[PATCH v5 2/3] doc: dt: add cyclone-ps-spi binding document

Joshua Clayton
2016-12-07T21:20:37Z

Describe a cyclone-ps-spi devicetree entry, required features

Signed-off-by: Joshua Clayton <stillcompiling@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
---
.../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