diff options
Diffstat (limited to 'drivers/iio/adc/ina2xx-adc.c')
| -rw-r--r-- | drivers/iio/adc/ina2xx-adc.c | 1104 |
1 files changed, 1104 insertions, 0 deletions
diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c new file mode 100644 index 000000000..74092f383 --- /dev/null +++ b/drivers/iio/adc/ina2xx-adc.c @@ -0,0 +1,1104 @@ +/* + * 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 <l-felten@ti.com> + * + * 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 <linux/delay.h> +#include <linux/i2c.h> +#include <linux/iio/iio.h> +#include <linux/iio/buffer.h> +#include <linux/iio/kfifo_buf.h> +#include <linux/iio/sysfs.h> +#include <linux/kthread.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/regmap.h> +#include <linux/sched/task.h> +#include <linux/util_macros.h> + +#include <linux/platform_data/ina2xx.h> + +/* 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_MASK_ENABLE 0x06 +#define INA226_CVRF BIT(3) + +#define INA2XX_MAX_REGISTERS 8 + +/* settings - depend on use case */ +#define INA219_CONFIG_DEFAULT 0x399F /* PGA=1/8, BRNG=32V */ +#define INA219_DEFAULT_IT 532 +#define INA219_DEFAULT_BRNG 1 /* 32V */ +#define INA219_DEFAULT_PGA 125 /* 1000/8 */ +#define INA226_CONFIG_DEFAULT 0x4327 +#define INA226_DEFAULT_AVG 4 +#define INA226_DEFAULT_IT 1110 + +#define INA2XX_RSHUNT_DEFAULT 10000 + +/* + * bit masks for reading the settings in the configuration register + * FIXME: use regmap_fields. + */ +#define INA2XX_MODE_MASK GENMASK(3, 0) + +/* Gain for VShunt: 1/8 (default), 1/4, 1/2, 1 */ +#define INA219_PGA_MASK GENMASK(12, 11) +#define INA219_SHIFT_PGA(val) ((val) << 11) + +/* VBus range: 32V (default), 16V */ +#define INA219_BRNG_MASK BIT(13) +#define INA219_SHIFT_BRNG(val) ((val) << 13) + +/* Averaging for VBus/VShunt/Power */ +#define INA226_AVG_MASK GENMASK(11, 9) +#define INA226_SHIFT_AVG(val) ((val) << 9) + +/* Integration time for VBus */ +#define INA219_ITB_MASK GENMASK(10, 7) +#define INA219_SHIFT_ITB(val) ((val) << 7) +#define INA226_ITB_MASK GENMASK(8, 6) +#define INA226_SHIFT_ITB(val) ((val) << 6) + +/* Integration time for VShunt */ +#define INA219_ITS_MASK GENMASK(6, 3) +#define INA219_SHIFT_ITS(val) ((val) << 3) +#define INA226_ITS_MASK GENMASK(5, 3) +#define INA226_SHIFT_ITS(val) ((val) << 3) + +/* INA219 Bus voltage register, low bits are flags */ +#define INA219_OVF BIT(0) +#define INA219_CNVR BIT(1) +#define INA219_BUS_VOLTAGE_SHIFT 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 { + const char *name; + u16 config_default; + int calibration_value; + int shunt_voltage_lsb; /* nV */ + int bus_voltage_shift; /* position of lsb */ + int bus_voltage_lsb; /* uV */ + /* fixed relation between current and power lsb, uW/uA */ + int power_lsb_factor; + enum ina2xx_ids chip_id; +}; + +struct ina2xx_chip_info { + struct regmap *regmap; + struct task_struct *task; + const struct ina2xx_config *config; + struct mutex state_lock; + unsigned int shunt_resistor_uohm; + int avg; + int int_time_vbus; /* Bus voltage integration time uS */ + int int_time_vshunt; /* Shunt voltage integration time uS */ + int range_vbus; /* Bus voltage maximum in V */ + int pga_gain_vshunt; /* Shunt voltage PGA gain */ + bool allow_async_readout; + /* data buffer needs space for channel data and timestamp */ + struct { + u16 chan[4]; + u64 ts __aligned(8); + } scan; +}; + +static const struct ina2xx_config ina2xx_config[] = { + [ina219] = { + .name = "ina219", + .config_default = INA219_CONFIG_DEFAULT, + .calibration_value = 4096, + .shunt_voltage_lsb = 10000, + .bus_voltage_shift = INA219_BUS_VOLTAGE_SHIFT, + .bus_voltage_lsb = 4000, + .power_lsb_factor = 20, + .chip_id = ina219, + }, + [ina226] = { + .name = "ina226", + .config_default = INA226_CONFIG_DEFAULT, + .calibration_value = 2048, + .shunt_voltage_lsb = 2500, + .bus_voltage_shift = 0, + .bus_voltage_lsb = 1250, + .power_lsb_factor = 25, + .chip_id = ina226, + }, +}; + +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) + return ret; + + if (is_signed_reg(chan->address)) + *val = (s16) regval; + else + *val = regval; + + if (chan->address == INA2XX_BUS_VOLTAGE) + *val >>= chip->config->bus_voltage_shift; + + 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 * lsb(nV) / 1000000 */ + *val = chip->config->shunt_voltage_lsb; + *val2 = 1000000; + return IIO_VAL_FRACTIONAL; + + case INA2XX_BUS_VOLTAGE: + /* processed (mV) = raw * lsb (uV) / 1000 */ + *val = chip->config->bus_voltage_lsb; + *val2 = 1000; + return IIO_VAL_FRACTIONAL; + + case INA2XX_CURRENT: + /* + * processed (mA) = raw * current_lsb (mA) + * current_lsb (mA) = shunt_voltage_lsb (nV) / + * shunt_resistor (uOhm) + */ + *val = chip->config->shunt_voltage_lsb; + *val2 = chip->shunt_resistor_uohm; + return IIO_VAL_FRACTIONAL; + + case INA2XX_POWER: + /* + * processed (mW) = raw * power_lsb (mW) + * power_lsb (mW) = power_lsb_factor (mW/mA) * + * current_lsb (mA) + */ + *val = chip->config->power_lsb_factor * + chip->config->shunt_voltage_lsb; + *val2 = chip->shunt_resistor_uohm; + return IIO_VAL_FRACTIONAL; + } + return -EINVAL; + + case IIO_CHAN_INFO_HARDWAREGAIN: + switch (chan->address) { + case INA2XX_SHUNT_VOLTAGE: + *val = chip->pga_gain_vshunt; + *val2 = 1000; + return IIO_VAL_FRACTIONAL; + + case INA2XX_BUS_VOLTAGE: + *val = chip->range_vbus == 32 ? 1 : 2; + return IIO_VAL_INT; + } + return -EINVAL; + } + + 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 + * https://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; +} + +/* Conversion times in uS. */ +static const int ina219_conv_time_tab_subsample[] = { 84, 148, 276, 532 }; +static const int ina219_conv_time_tab_average[] = { 532, 1060, 2130, 4260, + 8510, 17020, 34050, 68100}; + +static int ina219_lookup_int_time(unsigned int *val_us, int *bits) +{ + if (*val_us > 68100 || *val_us < 84) + return -EINVAL; + + if (*val_us <= 532) { + *bits = find_closest(*val_us, ina219_conv_time_tab_subsample, + ARRAY_SIZE(ina219_conv_time_tab_subsample)); + *val_us = ina219_conv_time_tab_subsample[*bits]; + } else { + *bits = find_closest(*val_us, ina219_conv_time_tab_average, + ARRAY_SIZE(ina219_conv_time_tab_average)); + *val_us = ina219_conv_time_tab_average[*bits]; + *bits |= 0x8; + } + + return 0; +} + +static int ina219_set_int_time_vbus(struct ina2xx_chip_info *chip, + unsigned int val_us, unsigned int *config) +{ + int bits, ret; + unsigned int val_us_best = val_us; + + ret = ina219_lookup_int_time(&val_us_best, &bits); + if (ret) + return ret; + + chip->int_time_vbus = val_us_best; + + *config &= ~INA219_ITB_MASK; + *config |= INA219_SHIFT_ITB(bits) & INA219_ITB_MASK; + + return 0; +} + +static int ina219_set_int_time_vshunt(struct ina2xx_chip_info *chip, + unsigned int val_us, unsigned int *config) +{ + int bits, ret; + unsigned int val_us_best = val_us; + + ret = ina219_lookup_int_time(&val_us_best, &bits); + if (ret) + return