xref: /linux/drivers/hwmon/ina3221.c (revision 4e0ae876f77bc01a7e77724dea57b4b82bd53244)
1 /*
2  * INA3221 Triple Current/Voltage Monitor
3  *
4  * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
5  *	Andrew F. Davis <afd@ti.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  */
16 
17 #include <linux/hwmon.h>
18 #include <linux/hwmon-sysfs.h>
19 #include <linux/i2c.h>
20 #include <linux/module.h>
21 #include <linux/mutex.h>
22 #include <linux/of.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/regmap.h>
25 
26 #define INA3221_DRIVER_NAME		"ina3221"
27 
28 #define INA3221_CONFIG			0x00
29 #define INA3221_SHUNT1			0x01
30 #define INA3221_BUS1			0x02
31 #define INA3221_SHUNT2			0x03
32 #define INA3221_BUS2			0x04
33 #define INA3221_SHUNT3			0x05
34 #define INA3221_BUS3			0x06
35 #define INA3221_CRIT1			0x07
36 #define INA3221_WARN1			0x08
37 #define INA3221_CRIT2			0x09
38 #define INA3221_WARN2			0x0a
39 #define INA3221_CRIT3			0x0b
40 #define INA3221_WARN3			0x0c
41 #define INA3221_MASK_ENABLE		0x0f
42 
43 #define INA3221_CONFIG_MODE_MASK	GENMASK(2, 0)
44 #define INA3221_CONFIG_MODE_POWERDOWN	0
45 #define INA3221_CONFIG_MODE_SHUNT	BIT(0)
46 #define INA3221_CONFIG_MODE_BUS		BIT(1)
47 #define INA3221_CONFIG_MODE_CONTINUOUS	BIT(2)
48 #define INA3221_CONFIG_VSH_CT_SHIFT	3
49 #define INA3221_CONFIG_VSH_CT_MASK	GENMASK(5, 3)
50 #define INA3221_CONFIG_VSH_CT(x)	(((x) & GENMASK(5, 3)) >> 3)
51 #define INA3221_CONFIG_VBUS_CT_SHIFT	6
52 #define INA3221_CONFIG_VBUS_CT_MASK	GENMASK(8, 6)
53 #define INA3221_CONFIG_VBUS_CT(x)	(((x) & GENMASK(8, 6)) >> 6)
54 #define INA3221_CONFIG_CHs_EN_MASK	GENMASK(14, 12)
55 #define INA3221_CONFIG_CHx_EN(x)	BIT(14 - (x))
56 
57 #define INA3221_CONFIG_DEFAULT		0x7127
58 #define INA3221_RSHUNT_DEFAULT		10000
59 
60 enum ina3221_fields {
61 	/* Configuration */
62 	F_RST,
63 
64 	/* Status Flags */
65 	F_CVRF,
66 
67 	/* Alert Flags */
68 	F_WF3, F_WF2, F_WF1,
69 	F_CF3, F_CF2, F_CF1,
70 
71 	/* sentinel */
72 	F_MAX_FIELDS
73 };
74 
75 static const struct reg_field ina3221_reg_fields[] = {
76 	[F_RST] = REG_FIELD(INA3221_CONFIG, 15, 15),
77 
78 	[F_CVRF] = REG_FIELD(INA3221_MASK_ENABLE, 0, 0),
79 	[F_WF3] = REG_FIELD(INA3221_MASK_ENABLE, 3, 3),
80 	[F_WF2] = REG_FIELD(INA3221_MASK_ENABLE, 4, 4),
81 	[F_WF1] = REG_FIELD(INA3221_MASK_ENABLE, 5, 5),
82 	[F_CF3] = REG_FIELD(INA3221_MASK_ENABLE, 7, 7),
83 	[F_CF2] = REG_FIELD(INA3221_MASK_ENABLE, 8, 8),
84 	[F_CF1] = REG_FIELD(INA3221_MASK_ENABLE, 9, 9),
85 };
86 
87 enum ina3221_channels {
88 	INA3221_CHANNEL1,
89 	INA3221_CHANNEL2,
90 	INA3221_CHANNEL3,
91 	INA3221_NUM_CHANNELS
92 };
93 
94 /**
95  * struct ina3221_input - channel input source specific information
96  * @label: label of channel input source
97  * @shunt_resistor: shunt resistor value of channel input source
98  * @disconnected: connection status of channel input source
99  */
100 struct ina3221_input {
101 	const char *label;
102 	int shunt_resistor;
103 	bool disconnected;
104 };
105 
106 /**
107  * struct ina3221_data - device specific information
108  * @pm_dev: Device pointer for pm runtime
109  * @regmap: Register map of the device
110  * @fields: Register fields of the device
111  * @inputs: Array of channel input source specific structures
112  * @lock: mutex lock to serialize sysfs attribute accesses
113  * @reg_config: Register value of INA3221_CONFIG
114  * @single_shot: running in single-shot operating mode
