[alsa-devel] [PATCH v4 02/12] docs: driver-api: add iio hw consumer section

[Jonathan Cameron]

On Thu, 9 Nov 2017 11:12:24 +0100
Arnaud Pouliquen <arnaud.pouliquen at st.com> wrote:

> This adds a section about the Hardware consumer
> Api of the IIO subsystem to the driver API
> documentation.
> 
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen at st.com>

Good little bit of docs.  A couple of minor formatting
comments inline.

Jonathan

> ---
>  Documentation/driver-api/iio/hw-consumer.rst | 50 ++++++++++++++++++++++++++++
>  Documentation/driver-api/iio/index.rst       |  1 +
>  2 files changed, 51 insertions(+)
>  create mode 100644 Documentation/driver-api/iio/hw-consumer.rst
> 
> diff --git a/Documentation/driver-api/iio/hw-consumer.rst b/Documentation/driver-api/iio/hw-consumer.rst
> new file mode 100644
> index 0000000..b777133
> --- /dev/null
> +++ b/Documentation/driver-api/iio/hw-consumer.rst
> @@ -0,0 +1,50 @@
> +===========
> +HW consumer
> +===========
> +An IIO device can be directly connected to another device in hardware. in this
> +case the buffers between IIO provider and IIO consumer are handled by hardware.
> +The Industrial I/O hw consumer offers a way to bond these IIO devices without
> +software buffer for data. The implementation can be found under
> +:file:`drivers/iio/buffer/hw-consumer.c`
> +
> +
> +* struct :c:type:`iio_hw_consumer` — Hardware consumer structure
> +* :c:func:`iio_hw_consumer_alloc` — Allocate IIO hardware consumer
> +* :c:func:`iio_hw_consumer_free` — Free IIO hardware consumer
> +* :c:func:`iio_hw_consumer_enable` — Enable IIO hardware consumer
> +* :c:func:`iio_hw_consumer_disable` — Disable IIO hardware consumer
> +
> +
> +HW consumer setup
> +=================
> +
> +As standard IIO device the implementation is based on IIO provider/consumer.
> +A typical IIO Hw conumer setup looks like this::

HW

> +
> +	static struct iio_hw_consumer *hwc;
> +
> +	static const struct iio_info adc_info = {
> +		.read_raw = adc_read_raw,
> +	};
> +
> +	static int adc_read_raw(struct iio_dev *indio_dev,
> +				struct iio_chan_spec const *chan, int *val,
> +				int *val2, long mask)
> +	{
> +		ret = iio_hw_consumer_enable(hwc);
> +
> +		/* Acquire data */

Blank line here to make it clear the Acquire data doesn't apply to
the line below but is representing a missing block.

> +		ret = iio_hw_consumer_disable(hwc);
> +	}
> +
> +	static int adc_probe(struct platform_device *pdev)
> +	{
> +		hwc = devm_iio_hw_consumer_alloc(&iio->dev);
> +	}
> +
> +More details
> +============
> +.. kernel-doc:: include/linux/iio/hw-consumer.h
> +.. kernel-doc:: drivers/iio/buffer/industrialio-hw-consumer.c
> +   :export:
> +
> diff --git a/Documentation/driver-api/iio/index.rst b/Documentation/driver-api/iio/index.rst
> index e5c3922..7fba341 100644
> --- a/Documentation/driver-api/iio/index.rst
> +++ b/Documentation/driver-api/iio/index.rst
> @@ -15,3 +15,4 @@ Contents:
>     buffers
>     triggers
>     triggered-buffers
> +   hw-consumer