// SPDX-License-Identifier: GPL-2.0
/*
 * Hidraw Userspace Example
 *
 * Copyright (c) 2010 Alan Ott <alan@signal11.us>
 * Copyright (c) 2010 Signal 11 Software
 *
 * The code may be used by anyone for any purpose,
 * and can serve as a starting point for developing
 * applications using hidraw.
 */

/* Linux */
#include <linux/types.h>
#include <linux/input.h>
#include <linux/hidraw.h>

#ifndef HIDIOCSFEATURE
#warning Please have your distro update the userspace kernel headers
#define HIDIOCSFEATURE(len)    _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x06, len)
#define HIDIOCGFEATURE(len)    _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x07, len)
#endif

/* Unix */
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

/* C */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>

int main(int argc, char **argv)
{
        int fd;
        int i, res, desc_size = 0;
        char buf[256];
        struct hidraw_report_descriptor rpt_desc;
        struct hidraw_devinfo info;
        char *device = "/dev/hidraw1";

        if (argc > 1)
                device = argv[1];

        /* Open the Device with non-blocking reads. In real life,
           don't use a hard coded path; use libudev instead. */
        fd = open(device, O_RDWR|O_NONBLOCK);

        if (fd < 0) {
                perror("Unable to open device");
                return 1;
        }

        memset(&rpt_desc, 0x0, sizeof(rpt_desc));
        memset(&info, 0x0, sizeof(info));
        memset(buf, 0x0, sizeof(buf));

        /* Send a Report to the Device */
        buf[0] = 0x7B; /* Report Number */
        buf[1] = 0x03;
        buf[2] = 0x40;
        buf[3] = 0x7D;
        for (i=4; i<66; i++)
                buf[i]=0x0;

        res = write(fd, buf, 64);
        if (res < 0) {
                printf("Error: %d\n", errno);
                perror("write");
        } //else {
                //printf("write() wrote %d bytes\n", res);
        //}

        sleep(1);

        /* Get a report from the device */
        res = read(fd, buf, 64);
        if (res < 0) {
                perror("read");
        } //else {
          //    printf("read() read %d bytes:\n\t", res);
          //    for (i = 0; i < res; i++)
          //            printf("%hhx ", buf[i]);
          //    puts("\n");
        //}

        printf("\n");
        { int chan=0,t,t1,t2,hu;
          printf("--------------------------------\n");
          printf("Channel | Temperature | Humidity\n");
          printf("================================\n");
          for (i=1; i<=24; i+=3) {
            chan+=1;
            t=(buf[i+1] + (buf[i] << 8)) ; 
            if (t < 0) {
              t+=256;
            }
            t1=buf[i];
            t2=buf[i+1];
            hu=buf[i+2];
            if (t1 != 0x7F && t2 != 0xFF && hu != 0xFF)
                  printf("% 5d        %04.1f        %2.2d\%\n",chan,t/10.0,hu);
          }
        }
        close(fd);
        return 0;
}