xref: /linux/drivers/hwmon/ina3221.c (revision 088e88be5a380cc4e81963a9a02815da465d144f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * INA3221 Triple Current/Voltage Monitor
4  *
5  * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
6  *	Andrew F. Davis <afd@ti.com>
7  */
8 
9 #include <linux/hwmon.h>
10 #include <linux/hwmon-sysfs.h>
11 #include <linux/i2c.h>
12 #include <linux/module.h>
13 #include <linux/mutex.h>
14 #include <linux/of.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/regmap.h>
17 #include <linux/util_macros.h>
18 
19 #define INA3221_DRIVER_NAME		"ina3221"
20 
21 #define INA3221_CONFIG			0x00
22 #define INA3221_SHUNT1			0x01
23 #define INA3221_BUS1			0x02
24 #define INA3221_SHUNT2			0x03
25 #define INA3221_BUS2			0x04
26 #define INA3221_SHUNT3			0x05
27 #define INA3221_BUS3			0x06
28 #define INA3221_CRIT1			0x07
29 #define INA3221_WARN1			0x08
30 #define INA3221_CRIT2			0x09
31 #define INA3221_WARN2			0x0a
32 #define INA3221_CRIT3			0x0b
33 #define INA3221_WARN3			0x0c
34 #define INA3221_MASK_ENABLE		0x0f
35 
36 #define INA3221_CONFIG_MODE_MASK	GENMASK(2, 0)
37 #define INA3221_CONFIG_MODE_POWERDOWN	0
38 #define INA3221_CONFIG_MODE_SHUNT	BIT(0)
39 #define INA3221_CONFIG_MODE_BUS		BIT(1)
40 #define INA3221_CONFIG_MODE_CONTINUOUS	BIT(2)
41 #define INA3221_CONFIG_VSH_CT_SHIFT	3
42 #define INA3221_CONFIG_VSH_CT_MASK	GENMASK(5, 3)
43 #define INA3221_CONFIG_VSH_CT(x)	(((x) & GENMASK(5, 3)) >> 3)
44 #define INA3221_CONFIG_VBUS_CT_SHIFT	6
45 #define INA3221_CONFIG_VBUS_CT_MASK	GENMASK(8, 6)
46 #define INA3221_CONFIG_VBUS_CT(x)	(((x) & GENMASK(8, 6)) >> 6)
47 #define INA3221_CONFIG_AVG_SHIFT	9
48 #define INA3221_CONFIG_AVG_MASK		GENMASK(11, 9)
49 #define INA3221_CONFIG_AVG(x)		(((x) & GENMASK(11, 9)) >> 9)
50 #define INA3221_CONFIG_CHs_EN_MASK	GENMASK(14, 12)
51 #define INA3221_CONFIG_CHx_EN(x)	BIT(14 - (x))
52 
53 #define INA3221_CONFIG_DEFAULT		0x7127
54 #define INA3221_RSHUNT_DEFAULT		10000
55 
56 enum ina3221_fields {
57 	/* Configuration */
58 	F_RST,
59 
60 	/* Status Flags */
61 	F_CVRF,
62 
63 	/* Alert Flags */
64 	F_WF3, F_WF2, F_WF1,
65 	F_CF3, F_CF2, F_CF1,
66 
67 	/* sentinel */
68 	F_MAX_FIELDS
69 };
70 
71 static const struct reg_field ina3221_reg_fields[] = {
72 	[F_RST] = REG_FIELD(INA3221_CONFIG, 15, 15),
73 
74 	[F_CVRF] = REG_FIELD(INA3221_MASK_ENABLE, 0, 0),
75 	[F_WF3] = REG_FIELD(INA3221_MASK_ENABLE, 3, 3),
76 	[F_WF2] = REG_FIELD(INA3221_MASK_ENABLE, 4, 4),
77 	[F_WF1] = REG_FIELD(INA3221_MASK_ENABLE, 5, 5),
78 	[F_CF3] = REG_FIELD(INA3221_MASK_ENABLE, 7, 7),
79 	[F_CF2] = REG_FIELD(INA3221_MASK_ENABLE, 8, 8),
80 	[F_CF1] = REG_FIELD(INA3221_MASK_ENABLE, 9, 9),
81 };
82 
83 enum ina3221_channels {
84 	INA3221_CHANNEL1,
85 	INA3221_CHANNEL2,
86 	INA3221_CHANNEL3,
87 	INA3221_NUM_CHANNELS
88 };
89 
90 /**
91  * struct ina3221_input - channel input source specific information
92  * @label: label of channel input source
93  * @shunt_resistor: shunt resistor value of channel input source
94  * @disconnected: connection status of channel input source
95  */
96 struct ina3221_input {
97 	const char *label;
98 	int shunt_resistor;
99 	bool disconnected;
100 };
101 
102 /**
103  * struct ina3221_data - device specific information
104  * @pm_dev: Device pointer for pm runtime
105  * @regmap: Register map of the device
106  * @fields: Register fields of the device
