trigger.h revision 1637db44413e32a0f100dd4bd164644e641842f7 
1/* The industrial I/O core, trigger handling functions
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#ifndef _IIO_TRIGGER_H_
10#define _IIO_TRIGGER_H_
11#define IIO_TRIGGER_NAME_LENGTH 20
12#define IIO_TRIGGER_ID_PREFIX "iio:trigger"
13#define IIO_TRIGGER_ID_FORMAT IIO_TRIGGER_ID_PREFIX "%d"
14
15
16/**
17 * struct iio_trigger - industrial I/O trigger device
18 *
19 * @id:			[INTERN] unique id number
20 * @name:		[DRIVER] unique name
21 * @dev:		[DRIVER] associated device (if relevant)
22 * @sysfs_dev:		[INTERN] sysfs relevant device
23 * @private_data:	[DRIVER] device specific data
24 * @list:		[INTERN] used in maintenance of global trigger list
25 * @alloc_list:		[DRIVER] used for driver specific trigger list
26 * @poll_func_list_lock:[INTERN] protection of the polling function list
27 * @pollfunc_list:	[INTERN] list of functions to run on trigger.
28 * @control_attrs:	[DRIVER] sysfs attributes relevant to trigger type
29 * @set_trigger_state:	[DRIVER] switch on/off the trigger on demand
30 * @timestamp:		[INTERN] timestamp usesd by some trigs (e.g. datardy)
31 * @owner:		[DRIVER] used to monitor usage count of the trigger.
32 **/
33struct iio_trigger {
34	int				id;
35	const char			*name;
36	struct device			dev;
37
38	void				*private_data;
39	struct list_head		list;
40	struct list_head		alloc_list;
41	spinlock_t			pollfunc_list_lock;
42	struct list_head		pollfunc_list;
43	const struct attribute_group	*control_attrs;
44	s64				timestamp;
45	struct module			*owner;
46	int use_count;
47
48	int (*set_trigger_state)(struct iio_trigger *trig, bool state);
49	int (*try_reenable)(struct iio_trigger *trig);
50};
51
52static inline struct iio_trigger *to_iio_trigger(struct device *d)
53{
54	return container_of(d, struct iio_trigger, dev);
55};
56
57static inline void iio_put_trigger(struct iio_trigger *trig)
58{
59	put_device(&trig->dev);
60	module_put(trig->owner);
61};
62
63static inline void iio_get_trigger(struct iio_trigger *trig)
64{
65	__module_get(trig->owner);
66	get_device(&trig->dev);
67};
68
69/**
70 * iio_trigger_read_name() - sysfs access function to get the trigger name
71 **/
72ssize_t iio_trigger_read_name(struct device *dev,
73			      struct device_attribute *attr,
74			      char *buf);
75
76#define IIO_TRIGGER_NAME_ATTR DEVICE_ATTR(name, S_IRUGO,		\
77					  iio_trigger_read_name,	\
78					  NULL);
79
80/**
81 * iio_trigger_find_by_name() - search global trigger list
82 **/
83struct iio_trigger *iio_trigger_find_by_name(const char *name, size_t len);
84
85/**
86 * iio_trigger_register() - register a trigger with the IIO core
87 * @trig_info:	trigger to be registered
88 **/
89int iio_trigger_register(struct iio_trigger *trig_info);
90
91/**
92 * iio_trigger_unregister() - unregister a trigger from the core
93 **/
94void iio_trigger_unregister(struct iio_trigger *trig_info);
95
96/**
97 * iio_trigger_attach_poll_func() - add a function pair to be run on trigger
98 * @trig:	trigger to which the function pair are being added
99 * @pf:	poll function pair
100 **/
101int iio_trigger_attach_poll_func(struct iio_trigger *trig,
102				 struct iio_poll_func *pf);
103
104/**
105 * iio_trigger_dettach_poll_func() -	remove function pair from those to be
106 *					run on trigger.
107 * @trig:	trigger from which the function is being removed.
108 * @pf:		poll function pair
109 **/
110int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
111				  struct iio_poll_func *pf);
112
113/**
114 * iio_trigger_poll() - called on a trigger occuring
115 * Typically called in relevant hardware interrupt handler.
116 **/
117void iio_trigger_poll(struct iio_trigger *);
118void iio_trigger_notify_done(struct iio_trigger *);
119
120/**
121 * struct iio_poll_func - poll function pair
122 *
123 * @list:			associate this with a triggers pollfunc_list
124 * @private_data:		data specific to device (passed into poll func)
125 * @poll_func_immediate:	function in here is run first. They should be
126 *				extremely lightweight.  Typically used for latch
127 *				control on sensor supporting it.
128 * @poll_func_main:		function in here is run after all immediates.
129 *				Reading from sensor etc typically involves
130 *				scheduling
131 *				from here.
132 *
133 * The two stage approach used here only important when multiple sensors are
134 * being triggered by a single trigger. This really comes into it's own with
135 * simultaneous sampling devices where a simple latch command can be used to
136 * make the device store the values on all inputs.
137 **/
138struct iio_poll_func {
139	struct				list_head list;
140	void				*private_data;
141	void (*poll_func_immediate)(struct iio_dev *indio_dev);
142	void (*poll_func_main)(struct iio_dev  *private_data);
143
144};
145
146struct iio_trigger *iio_allocate_trigger(void);
147
148void iio_free_trigger(struct iio_trigger *trig);
149
150
151#endif /* _IIO_TRIGGER_H_ */
152