industrialio-triggered-buffer.c

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 /*
 * Copyright (c) 2012 Analog Devices, Inc.
 *  Author: Lars-Peter Clausen <[email protected]>
 *
 * 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 = {
    .preenable = &iio_sw_buffer_preenable,
    .postenable = &iio_triggered_buffer_postenable,
    .predisable = &iio_triggered_buffer_predisable,
};

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)
{
    int ret;

    indio_dev->buffer = iio_kfifo_allocate(indio_dev);
    if (!indio_dev->buffer) {
        ret = -ENOMEM;
        goto error_ret;
    }

    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);

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 <[email protected]>");
MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
MODULE_LICENSE("GPL");