title: Use of count variable in register_chrdev_region
body: <p>As of I understand, the signature of the <code>register_chrdev_region</code> is described as follows</p>
  
  <pre><code>extern int register_chrdev_region(dev_t firstmajor,unsigned int count,const char*dev_name);
  //firstmajor: The major number requested for reservation of the dirver
  //dev_name: Name of the device associated with the major number(for procfs and sysfs)
  //count: Total number of contagious device numbes that is requested??
  </code></pre>
  
  <p>I don't get the usage of <code>count</code> arguement in the function (in <code>alloc_chrdev_region</code> as well). Please explain a simple use case of reserving contagious device numbers for the driver</p>
  
  <p>Reference 3.2.2 in <a href="http://www.makelinux.net/ldd3/chp-3-sect-2" rel="nofollow">http://www.makelinux.net/ldd3/chp-3-sect-2</a></p>