From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Lunn Subject: Re: [PATCH 2/8] cpufreq: add driver for Armada XP Date: Fri, 4 Jul 2014 16:15:41 +0200 Message-ID: <20140704141541.GE7773@lunn.ch> References: <1404467103-29644-1-git-send-email-thomas.petazzoni@free-electrons.com> <1404467103-29644-3-git-send-email-thomas.petazzoni@free-electrons.com> <20140704131247.2c8ecde2@free-electrons.com> <1404481934.4634.2.camel@weser.hi.pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from vps0.lunn.ch ([178.209.37.122]:42286 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751742AbaGDOUU (ORCPT ); Fri, 4 Jul 2014 10:20:20 -0400 Content-Disposition: inline In-Reply-To: <1404481934.4634.2.camel@weser.hi.pengutronix.de> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Lucas Stach Cc: Thomas Petazzoni , Viresh Kumar , Mike Turquette , "Rafael J. Wysocki" , Jason Cooper , Andrew Lunn , Sebastian Hesselbarth , Gregory Clement , "linux-pm@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Tawfik Bayouk , Nadav Haklai , Lior Amsalem , Ezequiel Garcia On Fri, Jul 04, 2014 at 03:52:14PM +0200, Lucas Stach wrote: > Am Freitag, den 04.07.2014, 13:12 +0200 schrieb Thomas Petazzoni: > [...] > > This doesn't work very well with the idea of having the OPP table > > statically encoded in to the Device Tree. Options are: > > > > - Improve the cpufreq-cpu0 driver so that the OPP table can be passed > > through platform_data, and therefore built dynamically by the > > platform code and passed when registering the cpufreq > > platform_device. > > > > - Dynamically build/update the OPP table in the Device Tree. > > This sounds like the right thing to do. Ideally your bootloader would do > this for you, so you don't have to encode those properties statically at > all. > > Barebox already has facilities to fixup any loaded device tree. Have a > look at of_register_fixup() there. We are talking about legacy devices here, which have been in the field for years. There is very little chance of a boot loader upgrade. Appended DT is the norm for these devices, and modifying the DT would have to happen in kernel. Andrew From mboxrd@z Thu Jan 1 00:00:00 1970 From: andrew@lunn.ch (Andrew Lunn) Date: Fri, 4 Jul 2014 16:15:41 +0200 Subject: [PATCH 2/8] cpufreq: add driver for Armada XP In-Reply-To: <1404481934.4634.2.camel@weser.hi.pengutronix.de> References: <1404467103-29644-1-git-send-email-thomas.petazzoni@free-electrons.com> <1404467103-29644-3-git-send-email-thomas.petazzoni@free-electrons.com> <20140704131247.2c8ecde2@free-electrons.com> <1404481934.4634.2.camel@weser.hi.pengutronix.de> Message-ID: <20140704141541.GE7773@lunn.ch> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Jul 04, 2014 at 03:52:14PM +0200, Lucas Stach wrote: > Am Freitag, den 04.07.2014, 13:12 +0200 schrieb Thomas Petazzoni: > [...] > > This doesn't work very well with the idea of having the OPP table > > statically encoded in to the Device Tree. Options are: > > > > - Improve the cpufreq-cpu0 driver so that the OPP table can be passed > > through platform_data, and therefore built dynamically by the > > platform code and passed when registering the cpufreq > > platform_device. > > > > - Dynamically build/update the OPP table in the Device Tree. > > This sounds like the right thing to do. Ideally your bootloader would do > this for you, so you don't have to encode those properties statically at > all. > > Barebox already has facilities to fixup any loaded device tree. Have a > look at of_register_fixup() there. We are talking about legacy devices here, which have been in the field for years. There is very little chance of a boot loader upgrade. Appended DT is the norm for these devices, and modifying the DT would have to happen in kernel. Andrew