xref: /linux/drivers/hwmon/ltc2947-core.c (revision 3a39d672e7f48b8d6b91a09afa4b55352773b4b5)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Analog Devices LTC2947 high precision power and energy monitor
4  *
5  * Copyright 2019 Analog Devices Inc.
6  */
7 #include <linux/bitfield.h>
8 #include <linux/bits.h>
9 #include <linux/clk.h>
10 #include <linux/device.h>
11 #include <linux/hwmon.h>
12 #include <linux/hwmon-sysfs.h>
13 #include <linux/module.h>
14 #include <linux/mod_devicetable.h>
15 #include <linux/property.h>
16 #include <linux/regmap.h>
17 
18 #include "ltc2947.h"
19 
20 /* register's */
21 #define LTC2947_REG_PAGE_CTRL		0xFF
22 #define LTC2947_REG_CTRL		0xF0
23 #define LTC2947_REG_TBCTL		0xE9
24 #define LTC2947_CONT_MODE_MASK		BIT(3)
25 #define LTC2947_CONT_MODE(x)		FIELD_PREP(LTC2947_CONT_MODE_MASK, x)
26 #define LTC2947_PRE_MASK		GENMASK(2, 0)
27 #define LTC2947_PRE(x)			FIELD_PREP(LTC2947_PRE_MASK, x)
28 #define LTC2947_DIV_MASK		GENMASK(7, 3)
29 #define LTC2947_DIV(x)			FIELD_PREP(LTC2947_DIV_MASK, x)
30 #define LTC2947_SHUTDOWN_MASK		BIT(0)
31 #define LTC2947_REG_ACCUM_POL		0xE1
32 #define LTC2947_ACCUM_POL_1_MASK	GENMASK(1, 0)
33 #define LTC2947_ACCUM_POL_1(x)		FIELD_PREP(LTC2947_ACCUM_POL_1_MASK, x)
34 #define LTC2947_ACCUM_POL_2_MASK	GENMASK(3, 2)
35 #define LTC2947_ACCUM_POL_2(x)		FIELD_PREP(LTC2947_ACCUM_POL_2_MASK, x)
36 #define LTC2947_REG_ACCUM_DEADBAND	0xE4
37 #define LTC2947_REG_GPIOSTATCTL		0x67
38 #define LTC2947_GPIO_EN_MASK		BIT(0)
39 #define LTC2947_GPIO_EN(x)		FIELD_PREP(LTC2947_GPIO_EN_MASK, x)
40 #define LTC2947_GPIO_FAN_EN_MASK	BIT(6)
41 #define LTC2947_GPIO_FAN_EN(x)		FIELD_PREP(LTC2947_GPIO_FAN_EN_MASK, x)
42 #define LTC2947_GPIO_FAN_POL_MASK	BIT(7)
43 #define LTC2947_GPIO_FAN_POL(x)		FIELD_PREP(LTC2947_GPIO_FAN_POL_MASK, x)
44 #define LTC2947_REG_GPIO_ACCUM		0xE3
45 /* 200Khz */
46 #define LTC2947_CLK_MIN			200000
47 /* 25Mhz */
48 #define LTC2947_CLK_MAX			25000000
49 #define LTC2947_PAGE0			0
50 #define LTC2947_PAGE1			1
51 /* Voltage registers */
52 #define LTC2947_REG_VOLTAGE		0xA0
53 #define LTC2947_REG_VOLTAGE_MAX		0x50
54 #define LTC2947_REG_VOLTAGE_MIN		0x52
55 #define LTC2947_REG_VOLTAGE_THRE_H	0x90
56 #define LTC2947_REG_VOLTAGE_THRE_L	0x92
57 #define LTC2947_REG_DVCC		0xA4
58 #define LTC2947_REG_DVCC_MAX		0x58
59 #define LTC2947_REG_DVCC_MIN		0x5A
60 #define LTC2947_REG_DVCC_THRE_H		0x98
61 #define LTC2947_REG_DVCC_THRE_L		0x9A
62 #define LTC2947_VOLTAGE_GEN_CHAN	0
63 #define LTC2947_VOLTAGE_DVCC_CHAN	1
64 /* in mV */
65 #define VOLTAGE_MAX			15500
66 #define VOLTAGE_MIN			-300
67 #define VDVCC_MAX			15000
68 #define VDVCC_MIN			4750
69 /* Current registers */
70 #define LTC2947_REG_CURRENT		0x90
71 #define LTC2947_REG_CURRENT_MAX		0x40
72 #define LTC2947_REG_CURRENT_MIN		0x42
73 #define LTC2947_REG_CURRENT_THRE_H	0x80
74 #define LTC2947_REG_CURRENT_THRE_L	0x82
75 /* in mA */
76 #define CURRENT_MAX			30000
77 #define CURRENT_MIN			-30000
78 /* Power registers */
79 #define LTC2947_REG_POWER		0x93
80 #define LTC2947_REG_POWER_MAX		0x44
81 #define LTC2947_REG_POWER_MIN		0x46
82 #define LTC2947_REG_POWER_THRE_H	0x84
83 #define LTC2947_REG_POWER_THRE_L	0x86
84 /* in uW */
85 #define POWER_MAX			450000000
86 #define POWER_MIN			-450000000
87 /* Temperature registers */
88 #define LTC2947_REG_TEMP		0xA2
89 #define LTC2947_REG_TEMP_MAX		0x54
90 #define LTC2947_REG_TEMP_MIN		0x56
91 #define LTC2947_REG_TEMP_THRE_H		0x94
92 #define LTC2947_REG_TEMP_THRE_L		0x96
93 #define LTC2947_REG_TEMP_FAN_THRE_H	0x9C
94 #define LTC2947_REG_TEMP_FAN_THRE_L	0x9E
95 #define LTC2947_TEMP_FAN_CHAN		1
96 /* in millidegress Celsius */
97 #define TEMP_MAX			85000
98 #define TEMP_MIN			-40000
99 /* Energy registers */
100 #define LTC2947_REG_ENERGY1		0x06
101 #define LTC2947_REG_ENERGY2		0x16
102 /* Status/Alarm/Overflow registers */
103 #define LTC2947_REG_STATUS		0x80
104 #define LTC2947_REG_STATVT		0x81
105 #define LTC2947_REG_STATIP		0x82
106 #define LTC2947_REG_STATVDVCC		0x87
107 
108 #define LTC2947_ALERTS_SIZE	(LTC2947_REG_STATVDVCC - LTC2947_REG_STATUS)
109 #define LTC2947_MAX_VOLTAGE_MASK	BIT(0)
110 #define LTC2947_MIN_VOLTAGE_MASK	BIT(1)
111 #define LTC2947_MAX_CURRENT_MASK	BIT(0)
112 #define LTC2947_MIN_CURRENT_MASK	BIT(1)
113 #define LTC2947_MAX_POWER_MASK		BIT(2)
114 #define LTC2947_MIN_POWER_MASK		BIT(3)
115 #define LTC2947_MAX_TEMP_MASK		BIT(2)
116 #define LTC2947_MIN_TEMP_MASK		BIT(3)
117 #define LTC2947_MAX_TEMP_FAN_MASK	BIT(4)
118 #define LTC2947_MIN_TEMP_FAN_MASK	BIT(5)
119 
120 struct ltc2947_data {
121 	struct regmap *map;
122 	struct device *dev;
123 	/*
124 	 * The mutex is needed because the device has 2 memory pages. When
125 	 * reading/writing the correct page needs to be set so that, the
126 	 * complete sequence select_page->read/write needs to be protected.
