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/iio.h>
26#include <linux/iio/buffer.h>
27#include <linux/iio/kfifo_buf.h>
28#include <linux/iio/sysfs.h>
29#include <linux/kthread.h>
30#include <linux/module.h>
31#include <linux/of.h>
32#include <linux/regmap.h>
33#include <linux/sched/task.h>
34#include <linux/util_macros.h>
35
36#include <linux/platform_data/ina2xx.h>
37
38/* INA2XX registers definition */
39#define INA2XX_CONFIG                   0x00
40#define INA2XX_SHUNT_VOLTAGE            0x01	/* readonly */
41#define INA2XX_BUS_VOLTAGE              0x02	/* readonly */
42#define INA2XX_POWER                    0x03	/* readonly */
43#define INA2XX_CURRENT                  0x04	/* readonly */
44#define INA2XX_CALIBRATION              0x05
45
46#define INA226_MASK_ENABLE		0x06
47#define INA226_CVRF			BIT(3)
48
49#define INA2XX_MAX_REGISTERS            8
50
51/* settings - depend on use case */
52#define INA219_CONFIG_DEFAULT           0x399F	/* PGA=1/8, BRNG=32V */
53#define INA219_DEFAULT_IT		532
54#define INA219_DEFAULT_BRNG             1   /* 32V */
55#define INA219_DEFAULT_PGA              125 /* 1000/8 */
56#define INA226_CONFIG_DEFAULT           0x4327
57#define INA226_DEFAULT_AVG              4
58#define INA226_DEFAULT_IT		1110
59
60#define INA2XX_RSHUNT_DEFAULT           10000
61
62/*
63 * bit masks for reading the settings in the configuration register
64 * FIXME: use regmap_fields.
65 */
66#define INA2XX_MODE_MASK	GENMASK(3, 0)
67
68/* Gain for VShunt: 1/8 (default), 1/4, 1/2, 1 */
69#define INA219_PGA_MASK		GENMASK(12, 11)
70#define INA219_SHIFT_PGA(val)	((val) << 11)
71
72/* VBus range: 32V (default), 16V */
73#define INA219_BRNG_MASK	BIT(13)
74#define INA219_SHIFT_BRNG(val)	((val) << 13)
75
76/* Averaging for VBus/VShunt/Power */
77#define INA226_AVG_MASK		GENMASK(11, 9)
78#define INA226_SHIFT_AVG(val)	((val) << 9)
79
80/* Integration time for VBus */
81#define INA219_ITB_MASK		GENMASK(10, 7)
82#define INA219_SHIFT_ITB(val)	((val) << 7)
83#define INA226_ITB_MASK		GENMASK(8, 6)
84#define INA226_SHIFT_ITB(val)	((val) << 6)
85
86/* Integration time for VShunt */
87#define INA219_ITS_MASK		GENMASK(6, 3)
88#define INA219_SHIFT_ITS(val)	((val) << 3)
89#define INA226_ITS_MASK		GENMASK(5, 3)
90#define INA226_SHIFT_ITS(val)	((val) << 3)
91
92/* INA219 Bus voltage register, low bits are flags */
93#define INA219_OVF		BIT(0)
94#define INA219_CNVR		BIT(1)
95#define INA219_BUS_VOLTAGE_SHIFT	3
96
97/* Cosmetic macro giving the sampling period for a full P=UxI cycle */
98#define SAMPLING_PERIOD(c)	((c->int_time_vbus + c->int_time_vshunt) \
99				 * c->avg)
100
101static bool ina2xx_is_writeable_reg(struct device *dev, unsigned int reg)
102{
103	return (reg == INA2XX_CONFIG) || (reg > INA2XX_CURRENT);
104}
105
106static bool ina2xx_is_volatile_reg(struct device *dev, unsigned int reg)
107{
108	return (reg != INA2XX_CONFIG);
109}
110
111static inline bool is_signed_reg(unsigned int reg)
112{
113	return (reg == INA2XX_SHUNT_VOLTAGE) || (reg == INA2XX_CURRENT);
114}
115
116static const struct regmap_config ina2xx_regmap_config = {
117	.reg_bits = 8,
118	.val_bits = 16,
119	.max_register = INA2XX_MAX_REGISTERS,
120	.writeable_reg = ina2xx_is_writeable_reg,
121	.volatile_reg = ina2xx_is_volatile_reg,
122};
123
124enum ina2xx_ids { ina219, ina226 };
125
126struct ina2xx_config {
127	const char *name;
128	u16 config_default;
129	int calibration_value;
130	int shunt_voltage_lsb;	/* nV */
131	int bus_voltage_shift;	/* position of lsb */
132	int bus_voltage_lsb;	/* uV */
133	/* fixed relation between current and power lsb, uW/uA */
134	int power_lsb_factor;
135	enum ina2xx_ids chip_id;
136};
137
138struct ina2xx_chip_info {
139	struct regmap *regmap;
140	struct task_struct *task;
141	const struct ina2xx_config *config;
142	struct mutex state_lock;
143	unsigned int shunt_resistor_uohm;
144	int avg;
145	int int_time_vbus; /* Bus voltage integration time uS */
