Re: [PATCH v2 1/1] iio: mtk-auxadc: update case IIO_CHAN_INFO_PROCESSED
From: Jonathan Cameron <jic23@kernel.org>
Date: 2021-09-05 11:17:03
Also in:
linux-devicetree, linux-iio, linux-mediatek, lkml
On Tue, 31 Aug 2021 13:42:07 +0800 Hui Liu [off-list ref] wrote:
Convert raw data to processed data, the processed data is input voltage. Signed-off-by: Hui Liu <redacted>
Looks very much to be a fix. Please track down appropriate patch and let me know what the Fixes: tag should be. If you reply to this thread I'll add it plus a not saying it is an ABI change, but a necessary one as the driver was previously buggy. Whilst we are here, what is the cali_data() function actually there for? Seems to only set *val = *val which is rather pointless. Thanks, Jonathan
quoted hunk
--- drivers/iio/adc/mt6577_auxadc.c | 8 ++++++++ 1 file changed, 8 insertions(+)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:
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