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/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>
32 #include <linux/platform_data/ina2xx.h>
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
42 #define INA226_ALERT_MASK GENMASK(2, 1)
43 #define INA266_CVRF BIT(3)
45 #define INA2XX_MAX_REGISTERS 8
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
53 #define INA2XX_RSHUNT_DEFAULT 10000
56 * bit mask for reading the averaging setting in the configuration register
57 * FIXME: use regmap_fields.
59 #define INA2XX_MODE_MASK GENMASK(3, 0)
61 #define INA226_AVG_MASK GENMASK(11, 9)
62 #define INA226_SHIFT_AVG(val) ((val) << 9)
64 /* Integration time for VBus */
65 #define INA226_ITB_MASK GENMASK(8, 6)
66 #define INA226_SHIFT_ITB(val) ((val) << 6)
68 /* Integration time for VShunt */
69 #define INA226_ITS_MASK GENMASK(5, 3)
70 #define INA226_SHIFT_ITS(val) ((val) << 3)
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) \
76 static bool ina2xx_is_writeable_reg(struct device *dev, unsigned int reg)
78 return (reg == INA2XX_CONFIG) || (reg > INA2XX_CURRENT);
81 static bool ina2xx_is_volatile_reg(struct device *dev, unsigned int reg)
83 return (reg != INA2XX_CONFIG);
86 static inline bool is_signed_reg(unsigned int reg)
88 return (reg == INA2XX_SHUNT_VOLTAGE) || (reg == INA2XX_CURRENT);
91 static const struct regmap_config ina2xx_regmap_config = {
94 .max_register = INA2XX_MAX_REGISTERS,
95 .writeable_reg = ina2xx_is_writeable_reg,
96 .volatile_reg = ina2xx_is_volatile_reg,
99 enum ina2xx_ids { ina219, ina226 };
101 struct ina2xx_config {
103 int calibration_factor;
105 int bus_voltage_shift;
106 int bus_voltage_lsb; /* uV */
107 int power_lsb; /* uW */
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;
117 int int_time_vbus; /* Bus voltage integration time uS */
118 int int_time_vshunt; /* Shunt voltage integration time uS */
119 bool allow_async_readout;
120 /* data buffer needs space for channel data and timestamp */
127 static const struct ina2xx_config ina2xx_config[] = {
129 .config_default = INA219_CONFIG_DEFAULT,
130 .calibration_factor = 40960000,
132 .bus_voltage_shift = 3,
133 .bus_voltage_lsb = 4000,
137 .config_default = INA226_CONFIG_DEFAULT,
138 .calibration_factor = 5120000,
140 .bus_voltage_shift = 0,
141 .bus_voltage_lsb = 1250,
146 static int ina2xx_read_raw(struct iio_dev *indio_dev,
147 struct iio_chan_spec const *chan,
148 int *val, int *val2, long mask)
151 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
155 case IIO_CHAN_INFO_RAW:
156 ret = regmap_read(chip->regmap, chan->address, ®val);
160 if (is_signed_reg(chan->address))
167 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
171 case IIO_CHAN_INFO_INT_TIME:
173 if (chan->address == INA2XX_SHUNT_VOLTAGE)
174 *val2 = chip->int_time_vshunt;
176 *val2 = chip->int_time_vbus;
178 return IIO_VAL_INT_PLUS_MICRO;
180 case IIO_CHAN_INFO_SAMP_FREQ:
182 * Sample freq is read only, it is a consequence of
183 * 1/AVG*(CT_bus+CT_shunt).
185 *val = DIV_ROUND_CLOSEST(1000000, SAMPLING_PERIOD(chip));
189 case IIO_CHAN_INFO_SCALE:
190 switch (chan->address) {
191 case INA2XX_SHUNT_VOLTAGE:
192 /* processed (mV) = raw/shunt_div */
193 *val2 = chip->config->shunt_div;
195 return IIO_VAL_FRACTIONAL;
197 case INA2XX_BUS_VOLTAGE:
198 /* processed (mV) = raw*lsb (uV) / (1000 << shift) */
199 *val = chip->config->bus_voltage_lsb;
200 *val2 = 1000 << chip->config->bus_voltage_shift;
201 return IIO_VAL_FRACTIONAL;
204 /* processed (mW) = raw*lsb (uW) / 1000 */
205 *val = chip->config->power_lsb;
207 return IIO_VAL_FRACTIONAL;
210 /* processed (mA) = raw (mA) */
220 * Available averaging rates for ina226. The indices correspond with
221 * the bit values expected by the chip (according to the ina226 datasheet,
222 * table 3 AVG bit settings, found at
223 * http://www.ti.com/lit/ds/symlink/ina226.pdf.