146	int int_time_vshunt; /* Shunt voltage integration time uS */
147	int range_vbus; /* Bus voltage maximum in V */
148	int pga_gain_vshunt; /* Shunt voltage PGA gain */
149	bool allow_async_readout;
150	/* data buffer needs space for channel data and timestamp */
151	struct {
152		u16 chan[4];
153		u64 ts __aligned(8);
154	} scan;
155};
156
157static const struct ina2xx_config ina2xx_config[] = {
158	[ina219] = {
159		.name = "ina219",
160		.config_default = INA219_CONFIG_DEFAULT,
161		.calibration_value = 4096,
162		.shunt_voltage_lsb = 10000,
163		.bus_voltage_shift = INA219_BUS_VOLTAGE_SHIFT,
164		.bus_voltage_lsb = 4000,
165		.power_lsb_factor = 20,
166		.chip_id = ina219,
167	},
168	[ina226] = {
169		.name = "ina226",
170		.config_default = INA226_CONFIG_DEFAULT,
171		.calibration_value = 2048,
172		.shunt_voltage_lsb = 2500,
173		.bus_voltage_shift = 0,
174		.bus_voltage_lsb = 1250,
175		.power_lsb_factor = 25,
176		.chip_id = ina226,
177	},
178};
179
180static int ina2xx_read_raw(struct iio_dev *indio_dev,
181			   struct iio_chan_spec const *chan,
182			   int *val, int *val2, long mask)
183{
184	int ret;
185	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
186	unsigned int regval;
187
188	switch (mask) {
189	case IIO_CHAN_INFO_RAW:
190		ret = regmap_read(chip->regmap, chan->address, &regval);
191		if (ret)
192			return ret;
193
194		if (is_signed_reg(chan->address))
195			*val = (s16) regval;
196		else
197			*val  = regval;
198
199		if (chan->address == INA2XX_BUS_VOLTAGE)
200			*val >>= chip->config->bus_voltage_shift;
201
202		return IIO_VAL_INT;
203
204	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
205		*val = chip->avg;
206		return IIO_VAL_INT;
207
208	case IIO_CHAN_INFO_INT_TIME:
209		*val = 0;
210		if (chan->address == INA2XX_SHUNT_VOLTAGE)
211			*val2 = chip->int_time_vshunt;
212		else
213			*val2 = chip->int_time_vbus;
214
215		return IIO_VAL_INT_PLUS_MICRO;
216
217	case IIO_CHAN_INFO_SAMP_FREQ:
218		/*
219		 * Sample freq is read only, it is a consequence of
220		 * 1/AVG*(CT_bus+CT_shunt).
221		 */
222		*val = DIV_ROUND_CLOSEST(1000000, SAMPLING_PERIOD(chip));
223
224		return IIO_VAL_INT;
225
226	case IIO_CHAN_INFO_SCALE:
227		switch (chan->address) {
228		case INA2XX_SHUNT_VOLTAGE:
229			/* processed (mV) = raw * lsb(nV) / 1000000 */
230			*val = chip->config->shunt_voltage_lsb;
231			*val2 = 1000000;
232			return IIO_VAL_FRACTIONAL;
233
234		case INA2XX_BUS_VOLTAGE:
235			/* processed (mV) = raw * lsb (uV) / 1000 */
236			*val = chip->config->bus_voltage_lsb;
237			*val2 = 1000;
238			return IIO_VAL_FRACTIONAL;
239
240		case INA2XX_CURRENT:
241			/*
242			 * processed (mA) = raw * current_lsb (mA)
243			 * current_lsb (mA) = shunt_voltage_lsb (nV) /
244			 *                    shunt_resistor (uOhm)
245			 */
246			*val = chip->config->shunt_voltage_lsb;
247			*val2 = chip->shunt_resistor_uohm;
248			return IIO_VAL_FRACTIONAL;
249
250		case INA2XX_POWER:
251			/*
252			 * processed (mW) = raw * power_lsb (mW)
253			 * power_lsb (mW) = power_lsb_factor (mW/mA) *
254			 *                  current_lsb (mA)
255			 */
256			*val = chip->config->power_lsb_factor *
257			       chip->config->shunt_voltage_lsb;
258			*val2 = chip->shunt_resistor_uohm;
259			return IIO_VAL_FRACTIONAL;
260		}
261		return -EINVAL;
262
263	case IIO_CHAN_INFO_HARDWAREGAIN:
264		switch (chan->address) {
265		case INA2XX_SHUNT_VOLTAGE:
266			*val = chip->pga_gain_vshunt;
267			*val2 = 1000;
268			return IIO_VAL_FRACTIONAL;
269
270		case INA2XX_BUS_VOLTAGE:
271			*val = chip->range_vbus == 32 ? 1 : 2;
272			return IIO_VAL_INT;
273		}
274		return -EINVAL;
275	}
276
277	return -EINVAL;
278}
279
280/*
281 * Available averaging rates for ina226. The indices correspond with
282 * the bit values expected by the chip (according to the ina226 datasheet,
283 * table 3 AVG bit settings, found at
284 * https://www.ti.com/lit/ds/symlink/ina226.pdf.
