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
drivers/iio/buffer/hw-consumer.c
- struct iio_hw_consumer — Hardware consumer structure 
- iio_hw_consumer_alloc()— Allocate IIO hardware consumer
- iio_hw_consumer_free()— Free IIO hardware consumer
- iio_hw_consumer_enable()— Enable IIO hardware consumer
- 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¶
Parameters
- struct device *dev
- Pointer to consumer device. 
Description
Returns a valid iio_hw_consumer on success or a ERR_PTR() on failure.
- 
void iio_hw_consumer_free(struct iio_hw_consumer *hwc)¶
- Free IIO hardware consumer 
Parameters
- struct iio_hw_consumer *hwc
- hw consumer to free. 
- 
struct iio_hw_consumer *devm_iio_hw_consumer_alloc(struct device *dev)¶
- Resource-managed - iio_hw_consumer_alloc()
Parameters
- struct device *dev
- Pointer to consumer device. 
Description
Managed iio_hw_consumer_alloc. iio_hw_consumer allocated with this function is automatically freed on driver detach.
returns pointer to allocated iio_hw_consumer on success, NULL on failure.
- 
int iio_hw_consumer_enable(struct iio_hw_consumer *hwc)¶
- Enable IIO hardware consumer 
Parameters
- struct iio_hw_consumer *hwc
- iio_hw_consumer to enable. 
Description
Returns 0 on success.
- 
void iio_hw_consumer_disable(struct iio_hw_consumer *hwc)¶
- Disable IIO hardware consumer 
Parameters
- struct iio_hw_consumer *hwc
- iio_hw_consumer to disable.