Staging: IIO: core support for device registration and management
authorJonathan Cameron <jic23@cam.ac.uk>
Tue, 18 Aug 2009 17:06:19 +0000 (18:06 +0100)
committerGreg Kroah-Hartman <gregkh@suse.de>
Tue, 15 Sep 2009 19:02:24 +0000 (12:02 -0700)
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/staging/Kconfig
drivers/staging/Makefile
drivers/staging/iio/Kconfig [new file with mode: 0644]
drivers/staging/iio/Makefile [new file with mode: 0644]
drivers/staging/iio/chrdev.h [new file with mode: 0644]
drivers/staging/iio/iio.h [new file with mode: 0644]
drivers/staging/iio/industrialio-core.c [new file with mode: 0644]
drivers/staging/iio/sysfs.h [new file with mode: 0644]
drivers/staging/iio/trigger_consumer.h [new file with mode: 0644]

index d08cd8d563171222275b3cca2b640c1fe59ee8cd..4d836a02343973c41a864252aa15042f396a7628 100644 (file)
@@ -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
index 9a23438bf7cb03aaf1a0f483bb2f9f6e013b09d3..f0c33eec012dc8a6ede53637a7dfe30bf67fd08f 100644 (file)
@@ -50,3 +50,4 @@ obj-$(CONFIG_HYPERV)          += hv/
 obj-$(CONFIG_VME_BUS)          += vme/
 obj-$(CONFIG_RAR_REGISTER)     += rar/
 obj-$(CONFIG_DX_SEP)           += sep/
+obj-$(CONFIG_IIO)              += iio/
diff --git a/drivers/staging/iio/Kconfig b/drivers/staging/iio/Kconfig
new file mode 100644 (file)
index 0000000..09e4101
--- /dev/null
@@ -0,0 +1,11 @@
+#
+# Industrial I/O subsytem configuration
+#
+
+menuconfig IIO
+       tristate "Industrial I/O support"
+       ---help---
+         The industrial I/O subsystem provides a unified framework for
+         drivers for many different types of embedded sensors using a
+         number of different physical interfaces (i2c, spi etc). See
+         Documentation/industrialio for more information.
diff --git a/drivers/staging/iio/Makefile b/drivers/staging/iio/Makefile
new file mode 100644 (file)
index 0000000..92b462a
--- /dev/null
@@ -0,0 +1,6 @@
+#
+# Makefile for the industrial I/O core.
+#
+
+obj-$(CONFIG_IIO) += industrialio.o
+industrialio-y := industrialio-core.o
diff --git a/drivers/staging/iio/chrdev.h b/drivers/staging/iio/chrdev.h
new file mode 100644 (file)
index 0000000..8bc64bf
--- /dev/null
@@ -0,0 +1,118 @@
+/* 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
diff --git a/drivers/staging/iio/iio.h b/drivers/staging/iio/iio.h
new file mode 100644 (file)
index 0000000..25ccb80
--- /dev/null
@@ -0,0 +1,411 @@
+/* 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_ */
diff --git a/drivers/staging/iio/industrialio-core.c b/drivers/staging/iio/industrialio-core.c
new file mode 100644 (file)
index 0000000..660a9c1
--- /dev/null
@@ -0,0 +1,851 @@
+/* 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.
