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");
113