107  * @inputs: Array of channel input source specific structures
108  * @lock: mutex lock to serialize sysfs attribute accesses
109  * @reg_config: Register value of INA3221_CONFIG
110  * @single_shot: running in single-shot operating mode
111  */
112 struct ina3221_data {
113 	struct device *pm_dev;
114 	struct regmap *regmap;
115 	struct regmap_field *fields[F_MAX_FIELDS];
116 	struct ina3221_input inputs[INA3221_NUM_CHANNELS];
117 	struct mutex lock;
118 	u32 reg_config;
119 
120 	bool single_shot;
121 };
122 
123 static inline bool ina3221_is_enabled(struct ina3221_data *ina, int channel)
124 {
125 	return pm_runtime_active(ina->pm_dev) &&
126 	       (ina->reg_config & INA3221_CONFIG_CHx_EN(channel));
127 }
128 
129 /* Lookup table for Bus and Shunt conversion times in usec */
130 static const u16 ina3221_conv_time[] = {
131 	140, 204, 332, 588, 1100, 2116, 4156, 8244,
132 };
133 
134 /* Lookup table for number of samples using in averaging mode */
135 static const int ina3221_avg_samples[] = {
136 	1, 4, 16, 64, 128, 256, 512, 1024,
137 };
138 
139 /* Converting update_interval in msec to conversion time in usec */
140 static inline u32 ina3221_interval_ms_to_conv_time(u16 config, int interval)
141 {
142 	u32 channels = hweight16(config & INA3221_CONFIG_CHs_EN_MASK);
143 	u32 samples_idx = INA3221_CONFIG_AVG(config);
144 	u32 samples = ina3221_avg_samples[samples_idx];
145 
146 	/* Bisect the result to Bus and Shunt conversion times */
147 	return DIV_ROUND_CLOSEST(interval * 1000 / 2, channels * samples);
148 }
149 
150 /* Converting CONFIG register value to update_interval in usec */
151 static inline u32 ina3221_reg_to_interval_us(u16 config)
152 {
153 	u32 channels = hweight16(config & INA3221_CONFIG_CHs_EN_MASK);
154 	u32 vbus_ct_idx = INA3221_CONFIG_VBUS_CT(config);
155 	u32 vsh_ct_idx = INA3221_CONFIG_VSH_CT(config);
156 	u32 samples_idx = INA3221_CONFIG_AVG(config);
157 	u32 samples = ina3221_avg_samples[samples_idx];
158 	u32 vbus_ct = ina3221_conv_time[vbus_ct_idx];
159 	u32 vsh_ct = ina3221_conv_time[vsh_ct_idx];
160 
161 	/* Calculate total conversion time */
162 	return channels * (vbus_ct + vsh_ct) * samples;
163 }
164 
165 static inline int ina3221_wait_for_data(struct ina3221_data *ina)
166 {
167 	u32 wait, cvrf;
168 
169 	wait = ina3221_reg_to_interval_us(ina->reg_config);
170 
171 	/* Polling the CVRF bit to make sure read data is ready */
172 	return regmap_field_read_poll_timeout(ina->fields[F_CVRF],
173 					      cvrf, cvrf, wait, 100000);
174 }
175 
176 static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
177 			      int *val)
178 {
179 	unsigned int regval;
180 	int ret;
181 
182 	ret = regmap_read(ina->regmap, reg, &regval);
183 	if (ret)
184 		return ret;
185 
186 	*val = sign_extend32(regval >> 3, 12);
187 
188 	return 0;
189 }
190 
191 static const u8 ina3221_in_reg[] = {
192 	INA3221_BUS1,
193 	INA3221_BUS2,
194 	INA3221_BUS3,
195 	INA3221_SHUNT1,
196 	INA3221_SHUNT2,
197 	INA3221_SHUNT3,
198 };
199 
200 static int ina3221_read_chip(struct device *dev, u32 attr, long *val)
201 {
202 	struct ina3221_data *ina = dev_get_drvdata(dev);
203 	int regval;
204 
205 	switch (attr) {
206 	case hwmon_chip_samples:
207 		regval = INA3221_CONFIG_AVG(ina->reg_config);
208 		*val = ina3221_avg_samples[regval];
209 		return 0;
210 	case hwmon_chip_update_interval:
211 		/* Return in msec */
212 		*val = ina3221_reg_to_interval_us(ina->reg_config);
