xref: /openbmc/linux/drivers/iio/adc/ina2xx-adc.c (revision 86bee12f)
1 /*
2  * INA2XX Current and Power Monitors
3  *
4  * Copyright 2015 Baylibre SAS.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * Based on linux/drivers/iio/adc/ad7291.c
11  * Copyright 2010-2011 Analog Devices Inc.
12  *
13  * Based on linux/drivers/hwmon/ina2xx.c
14  * Copyright 2012 Lothar Felten <l-felten@ti.com>
15  *
16  * Licensed under the GPL-2 or later.
17  *
18  * IIO driver for INA219-220-226-230-231
19  *
20  * Configurable 7-bit I2C slave address from 0x40 to 0x4F
21  */
22 
23 #include <linux/delay.h>
24 #include <linux/i2c.h>
25 #include <linux/iio/kfifo_buf.h>
26 #include <linux/iio/sysfs.h>
27 #include <linux/kthread.h>
28 #include <linux/module.h>
29 #include <linux/regmap.h>
30 #include <linux/util_macros.h>
31 
32 #include <linux/platform_data/ina2xx.h>
33 
34 /* INA2XX registers definition */
35 #define INA2XX_CONFIG                   0x00
36 #define INA2XX_SHUNT_VOLTAGE            0x01	/* readonly */
37 #define INA2XX_BUS_VOLTAGE              0x02	/* readonly */
38 #define INA2XX_POWER                    0x03	/* readonly */
39 #define INA2XX_CURRENT                  0x04	/* readonly */
40 #define INA2XX_CALIBRATION              0x05
41 
42 #define INA226_ALERT_MASK		GENMASK(2, 1)
43 #define INA266_CVRF			BIT(3)
44 
45 #define INA2XX_MAX_REGISTERS            8
46 
47 /* settings - depend on use case */
48 #define INA219_CONFIG_DEFAULT           0x399F	/* PGA=8 */
49 #define INA226_CONFIG_DEFAULT           0x4327
50 #define INA226_DEFAULT_AVG              4
51 #define INA226_DEFAULT_IT		1110
52 
53 #define INA2XX_RSHUNT_DEFAULT           10000
54 
55 /*
56  * bit mask for reading the averaging setting in the configuration register
57  * FIXME: use regmap_fields.
58  */
59 #define INA2XX_MODE_MASK	GENMASK(3, 0)
60 
61 #define INA226_AVG_MASK		GENMASK(11, 9)
62 #define INA226_SHIFT_AVG(val)	((val) << 9)
63 
64 /* Integration time for VBus */
65 #define INA226_ITB_MASK		GENMASK(8, 6)
66 #define INA226_SHIFT_ITB(val)	((val) << 6)
67 
68 /* Integration time for VShunt */
69 #define INA226_ITS_MASK		GENMASK(5, 3)
70 #define INA226_SHIFT_ITS(val)	((val) << 3)
71 
72 /* Cosmetic macro giving the sampling period for a full P=UxI cycle */
73 #define SAMPLING_PERIOD(c)	((c->int_time_vbus + c->int_time_vshunt) \
74 				 * c->avg)
75 
76 static bool ina2xx_is_writeable_reg(struct device *dev, unsigned int reg)
77 {
78 	return (reg == INA2XX_CONFIG) || (reg > INA2XX_CURRENT);
79 }
80 
81 static bool ina2xx_is_volatile_reg(struct device *dev, unsigned int reg)
82 {
83 	return (reg != INA2XX_CONFIG);
84 }
85 
86 static inline bool is_signed_reg(unsigned int reg)
87 {
88 	return (reg == INA2XX_SHUNT_VOLTAGE) || (reg == INA2XX_CURRENT);
89 }
90 
91 static const struct regmap_config ina2xx_regmap_config = {
92 	.reg_bits = 8,
93 	.val_bits = 16,
94 	.max_register = INA2XX_MAX_REGISTERS,
95 	.writeable_reg = ina2xx_is_writeable_reg,
96 	.volatile_reg = ina2xx_is_volatile_reg,
97 };
98 
99 enum ina2xx_ids { ina219, ina226 };
100 
101 struct ina2xx_config {
102 	u16 config_default;
103 	int calibration_factor;
104 	int shunt_div;
105 	int bus_voltage_shift;
106 	int bus_voltage_lsb;	/* uV */