+ *
+ * Based on elements of hwmon and input subsystems.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/idr.h>
+#include <linux/kdev_t.h>
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/interrupt.h>
+#include <linux/poll.h>
+#include <linux/cdev.h>
+#include "iio.h"
+#include "trigger_consumer.h"
+
+#define IIO_ID_PREFIX "device"
+#define IIO_ID_FORMAT IIO_ID_PREFIX "%d"
+
+/* IDR to assign each registered device a unique id*/
+static DEFINE_IDR(iio_idr);
+
+/* IDR for general event identifiers */
+static DEFINE_IDR(iio_event_idr);
+/* IDR to allocate character device minor numbers */
+static DEFINE_IDR(iio_chrdev_idr);
+/* Lock used to protect both of the above */
+static DEFINE_SPINLOCK(iio_idr_lock);
+
+dev_t iio_devt;
+EXPORT_SYMBOL(iio_devt);
+
+#define IIO_DEV_MAX 256
+static char *iio_nodename(struct device *dev)
+{
+       return kasprintf(GFP_KERNEL, "iio/%s", dev_name(dev));
+}
+
+struct class iio_class = {
+       .name = "iio",
+       .nodename = iio_nodename,
+};
+EXPORT_SYMBOL(iio_class);
+
+void __iio_change_event(struct iio_detected_event_list *ev,
+                       int ev_code,
+                       s64 timestamp)
+{
+       ev->ev.id = ev_code;
+       ev->ev.timestamp = timestamp;
+}
+EXPORT_SYMBOL(__iio_change_event);
+
+/* Used both in the interrupt line put events and the ring buffer ones */
+
+/* Note that in it's current form someone has to be listening before events
+ * are queued. Hence a client MUST open the chrdev before the ring buffer is
+ * switched on.
+ */
+ int __iio_push_event(struct iio_event_interface *ev_int,
+                    int ev_code,
+                    s64 timestamp,
+                    struct iio_shared_ev_pointer *
+                    shared_pointer_p)
+{
+       struct iio_detected_event_list *ev;
+       int ret = 0;
+
+       /* Does anyone care? */
+       mutex_lock(&ev_int->event_list_lock);
+       if (test_bit(IIO_BUSY_BIT_POS, &ev_int->handler.flags)) {
+               if (ev_int->current_events == ev_int->max_events)
+                       return 0;
+               ev = kmalloc(sizeof(*ev), GFP_KERNEL);
+               if (ev == NULL) {
+                       ret = -ENOMEM;
+                       goto error_ret;
+               }
+               ev->ev.id = ev_code;
+               ev->ev.timestamp = timestamp;
+               ev->shared_pointer = shared_pointer_p;
+               if (ev->shared_pointer)
+                       shared_pointer_p->ev_p = ev;
+
+               list_add_tail(&ev->list, &ev_int->det_events.list);
+               ev_int->current_events++;
+               mutex_unlock(&ev_int->event_list_lock);
+               wake_up_interruptible(&ev_int->wait);
+       } else
+               mutex_unlock(&ev_int->event_list_lock);
+
+error_ret:
+       return ret;
+}
+EXPORT_SYMBOL(__iio_push_event);
+
+int iio_push_event(struct iio_dev *dev_info,
+                  int ev_line,
+                  int ev_code,
+                  s64 timestamp)
+{
+       return __iio_push_event(&dev_info->event_interfaces[ev_line],
+                               ev_code, timestamp, NULL);
+}
+EXPORT_SYMBOL(iio_push_event);
+
+/* Generic interrupt line interrupt handler */
+irqreturn_t iio_interrupt_handler(int irq, void *_int_info)
+{
+       struct iio_interrupt *int_info = _int_info;
+       struct iio_dev *dev_info = int_info->dev_info;
+       struct iio_event_handler_list *p;
+       s64 time_ns;
+       unsigned long flags;
+
+       spin_lock_irqsave(&int_info->ev_list_lock, flags);
+       if (list_empty(&int_info->ev_list)) {
+               spin_unlock_irqrestore(&int_info->ev_list_lock, flags);
+               return IRQ_NONE;
+       }
+
+       time_ns = iio_get_time_ns();
+       /* detect single element list*/
+       if (list_is_singular(&int_info->ev_list)) {
+               disable_irq_nosync(irq);
+               p = list_first_entry(&int_info->ev_list,
+                                    struct iio_event_handler_list,
+                                    list);
+               /* single event handler - maybe shared */
+               p->handler(dev_info, 1, time_ns, !(p->refcount > 1));
+       } else
+               list_for_each_entry(p, &int_info->ev_list, list) {
+                       disable_irq_nosync(irq);
+                       p->handler(dev_info, 1, time_ns, 0);
+               }
+       spin_unlock_irqrestore(&int_info->ev_list_lock, flags);
+
+       return IRQ_HANDLED;
+}
+
+static struct iio_interrupt *iio_allocate_interrupt(void)
+{
+       struct iio_interrupt *i = kmalloc(sizeof *i, GFP_KERNEL);
+       if (i) {
+               spin_lock_init(&i->ev_list_lock);
+               INIT_LIST_HEAD(&i->ev_list);
+       }
+       return i;
+}
+
+/* Confirming the validity of supplied irq is left to drivers.*/
+int iio_register_interrupt_line(unsigned int irq,
+                               struct iio_dev *dev_info,
+                               int line_number,
+                               unsigned long type,
+                               const char *name)
+{
+       int ret;
+
+       dev_info->interrupts[line_number] = iio_allocate_interrupt();
+       if (dev_info->interrupts[line_number] == NULL) {
+               ret = -ENOMEM;
+               goto error_ret;
+       }
+       dev_info->interrupts[line_number]->line_number = line_number;
+       dev_info->interrupts[line_number]->irq = irq;
+       dev_info->interrupts[line_number]->dev_info = dev_info;
+
+       /* Possibly only request on demand?
