xref: /linux/drivers/hwmon/ina3221.c (revision 6315d93541f8a5f77c5ef5c4f25233e66d189603)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * INA3221 Triple Current/Voltage Monitor
4  *
5  * Copyright (C) 2016 Texas Instruments Incorporated - https://www.ti.com/
6  *	Andrew F. Davis <afd@ti.com>
7  */
8 
9 #include <linux/debugfs.h>
10 #include <linux/hwmon.h>
11 #include <linux/hwmon-sysfs.h>
12 #include <linux/i2c.h>
13 #include <linux/module.h>
14 #include <linux/mutex.h>
15 #include <linux/of.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/regmap.h>
18 #include <linux/util_macros.h>
19 
20 #define INA3221_DRIVER_NAME		"ina3221"
21 
22 #define INA3221_CONFIG			0x00
23 #define INA3221_SHUNT1			0x01
24 #define INA3221_BUS1			0x02
25 #define INA3221_SHUNT2			0x03
26 #define INA3221_BUS2			0x04
27 #define INA3221_SHUNT3			0x05
28 #define INA3221_BUS3			0x06
29 #define INA3221_CRIT1			0x07
30 #define INA3221_WARN1			0x08
31 #define INA3221_CRIT2			0x09
32 #define INA3221_WARN2			0x0a
33 #define INA3221_CRIT3			0x0b
34 #define INA3221_WARN3			0x0c
35 #define INA3221_SHUNT_SUM		0x0d
36 #define INA3221_CRIT_SUM		0x0e
37 #define INA3221_MASK_ENABLE		0x0f
38 
39 #define INA3221_CONFIG_MODE_MASK	GENMASK(2, 0)
40 #define INA3221_CONFIG_MODE_POWERDOWN	0
41 #define INA3221_CONFIG_MODE_SHUNT	BIT(0)
42 #define INA3221_CONFIG_MODE_BUS		BIT(1)
43 #define INA3221_CONFIG_MODE_CONTINUOUS	BIT(2)
44 #define INA3221_CONFIG_VSH_CT_SHIFT	3
45 #define INA3221_CONFIG_VSH_CT_MASK	GENMASK(5, 3)
46 #define INA3221_CONFIG_VSH_CT(x)	(((x) & GENMASK(5, 3)) >> 3)
47 #define INA3221_CONFIG_VBUS_CT_SHIFT	6
48 #define INA3221_CONFIG_VBUS_CT_MASK	GENMASK(8, 6)
49 #define INA3221_CONFIG_VBUS_CT(x)	(((x) & GENMASK(8, 6)) >> 6)
50 #define INA3221_CONFIG_AVG_SHIFT	9
51 #define INA3221_CONFIG_AVG_MASK		GENMASK(11, 9)
52 #define INA3221_CONFIG_AVG(x)		(((x) & GENMASK(11, 9)) >> 9)
53 #define INA3221_CONFIG_CHs_EN_MASK	GENMASK(14, 12)
54 #define INA3221_CONFIG_CHx_EN(x)	BIT(14 - (x))
55 
56 #define INA3221_MASK_ENABLE_SCC_MASK	GENMASK(14, 12)
57 
58 #define INA3221_CONFIG_DEFAULT		0x7127
59 #define INA3221_RSHUNT_DEFAULT		10000
60 
61 enum ina3221_fields {
62 	/* Configuration */
63 	F_RST,
64 
65 	/* Status Flags */
66 	F_CVRF,
67 
68 	/* Warning Flags */
69 	F_WF3, F_WF2, F_WF1,
70 
71 	/* Alert Flags: SF is the summation-alert flag */
72 	F_SF, F_CF3, F_CF2, F_CF1,
73 
74 	/* sentinel */
75 	F_MAX_FIELDS
76 };
77 
78 static const struct reg_field ina3221_reg_fields[] = {
79 	[F_RST] = REG_FIELD(INA3221_CONFIG, 15, 15),
80 
81 	[F_CVRF] = REG_FIELD(INA3221_MASK_ENABLE, 0, 0),
82 	[F_WF3] = REG_FIELD(INA3221_MASK_ENABLE, 3, 3),
83 	[F_WF2] = REG_FIELD(INA3221_MASK_ENABLE, 4, 4),
84 	[F_WF1] = REG_FIELD(INA3221_MASK_ENABLE, 5, 5),
85 	[F_SF] = REG_FIELD(INA3221_MASK_ENABLE, 6, 6),
86 	[F_CF3] = REG_FIELD(INA3221_MASK_ENABLE, 7, 7),
87 	[F_CF2] = REG_FIELD(INA3221_MASK_ENABLE, 8, 8),
88 	[F_CF1] = REG_FIELD(INA3221_MASK_ENABLE, 9, 9),
89 };
90 
91 enum ina3221_channels {
92 	INA3221_CHANNEL1,
93 	INA3221_CHANNEL2,
94 	INA3221_CHANNEL3,
95 	INA3221_NUM_CHANNELS
96 };
97 
98 /**
99  * struct ina3221_input - channel input source specific information
100  * @label: label of channel input source
101  * @shunt_resistor: shunt resistor value of channel input source
102  * @disconnected: connection status of channel input source
103  * @summation_disable: channel summation status of input source
104  */
105 struct ina3221_input {
106 	const char *label;
107 	int shunt_resistor;
108 	bool disconnected;
109 	bool summation_disable;
110 };
111 
112 /**
113  * struct ina3221_data - device specific information
114  * @pm_dev: Device pointer for pm runtime
115  * @regmap: Register map of the device
116  * @fields: Register fields of the device
117  * @inputs: Array of channel input source specific structures
118  * @lock: mutex lock to serialize sysfs attribute accesses
119  * @reg_config: Register value of INA3221_CONFIG
