From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757098AbcCCIZu (ORCPT ); Thu, 3 Mar 2016 03:25:50 -0500 Received: from mout01.posteo.de ([185.67.36.65]:48633 "EHLO mout01.posteo.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756785AbcCCIZr (ORCPT ); Thu, 3 Mar 2016 03:25:47 -0500 From: Martin Kepplinger To: jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, christoph.muellner@theobroma-systems.com, mfuzzey@parkeon.com Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: iio: mma8452: power saving features for v4.7 Date: Thu, 3 Mar 2016 09:24:00 +0100 Message-Id: <1456993444-21320-1-git-send-email-martink@posteo.de> X-Mailer: git-send-email 2.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The accelerometers supported by mma8452 can use significantly less power if configured accordingly. Let's make use of this: * add support for runtime power management (disabling the device after 2 seconds of inactivity), and * add a "power_modes" property to IIO sysfs, that offers a "low_power" *active* mode of operation that roughly consumes half the power of the default mode. If you don't have CONFIG_PM enabled, by default nothing changes for you. Here's how it's done and tested on MMA8653FC: [PATCH 1/4] iio: mma8452: coding style fixes [PATCH 2/4] iio: mma8452: avoid switching to active because of config [PATCH 3/4] iio: mma8452: add support for runtime power management [PATCH 4/4] iio: mma8452: add low_power mode