1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 * ipmi_si_sm.h
4 *
5 * State machine interface for low-level IPMI system management
6 * interface state machines.  This code is the interface between
7 * the ipmi_smi code (that handles the policy of a KCS, SMIC, or
8 * BT interface) and the actual low-level state machine.
9 *
10 * Author: MontaVista Software, Inc.
11 *         Corey Minyard <minyard@mvista.com>
12 *         source@mvista.com
13 *
14 * Copyright 2002 MontaVista Software Inc.
15 */
16
17#ifndef __IPMI_SI_SM_H__
18#define __IPMI_SI_SM_H__
19
20#include "ipmi_si.h"
21
22/*
23 * This is defined by the state machines themselves, it is an opaque
24 * data type for them to use.
25 */
26struct si_sm_data;
27
28/* Results of SMI events. */
29enum si_sm_result {
30	SI_SM_CALL_WITHOUT_DELAY, /* Call the driver again immediately */
31	SI_SM_CALL_WITH_DELAY,	/* Delay some before calling again. */
32	SI_SM_CALL_WITH_TICK_DELAY,/* Delay >=1 tick before calling again. */
33	SI_SM_TRANSACTION_COMPLETE, /* A transaction is finished. */
34	SI_SM_IDLE,		/* The SM is in idle state. */
35	SI_SM_HOSED,		/* The hardware violated the state machine. */
36
37	/*
38	 * The hardware is asserting attn and the state machine is
39	 * idle.
40	 */
41	SI_SM_ATTN
42};
43
44/* Handlers for the SMI state machine. */
45struct si_sm_handlers {
46	/*
47	 * Put the version number of the state machine here so the
48	 * upper layer can print it.
49	 */
50	char *version;
51
52	/*
53	 * Initialize the data and return the amount of I/O space to
54	 * reserve for the space.
55	 */
56	unsigned int (*init_data)(struct si_sm_data *smi,
57				  struct si_sm_io   *io);
58
59	/*
60	 * Start a new transaction in the state machine.  This will
61	 * return -2 if the state machine is not idle, -1 if the size
62	 * is invalid (to large or too small), or 0 if the transaction
63	 * is successfully completed.
64	 */
65	int (*start_transaction)(struct si_sm_data *smi,
66				 unsigned char *data, unsigned int size);
67
68	/*
69	 * Return the results after the transaction.  This will return
70	 * -1 if the buffer is too small, zero if no transaction is
71	 * present, or the actual length of the result data.
72	 */
73	int (*get_result)(struct si_sm_data *smi,
74			  unsigned char *data, unsigned int length);
75
76	/*
77	 * Call this periodically (for a polled interface) or upon
78	 * receiving an interrupt (for a interrupt-driven interface).
79	 * If interrupt driven, you should probably poll this
80	 * periodically when not in idle state.  This should be called
81	 * with the time that passed since the last call, if it is
82	 * significant.  Time is in microseconds.
83	 */
84	enum si_sm_result (*event)(struct si_sm_data *smi, long time);
85
86	/*
87	 * Attempt to detect an SMI.  Returns 0 on success or nonzero
88	 * on failure.
89	 */
90	int (*detect)(struct si_sm_data *smi);
91
92	/* The interface is shutting down, so clean it up. */
93	void (*cleanup)(struct si_sm_data *smi);
94
95	/* Return the size of the SMI structure in bytes. */
96	int (*size)(void);
97};
98
99/* Current state machines that we can use. */
100extern const struct si_sm_handlers kcs_smi_handlers;
101extern const struct si_sm_handlers smic_smi_handlers;
102extern const struct si_sm_handlers bt_smi_handlers;
103
104#endif /* __IPMI_SI_SM_H__ */
105