115  */
116 struct ina3221_data {
117 	struct device *pm_dev;
118 	struct regmap *regmap;
119 	struct regmap_field *fields[F_MAX_FIELDS];
120 	struct ina3221_input inputs[INA3221_NUM_CHANNELS];
121 	struct mutex lock;
122 	u32 reg_config;
123 
124 	bool single_shot;
125 };
126 
127 static inline bool ina3221_is_enabled(struct ina3221_data *ina, int channel)
128 {
129 	return pm_runtime_active(ina->pm_dev) &&
130 	       (ina->reg_config & INA3221_CONFIG_CHx_EN(channel));
131 }
132 
133 /* Lookup table for Bus and Shunt conversion times in usec */
134 static const u16 ina3221_conv_time[] = {
135 	140, 204, 332, 588, 1100, 2116, 4156, 8244,
136 };
137 
138 static inline int ina3221_wait_for_data(struct ina3221_data *ina)
139 {
140 	u32 channels = hweight16(ina->reg_config & INA3221_CONFIG_CHs_EN_MASK);
141 	u32 vbus_ct_idx = INA3221_CONFIG_VBUS_CT(ina->reg_config);
142 	u32 vsh_ct_idx = INA3221_CONFIG_VSH_CT(ina->reg_config);
143 	u32 vbus_ct = ina3221_conv_time[vbus_ct_idx];
144 	u32 vsh_ct = ina3221_conv_time[vsh_ct_idx];
145 	u32 wait, cvrf;
146 
147 	/* Calculate total conversion time */
148 	wait = channels * (vbus_ct + vsh_ct);
149 
150 	/* Polling the CVRF bit to make sure read data is ready */
151 	return regmap_field_read_poll_timeout(ina->fields[F_CVRF],
152 					      cvrf, cvrf, wait, 100000);
153 }
154 
155 static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
156 			      int *val)
157 {
158 	unsigned int regval;
159 	int ret;
160 
161 	ret = regmap_read(ina->regmap, reg, &regval);
162 	if (ret)
163 		return ret;
164 
165 	*val = sign_extend32(regval >> 3, 12);
166 
167 	return 0;
168 }
169 
170 static const u8 ina3221_in_reg[] = {
171 	INA3221_BUS1,
172 	INA3221_BUS2,
173 	INA3221_BUS3,
174 	INA3221_SHUNT1,
175 	INA3221_SHUNT2,
176 	INA3221_SHUNT3,
177 };
178 
179 static int ina3221_read_in(struct device *dev, u32 attr, int channel, long *val)
180 {
181 	const bool is_shunt = channel > INA3221_CHANNEL3;
182 	struct ina3221_data *ina = dev_get_drvdata(dev);
183 	u8 reg = ina3221_in_reg[channel];
184 	int regval, ret;
185 
186 	/* Translate shunt channel index to sensor channel index */
187 	channel %= INA3221_NUM_CHANNELS;
188 
189 	switch (attr) {
190 	case hwmon_in_input:
191 		if (!ina3221_is_enabled(ina, channel))
192 			return -ENODATA;
193 
194 		/* Write CONFIG register to trigger a single-shot measurement */
195 		if (ina->single_shot)
196 			regmap_write(ina->regmap, INA3221_CONFIG,
197 				     ina->reg_config);
198 
199 		ret = ina3221_wait_for_data(ina);
200 		if (ret)
201 			return ret;
202 
203 		ret = ina3221_read_value(ina, reg, &regval);
204 		if (ret)
205 			return ret;
206 
207 		/*
208 		 * Scale of shunt voltage (uV): LSB is 40uV
209 		 * Scale of bus voltage (mV): LSB is 8mV
210 		 */
211 		*val = regval * (is_shunt ? 40 : 8);
212 		return 0;
213 	case hwmon_in_enable:
214 		*val = ina3221_is_enabled(ina, channel);
215 		return 0;
216 	default:
217 		return -EOPNOTSUPP;
218 	}
219 }
220 
221 static const u8 ina3221_curr_reg[][INA3221_NUM_CHANNELS] = {
222 	[hwmon_curr_input] = { INA3221_SHUNT1, INA3221_SHUNT2, INA3221_SHUNT3 },
223 	[hwmon_curr_max] = { INA3221_WARN1, INA3221_WARN2, INA3221_WARN3 },
224 	[hwmon_curr_crit] = { INA3221_CRIT1, INA3221_CRIT2, INA3221_CRIT3 },
225 	[hwmon_curr_max_alarm] = { F_WF1, F_WF2, F_WF3 },
226 	[hwmon_curr_crit_alarm] = { F_CF1, F_CF2, F_CF3 },
227 };
228 
