Staging: IIO: core support for device registration and management

Signed-off-by: NJonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/Kconfig

@@ -137,5 +137,7 @@ source "drivers/staging/rar/Kconfig"
 
 source "drivers/staging/sep/Kconfig"
 
+source "drivers/staging/iio/Kconfig"
+
 endif # !STAGING_EXCLUDE_BUILD
 endif # STAGING

drivers/staging/Makefile

@@ -50,3 +50,4 @@ obj-$(CONFIG_HYPERV)		+= hv/
 obj-$(CONFIG_VME_BUS)		+= vme/
 obj-$(CONFIG_RAR_REGISTER)	+= rar/
 obj-$(CONFIG_DX_SEP)		+= sep/
+obj-$(CONFIG_IIO)		+= iio/

drivers/staging/iio/Kconfig

+#
+# Industrial I/O subsytem configuration
+#
+
+menuconfig IIO
+	tristate "Industrial I/O support"
+	---help---
+	  The industrial I/O subsystem provides a unified framework for
+	  drivers for many different types of embedded sensors using a
+	  number of different physical interfaces (i2c, spi etc). See
+	  Documentation/industrialio for more information.

drivers/staging/iio/Makefile

+#
+# Makefile for the industrial I/O core.
+#
+
+obj-$(CONFIG_IIO) += industrialio.o
+industrialio-y := industrialio-core.o

drivers/staging/iio/chrdev.h

+/* The industrial I/O core - character device related
+ *
+ * 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 _IIO_CHRDEV_H_
+#define _IIO_CHRDEV_H_
+struct iio_dev;
+
+/**
+ * struct iio_handler - Structure used to specify file operations
+ *			for a particular chrdev
+ * @chrdev:	character device structure
+ * @id:		the location in the handler table - used for deallocation.
+ * @flags:	file operations related flags including busy flag.
+ * @private:	handler specific data used by the fileops registered with
+ *		the chrdev.
+ */
+struct iio_handler {
+	struct cdev	chrdev;
+	int		id;
+	unsigned long	flags;
+	void		*private;
+};
+
+#define iio_cdev_to_handler(cd)				\
+	container_of(cd, struct iio_handler, chrdev)
+
+/**
+ * struct iio_event_data - The actual event being pushed to userspace
+ * @id:		event identifier
+ * @timestamp:	best estimate of time of event occurance (often from
+ *		the interrupt handler)
+ */
+struct iio_event_data {
+	int	id;
+	s64	timestamp;
+};
+
+/**
+ * struct iio_detected_event_list - list element for events that have occured
+ * @list:		linked list header
+ * @ev:			the event itself
+ * @shared_pointer:	used when the event is shared - i.e. can be escallated
+ *			on demand (eg ring buffer 50%->100% full)
+ */
+struct iio_detected_event_list {
+	struct list_head		list;
+	struct iio_event_data		ev;
+	struct iio_shared_ev_pointer	*shared_pointer;
+};
+/**
+ * struct iio_shared_ev_pointer - allows shared events to identify if currently
+ *				in the detected event list
+ * @ev_p:	pointer to detected event list element (null if not in list)
+ * @lock:	protect this element to prevent simultaneous edit and remove
+ */
+struct iio_shared_ev_pointer {
+	struct iio_detected_event_list	*ev_p;
+	spinlock_t			lock;
+};
+
+/**
+ * struct iio_event_interface - chrdev interface for an event line
+ * @dev:		device assocated with event interface
+ * @handler:		fileoperations and related control for the chrdev
+ * @wait:		wait queue to allow blocking reads of events
+ * @event_list_lock:	mutex to protect the list of detected events
+ * @det_events:		list of detected events
+ * @max_events:		maximum number of events before new ones are dropped
+ * @current_events:	number of events in detected list
+ * @id:			indentifier to allow the event interface to know which
+ *			physical line it corresponds to
+ * @owner:		ensure the driver module owns the file, not iio
+ * @private:		driver specific data
+ * @_name:		used internally to store the sysfs name for minor id
+ *			attribute
+ */
+struct iio_event_interface {
+	struct device				dev;
+	struct iio_handler			handler;
+	wait_queue_head_t			wait;
+	struct mutex				event_list_lock;
+	struct iio_detected_event_list		det_events;
+	int					max_events;
+	int					current_events;
+	int					id;
+	struct iio_chrdev_minor_attr		attr;
+	struct module				*owner;
+	void					*private;
+	char					_name[20];
+	char					_attrname[20];
+};
+
+/**
+ * struct iio_event_handler_list - element in list of handlers for events
+ * @list:		list header
+ * @refcount:		as the handler may be shared between multiple device
+ *			side events, reference counting ensures clean removal
+ * @exist_lock:		prevents race conditions related to refcount useage.
+ * @handler:		event handler function - called on event if this
+ *			event_handler is enabled.
+ *
+ * Each device has one list of these per interrupt line
+ **/
+struct iio_event_handler_list {
+	struct list_head	list;
+	int			refcount;
+	struct mutex		exist_lock;
+	int (*handler)(struct iio_dev *dev_info, int index, s64 timestamp,
+		       int no_test);
+};
+
+#endif

