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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 - 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
  61enum 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
  78static 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
  91enum 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 */
 105struct 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 */
 125struct 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
 139static 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 */
 158static 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 */
 181static 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 */
 186static 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 */
 191static 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 */
 202static 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
 214static 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
 225static 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
 247static 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
 257static 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
 277static 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
 324static 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
 334static 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
 396static 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
 438static 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
 484static 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
 522fail:
 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
 532static 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
 561static 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
 590static 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
 604static 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
 661static 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
 688static 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
 695static const struct hwmon_chip_info ina3221_chip_info = {
 696	.ops = &ina3221_hwmon_ops,
 697	.info = ina3221_info,
 698};
 699
 700/* Extra attribute groups */
 701static 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
 712static 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 */
 738static SENSOR_DEVICE_ATTR_RW(shunt1_resistor, ina3221_shunt, INA3221_CHANNEL1);
 739static SENSOR_DEVICE_ATTR_RW(shunt2_resistor, ina3221_shunt, INA3221_CHANNEL2);
 740static SENSOR_DEVICE_ATTR_RW(shunt3_resistor, ina3221_shunt, INA3221_CHANNEL3);
 741
 742static 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};
 748ATTRIBUTE_GROUPS(ina3221);
 749
 750static 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
 756static 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
 761static const struct regmap_config ina3221_regmap_config = {
 762	.reg_bits = 8,
 763	.val_bits = 16,
 764
 765	.cache_type = REGCACHE_MAPLE,
 766	.volatile_table = &ina3221_volatile_table,
 767};
 768
 769static 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
 813static 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
 836static 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
 930fail:
 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
 941static 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
 958static 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
 981static 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
1024static DEFINE_RUNTIME_DEV_PM_OPS(ina3221_pm, ina3221_suspend, ina3221_resume,
1025				 NULL);
1026
1027static const struct of_device_id ina3221_of_match_table[] = {
1028	{ .compatible = "ti,ina3221", },
1029	{ /* sentinel */ }
1030};
1031MODULE_DEVICE_TABLE(of, ina3221_of_match_table);
1032
1033static const struct i2c_device_id ina3221_ids[] = {
1034	{ "ina3221", 0 },
1035	{ /* sentinel */ }
1036};
1037MODULE_DEVICE_TABLE(i2c, ina3221_ids);
1038
1039static 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};
1049module_i2c_driver(ina3221_i2c_driver);
1050
1051MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
1052MODULE_DESCRIPTION("Texas Instruments INA3221 HWMon Driver");
1053MODULE_LICENSE("GPL v2");