213 		*val = DIV_ROUND_CLOSEST(*val, 1000);
214 		return 0;
215 	default:
216 		return -EOPNOTSUPP;
217 	}
218 }
219 
220 static int ina3221_read_in(struct device *dev, u32 attr, int channel, long *val)
221 {
222 	const bool is_shunt = channel > INA3221_CHANNEL3;
223 	struct ina3221_data *ina = dev_get_drvdata(dev);
224 	u8 reg = ina3221_in_reg[channel];
225 	int regval, ret;
226 
227 	/* Translate shunt channel index to sensor channel index */
228 	channel %= INA3221_NUM_CHANNELS;
229 
230 	switch (attr) {
231 	case hwmon_in_input:
232 		if (!ina3221_is_enabled(ina, channel))
233 			return -ENODATA;
234 
235 		/* Write CONFIG register to trigger a single-shot measurement */
236 		if (ina->single_shot)
237 			regmap_write(ina->regmap, INA3221_CONFIG,
238 				     ina->reg_config);
239 
240 		ret = ina3221_wait_for_data(ina);
241 		if (ret)
242 			return ret;
243 
244 		ret = ina3221_read_value(ina, reg, &regval);
245 		if (ret)
246 			return ret;
247 
248 		/*
249 		 * Scale of shunt voltage (uV): LSB is 40uV
250 		 * Scale of bus voltage (mV): LSB is 8mV
251 		 */
252 		*val = regval * (is_shunt ? 40 : 8);
253 		return 0;
254 	case hwmon_in_enable:
255 		*val = ina3221_is_enabled(ina, channel);
256 		return 0;
257 	default:
258 		return -EOPNOTSUPP;
259 	}
260 }
261 
262 static const u8 ina3221_curr_reg[][INA3221_NUM_CHANNELS] = {
263 	[hwmon_curr_input] = { INA3221_SHUNT1, INA3221_SHUNT2, INA3221_SHUNT3 },
264 	[hwmon_curr_max] = { INA3221_WARN1, INA3221_WARN2, INA3221_WARN3 },
265 	[hwmon_curr_crit] = { INA3221_CRIT1, INA3221_CRIT2, INA3221_CRIT3 },
266 	[hwmon_curr_max_alarm] = { F_WF1, F_WF2, F_WF3 },
267 	[hwmon_curr_crit_alarm] = { F_CF1, F_CF2, F_CF3 },
268 };
269 
270 static int ina3221_read_curr(struct device *dev, u32 attr,
271 			     int channel, long *val)
272 {
273 	struct ina3221_data *ina = dev_get_drvdata(dev);
274 	struct ina3221_input *input = &ina->inputs[channel];
275 	int resistance_uo = input->shunt_resistor;
276 	u8 reg = ina3221_curr_reg[attr][channel];
277 	int regval, voltage_nv, ret;
278 
279 	switch (attr) {
280 	case hwmon_curr_input:
281 		if (!ina3221_is_enabled(ina, channel))
282 			return -ENODATA;
283 
284 		/* Write CONFIG register to trigger a single-shot measurement */
285 		if (ina->single_shot)
286 			regmap_write(ina->regmap, INA3221_CONFIG,
287 				     ina->reg_config);
288 
289 		ret = ina3221_wait_for_data(ina);
290 		if (ret)
291 			return ret;
292 
293 		/* fall through */
294 	case hwmon_curr_crit:
295 	case hwmon_curr_max:
296 		ret = ina3221_read_value(ina, reg, &regval);
297 		if (ret)
298 			return ret;
299 
300 		/* Scale of shunt voltage: LSB is 40uV (40000nV) */
301 		voltage_nv = regval * 40000;
302 		/* Return current in mA */
303 		*val = DIV_ROUND_CLOSEST(voltage_nv, resistance_uo);
304 		return 0;
305 	case hwmon_curr_crit_alarm:
306 	case hwmon_curr_max_alarm:
307 		/* No actual register read if channel is disabled */
308 		if (!ina3221_is_enabled(ina, channel)) {
309 			/* Return 0 for alert flags */
310 			*val = 0;
311 			return 0;
312 		}
313 		ret = regmap_field_read(ina->fields[reg], &regval);
314 		if (ret)
315 			return ret;
316 		*val = regval;
317 		return 0;
318 	default:
319 		return -EOPNOTSUPP;
320 	}
321 }
322 
323 static int ina3221_write_chip(struct device *dev, u32 attr, long val)
324 {
325 	struct ina3221_data *ina = dev_get_drvdata(dev);
