xref: /linux/drivers/hwmon/ina3221.c (revision 3d0fe49454652117522f60bfbefb978ba0e5300b)
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  * @debugfs: Pointer to debugfs entry for device
120  * @reg_config: Register value of INA3221_CONFIG
121  * @summation_shunt_resistor: equivalent shunt resistor value for summation
122  * @summation_channel_control: Value written to SCC field in INA3221_MASK_ENABLE
123  * @single_shot: running in single-shot operating mode
124  */
125 struct ina3221_data {
126 	struct device *pm_dev;
127 	struct regmap *regmap;
128 	struct regmap_field *fields[F_MAX_FIELDS];
129 	struct ina3221_input inputs[INA3221_NUM_CHANNELS];
130 	struct mutex lock;
131 	struct dentry *debugfs;
132 	u32 reg_config;
133 	int summation_shunt_resistor;
134 	u32 summation_channel_control;
135 
136 	bool single_shot;
137 };
138 
139 static inline bool ina3221_is_enabled(struct ina3221_data *ina, int channel)
140 {
141 	/* Summation channel checks shunt resistor values */
142 	if (channel > INA3221_CHANNEL3)
143 		return ina->summation_shunt_resistor != 0;
144 
145 	return pm_runtime_active(ina->pm_dev) &&
146 	       (ina->reg_config & INA3221_CONFIG_CHx_EN(channel));
147 }
148 
149 /*
150  * Helper function to return the resistor value for current summation.
151  *
152  * There is a condition to calculate current summation -- all the shunt
153  * resistor values should be the same, so as to simply fit the formula:
154  *     current summation = shunt voltage summation / shunt resistor
155  *
156  * Returns the equivalent shunt resistor value on success or 0 on failure
157  */
158 static inline int ina3221_summation_shunt_resistor(struct ina3221_data *ina)
159 {
160 	struct ina3221_input *input = ina->inputs;
161 	int i, shunt_resistor = 0;
162 
163 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
164 		if (input[i].disconnected || !input[i].shunt_resistor ||
165 		    input[i].summation_disable)
166 			continue;
167 		if (!shunt_resistor) {
168 			/* Found the reference shunt resistor value */
169 			shunt_resistor = input[i].shunt_resistor;
170 		} else {
171 			/* No summation if resistor values are different */
172 			if (shunt_resistor != input[i].shunt_resistor)
173 				return 0;
174 		}
175 	}
176 
177 	return shunt_resistor;
178 }
179 
180 /* Lookup table for Bus and Shunt conversion times in usec */
181 static const u16 ina3221_conv_time[] = {
182 	140, 204, 332, 588, 1100, 2116, 4156, 8244,
183 };
184 
185 /* Lookup table for number of samples using in averaging mode */
186 static const int ina3221_avg_samples[] = {
187 	1, 4, 16, 64, 128, 256, 512, 1024,
188 };
189 
190 /* Converting update_interval in msec to conversion time in usec */
191 static inline u32 ina3221_interval_ms_to_conv_time(u16 config, int interval)
192 {
193 	u32 channels = hweight16(config & INA3221_CONFIG_CHs_EN_MASK);
194 	u32 samples_idx = INA3221_CONFIG_AVG(config);
195 	u32 samples = ina3221_avg_samples[samples_idx];
196 
197 	/* Bisect the result to Bus and Shunt conversion times */
198 	return DIV_ROUND_CLOSEST(interval * 1000 / 2, channels * samples);
199 }
200 
201 /* Converting CONFIG register value to update_interval in usec */
202 static inline u32 ina3221_reg_to_interval_us(u16 config)
203 {
204 	u32 channels = hweight16(config & INA3221_CONFIG_CHs_EN_MASK);
205 	u32 vbus_ct_idx = INA3221_CONFIG_VBUS_CT(config);
206 	u32 vsh_ct_idx = INA3221_CONFIG_VSH_CT(config);
207 	u32 vbus_ct = ina3221_conv_time[vbus_ct_idx];
208 	u32 vsh_ct = ina3221_conv_time[vsh_ct_idx];
209 
