title: why does the i2cdetect always gives UU on my RTC in embedded Linux
body: <p>I'd like to communicate read from my RTC in C code rather than the <code>"hwclock"</code> shell command.</p>
  
  <p>However, when I use <code>i2cdetect</code>, it shows <code>0x68</code>(which is my RTC slave address) is  having the status <code>"UU"</code>, which means "Probing was skipped, because this address is currently in use by a driver". And after I tried the <code>i2cget</code>, its givng "could bot set address to <code>0x68</code>: Device or resource busy".</p>
  
  <p>So I'm thinking if there are some problem in my Linux kernel that will force to read from my RTC all the time, or some other reason.</p>
  
  <p>Thanks</p>