120  * @summation_shunt_resistor: equivalent shunt resistor value for summation
121  * @summation_channel_control: Value written to SCC field in INA3221_MASK_ENABLE
122  * @single_shot: running in single-shot operating mode
123  */
124 struct ina3221_data {
125 	struct device *pm_dev;
126 	struct regmap *regmap;
127 	struct regmap_field *fields[F_MAX_FIELDS];
128 	struct ina3221_input inputs[INA3221_NUM_CHANNELS];
129 	struct mutex lock;
130 	u32 reg_config;
131 	int summation_shunt_resistor;
132 	u32 summation_channel_control;
133 
134 	bool single_shot;
135 };
136 
137 static inline bool ina3221_is_enabled(struct ina3221_data *ina, int channel)
138 {
139 	/* Summation channel checks shunt resistor values */
140 	if (channel > INA3221_CHANNEL3)
141 		return ina->summation_shunt_resistor != 0;
142 
143 	return pm_runtime_active(ina->pm_dev) &&
144 	       (ina->reg_config & INA3221_CONFIG_CHx_EN(channel));
145 }
146 
147 /*
148  * Helper function to return the resistor value for current summation.
149  *
150  * There is a condition to calculate current summation -- all the shunt
151  * resistor values should be the same, so as to simply fit the formula:
152  *     current summation = shunt voltage summation / shunt resistor
153  *
154  * Returns the equivalent shunt resistor value on success or 0 on failure
155  */
156 static inline int ina3221_summation_shunt_resistor(struct ina3221_data *ina)
157 {
158 	struct ina3221_input *input = ina->inputs;
159 	int i, shunt_resistor = 0;
160 
161 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
162 		if (input[i].disconnected || !input[i].shunt_resistor ||
163 		    input[i].summation_disable)
164 			continue;
165 		if (!shunt_resistor) {
166 			/* Found the reference shunt resistor value */
167 			shunt_resistor = input[i].shunt_resistor;
168 		} else {
169 			/* No summation if resistor values are different */
170 			if (shunt_resistor != input[i].shunt_resistor)
171 				return 0;
172 		}
173 	}
174 
175 	return shunt_resistor;
176 }
177 
178 /* Lookup table for Bus and Shunt conversion times in usec */
179 static const u16 ina3221_conv_time[] = {
180 	140, 204, 332, 588, 1100, 2116, 4156, 8244,
181 };
182 
183 /* Lookup table for number of samples using in averaging mode */
184 static const int ina3221_avg_samples[] = {
185 	1, 4, 16, 64, 128, 256, 512, 1024,
186 };
187 
188 /* Converting update_interval in msec to conversion time in usec */
189 static inline u32 ina3221_interval_ms_to_conv_time(u16 config, int interval)
190 {
191 	u32 channels = hweight16(config & INA3221_CONFIG_CHs_EN_MASK);
192 	u32 samples_idx = INA3221_CONFIG_AVG(config);
193 	u32 samples = ina3221_avg_samples[samples_idx];
194 
195 	/* Bisect the result to Bus and Shunt conversion times */
196 	return DIV_ROUND_CLOSEST(interval * 1000 / 2, channels * samples);
197 }
198 
199 /* Converting CONFIG register value to update_interval in usec */
200 static inline u32 ina3221_reg_to_interval_us(u16 config)
201 {
202 	u32 channels = hweight16(config & INA3221_CONFIG_CHs_EN_MASK);
203 	u32 vbus_ct_idx = INA3221_CONFIG_VBUS_CT(config);
204 	u32 vsh_ct_idx = INA3221_CONFIG_VSH_CT(config);
205 	u32 vbus_ct = ina3221_conv_time[vbus_ct_idx];
206 	u32 vsh_ct = ina3221_conv_time[vsh_ct_idx];
207 
208 	/* Calculate total conversion time */
209 	return channels * (vbus_ct + vsh_ct);
210 }
211 
212 static inline int ina3221_wait_for_data(struct ina3221_data *ina)
213 {
214 	u32 wait, cvrf;
215 
216 	wait = ina3221_reg_to_interval_us(ina->reg_config);
217 
218 	/* Polling the CVRF bit to make sure read data is ready */
219 	return regmap_field_read_poll_timeout(ina->fields[F_CVRF],
220 					      cvrf, cvrf, wait, wait * 2);
221 }
222 
223 static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
224 			      int *val)
225 {
226 	unsigned int regval;
227 	int ret;
228 
229 	ret = regmap_read(ina->regmap, reg, &regval);
230 	if (ret)
231 		return ret;
232 
233 	/*
234 	 * Shunt Voltage Sum register has 14-bit value with 1-bit shift
