Documentation/devicetree/bindings/fpga/xilinx-slave-serial.txt

   1 Xilinx Slave Serial SPI FPGA Manager
   2
   3 Xilinx Spartan-6 and 7 Series FPGAs support a method of loading the
   4 bitstream over what is referred to as "slave serial" interface.
   5 The slave serial link is not technically SPI, and might require extra
   6 circuits in order to play nicely with other SPI slaves on the same bus.
   7
   8 See:
   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
  13 Required 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
  19 Optional properties:
  20 - init-b-gpios: initialization status and configuration error pin
  21                 (referred to as INIT_B in the manual)
  22
  23 Example 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         };