210 	/* Calculate total conversion time */
211 	return channels * (vbus_ct + vsh_ct);
212 }
213 
214 static inline int ina3221_wait_for_data(struct ina3221_data *ina)
215 {
216 	u32 wait, cvrf;
217 
218 	wait = ina3221_reg_to_interval_us(ina->reg_config);
219 
220 	/* Polling the CVRF bit to make sure read data is ready */
221 	return regmap_field_read_poll_timeout(ina->fields[F_CVRF],
222 					      cvrf, cvrf, wait, wait * 2);
223 }
224 
225 static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
226 			      int *val)
227 {
228 	unsigned int regval;
229 	int ret;
230 
231 	ret = regmap_read(ina->regmap, reg, &regval);
232 	if (ret)
233 		return ret;
234 
235 	/*
236 	 * Shunt Voltage Sum register has 14-bit value with 1-bit shift
237 	 * Other Shunt Voltage registers have 12 bits with 3-bit shift
238 	 */
239 	if (reg == INA3221_SHUNT_SUM || reg == INA3221_CRIT_SUM)
240 		*val = sign_extend32(regval >> 1, 14);
241 	else
242 		*val = sign_extend32(regval >> 3, 12);
243 
244 	return 0;
245 }
246 
247 static const u8 ina3221_in_reg[] = {
248 	INA3221_BUS1,
249 	INA3221_BUS2,
250 	INA3221_BUS3,
251 	INA3221_SHUNT1,
252 	INA3221_SHUNT2,
253 	INA3221_SHUNT3,
254 	INA3221_SHUNT_SUM,
255 };
256 
257 static int ina3221_read_chip(struct device *dev, u32 attr, long *val)
258 {
259 	struct ina3221_data *ina = dev_get_drvdata(dev);
260 	int regval;
261 
262 	switch (attr) {
263 	case hwmon_chip_samples:
264 		regval = INA3221_CONFIG_AVG(ina->reg_config);
265 		*val = ina3221_avg_samples[regval];
266 		return 0;
267 	case hwmon_chip_update_interval:
268 		/* Return in msec */
269 		*val = ina3221_reg_to_interval_us(ina->reg_config);
270 		*val = DIV_ROUND_CLOSEST(*val, 1000);
271 		return 0;
272 	default:
273 		return -EOPNOTSUPP;
274 	}
275 }
276 
277 static int ina3221_read_in(struct device *dev, u32 attr, int channel, long *val)
278 {
279 	const bool is_shunt = channel > INA3221_CHANNEL3;
280 	struct ina3221_data *ina = dev_get_drvdata(dev);
281 	u8 reg = ina3221_in_reg[channel];
282 	int regval, ret;
283 
284 	/*
285 	 * Translate shunt channel index to sensor channel index except
286 	 * the 7th channel (6 since being 0-aligned) is for summation.
287 	 */
288 	if (channel != 6)
289 		channel %= INA3221_NUM_CHANNELS;
290 
291 	switch (attr) {
292 	case hwmon_in_input:
293 		if (!ina3221_is_enabled(ina, channel))
294 			return -ENODATA;
295 
296 		/* Write CONFIG register to trigger a single-shot measurement */
297 		if (ina->single_shot) {
298 			regmap_write(ina->regmap, INA3221_CONFIG,
299 				     ina->reg_config);
300 
301 			ret = ina3221_wait_for_data(ina);
302 			if (ret)
303 				return ret;
304 		}
305 
306 		ret = ina3221_read_value(ina, reg, &regval);
307 		if (ret)
308 			return ret;
309 
310 		/*
311 		 * Scale of shunt voltage (uV): LSB is 40uV
312 		 * Scale of bus voltage (mV): LSB is 8mV
313 		 */
314 		*val = regval * (is_shunt ? 40 : 8);
315 		return 0;
316 	case hwmon_in_enable:
317 		*val = ina3221_is_enabled(ina, channel);
318 		return 0;
319 	default:
320 		return -EOPNOTSUPP;
321 	}
322 }
323 
324 static const u8 ina3221_curr_reg[][INA3221_NUM_CHANNELS + 1] = {
325 	[hwmon_curr_input] = { INA3221_SHUNT1, INA3221_SHUNT2,
326 			       INA3221_SHUNT3, INA3221_SHUNT_SUM },
327 	[hwmon_curr_max] = { INA3221_WARN1, INA3221_WARN2, INA3221_WARN3, 0 },
328 	[hwmon_curr_crit] = { INA3221_CRIT1, INA3221_CRIT2,
329 			      INA3221_CRIT3, INA3221_CRIT_SUM },
330 	[hwmon_curr_max_alarm] = { F_WF1, F_WF2, F_WF3, 0 },
331 	[hwmon_curr_crit_alarm] = { F_CF1, F_CF2, F_CF3, F_SF },
332 };
333 
