From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757225Ab2BMQhS (ORCPT ); Mon, 13 Feb 2012 11:37:18 -0500 Received: from opensource.wolfsonmicro.com ([80.75.67.52]:37735 "EHLO opensource.wolfsonmicro.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755282Ab2BMQhQ (ORCPT ); Mon, 13 Feb 2012 11:37:16 -0500 Date: Mon, 13 Feb 2012 08:37:12 -0800 From: Mark Brown To: Laxman Dewangan Cc: "linux-kernel@vger.kernel.org" Subject: Re: Regulator enable/disable delay based on board design: How to handle? Message-ID: <20120213163711.GD3494@opensource.wolfsonmicro.com> References: <4F38D55A.5020208@nvidia.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="/3yNEOqWowh/8j+e" Content-Disposition: inline In-Reply-To: <4F38D55A.5020208@nvidia.com> X-Cookie: Your aim is high and to the right. User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --/3yNEOqWowh/8j+e Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Feb 13, 2012 at 02:48:18PM +0530, Laxman Dewangan wrote: > We observed that some of the rail enable/disable settling time > depends on the board design specially based on external capacitor > connected on > rails. This is observed mainly on VBUS regulator rail where > difference on the capacitance value which is connected on rail makes > the on/off > time to vary. Usually this would be handled via regulator driver platform data as the regulator will typically be designed with particular external components in mind and (especially in the case of DCDC convertors) may need to be configured differently depending on the choice of passive components. Many regulators also have some software control for the ramp rate, mainly intended to limit inrush currents on system startup, which can be varied at runtime if desired. --/3yNEOqWowh/8j+e Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAEBAgAGBQJPOTwsAAoJEBus8iNuMP3d/Z8P+waZR6/ICB6RvF8nUrQpGZlq XFvmMIFdYYwNroMH7CeCylOeDnXgw8lc6sofQNck0c+4/PhYvGkfe2X1B06hJzu4 wA3kS2StC5fKJmU3gWmbZsVoXXRcyUZ6vFdvkFH81KLLZohsvgTcXCNZApIdil2a NI4R9YrU5byrAh8Z8LbVD2ms1tOfyEFfULlsjkSgG4bDbL4BMe64/T47j9qEI5L5 200jAiAHAZlQXnQP8qg9+boT4fIXc7ueq1WEiriJ7KkDw+PZzdeHqKolR12o+1yD oRB+Yvx0769IKV4nyIGgEZPBNmuYSaTBFRNOdnaiG9hGLksm26/UHgaayoB20Soj vvaAYI4lCPLub+M2IBJUjio2cQ3zgPIsiw1Ncd1xJrBFGKDE7bZIRmfSo2PRqIvt +xB34h7QqITuEx2X8e6/NXqT+Ci15BiddpSFnuYfpSNe3Eus603ygEYZ6Z25WMX5 g00IVhhDEhsO/LJb+v4NXsJhS/SKMWCsWTmHvyN2Fws6pvb5H4DkrUNuyPl5mg5/ BUC9DrxSHWokMF6AXXIrcPPAyWnjFal20zlLzg9e17Q1XUyfEGosiovq2C19yLjY 1dv1MhSE5gRw8xdqwHanlsA84XYfSr/dtnq5mCkifrZKrSwyhdj9W3Ue0pGEB8+B lkSSa+BQm5dj4R+Hfzge =7PzK -----END PGP SIGNATURE----- --/3yNEOqWowh/8j+e--