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... 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-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html