326 	int ret, idx;
327 	u32 tmp;
328 
329 	switch (attr) {
330 	case hwmon_chip_samples:
331 		idx = find_closest(val, ina3221_avg_samples,
332 				   ARRAY_SIZE(ina3221_avg_samples));
333 
334 		tmp = (ina->reg_config & ~INA3221_CONFIG_AVG_MASK) |
335 		      (idx << INA3221_CONFIG_AVG_SHIFT);
336 		ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
337 		if (ret)
338 			return ret;
339 
340 		/* Update reg_config accordingly */
341 		ina->reg_config = tmp;
342 		return 0;
343 	case hwmon_chip_update_interval:
344 		tmp = ina3221_interval_ms_to_conv_time(ina->reg_config, val);
345 		idx = find_closest(tmp, ina3221_conv_time,
346 				   ARRAY_SIZE(ina3221_conv_time));
347 
348 		/* Update Bus and Shunt voltage conversion times */
349 		tmp = INA3221_CONFIG_VBUS_CT_MASK | INA3221_CONFIG_VSH_CT_MASK;
350 		tmp = (ina->reg_config & ~tmp) |
351 		      (idx << INA3221_CONFIG_VBUS_CT_SHIFT) |
352 		      (idx << INA3221_CONFIG_VSH_CT_SHIFT);
353 		ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
354 		if (ret)
355 			return ret;
356 
357 		/* Update reg_config accordingly */
358 		ina->reg_config = tmp;
359 		return 0;
360 	default:
361 		return -EOPNOTSUPP;
362 	}
363 }
364 
365 static int ina3221_write_curr(struct device *dev, u32 attr,
366 			      int channel, long val)
367 {
368 	struct ina3221_data *ina = dev_get_drvdata(dev);
369 	struct ina3221_input *input = &ina->inputs[channel];
370 	int resistance_uo = input->shunt_resistor;
371 	u8 reg = ina3221_curr_reg[attr][channel];
372 	int regval, current_ma, voltage_uv;
373 
374 	/* clamp current */
375 	current_ma = clamp_val(val,
376 			       INT_MIN / resistance_uo,
377 			       INT_MAX / resistance_uo);
378 
379 	voltage_uv = DIV_ROUND_CLOSEST(current_ma * resistance_uo, 1000);
380 
381 	/* clamp voltage */
382 	voltage_uv = clamp_val(voltage_uv, -163800, 163800);
383 
384 	/* 1 / 40uV(scale) << 3(register shift) = 5 */
385 	regval = DIV_ROUND_CLOSEST(voltage_uv, 5) & 0xfff8;
386 
387 	return regmap_write(ina->regmap, reg, regval);
388 }
389 
390 static int ina3221_write_enable(struct device *dev, int channel, bool enable)
391 {
392 	struct ina3221_data *ina = dev_get_drvdata(dev);
393 	u16 config, mask = INA3221_CONFIG_CHx_EN(channel);
394 	u16 config_old = ina->reg_config & mask;
395 	u32 tmp;
396 	int ret;
397 
398 	config = enable ? mask : 0;
399 
400 	/* Bypass if enable status is not being changed */
401 	if (config_old == config)
402 		return 0;
403 
404 	/* For enabling routine, increase refcount and resume() at first */
405 	if (enable) {
406 		ret = pm_runtime_get_sync(ina->pm_dev);
407 		if (ret < 0) {
408 			dev_err(dev, "Failed to get PM runtime\n");
409 			return ret;
410 		}
411 	}
412 
413 	/* Enable or disable the channel */
414 	tmp = (ina->reg_config & ~mask) | (config & mask);
415 	ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
416 	if (ret)
417 		goto fail;
418 
419 	/* Cache the latest config register value */
420 	ina->reg_config = tmp;
421 
422 	/* For disabling routine, decrease refcount or suspend() at last */
423 	if (!enable)
424 		pm_runtime_put_sync(ina->pm_dev);
425 
426 	return 0;
427 
428 fail:
429 	if (enable) {
430 		dev_err(dev, "Failed to enable channel %d: error %d\n",
431 			channel, ret);
432 		pm_runtime_put_sync(ina->pm_dev);
433 	}
434 
435 	return ret;
436 }
437 
