From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: Query: Regulator framework in EHCI driver Date: Wed, 4 Nov 2009 14:56:26 +0000 Message-ID: <20091104145626.GC30644@rakim.wolfsonmicro.main> References: <19F8576C6E063C45BE387C64729E73940436EEB912@dbde02.ent.ti.com> <20091103153046.GA30320@nokia.com> <19F8576C6E063C45BE387C64729E73940436F9375B@dbde02.ent.ti.com> <20091104133922.GD25044@sirena.org.uk> <5A47E75E594F054BAF48C5E4FC4B92AB030A67DE6A@dbde02.ent.ti.com> <20091104144126.GA30644@rakim.wolfsonmicro.main> <5A47E75E594F054BAF48C5E4FC4B92AB030A67DE7F@dbde02.ent.ti.com> <20091104144811.GB30644@rakim.wolfsonmicro.main> <5A47E75E594F054BAF48C5E4FC4B92AB030A67DE8A@dbde02.ent.ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from opensource.wolfsonmicro.com ([80.75.67.52]:46424 "EHLO opensource2.wolfsonmicro.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756128AbZKDO4W (ORCPT ); Wed, 4 Nov 2009 09:56:22 -0500 Content-Disposition: inline In-Reply-To: <5A47E75E594F054BAF48C5E4FC4B92AB030A67DE8A@dbde02.ent.ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Gadiyar, Anand" Cc: "Gupta, Ajay Kumar" , "felipe.balbi@nokia.com" , "linux-omap@vger.kernel.org" , "Aggarwal, Anuj" On Wed, Nov 04, 2009 at 08:20:46PM +0530, Gadiyar, Anand wrote: > I meant: for the same driver (say EHCI in this case) on two different > boards, if one of them needs a particular regulator (say the 1v8 from TWL4030) > and the other needs none at all (but needs the regulator API in general for > other devices on the board), then what would happen? Like I say, if the kernel is built with regulator support then a fixed voltage regulator should be defined representing the supply if it is provided by a fixed voltage regulator - if the supply is essential to the correct operation of the device this will reflect the actual hardware. If the supply is genuinely optional and need not be connected for correct operation of the device then the consumer driver should gracefully handle failure to acquire the regulator, for example by disabling functionality that depends on the additional supply, but this is relatively unusual.