misc/mei/hdcp: Verify L_prime

Request to ME to verify the LPrime received from HDCP sink.

On Success, ME FW will verify the received Lprime by calculating and
comparing with L.

This represents the completion of Locality Check.

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:
  Collected the Rb-ed by.
  Rebasing.
v7:
  Adjust to the new mei interface.
  Fix for Kdoc.
v8:
  K-Doc addition. [Tomas]
  memcpy for const length.
v9:
  renamed func as mei_hdcp_* [Tomas]
  Inline function is defined for DDI index [Tomas]
v10:
  K-Doc fix. [Tomas]
v11:
  Rebased.

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Acked-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1550772730-23280-10-git-send-email-ramalingam.c@intel.com

drivers/misc/mei/hdcp/mei_hdcp.c

@@ -351,6 +351,64 @@ mei_hdcp_initiate_locality_check(struct device *dev,
 	return 0;
 }
 
+/**
+ * mei_hdcp_verify_lprime() - Verify lprime.
+ * @dev: device corresponding to the mei_cl_device
+ * @data: Intel HW specific hdcp data
+ * @rx_lprime: LC_Send_L_prime msg for ME FW verification
+ *
+ * Return: 0 on Success, <0 on Failure
+ */
+static int
+mei_hdcp_verify_lprime(struct device *dev, struct hdcp_port_data *data,
+		       struct hdcp2_lc_send_lprime *rx_lprime)
+{
+	struct wired_cmd_validate_locality_in verify_lprime_in = { { 0 } };
+	struct wired_cmd_validate_locality_out verify_lprime_out = { { 0 } };
+	struct mei_cl_device *cldev;
+	ssize_t byte;
+
+	if (!dev || !data || !rx_lprime)
+		return -EINVAL;
+
+	cldev = to_mei_cl_device(dev);
+
+	verify_lprime_in.header.api_version = HDCP_API_VERSION;
+	verify_lprime_in.header.command_id = WIRED_VALIDATE_LOCALITY;
+	verify_lprime_in.header.status = ME_HDCP_STATUS_SUCCESS;
+	verify_lprime_in.header.buffer_len =
+					WIRED_CMD_BUF_LEN_VALIDATE_LOCALITY_IN;
+
+	verify_lprime_in.port.integrated_port_type = data->port_type;
+	verify_lprime_in.port.physical_port = mei_get_ddi_index(data->port);
+
+	memcpy(verify_lprime_in.l_prime, rx_lprime->l_prime,
+	       HDCP_2_2_L_PRIME_LEN);
+
+	byte = mei_cldev_send(cldev, (u8 *)&verify_lprime_in,
+			      sizeof(verify_lprime_in));
+	if (byte < 0) {
+		dev_dbg(dev, "mei_cldev_send failed. %zd\n", byte);
+		return byte;
+	}
+
+	byte = mei_cldev_recv(cldev, (u8 *)&verify_lprime_out,
+			      sizeof(verify_lprime_out));
+	if (byte < 0) {
+		dev_dbg(dev, "mei_cldev_recv failed. %zd\n", byte);
+		return byte;
+	}
+
+	if (verify_lprime_out.header.status != ME_HDCP_STATUS_SUCCESS) {
+		dev_dbg(dev, "ME cmd 0x%08X failed. status: 0x%X\n",
+			WIRED_VALIDATE_LOCALITY,
+			verify_lprime_out.header.status);
+		return -EIO;
+	}
+
+	return 0;
+}
+
 static const __attribute__((unused))
 struct i915_hdcp_component_ops mei_hdcp_ops = {
 	.owner = THIS_MODULE,
@@ -360,7 +418,7 @@ struct i915_hdcp_component_ops mei_hdcp_ops = {
 	.verify_hprime = mei_hdcp_verify_hprime,
 	.store_pairing_info = mei_hdcp_store_pairing_info,
 	.initiate_locality_check = mei_hdcp_initiate_locality_check,
-	.verify_lprime = NULL,
+	.verify_lprime = mei_hdcp_verify_lprime,
 	.get_session_key = NULL,
 	.repeater_check_flow_prepare_ack = NULL,
 	.verify_mprime = NULL,