[Intel-gfx] [PATCH v8 4/6] drm/hdcp: update content protection property with uevent

[Ramalingam C]

drm function is defined and exported to update a connector's
content protection property state and to generate a uevent along
with it.

Need ACK for the uevent from userspace consumer.

v2:
  Update only when state is different from old one.
v3:
  KDoc is added [Daniel]
v4:
  KDoc is extended bit more [pekka]

Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/drm_hdcp.c | 34 ++++++++++++++++++++++++++++++++++
 include/drm/drm_hdcp.h     |  2 ++
 2 files changed, 36 insertions(+)

diff --git a/drivers/gpu/drm/drm_hdcp.c b/drivers/gpu/drm/drm_hdcp.c
index ce235fd1c844..77433ee3d652 100644
--- a/drivers/gpu/drm/drm_hdcp.c
+++ b/drivers/gpu/drm/drm_hdcp.c
@@ -374,6 +374,10 @@ DRM_ENUM_NAME_FN(drm_get_hdcp_content_type_name,
  *
  * The content protection will be set to &drm_connector_state.content_protection
  *
+ * When kernel triggered content protection state change like DESIRED->ENABLED
+ * and ENABLED->DESIRED, will use drm_hdcp_update_content_protection() to update
+ * the content protection state of a connector.
+ *
  * Returns:
  * Zero on success, negative errno on failure.
  */
@@ -414,3 +418,33 @@ int drm_connector_attach_content_protection_property(
 	return 0;
 }
 EXPORT_SYMBOL(drm_connector_attach_content_protection_property);
+
+/**
+ * drm_hdcp_update_content_protection - Updates the content protection state
+ * of a connector
+ *
+ * @connector: drm_connector on which content protection state needs an update
+ * @val: New state of the content protection property
+ *
+ * This function can be used by display drivers, to update the kernel triggered
+ * content protection state changes of a drm_connector such as DESIRED->ENABLED
+ * and ENABLED->DESIRED. No uevent for DESIRED->UNDESIRED or ENABLED->UNDESIRED,
+ * as userspace is triggering such state change and kernel performs it without
+ * fail.This function update the new state of the property into the connector's
+ * state and generate an uevent to notify the userspace.
+ */
+void drm_hdcp_update_content_protection(struct drm_connector *connector,
+					u64 val)
+{
+	struct drm_device *dev = connector->dev;
+	struct drm_connector_state *state = connector->state;
+
+	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
+	if (state->content_protection == val)
+		return;
+
+	state->content_protection = val;
+	drm_sysfs_connector_status_event(connector,
+				 dev->mode_config.content_protection_property);
+}
+EXPORT_SYMBOL(drm_hdcp_update_content_protection);
diff --git a/include/drm/drm_hdcp.h b/include/drm/drm_hdcp.h
index 2970abdfaf12..dd864ac9ce85 100644
--- a/include/drm/drm_hdcp.h
+++ b/include/drm/drm_hdcp.h
@@ -292,4 +292,6 @@ bool drm_hdcp_check_ksvs_revoked(struct drm_device *dev,
 				 u8 *ksvs, u32 ksv_count);
 int drm_connector_attach_content_protection_property(
 		struct drm_connector *connector, bool hdcp_content_type);
+void drm_hdcp_update_content_protection(struct drm_connector *connector,
+					u64 val);
 #endif
-- 
2.19.1