2 * INA2XX Current and Power Monitors
4 * Copyright 2015 Baylibre SAS.
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.
10 * Based on linux/drivers/iio/adc/ad7291.c
11 * Copyright 2010-2011 Analog Devices Inc.
13 * Based on linux/drivers/hwmon/ina2xx.c
14 * Copyright 2012 Lothar Felten <l-felten@ti.com>
16 * Licensed under the GPL-2 or later.
18 * IIO driver for INA219-220-226-230-231
20 * Configurable 7-bit I2C slave address from 0x40 to 0x4F
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/regmap.h>
32 #include <linux/util_macros.h>
34 #include <linux/platform_data/ina2xx.h>
36 /* INA2XX registers definition */
37 #define INA2XX_CONFIG 0x00
38 #define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */
39 #define INA2XX_BUS_VOLTAGE 0x02 /* readonly */
40 #define INA2XX_POWER 0x03 /* readonly */
41 #define INA2XX_CURRENT 0x04 /* readonly */
42 #define INA2XX_CALIBRATION 0x05
44 #define INA226_ALERT_MASK GENMASK(2, 1)
45 #define INA266_CVRF BIT(3)
47 #define INA2XX_MAX_REGISTERS 8
49 /* settings - depend on use case */
50 #define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */
51 #define INA226_CONFIG_DEFAULT 0x4327
52 #define INA226_DEFAULT_AVG 4
53 #define INA226_DEFAULT_IT 1110
55 #define INA2XX_RSHUNT_DEFAULT 10000
58 * bit mask for reading the averaging setting in the configuration register
59 * FIXME: use regmap_fields.
61 #define INA2XX_MODE_MASK GENMASK(3, 0)
63 #define INA226_AVG_MASK GENMASK(11, 9)
64 #define INA226_SHIFT_AVG(val) ((val) << 9)
66 /* Integration time for VBus */
67 #define INA226_ITB_MASK GENMASK(8, 6)
68 #define INA226_SHIFT_ITB(val) ((val) << 6)
70 /* Integration time for VShunt */
71 #define INA226_ITS_MASK GENMASK(5, 3)
72 #define INA226_SHIFT_ITS(val) ((val) << 3)
74 /* Cosmetic macro giving the sampling period for a full P=UxI cycle */
75 #define SAMPLING_PERIOD(c) ((c->int_time_vbus + c->int_time_vshunt) \
78 static bool ina2xx_is_writeable_reg(struct device *dev, unsigned int reg)
80 return (reg == INA2XX_CONFIG) || (reg > INA2XX_CURRENT);
83 static bool ina2xx_is_volatile_reg(struct device *dev, unsigned int reg)
85 return (reg != INA2XX_CONFIG);
88 static inline bool is_signed_reg(unsigned int reg)
90 return (reg == INA2XX_SHUNT_VOLTAGE) || (reg == INA2XX_CURRENT);
93 static const struct regmap_config ina2xx_regmap_config = {
96 .max_register = INA2XX_MAX_REGISTERS,
97 .writeable_reg = ina2xx_is_writeable_reg,
98 .volatile_reg = ina2xx_is_volatile_reg,
101 enum ina2xx_ids { ina219, ina226 };
103 struct ina2xx_config {
105 int calibration_factor;
107 int bus_voltage_shift;
108 int bus_voltage_lsb; /* uV */
109 int power_lsb; /* uW */
112 struct ina2xx_chip_info {
113 struct regmap *regmap;
114 struct task_struct *task;
115 const struct ina2xx_config *config;
116 struct mutex state_lock;
117 unsigned int shunt_resistor;
119 int int_time_vbus; /* Bus voltage integration time uS */
120 int int_time_vshunt; /* Shunt voltage integration time uS */
121 bool allow_async_readout;
124 static const struct ina2xx_config ina2xx_config[] = {
126 .config_default = INA219_CONFIG_DEFAULT,
127 .calibration_factor = 40960000,
129 .bus_voltage_shift = 3,
130 .bus_voltage_lsb = 4000,
134 .config_default = INA226_CONFIG_DEFAULT,
135 .calibration_factor = 5120000,
137 .bus_voltage_shift = 0,
138 .bus_voltage_lsb = 1250,
143 static int ina2xx_read_raw(struct iio_dev *indio_dev,
144 struct iio_chan_spec const *chan,
145 int *val, int *val2, long mask)
148 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
152 case IIO_CHAN_INFO_RAW:
153 ret = regmap_read(chip->regmap, chan->address, ®val);
157 if (is_signed_reg(chan->address))
164 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
168 case IIO_CHAN_INFO_INT_TIME:
170 if (chan->address == INA2XX_SHUNT_VOLTAGE)
171 *val2 = chip->int_time_vshunt;
173 *val2 = chip->int_time_vbus;
175 return IIO_VAL_INT_PLUS_MICRO;
177 case IIO_CHAN_INFO_SAMP_FREQ:
179 * Sample freq is read only, it is a consequence of
180 * 1/AVG*(CT_bus+CT_shunt).
