link_msg.h File Reference

What crosses the link, independent of the transport: an op, a page, an offset, a count and up to a page of registers. More...

#include <stdint.h>

Go to the source code of this file.

Data Structures
struct	link_msg_t
	One link message: the op, the register window and its values. More...

Macros
#define	LINK_MAX_REGS   32
	Registers in a page, and therefore in the largest transfer.

Enumerations
enum	link_op_t {   LINK_OP_READ = 0x01 , LINK_OP_WRITE = 0x02 , LINK_OP_DATA = 0x03 , LINK_OP_ACK = 0x04 ,   LINK_OP_NACK = 0x05 }
	The operation a link message carries. More...
enum	link_nack_t {   LINK_NACK_BAD_PAGE = 1 , LINK_NACK_BAD_RANGE = 2 , LINK_NACK_READ_ONLY = 3 , LINK_NACK_BAD_VALUE = 4 ,   LINK_NACK_NOT_ARMED = 5 , LINK_NACK_BUSY = 6 }
	Reasons a NACK (negative acknowledge) carries. More...

Detailed Description

What crosses the link, independent of the transport: an op, a page, an offset, a count and up to a page of registers.

The dispatcher and the poller work on this struct; link_can.h maps it onto CAN (Controller Area Network) frames.

SPDX-License-Identifier: MIT

Enumeration Type Documentation

link_nack_t

enum link_nack_t

Reasons a NACK (negative acknowledge) carries.

Enumerator
LINK_NACK_BAD_RANGE	offset + count runs off the end of a page
LINK_NACK_BUSY	The value is good and something else holds what it names: a pin another page or an output has, or a resource the wiring needs. Freed, the same write is taken. TONE only, since 4.17 (LINK_MINOR_TONE_BUSY); an older IOmcu says BAD_VALUE.

link_op_t

enum link_op_t

The operation a link message carries.

Enumerator
LINK_OP_READ	host asks for COUNT registers from PAGE:OFFS
LINK_OP_WRITE	host sets them
LINK_OP_DATA	IOmcu answers a read
LINK_OP_ACK	IOmcu accepted a write
LINK_OP_NACK	IOmcu refused it; regs[0] says why