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 <n...@brown.name>
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,
>
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