Why Drupal does not see permission from custom module?
The hook is called hook_permission() in Drupal 7, it changed names from hook_perm() (Drupal 6)


  This hook can supply permissions that the module defines, so that they can be selected on the user permissions page and used to grant or restrict access to actions the module performs.


Make sure you clear Drupal's caches once you've made the change so it gets picked up.