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  * @setup_ops:		Buffer setup functions to use for this device.
23  *			If NULL the default setup functions for triggered
24  *			buffers will be used.
25  * @buffer_attrs:	Extra sysfs buffer attributes for this IIO buffer
26  *
27  * This function combines some common tasks which will normally be performed
28  * when setting up a triggered buffer. It will allocate the buffer and the
29  * pollfunc.
30  *
31  * Before calling this function the indio_dev structure should already be
32  * completely initialized, but not yet registered. In practice this means that
33  * this function should be called right before iio_device_register().
34  *
35  * To free the resources allocated by this function call
36  * iio_triggered_buffer_cleanup().
37  */
38 int iio_triggered_buffer_setup_ext(struct iio_dev *indio_dev,
39 	irqreturn_t (*h)(int irq, void *p),
40 	irqreturn_t (*thread)(int irq, void *p),
41 	const struct iio_buffer_setup_ops *setup_ops,
42 	const struct attribute **buffer_attrs)
43 {
44 	struct iio_buffer *buffer;
45 	int ret;
46 
47 	buffer = iio_kfifo_allocate();
48 	if (!buffer) {
49 		ret = -ENOMEM;
50 		goto error_ret;
51 	}
52 
53 	indio_dev->pollfunc = iio_alloc_pollfunc(h,
54 						 thread,
55 						 IRQF_ONESHOT,
56 						 indio_dev,
57 						 "%s_consumer%d",
58 						 indio_dev->name,
59 						 indio_dev->id);
60 	if (indio_dev->pollfunc == NULL) {
61 		ret = -ENOMEM;
62 		goto error_kfifo_free;
63 	}
64 
65 	/* Ring buffer functions - here trigger setup related */
66 	indio_dev->setup_ops = setup_ops;
67 
68 	/* Flag that polled ring buffering is possible */
69 	indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
70 
71 	buffer->attrs = buffer_attrs;
72 
73 	ret = iio_device_attach_buffer(indio_dev, buffer);
74 	if (ret < 0)
75 		goto error_dealloc_pollfunc;
76 
77 	return 0;
78 
79 error_dealloc_pollfunc:
80 	iio_dealloc_pollfunc(indio_dev->pollfunc);
81 error_kfifo_free:
82 	iio_kfifo_free(buffer);
83 error_ret:
84 	return ret;
85 }
86 EXPORT_SYMBOL(iio_triggered_buffer_setup_ext);
87 
88 /**
89  * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup_ext()
90  * @indio_dev: IIO device structure
91  */
92 void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
93 {
94 	iio_dealloc_pollfunc(indio_dev->pollfunc);
95 	iio_kfifo_free(indio_dev->buffer);
96 }
97 EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
98 
99 static void devm_iio_triggered_buffer_clean(struct device *dev, void *res)
100 {
101 	iio_triggered_buffer_cleanup(*(struct iio_dev **)res);
102 }
103 
104 int devm_iio_triggered_buffer_setup_ext(struct device *dev,
105 					struct iio_dev *indio_dev,
106 					irqreturn_t (*h)(int irq, void *p),
107 					irqreturn_t (*thread)(int irq, void *p),
108 					const struct iio_buffer_setup_ops *ops,
109 					const struct attribute **buffer_attrs)
110 {
111 	struct iio_dev **ptr;
112 	int ret;
113 
114 	ptr = devres_alloc(devm_iio_triggered_buffer_clean, sizeof(*ptr),
115 			   GFP_KERNEL);
116 	if (!ptr)
117 		return -ENOMEM;
118 
119 	*ptr = indio_dev;
120 
121 	ret = iio_triggered_buffer_setup_ext(indio_dev, h, thread, ops,
122 					     buffer_attrs);
123 	if (!ret)
124 		devres_add(dev, ptr);
125 	else
126 		devres_free(ptr);
127 
128 	return ret;
129 }
130 EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup_ext);
131 
132 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
133 MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
134 MODULE_LICENSE("GPL");
135