title: Where can I find the IRQ number in request_irq function?
body: <p>I'm learning device driver programming in Linux. I am wondering where I could find the IRQ number to be used as the "irq" parameter in the request_irq function?</p>
  
  <pre><code>int request_irq (unsigned int irq,
                   void (*handler) (int, void *, struct pt_regs *),
                   unsigned long irqflags,
                   const char *devname,
                   void *dev_id);  
  </code></pre>
  
  <p>Thanks</p>