847ec80bba
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
119 lines
3.6 KiB
C
119 lines
3.6 KiB
C
/* The industrial I/O core - character device related
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*
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* Copyright (c) 2008 Jonathan Cameron
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#ifndef _IIO_CHRDEV_H_
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#define _IIO_CHRDEV_H_
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struct iio_dev;
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/**
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* struct iio_handler - Structure used to specify file operations
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* for a particular chrdev
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* @chrdev: character device structure
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* @id: the location in the handler table - used for deallocation.
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* @flags: file operations related flags including busy flag.
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* @private: handler specific data used by the fileops registered with
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* the chrdev.
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*/
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struct iio_handler {
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struct cdev chrdev;
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int id;
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unsigned long flags;
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void *private;
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};
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#define iio_cdev_to_handler(cd) \
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container_of(cd, struct iio_handler, chrdev)
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/**
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* struct iio_event_data - The actual event being pushed to userspace
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* @id: event identifier
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* @timestamp: best estimate of time of event occurance (often from
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* the interrupt handler)
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*/
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struct iio_event_data {
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int id;
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s64 timestamp;
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};
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/**
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* struct iio_detected_event_list - list element for events that have occured
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* @list: linked list header
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* @ev: the event itself
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* @shared_pointer: used when the event is shared - i.e. can be escallated
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* on demand (eg ring buffer 50%->100% full)
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*/
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struct iio_detected_event_list {
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struct list_head list;
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struct iio_event_data ev;
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struct iio_shared_ev_pointer *shared_pointer;
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};
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/**
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* struct iio_shared_ev_pointer - allows shared events to identify if currently
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* in the detected event list
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* @ev_p: pointer to detected event list element (null if not in list)
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* @lock: protect this element to prevent simultaneous edit and remove
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*/
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struct iio_shared_ev_pointer {
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struct iio_detected_event_list *ev_p;
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spinlock_t lock;
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};
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/**
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* struct iio_event_interface - chrdev interface for an event line
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* @dev: device assocated with event interface
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* @handler: fileoperations and related control for the chrdev
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* @wait: wait queue to allow blocking reads of events
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* @event_list_lock: mutex to protect the list of detected events
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* @det_events: list of detected events
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* @max_events: maximum number of events before new ones are dropped
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* @current_events: number of events in detected list
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* @id: indentifier to allow the event interface to know which
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* physical line it corresponds to
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* @owner: ensure the driver module owns the file, not iio
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* @private: driver specific data
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* @_name: used internally to store the sysfs name for minor id
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* attribute
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*/
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struct iio_event_interface {
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struct device dev;
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struct iio_handler handler;
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wait_queue_head_t wait;
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struct mutex event_list_lock;
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struct iio_detected_event_list det_events;
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int max_events;
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int current_events;
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int id;
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struct iio_chrdev_minor_attr attr;
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struct module *owner;
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void *private;
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char _name[20];
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char _attrname[20];
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};
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/**
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* struct iio_event_handler_list - element in list of handlers for events
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* @list: list header
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* @refcount: as the handler may be shared between multiple device
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* side events, reference counting ensures clean removal
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* @exist_lock: prevents race conditions related to refcount useage.
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* @handler: event handler function - called on event if this
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* event_handler is enabled.
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*
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* Each device has one list of these per interrupt line
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**/
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struct iio_event_handler_list {
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struct list_head list;
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int refcount;
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struct mutex exist_lock;
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int (*handler)(struct iio_dev *dev_info, int index, s64 timestamp,
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int no_test);
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};
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#endif
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