Raspberry Pi 5

Introduction

The PAN9028 requires a fairly powerful host processor that executes the low-level Wi-Fi® and Bluetooth® drivers as well as some high-level Wi-Fi application software and a Bluetooth stack.

As an evaluation platform you can use the Raspberry Pi 5.

It does not have an on-board M.2 Key E slot for the PAN9028 M.2 device, but an additional SDIO interface and other peripherals can be enabled on the 40-pin expansion header.

To bring the PAN9028 M.2 device and the Raspberry Pi 5 together, you can use the M.2 to Raspberry Pi Adapter.

This guide shows you how to evaluate a Panasonic PAN9028 M.2 device on a Raspberry Pi 5 with the help of the M.2 to Raspberry Pi Adapter. But you have to be aware that only the basic bring-up is explained, not any advanced usage.

Hardware Modifications

You have to do some hardware modification to the PAN9028 M.2 device before you can use it together with the Raspberry Pi 5.

The following requirements must be met:

• You have a PAN9028 M.2 device.

SDIO and IO Reference Voltages

The interfaces on the 40-pin expansion header of the Raspberry Pi 5 operate with 3.3 V signal level, while the PAN9028 M.2 device operates with 1.8 V instead.

Because of this you have to modify the PAN9028 M.2 device as explained in Hardware Modifications in order to change the SDIO and IO reference voltages to 3.3 V.

Note

A signal level of 3.3 V limits the SDIO clock speed to 50 MHz, which also limits the maximum achievable data rate severely.

For further information please refer to the module product specification at

• Panasonic Industry Europe
• Panasonic Industrial Devices Sales Company of America

Host System Assembly

The following requirements must be met:

• You have a Raspberry Pi 5 (host system).

• You have a M.2 to Raspberry Pi Adapter.

• You have a modified PAN9028 M.2 device.

You have to do the following steps to assemble the system.

1. Mount the PAN9028 M.2 device 3 onto the M.2 to Raspberry Pi Adapter 2 as explained in First Steps.

2. Mount the M.2 to Raspberry Pi Adapter 2 onto the 40-pin expansion header of the Raspberry Pi 5 1.

3. Power the M.2 to Raspberry Pi Adapter through the USB-C connector 4, otherwise the adapter is non-functional.

Host System Setup

Initial Bring-Up

You have to follow the Getting Started guide to bring up your Raspberry Pi 5.

The guide assumes that you use a recent version of Raspberry Pi OS based on Debian version 12 ("bookworm").

Network Connectivity

You have to make sure that the Raspberry Pi 5 is on the same network as your development system, because you need to interact with your host system and maybe transfer files to it in later steps.

You have to check and remember the IP address of your host system for later use.

1. On your host system, retrieve the current network configuration for the on-board Ethernet port in a Terminal window.

   ip addr show eth0
   

   The output should look something like this:

   2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
     link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
     inet 192.168.187.100/24 brd 192.168.187.255 scope global dynamic noprefixroute eth0
       valid_lft 86089sec preferred_lft 86089sec
     inet6 fe80::xxxx:xxxx:xxxx:xxxx/64 scope link noprefixroute
       valid_lft forever preferred_lft forever
   

   The IP address of your host system is 192.168.187.100

Host System IP Address

For this host system the IP address is 192.168.187.100, but it may be different for yours.

In any case you have to use this IP address to communicate with your host system for the remainder of this document.

To check if your Raspberry Pi 5 has Internet connectivity execute the following steps.

1. Use the ping command.

   ping -n -c 2 8.8.8.8
   

   The output should look something like this:

   Pinging 8.8.8.8 with 32 bytes of data:
   Reply from 8.8.8.8: bytes=32 time=19ms TTL=116
   Reply from 8.8.8.8: bytes=32 time=17ms TTL=116
   [...]
   

   Your Raspberry Pi 5 has Internet connectivity.

Host System Remote Access

If you do not have any application for the SSH protocol yet, you can try the OpenSSH protocol suite.

It also includes tools for remote file operations like ssh and scp.

At the end of this process you should have a fully working system you can remotely log into.

Host System Configuration

The following requirements must be met:

• You have brought up your Raspberry Pi 5 as explained in Host System Setup.

• You can access your Raspberry Pi 5 remotely.

