1 /*
  2 * Copyright (c) 2012 Analog Devices, Inc.
  3 *  Author: Lars-Peter Clausen <lars@metafoo.de>
  4 *
  5 * This program is free software; you can redistribute it and/or modify it
  6 * under the terms of the GNU General Public License version 2 as published by
  7 * the Free Software Foundation.
  8 */
  9
 10#include <linux/kernel.h>
 11#include <linux/export.h>
 12#include <linux/module.h>
 13#include <linux/iio/iio.h>
 14#include <linux/iio/buffer.h>
 15#include <linux/iio/kfifo_buf.h>
 16#include <linux/iio/triggered_buffer.h>
 17#include <linux/iio/trigger_consumer.h>
 18
 19static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
 20	.postenable = &iio_triggered_buffer_postenable,
 21	.predisable = &iio_triggered_buffer_predisable,
 22};
 23
 24/**
 25 * iio_triggered_buffer_setup() - Setup triggered buffer and pollfunc
 26 * @indio_dev:		IIO device structure
 27 * @pollfunc_bh:	Function which will be used as pollfunc bottom half
 28 * @pollfunc_th:	Function which will be used as pollfunc top half
 29 * @setup_ops:		Buffer setup functions to use for this device.
 30 *			If NULL the default setup functions for triggered
 31 *			buffers will be used.
 32 *
 33 * This function combines some common tasks which will normally be performed
 34 * when setting up a triggered buffer. It will allocate the buffer and the
 35 * pollfunc, as well as register the buffer with the IIO core.
 36 *
 37 * Before calling this function the indio_dev structure should already be
 38 * completely initialized, but not yet registered. In practice this means that
 39 * this function should be called right before iio_device_register().
 40 *
 41 * To free the resources allocated by this function call
 42 * iio_triggered_buffer_cleanup().
 43 */
 44int iio_triggered_buffer_setup(struct iio_dev *indio_dev,
 45	irqreturn_t (*pollfunc_bh)(int irq, void *p),
 46	irqreturn_t (*pollfunc_th)(int irq, void *p),
 47	const struct iio_buffer_setup_ops *setup_ops)
 48{
 49	struct iio_buffer *buffer;
 50	int ret;
 51
 52	buffer = iio_kfifo_allocate(indio_dev);
 53	if (!buffer) {
 54		ret = -ENOMEM;
 55		goto error_ret;
 56	}
 57
 58	iio_device_attach_buffer(indio_dev, buffer);
 59
 60	indio_dev->pollfunc = iio_alloc_pollfunc(pollfunc_bh,
 61						 pollfunc_th,
 62						 IRQF_ONESHOT,
 63						 indio_dev,
 64						 "%s_consumer%d",
 65						 indio_dev->name,
 66						 indio_dev->id);
 67	if (indio_dev->pollfunc == NULL) {
 68		ret = -ENOMEM;
 69		goto error_kfifo_free;
 70	}
 71
 72	/* Ring buffer functions - here trigger setup related */
 73	if (setup_ops)
 74		indio_dev->setup_ops = setup_ops;
 75	else
 76		indio_dev->setup_ops = &iio_triggered_buffer_setup_ops;
 77
 78	/* Flag that polled ring buffering is possible */
 79	indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
 80
 81	ret = iio_buffer_register(indio_dev,
 82				  indio_dev->channels,
 83				  indio_dev->num_channels);
 84	if (ret)
 85		goto error_dealloc_pollfunc;
 86
 87	return 0;
 88
 89error_dealloc_pollfunc:
 90	iio_dealloc_pollfunc(indio_dev->pollfunc);
 91error_kfifo_free:
 92	iio_kfifo_free(indio_dev->buffer);
 93error_ret:
 94	return ret;
 95}
 96EXPORT_SYMBOL(iio_triggered_buffer_setup);
 97
 98/**
 99 * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup()
100 * @indio_dev: IIO device structure
101 */
102void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
103{
104	iio_buffer_unregister(indio_dev);
105	iio_dealloc_pollfunc(indio_dev->pollfunc);
106	iio_kfifo_free(indio_dev->buffer);
107}
108EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
109
110MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
111MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
112MODULE_LICENSE("GPL");