285 */
286static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
287
288static int ina226_set_average(struct ina2xx_chip_info *chip, unsigned int val,
289			      unsigned int *config)
290{
291	int bits;
292
293	if (val > 1024 || val < 1)
294		return -EINVAL;
295
296	bits = find_closest(val, ina226_avg_tab,
297			    ARRAY_SIZE(ina226_avg_tab));
298
299	chip->avg = ina226_avg_tab[bits];
300
301	*config &= ~INA226_AVG_MASK;
302	*config |= INA226_SHIFT_AVG(bits) & INA226_AVG_MASK;
303
304	return 0;
305}
306
307/* Conversion times in uS */
308static const int ina226_conv_time_tab[] = { 140, 204, 332, 588, 1100,
309					    2116, 4156, 8244 };
310
311static int ina226_set_int_time_vbus(struct ina2xx_chip_info *chip,
312				    unsigned int val_us, unsigned int *config)
313{
314	int bits;
315
316	if (val_us > 8244 || val_us < 140)
317		return -EINVAL;
318
319	bits = find_closest(val_us, ina226_conv_time_tab,
320			    ARRAY_SIZE(ina226_conv_time_tab));
321
322	chip->int_time_vbus = ina226_conv_time_tab[bits];
323
324	*config &= ~INA226_ITB_MASK;
325	*config |= INA226_SHIFT_ITB(bits) & INA226_ITB_MASK;
326
327	return 0;
328}
329
330static int ina226_set_int_time_vshunt(struct ina2xx_chip_info *chip,
331				      unsigned int val_us, unsigned int *config)
332{
333	int bits;
334
335	if (val_us > 8244 || val_us < 140)
336		return -EINVAL;
337
338	bits = find_closest(val_us, ina226_conv_time_tab,
339			    ARRAY_SIZE(ina226_conv_time_tab));
340
341	chip->int_time_vshunt = ina226_conv_time_tab[bits];
342
343	*config &= ~INA226_ITS_MASK;
344	*config |= INA226_SHIFT_ITS(bits) & INA226_ITS_MASK;
345
346	return 0;
347}
348
349/* Conversion times in uS. */
350static const int ina219_conv_time_tab_subsample[] = { 84, 148, 276, 532 };
351static const int ina219_conv_time_tab_average[] = { 532, 1060, 2130, 4260,
352						    8510, 17020, 34050, 68100};
353
354static int ina219_lookup_int_time(unsigned int *val_us, int *bits)
355{
356	if (*val_us > 68100 || *val_us < 84)
357		return -EINVAL;
358
359	if (*val_us <= 532) {
360		*bits = find_closest(*val_us, ina219_conv_time_tab_subsample,
361				    ARRAY_SIZE(ina219_conv_time_tab_subsample));
362		*val_us = ina219_conv_time_tab_subsample[*bits];
363	} else {
364		*bits = find_closest(*val_us, ina219_conv_time_tab_average,
365				    ARRAY_SIZE(ina219_conv_time_tab_average));
366		*val_us = ina219_conv_time_tab_average[*bits];
367		*bits |= 0x8;
368	}
369
370	return 0;
371}
372
373static int ina219_set_int_time_vbus(struct ina2xx_chip_info *chip,
374				    unsigned int val_us, unsigned int *config)
375{
376	int bits, ret;
377	unsigned int val_us_best = val_us;
378
379	ret = ina219_lookup_int_time(&val_us_best, &bits);
380	if (ret)
381		return ret;
382
383	chip->int_time_vbus = val_us_best;
384
385	*config &= ~INA219_ITB_MASK;
386	*config |= INA219_SHIFT_ITB(bits) & INA219_ITB_MASK;
387
388	return 0;
389}
390
391static int ina219_set_int_time_vshunt(struct ina2xx_chip_info *chip,
392				      unsigned int val_us, unsigned int *config)
393{
394	int bits, ret;
395	unsigned int val_us_best = val_us;
396
397	ret = ina219_lookup_int_time(&val_us_best, &bits);
398	if (ret)
399		return ret;
400
401	chip->int_time_vshunt = val_us_best;
402
403	*config &= ~INA219_ITS_MASK;
404	*config |= INA219_SHIFT_ITS(bits) & INA219_ITS_MASK;
405
406	return 0;
407}
408
409static const int ina219_vbus_range_tab[] = { 1, 2 };
410static int ina219_set_vbus_range_denom(struct ina2xx_chip_info *chip,
411				       unsigned int range,
412				       unsigned int *config)
413{
414	if (range == 1)
415		chip->range_vbus = 32;
416	else if (range == 2)
417		chip->range_vbus = 16;
418	else
419		return -EINVAL;
420
421	*config &= ~INA219_BRNG_MASK;
422	*config |= INA219_SHIFT_BRNG(range == 1 ? 1 : 0) & INA219_BRNG_MASK;
423
424	return 0;
425}
