diff options
| author | Hui Liu <hui.liu@mediatek.com> | 2021-09-26 10:30:28 +0300 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2021-09-26 14:30:09 +0300 |
| commit | c2980c64c7fd4585d684574c92d1624d44961edd (patch) | |
| tree | e0c1e7e038954bdf3552c1c90cd11c33b5807dac /drivers/iio | |
| parent | 9da1b86865ab4376408c58cd9fec332c8bdb5c73 (diff) | |
| download | linux-c2980c64c7fd4585d684574c92d1624d44961edd.tar.xz | |
iio: mtk-auxadc: fix case IIO_CHAN_INFO_PROCESSED
The previous driver does't apply the necessary scaling to take the
voltage range into account.
We change readback value from raw data to input voltage to fix case
IIO_CHAN_INFO_PROCESSED.
Fixes: ace4cdfe67be ("iio: adc: mt2701: Add Mediatek auxadc driver for mt2701.")
Signed-off-by: Hui Liu <hui.liu@mediatek.com>
Link: https://lore.kernel.org/r/20210926073028.11045-2-hui.liu@mediatek.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio')
| -rw-r--r-- | drivers/iio/adc/mt6577_auxadc.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/iio/adc/mt6577_auxadc.c b/drivers/iio/adc/mt6577_auxadc.c index 79c1dd68b909..d4fccd52ef08 100644 --- a/drivers/iio/adc/mt6577_auxadc.c +++ b/drivers/iio/adc/mt6577_auxadc.c @@ -82,6 +82,10 @@ static const struct iio_chan_spec mt6577_auxadc_iio_channels[] = { MT6577_AUXADC_CHANNEL(15), }; +/* For Voltage calculation */ +#define VOLTAGE_FULL_RANGE 1500 /* VA voltage */ +#define AUXADC_PRECISE 4096 /* 12 bits */ + static int mt_auxadc_get_cali_data(int rawdata, bool enable_cali) { return rawdata; @@ -191,6 +195,10 @@ static int mt6577_auxadc_read_raw(struct iio_dev *indio_dev, } if (adc_dev->dev_comp->sample_data_cali) *val = mt_auxadc_get_cali_data(*val, true); + + /* Convert adc raw data to voltage: 0 - 1500 mV */ + *val = *val * VOLTAGE_FULL_RANGE / AUXADC_PRECISE; + return IIO_VAL_INT; default: |