235 	 * Other Shunt Voltage registers have 12 bits with 3-bit shift
236 	 */
237 	if (reg == INA3221_SHUNT_SUM || reg == INA3221_CRIT_SUM)
238 		*val = sign_extend32(regval >> 1, 14);
239 	else
240 		*val = sign_extend32(regval >> 3, 12);
241 
242 	return 0;
243 }
244 
245 static const u8 ina3221_in_reg[] = {
246 	INA3221_BUS1,
247 	INA3221_BUS2,
248 	INA3221_BUS3,
249 	INA3221_SHUNT1,
250 	INA3221_SHUNT2,
251 	INA3221_SHUNT3,
252 	INA3221_SHUNT_SUM,
253 };
254 
255 static int ina3221_read_chip(struct device *dev, u32 attr, long *val)
256 {
257 	struct ina3221_data *ina = dev_get_drvdata(dev);
258 	int regval;
259 
260 	switch (attr) {
261 	case hwmon_chip_samples:
262 		regval = INA3221_CONFIG_AVG(ina->reg_config);
263 		*val = ina3221_avg_samples[regval];
264 		return 0;
265 	case hwmon_chip_update_interval:
266 		/* Return in msec */
267 		*val = ina3221_reg_to_interval_us(ina->reg_config);
268 		*val = DIV_ROUND_CLOSEST(*val, 1000);
269 		return 0;
270 	default:
271 		return -EOPNOTSUPP;
272 	}
273 }
274 
275 static int ina3221_read_in(struct device *dev, u32 attr, int channel, long *val)
276 {
277 	const bool is_shunt = channel > INA3221_CHANNEL3;
278 	struct ina3221_data *ina = dev_get_drvdata(dev);
279 	u8 reg = ina3221_in_reg[channel];
280 	int regval, ret;
281 
282 	/*
283 	 * Translate shunt channel index to sensor channel index except
284 	 * the 7th channel (6 since being 0-aligned) is for summation.
285 	 */
286 	if (channel != 6)
287 		channel %= INA3221_NUM_CHANNELS;
288 
289 	switch (attr) {
290 	case hwmon_in_input:
291 		if (!ina3221_is_enabled(ina, channel))
292 			return -ENODATA;
293 
294 		/* Write CONFIG register to trigger a single-shot measurement */
295 		if (ina->single_shot) {
296 			regmap_write(ina->regmap, INA3221_CONFIG,
297 				     ina->reg_config);
298 
299 			ret = ina3221_wait_for_data(ina);
300 			if (ret)
301 				return ret;
302 		}
303 
304 		ret = ina3221_read_value(ina, reg, &regval);
305 		if (ret)
306 			return ret;
307 
308 		/*
309 		 * Scale of shunt voltage (uV): LSB is 40uV
310 		 * Scale of bus voltage (mV): LSB is 8mV
311 		 */
312 		*val = regval * (is_shunt ? 40 : 8);
313 		return 0;
314 	case hwmon_in_enable:
315 		*val = ina3221_is_enabled(ina, channel);
316 		return 0;
317 	default:
318 		return -EOPNOTSUPP;
319 	}
320 }
321 
322 static const u8 ina3221_curr_reg[][INA3221_NUM_CHANNELS + 1] = {
323 	[hwmon_curr_input] = { INA3221_SHUNT1, INA3221_SHUNT2,
324 			       INA3221_SHUNT3, INA3221_SHUNT_SUM },
325 	[hwmon_curr_max] = { INA3221_WARN1, INA3221_WARN2, INA3221_WARN3, 0 },
326 	[hwmon_curr_crit] = { INA3221_CRIT1, INA3221_CRIT2,
327 			      INA3221_CRIT3, INA3221_CRIT_SUM },
328 	[hwmon_curr_max_alarm] = { F_WF1, F_WF2, F_WF3, 0 },
329 	[hwmon_curr_crit_alarm] = { F_CF1, F_CF2, F_CF3, F_SF },
330 };
331 
332 static int ina3221_read_curr(struct device *dev, u32 attr,
333 			     int channel, long *val)
334 {
335 	struct ina3221_data *ina = dev_get_drvdata(dev);
336 	struct ina3221_input *input = ina->inputs;
337 	u8 reg = ina3221_curr_reg[attr][channel];
338 	int resistance_uo, voltage_nv;
339 	int regval, ret;
340 
341 	if (channel > INA3221_CHANNEL3)
342 		resistance_uo = ina->summation_shunt_resistor;
343 	else
344 		resistance_uo = input[channel].shunt_resistor;
345 
346 	switch (attr) {
347 	case hwmon_curr_input:
348 		if (!ina3221_is_enabled(ina, channel))
349 			return -ENODATA;
350 
351 		/* Write CONFIG register to trigger a single-shot measurement */
352 		if (ina->single_shot) {
353 			regmap_write(ina->regmap, INA3221_CONFIG,
354 				     ina->reg_config);
355 
356 			ret = ina3221_wait_for_data(ina);
357 			if (ret)
358 				return ret;
359 		}
360 
361 		fallthrough;
362 	case hwmon_curr_crit:
363 	case hwmon_curr_max:
364 		if (!resistance_uo)
365 			return -ENODATA;
366 
367 		ret = ina3221_read_value(ina, reg, &regval);
368 		if (ret)
369 			return ret;
370 
371 		/* Scale of shunt voltage: LSB is 40uV (40000nV) */
372 		voltage_nv = regval * 40000;
