[PATCH v1 1/2] DRM: Create new Content Protection connector property

[PATCH v1 1/2] DRM: Create new Content Protection connector property

[Mark Yacoub]

From: Mark Yacoub <markyacoub@chromium.org>

[Why]
To enable Protected Content, some drivers require a key to be injected
from user space to enable HDCP on the connector.

[How]
Create new "Content Protection Property" of type "Blob"

Signed-off-by: Mark Yacoub <markyacoub@chromium.org>
---
 drivers/gpu/drm/drm_atomic_uapi.c | 9 +++++++++
 include/drm/drm_connector.h       | 6 ++++++
 include/drm/drm_mode_config.h     | 6 ++++++
 3 files changed, 21 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index d867e7f9f2cd5..e20bc57cdb05c 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -749,6 +749,11 @@ static int drm_atomic_connector_set_property(struct drm_connector *connector,
 		state->content_protection = val;
 	} else if (property == config->hdcp_content_type_property) {
 		state->hdcp_content_type = val;
+	} else if (property == config->content_protection_key_property) {
+		ret = drm_atomic_replace_property_blob_from_id(
+			dev, &state->content_protection_key, val, -1, -1,
+			&replaced);
+		return ret;
 	} else if (property == connector->colorspace_property) {
 		state->colorspace = val;
 	} else if (property == config->writeback_fb_id_property) {
@@ -843,6 +848,10 @@ drm_atomic_connector_get_property(struct drm_connector *connector,
 		*val = state->content_protection;
 	} else if (property == config->hdcp_content_type_property) {
 		*val = state->hdcp_content_type;
+	} else if (property == config->content_protection_key_property) {
+		*val = state->content_protection_key ?
+			       state->content_protection_key->base.id :
+			       0;
 	} else if (property == config->writeback_fb_id_property) {
 		/* Writeback framebuffer is one-shot, write and forget */
 		*val = 0;
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 7b5048516185c..2fbe51272bfeb 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -896,6 +896,12 @@ struct drm_connector_state {
 	 */
 	unsigned int content_protection;
 
+	/**
+	 * @content_protection_key: DRM blob property for holding the Content
+	 * Protection Key injected from user space.
+	 */
+	struct drm_property_blob *content_protection_key;
+
 	/**
 	 * @colorspace: State variable for Connector property to request
 	 * colorspace change on Sink. This is most commonly used to switch
diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index e5b053001d22e..615d1e5f57562 100644
--- a/include/drm/drm_mode_config.h
+++ b/include/drm/drm_mode_config.h
@@ -887,6 +887,12 @@ struct drm_mode_config {
 	 */
 	struct drm_property *hdcp_content_type_property;
 
+	/**
+	 * @content_protection_key_property: DRM blob property that receives the 
+	 * content protection key from user space to be injected into the kernel.
+	 */
+	struct drm_property *content_protection_key_property;
+
 	/* dumb ioctl parameters */
 	uint32_t preferred_depth, prefer_shadow;
 
-- 
2.40.0.634.g4ca3ef3211-goog

[PATCH v1 2/2] dp_hdcp: Get the hdcp key from the connector prop

[Mark Yacoub]

From: Mark Yacoub <markyacoub@chromium.org>

[Why]
To support protected content, the driver requires a key.
Currently, it's being injected from debugfs, which is not super useful
to run a user space in the wild.

[How]
When the key is needed, fetch the "Content Protection Property" on the
connector and get the key blob. Verify that the size is valid and use
it.

Signed-off-by: Mark Yacoub <markyacoub@chromium.org>
---
 drivers/gpu/drm/msm/dp/dp_hdcp.c | 66 +++++++++++++++++++++++++++++---
 1 file changed, 61 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_hdcp.c b/drivers/gpu/drm/msm/dp/dp_hdcp.c
index 191340971f943..4321d245b36c9 100644
--- a/drivers/gpu/drm/msm/dp/dp_hdcp.c
+++ b/drivers/gpu/drm/msm/dp/dp_hdcp.c
@@ -117,19 +117,61 @@ static bool dp_hdcp_are_keys_valid(struct drm_connector *connector,
 	return FIELD_GET(DP_HDCP_KEY_STATUS, val) == DP_HDCP_KEY_STATUS_VALID;
 }
 
