upiwin/src/sysinput.c

#include <stddef.h>
#include <signal.h>
#include <pthread.h>
#include "log.h"
#include "msg_queue.h"
#include "gpio.h"

PMSG_QUEUE Sys_Queue = NULL;

static pthread_t ithread;
static volatile sig_atomic_t running = 1;
static int last_bstate = 0;

static void *input_thread(void *arg)
{
  int st, tmp, mask;
  uintptr_t attr;
  
  while (running)
  {
    /* poll hardware buttons */
    st = Gpio_read_buttons();
    if (st != last_bstate)
    {
      tmp = last_bstate & ~st;
      for (attr = 1, mask = 1; attr <= 4; attr++, mask <<= 1)
      {
	if (tmp & mask)
	  MqPost1(Sys_Queue, 0, WM_HWBUTTONUP, attr);
      }
      tmp = st & ~last_bstate;
      for (attr = 1, mask = 1; attr <= 4; attr++, mask <<= 1)
      {
	if (tmp & mask)
	  MqPost1(Sys_Queue, 0, WM_HWBUTTONDOWN, attr);
      }
      last_bstate = st;
    }

    /* additional poll activity here */
  }
  return NULL;
}

int SysEnableInput(void)
{
  int rc;
  
  Sys_Queue = MqAlloc(64);
  if (!Sys_Queue)
  {
    Log(LFATAL, "Unable to allocate system message queue.");
    return 1;
  }
  running = 1;
  rc = pthread_create(&ithread, NULL, input_thread, NULL);
  if (rc != 0)
    Log(LFATAL, "Unable to start system input thread (%d).", rc);
  return rc;
}

void SysDisableInput(void)
{
  running = 0;
  pthread_join(ithread, NULL);
  MqDestroy(Sys_Queue);
  Sys_Queue = NULL;
}