tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
authored by
Lars-Peter Clausen
and committed by
Greg Kroah-Hartman
23f2d735
f5b81ddd
+133
+7
drivers/iio/Kconfig
+7
drivers/iio/Kconfig
···
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no buffer events so it is up to userspace to work out how
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often to read from the buffer.
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config IIO_TRIGGERED_BUFFER
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tristate
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select IIO_TRIGGER
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select IIO_KFIFO_BUF
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help
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Provides helper functions for setting up triggered buffers.
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endif # IIO_BUFFER
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config IIO_TRIGGER
+1
drivers/iio/Makefile
+1
drivers/iio/Makefile
+110
drivers/iio/industrialio-triggered-buffer.c
+110
drivers/iio/industrialio-triggered-buffer.c
···
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/*
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* Copyright (c) 2012 Analog Devices, Inc.
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* Author: Lars-Peter Clausen <lars@metafoo.de>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/module.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/buffer.h>
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#include <linux/iio/kfifo_buf.h>
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#include <linux/iio/triggered_buffer.h>
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#include <linux/iio/trigger_consumer.h>
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static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
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.preenable = &iio_sw_buffer_preenable,
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.postenable = &iio_triggered_buffer_postenable,
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.predisable = &iio_triggered_buffer_predisable,
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};
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/**
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* iio_triggered_buffer_setup() - Setup triggered buffer and pollfunc
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* @indio_dev: IIO device structure
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* @pollfunc_bh: Function which will be used as pollfunc bottom half
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* @pollfunc_th: Function which will be used as pollfunc top half
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* @setup_ops: Buffer setup functions to use for this device.
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* If NULL the default setup functions for triggered
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* buffers will be used.
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*
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* This function combines some common tasks which will normally be performed
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* when setting up a triggered buffer. It will allocate the buffer and the
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* pollfunc, as well as register the buffer with the IIO core.
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*
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* Before calling this function the indio_dev structure should already be
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* completely initialized, but not yet registered. In practice this means that
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* this function should be called right before iio_device_register().
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*
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* To free the resources allocated by this function call
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* iio_triggered_buffer_cleanup().
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*/
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int iio_triggered_buffer_setup(struct iio_dev *indio_dev,
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irqreturn_t (*pollfunc_bh)(int irq, void *p),
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irqreturn_t (*pollfunc_th)(int irq, void *p),
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const struct iio_buffer_setup_ops *setup_ops)
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{
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int ret;
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indio_dev->buffer = iio_kfifo_allocate(indio_dev);
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if (!indio_dev->buffer) {
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ret = -ENOMEM;
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goto error_ret;
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}
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indio_dev->pollfunc = iio_alloc_pollfunc(pollfunc_bh,
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pollfunc_th,
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IRQF_ONESHOT,
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indio_dev,
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"%s_consumer%d",
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indio_dev->name,
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indio_dev->id);
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if (indio_dev->pollfunc == NULL) {
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ret = -ENOMEM;
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goto error_kfifo_free;
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}
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/* Ring buffer functions - here trigger setup related */
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if (setup_ops)
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indio_dev->setup_ops = setup_ops;
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else
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indio_dev->setup_ops = &iio_triggered_buffer_setup_ops;
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/* Flag that polled ring buffering is possible */
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indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
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ret = iio_buffer_register(indio_dev,
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indio_dev->channels,
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indio_dev->num_channels);
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if (ret)
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goto error_dealloc_pollfunc;
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return 0;
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error_dealloc_pollfunc:
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iio_dealloc_pollfunc(indio_dev->pollfunc);
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error_kfifo_free:
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iio_kfifo_free(indio_dev->buffer);
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error_ret:
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return ret;
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}
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EXPORT_SYMBOL(iio_triggered_buffer_setup);
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/**
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* iio_triggered_buffer_cleanup() - Free resources allocated by iio_triggered_buffer_setup()
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* @indio_dev: IIO device structure
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*/
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void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev)
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{
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iio_buffer_unregister(indio_dev);
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iio_dealloc_pollfunc(indio_dev->pollfunc);
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iio_kfifo_free(indio_dev->buffer);
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}
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EXPORT_SYMBOL(iio_triggered_buffer_cleanup);
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MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
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MODULE_DESCRIPTION("IIO helper functions for setting up triggered buffers");
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MODULE_LICENSE("GPL");
+15
include/linux/iio/triggered_buffer.h
+15
include/linux/iio/triggered_buffer.h
···
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#ifndef _LINUX_IIO_TRIGGERED_BUFFER_H_
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#define _LINUX_IIO_TRIGGERED_BUFFER_H_
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#include <linux/interrupt.h>
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struct iio_dev;
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struct iio_buffer_setup_ops;
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int iio_triggered_buffer_setup(struct iio_dev *indio_dev,
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irqreturn_t (*pollfunc_bh)(int irq, void *p),
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irqreturn_t (*pollfunc_th)(int irq, void *p),
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const struct iio_buffer_setup_ops *setup_ops);
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void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev);
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#endif