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/kfifo_buf.h>
13 #include <linux/iio/triggered_buffer.h>
14 #include <linux/iio/trigger_consumer.h>
15 
16 static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
17 	.postenable = &iio_triggered_buffer_postenable,
18 	.predisable = &iio_triggered_buffer_predisable,
19 };
20 
21 /**
22  * iio_triggered_buffer_setup() - Setup triggered buffer and pollfunc
23  * @indio_dev:		IIO device structure
24  * @h:			Function which will be used as pollfunc top half
25  * @thread:		Function which will be used as pollfunc bottom half
26  * @setup_ops:		Buffer setup functions to use for this device.
27  *			If NULL the default setup functions for triggered
28  *			buffers will be used.
29  *
30  * This function combines some common tasks which will normally be performed
31  * when setting up a triggered buffer. It will allocate the buffer and the
32  * pollfunc.
33  *
34  * Before calling this function the indio_dev structure should already be
35  * completely initialized, but not yet registered. In practice this means that
36  * this function should be called right before iio_device_register().
37  *
38  * To free the resources allocated by this function call
39  * iio_triggered_buffer_cleanup().
40  */
41 int iio_triggered_buffer_setup(struct iio_dev *indio_dev,
42 	irqreturn_t (*h)(int irq, void *p),
43 	irqreturn_t (*thread)(int irq, void *p),
44 	const struct iio_buffer_setup_ops *setup_ops)
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 	iio_device_attach_buffer(indio_dev, buffer);
56 
57 	indio_dev->pollfunc = iio_alloc_pollfunc(h,
58 						 thread,
59 						 IRQF_ONESHOT,
60 						 indio_dev,
61 						 "%s_consumer%d",
62 						 indio_dev->name,
63 						 indio_dev->id);
64 	if (indio_dev->pollfunc == NULL) {
65 		ret = -ENOMEM;
66 		goto error_kfifo_free;
67 	}
68 
69 	/* Ring buffer functions - here trigger setup related */
70 	if (setup_ops)
71 		indio_dev->setup_ops = setup_ops;
72 	else
73 		indio_dev->setup_ops = &iio_triggered_buffer_setup_ops;
74 
75 	/* Flag that polled ring buffering is possible */
76 	indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
77 
78 	return 0;
79 
80 error_kfifo_free:
81 	iio_kfifo_free(indio_dev->buffer);
82 error_ret:
83 	return ret;
84 }
85 EXPORT_SYMBOL(iio_triggered_buffer_setup);
86 
87 /**
88  * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup()
89  * @indio_dev: IIO device structure
90  */
91 void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
92 {
93 	iio_dealloc_pollfunc(indio_dev->pollfunc);
94 	iio_kfifo_free(indio_dev->buffer);
95 }
96 EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
97 
98 static void devm_iio_triggered_buffer_clean(struct device *dev, void *res)
99 {
100 	iio_triggered_buffer_cleanup(*(struct iio_dev **)res);
101 }
102 
103 int devm_iio_triggered_buffer_setup(struct device *dev,
104 				    struct iio_dev *indio_dev,
105 				    irqreturn_t (*h)(int irq, void *p),
106 				    irqreturn_t (*thread)(int irq, void *p),
107 				    const struct iio_buffer_setup_ops *ops)
108 {
109 	struct iio_dev **ptr;
110 	int ret;
111 
112 	ptr = devres_alloc(devm_iio_triggered_buffer_clean, sizeof(*ptr),
113 			   GFP_KERNEL);
114 	if (!ptr)
115 		return -ENOMEM;
116 
117 	*ptr = indio_dev;
118 
119 	ret = iio_triggered_buffer_setup(indio_dev, h, thread, ops);
120 	if (!ret)
121 		devres_add(dev, ptr);
122 	else
123 		devres_free(ptr);
124 
125 	return ret;
126 }
127 EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup);
128 
129 void devm_iio_triggered_buffer_cleanup(struct device *dev,
130 				       struct iio_dev *indio_dev)
131 {
132 	int rc;
133 
134 	rc = devres_release(dev, devm_iio_triggered_buffer_clean,
135 			    devm_iio_device_match, indio_dev);
136 	WARN_ON(rc);
137 }
138 EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_cleanup);
139 
140 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
141 MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
142 MODULE_LICENSE("GPL");
143