void spi_free_slave(struct spi_slave *slave);
int spi_claim_bus(struct spi_slave *slave);
void spi_release_bus(struct spi_slave *slave);
int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
void spi_free_slave(struct spi_slave *slave);
int spi_claim_bus(struct spi_slave *slave);
void spi_release_bus(struct spi_slave *slave);
int spi_xfer(struct spi_slave *slave, unsigned int bitlen,