334 static int ina3221_read_curr(struct device *dev, u32 attr,
335 			     int channel, long *val)
336 {
337 	struct ina3221_data *ina = dev_get_drvdata(dev);
338 	struct ina3221_input *input = ina->inputs;
339 	u8 reg = ina3221_curr_reg[attr][channel];
340 	int resistance_uo, voltage_nv;
341 	int regval, ret;
342 
343 	if (channel > INA3221_CHANNEL3)
344 		resistance_uo = ina->summation_shunt_resistor;
345 	else
346 		resistance_uo = input[channel].shunt_resistor;
347 
348 	switch (attr) {
349 	case hwmon_curr_input:
350 		if (!ina3221_is_enabled(ina, channel))
351 			return -ENODATA;
352 
353 		/* Write CONFIG register to trigger a single-shot measurement */
354 		if (ina->single_shot) {
355 			regmap_write(ina->regmap, INA3221_CONFIG,
356 				     ina->reg_config);
357 
358 			ret = ina3221_wait_for_data(ina);
359 			if (ret)
360 				return ret;
361 		}
362 
363 		fallthrough;
364 	case hwmon_curr_crit:
365 	case hwmon_curr_max:
366 		if (!resistance_uo)
367 			return -ENODATA;
368 
369 		ret = ina3221_read_value(ina, reg, &regval);
370 		if (ret)
371 			return ret;
372 
373 		/* Scale of shunt voltage: LSB is 40uV (40000nV) */
374 		voltage_nv = regval * 40000;
375 		/* Return current in mA */
376 		*val = DIV_ROUND_CLOSEST(voltage_nv, resistance_uo);
377 		return 0;
378 	case hwmon_curr_crit_alarm:
379 	case hwmon_curr_max_alarm:
380 		/* No actual register read if channel is disabled */
381 		if (!ina3221_is_enabled(ina, channel)) {
382 			/* Return 0 for alert flags */
383 			*val = 0;
384 			return 0;
385 		}
386 		ret = regmap_field_read(ina->fields[reg], &regval);
387 		if (ret)
388 			return ret;
389 		*val = regval;
390 		return 0;
391 	default:
392 		return -EOPNOTSUPP;
393 	}
394 }
395 
396 static int ina3221_write_chip(struct device *dev, u32 attr, long val)
397 {
398 	struct ina3221_data *ina = dev_get_drvdata(dev);
399 	int ret, idx;
400 	u32 tmp;
401 
402 	switch (attr) {
403 	case hwmon_chip_samples:
404 		idx = find_closest(val, ina3221_avg_samples,
405 				   ARRAY_SIZE(ina3221_avg_samples));
406 
407 		tmp = (ina->reg_config & ~INA3221_CONFIG_AVG_MASK) |
408 		      (idx << INA3221_CONFIG_AVG_SHIFT);
409 		ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
410 		if (ret)
411 			return ret;
412 
413 		/* Update reg_config accordingly */
414 		ina->reg_config = tmp;
415 		return 0;
416 	case hwmon_chip_update_interval:
417 		tmp = ina3221_interval_ms_to_conv_time(ina->reg_config, val);
418 		idx = find_closest(tmp, ina3221_conv_time,
419 				   ARRAY_SIZE(ina3221_conv_time));
420 
421 		/* Update Bus and Shunt voltage conversion times */
422 		tmp = INA3221_CONFIG_VBUS_CT_MASK | INA3221_CONFIG_VSH_CT_MASK;
423 		tmp = (ina->reg_config & ~tmp) |
424 		      (idx << INA3221_CONFIG_VBUS_CT_SHIFT) |
425 		      (idx << INA3221_CONFIG_VSH_CT_SHIFT);
426 		ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
427 		if (ret)
428 			return ret;
429 
430 		/* Update reg_config accordingly */
431 		ina->reg_config = tmp;
432 		return 0;
433 	default:
434 		return -EOPNOTSUPP;
435 	}
436 }
437 
438 static int ina3221_write_curr(struct device *dev, u32 attr,
439 			      int channel, long val)
440 {
441 	struct ina3221_data *ina = dev_get_drvdata(dev);
442 	struct ina3221_input *input = ina->inputs;
443 	u8 reg = ina3221_curr_reg[attr][channel];
444 	int resistance_uo, current_ma, voltage_uv;
445 	int regval;
446 
447 	if (channel > INA3221_CHANNEL3)
448 		resistance_uo = ina->summation_shunt_resistor;
449 	else
450 		resistance_uo = input[channel].shunt_resistor;
451 
452 	if (!resistance_uo)
