drivers/staging/iio/iio.h - kernel/skids - Git at Google

 /* The industrial I/O core
  *
  * 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.
  */

 #ifndef _INDUSTRIAL_IO_H_
 #define _INDUSTRIAL_IO_H_

 #include <linux/device.h>
 #include <linux/cdev.h>
 #include "sysfs.h"
 #include "chrdev.h"

 /* IIO TODO LIST */
 /* Static device specific elements (conversion factors etc)
  * should be exported via sysfs
  *
  * Provide means of adjusting timer accuracy.
  * Currently assumes nano seconds.
  */

 /* Event interface flags */
 #define IIO_BUSY_BIT_POS 1

 struct iio_dev;

 /**
  * iio_get_time_ns() - utility function to get a time stamp for events etc
  **/
 static inline s64 iio_get_time_ns(void)
 {
 	struct timespec ts;
 	/*
 	 * calls getnstimeofday.
 	 * If hrtimers then up to ns accurate, if not microsecond.
 	 */
 	ktime_get_real_ts(&ts);

 	return timespec_to_ns(&ts);
 }

 /**
  * iio_add_event_to_list() - Wraps adding to event lists
  * @el:		the list element of the event to be handled.
  * @head:	the list associated with the event handler being used.
  *
  * Does reference counting to allow shared handlers.
  **/
 void iio_add_event_to_list(struct iio_event_handler_list *el,
 			   struct list_head *head);

 /**
  * iio_remove_event_from_list() - Wraps removing from event list
  * @el:		element to be removed
  * @head:	associate list head for the interrupt handler.
  *
  * Does reference counting to allow shared handlers.
  **/
 void iio_remove_event_from_list(struct iio_event_handler_list *el,
 				struct list_head *head);

 /* Device operating modes */
 #define INDIO_DIRECT_MODE		0x01
 #define INDIO_RING_TRIGGERED		0x02
 #define INDIO_RING_HARDWARE_BUFFER	0x08

 #define INDIO_ALL_RING_MODES (INDIO_RING_TRIGGERED | INDIO_RING_HARDWARE_BUFFER)

 /* Vast majority of this is set by the industrialio subsystem on a
  * call to iio_device_register. */

 /**
  * struct iio_dev - industrial I/O device
  * @id:			[INTERN] used to identify device internally
  * @dev_data:		[DRIVER] device specific data
  * @modes:		[DRIVER] operating modes supported by device
  * @currentmode:	[DRIVER] current operating mode
  * @dev:		[DRIVER] device structure, should be assigned a parent
  *			and owner
  * @attrs:		[DRIVER] general purpose device attributes
  * @driver_module:	[DRIVER] module structure used to ensure correct
  *			ownership of chrdevs etc
  * @num_interrupt_lines:[DRIVER] number of physical interrupt lines from device
  * @interrupts:		[INTERN] interrupt line specific event lists etc
  * @event_attrs:	[DRIVER] event control attributes
  * @event_conf_attrs:	[DRIVER] event configuration attributes
  * @event_interfaces:	[INTERN] event chrdevs associated with interrupt lines
  * @ring:		[DRIVER] any ring buffer present
  * @mlock:		[INTERN] lock used to prevent simultaneous device state
  *			changes
  * @scan_el_attrs:	[DRIVER] control of scan elements if that scan mode
  *			control method is used
  * @scan_count:	[INTERN] the number of elements in the current scan mode
  * @scan_mask:		[INTERN] bitmask used in masking scan mode elements
  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
  * @scan_timestamp:	[INTERN] does the scan mode include a timestamp
  * @trig:		[INTERN] current device trigger (ring buffer modes)
  * @pollfunc:		[DRIVER] function run on trigger being recieved
  **/
 struct iio_dev {
 	int				id;
 	void				*dev_data;
 	int				modes;
 	int				currentmode;
 	struct device			dev;
 	const struct attribute_group	*attrs;
 	struct module			*driver_module;

 	int				num_interrupt_lines;
 	struct iio_interrupt		**interrupts;
 	struct attribute_group		*event_attrs;
 	struct attribute_group		*event_conf_attrs;

 	struct iio_event_interface	*event_interfaces;

 	struct iio_ring_buffer		*ring;
 	struct mutex			mlock;

 	struct attribute_group		*scan_el_attrs;
 	int				scan_count;

 	u32				scan_mask;
 	u32				*available_scan_masks;
 	bool				scan_timestamp;
 	struct iio_trigger		*trig;
 	struct iio_poll_func		*pollfunc;
 };

