A Kernel story VIII: Document how to set CS active-high

In my quest to set SPI CS active-high on a Raspberry Pi with the Linux Kernel, I encountered several challenges due to the lack of clear documentation. To address this, I’ve contributed improvements to the existing documentation and provided practical examples.

• A new overlay example in the Raspberry Pi repository demonstrating how to invert the CS signal using cs-gpio with GPIO_ACTIVE_HIGH in the SPI controller and spi-cs-high in the peripheral property.
• Linux Kernel documentation updates explaining the above method and offering a simple devicetree example.

Find the details here:

• Raspberry Pi repository PR
• Linux Kernel documentation changes

I’m grateful for the assistance I received from the community. By contributing these improvements, I hope to give back and help others facing similar challenges.