Re: [PATCH] iio: adc: Add scaling support to exynos adc driver
From: Jonathan Cameron
Date: Sun May 10 2020 - 06:24:24 EST
On Fri, 8 May 2020 14:14:00 -0700
Jonathan Bakker <xc-racer2@xxxxxxx> wrote:
> 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@xxxxxxx>
Seems reasonable to me. I'd like an exynos Ack though before applying.
thanks,
Jonathan
> ---
> drivers/iio/adc/exynos_adc.c | 14 +++++++++++++-
> 1 file changed, 13 insertions(+), 1 deletion(-)
>
> 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, \
> }
>