373 		/* Return current in mA */
374 		*val = DIV_ROUND_CLOSEST(voltage_nv, resistance_uo);
375 		return 0;
376 	case hwmon_curr_crit_alarm:
377 	case hwmon_curr_max_alarm:
378 		/* No actual register read if channel is disabled */
379 		if (!ina3221_is_enabled(ina, channel)) {
380 			/* Return 0 for alert flags */
381 			*val = 0;
382 			return 0;
383 		}
384 		ret = regmap_field_read(ina->fields[reg], &regval);
385 		if (ret)
386 			return ret;
387 		*val = regval;
388 		return 0;
389 	default:
390 		return -EOPNOTSUPP;
391 	}
392 }
393 
394 static int ina3221_write_chip(struct device *dev, u32 attr, long val)
395 {
396 	struct ina3221_data *ina = dev_get_drvdata(dev);
397 	int ret, idx;
398 	u32 tmp;
399 
400 	switch (attr) {
401 	case hwmon_chip_samples:
402 		idx = find_closest(val, ina3221_avg_samples,
403 				   ARRAY_SIZE(ina3221_avg_samples));
404 
405 		tmp = (ina->reg_config & ~INA3221_CONFIG_AVG_MASK) |
406 		      (idx << INA3221_CONFIG_AVG_SHIFT);
407 		ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
408 		if (ret)
409 			return ret;
410 
411 		/* Update reg_config accordingly */
412 		ina->reg_config = tmp;
413 		return 0;
414 	case hwmon_chip_update_interval:
415 		tmp = ina3221_interval_ms_to_conv_time(ina->reg_config, val);
416 		idx = find_closest(tmp, ina3221_conv_time,
417 				   ARRAY_SIZE(ina3221_conv_time));
418 
419 		/* Update Bus and Shunt voltage conversion times */
420 		tmp = INA3221_CONFIG_VBUS_CT_MASK | INA3221_CONFIG_VSH_CT_MASK;
421 		tmp = (ina->reg_config & ~tmp) |
422 		      (idx << INA3221_CONFIG_VBUS_CT_SHIFT) |
423 		      (idx << INA3221_CONFIG_VSH_CT_SHIFT);
424 		ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
425 		if (ret)
426 			return ret;
427 
428 		/* Update reg_config accordingly */
429 		ina->reg_config = tmp;
430 		return 0;
431 	default:
432 		return -EOPNOTSUPP;
433 	}
434 }
435 
436 static int ina3221_write_curr(struct device *dev, u32 attr,
437 			      int channel, long val)
438 {
439 	struct ina3221_data *ina = dev_get_drvdata(dev);
440 	struct ina3221_input *input = ina->inputs;
441 	u8 reg = ina3221_curr_reg[attr][channel];
442 	int resistance_uo, current_ma, voltage_uv;
443 	int regval;
444 
445 	if (channel > INA3221_CHANNEL3)
446 		resistance_uo = ina->summation_shunt_resistor;
447 	else
448 		resistance_uo = input[channel].shunt_resistor;
449 
450 	if (!resistance_uo)
451 		return -EOPNOTSUPP;
452 
453 	/* clamp current */
454 	current_ma = clamp_val(val,
455 			       INT_MIN / resistance_uo,
456 			       INT_MAX / resistance_uo);
457 
458 	voltage_uv = DIV_ROUND_CLOSEST(current_ma * resistance_uo, 1000);
459 
460 	/* clamp voltage */
461 	voltage_uv = clamp_val(voltage_uv, -163800, 163800);
462 
463 	/*
464 	 * Formula to convert voltage_uv to register value:
465 	 *     regval = (voltage_uv / scale) << shift
466 	 * Note:
467 	 *     The scale is 40uV for all shunt voltage registers
468 	 *     Shunt Voltage Sum register left-shifts 1 bit
469 	 *     All other Shunt Voltage registers shift 3 bits
470 	 * Results:
471 	 *     SHUNT_SUM: (1 / 40uV) << 1 = 1 / 20uV
472 	 *     SHUNT[1-3]: (1 / 40uV) << 3 = 1 / 5uV
473 	 */
474 	if (reg == INA3221_SHUNT_SUM || reg == INA3221_CRIT_SUM)
475 		regval = DIV_ROUND_CLOSEST(voltage_uv, 20) & 0xfffe;
476 	else
477 		regval = DIV_ROUND_CLOSEST(voltage_uv, 5) & 0xfff8;
478 
479 	return regmap_write(ina->regmap, reg, regval);
480 }
481 
482 static int ina3221_write_enable(struct device *dev, int channel, bool enable)
483 {
484 	struct ina3221_data *ina = dev_get_drvdata(dev);
485 	u16 config, mask = INA3221_CONFIG_CHx_EN(channel);
486 	u16 config_old = ina->reg_config & mask;
487 	u32 tmp;
488 	int ret;
489 
490 	config = enable ? mask : 0;
491 
492 	/* Bypass if enable status is not being changed */
493 	if (config_old == config)
494 		return 0;
495 
496 	/* For enabling routine, increase refcount and resume() at first */
497 	if (enable) {
498 		ret = pm_runtime_resume_and_get(ina->pm_dev);