229 static int ina3221_read_curr(struct device *dev, u32 attr,
230 			     int channel, long *val)
231 {
232 	struct ina3221_data *ina = dev_get_drvdata(dev);
233 	struct ina3221_input *input = &ina->inputs[channel];
234 	int resistance_uo = input->shunt_resistor;
235 	u8 reg = ina3221_curr_reg[attr][channel];
236 	int regval, voltage_nv, ret;
237 
238 	switch (attr) {
239 	case hwmon_curr_input:
240 		if (!ina3221_is_enabled(ina, channel))
241 			return -ENODATA;
242 
243 		/* Write CONFIG register to trigger a single-shot measurement */
244 		if (ina->single_shot)
245 			regmap_write(ina->regmap, INA3221_CONFIG,
246 				     ina->reg_config);
247 
248 		ret = ina3221_wait_for_data(ina);
249 		if (ret)
250 			return ret;
251 
252 		/* fall through */
253 	case hwmon_curr_crit:
254 	case hwmon_curr_max:
255 		ret = ina3221_read_value(ina, reg, &regval);
256 		if (ret)
257 			return ret;
258 
259 		/* Scale of shunt voltage: LSB is 40uV (40000nV) */
260 		voltage_nv = regval * 40000;
261 		/* Return current in mA */
262 		*val = DIV_ROUND_CLOSEST(voltage_nv, resistance_uo);
263 		return 0;
264 	case hwmon_curr_crit_alarm:
265 	case hwmon_curr_max_alarm:
266 		/* No actual register read if channel is disabled */
267 		if (!ina3221_is_enabled(ina, channel)) {
268 			/* Return 0 for alert flags */
269 			*val = 0;
270 			return 0;
271 		}
272 		ret = regmap_field_read(ina->fields[reg], &regval);
273 		if (ret)
274 			return ret;
275 		*val = regval;
276 		return 0;
277 	default:
278 		return -EOPNOTSUPP;
279 	}
280 }
281 
282 static int ina3221_write_curr(struct device *dev, u32 attr,
283 			      int channel, long val)
284 {
285 	struct ina3221_data *ina = dev_get_drvdata(dev);
286 	struct ina3221_input *input = &ina->inputs[channel];
287 	int resistance_uo = input->shunt_resistor;
288 	u8 reg = ina3221_curr_reg[attr][channel];
289 	int regval, current_ma, voltage_uv;
290 
291 	/* clamp current */
292 	current_ma = clamp_val(val,
293 			       INT_MIN / resistance_uo,
294 			       INT_MAX / resistance_uo);
295 
296 	voltage_uv = DIV_ROUND_CLOSEST(current_ma * resistance_uo, 1000);
297 
298 	/* clamp voltage */
299 	voltage_uv = clamp_val(voltage_uv, -163800, 163800);
300 
301 	/* 1 / 40uV(scale) << 3(register shift) = 5 */
302 	regval = DIV_ROUND_CLOSEST(voltage_uv, 5) & 0xfff8;
303 
304 	return regmap_write(ina->regmap, reg, regval);
305 }
306 
307 static int ina3221_write_enable(struct device *dev, int channel, bool enable)
308 {
309 	struct ina3221_data *ina = dev_get_drvdata(dev);
310 	u16 config, mask = INA3221_CONFIG_CHx_EN(channel);
311 	u16 config_old = ina->reg_config & mask;
312 	int ret;
313 
314 	config = enable ? mask : 0;
315 
316 	/* Bypass if enable status is not being changed */
317 	if (config_old == config)
318 		return 0;
319 
320 	/* For enabling routine, increase refcount and resume() at first */
321 	if (enable) {
322 		ret = pm_runtime_get_sync(ina->pm_dev);
323 		if (ret < 0) {
324 			dev_err(dev, "Failed to get PM runtime\n");
325 			return ret;
326 		}
327 	}
328 
329 	/* Enable or disable the channel */
330 	ret = regmap_update_bits(ina->regmap, INA3221_CONFIG, mask, config);
331 	if (ret)
332 		goto fail;
333 
334 	/* Cache the latest config register value */
335 	ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
336 	if (ret)
337 		goto fail;
338 
339 	/* For disabling routine, decrease refcount or suspend() at last */
340 	if (!enable)
