Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760958AbYJMMfq (ORCPT ); Mon, 13 Oct 2008 08:35:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755649AbYJMMfi (ORCPT ); Mon, 13 Oct 2008 08:35:38 -0400 Received: from smtpeu1.atmel.com ([195.65.72.27]:42493 "EHLO bagnes.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754925AbYJMMfh (ORCPT ); Mon, 13 Oct 2008 08:35:37 -0400 Date: Mon, 13 Oct 2008 14:34:47 +0200 From: Haavard Skinnemoen To: Anders Blomdell Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] Make ATNGW100 serial ports configurable Message-ID: <20081013143447.5e0519b3@hskinnemo-gx745.norway.atmel.com> In-Reply-To: <48F32899.5000006@control.lth.se> References: <48EF6762.2080205@control.lth.se> <20081010165814.1c62eabf@hskinnemo-gx745.norway.atmel.com> <48EF7949.4010108@control.lth.se> <20081013122727.7298bd4a@hskinnemo-gx745.norway.atmel.com> <48F32899.5000006@control.lth.se> X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.11; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8bit X-OriginalArrivalTime: 13 Oct 2008 12:34:30.0924 (UTC) FILETIME=[0A2E0CC0:01C92D30] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2001 Lines: 44 Anders Blomdell wrote: > Haavard Skinnemoen wrote: > > Well, you could do it like that, but you could also just add another > > postcore_initcall. The only hook which is really needed is the "setup" > > part, and only if you have additional serial ports. > Does that mean that 'at32_add_device_usart(...);' is not needed? It's needed, but you don't need a hook in the main board code to do it. You can simply do static int __init my_expansion_board_init(void) { at32_add_device_usart(...); /* more stuff */ } postcore_initcall(my_expansion_board_init); > >> An even nicer way of handling it (provided that initialization does not need to > >> take place during boot), might be to do EXPORT_SYMBOL() on > >> at32_add_device_usart, at32_map_usart, etc and then write a loadable module that > >> handles the initialization. > > > > Hmm...why would that be nicer exactly? > You could compile your board specific inits outside the kernel tree, making it > much easier to follow kernel versions (not everyone gets their board specific > code into the kernel tree :-). Adding EXPORT_SYMBOLs purely for use by out-of-tree modules is generally frowned upon. And patching in an additional file to the build is just about the easiest thing you can do. > > What _I_ think would be a nicer way to do it is to implement support > > for flattened device trees and get rid of the board code entirely. Or > > almost entirely; it depends on how complete we can make the device tree. > I don't understand the above paragraph, could you please elaborate? http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/powerpc/booting-without-of.txt;h=de4063cb4fdc0ad6abea29d766cae78616837311;hb=HEAD Haavard -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/