127 	 */
128 	struct mutex lock;
129 	u32 lsb_energy;
130 	bool gpio_out;
131 };
132 
__ltc2947_val_read16(const struct ltc2947_data * st,const u8 reg,u64 * val)133 static int __ltc2947_val_read16(const struct ltc2947_data *st, const u8 reg,
134 				u64 *val)
135 {
136 	__be16 __val = 0;
137 	int ret;
138 
139 	ret = regmap_bulk_read(st->map, reg, &__val, 2);
140 	if (ret)
141 		return ret;
142 
143 	*val = be16_to_cpu(__val);
144 
145 	return 0;
146 }
147 
__ltc2947_val_read24(const struct ltc2947_data * st,const u8 reg,u64 * val)148 static int __ltc2947_val_read24(const struct ltc2947_data *st, const u8 reg,
149 				u64 *val)
150 {
151 	__be32 __val = 0;
152 	int ret;
153 
154 	ret = regmap_bulk_read(st->map, reg, &__val, 3);
155 	if (ret)
156 		return ret;
157 
158 	*val = be32_to_cpu(__val) >> 8;
159 
160 	return 0;
161 }
162 
__ltc2947_val_read64(const struct ltc2947_data * st,const u8 reg,u64 * val)163 static int __ltc2947_val_read64(const struct ltc2947_data *st, const u8 reg,
164 				u64 *val)
165 {
166 	__be64 __val = 0;
167 	int ret;
168 
169 	ret = regmap_bulk_read(st->map, reg, &__val, 6);
170 	if (ret)
171 		return ret;
172 
173 	*val = be64_to_cpu(__val) >> 16;
174 
175 	return 0;
176 }
177 
ltc2947_val_read(struct ltc2947_data * st,const u8 reg,const u8 page,const size_t size,s64 * val)178 static int ltc2947_val_read(struct ltc2947_data *st, const u8 reg,
179 			    const u8 page, const size_t size, s64 *val)
180 {
181 	int ret;
182 	u64 __val = 0;
183 
184 	mutex_lock(&st->lock);
185 
186 	ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, page);
187 	if (ret) {
188 		mutex_unlock(&st->lock);
189 		return ret;
190 	}
191 
192 	dev_dbg(st->dev, "Read val, reg:%02X, p:%d sz:%zu\n", reg, page,
193 		size);
194 
195 	switch (size) {
196 	case 2:
197 		ret = __ltc2947_val_read16(st, reg, &__val);
198 		break;
199 	case 3:
200 		ret = __ltc2947_val_read24(st, reg, &__val);
201 		break;
202 	case 6:
203 		ret = __ltc2947_val_read64(st, reg, &__val);
204 		break;
205 	default:
206 		ret = -EINVAL;
207 		break;
208 	}
209 
210 	mutex_unlock(&st->lock);
211 
212 	if (ret)
213 		return ret;
214 
215 	*val = sign_extend64(__val, (8 * size) - 1);
216 
217 	dev_dbg(st->dev, "Got s:%lld, u:%016llX\n", *val, __val);
218 
219 	return 0;
220 }
221 
__ltc2947_val_write64(const struct ltc2947_data * st,const u8 reg,const u64 val)222 static int __ltc2947_val_write64(const struct ltc2947_data *st, const u8 reg,
223 				 const u64 val)
224 {
225 	__be64 __val;
226 
227 	__val = cpu_to_be64(val << 16);
228 	return regmap_bulk_write(st->map, reg, &__val, 6);
229 }
230 
__ltc2947_val_write16(const struct ltc2947_data * st,const u8 reg,const u16 val)231 static int __ltc2947_val_write16(const struct ltc2947_data *st, const u8 reg,
232 				 const u16 val)
233 {
234 	__be16 __val;
235 
236 	__val = cpu_to_be16(val);
237 	return regmap_bulk_write(st->map, reg, &__val, 2);
238 }
239 
ltc2947_val_write(struct ltc2947_data * st,const u8 reg,const u8 page,const size_t size,const u64 val)240 static int ltc2947_val_write(struct ltc2947_data *st, const u8 reg,
241 			     const u8 page, const size_t size, const u64 val)
242 {
243 	int ret;
244 
245 	mutex_lock(&st->lock);
246 	/* set device on correct page */
247 	ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, page);
248 	if (ret) {
249 		mutex_unlock(&st->lock);
250 		return ret;
251 	}
252 
253 	dev_dbg(st->dev, "Write val, r:%02X, p:%d, sz:%zu, val:%016llX\n",
254 		reg, page, size, val);
255 
256 	switch (size) {
257 	case 2:
258 		ret = __ltc2947_val_write16(st, reg, val);
259 		break;
260 	case 6:
261 		ret = __ltc2947_val_write64(st, reg, val);
262 		break;
263 	default:
264 		ret = -EINVAL;
265 		break;
266 	}
267 
268 	mutex_unlock(&st->lock);
269 
270 	return ret;
271 }
272 
ltc2947_reset_history(struct ltc2947_data * st,const u8 reg_h,const u8 reg_l)273 static int ltc2947_reset_history(struct ltc2947_data *st, const u8 reg_h,
274 				 const u8 reg_l)
275 {
276 	int ret;
277 	/*
278 	 * let's reset the tracking register's. Tracking register's have all
279 	 * 2 bytes size
280 	 */
281 	ret = ltc2947_val_write(st, reg_h, LTC2947_PAGE0, 2, 0x8000U);
282 	if (ret)
283 		return ret;
284 
285 	return ltc2947_val_write(st, reg_l, LTC2947_PAGE0, 2, 0x7FFFU);
286 }
287 
ltc2947_alarm_read(struct ltc2947_data * st,const u8 reg,const u32 mask,long * val)288 static int ltc2947_alarm_read(struct ltc2947_data *st, const u8 reg,
289 			      const u32 mask, long *val)
290 {
291 	u8 offset = reg - LTC2947_REG_STATUS;
292 	/* +1 to include status reg */
293 	char alarms[LTC2947_ALERTS_SIZE + 1];
294 	int ret = 0;
295 
296 	memset(alarms, 0, sizeof(alarms));
297 
298 	mutex_lock(&st->lock);
299 
300 	ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, LTC2947_PAGE0);
301 	if (ret)
302 		goto unlock;
303 
304 	dev_dbg(st->dev, "Read alarm, reg:%02X, mask:%02X\n", reg, mask);
305 	/*
306 	 * As stated in the datasheet, when Threshold and Overflow registers
307 	 * are used, the status and all alert registers must be read in one
308 	 * multi-byte transaction.
