From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753038Ab1AYGMl (ORCPT ); Tue, 25 Jan 2011 01:12:41 -0500 Received: from mgw2.diku.dk ([130.225.96.92]:39934 "EHLO mgw2.diku.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752731Ab1AYGMk (ORCPT ); Tue, 25 Jan 2011 01:12:40 -0500 Date: Tue, 25 Jan 2011 07:12:34 +0100 (CET) From: Julia Lawall To: Jean-Christophe PLAGNIOL-VILLARD Cc: Russell King - ARM Linux , Ryan Mallon , Vasiliy Kulikov , kernel-janitors@vger.kernel.org, Nicolas Ferre , Andrew Victor , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/4] arch/arm/mach-at91/clock.c: Add missing IS_ERR test In-Reply-To: <20110125014428.GO24284@game.jcrosoft.org> Message-ID: References: <20110124200515.GA30963@albatros> <4D3DDD07.1030809@bluewatersys.com> <4D3DE35B.1030102@bluewatersys.com> <4D3DE9CD.2040800@bluewatersys.com> <4D3DF46A.1030009@bluewatersys.com> <20110124232302.GQ24104@n2100.arm.linux.org.uk> <20110125014428.GO24284@game.jcrosoft.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 25 Jan 2011, Jean-Christophe PLAGNIOL-VILLARD wrote: > On 23:23 Mon 24 Jan , Russell King - ARM Linux wrote: > > On Tue, Jan 25, 2011 at 10:51:38AM +1300, Ryan Mallon wrote: > > > You could, but it would not be helpful. Clock associations are used so > > > that _different_ devices can have the same function and map to the > > > correct clock. This is used when there are multiple instances of a > > > single peripheral. For example, the uart clocks work like this: > > > > > > at91_clock_associate("usart1_clk", &pdev->dev, "usart"); > > > > > > so then you can do this in a driver: > > > > > > uart_clk = clk_get(&pdev->dev, "usart"); > > > > > > Rather than: > > > > > > uart_clk = clk_get(NULL, "usart1_clk"); > > > > > > The former will find the correct uart clock for the device. Because each > > > uart is a separate device the correct clock will be selected for each uart. > > > > > > My point was that there should be no overlap between clk->name and > > > clk->function otherwise clk_get will not be able to return the correct > > > clock. > > > > It would be nice if AT91 could switch over to using clkdev at some > > point, which greatly helps with associating struct clk's with their > > device/function names - and reduces the amount of "different" code. > I working on it that's was one of the reason I move clkdev to drivers > as AT91 and AVR32 need to switch Shall I just leave the patch as is then? julia