fm_search.c

调频收音芯片TEA5767在mx21上的linux驱动程序

/************************************************************************
 *  File Name : fm_search.c
 *  Description :
 *      Test program of fm driver
 *  History :
 *      15-Sep-04       Aaron Shen              New
 ************************************************************************
 */

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <fcntl.h>


#define TEA5767HN_IOC_TEST_I2CRW 12
#define TEA5767HN_IOC_TEST_HILO 13
#define TEA5767HN_IOC_SET_BAND	14
#define TEA5767HN_IOC_AUTO_SEARCH	15
#define TEA5767HN_IOC_STEP_SEARCH_UP	16
#define TEA5767HN_IOC_STANDBY	17
#define TEA5767HN_IOC_STEP_SEARCH_DOWN		18

#define SOUND_MIXER_GARY_BYPASS  80417     //I define it to support bypass mode select

static unsigned int presets[20];
static unsigned char station_num = 0;

static unsigned char check_freq(unsigned int freq)           //don't store existing frequency
{
      unsigned char i;
	unsigned char flag = 0;

	for (i=0; i < station_num ; i++)
	{
	      if(freq != presets[i]) 
			flag = 0;
		else 
		{
		      flag = 1;
			return 0;
		}
	}
	return 1;
}

int main(int argc, char *argv[])
{
	unsigned int freq = 87500;//104800;  //KHz
	int audio_fd, mixer_fd, fm_fd;//, analog_fd;
	int choose = 0, next = 0;
	int i;

      printf("FM radio playing\n");

	audio_fd = open("/dev/dsp", O_WRONLY );
	if (audio_fd == -1) {
		printf ("dev/dsp");
		exit (-1);
	}

	mixer_fd = open("/dev/mixer", O_RDONLY);
       ioctl(mixer_fd, SOUND_MIXER_GARY_BYPASS, 0);

	fm_fd = open("/dev/misc/tea5767hn", O_RDWR);
	if(fm_fd < 0) {
		printf("Device FM radio /dev/misc/tea5767hn open error !\n");
		exit(-1);
	}
	
	while (station_num < 20) {
		 freq = ioctl(fm_fd, TEA5767HN_IOC_STEP_SEARCH_UP, freq);
		
		if ((freq > 87499) && (freq < 107999)) {
			if (check_freq(freq)) {
				presets[station_num] = freq;
			       //printf("FM Radio station %d:  %d.%d MHz \n",station_num+1, (presets[station_num]/1000), (presets[station_num]%1000));
                          station_num++;
				freq = freq - 50;
			}
		}
	}

	for (i=0; i<20; i++)
		printf("FM Radio station %d:  %d.%d MHz \n",i+1, (presets[i]/1000), (presets[i]%1000));
playback:
	printf("Please input station number(1-20) and press Enter:");
	scanf("%d", &choose);
	if ((choose > 0) && (choose < 21))
	{
	    printf("Now playing station %d:  %d.%d MHz \n",choose, (presets[choose-1]/1000), (presets[choose-1]%1000));
          ioctl(fm_fd, TEA5767HN_IOC_SET_BAND, presets[choose-1]);
	}
	else
	    printf("input wrong number, please input again! \n");
	
      printf("Please input '1 + Enter' to play another FM Radio station, or if you want to exit press '0 + Enter':");
      scanf("%d", &next);
	if (next == 1)
		goto playback;
	else
		return 1;
	
	return 0;
}