[PATCH v3 14/40] misc/mei/hdcp: Prepare Session Key

[Ramalingam C]

Request to ME to prepare the encrypted session key.

On Success, ME provides Encrypted session key. Functions 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]

Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
---
 drivers/misc/mei/hdcp/mei_hdcp.c | 58 ++++++++++++++++++++++++++++++++++++++++
 include/linux/mei_hdcp.h         |  8 ++++++
 2 files changed, 66 insertions(+)

diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c b/drivers/misc/mei/hdcp/mei_hdcp.c
index ea84177311b7..abfcc57863b8 100644
--- a/drivers/misc/mei/hdcp/mei_hdcp.c
+++ b/drivers/misc/mei/hdcp/mei_hdcp.c
@@ -420,6 +420,64 @@ int mei_verify_lprime(struct mei_cl_device *cldev, struct mei_hdcp_data *data,
 }
 EXPORT_SYMBOL(mei_verify_lprime);
 
+/**
+ * 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
+ */
+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. %d\n", (int)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. %d\n", (int)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 -1;
+	}
+
+	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;
+}
+EXPORT_SYMBOL(mei_get_session_key);
+
 void mei_cldev_state_notify_clients(struct mei_cl_device *cldev, bool enabled)
 {
 	if (enabled)
diff --git a/include/linux/mei_hdcp.h b/include/linux/mei_hdcp.h
index 792143563c46..534170d746af 100644
--- a/include/linux/mei_hdcp.h
+++ b/include/linux/mei_hdcp.h
@@ -126,6 +126,8 @@ int mei_initiate_locality_check(struct mei_cl_device *cldev,
 				struct hdcp2_lc_init *lc_init_data);
 int mei_verify_lprime(struct mei_cl_device *cldev, struct mei_hdcp_data *data,
 		      struct hdcp2_lc_send_lprime *rx_lprime);
+int mei_get_session_key(struct mei_cl_device *cldev, struct mei_hdcp_data *data,
+			struct hdcp2_ske_send_eks *ske_data);
 #else
 static int mei_cldev_register_notify(struct notifier_block *nb)
 {
@@ -178,5 +180,11 @@ int mei_verify_lprime(struct mei_cl_device *cldev, struct mei_hdcp_data *data,
 {
 	return -ENODEV;
 }
+static inline
+int mei_get_session_key(struct mei_cl_device *cldev, struct mei_hdcp_data *data,
+			struct hdcp2_ske_send_eks *ske_data)
+{
+	return -ENODEV;
+}
 #endif /* defined (CONFIG_INTEL_MEI_HDCP) */
 #endif /* defined (_LINUX_MEI_HDCP_H) */
-- 
2.7.4