMC6821_REG_PSV_TEMP,
142 		channel ? AMC6821_REG_RTEMP_FAN_CTRL : AMC6821_REG_LTEMP_FAN_CTRL
143 	};
144 	u8 regvals[3];
145 	int slope;
146 	int err;
147 
148 	err = regmap_multi_reg_read(regmap, regs, regvals, 3);
149 	if (err)
150 		return err;
151 	temps[0] = regvals[1];
152 	temps[1] = FIELD_GET(AMC6821_TEMP_LIMIT_MASK, regvals[2]) * 4;
153 
154 	/* slope is 32 >> <slope bits> in °C */
155 	slope = 32 >> FIELD_GET(AMC6821_TEMP_SLOPE_MASK, regvals[2]);
156 	if (slope)
157 		temps[2] = temps[1] + DIV_ROUND_CLOSEST(255 - regvals[0], slope);
158 	else
159 		temps[2] = 255;
160 
161 	return 0;
162 }
163 
164 static int amc6821_temp_read_values(struct regmap *regmap, u32 attr, int channel, long *val)
165 {
166 	int reg, err;
167 	u32 regval;
168 
169 	switch (attr) {
170 	case hwmon_temp_input:
171 		reg = channel ? AMC6821_REG_RTEMP_HI : AMC6821_REG_LTEMP_HI;
172 		break;
173 	case hwmon_temp_min:
174 		reg = channel ? AMC6821_REG_RTEMP_LIMIT_MIN : AMC6821_REG_LTEMP_LIMIT_MIN;
175 		break;
176 	case hwmon_temp_max:
177 		reg = channel ? AMC6821_REG_RTEMP_LIMIT_MAX : AMC6821_REG_LTEMP_LIMIT_MAX;
178 		break;
179 	case hwmon_temp_crit:
180 		reg = channel ? AMC6821_REG_RTEMP_CRIT : AMC6821_REG_LTEMP_CRIT;
181 		break;
182 	default:
183 		return -EOPNOTSUPP;
184 	}
185 	err = regmap_read(regmap, reg, &regval);
186 	if (err)
187 		return err;
188 	*val = sign_extend32(regval, 7) * 1000;
189 	return 0;
190 }
191 
192 static int amc6821_read_alarms(struct regmap *regmap, enum hwmon_sensor_types type,
193 			       u32 attr, int channel, long *val)
194 {
195 	int reg, mask, err;
196 	u32 regval;
197 
198 	switch (type) {
199 	case hwmon_temp:
200 		switch (attr) {
201 		case hwmon_temp_min_alarm:
202 			reg = AMC6821_REG_STAT1;
203 			mask = channel ? AMC6821_STAT1_RTL : AMC6821_STAT1_LTL;
204 			break;
205 		case hwmon_temp_max_alarm:
206 			reg = AMC6821_REG_STAT1;
207 			mask = channel ? AMC6821_STAT1_RTH : AMC6821_STAT1_LTH;
208 			break;
209 		case hwmon_temp_crit_alarm:
210 			reg = AMC6821_REG_STAT2;
211 			mask = channel ? AMC6821_STAT2_RTC : AMC6821_STAT2_LTC;
212 			break;
213 		case hwmon_temp_fault:
214 			reg = AMC6821_REG_STAT1;
215 			mask = AMC6821_STAT1_RTF;
216 			break;
217 		default:
218 			return -EOPNOTSUPP;
219 		}
220 		break;
221 	case hwmon_fan:
222 		switch (attr) {
223 		case hwmon_fan_fault:
224 			reg = AMC6821_REG_STAT1;
225 			mask = AMC6821_STAT1_FANS;
226 			break;
227 		default:
228 			return -EOPNOTSUPP;
229 		}
230 		break;
231 	default:
232 		return -EOPNOTSUPP;
233 	}
234 	err = regmap_read(regmap, reg, &regval);
235 	if (err)
236 		return err;
237 	*val = !!(regval & mask);
238 	return 0;
239 }
240 
241 static int amc6821_temp_read(struct device *dev, u32 attr, int channel, long *val)
242 {
243 	struct amc6821_data *data = dev_get_drvdata(dev);
244 
245 	switch (attr) {
246 	case hwmon_temp_input:
247 	case hwmon_temp_min:
248 	case hwmon_temp_max:
249 	case hwmon_temp_crit:
250 		return amc6821_temp_read_values(data->regmap, attr, channel, val);
251 	case hwmon_temp_min_alarm:
