From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752235AbdJDMCc (ORCPT ); Wed, 4 Oct 2017 08:02:32 -0400 Received: from 6.mo5.mail-out.ovh.net ([178.32.119.138]:33886 "EHLO 6.mo5.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752044AbdJDMCa (ORCPT ); Wed, 4 Oct 2017 08:02:30 -0400 Subject: Re: [Regulator] Request for clarification - GPIO controlled regulator, USB VBUS, To: Mark Brown Cc: linux-input@vger.kernel.org, "linux-kernel@vger.kernel.org" , Liam Girdwood References: <20171004103213.4ezs6ie6z6dq7pvh@sirena.co.uk> <20171004112704.beqzaxwsb5tg4nbm@sirena.co.uk> From: =?UTF-8?Q?=c5=81ukasz_Majewski?= Message-ID: Date: Wed, 4 Oct 2017 13:54:49 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20171004112704.beqzaxwsb5tg4nbm@sirena.co.uk> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Ovh-Tracer-Id: 14703408360875016770 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrfeelledrkeelgdegiecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfqggfjpdevjffgvefmvefgnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Mark, > On Wed, Oct 04, 2017 at 12:45:39PM +0200, Łukasz Majewski wrote: >>> On Tue, Oct 03, 2017 at 06:58:00PM +0200, Łukasz Majewski wrote: > >>> Perhaps this is something >>> that could be implemented generically for USB as it's a hotpluggable bus > >> In this case we use VBUS as a power supply voltage. The problem with >> regulator API used in this case is that we enable it on boot-up, but then we >> cannot "symulate hotplug" anymore. > > I don't really understand what you mean there, sorry. I do use "regulator-fixed" to control VBUS. The USB driver used regulator_enable/disable to supply power of VBUS. What I do want to achieve: For testing purpose I would like to enable/disable this supply (VBUS) and force/restart of re-enumeration. > The majority of > regulator usage is to supply power, use as reference voltages or > similar. > -- Best regards. Łukasz Majewski