alsa player not showing ad1938 in raspberry pi

Hi

     I want to use ad1938 with raspberry pi. I have added an entry for ad1938 in SPI devices of board file of raspberry pi.

#ifdef CONFIG_BCM2708_SPIDEV

static struct spi_board_info bcm2708_spi_devices[] = {

#ifdef CONFIG_SPI_SPIDEV

  {

  .modalias = "spidev",

  .max_speed_hz = 500000,

  .bus_num = 0,

  .chip_select = 0,

  .mode = SPI_MODE_0,

  }, {

  .modalias = "spidev",

  .max_speed_hz = 500000,

  .bus_num = 0,

  .chip_select = 1,

  .mode = SPI_MODE_0,

  },

#endif

        {

                .modalias = "ad1938",

  .max_speed_hz = 500000,

  .bus_num =0,

  .chip_select =0,

  .mode = SPI_MODE_0,

        }

};

#endif

      And I have cross compiled and installed driver for ad1938 into raspberry pi. I could see ad1938 in /sys/bus/spi/devices and in /sys/bus/spi/drivers folders. But "aplay -l" and "arecord -l" not showing ad1938 codec. Please help me in connecting ad1938 to raspberry pi.