252 	case hwmon_temp_max_alarm:
253 	case hwmon_temp_crit_alarm:
254 	case hwmon_temp_fault:
255 		return amc6821_read_alarms(data->regmap, hwmon_temp, attr, channel, val);
256 	default:
257 		return -EOPNOTSUPP;
258 	}
259 }
260 
261 static int amc6821_temp_write(struct device *dev, u32 attr, int channel, long val)
262 {
263 	struct amc6821_data *data = dev_get_drvdata(dev);
264 	int reg;
265 
266 	val = DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000);
267 
268 	switch (attr) {
269 	case hwmon_temp_min:
270 		reg = channel ? AMC6821_REG_RTEMP_LIMIT_MIN : AMC6821_REG_LTEMP_LIMIT_MIN;
271 		break;
272 	case hwmon_temp_max:
273 		reg = channel ? AMC6821_REG_RTEMP_LIMIT_MAX : AMC6821_REG_LTEMP_LIMIT_MAX;
274 		break;
275 	case hwmon_temp_crit:
276 		reg = channel ? AMC6821_REG_RTEMP_CRIT : AMC6821_REG_LTEMP_CRIT;
277 		break;
278 	default:
279 		return -EOPNOTSUPP;
280 	}
281 	return regmap_write(data->regmap, reg, val);
282 }
283 
284 static int amc6821_pwm_read(struct device *dev, u32 attr, long *val)
285 {
286 	struct amc6821_data *data = dev_get_drvdata(dev);
287 	struct regmap *regmap = data->regmap;
288 	u32 regval;
289 	int err;
290 
291 	switch (attr) {
292 	case hwmon_pwm_enable:
293 		err = regmap_read(regmap, AMC6821_REG_CONF1, &regval);
294 		if (err)
295 			return err;
296 		switch (regval & (AMC6821_CONF1_FDRC0 | AMC6821_CONF1_FDRC1)) {
297 		case 0:
298 			*val = 1;	/* manual */
299 			break;
300 		case AMC6821_CONF1_FDRC0:
301 			*val = 4;	/* target rpm (fan1_target) controlled */
302 			break;
303 		case AMC6821_CONF1_FDRC1:
304 			*val = 2;	/* remote temp controlled */
305 			break;
306 		default:
307 			*val = 3;	/* max(local, remote) temp controlled */
308 			break;
309 		}
310 		return 0;
311 	case hwmon_pwm_mode:
312 		err = regmap_read(regmap, AMC6821_REG_CONF2, &regval);
313 		if (err)
314 			return err;
315 		*val = !!(regval & AMC6821_CONF2_TACH_MODE);
316 		return 0;
317 	case hwmon_pwm_auto_channels_temp:
318 		err = regmap_read(regmap, AMC6821_REG_CONF1, &regval);
319 		if (err)
320 			return err;
321 		switch (regval & (AMC6821_CONF1_FDRC0 | AMC6821_CONF1_FDRC1)) {
322 		case 0:
323 		case AMC6821_CONF1_FDRC0:
324 			*val = 0;	/* manual or target rpm controlled */
325 			break;
326 		case AMC6821_CONF1_FDRC1:
327 			*val = 2;	/* remote temp controlled */
328 			break;
329 		default:
330 			*val = 3;	/* max(local, remote) temp controlled */
331 			break;
332 		}
333 		return 0;
334 	case hwmon_pwm_input:
335 		err = regmap_read(regmap, AMC6821_REG_DCY, &regval);
336 		if (err)
337 			return err;
338 		*val = regval;
339 		return 0;
340 	default:
341 		return -EOPNOTSUPP;
342 	}
343 }
344 
345 static int amc6821_pwm_write(struct device *dev, u32 attr, long val)
346 {
347 	struct amc6821_data *data = dev_get_drvdata(dev);
348 	struct regmap *regmap = data->regmap;
349 	u32 mode;
350 
351 	switch (attr) {
352 	case hwmon_pwm_enable:
353 		switch (val) {
354 		case 1:
355 			mode = 0;
356 			break;
357 		case 2:
358 			mode = AMC6821_CONF1_FDRC1;
359 			break;
360 		case 3:
361 			mode = AMC6821_CONF1_FDRC0 | AMC6821_CONF1_FDRC1;
