diff options
Diffstat (limited to 'drivers/iio/adc/ina2xx-adc.c')
-rw-r--r-- | drivers/iio/adc/ina2xx-adc.c | 317 |
1 files changed, 226 insertions, 91 deletions
diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c index 84a43871f7dc..0635a79864bf 100644 --- a/drivers/iio/adc/ina2xx-adc.c +++ b/drivers/iio/adc/ina2xx-adc.c @@ -44,13 +44,14 @@ #define INA226_MASK_ENABLE 0x06 #define INA226_CVRF BIT(3) -#define INA219_CNVR BIT(1) #define INA2XX_MAX_REGISTERS 8 /* settings - depend on use case */ -#define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */ +#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 @@ -63,6 +64,14 @@ */ #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) @@ -79,6 +88,11 @@ #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) @@ -110,11 +124,12 @@ enum ina2xx_ids { ina219, ina226 }; struct ina2xx_config { u16 config_default; - int calibration_factor; - int shunt_div; - int bus_voltage_shift; + int calibration_value; + int shunt_voltage_lsb; /* nV */ + int bus_voltage_shift; /* position of lsb */ int bus_voltage_lsb; /* uV */ - int power_lsb; /* uW */ + /* fixed relation between current and power lsb, uW/uA */ + int power_lsb_factor; enum ina2xx_ids chip_id; }; @@ -127,26 +142,28 @@ struct ina2xx_chip_info { 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; }; static const struct ina2xx_config ina2xx_config[] = { [ina219] = { .config_default = INA219_CONFIG_DEFAULT, - .calibration_factor = 40960000, - .shunt_div = 100, - .bus_voltage_shift = 3, + .calibration_value = 4096, + .shunt_voltage_lsb = 10000, + .bus_voltage_shift = INA219_BUS_VOLTAGE_SHIFT, .bus_voltage_lsb = 4000, - .power_lsb = 20000, + .power_lsb_factor = 20, .chip_id = ina219, }, [ina226] = { .config_default = INA226_CONFIG_DEFAULT, - .calibration_factor = 5120000, - .shunt_div = 400, + .calibration_value = 2048, + .shunt_voltage_lsb = 2500, .bus_voltage_shift = 0, .bus_voltage_lsb = 1250, - .power_lsb = 25000, + .power_lsb_factor = 25, .chip_id = ina226, }, }; @@ -170,6 +187,9 @@ static int ina2xx_read_raw(struct iio_dev *indio_dev, 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: @@ -197,26 +217,48 @@ static int ina2xx_read_raw(struct iio_dev *indio_dev, case IIO_CHAN_INFO_SCALE: switch (chan->address) { case INA2XX_SHUNT_VOLTAGE: - /* processed (mV) = raw/shunt_div */ - *val2 = chip->config->shunt_div; - *val = 1; + /* 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 << shift) */ + /* processed (mV) = raw * lsb (uV) / 1000 */ *val = chip->config->bus_voltage_lsb; - *val2 = 1000 << chip->config->bus_voltage_shift; + *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*lsb (uW) / 1000 */ - *val = chip->config->power_lsb; + /* + * 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; + } + + 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_CURRENT: - /* processed (mA) = raw (mA) */ - *val = 1; + case INA2XX_BUS_VOLTAGE: + *val = chip->range_vbus == 32 ? 1 : 2; return IIO_VAL_INT; } } @@ -353,6 +395,74 @@ static int ina219_set_int_time_vshunt(struct ina2xx_chip_info *chip, 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) @@ -395,6 +505,14 @@ static int ina2xx_write_raw(struct iio_dev *indio_dev, } 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; } @@ -434,25 +552,21 @@ static ssize_t ina2xx_allow_async_readout_store(struct device *dev, } /* - * Set current LSB to 1mA, shunt is in uOhms - * (equation 13 in datasheet). We hardcode a Current_LSB - * of 1.0 x10-3. The only remaining parameter is RShunt. - * There is no need to expose the CALIBRATION register - * to the user for now. But we need to reset this register - * if the user updates RShunt after driver init, e.g upon - * reading an EEPROM/Probe-type value. + * 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) { - u16 regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor, - chip->shunt_resistor_uohm); - - return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval); + 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 > chip->config->calibration_factor) + if (val == 0 || val > INT_MAX) return -EINVAL; chip->shunt_resistor_uohm = val; @@ -485,11 +599,6 @@ static ssize_t ina2xx_shunt_resistor_store(struct device *dev, if (ret) return ret; - /* Update the Calibration register */ - ret = ina2xx_set_calibration(chip); - if (ret) - return ret; - return len; } @@ -532,19 +641,23 @@ static ssize_t ina2xx_shunt_resistor_store(struct device *dev, * Sampling Freq is a consequence of the integration times of * the Voltage channels. */ -#define INA219_CHAN_VOLTAGE(_index, _address) { \ +#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_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', \ - .realbits = 16, \ + .shift = _shift, \ + .realbits = 16 - _shift, \ .storagebits = 16, \ .endianness = IIO_LE, \ } \ @@ -579,23 +692,18 @@ static const struct iio_chan_spec ina226_channels[] = { }; static const struct iio_chan_spec ina219_channels[] = { - INA219_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE), - INA219_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE), + 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_work_buffer(struct iio_dev *indio_dev) +static int ina2xx_conversion_ready(struct iio_dev *indio_dev) { struct ina2xx_chip_info *chip = iio_priv(indio_dev); - unsigned short data[8]; - int bit, ret, i = 0; - s64 time_a, time_b; + int ret; unsigned int alert; - int cnvr_need_clear = 0; - - time_a = iio_get_time_ns(indio_dev); /* * Because the timer thread and the chip conversion clock @@ -608,23 +716,31 @@ static int ina2xx_work_buffer(struct iio_dev *indio_dev) * For now, we do an extra read of the MASK_ENABLE register (INA226) * resp. the BUS_VOLTAGE register (INA219). */ - if (!chip->allow_async_readout) - do { - 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; - cnvr_need_clear = alert; - } + 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; + 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); + /* data buffer needs space for channel data and timestap */ + unsigned short data[4 + sizeof(s64)/sizeof(short)]; + int bit, ret, i = 0; + s64 time; - } while (!alert); + time = iio_get_time_ns(indio_dev); /* * Single register reads: bulk_read will not work with ina226/219 @@ -640,26 +756,11 @@ static int ina2xx_work_buffer(struct iio_dev *indio_dev) return ret; data[i++] = val; - - if (INA2XX_SHUNT_VOLTAGE + bit == INA2XX_POWER) - cnvr_need_clear = 0; - } - - /* Dummy read on INA219 power register to clear CNVR flag */ - if (cnvr_need_clear && chip->config->chip_id == ina219) { - unsigned int val; - - ret = regmap_read(chip->regmap, INA2XX_POWER, &val); - if (ret < 0) - return ret; } - time_b = iio_get_time_ns(indio_dev); + iio_push_to_buffers_with_timestamp(indio_dev, data, time); - iio_push_to_buffers_with_timestamp(indio_dev, - (unsigned int *)data, time_a); - - return (unsigned long)(time_b - time_a) / 1000; + return 0; }; static int ina2xx_capture_thread(void *data) @@ -667,7 +768,9 @@ 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 buffer_us; + int ret; + struct timespec64 next, now, delta; + s64 delay_us; /* * Poll a bit faster than the chip internal Fs, in case @@ -676,13 +779,43 @@ static int ina2xx_capture_thread(void *data) if (!chip->allow_async_readout) sampling_us -= 200; + ktime_get_ts64(&next); + do { - buffer_us = ina2xx_work_buffer(indio_dev); - if (buffer_us < 0) - return buffer_us; + while (!chip->allow_async_readout) { + ret = ina2xx_conversion_ready(indio_dev); + if (ret < 0) + return ret; - if (sampling_us > buffer_us) - udelay(sampling_us - buffer_us); + /* + * 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()); @@ -746,7 +879,6 @@ 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); @@ -780,6 +912,7 @@ static const struct attribute_group ina226_attribute_group = { 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, }; @@ -860,6 +993,8 @@ static int ina2xx_probe(struct i2c_client *client, 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); |