boards: riscv: icev_wireless: add fpga flashing instructions

Add instructions on flashing the FPGA via the shell.

Signed-off-by: Chris Friedt <[email protected]>

boards/riscv/icev_wireless/doc/index.rst

@@ -61,6 +61,8 @@ features:
 +-----------+------------+------------------+
 | ADC       | on-chip    |                  |
 +-----------+------------+------------------+
+| FPGA      | off-chip   | fpga_ice40       |
++-----------+------------+------------------+
 
 Other hardware features have not been enabled yet for this board.
 
@@ -108,9 +110,9 @@ For the :code:`Hello, world!` application, follow the instructions below.
 Since the Zephyr console is by default on the `usb_serial` device, we use
 the espressif monitor to view.
 
-.. code-block:: console
+.. code-block:: bash
 
-   $ west espressif monitor
+   west espressif monitor
 
 Debugging
 =========
@@ -119,7 +121,7 @@ As with much custom hardware, the ESP32C3 modules require patches to
 OpenOCD that are not upstreamed. Espressif maintains their own fork of
 the project. The custom OpenOCD can be obtained by running the following extension:
 
-.. code-block:: console
+.. code-block:: bash
 
    west espressif install
 
@@ -149,12 +151,82 @@ You can debug an application in the usual way. Here is an example for the
    :maybe-skip-config:
    :goals: debug
 
+Programming the FPGA
+====================
+
+Download and save the ICE-V Wireless `default bitstream`_ to the current working directory.
+
+.. code-block:: bash
+
+   curl -L -o bitstream.bin 'https://github.com/ICE-V-Wireless/ICE-V-Wireless/blob/main/Firmware/spiffs/bitstream.bin?raw=true'
+   printf "Bitstream size is 0x%x\n" $(wc -c bitstream.bin | awk '{print $1}')
+   printf "Bitstream CRC is %x\n" $(crc bitstream.bin)
+   truncate -s %4 bitstream.bin
+   printf "Rounded bitstream size is 0x%x\n" $(wc -c bitstream.bin | awk '{print $1}')
+
+Build and flash the :ref:`flash_shell` application.
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/drivers/flash_shell
+   :board: icev_wireless
+   :maybe-skip-config:
+   :goals: flash
+
+Open a terminal to the device via USB:
+
+.. code-block:: bash
+
+   minicom -D /dev/tty.usbmodem101 -b 115200
+
+Clear the `image-scratch` partition:
+
+.. code-block:: console
+
+   flash erase flash-controller@60002000 0x00210000 0x20000
+
+Prepare to load the ICE-V Wireless bitstream to the `image-scratch` partition:
+
+.. note::
+
+   Use the rounded bitstream size (0x1969c below), as `flash load` needs every
+   image padded to a multiple of 4 bytes.
+
+.. code-block:: console
+
+   flash load flash-controller@60002000 0x00210000 0x1969c
+
+Transmit the ICE-V Wireless bitstream  to the `image-scratch` partition:
+
+.. code-block:: bash
+
+   dd if=bitstream.bin of=/dev/tty.usbmodem101 bs=32 count=32
+
+Although unlikely, it may be possible that the bitstream was corrupted
+transferring serially, so it's a good idea to check the CRC value.
+
+.. code-block:: console
+
+   crc 0x3c210000 104090
+
+Load the bitstream from flash:
+
+.. note::
+
+   Use the unpadded bitstream size (104090 below) for `fpga load`.
+
+.. code-block:: console
+
+   fpga load fpga@0 0x00210000 104090
+
 References
 **********
 
 .. _ICE-V Wireless Github Project:
    https://github.com/ICE-V-Wireless/ICE-V-Wireless
 
+.. _ICE-V Wireless Default Bitstream:
+   https://github.com/ICE-V-Wireless/ICE-V-Wireless/blob/main/Firmware/spiffs/bitstream.bin
+
 .. _ESP32-C3-MINI-1 Datasheet:
    https://www.espressif.com/sites/default/files/documentation/esp32-c3-mini-1_datasheet_en.pdf
 

boards/riscv/icev_wireless/icev_wireless.dts

@@ -75,6 +75,29 @@
 	#size-cells = <0>;
 	pinctrl-0 = <&spim2_default>;
 	pinctrl-names = "default";
+
+	cs-gpios = <&gpio0 6 (GPIO_PUSH_PULL | GPIO_ACTIVE_LOW)>;
+
+	fpga0: fpga@0 {
+		status = "okay";
+		compatible = "lattice,ice40-fpga";
+
+		reg = <0>;
+		spi-max-frequency = <1000000>;
+
+		load-mode = <1>;
+		cdone-gpios = <&gpio0 0 0>;
+		creset-gpios = <&gpio0 1 (GPIO_PUSH_PULL | GPIO_ACTIVE_LOW)>;
+		clk-gpios = <&gpio0 5 (GPIO_PUSH_PULL | GPIO_ACTIVE_LOW)>;
+		pico-gpios = <&gpio0 7 (GPIO_PUSH_PULL | GPIO_ACTIVE_LOW)>;
+		mhz-delay-count = <4>;
+		gpios-set-reg = <0x60004008>;
+		gpios-clear-reg = <0x6000400c>;
+		config-delay-us = <2000>;
+		creset-delay-ns = <200>;
+		leading-clocks = <8>;
+		trailing-clocks = <160>;
+	};
 };
 
 &gpio0 {