Re: [RFC PATCH v2 3/7] iio: inkern: api for manipulating ext_info of iio channels

[Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>]

On 17/11/16 21:48, Peter Rosin wrote:
> Extend the inkern api with functions for reading and writing ext_info
> of iio channels.
I'd like Lars' feedback on this one.

Superficially looks fine to me but I am not as familiar with this interface
as Lars is ;) (he wrote it IIRC:)
> ---
>  drivers/iio/inkern.c         | 55 ++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/iio/consumer.h |  6 +++++
>  2 files changed, 61 insertions(+)
> 
> diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
> index cfca17ba2535..a8099b164222 100644
> --- a/drivers/iio/inkern.c
> +++ b/drivers/iio/inkern.c
> @@ -850,3 +850,58 @@ int iio_write_channel_raw(struct iio_channel *chan, int val)
>  	return ret;
>  }
>  EXPORT_SYMBOL_GPL(iio_write_channel_raw);
> +
> +int iio_get_channel_ext_info_count(struct iio_channel *chan)
> +{
> +	const struct iio_chan_spec_ext_info *ext_info;
> +	unsigned int i = 0;
> +
> +	if (!chan->channel->ext_info)
> +		return i;
> +
> +	for (ext_info = chan->channel->ext_info; ext_info->name; ext_info++)
> +		++i;
> +
> +	return i;
> +}
> +EXPORT_SYMBOL_GPL(iio_get_channel_ext_info_count);
> +
> +ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
> +				  const char *attr, char *buf)
> +{
> +	const struct iio_chan_spec_ext_info *ext_info;
> +
> +	if (!chan->channel->ext_info)
> +		return -EINVAL;
> +
> +	for (ext_info = chan->channel->ext_info; ext_info->name; ++ext_info) {
> +		if (strcmp(attr, ext_info->name))
> +			continue;
> +
> +		return ext_info->read(chan->indio_dev, ext_info->private,
> +				      chan->channel, buf);
> +	}
> +
> +	return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(iio_read_channel_ext_info);
> +
> +ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
> +				   const char *buf, size_t len)
> +{
> +	const struct iio_chan_spec_ext_info *ext_info;
> +
> +	if (!chan->channel->ext_info)
> +		return -EINVAL;
> +
> +	for (ext_info = chan->channel->ext_info; ext_info->name; ++ext_info) {
> +		if (strcmp(attr, ext_info->name))
> +			continue;
> +
> +		return ext_info->write(chan->indio_dev, ext_info->private,
> +				       chan->channel, buf, len);
> +	}
> +
> +	return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(iio_write_channel_ext_info);
> diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
> index 9a4f336d8b4a..471dece8729a 100644
> --- a/include/linux/iio/consumer.h
> +++ b/include/linux/iio/consumer.h
> @@ -299,4 +299,10 @@ int iio_read_channel_scale(struct iio_channel *chan, int *val,
>  int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
>  	int *processed, unsigned int scale);
>  
> +int iio_get_channel_ext_info_count(struct iio_channel *chan);
> +ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
> +				  const char *attr, char *buf);
> +ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
> +				   const char *buf, size_t len);
> +
>  #endif
>