iio: Add helper function for initializing triggered buffers

Add a helper function for executing the common tasks which are usually involved
in setting up a simple software ringbuffer. It will allocate the buffer,
allocate the pollfunc and register the buffer.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Lars-Peter Clausen 2012-06-18 18:33:48 +02:00 коммит произвёл Greg Kroah-Hartman
Родитель f5b81ddd12
Коммит 23f2d735a9
4 изменённых файлов: 133 добавлений и 0 удалений

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@ -30,6 +30,13 @@ config IIO_KFIFO_BUF
no buffer events so it is up to userspace to work out how
often to read from the buffer.
config IIO_TRIGGERED_BUFFER
tristate
select IIO_TRIGGER
select IIO_KFIFO_BUF
help
Provides helper functions for setting up triggered buffers.
endif # IIO_BUFFER
config IIO_TRIGGER

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@ -7,6 +7,7 @@ industrialio-y := industrialio-core.o industrialio-event.o inkern.o
industrialio-$(CONFIG_IIO_BUFFER) += industrialio-buffer.o
industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o
obj-$(CONFIG_IIO_TRIGGERED_BUFFER) += industrialio-triggered-buffer.o
obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o
obj-y += adc/

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@ -0,0 +1,110 @@
/*
* Copyright (c) 2012 Analog Devices, Inc.
* Author: Lars-Peter Clausen <lars@metafoo.de>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#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/kfifo_buf.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
.preenable = &iio_sw_buffer_preenable,
.postenable = &iio_triggered_buffer_postenable,
.predisable = &iio_triggered_buffer_predisable,
};
/**
* iio_triggered_buffer_setup() - Setup triggered buffer and pollfunc
* @indio_dev: IIO device structure
* @pollfunc_bh: Function which will be used as pollfunc bottom half
* @pollfunc_th: Function which will be used as pollfunc top half
* @setup_ops: Buffer setup functions to use for this device.
* If NULL the default setup functions for triggered
* buffers will be used.
*
* 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, as well as register the buffer with the IIO core.
*
* 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(struct iio_dev *indio_dev,
irqreturn_t (*pollfunc_bh)(int irq, void *p),
irqreturn_t (*pollfunc_th)(int irq, void *p),
const struct iio_buffer_setup_ops *setup_ops)
{
int ret;
indio_dev->buffer = iio_kfifo_allocate(indio_dev);
if (!indio_dev->buffer) {
ret = -ENOMEM;
goto error_ret;
}
indio_dev->pollfunc = iio_alloc_pollfunc(pollfunc_bh,
pollfunc_th,
IRQF_ONESHOT,
indio_dev,
"%s_consumer%d",
indio_dev->name,
indio_dev->id);
if (indio_dev->pollfunc == NULL) {
ret = -ENOMEM;
goto error_kfifo_free;
}
/* Ring buffer functions - here trigger setup related */
if (setup_ops)
indio_dev->setup_ops = setup_ops;
else
indio_dev->setup_ops = &iio_triggered_buffer_setup_ops;
/* Flag that polled ring buffering is possible */
indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
ret = iio_buffer_register(indio_dev,
indio_dev->channels,
indio_dev->num_channels);
if (ret)
goto error_dealloc_pollfunc;
return 0;
error_dealloc_pollfunc:
iio_dealloc_pollfunc(indio_dev->pollfunc);
error_kfifo_free:
iio_kfifo_free(indio_dev->buffer);
error_ret:
return ret;
}
EXPORT_SYMBOL(iio_triggered_buffer_setup);
/**
* iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup()
* @indio_dev: IIO device structure
*/
void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
{
iio_buffer_unregister(indio_dev);
iio_dealloc_pollfunc(indio_dev->pollfunc);
iio_kfifo_free(indio_dev->buffer);
}
EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
MODULE_LICENSE("GPL");

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@ -0,0 +1,15 @@
#ifndef _LINUX_IIO_TRIGGERED_BUFFER_H_
#define _LINUX_IIO_TRIGGERED_BUFFER_H_
#include <linux/interrupt.h>
struct iio_dev;
struct iio_buffer_setup_ops;
int iio_triggered_buffer_setup(struct iio_dev *indio_dev,
irqreturn_t (*pollfunc_bh)(int irq, void *p),
irqreturn_t (*pollfunc_th)(int irq, void *p),
const struct iio_buffer_setup_ops *setup_ops);
void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev);
#endif