[PATCH v5 11/40] drm/i915: Enable superior HDCP ver that is capable

[Ramalingam C]

Considering that HDCP2.2 is more secure than HDCP1.4, When a setup
supports HDCP2.2 and HDCP1.4, HDCP2.2 will be enabled.

v2:
  Included few optimization suggestions [Chris Wilson]
  Commit message is updated as per the rebased version.
v3:
  No changes.
v4:
  Extra comment added and Style issue fixed [Uma]
v5:
  Rebased as part of patch reordering.
  Flag is added for tracking hdcp2.2 encryption status.

Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
---
 drivers/gpu/drm/i915/intel_drv.h  |  1 +
 drivers/gpu/drm/i915/intel_hdcp.c | 90 +++++++++++++++++++++++++++++++++++----
 2 files changed, 83 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 2eeb82b04953..7624388eecd5 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -414,6 +414,7 @@ struct intel_hdcp {
 
 	/* HDCP2.2 related definitions */
 	bool hdcp2_supported;
+	bool hdcp2_in_use;
 
 	/*
 	 * Content Stream Type defined by content owner. TYPE0(0x0) content can
diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
index 32a1a3f39b65..b34e3b1587d6 100644
--- a/drivers/gpu/drm/i915/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/intel_hdcp.c
@@ -21,6 +21,60 @@
 					 (enum hdcp_physical_port)(port))
 
 static int intel_hdcp2_init(struct intel_connector *connector);
+static int _intel_hdcp2_enable(struct intel_connector *connector);
+static int _intel_hdcp2_disable(struct intel_connector *connector);
+static
+int intel_hdcp_read_valid_bksv(struct intel_digital_port *intel_dig_port,
+			       const struct intel_hdcp_shim *shim, u8 *bksv);
+static
+struct intel_digital_port *conn_to_dig_port(struct intel_connector *connector);
+
+static bool panel_supports_hdcp(struct intel_connector *connector)
+{
+	struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
+	struct intel_hdcp *hdcp = &connector->hdcp;
+	bool capable = false;
+	u8 bksv[5];
+
+	if (hdcp->hdcp_shim) {
+		if (hdcp->hdcp_shim->hdcp_capable) {
+			hdcp->hdcp_shim->hdcp_capable(intel_dig_port, &capable);
+		} else {
+			if (!intel_hdcp_read_valid_bksv(intel_dig_port,
+							hdcp->hdcp_shim, bksv))
+				capable = true;
+		}
+	}
+
+	return capable;
+}
+
+static inline
+bool panel_supports_hdcp2(struct intel_connector *connector)
+{
+	struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
+	struct intel_hdcp *hdcp = &connector->hdcp;
+	bool capable = false;
+
+	/* Check the panel's hdcp2.2 compliance if platform supports it. */
+	if (hdcp->hdcp2_supported)
+		hdcp->hdcp_shim->hdcp_2_2_capable(intel_dig_port, &capable);
+
+	return capable;
+}
+
+/* Is HDCP1.4 capable on Platform and Panel */
+static inline bool intel_hdcp_capable(struct intel_connector *connector)
+{
+	return (connector->hdcp.hdcp_shim && panel_supports_hdcp(connector));
+}
+
+/* Is HDCP2.2 capable on Platform and Panel */
+static inline bool intel_hdcp2_capable(struct intel_connector *connector)
+{
+	return (connector->hdcp.hdcp2_supported &&
+		panel_supports_hdcp2(connector));
+}
 
 static int intel_hdcp_poll_ksv_fifo(struct intel_digital_port *intel_dig_port,
 				    const struct intel_hdcp_shim *shim)
@@ -796,20 +850,27 @@ int intel_hdcp_init(struct intel_connector *connector,
 int intel_hdcp_enable(struct intel_connector *connector)
 {
 	struct intel_hdcp *hdcp = &connector->hdcp;
-	int ret;
+	int ret = -EINVAL;
 
 	if (!hdcp->hdcp_shim)
 		return -ENOENT;
 
 	mutex_lock(&hdcp->hdcp_mutex);
 
-	ret = _intel_hdcp_enable(connector);
-	if (ret)
-		goto out;
+	/*
+	 * Considering that HDCP2.2 is more secure than HDCP1.4, If the setup
+	 * is capable of HDCP2.2, it is preferred to use HDCP2.2.
+	 */
+	if (intel_hdcp2_capable(connector))
+		ret = _intel_hdcp2_enable(connector);
+	else if (intel_hdcp_capable(connector))
+		ret = _intel_hdcp_enable(connector);
+
+	if (!ret) {
+		hdcp->hdcp_value = DRM_MODE_CONTENT_PROTECTION_ENABLED;
+		schedule_work(&hdcp->hdcp_prop_work);
+	}
 
-	hdcp->hdcp_value = DRM_MODE_CONTENT_PROTECTION_ENABLED;
-	schedule_work(&hdcp->hdcp_prop_work);
-out:
 	mutex_unlock(&hdcp->hdcp_mutex);
 	return ret;
 }
@@ -826,7 +887,10 @@ int intel_hdcp_disable(struct intel_connector *connector)
 
 	if (hdcp->hdcp_value != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
 		hdcp->hdcp_value = DRM_MODE_CONTENT_PROTECTION_UNDESIRED;
-		ret = _intel_hdcp_disable(connector);
+		if (hdcp->hdcp2_in_use)
+			ret = _intel_hdcp2_disable(connector);
+		else
+			ret = _intel_hdcp_disable(connector);
 	}
 
 	mutex_unlock(&hdcp->hdcp_mutex);
@@ -928,6 +992,16 @@ int intel_hdcp_check_link(struct intel_connector *connector)
 	return ret;
 }
 
+static int _intel_hdcp2_enable(struct intel_connector *connector)
+{
+	return 0;
+}
+
+static int _intel_hdcp2_disable(struct intel_connector *connector)
+{
+	return 0;
+}
+
 static int i915_hdcp_component_master_bind(struct device *dev)
 {
 	struct drm_i915_private *dev_priv = kdev_to_i915(dev);
-- 
2.7.4