On Du, 2019-01-27 at 18:30 -0200, Renato Lui Geh wrote: > Previously, the AD7780 driver only supported gpio for the 'powerdown' > pin. This commit adds suppport for the 'gain' and 'filter' pin. > > Signed-off-by: Renato Lui Geh <renato...@gmail.com> > Signed-off-by: Giuliano Belinassi <giuliano.belina...@usp.br> > Co-developed-by: Giuliano Belinassi <giuliano.belina...@usp.br> > --- > Changes in v2: > - Filter reading changed to mHz > - Storing filter, gain and voltage to chip_info
Hi, Comments inline. Regards, Stefan > > drivers/staging/iio/adc/ad7780.c | 103 ++++++++++++++++++++++--- > include/linux/iio/adc/ad_sigma_delta.h | 5 ++ > 2 files changed, 99 insertions(+), 9 deletions(-) > > diff --git a/drivers/staging/iio/adc/ad7780.c > b/drivers/staging/iio/adc/ad7780.c > index c4a85789c2db..82394e31b168 100644 > --- a/drivers/staging/iio/adc/ad7780.c > +++ b/drivers/staging/iio/adc/ad7780.c > @@ -39,6 +39,15 @@ > #define AD7170_PATTERN (AD7780_PAT0 | AD7170_PAT2) > #define AD7170_PATTERN_MASK (AD7780_PAT0 | AD7780_PAT1 | AD7170_PAT2) > > +#define AD7780_GAIN_GPIO 0 > +#define AD7780_FILTER_GPIO 1 > + > +#define AD7780_GAIN_MIDPOINT 64 > +#define AD7780_FILTER_MIDPOINT 13350 > + > +static const unsigned int ad778x_gain[2] = { 1, 128 }; > +static const unsigned int ad778x_filter[2] = { 10000, 16700 }; I would name this array ad778x_odr_avail or something like that. We should also consider adding the option to read the available sampling frequencies from user space, but let's leave this for another commit. > + > struct ad7780_chip_info { > struct iio_chan_spec channel; > unsigned int pattern_mask; > @@ -50,7 +59,11 @@ struct ad7780_state { > const struct ad7780_chip_info *chip_info; > struct regulator *reg; > struct gpio_desc *powerdown_gpio; > - unsigned int gain; > + struct gpio_desc *gain_gpio; > + struct gpio_desc *filter_gpio; > + unsigned int gain; > + unsigned int filter; Also, this could be renamed as odr. > + unsigned int int_vref_mv; > > struct ad_sigma_delta sd; > }; > @@ -104,17 +117,65 @@ static int ad7780_read_raw(struct iio_dev > *indio_dev, > voltage_uv = regulator_get_voltage(st->reg); > if (voltage_uv < 0) > return voltage_uv; > - *val = (voltage_uv / 1000) * st->gain; > + voltage_uv /= 1000; > + *val = voltage_uv * st->gain; > *val2 = chan->scan_type.realbits - 1; > + st->int_vref_mv = voltage_uv; > return IIO_VAL_FRACTIONAL_LOG2; > case IIO_CHAN_INFO_OFFSET: > *val = -(1 << (chan->scan_type.realbits - 1)); > return IIO_VAL_INT; > + case IIO_CHAN_INFO_SAMP_FREQ: > + *val = st->filter; > + return IIO_VAL_INT; > } > > return -EINVAL; > } > > +static int ad7780_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, > + int val2, > + long m) > +{ > + struct ad7780_state *st = iio_priv(indio_dev); > + const struct ad7780_chip_info *chip_info = st->chip_info; > + int vref, gain; > + unsigned int full_scale; > + > + if (!chip_info->is_ad778x) > + return 0; > + > + switch (m) { > + case IIO_CHAN_INFO_SCALE: > + if (val != 0) > + return -EINVAL; > + > + vref = st->int_vref_mv * 1000000LL; From the datasheet, the VREF is ±5 V, therefore your vref variable will overflow. You probably need unsigned long long. > + full_scale = 1 << (chip_info->channel.scane_type.realbis > - 1); > + gain = DIV_ROUND_CLOSEST(vref, full_scale); > + gain = DIV_ROUND_CLOSEST(gain, val2); > + st->gain = gain; > + if (gain < AD7780_GAIN_MIDPOINT) > + gain = 0; > + else > + gain = 1; > + gpiod_set_value(st->gain_gpio, gain); > + break; > + case