 /*
  * These are mainly provided to allow for a change of implementation if a device
  * has a large number of scan elements
  */
 #define IIO_MAX_SCAN_LENGTH 31

 /* note 0 used as error indicator as it doesn't make sense. */
 static inline u32 iio_scan_mask_match(u32 *av_masks, u32 mask)
 {
 	while (*av_masks) {
 		if (!(~*av_masks & mask))
 			return *av_masks;
 		av_masks++;
 	}
 	return 0;
 }

 static inline int iio_scan_mask_query(struct iio_dev *dev_info, int bit)
 {
 	u32 mask;

 	if (bit > IIO_MAX_SCAN_LENGTH)
 		return -EINVAL;

 	if (!dev_info->scan_mask)
 		return 0;

 	if (dev_info->available_scan_masks)
 		mask = iio_scan_mask_match(dev_info->available_scan_masks,
 					dev_info->scan_mask);
 	else
 		mask = dev_info->scan_mask;

 	if (!mask)
 		return -EINVAL;

 	return !!(mask & (1 << bit));
 };

 static inline int iio_scan_mask_set(struct iio_dev *dev_info, int bit)
 {
 	u32 mask;
 	u32 trialmask = dev_info->scan_mask | (1 << bit);

 	if (bit > IIO_MAX_SCAN_LENGTH)
 		return -EINVAL;
 	if (dev_info->available_scan_masks) {
 		mask = iio_scan_mask_match(dev_info->available_scan_masks,
 					trialmask);
 		if (!mask)
 			return -EINVAL;
 	}
 	dev_info->scan_mask = trialmask;
 	dev_info->scan_count++;

 	return 0;
 };

 static inline int iio_scan_mask_clear(struct iio_dev *dev_info, int bit)
 {
 	if (bit > IIO_MAX_SCAN_LENGTH)
 		return -EINVAL;
 	dev_info->scan_mask &= ~(1 << bit);
 	dev_info->scan_count--;
 	return 0;
 };

 /**
  * iio_scan_mask_count_to_right() - how many scan elements occur before here
  * @dev_info: the iio_device whose scan mode we are querying
  * @bit: which number scan element is this
  **/
 static inline int iio_scan_mask_count_to_right(struct iio_dev *dev_info,
 						int bit)
 {
 	int count = 0;
 	int mask = (1 << bit);
 	if (bit > IIO_MAX_SCAN_LENGTH)
 		return -EINVAL;
 	while (mask) {
 		mask >>= 1;
 		if (mask & dev_info->scan_mask)
 			count++;
 	}

 	return count;
 }

 /**
  * iio_device_register() - register a device with the IIO subsystem
  * @dev_info:		Device structure filled by the device driver
  **/
 int iio_device_register(struct iio_dev *dev_info);

 /**
  * iio_device_unregister() - unregister a device from the IIO subsystem
  * @dev_info:		Device structure representing the device.
  **/
 void iio_device_unregister(struct iio_dev *dev_info);

 /**
  * struct iio_interrupt - wrapper used to allow easy handling of multiple
  *			physical interrupt lines
  * @dev_info:		the iio device for which the is an interrupt line
  * @line_number:	associated line number
  * @id:			idr allocated unique id number
  * @irq:		associate interrupt number
  * @ev_list:		event handler list for associated events
  * @ev_list_lock:	ensure only one access to list at a time
  **/
 struct iio_interrupt {
 	struct iio_dev			*dev_info;
 	int				line_number;
 	int				id;
 	int				irq;
 	struct list_head		ev_list;
 	spinlock_t			ev_list_lock;
 };

 #define to_iio_interrupt(i) container_of(i, struct iio_interrupt, ev_list)

