[PATCH v5 14/40] drm/i915: Enable and Disable HDCP2.2 port encryption

[Ramalingam C]

Implements the enable and disable functions for HDCP2.2 encryption
of the PORT.

v2:
  intel_wait_for_register is used instead of wait_for. [Chris Wilson]
v3:
  No Changes.
v4:
  Debug msg is added for timeout at Disable of Encryption [Uma]
  %s/HDCP2_CTL/HDCP2_CTL
v5:
  Rebased as part of patch reordering.
  HW state check is moved into WARN_ON [Daniel]

Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
---
 drivers/gpu/drm/i915/intel_hdcp.c | 48 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 46 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
index 1bb638485e07..d012a887a7e8 100644
--- a/drivers/gpu/drm/i915/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/intel_hdcp.c
@@ -17,6 +17,7 @@
 #include "i915_reg.h"
 
 #define KEY_LOAD_TRIES	5
+#define TIME_FOR_ENCRYPT_STATUS_CHANGE	32
 #define GET_MEI_DDI_INDEX(port)		(((port) == PORT_A) ? DDI_A : \
 					(enum hdcp_physical_port) (port))
 
@@ -1027,12 +1028,55 @@ static int hdcp2_authenticate_sink(struct intel_connector *connector)
 
 static int hdcp2_enable_encryption(struct intel_connector *connector)
 {
-	return 0;
+	struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
+	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
+	struct intel_hdcp *hdcp = &connector->hdcp;
+	enum port port = connector->encoder->port;
+	int ret;
+
+	WARN_ON(I915_READ(HDCP2_STATUS_DDI(port)) & LINK_ENCRYPTION_STATUS);
+
+	if (hdcp->hdcp_shim->toggle_signalling)
+		hdcp->hdcp_shim->toggle_signalling(intel_dig_port, true);
+
+	if (I915_READ(HDCP2_STATUS_DDI(port)) & LINK_AUTH_STATUS) {
+		/* Link is Authenticated. Now set for Encryption */
+		I915_WRITE(HDCP2_CTL_DDI(port),
+			   I915_READ(HDCP2_CTL_DDI(port)) |
+			   CTL_LINK_ENCRYPTION_REQ);
+	}
+
+	ret = intel_wait_for_register(dev_priv, HDCP2_STATUS_DDI(port),
+				      LINK_ENCRYPTION_STATUS,
+				      LINK_ENCRYPTION_STATUS,
+				      TIME_FOR_ENCRYPT_STATUS_CHANGE);
+
+	return ret;
 }
 
 static int hdcp2_disable_encryption(struct intel_connector *connector)
 {
-	return 0;
+	struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
+	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
+	struct intel_hdcp *hdcp = &connector->hdcp;
+	enum port port = connector->encoder->port;
+	int ret;
+
+	WARN_ON(!(I915_READ(HDCP2_STATUS_DDI(port)) & LINK_ENCRYPTION_STATUS));
+
+	I915_WRITE(HDCP2_CTL_DDI(port),
+		   I915_READ(HDCP2_CTL_DDI(port)) & ~CTL_LINK_ENCRYPTION_REQ);
+
+	ret = intel_wait_for_register(dev_priv, HDCP2_STATUS_DDI(port),
+				      LINK_ENCRYPTION_STATUS, 0x0,
+				      TIME_FOR_ENCRYPT_STATUS_CHANGE);
+	if (ret == -ETIMEDOUT)
+		DRM_DEBUG_KMS("Disable Encryption Timedout");
+
+	if (hdcp->hdcp_shim->toggle_signalling)
+		hdcp->hdcp_shim->toggle_signalling(intel_dig_port, false);
+
+	return ret;
 }
 
 static int hdcp2_authenticate_and_encrypt(struct intel_connector *connector)
-- 
2.7.4