Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753807AbaKHLwh (ORCPT ); Sat, 8 Nov 2014 06:52:37 -0500 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:37250 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753573AbaKHLwf (ORCPT ); Sat, 8 Nov 2014 06:52:35 -0500 Message-ID: <545E0401.2000505@kernel.org> Date: Sat, 08 Nov 2014 11:52:33 +0000 From: Jonathan Cameron User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: NeilBrown CC: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, GTA04 owners , "chr >> Doug Anderson" , Thorsten Nowak , Manuel Stahl , "christian.strobel@iis.fraunhofer.de >> Christian Strobel" Subject: Re: [PATCH] iio: gyro: itg3200: add suspend/resume support. References: <20141108111833.3829480c@notabene.brown> In-Reply-To: <20141108111833.3829480c@notabene.brown> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/11/14 00:18, NeilBrown wrote: > > > Unless we put the device to sleep when not it use, it wastes > 6mA. > > If the device is asleep on probe, the 'id' register > sometimes mis-reads - so reset first. If the device responds > at all a command sent to the address, it is almost certainly > the correct device already. > > Signed-off-by: NeilBrown Hi Neil, Looks fine to me - but you should have cc'd a few people from the listed driver authors. Will give them a few days to respond... Jonathan > > diff --git a/drivers/iio/gyro/itg3200_core.c b/drivers/iio/gyro/itg3200_core.c > index 6a8020d48140..394667fb23f9 100644 > --- a/drivers/iio/gyro/itg3200_core.c > +++ b/drivers/iio/gyro/itg3200_core.c > @@ -223,6 +223,7 @@ static int itg3200_initial_setup(struct iio_dev *indio_dev) > int ret; > u8 val; > > + ret = itg3200_reset(indio_dev); > ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_ADDRESS, &val); > if (ret) > goto err_ret; > @@ -351,6 +352,35 @@ static int itg3200_remove(struct i2c_client *client) > return 0; > } > > +#ifdef CONFIG_PM_SLEEP > +static int itg3200_suspend(struct device *dev) > +{ > + struct iio_dev *indio_dev = dev_get_drvdata(dev); > + struct itg3200 *st = iio_priv(indio_dev); > + int ret; > + > + dev_dbg(&st->i2c->dev, "suspend device"); > + > + ret = itg3200_write_reg_8(indio_dev, > + ITG3200_REG_POWER_MANAGEMENT, > + ITG3200_SLEEP); > + return ret; > +} > + > +static int itg3200_resume(struct device *dev) > +{ > + struct iio_dev *indio_dev = dev_get_drvdata(dev); > + > + itg3200_reset(indio_dev); > + return 0; > +} > + > +static SIMPLE_DEV_PM_OPS(itg3200_pm_ops, itg3200_suspend, itg3200_resume); > +#define ITG3200_PM_OPS (&itg3200_pm_ops) > +#else > +#define ITG3200_PM_OPS NULL > +#endif > + > static const struct i2c_device_id itg3200_id[] = { > { "itg3200", 0 }, > { } > @@ -361,6 +391,7 @@ static struct i2c_driver itg3200_driver = { > .driver = { > .owner = THIS_MODULE, > .name = "itg3200", > + .pm = ITG3200_PM_OPS, > }, > .id_table = itg3200_id, > .probe = itg3200_probe, > -- 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/