title: Cannot Figure Out PWM Overlay for BeagleBone Green Wireless
body: <p>I am new to BeagleBone Green Wireless (BBGW).  I just read Derek Molloy's <em>Exploring BeagleBone</em>.  Very good read, however, BBGW has Linux 4.4.9-ti-r25 and everything is quite different. Linux 4.4.9 no longer has the device tree source.  Just has the device tree overlays (.dto).  I am trying to experiment with the PWM's.  I loaded <code>am33xx_pwm-00A0.dtbo</code> and <code>BB-PWM1-00A0.dtbo</code> overlays found in <code>/lib/firmware</code>.  I presume these are default overlays for PWM1 but not sure.</p>
  
  <pre><code>export SLOTS=/sys/devices/platform/bone_capemgr/slots
  export PINS=/sys/kernel/debug/pinctrl/44e10800.pinmux/pins
  
  sudo sh -c "echo am33xx_pwm &gt; $SLOTS"
  sudo sh -c "echo BB-PWM1 &gt; $SLOTS"
  </code></pre>
  
  <p>They appear to be loaded correctly,</p>
  
  <pre><code>root@beaglebone:/lib/firmware# cat $SLOTS
   0: PF----  -1
   1: PF----  -1
   2: PF----  -1
   3: PF----  -1
   5: P-O-L-   0 Override Board Name,00A0,Override Manuf,am33xx_pwm
   7: P-O-L-   1 Override Board Name,00A0,Override Manuf,BB-PWM1
  </code></pre>
  
  <p>However, I cannot find where to access PWM1's properties.  Malloy says that they are in, <code>/sys/devices/ocp.3/pwm_test_p9_22.15</code>.  I could not find that directory and the closest I could find was <code>/sys/devices/platform/ocp/</code>.  There are several devices but nothing about PWM1.  Where can I find the location of PWM1's properties?  I want to change them using the <code>echo</code> command using this example,</p>
  
  <pre><code>sudo su
  echo 5000 &gt; duty
  echo 10000 &gt; period
  echo 1 &gt; run
  </code></pre>
  
  <p>If someone knows of a good document that would be helpful as well.  </p>