Dear Hector Palacios,
> Some LRADC channels have fixed pre-dividers and all have an optional
> divider by two which allows a maximum input voltage of VDDIO - 50mV.
>
> This patch
> - adds the scaling info flag to all channels
> - grabs the max reference voltage per channel from DT
> (where the fixed pre-dividers apply)
> - allows to read the scaling attribute (computed from the Vref)
>
> Signed-off-by: Hector Palacios <hector.palacios@xxxxxxxx>.
> ---
> drivers/staging/iio/adc/mxs-lradc.c | 81
> ++++++++++++++++++++++++------------- 1 file changed, 52 insertions(+), 29
> deletions(-)
>
> diff --git a/drivers/staging/iio/adc/mxs-lradc.c
> b/drivers/staging/iio/adc/mxs-lradc.c index 91282dc..99e5790 100644
> --- a/drivers/staging/iio/adc/mxs-lradc.c
> +++ b/drivers/staging/iio/adc/mxs-lradc.c
> @@ -141,6 +141,8 @@ struct mxs_lradc {
>
> struct completion completion;
>
> + uint32_t vref_mv[LRADC_MAX_TOTAL_CHANS];
> +
> /*
> * Touchscreen LRADC channels receives a private slot in the CTRL4
> * register, the slot #7. Therefore only 7 slots instead of 8 in the
> @@ -228,39 +230,12 @@ struct mxs_lradc {
> #define LRADC_RESOLUTION 12
> #define LRADC_SINGLE_SAMPLE_MASK ((1 << LRADC_RESOLUTION) - 1)
>
> -/*
> - * Raw I/O operations
> - */
> -static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
> +static int mxs_lradc_read_single(struct iio_dev *iio_dev,
> const struct iio_chan_spec *chan,
> int *val, int *val2, long m)
> {
> struct mxs_lradc *lradc = iio_priv(iio_dev);
> int ret;
> - unsigned long mask;
> -
> - if (m != IIO_CHAN_INFO_RAW)
> - return -EINVAL;
> -
> - /* Check for invalid channel */
> - if (chan->channel > LRADC_MAX_TOTAL_CHANS)
> - return -EINVAL;
This was already resolved, so this patch won't apply I'm afraid.
> - /* Validate the channel if it doesn't intersect with reserved chans. */
> - bitmap_set(&mask, chan->channel, 1);
> - ret = iio_validate_scan_mask_onehot(iio_dev, &mask);
> - if (ret)
> - return -EINVAL;
> -
> - /*
> - * See if there is no buffered operation in progess. If there is, simply
> - * bail out. This can be improved to support both buffered and raw IO at
> - * the same time, yet the code becomes horribly complicated. Therefore I
> - * applied KISS principle here.
> - */
> - ret = mutex_trylock(&lradc->lock);
> - if (!ret)
> - return -EBUSY;
>
> INIT_COMPLETION(lradc->completion);
>
> @@ -300,6 +275,47 @@ err:
> writel(LRADC_CTRL1_LRADC_IRQ_EN(0),
> lradc->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
>
> + return ret;
> +}
> +
> +/*
> + * Raw I/O operations
> + */
> +static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
> + const struct iio_chan_spec *chan,
> + int *val, int *val2, long m)
> +{
> + struct mxs_lradc *lradc = iio_priv(iio_dev);
> + int ret;
> +
> + /*
> + * See if there is no buffered operation in progress. If there is,
simply
> + * bail out. This can be improved to support both buffered and raw IO at
> + * the same time, yet the code becomes horribly complicated. Therefore I
> + * applied KISS principle here.
> + */
> + ret = mutex_trylock(&lradc->lock);
> + if (!ret)
> + return -EBUSY;
> +
> + /* Check for invalid channel */
> + if (chan->channel > LRADC_MAX_TOTAL_CHANS)
> + ret = -EINVAL;
> +
> + switch (m) {
> + case IIO_CHAN_INFO_RAW:
> + ret = mxs_lradc_read_single(iio_dev, chan, val, val2, m);
> + break;
> + case IIO_CHAN_INFO_SCALE:
> + *val = lradc->vref_mv[chan->channel];
> + *val2 = chan->scan_type.realbits;
> + ret = IIO_VAL_FRACTIONAL_LOG2;
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +
> mutex_unlock(&lradc->lock);
>
> return ret;
> @@ -821,7 +837,8 @@ static const struct iio_buffer_setup_ops
> mxs_lradc_buffer_ops = { .type = (chan_type),
\
> .indexed = 1, \
> .scan_index = (idx), \
> - .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> + BIT(IIO_CHAN_INFO_SCALE), \
> .channel = (idx), \
> .scan_type = { \
> .sign = 'u', \
> @@ -960,6 +977,12 @@ static int mxs_lradc_probe(struct platform_device
> *pdev) goto err_addr;
> }
>
> + /* Grab Vref array from DT */
> + ret = of_property_read_u32_array(node, "fsl,vref", lradc->vref_mv,
> + LRADC_MAX_TOTAL_CHANS);
> + if (ret)
> + goto err_addr;
> +
> platform_set_drvdata(pdev, iio);
>
> init_completion(&lradc->completion);
Otherwise:
Acked-by: Marek Vasut <marex@xxxxxxx>
Marek Vasut
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