+        * Can see this may complicate the handling of interrupts.
+        * However, with this approach we might end up handling lots of
+        * events no-one cares about.*/
+       ret = request_irq(irq,
+                         &iio_interrupt_handler,
+                         type,
+                         name,
+                         dev_info->interrupts[line_number]);
+
+error_ret:
+       return ret;
+}
+EXPORT_SYMBOL(iio_register_interrupt_line);
+
+/* This turns up an awful lot */
+ssize_t iio_read_const_attr(struct device *dev,
+                           struct device_attribute *attr,
+                           char *buf)
+{
+       return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
+}
+EXPORT_SYMBOL(iio_read_const_attr);
+
+/* Before this runs the interrupt generator must have been disabled */
+void iio_unregister_interrupt_line(struct iio_dev *dev_info, int line_number)
+{
+       /* make sure the interrupt handlers are all done */
+       flush_scheduled_work();
+       free_irq(dev_info->interrupts[line_number]->irq,
+                dev_info->interrupts[line_number]);
+       kfree(dev_info->interrupts[line_number]);
+}
+EXPORT_SYMBOL(iio_unregister_interrupt_line);
+
+/* Reference counted add and remove */
+void iio_add_event_to_list(struct iio_event_handler_list *el,
+                         struct list_head *head)
+{
+       unsigned long flags;
+       struct iio_interrupt *inter = to_iio_interrupt(head);
+
+       /* take mutex to protect this element */
+       mutex_lock(&el->exist_lock);
+       if (el->refcount == 0) {
+               /* Take the event list spin lock */
+               spin_lock_irqsave(&inter->ev_list_lock, flags);
+               list_add(&el->list, head);
+               spin_unlock_irqrestore(&inter->ev_list_lock, flags);
+       }
+       el->refcount++;
+       mutex_unlock(&el->exist_lock);
+}
+EXPORT_SYMBOL(iio_add_event_to_list);
+
+void iio_remove_event_from_list(struct iio_event_handler_list *el,
+                              struct list_head *head)
+{
+       unsigned long flags;
+       struct iio_interrupt *inter = to_iio_interrupt(head);
+
+       mutex_lock(&el->exist_lock);
+       el->refcount--;
+       if (el->refcount == 0) {
+               /* Take the event list spin lock */
+               spin_lock_irqsave(&inter->ev_list_lock, flags);
+               list_del_init(&el->list);
+               spin_unlock_irqrestore(&inter->ev_list_lock, flags);
+       }
+       mutex_unlock(&el->exist_lock);
+}
+EXPORT_SYMBOL(iio_remove_event_from_list);
+
+ssize_t iio_event_chrdev_read(struct file *filep,
+                             char *buf,
+                             size_t count,
+                             loff_t *f_ps)
+{
+       struct iio_event_interface *ev_int = filep->private_data;
+       struct iio_detected_event_list *el;
+       int ret;
+       size_t len;
+
+       mutex_lock(&ev_int->event_list_lock);
+       if (list_empty(&ev_int->det_events.list)) {
+               if (filep->f_flags & O_NONBLOCK) {
+                       ret = -EAGAIN;
+                       goto error_mutex_unlock;
+               }
+               mutex_unlock(&ev_int->event_list_lock);
+               /* Blocking on device; waiting for something to be there */
+               ret = wait_event_interruptible(ev_int->wait,
+                                              !list_empty(&ev_int
+                                                          ->det_events.list));
+               if (ret)
+                       goto error_ret;
+               /* Single access device so noone else can get the data */
+               mutex_lock(&ev_int->event_list_lock);