362 			break;
363 		case 4:
364 			mode = AMC6821_CONF1_FDRC0;
365 			break;
366 		default:
367 			return -EINVAL;
368 		}
369 		return regmap_update_bits(regmap, AMC6821_REG_CONF1,
370 					  AMC6821_CONF1_FDRC0 | AMC6821_CONF1_FDRC1,
371 					  mode);
372 	case hwmon_pwm_mode:
373 		if (val < 0 || val > 1)
374 			return -EINVAL;
375 		return regmap_update_bits(regmap, AMC6821_REG_CONF2,
376 					  AMC6821_CONF2_TACH_MODE,
377 					  val ? AMC6821_CONF2_TACH_MODE : 0);
378 		break;
379 	case hwmon_pwm_input:
380 		if (val < 0 || val > 255)
381 			return -EINVAL;
382 		return regmap_write(regmap, AMC6821_REG_DCY, val);
383 	default:
384 		return -EOPNOTSUPP;
385 	}
386 }
387 
388 static int amc6821_fan_read_rpm(struct regmap *regmap, u32 attr, long *val)
389 {
390 	int reg, err;
391 	u8 regs[2];
392 	u32 regval;
393 
394 	switch (attr) {
395 	case hwmon_fan_input:
396 		reg = AMC6821_REG_TDATA_LOW;
397 		break;
398 	case hwmon_fan_min:
399 		reg = AMC6821_REG_TACH_LLIMITL;
400 		break;
401 	case hwmon_fan_max:
402 		reg = AMC6821_REG_TACH_HLIMITL;
403 		break;
404 	case hwmon_fan_target:
405 		reg = AMC6821_REG_TACH_SETTINGL;
406 		break;
407 	default:
408 		return -EOPNOTSUPP;
409 	}
410 
411 	err = regmap_bulk_read(regmap, reg, regs, 2);
412 	if (err)
413 		return err;
414 
415 	regval = (regs[1] << 8) | regs[0];
416 	*val = regval ? 6000000 / regval : 0;
417 
418 	return 0;
419 }
420 
421 static int amc6821_fan_read(struct device *dev, u32 attr, long *val)
422 {
423 	struct amc6821_data *data = dev_get_drvdata(dev);
424 	struct regmap *regmap = data->regmap;
425 	u32 regval;
426 	int err;
427 
428 	switch (attr) {
429 	case hwmon_fan_input:
430 	case hwmon_fan_min:
431 	case hwmon_fan_max:
432 	case hwmon_fan_target:
433 		return amc6821_fan_read_rpm(regmap, attr, val);
434 	case hwmon_fan_fault:
435 		return amc6821_read_alarms(regmap, hwmon_fan, attr, 0, val);
436 	case hwmon_fan_pulses:
437 		err = regmap_read(regmap, AMC6821_REG_CONF4, &regval);
438 		if (err)
439 			return err;
440 		*val = (regval & AMC6821_CONF4_PSPR) ? 4 : 2;
441 		return 0;
442 	default:
443 		return -EOPNOTSUPP;
444 	}
445 }
446 
447 static int amc6821_fan_write(struct device *dev, u32 attr, long val)
448 {
449 	struct amc6821_data *data = dev_get_drvdata(dev);
450 	struct regmap *regmap = data->regmap;
451 	u8 regs[2];
452 	int reg;
453 
454 	if (attr == hwmon_fan_pulses) {
455 		if (val != 2 && val != 4)
456 			return -EINVAL;
457 		return regmap_update_bits(regmap, AMC6821_REG_CONF4,
458 					 AMC6821_CONF4_PSPR,
459 					 val == 4 ? AMC6821_CONF4_PSPR : 0);
460 	}
461 
462 	if (val < 0)
463 		return -EINVAL;
464 
465 	switch (attr) {
466 	case hwmon_fan_min:
467 		if (!val)	/* no unlimited minimum speed */
468 			return -EINVAL;
469 		reg = AMC6821_REG_TACH_LLIMITL;
470 		break;
471 	case hwmon_fan_max:
472 		reg = AMC6821_REG_TACH_HLIMITL;
473 		break;
474 	case hwmon_fan_target:
475 		if (!val)	/* no unlimited target speed */
476 			return -EINVAL;
477 		reg = AMC6821_REG_TACH_SETTINGL;
478 		break;
479 	default:
