Well, autotree is easy in the grammar, but harder later. The key is to use your own actions. You started that with the action for QUOTED_STRING, but you need more. I got this:

$VAR1 = [
          {
            'trailer' => ' #f',
            'str2' => ' *',
            'portLists' => undef,
            'str1' => ' /opt/mylib/s956M'
          }
        ];
[download]

from adding these actions:

my $grammar = <<'_EOGRAMMAR_';

      QUOTED_STRING : /"/ <skip:""> quoted_char(s?) /"/ {
                " " . join "", @{$item[3]} # leading space flags a str
+ing
      }

      quoted_char :
                /[^\\"]+/        { $item[1] }
                | /\\n/ { "\n" } { $item[1] }
                | /\\"/ { "\"" } { $item[1] }

     portDefinition: "dbSetCellPortTypes"
                     QUOTED_STRING QUOTED_STRING
                     portLists
                     QUOTED_STRING
                     { return {
                         str1      => $item[2],
                         str2      => $item[3],
                         portLists => $item[4],
                         trailer   => $item[5]
                     } }

     portLists: "'" "(" list(s?) ")" { $item[2] }
     list: "(" QUOTED_STRING(s) ")" { $item[2] }

_EOGRAMMAR_
[download]

I'd have better names for the string keys, if I knew what they were for.

Phil