From a8f65ba3c2655125c4933f2f6a7e1f4938859bba Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Tue, 8 Dec 2020 14:33:53 +0200 Subject: drm/dsc: add helper for calculating rc buffer size from DPCD Add a helper for calculating the rc buffer size from the DCPD offsets DP_DSC_RC_BUF_BLK_SIZE and DP_DSC_RC_BUF_SIZE. Cc: Alex Deucher Cc: Harry Wentland Cc: Manasi Navare Cc: Vandita Kulkarni Reviewed-by: Vandita Kulkarni Acked-by: Daniel Vetter Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/6c6aee22740fe7a8cf2b8e768bfda378850cf59a.1607429866.git.jani.nikula@intel.com --- drivers/gpu/drm/drm_dsc.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'drivers') diff --git a/drivers/gpu/drm/drm_dsc.c b/drivers/gpu/drm/drm_dsc.c index 09afbc01ea94..ff602f7ec65b 100644 --- a/drivers/gpu/drm/drm_dsc.c +++ b/drivers/gpu/drm/drm_dsc.c @@ -49,6 +49,33 @@ void drm_dsc_dp_pps_header_init(struct dp_sdp_header *pps_header) } EXPORT_SYMBOL(drm_dsc_dp_pps_header_init); +/** + * drm_dsc_dp_rc_buffer_size - get rc buffer size in bytes + * @rc_buffer_block_size: block size code, according to DPCD offset 62h + * @rc_buffer_size: number of blocks - 1, according to DPCD offset 63h + * + * return: + * buffer size in bytes, or 0 on invalid input + */ +int drm_dsc_dp_rc_buffer_size(u8 rc_buffer_block_size, u8 rc_buffer_size) +{ + int size = 1024 * (rc_buffer_size + 1); + + switch (rc_buffer_block_size) { + case DP_DSC_RC_BUF_BLK_SIZE_1: + return 1 * size; + case DP_DSC_RC_BUF_BLK_SIZE_4: + return 4 * size; + case DP_DSC_RC_BUF_BLK_SIZE_16: + return 16 * size; + case DP_DSC_RC_BUF_BLK_SIZE_64: + return 64 * size; + default: + return 0; + } +} +EXPORT_SYMBOL(drm_dsc_dp_rc_buffer_size); + /** * drm_dsc_pps_payload_pack() - Populates the DSC PPS * -- cgit v1.2.3