341 		pm_runtime_put_sync(ina->pm_dev);
342 
343 	return 0;
344 
345 fail:
346 	if (enable) {
347 		dev_err(dev, "Failed to enable channel %d: error %d\n",
348 			channel, ret);
349 		pm_runtime_put_sync(ina->pm_dev);
350 	}
351 
352 	return ret;
353 }
354 
355 static int ina3221_read(struct device *dev, enum hwmon_sensor_types type,
356 			u32 attr, int channel, long *val)
357 {
358 	struct ina3221_data *ina = dev_get_drvdata(dev);
359 	int ret;
360 
361 	mutex_lock(&ina->lock);
362 
363 	switch (type) {
364 	case hwmon_in:
365 		/* 0-align channel ID */
366 		ret = ina3221_read_in(dev, attr, channel - 1, val);
367 		break;
368 	case hwmon_curr:
369 		ret = ina3221_read_curr(dev, attr, channel, val);
370 		break;
371 	default:
372 		ret = -EOPNOTSUPP;
373 		break;
374 	}
375 
376 	mutex_unlock(&ina->lock);
377 
378 	return ret;
379 }
380 
381 static int ina3221_write(struct device *dev, enum hwmon_sensor_types type,
382 			 u32 attr, int channel, long val)
383 {
384 	struct ina3221_data *ina = dev_get_drvdata(dev);
385 	int ret;
386 
387 	mutex_lock(&ina->lock);
388 
389 	switch (type) {
390 	case hwmon_in:
391 		/* 0-align channel ID */
392 		ret = ina3221_write_enable(dev, channel - 1, val);
393 		break;
394 	case hwmon_curr:
395 		ret = ina3221_write_curr(dev, attr, channel, val);
396 		break;
397 	default:
398 		ret = -EOPNOTSUPP;
399 		break;
400 	}
401 
402 	mutex_unlock(&ina->lock);
403 
404 	return ret;
405 }
406 
407 static int ina3221_read_string(struct device *dev, enum hwmon_sensor_types type,
408 			       u32 attr, int channel, const char **str)
409 {
410 	struct ina3221_data *ina = dev_get_drvdata(dev);
411 	int index = channel - 1;
412 
413 	*str = ina->inputs[index].label;
414 
415 	return 0;
416 }
417 
418 static umode_t ina3221_is_visible(const void *drvdata,
419 				  enum hwmon_sensor_types type,
420 				  u32 attr, int channel)
421 {
422 	const struct ina3221_data *ina = drvdata;
423 	const struct ina3221_input *input = NULL;
424 
425 	switch (type) {
426 	case hwmon_in:
427 		/* Ignore in0_ */
428 		if (channel == 0)
429 			return 0;
430 
431 		switch (attr) {
432 		case hwmon_in_label:
433 			if (channel - 1 <= INA3221_CHANNEL3)
434 				input = &ina->inputs[channel - 1];
435 			/* Hide label node if label is not provided */
436 			return (input && input->label) ? 0444 : 0;
437 		case hwmon_in_input:
438 			return 0444;
439 		case hwmon_in_enable:
440 			return 0644;
441 		default:
442 			return 0;
443 		}
444 	case hwmon_curr:
445 		switch (attr) {
446 		case hwmon_curr_input:
447 		case hwmon_curr_crit_alarm:
448 		case hwmon_curr_max_alarm:
449 			return 0444;
450 		case hwmon_curr_crit:
451 		case hwmon_curr_max:
452 			return 0644;
453 		default:
454 			return 0;
455 		}
456 	default:
457 		return 0;
458 	}
459 }
460 
461 static const u32 ina3221_in_config[] = {
462 	/* 0: dummy, skipped in is_visible */
463 	HWMON_I_INPUT,
464 	/* 1-3: input voltage Channels */
465 	HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
466 	HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
467 	HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
468 	/* 4-6: shunt voltage Channels */
469 	HWMON_I_INPUT,
470 	HWMON_I_INPUT,
471 	HWMON_I_INPUT,
472 	0
473 };
474 
475 static const struct hwmon_channel_info ina3221_in = {
476 	.type = hwmon_in,
477 	.config = ina3221_in_config,
478 };
479 
480 #define INA3221_HWMON_CURR_CONFIG (HWMON_C_INPUT | \