ret; + + chip->int_time_vshunt = val_us_best; + + *config &= ~INA219_ITS_MASK; + *config |= INA219_SHIFT_ITS(bits) & INA219_ITS_MASK; + + return 0; +} + +static const int ina219_vbus_range_tab[] = { 1, 2 }; +static int ina219_set_vbus_range_denom(struct ina2xx_chip_info *chip, + unsigned int range, + unsigned int *config) +{ + if (range == 1) + chip->range_vbus = 32; + else if (range == 2) + chip->range_vbus = 16; + else + return -EINVAL; + + *config &= ~INA219_BRNG_MASK; + *config |= INA219_SHIFT_BRNG(range == 1 ? 1 : 0) & INA219_BRNG_MASK; + + return 0; +} + +static const int ina219_vshunt_gain_tab[] = { 125, 250, 500, 1000 }; +static const int ina219_vshunt_gain_frac[] = { + 125, 1000, 250, 1000, 500, 1000, 1000, 1000 }; + +static int ina219_set_vshunt_pga_gain(struct ina2xx_chip_info *chip, + unsigned int gain, + unsigned int *config) +{ + int bits; + + if (gain < 125 || gain > 1000) + return -EINVAL; + + bits = find_closest(gain, ina219_vshunt_gain_tab, + ARRAY_SIZE(ina219_vshunt_gain_tab)); + + chip->pga_gain_vshunt = ina219_vshunt_gain_tab[bits]; + bits = 3 - bits; + + *config &= ~INA219_PGA_MASK; + *config |= INA219_SHIFT_PGA(bits) & INA219_PGA_MASK; + + return 0; +} + +static int ina2xx_read_avail(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + const int **vals, int *type, int *length, + long mask) +{ + switch (mask) { + case IIO_CHAN_INFO_HARDWAREGAIN: + switch (chan->address) { + case INA2XX_SHUNT_VOLTAGE: + *type = IIO_VAL_FRACTIONAL; + *length = sizeof(ina219_vshunt_gain_frac) / sizeof(int); + *vals = ina219_vshunt_gain_frac; + return IIO_AVAIL_LIST; + + case INA2XX_BUS_VOLTAGE: + *type = IIO_VAL_INT; + *length = sizeof(ina219_vbus_range_tab) / sizeof(int); + *vals = ina219_vbus_range_tab; + return IIO_AVAIL_LIST; + } + } + + return -EINVAL; +} + +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); + unsigned int config, tmp; + int ret; + + if (iio_buffer_enabled(indio_dev)) + return -EBUSY; + + mutex_lock(&chip->state_lock); + + ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config); + if (ret) + 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 (chip->config->chip_id == ina226) { + 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); + } else { + if (chan->address == INA2XX_SHUNT_VOLTAGE) + ret = ina219_set_int_time_vshunt(chip, val2, + &tmp); + else + ret = ina219_set_int_time_vbus(chip, val2, + &tmp); + } + break; + + case IIO_CHAN_INFO_HARDWAREGAIN: + if (chan->address == INA2XX_SHUNT_VOLTAGE) + ret = ina219_set_vshunt_pga_gain(chip, val * 1000 + + val2 / 1000, &tmp); + else + ret = ina219_set_vbus_range_denom(chip, val, &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 sysfs_emit(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 = kstrtobool(buf, &val); + if (ret) + return ret; + + chip->allow_async_readout = val; + + return len; +} + +/* + * Calibration register is set to the best value, which eliminates + * truncation errors on calculating current register in hardware. + * According to datasheet (INA 226: eq. 3, INA219: eq. 4) the best values + * are 2048 for ina226 and 4096 for ina219. They are hardcoded as + * calibration_value. + */ +static int ina2xx_set_calibration(struct ina2xx_chip_info *chip) +{ + return regmap_write(chip->regmap, INA2XX_CALIBRATION, + chip->config->calibration_value); +} + +static int set_shunt_resistor(struct ina2xx_chip_info *chip, unsigned int val) +{ + if (val == 0 || val > INT_MAX) + return -EINVAL; + + chip->shunt_resistor_uohm = val; + + return 0; +} + +static ssize_t ina2xx_shunt_resistor_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev)); + int vals[2] = { chip->shunt_resistor_uohm, 1000000 }; + + return iio_format_value(buf, IIO_VAL_FRACTIONAL, 1, vals); +} + +static ssize_t ina2xx_shunt_resistor_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)); + int val, val_fract, ret; + + ret = iio_str_to_fixpoint(buf, 100000, &val, &val_fract); + if (ret) + return ret; + + ret = set_shunt_resistor(chip, val * 1000000 + val_fract); + if (ret) + return ret; + + return len; +} + +#define INA219_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), \ + .scan_index = (_index), \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 16, \ + .storagebits = 16, \ + .endianness = IIO_CPU, \ + } \ +} + +#define INA226_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_CPU, \ + } \ +} + +/* + * Sampling Freq is a consequence of the integration times of + * the Voltage channels. + */ +#define INA219_CHAN_VOLTAGE(_index, _address, _shift) { \ + .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) | \ + BIT(IIO_CHAN_INFO_HARDWAREGAIN), \ + .info_mask_separate_available = \ + BIT(IIO_CHAN_INFO_HARDWAREGAIN), \ + .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ), \ + .scan_index = (_index), \ + .scan_type = { \ + .sign = 'u', \ + .shift = _shift, \ + .realbits = 16 - _shift, \ + .storagebits = 16, \ + .endianness = IIO_LE, \ + } \ +} + +#define INA226_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), \ + .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, \ + } \ +} + + +static const struct iio_chan_spec ina226_channels[] = { + INA226_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE), + INA226_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE), + INA226_CHAN(IIO_POWER, 2, INA2XX_POWER), + INA226_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT), + IIO_CHAN_SOFT_TIMESTAMP(4), +}; + +static const struct iio_chan_spec ina219_channels[] = { + INA219_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE, 0), + INA219_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE, INA219_BUS_VOLTAGE_SHIFT), + INA219_CHAN(IIO_POWER, 2, INA2XX_POWER), + INA219_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT), + IIO_CHAN_SOFT_TIMESTAMP(4), +}; + +static int ina2xx_conversion_ready(struct iio_dev *indio_dev) +{ + struct ina2xx_chip_info *chip = iio_priv(indio_dev); + int ret; + unsigned int alert; + + /* + * 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 do an extra read of the MASK_ENABLE register (INA226) + * resp. the BUS_VOLTAGE register (INA219). + */ + if (chip->config->chip_id == ina226) { + ret = regmap_read(chip->regmap, + INA226_MASK_ENABLE, &alert); + alert &= INA226_CVRF; + } else { + ret = regmap_read(chip->regmap, + INA2XX_BUS_VOLTAGE, &alert); + alert &= INA219_CNVR; + } + + if (ret < 0) + return ret; + + return !!alert; +} + +static int ina2xx_work_buffer(struct iio_dev *indio_dev) +{ + struct ina2xx_chip_info *chip = iio_priv(indio_dev); + int bit, ret, i = 0; + s64 time; + + time = iio_get_time_ns(indio_dev); + + /* + * Single register reads: bulk_read will not work with ina226/219 + * as there is no auto-increment of the register pointer. + */ + 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; + + chip->scan.chan[i++] = val; + } + + iio_push_to_buffers_with_timestamp(indio_dev, &chip->scan, time); + + return 