426
427static const int ina219_vshunt_gain_tab[] = { 125, 250, 500, 1000 };
428static const int ina219_vshunt_gain_frac[] = {
429	125, 1000, 250, 1000, 500, 1000, 1000, 1000 };
430
431static int ina219_set_vshunt_pga_gain(struct ina2xx_chip_info *chip,
432				      unsigned int gain,
433				      unsigned int *config)
434{
435	int bits;
436
437	if (gain < 125 || gain > 1000)
438		return -EINVAL;
439
440	bits = find_closest(gain, ina219_vshunt_gain_tab,
441			    ARRAY_SIZE(ina219_vshunt_gain_tab));
442
443	chip->pga_gain_vshunt = ina219_vshunt_gain_tab[bits];
444	bits = 3 - bits;
445
446	*config &= ~INA219_PGA_MASK;
447	*config |= INA219_SHIFT_PGA(bits) & INA219_PGA_MASK;
448
449	return 0;
450}
451
452static int ina2xx_read_avail(struct iio_dev *indio_dev,
453			     struct iio_chan_spec const *chan,
454			     const int **vals, int *type, int *length,
455			     long mask)
456{
457	switch (mask) {
458	case IIO_CHAN_INFO_HARDWAREGAIN:
459		switch (chan->address) {
460		case INA2XX_SHUNT_VOLTAGE:
461			*type = IIO_VAL_FRACTIONAL;
462			*length = sizeof(ina219_vshunt_gain_frac) / sizeof(int);
463			*vals = ina219_vshunt_gain_frac;
464			return IIO_AVAIL_LIST;
465
466		case INA2XX_BUS_VOLTAGE:
467			*type = IIO_VAL_INT;
468			*length = sizeof(ina219_vbus_range_tab) / sizeof(int);
469			*vals = ina219_vbus_range_tab;
470			return IIO_AVAIL_LIST;
471		}
472	}
473
474	return -EINVAL;
475}
476
477static int ina2xx_write_raw(struct iio_dev *indio_dev,
478			    struct iio_chan_spec const *chan,
479			    int val, int val2, long mask)
480{
481	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
482	unsigned int config, tmp;
483	int ret;
484
485	if (iio_buffer_enabled(indio_dev))
486		return -EBUSY;
487
488	mutex_lock(&chip->state_lock);
489
490	ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config);
491	if (ret)
492		goto err;
493
494	tmp = config;
495
496	switch (mask) {
497	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
498		ret = ina226_set_average(chip, val, &tmp);
499		break;
500
501	case IIO_CHAN_INFO_INT_TIME:
502		if (chip->config->chip_id == ina226) {
503			if (chan->address == INA2XX_SHUNT_VOLTAGE)
504				ret = ina226_set_int_time_vshunt(chip, val2,
505								 &tmp);
506			else
507				ret = ina226_set_int_time_vbus(chip, val2,
508							       &tmp);
509		} else {
510			if (chan->address == INA2XX_SHUNT_VOLTAGE)
511				ret = ina219_set_int_time_vshunt(chip, val2,
512								 &tmp);
513			else
514				ret = ina219_set_int_time_vbus(chip, val2,
515							       &tmp);
516		}
517		break;
518
519	case IIO_CHAN_INFO_HARDWAREGAIN:
520		if (chan->address == INA2XX_SHUNT_VOLTAGE)
521			ret = ina219_set_vshunt_pga_gain(chip, val * 1000 +
522							 val2 / 1000, &tmp);
523		else
524			ret = ina219_set_vbus_range_denom(chip, val, &tmp);
525		break;
526
527	default:
528		ret = -EINVAL;
529	}
530
531	if (!ret && (tmp != config))
532		ret = regmap_write(chip->regmap, INA2XX_CONFIG, tmp);
533err:
534	mutex_unlock(&chip->state_lock);
535
536	return ret;
537}
538
539static ssize_t ina2xx_allow_async_readout_show(struct device *dev,
540					   struct device_attribute *attr,
541					   char *buf)
542{
543	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
544
545	return sysfs_emit(buf, "%d\n", chip->allow_async_readout);
546}
547
548static ssize_t ina2xx_allow_async_readout_store(struct device *dev,
549				struct device_attribute *attr,
550				const char *buf, size_t len)
551{
552	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
553	bool val;
554	int ret;
555
556	ret = kstrtobool(buf, &val);
557	if (ret)
558		return ret;
559
560	chip->allow_async_readout = val;
561
562	return len;
563}
564
565/*
566 * Calibration register is set to the best value, which eliminates
567 * truncation errors on calculating current register in hardware.
