From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dick Hollenbeck Subject: remapping advice sought Date: Tue, 15 Sep 2009 16:35:44 -0500 Message-ID: <4AB008B0.1020402@softplc.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from kcmailp02.birch.net ([216.212.0.97]:51188 "EHLO mx01.birch.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758680AbZIOVmW (ORCPT ); Tue, 15 Sep 2009 17:42:22 -0400 Received: from unknown (HELO [192.100.100.10]) ([65.16.135.194]) (envelope-sender ) by mx01.birch.net (qmail-ldap-1.03) with SMTP for ; 15 Sep 2009 21:35:45 -0000 Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: linux-serial@vger.kernel.org I made an ARM board with 6 serial ports. One port comes out on /dev/ttyAM0 and 5 others come out on /dev/ttyS0 through /dev/ttyS4. The ttyAM0 is implemented by an ARM CPU specific driver, while the ttyS* ports are implemented in an FPGA and use the 8250.c driver in a multi-port fashion with a shared IRQ. Our userspace code likes to think of serial ports being at /dev/ttyS0 through /dev/ttyS5 but this naming convention has not yet been achieved. (1) Are there any good reason why not to do this: (A) change my copy of the kernel code so that 8250.c exposes its serial ports at some other name than "ttyS". (B) use symlinks in /dev/ to map ttyS0 through ttyS5 onto ttyAM0 followed by the 8250 FPGA ports. (2) How hard and fast is the relationship between the name used in the driver 8250.c, to the name in the /dev/ directory? Can they be different without changing 8250.c source? (3) Is there a better way? Thanks, Dick