Enable Peripheral Interfaces

You have to modify the boot configuration of your system in order to enable additional peripheral interfaces on the 40-pin expansion header.

1. Add the following entries to the end of the configuration file config.txt using the nano editor.

   sudo nano /boot/firmware/config.txt
   

   config.txt

   dtoverlay=disable-wifi-pi5
   dtoverlay=disable-bt-pi5
   dtoverlay=sdio-pi5,poll_once=off
   dtoverlay=uart0-pi5,ctsrts
   dtoverlay=i2c1-pi5
   dtoverlay=spi0-1cs,cs0_pin=8
   dtoverlay=pca953x,tca6408
   gpio=7=op,dh
   

   The on-board Wi-Fi and Bluetooth are disabled, a UART interface is enabled on the expansion header with flow-control enabled, additional SDIO, I2C and SPI interfaces on the expansion header and support for I²C GPIO expanders is enabled, a GPIO is configured for application control.

Disable System Services

The Raspberry Pi OS runs some system services that integrate the on-board Wi-Fi and Bluetooth connectivity into the system and also automate certain tasks and behaviors.

During the evaluation of the PAN9028 module this is can create problems, so you have to change your system configuration to avoid this.

1. Mask certain system services to prevent them from running.

   sudo systemctl mask wpa_supplicant
   sudo systemctl mask hciuart
   sudo systemctl mask ModemManager
   

Rename Conflicting Drivers

The Linux kernel of the Raspberry Pi OS comes with pre-compiled drivers that conflict with the official device drivers that you install in a later step.

One way to resolve this conflict is to rename the existing drivers.

1. Rename the conflicting Wi-Fi drivers.

   cd /lib/modules/$(uname -r)/kernel/drivers/net/wireless/marvell/mwifiex
   sudo mv mwifiex.ko.xz mwifiex.ko.xz.bak
   sudo mv mwifiex_sdio.ko.xz mwifiex_sdio.ko.xz.bak
   

2. Rename the conflicting Bluetooth drivers.

   cd /lib/modules/$(uname -r)/kernel/drivers/bluetooth
   sudo mv btmrvl_sdio.ko.xz btmrvl_sdio.ko.xz.bak
   sudo mv btmrvl.ko.xz btmrvl.ko.xz.bak
   

System Reboot

You have to reboot the host system for these changes to take effect.

sudo reboot

Host System Software Installation

Compile the Device Driver

You have to retrieve and compile the driver for the PAN9028 module.

1. Clone the driver repository from NXP's GitHub space.

   cd ~
   git clone https://github.com/nxp-imx/mwifiex.git
   

2. Check out the specific branch that matches the running kernel most closely.

   cd ~/mwifiex/
   git checkout lf-6.6.23_2.0.0
   

3. Compile the driver.

   cd ~/mwifiex
   make CROSS_COMPILE= KERNELDIR=/lib/modules/$(uname -r)/build -j4 build
   

4. Create a global driver directory and copy the driver.

   sudo mkdir -p /lib/modules/$(uname -r)/extra
   cd ~/mwifiex
   sudo cp mlan.ko moal.ko /lib/modules/$(uname -r)/extra 
   

Install the Firmware

You have to download and install the firmware for the PAN9028 module.

1. Create the destination directory for the firmware and configuration files.

   sudo mkdir -p /lib/firmware/nxp/
   

2. Clone the firmware repository from NXP's GitHub space.

   cd ~
   git clone https://github.com/nxp-imx/imx-firmware.git
   cd imx-firmware/
   git checkout lf-6.6.23_2.0.0
   

3. Copy the firmware to the global firmware directory.

   cd ~/imx-firmware
   sudo cp nxp/FwImage_8987/sdiouart8987_combo_v0.bin /lib/firmware/nxp/
   

4. Copy the configuration file wifi_mod_para.conf to the global firmware directory.

   cd ~/imx-firmware
   sudo cp nxp/wifi_mod_para.conf /lib/firmware/nxp/
   

Wi-Fi

Bring Up

The newly compiled device drivers are not loaded into the Linux kernel automatically, you have to manually load them into the kernel prior to operation.

