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
|
/**********************************************************************
* Minolta Dimage V digital camera communication library *
* Copyright 2000,2001 Gus Hartmann *
* *
* This program is free software; you can redistribute it and/or *
* modify it under the terms of the GNU General Public License as *
* published by the Free Software Foundation; either version 2 of *
* the License, or (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public *
* License along with this program; if not, write to the *
* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA
* *
**********************************************************************/
/* $Id$ */
#include "config.h"
#include <stdio.h>
#include "dimagev.h"
#define GP_MODULE "dimagev"
/* This function takes an array of unsigned chars, as well as the length, and
creates a dimagev_packet ready for sending to the camera. Packets must be
of the form below:
bytes
--------------------------------------------------------------------
| 0 | 1 | 2 | 3 | 4 through ( n-4) | n-3 | n-2 | n-1 |
--------------------------------------------------------------------
| STX | Seq | Length | Payload | Checksum | ETX |
--------------------------------------------------------------------
STX and ETX are defined in dimage.h; their values are 0x02 and 0x03.
Seq is the sequence number; start at zero.
Payload is the good stuff.
Checksum is the sum of all bytes 0 through ( n-4 ) mod 65536.
A packet must be at least eight bytes, with at least one byte of payload.
*/
dimagev_packet *dimagev_make_packet(const unsigned char *const buffer, unsigned int length, unsigned int seq) {
unsigned int i=0, checksum=0;
dimagev_packet *p;
if ( ( p = calloc(1, sizeof(dimagev_packet) ) ) == NULL ) {
GP_DEBUG("dimagev_make_packet::unable to allocate packet");
return NULL;
}
p->length = length + 7;
p->buffer[0] = DIMAGEV_STX;
p->buffer[1] = seq & 0x000000ff;
p->buffer[2] = ( p->length & 0x0000ff00) >> 8;
p->buffer[3] = p->length & 0x000000ff;
memcpy(&(p->buffer[4]), buffer, (unsigned int) length);
/* Now the footer. */
for (i=0 ; i < p->length - 3 ; i++ )
{
checksum += (unsigned int) p->buffer[i];
}
p->buffer[(p->length - 3)] = (unsigned char) ((checksum & 0x0000ff00) >> 8 );
p->buffer[(p->length - 2)] = (unsigned char) ( checksum & 0x000000ff );
p->buffer[(p->length - 1)] = (unsigned char) DIMAGEV_ETX;
return p;
}
/* dimagev_verify_packet(): return GP_OK if valid packet, GP_ERROR otherwise. */
int dimagev_verify_packet(dimagev_packet *p) {
int i=0;
unsigned short correct_checksum=0, current_checksum=0;
/* All packets must start with DIMAGEV_STX and end with DIMAGEV_ETX. It's an easy check. */
if ( ( p->buffer[0] != (unsigned char) DIMAGEV_STX ) || ( p->buffer[(p->length - 1)] != (unsigned char) DIMAGEV_ETX ) ) {
GP_DEBUG( "dimagev_verify_packet::packet missing STX and/or ETX");
return GP_ERROR_CORRUPTED_DATA;
}
correct_checksum = (p->buffer[(p->length - 3)] * 256) + p->buffer[(p->length - 2)];
for ( i = 0 ; i < ( p->length - 3 ) ; i++ ) {
current_checksum += p->buffer[i];
}
if ( current_checksum != correct_checksum ) {