499 		if (ret < 0) {
500 			dev_err(dev, "Failed to get PM runtime\n");
501 			return ret;
502 		}
503 	}
504 
505 	/* Enable or disable the channel */
506 	tmp = (ina->reg_config & ~mask) | (config & mask);
507 	ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
508 	if (ret)
509 		goto fail;
510 
511 	/* Cache the latest config register value */
512 	ina->reg_config = tmp;
513 
514 	/* For disabling routine, decrease refcount or suspend() at last */
515 	if (!enable)
516 		pm_runtime_put_sync(ina->pm_dev);
517 
518 	return 0;
519 
520 fail:
521 	if (enable) {
522 		dev_err(dev, "Failed to enable channel %d: error %d\n",
523 			channel, ret);
524 		pm_runtime_put_sync(ina->pm_dev);
525 	}
526 
527 	return ret;
528 }
529 
530 static int ina3221_read(struct device *dev, enum hwmon_sensor_types type,
531 			u32 attr, int channel, long *val)
532 {
533 	struct ina3221_data *ina = dev_get_drvdata(dev);
534 	int ret;
535 
536 	mutex_lock(&ina->lock);
537 
538 	switch (type) {
539 	case hwmon_chip:
540 		ret = ina3221_read_chip(dev, attr, val);
541 		break;
542 	case hwmon_in:
543 		/* 0-align channel ID */
544 		ret = ina3221_read_in(dev, attr, channel - 1, val);
545 		break;
546 	case hwmon_curr:
547 		ret = ina3221_read_curr(dev, attr, channel, val);
548 		break;
549 	default:
550 		ret = -EOPNOTSUPP;
551 		break;
552 	}
553 
554 	mutex_unlock(&ina->lock);
555 
556 	return ret;
557 }
558 
559 static int ina3221_write(struct device *dev, enum hwmon_sensor_types type,
560 			 u32 attr, int channel, long val)
561 {
562 	struct ina3221_data *ina = dev_get_drvdata(dev);
563 	int ret;
564 
565 	mutex_lock(&ina->lock);
566 
567 	switch (type) {
568 	case hwmon_chip:
569 		ret = ina3221_write_chip(dev, attr, val);
570 		break;
571 	case hwmon_in:
572 		/* 0-align channel ID */
573 		ret = ina3221_write_enable(dev, channel - 1, val);
574 		break;
575 	case hwmon_curr:
576 		ret = ina3221_write_curr(dev, attr, channel, val);
577 		break;
578 	default:
579 		ret = -EOPNOTSUPP;
580 		break;
581 	}
582 
583 	mutex_unlock(&ina->lock);
584 
585 	return ret;
586 }
587 
588 static int ina3221_read_string(struct device *dev, enum hwmon_sensor_types type,
589 			       u32 attr, int channel, const char **str)
590 {
591 	struct ina3221_data *ina = dev_get_drvdata(dev);
592 	int index = channel - 1;
593 
594 	if (channel == 7)
595 		*str = "sum of shunt voltages";
596 	else
597 		*str = ina->inputs[index].label;
598 
599 	return 0;
600 }
601 
602 static umode_t ina3221_is_visible(const void *drvdata,
603 				  enum hwmon_sensor_types type,
604 				  u32 attr, int channel)
605 {
606 	const struct ina3221_data *ina = drvdata;
607 	const struct ina3221_input *input = NULL;
608 
609 	switch (type) {
610 	case hwmon_chip:
611 		switch (attr) {
612 		case hwmon_chip_samples:
613 		case hwmon_chip_update_interval:
614 			return 0644;
615 		default:
616 			return 0;
617 		}
618 	case hwmon_in:
619 		/* Ignore in0_ */
620 		if (channel == 0)
621 			return 0;
622 
623 		switch (attr) {
624 		case hwmon_in_label:
625 			if (channel - 1 <= INA3221_CHANNEL3)
626 				input = &ina->inputs[channel - 1];
627 			else if (channel == 7)
628 				return 0444;
629 			/* Hide label node if label is not provided */
630 			return (input && input->label) ? 0444 : 0;
631 		case hwmon_in_input:
632 			return 0444;
633 		case hwmon_in_enable:
634 			return 0644;
635 		default:
636 			return 0;
637 		}
638 	case hwmon_curr:
639 		switch (attr) {
640 		case hwmon_curr_input:
641 		case hwmon_curr_crit_alarm:
642 		case hwmon_curr_max_alarm:
643 			return 0444;
644 		case hwmon_curr_crit:
645 		case hwmon_curr_max:
646 			return 0644;
647 		default:
648 			return 0;
649 		}
650 	default:
651 		return 0;
652 	}
653 }
654 
655 #define INA3221_HWMON_CURR_CONFIG (HWMON_C_INPUT | \
656 				   HWMON_C_CRIT | HWMON_C_CRIT_ALARM | \
657 				   HWMON_C_MAX | HWMON_C_MAX_ALARM)
658 
659 static const struct hwmon_channel_info * const ina3221_info[] = {
660 	HWMON_CHANNEL_INFO(chip,