481 				   HWMON_C_CRIT | HWMON_C_CRIT_ALARM | \
482 				   HWMON_C_MAX | HWMON_C_MAX_ALARM)
483 
484 static const u32 ina3221_curr_config[] = {
485 	INA3221_HWMON_CURR_CONFIG,
486 	INA3221_HWMON_CURR_CONFIG,
487 	INA3221_HWMON_CURR_CONFIG,
488 	0
489 };
490 
491 static const struct hwmon_channel_info ina3221_curr = {
492 	.type = hwmon_curr,
493 	.config = ina3221_curr_config,
494 };
495 
496 static const struct hwmon_channel_info *ina3221_info[] = {
497 	&ina3221_in,
498 	&ina3221_curr,
499 	NULL
500 };
501 
502 static const struct hwmon_ops ina3221_hwmon_ops = {
503 	.is_visible = ina3221_is_visible,
504 	.read_string = ina3221_read_string,
505 	.read = ina3221_read,
506 	.write = ina3221_write,
507 };
508 
509 static const struct hwmon_chip_info ina3221_chip_info = {
510 	.ops = &ina3221_hwmon_ops,
511 	.info = ina3221_info,
512 };
513 
514 /* Extra attribute groups */
515 static ssize_t ina3221_shunt_show(struct device *dev,
516 				  struct device_attribute *attr, char *buf)
517 {
518 	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
519 	struct ina3221_data *ina = dev_get_drvdata(dev);
520 	unsigned int channel = sd_attr->index;
521 	struct ina3221_input *input = &ina->inputs[channel];
522 
523 	return snprintf(buf, PAGE_SIZE, "%d\n", input->shunt_resistor);
524 }
525 
526 static ssize_t ina3221_shunt_store(struct device *dev,
527 				   struct device_attribute *attr,
528 				   const char *buf, size_t count)
529 {
530 	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
531 	struct ina3221_data *ina = dev_get_drvdata(dev);
532 	unsigned int channel = sd_attr->index;
533 	struct ina3221_input *input = &ina->inputs[channel];
534 	int val;
535 	int ret;
536 
537 	ret = kstrtoint(buf, 0, &val);
538 	if (ret)
539 		return ret;
540 
541 	val = clamp_val(val, 1, INT_MAX);
542 
543 	input->shunt_resistor = val;
544 
545 	return count;
546 }
547 
548 /* shunt resistance */
549 static SENSOR_DEVICE_ATTR_RW(shunt1_resistor, ina3221_shunt, INA3221_CHANNEL1);
550 static SENSOR_DEVICE_ATTR_RW(shunt2_resistor, ina3221_shunt, INA3221_CHANNEL2);
551 static SENSOR_DEVICE_ATTR_RW(shunt3_resistor, ina3221_shunt, INA3221_CHANNEL3);
552 
553 static struct attribute *ina3221_attrs[] = {
554 	&sensor_dev_attr_shunt1_resistor.dev_attr.attr,
555 	&sensor_dev_attr_shunt2_resistor.dev_attr.attr,
556 	&sensor_dev_attr_shunt3_resistor.dev_attr.attr,
557 	NULL,
558 };
559 ATTRIBUTE_GROUPS(ina3221);
560 
561 static const struct regmap_range ina3221_yes_ranges[] = {
562 	regmap_reg_range(INA3221_CONFIG, INA3221_BUS3),
563 	regmap_reg_range(INA3221_MASK_ENABLE, INA3221_MASK_ENABLE),
564 };
565 
566 static const struct regmap_access_table ina3221_volatile_table = {
567 	.yes_ranges = ina3221_yes_ranges,
568 	.n_yes_ranges = ARRAY_SIZE(ina3221_yes_ranges),
569 };
570 
571 static const struct regmap_config ina3221_regmap_config = {
572 	.reg_bits = 8,
573 	.val_bits = 16,
574 
575 	.cache_type = REGCACHE_RBTREE,
576 	.volatile_table = &ina3221_volatile_table,
577 };
578 
579 static int ina3221_probe_child_from_dt(struct device *dev,
580 				       struct device_node *child,
581 				       struct ina3221_data *ina)
582 {
583 	struct ina3221_input *input;
584 	u32 val;
585 	int ret;
586 
587 	ret = of_property_read_u32(child, "reg", &val);
588 	if (ret) {
589 		dev_err(dev, "missing reg property of %pOFn\n", child);
590 		return ret;
591 	} else if (val > INA3221_CHANNEL3) {
