xref: /openbmc/linux/drivers/hwmon/ina3221.c (revision 2c6467d2)
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  */
115 struct ina3221_data {
116 	struct device *pm_dev;
117 	struct regmap *regmap;
118 	struct regmap_field *fields[F_MAX_FIELDS];
119 	struct ina3221_input inputs[INA3221_NUM_CHANNELS];
120 	struct mutex lock;
121 	u32 reg_config;
122 };
123 
124 static inline bool ina3221_is_enabled(struct ina3221_data *ina, int channel)
125 {
126 	return pm_runtime_active(ina->pm_dev) &&
127 	       (ina->reg_config & INA3221_CONFIG_CHx_EN(channel));
128 }
129 
130 /* Lookup table for Bus and Shunt conversion times in usec */
131 static const u16 ina3221_conv_time[] = {
132 	140, 204, 332, 588, 1100, 2116, 4156, 8244,
133 };
134 
135 static inline int ina3221_wait_for_data(struct ina3221_data *ina)
136 {
137 	u32 channels = hweight16(ina->reg_config & INA3221_CONFIG_CHs_EN_MASK);
138 	u32 vbus_ct_idx = INA3221_CONFIG_VBUS_CT(ina->reg_config);
139 	u32 vsh_ct_idx = INA3221_CONFIG_VSH_CT(ina->reg_config);
140 	u32 vbus_ct = ina3221_conv_time[vbus_ct_idx];
141 	u32 vsh_ct = ina3221_conv_time[vsh_ct_idx];
142 	u32 wait, cvrf;
143 
144 	/* Calculate total conversion time */
145 	wait = channels * (vbus_ct + vsh_ct);
146 
147 	/* Polling the CVRF bit to make sure read data is ready */
148 	return regmap_field_read_poll_timeout(ina->fields[F_CVRF],
149 					      cvrf, cvrf, wait, 100000);
150 }
151 
152 static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
153 			      int *val)
154 {
155 	unsigned int regval;
156 	int ret;
157 
158 	ret = regmap_read(ina->regmap, reg, &regval);
159 	if (ret)
160 		return ret;
161 
162 	*val = sign_extend32(regval >> 3, 12);
163 
164 	return 0;
165 }
166 
167 static const u8 ina3221_in_reg[] = {
168 	INA3221_BUS1,
169 	INA3221_BUS2,
170 	INA3221_BUS3,
171 	INA3221_SHUNT1,
172 	INA3221_SHUNT2,
173 	INA3221_SHUNT3,
174 };
175 
176 static int ina3221_read_in(struct device *dev, u32 attr, int channel, long *val)
177 {
178 	const bool is_shunt = channel > INA3221_CHANNEL3;
179 	struct ina3221_data *ina = dev_get_drvdata(dev);
180 	u8 reg = ina3221_in_reg[channel];
181 	int regval, ret;
182 
183 	/* Translate shunt channel index to sensor channel index */
184 	channel %= INA3221_NUM_CHANNELS;
185 
186 	switch (attr) {
187 	case hwmon_in_input:
188 		if (!ina3221_is_enabled(ina, channel))
189 			return -ENODATA;
190 
191 		ret = ina3221_wait_for_data(ina);
192 		if (ret)
193 			return ret;
194 
195 		ret = ina3221_read_value(ina, reg, &regval);
196 		if (ret)
197 			return ret;
198 
199 		/*
200 		 * Scale of shunt voltage (uV): LSB is 40uV
201 		 * Scale of bus voltage (mV): LSB is 8mV
202 		 */
203 		*val = regval * (is_shunt ? 40 : 8);
204 		return 0;
205 	case hwmon_in_enable:
206 		*val = ina3221_is_enabled(ina, channel);
207 		return 0;
208 	default:
209 		return -EOPNOTSUPP;
210 	}
211 }
212 
213 static const u8 ina3221_curr_reg[][INA3221_NUM_CHANNELS] = {
214 	[hwmon_curr_input] = { INA3221_SHUNT1, INA3221_SHUNT2, INA3221_SHUNT3 },
215 	[hwmon_curr_max] = { INA3221_WARN1, INA3221_WARN2, INA3221_WARN3 },
216 	[hwmon_curr_crit] = { INA3221_CRIT1, INA3221_CRIT2, INA3221_CRIT3 },
217 	[hwmon_curr_max_alarm] = { F_WF1, F_WF2, F_WF3 },
218 	[hwmon_curr_crit_alarm] = { F_CF1, F_CF2, F_CF3 },
219 };
220 
221 static int ina3221_read_curr(struct device *dev, u32 attr,
