1Xilinx Slave Serial SPI FPGA Manager
2
3Xilinx Spartan-6 and 7 Series FPGAs support a method of loading the
4bitstream over what is referred to as "slave serial" interface.
5The slave serial link is not technically SPI, and might require extra
6circuits in order to play nicely with other SPI slaves on the same bus.
7
8See:
9- https://www.xilinx.com/support/documentation/user_guides/ug380.pdf
10- https://www.xilinx.com/support/documentation/user_guides/ug470_7Series_Config.pdf
11- https://www.xilinx.com/support/documentation/application_notes/xapp583-fpga-configuration.pdf
12
13Required properties:
14- compatible: should contain "xlnx,fpga-slave-serial"
15- reg: spi chip select of the FPGA
16- prog_b-gpios: config pin (referred to as PROGRAM_B in the manual)
17- done-gpios: config status pin (referred to as DONE in the manual)
18
19Optional properties:
20- init-b-gpios: initialization status and configuration error pin
21                (referred to as INIT_B in the manual)
22
23Example for full FPGA configuration:
24
25	fpga-region0 {
26		compatible = "fpga-region";
27		fpga-mgr = <&fpga_mgr_spi>;
28		#address-cells = <0x1>;
29		#size-cells = <0x1>;
30	};
31
32	spi1: spi@10680 {
33		compatible = "marvell,armada-xp-spi", "marvell,orion-spi";
34		pinctrl-0 = <&spi0_pins>;
35		pinctrl-names = "default";
36		#address-cells = <1>;
37		#size-cells = <0>;
38		cell-index = <1>;
39		interrupts = <92>;
40		clocks = <&coreclk 0>;
41
42		fpga_mgr_spi: fpga-mgr@0 {
43			compatible = "xlnx,fpga-slave-serial";
44			spi-max-frequency = <60000000>;
45			spi-cpha;
46			reg = <0>;
47			prog_b-gpios = <&gpio0 29 GPIO_ACTIVE_LOW>;
48			init-b-gpios = <&gpio0 28 GPIO_ACTIVE_LOW>;
49			done-gpios = <&gpio0 9 GPIO_ACTIVE_HIGH>;
50		};
51	};
52