From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932113AbbJMKph (ORCPT ); Tue, 13 Oct 2015 06:45:37 -0400 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:53650 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751813AbbJMKpg (ORCPT ); Tue, 13 Oct 2015 06:45:36 -0400 From: Sascha Hauer To: linux-kernel@vger.kernel.org Cc: Liam Girdwood , Mark Brown , kernel@pengutronix.de, alkml@pengutronix.de Subject: [PATCH v2] regulator: Propagate voltage changes to supply regulators Date: Tue, 13 Oct 2015 12:45:23 +0200 Message-Id: <1444733131-26995-1-git-send-email-s.hauer@pengutronix.de> X-Mailer: git-send-email 2.6.1 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: sha@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In-Reply-To: Until now changing the voltage of a regulator only ever effected the regulator itself, but never its supplies. It's a common pattern though to put LDO regulators behind switching regulators. The switching regulators efficiently drop the input voltage but have a high ripple on their output. The output is then cleaned up by the LDOs. For higher energy efficiency the voltage drop at the LDOs should be minimized. This series adds support for such a scenario. Another case voltage propagation is useful is simple switches which are abstracted as regulators. These can now offer voltage settings to their consumers which are transparently passed to the switches supply. Please review, any input welcome. Changes since RFC (v1): - split into more patches - Only do voltage propagation when we have a supply and either a minimum dropout voltage is specified or the regulator is a switch (lacks a get_voltage operation) Sascha