Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755035Ab3HZJcq (ORCPT ); Mon, 26 Aug 2013 05:32:46 -0400 Received: from mail-oa0-f48.google.com ([209.85.219.48]:35236 "EHLO mail-oa0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751391Ab3HZJco (ORCPT ); Mon, 26 Aug 2013 05:32:44 -0400 MIME-Version: 1.0 In-Reply-To: <20130824001345.GD14810@roeck-us.net> References: <20130820192650.GA19470@srcf.ucam.org> <6438184.2yT2NMB1CE@vostro.rjw.lan> <20130821233942.GA21502@srcf.ucam.org> <1810269.JOHnJ0H7P9@vostro.rjw.lan> <20130822000306.GA21785@srcf.ucam.org> <1377300343.5259.84.camel@dvhart-mobl4.amr.corp.intel.com> <20130823233805.GA1801@srcf.ucam.org> <1377301548.5259.91.camel@dvhart-mobl4.amr.corp.intel.com> <20130824001345.GD14810@roeck-us.net> Date: Mon, 26 Aug 2013 11:32:44 +0200 Message-ID: Subject: Re: ACPI vs Device Tree - moving forward From: Linus Walleij To: Guenter Roeck Cc: Darren Hart , Matthew Garrett , "Rafael J. Wysocki" , "linux-kernel@vger.kernel.org" , ACPI Devel Maling List , "H. Peter Anvin" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1541 Lines: 39 On Sat, Aug 24, 2013 at 2:13 AM, Guenter Roeck wrote: > Did the group conclude that the idea of FDT augmenting ACPI is not feasible ? I don't think anyone really knows. For example: how to specify a few config options through a FDT augmented ACPI system is trivial. Passing system-wide resources such as clocks, regulators, pin control handles, GPIOs, interrupts and DMA channels is a criss-cross operation and nobody knows if that will work because nobody tried to hash out the details of. > If not, the key question for me is how to implement it, and how to handle > all its little problems. It seems like we are in the "teenagers talking about sex" situation, everybody is talking about it but nobody is really doing it. Which makes it all pretty theoretical. > If yes, the key question for me is how to handle all the drivers which > assume fdt-style properties, and how to express all that information in ACPI > in a way which does not require a substantial driver rewrite (and, as you point > out, how that data would be described in ACPI consistently across multiple > vendors). For GPIO we have this: drivers/gpio/gpiolib-of.c drivers/gpio/gpiolib-acpi.c So one thing is clear: for this resource we're going to have two implementations. Yours, Linus Walleij -- 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/