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
19 static 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 */
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)44 int 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
89 error_dealloc_pollfunc:
90 iio_dealloc_pollfunc(indio_dev->pollfunc);
91 error_kfifo_free:
92 iio_kfifo_free(indio_dev->buffer);
93 error_ret:
94 return ret;
95 }
96 EXPORT_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 */
iio_triggered_buffer_cleanup(struct iio_dev * indio_dev)102 void 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 }
108 EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
109
110 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
111 MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
112 MODULE_LICENSE("GPL");
113