Embedded module TQMLS1028A - YOCTO Linux BSP documentation


There are two GPIO buttons on the MBL1028A. They are bound to the gpio-keys driver, and can be tested with the evtest tool.

GPIO Button Overview

Reference Button
S4 Key 1
S4 Key 2

GPIO Button Location

The buttons are available in the sysfs via the device /dev/input/event0 and can be tested with the evtest tool.

evtest /dev/input/event0


The STKLS1028A provides the CAN Interfaces can0 and can1.

CAN configuration

DIP switch S1 is used to configure the CAN interfaces CAN0 and CAN1.

Function S1-1 S1-2
CAN-Bus not terminated OFF OFF
not defined (illegal state) OFF ON
not defined (illegal state) ON OFF
CAN-Bus terminated with 120 Ohm ON ON

CAN Loopback

CAN0 -> CAN1

candump can0&
cansend can1 5A1#11.2233.44556677.88

CAN1 -> CAN0

candump can1&
cansend can0 5A1#11.2233.44556677.88


The STKLS1028A provides one 4 Port TSN Gbit Ethernet Switch and two 10/100/1000 Ethernet Interfaces.

Configure the ethernet switch in bridge mode

The TSN switch of the STKLS1028A is not configured by default. The master interface eno2 is enabled by default, so it is not necessary to bring it up manually.

Single port configuration

Every single switch port acts as a configurable Ethernet port

# Configure each single switch interface and bring it up.
$ ip addr add dev swp0 && ip link set swp0 up
$ ip addr add dev swp1 && ip link set swp1 up
$ ip addr add dev swp2 && ip link set swp2 up
$ ip addr add dev swp3 && ip link set swp3 up
Bridge configuration

Every switch port is part of one configurable Ethernet bridge.

# Create a bridge device in this example it is called switch
$ ip link add name switch type bridge
# Bring up the bridge device 
$ ip link set switch up
# Add the interfaces to the bridge device switch and bring them up.
$ ip link set swp0 master switch && ip link set swp0 up
$ ip link set swp1 master switch && ip link set swp1 up
$ ip link set swp2 master switch && ip link set swp2 up
$ ip link set swp3 master switch && ip link set swp3 up
# Configure bridge device
$ ip addr add dev switch 


In U-Boot enetc-1 is configured as default interface. The IP configuration can be done statically or by a DHCP server in the network.

IP configuration via DHCP

For a configuration via a DHCP server, use the dhcp command in U-Boot.

Static IP configuration For a static IP configuration the following, U-Boot environment variables must be set:

setenv ipaddr <ipaddr> 
(e.g.: setenv ipaddr
setenv netmask <netmask> 
(e.g.: setenv netmask


Both Ethernet Interfaces, eno0 and eno1, are activated in Linux.

For a temporary static configuration the ip command can be used, below some useful ip commands are listed:

Activate a specific interface
e.g. eno1

ip link set eno1 up

Disable a specific interace
e.g. eno1

ip link set eno1 down

Show ip address for a specific interface
e.g. eno1

ip addr show eno1

Show statistic for a specific interface
e.g. eno1

ip -s link show eno1

Set ip address for a specific interface
e.g. eno1

ip addr add dev eno1

Show statistic of all interfaces

ip -s link

Set default gateway for a specific interfaces
e.g. set gateway ip for eno1

ip route add default via dev eno1

If a DHCP server is available in the network environment the ip configuration can be received from it. To do so execute the udhcpc command, by default eth0 is used.
To configure another interface via dhcp the parameter -i followed by the interface name e.g. eno1 must be given.
e.g. eno1

udhcpc -i eno1


An overview of the onboard i2c devices is available here


Select i2c bus device

i2c dev [0,2]

Show all devices connected to the i2c bus currently selected:

i2c probe


Detect all devices connected to a i2c bus:

i2cdetect [0,2]


To set the hardware clock to the actual time and date use the following commands:

date -s [YYYY.]MM.DD-hh:mm[:ss]
hwclock -w

Temperature Sensors

The STKLS1028A has two temperature sensors, both are located on the TQMLS1028A SOM.

Device I²C Address
TQMLS1028A 0x4C
TQMLS1028A 0x18

Read TQMLS1028A Temperature Sensor

cat /sys/devices/platform/soc/2000000.i2c/i2c-0/0-004c/hwmon/hwmon1/temp1_input
cat /sys/devices/platform/soc/2000000.i2c/i2c-0/0-0018/hwmon/hwmon0/temp1_input

Read CPU internal Temperature Sensor
The QorIQ® Layerscape 1028A CPU has an internal TMU that supports one thermal zone, it can be read by the commands below:

Thermal zone0

cat /sys/devices/virtual/thermal/thermal_zone0/temp


With lsusb you can see all connected usb devices. To mount a partition of an usb stick you can excute mount /dev/<partition> <mount dir> (e.g. mount /dev/sdb1 /mnt). This will mount the first partition of sdb to /mnt. To unmount the device execute umount <mount dir> (e.g. umount /mnt).

User LED

The MBLS1028A has two user controllable LEDs, the behavior of these LEDs can be selected by several triggers.

User LED Overview

Reference LED name color linux filesystem
V55 led1 green /sys/class/leds/led1
V56 led2 green /sys/class/leds/led2

User LED Location

The user LED's are located in /sys/devices/platform/gpio-leds/leds/.
To change the behaviour a specific LED, the value in the file trigger must be overwritten.

The following values are valid:

For example set the trigger of led1 to heartbeat

echo heartbeat > /sys/class/leds/led1/trigger

  • Last modified: 2023/03/31 10:20