common/mctp/mctp.h

#ifndef _MCTP_H
#define _MCTP_H

#ifdef __cplusplus
extern "C" {
#endif

#include <stdint.h>
#include <sys/printk.h>
#include <zephyr.h>

#define MCTP_DEBUG 1

#define MCTP_SUCCESS 0
#define MCTP_ERROR 1

#define MCTP_TX_QUEUE_SIZE 16

#define MSG_ASSEMBLY_BUF_SIZE 1024

#define MCTP_RX_TASK_STACK_SIZE 4096
#define MCTP_TX_TASK_STACK_SIZE 1024
#define MCTP_TASK_NAME_LEN 32

#define MCTP_DEFAULT_ENDPOINT 0x0A
#define MCTP_NULL_EID 0x00

#define MCTP_DEFAULT_MSG_MAX_SIZE 64
#define MCTP_TRANSPORT_HEADER_SIZE 4
#define MCTP_MEDIUM_META_SIZE_SMBUS 3
#define MCTP_PEC_SIZE 1 /* SMBUS/I3C */
#define MCTP_META_INFO_SIZE (MCTP_TRANSPORT_HEADER_SIZE + MCTP_PEC_SIZE)

#define MCTP_MAX_MSG_TAG_NUM 8

#define MCTP_HDR_HDR_VER 0x01
#define MCTP_HDR_SEQ_MASK 0x03
#define MCTP_HDR_TAG_MASK 0x07

typedef enum {
	MCTP_MSG_TYPE_CTRL = 0x00,
	MCTP_MSG_TYPE_PLDM,
	MCTP_MSG_TYPE_NCSI,
	MCTP_MSG_TYPE_ETH,
	MCTP_MSG_TYPE_NVME,
	MCTP_MSG_TYPE_VEN_DEF_PCI = 0x7E,
	MCTP_MSG_TYPE_VEN_DEF_IANA = 0x7F
} MCTP_MSG_TYPE;

typedef enum {
	MCTP_MEDIUM_TYPE_UNKNOWN = 0,
	MCTP_MEDIUM_TYPE_SMBUS,
	MCTP_MEDIUM_TYPE_I3C,
	MCTP_MEDIUM_TYPE_MAX
} MCTP_MEDIUM_TYPE;

/* smbus extra medium data of endpoint */
typedef struct _mctp_i3c_ext_params {
	uint8_t addr; /* 8 bit address */
	uint32_t dummy; // TODO: test only
} mctp_i3c_ext_params;

/* smbus extra medium data of endpoint */
typedef struct _mctp_smbus_ext_params {
	uint8_t addr; /* 8 bit address */
} mctp_smbus_ext_params;

/* mctp extra parameters prototype */
typedef struct _mctp_ext_params {
	/* mctp transport layer parameters */
	uint8_t tag_owner;
	uint8_t msg_tag;
	uint8_t ep;

	/* medium parameters */
	MCTP_MEDIUM_TYPE type;
	union {
		mctp_smbus_ext_params smbus_ext_params;
		mctp_i3c_ext_params i3c_ext_params;
	};
} mctp_ext_params;

/* mctp recevice data callback function prototype */
/* ext_params shoule be bypass to mctp_send_msg if need */
typedef uint8_t (*mctp_fn_cb)(void *mctp_p, uint8_t *buf, uint32_t len, mctp_ext_params ext_params);

/* medium write/read function prototype */
typedef uint16_t (*medium_tx)(void *mctp_p, uint8_t *buf, uint32_t len, mctp_ext_params ext_params);
typedef uint16_t (*medium_rx)(void *mctp_p, uint8_t *buf, uint32_t len,
			      mctp_ext_params *ext_params);

/* prototype for destitation endpoint resloved */
typedef uint8_t (*endpoint_resolve)(uint8_t dest_endpoint, void **mctp_inst,
				    mctp_ext_params *ext_params);

