1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/combjs.c	Wed Jul 13 07:12:57 2011 +0300
     1.3 @@ -0,0 +1,313 @@
     1.4 +/*
     1.5 +combjs - combine multiple joysticks in one virtual joystick
     1.6 +Copyright (C) 2011  John Tsiombikas <nuclear@member.fsf.org>
     1.7 +
     1.8 +This program is free software: you can redistribute it and/or modify
     1.9 +it under the terms of the GNU General Public License as published by
    1.10 +the Free Software Foundation, either version 3 of the License, or
    1.11 +(at your option) any later version.
    1.12 +
    1.13 +This program is distributed in the hope that it will be useful,
    1.14 +but WITHOUT ANY WARRANTY; without even the implied warranty of
    1.15 +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    1.16 +GNU General Public License for more details.
    1.17 +
    1.18 +You should have received a copy of the GNU General Public License
    1.19 +along with this program.  If not, see <http://www.gnu.org/licenses/>.
    1.20 +*/
    1.21 +
    1.22 +#include <stdio.h>
    1.23 +#include <stdlib.h>
    1.24 +#include <string.h>
    1.25 +#include <errno.h>
    1.26 +#include <limits.h>
    1.27 +#include <signal.h>
    1.28 +#include <unistd.h>
    1.29 +#include <fcntl.h>
    1.30 +#include <sys/select.h>
    1.31 +#include <sys/ioctl.h>
    1.32 +#include <linux/joystick.h>
    1.33 +#include <linux/input.h>
    1.34 +#include <linux/uinput.h>
    1.35 +
    1.36 +#define DBG_MAX_BN	32
    1.37 +
    1.38 +struct joystick {
    1.39 +	char *name;
    1.40 +	int fd;
    1.41 +	int num_bn, num_axes;
    1.42 +	int bn_offset, axis_offset;
    1.43 +
    1.44 +	struct joystick *next;
    1.45 +};
    1.46 +
    1.47 +void cleanup(void);
    1.48 +int create_virt_js(const char *uinput_dev, const char *devname);
    1.49 +int handle_event(struct joystick *js, struct js_event *ev);
    1.50 +int add_joystick(const char *devfile);
    1.51 +void sig_handler(int sig);
    1.52 +int proc_cmdline(int argc, char **argv);
    1.53 +void print_usage(const char *argv0);
    1.54 +
    1.55 +
    1.56 +int vfd = -1;
    1.57 +const char *virt_dev_name = "combjs - virtual multi-joystick combiner";
    1.58 +const char *uinput_dev_name = "/dev/uinput";
    1.59 +struct joystick *jslist, *jstail;
    1.60 +int num_vaxes, num_vbn;
    1.61 +
    1.62 +
    1.63 +int main(int argc, char **argv)
    1.64 +{
    1.65 +	signal(SIGINT, sig_handler);
    1.66 +	signal(SIGQUIT, sig_handler);
    1.67 +	signal(SIGTERM, sig_handler);
    1.68 +
    1.69 +	if(proc_cmdline(argc, argv) == -1) {
    1.70 +		return 1;
    1.71 +	}
    1.72 +
    1.73 +	if((vfd = create_virt_js(uinput_dev_name, virt_dev_name)) == -1) {
    1.74 +		cleanup();
    1.75 +		return 1;
    1.76 +	}
    1.77 +
    1.78 +	for(;;) {
    1.79 +		fd_set rdset;
    1.80 +		struct joystick *js = jslist;
    1.81 +		int maxfd = jstail->fd;	/* XXX precalc */
    1.82 +
    1.83 +		FD_ZERO(&rdset);
    1.84 +		while(js) {
    1.85 +			FD_SET(js->fd, &rdset);
    1.86 +			if(js->fd > maxfd) {
    1.87 +				maxfd = js->fd;
    1.88 +			}
    1.89 +			js = js->next;
    1.90 +		}
    1.91 +
    1.92 +		while(select(maxfd + 1, &rdset, 0, 0, 0) == -1 && errno == EINTR);
    1.93 +
    1.94 +		js = jslist;
    1.95 +		while(js) {
