From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753354Ab2AYF46 (ORCPT ); Wed, 25 Jan 2012 00:56:58 -0500 Received: from mail-qw0-f53.google.com ([209.85.216.53]:55940 "EHLO mail-qw0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752408Ab2AYF44 (ORCPT ); Wed, 25 Jan 2012 00:56:56 -0500 Message-ID: <4F1F99A5.1000206@kernel.org> Date: Wed, 25 Jan 2012 00:56:53 -0500 From: Len Brown User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.22) Gecko/20110906 Fedora/3.1.14-1.fc14 Lightning/1.0b3pre Thunderbird/3.1.14 MIME-Version: 1.0 To: Guillaume Knispel CC: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, Guillaume Knispel , Xavier Carcelle , =?ISO-8859-1?Q?No=E9_Rubinst?= =?ISO-8859-1?Q?ein?= Subject: Re: How to "register" a GSI for a non PCI non ISA device References: <20120124184203.1b0878c2@xilun> In-Reply-To: <20120124184203.1b0878c2@xilun> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/24/2012 12:42 PM, Guillaume Knispel wrote: > Hi, > > I'm building a PC platform with additional non-PCI and non-ISA devices: > they are basically simple telecom chipsets connected to an SPI and an > old school parallel bus (Intel LEB bus) and GPIO pins that can be used > as interrupts through the IO APIC which exposes 40 GSI. From the point > of view of the software the SPI, LEB, and GPIO are provided by PCI > devices (in reality they are embedded controllers in an Intel SoC > 80579). Anyway I'm not sure the additional GSI are described anywhere > in whatever black magic ACPI / legacy BIOS table they could be > (but I've complete control over the FW, so I can had whatever is > needed when I know it). What is the benefit of implementing ACPI on this custom system? -Len > But as my devices are neither PCI nor ISA, I don't know how i can get > access to the custom GSI interrupt from a LKM. acpi_register_gsi() used > to be exported but is not anymore and I guess this is mandatory that > this function is called to prepare internal structures (maybe irq_desc) > and most importantly to configure to level triggering active low. > > So I'm thinking about writing black magic DSDT stuffs or whatever, > which i might be able to sort of do after reading the fabulous ACPI > specifications. Any feedback or pointer would be highly welcome. > > BTW when Linux devs says that bios writers are writing shit, yeah, they > do, and given the state of complexity of the PC platform, I'm at the > risk to do it too because I'm not supposed to delay the production of > our system by one additional year just to completely learn how the > shitty PC "standards" are supposed to work. From a more personal > point of view when I'm reading the ACPI or other related specs tainted > by MS and their desire to put GUID everywhere and other terrible ideas, > I would rather prefer being high to not endure that much pain. > > As more and more x86 systems are directly designed to run Linux and > only tested with it, with some of those (like our own) being built > by people having complete control on the board and firmware (Coreboot), > maybe it is time to define a legacy-free variant of the x86 plateform > (especially on the FW/OS interface) for the free software and free > hardware design world, so that we aren't restricted and slowed down by > retro-compatible technologies dedicated at running MS-DOS and created > with the explicit goal to be hard to use for anything else than > Windows NT. > > Cheers!