On Mi, 2018-11-28 at 16:15 -0200, Giuliano Belinassi 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: Giuliano Belinassi <giuliano.belinassi@xxxxxx> > --- > Changes in v2: > - Now this patch is part of the patchset that aims to remove ad7780 > out of staging. https://marc.info/?l=linux-iio&m=154282349808890&w=2 > - Also, now it reads voltage and filter values from the userspace > instead of gpio pin states. Hello, Please see bellow. > > drivers/staging/iio/adc/ad7780.c | 78 ++++++++++++++++++++++++-- > include/linux/iio/adc/ad_sigma_delta.h | 5 ++ > 2 files changed, 79 insertions(+), 4 deletions(-) > > diff --git a/drivers/staging/iio/adc/ad7780.c > b/drivers/staging/iio/adc/ad7780.c > index c4a85789c2db..05979a79fda3 100644 > --- a/drivers/staging/iio/adc/ad7780.c > +++ b/drivers/staging/iio/adc/ad7780.c > @@ -39,6 +39,12 @@ > #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 > + > struct ad7780_chip_info { > struct iio_chan_spec channel; > unsigned int pattern_mask; > @@ -50,6 +56,8 @@ struct ad7780_state { > const struct ad7780_chip_info *chip_info; > struct regulator *reg; > struct gpio_desc *powerdown_gpio; > + struct gpio_desc *gain_gpio; > + struct gpio_desc *filter_gpio; > unsigned int gain; > > struct ad_sigma_delta sd; > @@ -115,18 +123,65 @@ static int ad7780_read_raw(struct iio_dev > *indio_dev, > 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 uvref, gain; > + unsigned int full_scale; > + > + if (!chip_info->is_ad778x) > + return 0; > + > + switch (m) { > + case IIO_CHAN_INFO_SCALE: > + if (val != 0) > + return -EINVAL; > + > + uvref = regulator_get_voltage(st->reg); regulator_get_voltage() has already been called in the probe function and the result is stored in st->int_vref_mv. My suggestion would be to use a local vref variable declared as unsigned int. It is my fault that I haven't explained correctly in the previous email, but you need to multiply vref_mv with 1000000LL in order to get the right precision: vref = st->int_vref_mv * 1000000LL. Afterwards you will be able to perform the divisions. > + > + if (uvref < 0) > + return uvref; > + > + full_scale = 1 << (chip_info->channel.scan_type.realbits > - 1); > + gain = DIV_ROUND_CLOSEST(uvref, full_scale); > + gain = DIV_ROUND_CLOSEST(gain, val2); > + > + gpiod_set_value(st->gain_gpio, gain < > AD7780_GAIN_MIDPOINT ? 0 : 1); Once the gain is set, you can store it in st->gain variable. > + case IIO_CHAN_INFO_SAMP_FREQ: > + if (val2 != 0) > + return -EINVAL; > + > + gpiod_set_value(st->filter_gpio, val < > AD7780_FILTER_MIDPOINT ? 0 : 1); This is probably fine, although I am not a big fan of the ternary operator. A simple if else statement would do. However, I don't feel strongly about it, so feel free to disagree. > + break; > + } > + > + return 0; > +} > + > static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta, > unsigned int raw_sample) > { > struct ad7780_state *st = ad_sigma_delta_to_ad7780(sigma_delta); > const struct ad7780_chip_info *chip_info = st->chip_info; > + int val; > > if ((raw_sample & AD7780_ERR) || > ((raw_sample & chip_info->pattern_mask) != chip_info- > >pattern)) > return -EIO; > > if (chip_info->is_ad778x) { > - if (raw_sample & AD7780_GAIN) > + val = raw_sample & AD7780_GAIN; > + > + if (val != gpiod_get_value(st->gain_gpio)) > + return -EIO; It is not obvious to me what is the point of this check. Maybe you can add a comment? > + > + if (val) > st->gain = 1; > else > st->gain = 128; Do we still need this? I am not convinced. > @@ -141,18 +196,20 @@ 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 +230,7 @@ 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 +280,18 @@ 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)) { if the GPIO is optional, then we should continue in case of -ENODEV. Shouldn't we have a devm_gpiod_get_optional() call also for filter_gpio? > + ret = PTR_ERR(st->gain_gpio); > + dev_err(&spi->dev, "Failed to request gain 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 730ead1a46df..6cadab6fd5fd 100644 > --- a/include/linux/iio/adc/ad_sigma_delta.h > +++ b/include/linux/iio/adc/ad_sigma_delta.h > @@ -173,6 +173,11 @@ 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)) > + > #define AD_SD_TEMP_CHANNEL(_si, _address, _bits, _storagebits, _shift) \ > __AD_SD_CHANNEL(_si, 0, -1, _address, _bits, \ > _storagebits, _shift, NULL, IIO_TEMP, \ _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