222 			     int channel, long *val)
223 {
224 	struct ina3221_data *ina = dev_get_drvdata(dev);
225 	struct ina3221_input *input = &ina->inputs[channel];
226 	int resistance_uo = input->shunt_resistor;
227 	u8 reg = ina3221_curr_reg[attr][channel];
228 	int regval, voltage_nv, ret;
229 
230 	switch (attr) {
231 	case hwmon_curr_input:
232 		if (!ina3221_is_enabled(ina, channel))
233 			return -ENODATA;
234 
235 		ret = ina3221_wait_for_data(ina);
236 		if (ret)
237 			return ret;
238 
239 		/* fall through */
240 	case hwmon_curr_crit:
241 	case hwmon_curr_max:
242 		ret = ina3221_read_value(ina, reg, &regval);
243 		if (ret)
244 			return ret;
245 
246 		/* Scale of shunt voltage: LSB is 40uV (40000nV) */
247 		voltage_nv = regval * 40000;
248 		/* Return current in mA */
249 		*val = DIV_ROUND_CLOSEST(voltage_nv, resistance_uo);
250 		return 0;
251 	case hwmon_curr_crit_alarm:
252 	case hwmon_curr_max_alarm:
253 		/* No actual register read if channel is disabled */
254 		if (!ina3221_is_enabled(ina, channel)) {
255 			/* Return 0 for alert flags */
256 			*val = 0;
257 			return 0;
258 		}
259 		ret = regmap_field_read(ina->fields[reg], &regval);
260 		if (ret)
261 			return ret;
262 		*val = regval;
263 		return 0;
264 	default:
265 		return -EOPNOTSUPP;
266 	}
267 }
268 
269 static int ina3221_write_curr(struct device *dev, u32 attr,
270 			      int channel, long val)
271 {
272 	struct ina3221_data *ina = dev_get_drvdata(dev);
273 	struct ina3221_input *input = &ina->inputs[channel];
274 	int resistance_uo = input->shunt_resistor;
275 	u8 reg = ina3221_curr_reg[attr][channel];
276 	int regval, current_ma, voltage_uv;
277 
278 	/* clamp current */
279 	current_ma = clamp_val(val,
280 			       INT_MIN / resistance_uo,
281 			       INT_MAX / resistance_uo);
282 
283 	voltage_uv = DIV_ROUND_CLOSEST(current_ma * resistance_uo, 1000);
284 
285 	/* clamp voltage */
286 	voltage_uv = clamp_val(voltage_uv, -163800, 163800);
287 
288 	/* 1 / 40uV(scale) << 3(register shift) = 5 */
289 	regval = DIV_ROUND_CLOSEST(voltage_uv, 5) & 0xfff8;
290 
291 	return regmap_write(ina->regmap, reg, regval);
292 }
293 
294 static int ina3221_write_enable(struct device *dev, int channel, bool enable)
295 {
296 	struct ina3221_data *ina = dev_get_drvdata(dev);
297 	u16 config, mask = INA3221_CONFIG_CHx_EN(channel);
298 	u16 config_old = ina->reg_config & mask;
299 	int ret;
300 
301 	config = enable ? mask : 0;
302 
303 	/* Bypass if enable status is not being changed */
304 	if (config_old == config)
305 		return 0;
306 
307 	/* For enabling routine, increase refcount and resume() at first */
308 	if (enable) {
309 		ret = pm_runtime_get_sync(ina->pm_dev);
310 		if (ret < 0) {
311 			dev_err(dev, "Failed to get PM runtime\n");
312 			return ret;
313 		}
314 	}
315 
316 	/* Enable or disable the channel */
317 	ret = regmap_update_bits(ina->regmap, INA3221_CONFIG, mask, config);
318 	if (ret)
319 		goto fail;
320 
321 	/* Cache the latest config register value */
322 	ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
323 	if (ret)
324 		goto fail;
325 
326 	/* For disabling routine, decrease refcount or suspend() at last */
327 	if (!enable)
328 		pm_runtime_put_sync(ina->pm_dev);
329 
330 	return 0;
331 
332 fail:
333 	if (enable) {
334 		dev_err(dev, "Failed to enable channel %d: error %d\n",
