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 */
 39int 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 iio_dev_attr **buffer_attrs)
 45{
 46	struct iio_buffer *buffer;
 47	int ret;
 48
 49	/*
 50	 * iio_triggered_buffer_cleanup() assumes that the buffer allocated here
 51	 * is assigned to indio_dev->buffer but this is only the case if this
 52	 * function is the first caller to iio_device_attach_buffer(). If
 53	 * indio_dev->buffer is already set then we can't proceed otherwise the
 54	 * cleanup function will try to free a buffer that was not allocated here.
 55	 */
 56	if (indio_dev->buffer)
 57		return -EADDRINUSE;
 58
 59	buffer = iio_kfifo_allocate();
 60	if (!buffer) {
 61		ret = -ENOMEM;
 62		goto error_ret;
 63	}
 64
 65	indio_dev->pollfunc = iio_alloc_pollfunc(h,
 66						 thread,
 67						 IRQF_ONESHOT,
 68						 indio_dev,
 69						 "%s_consumer%d",
 70						 indio_dev->name,
 71						 iio_device_id(indio_dev));
 72	if (indio_dev->pollfunc == NULL) {
 73		ret = -ENOMEM;
 74		goto error_kfifo_free;
 75	}
 76
 77	/* Ring buffer functions - here trigger setup related */
 78	indio_dev->setup_ops = setup_ops;
 79
 80	/* Flag that polled ring buffering is possible */
 81	indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
 82
 83	buffer->direction = direction;
 84	buffer->attrs = buffer_attrs;
 85
 86	ret = iio_device_attach_buffer(indio_dev, buffer);
 87	if (ret < 0)
 88		goto error_dealloc_pollfunc;
 89
 90	return 0;
 91
 92error_dealloc_pollfunc:
 93	iio_dealloc_pollfunc(indio_dev->pollfunc);
 94error_kfifo_free:
 95	iio_kfifo_free(buffer);
 96error_ret:
 97	return ret;
 98}
 99EXPORT_SYMBOL(iio_triggered_buffer_setup_ext);
100
101/**
102 * iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup_ext()
103 * @indio_dev: IIO device structure
104 */
105void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
106{
107	iio_dealloc_pollfunc(indio_dev->pollfunc);
108	iio_kfifo_free(indio_dev->buffer);
109}
110EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
111
112static void devm_iio_triggered_buffer_clean(void *indio_dev)
113{
114	iio_triggered_buffer_cleanup(indio_dev);
115}
116
117int devm_iio_triggered_buffer_setup_ext(struct device *dev,
118					struct iio_dev *indio_dev,
119					irqreturn_t (*h)(int irq, void *p),
120					irqreturn_t (*thread)(int irq, void *p),
121					enum iio_buffer_direction direction,
122					const struct iio_buffer_setup_ops *ops,
123					const struct iio_dev_attr **buffer_attrs)
124{
125	int ret;
126
127	ret = iio_triggered_buffer_setup_ext(indio_dev, h, thread, direction,
128					     ops, buffer_attrs);
129	if (ret)
130		return ret;
131
132	return devm_add_action_or_reset(dev, devm_iio_triggered_buffer_clean,
133					indio_dev);
134}
135EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup_ext);
136
137MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
138MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
139MODULE_LICENSE("GPL");