309 	 */
310 	ret = regmap_bulk_read(st->map, LTC2947_REG_STATUS, alarms,
311 			       sizeof(alarms));
312 	if (ret)
313 		goto unlock;
314 
315 	/* get the alarm */
316 	*val = !!(alarms[offset] & mask);
317 unlock:
318 	mutex_unlock(&st->lock);
319 	return ret;
320 }
321 
ltc2947_show_value(struct device * dev,struct device_attribute * da,char * buf)322 static ssize_t ltc2947_show_value(struct device *dev,
323 				  struct device_attribute *da, char *buf)
324 {
325 	struct ltc2947_data *st = dev_get_drvdata(dev);
326 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
327 	int ret;
328 	s64 val = 0;
329 
330 	ret = ltc2947_val_read(st, attr->index, LTC2947_PAGE0, 6, &val);
331 	if (ret)
332 		return ret;
333 
334 	/* value in microJoule. st->lsb_energy was multiplied by 10E9 */
335 	val = div_s64(val * st->lsb_energy, 1000);
336 
337 	return sprintf(buf, "%lld\n", val);
338 }
339 
ltc2947_read_temp(struct device * dev,const u32 attr,long * val,const int channel)340 static int ltc2947_read_temp(struct device *dev, const u32 attr, long *val,
341 			     const int channel)
342 {
343 	int ret;
344 	struct ltc2947_data *st = dev_get_drvdata(dev);
345 	s64 __val = 0;
346 
347 	switch (attr) {
348 	case hwmon_temp_input:
349 		ret = ltc2947_val_read(st, LTC2947_REG_TEMP, LTC2947_PAGE0,
350 				       2, &__val);
351 		break;
352 	case hwmon_temp_highest:
353 		ret = ltc2947_val_read(st, LTC2947_REG_TEMP_MAX, LTC2947_PAGE0,
354 				       2, &__val);
355 		break;
356 	case hwmon_temp_lowest:
357 		ret = ltc2947_val_read(st, LTC2947_REG_TEMP_MIN, LTC2947_PAGE0,
358 				       2, &__val);
359 		break;
360 	case hwmon_temp_max_alarm:
361 		if (channel == LTC2947_TEMP_FAN_CHAN)
362 			return ltc2947_alarm_read(st, LTC2947_REG_STATVT,
363 						  LTC2947_MAX_TEMP_FAN_MASK,
364 						  val);
365 
366 		return ltc2947_alarm_read(st, LTC2947_REG_STATVT,
367 					  LTC2947_MAX_TEMP_MASK, val);
368 	case hwmon_temp_min_alarm:
369 		if (channel == LTC2947_TEMP_FAN_CHAN)
370 			return	ltc2947_alarm_read(st, LTC2947_REG_STATVT,
371 						   LTC2947_MIN_TEMP_FAN_MASK,
372 						   val);
373 
374 		return	ltc2947_alarm_read(st, LTC2947_REG_STATVT,
375 					   LTC2947_MIN_TEMP_MASK, val);
376 	case hwmon_temp_max:
377 		if (channel == LTC2947_TEMP_FAN_CHAN)
378 			ret = ltc2947_val_read(st, LTC2947_REG_TEMP_FAN_THRE_H,
379 					       LTC2947_PAGE1, 2, &__val);
380 		else
381 			ret = ltc2947_val_read(st, LTC2947_REG_TEMP_THRE_H,
382 					       LTC2947_PAGE1, 2, &__val);
383 		break;
384 	case hwmon_temp_min:
385 		if (channel == LTC2947_TEMP_FAN_CHAN)
386 			ret = ltc2947_val_read(st, LTC2947_REG_TEMP_FAN_THRE_L,
387 					       LTC2947_PAGE1, 2, &__val);
388 		else
389 			ret = ltc2947_val_read(st, LTC2947_REG_TEMP_THRE_L,
390 					       LTC2947_PAGE1, 2, &__val);
391 		break;
392 	default:
393 		return -ENOTSUPP;
394 	}
395 
396 	if (ret)
397 		return ret;
398 
399 	/* in milidegrees celcius, temp is given by: */
400 	*val = (__val * 204) + 5500;
401 
402 	return 0;
403 }
404 
ltc2947_read_power(struct device * dev,const u32 attr,long * val)405 static int ltc2947_read_power(struct device *dev, const u32 attr, long *val)
406 {
407 	struct ltc2947_data *st = dev_get_drvdata(dev);
408 	int ret;
409 	u32 lsb = 200000; /* in uW */
410 	s64 __val = 0;
411 
412 	switch (attr) {
413 	case hwmon_power_input:
414 		ret = ltc2947_val_read(st, LTC2947_REG_POWER, LTC2947_PAGE0,
415 				       3, &__val);
416 		lsb = 50000;
417 		break;
418 	case hwmon_power_input_highest:
419 		ret = ltc2947_val_read(st, LTC2947_REG_POWER_MAX, LTC2947_PAGE0,
420 				       2, &__val);
421 		break;
422 	case hwmon_power_input_lowest:
423 		ret = ltc2947_val_read(st, LTC2947_REG_POWER_MIN, LTC2947_PAGE0,
424 				       2, &__val);
425 		break;
426 	case hwmon_power_max_alarm:
427 		return ltc2947_alarm_read(st, LTC2947_REG_STATIP,
428 					  LTC2947_MAX_POWER_MASK, val);
429 	case hwmon_power_min_alarm:
430 		return ltc2947_alarm_read(st, LTC2947_REG_STATIP,
431 					  LTC2947_MIN_POWER_MASK, val);
432 	case hwmon_power_max:
433 		ret = ltc2947_val_read(st, LTC2947_REG_POWER_THRE_H,
434 				       LTC2947_PAGE1, 2, &__val);
435 		break;
436 	case hwmon_power_min:
437 		ret = ltc2947_val_read(st, LTC2947_REG_POWER_THRE_L,
438 				       LTC2947_PAGE1, 2, &__val);
439 		break;
440 	default:
441 		return -ENOTSUPP;
442 	}
443 
444 	if (ret)
445 		return ret;
446 
447 	*val = __val * lsb;
448 
449 	return 0;
450 }
451 
ltc2947_read_curr(struct device * dev,const u32 attr,long * val)452 static int ltc2947_read_curr(struct device *dev, const u32 attr, long *val)