335 			channel, ret);
336 		pm_runtime_put_sync(ina->pm_dev);
337 	}
338 
339 	return ret;
340 }
341 
342 static int ina3221_read(struct device *dev, enum hwmon_sensor_types type,
343 			u32 attr, int channel, long *val)
344 {
345 	struct ina3221_data *ina = dev_get_drvdata(dev);
346 	int ret;
347 
348 	mutex_lock(&ina->lock);
349 
350 	switch (type) {
351 	case hwmon_in:
352 		/* 0-align channel ID */
353 		ret = ina3221_read_in(dev, attr, channel - 1, val);
354 		break;
355 	case hwmon_curr:
356 		ret = ina3221_read_curr(dev, attr, channel, val);
357 		break;
358 	default:
359 		ret = -EOPNOTSUPP;
360 		break;
361 	}
362 
363 	mutex_unlock(&ina->lock);
364 
365 	return ret;
366 }
367 
368 static int ina3221_write(struct device *dev, enum hwmon_sensor_types type,
369 			 u32 attr, int channel, long val)
370 {
371 	struct ina3221_data *ina = dev_get_drvdata(dev);
372 	int ret;
373 
374 	mutex_lock(&ina->lock);
375 
376 	switch (type) {
377 	case hwmon_in:
378 		/* 0-align channel ID */
379 		ret = ina3221_write_enable(dev, channel - 1, val);
380 		break;
381 	case hwmon_curr:
382 		ret = ina3221_write_curr(dev, attr, channel, val);
383 		break;
384 	default:
385 		ret = -EOPNOTSUPP;
386 		break;
387 	}
388 
389 	mutex_unlock(&ina->lock);
390 
391 	return ret;
392 }
393 
394 static int ina3221_read_string(struct device *dev, enum hwmon_sensor_types type,
395 			       u32 attr, int channel, const char **str)
396 {
397 	struct ina3221_data *ina = dev_get_drvdata(dev);
398 	int index = channel - 1;
399 
400 	*str = ina->inputs[index].label;
401 
402 	return 0;
403 }
404 
405 static umode_t ina3221_is_visible(const void *drvdata,
406 				  enum hwmon_sensor_types type,
407 				  u32 attr, int channel)
408 {
409 	const struct ina3221_data *ina = drvdata;
410 	const struct ina3221_input *input = NULL;
411 
412 	switch (type) {
413 	case hwmon_in:
414 		/* Ignore in0_ */
415 		if (channel == 0)
416 			return 0;
417 
418 		switch (attr) {
419 		case hwmon_in_label:
420 			if (channel - 1 <= INA3221_CHANNEL3)
421 				input = &ina->inputs[channel - 1];
422 			/* Hide label node if label is not provided */
423 			return (input && input->label) ? 0444 : 0;
424 		case hwmon_in_input:
425 			return 0444;
426 		case hwmon_in_enable:
427 			return 0644;
428 		default:
429 			return 0;
430 		}
431 	case hwmon_curr:
432 		switch (attr) {
433 		case hwmon_curr_input:
434 		case hwmon_curr_crit_alarm:
435 		case hwmon_curr_max_alarm:
436 			return 0444;
437 		case hwmon_curr_crit:
438 		case hwmon_curr_max:
439 			return 0644;
440 		default:
441 			return 0;
442 		}
443 	default:
444 		return 0;
445 	}
446 }
447 
448 static const u32 ina3221_in_config[] = {
449 	/* 0: dummy, skipped in is_visible */
450 	HWMON_I_INPUT,
451 	/* 1-3: input voltage Channels */
452 	HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
453 	HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
454 	HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
455 	/* 4-6: shunt voltage Channels */
456 	HWMON_I_INPUT,
457 	HWMON_I_INPUT,
458 	HWMON_I_INPUT,
459 	0
460 };
461 
462 static const struct hwmon_channel_info ina3221_in = {
463 	.type = hwmon_in,
464 	.config = ina3221_in_config,
465 };
466 
467 #define INA3221_HWMON_CURR_CONFIG (HWMON_C_INPUT | \
468 				   HWMON_C_CRIT | HWMON_C_CRIT_ALARM | \