+       }
+
+       el = list_first_entry(&ev_int->det_events.list,
+                             struct iio_detected_event_list,
+                             list);
+       len = sizeof el->ev;
+       if (copy_to_user(buf, &(el->ev), len)) {
+               ret = -EFAULT;
+               goto error_mutex_unlock;
+       }
+       list_del(&el->list);
+       ev_int->current_events--;
+       mutex_unlock(&ev_int->event_list_lock);
+       /*
+        * Possible concurency issue if an update of this event is on its way
+        * through. May lead to new even being removed whilst the reported event
+        * was the unescalated event. In typical use case this is not a problem
+        * as userspace will say read half the buffer due to a 50% full event
+        * which would make the correct 100% full incorrect anyway.
+        */
+       spin_lock(&el->shared_pointer->lock);
+       if (el->shared_pointer)
+               (el->shared_pointer->ev_p) = NULL;
+       spin_unlock(&el->shared_pointer->lock);
+
+       kfree(el);
+
+       return len;
+
+error_mutex_unlock:
+       mutex_unlock(&ev_int->event_list_lock);
+error_ret:
+
+       return ret;
+}
+
+int iio_event_chrdev_release(struct inode *inode, struct file *filep)
+{
+       struct iio_handler *hand = iio_cdev_to_handler(inode->i_cdev);
+       struct iio_event_interface *ev_int = hand->private;
+       struct iio_detected_event_list *el, *t;
+
+       mutex_lock(&ev_int->event_list_lock);
+       clear_bit(IIO_BUSY_BIT_POS, &ev_int->handler.flags);
+       /*
+        * In order to maintain a clean state for reopening,
+        * clear out any awaiting events. The mask will prevent
+        * any new __iio_push_event calls running.
+        */
+       list_for_each_entry_safe(el, t, &ev_int->det_events.list, list) {
+               list_del(&el->list);
+               kfree(el);
+       }
+       mutex_unlock(&ev_int->event_list_lock);
+
+       return 0;
+}
+
+int iio_event_chrdev_open(struct inode *inode, struct file *filep)
+{
+       struct iio_handler *hand = iio_cdev_to_handler(inode->i_cdev);
+       struct iio_event_interface *ev_int = hand->private;
+
+       mutex_lock(&ev_int->event_list_lock);
+       if (test_and_set_bit(IIO_BUSY_BIT_POS, &hand->flags)) {
+               fops_put(filep->f_op);
+               mutex_unlock(&ev_int->event_list_lock);
+               return -EBUSY;
+       }
+       filep->private_data = hand->private;
+       mutex_unlock(&ev_int->event_list_lock);
+
+       return 0;
+}
+
+static const struct file_operations iio_event_chrdev_fileops = {
+       .read =  iio_event_chrdev_read,
+       .release = iio_event_chrdev_release,
+       .open = iio_event_chrdev_open,
+       .owner = THIS_MODULE,
+};
+
+static void iio_event_dev_release(struct device *dev)
+{
+       struct iio_event_interface *ev_int
+               = container_of(dev, struct iio_event_interface, dev);
+       cdev_del(&ev_int->handler.chrdev);
+       iio_device_free_chrdev_minor(MINOR(dev->devt));
+};
+
+static struct device_type iio_event_type = {
+       .release = iio_event_dev_release,
+};
+
+int iio_device_get_chrdev_minor(void)
+{
+       int ret, val;
+
+idr_again:
+       if (unlikely(idr_pre_get(&iio_chrdev_idr, GFP_KERNEL) == 0))
+               return -ENOMEM;
+       spin_lock(&iio_idr_lock);
+       ret = idr_get_new(&iio_chrdev_idr, NULL, &val);
+       spin_unlock(&iio_idr_lock);
+       if (unlikely(ret == -EAGAIN))
+               goto idr_again;
+       else if (unlikely(ret))
+               return ret;
+       if (val > IIO_DEV_MAX)
+               return -ENOMEM;
+       return val;
+}
+
+void iio_device_free_chrdev_minor(int val)
