misc/mei/hdcp: Initiate Wired HDCP2.2 Tx Session

Request ME FW to start the HDCP2.2 session for an intel port.
Prepares payloads for command WIRED_INITIATE_HDCP2_SESSION and sends
to ME FW.

On Success, ME FW will start a HDCP2.2 session for the port and
provides the content for HDCP2.2 AKE_Init message.

v2: Rebased.
v3:
  cldev is add as a separate parameter [Tomas]
  Redundant comment and typecast are removed [Tomas]
v4:
  %zd is used for size [Alexander]
  %s/return -1/return -EIO [Alexander]
  Spellings in commit msg is fixed [Uma]
v5: Rebased.
v6:
  Collected the rb-ed by.
  Realigning the patches in the series.
v7:
  Adjust to the new mei interface.
  Fix for kdoc.
v8:
  K-Doc Addition.
  memcpy for const length.
v9:
  s/mei_hdcp_ddi/mei_fw_ddi
  s/i915_port/mei_i915_port [Tomas]
  renamed func as mei_hdcp_* [Tomas]
  Instead of macro, inline func for ddi index is used. [Tomas]
v10:
  Switch case for the coversion between i915_port to mei_ddi [Tomas]
  Kernel doc fix.
v11:
  mei_hdcp_ops is defined as const. [Tomas]

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1550772730-23280-5-git-send-email-ramalingam.c@intel.com

drivers/misc/mei/hdcp/mei_hdcp.c

@@ -23,6 +23,100 @@
 #include <linux/slab.h>
 #include <linux/uuid.h>
 #include <linux/mei_cl_bus.h>
+#include <drm/drm_connector.h>
+#include <drm/i915_component.h>
+#include <drm/i915_mei_hdcp_interface.h>
+
+#include "mei_hdcp.h"
+
+static inline u8 mei_get_ddi_index(enum port port)
+{
+	switch (port) {
+	case PORT_A:
+		return MEI_DDI_A;
+	case PORT_B ... PORT_F:
+		return (u8)port;
+	default:
+		return MEI_DDI_INVALID_PORT;
+	}
+}
+
+/**
+ * mei_hdcp_initiate_session() - Initiate a Wired HDCP2.2 Tx Session in ME FW
+ * @dev: device corresponding to the mei_cl_device
+ * @data: Intel HW specific hdcp data
+ * @ake_data: AKE_Init msg output.
+ *
+ * Return:  0 on Success, <0 on Failure.
+ */
+static int
+mei_hdcp_initiate_session(struct device *dev, struct hdcp_port_data *data,
+			  struct hdcp2_ake_init *ake_data)
+{
+	struct wired_cmd_initiate_hdcp2_session_in session_init_in = { { 0 } };
+	struct wired_cmd_initiate_hdcp2_session_out
+						session_init_out = { { 0 } };
+	struct mei_cl_device *cldev;
+	ssize_t byte;
+
+	if (!dev || !data || !ake_data)
+		return -EINVAL;
+
+	cldev = to_mei_cl_device(dev);
+
+	session_init_in.header.api_version = HDCP_API_VERSION;
+	session_init_in.header.command_id = WIRED_INITIATE_HDCP2_SESSION;
+	session_init_in.header.status = ME_HDCP_STATUS_SUCCESS;
+	session_init_in.header.buffer_len =
+				WIRED_CMD_BUF_LEN_INITIATE_HDCP2_SESSION_IN;
+
+	session_init_in.port.integrated_port_type = data->port_type;
+	session_init_in.port.physical_port = mei_get_ddi_index(data->port);
+	session_init_in.protocol = data->protocol;
+
+	byte = mei_cldev_send(cldev, (u8 *)&session_init_in,
+			      sizeof(session_init_in));
+	if (byte < 0) {
+		dev_dbg(dev, "mei_cldev_send failed. %zd\n", byte);
+		return byte;
+	}
+
+	byte = mei_cldev_recv(cldev, (u8 *)&session_init_out,
+			      sizeof(session_init_out));
+	if (byte < 0) {
+		dev_dbg(dev, "mei_cldev_recv failed. %zd\n", byte);
+		return byte;
+	}
+
+	if (session_init_out.header.status != ME_HDCP_STATUS_SUCCESS) {
+		dev_dbg(dev, "ME cmd 0x%08X Failed. Status: 0x%X\n",
+			WIRED_INITIATE_HDCP2_SESSION,
+			session_init_out.header.status);
+		return -EIO;
+	}
+
+	ake_data->msg_id = HDCP_2_2_AKE_INIT;
+	ake_data->tx_caps = session_init_out.tx_caps;
+	memcpy(ake_data->r_tx, session_init_out.r_tx, HDCP_2_2_RTX_LEN);
+
+	return 0;
+}
+
+static const __attribute__((unused))
+struct i915_hdcp_component_ops mei_hdcp_ops = {
+	.owner = THIS_MODULE,
+	.initiate_hdcp2_session = mei_hdcp_initiate_session,
+	.verify_receiver_cert_prepare_km = NULL,
+	.verify_hprime = NULL,
+	.store_pairing_info = NULL,
+	.initiate_locality_check = NULL,
+	.verify_lprime = NULL,
+	.get_session_key = NULL,
+	.repeater_check_flow_prepare_ack = NULL,
+	.verify_mprime = NULL,
+	.enable_hdcp_authentication = NULL,
+	.close_hdcp_session = NULL,
+};
 
 static int mei_hdcp_probe(struct mei_cl_device *cldev,
 			  const struct mei_cl_device_id *id)

drivers/misc/mei/hdcp/mei_hdcp.h

@@ -363,4 +363,15 @@ struct wired_cmd_repeater_auth_stream_req_out {
 	struct hdcp_port_id	port;
 } __packed;
 
+enum mei_fw_ddi {
+	MEI_DDI_INVALID_PORT = 0x0,
+
+	MEI_DDI_B = 1,
+	MEI_DDI_C,
+	MEI_DDI_D,
+	MEI_DDI_E,
+	MEI_DDI_F,
+	MEI_DDI_A = 7,
+	MEI_DDI_RANGE_END = MEI_DDI_A,
+};
 #endif /* __MEI_HDCP_H__ */