{{{#!html
          <div id="wikipage" class="trac-content"><h1 id="GW52xxUSBSteering"><b style="color:#000;background:#66ffff">GW52xx USB Steering</b></h1>
<p>
The GW52xx 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.
</p>
<h2 id="Option1-Bootloader-Recommended">Option 1 - Bootloader - Recommended</h2>
<ul><li><strong>Recommended</strong>- This can be done with settings in the bootloader as shown here: <a class="wiki" href="/wiki/ventana/bootloader#USBFront-panelvsPCIesocketrouting">GW52xx Bootloader Configuration</a>
</li></ul><h2 id="Option2-CommandLine">Option 2 - Command Line</h2>
<p>
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.
</p>
<p>
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:
</p>
<pre class="wiki">echo 2 &gt; /sys/class/gpio/export
echo out &gt; /sys/class/gpio/gpio2/direction
echo 1 &gt; /sys/class/gpio/gpio2/value
</pre><p>
Additionally, to accomplish this switching back and forth <strong>during run time</strong>, please use the script below:
</p>
<pre class="wiki">#!/bin/sh
#
# GW52xx:
#  Dynamically switch USB OTG from front-panel (fp) and PCIe socket (pci)
#  at run-time and trigger re-enumeration
#
# usage: gw52xx-usbswitch fp|pci
#
[ -d /sys/class/gpio/gpio2 ] || {
  echo "setup"
  devmem 0x20e0224 32 0x15 # hack to set SION bit in case we want read-back
  echo 2 &gt; /sys/class/gpio/export
  echo out &gt; /sys/class/gpio/gpio2/direction
}
case "$1" in
  fp)  echo 0 &gt; /sys/class/gpio/gpio2/value;;
  pci) echo 1 &gt; /sys/class/gpio/gpio2/value;;
esac
# set GPIO_2 pad-mux to GPIO1__IO2 to effectively let OTG_ID go interally go
# high and trigger a mode-switch to client-mode and thus disconnect
devmem 0x20e0210 32 0x5
# set GPIO_2 pad-mux back to USBOTG_IDSEL to let OTG_ID get pulled down by
# attached cable and trigger a mode-switch to host-mode and thus enumerate
devmem 0x20e0210 32 0x3
</pre
}}}