From 7df1ed6ddf3da52b020ef3c3f5597bc628c3e58e Mon Sep 17 00:00:00 2001 From: Jessica Zhang Date: Wed, 24 May 2023 10:45:14 -0700 Subject: drm/display/dsc: Add flatness and initial scale value calculations Add helpers to calculate det_thresh_flatness and initial_scale_value as these calculations are defined within the DSC spec. Reviewed-by: Marijn Suijten Reviewed-by: Dmitry Baryshkov Signed-off-by: Jessica Zhang Patchwork: https://patchwork.freedesktop.org/patch/539282/ Link: https://lore.kernel.org/r/20230329-rfc-msm-dsc-helper-v14-1-bafc7be95691@quicinc.com Signed-off-by: Dmitry Baryshkov --- drivers/gpu/drm/display/drm_dsc_helper.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'drivers/gpu/drm/display') diff --git a/drivers/gpu/drm/display/drm_dsc_helper.c b/drivers/gpu/drm/display/drm_dsc_helper.c index fc187a8d8873..4efb6236d22c 100644 --- a/drivers/gpu/drm/display/drm_dsc_helper.c +++ b/drivers/gpu/drm/display/drm_dsc_helper.c @@ -1413,3 +1413,27 @@ int drm_dsc_compute_rc_parameters(struct drm_dsc_config *vdsc_cfg) return 0; } EXPORT_SYMBOL(drm_dsc_compute_rc_parameters); + +/** + * drm_dsc_initial_scale_value() - Calculate the initial scale value for the given DSC config + * @dsc: Pointer to DRM DSC config struct + * + * Return: Calculated initial scale value + */ +u8 drm_dsc_initial_scale_value(const struct drm_dsc_config *dsc) +{ + return 8 * dsc->rc_model_size / (dsc->rc_model_size - dsc->initial_offset); +} +EXPORT_SYMBOL(drm_dsc_initial_scale_value); + +/** + * drm_dsc_flatness_det_thresh() - Calculate the flatness_det_thresh for the given DSC config + * @dsc: Pointer to DRM DSC config struct + * + * Return: Calculated flatness det thresh value + */ +u32 drm_dsc_flatness_det_thresh(const struct drm_dsc_config *dsc) +{ + return 2 << (dsc->bits_per_component - 8); +} +EXPORT_SYMBOL(drm_dsc_flatness_det_thresh); -- cgit v1.2.3