industrialio-triggered-buffer.c
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/*
* Copyright (c) 2012 Analog Devices, Inc.
* Author: Lars-Peter Clausen <lars@metafoo.de>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/kfifo_buf.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
.postenable = &iio_triggered_buffer_postenable,
.predisable = &iio_triggered_buffer_predisable,
};
/**
* iio_triggered_buffer_setup() - Setup triggered buffer and pollfunc
* @indio_dev: IIO device structure
* @pollfunc_bh: Function which will be used as pollfunc bottom half
* @pollfunc_th: Function which will be used as pollfunc top half
* @setup_ops: Buffer setup functions to use for this device.
* If NULL the default setup functions for triggered
* buffers will be used.
*
* This function combines some common tasks which will normally be performed
* when setting up a triggered buffer. It will allocate the buffer and the
* pollfunc, as well as register the buffer with the IIO core.
*
* Before calling this function the indio_dev structure should already be
* completely initialized, but not yet registered. In practice this means that
* this function should be called right before iio_device_register().
*
* To free the resources allocated by this function call
* iio_triggered_buffer_cleanup().
*/
int iio_triggered_buffer_setup(struct iio_dev *indio_dev,
irqreturn_t (*pollfunc_bh)(int irq, void *p),
irqreturn_t (*pollfunc_th)(int irq, void *p),
const struct iio_buffer_setup_ops *setup_ops)
{
struct iio_buffer *buffer;
int ret;
buffer = iio_kfifo_allocate(indio_dev);
if (!buffer) {
ret = -ENOMEM;
goto error_ret;
}
iio_device_attach_buffer(indio_dev, buffer);
indio_dev->pollfunc = iio_alloc_pollfunc(pollfunc_bh,
pollfunc_th,
IRQF_ONESHOT,
indio_dev,
"%s_consumer%d",
indio_dev->name,
indio_dev->id);
if (indio_dev->pollfunc == NULL) {
ret = -ENOMEM;
goto error_kfifo_free;
}
/* Ring buffer functions - here trigger setup related */
if (setup_ops)
indio_dev->setup_ops = setup_ops;
else
indio_dev->setup_ops = &iio_triggered_buffer_setup_ops;
/* Flag that polled ring buffering is possible */
indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
ret = iio_buffer_register(indio_dev,
indio_dev->channels,
indio_dev->num_channels);
if (ret)
goto error_dealloc_pollfunc;
return 0;
error_dealloc_pollfunc:
iio_dealloc_pollfunc(indio_dev->pollfunc);
error_kfifo_free:
iio_kfifo_free(indio_dev->buffer);
error_ret:
return ret;
}
EXPORT_SYMBOL(iio_triggered_buffer_setup);
/**
* iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup()
* @indio_dev: IIO device structure
*/
void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
{
iio_buffer_unregister(indio_dev);
iio_dealloc_pollfunc(indio_dev->pollfunc);
iio_kfifo_free(indio_dev->buffer);
}
EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
MODULE_LICENSE("GPL");