1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
|
/*
* Copyright (C) 1995 Advanced RISC Machines Limited. All rights reserved.
*
* This software may be freely used, copied, modified, and distributed
* provided that the above copyright notice is preserved in all copies of the
* software.
*/
/* -*-C-*-
*
* $Revision$
* $Date$
*
*/
#ifndef angsd_devsw_h
#define angsd_devsw_h
#include "devclnt.h"
#include "adperr.h"
#include "drivers.h"
#ifndef __cplusplus
typedef struct Packet Packet;
typedef struct DevSWState DevSWState;
#endif
/*
* the basic structure used for passing packets around
*/
struct Packet
{
struct Packet *pk_next; /* XXX first field in struct */
unsigned int pk_length;
unsigned char *pk_buffer;
};
/*
* control structure, used for maintaining device switcher state
*/
struct DevSWState
{
unsigned int ds_opendevchans; /* bitmap of open device channels */
/*
* queue of packets read for the various device channels
*/
Packet *ds_readqueue[DC_NUM_CHANNELS];
/*
* structures for managing active read and write operations
*/
Packet *ds_nextreadpacket;
DriverCall ds_activeread;
DriverCall ds_activewrite;
};
#ifdef __cplusplus
extern "C" {
#endif
/*
* Function: DevSW_AllocatePacket
* Purpose: Claim some memory to hold a struct Packet, and the buffer for
* that packet.
*
* Params:
* Input: length Size of the buffer in struct Packet.
*
* Returns:
* OK: Pointer to the newly malloc()ed Packet.
* Error: NULL
*/
Packet *DevSW_AllocatePacket(const unsigned int length);
/*
* Function: DevSW_FreePacket
* Purpose: Free the memory associated with a struct Packet.
*
* Pre-conditions The structure must have been originally claimed
* via DevSW_AllocatePacket.
*
* Params:
* Input: pk The packet to be freed.
*
* Returns: Nothing
*/
void DevSW_FreePacket(Packet *pk);
/*
* Function: DevSW_Open
* Purpose: Open the specified device driver
*
* Params:
* Input: name Identifies which device to open. This can either be
* a host specific identifier (e.g. "/dev/ttya",
* "COM1:"), or a number which is used to refer to
* `standard' interfaces, so "1" would be the first host
* interface, "2" the second, and so on.
*
* arg Driver specific arguments. For example, some serial
* drivers accept speed and control arguments such as
* "9600" or "19200/NO_BREAK". These arguments are
* completely free-form: it is the individual drivers
* which do the necessary interpretation.
*
* type The type of packet the caller is interested in. Only
* one open is allowed for each type of packet.
*
* In/Out: device The device driver to open
*
* Returns:
* OK: adp_ok
* Error: adp_device_open_failed
* adp_device_already_open
* adp_malloc_failure
*/
AdpErrs DevSW_Open(DeviceDescr *device, const char *name, const char *arg,
const DevChanID type);
/*
* Function: DevSW_Match
* Purpose: Minimal veneer for DeviceMatch
*
* Params:
* Input: device The device driver to match.
*
* name Identifies which device to open. This can either be
* a host specific identifier (e.g. "/dev/ttya",
* "COM1:"), or a number which is used to refer to
* `standard' interfaces, so "1" would be the first host
* interface, "2" the second, and so on.
*
* arg Driver specific arguments. For example, some serial
* drivers accept speed and control arguments such as
* "9600" or "19200/NO_BREAK". These arguments are
* completely free-form: it is the individual drivers
* which do the necessary interpretation.
*
* Returns:
* OK: adp_ok
* Error: adp_failed
*/
AdpErrs DevSW_Match(const DeviceDescr *device, const char *name,
const char *arg);
/*
* Function: DevSW_Close
* Purpose: Close the specified device driver. All packets of the type
* used by the caller held within the switching layer will
* be discarded.
*
* Pre-conditions: Device must have been previously opened.
*
* Params:
* Input: device The device driver to close
*
* type The type of packet the caller was interested in.
*
* Returns:
* OK: adp_ok
* Error: adp_device_not_open
*/
AdpErrs DevSW_Close(const DeviceDescr *device, const DevChanID type);
/*
* Function: DevSW_Read
* Purpose: Read a packet of appropriate type from the device driver
*
* Params:
* Input: device The device driver to read packet from.
*
* type The type of packet the caller is interested in.
*
* Output: packet Pointer to new packet (if one is available)
* NULL (if no complete packet is available)
*
* Input: block If TRUE, read may safely block for a short period
* of time (say up to 20ms), to avoid high CPU load
* whilst waiting for a reply.
* If FALSE, read MUST NOT block.
*
* Returns:
* OK: adp_ok
* Error: adp_bad_packet
*
* Post-conditions: The calling function is responsible for freeing the
* resources used by the packet when it is no longer
* needed.
*/
AdpErrs DevSW_Read(const DeviceDescr *device, const DevChanID type,
Packet **packet, bool block);
/*
* Function: DevSW_Write
* Purpose: Try to write a packet to the device driver. The write will
* be bounced if another write is still in progress.
*
* Params:
* Input: device The device driver to write a packet to.
*
* packet The packet to be written.
*
* type The type to be assigned to the packet.
*
* Returns:
* OK: adp_ok
* Error: adp_illegal_args
* adp_write_busy
*
* Post-conditions: The calling function retains "ownership" of the packet,
* i.e. it is responsible for freeing the resources used
* by the packet when it is no longer needed.
*/
AdpErrs DevSW_Write(const DeviceDescr *device, Packet *packet, DevChanID type);
/*
* Function: DevSW_FlushPendingWrite
* Purpose: If a write is in progress, give it a chance to finish.
*
* Params:
* Input: device The device driver to flush.
*
* Returns:
* adp_ok no pending write, or write flushed completely
* adp_write_busy pending write not flushed completely
*/
AdpErrs DevSW_FlushPendingWrite(const DeviceDescr *device);
/*
* Function: DevSW_Ioctl
* Purpose: Perform miscellaneous control operations. This is a minimal
* veneer to DeviceIoctl.
*
* Params:
* Input: device The device driver to control.
*
* opcode Reason code indicating the operation to perform.
*
* In/Out: args Pointer to opcode-sensitive arguments/result space.
*
* Returns:
* OK: adp_ok
* Error: adp_failed
*/
AdpErrs DevSW_Ioctl(const DeviceDescr *device, const int opcode, void *args);
/*
* Function: DevSW_WriteFinished
* Purpose: Return TRUE if the active device has finished writing
* the last packet to be sent, or FALSE if a packet is still
* being transmitted.
*
* Params:
* Input: device The device driver to check.
*
* Returns:
* TRUE: write finished or inactive
* FALSE: write in progress
*/
bool DevSW_WriteFinished(const DeviceDescr *device);
#ifdef __cplusplus
}
#endif
#endif /* ndef angsd_devsw_h */
/* EOF devsw.h */
|