480 		return -EOPNOTSUPP;
481 	}
482 
483 	val = val ? 6000000 / clamp_val(val, 1, 6000000) : 0;
484 	val = clamp_val(val, 0, 0xffff);
485 
486 	regs[0] = val & 0xff;
487 	regs[1] = val >> 8;
488 
489 	return regmap_bulk_write(data->regmap, reg, regs, 2);
490 }
491 
492 static ssize_t temp_auto_point_temp_show(struct device *dev,
493 					 struct device_attribute *devattr,
494 					 char *buf)
495 {
496 	struct amc6821_data *data = dev_get_drvdata(dev);
497 	int ix = to_sensor_dev_attr_2(devattr)->index;
498 	int nr = to_sensor_dev_attr_2(devattr)->nr;
499 	u8 temps[3];
500 	int err;
501 
502 	mutex_lock(&data->update_lock);
503 	err = amc6821_get_auto_point_temps(data->regmap, nr, temps);
504 	mutex_unlock(&data->update_lock);
505 	if (err)
506 		return err;
507 
508 	return sysfs_emit(buf, "%d\n", temps[ix] * 1000);
509 }
510 
511 static ssize_t pwm1_auto_point_pwm_show(struct device *dev,
512 					struct device_attribute *devattr,
513 					char *buf)
514 {
515 	struct amc6821_data *data = dev_get_drvdata(dev);
516 	int ix = to_sensor_dev_attr(devattr)->index;
517 	u32 val;
518 	int err;
519 
520 	switch (ix) {
521 	case 0:
522 		val = 0;
523 		break;
524 	case 1:
525 		err = regmap_read(data->regmap, AMC6821_REG_DCY_LOW_TEMP, &val);
526 		if (err)
527 			return err;
528 		break;
529 	default:
530 		val = 255;
531 		break;
532 	}
533 	return sysfs_emit(buf, "%d\n", val);
534 }
535 
536 /*
537  * Set TEMP[0-4] (low temperature) and SLP[0-2] (slope) of local or remote
538  * TEMP-FAN control register.
539  *
540  * Return 0 on success or negative error code.
541  *
542  * Channel 0: local, channel 1: remote
543  */
544 static inline int set_slope_register(struct regmap *regmap, int channel, u8 *temps)
545 {
546 	u8 regval = FIELD_PREP(AMC6821_TEMP_LIMIT_MASK, temps[1] / 4);
547 	u8 tmp, dpwm;
548 	int err, dt;
549 	u32 pwm;
550 
551 	err = regmap_read(regmap, AMC6821_REG_DCY_LOW_TEMP, &pwm);
552 	if (err)
553 		return err;
554 
555 	dpwm = 255 - pwm;
556 
557 	dt = temps[2] - temps[1];
558 	for (tmp = 4; tmp > 0; tmp--) {
559 		if (dt * (32 >> tmp) >= dpwm)
560 			break;
561 	}
562 	regval |= FIELD_PREP(AMC6821_TEMP_SLOPE_MASK, tmp);
563 
564 	return regmap_write(regmap,
565 			    channel ? AMC6821_REG_RTEMP_FAN_CTRL : AMC6821_REG_LTEMP_FAN_CTRL,
566 			    regval);
567 }
568 
569 static ssize_t temp_auto_point_temp_store(struct device *dev,
570 					  struct device_attribute *attr,
571 					  const char *buf, size_t count)
572 {
573 	struct amc6821_data *data = dev_get_drvdata(dev);
574 	int ix = to_sensor_dev_attr_2(attr)->index;
575 	int nr = to_sensor_dev_attr_2(attr)->nr;
576 	struct regmap *regmap = data->regmap;
577 	u8 temps[3], otemps[3];
578 	long val;
579 	int ret;
580 
581 	ret = kstrtol(buf, 10, &val);
582 	if (ret)
583 		return ret;
584 
585 	mutex_lock(&data->update_lock);
586 
587 	ret = amc6821_get_auto_point_temps(data->regmap, nr, temps);
588 	if (ret)
589 		goto unlock;
590 
591 	switch (ix) {
592 	case 0:
593 		/*
594 		 * Passive cooling temperature. Range limit against low limit
595 		 * of both channels.
