Describe a cyclone-ps-spi devicetree entry, required features Signed-off-by: Joshua Clayton <stillcompiling@xxxxxxxxx> --- .../bindings/fpga/altera-passive-serial.txt | 25 ++++++++++++++++++++++ 1 file changed, 25 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 0000000..b5f0bb5 --- /dev/null +++ b/Documentation/devicetree/bindings/fpga/altera-passive-serial.txt @@ -0,0 +1,25 @@ +Altera Cyclone Passive Serial SPI FPGA Manager + +Altera Cyclone 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: should contain "altr,fpga-passive-serial" +- reg: spi chip select of the FPGA +- nstat-gpios: status pin (referred to as nSTATUS in the cyclone manual) +- nconfig-gpios: config pin (referred to as nCONFIG in the cyclone manual) +- confd-gpios: confd pin (referred to as CONF_DONE in the cyclone manual) + +Example: + fpga_spi: evi-fpga-spi@0 { + compatible = "altr,cyclone-ps-spi-fpga-mgr"; + 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>; + }; -- 2.9.3 -- 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
