[4/5] Documentation: Add binding document for Lattice iCE40 FPGA manager

Commit Message

Alan Tull Feb. 27, 2017, 10:14 p.m. UTC

From: Joel Holdsworth <[e-mail]>

This adds documentation of the device tree bindings of the Lattice iCE40
FPGA driver for the FPGA manager framework.

Signed-off-by: Joel Holdsworth <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Acked-by: Alan Tull <[e-mail]>
Acked-by: Moritz Fischer <[e-mail]>
Acked-by: Marek Vasut <[e-mail]>
---
 .../bindings/fpga/lattice-ice40-fpga-mgr.txt        | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/fpga/lattice-ice40-fpga-mgr.txt

Patch

diff --git a/Documentation/devicetree/bindings/fpga/lattice-ice40-fpga-mgr.txt b/Documentation/devicetree/bindings/fpga/lattice-ice40-fpga-mgr.txt
new file mode 100644
index 0000000..4dc4124
--- /dev/null
+++ b/Documentation/devicetree/bindings/fpga/lattice-ice40-fpga-mgr.txt
@@ -0,0 +1,21 @@ 
+Lattice iCE40 FPGA Manager
+
+Required properties:
+- compatible:		Should contain "lattice,ice40-fpga-mgr"
+- reg:			SPI chip select
+- spi-max-frequency:	Maximum SPI frequency (>=1000000, <=25000000)
+- cdone-gpios:		GPIO input connected to CDONE pin
+- reset-gpios:		Active-low GPIO output connected to CRESET_B pin. Note
+			that unless the GPIO is held low during startup, the
+			FPGA will enter Master SPI mode and drive SCK with a
+			clock signal potentially jamming other devices on the
+			bus until the firmware is loaded.
+
+Example:
+	fpga: fpga@0 {
+		compatible = "lattice,ice40-fpga-mgr";
+		reg = <0>;
+		spi-max-frequency = <1000000>;
+		cdone-gpios = <&gpio 24 GPIO_ACTIVE_HIGH>;
+		reset-gpios = <&gpio 22 GPIO_ACTIVE_LOW>;
+	};