drivers/staging/iio/iio.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
+ * @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;
+
+	u16				scan_mask;
+	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 15
+
+static inline int iio_scan_mask_query(struct iio_dev *dev_info, int bit)
+{
+	if (bit > IIO_MAX_SCAN_LENGTH)
+		return -EINVAL;
+	else
+		return !!(dev_info->scan_mask & (1 << bit));
+};
+
+static inline int iio_scan_mask_set(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;
+};
+
+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 occured
+ **/
+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 dependant, typically a register address
+ * @_mask: driver dependant, typically a bit mask for a register
+ * @_st: driver dependant, 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 escallation
+ * @ev:			the evnet 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 class iio_class;
+
+/**
+ * iio_put_device() - reference counted deallocated 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 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
+ **/
+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 enabled
+ **/
+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_ */

drivers/staging/iio/sysfs.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.
+ *
+ * General attributes
+ */
+
+#ifndef _INDUSTRIAL_IO_SYSFS_H_
+#define _INDUSTRIAL_IO_SYSFS_H_
+
+#include "iio.h"
+
+/**
+ * struct iio_event_attribute - event control attribute
+ * @dev_attr:	underlying device attribute
+ * @mask:	mask for the event when detecting
+ * @listel:	list header to allow addition to list of event handlers
+*/
+struct iio_event_attr {
+	struct device_attribute dev_attr;
+	int mask;
+	struct iio_event_handler_list *listel;
+};
+
+#define to_iio_event_attr(_dev_attr) \
+	container_of(_dev_attr, struct iio_event_attr, dev_attr)
+
+/**
+ * struct iio_chrdev_minor_attr - simple attribute to allow reading of chrdev
+ *				minor number
+ * @dev_attr:	underlying device attribute
+ * @minor:	the minor number
+ */
+struct iio_chrdev_minor_attr {
+	struct device_attribute dev_attr;
+	int minor;
+};
+
+void
+__init_iio_chrdev_minor_attr(struct iio_chrdev_minor_attr *minor_attr,
+			   const char *name,
+			   struct module *owner,
+			   int id);
+
+
+#define to_iio_chrdev_minor_attr(_dev_attr) \
+	container_of(_dev_attr, struct iio_chrdev_minor_attr, dev_attr);
+
+/**
+ * struct iio_dev_attr - iio specific device attribute
+ * @dev_attr:	underlying device attribute
+ * @address:	associated register address
+ */
+struct iio_dev_attr {
+	struct device_attribute dev_attr;
+	int address;
+	int val2;
+};
+
+#define to_iio_dev_attr(_dev_attr)				\
