# Device tree configuration of SPI, UART, and I2C Source: [https://docs.qualcomm.com/doc/80-88500-4/topic/105_Device_tree_configuration.html](https://docs.qualcomm.com/doc/80-88500-4/topic/105_Device_tree_configuration.html) All the 20 instances of I2C and SPI, and 4 instances of UART are defined in the src/kernel/MSM-5.4/arch/arm64/boot/dts/vendor/qcom/kona-qupv3.dtsi file. The status field for the required instances must be marked ok. Example: qupv3_se0_i2c: i2c@XX0000 { …… …… …… status = “ok"; }; Copy to clipboard The QUPAC\_Access file in TZ at \trustzone\_images\core\settings\buses\qup\_accesscontrol\qupv3\config\8250\QUPAC\_Access.c must be modified in accordance with DTSI to select the required protocol. Table : Device drivers | Protocol | Driver path | | --- | --- | | UART | /kernel/drivers/tty/serial/msm\_geni\_serial.c | | SPI | /kernel/drivers/spi/spi-geni-qcom.c | | I2C | /kernel/drivers/i2c/busses/i2c-qcom-geni.c | **Parent Topic:** [Bus protocols](https://docs.qualcomm.com/doc/80-88500-4/topic/103_Bus_protocols.html) Last Published: Aug 18, 2023 [Previous Topic QUP pin configuration](https://docs.qualcomm.com/bundle/publicresource/80-88500-4/topics/104_QUP_GPIO_assignment.md) [Next Topic USB](https://docs.qualcomm.com/bundle/publicresource/80-88500-4/topics/106_USB.md)