[PATCH v6 31/35] misc/mei/hdcp: Prepare Session Key

[Ramalingam C]

Request to ME to prepare the encrypted session key.

On Success, ME provides Encrypted session key. Function populates
the HDCP2.2 authentication msg SKE_Send_Eks.

v2:
  Rebased.
v3:
  cldev is passed as first parameter [Tomas]
  Redundant comments and cast are removed [Tomas]
v4:
  %zd for ssize_t [Alexander]
  %s/return -1/return -EIO [Alexander]
  Style fixed [Uma]
v5:
  Rebased.
v6:
  No change.

Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
---
 drivers/misc/mei/hdcp/mei_hdcp.c | 62 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 60 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c b/drivers/misc/mei/hdcp/mei_hdcp.c
index c2d6d815354c..eb35e22fdeff 100644
--- a/drivers/misc/mei/hdcp/mei_hdcp.c
+++ b/drivers/misc/mei/hdcp/mei_hdcp.c
@@ -423,6 +423,65 @@ static int mei_verify_lprime(struct mei_cl_device *cldev,
 	return 0;
 }
 
+/*
+ * mei_get_session_key:
+ *	Function to prepare SKE_Send_Eks.
+ *
+ * cldev		: Pointer for mei client device
+ * data			: Intel HW specific Data
+ * ske_data		: Pointer for SKE_Send_Eks.
+ *
+ * Returns 0 on Success, <0 on Failure
+ */
+static int mei_get_session_key(struct mei_cl_device *cldev,
+			       struct mei_hdcp_data *data,
+			       struct hdcp2_ske_send_eks *ske_data)
+{
+	struct wired_cmd_get_session_key_in get_skey_in = { { 0 } };
+	struct wired_cmd_get_session_key_out get_skey_out = { { 0 } };
+	struct device *dev;
+	ssize_t byte;
+
+	if (!data || !ske_data)
+		return -EINVAL;
+
+	dev = &cldev->dev;
+
+	get_skey_in.header.api_version = HDCP_API_VERSION;
+	get_skey_in.header.command_id = WIRED_GET_SESSION_KEY;
+	get_skey_in.header.status = ME_HDCP_STATUS_SUCCESS;
+	get_skey_in.header.buffer_len = WIRED_CMD_BUF_LEN_GET_SESSION_KEY_IN;
+
+	get_skey_in.port.integrated_port_type = data->port_type;
+	get_skey_in.port.physical_port = data->port;
+
+	byte = mei_cldev_send(cldev, (u8 *)&get_skey_in, sizeof(get_skey_in));
+	if (byte < 0) {
+		dev_dbg(dev, "mei_cldev_send failed. %zd\n", byte);
+		return byte;
+	}
+
+	byte = mei_cldev_recv(cldev, (u8 *)&get_skey_out, sizeof(get_skey_out));
+
+	if (byte < 0) {
+		dev_dbg(dev, "mei_cldev_recv failed. %zd\n", byte);
+		return byte;
+	}
+
+	if (get_skey_out.header.status != ME_HDCP_STATUS_SUCCESS) {
+		dev_dbg(dev, "ME cmd 0x%08X failed. status: 0x%X\n",
+			WIRED_GET_SESSION_KEY, get_skey_out.header.status);
+		return -EIO;
+	}
+
+	ske_data->msg_id = HDCP_2_2_SKE_SEND_EKS;
+	memcpy(ske_data->e_dkey_ks, get_skey_out.e_dkey_ks,
+	       HDCP_2_2_E_DKEY_KS_LEN);
+	memcpy(ske_data->riv, get_skey_out.r_iv, HDCP_2_2_RIV_LEN);
+
+	return 0;
+}
+
 struct i915_hdcp_component_ops mei_hdcp_component_ops = {
 	.owner					= THIS_MODULE,
 	.initiate_hdcp2_session			= mei_initiate_hdcp2_session,
@@ -432,7 +491,7 @@ struct i915_hdcp_component_ops mei_hdcp_component_ops = {
 	.store_pairing_info			= mei_store_pairing_info,
 	.initiate_locality_check		= mei_initiate_locality_check,
 	.verify_lprime				= mei_verify_lprime,
-	.get_session_key			= NULL,
+	.get_session_key			= mei_get_session_key,
 	.repeater_check_flow_prepare_ack	= NULL,
 	.verify_mprime				= NULL,
 	.enable_hdcp_authentication		= NULL,
@@ -441,7 +500,6 @@ struct i915_hdcp_component_ops mei_hdcp_component_ops = {
 
 static int mei_hdcp_component_bind(struct device *mei_kdev,
 				   struct device *i915_kdev, void *data)
-
 {
 	struct i915_component_master *comp = data;
 
-- 
2.7.4