182 *val = DIV_ROUND_CLOSEST(1000000, SAMPLING_PERIOD(chip));
186 case IIO_CHAN_INFO_SCALE:
187 switch (chan->address) {
188 case INA2XX_SHUNT_VOLTAGE:
189 /* processed (mV) = raw/shunt_div */
190 *val2 = chip->config->shunt_div;
192 return IIO_VAL_FRACTIONAL;
194 case INA2XX_BUS_VOLTAGE:
195 /* processed (mV) = raw*lsb (uV) / (1000 << shift) */
196 *val = chip->config->bus_voltage_lsb;
197 *val2 = 1000 << chip->config->bus_voltage_shift;
198 return IIO_VAL_FRACTIONAL;
201 /* processed (mW) = raw*lsb (uW) / 1000 */
202 *val = chip->config->power_lsb;
204 return IIO_VAL_FRACTIONAL;
207 /* processed (mA) = raw (mA) */
217 * Available averaging rates for ina226. The indices correspond with
218 * the bit values expected by the chip (according to the ina226 datasheet,
219 * table 3 AVG bit settings, found at
220 * http://www.ti.com/lit/ds/symlink/ina226.pdf.
222 static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
224 static int ina226_set_average(struct ina2xx_chip_info *chip, unsigned int val,
225 unsigned int *config)
229 if (val > 1024 || val < 1)
232 bits = find_closest(val, ina226_avg_tab,
233 ARRAY_SIZE(ina226_avg_tab));
235 chip->avg = ina226_avg_tab[bits];
237 *config &= ~INA226_AVG_MASK;
238 *config |= INA226_SHIFT_AVG(bits) & INA226_AVG_MASK;
243 /* Conversion times in uS */
244 static const int ina226_conv_time_tab[] = { 140, 204, 332, 588, 1100,
247 static int ina226_set_int_time_vbus(struct ina2xx_chip_info *chip,
248 unsigned int val_us, unsigned int *config)
252 if (val_us > 8244 || val_us < 140)
255 bits = find_closest(val_us, ina226_conv_time_tab,
256 ARRAY_SIZE(ina226_conv_time_tab));
258 chip->int_time_vbus = ina226_conv_time_tab[bits];
260 *config &= ~INA226_ITB_MASK;
261 *config |= INA226_SHIFT_ITB(bits) & INA226_ITB_MASK;
266 static int ina226_set_int_time_vshunt(struct ina2xx_chip_info *chip,
267 unsigned int val_us, unsigned int *config)
271 if (val_us > 8244 || val_us < 140)
274 bits = find_closest(val_us, ina226_conv_time_tab,
275 ARRAY_SIZE(ina226_conv_time_tab));
277 chip->int_time_vshunt = ina226_conv_time_tab[bits];
279 *config &= ~INA226_ITS_MASK;
280 *config |= INA226_SHIFT_ITS(bits) & INA226_ITS_MASK;
285 static int ina2xx_write_raw(struct iio_dev *indio_dev,
286 struct iio_chan_spec const *chan,
287 int val, int val2, long mask)
289 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
290 unsigned int config, tmp;
293 if (iio_buffer_enabled(indio_dev))
296 mutex_lock(&chip->state_lock);
298 ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config);
305 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
306 ret = ina226_set_average(chip, val, &tmp);
309 case IIO_CHAN_INFO_INT_TIME:
310 if (chan->address == INA2XX_SHUNT_VOLTAGE)
311 ret = ina226_set_int_time_vshunt(chip, val2, &tmp);
313 ret = ina226_set_int_time_vbus(chip, val2, &tmp);
320 if (!ret && (tmp != config))
321 ret = regmap_write(chip->regmap, INA2XX_CONFIG, tmp);
323 mutex_unlock(&chip->state_lock);
328 static ssize_t ina2xx_allow_async_readout_show(struct device *dev,
329 struct device_attribute *attr,
332 struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
334 return sprintf(buf, "%d\n", chip->allow_async_readout);
