drivers: tee: optee: discover OP-TEE services

This change defines resources for OP-TEE service drivers to register
themselves for being bound to when OP-TEE firmware reports the related
service is supported. OP-TEE services are discovered during optee
driver probe sequence which mandates optee driver is always probe once
bound.

Discovery of optee services and binding to related U-Boot drivers is
embedded upon configuration switch CONFIG_OPTEE_SERVICE_DISCOVERY.

Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
diff --git a/include/tee/optee_service.h b/include/tee/optee_service.h
new file mode 100644
index 0000000..fca468a
--- /dev/null
+++ b/include/tee/optee_service.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * (C) Copyright 2022 Linaro Limited
+ */
+
+#ifndef _OPTEE_SERVICE_H
+#define _OPTEE_SERVICE_H
+
+/*
+ * struct optee_service - Discoverable OP-TEE service
+ *
+ * @driver_name - Name of the related driver
+ * @uuid - UUID of the OP-TEE service related to the driver
+ *
+ * Use macro OPTEE_SERVICE_DRIVER() to register a driver related to an
+ * OP-TEE service discovered when driver asks OP-TEE services enumaration.
+ */
+struct optee_service {
+	const char *driver_name;
+	const struct tee_optee_ta_uuid uuid;
+};
+
+#ifdef CONFIG_OPTEE_SERVICE_DISCOVERY
+#define OPTEE_SERVICE_DRIVER(__name, __uuid, __drv_name) \
+	ll_entry_declare(struct optee_service, __name, optee_service) = { \
+		.uuid = __uuid, \
+		.driver_name = __drv_name, \
+	}
+#else
+#define OPTEE_SERVICE_DRIVER(__name, __uuid, __drv_name) \
+	static int __name##__COUNTER__ __always_unused
+#endif
+
+#endif /* _OPTEE_SERVICE_H */