CONFIG_SPI_0=y CONFIG_SPI_0_NRF_SPI=y CONFIG_SPI_LOOPBACK_DRV_NAME="SPI_0" CONFIG_SPI_LOOPBACK_CS_GPIO=y CONFIG_SPI_LOOPBACK_CS_CTRL_GPIO_DRV_NAME="GPIO_0" CONFIG_SPI_LOOPBACK_CS_CTRL_GPIO_PIN=28