    1.96 +			if(FD_ISSET(js->fd, &rdset)) {
    1.97 +				struct js_event ev;
    1.98 +				if(read(js->fd, &ev, sizeof ev) > 0) {
    1.99 +					handle_event(js, &ev);
   1.100 +				}
   1.101 +			}
   1.102 +			js = js->next;
   1.103 +		}
   1.104 +	}
   1.105 +
   1.106 +	return 0;
   1.107 +}
   1.108 +
   1.109 +void cleanup(void)
   1.110 +{
   1.111 +	while(jslist) {
   1.112 +		struct joystick *js = jslist;
   1.113 +		jslist = jslist->next;
   1.114 +
   1.115 +		close(js->fd);
   1.116 +		free(js->name);
   1.117 +		free(js);
   1.118 +	}
   1.119 +
   1.120 +	if(vfd >= 0) {
   1.121 +		ioctl(vfd, UI_DEV_DESTROY);
   1.122 +		close(vfd);
   1.123 +	}
   1.124 +}
   1.125 +
   1.126 +int create_virt_js(const char *uinput_dev, const char *devname)
   1.127 +{
   1.128 +	int i, fd;
   1.129 +	struct uinput_user_dev uidev;
   1.130 +
   1.131 +	if((fd = open(uinput_dev, O_WRONLY | O_NONBLOCK)) == -1) {
   1.132 +		perror("failed to open uinput device");
   1.133 +		return -1;
   1.134 +	}
   1.135 +
   1.136 +	if(ioctl(fd, UI_SET_EVBIT, EV_ABS) == -1) {
   1.137 +		close(fd);
   1.138 +		return -1;
   1.139 +	}
   1.140 +	if(ioctl(fd, UI_SET_EVBIT, EV_KEY) == -1) {
   1.141 +		close(fd);
   1.142 +		return -1;
   1.143 +	}
   1.144 +	if(ioctl(fd, UI_SET_EVBIT, EV_SYN) == -1) {
   1.145 +		close(fd);
   1.146 +		return -1;
   1.147 +	}
   1.148 +
   1.149 +	memset(&uidev, 0, sizeof uidev);
   1.150 +	strncpy(uidev.name, devname, UINPUT_MAX_NAME_SIZE);
   1.151 +	uidev.id.bustype = BUS_USB;
   1.152 +	uidev.id.vendor = 0x1234;
   1.153 +	uidev.id.product = 0xfedc;
   1.154 +	uidev.id.version = 1;
   1.155 +
   1.156 +	for(i=0; i<num_vbn; i++) {
   1.157 +		if(i >= DBG_MAX_BN) break;
   1.158 +		ioctl(fd, UI_SET_KEYBIT, i + BTN_0);
   1.159 +	}
   1.160 +
   1.161 +	for(i=0; i<num_vaxes; i++) {
   1.162 +		ioctl(fd, UI_SET_ABSBIT, i);
   1.163 +		uidev.absmin[i] = SHRT_MIN;
   1.164 +		uidev.absmax[i] = SHRT_MAX;
   1.165 +	}
   1.166 +
   1.167 +	if(write(fd, &uidev, sizeof uidev) == -1) {
   1.168 +		perror("failed to set virtual device parameters");
   1.169 +		close(fd);
   1.170 +		return -1;
   1.171 +	}
   1.172 +
   1.173 +	if(ioctl(fd, UI_DEV_CREATE) == -1) {
   1.174 +		perror("failed to create the virtual device");
   1.175 +		close(fd);
   1.176 +		return -1;
   1.177 +	}
   1.178 +	return fd;
   1.179 +}
   1.180 +
   1.181 +int handle_event(struct joystick *js, struct js_event *evin)
   1.182 +{
   1.183 +	struct input_event evout;
   1.184 +
   1.185 +	memset(&evout, 0, sizeof evout);
   1.186 +
   1.187 +	if(evin->type & JS_EVENT_AXIS) {
   1.188 +		evout.type = EV_ABS;
   1.189 +		evout.code = evin->number + js->axis_offset;
   1.190 +		evout.value = evin->value;
   1.191 +
   1.192 +	} else if(evin->type & JS_EVENT_BUTTON) {
   1.193 +		evout.type = EV_KEY;
   1.194 +		evout.code = evin->number + js->bn_offset + BTN_0;
   1.195 +		evout.value = evin->value;
   1.196 +
   1.197 +		if(evout.code >= BTN_0 + DBG_MAX_BN) return 0;
   1.198 +
   1.199 +	} else {
   1.200 +		return 0;
   1.201 +	}
   1.202 +
   1.203 +	if(write(vfd, &evout, sizeof evout) == -1) {
   1.204 +		perror("failed to generate virtual joystick event");
   1.205 +		return -1;
   1.206 +	}
   1.207 +	return 0;
   1.208 +}
   1.209 +
   1.210 +int add_joystick(const char *devfile)
   1.211 +{