661 			   HWMON_C_SAMPLES,
662 			   HWMON_C_UPDATE_INTERVAL),
663 	HWMON_CHANNEL_INFO(in,
664 			   /* 0: dummy, skipped in is_visible */
665 			   HWMON_I_INPUT,
666 			   /* 1-3: input voltage Channels */
667 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
668 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
669 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
670 			   /* 4-6: shunt voltage Channels */
671 			   HWMON_I_INPUT,
672 			   HWMON_I_INPUT,
673 			   HWMON_I_INPUT,
674 			   /* 7: summation of shunt voltage channels */
675 			   HWMON_I_INPUT | HWMON_I_LABEL),
676 	HWMON_CHANNEL_INFO(curr,
677 			   /* 1-3: current channels*/
678 			   INA3221_HWMON_CURR_CONFIG,
679 			   INA3221_HWMON_CURR_CONFIG,
680 			   INA3221_HWMON_CURR_CONFIG,
681 			   /* 4: summation of current channels */
682 			   HWMON_C_INPUT | HWMON_C_CRIT | HWMON_C_CRIT_ALARM),
683 	NULL
684 };
685 
686 static const struct hwmon_ops ina3221_hwmon_ops = {
687 	.is_visible = ina3221_is_visible,
688 	.read_string = ina3221_read_string,
689 	.read = ina3221_read,
690 	.write = ina3221_write,
691 };
692 
693 static const struct hwmon_chip_info ina3221_chip_info = {
694 	.ops = &ina3221_hwmon_ops,
695 	.info = ina3221_info,
696 };
697 
698 /* Extra attribute groups */
699 static ssize_t ina3221_shunt_show(struct device *dev,
700 				  struct device_attribute *attr, char *buf)
701 {
702 	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
703 	struct ina3221_data *ina = dev_get_drvdata(dev);
704 	unsigned int channel = sd_attr->index;
705 	struct ina3221_input *input = &ina->inputs[channel];
706 
707 	return sysfs_emit(buf, "%d\n", input->shunt_resistor);
708 }
709 
710 static ssize_t ina3221_shunt_store(struct device *dev,
711 				   struct device_attribute *attr,
712 				   const char *buf, size_t count)
713 {
714 	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
715 	struct ina3221_data *ina = dev_get_drvdata(dev);
716 	unsigned int channel = sd_attr->index;
717 	struct ina3221_input *input = &ina->inputs[channel];
718 	int val;
719 	int ret;
720 
721 	ret = kstrtoint(buf, 0, &val);
722 	if (ret)
723 		return ret;
724 
725 	val = clamp_val(val, 1, INT_MAX);
726 
727 	input->shunt_resistor = val;
728 
729 	/* Update summation_shunt_resistor for summation channel */
730 	ina->summation_shunt_resistor = ina3221_summation_shunt_resistor(ina);
731 
732 	return count;
733 }
734 
735 /* shunt resistance */
736 static SENSOR_DEVICE_ATTR_RW(shunt1_resistor, ina3221_shunt, INA3221_CHANNEL1);
737 static SENSOR_DEVICE_ATTR_RW(shunt2_resistor, ina3221_shunt, INA3221_CHANNEL2);
738 static SENSOR_DEVICE_ATTR_RW(shunt3_resistor, ina3221_shunt, INA3221_CHANNEL3);
739 
740 static struct attribute *ina3221_attrs[] = {
741 	&sensor_dev_attr_shunt1_resistor.dev_attr.attr,
742 	&sensor_dev_attr_shunt2_resistor.dev_attr.attr,
743 	&sensor_dev_attr_shunt3_resistor.dev_attr.attr,
744 	NULL,
745 };
746 ATTRIBUTE_GROUPS(ina3221);
747 
748 static const struct regmap_range ina3221_yes_ranges[] = {
749 	regmap_reg_range(INA3221_CONFIG, INA3221_BUS3),
750 	regmap_reg_range(INA3221_SHUNT_SUM, INA3221_SHUNT_SUM),
751 	regmap_reg_range(INA3221_MASK_ENABLE, INA3221_MASK_ENABLE),
752 };
753 
754 static const struct regmap_access_table ina3221_volatile_table = {
755 	.yes_ranges = ina3221_yes_ranges,
756 	.n_yes_ranges = ARRAY_SIZE(ina3221_yes_ranges),
757 };
758 
759 static const struct regmap_config ina3221_regmap_config = {
760 	.reg_bits = 8,
761 	.val_bits = 16,
762 
763 	.cache_type = REGCACHE_MAPLE,
764 	.volatile_table = &ina3221_volatile_table,
765 };
766 
767 static int ina3221_probe_child_from_dt(struct device *dev,
768 				       struct device_node *child,
769 				       struct ina3221_data *ina)
770 {
771 	struct ina3221_input *input;
772 	u32 val;
773 	int ret;
774 
775 	ret = of_property_read_u32(child, "reg", &val);
776 	if (ret) {
777 		dev_err(dev, "missing reg property of %pOFn\n", child);
778 		return ret;
