title: Use of pci_iomap() and ioremap_nocache() functions in UART(8250) driver
body: <ul>
  <li>I'm understanding driver code for UART- <strong>8250.c</strong> and <strong>8250_pci.c</strong> from Linux.</li>
  <li><p>I've problem in understanding use of <strong>pci_iomap</strong> and <strong>ioremap_nocache</strong> function call.</p>
  
  <p>1) Means why they are used in code? </p>
  
  <p>2) And what is significance of  Address return by both functions?</p></li>
  </ul>
  
  <p>Need help.Thanks.</p>