+	container_of(_dev_attr, struct iio_dev_attr, dev_attr)
+
+ssize_t iio_read_const_attr(struct device *dev,
+			    struct device_attribute *attr,
+			    char *len);
+
+/**
+ * struct iio_const_attr - constant device specific attribute
+ *                         often used for things like available modes
+ */
+struct iio_const_attr {
+	const char *string;
+	struct device_attribute dev_attr;
+};
+
+#define to_iio_const_attr(_dev_attr) \
+	container_of(_dev_attr, struct iio_const_attr, dev_attr)
+
+/* Some attributes will be hard coded (device dependant) and not require an
+   address, in these cases pass a negative */
+#define IIO_ATTR(_name, _mode, _show, _store, _addr)		\
+	{ .dev_attr = __ATTR(_name, _mode, _show, _store),	\
+	  .address = _addr }
+
+#define IIO_ATTR_2(_name, _mode, _show, _store, _addr, _val2)	\
+	{ .dev_attr = __ATTR(_name, _mode, _show, _store),	\
+			.address = _addr,			\
+			.val2 = _val2 }
+
+#define IIO_DEVICE_ATTR(_name, _mode, _show, _store, _addr)	\
+	struct iio_dev_attr iio_dev_attr_##_name		\
+	= IIO_ATTR(_name, _mode, _show, _store, _addr)
+
+
+#define IIO_DEVICE_ATTR_2(_name, _mode, _show, _store, _addr, _val2)	\
+	struct iio_dev_attr iio_dev_attr_##_name			\
+	= IIO_ATTR_2(_name, _mode, _show, _store, _addr, _val2)
+
+#define IIO_CONST_ATTR(_name, _string)					\
+	struct iio_const_attr iio_const_attr_##_name			\
+	= { .string = _string,						\
+	    .dev_attr = __ATTR(_name, S_IRUGO, iio_read_const_attr, NULL)}
+
+/* Generic attributes of onetype or another */
+
+/**
+ * IIO_DEV_ATTR_REG: revision number for the device
+ *
+ * Very much device dependent.
+ **/
+#define IIO_DEV_ATTR_REV(_show)			\
+	IIO_DEVICE_ATTR(revision, S_IRUGO, _show, NULL, 0)
+/**
+ * IIO_DEV_ATTR_NAME: chip type dependant identifier
+ **/
+#define IIO_DEV_ATTR_NAME(_show)				\
+	IIO_DEVICE_ATTR(name, S_IRUGO, _show, NULL, 0)
+
+/**
+ * IIO_DEV_ATTR_SAMP_FREQ: sets any internal clock frequency
+ **/
+#define IIO_DEV_ATTR_SAMP_FREQ(_mode, _show, _store)			\
+	IIO_DEVICE_ATTR(sampling_frequency, _mode, _show, _store, 0)
+
+/**
+ * IIO_DEV_ATTR_AVAIL_SAMP_FREQ: list available sampling frequencies.
+ *
+ * May be mode dependant on some devices
+ **/
+#define IIO_DEV_ATTR_AVAIL_SAMP_FREQ(_show)				\
+	IIO_DEVICE_ATTR(available_sampling_frequency, S_IRUGO, _show, NULL, 0)
+
+/**
+ * IIO_DEV_ATTR_CONST_AVAIL_SAMP_FREQ: list available sampling frequencies.
+ *
+ * Constant version
+ **/
+#define IIO_CONST_ATTR_AVAIL_SAMP_FREQ(_string)	\
+	IIO_CONST_ATTR(available_sampling_frequency, _string)
+/**
+ * IIO_DEV_ATTR_SCAN_MODE: select a scan mode
+ *
+ * This is used when only certain combinations of inputs may be read in one
+ * scan.
+ **/
+#define IIO_DEV_ATTR_SCAN_MODE(_mode, _show, _store)		\