337 static ssize_t ina2xx_allow_async_readout_store(struct device *dev,
338 struct device_attribute *attr,
339 const char *buf, size_t len)
341 struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
345 ret = strtobool((const char *) buf, &val);
349 chip->allow_async_readout = val;
355 * Set current LSB to 1mA, shunt is in uOhms
356 * (equation 13 in datasheet). We hardcode a Current_LSB
357 * of 1.0 x10-6. The only remaining parameter is RShunt.
358 * There is no need to expose the CALIBRATION register
359 * to the user for now. But we need to reset this register
360 * if the user updates RShunt after driver init, e.g upon
361 * reading an EEPROM/Probe-type value.
363 static int ina2xx_set_calibration(struct ina2xx_chip_info *chip)
365 u16 regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor,
366 chip->shunt_resistor);
368 return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval);
371 static int set_shunt_resistor(struct ina2xx_chip_info *chip, unsigned int val)
373 if (val <= 0 || val > chip->config->calibration_factor)
376 chip->shunt_resistor = val;
381 static ssize_t ina2xx_shunt_resistor_show(struct device *dev,
382 struct device_attribute *attr,
385 struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
387 return sprintf(buf, "%d\n", chip->shunt_resistor);
390 static ssize_t ina2xx_shunt_resistor_store(struct device *dev,
391 struct device_attribute *attr,
392 const char *buf, size_t len)
394 struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
398 ret = kstrtoul((const char *) buf, 10, &val);
402 ret = set_shunt_resistor(chip, val);
406 /* Update the Calibration register */
407 ret = ina2xx_set_calibration(chip);
414 #define INA2XX_CHAN(_type, _index, _address) { \
416 .address = (_address), \
418 .channel = (_index), \
419 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \
420 | BIT(IIO_CHAN_INFO_SCALE), \
421 .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
422 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
423 .scan_index = (_index), \
428 .endianness = IIO_CPU, \
433 * Sampling Freq is a consequence of the integration times of
434 * the Voltage channels.
436 #define INA2XX_CHAN_VOLTAGE(_index, _address) { \
437 .type = IIO_VOLTAGE, \
438 .address = (_address), \
440 .channel = (_index), \
441 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
442 BIT(IIO_CHAN_INFO_SCALE) | \
443 BIT(IIO_CHAN_INFO_INT_TIME), \
444 .scan_index = (_index), \
449 .endianness = IIO_LE, \
453 static const struct iio_chan_spec ina2xx_channels[] = {
454 INA2XX_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
455 INA2XX_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
456 INA2XX_CHAN(IIO_POWER, 2, INA2XX_POWER),
457 INA2XX_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
458 IIO_CHAN_SOFT_TIMESTAMP(4),
461 static int ina2xx_work_buffer(struct iio_dev *indio_dev)
463 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
464 unsigned short data[8];
469 time_a = iio_get_time_ns(indio_dev);
472 * Because the timer thread and the chip conversion clock
473 * are asynchronous, the period difference will eventually
474 * result in reading V[k-1] again, or skip V[k] at time Tk.
