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