0; +}; + +static int ina2xx_capture_thread(void *data) +{ + struct iio_dev *indio_dev = data; + struct ina2xx_chip_info *chip = iio_priv(indio_dev); + int sampling_us = SAMPLING_PERIOD(chip); + int ret; + struct timespec64 next, now, delta; + s64 delay_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; + + ktime_get_ts64(&next); + + do { + while (!chip->allow_async_readout) { + ret = ina2xx_conversion_ready(indio_dev); + if (ret < 0) + return ret; + + /* + * If the conversion was not yet finished, + * reset the reference timestamp. + */ + if (ret == 0) + ktime_get_ts64(&next); + else + break; + } + + ret = ina2xx_work_buffer(indio_dev); + if (ret < 0) + return ret; + + ktime_get_ts64(&now); + + /* + * Advance the timestamp for the next poll by one sampling + * interval, and sleep for the remainder (next - now) + * In case "next" has already passed, the interval is added + * multiple times, i.e. samples are dropped. + */ + do { + timespec64_add_ns(&next, 1000 * sampling_us); + delta = timespec64_sub(next, now); + delay_us = div_s64(timespec64_to_ns(&delta), 1000); + } while (delay_us <= 0); + + usleep_range(delay_us, (delay_us * 3) >> 1); + + } 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); + struct task_struct *task; + + dev_dbg(&indio_dev->dev, "Enabling buffer w/ scan_mask %02x, freq = %d, avg =%u\n", + (unsigned int)(*indio_dev->active_scan_mask), + 1000000 / sampling_us, chip->avg); + + dev_dbg(&indio_dev->dev, "Expected work period: %u us\n", sampling_us); + dev_dbg(&indio_dev->dev, "Async readout mode: %d\n", + chip->allow_async_readout); + + task = kthread_run(ina2xx_capture_thread, (void *)indio_dev, + "%s:%d-%uus", indio_dev->name, + iio_device_id(indio_dev), + sampling_us); + if (IS_ERR(task)) + return PTR_ERR(task); + + chip->task = task; + + return 0; +} + +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_NAMED(ina219_integration_time_available, + integration_time_available, + "0.000084 0.000148 0.000276 0.000532 0.001060 0.002130 0.004260 0.008510 0.017020 0.034050 0.068100"); + +static IIO_CONST_ATTR_NAMED(ina226_integration_time_available, + integration_time_available, + "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 IIO_DEVICE_ATTR(in_shunt_resistor, S_IRUGO | S_IWUSR, + ina2xx_shunt_resistor_show, + ina2xx_shunt_resistor_store, 0); + +static struct attribute *ina219_attributes[] = { + &iio_dev_attr_in_allow_async_readout.dev_attr.attr, + &iio_const_attr_ina219_integration_time_available.dev_attr.attr, + &iio_dev_attr_in_shunt_resistor.dev_attr.attr, + NULL, +}; + +static struct attribute *ina226_attributes[] = { + &iio_dev_attr_in_allow_async_readout.dev_attr.attr, + &iio_const_attr_ina226_integration_time_available.dev_attr.attr, + &iio_dev_attr_in_shunt_resistor.dev_attr.attr, + NULL, +}; + +static const struct attribute_group ina219_attribute_group = { + .attrs = ina219_attributes, +}; + +static const struct attribute_group ina226_attribute_group = { + .attrs = ina226_attributes, +}; + +static const struct iio_info ina219_info = { + .attrs = &ina219_attribute_group, + .read_raw = ina2xx_read_raw, + .read_avail = ina2xx_read_avail, + .write_raw = ina2xx_write_raw, + .debugfs_reg_access = ina2xx_debug_reg, +}; + +static const struct iio_info ina226_info = { + .attrs = &ina226_attribute_group, + .read_raw = ina2xx_read_raw, + .write_raw = ina2xx_write_raw, + .debugfs_reg_access = ina2xx_debug_reg, +}; + +/* Initialize