107 	int power_lsb;		/* uW */
108 };
109 
110 struct ina2xx_chip_info {
111 	struct regmap *regmap;
112 	struct task_struct *task;
113 	const struct ina2xx_config *config;
114 	struct mutex state_lock;
115 	unsigned int shunt_resistor;
116 	int avg;
117 	s64 prev_ns; /* track buffer capture time, check for underruns */
118 	int int_time_vbus; /* Bus voltage integration time uS */
119 	int int_time_vshunt; /* Shunt voltage integration time uS */
120 	bool allow_async_readout;
121 };
122 
123 static const struct ina2xx_config ina2xx_config[] = {
124 	[ina219] = {
125 		.config_default = INA219_CONFIG_DEFAULT,
126 		.calibration_factor = 40960000,
127 		.shunt_div = 100,
128 		.bus_voltage_shift = 3,
129 		.bus_voltage_lsb = 4000,
130 		.power_lsb = 20000,
131 	},
132 	[ina226] = {
133 		.config_default = INA226_CONFIG_DEFAULT,
134 		.calibration_factor = 5120000,
135 		.shunt_div = 400,
136 		.bus_voltage_shift = 0,
137 		.bus_voltage_lsb = 1250,
138 		.power_lsb = 25000,
139 	},
140 };
141 
142 static int ina2xx_read_raw(struct iio_dev *indio_dev,
143 			   struct iio_chan_spec const *chan,
144 			   int *val, int *val2, long mask)
145 {
146 	int ret;
147 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
148 	unsigned int regval;
149 
150 	switch (mask) {
151 	case IIO_CHAN_INFO_RAW:
152 		ret = regmap_read(chip->regmap, chan->address, &regval);
153 		if (ret)
154 			return ret;
155 
156 		if (is_signed_reg(chan->address))
157 			*val = (s16) regval;
158 		else
159 			*val  = regval;
160 
161 		return IIO_VAL_INT;
162 
163 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
164 		*val = chip->avg;
165 		return IIO_VAL_INT;
166 
167 	case IIO_CHAN_INFO_INT_TIME:
168 		*val = 0;
169 		if (chan->address == INA2XX_SHUNT_VOLTAGE)
170 			*val2 = chip->int_time_vshunt;
171 		else
172 			*val2 = chip->int_time_vbus;
173 
174 		return IIO_VAL_INT_PLUS_MICRO;
175 
176 	case IIO_CHAN_INFO_SAMP_FREQ:
177 		/*
178 		 * Sample freq is read only, it is a consequence of
179 		 * 1/AVG*(CT_bus+CT_shunt).
180 		 */
181 		*val = DIV_ROUND_CLOSEST(1000000, SAMPLING_PERIOD(chip));
182 
183 		return IIO_VAL_INT;
184 
185 	case IIO_CHAN_INFO_SCALE:
186 		switch (chan->address) {
187 		case INA2XX_SHUNT_VOLTAGE:
188 			/* processed (mV) = raw/shunt_div */
189 			*val2 = chip->config->shunt_div;
190 			*val = 1;
191 			return IIO_VAL_FRACTIONAL;
192 
193 		case INA2XX_BUS_VOLTAGE:
194 			/* processed (mV) = raw*lsb (uV) / (1000 << shift) */
195 			*val = chip->config->bus_voltage_lsb;
196 			*val2 = 1000 << chip->config->bus_voltage_shift;
197 			return IIO_VAL_FRACTIONAL;
198 
199 		case INA2XX_POWER:
200 			/* processed (mW) = raw*lsb (uW) / 1000 */
201 			*val = chip->config->power_lsb;
202 			*val2 = 1000;
203 			return IIO_VAL_FRACTIONAL;
204 
205 		case INA2XX_CURRENT:
206 			/* processed (mA) = raw (mA) */
207 			*val = 1;
208 			return IIO_VAL_INT;
209 		}
210 	}
211 
212 	return -EINVAL;
213 }
214 
215 /*
216  * Available averaging rates for ina226. The indices correspond with
217  * the bit values expected by the chip (according to the ina226 datasheet,
218  * table 3 AVG bit settings, found at
219  * http://www.ti.com/lit/ds/symlink/ina226.pdf.
