linux/drivers/iio/iio_core.h
Lars-Peter Clausen 3e1b6c95b9 iio: Move buffer registration to the core
Originally device and buffer registration were kept as separate operations
in IIO to allow to register two distinct sets of channels for buffered and
non-buffered operations. This has since already been further restricted and
the channel set registered for the buffer needs to be a subset of the
channel set registered for the device. Additionally the possibility to not
have a raw (or processed) attribute for a channel which was registered for
the device was added a while ago. This means it is possible to not register
any device level attributes for a channel even if it is registered for the
device. Also if a channel's scan_index is set to -1 and the channel is
registered for the buffer it is ignored.

So in summary it means it is possible to register the same channel array for
both the device and the buffer yet still end up with distinctive sets of
channels for both of them. This makes the argument for having to have to
manually register the channels for both the device and the buffer invalid.
Considering that the vast majority of all drivers want to register the same
set of channels for both the buffer and the device it makes sense to move
the buffer registration into the core to avoid some boiler-plate code in the
device driver setup path.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2014-12-12 12:28:31 +00:00

82 lines
2.4 KiB
C

/* The industrial I/O core function defs.
*
* Copyright (c) 2008 Jonathan Cameron
*
* 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.
*
* These definitions are meant for use only within the IIO core, not individual
* drivers.
*/
#ifndef _IIO_CORE_H_
#define _IIO_CORE_H_
#include <linux/kernel.h>
#include <linux/device.h>
struct iio_chan_spec;
struct iio_dev;
extern struct device_type iio_device_type;
int __iio_add_chan_devattr(const char *postfix,
struct iio_chan_spec const *chan,
ssize_t (*func)(struct device *dev,
struct device_attribute *attr,
char *buf),
ssize_t (*writefunc)(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len),
u64 mask,
enum iio_shared_by shared_by,
struct device *dev,
struct list_head *attr_list);
void iio_free_chan_devattr_list(struct list_head *attr_list);
ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals);
/* Event interface flags */
#define IIO_BUSY_BIT_POS 1
#ifdef CONFIG_IIO_BUFFER
struct poll_table_struct;
unsigned int iio_buffer_poll(struct file *filp,
struct poll_table_struct *wait);
ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
size_t n, loff_t *f_ps);
int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev);
void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev);
#define iio_buffer_poll_addr (&iio_buffer_poll)
#define iio_buffer_read_first_n_outer_addr (&iio_buffer_read_first_n_outer)
void iio_disable_all_buffers(struct iio_dev *indio_dev);
void iio_buffer_wakeup_poll(struct iio_dev *indio_dev);
#else
#define iio_buffer_poll_addr NULL
#define iio_buffer_read_first_n_outer_addr NULL
static inline int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
{
return 0;
}
static inline void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) {}
static inline void iio_disable_all_buffers(struct iio_dev *indio_dev) {}
static inline void iio_buffer_wakeup_poll(struct iio_dev *indio_dev) {}
#endif
int iio_device_register_eventset(struct iio_dev *indio_dev);
void iio_device_unregister_eventset(struct iio_dev *indio_dev);
void iio_device_wakeup_eventset(struct iio_dev *indio_dev);
int iio_event_getfd(struct iio_dev *indio_dev);
#endif