drivers/char/ipmi/ipmi_si_sm.h

   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  */
  26 struct si_sm_data;
  27
  28 /* Results of SMI events. */
  29 enum 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. */
  45 struct 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. */
 100 extern const struct si_sm_handlers kcs_smi_handlers;
 101 extern const struct si_sm_handlers smic_smi_handlers;
 102 extern const struct si_sm_handlers bt_smi_handlers;
 103
 104 #endif /* __IPMI_SI_SM_H__ */