summaryrefslogtreecommitdiff
path: root/drivers/iio/buffer/industrialio-triggered-buffer.c
blob: c06515987e7a7cae91e57610243ac3aabba52ebd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
// SPDX-License-Identifier: GPL-2.0-only
 /*
 * Copyright (c) 2012 Analog Devices, Inc.
 *  Author: Lars-Peter Clausen <lars@metafoo.de>
 */

#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/buffer_impl.h>
#include <linux/iio/kfifo_buf.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>

/**
 * iio_triggered_buffer_setup_ext() - Setup triggered buffer and pollfunc
 * @indio_dev:		IIO device structure
 * @h:			Function which will be used as pollfunc top half
 * @thread:		Function which will be used as pollfunc bottom half
 * @direction:		Direction of the data stream (in/out).
 * @setup_ops:		Buffer setup functions to use for this device.
 *			If NULL the default setup functions for triggered
 *			buffers will be used.
 * @buffer_attrs:	Extra sysfs buffer attributes for this IIO buffer
 *
 * 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.
 *
 * 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_ext(struct iio_dev *indio_dev,
	irqreturn_t (*h)(int irq, void *p),
	irqreturn_t (*thread)(int irq, void *p),
	enum iio_buffer_direction direction,
	const struct iio_buffer_setup_ops *setup_ops,
	const struct iio_dev_attr **buffer_attrs)
{
	struct iio_buffer *buffer;
	int ret;

	/*
	 * iio_triggered_buffer_cleanup() assumes that the buffer allocated here
	 * is assigned to indio_dev->buffer but this is only the case if this
	 * function is the first caller to iio_device_attach_buffer(). If
	 * indio_dev->buffer is already set then we can't proceed otherwise the
	 * cleanup function will try to free a buffer that was not allocated here.
	 */
	if (indio_dev->buffer)
		return -EADDRINUSE;

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

	indio_dev->pollfunc = iio_alloc_pollfunc(h,
						 thread,
						 IRQF_ONESHOT,
						 indio_dev,
						 "%s_consumer%d",
						 indio_dev->name,
						 iio_device_id(indio_dev));
	if (indio_dev->pollfunc == NULL) {
		ret = -ENOMEM;
		goto error_kfifo_free;
	}

	/* Ring buffer functions - here trigger setup related */
	indio_dev->setup_ops = setup_ops;

	/* Flag that polled ring buffering is possible */
	indio_dev->modes |= INDIO_BUFFER_TRIGGERED;

	buffer->direction = direction;
	buffer->attrs = buffer_attrs;

	ret = iio_device_attach_buffer(indio_dev, buffer);
	if (ret < 0)
		goto error_dealloc_pollfunc;

	return 0;

error_dealloc_pollfunc:
	iio_dealloc_pollfunc(indio_dev->pollfunc);
error_kfifo_free:
	iio_kfifo_free(buffer);
error_ret:
	return ret;
}
EXPORT_SYMBOL(iio_triggered_buffer_setup_ext);

/**
 * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup_ext()
 * @indio_dev: IIO device structure
 */
void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
{
	iio_dealloc_pollfunc(indio_dev->pollfunc);
	iio_kfifo_free(indio_dev->buffer);
}
EXPORT_SYMBOL(iio_triggered_buffer_cleanup);

static void devm_iio_triggered_buffer_clean(void *indio_dev)
{
	iio_triggered_buffer_cleanup(indio_dev);
}

int devm_iio_triggered_buffer_setup_ext(struct device *dev,
					struct iio_dev *indio_dev,
					irqreturn_t (*h)(int irq, void *p),
					irqreturn_t (*thread)(int irq, void *p),
					enum iio_buffer_direction direction,
					const struct iio_buffer_setup_ops *ops,
					const struct iio_dev_attr **buffer_attrs)
{
	int ret;

	ret = iio_triggered_buffer_setup_ext(indio_dev, h, thread, direction,
					     ops, buffer_attrs);
	if (ret)
		return ret;

	return devm_add_action_or_reset(dev, devm_iio_triggered_buffer_clean,
					indio_dev);
}
EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup_ext);

MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
MODULE_LICENSE("GPL");