[Freedreno] [PATCH v2 3/3] dp_hdcp: Get the hdcp key from the connector prop

[Mark Yacoub]

From: Mark Yacoub <markyac...@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 <markyac...@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