Describe an altera-passive-serial devicetree entry, required features Signed-off-by: Joshua Clayton <stillcompiling@xxxxxxxxx> Acked-by: Rob Herring <robh@xxxxxxxxxx> --- .../bindings/fpga/altera-passive-serial.txt | 29 ++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 Documentation/devicetree/bindings/fpga/altera-passive-serial.txt diff --git a/Documentation/devicetree/bindings/fpga/altera-passive-serial.txt b/Documentation/devicetree/bindings/fpga/altera-passive-serial.txt new file mode 100644 index 000000000000..48478bc07e29 --- /dev/null +++ b/Documentation/devicetree/bindings/fpga/altera-passive-serial.txt @@ -0,0 +1,29 @@ +Altera Passive Serial SPI FPGA Manager + +Altera FPGAs support a method of loading the bitstream over what is +referred to as "passive serial". +The passive serial link is not technically SPI, and might require extra +circuits in order to play nicely with other SPI slaves on the same bus. + +See https://www.altera.com/literature/hb/cyc/cyc_c51013.pdf + +Required properties: +- compatible: Must be one of the following: + "altr,fpga-passive-serial", + "altr,fpga-arria10-passive-serial" +- reg: SPI chip select of the FPGA +- nconfig-gpios: config pin (referred to as nCONFIG in the manual) +- nstat-gpios: status pin (referred to as nSTATUS in the manual) + +Optional properties: +- confd-gpios: confd pin (referred to as CONF_DONE in the manual) + +Example: + fpga: fpga@0 { + compatible = "altr,fpga-passive-serial"; + spi-max-frequency = <20000000>; + reg = <0>; + nconfig-gpios = <&gpio4 9 GPIO_ACTIVE_LOW>; + nstat-gpios = <&gpio4 11 GPIO_ACTIVE_LOW>; + confd-gpios = <&gpio4 12 GPIO_ACTIVE_LOW>; + }; -- 2.11.0 -- 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
