C compiler

Write a program to control the brightness of an LED using PWM output of Raspberry Pi. Once the program is executed, the LED starts to turn on and gradually goes from off to maximum brightness. Once it has reached maximum brightness, it starts to dim down until it turns completely off again. The time it takes for the LED to reach from off state to maximum brightness is asked from the user at the beginning of the program. The dimming down should take the same time.