view django models.LogEntry in admin, disable create / edit / delete

log_entry_admin.py

class LogEntryAdmin(admin.ModelAdmin):
    list_display = ('action_time', 'user', 'object_repr', 'action_flag')
    list_per_page = 20
    list_display_links = None

    search_fields = ['=user__username', ]
    fieldsets = [(None, {'fields': ()}), ]

    def has_add_permission(self, request):
        return False

    def has_delete_permission(self, request, obj=None):
        return False