 /**
  * iio_register_interrupt_line() - Tell IIO about interrupt lines
  *
  * @irq:		Typically provided via platform data
  * @dev_info:		IIO device info structure for device
  * @line_number:	Which interrupt line of the device is this?
  * @type:		Interrupt type (e.g. edge triggered etc)
  * @name:		Identifying name.
  **/
 int iio_register_interrupt_line(unsigned int			irq,
 				struct iio_dev			*dev_info,
 				int				line_number,
 				unsigned long			type,
 				const char			*name);

 void iio_unregister_interrupt_line(struct iio_dev *dev_info,
 				   int line_number);


 /**
  * iio_push_event() - try to add event to the list for userspace reading
  * @dev_info:		IIO device structure
  * @ev_line:		Which event line (hardware interrupt)
  * @ev_code:		What event
  * @timestamp:		When the event occurred
  **/
 int iio_push_event(struct iio_dev *dev_info,
 		  int ev_line,
 		  int ev_code,
 		  s64 timestamp);

 /**
  * struct iio_work_cont - container for when singleton handler case matters
  * @ws:			[DEVICE] work_struct when not only possible event
  * @ws_nocheck:		[DEVICE] work_struct when only possible event
  * @address:		[DEVICE] associated register address
  * @mask:		[DEVICE] associated mask for identifying event source
  * @st:			[DEVICE] device specific state information
  **/
 struct iio_work_cont {
 	struct work_struct	ws;
 	struct work_struct	ws_nocheck;
 	int			address;
 	int			mask;
 	void			*st;
 };

 #define to_iio_work_cont_check(_ws)			\
 	container_of(_ws, struct iio_work_cont, ws)

 #define to_iio_work_cont_no_check(_ws)				\
 	container_of(_ws, struct iio_work_cont, ws_nocheck)

 /**
  * iio_init_work_cont() - intiialize the elements of a work container
  * @cont: the work container
  * @_checkfunc: function called when there are multiple possible int sources
  * @_nocheckfunc: function for when there is only one int source
  * @_add: driver dependent, typically a register address
  * @_mask: driver dependent, typically a bit mask for a register
  * @_st: driver dependent, typically pointer to a device state structure
  **/
 static inline void
 iio_init_work_cont(struct iio_work_cont *cont,
 		   void (*_checkfunc)(struct work_struct *),
 		   void (*_nocheckfunc)(struct work_struct *),
 		   int _add, int _mask, void *_st)
 {
 	INIT_WORK(&(cont)->ws, _checkfunc);
 	INIT_WORK(&(cont)->ws_nocheck, _nocheckfunc);
 	cont->address = _add;
 	cont->mask = _mask;
 	cont->st = _st;
 }
 /**
  * __iio_push_event() - tries to add an event to the list associated with a chrdev
  * @ev_int:		the event interface to which we are pushing the event
  * @ev_code:		the outgoing event code
  * @timestamp:		timestamp of the event
  * @shared_pointer_p:	the shared event pointer
  **/
 int __iio_push_event(struct iio_event_interface *ev_int,
 		    int ev_code,
 		    s64 timestamp,
 		    struct iio_shared_ev_pointer*
 		    shared_pointer_p);
 /**
  * __iio_change_event() - change an event code in case of event escalation
  * @ev:			the event to be changed
  * @ev_code:		new event code
  * @timestamp:		new timestamp
  **/
 void __iio_change_event(struct iio_detected_event_list *ev,
 			int ev_code,
 			s64 timestamp);

 /**
  * iio_setup_ev_int() - configure an event interface (chrdev)
  * @name:		name used for resulting sysfs directory etc.
  * @ev_int:		interface we are configuring
  * @owner:		module that is responsible for registering this ev_int
  * @dev:		device whose ev_int this is
  **/
 int iio_setup_ev_int(struct iio_event_interface *ev_int,
 		     const char *name,
 		     struct module *owner,
 		     struct device *dev);

 void iio_free_ev_int(struct iio_event_interface *ev_int);

 /**
  * iio_allocate_chrdev() - Allocate a chrdev
  * @handler:	struct that contains relevant file handling for chrdev
  * @dev_info:	iio_dev for which chrdev is being created
  **/
 int iio_allocate_chrdev(struct iio_handler *handler, struct iio_dev *dev_info);
 void iio_deallocate_chrdev(struct iio_handler *handler);

