From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752490AbaHRJBK (ORCPT ); Mon, 18 Aug 2014 05:01:10 -0400 Received: from mail-bn1lp0144.outbound.protection.outlook.com ([207.46.163.144]:24377 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750906AbaHRJBI (ORCPT ); Mon, 18 Aug 2014 05:01:08 -0400 Date: Mon, 18 Aug 2014 17:00:59 +0800 From: Peter Chen To: Philippe Reynes CC: , , "linux-arm-kernel@lists.infradead.org" , , Subject: Re: [RFC] usb issue on imx27: 3 clocks are needed Message-ID: <20140818090056.GA29393@peterchendt> References: <53EF7AF6.2000405@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <53EF7AF6.2000405@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-EOPAttributedMessage: 0 X-Forefront-Antispam-Report: CIP:192.88.168.50;CTRY:US;IPV:CAL;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(10019005)(6009001)(189002)(45984002)(199003)(53754006)(24454002)(51704005)(102836001)(81342001)(23726002)(99396002)(50466002)(83506001)(33656002)(79102001)(33716001)(64706001)(80022001)(20776003)(81542001)(26826002)(110136001)(47776003)(46406003)(77982001)(106466001)(105606002)(95666004)(50986999)(76482001)(87936001)(104016003)(1411001)(57986006)(44976005)(83322001)(6806004)(54356999)(4396001)(68736004)(84676001)(21056001)(97736001)(92726001)(85306004)(107046002)(31966008)(86362001)(76176999)(74502001)(92566001)(74662001)(85852003)(97756001)(46102001)(83072002);DIR:OUT;SFP:1102;SCL:1;SRVR:BL2PR03MB337;H:tx30smr01.am.freescale.net;FPR:;MLV:ovrnspm;PTR:InfoDomainNonexistent;MX:1;A:1;LANG:en; X-Microsoft-Antispam: BCL:0;PCL:0;RULEID:;UriScan:; X-Forefront-PRVS: 03077579FF Authentication-Results: spf=fail (sender IP is 192.88.168.50) smtp.mailfrom=Peter.Chen@freescale.com; X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Aug 16, 2014 at 05:38:30PM +0200, Philippe Reynes wrote: > Hi all, > > i.MX27's usb needs three clocks (usb_ipg_gate, usb_ahb_gate and usb_div) > but the current chipidea driver implementation, and devicetree, provides > only ipg and ahb. Consequently, if the bootloader don't enable the last > one, the kernel will crash. > > Our approach/idea is to add a second, optionnal, clock in ci_hdrc_imx.c > with 'per' name in devicetree and to add clock name 'main_clk' for mandatory clock. > This approach it correct? Or an other approach seems better? > Thank you very much for your point of view. > It is ok for me to have ipg, ahb and per clocks at driver, but how can you maintain DT consistent? Can you accept open ipg and per always on at clock.c? -- Best Regards, Peter Chen