453 {
454 	struct ltc2947_data *st = dev_get_drvdata(dev);
455 	int ret;
456 	u8 lsb = 12; /* in mA */
457 	s64 __val = 0;
458 
459 	switch (attr) {
460 	case hwmon_curr_input:
461 		ret = ltc2947_val_read(st, LTC2947_REG_CURRENT,
462 				       LTC2947_PAGE0, 3, &__val);
463 		lsb = 3;
464 		break;
465 	case hwmon_curr_highest:
466 		ret = ltc2947_val_read(st, LTC2947_REG_CURRENT_MAX,
467 				       LTC2947_PAGE0, 2, &__val);
468 		break;
469 	case hwmon_curr_lowest:
470 		ret = ltc2947_val_read(st, LTC2947_REG_CURRENT_MIN,
471 				       LTC2947_PAGE0, 2, &__val);
472 		break;
473 	case hwmon_curr_max_alarm:
474 		return ltc2947_alarm_read(st, LTC2947_REG_STATIP,
475 					  LTC2947_MAX_CURRENT_MASK, val);
476 	case hwmon_curr_min_alarm:
477 		return ltc2947_alarm_read(st, LTC2947_REG_STATIP,
478 					  LTC2947_MIN_CURRENT_MASK, val);
479 	case hwmon_curr_max:
480 		ret = ltc2947_val_read(st, LTC2947_REG_CURRENT_THRE_H,
481 				       LTC2947_PAGE1, 2, &__val);
482 		break;
483 	case hwmon_curr_min:
484 		ret = ltc2947_val_read(st, LTC2947_REG_CURRENT_THRE_L,
485 				       LTC2947_PAGE1, 2, &__val);
486 		break;
487 	default:
488 		return -ENOTSUPP;
489 	}
490 
491 	if (ret)
492 		return ret;
493 
494 	*val = __val * lsb;
495 
496 	return 0;
497 }
498 
ltc2947_read_in(struct device * dev,const u32 attr,long * val,const int channel)499 static int ltc2947_read_in(struct device *dev, const u32 attr, long *val,
500 			   const int channel)
501 {
502 	struct ltc2947_data *st = dev_get_drvdata(dev);
503 	int ret;
504 	u8 lsb = 2; /* in mV */
505 	s64 __val = 0;
506 
507 	if (channel < 0 || channel > LTC2947_VOLTAGE_DVCC_CHAN) {
508 		dev_err(st->dev, "Invalid chan%d for voltage", channel);
509 		return -EINVAL;
510 	}
511 
512 	switch (attr) {
513 	case hwmon_in_input:
514 		if (channel == LTC2947_VOLTAGE_DVCC_CHAN) {
515 			ret = ltc2947_val_read(st, LTC2947_REG_DVCC,
516 					       LTC2947_PAGE0, 2, &__val);
517 			lsb = 145;
518 		} else {
519 			ret = ltc2947_val_read(st, LTC2947_REG_VOLTAGE,
520 					       LTC2947_PAGE0, 2, &__val);
521 		}
522 		break;
523 	case hwmon_in_highest:
524 		if (channel == LTC2947_VOLTAGE_DVCC_CHAN) {
525 			ret = ltc2947_val_read(st, LTC2947_REG_DVCC_MAX,
526 					       LTC2947_PAGE0, 2, &__val);
527 			lsb = 145;
528 		} else {
529 			ret = ltc2947_val_read(st, LTC2947_REG_VOLTAGE_MAX,
530 					       LTC2947_PAGE0, 2, &__val);
531 		}
532 		break;
533 	case hwmon_in_lowest:
534 		if (channel == LTC2947_VOLTAGE_DVCC_CHAN) {
535 			ret = ltc2947_val_read(st, LTC2947_REG_DVCC_MIN,
536 					       LTC2947_PAGE0, 2, &__val);
537 			lsb = 145;
538 		} else {
539 			ret = ltc2947_val_read(st, LTC2947_REG_VOLTAGE_MIN,
540 					       LTC2947_PAGE0, 2, &__val);
541 		}
542 		break;
543 	case hwmon_in_max_alarm:
544 		if (channel == LTC2947_VOLTAGE_DVCC_CHAN)
545 			return ltc2947_alarm_read(st, LTC2947_REG_STATVDVCC,
546 						  LTC2947_MAX_VOLTAGE_MASK,
547 						  val);
548 
549 		return ltc2947_alarm_read(st, LTC2947_REG_STATVT,
550 					  LTC2947_MAX_VOLTAGE_MASK, val);
551 	case hwmon_in_min_alarm:
552 		if (channel == LTC2947_VOLTAGE_DVCC_CHAN)
553 			return ltc2947_alarm_read(st, LTC2947_REG_STATVDVCC,
554 						  LTC2947_MIN_VOLTAGE_MASK,
555 						  val);
556 
557 		return ltc2947_alarm_read(st, LTC2947_REG_STATVT,
558 					  LTC2947_MIN_VOLTAGE_MASK, val);
559 	case hwmon_in_max:
560 		if (channel == LTC2947_VOLTAGE_DVCC_CHAN) {
561 			ret = ltc2947_val_read(st, LTC2947_REG_DVCC_THRE_H,
562 					       LTC2947_PAGE1, 2, &__val);
563 			lsb = 145;
564 		} else {
565 			ret = ltc2947_val_read(st, LTC2947_REG_VOLTAGE_THRE_H,
566 					       LTC2947_PAGE1, 2, &__val);
567 		}
568 		break;
569 	case hwmon_in_min:
570 		if (channel == LTC2947_VOLTAGE_DVCC_CHAN) {
571 			ret = ltc2947_val_read(st, LTC2947_REG_DVCC_THRE_L,
572 					       LTC2947_PAGE1, 2, &__val);
573 			lsb = 145;
574 		} else {
575 			ret = ltc2947_val_read(st, LTC2947_REG_VOLTAGE_THRE_L,
576 					       LTC2947_PAGE1, 2, &__val);
577 		}
578 		break;
579 	default:
580 		return -ENOTSUPP;
581 	}
582 
583 	if (ret)
584 		return ret;
585 
586 	*val = __val * lsb;
587 
588 	return 0;
589 }
590 
ltc2947_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)591 static int ltc2947_read(struct device *dev, enum hwmon_sensor_types type,
592 			u32 attr, int channel, long *val)
593 {
594 	switch (type) {
595 	case hwmon_in:
596 		return ltc2947_read_in(dev, attr, val, channel);
597 	case hwmon_curr:
598 		return ltc2947_read_curr(dev, attr, val);
599 	case hwmon_power:
600 		return ltc2947_read_power(dev, attr, val);
601 	case hwmon_temp:
602 		return ltc2947_read_temp(dev, attr, val, channel);
603 	default:
604 		return -ENOTSUPP;
605 	}
606 }
607 
ltc2947_write_temp(struct device * dev,const u32 attr,long val,const int channel)608 static int ltc2947_write_temp(struct device *dev, const u32 attr,
609 			      long val, const int channel)
610 {
611 	struct ltc2947_data *st = dev_get_drvdata(dev);
612 
613 	if (channel < 0 || channel > LTC2947_TEMP_FAN_CHAN) {
614 		dev_err(st->dev, "Invalid chan%d for temperature", channel);
615 		return -EINVAL;
616 	}
617 
618 	switch (attr) {
619 	case hwmon_temp_reset_history:
620 		if (val != 1)
621 			return -EINVAL;
622 		return ltc2947_reset_history(st, LTC2947_REG_TEMP_MAX,
623 					     LTC2947_REG_TEMP_MIN);
624 	case hwmon_temp_max:
625 		val = clamp_val(val, TEMP_MIN, TEMP_MAX);
626 		if (channel == LTC2947_TEMP_FAN_CHAN) {
627 			if (!st->gpio_out)
628 				return -ENOTSUPP;
629 
630 			return ltc2947_val_write(st,
631 					LTC2947_REG_TEMP_FAN_THRE_H,
632 					LTC2947_PAGE1, 2,
633 					DIV_ROUND_CLOSEST(val - 550, 204));
634 		}
635 
636 		return ltc2947_val_write(st, LTC2947_REG_TEMP_THRE_H,
637 					 LTC2947_PAGE1, 2,
638 					 DIV_ROUND_CLOSEST(val - 550, 204));
639 	case hwmon_temp_min:
640 		val = clamp_val(val, TEMP_MIN, TEMP_MAX);
641 		if (channel == LTC2947_TEMP_FAN_CHAN) {
642 			if (!st->gpio_out)
643 				return -ENOTSUPP;
644 
645 			return ltc2947_val_write(st,
646 					LTC2947_REG_TEMP_FAN_THRE_L,
647 					LTC2947_PAGE1, 2,
648 					DIV_ROUND_CLOSEST(val - 550, 204));
649 		}
650 
651 		return ltc2947_val_write(st, LTC2947_REG_TEMP_THRE_L,
652 					 LTC2947_PAGE1, 2,
653 					 DIV_ROUND_CLOSEST(val - 550, 204));
654 	default:
655 		return -ENOTSUPP;
656 	}
657 }
658 
ltc2947_write_power(struct device * dev,const u32 attr,long val)659 static int ltc2947_write_power(struct device *dev, const u32 attr,
660 			       long val)
661 {
662 	struct ltc2947_data *st = dev_get_drvdata(dev);
663 
664 	switch (attr) {
665 	case hwmon_power_reset_history:
666 		if (val != 1)
667 			return -EINVAL;
668 		return ltc2947_reset_history(st, LTC2947_REG_POWER_MAX,
669 					     LTC2947_REG_POWER_MIN);
670 	case hwmon_power_max:
671 		val = clamp_val(val, POWER_MIN, POWER_MAX);
672 		return ltc2947_val_write(st, LTC2947_REG_POWER_THRE_H,
673 					 LTC2947_PAGE1, 2,
674 					 DIV_ROUND_CLOSEST(val, 200000));
675 	case hwmon_power_min:
676 		val = clamp_val(val, POWER_MIN, POWER_MAX);
677 		return ltc2947_val_write(st, LTC2947_REG_POWER_THRE_L,
678 					 LTC2947_PAGE1, 2,
679 					 DIV_ROUND_CLOSEST(val, 200000));
680 	default:
681 		return -ENOTSUPP;
682 	}
683 }
684 
ltc2947_write_curr(struct device * dev,const u32 attr,long val)685 static int ltc2947_write_curr(struct device *dev, const u32 attr,
686 			      long val)
687 {
688 	struct ltc2947_data *st = dev_get_drvdata(dev);
689 
690 	switch (attr) {
691 	case hwmon_curr_reset_history:
692 		if (val != 1)
693 			return -EINVAL;
694 		return ltc2947_reset_history(st, LTC2947_REG_CURRENT_MAX,
695 					     LTC2947_REG_CURRENT_MIN);
696 	case hwmon_curr_max:
697 		val = clamp_val(val, CURRENT_MIN, CURRENT_MAX);
698 		return ltc2947_val_write(st, LTC2947_REG_CURRENT_THRE_H,
699 					 LTC2947_PAGE1, 2,
700 					 DIV_ROUND_CLOSEST(val, 12));
701 	case hwmon_curr_min:
702 		val = clamp_val(val, CURRENT_MIN, CURRENT_MAX);
703 		return ltc2947_val_write(st, LTC2947_REG_CURRENT_THRE_L,
704 					 LTC2947_PAGE1, 2,
705 					 DIV_ROUND_CLOSEST(val, 12));
706 	default:
707 		return -ENOTSUPP;
708 	}
709 }
710 
ltc2947_write_in(struct device * dev,const u32 attr,long val,const int channel)711 static int ltc2947_write_in(struct device *dev, const u32 attr, long val,
712 			    const int channel)
713 {
714 	struct ltc2947_data *st = dev_get_drvdata(dev);
715 
716 	if (channel > LTC2947_VOLTAGE_DVCC_CHAN) {
717 		dev_err(st->dev, "Invalid chan%d for voltage", channel);
718 		return -EINVAL;
719 	}
720 
721 	switch (attr) {
722 	case hwmon_in_reset_history:
723 		if (val != 1)
724 			return -EINVAL;
725 
726 		if (channel == LTC2947_VOLTAGE_DVCC_CHAN)
727 			return ltc2947_reset_history(st, LTC2947_REG_DVCC_MAX,
728 						     LTC2947_REG_DVCC_MIN);
729 
730 		return ltc2947_reset_history(st, LTC2947_REG_VOLTAGE_MAX,
731 					     LTC2947_REG_VOLTAGE_MIN);
732 	case hwmon_in_max:
733 		if (channel == LTC2947_VOLTAGE_DVCC_CHAN) {
734 			val = clamp_val(val, VDVCC_MIN, VDVCC_MAX);