568 * According to datasheet (INA 226: eq. 3, INA219: eq. 4) the best values
569 * are 2048 for ina226 and 4096 for ina219. They are hardcoded as
570 * calibration_value.
571 */
572static int ina2xx_set_calibration(struct ina2xx_chip_info *chip)
573{
574	return regmap_write(chip->regmap, INA2XX_CALIBRATION,
575			    chip->config->calibration_value);
576}
577
578static int set_shunt_resistor(struct ina2xx_chip_info *chip, unsigned int val)
579{
580	if (val == 0 || val > INT_MAX)
581		return -EINVAL;
582
583	chip->shunt_resistor_uohm = val;
584
585	return 0;
586}
587
588static ssize_t ina2xx_shunt_resistor_show(struct device *dev,
589					  struct device_attribute *attr,
590					  char *buf)
591{
592	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
593	int vals[2] = { chip->shunt_resistor_uohm, 1000000 };
594
595	return iio_format_value(buf, IIO_VAL_FRACTIONAL, 1, vals);
596}
597
598static ssize_t ina2xx_shunt_resistor_store(struct device *dev,
599					   struct device_attribute *attr,
600					   const char *buf, size_t len)
601{
602	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
603	int val, val_fract, ret;
604
605	ret = iio_str_to_fixpoint(buf, 100000, &val, &val_fract);
606	if (ret)
607		return ret;
608
609	ret = set_shunt_resistor(chip, val * 1000000 + val_fract);
610	if (ret)
611		return ret;
612
613	return len;
614}
615
616#define INA219_CHAN(_type, _index, _address) { \
617	.type = (_type), \
618	.address = (_address), \
619	.indexed = 1, \
620	.channel = (_index), \
621	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
622			      BIT(IIO_CHAN_INFO_SCALE), \
623	.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
624	.scan_index = (_index), \
625	.scan_type = { \
626		.sign = 'u', \
627		.realbits = 16, \
628		.storagebits = 16, \
629		.endianness = IIO_CPU, \
630	} \
631}
632
633#define INA226_CHAN(_type, _index, _address) { \
634	.type = (_type), \
635	.address = (_address), \
636	.indexed = 1, \
637	.channel = (_index), \
638	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
639			      BIT(IIO_CHAN_INFO_SCALE), \
640	.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
641				   BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
642	.scan_index = (_index), \
643	.scan_type = { \
644		.sign = 'u', \
645		.realbits = 16, \
646		.storagebits = 16, \
647		.endianness = IIO_CPU, \
648	} \
649}
650
651/*
652 * Sampling Freq is a consequence of the integration times of
653 * the Voltage channels.
654 */
655#define INA219_CHAN_VOLTAGE(_index, _address, _shift) { \
656	.type = IIO_VOLTAGE, \
657	.address = (_address), \
658	.indexed = 1, \
659	.channel = (_index), \
660	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
661			      BIT(IIO_CHAN_INFO_SCALE) | \
662			      BIT(IIO_CHAN_INFO_INT_TIME) | \
663			      BIT(IIO_CHAN_INFO_HARDWAREGAIN), \
664	.info_mask_separate_available = \
665			      BIT(IIO_CHAN_INFO_HARDWAREGAIN), \
666	.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
667	.scan_index = (_index), \
668	.scan_type = { \
669		.sign = 'u', \
670		.shift = _shift, \
671		.realbits = 16 - _shift, \
672		.storagebits = 16, \
673		.endianness = IIO_LE, \
674	} \
675}
676
677#define INA226_CHAN_VOLTAGE(_index, _address) { \
678	.type = IIO_VOLTAGE, \
679	.address = (_address), \
680	.indexed = 1, \
681	.channel = (_index), \
682	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
683			      BIT(IIO_CHAN_INFO_SCALE) | \
684			      BIT(IIO_CHAN_INFO_INT_TIME), \
685	.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
686				   BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
687	.scan_index = (_index), \
688	.scan_type = { \
689		.sign = 'u', \
690		.realbits = 16, \
691		.storagebits = 16, \
692		.endianness = IIO_LE, \
693	} \
694}
695
696
697static const struct iio_chan_spec ina226_channels[] = {
698	INA226_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
699	INA226_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
700	INA226_CHAN(IIO_POWER, 2, INA2XX_POWER),
701	INA226_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
702	IIO_CHAN_SOFT_TIMESTAMP(4),
703};
704
705static const struct iio_chan_spec ina219_channels[] = {
706	INA219_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE, 0),
707	INA219_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE, INA219_BUS_VOLTAGE_SHIFT),
708	INA219_CHAN(IIO_POWER, 2, INA2XX_POWER),
709	INA219_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
710	IIO_CHAN_SOFT_TIMESTAMP(4),
711};
712
713static int ina2xx_conversion_ready(struct iio_dev *indio_dev)
714{
715	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
716	int ret;
717	unsigned int alert;
718
719	/*
720	 * Because the timer thread and the chip conversion clock
721	 * are asynchronous, the period difference will eventually
722	 * result in reading V[k-1] again, or skip V[k] at time Tk.
