xref: /OK3568_Linux_fs/kernel/Documentation/driver-api/iio/hw-consumer.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun===========
2*4882a593SmuzhiyunHW consumer
3*4882a593Smuzhiyun===========
4*4882a593SmuzhiyunAn IIO device can be directly connected to another device in hardware. In this
5*4882a593Smuzhiyuncase the buffers between IIO provider and IIO consumer are handled by hardware.
6*4882a593SmuzhiyunThe Industrial I/O HW consumer offers a way to bond these IIO devices without
7*4882a593Smuzhiyunsoftware buffer for data. The implementation can be found under
8*4882a593Smuzhiyun:file:`drivers/iio/buffer/hw-consumer.c`
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun* struct iio_hw_consumer — Hardware consumer structure
12*4882a593Smuzhiyun* :c:func:`iio_hw_consumer_alloc` — Allocate IIO hardware consumer
13*4882a593Smuzhiyun* :c:func:`iio_hw_consumer_free` — Free IIO hardware consumer
14*4882a593Smuzhiyun* :c:func:`iio_hw_consumer_enable` — Enable IIO hardware consumer
15*4882a593Smuzhiyun* :c:func:`iio_hw_consumer_disable` — Disable IIO hardware consumer
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun
18*4882a593SmuzhiyunHW consumer setup
19*4882a593Smuzhiyun=================
20*4882a593Smuzhiyun
21*4882a593SmuzhiyunAs standard IIO device the implementation is based on IIO provider/consumer.
22*4882a593SmuzhiyunA typical IIO HW consumer setup looks like this::
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun	static struct iio_hw_consumer *hwc;
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun	static const struct iio_info adc_info = {
27*4882a593Smuzhiyun		.read_raw = adc_read_raw,
28*4882a593Smuzhiyun	};
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun	static int adc_read_raw(struct iio_dev *indio_dev,
31*4882a593Smuzhiyun				struct iio_chan_spec const *chan, int *val,
32*4882a593Smuzhiyun				int *val2, long mask)
33*4882a593Smuzhiyun	{
34*4882a593Smuzhiyun		ret = iio_hw_consumer_enable(hwc);
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun		/* Acquire data */
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun		ret = iio_hw_consumer_disable(hwc);
39*4882a593Smuzhiyun	}
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun	static int adc_probe(struct platform_device *pdev)
42*4882a593Smuzhiyun	{
43*4882a593Smuzhiyun		hwc = devm_iio_hw_consumer_alloc(&iio->dev);
44*4882a593Smuzhiyun	}
45*4882a593Smuzhiyun
46*4882a593SmuzhiyunMore details
47*4882a593Smuzhiyun============
48*4882a593Smuzhiyun.. kernel-doc:: drivers/iio/buffer/industrialio-hw-consumer.c
49*4882a593Smuzhiyun   :export:
50*4882a593Smuzhiyun
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