453 		return -EOPNOTSUPP;
454 
455 	/* clamp current */
456 	current_ma = clamp_val(val,
457 			       INT_MIN / resistance_uo,
458 			       INT_MAX / resistance_uo);
459 
460 	voltage_uv = DIV_ROUND_CLOSEST(current_ma * resistance_uo, 1000);
461 
462 	/* clamp voltage */
463 	voltage_uv = clamp_val(voltage_uv, -163800, 163800);
464 
465 	/*
466 	 * Formula to convert voltage_uv to register value:
467 	 *     regval = (voltage_uv / scale) << shift
468 	 * Note:
469 	 *     The scale is 40uV for all shunt voltage registers
470 	 *     Shunt Voltage Sum register left-shifts 1 bit
471 	 *     All other Shunt Voltage registers shift 3 bits
472 	 * Results:
473 	 *     SHUNT_SUM: (1 / 40uV) << 1 = 1 / 20uV
474 	 *     SHUNT[1-3]: (1 / 40uV) << 3 = 1 / 5uV
475 	 */
476 	if (reg == INA3221_SHUNT_SUM || reg == INA3221_CRIT_SUM)
477 		regval = DIV_ROUND_CLOSEST(voltage_uv, 20) & 0xfffe;
478 	else
479 		regval = DIV_ROUND_CLOSEST(voltage_uv, 5) & 0xfff8;
480 
481 	return regmap_write(ina->regmap, reg, regval);
482 }
483 
484 static int ina3221_write_enable(struct device *dev, int channel, bool enable)
485 {
486 	struct ina3221_data *ina = dev_get_drvdata(dev);
487 	u16 config, mask = INA3221_CONFIG_CHx_EN(channel);
488 	u16 config_old = ina->reg_config & mask;
489 	u32 tmp;
490 	int ret;
491 
492 	config = enable ? mask : 0;
493 
494 	/* Bypass if enable status is not being changed */
495 	if (config_old == config)
496 		return 0;
497 
498 	/* For enabling routine, increase refcount and resume() at first */
499 	if (enable) {
500 		ret = pm_runtime_resume_and_get(ina->pm_dev);
501 		if (ret < 0) {
502 			dev_err(dev, "Failed to get PM runtime\n");
503 			return ret;
504 		}
505 	}
506 
507 	/* Enable or disable the channel */
508 	tmp = (ina->reg_config & ~mask) | (config & mask);
509 	ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
510 	if (ret)
511 		goto fail;
512 
513 	/* Cache the latest config register value */
514 	ina->reg_config = tmp;
515 
516 	/* For disabling routine, decrease refcount or suspend() at last */
517 	if (!enable)
518 		pm_runtime_put_sync(ina->pm_dev);
519 
520 	return 0;
521 
522 fail:
523 	if (enable) {
524 		dev_err(dev, "Failed to enable channel %d: error %d\n",
525 			channel, ret);
526 		pm_runtime_put_sync(ina->pm_dev);
527 	}
528 
529 	return ret;
530 }
531 
532 static int ina3221_read(struct device *dev, enum hwmon_sensor_types type,
533 			u32 attr, int channel, long *val)
534 {
535 	struct ina3221_data *ina = dev_get_drvdata(dev);
536 	int ret;
537 
538 	mutex_lock(&ina->lock);
539 
540 	switch (type) {
541 	case hwmon_chip:
542 		ret = ina3221_read_chip(dev, attr, val);
543 		break;
544 	case hwmon_in:
545 		/* 0-align channel ID */
546 		ret = ina3221_read_in(dev, attr, channel - 1, val);
547 		break;
548 	case hwmon_curr:
549 		ret = ina3221_read_curr(dev, attr, channel, val);
550 		break;
551 	default:
552 		ret = -EOPNOTSUPP;
553 		break;
554 	}
555 
556 	mutex_unlock(&ina->lock);
557 
558 	return ret;
559 }
560 
561 static int ina3221_write(struct device *dev, enum hwmon_sensor_types type,
562 			 u32 attr, int channel, long val)
563 {
564 	struct ina3221_data *ina = dev_get_drvdata(dev);
565 	int ret;
566 
567 	mutex_lock(&ina->lock);
568 
569 	switch (type) {
570 	case hwmon_chip:
571 		ret = ina3221_write_chip(dev, attr, val);
572 		break;
573 	case hwmon_in:
574 		/* 0-align channel ID */
575 		ret = ina3221_write_enable(dev, channel - 1, val);
576 		break;
577 	case hwmon_curr:
578 		ret = ina3221_write_curr(dev, attr, channel, val);
579 		break;
