From 2ef8d0f7de0ec0bc30c48e5f544a6082eb03e9f7 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 4 Sep 2020 14:53:53 +0300 Subject: [PATCH] drm/dp: Add helpers for DFP YCbCr 4:2:0 handling MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add helpers to determine whether the DFP supports YCbCr 4:2:0 passthrough or YCbCr 4:4:4->4:2:0 conversion. v2: Add kdocs (Lyude) Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200904115354.25336-18-ville.syrjala@linux.intel.com Reviewed-by: Lyude Paul Acked-by: Daniel Vetter --- drivers/gpu/drm/drm_dp_helper.c | 60 +++++++++++++++++++++++++++++++++ include/drm/drm_dp_helper.h | 8 +++++ 2 files changed, 68 insertions(+) diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 63ac94c54e95..90807a6b415c 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -808,6 +808,66 @@ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], } EXPORT_SYMBOL(drm_dp_downstream_max_bpc); +/** + * drm_dp_downstream_420_passthrough() - determine downstream facing port + * YCbCr 4:2:0 pass-through capability + * @dpcd: DisplayPort configuration data + * @port_cap: downstream facing port capabilities + * + * Returns: whether the downstream facing port can pass through YCbCr 4:2:0 + */ +bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + if (!drm_dp_is_branch(dpcd)) + return false; + + if (dpcd[DP_DPCD_REV] < 0x13) + return false; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP: + return true; + case DP_DS_PORT_TYPE_HDMI: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return false; + + return port_cap[3] & DP_DS_HDMI_YCBCR420_PASS_THROUGH; + default: + return false; + } +} +EXPORT_SYMBOL(drm_dp_downstream_420_passthrough); + +/** + * drm_dp_downstream_444_to_420_conversion() - determine downstream facing port + * YCbCr 4:4:4->4:2:0 conversion capability + * @dpcd: DisplayPort configuration data + * @port_cap: downstream facing port capabilities + * + * Returns: whether the downstream facing port can convert YCbCr 4:4:4 to 4:2:0 + */ +bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]) +{ + if (!drm_dp_is_branch(dpcd)) + return false; + + if (dpcd[DP_DPCD_REV] < 0x13) + return false; + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_HDMI: + if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0) + return false; + + return port_cap[3] & DP_DS_HDMI_YCBCR444_TO_420_CONV; + default: + return false; + } +} +EXPORT_SYMBOL(drm_dp_downstream_444_to_420_conversion); + /** * drm_dp_downstream_mode() - return a mode for downstream facing port * @dpcd: DisplayPort configuration data diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index fbba4a0f7366..c9f2851904d0 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -407,6 +407,10 @@ struct drm_device; # define DP_DS_DVI_HIGH_COLOR_DEPTH (1 << 2) /* offset 3 for HDMI */ # define DP_DS_HDMI_FRAME_SEQ_TO_FRAME_PACK (1 << 0) +# define DP_DS_HDMI_YCBCR422_PASS_THROUGH (1 << 1) +# define DP_DS_HDMI_YCBCR420_PASS_THROUGH (1 << 2) +# define DP_DS_HDMI_YCBCR444_TO_422_CONV (1 << 3) +# define DP_DS_HDMI_YCBCR444_TO_420_CONV (1 << 4) #define DP_MAX_DOWNSTREAM_PORTS 0x10 @@ -1663,6 +1667,10 @@ int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], const u8 port_cap[4], const struct edid *edid); +bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]); +bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4]); struct drm_display_mode *drm_dp_downstream_mode(struct drm_device *dev, const u8 dpcd[DP_RECEIVER_CAP_SIZE], const u8 port_cap[4]); -- 2.49.0