combjs: 15293518d92b combjs.c

combjs

view combjs.c @ 0:15293518d92b

first version, combined joystick seems to be working, max 32 buttons.

author	John Tsiombikas <nuclear@member.fsf.org>
date	Wed, 13 Jul 2011 07:12:57 +0300
parents
children	dd02002227a2

line source

1 /*

2 combjs - combine multiple joysticks in one virtual joystick

5 This program is free software: you can redistribute it and/or modify

6 it under the terms of the GNU General Public License as published by

7 the Free Software Foundation, either version 3 of the License, or

8 (at your option) any later version.

10 This program is distributed in the hope that it will be useful,

11 but WITHOUT ANY WARRANTY; without even the implied warranty of

12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

13 GNU General Public License for more details.

15 You should have received a copy of the GNU General Public License

16 along with this program. If not, see <http://www.gnu.org/licenses/>.

17 */

19 #include <stdio.h>

20 #include <stdlib.h>

21 #include <string.h>

22 #include <errno.h>

23 #include <limits.h>

24 #include <signal.h>

25 #include <unistd.h>

26 #include <fcntl.h>

27 #include <sys/select.h>

28 #include <sys/ioctl.h>

29 #include <linux/joystick.h>

30 #include <linux/input.h>

31 #include <linux/uinput.h>

33 #define DBG_MAX_BN 32

35 struct joystick {

36 char *name;

37 int fd;

38 int num_bn, num_axes;

39 int bn_offset, axis_offset;

41 struct joystick *next;

42 };

44 void cleanup(void);

45 int create_virt_js(const char *uinput_dev, const char *devname);

46 int handle_event(struct joystick *js, struct js_event *ev);

47 int add_joystick(const char *devfile);

48 void sig_handler(int sig);

49 int proc_cmdline(int argc, char **argv);

50 void print_usage(const char *argv0);

53 int vfd = -1;

54 const char *virt_dev_name = "combjs - virtual multi-joystick combiner";

55 const char *uinput_dev_name = "/dev/uinput";

56 struct joystick *jslist, *jstail;

57 int num_vaxes, num_vbn;

60 int main(int argc, char **argv)

61 {

62 signal(SIGINT, sig_handler);

63 signal(SIGQUIT, sig_handler);

64 signal(SIGTERM, sig_handler);

66 if(proc_cmdline(argc, argv) == -1) {

67 return 1;

68 }

70 if((vfd = create_virt_js(uinput_dev_name, virt_dev_name)) == -1) {

71 cleanup();

72 return 1;

73 }

75 for(;;) {

76 fd_set rdset;

77 struct joystick *js = jslist;

78 int maxfd = jstail->fd; /* XXX precalc */

80 FD_ZERO(&rdset);

81 while(js) {

82 FD_SET(js->fd, &rdset);

83 if(js->fd > maxfd) {

84 maxfd = js->fd;

85 }

86 js = js->next;

87 }

89 while(select(maxfd + 1, &rdset, 0, 0, 0) == -1 && errno == EINTR);

91 js = jslist;

92 while(js) {

93 if(FD_ISSET(js->fd, &rdset)) {

94 struct js_event ev;

95 if(read(js->fd, &ev, sizeof ev) > 0) {

96 handle_event(js, &ev);

97 }

98 }

99 js = js->next;

100 }

101 }

102

103 return 0;

104 }

105

106 void cleanup(void)

107 {

108 while(jslist) {

109 struct joystick *js = jslist;

110 jslist = jslist->next;

111

112 close(js->fd);

113 free(js->name);

114 free(js);

115 }

116

117 if(vfd >= 0) {

118 ioctl(vfd, UI_DEV_DESTROY);

119 close(vfd);

120 }

121 }

122

123 int create_virt_js(const char *uinput_dev, const char *devname)

124 {

125 int i, fd;

126 struct uinput_user_dev uidev;

127

128 if((fd = open(uinput_dev, O_WRONLY | O_NONBLOCK)) == -1) {

129 perror("failed to open uinput device");

130 return -1;

131 }

132

133 if(ioctl(fd, UI_SET_EVBIT, EV_ABS) == -1) {

134 close(fd);

135 return -1;

136 }

137 if(ioctl(fd, UI_SET_EVBIT, EV_KEY) == -1) {

138 close(fd);

139 return -1;

140 }

141 if(ioctl(fd, UI_SET_EVBIT, EV_SYN) == -1) {

142 close(fd);

143 return -1;

144 }

145

146 memset(&uidev, 0, sizeof uidev);

147 strncpy(uidev.name, devname, UINPUT_MAX_NAME_SIZE);

148 uidev.id.bustype = BUS_USB;

149 uidev.id.vendor = 0x1234;

150 uidev.id.product = 0xfedc;

151 uidev.id.version = 1;

152

153 for(i=0; i<num_vbn; i++) {

154 if(i >= DBG_MAX_BN) break;

155 ioctl(fd, UI_SET_KEYBIT, i + BTN_0);

