Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 1 | /* The industrial I/O core - character device related |
| 2 | * |
| 3 | * Copyright (c) 2008 Jonathan Cameron |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 as published by |
| 7 | * the Free Software Foundation. |
| 8 | */ |
| 9 | |
| 10 | #ifndef _IIO_CHRDEV_H_ |
| 11 | #define _IIO_CHRDEV_H_ |
| 12 | struct iio_dev; |
| 13 | |
| 14 | /** |
| 15 | * struct iio_handler - Structure used to specify file operations |
| 16 | * for a particular chrdev |
| 17 | * @chrdev: character device structure |
| 18 | * @id: the location in the handler table - used for deallocation. |
| 19 | * @flags: file operations related flags including busy flag. |
| 20 | * @private: handler specific data used by the fileops registered with |
| 21 | * the chrdev. |
| 22 | */ |
| 23 | struct iio_handler { |
| 24 | struct cdev chrdev; |
| 25 | int id; |
| 26 | unsigned long flags; |
| 27 | void *private; |
| 28 | }; |
| 29 | |
| 30 | #define iio_cdev_to_handler(cd) \ |
| 31 | container_of(cd, struct iio_handler, chrdev) |
| 32 | |
| 33 | /** |
| 34 | * struct iio_event_data - The actual event being pushed to userspace |
| 35 | * @id: event identifier |
| 36 | * @timestamp: best estimate of time of event occurance (often from |
| 37 | * the interrupt handler) |
| 38 | */ |
| 39 | struct iio_event_data { |
| 40 | int id; |
| 41 | s64 timestamp; |
| 42 | }; |
| 43 | |
| 44 | /** |
| 45 | * struct iio_detected_event_list - list element for events that have occured |
| 46 | * @list: linked list header |
| 47 | * @ev: the event itself |
| 48 | * @shared_pointer: used when the event is shared - i.e. can be escallated |
| 49 | * on demand (eg ring buffer 50%->100% full) |
| 50 | */ |
| 51 | struct iio_detected_event_list { |
| 52 | struct list_head list; |
| 53 | struct iio_event_data ev; |
| 54 | struct iio_shared_ev_pointer *shared_pointer; |
| 55 | }; |
| 56 | /** |
| 57 | * struct iio_shared_ev_pointer - allows shared events to identify if currently |
| 58 | * in the detected event list |
| 59 | * @ev_p: pointer to detected event list element (null if not in list) |
| 60 | * @lock: protect this element to prevent simultaneous edit and remove |
| 61 | */ |
| 62 | struct iio_shared_ev_pointer { |
| 63 | struct iio_detected_event_list *ev_p; |
| 64 | spinlock_t lock; |
| 65 | }; |
| 66 | |
| 67 | /** |
| 68 | * struct iio_event_interface - chrdev interface for an event line |
| 69 | * @dev: device assocated with event interface |
| 70 | * @handler: fileoperations and related control for the chrdev |
| 71 | * @wait: wait queue to allow blocking reads of events |
| 72 | * @event_list_lock: mutex to protect the list of detected events |
| 73 | * @det_events: list of detected events |
| 74 | * @max_events: maximum number of events before new ones are dropped |
| 75 | * @current_events: number of events in detected list |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 76 | * @owner: ensure the driver module owns the file, not iio |
| 77 | * @private: driver specific data |
| 78 | * @_name: used internally to store the sysfs name for minor id |
| 79 | * attribute |
Randy Dunlap | 4c57260 | 2009-10-04 19:34:02 -0700 | [diff] [blame] | 80 | * @_attrname: the event interface's attribute name |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 81 | */ |
| 82 | struct iio_event_interface { |
| 83 | struct device dev; |
| 84 | struct iio_handler handler; |
| 85 | wait_queue_head_t wait; |
| 86 | struct mutex event_list_lock; |
| 87 | struct iio_detected_event_list det_events; |
| 88 | int max_events; |
| 89 | int current_events; |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 90 | struct module *owner; |
| 91 | void *private; |
Jonathan Cameron | ba5c6fb | 2010-05-04 14:43:06 +0100 | [diff] [blame] | 92 | char _name[35]; |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 93 | char _attrname[20]; |
| 94 | }; |
| 95 | |
| 96 | /** |
| 97 | * struct iio_event_handler_list - element in list of handlers for events |
| 98 | * @list: list header |
| 99 | * @refcount: as the handler may be shared between multiple device |
| 100 | * side events, reference counting ensures clean removal |
| 101 | * @exist_lock: prevents race conditions related to refcount useage. |
| 102 | * @handler: event handler function - called on event if this |
| 103 | * event_handler is enabled. |
| 104 | * |
Randy Dunlap | 4c57260 | 2009-10-04 19:34:02 -0700 | [diff] [blame] | 105 | * Each device has one list of these per interrupt line. |
Jonathan Cameron | 847ec80 | 2009-08-18 18:06:19 +0100 | [diff] [blame] | 106 | **/ |
| 107 | struct iio_event_handler_list { |
| 108 | struct list_head list; |
| 109 | int refcount; |
| 110 | struct mutex exist_lock; |
| 111 | int (*handler)(struct iio_dev *dev_info, int index, s64 timestamp, |
| 112 | int no_test); |
| 113 | }; |
| 114 | |
| 115 | #endif |