220  */
221 static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
222 
223 static int ina226_set_average(struct ina2xx_chip_info *chip, unsigned int val,
224 			      unsigned int *config)
225 {
226 	int bits;
227 
228 	if (val > 1024 || val < 1)
229 		return -EINVAL;
230 
231 	bits = find_closest(val, ina226_avg_tab,
232 			    ARRAY_SIZE(ina226_avg_tab));
233 
234 	chip->avg = ina226_avg_tab[bits];
235 
236 	*config &= ~INA226_AVG_MASK;
237 	*config |= INA226_SHIFT_AVG(bits) & INA226_AVG_MASK;
238 
239 	return 0;
240 }
241 
242 /* Conversion times in uS */
243 static const int ina226_conv_time_tab[] = { 140, 204, 332, 588, 1100,
244 					    2116, 4156, 8244 };
245 
246 static int ina226_set_int_time_vbus(struct ina2xx_chip_info *chip,
247 				    unsigned int val_us, unsigned int *config)
248 {
249 	int bits;
250 
251 	if (val_us > 8244 || val_us < 140)
252 		return -EINVAL;
253 
254 	bits = find_closest(val_us, ina226_conv_time_tab,
255 			    ARRAY_SIZE(ina226_conv_time_tab));
256 
257 	chip->int_time_vbus = ina226_conv_time_tab[bits];
258 
259 	*config &= ~INA226_ITB_MASK;
260 	*config |= INA226_SHIFT_ITB(bits) & INA226_ITB_MASK;
261 
262 	return 0;
263 }
264 
265 static int ina226_set_int_time_vshunt(struct ina2xx_chip_info *chip,
266 				      unsigned int val_us, unsigned int *config)
267 {
268 	int bits;
269 
270 	if (val_us > 8244 || val_us < 140)
271 		return -EINVAL;
272 
273 	bits = find_closest(val_us, ina226_conv_time_tab,
274 			    ARRAY_SIZE(ina226_conv_time_tab));
275 
276 	chip->int_time_vshunt = ina226_conv_time_tab[bits];
277 
278 	*config &= ~INA226_ITS_MASK;
279 	*config |= INA226_SHIFT_ITS(bits) & INA226_ITS_MASK;
280 
281 	return 0;
282 }
283 
284 static int ina2xx_write_raw(struct iio_dev *indio_dev,
285 			    struct iio_chan_spec const *chan,
286 			    int val, int val2, long mask)
287 {
288 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
289 	unsigned int config, tmp;
290 	int ret;
291 
292 	if (iio_buffer_enabled(indio_dev))
293 		return -EBUSY;
294 
295 	mutex_lock(&chip->state_lock);
296 
297 	ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config);
298 	if (ret)
299 		goto err;
300 
301 	tmp = config;
302 
303 	switch (mask) {
304 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
305 		ret = ina226_set_average(chip, val, &tmp);
306 		break;
307 
308 	case IIO_CHAN_INFO_INT_TIME:
309 		if (chan->address == INA2XX_SHUNT_VOLTAGE)
310 			ret = ina226_set_int_time_vshunt(chip, val2, &tmp);
311 		else
312 			ret = ina226_set_int_time_vbus(chip, val2, &tmp);
313 		break;
314 
315 	default:
316 		ret = -EINVAL;
317 	}
318 
319 	if (!ret && (tmp != config))
320 		ret = regmap_write(chip->regmap, INA2XX_CONFIG, tmp);
321 err:
322 	mutex_unlock(&chip->state_lock);
323 
324 	return ret;
325 }
326 
327 static ssize_t ina2xx_allow_async_readout_show(struct device *dev,
328 					   struct device_attribute *attr,
329 					   char *buf)
330 {
331 	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
332 
333 	return sprintf(buf, "%d\n", chip->allow_async_readout);
334 }
335 
336 static ssize_t ina2xx_allow_async_readout_store(struct device *dev,
337 				struct device_attribute *attr,
338 				const char *buf, size_t len)
339 {
340 	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
341 	bool val;
342 	int ret;
343 
344 	ret = strtobool((const char *) buf, &val);
345 	if (ret)
346 		return ret;
347 
348 	chip->allow_async_readout = val;
349 
350 	return len;
351 }
352 
353 /*
354  * Set current LSB to 1mA, shunt is in uOhms
355  * (equation 13 in datasheet). We hardcode a Current_LSB
356  * of 1.0 x10-6. The only remaining parameter is RShunt.
357  * There is no need to expose the CALIBRATION register
358  * to the user for now. But we need to reset this register
359  * if the user updates RShunt after driver init, e.g upon
360  * reading an EEPROM/Probe-type value.
