blink1raw.c

/* 
 * blinkraw.c
 *
 * fgmr 2012-09-22
 *
 * playing with the hidraw interface to blink(1)
 * 
 * Thank you Alan Ott for
 * http://lxr.free-electrons.com/source/samples/hidraw/hid-example.c
 */

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

#ifndef HIDIOCSFEATURE
#define HIDIOCSFEATURE(len) _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x06, len)
#define HIDIOCGFEATURE(len) _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x07, len)
#endif /* HIDIOCSFEATURE */

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

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <stdarg.h>
#include <ctype.h>

static void
usage(const char* hunh) {
  if (NULL != hunh) {
    fprintf(stderr, "Can't understand %s\n", hunh);
  }

  fprintf(stderr,
          "Usage: blinkraw {arg, ...}\n"
          "  /dev/whatever  -- open device\n"
          "  ./whatever     -- open device\n"
          "  =R,G,B,t       -- fade to color\n"
          "  :R,G,B         -- set color (now)\n"
          "  @step:R,G,B,t  -- set step\n"
          "  +step          -- start playing at step\n"
          "  -[step]        -- stop playing at step (default zero)\n"
          "  %%              -- clear all steps\n"
          "  _              -- turn off\n"
          "  _t             -- fade off\n"
          "\n"
          "       step is on [0,15]\n",
          "       R, G, B are on [0, 255]\n"
          "       t is time in centiseconds\n"
          "\n"
          "    Arguments are applied in order.  A new device, which is\n"
          "    a valid blink(1) device, will become the new target.\n"
          "\n"
          "    Example:\n"
          "    # blinkraw /dev/hidraw* % =255,0,0,100\n"
          );
  exit(1);
}

static void
color(int fd, char action, int R, int G, int B, int T, int step) {
  char buf[16];
  int rc;