+	IIO_DEVICE_ATTR(scan_mode, _mode, _show, _store, 0)
+/**
+ * IIO_DEV_ATTR_AVAIL_SCAN_MODES: list available scan modes
+ **/
+#define IIO_DEV_ATTR_AVAIL_SCAN_MODES(_show)				\
+	IIO_DEVICE_ATTR(available_scan_modes, S_IRUGO, _show, NULL, 0)
+
+/**
+ * IIO_DEV_ATTR_SCAN: result of scan of multiple channels
+ **/
+#define IIO_DEV_ATTR_SCAN(_show)		\
+	IIO_DEVICE_ATTR(scan, S_IRUGO, _show, NULL, 0);
+
+/**
+ * IIO_DEV_ATTR_INPUT: direct read of a single input channel
+ **/
+#define IIO_DEV_ATTR_INPUT(_number, _show)				\
+	IIO_DEVICE_ATTR(in##_number, S_IRUGO, _show, NULL, _number)
+
+
+/**
+ * IIO_DEV_ATTR_SW_RING_ENABLE: enable software ring buffer
+ *
+ * Success may be dependant on attachment of trigger previously
+ **/
+#define IIO_DEV_ATTR_SW_RING_ENABLE(_show, _store)			\
+	IIO_DEVICE_ATTR(sw_ring_enable, S_IRUGO | S_IWUSR, _show, _store, 0)
+
+/**
+ * IIO_DEV_ATTR_HW_RING_ENABLE: enable hardware ring buffer
+ *
+ * This is a different attribute from the software one as one can invision
+ * schemes where a combination of the two may be used.
+ **/
+#define IIO_DEV_ATTR_HW_RING_ENABLE(_show, _store)			\
+	IIO_DEVICE_ATTR(hw_ring_enable, S_IRUGO | S_IWUSR, _show, _store, 0)
+
+/**
+ * IIO_DEV_ATTR_BPSE: set number of bits per scan element
+ **/
+#define IIO_DEV_ATTR_BPSE(_mode, _show, _store)		\
+	IIO_DEVICE_ATTR(bpse, _mode, _show, _store, 0)
+
+/**
+ * IIO_DEV_ATTR_BPSE_AVAILABLE: no of bits per scan element supported
+ **/
+#define IIO_DEV_ATTR_BPSE_AVAILABLE(_show)				\
+	IIO_DEVICE_ATTR(bpse_available, S_IRUGO, _show, NULL, 0)
+
+/**
+ * IIO_DEV_ATTR_TEMP: many sensors have auxiliary temperature sensors
+ **/
+#define IIO_DEV_ATTR_TEMP(_show)			\
+	IIO_DEVICE_ATTR(temp, S_IRUGO, _show, NULL, 0)
+/**
+ * IIO_EVENT_SH: generic shared event handler
+ *
+ * This is used in cases where more than one event may result from a single
+ * handler.  Often the case that some alarm register must be read and multiple
+ * alarms may have been triggered.
+ **/
+#define IIO_EVENT_SH(_name, _handler)					\
+	static struct iio_event_handler_list				\
+	iio_event_##_name = {						\
+		.handler = _handler,					\
+		.refcount = 0,						\
+		.exist_lock = __MUTEX_INITIALIZER(iio_event_##_name	\
+						  .exist_lock),		\
+		.list = {						\
+			.next = &iio_event_##_name.list,		\
+			.prev = &iio_event_##_name.list,		\
+		},							\
+	};
+/**
+ * IIO_EVENT_ATTR_SH: generic shared event attribute
+ *
+ * An attribute with an associated IIO_EVENT_SH
+ **/
+#define IIO_EVENT_ATTR_SH(_name, _ev_list, _show, _store, _mask)	\
+	static struct iio_event_attr					\
+	iio_event_attr_##_name						\
+	= { .dev_attr = __ATTR(_name, S_IRUGO | S_IWUSR,		\
+			       _show, _store),				\