 /* Used to distinguish between bipolar and unipolar scan elemenents.
  * Whilst this may seem obvious, we may well want to change the representation
  * in the future!*/
 #define IIO_SIGNED(a) -(a)
 #define IIO_UNSIGNED(a) (a)

 extern dev_t iio_devt;
 extern struct bus_type iio_bus_type;

 /**
  * iio_put_device() - reference counted deallocation of struct device
  * @dev: the iio_device containing the device
  **/
 static inline void iio_put_device(struct iio_dev *dev)
 {
 	if (dev)
 		put_device(&dev->dev);
 };

 /**
  * to_iio_dev() - get iio_dev for which we have the struct device
  * @d: the struct device
  **/
 static inline struct iio_dev *to_iio_dev(struct device *d)
 {
 	return container_of(d, struct iio_dev, dev);
 };

 /**
  * iio_dev_get_devdata() - helper function gets device specific data
  * @d: the iio_dev associated with the device
  **/
 static inline void *iio_dev_get_devdata(struct iio_dev *d)
 {
 	return d->dev_data;
 }

 /**
  * iio_allocate_device() - allocate an iio_dev from a driver
  **/
 struct iio_dev *iio_allocate_device(void);

 /**
  * iio_free_device() - free an iio_dev from a driver
  * @dev: the iio_dev associated with the device
  **/
 void iio_free_device(struct iio_dev *dev);

 /**
  * iio_put() - internal module reference count reduce
  **/
 void iio_put(void);

 /**
  * iio_get() - internal module reference count increase
  **/
 void iio_get(void);

 /* Ring buffer related */
 int iio_device_get_chrdev_minor(void);
 void iio_device_free_chrdev_minor(int val);

 /**
  * iio_ring_enabled() - helper function to test if any form of ring is enabled
  * @dev_info:		IIO device info structure for device
  **/
 static inline bool iio_ring_enabled(struct iio_dev *dev_info)
 {
 	return dev_info->currentmode
 		& (INDIO_RING_TRIGGERED
 		   | INDIO_RING_HARDWARE_BUFFER);
 };

 struct idr;

 int iio_get_new_idr_val(struct idr *this_idr);
 void iio_free_idr_val(struct idr *this_idr, int id);
 #endif /* _INDUSTRIAL_IO_H_ */
	/* The industrial I/O core
	*
	* 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.
	*/

	#ifndef _INDUSTRIAL_IO_H_
	#define _INDUSTRIAL_IO_H_

	#include <linux/device.h>
	#include <linux/cdev.h>
	#include "sysfs.h"
	#include "chrdev.h"

	/* IIO TODO LIST */
	/* Static device specific elements (conversion factors etc)
	* should be exported via sysfs
	*
	* Provide means of adjusting timer accuracy.
	* Currently assumes nano seconds.
	*/

	/* Event interface flags */
	#define IIO_BUSY_BIT_POS 1

	struct iio_dev;

	/**
	* iio_get_time_ns() - utility function to get a time stamp for events etc
	**/
	static inline s64 iio_get_time_ns(void)
	{
	struct timespec ts;
	/*
	* calls getnstimeofday.
	* If hrtimers then up to ns accurate, if not microsecond.
	*/
	ktime_get_real_ts(&ts);

	return timespec_to_ns(&ts);
	}

	/**
	* iio_add_event_to_list() - Wraps adding to event lists
	* @el: the list element of the event to be handled.
	* @head: the list associated with the event handler being used.
	*
	* Does reference counting to allow shared handlers.
	**/
	void iio_add_event_to_list(struct iio_event_handler_list *el,
	struct list_head *head);

	/**
	* iio_remove_event_from_list() - Wraps removing from event list
	* @el: element to be removed
	* @head: associate list head for the interrupt handler.
	*
	* Does reference counting to allow shared handlers.
	**/
	void iio_remove_event_from_list(struct iio_event_handler_list *el,
	struct list_head *head);

	/* Device operating modes */
	#define INDIO_DIRECT_MODE 0x01
	#define INDIO_RING_TRIGGERED 0x02
	#define INDIO_RING_HARDWARE_BUFFER 0x08

