Re: [PATCH] iio: gyro: itg3200: add suspend/resume support.

From: NeilBrown
Date: Sun Nov 09 2014 - 17:58:00 EST


On Sat, 08 Nov 2014 11:52:33 +0000 Jonathan Cameron <jic23@xxxxxxxxxx> wrote:

> 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 <neil@xxxxxxxxxx>
> 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...

Over-dependence on get_maintainers.pl I guess. :-(

Thanks,
NeilBrown


>
> 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,
> >

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