On Fri, 24 Aug 2018 22:24:47 +0200
Marcus Folkesson <marcus.folkesson@xxxxxxxxx> wrote:
> The `vref` regulator is declared as optional in the device-tree binding,
> but the driver does require it.
>
> Go for the device-tree binding and make the `vref` regulator optional.
>
> Signed-off-by: Marcus Folkesson <marcus.folkesson@xxxxxxxxx>
Hmm.
If you do a voltage get on a stub regulator it will return an
error (IIRC).
So I am unconvinced this actually makes any real difference?
What am I missing?
Jonathan
> ---
> drivers/iio/dac/ti-dac5571.c | 30 ++++++++++++++++++++++--------
> 1 file changed, 22 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/iio/dac/ti-dac5571.c b/drivers/iio/dac/ti-dac5571.c
> index f6dcd8bce2b0..bf21cc312096 100644
> --- a/drivers/iio/dac/ti-dac5571.c
> +++ b/drivers/iio/dac/ti-dac5571.c
> @@ -251,6 +251,9 @@ static int dac5571_read_raw(struct iio_dev *indio_dev,
> return IIO_VAL_INT;
>
> case IIO_CHAN_INFO_SCALE:
> + if (!data->vref)
> + return -EOPNOTSUPP;
> +
> ret = regulator_get_voltage(data->vref);
> if (ret < 0)
> return ret;
> @@ -335,13 +338,21 @@ static int dac5571_probe(struct i2c_client *client,
> indio_dev->num_channels = spec->num_channels;
> data->spec = spec;
>
> - data->vref = devm_regulator_get(dev, "vref");
> - if (IS_ERR(data->vref))
> - return PTR_ERR(data->vref);
> + data->vref = devm_regulator_get_optional(dev, "vref");
> + if (IS_ERR(data->vref)) {
> + if (PTR_ERR(data->vref) == -ENODEV) {
> + data->vref = NULL;
> + } else {
> + dev_err(dev, "failed to get regulator (%ld)\n",
> + PTR_ERR(data->vref));
> + return PTR_ERR(data->vref);
That is as likely as not a deferred probe so it should not be
as noisy as this. It may happen during a normal boot process a lot
of times.
> + }
>
> - ret = regulator_enable(data->vref);
> - if (ret < 0)
> - return ret;
> + } else {
> + ret = regulator_enable(data->vref);
> + if (ret)
> + return ret;
> + }
>
> mutex_init(&data->lock);
>
> @@ -373,7 +384,9 @@ static int dac5571_probe(struct i2c_client *client,
> return 0;
>
> err:
> - regulator_disable(data->vref);
> + if (data->vref)
> + regulator_disable(data->vref);
> +
> return ret;
> }
>
> @@ -383,7 +396,8 @@ static int dac5571_remove(struct i2c_client *i2c)
> struct dac5571_data *data = iio_priv(indio_dev);
>
> iio_device_unregister(indio_dev);
> - regulator_disable(data->vref);
> + if (data->vref)
> + regulator_disable(data->vref);
>
> return 0;
> }
