Messages in this thread | | | From | Renato Lui Geh <> | Date | Thu, 14 Feb 2019 18:31:12 -0200 | Subject | Re: [PATCH v3 1/4] staging: iio: ad7780: add gain & filter gpio support |
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Hi Jonathan,
Thanks for the review. Comments inline.
Renato
On 02/09, Jonathan Cameron wrote: >On Tue, 5 Feb 2019 15:13:00 -0200 >Renato Lui Geh <renatogeh@gmail.com> 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 <renatogeh@gmail.com> >> Signed-off-by: Giuliano Belinassi <giuliano.belinassi@usp.br> >> Co-developed-by: Giuliano Belinassi <giuliano.belinassi@usp.br> >Comments inline. > >> --- >> Changes in v3: >> - Renamed ad7780_chip_info's filter to odr >> - Renamed ad778x_filter to ad778x_odr_avail >> - Changed vref variable from unsigned int to unsigned long long to >> avoid overflow >> - Removed unnecessary AD_SD_CHANNEL macro >> >> drivers/staging/iio/adc/ad7780.c | 95 ++++++++++++++++++++++++++++++-- >> 1 file changed, 89 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/staging/iio/adc/ad7780.c b/drivers/staging/iio/adc/ad7780.c >> index c4a85789c2db..6e4357800d31 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 >What are these for?
Sorry about that. That's leftover from a previous attempt. > >> + >> +#define AD7780_GAIN_MIDPOINT 64 >> +#define AD7780_FILTER_MIDPOINT 13350 >> + >> +static const unsigned int ad778x_gain[2] = { 1, 128 }; >> +static const unsigned int ad778x_odr_avail[2] = { 10000, 16700 }; >> + >> 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 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->odr; >> + 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; >> + unsigned long long vref; >> + unsigned int full_scale, gain; >> + >> + 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; >> + full_scale = 1 << (chip_info->channel.scan_type.realbits - 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->odr = ad778x_odr_avail[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->odr = ad778x_odr_avail[raw_sample & AD7780_FILTER]; >> } >> >> return 0; >> @@ -173,6 +232,7 @@ 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 +282,29 @@ 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", > >These are not particularly standard names (basically not "reset"), >so they should be vendor prefixed, so that people know to go >look at the device specific binding.
I see. Should they be something like "adi,gain" and "adi,filter"? Am I correct to assume that I'll have to somehow mention these in the dt-binding? > >> + 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; >
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