[PATCH 36/40] iio: adc: ti_am335x_adc: Add the scale information

Miquel Raynal
2021-08-25T15:35:07Z

Without the scale, the values returned to the user are just a picture of
the input voltage against the full scale range of the ADC. We need to
provide the actual conversion factor to get milli-Volts values.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
drivers/iio/adc/ti_am335x_adc.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
index d4619fd6fd54..f644898b47dd 100644
--- a/drivers/iio/adc/ti_am335x_adc.c
+++ b/drivers/iio/adc/ti_am335x_adc.c
@@ -417,6 +417,7 @@ static int tiadc_channel_init(struct device *dev, struct iio_dev *indio_dev,
chan->indexed = 1;
chan->channel = adc_dev->channel_line[i];
chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
+ chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
chan->datasheet_name = chan_name_ain[chan->channel];
chan->scan_index = i;
chan->scan_type.sign = 'u';
@@ -441,6 +442,23 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
unsigned long timeout;
int ret;

+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ break;
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_VOLTAGE:
+ *val = 1800;
+ *val2 = chan->scan_type.realbits;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ default:
+ return -EINVAL;
+ }
+ break;
+ default:
+ return -EINVAL;
+ }
+
if (iio_buffer_enabled(indio_dev))
return -EBUSY;

--
2.27.0