the configuration and calibration registers. */ +static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config) +{ + int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config); + if (ret) + return ret; + + return ina2xx_set_calibration(chip); +} + +static int ina2xx_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct ina2xx_chip_info *chip; + struct iio_dev *indio_dev; + unsigned int val; + enum ina2xx_ids type; + int ret; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip)); + if (!indio_dev) + return -ENOMEM; + + chip = iio_priv(indio_dev); + + /* This is only used for device removal purposes. */ + i2c_set_clientdata(client, indio_dev); + + 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); + } + + if (client->dev.of_node) + type = (uintptr_t)of_device_get_match_data(&client->dev); + else + type = id->driver_data; + chip->config = &ina2xx_config[type]; + + mutex_init(&chip->state_lock); + + 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; + } + + ret = set_shunt_resistor(chip, val); + if (ret) + return ret; + + /* Patch the current config register with default. */ + val = chip->config->config_default; + + if (type == 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); + } else { + chip->avg = 1; + ina219_set_int_time_vbus(chip, INA219_DEFAULT_IT, &val); + ina219_set_int_time_vshunt(chip, INA219_DEFAULT_IT, &val); + ina219_set_vbus_range_denom(chip, INA219_DEFAULT_BRNG, &val); + ina219_set_vshunt_pga_gain(chip, INA219_DEFAULT_PGA, &val); + } + + ret = ina2xx_init(chip, val); + if (ret) { + dev_err(&client->dev, "error configuring the device\n"); + return ret; + } + + indio_dev->modes = INDIO_DIRECT_MODE; + if (type == ina226) { + indio_dev->channels = ina226_channels; + indio_dev->num_channels = ARRAY_SIZE(ina226_channels); + indio_dev->info = &ina226_info; + } else { + indio_dev->channels = ina219_channels; + indio_dev->num_channels = ARRAY_SIZE(ina219_channels); + indio_dev->info = &ina219_info; + } + indio_dev->name = id ? id->name : chip->config->name; + + ret = devm_iio_kfifo_buffer_setup(&client->dev, indio_dev, + &ina2xx_setup_ops); + if (ret) + return ret; + + return iio_device_register(indio_dev); +} + +static void ina2xx_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct ina2xx_chip_info *chip = iio_priv(indio_dev); + int ret; + + iio_device_unregister(indio_dev); + + /* Powerdown */ + ret = regmap_update_bits(chip->regmap, INA2XX_CONFIG, + INA2XX_MODE_MASK, 0); + if (ret) + dev_warn(&client->dev, "Failed to power down device (%pe)\n", + ERR_PTR(ret)); +} + +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 const struct of_device_id ina2xx_of_match[] = { + { + .compatible = "ti,ina219", + .data = (void *)ina219 + }, + { + .compatible = "ti,ina220", + .data = (void *)ina219 + }, + { + .compatible = "ti,ina226", + .data = (void *)ina226 + }, + { + .compatible = "ti,ina230", + .data = (void *)ina226 + }, + { + .compatible = "ti,ina231", + .data = (void *)ina226 + }, + {}, +}; +MODULE_DEVICE_TABLE(of, ina2xx_of_match); + +static struct i2c_driver ina2xx_driver = { + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = ina2xx_of_match, + }, + .probe = ina2xx_probe, + .remove = ina2xx_remove, + .id_table = ina2xx_id, +}; +module_i2c_driver(ina2xx_driver); + +MODULE_AUTHOR("Marc Titinger <marc.titinger@baylibre.com>"); +MODULE_DESCRIPTION("Texas Instruments INA2XX ADC driver"); +MODULE_LICENSE("GPL v2"); |