/* * INA2XX Current and Power Monitors * * Copyright 2015 Baylibre SAS. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * Based on linux/drivers/iio/adc/ad7291.c * Copyright 2010-2011 Analog Devices Inc. * * Based on linux/drivers/hwmon/ina2xx.c * Copyright 2012 Lothar Felten * * Licensed under the GPL-2 or later. * * IIO driver for INA219-220-226-230-231 * * Configurable 7-bit I2C slave address from 0x40 to 0x4F */ #include #include #include #include #include #include #include #include #include /* INA2XX registers definition */ #define INA2XX_CONFIG 0x00 #define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */ #define INA2XX_BUS_VOLTAGE 0x02 /* readonly */ #define INA2XX_POWER 0x03 /* readonly */ #define INA2XX_CURRENT 0x04 /* readonly */ #define INA2XX_CALIBRATION 0x05 #define INA226_ALERT_MASK 0x06 #define INA266_CVRF BIT(3) #define INA2XX_MAX_REGISTERS 8 /* settings - depend on use case */ #define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */ #define INA226_CONFIG_DEFAULT 0x4327 #define INA226_DEFAULT_AVG 4 #define INA226_DEFAULT_IT 1110 #define INA2XX_RSHUNT_DEFAULT 10000 /* * bit mask for reading the averaging setting in the configuration register * FIXME: use regmap_fields. */ #define INA2XX_MODE_MASK GENMASK(3, 0) #define INA226_AVG_MASK GENMASK(11, 9) #define INA226_SHIFT_AVG(val) ((val) << 9) /* Integration time for VBus */ #define INA226_ITB_MASK GENMASK(8, 6) #define INA226_SHIFT_ITB(val) ((val) << 6) /* Integration time for VShunt */ #define INA226_ITS_MASK GENMASK(5, 3) #define INA226_SHIFT_ITS(val) ((val) << 3) /* Cosmetic macro giving the sampling period for a full P=UxI cycle */ #define SAMPLING_PERIOD(c) ((c->int_time_vbus + c->int_time_vshunt) \ * c->avg) static bool ina2xx_is_writeable_reg(struct device *dev, unsigned int reg) { return (reg == INA2XX_CONFIG) || (reg > INA2XX_CURRENT); } static bool ina2xx_is_volatile_reg(struct device *dev, unsigned int reg) { return (reg != INA2XX_CONFIG); } static inline bool is_signed_reg(unsigned int reg) { return (reg == INA2XX_SHUNT_VOLTAGE) || (reg == INA2XX_CURRENT); } static const struct regmap_config ina2xx_regmap_config = { .reg_bits = 8, .val_bits = 16, .max_register = INA2XX_MAX_REGISTERS, .writeable_reg = ina2xx_is_writeable_reg, .volatile_reg = ina2xx_is_volatile_reg, }; enum ina2xx_ids { ina219, ina226 }; struct ina2xx_config { u16 config_default; int calibration_factor; int shunt_div; int bus_voltage_shift; int bus_voltage_lsb; /* uV */ int power_lsb; /* uW */ }; struct ina2xx_chip_info { struct regmap *regmap; struct task_struct *task; const struct ina2xx_config *config; struct mutex state_lock; long rshunt; int avg; s64 prev_ns; /* track buffer capture time, check for underruns*/ int int_time_vbus; /* Bus voltage integration time uS */ int int_time_vshunt; /* Shunt voltage integration time uS */ bool allow_async_readout; }; static const struct ina2xx_config ina2xx_config[] = { [ina219] = { .config_default = INA219_CONFIG_DEFAULT, .calibration_factor = 40960000, .shunt_div = 100, .bus_voltage_shift = 3, .bus_voltage_lsb = 4000, .power_lsb = 20000, }, [ina226] = { .config_default = INA226_CONFIG_DEFAULT, .calibration_factor = 5120000, .shunt_div = 400, .bus_voltage_shift = 0, .bus_voltage_lsb = 1250, .power_lsb = 25000, }, }; static int ina2xx_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { int ret; struct ina2xx_chip_info *chip = iio_priv(indio_dev); unsigned int regval; switch (mask) { case IIO_CHAN_INFO_RAW: ret = regmap_read(chip->regmap, chan->address, ®val); if (ret < 0) return ret; if (is_signed_reg(chan->address)) *val = (s16) regval; else *val = regval; return IIO_VAL_INT; case IIO_CHAN_INFO_OVERSAMPLING_RATIO: *val = chip->avg; return IIO_VAL_INT; case IIO_CHAN_INFO_INT_TIME: *val = 0; if (chan->address == INA2XX_SHUNT_VOLTAGE) *val2 = chip->int_time_vshunt; else *val2 = chip->int_time_vbus; return IIO_VAL_INT_PLUS_MICRO; case IIO_CHAN_INFO_SAMP_FREQ: /* * Sample freq is read only, it is a consequence of * 1/AVG*(CT_bus+CT_shunt). */ *val = DIV_ROUND_CLOSEST(1000000, SAMPLING_PERIOD(chip)); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: switch (chan->address) { case INA2XX_SHUNT_VOLTAGE: /* processed (mV) = raw*1000/shunt_div */ *val2 = chip->config->shunt_div; *val = 1000; return IIO_VAL_FRACTIONAL; case INA2XX_BUS_VOLTAGE: /* processed (mV) = raw*lsb (uV) / (1000 << shift) */ *val = chip->config->bus_voltage_lsb; *val2 = 1000 << chip->config->bus_voltage_shift; return IIO_VAL_FRACTIONAL; case INA2XX_POWER: /* processed (mW) = raw*lsb (uW) / 1000 */ *val = chip->config->power_lsb; *val2 = 1000; return IIO_VAL_FRACTIONAL; case INA2XX_CURRENT: /* processed (mA) = raw (mA) */ *val = 1; return IIO_VAL_INT; } } return -EINVAL; } /* * Available averaging rates for ina226. The indices correspond with * the bit values expected by the chip (according to the ina226 datasheet, * table 3 AVG bit settings, found at * http://www.ti.com/lit/ds/symlink/ina226.pdf. */ static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 }; static int ina226_set_average(struct ina2xx_chip_info *chip, unsigned int val, unsigned int *config) { int bits; if (val > 1024 || val < 1) return -EINVAL; bits = find_closest(val, ina226_avg_tab, ARRAY_SIZE(ina226_avg_tab)); chip->avg = ina226_avg_tab[bits]; *config &= ~INA226_AVG_MASK; *config |= INA226_SHIFT_AVG(bits) & INA226_AVG_MASK; return 0; } /* Conversion times in uS */ static const int ina226_conv_time_tab[] = { 140, 204, 332, 588, 1100, 2116, 4156, 8244 }; static int ina226_set_int_time_vbus(struct ina2xx_chip_info *chip, unsigned int val_us, unsigned int *config) { int bits; if (val_us > 8244 || val_us < 140) return -EINVAL; bits = find_closest(val_us, ina226_conv_time_tab, ARRAY_SIZE(ina226_conv_time_tab)); chip->int_time_vbus = ina226_conv_time_tab[bits]; *config &= ~INA226_ITB_MASK; *config |= INA226_SHIFT_ITB(bits) & INA226_ITB_MASK; return 0; } static int ina226_set_int_time_vshunt(struct ina2xx_chip_info *chip, unsigned int val_us, unsigned int *config) { int bits; if (val_us > 8244 || val_us < 140) return -EINVAL; bits = find_closest(val_us, ina226_conv_time_tab, ARRAY_SIZE(ina226_conv_time_tab)); chip->int_time_vshunt = ina226_conv_time_tab[bits]; *config &= ~INA226_ITS_MASK; *config |= INA226_SHIFT_ITS(bits) & INA226_ITS_MASK; return 0; } static int ina2xx_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { struct ina2xx_chip_info *chip = iio_priv(indio_dev); int ret; unsigned int config, tmp; if (iio_buffer_enabled(indio_dev)) return -EBUSY; mutex_lock(&chip->state_lock); ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config); if (ret < 0) goto _err; tmp = config; switch (mask) { case IIO_CHAN_INFO_OVERSAMPLING_RATIO: ret = ina226_set_average(chip, val, &tmp); break; case IIO_CHAN_INFO_INT_TIME: if (chan->address == INA2XX_SHUNT_VOLTAGE) ret = ina226_set_int_time_vshunt(chip, val2, &tmp); else ret = ina226_set_int_time_vbus(chip, val2, &tmp); break; default: ret = -EINVAL; } if (!ret && (tmp != config)) ret = regmap_write(chip->regmap, INA2XX_CONFIG, tmp); _err: mutex_unlock(&chip->state_lock); return ret; } static ssize_t ina2xx_allow_async_readout_show(struct device *dev, struct device_attribute *attr, char *buf) { struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev)); return sprintf(buf, "%d\n", chip->allow_async_readout); } static ssize_t ina2xx_allow_async_readout_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev)); bool val; int ret; ret = strtobool((const char *) buf, &val); if (ret) return ret; chip->allow_async_readout = val; return len; } #define INA2XX_CHAN(_type, _index, _address) { \ .type = (_type), \ .address = (_address), \ .indexed = 1, \ .channel = (_index), \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \ | BIT(IIO_CHAN_INFO_SCALE), \ .