From mboxrd@z Thu Jan 1 00:00:00 1970 From: Abhijeet Dharmapurikar Subject: platform data and mfd design question Date: Tue, 15 Feb 2011 13:51:16 -0800 Message-ID: <4D5AF554.2030208@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from wolverine02.qualcomm.com ([199.106.114.251]:42977 "EHLO wolverine02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755848Ab1BOVvW (ORCPT ); Tue, 15 Feb 2011 16:51:22 -0500 Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: dilinger@queued.net, Samuel Ortiz Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Mark Brown , Ian Lartey , Dimitris Papastamos , Linus Walleij , Srinidhi Kasagar , Michael Hennerich , linux-arm-msm@vger.kernel.org Currently all the mfd devices declare their struct mfd_cell sub_devices[] array within the core driver. The platform data to them is either passed in as a part of the core driver's platform data. Msm on the other hand declares the struct mfd_cell subdevice[] array in the board file and passes this on to the core driver via platfom data. This code can be found here (sorry for the long url - it is convinient to click on it), https://www.codeaurora.org/gitweb/quic/la/?p=kernel/msm.git;a=blob;f=arch/arm/mach-msm/board-msm8x60.c;h=ed9e9a7674b5ee443f25af828a0044ff99fac483;hb=refs/heads/android-msm-2.6.35 look for static struct mfd_cell pm8058_subdevs[] This gives one the convenience of changing the mfd_cells and their platform data in the board file itself. There are boards where the platform data of some cells changes and in some cases we dont even add a particular cell. This design makes the core driver very light weight. All it does is calls mfd_add_devices on the cell array passed from its platform data. Will this be acceptable in mainline OR do we need to change to follow how others in drivers/mfd do it which is to define the mfd_cell array in the core file itself and manipulate their platform data before doing mfd_add_devices. -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.