	#define INDIO_ALL_RING_MODES (INDIO_RING_TRIGGERED \| INDIO_RING_HARDWARE_BUFFER)

	/* Vast majority of this is set by the industrialio subsystem on a
	* call to iio_device_register. */

	/**
	* struct iio_dev - industrial I/O device
	* @id: [INTERN] used to identify device internally
	* @dev_data: [DRIVER] device specific data
	* @modes: [DRIVER] operating modes supported by device
	* @currentmode: [DRIVER] current operating mode
	* @dev: [DRIVER] device structure, should be assigned a parent
	* and owner
	* @attrs: [DRIVER] general purpose device attributes
	* @driver_module: [DRIVER] module structure used to ensure correct
	* ownership of chrdevs etc
	* @num_interrupt_lines:[DRIVER] number of physical interrupt lines from device
	* @interrupts: [INTERN] interrupt line specific event lists etc
	* @event_attrs: [DRIVER] event control attributes
	* @event_conf_attrs: [DRIVER] event configuration attributes
	* @event_interfaces: [INTERN] event chrdevs associated with interrupt lines
	* @ring: [DRIVER] any ring buffer present
	* @mlock: [INTERN] lock used to prevent simultaneous device state
	* changes
	* @scan_el_attrs: [DRIVER] control of scan elements if that scan mode
	* control method is used
	* @scan_count: [INTERN] the number of elements in the current scan mode
	* @scan_mask: [INTERN] bitmask used in masking scan mode elements
	* @available_scan_masks: [DRIVER] optional array of allowed bitmasks
	* @scan_timestamp: [INTERN] does the scan mode include a timestamp
	* @trig: [INTERN] current device trigger (ring buffer modes)
	* @pollfunc: [DRIVER] function run on trigger being recieved
	**/
	struct iio_dev {
	int id;
	void *dev_data;
	int modes;
	int currentmode;
	struct device dev;
	const struct attribute_group *attrs;
	struct module *driver_module;

	int num_interrupt_lines;
	struct iio_interrupt **interrupts;
	struct attribute_group *event_attrs;
	struct attribute_group *event_conf_attrs;

	struct iio_event_interface *event_interfaces;

	struct iio_ring_buffer *ring;
	struct mutex mlock;

	struct attribute_group *scan_el_attrs;
	int scan_count;

	u32 scan_mask;
	u32 *available_scan_masks;
	bool scan_timestamp;
	struct iio_trigger *trig;
	struct iio_poll_func *pollfunc;
	};

	/*
	* These are mainly provided to allow for a change of implementation if a device
	* has a large number of scan elements
	*/
	#define IIO_MAX_SCAN_LENGTH 31

	/* note 0 used as error indicator as it doesn't make sense. */
	static inline u32 iio_scan_mask_match(u32 *av_masks, u32 mask)
	{
	while (*av_masks) {
	if (!(~*av_masks & mask))
	return *av_masks;
	av_masks++;
	}
	return 0;
	}

	static inline int iio_scan_mask_query(struct iio_dev *dev_info, int bit)
	{
	u32 mask;

	if (bit > IIO_MAX_SCAN_LENGTH)
	return -EINVAL;

	if (!dev_info->scan_mask)
	return 0;

	if (dev_info->available_scan_masks)
	mask = iio_scan_mask_match(dev_info->available_scan_masks,
	dev_info->scan_mask);
	else
	mask = dev_info->scan_mask;

	if (!mask)
	return -EINVAL;

	return !!(mask & (1 << bit));
	};

	static inline int iio_scan_mask_set(struct iio_dev *dev_info, int bit)
	{
	u32 mask;
	u32 trialmask = dev_info->scan_mask \| (1 << bit);

	if (bit > IIO_MAX_SCAN_LENGTH)
	return -EINVAL;
	if (dev_info->available_scan_masks) {
	mask = iio_scan_mask_match(dev_info->available_scan_masks,
	trialmask);
	if (!mask)
	return -EINVAL;
	}
	dev_info->scan_mask = trialmask;
	dev_info->scan_count++;

	return 0;
	};

	static inline int iio_scan_mask_clear(struct iio_dev *dev_info, int bit)
	{
	if (bit > IIO_MAX_SCAN_LENGTH)
	return -EINVAL;
	dev_info->scan_mask &= ~(1 << bit);
	dev_info->scan_count--;
	return 0;
	};