225 static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
227 static int ina226_set_average(struct ina2xx_chip_info *chip, unsigned int val,
228 unsigned int *config)
232 if (val > 1024 || val < 1)
235 bits = find_closest(val, ina226_avg_tab,
236 ARRAY_SIZE(ina226_avg_tab));
238 chip->avg = ina226_avg_tab[bits];
240 *config &= ~INA226_AVG_MASK;
241 *config |= INA226_SHIFT_AVG(bits) & INA226_AVG_MASK;
246 /* Conversion times in uS */
247 static const int ina226_conv_time_tab[] = { 140, 204, 332, 588, 1100,
250 static int ina226_set_int_time_vbus(struct ina2xx_chip_info *chip,
251 unsigned int val_us, unsigned int *config)
255 if (val_us > 8244 || val_us < 140)
258 bits = find_closest(val_us, ina226_conv_time_tab,
259 ARRAY_SIZE(ina226_conv_time_tab));
261 chip->int_time_vbus = ina226_conv_time_tab[bits];
263 *config &= ~INA226_ITB_MASK;
264 *config |= INA226_SHIFT_ITB(bits) & INA226_ITB_MASK;
269 static int ina226_set_int_time_vshunt(struct ina2xx_chip_info *chip,
270 unsigned int val_us, unsigned int *config)
274 if (val_us > 8244 || val_us < 140)
277 bits = find_closest(val_us, ina226_conv_time_tab,
278 ARRAY_SIZE(ina226_conv_time_tab));
280 chip->int_time_vshunt = ina226_conv_time_tab[bits];
282 *config &= ~INA226_ITS_MASK;
283 *config |= INA226_SHIFT_ITS(bits) & INA226_ITS_MASK;
288 static int ina2xx_write_raw(struct iio_dev *indio_dev,
289 struct iio_chan_spec const *chan,
290 int val, int val2, long mask)
292 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
293 unsigned int config, tmp;
296 if (iio_buffer_enabled(indio_dev))
299 mutex_lock(&chip->state_lock);
301 ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config);
308 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
309 ret = ina226_set_average(chip, val, &tmp);
312 case IIO_CHAN_INFO_INT_TIME:
313 if (chan->address == INA2XX_SHUNT_VOLTAGE)
314 ret = ina226_set_int_time_vshunt(chip, val2, &tmp);
316 ret = ina226_set_int_time_vbus(chip, val2, &tmp);
323 if (!ret && (tmp != config))
324 ret = regmap_write(chip->regmap, INA2XX_CONFIG, tmp);
326 mutex_unlock(&chip->state_lock);
331 static ssize_t ina2xx_allow_async_readout_show(struct device *dev,
332 struct device_attribute *attr,
335 struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
337 return sprintf(buf, "%d\n", chip->allow_async_readout);
340 static ssize_t ina2xx_allow_async_readout_store(struct device *dev,
341 struct device_attribute *attr,
342 const char *buf, size_t len)
344 struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
348 ret = strtobool((const char *) buf, &val);
352 chip->allow_async_readout = val;
358 * Set current LSB to 1mA, shunt is in uOhms
359 * (equation 13 in datasheet). We hardcode a Current_LSB
360 * of 1.0 x10-6. The only remaining parameter is RShunt.
361 * There is no need to expose the CALIBRATION register
362 * to the user for now. But we need to reset this register
363 * if the user updates RShunt after driver init, e.g upon
364 * reading an EEPROM/Probe-type value.
