Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753809Ab3DOQVk (ORCPT ); Mon, 15 Apr 2013 12:21:40 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:39910 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752558Ab3DOQVj (ORCPT ); Mon, 15 Apr 2013 12:21:39 -0400 Message-ID: <516C2905.8000200@ti.com> Date: Mon, 15 Apr 2013 19:21:25 +0300 From: Andrii Tseglytskyi User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130329 Thunderbird/17.0.5 MIME-Version: 1.0 To: Mark Brown CC: Grygorii Strashko , Liam Girdwood , , Mike Turquette , Nishanth Menon , Tero Kristo , linux-omap , linux-arm Subject: Re: [RFC v1] regulator: core: introduce regulator chain locking scheme References: <1366031015-17073-1-git-send-email-grygorii.strashko@ti.com> <1366031015-17073-2-git-send-email-grygorii.strashko@ti.com> <20130415155040.GD15837@opensource.wolfsonmicro.com> In-Reply-To: <20130415155040.GD15837@opensource.wolfsonmicro.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.167.145.64] X-EXCLAIMER-MD-CONFIG: f9c360f5-3d1e-4c3c-8703-f45bf52eff6b Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1036 Lines: 32 Hi Mark, On 04/15/2013 06:50 PM, Mark Brown wrote: >> In addition, such locking scheme allows to have access to the supplier >> regulator API from inside child's (consumer) regulator API. > I've still not seen any use case articulated for doing this... Use case is introduced in ABB series: http://www.mail-archive.com/linux-omap@vger.kernel.org/msg88293.html During voltage scaling we would like to have the following sequence: cpufreq_cpu0 | |---> set_voltage(ABB) | |->set_voltage(AVS) | |-->set_voltage(smps123) Where smps123 is a regulator, connected ot i2c bus. In this particular case "regulator chain" guarantees proper order of calls of voltage scaling sequence. Regards, Andrii -- 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/