361  */
362 static int ina2xx_set_calibration(struct ina2xx_chip_info *chip)
363 {
364 	u16 regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor,
365 				   chip->shunt_resistor);
366 
367 	return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval);
368 }
369 
370 static int set_shunt_resistor(struct ina2xx_chip_info *chip, unsigned int val)
371 {
372 	if (val <= 0 || val > chip->config->calibration_factor)
373 		return -EINVAL;
374 
375 	chip->shunt_resistor = val;
376 
377 	return 0;
378 }
379 
380 static ssize_t ina2xx_shunt_resistor_show(struct device *dev,
381 					  struct device_attribute *attr,
382 					  char *buf)
383 {
384 	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
385 
386 	return sprintf(buf, "%d\n", chip->shunt_resistor);
387 }
388 
389 static ssize_t ina2xx_shunt_resistor_store(struct device *dev,
390 					   struct device_attribute *attr,
391 					   const char *buf, size_t len)
392 {
393 	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
394 	unsigned long val;
395 	int ret;
396 
397 	ret = kstrtoul((const char *) buf, 10, &val);
398 	if (ret)
399 		return ret;
400 
401 	ret = set_shunt_resistor(chip, val);
402 	if (ret)
403 		return ret;
404 
405 	/* Update the Calibration register */
406 	ret = ina2xx_set_calibration(chip);
407 	if (ret)
408 		return ret;
409 
410 	return len;
411 }
412 
413 #define INA2XX_CHAN(_type, _index, _address) { \
414 	.type = (_type), \
415 	.address = (_address), \
416 	.indexed = 1, \
417 	.channel = (_index), \
418 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \
419 	| BIT(IIO_CHAN_INFO_SCALE), \
420 	.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
421 				   BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
422 	.scan_index = (_index), \
423 	.scan_type = { \
424 		.sign = 'u', \
425 		.realbits = 16, \
426 		.storagebits = 16, \
427 		.endianness = IIO_CPU, \
428 	} \
429 }
430 
431 /*
432  * Sampling Freq is a consequence of the integration times of
433  * the Voltage channels.
434  */
435 #define INA2XX_CHAN_VOLTAGE(_index, _address) { \
436 	.type = IIO_VOLTAGE, \
437 	.address = (_address), \
438 	.indexed = 1, \
439 	.channel = (_index), \
440 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
441 			      BIT(IIO_CHAN_INFO_SCALE) | \
442 			      BIT(IIO_CHAN_INFO_INT_TIME), \
443 	.scan_index = (_index), \
444 	.scan_type = { \
445 		.sign = 'u', \
446 		.realbits = 16, \
447 		.storagebits = 16, \
448 		.endianness = IIO_LE, \
449 	} \
450 }
451 
452 static const struct iio_chan_spec ina2xx_channels[] = {
453 	INA2XX_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
454 	INA2XX_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
455 	INA2XX_CHAN(IIO_POWER, 2, INA2XX_POWER),
456 	INA2XX_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
457 	IIO_CHAN_SOFT_TIMESTAMP(4),
458 };
459 
460 static int ina2xx_work_buffer(struct iio_dev *indio_dev)
461 {
462 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
463 	unsigned short data[8];
464 	int bit, ret, i = 0;
465 	s64 time_a, time_b;
466 	unsigned int alert;
467 
468 	time_a = iio_get_time_ns();
469 
470 	/*
471 	 * Because the timer thread and the chip conversion clock
472 	 * are asynchronous, the period difference will eventually
473 	 * result in reading V[k-1] again, or skip V[k] at time Tk.
474 	 * In order to resync the timer with the conversion process
475 	 * we check the ConVersionReadyFlag.
476 	 * On hardware that supports using the ALERT pin to toggle a
477 	 * GPIO a triggered buffer could be used instead.
478 	 * For now, we pay for that extra read of the ALERT register
479 	 */
480 	if (!chip->allow_async_readout)
481 		do {
482 			ret = regmap_read(chip->regmap, INA226_ALERT_MASK,
483 					  &alert);
484 			if (ret < 0)
485 				return ret;
486 
487 			alert &= INA266_CVRF;
488 		} while (!alert);
489 
490 	/*
491 	 * Single register reads: bulk_read will not work with ina226
492 	 * as there is no auto-increment of the address register for
493 	 * data length longer than 16bits.