   1.212 +	struct joystick *js;
   1.213 +	char buf[512];
   1.214 +
   1.215 +	if(!(js = calloc(1, sizeof *js))) {
   1.216 +		perror("failed to allocate memory");
   1.217 +		goto err;
   1.218 +	}
   1.219 +
   1.220 +	if((js->fd = open(devfile, O_RDONLY | O_NONBLOCK)) == -1) {
   1.221 +		fprintf(stderr, "failed to open %s: %s\n", devfile, strerror(errno));
   1.222 +		goto err;
   1.223 +	}
   1.224 +
   1.225 +	if(ioctl(js->fd, JSIOCGNAME(sizeof buf), buf) == -1) {
   1.226 +		fprintf(stderr, "failed to get joystick name for %s: %s\n", devfile, strerror(errno));
   1.227 +		strcpy(buf, "<unknown>");
   1.228 +	}
   1.229 +	if(!(js->name = malloc(strlen(buf) + 1))) {
   1.230 +		perror("failed to allocate memory");
   1.231 +		goto err;
   1.232 +	}
   1.233 +	strcpy(js->name, buf);
   1.234 +
   1.235 +	if(ioctl(js->fd, JSIOCGBUTTONS, &js->num_bn) == -1) {
   1.236 +		fprintf(stderr, "failed to get joystick %s's number of buttons: %s\n", devfile, strerror(errno));
   1.237 +		goto err;
   1.238 +	}
   1.239 +	if(ioctl(js->fd, JSIOCGAXES, &js->num_axes) == -1) {
   1.240 +		fprintf(stderr, "failed to get joystick %s's number of axes: %s\n", devfile, strerror(errno));
   1.241 +		goto err;
   1.242 +	}
   1.243 +
   1.244 +	if(!jstail) {
   1.245 +		jslist = jstail = js;
   1.246 +	} else {
   1.247 +		js->axis_offset = jstail->axis_offset + jstail->num_axes;
   1.248 +		js->bn_offset = jstail->bn_offset + jstail->num_bn;
   1.249 +		jstail->next = js;
   1.250 +		jstail = js;
   1.251 +	}
   1.252 +
   1.253 +	num_vaxes = js->axis_offset + js->num_axes;
   1.254 +	num_vbn = js->bn_offset + js->num_bn;
   1.255 +
   1.256 +	printf("added joystick %s: %s\n", devfile, js->name);
   1.257 +	printf("  - %d axes (offset: %d)\n", js->num_axes, js->axis_offset);
   1.258 +	printf("  - %d buttons (offset: %d)\n", js->num_bn, js->bn_offset);
   1.259 +	return 0;
   1.260 +
   1.261 +err:
   1.262 +	if(js) {
   1.263 +		close(js->fd);
   1.264 +		free(js->name);
   1.265 +		free(js);
   1.266 +	}
   1.267 +	return -1;
   1.268 +}
   1.269 +
   1.270 +void sig_handler(int sig)
   1.271 +{
   1.272 +	cleanup();
   1.273 +	exit(0);
   1.274 +}
   1.275 +
   1.276 +int proc_cmdline(int argc, char **argv)
   1.277 +{
   1.278 +	int i;
   1.279 +
   1.280 +	for(i=1; i<argc; i++) {
   1.281 +		if(argv[i][0] == '-') {
   1.282 +			if(argv[i][2] == 0) {
   1.283 +				switch(argv[i][1]) {
   1.284 +				case 'h':
   1.285 +					print_usage(argv[0]);
   1.286 +					exit(0);
   1.287 +
   1.288 +				default:
   1.289 +					fprintf(stderr, "invalid argument: %s\n", argv[i]);
   1.290 +					print_usage(argv[0]);
   1.291 +					return -1;
   1.292 +				}
   1.293 +			} else {
   1.294 +				fprintf(stderr, "invalid argument: %s\n", argv[i]);
   1.295 +				print_usage(argv[0]);
   1.296 +			}
   1.297 +		} else {
   1.298 +			if(add_joystick(argv[i]) == -1) {
   1.299 +				return -1;
   1.300 +			}
   1.301 +		}
   1.302 +	}
   1.303 +
   1.304 +	if(!jslist) {
   1.305 +		fprintf(stderr, "no joystick devices specified\n");
   1.306 +		print_usage(argv[0]);
   1.307 +		return -1;
   1.308 +	}
   1.309 +
   1.310 +	return 0;
   1.311 +}
   1.312 +
   1.313 +void print_usage(const char *argv0)
   1.314 +{
   1.315 +	printf("usage: %s <dev 0> [dev1] ... [dev n]\n", argv0);
   1.316 +}