Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752824AbbBSSov (ORCPT ); Thu, 19 Feb 2015 13:44:51 -0500 Received: from li42-95.members.linode.com ([209.123.162.95]:37308 "EHLO li42-95.members.linode.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751736AbbBSSot convert rfc822-to-8bit (ORCPT ); Thu, 19 Feb 2015 13:44:49 -0500 Subject: Re: [PATCH 3/4] arm: am33xx: DT quirks for am33xx based beaglebone variants Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2070.6\)) Content-Type: text/plain; charset=utf-8 From: Pantelis Antoniou In-Reply-To: <20150219183600.GG32521@atomide.com> Date: Thu, 19 Feb 2015 20:44:39 +0200 Cc: Grant Likely , Matt Porter , Koen Kooi , Guenter Roeck , Ludovic Desroches , Rob Herring , Nicolas Ferre , devicetree@vger.kernel.org, Linux Kernel Mailing List , linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 8BIT Message-Id: <145DEB3E-A20E-4390-84B1-4B30E7C3D841@antoniou-consulting.com> References: <1424271576-1952-1-git-send-email-pantelis.antoniou@konsulko.com> <1424271576-1952-4-git-send-email-pantelis.antoniou@konsulko.com> <20150219181656.GF32521@atomide.com> <9C7BFC7C-0751-4233-927F-D01AF078704B@antoniou-consulting.com> <20150219183600.GG32521@atomide.com> To: Tony Lindgren X-Mailer: Apple Mail (2.2070.6) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1712 Lines: 52 Hi Tony, > On Feb 19, 2015, at 20:36 , Tony Lindgren wrote: > > * Pantelis Antoniou [150219 10:32]: >>> On Feb 19, 2015, at 20:16 , Tony Lindgren wrote: >>> >>> Uhh I don't like the idea of duplicating the i2c-omap.c driver under >>> arch/arm.. And in general we should initialize things later rather >>> than earlier. >>> >>> What's stopping doing these quirk checks later on time with just >>> a regular device driver, something like drivers/misc/bbone-quirks.c? >>> >> >> We have no choice; we are way early in the boot process, right after >> the device tree unflattening step. > > To me it seems the dt patching part should be done with minimal > code before any driver like features.. > The way it’s done right now is with minimal code. Reading the EEPROM is required. >> I’ve toyed with the idea of using early platform devices but the omap-i2c driver >> would need some tender love and care to make it work, and I didn’t want to get >> bogged down with i2c driver details at this point. > > ..so how about just parse a kernel cmdline for the quirks to apply > based on a version string or similar? That can be easily populated > by u-boot or set manually with setenv. > > That leaves out the need for tinkering with i2c super early in > the kernel for revision detection. > You assume there’s going to be a bootloader… > Regards, > > Tony Regards — Pantelis -- 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/