hw/ast-bmc: Initialize ast lpc mctp binding

The Management Component Transport Protocol (MCTP) defines a communication
model intended to facilitate communication.

This patch initialize MCTP binding over LPC Bus interface.

Several steps must be performed:
- Initialize the MCTP core (mctp_init()).
- Initialize a hardware binding as AST LPC mode host (mctp_astlpc_init()).
- Register the hardware binding with the core (mctp_register_bus()), using
a predefined EID (Host default is 9).

To transmit a MCTP message, mctp_message_tx() is used.
To receive a MCTP message, a callback need to be provided and registered
through mctp_set_rx_all().

For the transfer of MCTP messages, two basics components are used:
- A window of the LPC FW address space, where reads and writes are
forwarded to BMC memory.
- An interrupt mechanism using the KCS interface.

hw/ast-bmc/ast-mctp.c is compilated if the compiler flag CONFIG_PLDM is
set.

Reviewed-by: Abhishek Singh Tomar <abhishek@linux.ibm.com>
Signed-off-by: Christophe Lombard <clombard@linux.ibm.com>
Signed-off-by: Reza Arbab <arbab@linux.ibm.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/include/ast.h b/include/ast.h
index 5e93239..79efe4f 100644
--- a/include/ast.h
+++ b/include/ast.h
@@ -91,6 +91,26 @@ void ast_setup_ibt(uint16_t io_base, uint8_t irq);
 /* MBOX configuration */
 void ast_setup_sio_mbox(uint16_t io_base, uint8_t irq);
 
+/* MCTP configuration */
+
+/*
+ * EID is the MCTP endpoint ID, which aids in routing MCTP packets.
+ * For the EIDs: the valid range is 8-254.
+ * We are saying that BMC is EID 8 and Skiboot is HOST_EID 9
+ */
+#define BMC_EID  8
+#define HOST_EID 9
+
+enum mctp_msg_type {
+	MCTP_MSG_TYPE_CONTROL = 0x00,
+	MCTP_MSG_TYPE_PLDM    = 0x01,
+};
+
+int ast_mctp_message_tx(bool tag_owner, uint8_t msg_tag,
+			uint8_t *msg, int msg_len);
+int ast_mctp_init(void);
+void ast_mctp_exit(void);
+
 #endif /* __SKIBOOT__ */
 
 /*