my ipod touch 4 has passcode locked and i connected to itunes nothing happened and my home button is broke. How do I get it unlocked?

If you previously turned on FIndMyiPod on the iPod in Settings>iCloud and wifi is on and connected go to iCloud: Find My iPhone, sign in and go to FIndMyiPhone and use Remote Wipe to erase the contents of your device. If you have been using iCloud to back up, you may be able to restore the most recent backup to reset the passcode after the device has been erased.

You can also wipe the iOS device by installing the FindMyiPhone app on another iOS device and using that app to wipe the device.

or

Use the method specified here to place the iPod in Recovery mode.

Turn on without Home/Power Button

Then restore via iTunes

For how to restore:

iTunes: Restoring iOS software

To restore from backup see:

iOS: Back up and restore your iOS device with iCloud or iTunes

If you restore from iCloud backup the apps will be automatically downloaded. If you restore from iTunes backup the apps and music have to be in the iTunes library since synced media like apps and music are not included in the backup of the iOS device that iTunes makes.

You can redownload most iTunes purchases by:

Downloading past purchases from the App Store, iBookstore, and iTunes Store