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iio: adc: ti_am335x_adc: Add the scale information

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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>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211015081506.933180-45-miquel.raynal@bootlin.com
This commit is contained in:
Miquel Raynal 2021-10-15 10:15:02 +02:00 committed by Lee Jones
parent 789e5ebcc6
commit 3af9935499
1 changed files with 18 additions and 0 deletions
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18
drivers/iio/adc/ti_am335x_adc.c
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@ -417,6 +417,7 @@ static int tiadc_channel_init(struct device *dev, struct iio_dev *indio_dev,
chan->indexed = 1; chan->indexed = 1;
chan->channel = adc_dev->channel_line[i]; chan->channel = adc_dev->channel_line[i];
chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW); 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->datasheet_name = chan_name_ain[chan->channel];
chan->scan_index = i; chan->scan_index = i;
chan->scan_type.sign = 'u'; chan->scan_type.sign = 'u';
@ -441,6 +442,23 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
unsigned long timeout; unsigned long timeout;
int ret; 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)) if (iio_buffer_enabled(indio_dev))
return -EBUSY; return -EBUSY;