580 	default:
581 		ret = -EOPNOTSUPP;
582 		break;
583 	}
584 
585 	mutex_unlock(&ina->lock);
586 
587 	return ret;
588 }
589 
590 static int ina3221_read_string(struct device *dev, enum hwmon_sensor_types type,
591 			       u32 attr, int channel, const char **str)
592 {
593 	struct ina3221_data *ina = dev_get_drvdata(dev);
594 	int index = channel - 1;
595 
596 	if (channel == 7)
597 		*str = "sum of shunt voltages";
598 	else
599 		*str = ina->inputs[index].label;
600 
601 	return 0;
602 }
603 
604 static umode_t ina3221_is_visible(const void *drvdata,
605 				  enum hwmon_sensor_types type,
606 				  u32 attr, int channel)
607 {
608 	const struct ina3221_data *ina = drvdata;
609 	const struct ina3221_input *input = NULL;
610 
611 	switch (type) {
612 	case hwmon_chip:
613 		switch (attr) {
614 		case hwmon_chip_samples:
615 		case hwmon_chip_update_interval:
616 			return 0644;
617 		default:
618 			return 0;
619 		}
620 	case hwmon_in:
621 		/* Ignore in0_ */
622 		if (channel == 0)
623 			return 0;
624 
625 		switch (attr) {
626 		case hwmon_in_label:
627 			if (channel - 1 <= INA3221_CHANNEL3)
628 				input = &ina->inputs[channel - 1];
629 			else if (channel == 7)
630 				return 0444;
631 			/* Hide label node if label is not provided */
632 			return (input && input->label) ? 0444 : 0;
633 		case hwmon_in_input:
634 			return 0444;
635 		case hwmon_in_enable:
636 			return 0644;
637 		default:
638 			return 0;
639 		}
640 	case hwmon_curr:
641 		switch (attr) {
642 		case hwmon_curr_input:
643 		case hwmon_curr_crit_alarm:
644 		case hwmon_curr_max_alarm:
645 			return 0444;
646 		case hwmon_curr_crit:
647 		case hwmon_curr_max:
648 			return 0644;
649 		default:
650 			return 0;
651 		}
652 	default:
653 		return 0;
654 	}
655 }
656 
657 #define INA3221_HWMON_CURR_CONFIG (HWMON_C_INPUT | \
658 				   HWMON_C_CRIT | HWMON_C_CRIT_ALARM | \
659 				   HWMON_C_MAX | HWMON_C_MAX_ALARM)
660 
661 static const struct hwmon_channel_info * const ina3221_info[] = {
662 	HWMON_CHANNEL_INFO(chip,
663 			   HWMON_C_SAMPLES,
664 			   HWMON_C_UPDATE_INTERVAL),
665 	HWMON_CHANNEL_INFO(in,
666 			   /* 0: dummy, skipped in is_visible */
667 			   HWMON_I_INPUT,
668 			   /* 1-3: input voltage Channels */
669 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
670 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
671 			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
672 			   /* 4-6: shunt voltage Channels */
673 			   HWMON_I_INPUT,
674 			   HWMON_I_INPUT,
675 			   HWMON_I_INPUT,
676 			   /* 7: summation of shunt voltage channels */
677 			   HWMON_I_INPUT | HWMON_I_LABEL),
678 	HWMON_CHANNEL_INFO(curr,
679 			   /* 1-3: current channels*/
680 			   INA3221_HWMON_CURR_CONFIG,
681 			   INA3221_HWMON_CURR_CONFIG,
682 			   INA3221_HWMON_CURR_CONFIG,
683 			   /* 4: summation of current channels */
684 			   HWMON_C_INPUT | HWMON_C_CRIT | HWMON_C_CRIT_ALARM),
685 	NULL
686 };
687 
688 static const struct hwmon_ops ina3221_hwmon_ops = {
689 	.is_visible = ina3221_is_visible,
690 	.read_string = ina3221_read_string,
691 	.read = ina3221_read,
692 	.write = ina3221_write,
693 };
694 
695 static const struct hwmon_chip_info ina3221_chip_info = {
696 	.ops = &ina3221_hwmon_ops,
697 	.info = ina3221_info,
698 };
699 
700 /* Extra attribute groups */
701 static ssize_t ina3221_shunt_show(struct device *dev,
702 				  struct device_attribute *attr, char *buf)
703 {
704 	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
705 	struct ina3221_data *ina = dev_get_drvdata(dev);
