On Fri, 16 Dec 2016, Joshua Clayton wrote: > Describe a cyclone-ps-spi devicetree entry, required features > > Signed-off-by: Joshua Clayton <stillcompil...@gmail.com> > Acked-by: Rob Herring <r...@kernel.org>
Acked-by: Alan Tull <at...@opensource.altera.com> > --- > .../bindings/fpga/cyclone-ps-spi-fpga-mgr.txt | 25 > ++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > create mode 100644 > Documentation/devicetree/bindings/fpga/cyclone-ps-spi-fpga-mgr.txt > > diff --git > a/Documentation/devicetree/bindings/fpga/cyclone-ps-spi-fpga-mgr.txt > b/Documentation/devicetree/bindings/fpga/cyclone-ps-spi-fpga-mgr.txt > new file mode 100644 > index 0000000..3f515c7 > --- /dev/null > +++ b/Documentation/devicetree/bindings/fpga/cyclone-ps-spi-fpga-mgr.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,cyclone-ps-spi-fpga-mgr" > +- reg : spi slave id of the fpga > +- config-gpios : config pin (referred to as nCONFIG in the cyclone manual) > +- status-gpios : status pin (referred to as nSTATUS in the cyclone manual) > + > +both gpios pins are normally active low open drain. > + > +Example: > + fpga_spi: evi-fpga-spi@0 { > + compatible = "altr,cyclone-ps-spi-fpga-mgr"; > + spi-max-frequency = <20000000>; > + reg = <0>; > + config-gpios = <&gpio4 9 GPIO_ACTIVE_LOW>; > + status-gpios = <&gpio4 11 GPIO_ACTIVE_LOW>; > + }; > -- > 2.9.3 > >