592 		dev_err(dev, "invalid reg %d of %pOFn\n", val, child);
593 		return ret;
594 	}
595 
596 	input = &ina->inputs[val];
597 
598 	/* Log the disconnected channel input */
599 	if (!of_device_is_available(child)) {
600 		input->disconnected = true;
601 		return 0;
602 	}
603 
604 	/* Save the connected input label if available */
605 	of_property_read_string(child, "label", &input->label);
606 
607 	/* Overwrite default shunt resistor value optionally */
608 	if (!of_property_read_u32(child, "shunt-resistor-micro-ohms", &val)) {
609 		if (val < 1 || val > INT_MAX) {
610 			dev_err(dev, "invalid shunt resistor value %u of %pOFn\n",
611 				val, child);
612 			return -EINVAL;
613 		}
614 		input->shunt_resistor = val;
615 	}
616 
617 	return 0;
618 }
619 
620 static int ina3221_probe_from_dt(struct device *dev, struct ina3221_data *ina)
621 {
622 	const struct device_node *np = dev->of_node;
623 	struct device_node *child;
624 	int ret;
625 
626 	/* Compatible with non-DT platforms */
627 	if (!np)
628 		return 0;
629 
630 	ina->single_shot = of_property_read_bool(np, "ti,single-shot");
631 
632 	for_each_child_of_node(np, child) {
633 		ret = ina3221_probe_child_from_dt(dev, child, ina);
634 		if (ret)
635 			return ret;
636 	}
637 
638 	return 0;
639 }
640 
641 static int ina3221_probe(struct i2c_client *client,
642 			 const struct i2c_device_id *id)
643 {
644 	struct device *dev = &client->dev;
645 	struct ina3221_data *ina;
646 	struct device *hwmon_dev;
647 	int i, ret;
648 
649 	ina = devm_kzalloc(dev, sizeof(*ina), GFP_KERNEL);
650 	if (!ina)
651 		return -ENOMEM;
652 
653 	ina->regmap = devm_regmap_init_i2c(client, &ina3221_regmap_config);
654 	if (IS_ERR(ina->regmap)) {
655 		dev_err(dev, "Unable to allocate register map\n");
656 		return PTR_ERR(ina->regmap);
657 	}
658 
659 	for (i = 0; i < F_MAX_FIELDS; i++) {
660 		ina->fields[i] = devm_regmap_field_alloc(dev,
661 							 ina->regmap,
662 							 ina3221_reg_fields[i]);
663 		if (IS_ERR(ina->fields[i])) {
664 			dev_err(dev, "Unable to allocate regmap fields\n");
665 			return PTR_ERR(ina->fields[i]);
666 		}
667 	}
668 
669 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
670 		ina->inputs[i].shunt_resistor = INA3221_RSHUNT_DEFAULT;
671 
672 	ret = ina3221_probe_from_dt(dev, ina);
673 	if (ret) {
674 		dev_err(dev, "Unable to probe from device tree\n");
675 		return ret;
676 	}
677 
678 	/* The driver will be reset, so use reset value */
679 	ina->reg_config = INA3221_CONFIG_DEFAULT;
680 
681 	/* Clear continuous bit to use single-shot mode */
682 	if (ina->single_shot)
683 		ina->reg_config &= ~INA3221_CONFIG_MODE_CONTINUOUS;
684 
685 	/* Disable channels if their inputs are disconnected */
686 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
687 		if (ina->inputs[i].disconnected)
688 			ina->reg_config &= ~INA3221_CONFIG_CHx_EN(i);
689 	}
690 
691 	ina->pm_dev = dev;
692 	mutex_init(&ina->lock);
693 	dev_set_drvdata(dev, ina);
694 
695 	/* Enable PM runtime -- status is suspended by default */
696 	pm_runtime_enable(ina->pm_dev);
697 
698 	/* Initialize (resume) the device */
699 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
700 		if (ina->inputs[i].disconnected)
701 			continue;
702 		/* Match the refcount with number of enabled channels */
703 		ret = pm_runtime_get_sync(ina->pm_dev);
704 		if (ret < 0)
705 			goto fail;
706 	}
707 
708 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, ina,
