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__ */