IIO_CHAN_INFO_SAMP_FREQ: > + if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT) > + val = 0; > + else > + val = 1; > + st->filter = ad778x_filter[val]; > + gpiod_set_value(st->filter_gpio, val); > + break; > + } > + > + return 0; > +} > + > static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta, > unsigned int raw_sample) > { > @@ -126,10 +187,8 @@ static int ad7780_postprocess_sample(struct > ad_sigma_delta *sigma_delta, > return -EIO; > > if (chip_info->is_ad778x) { > - if (raw_sample & AD7780_GAIN) > - st->gain = 1; > - else > - st->gain = 128; > + st->gain = ad778x_gain[raw_sample & AD7780_GAIN]; > + st->filter = ad778x_filter[raw_sample & AD7780_FILTER]; > } > > return 0; > @@ -141,18 +200,20 @@ static const struct ad_sigma_delta_info > ad7780_sigma_delta_info = { > .has_registers = false, > }; > > -#define AD7780_CHANNEL(bits, wordsize) \ > +#define AD7170_CHANNEL(bits, wordsize) \ > AD_SD_CHANNEL_NO_SAMP_FREQ(1, 0, 0, bits, 32, wordsize - bits) > +#define AD7780_CHANNEL(bits, wordsize) \ > + AD_SD_CHANNEL_GAIN_FILTER(1, 0, 0, bits, 32, wordsize - bits) > > static const struct ad7780_chip_info ad7780_chip_info_tbl[] = { > [ID_AD7170] = { > - .channel = AD7780_CHANNEL(12, 24), > + .channel = AD7170_CHANNEL(12, 24), > .pattern = AD7170_PATTERN, > .pattern_mask = AD7170_PATTERN_MASK, > .is_ad778x = false, > }, > [ID_AD7171] = { > - .channel = AD7780_CHANNEL(16, 24), > + .channel = AD7170_CHANNEL(16, 24), > .pattern = AD7170_PATTERN, > .pattern_mask = AD7170_PATTERN_MASK, > .is_ad778x = false, > @@ -173,6 +234,7 @@ static const struct ad7780_chip_info > ad7780_chip_info_tbl[] = { > > static const struct iio_info ad7780_info = { > .read_raw = ad7780_read_raw, > + .write_raw = ad7780_write_raw, > }; > > static int ad7780_probe(struct spi_device *spi) > @@ -222,6 +284,29 @@ static int ad7780_probe(struct spi_device *spi) > goto error_disable_reg; > } > > + if (st->chip_info->is_ad778x) { > + st->gain_gpio = devm_gpiod_get_optional(&spi->dev, > + "gain", > + GPIOD_OUT_HIGH); > + if (IS_ERR(st->gain_gpio)) { > + ret = PTR_ERR(st->gain_gpio); > + dev_err(&spi->dev, "Failed to request gain GPIO: > %d\n", > + ret); > + goto error_disable_reg; > + } > + > + st->filter_gpio = devm_gpiod_get_optional(&spi->dev, > + "filter", > + GPIOD_OUT_HIGH) > ; > + if (IS_ERR(st->filter_gpio)) { > + ret = PTR_ERR(st->filter_gpio); > + dev_err(&spi->dev, > + "Failed to request filter GPIO: %d\n", > + ret); > + goto error_disable_reg; > + } > + } > + > ret = ad_sd_setup_buffer_and_trigger(indio_dev); > if (ret) > goto error_disable_reg; > diff --git a/include/linux/iio/adc/ad_sigma_delta.h > b/include/linux/iio/adc/ad_sigma_delta.h > index 7e84351fa2c0..c01da869de83 100644 > --- a/include/linux/iio/adc/ad_sigma_delta.h > +++ b/include/linux/iio/adc/ad_sigma_delta.h > @@ -176,6 +176,11 @@ int ad_sd_validate_trigger(struct iio_dev > *indio_dev, struct iio_trigger *trig); > __AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \ > _storagebits, _shift, NULL, IIO_VOLTAGE, 0) > > +#define AD_SD_CHANNEL_GAIN_FILTER(_si, _channel, _address, _bits, \ > + _storagebits, _shift) \ > + __AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \ > + _storagebits, _shift, NULL, IIO_VOLTAGE, > BIT(IIO_CHAN_INFO_RAW)) > + Do you need to define a new macro? > #define AD_SD_TEMP_CHANNEL(_si, _address, _bits, _storagebits, _shift) \ > __AD_SD_CHANNEL(_si, 0, -1, _address, _bits, \ > _storagebits, _shift, NULL, IIO_TEMP, \ > -- > 2.20.1 >