709 							 &ina3221_chip_info,
710 							 ina3221_groups);
711 	if (IS_ERR(hwmon_dev)) {
712 		dev_err(dev, "Unable to register hwmon device\n");
713 		ret = PTR_ERR(hwmon_dev);
714 		goto fail;
715 	}
716 
717 	return 0;
718 
719 fail:
720 	pm_runtime_disable(ina->pm_dev);
721 	pm_runtime_set_suspended(ina->pm_dev);
722 	/* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
723 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
724 		pm_runtime_put_noidle(ina->pm_dev);
725 	mutex_destroy(&ina->lock);
726 
727 	return ret;
728 }
729 
730 static int ina3221_remove(struct i2c_client *client)
731 {
732 	struct ina3221_data *ina = dev_get_drvdata(&client->dev);
733 	int i;
734 
735 	pm_runtime_disable(ina->pm_dev);
736 	pm_runtime_set_suspended(ina->pm_dev);
737 
738 	/* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
739 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
740 		pm_runtime_put_noidle(ina->pm_dev);
741 
742 	mutex_destroy(&ina->lock);
743 
744 	return 0;
745 }
746 
747 static int __maybe_unused ina3221_suspend(struct device *dev)
748 {
749 	struct ina3221_data *ina = dev_get_drvdata(dev);
750 	int ret;
751 
752 	/* Save config register value and enable cache-only */
753 	ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
754 	if (ret)
755 		return ret;
756 
757 	/* Set to power-down mode for power saving */
758 	ret = regmap_update_bits(ina->regmap, INA3221_CONFIG,
759 				 INA3221_CONFIG_MODE_MASK,
760 				 INA3221_CONFIG_MODE_POWERDOWN);
761 	if (ret)
762 		return ret;
763 
764 	regcache_cache_only(ina->regmap, true);
765 	regcache_mark_dirty(ina->regmap);
766 
767 	return 0;
768 }
769 
770 static int __maybe_unused ina3221_resume(struct device *dev)
771 {
772 	struct ina3221_data *ina = dev_get_drvdata(dev);
773 	int ret;
774 
775 	regcache_cache_only(ina->regmap, false);
776 
777 	/* Software reset the chip */
778 	ret = regmap_field_write(ina->fields[F_RST], true);
779 	if (ret) {
780 		dev_err(dev, "Unable to reset device\n");
781 		return ret;
782 	}
783 
784 	/* Restore cached register values to hardware */
785 	ret = regcache_sync(ina->regmap);
786 	if (ret)
787 		return ret;
788 
789 	/* Restore config register value to hardware */
790 	ret = regmap_write(ina->regmap, INA3221_CONFIG, ina->reg_config);
791 	if (ret)
792 		return ret;
793 
794 	return 0;
795 }
796 
797 static const struct dev_pm_ops ina3221_pm = {
798 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
799 				pm_runtime_force_resume)
800 	SET_RUNTIME_PM_OPS(ina3221_suspend, ina3221_resume, NULL)
801 };
802 
803 static const struct of_device_id ina3221_of_match_table[] = {
804 	{ .compatible = "ti,ina3221", },
805 	{ /* sentinel */ }
806 };
807 MODULE_DEVICE_TABLE(of, ina3221_of_match_table);
808 
809 static const struct i2c_device_id ina3221_ids[] = {
810 	{ "ina3221", 0 },
811 	{ /* sentinel */ }
812 };
813 MODULE_DEVICE_TABLE(i2c, ina3221_ids);
814 
815 static struct i2c_driver ina3221_i2c_driver = {
816 	.probe = ina3221_probe,
817 	.remove = ina3221_remove,
818 	.driver = {
819 		.name = INA3221_DRIVER_NAME,
820 		.of_match_table = ina3221_of_match_table,
821 		.pm = &ina3221_pm,
822 	},
823 	.id_table = ina3221_ids,
824 };
825 module_i2c_driver(ina3221_i2c_driver);
826 
827 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
828 MODULE_DESCRIPTION("Texas Instruments INA3221 HWMon Driver");
829 MODULE_LICENSE("GPL v2");
830