On Thu, 13 Jul 2017 01:31:59 +0900 Akinobu Mita <akinobu.mita@xxxxxxxxx> wrote: > The ti-ads1015 driver supports ADS1015 and ADS1115 devices. The same > scale information is used for both devices in this driver, however they > have actually different values and the ADS1115's one is not correct. > > These devices have the same full-scale input voltage range for each PGA > selection. So instead of adding another hardcoded scale information, > compute a correct scale on demand from each device's resolution. > > Cc: Daniel Baluta <daniel.baluta@xxxxxxxxx> > Cc: Jonathan Cameron <jic23@xxxxxxxxxx> > Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx> Looks good to me. Cc'd to Daniel's current address. > --- > drivers/iio/adc/ti-ads1015.c | 47 ++++++++++++++++++++++---------------------- > 1 file changed, 23 insertions(+), 24 deletions(-) > > diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c > index 94c2221..1edf323 100644 > --- a/drivers/iio/adc/ti-ads1015.c > +++ b/drivers/iio/adc/ti-ads1015.c > @@ -81,18 +81,12 @@ static const unsigned int ads1115_data_rate[] = { > 8, 16, 32, 64, 128, 250, 475, 860 > }; > > -static const struct { > - int scale; > - int uscale; > -} ads1015_scale[] = { > - {3, 0}, > - {2, 0}, > - {1, 0}, > - {0, 500000}, > - {0, 250000}, > - {0, 125000}, > - {0, 125000}, > - {0, 125000}, > +/* > + * Translation from PGA bits to full-scale positive and negative input voltage > + * range in mV > + */ > +static int ads1015_fullscale_range[] = { > + 6144, 4096, 2048, 1024, 512, 256, 256, 256 > }; > > #define ADS1015_V_CHAN(_chan, _addr) { \ > @@ -300,15 +294,17 @@ static irqreturn_t ads1015_trigger_handler(int irq, void *p) > return IRQ_HANDLED; > } > > -static int ads1015_set_scale(struct ads1015_data *data, int chan, > +static int ads1015_set_scale(struct ads1015_data *data, > + struct iio_chan_spec const *chan, > int scale, int uscale) > { > int i; > + int fullscale = div_s64((scale * 1000000LL + uscale) << > + (chan->scan_type.realbits - 1), 1000000); > > - for (i = 0; i < ARRAY_SIZE(ads1015_scale); i++) { > - if (ads1015_scale[i].scale == scale && > - ads1015_scale[i].uscale == uscale) { > - data->channel_data[chan].pga = i; > + for (i = 0; i < ARRAY_SIZE(ads1015_fullscale_range); i++) { > + if (ads1015_fullscale_range[i] == fullscale) { > + data->channel_data[chan->address].pga = i; > return 0; > } > } > @@ -369,9 +365,9 @@ static int ads1015_read_raw(struct iio_dev *indio_dev, > } > case IIO_CHAN_INFO_SCALE: > idx = data->channel_data[chan->address].pga; > - *val = ads1015_scale[idx].scale; > - *val2 = ads1015_scale[idx].uscale; > - ret = IIO_VAL_INT_PLUS_MICRO; > + *val = ads1015_fullscale_range[idx]; > + *val2 = chan->scan_type.realbits - 1; > + ret = IIO_VAL_FRACTIONAL_LOG2; > break; > case IIO_CHAN_INFO_SAMP_FREQ: > idx = data->channel_data[chan->address].data_rate; > @@ -398,7 +394,7 @@ static int ads1015_write_raw(struct iio_dev *indio_dev, > mutex_lock(&data->lock); > switch (mask) { > case IIO_CHAN_INFO_SCALE: > - ret = ads1015_set_scale(data, chan->address, val, val2); > + ret = ads1015_set_scale(data, chan, val, val2); > break; > case IIO_CHAN_INFO_SAMP_FREQ: > ret = ads1015_set_data_rate(data, chan->address, val); > @@ -430,7 +426,10 @@ static const struct iio_buffer_setup_ops ads1015_buffer_setup_ops = { > .validate_scan_mask = &iio_validate_scan_mask_onehot, > }; > > -static IIO_CONST_ATTR(scale_available, "3 2 1 0.5 0.25 0.125"); > +static IIO_CONST_ATTR_NAMED(ads1015_scale_available, scale_available, > + "3 2 1 0.5 0.25 0.125"); > +static IIO_CONST_ATTR_NAMED(ads1115_scale_available, scale_available, > + "0.1875 0.125 0.0625 0.03125 0.015625 0.007813"); > > static IIO_CONST_ATTR_NAMED(ads1015_sampling_frequency_available, > sampling_frequency_available, "128 250 490 920 1600 2400 3300"); > @@ -438,7 +437,7 @@ static IIO_CONST_ATTR_NAMED(ads1115_sampling_frequency_available, > sampling_frequency_available, "8 16 32 64 128 250 475 860"); > > static struct attribute *ads1015_attributes[] = { > - &iio_const_attr_scale_available.dev_attr.attr, > + &iio_const_attr_ads1015_scale_available.dev_attr.attr, > &iio_const_attr_ads1015_sampling_frequency_available.dev_attr.attr, > NULL, > }; > @@ -448,7 +447,7 @@ static const struct attribute_group ads1015_attribute_group = { > }; > > static struct attribute *ads1115_attributes[] = { > - &iio_const_attr_scale_available.dev_attr.attr, > + &iio_const_attr_ads1115_scale_available.dev_attr.attr, > &iio_const_attr_ads1115_sampling_frequency_available.dev_attr.attr, > NULL, > }; -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html