494 	 */
495 	for_each_set_bit(bit, indio_dev->active_scan_mask,
496 			 indio_dev->masklength) {
497 		unsigned int val;
498 
499 		ret = regmap_read(chip->regmap,
500 				  INA2XX_SHUNT_VOLTAGE + bit, &val);
501 		if (ret < 0)
502 			return ret;
503 
504 		data[i++] = val;
505 	}
506 
507 	time_b = iio_get_time_ns();
508 
509 	iio_push_to_buffers_with_timestamp(indio_dev,
510 					   (unsigned int *)data, time_a);
511 
512 	chip->prev_ns = time_a;
513 
514 	return (unsigned long)(time_b - time_a) / 1000;
515 };
516 
517 static int ina2xx_capture_thread(void *data)
518 {
519 	struct iio_dev *indio_dev = data;
520 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
521 	unsigned int sampling_us = SAMPLING_PERIOD(chip);
522 	int buffer_us;
523 
524 	/*
525 	 * Poll a bit faster than the chip internal Fs, in case
526 	 * we wish to sync with the conversion ready flag.
527 	 */
528 	if (!chip->allow_async_readout)
529 		sampling_us -= 200;
530 
531 	do {
532 		buffer_us = ina2xx_work_buffer(indio_dev);
533 		if (buffer_us < 0)
534 			return buffer_us;
535 
536 		if (sampling_us > buffer_us)
537 			udelay(sampling_us - buffer_us);
538 
539 	} while (!kthread_should_stop());
540 
541 	return 0;
542 }
543 
544 static int ina2xx_buffer_enable(struct iio_dev *indio_dev)
545 {
546 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
547 	unsigned int sampling_us = SAMPLING_PERIOD(chip);
548 
549 	dev_dbg(&indio_dev->dev, "Enabling buffer w/ scan_mask %02x, freq = %d, avg =%u\n",
550 		(unsigned int)(*indio_dev->active_scan_mask),
551 		1000000 / sampling_us, chip->avg);
552 
553 	dev_dbg(&indio_dev->dev, "Expected work period: %u us\n", sampling_us);
554 	dev_dbg(&indio_dev->dev, "Async readout mode: %d\n",
555 		chip->allow_async_readout);
556 
557 	chip->prev_ns = iio_get_time_ns();
558 
559 	chip->task = kthread_run(ina2xx_capture_thread, (void *)indio_dev,
560 				 "%s:%d-%uus", indio_dev->name, indio_dev->id,
561 				 sampling_us);
562 
563 	return PTR_ERR_OR_ZERO(chip->task);
564 }
565 
566 static int ina2xx_buffer_disable(struct iio_dev *indio_dev)
567 {
568 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
569 
570 	if (chip->task) {
571 		kthread_stop(chip->task);
572 		chip->task = NULL;
573 	}
574 
575 	return 0;
576 }
577 
578 static const struct iio_buffer_setup_ops ina2xx_setup_ops = {
579 	.postenable = &ina2xx_buffer_enable,
580 	.predisable = &ina2xx_buffer_disable,
581 };
582 
583 static int ina2xx_debug_reg(struct iio_dev *indio_dev,
584 			    unsigned reg, unsigned writeval, unsigned *readval)
585 {
586 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
587 
588 	if (!readval)
589 		return regmap_write(chip->regmap, reg, writeval);
590 
591 	return regmap_read(chip->regmap, reg, readval);
592 }
593 
594 /* Possible integration times for vshunt and vbus */
595 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.000140 0.000204 0.000332 0.000588 0.001100 0.002116 0.004156 0.008244");
596 
597 static IIO_DEVICE_ATTR(in_allow_async_readout, S_IRUGO | S_IWUSR,
598 		       ina2xx_allow_async_readout_show,
599 		       ina2xx_allow_async_readout_store, 0);
600 
601 static IIO_DEVICE_ATTR(in_shunt_resistor, S_IRUGO | S_IWUSR,
602 		       ina2xx_shunt_resistor_show,
603 		       ina2xx_shunt_resistor_store, 0);
604 
605 static struct attribute *ina2xx_attributes[] = {
606 	&iio_dev_attr_in_allow_async_readout.dev_attr.attr,
607 	&iio_const_attr_integration_time_available.dev_attr.attr,
608 	&iio_dev_attr_in_shunt_resistor.dev_attr.attr,
609 	NULL,
610 };
611 
612 static const struct attribute_group ina2xx_attribute_group = {
613 	.attrs = ina2xx_attributes,
614 };
615 
616 static const struct iio_info ina2xx_info = {
