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authorJonathan Bakker <xc-racer2@live.ca>2020-05-08 14:14:00 -0700
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2020-05-16 17:31:12 +0100
commit754718a5b43c851546c3bb70e8d41bf81cb42b30 (patch)
tree920da4779d768c14958b68249b5d8484b6bf9859 /drivers/iio
parent5cb1a5481cc3a1101457abd6abffc9b168bc7bb4 (diff)
iio: adc: Add scaling support to exynos adc driver
Currently the driver only exposes the raw counts. As we have the regulator voltage and the maximum value (stored in the data mask), we can trivially produce a scaling fraction of voltage / max value. This assumes that the regulator voltage is in fact the max voltage, which appears to be the case for all mainline dts and cross referenced with the public Exynos4412 and S5PV210 datasheets. Signed-off-by: Jonathan Bakker <xc-racer2@live.ca> Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio')
-rw-r--r--drivers/iio/adc/exynos_adc.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
index 22131a677445..9d29b56805cd 100644
--- a/drivers/iio/adc/exynos_adc.c
+++ b/drivers/iio/adc/exynos_adc.c
@@ -531,8 +531,19 @@ static int exynos_read_raw(struct iio_dev *indio_dev,
unsigned long timeout;
int ret;
- if (mask != IIO_CHAN_INFO_RAW)
+ if (mask == IIO_CHAN_INFO_SCALE) {
+ ret = regulator_get_voltage(info->vdd);
+ if (ret < 0)
+ return ret;
+
+ /* Regulator voltage is in uV, but need mV */
+ *val = ret / 1000;
+ *val2 = info->data->mask;
+
+ return IIO_VAL_FRACTIONAL;
+ } else if (mask != IIO_CHAN_INFO_RAW) {
return -EINVAL;
+ }
mutex_lock(&indio_dev->mlock);
reinit_completion(&info->completion);
@@ -683,6 +694,7 @@ static const struct iio_info exynos_adc_iio_info = {
.channel = _index, \
.address = _index, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE), \
.datasheet_name = _id, \
}