+{
+       spin_lock(&iio_idr_lock);
+       idr_remove(&iio_chrdev_idr, val);
+       spin_unlock(&iio_idr_lock);
+}
+
+int iio_setup_ev_int(struct iio_event_interface *ev_int,
+                    const char *name,
+                    struct module *owner,
+                    struct device *dev)
+{
+       int ret, minor;
+
+       ev_int->dev.class = &iio_class;
+       ev_int->dev.parent = dev;
+       ev_int->dev.type = &iio_event_type;
+       device_initialize(&ev_int->dev);
+
+       minor = iio_device_get_chrdev_minor();
+       if (minor < 0) {
+               ret = minor;
+               goto error_device_put;
+       }
+       ev_int->dev.devt = MKDEV(MAJOR(iio_devt), minor);
+       dev_set_name(&ev_int->dev, "%s", name);
+
+       ret = device_add(&ev_int->dev);
+       if (ret)
+               goto error_free_minor;
+
+       cdev_init(&ev_int->handler.chrdev, &iio_event_chrdev_fileops);
+       ev_int->handler.chrdev.owner = owner;
+
+       mutex_init(&ev_int->event_list_lock);
+       /* discussion point - make this variable? */
+       ev_int->max_events = 10;
+       ev_int->current_events = 0;
+       INIT_LIST_HEAD(&ev_int->det_events.list);
+       init_waitqueue_head(&ev_int->wait);
+       ev_int->handler.private = ev_int;
+       ev_int->handler.flags = 0;
+
+       ret = cdev_add(&ev_int->handler.chrdev, ev_int->dev.devt, 1);
+       if (ret)
+               goto error_unreg_device;
+
+       return 0;
+
+error_unreg_device:
+       device_unregister(&ev_int->dev);
+error_free_minor:
+       iio_device_free_chrdev_minor(minor);
+error_device_put:
+       put_device(&ev_int->dev);
+
+       return ret;
+}
+
+void iio_free_ev_int(struct iio_event_interface *ev_int)
+{
+       device_unregister(&ev_int->dev);
+       put_device(&ev_int->dev);
+}
+
+static int __init iio_dev_init(void)
+{
+       int err;
+
+       err = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
+       if (err < 0)
+               printk(KERN_ERR "%s: failed to allocate char dev region\n",
+                      __FILE__);
+
+       return err;
+}
+
+static void __exit iio_dev_exit(void)
+{
+       if (iio_devt)
+               unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
+}
+
+static int __init iio_init(void)
+{
+       int ret;
+
+       /* Create sysfs class */
+       ret  = class_register(&iio_class);
+       if (ret < 0) {
+               printk(KERN_ERR
+                      "%s could not create sysfs class\n",
+                       __FILE__);
+               goto error_nothing;
+       }
+
+       ret = iio_dev_init();
+       if (ret < 0)
+               goto error_unregister_class;
+
+       return 0;
+
+error_unregister_class:
+       class_unregister(&iio_class);
+error_nothing:
+       return ret;
+}
+
+static void __exit iio_exit(void)
+{
+       iio_dev_exit();
+       class_unregister(&iio_class);
+}
+
+static int iio_device_register_sysfs(struct iio_dev *dev_info)
+{
+       int ret = 0;
+
+       ret = sysfs_create_group(&dev_info->dev.kobj, dev_info->attrs);
+       if (ret) {
+               dev_err(dev_info->dev.parent,
+                       "Failed to register sysfs hooks\n");
+               goto error_ret;
+       }
+
+       if (dev_info->scan_el_attrs) {
+               ret = sysfs_create_group(&dev_info->dev.kobj,
+                                        dev_info->scan_el_attrs);
+               if (ret)
+                       dev_err(&dev_info->dev,
+                               "Failed to add sysfs scan els\n");
+       }
+
+error_ret:
+       return ret;
+}
+
+static void iio_device_unregister_sysfs(struct iio_dev *dev_info)
+{
+       if (dev_info->scan_el_attrs)
