* Re: [PATCH v2 1/1] iio: mtk-auxadc: update case IIO_CHAN_INFO_PROCESSED
[not found] ` <20210831054207.13236-2-hui.liu@mediatek.com>
@ 2021-09-05 11:20 ` Jonathan Cameron
0 siblings, 0 replies; only message in thread
From: Jonathan Cameron @ 2021-09-05 11:20 UTC (permalink / raw)
To: Hui Liu
Cc: robh+dt, lars, pmeerw, srv_heupstream, zhiyong.tao, chun-hung.wu,
yingjoe.chen, seiya.wang, ben.tseng, matthias.bgg, s.hauer,
devicetree, linux-kernel, linux-arm-kernel, linux-iio,
linux-mediatek
On Tue, 31 Aug 2021 13:42:07 +0800
Hui Liu <hui.liu@mediatek.com> wrote:
> Convert raw data to processed data, the processed data is input voltage.
>
> Signed-off-by: Hui Liu <hui.liu@mediatek.com>
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
> ---
> 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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