469 				   HWMON_C_MAX | HWMON_C_MAX_ALARM)
470 
471 static const u32 ina3221_curr_config[] = {
472 	INA3221_HWMON_CURR_CONFIG,
473 	INA3221_HWMON_CURR_CONFIG,
474 	INA3221_HWMON_CURR_CONFIG,
475 	0
476 };
477 
478 static const struct hwmon_channel_info ina3221_curr = {
479 	.type = hwmon_curr,
480 	.config = ina3221_curr_config,
481 };
482 
483 static const struct hwmon_channel_info *ina3221_info[] = {
484 	&ina3221_in,
485 	&ina3221_curr,
486 	NULL
487 };
488 
489 static const struct hwmon_ops ina3221_hwmon_ops = {
490 	.is_visible = ina3221_is_visible,
491 	.read_string = ina3221_read_string,
492 	.read = ina3221_read,
493 	.write = ina3221_write,
494 };
495 
496 static const struct hwmon_chip_info ina3221_chip_info = {
497 	.ops = &ina3221_hwmon_ops,
498 	.info = ina3221_info,
499 };
500 
501 /* Extra attribute groups */
502 static ssize_t ina3221_show_shunt(struct device *dev,
503 				  struct device_attribute *attr, char *buf)
504 {
505 	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
506 	struct ina3221_data *ina = dev_get_drvdata(dev);
507 	unsigned int channel = sd_attr->index;
508 	struct ina3221_input *input = &ina->inputs[channel];
509 
510 	return snprintf(buf, PAGE_SIZE, "%d\n", input->shunt_resistor);
511 }
512 
513 static ssize_t ina3221_set_shunt(struct device *dev,
514 				 struct device_attribute *attr,
515 				 const char *buf, size_t count)
516 {
517 	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
518 	struct ina3221_data *ina = dev_get_drvdata(dev);
519 	unsigned int channel = sd_attr->index;
520 	struct ina3221_input *input = &ina->inputs[channel];
521 	int val;
522 	int ret;
523 
524 	ret = kstrtoint(buf, 0, &val);
525 	if (ret)
526 		return ret;
527 
528 	val = clamp_val(val, 1, INT_MAX);
529 
530 	input->shunt_resistor = val;
531 
532 	return count;
533 }
534 
535 /* shunt resistance */
536 static SENSOR_DEVICE_ATTR(shunt1_resistor, S_IRUGO | S_IWUSR,
537 		ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL1);
538 static SENSOR_DEVICE_ATTR(shunt2_resistor, S_IRUGO | S_IWUSR,
539 		ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL2);
540 static SENSOR_DEVICE_ATTR(shunt3_resistor, S_IRUGO | S_IWUSR,
541 		ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL3);
542 
543 static struct attribute *ina3221_attrs[] = {
544 	&sensor_dev_attr_shunt1_resistor.dev_attr.attr,
545 	&sensor_dev_attr_shunt2_resistor.dev_attr.attr,
546 	&sensor_dev_attr_shunt3_resistor.dev_attr.attr,
547 	NULL,
548 };
549 ATTRIBUTE_GROUPS(ina3221);
550 
551 static const struct regmap_range ina3221_yes_ranges[] = {
552 	regmap_reg_range(INA3221_CONFIG, INA3221_BUS3),
553 	regmap_reg_range(INA3221_MASK_ENABLE, INA3221_MASK_ENABLE),
554 };
555 
556 static const struct regmap_access_table ina3221_volatile_table = {
557 	.yes_ranges = ina3221_yes_ranges,
558 	.n_yes_ranges = ARRAY_SIZE(ina3221_yes_ranges),
559 };
560 
561 static const struct regmap_config ina3221_regmap_config = {
562 	.reg_bits = 8,
563 	.val_bits = 16,
564 
565 	.cache_type = REGCACHE_RBTREE,
566 	.volatile_table = &ina3221_volatile_table,
567 };
568 
569 static int ina3221_probe_child_from_dt(struct device *dev,
570 				       struct device_node *child,
571 				       struct ina3221_data *ina)
572 {
573 	struct ina3221_input *input;
574 	u32 val;
575 	int ret;
576 