706 	unsigned int channel = sd_attr->index;
707 	struct ina3221_input *input = &ina->inputs[channel];
708 
709 	return sysfs_emit(buf, "%d\n", input->shunt_resistor);
710 }
711 
712 static ssize_t ina3221_shunt_store(struct device *dev,
713 				   struct device_attribute *attr,
714 				   const char *buf, size_t count)
715 {
716 	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
717 	struct ina3221_data *ina = dev_get_drvdata(dev);
718 	unsigned int channel = sd_attr->index;
719 	struct ina3221_input *input = &ina->inputs[channel];
720 	int val;
721 	int ret;
722 
723 	ret = kstrtoint(buf, 0, &val);
724 	if (ret)
725 		return ret;
726 
727 	val = clamp_val(val, 1, INT_MAX);
728 
729 	input->shunt_resistor = val;
730 
731 	/* Update summation_shunt_resistor for summation channel */
732 	ina->summation_shunt_resistor = ina3221_summation_shunt_resistor(ina);
733 
734 	return count;
735 }
736 
737 /* shunt resistance */
738 static SENSOR_DEVICE_ATTR_RW(shunt1_resistor, ina3221_shunt, INA3221_CHANNEL1);
739 static SENSOR_DEVICE_ATTR_RW(shunt2_resistor, ina3221_shunt, INA3221_CHANNEL2);
740 static SENSOR_DEVICE_ATTR_RW(shunt3_resistor, ina3221_shunt, INA3221_CHANNEL3);
741 
742 static struct attribute *ina3221_attrs[] = {
743 	&sensor_dev_attr_shunt1_resistor.dev_attr.attr,
744 	&sensor_dev_attr_shunt2_resistor.dev_attr.attr,
745 	&sensor_dev_attr_shunt3_resistor.dev_attr.attr,
746 	NULL,
747 };
748 ATTRIBUTE_GROUPS(ina3221);
749 
750 static const struct regmap_range ina3221_yes_ranges[] = {
751 	regmap_reg_range(INA3221_CONFIG, INA3221_BUS3),
752 	regmap_reg_range(INA3221_SHUNT_SUM, INA3221_SHUNT_SUM),
753 	regmap_reg_range(INA3221_MASK_ENABLE, INA3221_MASK_ENABLE),
754 };
755 
756 static const struct regmap_access_table ina3221_volatile_table = {
757 	.yes_ranges = ina3221_yes_ranges,
758 	.n_yes_ranges = ARRAY_SIZE(ina3221_yes_ranges),
759 };
760 
761 static const struct regmap_config ina3221_regmap_config = {
762 	.reg_bits = 8,
763 	.val_bits = 16,
764 
765 	.cache_type = REGCACHE_RBTREE,
766 	.volatile_table = &ina3221_volatile_table,
767 };
768 
769 static int ina3221_probe_child_from_dt(struct device *dev,
770 				       struct device_node *child,
771 				       struct ina3221_data *ina)
772 {
773 	struct ina3221_input *input;
774 	u32 val;
775 	int ret;
776 
777 	ret = of_property_read_u32(child, "reg", &val);
778 	if (ret) {
779 		dev_err(dev, "missing reg property of %pOFn\n", child);
780 		return ret;
781 	} else if (val > INA3221_CHANNEL3) {
782 		dev_err(dev, "invalid reg %d of %pOFn\n", val, child);
783 		return -EINVAL;
784 	}
785 
786 	input = &ina->inputs[val];
787 
788 	/* Log the disconnected channel input */
789 	if (!of_device_is_available(child)) {
790 		input->disconnected = true;
791 		return 0;
792 	}
793 
794 	/* Save the connected input label if available */
795 	of_property_read_string(child, "label", &input->label);
796 
797 	/* summation channel control */
798 	input->summation_disable = of_property_read_bool(child, "ti,summation-disable");
799 
800 	/* Overwrite default shunt resistor value optionally */
801 	if (!of_property_read_u32(child, "shunt-resistor-micro-ohms", &val)) {
802 		if (val < 1 || val > INT_MAX) {
803 			dev_err(dev, "invalid shunt resistor value %u of %pOFn\n",
804 				val, child);
805 			return -EINVAL;
806 		}
807 		input->shunt_resistor = val;
808 	}
809 
810 	return 0;
811 }
812 
813 static int ina3221_probe_from_dt(struct device *dev, struct ina3221_data *ina)
814 {
815 	const struct device_node *np = dev->of_node;
816 	struct device_node *child;
817 	int ret;