/* smbus config for mctp medium_conf */
typedef struct _mctp_i3c_conf {
	uint8_t bus;
	uint8_t addr;
	uint32_t dummy;
} mctp_i3c_conf;

/* smbus config for mctp medium_conf */
typedef struct _mctp_smbus_conf {
	uint8_t bus;
	uint8_t addr;
} mctp_smbus_conf;

/* mctp medium conf */
typedef union {
	mctp_smbus_conf smbus_conf;
	mctp_i3c_conf i3c_conf;
} mctp_medium_conf;

/* mctp tx message struct */
typedef struct __attribute__((aligned(4))) {
	uint8_t is_bridge_packet;
	uint8_t *buf;
	uint16_t len;
	mctp_ext_params ext_params;
} mctp_tx_msg;

/* mctp main struct */
typedef struct _mctp {
	uint8_t is_servcie_start;
	MCTP_MEDIUM_TYPE medium_type;
	uint8_t endpoint;
	uint16_t max_msg_size;

	/* medium related */
	mctp_medium_conf medium_conf;
	medium_rx read_data;
	medium_tx write_data;

	/* get mctp route information by application layer */
	endpoint_resolve ep_resolve;

	/* read/write task */
	k_tid_t mctp_rx_task_tid;
	k_tid_t mctp_tx_task_tid;
	struct k_thread rx_task_thread_data;
	struct k_thread tx_task_thread_data;
	K_KERNEL_STACK_MEMBER(rx_task_stack_area, MCTP_RX_TASK_STACK_SIZE);
	K_KERNEL_STACK_MEMBER(tx_task_stack_area, MCTP_TX_TASK_STACK_SIZE);
	uint8_t mctp_rx_task_name[MCTP_TASK_NAME_LEN];
	uint8_t mctp_tx_task_name[MCTP_TASK_NAME_LEN];

	/* write queue */
	struct k_msgq mctp_tx_queue;

	/* point to the rx message buffer that is assembling */
	struct {
		uint8_t *buf;
		uint16_t offset;
	} temp_msg_buf[MCTP_MAX_MSG_TAG_NUM];

	/* the callback when recevie mctp data */
	mctp_fn_cb rx_cb;

	/* for pldm instance id */
	uint8_t pldm_inst_id;
} mctp;

/* public function */
mctp *mctp_init(void);

uint8_t mctp_deinit(mctp *mctp_inst);

uint8_t mctp_set_medium_configure(mctp *mctp_inst, MCTP_MEDIUM_TYPE medium_type,
				  mctp_medium_conf medium_conf);

/* medium_conf should be freed by application */
uint8_t mctp_get_medium_configure(mctp *mctp_inst, MCTP_MEDIUM_TYPE *medium_type,
				  mctp_medium_conf *medium_conf);

/* mctp service start */
uint8_t mctp_start(mctp *mctp_inst);

/* mctp service stop */
uint8_t mctp_stop(mctp *mctp_inst);

/* send message to destination endpoint */
uint8_t mctp_send_msg(mctp *mctp_inst, uint8_t *buf, uint16_t len, mctp_ext_params ext_params);

/* bridge message to destination endpoint */
uint8_t mctp_bridge_msg(mctp *mctp_inst, uint8_t *buf, uint16_t len, mctp_ext_params ext_params);

/* medium init/deinit */
uint8_t mctp_smbus_init(mctp *mctp_inst, mctp_medium_conf medium_conf);
uint8_t mctp_smbus_deinit(mctp *mctp_inst);

/* register endpoint resolve function */
uint8_t mctp_reg_endpoint_resolve_func(mctp *mctp_inst, endpoint_resolve resolve_fn);

/* register callback function when the mctp message is received */
uint8_t mctp_reg_msg_rx_func(mctp *mctp_inst, mctp_fn_cb rx_cb);

#ifdef __cplusplus
}
#endif

#endif /* _MCTP_H */