Re: [PATCH 4/4] iio: mpl3115: Use scan_type.shift and realbit in mpl3115_read_raw

[Jonathan Cameron <jic23@kernel.org>]

On Mon,  1 Nov 2021 00:18:22 -0700
Gwendal Grignou <gwendal@chromium.org> wrote:

> When processing raw data using channel scan_type.shift as source of
> trust to shift data appropriately.
> When processing the temperature channel, use a 16bit big endian variable
> as buffer to increase conversion readability.
> 
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>

This one looks fine to me, will pick up when rest are read if no
one else comments,

Jonathan

> ---
>  drivers/iio/pressure/mpl3115.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iio/pressure/mpl3115.c b/drivers/iio/pressure/mpl3115.c
> index 1eb9e7b29e050..e95b9a5475b4e 100644
> --- a/drivers/iio/pressure/mpl3115.c
> +++ b/drivers/iio/pressure/mpl3115.c
> @@ -74,7 +74,6 @@ static int mpl3115_read_raw(struct iio_dev *indio_dev,
>  			    int *val, int *val2, long mask)
>  {
>  	struct mpl3115_data *data = iio_priv(indio_dev);
> -	__be32 tmp = 0;
>  	int ret;
>  
>  	switch (mask) {
> @@ -84,7 +83,9 @@ static int mpl3115_read_raw(struct iio_dev *indio_dev,
>  			return ret;
>  
>  		switch (chan->type) {
> -		case IIO_PRESSURE: /* in 0.25 pascal / LSB */
> +		case IIO_PRESSURE: { /* in 0.25 pascal / LSB */
> +			__be32 tmp = 0;
> +
>  			mutex_lock(&data->lock);
>  			ret = mpl3115_request(data);
>  			if (ret < 0) {
> @@ -96,10 +97,13 @@ static int mpl3115_read_raw(struct iio_dev *indio_dev,
>  			mutex_unlock(&data->lock);
>  			if (ret < 0)
>  				break;
> -			*val = be32_to_cpu(tmp) >> 12;
> +			*val = be32_to_cpu(tmp) >> chan->scan_type.shift;
>  			ret = IIO_VAL_INT;
>  			break;
> -		case IIO_TEMP: /* in 0.0625 celsius / LSB */
> +		}
> +		case IIO_TEMP: { /* in 0.0625 celsius / LSB */
> +			__be16 tmp;
> +
>  			mutex_lock(&data->lock);
>  			ret = mpl3115_request(data);
>  			if (ret < 0) {
> @@ -111,9 +115,11 @@ static int mpl3115_read_raw(struct iio_dev *indio_dev,
>  			mutex_unlock(&data->lock);
>  			if (ret < 0)
>  				break;
> -			*val = sign_extend32(be32_to_cpu(tmp) >> 20, 11);
> +			*val = sign_extend32(be16_to_cpu(tmp) >> chan->scan_type.shift,
> +					     chan->scan_type.realbits - 1);
>  			ret = IIO_VAL_INT;
>  			break;
> +		}
>  		default:
>  			ret = -EINVAL;
>  			break;