rp23xx: add CYW43439 wifi driver and Pimoroni Pico Plus 2 W board

Documentation/platforms/arm/rp23xx/boards/pimoroni-pico-plus-2-w/index.rst

@@ -0,0 +1,276 @@
+======================
+Pimoroni Pico Plus 2 W
+======================
+
+.. tags:: chip:rp2350, chip:rp2350b, wifi
+
+The `Pimoroni Pico Plus 2 W <https://shop.pimoroni.com/products/pimoroni-pico-plus-2-w>`_
+is a Raspberry Pi Pico form-factor board built around the RP2350B -- the 80-pin
+variant of the RP2350 with 48 GPIOs.  It adds 16MB of flash, 8MB of PSRAM, a
+USB-C connector, a Qw/ST (Qwiic/STEMMA QT) connector, and an Infineon CYW43439
+for 2.4GHz WiFi and Bluetooth.  The radio is carried on a Raspberry Pi RM2
+module, which is where the CYW43439 lives.
+
+.. figure:: pimoroni-pico-plus-2-w.jpg
+   :align: center
+
+   Pimoroni Pico Plus 2 W, front and back (photo: Pimoroni)
+
+Features
+========
+
+* RP2350B microcontroller chip (QFN-80 package)
+* Dual-core ARM Cortex-M33 processor at up to 150MHz, with FPU and DSP
+* Also contains two Hazard3 RISC-V cores, selectable instead of the M33 pair
+* 520kB of on-chip SRAM
+* 16MB of on-board QSPI flash
+* 8MB of on-board QSPI PSRAM (chip select on GPIO 47)
+* 48 multi-function GPIO pins, 30 of them on the castellated headers
+* 4x UART, 2x SPI, 2x I2C, 8x 12-bit ADC, 24x PWM channels
+* 12x Programmable IO (PIO) state machines across 3 PIO blocks
+* USB-C, supporting device and host
+* Infineon CYW43439 for 2.4GHz WiFi 4 (802.11n) and Bluetooth 5.2
+* Qw/ST connector on I2C0
+* BOOT and RESET buttons; BOOT is also readable at runtime on GPIO 45
+* Battery connector with charging, and VSYS monitoring on GPIO 43
+
+Serial Console
+==============
+
+By default the serial console is UART0 on GPIO 0 (TX, pin 1) and GPIO 1
+(RX, pin 2), at 115200-8N1.
+
+The board can instead be configured to put the console on the USB-C connector
+(the ``usbnsh`` configuration).  Note that the RP2350 USB device support is
+still marked experimental in NuttX and the CDC/ACM console is known to corrupt
+data and stop responding after a handful of commands.  Prefer the UART console
+for anything that matters.
+
+Wireless Communication
+======================
+
+The on-board Infineon CYW43439 is reached over a half-duplex gSPI bus driven by
+a PIO state machine, implemented in ``arch/arm/src/rp23xx/rp23xx_cyw43439.c``.
+It presents itself as the ``wlan0`` network device and supports 2.4GHz WiFi 4
+(802.11n) in station mode.  Bluetooth is not supported.
+
+The chip's firmware is not downloaded until ``wlan0`` is brought up, so nothing
+on the wireless chip -- including the LED, see below -- responds before that.
+
+CYW43439 firmware
+-----------------
+
+The driver links the wireless chip's firmware and CLM blob into the NuttX
+binary, so a copy has to be available at build time.  ``CONFIG_CYW43439_FIRMWARE_BIN_PATH``
+points at it and defaults to::
+
+  ${PICO_SDK_PATH}/lib/cyw43-driver/firmware/43439A0-7.95.49.00.combined
+
+This is the WiFi firmware padded up to a 256-byte boundary with the CLM blob
+appended, and ``CONFIG_CYW43439_FIRMWARE_LEN`` is the *unpadded* length of just
+the firmware part (224190 bytes for this release).
+
+pico-sdk 2.x no longer ships that file as a binary -- it only carries the same
+bytes as a C array in ``lib/cyw43-driver/firmware/w43439A0_7_95_49_00_combined.h``.
+If that is all you have, convert the array back to a binary, for example::
+
+  $ python3 -c '
+  import re, sys
+  text = open(sys.argv[1]).read()
+  body = text.split("{", 1)[1].split("};", 1)[0]
+  data = bytes(int(b, 16) for b in re.findall(r"0x([0-9a-fA-F]{2})", body))
+  open(sys.argv[2], "wb").write(data)
+  ' ${PICO_SDK_PATH}/lib/cyw43-driver/firmware/w43439A0_7_95_49_00_combined.h \
+    ${PICO_SDK_PATH}/lib/cyw43-driver/firmware/43439A0-7.95.49.00.combined
+
+The header's own ``CYW43_WIFI_FW_LEN`` and ``CYW43_CLM_LEN`` macros tell you the
