[PATCH 1/2] drm: report dp downstream port type as a subconnector property

[Oleg Vasilev <oleg.vasilev@intel.com>]

Currently, downstream port type is only reported in debugfs. This
information should be considered important since it reflects the actual
physical connector type. Some userspace (e.g. window compositors)
may want to show this info to a user.

The 'subconnector' property is already utilized for DVI-I and TV-out for
reporting connector subtype.

The initial motivation for this feature came from i2c test [1].
It is supposed to be skipped on VGA connectors, but it cannot
detect VGA over DP and fails instead.

[1]: https://bugs.freedesktop.org/show_bug.cgi?id=104097
Signed-off-by: Oleg Vasilev <oleg.vasilev@intel.com>
---
 drivers/gpu/drm/drm_connector.c | 38 +++++++++++++++++++++++++++++++--
 drivers/gpu/drm/drm_dp_helper.c | 36 +++++++++++++++++++++++++++++++
 include/drm/drm_connector.h     |  2 ++
 include/drm/drm_dp_helper.h     |  3 +++
 include/drm/drm_mode_config.h   |  6 ++++++
 include/uapi/drm/drm_mode.h     | 22 ++++++++++++-------
 6 files changed, 97 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 068d4b05f1be..95cd51254be6 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -793,7 +793,7 @@ static const struct drm_prop_enum_list drm_dvi_i_select_enum_list[] = {
 DRM_ENUM_NAME_FN(drm_get_dvi_i_select_name, drm_dvi_i_select_enum_list)
 
 static const struct drm_prop_enum_list drm_dvi_i_subconnector_enum_list[] = {
-	{ DRM_MODE_SUBCONNECTOR_Unknown,   "Unknown"   }, /* DVI-I and TV-out */
+	{ DRM_MODE_SUBCONNECTOR_Unknown,   "Unknown"   }, /* DVI-I, TV-out and DP */
 	{ DRM_MODE_SUBCONNECTOR_DVID,      "DVI-D"     }, /* DVI-I  */
 	{ DRM_MODE_SUBCONNECTOR_DVIA,      "DVI-A"     }, /* DVI-I  */
 };
@@ -810,7 +810,7 @@ static const struct drm_prop_enum_list drm_tv_select_enum_list[] = {
 DRM_ENUM_NAME_FN(drm_get_tv_select_name, drm_tv_select_enum_list)
 
 static const struct drm_prop_enum_list drm_tv_subconnector_enum_list[] = {
-	{ DRM_MODE_SUBCONNECTOR_Unknown,   "Unknown"   }, /* DVI-I and TV-out */
+	{ DRM_MODE_SUBCONNECTOR_Unknown,   "Unknown"   }, /* DVI-I, TV-out and DP */
 	{ DRM_MODE_SUBCONNECTOR_Composite, "Composite" }, /* TV-out */
 	{ DRM_MODE_SUBCONNECTOR_SVIDEO,    "SVIDEO"    }, /* TV-out */
 	{ DRM_MODE_SUBCONNECTOR_Component, "Component" }, /* TV-out */
@@ -819,6 +819,19 @@ static const struct drm_prop_enum_list drm_tv_subconnector_enum_list[] = {
 DRM_ENUM_NAME_FN(drm_get_tv_subconnector_name,
 		 drm_tv_subconnector_enum_list)
 
