linux/drivers/iio/buffer/industrialio-hw-consumer.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2017 Analog Devices Inc.
* Author: Lars-Peter Clausen <lars@metafoo.de>
*/
#include <linux/err.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/iio/consumer.h>
#include <linux/iio/hw-consumer.h>
#include <linux/iio/buffer_impl.h>
/**
* struct iio_hw_consumer - IIO hw consumer block
* @buffers: hardware buffers list head.
* @channels: IIO provider channels.
*/
struct iio_hw_consumer {
struct list_head buffers;
struct iio_channel *channels;
};
struct hw_consumer_buffer {
struct list_head head;
struct iio_dev *indio_dev;
struct iio_buffer buffer;
long scan_mask[];
};
static struct hw_consumer_buffer *iio_buffer_to_hw_consumer_buffer(
struct iio_buffer *buffer)
{
return container_of(buffer, struct hw_consumer_buffer, buffer);
}
static void iio_hw_buf_release(struct iio_buffer *buffer)
{
struct hw_consumer_buffer *hw_buf =
iio_buffer_to_hw_consumer_buffer(buffer);
kfree(hw_buf);
}
static const struct iio_buffer_access_funcs iio_hw_buf_access = {
.release = &iio_hw_buf_release,
.modes = INDIO_BUFFER_HARDWARE,
};
static struct hw_consumer_buffer *iio_hw_consumer_get_buffer(
struct iio_hw_consumer *hwc, struct iio_dev *indio_dev)
{
size_t mask_size = BITS_TO_LONGS(indio_dev->masklength) * sizeof(long);
struct hw_consumer_buffer *buf;
list_for_each_entry(buf, &hwc->buffers, head) {
if (buf->indio_dev == indio_dev)
return buf;
}
buf = kzalloc(sizeof(*buf) + mask_size, GFP_KERNEL);
if (!buf)
return NULL;
buf->buffer.access = &iio_hw_buf_access;
buf->indio_dev = indio_dev;
buf->buffer.scan_mask = buf->scan_mask;
iio_buffer_init(&buf->buffer);
list_add_tail(&buf->head, &hwc->buffers);
return buf;
}
/**
* iio_hw_consumer_alloc() - Allocate IIO hardware consumer
* @dev: Pointer to consumer device.
*
* Returns a valid iio_hw_consumer on success or a ERR_PTR() on failure.
*/
struct iio_hw_consumer *iio_hw_consumer_alloc(struct device *dev)
{
struct hw_consumer_buffer *buf;
struct iio_hw_consumer *hwc;
struct iio_channel *chan;
int ret;
hwc = kzalloc(sizeof(*hwc), GFP_KERNEL);
if (!hwc)
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&hwc->buffers);
hwc->channels = iio_channel_get_all(dev);
if (IS_ERR(hwc->channels)) {
ret = PTR_ERR(hwc->channels);
goto err_free_hwc;
}
chan = &hwc->channels[0];
while (chan->indio_dev) {
buf = iio_hw_consumer_get_buffer(hwc, chan->indio_dev);
if (!buf) {
ret = -ENOMEM;
goto err_put_buffers;
}
set_bit(chan->channel->scan_index, buf->buffer.scan_mask);
chan++;
}
return hwc;
err_put_buffers:
list_for_each_entry(buf, &hwc->buffers, head)
iio_buffer_put(&buf->buffer);
iio_channel_release_all(hwc->channels);
err_free_hwc:
kfree(hwc);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(iio_hw_consumer_alloc);
/**
* iio_hw_consumer_free() - Free IIO hardware consumer
* @hwc: hw consumer to free.
*/
void iio_hw_consumer_free(struct iio_hw_consumer *hwc)
{
struct hw_consumer_buffer *buf, *n;
iio_channel_release_all(hwc->channels);
list_for_each_entry_safe(buf, n, &hwc->buffers, head)
iio_buffer_put(&buf->buffer);
kfree(hwc);
}
EXPORT_SYMBOL_GPL(iio_hw_consumer_free);
/**
* iio_hw_consumer_enable() - Enable IIO hardware consumer
* @hwc: iio_hw_consumer to enable.
*
* Returns 0 on success.
*/
int iio_hw_consumer_enable(struct iio_hw_consumer *hwc)
{
struct hw_consumer_buffer *buf;
int ret;
list_for_each_entry(buf, &hwc->buffers, head) {
ret = iio_update_buffers(buf->indio_dev, &buf->buffer, NULL);
if (ret)
goto err_disable_buffers;
}
return 0;
err_disable_buffers:
list_for_each_entry_continue_reverse(buf, &hwc->buffers, head)
iio_update_buffers(buf->indio_dev, NULL, &buf->buffer);
return ret;
}
EXPORT_SYMBOL_GPL(iio_hw_consumer_enable);
/**
* iio_hw_consumer_disable() - Disable IIO hardware consumer
* @hwc: iio_hw_consumer to disable.
*/
void iio_hw_consumer_disable(struct iio_hw_consumer *hwc)
{
struct hw_consumer_buffer *buf;
list_for_each_entry(buf, &hwc->buffers, head)
iio_update_buffers(buf->indio_dev, NULL, &buf->buffer);
}
EXPORT_SYMBOL_GPL(iio_hw_consumer_disable);
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("Hardware consumer buffer the IIO framework");
MODULE_LICENSE("GPL v2");