Version 7 (modified by Tim Harvey, 4 years ago) ( diff )

remove useless devmem register manipulations

GW52xx USB Steering

The GW52xx has two Mini-PCIe slots.

  • Mini-PCIe J7 - USB Always active, on board SIM slot routed to J7
  • Mini-PCIe J8 - USB shared with front panel OTG port
    • The SBC has the ability to route the OTG USB between a Mini-PCIe slot J8 and the front panel micro connector. This can be controlled through software.

This can be done with settings in the bootloader as shown here:

Option 2 - Command Line

The steering is controlled via GPIO2. This can be controlled in Linux at the command line once the board is booted and access to the serial console is acquired.

Setting the GPIO high will route to the Mini-PCIe slot and setting the GPIO low (0) will route it to the front panel connector:

# export gpio2 for userspace control and configure as output
echo 2 > /sys/class/gpio/export #export control of GPIO-2 to user space
echo out > /sys/class/gpio/gpio2/direction #set to an output
# set value low to steer USB OTG to front-panel
echo 0 > /sys/class/gpio/gpio2/value
# set value high to steer USB OTG to miniPCIe
echo 1 > /sys/class/gpio/gpio2/value
Note: See TracWiki for help on using the wiki.