+static bool dp_hdcp_get_key_from_connector(struct drm_connector *connector,
+					   struct drm_bridge *bridge)
+{
+	struct drm_property_blob *key_blob;
+	u8 *raw_key;
+	int ret;
+	struct dp_hdcp *hdcp;
+	struct drm_device *dev = connector->dev;
+	struct drm_property *prop =
+		dev->mode_config.content_protection_key_property;
+
+	if (!prop)
+		return false;
+
+	key_blob = connector->state->content_protection_key;
+	if (!key_blob)
+		return false;
+
+	raw_key = key_blob->data;
+
+	if (key_blob->length !=
+	    DRM_HDCP_KSV_LEN + DP_HDCP_NUM_KEYS * DP_HDCP_KEY_LEN) {
+		drm_dbg_atomic(
+			dev,
+			"[CONNECTOR:%d:%s] Content Protection Key is a blob that we don't expect.\n",
+			connector->base.id, connector->name);
+		return false;
+	}
+
+	hdcp = dp_display_bridge_to_hdcp(bridge);
+	ret = dp_hdcp_ingest_key(hdcp, key_blob->data, key_blob->length);
+	if (ret)
+		return false;
+
+	return true;
+}
+
 static int dp_hdcp_load_keys(struct drm_connector *connector, void *driver_data)
 {
 	struct drm_bridge *bridge = (struct drm_bridge *)driver_data;
 	struct dp_hdcp *hdcp = dp_display_bridge_to_hdcp(bridge);
 	int i, ret = 0;
+	bool is_hdcp_key_valid;
 
 	mutex_lock(&hdcp->key_lock);
+	is_hdcp_key_valid = hdcp->key.valid;
+	mutex_unlock(&hdcp->key_lock);
 
-	if (!hdcp->key.valid) {
-		ret = -ENOENT;
-		goto out;
+	if (!is_hdcp_key_valid &&
+	    !dp_hdcp_get_key_from_connector(connector, bridge)) {
+		return -ENOENT;
 	}
 
+	mutex_lock(&hdcp->key_lock);
+
 	dp_catalog_hdcp_write_aksv(hdcp->catalog, hdcp->key.ksv.words);
 
 
@@ -139,7 +181,6 @@ static int dp_hdcp_load_keys(struct drm_connector *connector, void *driver_data)
 	}
 	dp_catalog_hdcp_post_write_key(hdcp->catalog);
 
-out:
 	mutex_unlock(&hdcp->key_lock);
 	return ret;
 }
@@ -346,6 +387,8 @@ int dp_hdcp_attach(struct dp_hdcp *hdcp, struct drm_connector *connector,
 		   struct drm_bridge *bridge, struct dp_catalog *catalog)
 {
 	struct drm_hdcp_helper_data *helper_data;
+	struct drm_device *dev;
+	struct drm_property *prop;
 
 	/* HDCP is not configured for this device */
 	if (!hdcp->parser->io.dp_controller.hdcp_key.base)
@@ -357,7 +400,20 @@ int dp_hdcp_attach(struct dp_hdcp *hdcp, struct drm_connector *connector,
 		return PTR_ERR(helper_data);
 
 	helper_data->driver_data = bridge;
-	hdcp->dev = connector->dev;
+
+	dev = connector->dev;
+	prop = dev->mode_config.content_protection_key_property;
+	if (!prop) {
+		prop = drm_property_create(dev, DRM_MODE_PROP_BLOB,
+					   "Content Protection Key", 0);
+	}
+	if (!prop)
+		return -1;
+	drm_object_attach_property(&connector->base, prop,
+				   DRM_MODE_HDCP_CONTENT_TYPE0);
+	dev->mode_config.content_protection_key_property = prop;
+
+	hdcp->dev = dev;
 	hdcp->connector = connector;
 	hdcp->helper_data = helper_data;
 	hdcp->catalog = catalog;
-- 
2.40.0.634.g4ca3ef3211-goog