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 .preenable = &iio_sw_buffer_preenable,
21 .postenable = &iio_triggered_buffer_postenable,
22 .predisable = &iio_triggered_buffer_predisable,
23 };
24
25 /**
26 * iio_triggered_buffer_setup() - Setup triggered buffer and pollfunc
27 * @indio_dev: IIO device structure
28 * @pollfunc_bh: Function which will be used as pollfunc bottom half
29 * @pollfunc_th: Function which will be used as pollfunc top half
30 * @setup_ops: Buffer setup functions to use for this device.
31 * If NULL the default setup functions for triggered
32 * buffers will be used.
33 *
34 * This function combines some common tasks which will normally be performed
35 * when setting up a triggered buffer. It will allocate the buffer and the
36 * pollfunc, as well as register the buffer with the IIO core.
37 *
38 * Before calling this function the indio_dev structure should already be
39 * completely initialized, but not yet registered. In practice this means that
40 * this function should be called right before iio_device_register().
41 *
42 * To free the resources allocated by this function call
43 * iio_triggered_buffer_cleanup().
44 */
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)45 int iio_triggered_buffer_setup(struct iio_dev *indio_dev,
46 irqreturn_t (*pollfunc_bh)(int irq, void *p),
47 irqreturn_t (*pollfunc_th)(int irq, void *p),
48 const struct iio_buffer_setup_ops *setup_ops)
49 {
50 int ret;
51
52 indio_dev->buffer = iio_kfifo_allocate(indio_dev);
53 if (!indio_dev->buffer) {
54 ret = -ENOMEM;
55 goto error_ret;
56 }
57
58 indio_dev->pollfunc = iio_alloc_pollfunc(pollfunc_bh,
59 pollfunc_th,
60 IRQF_ONESHOT,
61 indio_dev,
62 "%s_consumer%d",
63 indio_dev->name,
64 indio_dev->id);
65 if (indio_dev->pollfunc == NULL) {
66 ret = -ENOMEM;
67 goto error_kfifo_free;
68 }
69
70 /* Ring buffer functions - here trigger setup related */
71 if (setup_ops)
72 indio_dev->setup_ops = setup_ops;
73 else
74 indio_dev->setup_ops = &iio_triggered_buffer_setup_ops;
75
76 /* Flag that polled ring buffering is possible */
77 indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
78
79 ret = iio_buffer_register(indio_dev,
80 indio_dev->channels,
81 indio_dev->num_channels);
82 if (ret)
83 goto error_dealloc_pollfunc;
84
85 return 0;
86
87 error_dealloc_pollfunc:
88 iio_dealloc_pollfunc(indio_dev->pollfunc);
89 error_kfifo_free:
90 iio_kfifo_free(indio_dev->buffer);
91 error_ret:
92 return ret;
93 }
94 EXPORT_SYMBOL(iio_triggered_buffer_setup);
95
96 /**
97 * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup()
98 * @indio_dev: IIO device structure
99 */
iio_triggered_buffer_cleanup(struct iio_dev * indio_dev)100 void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
101 {
102 iio_buffer_unregister(indio_dev);
103 iio_dealloc_pollfunc(indio_dev->pollfunc);
104 iio_kfifo_free(indio_dev->buffer);
105 }
106 EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
107
108 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
109 MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
110 MODULE_LICENSE("GPL");
111