735 			return ltc2947_val_write(st, LTC2947_REG_DVCC_THRE_H,
736 						 LTC2947_PAGE1, 2,
737 						 DIV_ROUND_CLOSEST(val, 145));
738 		}
739 
740 		val = clamp_val(val, VOLTAGE_MIN, VOLTAGE_MAX);
741 		return ltc2947_val_write(st, LTC2947_REG_VOLTAGE_THRE_H,
742 					 LTC2947_PAGE1, 2,
743 					 DIV_ROUND_CLOSEST(val, 2));
744 	case hwmon_in_min:
745 		if (channel == LTC2947_VOLTAGE_DVCC_CHAN) {
746 			val = clamp_val(val, VDVCC_MIN, VDVCC_MAX);
747 			return ltc2947_val_write(st, LTC2947_REG_DVCC_THRE_L,
748 						 LTC2947_PAGE1, 2,
749 						 DIV_ROUND_CLOSEST(val, 145));
750 		}
751 
752 		val = clamp_val(val, VOLTAGE_MIN, VOLTAGE_MAX);
753 		return ltc2947_val_write(st, LTC2947_REG_VOLTAGE_THRE_L,
754 					 LTC2947_PAGE1, 2,
755 					 DIV_ROUND_CLOSEST(val, 2));
756 	default:
757 		return -ENOTSUPP;
758 	}
759 }
760 
ltc2947_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)761 static int ltc2947_write(struct device *dev,
762 			 enum hwmon_sensor_types type,
763 			 u32 attr, int channel, long val)
764 {
765 	switch (type) {
766 	case hwmon_in:
767 		return ltc2947_write_in(dev, attr, val, channel);
768 	case hwmon_curr:
769 		return ltc2947_write_curr(dev, attr, val);
770 	case hwmon_power:
771 		return ltc2947_write_power(dev, attr, val);
772 	case hwmon_temp:
773 		return ltc2947_write_temp(dev, attr, val, channel);
774 	default:
775 		return -ENOTSUPP;
776 	}
777 }
778 
ltc2947_read_labels(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,const char ** str)779 static int ltc2947_read_labels(struct device *dev,
780 			       enum hwmon_sensor_types type,
781 			       u32 attr, int channel, const char **str)
782 {
783 	switch (type) {
784 	case hwmon_in:
785 		if (channel == LTC2947_VOLTAGE_DVCC_CHAN)
786 			*str = "DVCC";
787 		else
788 			*str = "VP-VM";
789 		return 0;
790 	case hwmon_curr:
791 		*str = "IP-IM";
792 		return 0;
793 	case hwmon_temp:
794 		if (channel == LTC2947_TEMP_FAN_CHAN)
795 			*str = "TEMPFAN";
796 		else
797 			*str = "Ambient";
798 		return 0;
799 	case hwmon_power:
800 		*str = "Power";
801 		return 0;
802 	default:
803 		return -ENOTSUPP;
804 	}
805 }
806 
ltc2947_in_is_visible(const u32 attr)807 static int ltc2947_in_is_visible(const u32 attr)
808 {
809 	switch (attr) {
810 	case hwmon_in_input:
811 	case hwmon_in_highest:
812 	case hwmon_in_lowest:
813 	case hwmon_in_max_alarm:
814 	case hwmon_in_min_alarm:
815 	case hwmon_in_label:
816 		return 0444;
817 	case hwmon_in_reset_history:
818 		return 0200;
819 	case hwmon_in_max:
820 	case hwmon_in_min:
821 		return 0644;
822 	default:
823 		return 0;
824 	}
825 }
826 
ltc2947_curr_is_visible(const u32 attr)827 static int ltc2947_curr_is_visible(const u32 attr)
828 {
829 	switch (attr) {
830 	case hwmon_curr_input:
831 	case hwmon_curr_highest:
832 	case hwmon_curr_lowest:
833 	case hwmon_curr_max_alarm:
834 	case hwmon_curr_min_alarm:
835 	case hwmon_curr_label:
836 		return 0444;
837 	case hwmon_curr_reset_history:
838 		return 0200;
839 	case hwmon_curr_max:
840 	case hwmon_curr_min:
841 		return 0644;
842 	default:
843 		return 0;
844 	}
845 }
846 
ltc2947_power_is_visible(const u32 attr)847 static int ltc2947_power_is_visible(const u32 attr)
848 {
849 	switch (attr) {
850 	case hwmon_power_input:
851 	case hwmon_power_input_highest:
852 	case hwmon_power_input_lowest:
853 	case hwmon_power_label:
854 	case hwmon_power_max_alarm:
855 	case hwmon_power_min_alarm:
856 		return 0444;
857 	case hwmon_power_reset_history:
858 		return 0200;
859 	case hwmon_power_max:
860 	case hwmon_power_min:
861 		return 0644;
862 	default:
863 		return 0;
864 	}
865 }
866 
ltc2947_temp_is_visible(const u32 attr)867 static int ltc2947_temp_is_visible(const u32 attr)
868 {
869 	switch (attr) {
870 	case hwmon_temp_input:
871 	case hwmon_temp_highest:
872 	case hwmon_temp_lowest:
873 	case hwmon_temp_max_alarm:
874 	case hwmon_temp_min_alarm:
875 	case hwmon_temp_label:
876 		return 0444;
877 	case hwmon_temp_reset_history:
878 		return 0200;
879 	case hwmon_temp_max:
880 	case hwmon_temp_min:
881 		return 0644;
882 	default:
883 		return 0;
884 	}
885 }
886 
ltc2947_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)887 static umode_t ltc2947_is_visible(const void *data,
888 				  enum hwmon_sensor_types type,
889 				  u32 attr, int channel)
890 {
891 	switch (type) {
892 	case hwmon_in:
893 		return ltc2947_in_is_visible(attr);
894 	case hwmon_curr:
895 		return ltc2947_curr_is_visible(attr);
896 	case hwmon_power:
897 		return ltc2947_power_is_visible(attr);
898 	case hwmon_temp:
