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  */
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 attribute ** buffer_attrs)39 int 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 attribute **buffer_attrs)
45 {
46 	struct iio_buffer *buffer;
47 	int ret;
48 
49 	buffer = iio_kfifo_allocate();
50 	if (!buffer) {
51 		ret = -ENOMEM;
52 		goto error_ret;
53 	}
54 
55 	indio_dev->pollfunc = iio_alloc_pollfunc(h,
56 						 thread,
57 						 IRQF_ONESHOT,
58 						 indio_dev,
59 						 "%s_consumer%d",
60 						 indio_dev->name,
61 						 iio_device_id(indio_dev));
62 	if (indio_dev->pollfunc == NULL) {
63 		ret = -ENOMEM;
64 		goto error_kfifo_free;
65 	}
66 
67 	/* Ring buffer functions - here trigger setup related */
68 	indio_dev->setup_ops = setup_ops;
69 
70 	/* Flag that polled ring buffering is possible */
71 	indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
72 
73 	buffer->direction = direction;
74 	buffer->attrs = buffer_attrs;
75 
76 	ret = iio_device_attach_buffer(indio_dev, buffer);
77 	if (ret < 0)
78 		goto error_dealloc_pollfunc;
79 
80 	return 0;
81 
82 error_dealloc_pollfunc:
83 	iio_dealloc_pollfunc(indio_dev->pollfunc);
84 error_kfifo_free:
85 	iio_kfifo_free(buffer);
86 error_ret:
87 	return ret;
88 }
89 EXPORT_SYMBOL(iio_triggered_buffer_setup_ext);
90 
91 /**
92  * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup_ext()
93  * @indio_dev: IIO device structure
94  */
iio_triggered_buffer_cleanup(struct iio_dev * indio_dev)95 void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
96 {
97 	iio_dealloc_pollfunc(indio_dev->pollfunc);
98 	iio_kfifo_free(indio_dev->buffer);
99 }
100 EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
101 
devm_iio_triggered_buffer_clean(void * indio_dev)102 static void devm_iio_triggered_buffer_clean(void *indio_dev)
103 {
104 	iio_triggered_buffer_cleanup(indio_dev);
105 }
106 
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 attribute ** buffer_attrs)107 int devm_iio_triggered_buffer_setup_ext(struct device *dev,
108 					struct iio_dev *indio_dev,
109 					irqreturn_t (*h)(int irq, void *p),
110 					irqreturn_t (*thread)(int irq, void *p),
111 					enum iio_buffer_direction direction,
112 					const struct iio_buffer_setup_ops *ops,
113 					const struct attribute **buffer_attrs)
114 {
115 	int ret;
116 
117 	ret = iio_triggered_buffer_setup_ext(indio_dev, h, thread, direction,
118 					     ops, buffer_attrs);
119 	if (ret)
120 		return ret;
121 
122 	return devm_add_action_or_reset(dev, devm_iio_triggered_buffer_clean,
123 					indio_dev);
124 }
125 EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup_ext);
126 
127 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
128 MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
129 MODULE_LICENSE("GPL");
130