xref: /openbmc/linux/drivers/char/ipmi/ipmi_si_sm.h (revision 3213486f)
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 #include <linux/ipmi.h>
18 
19 /*
20  * This is defined by the state machines themselves, it is an opaque
21  * data type for them to use.
22  */
23 struct si_sm_data;
24 
25 enum si_type {
26 	SI_TYPE_INVALID, SI_KCS, SI_SMIC, SI_BT
27 };
28 
29 enum ipmi_addr_space {
30 	IPMI_IO_ADDR_SPACE, IPMI_MEM_ADDR_SPACE
31 };
32 
33 /*
34  * The structure for doing I/O in the state machine.  The state
35  * machine doesn't have the actual I/O routines, they are done through
36  * this interface.
37  */
38 struct si_sm_io {
39 	unsigned char (*inputb)(const struct si_sm_io *io, unsigned int offset);
40 	void (*outputb)(const struct si_sm_io *io,
41 			unsigned int  offset,
42 			unsigned char b);
43 
44 	/*
45 	 * Generic info used by the actual handling routines, the
46 	 * state machine shouldn't touch these.
47 	 */
48 	void __iomem *addr;
49 	unsigned int regspacing;
50 	unsigned int regsize;
51 	unsigned int regshift;
52 	enum ipmi_addr_space addr_space;
53 	unsigned long addr_data;
54 	enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
55 	void (*addr_source_cleanup)(struct si_sm_io *io);
56 	void *addr_source_data;
57 	union ipmi_smi_info_union addr_info;
58 
59 	int (*io_setup)(struct si_sm_io *info);
60 	void (*io_cleanup)(struct si_sm_io *info);
61 	unsigned int io_size;
62 
63 	int irq;
64 	int (*irq_setup)(struct si_sm_io *io);
65 	void *irq_handler_data;
66 	void (*irq_cleanup)(struct si_sm_io *io);
67 
68 	u8 slave_addr;
69 	enum si_type si_type;
70 	struct device *dev;
71 };
72 
73 /* Results of SMI events. */
74 enum si_sm_result {
75 	SI_SM_CALL_WITHOUT_DELAY, /* Call the driver again immediately */
76 	SI_SM_CALL_WITH_DELAY,	/* Delay some before calling again. */
77 	SI_SM_CALL_WITH_TICK_DELAY,/* Delay >=1 tick before calling again. */
78 	SI_SM_TRANSACTION_COMPLETE, /* A transaction is finished. */
79 	SI_SM_IDLE,		/* The SM is in idle state. */
80 	SI_SM_HOSED,		/* The hardware violated the state machine. */
81 
82 	/*
83 	 * The hardware is asserting attn and the state machine is
84 	 * idle.
85 	 */
86 	SI_SM_ATTN
87 };
88 
89 /* Handlers for the SMI state machine. */
90 struct si_sm_handlers {
91 	/*
92 	 * Put the version number of the state machine here so the
93 	 * upper layer can print it.
94 	 */
95 	char *version;
96 
97 	/*
98 	 * Initialize the data and return the amount of I/O space to
99 	 * reserve for the space.
100 	 */
101 	unsigned int (*init_data)(struct si_sm_data *smi,
102 				  struct si_sm_io   *io);
103 
104 	/*
105 	 * Start a new transaction in the state machine.  This will
106 	 * return -2 if the state machine is not idle, -1 if the size
107 	 * is invalid (to large or too small), or 0 if the transaction
108 	 * is successfully completed.
109 	 */
110 	int (*start_transaction)(struct si_sm_data *smi,
111 				 unsigned char *data, unsigned int size);
112 
113 	/*
114 	 * Return the results after the transaction.  This will return
115 	 * -1 if the buffer is too small, zero if no transaction is
116 	 * present, or the actual length of the result data.
117 	 */
118 	int (*get_result)(struct si_sm_data *smi,
119 			  unsigned char *data, unsigned int length);
120 
121 	/*
122 	 * Call this periodically (for a polled interface) or upon
123 	 * receiving an interrupt (for a interrupt-driven interface).
124 	 * If interrupt driven, you should probably poll this
125 	 * periodically when not in idle state.  This should be called
126 	 * with the time that passed since the last call, if it is
127 	 * significant.  Time is in microseconds.
128 	 */
129 	enum si_sm_result (*event)(struct si_sm_data *smi, long time);
130 
131 	/*
132 	 * Attempt to detect an SMI.  Returns 0 on success or nonzero
133 	 * on failure.
134 	 */
135 	int (*detect)(struct si_sm_data *smi);
136 
137 	/* The interface is shutting down, so clean it up. */
138 	void (*cleanup)(struct si_sm_data *smi);
139 
140 	/* Return the size of the SMI structure in bytes. */
141 	int (*size)(void);
142 };
143 
144 /* Current state machines that we can use. */
145 extern const struct si_sm_handlers kcs_smi_handlers;
146 extern const struct si_sm_handlers smic_smi_handlers;
147 extern const struct si_sm_handlers bt_smi_handlers;
148 
149