title: How to - device tree node for platform/miscdevice
body: <p>I am trying to create a very basic platform/miscdevice driver for the beaglebone black, but cannot get the device tree to compile when adding the corresponding node.
  (I am trying to get the bare minimum working here. Will add more information to the node once I have got the basics working, and can probe successfully)</p>
  <p>I have been following this guide (among others):
  <a href="https://elinux.org/BeagleBone_and_the_3.8_Kernel" rel="nofollow noreferrer">https://elinux.org/BeagleBone_and_the_3.8_Kernel</a></p>
  <p>I am trying to add the device node to the OCP part of the device tree, as instructed on several guides I have found.
  This is for beaglebone black - example shown from my addition to am33xx.dtsi:</p>
  <pre><code>ocp {
      compatible = &quot;simple-bus&quot;;
      #address-cells = &lt;1&gt;;
      #size-cells = &lt;1&gt;;
      ranges;
      ti,hwmods = &quot;l3_main&quot;;
  
      /* MY ADDITION *****************/
      beep {
          compatible = &quot;my-beep&quot;
      };
      /*******************************/
  
      ..... (other nodes)
  };
  </code></pre>
  <p>I have tried adding this node to am33xx.dtsi, am335x-bone-common.dtsi and building with buildroot.
  And have also tried adding the node to am335x-boneblack.dts, then trying to manually make the dtb.
  Neither method will compile the device tree binary (it is saying there is error)</p>
  <p>I am fairly sure the entry should be in am33xx.dtsi however.</p>
  <p>Can anyone guide how a very basic platform/miscdevice node entry should be structured correctly? Should it even be in ocp?</p>