	/**
	* iio_scan_mask_count_to_right() - how many scan elements occur before here
	* @dev_info: the iio_device whose scan mode we are querying
	* @bit: which number scan element is this
	**/
	static inline int iio_scan_mask_count_to_right(struct iio_dev *dev_info,
	int bit)
	{
	int count = 0;
	int mask = (1 << bit);
	if (bit > IIO_MAX_SCAN_LENGTH)
	return -EINVAL;
	while (mask) {
	mask >>= 1;
	if (mask & dev_info->scan_mask)
	count++;
	}

	return count;
	}

	/**
	* iio_device_register() - register a device with the IIO subsystem
	* @dev_info: Device structure filled by the device driver
	**/
	int iio_device_register(struct iio_dev *dev_info);

	/**
	* iio_device_unregister() - unregister a device from the IIO subsystem
	* @dev_info: Device structure representing the device.
	**/
	void iio_device_unregister(struct iio_dev *dev_info);

	/**
	* struct iio_interrupt - wrapper used to allow easy handling of multiple
	* physical interrupt lines
	* @dev_info: the iio device for which the is an interrupt line
	* @line_number: associated line number
	* @id: idr allocated unique id number
	* @irq: associate interrupt number
	* @ev_list: event handler list for associated events
	* @ev_list_lock: ensure only one access to list at a time
	**/
	struct iio_interrupt {
	struct iio_dev *dev_info;
	int line_number;
	int id;
	int irq;
	struct list_head ev_list;
	spinlock_t ev_list_lock;
	};

	#define to_iio_interrupt(i) container_of(i, struct iio_interrupt, ev_list)

	/**
	* iio_register_interrupt_line() - Tell IIO about interrupt lines
	*
	* @irq: Typically provided via platform data
	* @dev_info: IIO device info structure for device
	* @line_number: Which interrupt line of the device is this?
	* @type: Interrupt type (e.g. edge triggered etc)
	* @name: Identifying name.
	**/
	int iio_register_interrupt_line(unsigned int irq,
	struct iio_dev *dev_info,
	int line_number,
	unsigned long type,
	const char *name);

	void iio_unregister_interrupt_line(struct iio_dev *dev_info,
	int line_number);



	/**
	* iio_push_event() - try to add event to the list for userspace reading
	* @dev_info: IIO device structure
	* @ev_line: Which event line (hardware interrupt)
	* @ev_code: What event
	* @timestamp: When the event occurred
	**/
	int iio_push_event(struct iio_dev *dev_info,
	int ev_line,
	int ev_code,
	s64 timestamp);

	/**
	* struct iio_work_cont - container for when singleton handler case matters
	* @ws: [DEVICE] work_struct when not only possible event
	* @ws_nocheck: [DEVICE] work_struct when only possible event
	* @address: [DEVICE] associated register address
	* @mask: [DEVICE] associated mask for identifying event source
	* @st: [DEVICE] device specific state information
	**/
	struct iio_work_cont {
	struct work_struct ws;
	struct work_struct ws_nocheck;
	int address;
	int mask;
	void *st;
	};

	#define to_iio_work_cont_check(_ws) \
	container_of(_ws, struct iio_work_cont, ws)

	#define to_iio_work_cont_no_check(_ws) \
	container_of(_ws, struct iio_work_cont, ws_nocheck)

