From: Ville Syrjälä <ville.syrj...@linux.intel.com>
Add a few helpers to let us better identify which kind of DFP
we're dealing with.
Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com>
---
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 c21bbfc3d714..0fcb94f7dbe5 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 86461a40066b..4f946826dfce 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],
--
2.26.2
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