438 static int ina3221_read(struct device *dev, enum hwmon_sensor_types type,
439 			u32 attr, int channel, long *val)
440 {
441 	struct ina3221_data *ina = dev_get_drvdata(dev);
442 	int ret;
443 
444 	mutex_lock(&ina->lock);
445 
446 	switch (type) {
447 	case hwmon_chip:
448 		ret = ina3221_read_chip(dev, attr, val);
449 		break;
450 	case hwmon_in:
451 		/* 0-align channel ID */
452 		ret = ina3221_read_in(dev, attr, channel - 1, val);
453 		break;
454 	case hwmon_curr:
455 		ret = ina3221_read_curr(dev, attr, channel, val);
456 		break;
457 	default:
458 		ret = -EOPNOTSUPP;
459 		break;
460 	}
461 
462 	mutex_unlock(&ina->lock);
463 
464 	return ret;
465 }
466 
467 static int ina3221_write(struct device *dev, enum hwmon_sensor_types type,
468 			 u32 attr, int channel, long val)
469 {
470 	struct ina3221_data *ina = dev_get_drvdata(dev);
471 	int ret;
472 
473 	mutex_lock(&ina->lock);
474 
475 	switch (type) {
476 	case hwmon_chip:
477 		ret = ina3221_write_chip(dev, attr, val);
478 		break;
479 	case hwmon_in:
480 		/* 0-align channel ID */
481 		ret = ina3221_write_enable(dev, channel - 1, val);
482 		break;
483 	case hwmon_curr:
484 		ret = ina3221_write_curr(dev, attr, channel, val);
485 		break;
486 	default:
487 		ret = -EOPNOTSUPP;
488 		break;
489 	}
490 
491 	mutex_unlock(&ina->lock);
492 
493 	return ret;
494 }
495 
496 static int ina3221_read_string(struct device *dev, enum hwmon_sensor_types type,
497 			       u32 attr, int channel, const char **str)
498 {
499 	struct ina3221_data *ina = dev_get_drvdata(dev);
500 	int index = channel - 1;
501 
502 	*str = ina->inputs[index].label;
503 
504 	return 0;
505 }
506 
507 static umode_t ina3221_is_visible(const void *drvdata,
508 				  enum hwmon_sensor_types type,
509 				  u32 attr, int channel)
510 {
511 	const struct ina3221_data *ina = drvdata;
512 	const struct ina3221_input *input = NULL;
513 
514 	switch (type) {
515 	case hwmon_chip:
516 		switch (attr) {
517 		case hwmon_chip_samples:
518 		case hwmon_chip_update_interval:
519 			return 0644;
520 		default:
521 			return 0;
522 		}
523 	case hwmon_in:
524 		/* Ignore in0_ */
525 		if (channel == 0)
526 			return 0;
527 
528 		switch (attr) {
529 		case hwmon_in_label:
530 			if (channel - 1 <= INA3221_CHANNEL3)
531 				input = &ina->inputs[channel - 1];
532 			/* Hide label node if label is not provided */
533 			return (input && input->label) ? 0444 : 0;
534 		case hwmon_in_input:
535 			return 0444;
536 		case hwmon_in_enable:
537 			return 0644;
538 		default:
539 			return 0;
540 		}
541 	case hwmon_curr:
542 		switch (attr) {
543 		case hwmon_curr_input:
544 		case hwmon_curr_crit_alarm:
545 		case hwmon_curr_max_alarm:
546 			return 0444;
547 		case hwmon_curr_crit:
548 		case hwmon_curr_max:
549 			return 0644;
550 		default:
551 			return 0;
552 		}
553 	default:
554 		return 0;
555 	}
556 }
557 
558 #define INA3221_HWMON_CURR_CONFIG (HWMON_C_INPUT | \
559 				   HWMON_C_CRIT | HWMON_C_CRIT_ALARM | \
560 				   HWMON_C_MAX | HWMON_C_MAX_ALARM)
561 
562 static const struct hwmon_channel_info *ina3221_info[] = {
563 	HWMON_CHANNEL_INFO(chip,
564 			   HWMON_C_SAMPLES,
565 			   HWMON_C_UPDATE_INTERVAL),
566 	HWMON_CHANNEL_INFO(in,
567 			   /* 0: dummy, skipped in is_visible */
568 			   HWMON_I_INPUT,
569 			   /* 1-3: input voltage Channels */
570 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