723	 * In order to resync the timer with the conversion process
724	 * we check the ConVersionReadyFlag.
725	 * On hardware that supports using the ALERT pin to toggle a
726	 * GPIO a triggered buffer could be used instead.
727	 * For now, we do an extra read of the MASK_ENABLE register (INA226)
728	 * resp. the BUS_VOLTAGE register (INA219).
729	 */
730	if (chip->config->chip_id == ina226) {
731		ret = regmap_read(chip->regmap,
732				  INA226_MASK_ENABLE, &alert);
733		alert &= INA226_CVRF;
734	} else {
735		ret = regmap_read(chip->regmap,
736				  INA2XX_BUS_VOLTAGE, &alert);
737		alert &= INA219_CNVR;
738	}
739
740	if (ret < 0)
741		return ret;
742
743	return !!alert;
744}
745
746static int ina2xx_work_buffer(struct iio_dev *indio_dev)
747{
748	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
749	int bit, ret, i = 0;
750	s64 time;
751
752	time = iio_get_time_ns(indio_dev);
753
754	/*
755	 * Single register reads: bulk_read will not work with ina226/219
756	 * as there is no auto-increment of the register pointer.
757	 */
758	for_each_set_bit(bit, indio_dev->active_scan_mask,
759			 indio_dev->masklength) {
760		unsigned int val;
761
762		ret = regmap_read(chip->regmap,
763				  INA2XX_SHUNT_VOLTAGE + bit, &val);
764		if (ret < 0)
765			return ret;
766
767		chip->scan.chan[i++] = val;
768	}
769
770	iio_push_to_buffers_with_timestamp(indio_dev, &chip->scan, time);
771
772	return 0;
773};
774
775static int ina2xx_capture_thread(void *data)
776{
777	struct iio_dev *indio_dev = data;
778	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
779	int sampling_us = SAMPLING_PERIOD(chip);
780	int ret;
781	struct timespec64 next, now, delta;
782	s64 delay_us;
783
784	/*
785	 * Poll a bit faster than the chip internal Fs, in case
786	 * we wish to sync with the conversion ready flag.
787	 */
788	if (!chip->allow_async_readout)
789		sampling_us -= 200;
790
791	ktime_get_ts64(&next);
792
793	do {
794		while (!chip->allow_async_readout) {
795			ret = ina2xx_conversion_ready(indio_dev);
796			if (ret < 0)
797				return ret;
798
799			/*
800			 * If the conversion was not yet finished,
801			 * reset the reference timestamp.
802			 */
803			if (ret == 0)
804				ktime_get_ts64(&next);
805			else
806				break;
807		}
808
809		ret = ina2xx_work_buffer(indio_dev);
810		if (ret < 0)
811			return ret;
812
813		ktime_get_ts64(&now);
814
815		/*
816		 * Advance the timestamp for the next poll by one sampling
817		 * interval, and sleep for the remainder (next - now)
818		 * In case "next" has already passed, the interval is added
819		 * multiple times, i.e. samples are dropped.