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ .scan_index = (_index), \ .scan_type = { \ .sign = 'u', \ .realbits = 16, \ .storagebits = 16, \ .endianness = IIO_LE, \ } \ } /* * Sampling Freq is a consequence of the integration times of * the Voltage channels. */ #define INA2XX_CHAN_VOLTAGE(_index, _address) { \ .type = IIO_VOLTAGE, \ .address = (_address), \ .indexed = 1, \ .channel = (_index), \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ BIT(IIO_CHAN_INFO_SCALE) | \ BIT(IIO_CHAN_INFO_INT_TIME), \ .scan_index = (_index), \ .scan_type = { \ .sign = 'u', \ .realbits = 16, \ .storagebits = 16, \ .endianness = IIO_LE, \ } \ } static const struct iio_chan_spec ina2xx_channels[] = { INA2XX_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE), INA2XX_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE), INA2XX_CHAN(IIO_CURRENT, 2, INA2XX_CURRENT), INA2XX_CHAN(IIO_POWER, 3, INA2XX_POWER), IIO_CHAN_SOFT_TIMESTAMP(4), }; static int ina2xx_work_buffer(struct iio_dev *indio_dev) { struct ina2xx_chip_info *chip = iio_priv(indio_dev); unsigned short data[8]; int bit, ret, i = 0; unsigned long buffer_us, elapsed_us; s64 time_a, time_b; unsigned int alert; time_a = iio_get_time_ns(); /* * Because the timer thread and the chip conversion clock * are asynchronous, the period difference will eventually * result in reading V[k-1] again, or skip V[k] at time Tk. * In order to resync the timer with the conversion process * we check the ConVersionReadyFlag. * On hardware that supports using the ALERT pin to toggle a * GPIO a triggered buffer could be used instead. * For now, we pay for that extra read of the ALERT register */ if (!chip->allow_async_readout) do { ret = regmap_read(chip->regmap, INA226_ALERT_MASK, &alert); if (ret < 0) return ret; alert &= INA266_CVRF; trace_printk("Conversion ready: %d\n", !!alert); } while (!alert); /* * Single register reads: bulk_read will not work with ina226 * as there is no auto-increment of the address register for * data length longer than 16bits. */ for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->masklength) { unsigned int val; ret = regmap_read(chip->regmap, INA2XX_SHUNT_VOLTAGE + bit, &val); if (ret < 0) return ret; data[i++] = val; } time_b = iio_get_time_ns(); iio_push_to_buffers_with_timestamp(indio_dev, (unsigned int *)data, time_a); buffer_us = (unsigned long)(time_b - time_a) / 1000; elapsed_us = (unsigned long)(time_a - chip->prev_ns) / 1000; trace_printk("uS: elapsed: %lu, buf: %lu\n", elapsed_us, buffer_us); chip->prev_ns = time_a; return buffer_us; }; static int ina2xx_capture_thread(void *data) { struct iio_dev *indio_dev = (struct iio_dev *)data; struct ina2xx_chip_info *chip = iio_priv(indio_dev); unsigned int sampling_us = SAMPLING_PERIOD(chip); int buffer_us; /* * Poll a bit faster than the chip internal Fs, in case * we wish to sync with the conversion ready flag. */ if (!chip->allow_async_readout) sampling_us -= 200; do { buffer_us = ina2xx_work_buffer(indio_dev); if (buffer_us < 0) return buffer_us; if (sampling_us > buffer_us) udelay(sampling_us - buffer_us); } while (!kthread_should_stop()); return 0; } static int ina2xx_buffer_enable(struct iio_dev *indio_dev) { struct ina2xx_chip_info *chip = iio_priv(indio_dev); unsigned int sampling_us = SAMPLING_PERIOD(chip); trace_printk("Enabling buffer w/ scan_mask %02x, freq = %d, avg =%u\n", (unsigned int)(*indio_dev->active_scan_mask), 1000000/sampling_us, chip->avg); trace_printk("Expected work period: %u us\n", sampling_us); trace_printk("Async readout mode: %d\n", chip->allow_async_readout); chip->prev_ns = iio_get_time_ns(); chip->task = kthread_run(ina2xx_capture_thread, (void *)indio_dev, "ina2xx-%uus", sampling_us); return PTR_ERR_OR_ZERO(chip->task); } static int ina2xx_buffer_disable(struct iio_dev *indio_dev) { struct ina2xx_chip_info *chip = iio_priv(indio_dev); if (chip->task) { kthread_stop(chip->task); chip->task = NULL; } return 0; } static const struct iio_buffer_setup_ops ina2xx_setup_ops = { .postenable = &ina2xx_buffer_enable, .predisable = &ina2xx_buffer_disable, }; static int ina2xx_debug_reg(struct iio_dev *indio_dev, unsigned reg, unsigned writeval, unsigned *readval) { struct ina2xx_chip_info *chip = iio_priv(indio_dev); if (!readval) return regmap_write(chip->regmap, reg, writeval); return regmap_read(chip->regmap, reg, readval); } /* Possible