818 
819 	/* Compatible with non-DT platforms */
820 	if (!np)
821 		return 0;
822 
823 	ina->single_shot = of_property_read_bool(np, "ti,single-shot");
824 
825 	for_each_child_of_node(np, child) {
826 		ret = ina3221_probe_child_from_dt(dev, child, ina);
827 		if (ret) {
828 			of_node_put(child);
829 			return ret;
830 		}
831 	}
832 
833 	return 0;
834 }
835 
836 static int ina3221_probe(struct i2c_client *client)
837 {
838 	struct device *dev = &client->dev;
839 	struct ina3221_data *ina;
840 	struct device *hwmon_dev;
841 	char name[32];
842 	int i, ret;
843 
844 	ina = devm_kzalloc(dev, sizeof(*ina), GFP_KERNEL);
845 	if (!ina)
846 		return -ENOMEM;
847 
848 	ina->regmap = devm_regmap_init_i2c(client, &ina3221_regmap_config);
849 	if (IS_ERR(ina->regmap)) {
850 		dev_err(dev, "Unable to allocate register map\n");
851 		return PTR_ERR(ina->regmap);
852 	}
853 
854 	for (i = 0; i < F_MAX_FIELDS; i++) {
855 		ina->fields[i] = devm_regmap_field_alloc(dev,
856 							 ina->regmap,
857 							 ina3221_reg_fields[i]);
858 		if (IS_ERR(ina->fields[i])) {
859 			dev_err(dev, "Unable to allocate regmap fields\n");
860 			return PTR_ERR(ina->fields[i]);
861 		}
862 	}
863 
864 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
865 		ina->inputs[i].shunt_resistor = INA3221_RSHUNT_DEFAULT;
866 
867 	ret = ina3221_probe_from_dt(dev, ina);
868 	if (ret) {
869 		dev_err(dev, "Unable to probe from device tree\n");
870 		return ret;
871 	}
872 
873 	/* The driver will be reset, so use reset value */
874 	ina->reg_config = INA3221_CONFIG_DEFAULT;
875 
876 	/* Clear continuous bit to use single-shot mode */
877 	if (ina->single_shot)
878 		ina->reg_config &= ~INA3221_CONFIG_MODE_CONTINUOUS;
879 
880 	/* Disable channels if their inputs are disconnected */
881 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
882 		if (ina->inputs[i].disconnected)
883 			ina->reg_config &= ~INA3221_CONFIG_CHx_EN(i);
884 	}
885 
886 	/* Initialize summation_shunt_resistor for summation channel control */
887 	ina->summation_shunt_resistor = ina3221_summation_shunt_resistor(ina);
888 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
889 		if (!ina->inputs[i].summation_disable)
890 			ina->summation_channel_control |= BIT(14 - i);
891 	}
892 
893 	ina->pm_dev = dev;
894 	mutex_init(&ina->lock);
895 	dev_set_drvdata(dev, ina);
896 
897 	/* Enable PM runtime -- status is suspended by default */
898 	pm_runtime_enable(ina->pm_dev);
899 
900 	/* Initialize (resume) the device */
901 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
902 		if (ina->inputs[i].disconnected)
903 			continue;
904 		/* Match the refcount with number of enabled channels */
905 		ret = pm_runtime_get_sync(ina->pm_dev);
906 		if (ret < 0)
907 			goto fail;
908 	}
909 
910 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, ina,
911 							 &ina3221_chip_info,
912 							 ina3221_groups);
913 	if (IS_ERR(hwmon_dev)) {
914 		dev_err(dev, "Unable to register hwmon device\n");
915 		ret = PTR_ERR(hwmon_dev);
916 		goto fail;
917 	}
918 
919 	scnprintf(name, sizeof(name), "%s-%s", INA3221_DRIVER_NAME, dev_name(dev));
920 	ina->debugfs = debugfs_create_dir(name, NULL);
921 
922 	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
923 		scnprintf(name, sizeof(name), "in%d_summation_disable", i);
924 		debugfs_create_bool(name, 0400, ina->debugfs,
925 				    &ina->inputs[i].summation_disable);
926 	}
927 
928 	return 0;
929 
930 fail:
931 	pm_runtime_disable(ina->pm_dev);
932 	pm_runtime_set_suspended(ina->pm_dev);