+lengths to expect: 224190 + 984, in a 225240-byte file.
+
+If the file is missing the build still succeeds, but a placeholder is linked in
+and the wireless chip will not come up.
+
+User LED
+========
+
+**The board's only LED is wired to GPIO 0 of the CYW43439, not to a pin of the
+RP2350.** Setting it therefore means an iovar request over the gSPI bus, which
+has two consequences:
+
+* The LED does not respond until ``wlan0`` has been brought up, because that is
+  when the wireless chip's firmware is downloaded.  Before that, every write
+  fails with ``-EIO``.
+* Driving the LED blocks, so it cannot be done from interrupt context.  That
+  rules out ``CONFIG_ARCH_LEDS``, whose ``board_autoled_on()`` is called from
+  interrupt handlers and from assertion handling.  This board therefore
+  supports ``CONFIG_USERLED`` only, and a build with ``CONFIG_ARCH_LEDS``
+  enabled is rejected with an explicit error.
+
+With ``CONFIG_USERLED`` the LED appears as ``/dev/userleds`` and can be driven
+with the ``leds`` example.  Board code can also reach it, and the CYW43439's
+other two GPIOs, through ``include/rp23xx_extra_gpio.h``:
+
+===== ========= ==============================================================
+GPIO  Direction Function
+===== ========= ==============================================================
+0     output    On-board LED
+1     output    Voltage regulator mode: 1 selects PWM (less ripple) over PFM
+2     input     Non-zero if power is coming from USB or the VBUS pin
+===== ========= ==============================================================
+
+Buttons
+-------
+
+The board has two physical buttons, BOOT and RESET.
+
+BOOT is also wired to GPIO 45, active low, so once NuttX is running it can be
+read as an ordinary user button -- this is the pin pico-sdk calls
+``PIMORONI_PICO_PLUS2_W_USER_SW_PIN``.  It appears as ``/dev/buttons`` with
+``CONFIG_INPUT_BUTTONS``, and is the single button reported by
+``board_buttons()``.  RESET is not readable as a GPIO.
+
+The internal pull-up is enabled on GPIO 45, and must be: erratum RP2350-E9
+means a floating Bank 0 input on RP2350 A2 leaks around 120uA and settles at
+roughly 2.2V, which the internal pull-down is far too weak to overcome.  The
+pull-up is unaffected by the erratum.
+
+Held down while power is applied or while RESET is released, BOOT instead makes
+the RP2350 come up in bootloader mode, where it appears as a storage device over
+USB; copying a .UF2 file to it replaces the flash contents.
+
+Pin Mapping
+===========
+
+The castellated headers follow the Raspberry Pi Pico pinout, with the RP2350B's
+extra GPIOs brought out on the two rows of pads inside the headers.
+
+===== ========== =============================================================
+Pin   Signal     Notes
+===== ========== =============================================================
+1     GPIO0      Default TX for UART0 serial console
+2     GPIO1      Default RX for UART0 serial console
+3     Ground
+4     GPIO2
+5     GPIO3
+6     GPIO4      Default SDA for I2C0, also on the Qw/ST connector
+7     GPIO5      Default SCL for I2C0, also on the Qw/ST connector
+8     Ground
+9     GPIO6
+10    GPIO7
+11    GPIO8
+12    GPIO9
+13    Ground
+14    GPIO10
+15    GPIO11
+16    GPIO12
+17    GPIO13
+18    Ground
+19    GPIO14
+20    GPIO15
+21    GPIO16     Default RX for SPI0
+22    GPIO17     Default CSn for SPI0
+23    Ground
+24    GPIO18     Default SCK for SPI0
+25    GPIO19     Default TX for SPI0
+26    GPIO20
+27    GPIO21
+28    Ground
+29    GPIO22
+30    Run
+31    GPIO26     ADC0
+32    GPIO27     ADC1
+33    AGND       Analog ground
+34    GPIO28     ADC2
+35    ADC_VREF   Analog reference voltage
+36    3V3        Power output to peripherals
+37    3V3_EN     Pull to ground to turn off
+38    Ground
