Re: [PATCH 1/7] iio: inkern: API for reading available iio channel attribute values

[Jonathan Cameron <jic23@kernel.org>]

On Sun, 17 Feb 2019 15:29:10 +0100
Artur Rojek <contact@artur-rojek.eu> wrote:

> Extend the inkern API with a function for reading available
> attribute values of iio channels.
> 
> Signed-off-by: Artur Rojek <contact@artur-rojek.eu>

Hmm. It would have been cleaner if we'd done the generic version
in the first place rather than just having the raw value
equivalent of this.

Would you mind sending a follow up patch to convert that call
over to a simple stub around this function?
The alternative would be to convert the few users over to this
function.  Hmm. Probably best to just share the code as much as
possible and for now leave the old function in place.

Anyhow, this looks good ;)

Given the battery driver is tied up with this, it will make sense
for them to go together.  Probably a case for an immutable branch
either in iio or the relevant battery tree.

Assuming it'll be the battery tree.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The cleanup suggested above can follow at some later time.

Thanks,

Jonathan


> ---
>  drivers/iio/inkern.c         | 20 ++++++++++++++++++++
>  include/linux/iio/consumer.h | 14 ++++++++++++++
>  2 files changed, 34 insertions(+)
> 
> diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
> index 06ca3f7fcc44..f19dbde3c945 100644
> --- a/drivers/iio/inkern.c
> +++ b/drivers/iio/inkern.c
> @@ -733,6 +733,26 @@ static int iio_channel_read_avail(struct iio_channel *chan,
>  						 vals, type, length, info);
>  }
>  
> +int iio_read_avail_channel_attribute(struct iio_channel *chan,
> +				     const int **vals, int *type, int *length,
> +				     enum iio_chan_info_enum attribute)
> +{
> +	int ret;
> +
> +	mutex_lock(&chan->indio_dev->info_exist_lock);
> +	if (!chan->indio_dev->info) {
> +		ret = -ENODEV;
> +		goto err_unlock;
> +	}
> +
> +	ret = iio_channel_read_avail(chan, vals, type, length, attribute);
> +err_unlock:
> +	mutex_unlock(&chan->indio_dev->info_exist_lock);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(iio_read_avail_channel_attribute);
> +
>  int iio_read_avail_channel_raw(struct iio_channel *chan,
>  			       const int **vals, int *length)
>  {
> diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
> index 9887f4f8e2a8..b2d34831ed7c 100644
> --- a/include/linux/iio/consumer.h
> +++ b/include/linux/iio/consumer.h
> @@ -290,6 +290,20 @@ int iio_read_max_channel_raw(struct iio_channel *chan, int *val);
>  int iio_read_avail_channel_raw(struct iio_channel *chan,
>  			       const int **vals, int *length);
>  
> +/**
> + * iio_read_avail_channel_attribute() - read available channel attribute values
> + * @chan:		The channel being queried.
> + * @vals:		Available values read back.
> + * @type:		Type of values read back.
> + * @length:		Number of entries in vals.
> + * @attribute:		info attribute to be read back.
> + *
> + * Returns an error code, IIO_AVAIL_RANGE or IIO_AVAIL_LIST.
> + */
> +int iio_read_avail_channel_attribute(struct iio_channel *chan,
> +				     const int **vals, int *type, int *length,
> +				     enum iio_chan_info_enum attribute);
> +
>  /**
>   * iio_get_channel_type() - get the type of a channel
>   * @channel:		The channel being queried.