linux-stable/drivers/iio/buffer/industrialio-triggered-buffer.c
Matti Vaittinen 0a33755c4b iio: Don't silently expect attribute types
The iio_triggered_buffer_setup_ext() and the
devm_iio_kfifo_buffer_setup_ext() were changed by
commit 15097c7a1a ("iio: buffer: wrap all buffer attributes into iio_dev_attr")
to silently expect that all attributes given in buffer_attrs array are
device-attributes. This expectation was not forced by the API - and some
drivers did register attributes created by IIO_CONST_ATTR().

When using IIO_CONST_ATTRs the added attribute "wrapping" does not copy
the pointer to stored string constant and when the sysfs file is read the
kernel will access to invalid location.

Change the function signatures to expect an array of iio_dev_attrs to
avoid similar errors in the future.

Merge conflict resolved whilst applying due to patch crossing with
two new drivers (kx022a accelerometer and ad4130 ADC).

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/63f54787a684eb1232f1c5d275a09c786987fe4a.1664782676.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2022-11-23 19:44:04 +00:00

129 lines
3.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2012 Analog Devices, Inc.
* Author: Lars-Peter Clausen <lars@metafoo.de>
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/buffer_impl.h>
#include <linux/iio/kfifo_buf.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
/**
* iio_triggered_buffer_setup_ext() - Setup triggered buffer and pollfunc
* @indio_dev: IIO device structure
* @h: Function which will be used as pollfunc top half
* @thread: Function which will be used as pollfunc bottom half
* @direction: Direction of the data stream (in/out).
* @setup_ops: Buffer setup functions to use for this device.
* If NULL the default setup functions for triggered
* buffers will be used.
* @buffer_attrs: Extra sysfs buffer attributes for this IIO buffer
*
* This function combines some common tasks which will normally be performed
* when setting up a triggered buffer. It will allocate the buffer and the
* pollfunc.
*
* Before calling this function the indio_dev structure should already be
* completely initialized, but not yet registered. In practice this means that
* this function should be called right before iio_device_register().
*
* To free the resources allocated by this function call
* iio_triggered_buffer_cleanup().
*/
int iio_triggered_buffer_setup_ext(struct iio_dev *indio_dev,
irqreturn_t (*h)(int irq, void *p),
irqreturn_t (*thread)(int irq, void *p),
enum iio_buffer_direction direction,
const struct iio_buffer_setup_ops *setup_ops,
const struct iio_dev_attr **buffer_attrs)
{
struct iio_buffer *buffer;
int ret;
buffer = iio_kfifo_allocate();
if (!buffer) {
ret = -ENOMEM;
goto error_ret;
}
indio_dev->pollfunc = iio_alloc_pollfunc(h,
thread,
IRQF_ONESHOT,
indio_dev,
"%s_consumer%d",
indio_dev->name,
iio_device_id(indio_dev));
if (indio_dev->pollfunc == NULL) {
ret = -ENOMEM;
goto error_kfifo_free;
}
/* Ring buffer functions - here trigger setup related */
indio_dev->setup_ops = setup_ops;
/* Flag that polled ring buffering is possible */
indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
buffer->direction = direction;
buffer->attrs = buffer_attrs;
ret = iio_device_attach_buffer(indio_dev, buffer);
if (ret < 0)
goto error_dealloc_pollfunc;
return 0;
error_dealloc_pollfunc:
iio_dealloc_pollfunc(indio_dev->pollfunc);
error_kfifo_free:
iio_kfifo_free(buffer);
error_ret:
return ret;
}
EXPORT_SYMBOL(iio_triggered_buffer_setup_ext);
/**
* iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup_ext()
* @indio_dev: IIO device structure
*/
void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
{
iio_dealloc_pollfunc(indio_dev->pollfunc);
iio_kfifo_free(indio_dev->buffer);
}
EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
static void devm_iio_triggered_buffer_clean(void *indio_dev)
{
iio_triggered_buffer_cleanup(indio_dev);
}
int devm_iio_triggered_buffer_setup_ext(struct device *dev,
struct iio_dev *indio_dev,
irqreturn_t (*h)(int irq, void *p),
irqreturn_t (*thread)(int irq, void *p),
enum iio_buffer_direction direction,
const struct iio_buffer_setup_ops *ops,
const struct iio_dev_attr **buffer_attrs)
{
int ret;
ret = iio_triggered_buffer_setup_ext(indio_dev, h, thread, direction,
ops, buffer_attrs);
if (ret)
return ret;
return devm_add_action_or_reset(dev, devm_iio_triggered_buffer_clean,
indio_dev);
}
EXPORT_SYMBOL_GPL(devm_iio_triggered_buffer_setup_ext);
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
MODULE_LICENSE("GPL");