Re: [PATCHv4 3/3] iio: mxs-lradc: add write_raw function to modify scale

[Jonathan Cameron <jic23@kernel.org>]

On 12/07/13 00:24, Alexandre Belloni wrote:
> From: Hector Palacios <hector.palacios@digi.com>
>
> Added write_raw function to manipulate the optional divider_by_two
> through the scaling attribute out of the available scales.
>
> Signed-off-by: Hector Palacios <hector.palacios@digi.com>
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Looks good to me - make that little tiny tweak I mentioned in the previous
patch and I'll be happy to take these.

Thanks,

Jonathan

> ---
>  drivers/staging/iio/adc/mxs-lradc.c | 56 ++++++++++++++++++++++++++++++++++++-
>  1 file changed, 55 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c
> index eca766dce644..a58c6aaa94d3 100644
> --- a/drivers/staging/iio/adc/mxs-lradc.c
> +++ b/drivers/staging/iio/adc/mxs-lradc.c
> @@ -301,6 +301,7 @@ struct mxs_lradc {
>  #define	LRADC_CTRL1_LRADC_IRQ_OFFSET		0
>
>  #define	LRADC_CTRL2				0x20
> +#define	LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET	24
>  #define	LRADC_CTRL2_TEMPSENSE_PWD		(1 << 15)
>
>  #define	LRADC_STATUS				0x40
> @@ -918,7 +919,8 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>  		}
>
>  		*val = lradc->vref_mv[chan->channel];
> -		*val2 = chan->scan_type.realbits;
> +		*val2 = chan->scan_type.realbits -
> +			lradc->is_divided[chan->channel];
>  		return IIO_VAL_FRACTIONAL_LOG2;
>
>  	case IIO_CHAN_INFO_OFFSET:
> @@ -942,6 +944,56 @@ static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
>  	return -EINVAL;
>  }
>
> +static int mxs_lradc_write_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);
> +	struct mxs_lradc_scale *scale_avail =
> +			lradc->scale_avail[chan->channel];
> +	int ret;
> +
> +	ret = mutex_trylock(&lradc->lock);
> +	if (!ret)
> +		return -EBUSY;
> +
> +	switch (m) {
> +	case IIO_CHAN_INFO_SCALE:
> +		ret = -EINVAL;
> +		if (val == scale_avail[MXS_LRADC_DIV_DISABLED].integer &&
> +		    val2 == scale_avail[MXS_LRADC_DIV_DISABLED].nano) {
> +			/* divider by two disabled */
> +			writel(1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
> +			       lradc->base + LRADC_CTRL2 + STMP_OFFSET_REG_CLR);
> +			lradc->is_divided[chan->channel] = 0;
> +			ret = 0;
> +		} else if (val == scale_avail[MXS_LRADC_DIV_ENABLED].integer &&
> +			   val2 == scale_avail[MXS_LRADC_DIV_ENABLED].nano) {
> +			/* divider by two enabled */
> +			writel(1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
> +			       lradc->base + LRADC_CTRL2 + STMP_OFFSET_REG_SET);
> +			lradc->is_divided[chan->channel] = 1;
> +			ret = 0;
> +		}
> +
> +		break;
> +	default:
> +		ret = -EINVAL;
> +		break;
> +	}
> +
> +	mutex_unlock(&lradc->lock);
> +
> +	return ret;
> +}
> +
> +static int mxs_lradc_write_raw_get_fmt(struct iio_dev *iio_dev,
> +				       const struct iio_chan_spec *chan,
> +				       long m)
> +{
> +	return IIO_VAL_INT_PLUS_NANO;
> +}
> +
>  static ssize_t mxs_lradc_show_scale_available_ch(struct device *dev,
>  		struct device_attribute *attr,
>  		char *buf,
> @@ -1019,6 +1071,8 @@ static const struct attribute_group mxs_lradc_attribute_group = {
>  static const struct iio_info mxs_lradc_iio_info = {
>  	.driver_module		= THIS_MODULE,
>  	.read_raw		= mxs_lradc_read_raw,
> +	.write_raw		= mxs_lradc_write_raw,
> +	.write_raw_get_fmt	= mxs_lradc_write_raw_get_fmt,
>  	.attrs			= &mxs_lradc_attribute_group,
>  };
>
>