+static const struct drm_prop_enum_list drm_dp_subconnector_enum_list[] = {
+	{ DRM_MODE_SUBCONNECTOR_Unknown,   "Unknown"   }, /* DVI-I, TV-out and DP */
+	{ DRM_MODE_SUBCONNECTOR_VGA,	   "VGA"       }, /* DP */
+	{ DRM_MODE_SUBCONNECTOR_DVI,	   "DVI"       }, /* DP */
+	{ DRM_MODE_SUBCONNECTOR_HDMI,	   "HDMI"      }, /* DP */
+	{ DRM_MODE_SUBCONNECTOR_DP,        "DP"        }, /* DP */
+	{ DRM_MODE_SUBCONNECTOR_Wireless,  "Wireless"  }, /* DP */
+	{ DRM_MODE_SUBCONNECTOR_Native,	   "Native"    }, /* DP */
+};
+
+DRM_ENUM_NAME_FN(drm_get_dp_subconnector_name,
+		 drm_dp_subconnector_enum_list)
+
 static const struct drm_prop_enum_list hdmi_colorspaces[] = {
 	/* For Default case, driver will set the colorspace */
 	{ DRM_MODE_COLORIMETRY_DEFAULT, "Default" },
@@ -1128,6 +1141,27 @@ int drm_mode_create_dvi_i_properties(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_mode_create_dvi_i_properties);
 
+/**
+ * drm_mode_create_dp_properties - create DP specific connector properties
+ * @dev: DRM device
+ *
+ * Called by a driver the first time a DP connector is made.
+ */
+void drm_mode_create_dp_properties(struct drm_device *dev)
+{
+	struct drm_property *dp_subconnector;
+
+	if (dev->mode_config.dp_subconnector_property)
+		return;
+
+	dp_subconnector = drm_property_create_enum(dev, DRM_MODE_PROP_IMMUTABLE,
+						   "subconnector",
+						   drm_dp_subconnector_enum_list,
+						   ARRAY_SIZE(drm_dp_subconnector_enum_list));
+	dev->mode_config.dp_subconnector_property = dp_subconnector;
+}
+EXPORT_SYMBOL(drm_mode_create_dp_properties);
+
 /**
  * DOC: HDMI connector properties
  *
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 0b994d083a89..63d8f0b8492c 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -662,6 +662,42 @@ void drm_dp_downstream_debug(struct seq_file *m,
 }
 EXPORT_SYMBOL(drm_dp_downstream_debug);
 
+/**
+ * drm_dp_downstream_subconnector_type() - get DP branch device type
+ * @dpcd: DisplayPort configuration data
+ * @port_cap: port capabilities
+ *
+ */
+enum drm_mode_subconnector
+drm_dp_downstream_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+				    const u8 port_cap[4])
+{
+	int type = port_cap[0] & DP_DS_PORT_TYPE_MASK;
+	bool branch_device_present = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
+				     DP_DWN_STRM_PORT_PRESENT;
+
+	if (!branch_device_present)
+		return DRM_MODE_SUBCONNECTOR_Native;
+
+	switch (type) {
+	case DP_DS_PORT_TYPE_DP:
+	case DP_DS_PORT_TYPE_DP_DUALMODE:
+		return DRM_MODE_SUBCONNECTOR_DP;
+	case DP_DS_PORT_TYPE_VGA:
+		return DRM_MODE_SUBCONNECTOR_VGA;
+	case DP_DS_PORT_TYPE_DVI:
+		return DRM_MODE_SUBCONNECTOR_DVI;
+	case DP_DS_PORT_TYPE_HDMI:
+		return DRM_MODE_SUBCONNECTOR_HDMI;
+	case DP_DS_PORT_TYPE_WIRELESS:
+		return DRM_MODE_SUBCONNECTOR_Wireless;
+	case DP_DS_PORT_TYPE_NON_EDID:
+	default:
+		return DRM_MODE_SUBCONNECTOR_Unknown;
+	}
+}
+EXPORT_SYMBOL(drm_dp_downstream_subconnector_type);
+
 /*
  * I2C-over-AUX implementation
  */
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 4c30d751487a..66f0b2a59c9c 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -1483,9 +1483,11 @@ const char *drm_get_dvi_i_subconnector_name(int val);
 const char *drm_get_dvi_i_select_name(int val);
 const char *drm_get_tv_subconnector_name(int val);
 const char *drm_get_tv_select_name(int val);
+const char *drm_get_dp_subconnector_name(int val);
 const char *drm_get_content_protection_name(int val);
 