899 		return ltc2947_temp_is_visible(attr);
900 	default:
901 		return 0;
902 	}
903 }
904 
905 static const struct hwmon_channel_info * const ltc2947_info[] = {
906 	HWMON_CHANNEL_INFO(in,
907 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
908 			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_RESET_HISTORY |
909 			   HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM |
910 			   HWMON_I_LABEL,
911 			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
912 			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_RESET_HISTORY |
913 			   HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM |
914 			   HWMON_I_LABEL),
915 	HWMON_CHANNEL_INFO(curr,
916 			   HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST |
917 			   HWMON_C_MAX | HWMON_C_MIN | HWMON_C_RESET_HISTORY |
918 			   HWMON_C_MIN_ALARM | HWMON_C_MAX_ALARM |
919 			   HWMON_C_LABEL),
920 	HWMON_CHANNEL_INFO(power,
921 			   HWMON_P_INPUT | HWMON_P_INPUT_LOWEST |
922 			   HWMON_P_INPUT_HIGHEST | HWMON_P_MAX | HWMON_P_MIN |
923 			   HWMON_P_RESET_HISTORY | HWMON_P_MAX_ALARM |
924 			   HWMON_P_MIN_ALARM | HWMON_P_LABEL),
925 	HWMON_CHANNEL_INFO(temp,
926 			   HWMON_T_INPUT | HWMON_T_LOWEST | HWMON_T_HIGHEST |
927 			   HWMON_T_MAX | HWMON_T_MIN | HWMON_T_RESET_HISTORY |
928 			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
929 			   HWMON_T_LABEL,
930 			   HWMON_T_MAX_ALARM | HWMON_T_MIN_ALARM | HWMON_T_MAX |
931 			   HWMON_T_MIN | HWMON_T_LABEL),
932 	NULL
933 };
934 
935 static const struct hwmon_ops ltc2947_hwmon_ops = {
936 	.is_visible = ltc2947_is_visible,
937 	.read = ltc2947_read,
938 	.write = ltc2947_write,
939 	.read_string = ltc2947_read_labels,
940 };
941 
942 static const struct hwmon_chip_info ltc2947_chip_info = {
943 	.ops = &ltc2947_hwmon_ops,
944 	.info = ltc2947_info,
945 };
946 
947 /* energy attributes are 6bytes wide so we need u64 */
948 static SENSOR_DEVICE_ATTR(energy1_input, 0444, ltc2947_show_value, NULL,
949 			  LTC2947_REG_ENERGY1);
950 static SENSOR_DEVICE_ATTR(energy2_input, 0444, ltc2947_show_value, NULL,
951 			  LTC2947_REG_ENERGY2);
952 
953 static struct attribute *ltc2947_attrs[] = {
954 	&sensor_dev_attr_energy1_input.dev_attr.attr,
955 	&sensor_dev_attr_energy2_input.dev_attr.attr,
956 	NULL,
957 };
958 ATTRIBUTE_GROUPS(ltc2947);
959 
ltc2947_setup(struct ltc2947_data * st)960 static int ltc2947_setup(struct ltc2947_data *st)
961 {
962 	int ret;
963 	struct clk *extclk;
964 	u32 dummy, deadband, pol;
965 	u32 accum[2];
966 
967 	/* clear status register by reading it */
968 	ret = regmap_read(st->map, LTC2947_REG_STATUS, &dummy);
969 	if (ret)
970 		return ret;
971 	/*
972 	 * Set max/min for power here since the default values x scale
973 	 * would overflow on 32bit arch
974 	 */
975 	ret = ltc2947_val_write(st, LTC2947_REG_POWER_THRE_H, LTC2947_PAGE1, 2,
976 				POWER_MAX / 200000);
977 	if (ret)
978 		return ret;
979 
980 	ret = ltc2947_val_write(st, LTC2947_REG_POWER_THRE_L, LTC2947_PAGE1, 2,
981 				POWER_MIN / 200000);
982 	if (ret)
983 		return ret;
984 
985 	/* check external clock presence */
986 	extclk = devm_clk_get_optional_enabled(st->dev, NULL);
987 	if (IS_ERR(extclk))
988 		return dev_err_probe(st->dev, PTR_ERR(extclk),
989 				     "Failed to get external clock\n");
990 
991 	if (extclk) {
992 		unsigned long rate_hz;
993 		u8 pre = 0, div, tbctl;
994 		u64 aux;
995 
996 		/* let's calculate and set the right valus in TBCTL */
997 		rate_hz = clk_get_rate(extclk);
998 		if (rate_hz < LTC2947_CLK_MIN || rate_hz > LTC2947_CLK_MAX) {
999 			dev_err(st->dev, "Invalid rate:%lu for external clock",
1000 				rate_hz);
1001 			return -EINVAL;
1002 		}
1003 
1004 		/* as in table 1 of the datasheet */
1005 		if (rate_hz >= LTC2947_CLK_MIN && rate_hz <= 1000000)
1006 			pre = 0;
1007 		else if (rate_hz > 1000000 && rate_hz <= 2000000)
1008 			pre = 1;
1009 		else if (rate_hz > 2000000 && rate_hz <= 4000000)
1010 			pre = 2;
1011 		else if (rate_hz > 4000000 && rate_hz <= 8000000)
1012 			pre = 3;
1013 		else if (rate_hz > 8000000 && rate_hz <= 16000000)
1014 			pre = 4;
1015 		else if (rate_hz > 16000000 && rate_hz <= LTC2947_CLK_MAX)
1016 			pre = 5;
1017 		/*
1018 		 * Div is given by:
1019 		 *	floor(fref / (2^PRE * 32768))
1020 		 */
1021 		div = rate_hz / ((1 << pre) * 32768);
1022 		tbctl = LTC2947_PRE(pre) | LTC2947_DIV(div);
1023 
1024 		ret = regmap_write(st->map, LTC2947_REG_TBCTL, tbctl);
1025 		if (ret)
1026 			return ret;
1027 		/*
1028 		 * The energy lsb is given by (in W*s):
1029 		 *      06416 * (1/fref) * 2^PRE * (DIV + 1)
