SP7021_SPI_DATA_SIZE
xfer_cnt = xfer->len / SP7021_SPI_DATA_SIZE;
last_len = xfer->len % SP7021_SPI_DATA_SIZE;
xfer_len = SP7021_SPI_DATA_SIZE;
pspim->tx_buf = xfer->tx_buf + i * SP7021_SPI_DATA_SIZE;
pspim->rx_buf = xfer->rx_buf + i * SP7021_SPI_DATA_SIZE;