APPLE_SPI_CTRL
reg_write(spi, APPLE_SPI_CTRL, APPLE_SPI_CTRL_RX_RESET | APPLE_SPI_CTRL_TX_RESET);
reg_write(spi, APPLE_SPI_CTRL, APPLE_SPI_CTRL_RX_RESET | APPLE_SPI_CTRL_TX_RESET);
reg_write(spi, APPLE_SPI_CTRL, APPLE_SPI_CTRL_RUN);
reg_write(spi, APPLE_SPI_CTRL, 0);