+               sysfs_remove_group(&dev_info->dev.kobj,
+                                  dev_info->scan_el_attrs);
+
+       sysfs_remove_group(&dev_info->dev.kobj, dev_info->attrs);
+}
+
+int iio_get_new_idr_val(struct idr *this_idr)
+{
+       int ret;
+       int val;
+
+idr_again:
+       if (unlikely(idr_pre_get(this_idr, GFP_KERNEL) == 0))
+               return -ENOMEM;
+
+       spin_lock(&iio_idr_lock);
+       ret = idr_get_new(this_idr, NULL, &val);
+       spin_unlock(&iio_idr_lock);
+       if (unlikely(ret == -EAGAIN))
+               goto idr_again;
+       else if (unlikely(ret))
+               return ret;
+
+       return val;
+}
+EXPORT_SYMBOL(iio_get_new_idr_val);
+
+void iio_free_idr_val(struct idr *this_idr, int id)
+{
+       spin_lock(&iio_idr_lock);
+       idr_remove(this_idr, id);
+       spin_unlock(&iio_idr_lock);
+}
+EXPORT_SYMBOL(iio_free_idr_val);
+
+static int iio_device_register_id(struct iio_dev *dev_info,
+                                 struct idr *this_idr)
+{
+
+       dev_info->id = iio_get_new_idr_val(&iio_idr);
+       if (dev_info->id < 0)
+               return dev_info->id;
+       return 0;
+}
+
+static void iio_device_unregister_id(struct iio_dev *dev_info)
+{
+       iio_free_idr_val(&iio_idr, dev_info->id);
+}
+
+static inline int __iio_add_event_config_attrs(struct iio_dev *dev_info, int i)
+{
+       int ret;
+       /*p for adding, q for removing */
+       struct attribute **attrp, **attrq;
+
+       if (dev_info->event_conf_attrs && dev_info->event_conf_attrs[i].attrs) {
+               attrp = dev_info->event_conf_attrs[i].attrs;
+               while (*attrp) {
+                       ret =  sysfs_add_file_to_group(&dev_info->dev.kobj,
+                                                      *attrp,
+                                                      dev_info
+                                                      ->event_attrs[i].name);
+                       if (ret)
+                               goto error_ret;
+                       attrp++;
+               }
+       }
+       return 0;
+
+error_ret:
+       attrq = dev_info->event_conf_attrs[i].attrs;
+       while (attrq != attrp) {
+                       sysfs_remove_file_from_group(&dev_info->dev.kobj,
+                                            *attrq,
+                                            dev_info->event_attrs[i].name);
+               attrq++;
+       }
+
+       return ret;
+}
+
+static inline int __iio_remove_event_config_attrs(struct iio_dev *dev_info,
+                                                 int i)
+{
+       struct attribute **attrq;
+
+       if (dev_info->event_conf_attrs
+               && dev_info->event_conf_attrs[i].attrs) {
+               attrq = dev_info->event_conf_attrs[i].attrs;
+               while (*attrq) {
+                       sysfs_remove_file_from_group(&dev_info->dev.kobj,
+                                                    *attrq,
+                                                    dev_info
+                                                    ->event_attrs[i].name);
+                       attrq++;
+               }
+       }
+
+       return 0;
+}
+
+static int iio_device_register_eventset(struct iio_dev *dev_info)
+{
+       int ret = 0, i, j;
+
+       if (dev_info->num_interrupt_lines == 0)
+               return 0;
+
+       dev_info->event_interfaces =
+               kzalloc(sizeof(struct iio_event_interface)
+                       *dev_info->num_interrupt_lines,
+                       GFP_KERNEL);
+       if (dev_info->event_interfaces == NULL) {
+               ret = -ENOMEM;
+               goto error_ret;
+       }
