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    SubjectRe: [PATCH v2 2/5] doc: dt: add cyclone-spi binding document
    On Fri, Oct 28, 2016 at 09:56:39AM -0700, Joshua Clayton wrote:
    > Describe a cyclonei-ps-spi devicetree entry, required features
    >
    > Signed-off-by: Joshua Clayton <stillcompiling@gmail.com>
    > ---
    > .../bindings/fpga/cyclone-ps-spi-fpga-mgr.txt | 23 ++++++++++++++++++++++
    > 1 file changed, 23 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..c942281
    > --- /dev/null
    > +++ b/Documentation/devicetree/bindings/fpga/cyclone-ps-spi-fpga-mgr.txt
    > @@ -0,0 +1,23 @@
    > +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-gpio : config pin (referred to as nCONFIG in the cyclone manual)
    > +- status-gpio : status pin (referred to as nSTATUS in the cyclone manual)

    '-gpios' is the preferred form.

    Looks like active low to me with nXXXX, but the example says active
    high. Please be specific here.

    > +
    > +Example:
    > + fpga_spi: evi-fpga-spi@0 {
    > + compatible = "altr,cyclone-ps-spi-fpga-mgr";
    > + spi-max-frequency = <20000000>;
    > + reg = <0>;
    > + config-gpio = <&gpio4 9 GPIO_ACTIVE_HIGH>;
    > + status-gpio = <&gpio4 11 GPIO_ACTIVE_HIGH>;
    > + };
    > --
    > 2.7.4
    >

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