820		 */
821		do {
822			timespec64_add_ns(&next, 1000 * sampling_us);
823			delta = timespec64_sub(next, now);
824			delay_us = div_s64(timespec64_to_ns(&delta), 1000);
825		} while (delay_us <= 0);
826
827		usleep_range(delay_us, (delay_us * 3) >> 1);
828
829	} while (!kthread_should_stop());
830
831	return 0;
832}
833
834static int ina2xx_buffer_enable(struct iio_dev *indio_dev)
835{
836	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
837	unsigned int sampling_us = SAMPLING_PERIOD(chip);
838	struct task_struct *task;
839
840	dev_dbg(&indio_dev->dev, "Enabling buffer w/ scan_mask %02x, freq = %d, avg =%u\n",
841		(unsigned int)(*indio_dev->active_scan_mask),
842		1000000 / sampling_us, chip->avg);
843
844	dev_dbg(&indio_dev->dev, "Expected work period: %u us\n", sampling_us);
845	dev_dbg(&indio_dev->dev, "Async readout mode: %d\n",
846		chip->allow_async_readout);
847
848	task = kthread_run(ina2xx_capture_thread, (void *)indio_dev,
849			   "%s:%d-%uus", indio_dev->name,
850			   iio_device_id(indio_dev),
851			   sampling_us);
852	if (IS_ERR(task))
853		return PTR_ERR(task);
854
855	chip->task = task;
856
857	return 0;
858}
859
860static int ina2xx_buffer_disable(struct iio_dev *indio_dev)
861{
862	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
863
864	if (chip->task) {
865		kthread_stop(chip->task);
866		chip->task = NULL;
867	}
868
869	return 0;
870}
871
872static const struct iio_buffer_setup_ops ina2xx_setup_ops = {
873	.postenable = &ina2xx_buffer_enable,
874	.predisable = &ina2xx_buffer_disable,
875};
876
877static int ina2xx_debug_reg(struct iio_dev *indio_dev,
878			    unsigned reg, unsigned writeval, unsigned *readval)
879{
880	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
881
882	if (!readval)
883		return regmap_write(chip->regmap, reg, writeval);
884
885	return regmap_read(chip->regmap, reg, readval);
886}
887
888/* Possible integration times for vshunt and vbus */
889static IIO_CONST_ATTR_NAMED(ina219_integration_time_available,
890			    integration_time_available,
891			    "0.000084 0.000148 0.000276 0.000532 0.001060 0.002130 0.004260 0.008510 0.017020 0.034050 0.068100");
892
893static IIO_CONST_ATTR_NAMED(ina226_integration_time_available,
894			    integration_time_available,
895			    "0.000140 0.000204 0.000332 0.000588 0.001100 0.002116 0.004156 0.008244");
896
897static IIO_DEVICE_ATTR(in_allow_async_readout, S_IRUGO | S_IWUSR,
898		       ina2xx_allow_async_readout_show,
899		       ina2xx_allow_async_readout_store, 0);
900
901static IIO_DEVICE_ATTR(in_shunt_resistor, S_IRUGO | S_IWUSR,
902		       ina2xx_shunt_resistor_show,
903		       ina2xx_shunt_resistor_store, 0);
904
905static struct attribute *ina219_attributes[] = {
906	&iio_dev_attr_in_allow_async_readout.dev_attr.attr,
907	&iio_const_attr_ina219_integration_time_available.dev_attr.attr,
908	&iio_dev_attr_in_shunt_resistor.dev_attr.attr,
909	NULL,
910};
911
912static struct attribute *ina226_attributes[] = {
913	&iio_dev_attr_in_allow_async_readout.dev_attr.attr,
914	&iio_const_attr_ina226_integration_time_available.dev_attr.attr,
915	&iio_dev_attr_in_shunt_resistor.dev_attr.attr,
916	NULL,
917};
918
919static const struct attribute_group ina219_attribute_group = {
920	.attrs = ina219_attributes,
921};
922
923static const struct attribute_group ina226_attribute_group = {
924	.attrs = ina226_attributes,
925};
926
927static const struct iio_info ina219_info = {
928	.attrs = &ina219_attribute_group,
929	.read_raw = ina2xx_read_raw,
930	.read_avail = ina2xx_read_avail,
931	.write_raw = ina2xx_write_raw,
932	.debugfs_reg_access = ina2xx_debug_reg,
933};
934
935static const struct iio_info ina226_info = {
936	.attrs = &ina226_attribute_group,
937	.read_raw = ina2xx_read_raw,
938	.write_raw = ina2xx_write_raw,
939	.debugfs_reg_access = ina2xx_debug_reg,
940};
941
942/* Initialize the configuration and calibration registers. */
943static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config)
944{
945	int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config);
946	if (ret)
947		return ret;
948
949	return ina2xx_set_calibration(chip);
950}
951
952static int ina2xx_probe(struct i2c_client *client)
953{
954	const struct i2c_device_id *id = i2c_client_get_device_id(client);