596 		 */
597 		ret = amc6821_get_auto_point_temps(data->regmap, 1 - nr, otemps);
598 		if (ret)
599 			goto unlock;
600 		val = DIV_ROUND_CLOSEST(clamp_val(val, 0, 63000), 1000);
601 		val = clamp_val(val, 0, min(temps[1], otemps[1]));
602 		ret = regmap_write(regmap, AMC6821_REG_PSV_TEMP, val);
603 		break;
604 	case 1:
605 		/*
606 		 * Low limit; must be between passive and high limit,
607 		 * and not exceed 124. Step size is 4 degrees C.
608 		 */
609 		val = clamp_val(val, DIV_ROUND_UP(temps[0], 4) * 4000, 124000);
610 		temps[1] = DIV_ROUND_CLOSEST(val, 4000) * 4;
611 		val = temps[1] / 4;
612 		/* Auto-adjust high limit if necessary */
613 		temps[2] = clamp_val(temps[2], temps[1] + 1, 255);
614 		ret = set_slope_register(regmap, nr, temps);
615 		break;
616 	case 2:
617 		/* high limit, must be higher than low limit */
618 		val = clamp_val(val, (temps[1] + 1) * 1000, 255000);
619 		temps[2] = DIV_ROUND_CLOSEST(val, 1000);
620 		ret = set_slope_register(regmap, nr, temps);
621 		break;
622 	default:
623 		ret = -EINVAL;
624 		break;
625 	}
626 unlock:
627 	mutex_unlock(&data->update_lock);
628 	return ret ? : count;
629 }
630 
631 static ssize_t pwm1_auto_point_pwm_store(struct device *dev,
632 					 struct device_attribute *attr,
633 					 const char *buf, size_t count)
634 {
635 	struct amc6821_data *data = dev_get_drvdata(dev);
636 	struct regmap *regmap = data->regmap;
637 	int i, ret;
638 	u8 val;
639 
640 	ret = kstrtou8(buf, 10, &val);
641 	if (ret)
642 		return ret;
643 
644 	mutex_lock(&data->update_lock);
645 	ret = regmap_write(regmap, AMC6821_REG_DCY_LOW_TEMP, val);
646 	if (ret)
647 		goto unlock;
648 
649 	for (i = 0; i < 2; i++) {
650 		u8 temps[3];
651 
652 		ret = amc6821_get_auto_point_temps(regmap, i, temps);
653 		if (ret)
654 			break;
655 		ret = set_slope_register(regmap, i, temps);
656 		if (ret)
657 			break;
658 	}
659 unlock:
660 	mutex_unlock(&data->update_lock);
661 	return ret ? : count;
662 }
663 
664 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point1_pwm, pwm1_auto_point_pwm, 0);
665 static SENSOR_DEVICE_ATTR_RW(pwm1_auto_point2_pwm, pwm1_auto_point_pwm, 1);
666 static SENSOR_DEVICE_ATTR_RO(pwm1_auto_point3_pwm, pwm1_auto_point_pwm, 2);
667 static SENSOR_DEVICE_ATTR_2_RO(temp1_auto_point1_temp, temp_auto_point_temp,
668 			       0, 0);
669 static SENSOR_DEVICE_ATTR_2_RW(temp1_auto_point2_temp, temp_auto_point_temp,
670 			       0, 1);
671 static SENSOR_DEVICE_ATTR_2_RW(temp1_auto_point3_temp, temp_auto_point_temp,
672 			       0, 2);
673 
674 static SENSOR_DEVICE_ATTR_2_RW(temp2_auto_point1_temp, temp_auto_point_temp,
675 			       1, 0);
676 static SENSOR_DEVICE_ATTR_2_RW(temp2_auto_point2_temp, temp_auto_point_temp,
677 			       1, 1);
678 static SENSOR_DEVICE_ATTR_2_RW(temp2_auto_point3_temp, temp_auto_point_temp,
679 			       1, 2);
680 
681 static struct attribute *amc6821_attrs[] = {
682 	&sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
683 	&sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
684 	&sensor_dev_attr_pwm1_auto_point3_pwm.dev_attr.attr,
685 	&sensor_dev_attr_temp1_auto_point1_temp.dev_attr.attr,
686 	&sensor_dev_attr_temp1_auto_point2_temp.dev_attr.attr,
687 	&sensor_dev_attr_temp1_auto_point3_temp.dev_attr.attr,
688 	&sensor_dev_attr_temp2_auto_point1_temp.dev_attr.attr,