GP_DEBUG( "dimagev_verify_packet::checksum bytes were %02x%02x, checksum was %d, should be %d", p->buffer[( p->length - 3) ], p->buffer[ ( p->length -2 ) ], current_checksum, correct_checksum);
return GP_ERROR_CORRUPTED_DATA;
} else {
return GP_OK;
}
}
dimagev_packet *dimagev_read_packet(dimagev_t *dimagev) {
dimagev_packet *p;
unsigned char char_buffer;
if ( ( p = malloc(sizeof(dimagev_packet)) ) == NULL ) {
GP_DEBUG("dimagev_read_packet::unable to allocate packet");
return NULL;
}
if ( gp_port_read(dimagev->dev, (char *)p->buffer, 4) < GP_OK ) {
GP_DEBUG( "dimagev_read_packet::unable to read packet header - will try to send NAK");
free(p);
/* Send a NAK */
char_buffer = DIMAGEV_NAK;
if ( gp_port_write(dimagev->dev, (char *)&char_buffer, 1) < GP_OK ) {
GP_DEBUG( "dimagev_read_packet::unable to send NAK");
return NULL;
}
/* Who likes recursion? */
return dimagev_read_packet(dimagev);
}
p->length = ( p->buffer[2] * 256 ) + ( p->buffer[3] );
if ( gp_port_read(dimagev->dev, (char *)&(p->buffer[4]), ( p->length - 4)) < GP_OK ) {
GP_DEBUG( "dimagev_read_packet::unable to read packet body - will try to send NAK");
free(p);
/* Send a NAK */
char_buffer = DIMAGEV_NAK;
if ( gp_port_write(dimagev->dev, (char *)&char_buffer, 1) < GP_OK ) {
GP_DEBUG( "dimagev_read_packet::unable to send NAK");
return NULL;
}
/* Who likes recursion? */
return dimagev_read_packet(dimagev);
}
/* Now we *should* have a packet. Let's do a sanity check. */
if ( dimagev_verify_packet(p) < GP_OK ) {
GP_DEBUG( "dimagev_read_packet::got an invalid packet - will try to send NAK");
free(p);
/* Send a NAK */
char_buffer = DIMAGEV_NAK;
if ( gp_port_write(dimagev->dev, (char *)&char_buffer, 1) < GP_OK ) {
GP_DEBUG( "dimagev_read_packet::unable to send NAK");
return NULL;
}
/* Who likes recursion? */
return dimagev_read_packet(dimagev);
}
return p;
}
void dimagev_dump_packet(dimagev_packet *p) {
int i=0;
printf("Packet length is %d\n", p->length);
for ( i = 0 ; i < p->length ; i++ ) {
printf("%02x ",(unsigned int) p->buffer[i]);
}
printf("\n");
return;
}
dimagev_packet *dimagev_strip_packet(dimagev_packet *p) {
dimagev_packet *stripped;
/* All camera packets must start with DIMAGEV_STX and end with DIMAGEV_ETX. */
/* Packets used as strings shouldn't have these. It's an easy check. */
if ( ( p->buffer[0] != (unsigned char) DIMAGEV_STX ) || ( p->buffer[(p->length - 1)] != (unsigned char) DIMAGEV_ETX ) ) {
return NULL;
}
if ( ( stripped = malloc(sizeof(dimagev_packet)) ) == NULL ) {
GP_DEBUG("dimagev_strip_packet::unable to allocate destination packet");
return NULL;
}
stripped->length = ( p->length - 7 );
memcpy(stripped->buffer, &(p->buffer[4]), stripped->length);
return stripped;
}
unsigned char dimagev_decimal_to_bcd(unsigned char decimal) {
unsigned char bcd = (unsigned char) 0;
int tensdigit = 0;
if ( decimal > (unsigned char) 99 ) {
/* No good way to handle this. */
return (unsigned char) 0;
} else {
tensdigit = decimal / 10;
bcd = tensdigit * 16;
bcd += decimal % 10;
return bcd;
}
}
unsigned char dimagev_bcd_to_decimal(unsigned char bcd) {
if ( bcd > 99 ) {
/* The highest value that we can handle in BCD */
return (unsigned char) 99;
} else {
return ((bcd/16)*10 + (bcd%16));
}
}
int dimagev_packet_sequence(dimagev_packet *p) {
return (int) p->buffer[1];
}
|