779 	} else if (val > INA3221_CHANNEL3) {
780 		dev_err(dev, "invalid reg %d of %pOFn\n", val, child);
781 		return -EINVAL;
782 	}
783 
784 	input = &ina->inputs[val];
785 
786 	/* Log the disconnected channel input */
787 	if (!of_device_is_available(child)) {
788 		input->disconnected = true;
789 		return 0;
790 	}
791 
792 	/* Save the connected input label if available */
793 	of_property_read_string(child, "label", &input->label);
794 
795 	/* summation channel control */
796 	input->summation_disable = of_property_read_bool(child, "ti,summation-disable");
797 
798 	/* Overwrite default shunt resistor value optionally */
799 	if (!of_property_read_u32(child, "shunt-resistor-micro-ohms", &val)) {
800 		if (val < 1 || val > INT_MAX) {
801 			dev_err(dev, "invalid shunt resistor value %u of %pOFn\n",
802 				val, child);
803 			return -EINVAL;
804 		}
805 		input->shunt_resistor = val;
806 	}
807 
808 	return 0;
809 }
810 
811 static int ina3221_probe_from_dt(struct device *dev, struct ina3221_data *ina)
812 {
813 	const struct device_node *np = dev->of_node;
814 	int ret;
815 
816 	/* Compatible with non-DT platforms */
817 	if (!np)
818 		return 0;
819 
820 	ina->single_shot = of_property_read_bool(np, "ti,single-shot");
821 
822 	for_each_child_of_node_scoped(np, child) {
823 		ret = ina3221_probe_child_from_dt(dev, child, ina);
824 		if (ret)
825 			return ret;
826 	}
827 
828 	return 0;
829 }
830 
831 static int ina3221_probe(struct i2c_client *client)
832 {
833 	struct device *dev = &client->dev;
834 	struct ina3221_data *ina;
835 	struct device *hwmon_dev;
836 	char name[32];
837 	int i, ret;
838 
839 	ina = devm_kzalloc(dev, sizeof(*ina), GFP_KERNEL);
840 	if (!ina)
841 		return -ENOMEM;
842 
843 	ina->regmap = devm_regmap_init_i2c(client, &ina3221_regmap_config);
844 	if (IS_ERR(ina->regmap)) {
845 		dev_err(dev, "Unable to allocate register map\n");
846 		return PTR_ERR(ina->regmap);
847 	}
848 
849 	for (i = 0; i < F_MAX_FIELDS; i++) {
850 		ina->fields[i] = devm_regmap_field_alloc(dev,
851 							 ina->regmap,
852 							 ina3221_reg_fields[i]);
853 		if (IS_ERR(ina->fields[i])) {
854 			dev_err(dev, "Unable to allocate regmap fields\n");
855 			return PTR_ERR(ina->fields[i]);
856 		}
857 	}
858 
859 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
860 		ina->inputs[i].shunt_resistor = INA3221_RSHUNT_DEFAULT;
861 
862 	ret = ina3221_probe_from_dt(dev, ina);
863 	if (ret) {
864 		dev_err(dev, "Unable to probe from device tree\n");
865 		return ret;
866 	}
867 
868 	/* The driver will be reset, so use reset value */
869 	ina->reg_config = INA3221_CONFIG_DEFAULT;
870 
871 	/* Clear continuous bit to use single-shot mode */
872 	if (ina->single_shot)
873 		ina->reg_config &= ~INA3221_CONFIG_MODE_CONTINUOUS;
874 
875 	/* Disable channels if their inputs are disconnected */
876 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
877 		if (ina->inputs[i].disconnected)
878 			ina->reg_config &= ~INA3221_CONFIG_CHx_EN(i);
879 	}
880 
881 	/* Initialize summation_shunt_resistor for summation channel control */
882 	ina->summation_shunt_resistor = ina3221_summation_shunt_resistor(ina);
883 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
884 		if (!ina->inputs[i].summation_disable)
885 			ina->summation_channel_control |= BIT(14 - i);
886 	}
887 
888 	ina->pm_dev = dev;
889 	mutex_init(&ina->lock);
890 	dev_set_drvdata(dev, ina);
891 
892 	/* Enable PM runtime -- status is suspended by default */
893 	pm_runtime_enable(ina->pm_dev);
894 
895 	/* Initialize (resume) the device */
896 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
897 		if (ina->inputs[i].disconnected)
898 			continue;
899 		/* Match the refcount with number of enabled channels */
900 		ret = pm_runtime_get_sync(ina->pm_dev);
901 		if (ret < 0)
902 			goto fail;
903 	}
904 
905 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, ina,
906 							 &ina3221_chip_info,
907 							 ina3221_groups);
908 	if (IS_ERR(hwmon_dev)) {