571 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
572 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
573 			   /* 4-6: shunt voltage Channels */
574 			   HWMON_I_INPUT,
575 			   HWMON_I_INPUT,
576 			   HWMON_I_INPUT),
577 	HWMON_CHANNEL_INFO(curr,
578 			   INA3221_HWMON_CURR_CONFIG,
579 			   INA3221_HWMON_CURR_CONFIG,
580 			   INA3221_HWMON_CURR_CONFIG),
581 	NULL
582 };
583 
584 static const struct hwmon_ops ina3221_hwmon_ops = {
585 	.is_visible = ina3221_is_visible,
586 	.read_string = ina3221_read_string,
587 	.read = ina3221_read,
588 	.write = ina3221_write,
589 };
590 
591 static const struct hwmon_chip_info ina3221_chip_info = {
592 	.ops = &ina3221_hwmon_ops,
593 	.info = ina3221_info,
594 };
595 
596 /* Extra attribute groups */
597 static ssize_t ina3221_shunt_show(struct device *dev,
598 				  struct device_attribute *attr, char *buf)
599 {
600 	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
601 	struct ina3221_data *ina = dev_get_drvdata(dev);
602 	unsigned int channel = sd_attr->index;
603 	struct ina3221_input *input = &ina->inputs[channel];
604 
605 	return snprintf(buf, PAGE_SIZE, "%d\n", input->shunt_resistor);
606 }
607 
608 static ssize_t ina3221_shunt_store(struct device *dev,
609 				   struct device_attribute *attr,
610 				   const char *buf, size_t count)
611 {
612 	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
613 	struct ina3221_data *ina = dev_get_drvdata(dev);
614 	unsigned int channel = sd_attr->index;
615 	struct ina3221_input *input = &ina->inputs[channel];
616 	int val;
617 	int ret;
618 
619 	ret = kstrtoint(buf, 0, &val);
620 	if (ret)
621 		return ret;
622 
623 	val = clamp_val(val, 1, INT_MAX);
624 
625 	input->shunt_resistor = val;
626 
627 	return count;
628 }
629 
630 /* shunt resistance */
631 static SENSOR_DEVICE_ATTR_RW(shunt1_resistor, ina3221_shunt, INA3221_CHANNEL1);
632 static SENSOR_DEVICE_ATTR_RW(shunt2_resistor, ina3221_shunt, INA3221_CHANNEL2);
633 static SENSOR_DEVICE_ATTR_RW(shunt3_resistor, ina3221_shunt, INA3221_CHANNEL3);
634 
635 static struct attribute *ina3221_attrs[] = {
636 	&sensor_dev_attr_shunt1_resistor.dev_attr.attr,
637 	&sensor_dev_attr_shunt2_resistor.dev_attr.attr,
638 	&sensor_dev_attr_shunt3_resistor.dev_attr.attr,
639 	NULL,
640 };
641 ATTRIBUTE_GROUPS(ina3221);
642 
643 static const struct regmap_range ina3221_yes_ranges[] = {
644 	regmap_reg_range(INA3221_CONFIG, INA3221_BUS3),
645 	regmap_reg_range(INA3221_MASK_ENABLE, INA3221_MASK_ENABLE),
646 };
647 
648 static const struct regmap_access_table ina3221_volatile_table = {
649 	.yes_ranges = ina3221_yes_ranges,
650 	.n_yes_ranges = ARRAY_SIZE(ina3221_yes_ranges),
651 };
652 
653 static const struct regmap_config ina3221_regmap_config = {
654 	.reg_bits = 8,
655 	.val_bits = 16,
656 
657 	.cache_type = REGCACHE_RBTREE,
658 	.volatile_table = &ina3221_volatile_table,
659 };
660 
661 static int ina3221_probe_child_from_dt(struct device *dev,
662 				       struct device_node *child,
663 				       struct ina3221_data *ina)
664 {
665 	struct ina3221_input *input;
666 	u32 val;
667 	int ret;
668 
669 	ret = of_property_read_u32(child, "reg", &val);
670 	if (ret) {
671 		dev_err(dev, "missing reg property of %pOFn\n", child);
672 		return ret;
673 	} else if (val > INA3221_CHANNEL3) {
674 		dev_err(dev, "invalid reg %d of %pOFn\n", val, child);
675 		return ret;
676 	}
677 
678 	input = &ina->inputs[val];