+
+       dev_info->interrupts = kzalloc(sizeof(struct iio_interrupt *)
+                                      *dev_info->num_interrupt_lines,
+                                      GFP_KERNEL);
+       if (dev_info->interrupts == NULL) {
+               ret = -ENOMEM;
+               goto error_free_event_interfaces;
+       }
+
+       for (i = 0; i < dev_info->num_interrupt_lines; i++) {
+               dev_info->event_interfaces[i].owner = dev_info->driver_module;
+               ret = iio_get_new_idr_val(&iio_event_idr);
+               if (ret)
+                       goto error_free_setup_ev_ints;
+               else
+                       dev_info->event_interfaces[i].id = ret;
+
+               snprintf(dev_info->event_interfaces[i]._name, 20,
+                        "event_line%d",
+                       dev_info->event_interfaces[i].id);
+
+               ret = iio_setup_ev_int(&dev_info->event_interfaces[i],
+                                      (const char *)(dev_info
+                                                     ->event_interfaces[i]
+                                                     ._name),
+                                      dev_info->driver_module,
+                                      &dev_info->dev);
+               if (ret) {
+                       dev_err(&dev_info->dev,
+                               "Could not get chrdev interface\n");
+                       iio_free_idr_val(&iio_event_idr,
+                                        dev_info->event_interfaces[i].id);
+                       goto error_free_setup_ev_ints;
+               }
+       }
+
+       for (i = 0; i < dev_info->num_interrupt_lines; i++) {
+               snprintf(dev_info->event_interfaces[i]._attrname, 20,
+                       "event_line%d_sources", i);
+               dev_info->event_attrs[i].name
+                       = (const char *)
+                       (dev_info->event_interfaces[i]._attrname);
+               ret = sysfs_create_group(&dev_info->dev.kobj,
+                                        &dev_info->event_attrs[i]);
+               if (ret) {
+                       dev_err(&dev_info->dev,
+                               "Failed to register sysfs for event attrs");
+                       goto error_remove_sysfs_interfaces;
+               }
+       }
+
+       for (i = 0; i < dev_info->num_interrupt_lines; i++) {
+               ret = __iio_add_event_config_attrs(dev_info, i);
+               if (ret)
+                       goto error_unregister_config_attrs;
+       }
+
+       return 0;
+
+error_unregister_config_attrs:
+       for (j = 0; j < i; j++)
+               __iio_remove_event_config_attrs(dev_info, i);
+       i = dev_info->num_interrupt_lines - 1;
+error_remove_sysfs_interfaces:
+       for (j = 0; j < i; j++)
+               sysfs_remove_group(&dev_info->dev.kobj,
+                                  &dev_info->event_attrs[j]);
+       i = dev_info->num_interrupt_lines - 1;
+error_free_setup_ev_ints:
+       for (j = 0; j < i; j++) {
+               iio_free_idr_val(&iio_event_idr,
+                                dev_info->event_interfaces[i].id);
+               iio_free_ev_int(&dev_info->event_interfaces[j]);
+       }
+       kfree(dev_info->interrupts);
+error_free_event_interfaces:
+       kfree(dev_info->event_interfaces);
+error_ret:
+
+       return ret;
+}
+
+static void iio_device_unregister_eventset(struct iio_dev *dev_info)
+{
+       int i;
+
+       if (dev_info->num_interrupt_lines == 0)
+               return;
+       for (i = 0; i < dev_info->num_interrupt_lines; i++)
+               sysfs_remove_group(&dev_info->dev.kobj,
