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847ec80b JC |
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 | |
76 | * @id: indentifier to allow the event interface to know which | |
77 | * physical line it corresponds to | |
4c572605 | 78 | * @attr: this chrdev's minor number sysfs attribute |
847ec80b JC |
79 | * @owner: ensure the driver module owns the file, not iio |
80 | * @private: driver specific data | |
81 | * @_name: used internally to store the sysfs name for minor id | |
82 | * attribute | |
4c572605 | 83 | * @_attrname: the event interface's attribute name |
847ec80b JC |
84 | */ |
85 | struct iio_event_interface { | |
86 | struct device dev; | |
87 | struct iio_handler handler; | |
88 | wait_queue_head_t wait; | |
89 | struct mutex event_list_lock; | |
90 | struct iio_detected_event_list det_events; | |
91 | int max_events; | |
92 | int current_events; | |
93 | int id; | |
94 | struct iio_chrdev_minor_attr attr; | |
95 | struct module *owner; | |
96 | void *private; | |
97 | char _name[20]; | |
98 | char _attrname[20]; | |
99 | }; | |
100 | ||
101 | /** | |
102 | * struct iio_event_handler_list - element in list of handlers for events | |
103 | * @list: list header | |
104 | * @refcount: as the handler may be shared between multiple device | |
105 | * side events, reference counting ensures clean removal | |
106 | * @exist_lock: prevents race conditions related to refcount useage. | |
107 | * @handler: event handler function - called on event if this | |
108 | * event_handler is enabled. | |
109 | * | |
4c572605 | 110 | * Each device has one list of these per interrupt line. |
847ec80b JC |
111 | **/ |
112 | struct iio_event_handler_list { | |
113 | struct list_head list; | |
114 | int refcount; | |
115 | struct mutex exist_lock; | |
116 | int (*handler)(struct iio_dev *dev_info, int index, s64 timestamp, | |
117 | int no_test); | |
118 | }; | |
119 | ||
120 | #endif |