+39    VSYS       +5V supply to the board
+40    VBUS       Connected to USB +5V
+===== ========== =============================================================
+
+Other RP2350B Pins
+==================
+
+===== ================================================================
+GPIO  Function
+===== ================================================================
+23    Output - CYW43439 power enable (WL_REG_ON)
+24    I/O    - CYW43439 gSPI data line, doubles as its interrupt request
+25    Output - CYW43439 chip select
+29    Output - CYW43439 gSPI clock
+43    Input  - VSYS monitoring, via ADC
+45    Input  - BOOT button, active low, readable as a user button
+47    Output - PSRAM chip select
+===== ================================================================
+
+Note that GPIO 23, 24, 25 and 29 are the same pins the Raspberry Pi Pico W uses
+for its CYW43439, so the wireless wiring is identical despite the larger
+package.  Do not use them for anything else.
+
+Installation & Build
+====================
+
+For instructions on how to install the build dependencies and create a NuttX
+image for this board, consult the main :doc:`RP23XX documentation <../../index>`.
+
+Configurations
+==============
+
+All configurations listed below can be configured using the following command
+in the ``nuttx`` directory (again, consult the main
+:doc:`RP23XX documentation <../../index>`):
+
+.. code:: console
+
+   $ ./tools/configure.sh pimoroni-pico-plus-2-w:<configname>
+
+nsh
+---
+
+Basic NuttShell configuration, console on UART0 at 115200 bps.  The wireless
+chip is not enabled, so this configuration has no network and no LED.
+
+usbnsh
+------
+
+Basic NuttShell configuration with the console on USB CDC/ACM at 115200 bps.
+See the caveat under `Serial Console`_.
+
+wifi
+----
+
+NuttShell configuration with the console on UART0 at 115200 bps and the
+CYW43439 enabled: ``wlan0`` in station mode, WAPI, DHCP client, DNS client and
+``ping``.  ``/dev/userleds`` and ``/dev/buttons`` are registered too.
+
+After loading this configuration, set the country code to match your region in
+:menuselection:`Device Drivers --> Wireless Device Support --> IEEE 802.11 Device Support`,
+and set your network's credentials in
+:menuselection:`Application Configuration --> Network Utilities --> Network initialization --> WAPI Configuration`.
+
+Alternatively, leave the built-in credentials alone and associate at runtime:
+
+.. code:: console
+
+   nsh> wapi mode wlan0 2
+   nsh> wapi psk wlan0 "my-passphrase" 3 2
+   nsh> wapi essid wlan0 my-ssid 1
+   nsh> renew wlan0
+   nsh> ifconfig
+   lo    Link encap:Local Loopback at RUNNING mtu 1518
+      inet addr:127.0.0.1 DRaddr:127.0.0.1 Mask:255.0.0.0
+
+   wlan0    Link encap:Ethernet HWaddr 28:cd:c1:ff:d3:be at RUNNING mtu 576
+      inet addr:192.168.0.118 DRaddr:192.168.0.1 Mask:255.255.255.0
+
+   nsh> ping -c 3 8.8.8.8
+   PING 8.8.8.8 56 bytes of data
+   56 bytes from 8.8.8.8: icmp_seq=0 time=20.0 ms
+   56 bytes from 8.8.8.8: icmp_seq=1 time=10.0 ms
+   56 bytes from 8.8.8.8: icmp_seq=2 time=10.0 ms
+   3 packets transmitted, 3 received, 0% packet loss, time 3030 ms
+   rtt min/avg/max/mdev = 10.000/13.333/20.000/4.714 ms
+
+The ``3`` and ``2`` arguments to ``wapi psk`` select WPA_ALG_CCMP and WPA_VER_2;
+run ``wapi help`` for the other values.  ``wapi scan wlan0`` lists the visible
+access points.

arch/arm/src/rp23xx/CMakeLists.txt

@@ -117,4 +117,8 @@ if(CONFIG_RP23XX_OTP)
   list(APPEND SRCS rp23xx_otp.c)
 endif()
 
+if(CONFIG_IEEE80211_INFINEON_CYW43439)
+  list(APPEND SRCS rp23xx_cyw43439.c)
+endif()
+
 target_sources(arch PRIVATE ${SRCS})

arch/arm/src/rp23xx/Make.defs

@@ -121,3 +121,7 @@ endif
 ifeq ($(CONFIG_RP23XX_OTP),y)
 CHIP_CSRCS += rp23xx_otp.c
 endif
+
+ifeq ($(CONFIG_IEEE80211_INFINEON_CYW43439),y)
+CHIP_CSRCS += rp23xx_cyw43439.c
+endif