475 * In order to resync the timer with the conversion process
476 * we check the ConVersionReadyFlag.
477 * On hardware that supports using the ALERT pin to toggle a
478 * GPIO a triggered buffer could be used instead.
479 * For now, we pay for that extra read of the ALERT register
481 if (!chip->allow_async_readout)
483 ret = regmap_read(chip->regmap, INA226_ALERT_MASK,
488 alert &= INA266_CVRF;
492 * Single register reads: bulk_read will not work with ina226
493 * as there is no auto-increment of the address register for
494 * data length longer than 16bits.
496 for_each_set_bit(bit, indio_dev->active_scan_mask,
497 indio_dev->masklength) {
500 ret = regmap_read(chip->regmap,
501 INA2XX_SHUNT_VOLTAGE + bit, &val);
508 time_b = iio_get_time_ns(indio_dev);
510 iio_push_to_buffers_with_timestamp(indio_dev,
511 (unsigned int *)data, time_a);
513 return (unsigned long)(time_b - time_a) / 1000;
516 static int ina2xx_capture_thread(void *data)
518 struct iio_dev *indio_dev = data;
519 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
520 unsigned int sampling_us = SAMPLING_PERIOD(chip);
524 * Poll a bit faster than the chip internal Fs, in case
525 * we wish to sync with the conversion ready flag.
527 if (!chip->allow_async_readout)
531 buffer_us = ina2xx_work_buffer(indio_dev);
535 if (sampling_us > buffer_us)
536 udelay(sampling_us - buffer_us);
538 } while (!kthread_should_stop());
543 static int ina2xx_buffer_enable(struct iio_dev *indio_dev)
545 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
546 unsigned int sampling_us = SAMPLING_PERIOD(chip);
548 dev_dbg(&indio_dev->dev, "Enabling buffer w/ scan_mask %02x, freq = %d, avg =%u\n",
549 (unsigned int)(*indio_dev->active_scan_mask),
550 1000000 / sampling_us, chip->avg);
552 dev_dbg(&indio_dev->dev, "Expected work period: %u us\n", sampling_us);
553 dev_dbg(&indio_dev->dev, "Async readout mode: %d\n",
554 chip->allow_async_readout);
556 chip->task = kthread_run(ina2xx_capture_thread, (void *)indio_dev,
557 "%s:%d-%uus", indio_dev->name, indio_dev->id,
560 return PTR_ERR_OR_ZERO(chip->task);
563 static int ina2xx_buffer_disable(struct iio_dev *indio_dev)
565 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
568 kthread_stop(chip->task);
575 static const struct iio_buffer_setup_ops ina2xx_setup_ops = {
576 .postenable = &ina2xx_buffer_enable,
577 .predisable = &ina2xx_buffer_disable,
580 static int ina2xx_debug_reg(struct iio_dev *indio_dev,
581 unsigned reg, unsigned writeval, unsigned *readval)
583 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
586 return regmap_write(chip->regmap, reg, writeval);
588 return regmap_read(chip->regmap, reg, readval);
591 /* Possible integration times for vshunt and vbus */
592 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.000140 0.000204 0.000332 0.000588 0.001100 0.002116 0.004156 0.008244");
594 static IIO_DEVICE_ATTR(in_allow_async_readout, S_IRUGO | S_IWUSR,
595 ina2xx_allow_async_readout_show,
596 ina2xx_allow_async_readout_store, 0);
598 static IIO_DEVICE_ATTR(in_shunt_resistor, S_IRUGO | S_IWUSR,
599 ina2xx_shunt_resistor_show,
600 ina2xx_shunt_resistor_store, 0);
602 static struct attribute *ina2xx_attributes[] = {
603 &iio_dev_attr_in_allow_async_readout.dev_attr.attr,
