I am currently using a QRB5165 board (withint VOXL 2) with Ubuntu and I need more UART ports for my project.
I would like to convert the SPI ports to UART as I'm currently not using SPI. However, I would like to do this without adding additional hardware such as a micro-controller or bit banging.
Is it possible to reconfigure the SPI ports to UART by only changing the kernel device tree?
I can see in the embedded linux documentation: 80-27572-2_REV_A_QRB5165_LE_1_0_Linux_Embedded_Platform_Software_Programming_Guide.pdf (qualcomm.com)
that it is possible to configure the QUP s for the board and that they all seem to support the three main communication protocols (UART, SPI, I2C).
As such, my initial idea was to reconfigure the QUP (specifically QUP se11) of the board from SPI to UART.
My initial idea was to:
1) Remove the code configuring it to SPI
2) Follow the documentation here: Qualcomm Universal Peripheral (QUP) v3, in particur 3.1 Configure UART in the kernel,
to add the UART kernel using the same QUP and pins (QUP se 11, pins 60-63).
Do you believe this would work ?
If not, would you know of another way ?