679 
680 	/* Log the disconnected channel input */
681 	if (!of_device_is_available(child)) {
682 		input->disconnected = true;
683 		return 0;
684 	}
685 
686 	/* Save the connected input label if available */
687 	of_property_read_string(child, "label", &input->label);
688 
689 	/* Overwrite default shunt resistor value optionally */
690 	if (!of_property_read_u32(child, "shunt-resistor-micro-ohms", &val)) {
691 		if (val < 1 || val > INT_MAX) {
692 			dev_err(dev, "invalid shunt resistor value %u of %pOFn\n",
693 				val, child);
694 			return -EINVAL;
695 		}
696 		input->shunt_resistor = val;
697 	}
698 
699 	return 0;
700 }
701 
702 static int ina3221_probe_from_dt(struct device *dev, struct ina3221_data *ina)
703 {
704 	const struct device_node *np = dev->of_node;
705 	struct device_node *child;
706 	int ret;
707 
708 	/* Compatible with non-DT platforms */
709 	if (!np)
710 		return 0;
711 
712 	ina->single_shot = of_property_read_bool(np, "ti,single-shot");
713 
714 	for_each_child_of_node(np, child) {
715 		ret = ina3221_probe_child_from_dt(dev, child, ina);
716 		if (ret) {
717 			of_node_put(child);
718 			return ret;
719 		}
720 	}
721 
722 	return 0;
723 }
724 
725 static int ina3221_probe(struct i2c_client *client,
726 			 const struct i2c_device_id *id)
727 {
728 	struct device *dev = &client->dev;
729 	struct ina3221_data *ina;
730 	struct device *hwmon_dev;
731 	int i, ret;
732 
733 	ina = devm_kzalloc(dev, sizeof(*ina), GFP_KERNEL);
734 	if (!ina)
735 		return -ENOMEM;
736 
737 	ina->regmap = devm_regmap_init_i2c(client, &ina3221_regmap_config);
738 	if (IS_ERR(ina->regmap)) {
739 		dev_err(dev, "Unable to allocate register map\n");
740 		return PTR_ERR(ina->regmap);
741 	}
742 
743 	for (i = 0; i < F_MAX_FIELDS; i++) {
744 		ina->fields[i] = devm_regmap_field_alloc(dev,
745 							 ina->regmap,
746 							 ina3221_reg_fields[i]);
747 		if (IS_ERR(ina->fields[i])) {
748 			dev_err(dev, "Unable to allocate regmap fields\n");
749 			return PTR_ERR(ina->fields[i]);
750 		}
751 	}
752 
753 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
754 		ina->inputs[i].shunt_resistor = INA3221_RSHUNT_DEFAULT;
755 
756 	ret = ina3221_probe_from_dt(dev, ina);
757 	if (ret) {
758 		dev_err(dev, "Unable to probe from device tree\n");
759 		return ret;
760 	}
761 
762 	/* The driver will be reset, so use reset value */
763 	ina->reg_config = INA3221_CONFIG_DEFAULT;
764 
765 	/* Clear continuous bit to use single-shot mode */
766 	if (ina->single_shot)
767 		ina->reg_config &= ~INA3221_CONFIG_MODE_CONTINUOUS;
768 
769 	/* Disable channels if their inputs are disconnected */
770 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
771 		if (ina->inputs[i].disconnected)
772 			ina->reg_config &= ~INA3221_CONFIG_CHx_EN(i);
773 	}
774 
775 	ina->pm_dev = dev;
776 	mutex_init(&ina->lock);
777 	dev_set_drvdata(dev, ina);
778 
779 	/* Enable PM runtime -- status is suspended by default */
780 	pm_runtime_enable(ina->pm_dev);
781 
782 	/* Initialize (resume) the device */
783 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
784 		if (ina->inputs[i].disconnected)
785 			continue;
786 		/* Match the refcount with number of enabled channels */
787 		ret = pm_runtime_get_sync(ina->pm_dev);
788 		if (ret < 0)
789 			goto fail;
790 	}
791 
792 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, ina,