955	struct ina2xx_chip_info *chip;
956	struct iio_dev *indio_dev;
957	unsigned int val;
958	enum ina2xx_ids type;
959	int ret;
960
961	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
962	if (!indio_dev)
963		return -ENOMEM;
964
965	chip = iio_priv(indio_dev);
966
967	/* This is only used for device removal purposes. */
968	i2c_set_clientdata(client, indio_dev);
969
970	chip->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
971	if (IS_ERR(chip->regmap)) {
972		dev_err(&client->dev, "failed to allocate register map\n");
973		return PTR_ERR(chip->regmap);
974	}
975
976	if (client->dev.of_node)
977		type = (uintptr_t)of_device_get_match_data(&client->dev);
978	else
979		type = id->driver_data;
980	chip->config = &ina2xx_config[type];
981
982	mutex_init(&chip->state_lock);
983
984	if (of_property_read_u32(client->dev.of_node,
985				 "shunt-resistor", &val) < 0) {
986		struct ina2xx_platform_data *pdata =
987		    dev_get_platdata(&client->dev);
988
989		if (pdata)
990			val = pdata->shunt_uohms;
991		else
992			val = INA2XX_RSHUNT_DEFAULT;
993	}
994
995	ret = set_shunt_resistor(chip, val);
996	if (ret)
997		return ret;
998
999	/* Patch the current config register with default. */
1000	val = chip->config->config_default;
1001
1002	if (type == ina226) {
1003		ina226_set_average(chip, INA226_DEFAULT_AVG, &val);
1004		ina226_set_int_time_vbus(chip, INA226_DEFAULT_IT, &val);
1005		ina226_set_int_time_vshunt(chip, INA226_DEFAULT_IT, &val);
1006	} else {
1007		chip->avg = 1;
1008		ina219_set_int_time_vbus(chip, INA219_DEFAULT_IT, &val);
1009		ina219_set_int_time_vshunt(chip, INA219_DEFAULT_IT, &val);
1010		ina219_set_vbus_range_denom(chip, INA219_DEFAULT_BRNG, &val);
1011		ina219_set_vshunt_pga_gain(chip, INA219_DEFAULT_PGA, &val);
1012	}
1013
1014	ret = ina2xx_init(chip, val);
1015	if (ret) {
1016		dev_err(&client->dev, "error configuring the device\n");
1017		return ret;
1018	}
1019
1020	indio_dev->modes = INDIO_DIRECT_MODE;
1021	if (type == ina226) {
1022		indio_dev->channels = ina226_channels;
1023		indio_dev->num_channels = ARRAY_SIZE(ina226_channels);
1024		indio_dev->info = &ina226_info;
1025	} else {
1026		indio_dev->channels = ina219_channels;
1027		indio_dev->num_channels = ARRAY_SIZE(ina219_channels);
1028		indio_dev->info = &ina219_info;
1029	}
1030	indio_dev->name = id ? id->name : chip->config->name;
1031
1032	ret = devm_iio_kfifo_buffer_setup(&client->dev, indio_dev,
1033					  &ina2xx_setup_ops);
1034	if (ret)
1035		return ret;
1036
1037	return iio_device_register(indio_dev);
1038}
1039
1040static void ina2xx_remove(struct i2c_client *client)
1041{
1042	struct iio_dev *indio_dev = i2c_get_clientdata(client);
1043	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
1044	int ret;
1045
1046	iio_device_unregister(indio_dev);
1047
1048	/* Powerdown */
1049	ret = regmap_update_bits(chip->regmap, INA2XX_CONFIG,
1050				 INA2XX_MODE_MASK, 0);
1051	if (ret)
1052		dev_warn(&client->dev, "Failed to power down device (%pe)\n",
1053			 ERR_PTR(ret));
1054}
1055
1056static const struct i2c_device_id ina2xx_id[] = {
1057	{"ina219", ina219},
1058	{"ina220", ina219},
1059	{"ina226", ina226},
1060	{"ina230", ina226},
1061	{"ina231", ina226},
1062	{}
1063};
1064MODULE_DEVICE_TABLE(i2c, ina2xx_id);
1065
1066static const struct of_device_id ina2xx_of_match[] = {
1067	{
1068		.compatible = "ti,ina219",
1069		.data = (void *)ina219
1070	},
1071	{
1072		.compatible = "ti,ina220",
1073		.data = (void *)ina219
1074	},
1075	{
1076		.compatible = "ti,ina226",
1077		.data = (void *)ina226
1078	},
1079	{
1080		.compatible = "ti,ina230",
1081		.data = (void *)ina226
1082	},
1083	{
1084		.compatible = "ti,ina231",
1085		.data = (void *)ina226
1086	},
1087	{},
1088};
1089MODULE_DEVICE_TABLE(of, ina2xx_of_match);
1090
1091static struct i2c_driver ina2xx_driver = {
1092	.driver = {
1093		   .name = KBUILD_MODNAME,
1094		   .of_match_table = ina2xx_of_match,
1095	},
1096	.probe = ina2xx_probe,
1097	.remove = ina2xx_remove,
1098	.id_table = ina2xx_id,
1099};
1100module_i2c_driver(ina2xx_driver);
1101
1102MODULE_AUTHOR("Marc Titinger <marc.titinger@baylibre.com>");
1103MODULE_DESCRIPTION("Texas Instruments INA2XX ADC driver");
1104MODULE_LICENSE("GPL v2");
1105