 int drm_mode_create_dvi_i_properties(struct drm_device *dev);
+void drm_mode_create_dp_properties(struct drm_device *dev);
 int drm_mode_create_tv_margin_properties(struct drm_device *dev);
 int drm_mode_create_tv_properties(struct drm_device *dev,
 				  unsigned int num_modes,
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 397896b5b21a..38792c1afed8 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1372,6 +1372,9 @@ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
 int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]);
 void drm_dp_downstream_debug(struct seq_file *m, const u8 dpcd[DP_RECEIVER_CAP_SIZE],
 			     const u8 port_cap[4], struct drm_dp_aux *aux);
+enum drm_mode_subconnector
+drm_dp_downstream_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+				    const u8 port_cap[4]);
 
 void drm_dp_aux_init(struct drm_dp_aux *aux);
 int drm_dp_aux_register(struct drm_dp_aux *aux);
diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index 759d462d028b..957d99a34843 100644
--- a/include/drm/drm_mode_config.h
+++ b/include/drm/drm_mode_config.h
@@ -680,6 +680,12 @@ struct drm_mode_config {
 	 */
 	struct drm_property *dvi_i_select_subconnector_property;
 
+	/**
+	 * @dp_subconnector_property: Optional DP property to differentiate
+	 * between different DP downstream port types.
+	 */
+	struct drm_property *dp_subconnector_property;
+
 	/**
 	 * @tv_subconnector_property: Optional TV property to differentiate
 	 * between different TV connector types.
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
index 5ab331e5dc23..9808464bdb63 100644
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -332,14 +332,20 @@ struct drm_mode_get_encoder {
 /* This is for connectors with multiple signal types. */
 /* Try to match DRM_MODE_CONNECTOR_X as closely as possible. */
 enum drm_mode_subconnector {
-	DRM_MODE_SUBCONNECTOR_Automatic = 0,
-	DRM_MODE_SUBCONNECTOR_Unknown = 0,
-	DRM_MODE_SUBCONNECTOR_DVID = 3,
-	DRM_MODE_SUBCONNECTOR_DVIA = 4,
-	DRM_MODE_SUBCONNECTOR_Composite = 5,
-	DRM_MODE_SUBCONNECTOR_SVIDEO = 6,
-	DRM_MODE_SUBCONNECTOR_Component = 8,
-	DRM_MODE_SUBCONNECTOR_SCART = 9,
+	DRM_MODE_SUBCONNECTOR_Automatic  = 0,  /* DVI-I, TV     */
+	DRM_MODE_SUBCONNECTOR_Unknown    = 0,  /* DVI-I, TV, DP */
+	DRM_MODE_SUBCONNECTOR_VGA	 = 1,  /*            DP */
+	DRM_MODE_SUBCONNECTOR_DVI	 = 2,  /*            DP */
+	DRM_MODE_SUBCONNECTOR_DVID	 = 3,  /* DVI-I         */
+	DRM_MODE_SUBCONNECTOR_DVIA	 = 4,  /* DVI-I         */
+	DRM_MODE_SUBCONNECTOR_Composite  = 5,  /*        TV     */
+	DRM_MODE_SUBCONNECTOR_SVIDEO	 = 6,  /*        TV     */
+	DRM_MODE_SUBCONNECTOR_Component  = 8,  /*        TV     */
+	DRM_MODE_SUBCONNECTOR_SCART	 = 9,  /*        TV     */
+	DRM_MODE_SUBCONNECTOR_DP	 = 10, /*            DP */
+	DRM_MODE_SUBCONNECTOR_HDMI       = 11, /*            DP */
+	DRM_MODE_SUBCONNECTOR_Native     = 15, /*            DP */
+	DRM_MODE_SUBCONNECTOR_Wireless   = 19, /*            DP */
 };
 
 #define DRM_MODE_CONNECTOR_Unknown	0
-- 
2.22.0

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