793 							 &ina3221_chip_info,
794 							 ina3221_groups);
795 	if (IS_ERR(hwmon_dev)) {
796 		dev_err(dev, "Unable to register hwmon device\n");
797 		ret = PTR_ERR(hwmon_dev);
798 		goto fail;
799 	}
800 
801 	return 0;
802 
803 fail:
804 	pm_runtime_disable(ina->pm_dev);
805 	pm_runtime_set_suspended(ina->pm_dev);
806 	/* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
807 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
808 		pm_runtime_put_noidle(ina->pm_dev);
809 	mutex_destroy(&ina->lock);
810 
811 	return ret;
812 }
813 
814 static int ina3221_remove(struct i2c_client *client)
815 {
816 	struct ina3221_data *ina = dev_get_drvdata(&client->dev);
817 	int i;
818 
819 	pm_runtime_disable(ina->pm_dev);
820 	pm_runtime_set_suspended(ina->pm_dev);
821 
822 	/* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
823 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
824 		pm_runtime_put_noidle(ina->pm_dev);
825 
826 	mutex_destroy(&ina->lock);
827 
828 	return 0;
829 }
830 
831 static int __maybe_unused ina3221_suspend(struct device *dev)
832 {
833 	struct ina3221_data *ina = dev_get_drvdata(dev);
834 	int ret;
835 
836 	/* Save config register value and enable cache-only */
837 	ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
838 	if (ret)
839 		return ret;
840 
841 	/* Set to power-down mode for power saving */
842 	ret = regmap_update_bits(ina->regmap, INA3221_CONFIG,
843 				 INA3221_CONFIG_MODE_MASK,
844 				 INA3221_CONFIG_MODE_POWERDOWN);
845 	if (ret)
846 		return ret;
847 
848 	regcache_cache_only(ina->regmap, true);
849 	regcache_mark_dirty(ina->regmap);
850 
851 	return 0;
852 }
853 
854 static int __maybe_unused ina3221_resume(struct device *dev)
855 {
856 	struct ina3221_data *ina = dev_get_drvdata(dev);
857 	int ret;
858 
859 	regcache_cache_only(ina->regmap, false);
860 
861 	/* Software reset the chip */
862 	ret = regmap_field_write(ina->fields[F_RST], true);
863 	if (ret) {
864 		dev_err(dev, "Unable to reset device\n");
865 		return ret;
866 	}
867 
868 	/* Restore cached register values to hardware */
869 	ret = regcache_sync(ina->regmap);
870 	if (ret)
871 		return ret;
872 
873 	/* Restore config register value to hardware */
874 	ret = regmap_write(ina->regmap, INA3221_CONFIG, ina->reg_config);
875 	if (ret)
876 		return ret;
877 
878 	return 0;
879 }
880 
881 static const struct dev_pm_ops ina3221_pm = {
882 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
883 				pm_runtime_force_resume)
884 	SET_RUNTIME_PM_OPS(ina3221_suspend, ina3221_resume, NULL)
885 };
886 
887 static const struct of_device_id ina3221_of_match_table[] = {
888 	{ .compatible = "ti,ina3221", },
889 	{ /* sentinel */ }
890 };
891 MODULE_DEVICE_TABLE(of, ina3221_of_match_table);
892 
893 static const struct i2c_device_id ina3221_ids[] = {
894 	{ "ina3221", 0 },
895 	{ /* sentinel */ }
896 };
897 MODULE_DEVICE_TABLE(i2c, ina3221_ids);
898 
899 static struct i2c_driver ina3221_i2c_driver = {
900 	.probe = ina3221_probe,
901 	.remove = ina3221_remove,
902 	.driver = {
903 		.name = INA3221_DRIVER_NAME,
904 		.of_match_table = ina3221_of_match_table,
905 		.pm = &ina3221_pm,
906 	},
907 	.id_table = ina3221_ids,
908 };
909 module_i2c_driver(ina3221_i2c_driver);
910 
911 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
912 MODULE_DESCRIPTION("Texas Instruments INA3221 HWMon Driver");
913 MODULE_LICENSE("GPL v2");
914