+	    .mask = _mask,						\
+	    .listel = &_ev_list };
+
+/**
+ * IIO_EVENT_ATTR: non shared event attribute
+ **/
+#define IIO_EVENT_ATTR(_name, _show, _store, _mask, _handler)		\
+	static struct iio_event_handler_list				\
+	iio_event_##_name = {						\
+		.handler = _handler,					\
+	};								\
+	static struct							\
+	iio_event_attr							\
+	iio_event_attr_##_name						\
+	= { .dev_attr = __ATTR(_name, S_IRUGO | S_IWUSR,		\
+			       _show, _store),				\
+	    .mask = _mask,						\
+	    .listel = &iio_event_##_name };				\
+
+/**
+ * IIO_EVENT_ATTR_DATA_RDY: event driven by data ready signal
+ *
+ * Not typically implemented in devices where full triggering support
+ * has been implemented
+ **/
+#define IIO_EVENT_ATTR_DATA_RDY(_show, _store, _mask, _handler) \
+	IIO_EVENT_ATTR(data_rdy, _show, _store, _mask, _handler)
+
+#define IIO_EVENT_CODE_DATA_RDY		100
+#define IIO_EVENT_CODE_RING_BASE	200
+#define IIO_EVENT_CODE_ACCEL_BASE	300
+#define IIO_EVENT_CODE_GYRO_BASE	400
+#define IIO_EVENT_CODE_ADC_BASE		500
+#define IIO_EVENT_CODE_MISC_BASE	600
+
+#define IIO_EVENT_CODE_DEVICE_SPECIFIC	1000
+
+/**
+ * IIO_EVENT_ATTR_RING_50_FULL: ring buffer event to indicate 50% full
+ **/
+#define IIO_EVENT_ATTR_RING_50_FULL(_show, _store, _mask, _handler)	\
+	IIO_EVENT_ATTR(ring_50_full, _show, _store, _mask, _handler)
+
+/**
+ * IIO_EVENT_ATTR_RING_50_FULL_SH: shared ring event to indicate 50% full
+ **/
+#define IIO_EVENT_ATTR_RING_50_FULL_SH(_evlist, _show, _store, _mask)	\
+	IIO_EVENT_ATTR_SH(ring_50_full, _evlist, _show, _store, _mask)
+
+/**
+ * IIO_EVENT_ATTR_RING_75_FULL_SH: shared ring event to indicate 75% full
+ **/
+#define IIO_EVENT_ATTR_RING_75_FULL_SH(_evlist, _show, _store, _mask)	\
+	IIO_EVENT_ATTR_SH(ring_75_full, _evlist, _show, _store, _mask)
+
+#define IIO_EVENT_CODE_RING_50_FULL	IIO_EVENT_CODE_RING_BASE
+#define IIO_EVENT_CODE_RING_75_FULL	(IIO_EVENT_CODE_RING_BASE + 1)
+#define IIO_EVENT_CODE_RING_100_FULL	(IIO_EVENT_CODE_RING_BASE + 2)
+
+#endif /* _INDUSTRIAL_IO_SYSFS_H_ */

drivers/staging/iio/trigger_consumer.h

+
+/* The industrial I/O core, trigger consumer handling functions
+ *
+ * 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.
+ */
+
+/**
+ * iio_device_register_trigger_consumer() - set up an iio_dev to use triggers.
+ * @dev_info: iio_dev associated with the device that will consume the trigger
+ **/
+int iio_device_register_trigger_consumer(struct iio_dev *dev_info)
+{
+	return 0;
+};
+/**
+ * iio_device_unregister_trigger_consumer() - reverse the registration process
+. * @dev_info: iio_dev associated with the device that consumed the trigger
+ **/
+int iio_device_unregister_trigger_consumer(struct iio_dev *dev_info)
+{
+	return 0;
+};