604 &iio_const_attr_integration_time_available.dev_attr.attr,
605 &iio_dev_attr_in_shunt_resistor.dev_attr.attr,
609 static const struct attribute_group ina2xx_attribute_group = {
610 .attrs = ina2xx_attributes,
613 static const struct iio_info ina2xx_info = {
614 .driver_module = THIS_MODULE,
615 .attrs = &ina2xx_attribute_group,
616 .read_raw = ina2xx_read_raw,
617 .write_raw = ina2xx_write_raw,
618 .debugfs_reg_access = ina2xx_debug_reg,
621 /* Initialize the configuration and calibration registers. */
622 static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config)
624 int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config);
628 return ina2xx_set_calibration(chip);
631 static int ina2xx_probe(struct i2c_client *client,
632 const struct i2c_device_id *id)
634 struct ina2xx_chip_info *chip;
635 struct iio_dev *indio_dev;
636 struct iio_buffer *buffer;
640 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
644 chip = iio_priv(indio_dev);
646 /* This is only used for device removal purposes. */
647 i2c_set_clientdata(client, indio_dev);
649 chip->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
650 if (IS_ERR(chip->regmap)) {
651 dev_err(&client->dev, "failed to allocate register map\n");
652 return PTR_ERR(chip->regmap);
655 chip->config = &ina2xx_config[id->driver_data];
657 mutex_init(&chip->state_lock);
659 if (of_property_read_u32(client->dev.of_node,
660 "shunt-resistor", &val) < 0) {
661 struct ina2xx_platform_data *pdata =
662 dev_get_platdata(&client->dev);
665 val = pdata->shunt_uohms;
667 val = INA2XX_RSHUNT_DEFAULT;
670 ret = set_shunt_resistor(chip, val);
674 /* Patch the current config register with default. */
675 val = chip->config->config_default;
677 if (id->driver_data == ina226) {
678 ina226_set_average(chip, INA226_DEFAULT_AVG, &val);
679 ina226_set_int_time_vbus(chip, INA226_DEFAULT_IT, &val);
680 ina226_set_int_time_vshunt(chip, INA226_DEFAULT_IT, &val);
683 ret = ina2xx_init(chip, val);
685 dev_err(&client->dev, "error configuring the device\n");
689 indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
690 indio_dev->dev.parent = &client->dev;
691 indio_dev->dev.of_node = client->dev.of_node;
692 indio_dev->channels = ina2xx_channels;
693 indio_dev->num_channels = ARRAY_SIZE(ina2xx_channels);
694 indio_dev->name = id->name;
695 indio_dev->info = &ina2xx_info;
696 indio_dev->setup_ops = &ina2xx_setup_ops;
698 buffer = devm_iio_kfifo_allocate(&indio_dev->dev);
702 iio_device_attach_buffer(indio_dev, buffer);
704 return iio_device_register(indio_dev);
707 static int ina2xx_remove(struct i2c_client *client)
709 struct iio_dev *indio_dev = i2c_get_clientdata(client);
710 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
712 iio_device_unregister(indio_dev);
715 return regmap_update_bits(chip->regmap, INA2XX_CONFIG,
716 INA2XX_MODE_MASK, 0);
719 static const struct i2c_device_id ina2xx_id[] = {
727 MODULE_DEVICE_TABLE(i2c, ina2xx_id);
729 static struct i2c_driver ina2xx_driver = {
731 .name = KBUILD_MODNAME,
733 .probe = ina2xx_probe,
734 .remove = ina2xx_remove,
735 .id_table = ina2xx_id,
737 module_i2c_driver(ina2xx_driver);
739 MODULE_AUTHOR("Marc Titinger <marc.titinger@baylibre.com>");
740 MODULE_DESCRIPTION("Texas Instruments INA2XX ADC driver");
741 MODULE_LICENSE("GPL v2");