689 	&sensor_dev_attr_temp2_auto_point2_temp.dev_attr.attr,
690 	&sensor_dev_attr_temp2_auto_point3_temp.dev_attr.attr,
691 	NULL
692 };
693 ATTRIBUTE_GROUPS(amc6821);
694 
695 static int amc6821_read(struct device *dev, enum hwmon_sensor_types type,
696 			u32 attr, int channel, long *val)
697 {
698 	switch (type) {
699 	case hwmon_temp:
700 		return amc6821_temp_read(dev, attr, channel, val);
701 	case hwmon_fan:
702 		return amc6821_fan_read(dev, attr, val);
703 	case hwmon_pwm:
704 		return amc6821_pwm_read(dev, attr, val);
705 	default:
706 		return -EOPNOTSUPP;
707 	}
708 }
709 
710 static int amc6821_write(struct device *dev, enum hwmon_sensor_types type,
711 			 u32 attr, int channel, long val)
712 {
713 	switch (type) {
714 	case hwmon_temp:
715 		return amc6821_temp_write(dev, attr, channel, val);
716 	case hwmon_fan:
717 		return amc6821_fan_write(dev, attr, val);
718 	case hwmon_pwm:
719 		return amc6821_pwm_write(dev, attr, val);
720 	default:
721 		return -EOPNOTSUPP;
722 	}
723 }
724 
725 static umode_t amc6821_is_visible(const void *data,
726 				  enum hwmon_sensor_types type,
727 				  u32 attr, int channel)
728 {
729 	switch (type) {
730 	case hwmon_temp:
731 		switch (attr) {
732 		case hwmon_temp_input:
733 		case hwmon_temp_min_alarm:
734 		case hwmon_temp_max_alarm:
735 		case hwmon_temp_crit_alarm:
736 		case hwmon_temp_fault:
737 			return 0444;
738 		case hwmon_temp_min:
739 		case hwmon_temp_max:
740 		case hwmon_temp_crit:
741 			return 0644;
742 		default:
743 			return 0;
744 		}
745 	case hwmon_fan:
746 		switch (attr) {
747 		case hwmon_fan_input:
748 		case hwmon_fan_fault:
749 			return 0444;
750 		case hwmon_fan_pulses:
751 		case hwmon_fan_min:
752 		case hwmon_fan_max:
753 		case hwmon_fan_target:
754 			return 0644;
755 		default:
756 			return 0;
757 		}
758 	case hwmon_pwm:
759 		switch (attr) {
760 		case hwmon_pwm_mode:
761 		case hwmon_pwm_enable:
762 		case hwmon_pwm_input:
763 			return 0644;
764 		case hwmon_pwm_auto_channels_temp:
765 			return 0444;
766 		default:
767 			return 0;
768 		}
769 	default:
770 		return 0;
771 	}
772 }
773 
774 static const struct hwmon_channel_info * const amc6821_info[] = {
775 	HWMON_CHANNEL_INFO(temp,
776 			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
777 			   HWMON_T_CRIT | HWMON_T_MIN_ALARM |
778 			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM,
779 			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
780 			   HWMON_T_CRIT | HWMON_T_MIN_ALARM |
781 			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM |
782 			   HWMON_T_FAULT),
783 	HWMON_CHANNEL_INFO(fan,
784 			   HWMON_F_INPUT | HWMON_F_MIN | HWMON_F_MAX |
785 			   HWMON_F_TARGET | HWMON_F_PULSES | HWMON_F_FAULT),
786 	HWMON_CHANNEL_INFO(pwm,
787 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE | HWMON_PWM_MODE |
788 			   HWMON_PWM_AUTO_CHANNELS_TEMP),
789 	NULL
790 };
791 
792 static const struct hwmon_ops amc6821_hwmon_ops = {
793 	.is_visible = amc6821_is_visible,
794 	.read = amc6821_read,
795 	.write = amc6821_write,
796 };
797 
798 static const struct hwmon_chip_info amc6821_chip_info = {
799 	.ops = &amc6821_hwmon_ops,
800 	.info = amc6821_info,
801 };
802 
803 /* Return 0 if detection is successful, -ENODEV otherwise */
