From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kalle Jokiniemi Subject: Re: [PATCH 0/1] TWL: USB: disable VUSB regulators Date: Fri, 23 Jan 2009 12:55:19 +0200 Message-ID: <1232708119.6515.443.camel@ubuntu> References: <1232543718-18199-1-git-send-email-kalle.jokiniemi@digia.com> <200901211238.33229.david-b@pacbell.net> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from sally.edelkey.net ([213.138.147.136]:47250 "EHLO sally.edelkey.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752501AbZAWKzc (ORCPT ); Fri, 23 Jan 2009 05:55:32 -0500 In-Reply-To: <200901211238.33229.david-b@pacbell.net> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: David Brownell Cc: linux-omap@vger.kernel.org, felipe.balbi@nokia.com Hi Dave, Sorry for the late response, I was out of office yesterday. On Wed, 2009-01-21 at 12:38 -0800, David Brownell wrote: > On Wednesday 21 January 2009, Kalle Jokiniemi wrote: > > The TWL5030/4030 internal VUSB regulators are eating current > > like small piggies. > > Feral pigs are a big problem in many places ... > no surprise that feral code is too! > > > > The following patch makes an aptempt at > > making the twl4030-usb consumer driver dynamically disable > > and enable the regulators it needs. > > Thanks, I'll have a look. It's a bit different > from some old hacks I didn't finish debugging. > > Shouldn't the power down sequence mirror the > power up sequence? Up 1.5, 1.8, 3.1 ... then > down 3.1, 1.8, 1.5? Or does that matter? Good question. The TRM tells quite little on these VUSB regulators, other than they supply the USB sub-chip in TWL. For VUSB3V1 there is a bit more information, telling that it supplies USB PHY, CEA Carkit modules and MCPC (seems to be some special usb UART specification). I would think they all can be shut down in whatever order, if there is nothing connected to the usb connector. > > Also, I'm thinking that the DEV_GRP and TYPE > register updates belong in regulator code, not > transceiver code. That's something to take care > of with a separate patch though. I agree. - Kalle > > - Dave