hid_detect.c

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/* $Header: /var/cvs/mbdyn/mbdyn/mbdyn-1.0/modules/module-hid/hid_detect.c,v 1.5 2017/01/12 14:52:24 masarati Exp $ */
/* 
 * MBDyn (C) is a multibody analysis code. 
 * http://www.mbdyn.org
 *
 * Copyright (C) 1996-2017
 *
 * Pierangelo Masarati  <masarati@aero.polimi.it>
 * Paolo Mantegazza     <mantegazza@aero.polimi.it>
 *
 * Dipartimento di Ingegneria Aerospaziale - Politecnico di Milano
 * via La Masa, 34 - 20156 Milano, Italy
 * http://www.aero.polimi.it
 *
 * Changing this copyright notice is forbidden.
 *
 * 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 (version 2 of the License).
 * 
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "stdlib.h"
#include "unistd.h"
#include "stdio.h"
#include "errno.h"
#include "stdint.h"
#include "string.h"

#define LO(x) ((x) & 0x0F)
#define HI(x) (((x) & 0xF0) >> 8)
#define HEX(x) ("0123456789abcdef"[(x)])

static const char *
type2str(uint8_t type)
{
        switch (type) {
        case 1:
                return "button";
        case 2:
                return "linctl";
        }
        return "unknwn";
}

int
main(int argc, char *argv[])
{
        FILE *fd;

        const char *device = "/dev/input/js0";
        
        if (argc > 1) {
                device = argv[1];
        }

        fd = fopen(device, "r");
        if (fd == NULL) {
                int save_errno = errno;
                fprintf(stderr, "fopen(\"%s\")=%d %s\n", device, save_errno, strerror(save_errno));
                exit(EXIT_FAILURE);
        }

        int nbt = 0, nlc = 0;
        uint8_t maxbt = 0, maxlc = 0;
        int preamble = 1;

        for (;;) {
                char buf[8];
                uint32_t cnt;
                int16_t value;
                uint8_t type, idx;

                size_t rc;

                rc = fread((void *)&buf[0], 1, sizeof(buf), fd);
                if (rc < 1) {
                        fprintf(stderr, "fread returned no data\n");
                        break;
                }

                cnt = *((uint32_t *)&buf[0]);
                value = *((int16_t *)&buf[4]);
                type = *((uint8_t *)&buf[6]);
                idx = *((uint8_t *)&buf[7]);

                if (preamble) {
                        if (!(type & 0x80U)) {
                                printf("buttons=%d (max=%u) linear controls=%d (max=%u)\n\n", nbt, maxbt, nlc, maxlc);
                                preamble = 0;

                        } else {
                                switch (type & 0x7FU) {
                                case 1:
                                        nbt++;
                                        if (idx > maxbt) {
                                                maxbt = idx;
                                        }
                                        break;

                                case 2:
                                        nlc++;
                                        if (idx > maxlc) {
                                                maxlc = idx;
                                        }
                                        break;
                                }

                                printf("0x%8x %s[%2u]=%6d\n", cnt, type2str(type & 0x7FU), idx, value);

                                continue;
                        }
                }

                printf("0x%8x %s[%2u]=%6d\n", cnt, type2str(type), idx, value);
        }

        return 0;
}