Hi Kieran,
Thank you for the patch.
On Mon, May 13, 2019 at 09:13:54PM +0100, Kieran Bingham wrote:
> The 'mp' value is used through several calculations in determining the
> scaling factors of the UDS. This determines the pre-scaling filter
> binning value. Factor this out so that it can be reused in further
> calculations, and also ensure that if the BLADV control is ever changed
> only a single function needs to be modified.
>
> Signed-off-by: Kieran Bingham <kieran.bingham+rene...@ideasonboard.com>
> ---
> drivers/media/platform/vsp1/vsp1_uds.c | 26 ++++++++++++++++++--------
> 1 file changed, 18 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/media/platform/vsp1/vsp1_uds.c
> b/drivers/media/platform/vsp1/vsp1_uds.c
> index 27012af973b2..effebfc0c862 100644
> --- a/drivers/media/platform/vsp1/vsp1_uds.c
> +++ b/drivers/media/platform/vsp1/vsp1_uds.c
> @@ -46,6 +46,22 @@ void vsp1_uds_set_alpha(struct vsp1_entity *entity, struct
> vsp1_dl_body *dlb,
> alpha << VI6_UDS_ALPVAL_VAL0_SHIFT);
> }
>
> +/*
> + * Determine the pre-filter binning divider.
> + *
> + * The UDS uses a two stage filter scaler process. This determines the
> + * rate at which pixels are reduced for large down-scaling ratios before
I would say "reduced by binning". Apart from this,
Reviewed-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
> + * being fed into the bicubic filter.
> + *
> + * This calculation assumes that the BLADV bit is unset.
> + */
> +static unsigned int uds_pre_scaling_divisor(int ratio)
> +{
> + unsigned int mp = ratio / 4096;
> +
> + return mp < 4 ? 1 : (mp < 8 ? 2 : 4);
> +}
> +
> /*
> * uds_output_size - Return the output size for an input size and scaling
> ratio
> * @input: input size in pixels
> @@ -55,10 +71,7 @@ static unsigned int uds_output_size(unsigned int input,
> unsigned int ratio)
> {
> if (ratio > 4096) {
> /* Down-scaling */
> - unsigned int mp;
> -
> - mp = ratio / 4096;
> - mp = mp < 4 ? 1 : (mp < 8 ? 2 : 4);
> + unsigned int mp = uds_pre_scaling_divisor(ratio);
>
> return (input - 1) / mp * mp * 4096 / ratio + 1;
> } else {
> @@ -88,10 +101,7 @@ static unsigned int uds_passband_width(unsigned int ratio)
> {
> if (ratio >= 4096) {
> /* Down-scaling */
> - unsigned int mp;
> -
> - mp = ratio / 4096;
> - mp = mp < 4 ? 1 : (mp < 8 ? 2 : 4);
> + unsigned int mp = uds_pre_scaling_divisor(ratio);
>
> return 64 * 4096 * mp / ratio;
> } else {
--
Regards,
Laurent Pinchart