1030 		 * The value is multiplied by 10E9
1031 		 */
1032 		aux = (div + 1) * ((1 << pre) * 641600000ULL);
1033 		st->lsb_energy = DIV_ROUND_CLOSEST_ULL(aux, rate_hz);
1034 	} else {
1035 		/* 19.89E-6 * 10E9 */
1036 		st->lsb_energy = 19890;
1037 	}
1038 	ret = device_property_read_u32_array(st->dev, "adi,accumulator-ctl-pol",
1039 					     accum, ARRAY_SIZE(accum));
1040 	if (!ret) {
1041 		u32 accum_reg = LTC2947_ACCUM_POL_1(accum[0]) |
1042 				LTC2947_ACCUM_POL_2(accum[1]);
1043 
1044 		ret = regmap_write(st->map, LTC2947_REG_ACCUM_POL, accum_reg);
1045 		if (ret)
1046 			return ret;
1047 	}
1048 	ret = device_property_read_u32(st->dev,
1049 				       "adi,accumulation-deadband-microamp",
1050 				       &deadband);
1051 	if (!ret) {
1052 		/* the LSB is the same as the current, so 3mA */
1053 		ret = regmap_write(st->map, LTC2947_REG_ACCUM_DEADBAND,
1054 				   deadband / (1000 * 3));
1055 		if (ret)
1056 			return ret;
1057 	}
1058 	/* check gpio cfg */
1059 	ret = device_property_read_u32(st->dev, "adi,gpio-out-pol", &pol);
1060 	if (!ret) {
1061 		/* setup GPIO as output */
1062 		u32 gpio_ctl = LTC2947_GPIO_EN(1) | LTC2947_GPIO_FAN_EN(1) |
1063 			LTC2947_GPIO_FAN_POL(pol);
1064 
1065 		st->gpio_out = true;
1066 		ret = regmap_write(st->map, LTC2947_REG_GPIOSTATCTL, gpio_ctl);
1067 		if (ret)
1068 			return ret;
1069 	}
1070 	ret = device_property_read_u32_array(st->dev, "adi,gpio-in-accum",
1071 					     accum, ARRAY_SIZE(accum));
1072 	if (!ret) {
1073 		/*
1074 		 * Setup the accum options. The gpioctl is already defined as
1075 		 * input by default.
1076 		 */
1077 		u32 accum_val = LTC2947_ACCUM_POL_1(accum[0]) |
1078 				LTC2947_ACCUM_POL_2(accum[1]);
1079 
1080 		if (st->gpio_out) {
1081 			dev_err(st->dev,
1082 				"Cannot have input gpio config if already configured as output");
1083 			return -EINVAL;
1084 		}
1085 
1086 		ret = regmap_write(st->map, LTC2947_REG_GPIO_ACCUM, accum_val);
1087 		if (ret)
1088 			return ret;
1089 	}
1090 
1091 	/* set continuos mode */
1092 	return regmap_update_bits(st->map, LTC2947_REG_CTRL,
1093 				  LTC2947_CONT_MODE_MASK, LTC2947_CONT_MODE(1));
1094 }
1095 
ltc2947_core_probe(struct regmap * map,const char * name)1096 int ltc2947_core_probe(struct regmap *map, const char *name)
1097 {
1098 	struct ltc2947_data *st;
1099 	struct device *dev = regmap_get_device(map);
1100 	struct device *hwmon;
1101 	int ret;
1102 
1103 	st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
1104 	if (!st)
1105 		return -ENOMEM;
1106 
1107 	st->map = map;
1108 	st->dev = dev;
1109 	dev_set_drvdata(dev, st);
1110 	mutex_init(&st->lock);
1111 
1112 	ret = ltc2947_setup(st);
1113 	if (ret)
1114 		return ret;
1115 
1116 	hwmon = devm_hwmon_device_register_with_info(dev, name, st,
1117 						     &ltc2947_chip_info,
1118 						     ltc2947_groups);
1119 	return PTR_ERR_OR_ZERO(hwmon);
1120 }
1121 EXPORT_SYMBOL_GPL(ltc2947_core_probe);
1122 
ltc2947_resume(struct device * dev)1123 static int ltc2947_resume(struct device *dev)
1124 {
1125 	struct ltc2947_data *st = dev_get_drvdata(dev);
1126 	u32 ctrl = 0;
1127 	int ret;
1128 
1129 	/* dummy read to wake the device */
1130 	ret = regmap_read(st->map, LTC2947_REG_CTRL, &ctrl);
1131 	if (ret)
1132 		return ret;
1133 	/*
1134 	 * Wait for the device. It takes 100ms to wake up so, 10ms extra
1135 	 * should be enough.
1136 	 */
1137 	msleep(110);
1138 	ret = regmap_read(st->map, LTC2947_REG_CTRL, &ctrl);
1139 	if (ret)
1140 		return ret;
1141 	/* ctrl should be 0 */
1142 	if (ctrl != 0) {
1143 		dev_err(st->dev, "Device failed to wake up, ctl:%02X\n", ctrl);
1144 		return -ETIMEDOUT;
1145 	}
1146 
1147 	/* set continuous mode */
1148 	return regmap_update_bits(st->map, LTC2947_REG_CTRL,
1149 				  LTC2947_CONT_MODE_MASK, LTC2947_CONT_MODE(1));
1150 }
1151 
ltc2947_suspend(struct device * dev)1152 static int ltc2947_suspend(struct device *dev)
1153 {
1154 	struct ltc2947_data *st = dev_get_drvdata(dev);
1155 
1156 	return regmap_update_bits(st->map, LTC2947_REG_CTRL,
1157 				  LTC2947_SHUTDOWN_MASK, 1);
1158 }
1159 
1160 EXPORT_SIMPLE_DEV_PM_OPS(ltc2947_pm_ops, ltc2947_suspend, ltc2947_resume);
1161 
1162 const struct of_device_id ltc2947_of_match[] = {
1163 	{ .compatible = "adi,ltc2947" },
1164 	{}
1165 };
1166 EXPORT_SYMBOL_GPL(ltc2947_of_match);
1167 MODULE_DEVICE_TABLE(of, ltc2947_of_match);
1168 
1169 MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>");
1170 MODULE_DESCRIPTION("LTC2947 power and energy monitor core driver");
1171 MODULE_LICENSE("GPL");
1172