617 	.driver_module = THIS_MODULE,
618 	.attrs = &ina2xx_attribute_group,
619 	.read_raw = ina2xx_read_raw,
620 	.write_raw = ina2xx_write_raw,
621 	.debugfs_reg_access = ina2xx_debug_reg,
622 };
623 
624 /* Initialize the configuration and calibration registers. */
625 static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config)
626 {
627 	int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config);
628 	if (ret)
629 		return ret;
630 
631 	return ina2xx_set_calibration(chip);
632 }
633 
634 static int ina2xx_probe(struct i2c_client *client,
635 			const struct i2c_device_id *id)
636 {
637 	struct ina2xx_chip_info *chip;
638 	struct iio_dev *indio_dev;
639 	struct iio_buffer *buffer;
640 	unsigned int val;
641 	int ret;
642 
643 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
644 	if (!indio_dev)
645 		return -ENOMEM;
646 
647 	chip = iio_priv(indio_dev);
648 
649 	/* This is only used for device removal purposes. */
650 	i2c_set_clientdata(client, indio_dev);
651 
652 	chip->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
653 	if (IS_ERR(chip->regmap)) {
654 		dev_err(&client->dev, "failed to allocate register map\n");
655 		return PTR_ERR(chip->regmap);
656 	}
657 
658 	chip->config = &ina2xx_config[id->driver_data];
659 
660 	mutex_init(&chip->state_lock);
661 
662 	if (of_property_read_u32(client->dev.of_node,
663 				 "shunt-resistor", &val) < 0) {
664 		struct ina2xx_platform_data *pdata =
665 		    dev_get_platdata(&client->dev);
666 
667 		if (pdata)
668 			val = pdata->shunt_uohms;
669 		else
670 			val = INA2XX_RSHUNT_DEFAULT;
671 	}
672 
673 	ret = set_shunt_resistor(chip, val);
674 	if (ret)
675 		return ret;
676 
677 	/* Patch the current config register with default. */
678 	val = chip->config->config_default;
679 
680 	if (id->driver_data == ina226) {
681 		ina226_set_average(chip, INA226_DEFAULT_AVG, &val);
682 		ina226_set_int_time_vbus(chip, INA226_DEFAULT_IT, &val);
683 		ina226_set_int_time_vshunt(chip, INA226_DEFAULT_IT, &val);
684 	}
685 
686 	ret = ina2xx_init(chip, val);
687 	if (ret) {
688 		dev_err(&client->dev, "error configuring the device\n");
689 		return ret;
690 	}
691 
692 	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
693 	indio_dev->dev.parent = &client->dev;
694 	indio_dev->channels = ina2xx_channels;
695 	indio_dev->num_channels = ARRAY_SIZE(ina2xx_channels);
696 	indio_dev->name = id->name;
697 	indio_dev->info = &ina2xx_info;
698 	indio_dev->setup_ops = &ina2xx_setup_ops;
699 
700 	buffer = devm_iio_kfifo_allocate(&indio_dev->dev);
701 	if (!buffer)
702 		return -ENOMEM;
703 
704 	iio_device_attach_buffer(indio_dev, buffer);
705 
706 	return iio_device_register(indio_dev);
707 }
708 
709 static int ina2xx_remove(struct i2c_client *client)
710 {
711 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
712 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
713 
714 	iio_device_unregister(indio_dev);
715 
716 	/* Powerdown */
717 	return regmap_update_bits(chip->regmap, INA2XX_CONFIG,
718 				  INA2XX_MODE_MASK, 0);
719 }
720 
721 static const struct i2c_device_id ina2xx_id[] = {
722 	{"ina219", ina219},
723 	{"ina220", ina219},
724 	{"ina226", ina226},
725 	{"ina230", ina226},
726 	{"ina231", ina226},
727 	{}
728 };
729 MODULE_DEVICE_TABLE(i2c, ina2xx_id);
730 
731 static struct i2c_driver ina2xx_driver = {
732 	.driver = {
733 		   .name = KBUILD_MODNAME,
734 	},
735 	.probe = ina2xx_probe,
736 	.remove = ina2xx_remove,
737 	.id_table = ina2xx_id,
738 };
739 module_i2c_driver(ina2xx_driver);
740 
741 MODULE_AUTHOR("Marc Titinger <marc.titinger@baylibre.com>");
742 MODULE_DESCRIPTION("Texas Instruments INA2XX ADC driver");
743 MODULE_LICENSE("GPL v2");
744