577 	ret = of_property_read_u32(child, "reg", &val);
578 	if (ret) {
579 		dev_err(dev, "missing reg property of %pOFn\n", child);
580 		return ret;
581 	} else if (val > INA3221_CHANNEL3) {
582 		dev_err(dev, "invalid reg %d of %pOFn\n", val, child);
583 		return ret;
584 	}
585 
586 	input = &ina->inputs[val];
587 
588 	/* Log the disconnected channel input */
589 	if (!of_device_is_available(child)) {
590 		input->disconnected = true;
591 		return 0;
592 	}
593 
594 	/* Save the connected input label if available */
595 	of_property_read_string(child, "label", &input->label);
596 
597 	/* Overwrite default shunt resistor value optionally */
598 	if (!of_property_read_u32(child, "shunt-resistor-micro-ohms", &val)) {
599 		if (val < 1 || val > INT_MAX) {
600 			dev_err(dev, "invalid shunt resistor value %u of %pOFn\n",
601 				val, child);
602 			return -EINVAL;
603 		}
604 		input->shunt_resistor = val;
605 	}
606 
607 	return 0;
608 }
609 
610 static int ina3221_probe_from_dt(struct device *dev, struct ina3221_data *ina)
611 {
612 	const struct device_node *np = dev->of_node;
613 	struct device_node *child;
614 	int ret;
615 
616 	/* Compatible with non-DT platforms */
617 	if (!np)
618 		return 0;
619 
620 	for_each_child_of_node(np, child) {
621 		ret = ina3221_probe_child_from_dt(dev, child, ina);
622 		if (ret)
623 			return ret;
624 	}
625 
626 	return 0;
627 }
628 
629 static int ina3221_probe(struct i2c_client *client,
630 			 const struct i2c_device_id *id)
631 {
632 	struct device *dev = &client->dev;
633 	struct ina3221_data *ina;
634 	struct device *hwmon_dev;
635 	int i, ret;
636 
637 	ina = devm_kzalloc(dev, sizeof(*ina), GFP_KERNEL);
638 	if (!ina)
639 		return -ENOMEM;
640 
641 	ina->regmap = devm_regmap_init_i2c(client, &ina3221_regmap_config);
642 	if (IS_ERR(ina->regmap)) {
643 		dev_err(dev, "Unable to allocate register map\n");
644 		return PTR_ERR(ina->regmap);
645 	}
646 
647 	for (i = 0; i < F_MAX_FIELDS; i++) {
648 		ina->fields[i] = devm_regmap_field_alloc(dev,
649 							 ina->regmap,
650 							 ina3221_reg_fields[i]);
651 		if (IS_ERR(ina->fields[i])) {
652 			dev_err(dev, "Unable to allocate regmap fields\n");
653 			return PTR_ERR(ina->fields[i]);
654 		}
655 	}
656 
657 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
658 		ina->inputs[i].shunt_resistor = INA3221_RSHUNT_DEFAULT;
659 
660 	ret = ina3221_probe_from_dt(dev, ina);
661 	if (ret) {
662 		dev_err(dev, "Unable to probe from device tree\n");
663 		return ret;
664 	}
665 
666 	/* The driver will be reset, so use reset value */
667 	ina->reg_config = INA3221_CONFIG_DEFAULT;
668 
669 	/* Disable channels if their inputs are disconnected */
670 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
671 		if (ina->inputs[i].disconnected)
672 			ina->reg_config &= ~INA3221_CONFIG_CHx_EN(i);
673 	}
674 
675 	ina->pm_dev = dev;
676 	mutex_init(&ina->lock);
677 	dev_set_drvdata(dev, ina);
678 
679 	/* Enable PM runtime -- status is suspended by default */
680 	pm_runtime_enable(ina->pm_dev);
681 
682 	/* Initialize (resume) the device */
683 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
684 		if (ina->inputs[i].disconnected)
685 			continue;
686 		/* Match the refcount with number of enabled channels */
687 		ret = pm_runtime_get_sync(ina->pm_dev);
688 		if (ret < 0)
689 			goto fail;
690 	}
691 