933 	/* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
934 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
935 		pm_runtime_put_noidle(ina->pm_dev);
936 	mutex_destroy(&ina->lock);
937 
938 	return ret;
939 }
940 
941 static void ina3221_remove(struct i2c_client *client)
942 {
943 	struct ina3221_data *ina = dev_get_drvdata(&client->dev);
944 	int i;
945 
946 	debugfs_remove_recursive(ina->debugfs);
947 
948 	pm_runtime_disable(ina->pm_dev);
949 	pm_runtime_set_suspended(ina->pm_dev);
950 
951 	/* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
952 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
953 		pm_runtime_put_noidle(ina->pm_dev);
954 
955 	mutex_destroy(&ina->lock);
956 }
957 
958 static int ina3221_suspend(struct device *dev)
959 {
960 	struct ina3221_data *ina = dev_get_drvdata(dev);
961 	int ret;
962 
963 	/* Save config register value and enable cache-only */
964 	ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
965 	if (ret)
966 		return ret;
967 
968 	/* Set to power-down mode for power saving */
969 	ret = regmap_update_bits(ina->regmap, INA3221_CONFIG,
970 				 INA3221_CONFIG_MODE_MASK,
971 				 INA3221_CONFIG_MODE_POWERDOWN);
972 	if (ret)
973 		return ret;
974 
975 	regcache_cache_only(ina->regmap, true);
976 	regcache_mark_dirty(ina->regmap);
977 
978 	return 0;
979 }
980 
981 static int ina3221_resume(struct device *dev)
982 {
983 	struct ina3221_data *ina = dev_get_drvdata(dev);
984 	int ret;
985 
986 	regcache_cache_only(ina->regmap, false);
987 
988 	/* Software reset the chip */
989 	ret = regmap_field_write(ina->fields[F_RST], true);
990 	if (ret) {
991 		dev_err(dev, "Unable to reset device\n");
992 		return ret;
993 	}
994 
995 	/* Restore cached register values to hardware */
996 	ret = regcache_sync(ina->regmap);
997 	if (ret)
998 		return ret;
999 
1000 	/* Restore config register value to hardware */
1001 	ret = regmap_write(ina->regmap, INA3221_CONFIG, ina->reg_config);
1002 	if (ret)
1003 		return ret;
1004 
1005 	/* Initialize summation channel control */
1006 	if (ina->summation_shunt_resistor) {
1007 		/*
1008 		 * Sum only channels that are not disabled for summation.
1009 		 * Shunt measurements of disconnected channels should
1010 		 * be 0, so it does not matter for summation.
1011 		 */
1012 		ret = regmap_update_bits(ina->regmap, INA3221_MASK_ENABLE,
1013 					 INA3221_MASK_ENABLE_SCC_MASK,
1014 					 ina->summation_channel_control);
1015 		if (ret) {
1016 			dev_err(dev, "Unable to control summation channel\n");
1017 			return ret;
1018 		}
1019 	}
1020 
1021 	return 0;
1022 }
1023 
1024 static DEFINE_RUNTIME_DEV_PM_OPS(ina3221_pm, ina3221_suspend, ina3221_resume,
1025 				 NULL);
1026 
1027 static const struct of_device_id ina3221_of_match_table[] = {
1028 	{ .compatible = "ti,ina3221", },
1029 	{ /* sentinel */ }
1030 };
1031 MODULE_DEVICE_TABLE(of, ina3221_of_match_table);
1032 
1033 static const struct i2c_device_id ina3221_ids[] = {
1034 	{ "ina3221", 0 },
1035 	{ /* sentinel */ }
1036 };
1037 MODULE_DEVICE_TABLE(i2c, ina3221_ids);
1038 
1039 static struct i2c_driver ina3221_i2c_driver = {
1040 	.probe = ina3221_probe,
1041 	.remove = ina3221_remove,
1042 	.driver = {
1043 		.name = INA3221_DRIVER_NAME,
1044 		.of_match_table = ina3221_of_match_table,
1045 		.pm = pm_ptr(&ina3221_pm),
1046 	},
1047 	.id_table = ina3221_ids,
1048 };
1049 module_i2c_driver(ina3221_i2c_driver);
1050 
1051 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
1052 MODULE_DESCRIPTION("Texas Instruments INA3221 HWMon Driver");
1053 MODULE_LICENSE("GPL v2");
1054