804 static int amc6821_detect(struct i2c_client *client, 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 	strscpy(info->type, "amc6821", I2C_NAME_SIZE);
843 
844 	return 0;
845 }
846 
847 static int amc6821_init_client(struct amc6821_data *data)
848 {
849 	struct regmap *regmap = data->regmap;
850 	int err;
851 
852 	if (init) {
853 		err = regmap_set_bits(regmap, AMC6821_REG_CONF4, AMC6821_CONF4_MODE);
854 		if (err)
855 			return err;
856 		err = regmap_clear_bits(regmap, AMC6821_REG_CONF3, AMC6821_CONF3_THERM_FAN_EN);
857 		if (err)
858 			return err;
859 		err = regmap_clear_bits(regmap, AMC6821_REG_CONF2,
860 					AMC6821_CONF2_RTFIE |
861 					AMC6821_CONF2_LTOIE |
862 					AMC6821_CONF2_RTOIE);
863 		if (err)
864 			return err;
865 
866 		err = regmap_update_bits(regmap, AMC6821_REG_CONF1,
867 					 AMC6821_CONF1_THERMOVIE | AMC6821_CONF1_FANIE |
868 					 AMC6821_CONF1_START | AMC6821_CONF1_PWMINV,
869 					 AMC6821_CONF1_START |
870 					 (pwminv ? AMC6821_CONF1_PWMINV : 0));
871 		if (err)
872 			return err;
873 	}
874 	return 0;
875 }
876 
877 static bool amc6821_volatile_reg(struct device *dev, unsigned int reg)
878 {
879 	switch (reg) {
880 	case AMC6821_REG_STAT1:
881 	case AMC6821_REG_STAT2:
882 	case AMC6821_REG_TEMP_LO:
883 	case AMC6821_REG_TDATA_LOW:
884 	case AMC6821_REG_LTEMP_HI:
885 	case AMC6821_REG_RTEMP_HI:
886 	case AMC6821_REG_TDATA_HI:
887 		return true;
888 	default:
889 		return false;
890 	}
891 }
892 
893 static const struct regmap_config amc6821_regmap_config = {
894 	.reg_bits = 8,
895 	.val_bits = 8,
896 	.max_register = AMC6821_REG_CONF3,
897 	.volatile_reg = amc6821_volatile_reg,
898 	.cache_type = REGCACHE_MAPLE,
899 };
900 
901 static int amc6821_probe(struct i2c_client *client)
902 {
903 	struct device *dev = &client->dev;
904 	struct amc6821_data *data;
905 	struct device *hwmon_dev;
906 	struct regmap *regmap;
907 	int err;
908 
909 	data = devm_kzalloc(dev, sizeof(struct amc6821_data), GFP_KERNEL);
910 	if (!data)
911 		return -ENOMEM;
912 
913 	regmap = devm_regmap_init_i2c(client, &amc6821_regmap_config);
914 	if (IS_ERR(regmap))
915 		return dev_err_probe(dev, PTR_ERR(regmap),
916 				     "Failed to initialize regmap\n");
917 	data->regmap = regmap;
918 
919 	err = amc6821_init_client(data);
920 	if (err)
921 		return err;
922 
923 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
924 							 data, &amc6821_chip_info,
925 							 amc6821_groups);
926 	return PTR_ERR_OR_ZERO(hwmon_dev);
927 }
928 
929 static const struct i2c_device_id amc6821_id[] = {
930 	{ "amc6821", 0 },
931 	{ }
932 };
933 
934 MODULE_DEVICE_TABLE(i2c, amc6821_id);
935 
936 static const struct of_device_id __maybe_unused amc6821_of_match[] = {
937 	{
938 		.compatible = "ti,amc6821",
939 	},
940 	{ }
941 };
942 
943 MODULE_DEVICE_TABLE(of, amc6821_of_match);
944 
945 static struct i2c_driver amc6821_driver = {
946 	.class = I2C_CLASS_HWMON,
947 	.driver = {
948 		.name	= "amc6821",
949 		.of_match_table = of_match_ptr(amc6821_of_match),
950 	},
951 	.probe = amc6821_probe,
952 	.id_table = amc6821_id,
953 	.detect = amc6821_detect,
954 	.address_list = normal_i2c,
955 };
956 
957 module_i2c_driver(amc6821_driver);
958 
959 MODULE_LICENSE("GPL");
960 MODULE_AUTHOR("T. Mertelj <tomaz.mertelj@guest.arnes.si>");
961 MODULE_DESCRIPTION("Texas Instruments amc6821 hwmon driver");
962