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 */
 36int 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
 72error_kfifo_free:
 73	iio_kfifo_free(indio_dev->buffer);
 74error_ret:
 75	return ret;
 76}
 77EXPORT_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 */
 83void 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}
 88EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
 89
 90static void devm_iio_triggered_buffer_clean(struct device *dev, void *res)
 91{
 92	iio_triggered_buffer_cleanup(*(struct iio_dev **)res);
 93}
 94
 95int 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}
119EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup);
120
121MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
122MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
123MODULE_LICENSE("GPL");