366 static int ina2xx_set_calibration(struct ina2xx_chip_info *chip)
368 u16 regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor,
369 chip->shunt_resistor);
371 return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval);
374 static int set_shunt_resistor(struct ina2xx_chip_info *chip, unsigned int val)
376 if (val <= 0 || val > chip->config->calibration_factor)
379 chip->shunt_resistor = val;
384 static ssize_t ina2xx_shunt_resistor_show(struct device *dev,
385 struct device_attribute *attr,
388 struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
390 return sprintf(buf, "%d\n", chip->shunt_resistor);
393 static ssize_t ina2xx_shunt_resistor_store(struct device *dev,
394 struct device_attribute *attr,
395 const char *buf, size_t len)
397 struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
401 ret = kstrtoul((const char *) buf, 10, &val);
405 ret = set_shunt_resistor(chip, val);
409 /* Update the Calibration register */
410 ret = ina2xx_set_calibration(chip);
417 #define INA2XX_CHAN(_type, _index, _address) { \
419 .address = (_address), \
421 .channel = (_index), \
422 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \
423 | BIT(IIO_CHAN_INFO_SCALE), \
424 .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
425 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
426 .scan_index = (_index), \
431 .endianness = IIO_CPU, \
436 * Sampling Freq is a consequence of the integration times of
437 * the Voltage channels.
439 #define INA2XX_CHAN_VOLTAGE(_index, _address) { \
440 .type = IIO_VOLTAGE, \
441 .address = (_address), \
443 .channel = (_index), \
444 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
445 BIT(IIO_CHAN_INFO_SCALE) | \
446 BIT(IIO_CHAN_INFO_INT_TIME), \
447 .scan_index = (_index), \
452 .endianness = IIO_LE, \
456 static const struct iio_chan_spec ina2xx_channels[] = {
457 INA2XX_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
458 INA2XX_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
459 INA2XX_CHAN(IIO_POWER, 2, INA2XX_POWER),
460 INA2XX_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
461 IIO_CHAN_SOFT_TIMESTAMP(4),
464 static int ina2xx_work_buffer(struct iio_dev *indio_dev)
466 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
471 time_a = iio_get_time_ns(indio_dev);
474 * Because the timer thread and the chip conversion clock
475 * are asynchronous, the period difference will eventually
476 * result in reading V[k-1] again, or skip V[k] at time Tk.
477 * In order to resync the timer with the conversion process
478 * we check the ConVersionReadyFlag.
479 * On hardware that supports using the ALERT pin to toggle a
480 * GPIO a triggered buffer could be used instead.
481 * For now, we pay for that extra read of the ALERT register
483 if (!chip->allow_async_readout)
485 ret = regmap_read(chip->regmap, INA226_ALERT_MASK,
490 alert &= INA266_CVRF;
494 * Single register reads: bulk_read will not work with ina226
495 * as there is no auto-increment of the address register for
496 * data length longer than 16bits.
498 for_each_set_bit(bit, indio_dev->active_scan_mask,
499 indio_dev->masklength) {
502 ret = regmap_read(chip->regmap,
503 INA2XX_SHUNT_VOLTAGE + bit, &val);
507 chip->scan.chan[i++] = val;
510 time_b = iio_get_time_ns(indio_dev);
512 iio_push_to_buffers_with_timestamp(indio_dev, &chip->scan, time_a);
514 return (unsigned long)(time_b - time_a) / 1000;
517 static int ina2xx_capture_thread(void *data)
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);
525 * Poll a bit faster than the chip internal Fs, in case
526 * we wish to sync with the conversion ready flag.
528 if (!chip->allow_async_readout)
532 buffer_us = ina2xx_work_buffer(indio_dev);
536 if (sampling_us > buffer_us)
537 udelay(sampling_us - buffer_us);
539 } while (!kthread_should_stop());
544 static int ina2xx_buffer_enable(struct iio_dev *indio_dev)
546 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
547 unsigned int sampling_us = SAMPLING_PERIOD(chip);
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);
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);
557 chip->task = kthread_run(ina2xx_capture_thread, (void *)indio_dev,
558 "%s:%d-%uus", indio_dev->name, indio_dev->id,
561 return PTR_ERR_OR_ZERO(chip->task);
564 static int ina2xx_buffer_disable(struct iio_dev *indio_dev)
566 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
