| 1 | /* |
| 2 | * Copyright (C) 1995 Advanced RISC Machines Limited. All rights reserved. |
| 3 | * |
| 4 | * This software may be freely used, copied, modified, and distributed |
| 5 | * provided that the above copyright notice is preserved in all copies of the |
| 6 | * software. |
| 7 | */ |
| 8 | |
| 9 | /* -*-C-*- |
| 10 | * |
| 11 | * $Revision$ |
| 12 | * $Date$ |
| 13 | * |
| 14 | * |
| 15 | * Project: ANGEL |
| 16 | * |
| 17 | * Title: Definitions for device driver interface. |
| 18 | */ |
| 19 | #ifndef angsd_drivers_h |
| 20 | #define angsd_drivers_h |
| 21 | |
| 22 | #include "rxtx.h" |
| 23 | |
| 24 | #ifndef __cplusplus |
| 25 | typedef struct DeviceDescr DeviceDescr; |
| 26 | typedef struct DriverCall DriverCall; |
| 27 | #endif |
| 28 | |
| 29 | /* |
| 30 | * used to pass packets across the driver interface |
| 31 | */ |
| 32 | struct DriverCall |
| 33 | { |
| 34 | struct data_packet dc_packet; |
| 35 | void *dc_context; |
| 36 | }; |
| 37 | |
| 38 | /* |
| 39 | * used to describe a device driver |
| 40 | */ |
| 41 | struct DeviceDescr |
| 42 | { |
| 43 | char *DeviceName; |
| 44 | int (*DeviceOpen)(const char *name, const char *arg); |
| 45 | int (*DeviceMatch)(const char *name, const char *arg); |
| 46 | void (*DeviceClose)(void); |
| 47 | int (*DeviceRead)(DriverCall *dc, bool block); |
| 48 | int (*DeviceWrite)(DriverCall *dc); |
| 49 | int (*DeviceIoctl)(const int opcode, void *args); |
| 50 | void *SwitcherState; /* used by switcher interface */ |
| 51 | }; |
| 52 | |
| 53 | /* |
| 54 | * Function: DeviceOpen |
| 55 | * |
| 56 | * Purpose: Open a communications device |
| 57 | * |
| 58 | * Pre-conditions: No previous open is still active |
| 59 | * |
| 60 | * Params: |
| 61 | * Input: name Identifies which device to open. This can either be |
| 62 | * a host specific identifier (e.g. "/dev/ttya", |
| 63 | * "COM1:"), or a number which is used to refer to |
| 64 | * `standard' interfaces, so "1" would be the first host |
| 65 | * interface, "2" the second, and so on. |
| 66 | * |
| 67 | * arg Driver specific arguments. For example, some serial |
| 68 | * drivers accept speed and control arguments such as |
| 69 | * "9600" or "19200/NO_BREAK". These arguments are |
| 70 | * completely free-form: it is the individual drivers |
| 71 | * which do the necessary interpretation. |
| 72 | * |
| 73 | * Returns: |
| 74 | * OK: 0 |
| 75 | * Error: -1 |
| 76 | */ |
| 77 | extern int DeviceOpen(const char *name, const char *arg); |
| 78 | |
| 79 | /* |
| 80 | * Function: DeviceMatch |
| 81 | * |
| 82 | * Purpose: Check whether parameters are OK to be passed to DeviceOpen |
| 83 | * |
| 84 | * Params: |
| 85 | * Input: name Identifies which device to open. This can either be |
| 86 | * a host specific identifier (e.g. "/dev/ttya", |
| 87 | * "COM1:"), or a number which is used to refer to |
| 88 | * `standard' interfaces, so "1" would be the first host |
| 89 | * interface, "2" the second, and so on. |
| 90 | * |
| 91 | * arg Driver specific arguments. For example, some serial |
| 92 | * drivers accept speed and control arguments such as |
| 93 | * "9600" or "19200/NO_BREAK". These arguments are |
| 94 | * completely free-form: it is the individual drivers |
| 95 | * which do the necessary interpretation. |
| 96 | * |
| 97 | * Returns: |
| 98 | * OK: 0 |
| 99 | * Error: -1 |
| 100 | */ |
| 101 | extern int DeviceMatch(const char *name, const char *arg); |
| 102 | |
| 103 | /* |
