LEARN DRIVERS

Hello friends,
I am new to ARM,and i want to learn how to write driver for a program that too in LPC2378.

void driver()
{ PINSEL4=0X00000000; PINMODE4=0X00000002; FIO2DIR=0X000000FF; FIO2PIN=0X00000000; RTC_PREINT=0X0000016E; RTC_PREFRAC=0X00006500; PCONP = 0X00000200; RTC_SEC = 0X00000000; RTC_MIN = 0X00000000; RTC_HOUR = 0X00000000; RTC_CCR = 0X00000001;

This is one of the example for Real Time Clock.I want to learn how to configure drivers for any other peripherals like LED,UARTS,etc.I have referred user manual as well as my LPC2378 data sheet but m not able to get the proper idea.

Thanks.