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  * @h:			Function which will be used as pollfunc top half
28  * @thread:		Function which will be used as pollfunc bottom 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.
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  */
44 int iio_triggered_buffer_setup(struct iio_dev *indio_dev,
45 	irqreturn_t (*h)(int irq, void *p),
46 	irqreturn_t (*thread)(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();
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(h,
61 						 thread,
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 	return 0;
82 
83 error_kfifo_free:
84 	iio_kfifo_free(indio_dev->buffer);
85 error_ret:
86 	return ret;
87 }
88 EXPORT_SYMBOL(iio_triggered_buffer_setup);
89 
90 /**
91  * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup()
92  * @indio_dev: IIO device structure
93  */
94 void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
95 {
96 	iio_dealloc_pollfunc(indio_dev->pollfunc);
97 	iio_kfifo_free(indio_dev->buffer);
98 }
99 EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
100 
101 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
102 MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
103 MODULE_LICENSE("GPL");
104