| 104 | * Function: DeviceClose |
| 105 | * |
| 106 | * Purpose: Close a communications device |
| 107 | * |
| 108 | * Pre-conditions: Device must have been previously opened |
| 109 | * |
| 110 | * Params: None |
| 111 | * |
| 112 | * Returns: Nothing |
| 113 | */ |
| 114 | extern void DeviceClose(void); |
| 115 | |
| 116 | /* |
| 117 | * Function: DeviceRead |
| 118 | * |
| 119 | * Purpose: Try to read a complete packet from a communications device. |
| 120 | * This read must usually be non-blocking, i.e. it should read as |
| 121 | * many data from the device as needed to complete the packet, |
| 122 | * but it should not wait if the packet is not complete, and no |
| 123 | * more data are currently available from the device. |
| 124 | * As an optimisation the read can optionally block when 'block' |
| 125 | * is TRUE, but only for a short time. It is acceptable for the |
| 126 | * 'block' parameter to be ignored in which case all reads |
| 127 | * should be non-blocking. |
| 128 | * |
| 129 | * Pre-conditions: Device has been opened via DeviceOpen() |
| 130 | * |
| 131 | * Params: |
| 132 | * In/Out: dc Describes the packet being read (dc->dc_packet); |
| 133 | * dc->dc_context is for the driver to store private |
| 134 | * context, and is guaranteed to be NULL the first |
| 135 | * time DeviceRead is called for a given packet. |
| 136 | * |
| 137 | * In: block If TRUE, read may safely block for a short period |
| 138 | * of time (say up to 20ms), to avoid high CPU load |
| 139 | * whilst waiting for a reply. |
| 140 | * If FALSE, read MUST NOT block. |
| 141 | * |
| 142 | * Returns: |
| 143 | * OK: 1 (packet is complete) |
| 144 | * 0 (packet is not yet complete) |
| 145 | * Error: -1 bad packet |
| 146 | * |
| 147 | * Post-conditions: should a calamatous error occur panic() will be called |
| 148 | */ |
| 149 | extern int DeviceRead(DriverCall *dc, bool block); |
| 150 | |
| 151 | /* |
| 152 | * Function: DeviceWrite |
| 153 | * |
| 154 | * Purpose: Try to write a packet to a communications device. This write |
| 155 | * must be non-blocking, i.e. it should write as many data to |
| 156 | * the device as is immediately possible, but should not wait |
| 157 | * for space to send any more after that. |
| 158 | * |
| 159 | * Pre-conditions: Device has been opened via DeviceOpen() |
| 160 | * |
| 161 | * Params: |
| 162 | * In/Out: dc Describes the packet being written (dc->dc_packet); |
| 163 | * dc->dc_context is for the driver to store private |
| 164 | * context, and is guaranteed to be NULL the first |
| 165 | * time DeviceWrite is called for a given packet. |
| 166 | * |
| 167 | * Returns: |
| 168 | * OK: 1 (all of the packet has been written) |
| 169 | * 0 (some of the packet remains to be written) |
| 170 | * Error: -1 |
| 171 | */ |
| 172 | extern int DeviceWrite(DriverCall *dc); |
| 173 | |
| 174 | /* |
| 175 | * Function: DeviceIoctl |
| 176 | * |
| 177 | * Purpose: Perform miscellaneous driver operations |
| 178 | * |
| 179 | * Pre-conditions: Device has been open via DeviceOpen() |
| 180 | * |
| 181 | * Params: |
| 182 | * Input: opcode Reason code indicating the operation to perform |
| 183 | * In/Out: args Pointer to opcode-sensitive arguments/result space |
| 184 | * |
| 185 | * Returns: |
| 186 | * OK: 0 |
| 187 | * Error: -1 |
| 188 | */ |
| 189 | extern int DeviceIoctl(const int opcode, void *args); |
| 190 | |
| 191 | #endif /* !defined(angsd_drivers_h) */ |
| 192 | |
| 193 | /* EOF drivers.h */ |