From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753380AbaGDE7U (ORCPT ); Fri, 4 Jul 2014 00:59:20 -0400 Received: from mail-lb0-f176.google.com ([209.85.217.176]:61799 "EHLO mail-lb0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751320AbaGDE7S (ORCPT ); Fri, 4 Jul 2014 00:59:18 -0400 MIME-Version: 1.0 X-Originating-IP: [89.139.36.201] In-Reply-To: <53B59471.30703@ti.com> References: <1398904476-26200-1-git-send-email-s-anna@ti.com> <1398904476-26200-5-git-send-email-s-anna@ti.com> <53B47626.4040506@ti.com> <53B59471.30703@ti.com> From: Ohad Ben-Cohen Date: Fri, 4 Jul 2014 07:58:56 +0300 Message-ID: Subject: Re: [PATCHv5 04/15] hwspinlock/core: add common OF helpers To: Suman Anna Cc: Mark Rutland , Kumar Gala , Tony Lindgren , Josh Cartwright , Bjorn Andersson , "linux-kernel@vger.kernel.org" , "linux-omap@vger.kernel.org" , "devicetree@vger.kernel.org" , linux-arm Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Suman, On Thu, Jul 3, 2014 at 8:35 PM, Suman Anna wrote: > Not at the moment, with the existing platform implementations. So, if I > understand you correctly, you are asking to leave out the xlate ops and > make the of_hwspin_lock_simple_xlate() internal until a need for an > xlate method arises. Yes, please. It seems to me this way we're reducing complexity without compromising anything. > This also means, we only support a value of 1 for #hwlock-cells. When a different #hwlock-cells value shows up, someone would have to write a new xlate implementation anyway. At the same time, the xlate ops could be brought back quite easily. Since we're not imposing anything on the DT data, this doesn't affect our ability to support these scenarios in the future, but unless I'm missing a current use case, these scenarios right now seems somewhat fictional. > But, that would mean DT-based client users would have to invoke two > function calls to request a hwspinlock. We already have an API to get > the lock id given a hwspinlock - hwspin_lock_get_id(), so I added the OF > API for requesting a lock directly rather than giving an OF API for > getting the lock id. This is in keeping in convention with what other > drivers do normally - a regular get and an OF get. I can modify it if > you still prefer the OF API for getting a global lock id, but I feel its > a burden for client users. Let's discuss this. I was actually thinking of the more general use case of an heterogenous system: - driver gets the global lock id from a remote processor - driver then requests the specific lock Looking at these cases, the OF scenario only differs in the small part of fetching the lock id, and if we keep the regular request_specific API we'll have more common code between drivers. What do you think? > Also, do you prefer an open property-name in client users (like I am > doing at the moment) or imposing a standard property name "hwlocks"? Good point - I think we can start with an imposed "hwlocks" name, and evolve in the future as needed (again, only because we're not really imposing anything on the DT data - this is just kernel code that we could always extend as needed). Thanks, Ohad.