	/**
	* iio_init_work_cont() - intiialize the elements of a work container
	* @cont: the work container
	* @_checkfunc: function called when there are multiple possible int sources
	* @_nocheckfunc: function for when there is only one int source
	* @_add: driver dependent, typically a register address
	* @_mask: driver dependent, typically a bit mask for a register
	* @_st: driver dependent, typically pointer to a device state structure
	**/
	static inline void
	iio_init_work_cont(struct iio_work_cont *cont,
	void (_checkfunc)(struct work_struct ),
	void (_nocheckfunc)(struct work_struct ),
	int _add, int _mask, void *_st)
	{
	INIT_WORK(&(cont)->ws, _checkfunc);
	INIT_WORK(&(cont)->ws_nocheck, _nocheckfunc);
	cont->address = _add;
	cont->mask = _mask;
	cont->st = _st;
	}
	/**
	* __iio_push_event() - tries to add an event to the list associated with a chrdev
	* @ev_int: the event interface to which we are pushing the event
	* @ev_code: the outgoing event code
	* @timestamp: timestamp of the event
	* @shared_pointer_p: the shared event pointer
	**/
	int __iio_push_event(struct iio_event_interface *ev_int,
	int ev_code,
	s64 timestamp,
	struct iio_shared_ev_pointer*
	shared_pointer_p);
	/**
	* __iio_change_event() - change an event code in case of event escalation
	* @ev: the event to be changed
	* @ev_code: new event code
	* @timestamp: new timestamp
	**/
	void __iio_change_event(struct iio_detected_event_list *ev,
	int ev_code,
	s64 timestamp);

	/**
	* iio_setup_ev_int() - configure an event interface (chrdev)
	* @name: name used for resulting sysfs directory etc.
	* @ev_int: interface we are configuring
	* @owner: module that is responsible for registering this ev_int
	* @dev: device whose ev_int this is
	**/
	int iio_setup_ev_int(struct iio_event_interface *ev_int,
	const char *name,
	struct module *owner,
	struct device *dev);

	void iio_free_ev_int(struct iio_event_interface *ev_int);

	/**
	* iio_allocate_chrdev() - Allocate a chrdev
	* @handler: struct that contains relevant file handling for chrdev
	* @dev_info: iio_dev for which chrdev is being created
	**/
	int iio_allocate_chrdev(struct iio_handler handler, struct iio_dev dev_info);
	void iio_deallocate_chrdev(struct iio_handler *handler);

	/* Used to distinguish between bipolar and unipolar scan elemenents.
	* Whilst this may seem obvious, we may well want to change the representation
	* in the future!*/
	#define IIO_SIGNED(a) -(a)
	#define IIO_UNSIGNED(a) (a)

	extern dev_t iio_devt;
	extern struct bus_type iio_bus_type;

	/**
	* iio_put_device() - reference counted deallocation of struct device
	* @dev: the iio_device containing the device
	**/
	static inline void iio_put_device(struct iio_dev *dev)
	{
	if (dev)
	put_device(&dev->dev);
	};

	/**
	* to_iio_dev() - get iio_dev for which we have the struct device
	* @d: the struct device
	**/
	static inline struct iio_dev to_iio_dev(struct device d)
	{
	return container_of(d, struct iio_dev, dev);
	};

	/**
	* iio_dev_get_devdata() - helper function gets device specific data
	* @d: the iio_dev associated with the device
	**/
	static inline void iio_dev_get_devdata(struct iio_dev d)
	{
	return d->dev_data;
	}

	/**
	* iio_allocate_device() - allocate an iio_dev from a driver
	**/
	struct iio_dev *iio_allocate_device(void);

	/**
	* iio_free_device() - free an iio_dev from a driver
	* @dev: the iio_dev associated with the device
	**/
	void iio_free_device(struct iio_dev *dev);

	/**
	* iio_put() - internal module reference count reduce
	**/
	void iio_put(void);

	/**
	* iio_get() - internal module reference count increase
	**/
	void iio_get(void);

	/* Ring buffer related */
	int iio_device_get_chrdev_minor(void);
	void iio_device_free_chrdev_minor(int val);

	/**
	* iio_ring_enabled() - helper function to test if any form of ring is enabled
	* @dev_info: IIO device info structure for device
	**/
	static inline bool iio_ring_enabled(struct iio_dev *dev_info)
	{
	return dev_info->currentmode
	& (INDIO_RING_TRIGGERED
	\| INDIO_RING_HARDWARE_BUFFER);
	};

	struct idr;

	int iio_get_new_idr_val(struct idr *this_idr);
	void iio_free_idr_val(struct idr *this_idr, int id);
	#endif /* _INDUSTRIAL_IO_H_ */