569 kthread_stop(chip->task);
576 static const struct iio_buffer_setup_ops ina2xx_setup_ops = {
577 .postenable = &ina2xx_buffer_enable,
578 .predisable = &ina2xx_buffer_disable,
581 static int ina2xx_debug_reg(struct iio_dev *indio_dev,
582 unsigned reg, unsigned writeval, unsigned *readval)
584 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
587 return regmap_write(chip->regmap, reg, writeval);
589 return regmap_read(chip->regmap, reg, readval);
592 /* Possible integration times for vshunt and vbus */
593 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.000140 0.000204 0.000332 0.000588 0.001100 0.002116 0.004156 0.008244");
595 static IIO_DEVICE_ATTR(in_allow_async_readout, S_IRUGO | S_IWUSR,
596 ina2xx_allow_async_readout_show,
597 ina2xx_allow_async_readout_store, 0);
599 static IIO_DEVICE_ATTR(in_shunt_resistor, S_IRUGO | S_IWUSR,
600 ina2xx_shunt_resistor_show,
601 ina2xx_shunt_resistor_store, 0);
603 static struct attribute *ina2xx_attributes[] = {
604 &iio_dev_attr_in_allow_async_readout.dev_attr.attr,
605 &iio_const_attr_integration_time_available.dev_attr.attr,
606 &iio_dev_attr_in_shunt_resistor.dev_attr.attr,
610 static const struct attribute_group ina2xx_attribute_group = {
611 .attrs = ina2xx_attributes,
614 static const struct iio_info ina2xx_info = {
615 .driver_module = THIS_MODULE,
616 .attrs = &ina2xx_attribute_group,
617 .read_raw = ina2xx_read_raw,
618 .write_raw = ina2xx_write_raw,
619 .debugfs_reg_access = ina2xx_debug_reg,
622 /* Initialize the configuration and calibration registers. */
623 static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config)
625 int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config);
629 return ina2xx_set_calibration(chip);
632 static int ina2xx_probe(struct i2c_client *client,
633 const struct i2c_device_id *id)
635 struct ina2xx_chip_info *chip;
636 struct iio_dev *indio_dev;
637 struct iio_buffer *buffer;
641 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
645 chip = iio_priv(indio_dev);
647 /* This is only used for device removal purposes. */
648 i2c_set_clientdata(client, indio_dev);
650 chip->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
651 if (IS_ERR(chip->regmap)) {
652 dev_err(&client->dev, "failed to allocate register map\n");
653 return PTR_ERR(chip->regmap);
656 chip->config = &ina2xx_config[id->driver_data];
658 mutex_init(&chip->state_lock);
660 if (of_property_read_u32(client->dev.of_node,
661 "shunt-resistor", &val) < 0) {
662 struct ina2xx_platform_data *pdata =
663 dev_get_platdata(&client->dev);
666 val = pdata->shunt_uohms;
668 val = INA2XX_RSHUNT_DEFAULT;
671 ret = set_shunt_resistor(chip, val);
675 /* Patch the current config register with default. */
676 val = chip->config->config_default;
678 if (id->driver_data == ina226) {
679 ina226_set_average(chip, INA226_DEFAULT_AVG, &val);
680 ina226_set_int_time_vbus(chip, INA226_DEFAULT_IT, &val);
681 ina226_set_int_time_vshunt(chip, INA226_DEFAULT_IT, &val);
684 ret = ina2xx_init(chip, val);
686 dev_err(&client->dev, "error configuring the device\n");
690 indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
691 indio_dev->dev.parent = &client->dev;
692 indio_dev->dev.of_node = client->dev.of_node;
693 indio_dev->channels = ina2xx_channels;
694 indio_dev->num_channels = ARRAY_SIZE(ina2xx_channels);
695 indio_dev->name = id->name;
696 indio_dev->info = &ina2xx_info;
697 indio_dev->setup_ops = &ina2xx_setup_ops;
699 buffer = devm_iio_kfifo_allocate(&indio_dev->dev);
703 iio_device_attach_buffer(indio_dev, buffer);
705 return iio_device_register(indio_dev);
708 static int ina2xx_remove(struct i2c_client *client)
710 struct iio_dev *indio_dev = i2c_get_clientdata(client);
711 struct ina2xx_chip_info *chip = iio_priv(indio_dev);
713 iio_device_unregister(indio_dev);
716 return regmap_update_bits(chip->regmap, INA2XX_CONFIG,
717 INA2XX_MODE_MASK, 0);
720 static const struct i2c_device_id ina2xx_id[] = {
728 MODULE_DEVICE_TABLE(i2c, ina2xx_id);
730 static struct i2c_driver ina2xx_driver = {
732 .name = KBUILD_MODNAME,
734 .probe = ina2xx_probe,
735 .remove = ina2xx_remove,
736 .id_table = ina2xx_id,
738 module_i2c_driver(ina2xx_driver);
740 MODULE_AUTHOR("Marc Titinger <marc.titinger@baylibre.com>");
741 MODULE_DESCRIPTION("Texas Instruments INA2XX ADC driver");
742 MODULE_LICENSE("GPL v2");