integration times for vshunt and vbus */ static IIO_CONST_ATTR_INT_TIME_AVAIL \ ("0.000140 0.000204 0.000332 0.000588 0.001100 0.002116 0.004156 0.008244"); static IIO_DEVICE_ATTR(in_allow_async_readout, S_IRUGO | S_IWUSR, ina2xx_allow_async_readout_show, ina2xx_allow_async_readout_store, 0); static struct attribute *ina2xx_attributes[] = { &iio_dev_attr_in_allow_async_readout.dev_attr.attr, &iio_const_attr_integration_time_available.dev_attr.attr, NULL, }; static const struct attribute_group ina2xx_attribute_group = { .attrs = ina2xx_attributes, }; static const struct iio_info ina2xx_info = { .debugfs_reg_access = &ina2xx_debug_reg, .read_raw = &ina2xx_read_raw, .write_raw = &ina2xx_write_raw, .attrs = &ina2xx_attribute_group, .driver_module = THIS_MODULE, }; /* Initialize the configuration and calibration registers. */ static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config) { u16 regval; int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config); if (ret < 0) return ret; /* * Set current LSB to 1mA, shunt is in uOhms * (equation 13 in datasheet). We hardcode a Current_LSB * of 1.0 x10-6. The only remaining parameter is RShunt. * There is no need to expose the CALIBRATION register * to the user for now. */ regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor, chip->rshunt); return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval); } static int ina2xx_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct ina2xx_chip_info *chip; struct iio_dev *indio_dev; struct iio_buffer *buffer; int ret; unsigned int val; indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip)); if (!indio_dev) return -ENOMEM; chip = iio_priv(indio_dev); chip->config = &ina2xx_config[id->driver_data]; if (of_property_read_u32(client->dev.of_node, "shunt-resistor", &val) < 0) { struct ina2xx_platform_data *pdata = dev_get_platdata(&client->dev); if (pdata) val = pdata->shunt_uohms; else val = INA2XX_RSHUNT_DEFAULT; } if (val <= 0 || val > chip->config->calibration_factor) return -ENODEV; chip->rshunt = val; mutex_init(&chip->state_lock); /* This is only used for device removal purposes. */ i2c_set_clientdata(client, indio_dev); indio_dev->name = id->name; indio_dev->channels = ina2xx_channels; indio_dev->num_channels = ARRAY_SIZE(ina2xx_channels); indio_dev->dev.parent = &client->dev; indio_dev->info = &ina2xx_info; indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE; chip->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config); if (IS_ERR(chip->regmap)) { dev_err(&client->dev, "failed to allocate register map\n"); return PTR_ERR(chip->regmap); } /* Patch the current config register with default. */ val = chip->config->config_default; if (id->driver_data == ina226) { ina226_set_average(chip, INA226_DEFAULT_AVG, &val); ina226_set_int_time_vbus(chip, INA226_DEFAULT_IT, &val); ina226_set_int_time_vshunt(chip, INA226_DEFAULT_IT, &val); } ret = ina2xx_init(chip, val); if (ret < 0) { dev_err(&client->dev, "error configuring the device: %d\n", ret); return -ENODEV; } buffer = devm_iio_kfifo_allocate(&indio_dev->dev); if (!buffer) return -ENOMEM; indio_dev->setup_ops = &ina2xx_setup_ops; iio_device_attach_buffer(indio_dev, buffer); return iio_device_register(indio_dev); } static int ina2xx_remove(struct i2c_client *client) { struct iio_dev *indio_dev = i2c_get_clientdata(client); struct ina2xx_chip_info *chip = iio_priv(indio_dev); iio_device_unregister(indio_dev); /* Powerdown */ return regmap_update_bits(chip->regmap, INA2XX_CONFIG, INA2XX_MODE_MASK, 0); } static const struct i2c_device_id ina2xx_id[] = { {"ina219", ina219}, {"ina220", ina219}, {"ina226", ina226}, {"ina230", ina226}, {"ina231", ina226}, {} }; MODULE_DEVICE_TABLE(i2c, ina2xx_id); static struct i2c_driver ina2xx_driver = { .driver = { .name = KBUILD_MODNAME, }, .probe = ina2xx_probe, .remove = ina2xx_remove, .id_table = ina2xx_id, }; module_i2c_driver(ina2xx_driver); MODULE_AUTHOR("Marc Titinger "); MODULE_DESCRIPTION("Texas Instruments INA2XX ADC driver"); MODULE_LICENSE("GPL v2");