Messages in this thread | | | Subject | Re: [PATCH 3/3] iio: adc: ina2xx: Allow setting Shunt Voltage PGA gain and Bus Voltage range | From | Maciej Purski <> | Date | Mon, 09 Oct 2017 10:36:16 +0200 |
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On 10/08/2017 12:07 PM, Jonathan Cameron wrote: > On Sun, 1 Oct 2017 21:48:18 +0200 > Stefan Brüns <stefan.bruens@rwth-aachen.de> wrote: > >> Reducing shunt and bus voltage range improves the accuracy, so allow >> altering the default settings. >> >> Both settings are exposed as gain values. While for the shunt voltage >> this is straightforward, the bus range settings of 32V (default) and 16V >> are mapped to gain values of 1 resp. 2, to provide a uniform API to >> userspace. >> >> As the gain settings are incorporated into the raw values by the sensor >> itself, adjusting of the scale attributes is not necessary. >> >> Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de> > > cc'd Maciej Purski who is working to improve the current calibration > elements - I'd like you both to review each others patches if possible > as the ABI is getting complex in here! > > I think what you have here won't interfere with Maciej's work, but > would like you two to confirm that. Note that patch set probably > needs a revision as I've suggested a rather different approach. > > Thanks, > > Jonathan >
Hi, it looks fine to me. The patches shouldn't interfere with each other.
Regards,
Maciej
>> >> --- >> >> drivers/iio/adc/ina2xx-adc.c | 111 +++++++++++++++++++++++++++++++++++++++++-- >> 1 file changed, 108 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c >> index 1930f853e8c5..7e9ce43ad15d 100644 >> --- a/drivers/iio/adc/ina2xx-adc.c >> +++ b/drivers/iio/adc/ina2xx-adc.c >> @@ -48,8 +48,10 @@ >> #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 >> @@ -62,6 +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) >> @@ -131,6 +141,8 @@ 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; >> }; >> >> @@ -227,6 +239,18 @@ static int ina2xx_read_raw(struct iio_dev *indio_dev, >> *val = 1; >> return IIO_VAL_INT; >> } >> + >> + 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; >> @@ -361,6 +385,74 @@ 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) >> @@ -403,6 +495,14 @@ 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 * 1000000 + >> + val2, &tmp); >> + else >> + ret = ina219_set_vbus_range_denom(chip, val, &tmp); >> + break; >> + >> default: >> ret = -EINVAL; >> } >> @@ -547,7 +647,10 @@ static ssize_t ina2xx_shunt_resistor_store(struct device *dev, >> .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 = { \ >> @@ -758,7 +861,6 @@ 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); >> @@ -793,6 +895,7 @@ static const struct iio_info ina219_info = { >> .driver_module = THIS_MODULE, >> .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, >> }; >> @@ -874,6 +977,8 @@ 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); > > > >
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