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  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
 56enum 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
 71static 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
 83enum 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 */
 96struct 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 */
112struct 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
123static 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 */
130static 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 */
135static 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 */
140static 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 */
151static 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
165static 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, wait * 2);
174}
175
176static 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
191static 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
200static 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
220static 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
262static 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
270static 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
323static 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
365static 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
390static 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
428fail:
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
438static 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
467static 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
496static 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
507static 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
562static 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
584static 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
591static const struct hwmon_chip_info ina3221_chip_info = {
592	.ops = &ina3221_hwmon_ops,
593	.info = ina3221_info,
594};
595
596/* Extra attribute groups */
597static 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
608static 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 */
631static SENSOR_DEVICE_ATTR_RW(shunt1_resistor, ina3221_shunt, INA3221_CHANNEL1);
632static SENSOR_DEVICE_ATTR_RW(shunt2_resistor, ina3221_shunt, INA3221_CHANNEL2);
633static SENSOR_DEVICE_ATTR_RW(shunt3_resistor, ina3221_shunt, INA3221_CHANNEL3);
634
635static 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};
641ATTRIBUTE_GROUPS(ina3221);
642
643static 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
648static 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
653static 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
661static 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
702static 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
725static 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
803fail:
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
814static 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
831static 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
854static 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
881static 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
887static const struct of_device_id ina3221_of_match_table[] = {
888	{ .compatible = "ti,ina3221", },
889	{ /* sentinel */ }
890};
891MODULE_DEVICE_TABLE(of, ina3221_of_match_table);
892
893static const struct i2c_device_id ina3221_ids[] = {
894	{ "ina3221", 0 },
895	{ /* sentinel */ }
896};
897MODULE_DEVICE_TABLE(i2c, ina3221_ids);
898
899static 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};
909module_i2c_driver(ina3221_i2c_driver);
910
911MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
912MODULE_DESCRIPTION("Texas Instruments INA3221 HWMon Driver");
913MODULE_LICENSE("GPL v2");