disp: hdcp: add driver to handle userspace interactions

Create a new driver to handle sysfs and topology events that are
related to application/userspace layer interactions for HDCP
functionality. In turn, this will create a clear separation from
the HDCP QSEECOM layer that defines the communication mechanism
between the kernel and the TrustZone layers.

This implementation is based on a snapshot of the msm_hdcp
driver as of this commit 10ffbfa2c7e03c09 ("drm/msm/dp: Snapshot
of DP and supporting files") on kernel 4.19 project.

Change-Id: I834620420b8d6a580f1905a2b3250cf4e5b8f293
Signed-off-by: Tatenda Chipeperekwa <tatendac@codeaurora.org>

include/uapi/display/hdcp/msm_hdmi_hdcp_mgr.h

@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
+/*
+ * Copyright (c) 2017-2020, The Linux Foundation. All rights reserved.
+ */
+
+#ifndef _UAPI__MSM_HDMI_HDCP_MGR_H
+#define _UAPI__MSM_HDMI_HDCP_MGR_H
+
+enum DS_TYPE {  /* type of downstream device */
+	DS_UNKNOWN,
+	DS_RECEIVER,
+	DS_REPEATER,
+};
+
+enum {
+	MSG_ID_IDX,
+	RET_CODE_IDX,
+	HEADER_LEN,
+};
+
+enum RET_CODE {
+	HDCP_NOT_AUTHED,
+	HDCP_AUTHED,
+	HDCP_DISABLE,
+};
+
+enum MSG_ID { /* List of functions expected to be called after it */
+	DOWN_CHECK_TOPOLOGY,
+	UP_REQUEST_TOPOLOGY,
+	UP_SEND_TOPOLOGY,
+	DOWN_REQUEST_TOPOLOGY,
+	MSG_NUM,
+};
+
+enum SOURCE_ID {
+	HDCP_V1_TX,
+	HDCP_V1_RX,
+	HDCP_V2_RX,
+	HDCP_V2_TX,
+	SRC_NUM,
+};
+
+/*
+ * how to parse sysfs params buffer
+ * from hdcp_tx driver.
+ */
+
+struct HDCP_V2V1_MSG_TOPOLOGY {
+	/* indicates downstream's type */
+	uint32_t ds_type;
+	uint8_t bksv[5];
+	uint8_t dev_count;
+	uint8_t depth;
+	uint8_t ksv_list[5 * 127];
+	uint32_t max_cascade_exceeded;
+	uint32_t max_dev_exceeded;
+};
+
+#endif /* _UAPI__MSM_HDMI_HDCP_MGR_H */