4 files changed, 134 insertions, 0 deletions
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 4ec5fa6670a..88f10c46221 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -94,6 +94,7 @@ enum uclass_id {
 	UCLASS_RESET,		/* Reset controller device */
 	UCLASS_RNG,		/* Random Number Generator */
 	UCLASS_RTC,		/* Real time clock device */
+	UCLASS_SCMI_AGENT,	/* Interface with an SCMI server */
 	UCLASS_SCSI,		/* SCSI device */
 	UCLASS_SERIAL,		/* Serial UART */
 	UCLASS_SIMPLE_BUS,	/* Bus with child devices */
diff --git a/include/scmi_agent-uclass.h b/include/scmi_agent-uclass.h
new file mode 100644
index 00000000000..a501d1b4825
--- /dev/null
+++ b/include/scmi_agent-uclass.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2019-2020 Linaro Limited.
+ */
+#ifndef _SCMI_AGENT_UCLASS_H
+#define _SCMI_AGENT_UCLASS_H
+
+struct udevice;
+struct scmi_msg;
+
+/**
+ * struct scmi_transport_ops - The functions that a SCMI transport layer must implement.
+ */
+struct scmi_agent_ops {
+	/*
+	 * process_msg - Request transport to get the SCMI message processed
+	 *
+	 * @agent:		Agent using the transport
+	 * @msg:		SCMI message to be transmitted
+	 */
+	int (*process_msg)(struct udevice *dev, struct scmi_msg *msg);
+};
+
+#endif /* _SCMI_TRANSPORT_UCLASS_H */
diff --git a/include/scmi_agent.h b/include/scmi_agent.h
new file mode 100644
index 00000000000..f1be9ff2091
--- /dev/null
+++ b/include/scmi_agent.h
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
+/*
+ * Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
+ * Copyright (C) 2019-2020, Linaro Limited
+ *
+ * An SCMI agent device represent on communication path from a
+ * device driver to the remote SCMI server which driver sends
+ * messages to and receives response messages from.
+ */
+#ifndef SCMI_AGENT_H
+#define SCMI_AGENT_H
+
+#include <asm/types.h>
+
+struct udevice;
+
+/*
+ * struct scmi_msg - Context of a SCMI message sent and the response received
+ *
+ * @protocol_id:	SCMI protocol ID
+ * @message_id:		SCMI message ID for a defined protocol ID
+ * @in_msg:		Pointer to the message payload sent by the driver
+ * @in_msg_sz:		Byte size of the message payload sent
+ * @out_msg:		Pointer to buffer to store response message payload
+ * @out_msg_sz:		Byte size of the response buffer and response payload
+ */
+struct scmi_msg {
+	unsigned int protocol_id;
+	unsigned int message_id;
+	u8 *in_msg;
+	size_t in_msg_sz;
+	u8 *out_msg;
+	size_t out_msg_sz;
+};
+
+/* Helper macro to match a message on input/output array references */
+#define SCMI_MSG_IN(_protocol, _message, _in_array, _out_array) \
+	(struct scmi_msg){			\
+		.protocol_id = (_protocol),	\
+		.message_id = (_message),	\
+		.in_msg = (uint8_t *)&(_in_array),	\
+		.in_msg_sz = sizeof(_in_array),	\
+		.out_msg = (uint8_t *)&(_out_array),	\
+		.out_msg_sz = sizeof(_out_array),	\
+	}
+
+/**
+ * scmi_send_and_process_msg() - send and process a SCMI message
+ *
+ * Send a message to a SCMI server through a target SCMI agent device.
+ * Caller sets scmi_msg::out_msg_sz to the output message buffer size.
+ * On return, scmi_msg::out_msg_sz stores the response payload size.
+ *
+ * @dev:	SCMI agent device
+ * @msg:	Message structure reference
+ * @return 0 on success and a negative errno on failure
+ */
+int devm_scmi_process_msg(struct udevice *dev, struct scmi_msg *msg);
+
+/**
+ * scmi_to_linux_errno() - Convert an SCMI error code into a Linux errno code
+ *
+ * @scmi_errno:	SCMI error code value
+ * @return 0 for successful status and a negative errno otherwise
+ */
+int scmi_to_linux_errno(s32 scmi_errno);
+
+#endif /* SCMI_H */
diff --git a/include/scmi_protocols.h b/include/scmi_protocols.h
new file mode 100644
index 00000000000..86a2d109c8c
--- /dev/null
+++ b/include/scmi_protocols.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
+/*
+ * Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
+ * Copyright (C) 2019-2020, Linaro Limited
+ */
+#ifndef _SCMI_PROTOCOLS_H
+#define _SCMI_PROTOCOLS_H
+
+#include <linux/bitops.h>
+
+/*
+ * Subset the SCMI protocols definition
+ * based on SCMI specification v2.0 (DEN0056B)
+ * https://developer.arm.com/docs/den0056/b
+ */
+
+enum scmi_std_protocol {
+	SCMI_PROTOCOL_ID_BASE = 0x10,
+	SCMI_PROTOCOL_ID_POWER_DOMAIN = 0x11,
+	SCMI_PROTOCOL_ID_SYSTEM = 0x12,
+	SCMI_PROTOCOL_ID_PERF = 0x13,
+	SCMI_PROTOCOL_ID_CLOCK = 0x14,
+	SCMI_PROTOCOL_ID_SENSOR = 0x15,
+	SCMI_PROTOCOL_ID_RESET_DOMAIN = 0x16,
+};
+
+enum scmi_status_code {
+	SCMI_SUCCESS =  0,
+	SCMI_NOT_SUPPORTED = -1,
+	SCMI_INVALID_PARAMETERS = -2,
+	SCMI_DENIED = -3,
+	SCMI_NOT_FOUND = -4,
+	SCMI_OUT_OF_RANGE = -5,
+	SCMI_BUSY = -6,
+	SCMI_COMMS_ERROR = -7,
+	SCMI_GENERIC_ERROR = -8,
+	SCMI_HARDWARE_ERROR = -9,
+	SCMI_PROTOCOL_ERROR = -10,
+};
+
+#endif /* _SCMI_PROTOCOLS_H */