909 		dev_err(dev, "Unable to register hwmon device\n");
910 		ret = PTR_ERR(hwmon_dev);
911 		goto fail;
912 	}
913 
914 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
915 		scnprintf(name, sizeof(name), "in%d_summation_disable", i);
916 		debugfs_create_bool(name, 0400, client->debugfs,
917 				    &ina->inputs[i].summation_disable);
918 	}
919 
920 	return 0;
921 
922 fail:
923 	pm_runtime_disable(ina->pm_dev);
924 	pm_runtime_set_suspended(ina->pm_dev);
925 	/* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
926 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
927 		pm_runtime_put_noidle(ina->pm_dev);
928 	mutex_destroy(&ina->lock);
929 
930 	return ret;
931 }
932 
933 static void ina3221_remove(struct i2c_client *client)
934 {
935 	struct ina3221_data *ina = dev_get_drvdata(&client->dev);
936 	int i;
937 
938 	pm_runtime_disable(ina->pm_dev);
939 	pm_runtime_set_suspended(ina->pm_dev);
940 
941 	/* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
942 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
943 		pm_runtime_put_noidle(ina->pm_dev);
944 
945 	mutex_destroy(&ina->lock);
946 }
947 
948 static int ina3221_suspend(struct device *dev)
949 {
950 	struct ina3221_data *ina = dev_get_drvdata(dev);
951 	int ret;
952 
953 	/* Save config register value and enable cache-only */
954 	ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
955 	if (ret)
956 		return ret;
957 
958 	/* Set to power-down mode for power saving */
959 	ret = regmap_update_bits(ina->regmap, INA3221_CONFIG,
960 				 INA3221_CONFIG_MODE_MASK,
961 				 INA3221_CONFIG_MODE_POWERDOWN);
962 	if (ret)
963 		return ret;
964 
965 	regcache_cache_only(ina->regmap, true);
966 	regcache_mark_dirty(ina->regmap);
967 
968 	return 0;
969 }
970 
971 static int ina3221_resume(struct device *dev)
972 {
973 	struct ina3221_data *ina = dev_get_drvdata(dev);
974 	int ret;
975 
976 	regcache_cache_only(ina->regmap, false);
977 
978 	/* Software reset the chip */
979 	ret = regmap_field_write(ina->fields[F_RST], true);
980 	if (ret) {
981 		dev_err(dev, "Unable to reset device\n");
982 		return ret;
983 	}
984 
985 	/* Restore cached register values to hardware */
986 	ret = regcache_sync(ina->regmap);
987 	if (ret)
988 		return ret;
989 
990 	/* Restore config register value to hardware */
991 	ret = regmap_write(ina->regmap, INA3221_CONFIG, ina->reg_config);
992 	if (ret)
993 		return ret;
994 
995 	/* Initialize summation channel control */
996 	if (ina->summation_shunt_resistor) {
997 		/*
998 		 * Sum only channels that are not disabled for summation.
999 		 * Shunt measurements of disconnected channels should
1000 		 * be 0, so it does not matter for summation.
1001 		 */
1002 		ret = regmap_update_bits(ina->regmap, INA3221_MASK_ENABLE,
1003 					 INA3221_MASK_ENABLE_SCC_MASK,
1004 					 ina->summation_channel_control);
1005 		if (ret) {
1006 			dev_err(dev, "Unable to control summation channel\n");
1007 			return ret;
1008 		}
1009 	}
1010 
1011 	return 0;
1012 }
1013 
1014 static DEFINE_RUNTIME_DEV_PM_OPS(ina3221_pm, ina3221_suspend, ina3221_resume,
1015 				 NULL);
1016 
1017 static const struct of_device_id ina3221_of_match_table[] = {
1018 	{ .compatible = "ti,ina3221", },
1019 	{ /* sentinel */ }
1020 };
1021 MODULE_DEVICE_TABLE(of, ina3221_of_match_table);
1022 
1023 static const struct i2c_device_id ina3221_ids[] = {
1024 	{ "ina3221" },
1025 	{ /* sentinel */ }
1026 };
1027 MODULE_DEVICE_TABLE(i2c, ina3221_ids);
1028 
1029 static struct i2c_driver ina3221_i2c_driver = {
1030 	.probe = ina3221_probe,
1031 	.remove = ina3221_remove,
1032 	.driver = {
1033 		.name = INA3221_DRIVER_NAME,
1034 		.of_match_table = ina3221_of_match_table,
1035 		.pm = pm_ptr(&ina3221_pm),
1036 	},
1037 	.id_table = ina3221_ids,
1038 };
1039 module_i2c_driver(ina3221_i2c_driver);
1040 
1041 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
1042 MODULE_DESCRIPTION("Texas Instruments INA3221 HWMon Driver");
1043 MODULE_LICENSE("GPL v2");
1044