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Commit 23f2d735 authored by Lars-Peter Clausen's avatar Lars-Peter Clausen Committed by Greg Kroah-Hartman
Browse files

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: default avatarLars-Peter Clausen <lars@metafoo.de>
Acked-by: default avatarJonathan Cameron <jic23@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f5b81ddd

drivers/iio/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -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

drivers/iio/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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/

drivers/iio/industrialio-triggered-buffer.c

0 → 100644
+110 −0
Original line number Diff line number Diff line 
 /*

 * 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");

include/linux/iio/triggered_buffer.h

0 → 100644
+15 −0
Original line number Diff line number Diff line 
#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