BlackBerry Passport - Lock device when holstered.
To prevent accidental dailing or manipulation, you can configure your BlackBerry Passport to automatically enable the lockscreen when the later is placed into its sleeve or case.
To enable this feature:
- From the homescreen, swipe your finger from the top of your screen to open the quick settings menu.
- Tap on Settings
- Tap on Security and Privacy > Device Password.
- Enable Lock Device When Holstered.