1. Make sure that Linux kernel module dependency database is up-to-date.

   sudo depmod -a
   

2. Load the modules into the Linux kernel.

   sudo modprobe mlan
   sudo modprobe moal mod_para=nxp/wifi_mod_para.conf 
   

3. Check the Linux kernel log.

   sudo dmesg
   

   The output should look something like this:

   [  541.095842] fw_name=nxp/sdiouart8987_combo_v0.bin
   [  541.100571] SDIO: max_segs=128 max_seg_size=65536
   [  541.105295] rx_work=1 cpu_num=4
   [  541.108445] Enable moal_recv_amsdu_packet
   [  541.108451] Attach mlan adapter operations.card_type is 0x105.
   [  541.108767] wlan: Enable TX SG mode
   [  541.108770] wlan: Enable RX SG mode
   [  541.109583] Request firmware: nxp/sdiouart8987_combo_v0.bin
   [  541.383340] Wlan: FW download over, firmwarelen=625084 downloaded 615980
   [  542.321457] WLAN FW is active
   [  542.324435] on_time is 541839042441
   [  543.398906] VDLL image: len=9104
   [  543.399654] fw_cap_info=0x181d6f03, dev_cap_mask=0xffffffff
   [  543.399661] max_p2p_conn = 8, max_sta_conn = 8
   [  543.399896] SDIO rx aggr: 1 block_size=512
   [  543.399907] wlan: Enable RX SG mode
   [  543.399909] mpa_rx_buf_size=65280
   [...]
   [  543.408951] call regulatory_set_wiphy_regd US
   [  543.408976] ForceRegionRule is set in the on-chip OTP memory
   [  543.413376] 11D: Error setting domain info in FW
   [...]
   [  543.414984] Register NXP 802.11 Adapter mlan0
   [  543.422141] Register NXP 802.11 Adapter uap0
   [...]
   [  543.437884] Register NXP 802.11 Adapter wfd0
   [  543.443263] wlan: version = SD8987----16.92.21.p119.3-MM6X16437.p21-GPL-(FP92) 
   [  543.451664] Set REG 0x80002328: 0x13d57 slew_rate=3
   [  543.468394] uap0: Skip change virtual intf type on uap: from 3 to 2
   

Note

If you can't see that the PAN9028 M.2 device was detected, press the reset button 6 button of the M.2 to Raspberry Pi Adapter briefly once.

This resets the PAN9028 module, but also triggers the detection in the Linux kernel again.

You can now check the functionality of the driver.

1. Use the ip command to verify that the mlan0 network interface for the PAN9028 is now available.

   ip addr show mlan0
   

   The output should look something like this:

   3: mlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
     link/ether 34:32:e6:xx:xx:xx brd ff:ff:ff:ff:ff:ff
   

Usage

You have to follow these steps to check if Wi-Fi is functional.

1. Bring up the Wi-Fi interface.

   sudo ip link set dev mlan0 up
   

2. Execute a Wi-Fi scan.

   sudo iw dev mlan0 scan
   

   You can see that nearby Wi-Fi networks are discovered successfully.

Bluetooth

The following requirements must be met:

• You have successfully brought up the Wi-Fi portion as explained in Wi-Fi.

Bring Up

You have to follow these steps to bring up the Bluetooth interface.

1. Initialize the Bluetooth interface.

   sudo hciattach /dev/ttyAMA0 any 3000000 flow
   

   The output should look something like this:

   Device setup complete
   

2. Bring up the Bluetooth interface.

   sudo hciconfig hci0 up
   

Usage

You have to follow these steps to check if Bluetooth is functional.

1. Execute a Bluetooth scan.

   bluetoothctl scan on
   

   You can see that nearby Bluetooth devices that are advertising are discovered successfully.

Appendix

The PAN9028 module has a couple of special function pins that are routed to the 40-pin expansion header as follows.

Raspberry Pi	M.2 Specification	PAN9028	Description
GPIO 5	W_DISABLE1#	PDn	Power Down
GPIO 6	W_DISABLE#2	IND_RST_BT	Bluetooth reset
GPIO 4	SDIO_RST#	IND_RST_WL	Wi-Fi reset

You can manually control the special function pins using the pinctrl tool. For example:

1. Apply GND to GPIO 5 to signal power down to the module.

   pinctrl set 5 op pu dl
   

2. Apply VCC to GPIO 5 to enable the module again.

   pinctrl set 5 op pu dh