Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932249Ab2K1PBP (ORCPT ); Wed, 28 Nov 2012 10:01:15 -0500 Received: from smtp181.dfw.emailsrvr.com ([67.192.241.181]:36999 "EHLO smtp181.dfw.emailsrvr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755501Ab2K1PBN (ORCPT ); Wed, 28 Nov 2012 10:01:13 -0500 Message-ID: <50B6273B.1000007@calxeda.com> Date: Wed, 28 Nov 2012 09:01:15 -0600 From: Mark Langsdorf User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Shawn Guo CC: "linux-kernel@vger.kernel.org" , "cpufreq@vger.kernel.org" , "linux-pm@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "devicetree-discuss@lists.ozlabs.org" Subject: Re: [PATCH 6/6 v6] cpufreq, highbank: add support for highbank cpufreq References: <1351631056-25938-1-git-send-email-mark.langsdorf@calxeda.com> <1354046672-7392-1-git-send-email-mark.langsdorf@calxeda.com> <1354046672-7392-7-git-send-email-mark.langsdorf@calxeda.com> <20121128023240.GA28170@S2100-06.ap.freescale.net> <50B60E9C.9000405@calxeda.com> <20121128145759.GB28170@S2100-06.ap.freescale.net> <20121128151741.GC28170@S2100-06.ap.freescale.net> In-Reply-To: <20121128151741.GC28170@S2100-06.ap.freescale.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1401 Lines: 33 On 11/28/2012 09:17 AM, Shawn Guo wrote: > On Wed, Nov 28, 2012 at 10:58:02PM +0800, Shawn Guo wrote: >> On Wed, Nov 28, 2012 at 07:16:12AM -0600, Mark Langsdorf wrote: >>> I'd >>> have to move most of the logic of hb_set_target() into >>> clk_highbank.c:clk_pll_set_rate() and then add extra logic for when >>> cpufreq is not enabled/loaded. >> >> You only need to move hb_voltage_change() into cpu clock's .set_rate() >> hook with no need of checking if cpufreq is enabled or not. >> > Need to also check whether frequency or voltage should be changed first > in .set_rate() though. Yes, that's entirely what I meant when I said that I would need to move most of the hb_set_target() logic into .set_rate(). I would also need to account for retries if the voltage set operation fails, which it sometimes does. The ECME handles changing the voltage but doesn't look like a voltage regulator. Amongst other things, by design it doesn't export meaningful voltage information to Linux. I tried to get cpufreq-clk0 to work with the Highbank design and it ended up being much easier and more sane to create a separate driver. --Mark Langsdorf Calxeda, Inc. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/