[PATCH v9 1/3] doc: dt: add cyclone-ps-spi binding document
From: Joshua Clayton <hidden>
Date: 2017-01-24 22:19:57
Also in:
linux-devicetree, lkml
Subsystem:
fpga manager framework, open firmware and flattened device tree bindings, the rest · Maintainers:
Moritz Fischer, Xu Yilun, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
Describe a cyclone-ps-spi devicetree entry, required features Signed-off-by: Joshua Clayton <redacted> --- .../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 0000000..774e6a7
--- /dev/null
+++ b/Documentation/devicetree/bindings/fpga/altera-passive-serial.txt@@ -0,0 +1,29 @@ +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 +- nconfig-gpios: config pin (referred to as nCONFIG in the cyclone manual) +- nstat-gpios: status pin (referred to as nSTATUS in the cyclone manual) + +Optional properties: +- confd-gpios: confd pin (referred to as CONF_DONE in the cyclone manual) + + + +Example: + fpga_spi: evi-fpga-spi at 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>; + };
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2.9.3