1// SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2012 Analog Devices, Inc.
4 *  Author: Lars-Peter Clausen <lars@metafoo.de>
5 */
6
7#include <linux/kernel.h>
8#include <linux/export.h>
9#include <linux/module.h>
10#include <linux/iio/iio.h>
11#include <linux/iio/buffer.h>
12#include <linux/iio/buffer_impl.h>
13#include <linux/iio/kfifo_buf.h>
14#include <linux/iio/triggered_buffer.h>
15#include <linux/iio/trigger_consumer.h>
16
17/**
18 * iio_triggered_buffer_setup_ext() - Setup triggered buffer and pollfunc
19 * @indio_dev:		IIO device structure
20 * @h:			Function which will be used as pollfunc top half
21 * @thread:		Function which will be used as pollfunc bottom half
22 * @direction:		Direction of the data stream (in/out).
23 * @setup_ops:		Buffer setup functions to use for this device.
24 *			If NULL the default setup functions for triggered
25 *			buffers will be used.
26 * @buffer_attrs:	Extra sysfs buffer attributes for this IIO buffer
27 *
28 * This function combines some common tasks which will normally be performed
29 * when setting up a triggered buffer. It will allocate the buffer and the
30 * pollfunc.
31 *
32 * Before calling this function the indio_dev structure should already be
33 * completely initialized, but not yet registered. In practice this means that
34 * this function should be called right before iio_device_register().
35 *
36 * To free the resources allocated by this function call
37 * iio_triggered_buffer_cleanup().
38 */
39int iio_triggered_buffer_setup_ext(struct iio_dev *indio_dev,
40	irqreturn_t (*h)(int irq, void *p),
41	irqreturn_t (*thread)(int irq, void *p),
42	enum iio_buffer_direction direction,
43	const struct iio_buffer_setup_ops *setup_ops,
44	const struct iio_dev_attr **buffer_attrs)
45{
46	struct iio_buffer *buffer;
47	int ret;
48
49	/*
50	 * iio_triggered_buffer_cleanup() assumes that the buffer allocated here
51	 * is assigned to indio_dev->buffer but this is only the case if this
52	 * function is the first caller to iio_device_attach_buffer(). If
53	 * indio_dev->buffer is already set then we can't proceed otherwise the
54	 * cleanup function will try to free a buffer that was not allocated here.
55	 */
56	if (indio_dev->buffer)
57		return -EADDRINUSE;
58
59	buffer = iio_kfifo_allocate();
60	if (!buffer) {
61		ret = -ENOMEM;
62		goto error_ret;
63	}
64
65	indio_dev->pollfunc = iio_alloc_pollfunc(h,
66						 thread,
67						 IRQF_ONESHOT,
68						 indio_dev,
69						 "%s_consumer%d",
70						 indio_dev->name,
71						 iio_device_id(indio_dev));
72	if (indio_dev->pollfunc == NULL) {
73		ret = -ENOMEM;
74		goto error_kfifo_free;
75	}
76
77	/* Ring buffer functions - here trigger setup related */
78	indio_dev->setup_ops = setup_ops;
79
80	/* Flag that polled ring buffering is possible */
81	indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
82
83	buffer->direction = direction;
84	buffer->attrs = buffer_attrs;
85
86	ret = iio_device_attach_buffer(indio_dev, buffer);
87	if (ret < 0)
88		goto error_dealloc_pollfunc;
89
90	return 0;
91
92error_dealloc_pollfunc:
93	iio_dealloc_pollfunc(indio_dev->pollfunc);
94error_kfifo_free:
95	iio_kfifo_free(buffer);
96error_ret:
97	return ret;
98}
99EXPORT_SYMBOL(iio_triggered_buffer_setup_ext);
100
101/**
102 * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup_ext()
103 * @indio_dev: IIO device structure
104 */
105void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
106{
107	iio_dealloc_pollfunc(indio_dev->pollfunc);
108	iio_kfifo_free(indio_dev->buffer);
109}
110EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
111
112static void devm_iio_triggered_buffer_clean(void *indio_dev)
113{
114	iio_triggered_buffer_cleanup(indio_dev);
115}
116
117int devm_iio_triggered_buffer_setup_ext(struct device *dev,
118					struct iio_dev *indio_dev,
119					irqreturn_t (*h)(int irq, void *p),
120					irqreturn_t (*thread)(int irq, void *p),
121					enum iio_buffer_direction direction,
122					const struct iio_buffer_setup_ops *ops,
123					const struct iio_dev_attr **buffer_attrs)
124{
125	int ret;
126
127	ret = iio_triggered_buffer_setup_ext(indio_dev, h, thread, direction,
128					     ops, buffer_attrs);
129	if (ret)
130		return ret;
131
132	return devm_add_action_or_reset(dev, devm_iio_triggered_buffer_clean,
133					indio_dev);
134}
135EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup_ext);
136
137MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
138MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
139MODULE_LICENSE("GPL");
140