+                                  &dev_info->event_attrs[i]);
+
+       for (i = 0; i < dev_info->num_interrupt_lines; i++) {
+               iio_free_idr_val(&iio_event_idr,
+                                dev_info->event_interfaces[i].id);
+               iio_free_ev_int(&dev_info->event_interfaces[i]);
+       }
+       kfree(dev_info->interrupts);
+       kfree(dev_info->event_interfaces);
+}
+
+static void iio_dev_release(struct device *device)
+{
+       struct iio_dev *dev = to_iio_dev(device);
+
+       iio_put();
+       kfree(dev);
+}
+
+static struct device_type iio_dev_type = {
+       .name = "iio_device",
+       .release = iio_dev_release,
+};
+
+struct iio_dev *iio_allocate_device(void)
+{
+       struct iio_dev *dev = kzalloc(sizeof *dev, GFP_KERNEL);
+
+       if (dev) {
+               dev->dev.type = &iio_dev_type;
+               dev->dev.class = &iio_class;
+               device_initialize(&dev->dev);
+               dev_set_drvdata(&dev->dev, (void *)dev);
+               mutex_init(&dev->mlock);
+               iio_get();
+       }
+
+       return dev;
+}
+EXPORT_SYMBOL(iio_allocate_device);
+
+void iio_free_device(struct iio_dev *dev)
+{
+       if (dev)
+               iio_put_device(dev);
+}
+EXPORT_SYMBOL(iio_free_device);
+
+int iio_device_register(struct iio_dev *dev_info)
+{
+       int ret;
+
+       ret = iio_device_register_id(dev_info, &iio_idr);
+       if (ret) {
+               dev_err(&dev_info->dev, "Failed to get id\n");
+               goto error_ret;
+       }
+       dev_set_name(&dev_info->dev, "device%d", dev_info->id);
+
+       ret = device_add(&dev_info->dev);
+       if (ret)
+               goto error_free_idr;
+       ret = iio_device_register_sysfs(dev_info);
+       if (ret) {
+               dev_err(dev_info->dev.parent,
+                       "Failed to register sysfs interfaces\n");
+               goto error_del_device;
+       }
+       ret = iio_device_register_eventset(dev_info);
+       if (ret) {
+               dev_err(dev_info->dev.parent,
+                       "Failed to register event set \n");
+               goto error_free_sysfs;
+       }
+       if (dev_info->modes & INDIO_RING_TRIGGERED)
+               iio_device_register_trigger_consumer(dev_info);
+
+       return 0;
+
+error_free_sysfs:
+       iio_device_unregister_sysfs(dev_info);
+error_del_device:
+       device_del(&dev_info->dev);
+error_free_idr:
+       iio_device_unregister_id(dev_info);
+error_ret:
+       return ret;
+}
+EXPORT_SYMBOL(iio_device_register);
+
+void iio_device_unregister(struct iio_dev *dev_info)
+{
+       if (dev_info->modes & INDIO_RING_TRIGGERED)
+               iio_device_unregister_trigger_consumer(dev_info);
+       iio_device_unregister_eventset(dev_info);
+       iio_device_unregister_sysfs(dev_info);
+       iio_device_unregister_id(dev_info);
+       device_unregister(&dev_info->dev);
+}
+EXPORT_SYMBOL(iio_device_unregister);
+
+void iio_put(void)
+{
+       module_put(THIS_MODULE);
+}
+
+void iio_get(void)
+{
+       __module_get(THIS_MODULE);
+}
+
+subsys_initcall(iio_init);
+module_exit(iio_exit);
+
+MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
+MODULE_DESCRIPTION("Industrial I/O core");
+MODULE_LICENSE("GPL");
diff --git a/drivers/staging/iio/sysfs.h b/drivers/staging/iio/sysfs.h
new file mode 100644 (file)
index 0000000..bfe4055
--- /dev/null
@@ -0,0 +1,293 @@
+/* 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_ */
diff --git a/drivers/staging/iio/trigger_consumer.h b/drivers/staging/iio/trigger_consumer.h
new file mode 100644 (file)
index 0000000..a605389
--- /dev/null
@@ -0,0 +1,26 @@
+
+/* 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;
+};