Hello, I wrote this driver for USART IP that is found in AT91 and SAMA5 SoCs. The IP has an internal chip select, but is not used because is deasserted and asserted after every byte sent over the wires. Gpio chip selects are used instead of internal one. The driver works with actual USART nodes from device tree of boards, but compatible must be changed, SCK pin muxed and cs-gpio, size-cells and address-cells must be added. Of course, at the end of the wires must be an SPI slave linked, not a serial console. :) I tested the driver on sama5d4-xplained and sama5d3-xplained and works without issues. Radu Pirea (3): MAINTAINERS: add usart spi driver dt-bindings: add binding for at91-usart in spi mode spi: at91-usart: add driver for at91-usart as spi .../bindings/spi/microchip,at91-usart-spi.txt | 24 + MAINTAINERS | 7 + drivers/spi/Kconfig | 8 + drivers/spi/Makefile | 1 + drivers/spi/spi-at91-usart.c | 545 ++++++++++++++++++ 5 files changed, 585 insertions(+) create mode 100644 Documentation/devicetree/bindings/spi/microchip,at91-usart-spi.txt create mode 100644 drivers/spi/spi-at91-usart.c -- 2.17.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
