From 38784f6f880580cbe168edbe7ba38c161dee3216 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 4 Sep 2020 14:53:42 +0300 Subject: [PATCH] drm/dp: Add helpers to identify downstream facing port types MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add a few helpers to let us better identify which kind of DFP we're dealing with. v2: Use Returns: for kdoc (Lyude) Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20200904115354.25336-7-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 | 5 ++++ 2 files changed, 65 insertions(+) diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index c21bbfc..56a3ba1 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -363,6 +363,66 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, } EXPORT_SYMBOL(drm_dp_dpcd_read_link_status); +static bool is_edid_digital_input_dp(const struct edid *edid) +{ + return edid && edid->revision >= 4 && + edid->input & DRM_EDID_INPUT_DIGITAL && + (edid->input & DRM_EDID_DIGITAL_TYPE_MASK) == DRM_EDID_DIGITAL_TYPE_DP; +} + +/** + * drm_dp_downstream_is_type() - is the downstream facing port of certain type? + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * + * Caveat: Only works with DPCD 1.1+ port caps. + * + * Returns: whether the downstream facing port matches the type. + */ +bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], u8 type) +{ + return drm_dp_is_branch(dpcd) && + dpcd[DP_DPCD_REV] >= 0x11 && + (port_cap[0] & DP_DS_PORT_TYPE_MASK) == type; +} +EXPORT_SYMBOL(drm_dp_downstream_is_type); + +/** + * drm_dp_downstream_is_tmds() - is the downstream facing port TMDS? + * @dpcd: DisplayPort configuration data + * @port_cap: port capabilities + * @edid: EDID + * + * Returns: whether the downstream facing port is TMDS (HDMI/DVI). + */ +bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct edid *edid) +{ + if (dpcd[DP_DPCD_REV] < 0x11) { + switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) { + case DP_DWN_STRM_PORT_TYPE_TMDS: + return true; + default: + return false; + } + } + + switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) { + case DP_DS_PORT_TYPE_DP_DUALMODE: + if (is_edid_digital_input_dp(edid)) + return false; + fallthrough; + case DP_DS_PORT_TYPE_DVI: + case DP_DS_PORT_TYPE_HDMI: + return true; + default: + return false; + } +} +EXPORT_SYMBOL(drm_dp_downstream_is_tmds); + /** * drm_dp_send_real_edid_checksum() - send back real edid checksum value * @aux: DisplayPort AUX channel diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 86461a4..4f94682 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1638,6 +1638,11 @@ bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux, int drm_dp_read_downstream_info(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE], u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]); +bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], u8 type); +bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE], + const u8 port_cap[4], + const struct edid *edid); int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], const u8 port_cap[4]); int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], -- 2.7.4