Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 51 insertions, 0 deletions

diff --git a/Documentation/driver-api/iio/hw-consumer.rst b/Documentation/driver-api/iio/hw-consumer.rst
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+===========
+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 consumer setup looks like this::
+
+	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 */
+
+		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:
+