trigger.h revision 3f72395ee595a2a2fe1ed01c006c4f0cce313512 
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#include <linux/irq.h>
10
11#ifndef _IIO_TRIGGER_H_
12#define _IIO_TRIGGER_H_
13
14struct iio_subirq {
15	bool enabled;
16};
17
18/**
19 * struct iio_trigger_ops - operations structure for an iio_trigger.
20 * @owner:		used to monitor usage count of the trigger.
21 * @set_trigger_state:	switch on/off the trigger on demand
22 * @try_reenable:	function to reenable the trigger when the
23 *			use count is zero (may be NULL)
24 * @validate_device:	function to validate the device when the
25 *			current trigger gets changed.
26 *
27 * This is typically static const within a driver and shared by
28 * instances of a given device.
29 **/
30struct iio_trigger_ops {
31	struct module			*owner;
32	int (*set_trigger_state)(struct iio_trigger *trig, bool state);
33	int (*try_reenable)(struct iio_trigger *trig);
34	int (*validate_device)(struct iio_trigger *trig,
35			       struct iio_dev *indio_dev);
36};
37
38
39/**
40 * struct iio_trigger - industrial I/O trigger device
41 *
42 * @id:			[INTERN] unique id number
43 * @name:		[DRIVER] unique name
44 * @dev:		[DRIVER] associated device (if relevant)
45 * @private_data:	[DRIVER] device specific data
46 * @list:		[INTERN] used in maintenance of global trigger list
47 * @alloc_list:		[DRIVER] used for driver specific trigger list
48 * @owner:		[DRIVER] used to monitor usage count of the trigger.
49 * @use_count:		use count for the trigger
50 * @subirq_chip:	[INTERN] associate 'virtual' irq chip.
51 * @subirq_base:	[INTERN] base number for irqs provided by trigger.
52 * @subirqs:		[INTERN] information about the 'child' irqs.
53 * @pool:		[INTERN] bitmap of irqs currently in use.
54 * @pool_lock:		[INTERN] protection of the irq pool.
55 **/
56struct iio_trigger {
57	const struct iio_trigger_ops	*ops;
58	int				id;
59	const char			*name;
60	struct device			dev;
61
62	void				*private_data;
63	struct list_head		list;
64	struct list_head		alloc_list;
65	struct module			*owner;
66	int use_count;
67
68	struct irq_chip			subirq_chip;
69	int				subirq_base;
70
71	struct iio_subirq subirqs[CONFIG_IIO_CONSUMERS_PER_TRIGGER];
72	unsigned long pool[BITS_TO_LONGS(CONFIG_IIO_CONSUMERS_PER_TRIGGER)];
73	struct mutex			pool_lock;
74};
75
76
77static inline struct iio_trigger *to_iio_trigger(struct device *d)
78{
79	return container_of(d, struct iio_trigger, dev);
80};
81
82static inline void iio_put_trigger(struct iio_trigger *trig)
83{
84	module_put(trig->ops->owner);
85	put_device(&trig->dev);
86};
87
88static inline void iio_get_trigger(struct iio_trigger *trig)
89{
90	get_device(&trig->dev);
91	__module_get(trig->ops->owner);
92};
93
94/**
95 * iio_trigger_register() - register a trigger with the IIO core
96 * @trig_info:	trigger to be registered
97 **/
98int iio_trigger_register(struct iio_trigger *trig_info);
99
100/**
101 * iio_trigger_unregister() - unregister a trigger from the core
102 * @trig_info:	trigger to be unregistered
103 **/
104void iio_trigger_unregister(struct iio_trigger *trig_info);
105
106/**
107 * iio_trigger_attach_poll_func() - add a function pair to be run on trigger
108 * @trig:	trigger to which the function pair are being added
109 * @pf:		poll function pair
110 **/
111int iio_trigger_attach_poll_func(struct iio_trigger *trig,
112				 struct iio_poll_func *pf);
113
114/**
115 * iio_trigger_dettach_poll_func() -	remove function pair from those to be
116 *					run on trigger
117 * @trig:	trigger from which the function is being removed
118 * @pf:		poll function pair
119 **/
120int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
121				  struct iio_poll_func *pf);
122
123/**
124 * iio_trigger_poll() - called on a trigger occurring
125 * @trig: trigger which occurred
126 *
127 * Typically called in relevant hardware interrupt handler.
128 **/
129void iio_trigger_poll(struct iio_trigger *trig, s64 time);
130void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time);
131
132
133irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private);
134
135static inline int iio_trigger_get_irq(struct iio_trigger *trig)
136{
137	int ret;
138	mutex_lock(&trig->pool_lock);
139	ret = bitmap_find_free_region(trig->pool,
140				      CONFIG_IIO_CONSUMERS_PER_TRIGGER,
141				      ilog2(1));
142	mutex_unlock(&trig->pool_lock);
143	if (ret >= 0)
144		ret += trig->subirq_base;
145
146	return ret;
147};
148
149static inline void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
150{
151	mutex_lock(&trig->pool_lock);
152	clear_bit(irq - trig->subirq_base, trig->pool);
153	mutex_unlock(&trig->pool_lock);
154};
155
156struct iio_trigger *iio_allocate_trigger(const char *fmt, ...)
157	__attribute__((format(printf, 1, 2)));
158void iio_free_trigger(struct iio_trigger *trig);
159
160#endif /* _IIO_TRIGGER_H_ */
161