156 }

157

158 for(i=0; i<num_vaxes; i++) {

159 ioctl(fd, UI_SET_ABSBIT, i);

160 uidev.absmin[i] = SHRT_MIN;

161 uidev.absmax[i] = SHRT_MAX;

162 }

163

164 if(write(fd, &uidev, sizeof uidev) == -1) {

165 perror("failed to set virtual device parameters");

166 close(fd);

167 return -1;

168 }

169

170 if(ioctl(fd, UI_DEV_CREATE) == -1) {

171 perror("failed to create the virtual device");

172 close(fd);

173 return -1;

174 }

175 return fd;

176 }

177

178 int handle_event(struct joystick *js, struct js_event *evin)

179 {

180 struct input_event evout;

181

182 memset(&evout, 0, sizeof evout);

183

184 if(evin->type & JS_EVENT_AXIS) {

185 evout.type = EV_ABS;

186 evout.code = evin->number + js->axis_offset;

187 evout.value = evin->value;

188

189 } else if(evin->type & JS_EVENT_BUTTON) {

190 evout.type = EV_KEY;

191 evout.code = evin->number + js->bn_offset + BTN_0;

192 evout.value = evin->value;

193

194 if(evout.code >= BTN_0 + DBG_MAX_BN) return 0;

195

196 } else {

197 return 0;

198 }

199

200 if(write(vfd, &evout, sizeof evout) == -1) {

201 perror("failed to generate virtual joystick event");

202 return -1;

203 }

204 return 0;

205 }

206

207 int add_joystick(const char *devfile)

208 {

209 struct joystick *js;

210 char buf[512];

211

212 if(!(js = calloc(1, sizeof *js))) {

213 perror("failed to allocate memory");

214 goto err;

215 }

216

217 if((js->fd = open(devfile, O_RDONLY | O_NONBLOCK)) == -1) {

218 fprintf(stderr, "failed to open %s: %s\n", devfile, strerror(errno));

219 goto err;

220 }

221

222 if(ioctl(js->fd, JSIOCGNAME(sizeof buf), buf) == -1) {

223 fprintf(stderr, "failed to get joystick name for %s: %s\n", devfile, strerror(errno));

224 strcpy(buf, "<unknown>");

225 }

226 if(!(js->name = malloc(strlen(buf) + 1))) {

227 perror("failed to allocate memory");

228 goto err;

229 }

230 strcpy(js->name, buf);

231

232 if(ioctl(js->fd, JSIOCGBUTTONS, &js->num_bn) == -1) {

233 fprintf(stderr, "failed to get joystick %s's number of buttons: %s\n", devfile, strerror(errno));

234 goto err;

235 }

236 if(ioctl(js->fd, JSIOCGAXES, &js->num_axes) == -1) {

237 fprintf(stderr, "failed to get joystick %s's number of axes: %s\n", devfile, strerror(errno));

238 goto err;

239 }

240

241 if(!jstail) {

242 jslist = jstail = js;

243 } else {

244 js->axis_offset = jstail->axis_offset + jstail->num_axes;

245 js->bn_offset = jstail->bn_offset + jstail->num_bn;

246 jstail->next = js;

247 jstail = js;

248 }

249

250 num_vaxes = js->axis_offset + js->num_axes;

251 num_vbn = js->bn_offset + js->num_bn;

252

253 printf("added joystick %s: %s\n", devfile, js->name);

254 printf(" - %d axes (offset: %d)\n", js->num_axes, js->axis_offset);

255 printf(" - %d buttons (offset: %d)\n", js->num_bn, js->bn_offset);

256 return 0;

257

258 err:

259 if(js) {

260 close(js->fd);

261 free(js->name);

262 free(js);

263 }

264 return -1;

265 }

266

267 void sig_handler(int sig)

268 {

269 cleanup();

270 exit(0);

271 }

272

273 int proc_cmdline(int argc, char **argv)

274 {

275 int i;

276

277 for(i=1; i<argc; i++) {

278 if(argv[i][0] == '-') {

279 if(argv[i][2] == 0) {

280 switch(argv[i][1]) {

281 case 'h':

282 print_usage(argv[0]);

283 exit(0);

284

285 default:

286 fprintf(stderr, "invalid argument: %s\n", argv[i]);

287 print_usage(argv[0]);

288 return -1;

289 }

290 } else {

291 fprintf(stderr, "invalid argument: %s\n", argv[i]);

292 print_usage(argv[0]);

293 }

294 } else {

295 if(add_joystick(argv[i]) == -1) {

296 return -1;

297 }

298 }

299 }

300

301 if(!jslist) {

302 fprintf(stderr, "no joystick devices specified\n");

303 print_usage(argv[0]);

304 return -1;

305 }

306

307 return 0;

308 }

309

310 void print_usage(const char *argv0)

311 {

312 printf("usage: %s <dev 0> [dev1] ... [dev n]\n", argv0);

313 }