Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932249AbYBTRJa (ORCPT ); Wed, 20 Feb 2008 12:09:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1765106AbYBTRIx (ORCPT ); Wed, 20 Feb 2008 12:08:53 -0500 Received: from opensource.wolfsonmicro.com ([80.75.67.52]:35637 "EHLO opensource2.wolfsonmicro.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1765524AbYBTRIt (ORCPT ); Wed, 20 Feb 2008 12:08:49 -0500 Subject: [UPDATED v2][PATCH 0/6] regulator: voltage and current regulator framework From: Liam Girdwood To: Andrew Morton Cc: linux-kernel , linux-arm-kernel , Mark Brown Content-Type: text/plain Date: Wed, 20 Feb 2008 17:08:46 +0000 Message-Id: <1203527326.4071.88.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.8.3 (2.8.3-2.fc6) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3449 Lines: 80 Version 2 with thanks to Sam Ravnborg, Mariusz Kozlowski, David Brownell and Laura Lawrence for their comments. This patch series provides a generic framework to allow device drivers to control voltage and current regulators on SoC based devices (e.g. phones, gps, media players). The intention is to allow systems to dynamically control regulator output in order to save power and prolong battery life. This applies to both voltage regulators (where voltage output is controllable) and current sinks (where current output is controllable). The framework is designed around SoC based devices but may also be relevant to non SoC devices. It's also been designed against two Power Management ICs (PMICs) currently on the market - namely the Freescale MC13783 and the Wolfson WM8350. However it is quite generic and should apply to all PMICs. The framework provides several interfaces :- 1. Client or Consumer driver API. This uses a similar API to the kernel clock interface in that client or consumer drivers can get and put a regulator (like they can with clocks atm) and get/set voltage, current, mode, enable and disable. This should allow clients complete control over their supply voltage and current. This API also compiles out if not in use so drivers can be reused in systems with no PMIC power control. 2. Regulator driver API. This allows regulator drivers to register their regulators and provide operations to the core. It also has a notifier call chain for propagating regulator events to clients. 3. Platform API. This API is for platform/device specific code and allows the creation of voltage/current domains (with constraints) for each regulator. It can provide regulator constraints that will prevent device damage through over voltage or over current caused by buggy client drivers. It also allows the creation of a regulator tree whereby some regulators are supplied by others (similar to a clock tree). 4. Userspace. The framework also exports a lot of useful voltage/current data to userspace via sysfs. This could be used to monitor device and regulator power and status. Fwiw, there is a project page here :- http://opensource.wolfsonmicro.com/node/15 and code in our public git tree that currently shows this API in use:- http://opensource.wolfsonmicro.com/cgi-bin/gitweb.cgi?p=linux-2.6-audioplus.git;a=shortlog;h=imx31 All the relevant files are under include/linux/regulator and drivers/regulator. There are client drivers here :- http://opensource.wolfsonmicro.com/cgi-bin/gitweb.cgi?p=linux-2.6-audioplus.git;a=blob;f=arch/arm/mach-mx3/cpufreq.c;h=77f03d85fef6b29b0ca2e820d38d9ebb068e7bf7;hb=imx31 http://opensource.wolfsonmicro.com/cgi-bin/gitweb.cgi?p=linux-2.6-audioplus.git;a=blob;f=drivers/leds/leds-wm8350.c;h=a81bbf9154b4de13c029aee0613294562a03f506;hb=imx31 http://opensource.wolfsonmicro.com/cgi-bin/gitweb.cgi?p=linux-2.6-audioplus.git;a=blob;f=drivers/video/backlight/wm8350_bl.c;h=3eafb83683b7f242ec78ff620431307c25e23202;hb=imx31 http://opensource.wolfsonmicro.com/cgi-bin/gitweb.cgi?p=linux-2.6-audioplus.git;a=blob;f=sound/soc/imx/imx32ads-wm8350.c;h=aae347ac556203fbdb64d71f4dc0be7df250767a;hb=imx31 Patch follows. Liam -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/