Re: [PATCH] iio: dac: ti-dac5571: make vref regulator optional

2018-08-25 Thread Jonathan Cameron
On Fri, 24 Aug 2018 22:24:47 +0200
Marcus Folkesson  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 
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;
>  }



[PATCH] iio: dac: ti-dac5571: make vref regulator optional

2018-08-24 Thread Marcus Folkesson
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 
---
 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);
+   }
 
-   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;
 }
-- 
2.18.0