692 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, ina,
693 							 &ina3221_chip_info,
694 							 ina3221_groups);
695 	if (IS_ERR(hwmon_dev)) {
696 		dev_err(dev, "Unable to register hwmon device\n");
697 		ret = PTR_ERR(hwmon_dev);
698 		goto fail;
699 	}
700 
701 	return 0;
702 
703 fail:
704 	pm_runtime_disable(ina->pm_dev);
705 	pm_runtime_set_suspended(ina->pm_dev);
706 	/* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
707 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
708 		pm_runtime_put_noidle(ina->pm_dev);
709 	mutex_destroy(&ina->lock);
710 
711 	return ret;
712 }
713 
714 static int ina3221_remove(struct i2c_client *client)
715 {
716 	struct ina3221_data *ina = dev_get_drvdata(&client->dev);
717 	int i;
718 
719 	pm_runtime_disable(ina->pm_dev);
720 	pm_runtime_set_suspended(ina->pm_dev);
721 
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 
726 	mutex_destroy(&ina->lock);
727 
728 	return 0;
729 }
730 
731 static int __maybe_unused ina3221_suspend(struct device *dev)
732 {
733 	struct ina3221_data *ina = dev_get_drvdata(dev);
734 	int ret;
735 
736 	/* Save config register value and enable cache-only */
737 	ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
738 	if (ret)
739 		return ret;
740 
741 	/* Set to power-down mode for power saving */
742 	ret = regmap_update_bits(ina->regmap, INA3221_CONFIG,
743 				 INA3221_CONFIG_MODE_MASK,
744 				 INA3221_CONFIG_MODE_POWERDOWN);
745 	if (ret)
746 		return ret;
747 
748 	regcache_cache_only(ina->regmap, true);
749 	regcache_mark_dirty(ina->regmap);
750 
751 	return 0;
752 }
753 
754 static int __maybe_unused ina3221_resume(struct device *dev)
755 {
756 	struct ina3221_data *ina = dev_get_drvdata(dev);
757 	int ret;
758 
759 	regcache_cache_only(ina->regmap, false);
760 
761 	/* Software reset the chip */
762 	ret = regmap_field_write(ina->fields[F_RST], true);
763 	if (ret) {
764 		dev_err(dev, "Unable to reset device\n");
765 		return ret;
766 	}
767 
768 	/* Restore cached register values to hardware */
769 	ret = regcache_sync(ina->regmap);
770 	if (ret)
771 		return ret;
772 
773 	/* Restore config register value to hardware */
774 	ret = regmap_write(ina->regmap, INA3221_CONFIG, ina->reg_config);
775 	if (ret)
776 		return ret;
777 
778 	return 0;
779 }
780 
781 static const struct dev_pm_ops ina3221_pm = {
782 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
783 				pm_runtime_force_resume)
784 	SET_RUNTIME_PM_OPS(ina3221_suspend, ina3221_resume, NULL)
785 };
786 
787 static const struct of_device_id ina3221_of_match_table[] = {
788 	{ .compatible = "ti,ina3221", },
789 	{ /* sentinel */ }
790 };
791 MODULE_DEVICE_TABLE(of, ina3221_of_match_table);
792 
793 static const struct i2c_device_id ina3221_ids[] = {
794 	{ "ina3221", 0 },
795 	{ /* sentinel */ }
796 };
797 MODULE_DEVICE_TABLE(i2c, ina3221_ids);
798 
799 static struct i2c_driver ina3221_i2c_driver = {
800 	.probe = ina3221_probe,
801 	.remove = ina3221_remove,
802 	.driver = {
803 		.name = INA3221_DRIVER_NAME,
804 		.of_match_table = ina3221_of_match_table,
805 		.pm = &ina3221_pm,
806 	},
807 	.id_table = ina3221_ids,
808 };
809 module_i2c_driver(ina3221_i2c_driver);
810 
811 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
812 MODULE_DESCRIPTION("Texas Instruments INA3221 HWMon Driver");
813 MODULE_LICENSE("GPL v2");
814