trigger.h revision e65bc6ac6fa54959ac0b3712b0f35bbf073c073e 
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/**
77 * struct iio_poll_func - poll function pair
78 *
79 * @indio_dev:			data specific to device (passed into poll func)
80 * @h:				the function that is actually run on trigger
81 * @thread:			threaded interrupt part
82 * @type:			the type of interrupt (basically if oneshot)
83 * @name:			name used to identify the trigger consumer.
84 * @irq:			the corresponding irq as allocated from the
85 *				trigger pool
86 * @timestamp:			some devices need a timestamp grabbed as soon
87 *				as possible after the trigger - hence handler
88 *				passes it via here.
89 **/
90struct iio_poll_func {
91	struct iio_dev *indio_dev;
92	irqreturn_t (*h)(int irq, void *p);
93	irqreturn_t (*thread)(int irq, void *p);
94	int type;
95	char *name;
96	int irq;
97	s64 timestamp;
98};
99
100static inline struct iio_trigger *to_iio_trigger(struct device *d)
101{
102	return container_of(d, struct iio_trigger, dev);
103};
104
105static inline void iio_put_trigger(struct iio_trigger *trig)
106{
107	module_put(trig->ops->owner);
108	put_device(&trig->dev);
109};
110
111static inline void iio_get_trigger(struct iio_trigger *trig)
112{
113	get_device(&trig->dev);
114	__module_get(trig->ops->owner);
115};
116
117/**
118 * iio_trigger_register() - register a trigger with the IIO core
119 * @trig_info:	trigger to be registered
120 **/
121int iio_trigger_register(struct iio_trigger *trig_info);
122
123/**
124 * iio_trigger_unregister() - unregister a trigger from the core
125 * @trig_info:	trigger to be unregistered
126 **/
127void iio_trigger_unregister(struct iio_trigger *trig_info);
128
129/**
130 * iio_trigger_attach_poll_func() - add a function pair to be run on trigger
131 * @trig:	trigger to which the function pair are being added
132 * @pf:		poll function pair
133 **/
134int iio_trigger_attach_poll_func(struct iio_trigger *trig,
135				 struct iio_poll_func *pf);
136
137/**
138 * iio_trigger_dettach_poll_func() -	remove function pair from those to be
139 *					run on trigger
140 * @trig:	trigger from which the function is being removed
141 * @pf:		poll function pair
142 **/
143int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
144				  struct iio_poll_func *pf);
145
146/**
147 * iio_trigger_poll() - called on a trigger occurring
148 * @trig: trigger which occurred
149 *
150 * Typically called in relevant hardware interrupt handler.
151 **/
152void iio_trigger_poll(struct iio_trigger *trig, s64 time);
153void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time);
154void iio_trigger_notify_done(struct iio_trigger *trig);
155
156irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private);
157
158static inline int iio_trigger_get_irq(struct iio_trigger *trig)
159{
160	int ret;
161	mutex_lock(&trig->pool_lock);
162	ret = bitmap_find_free_region(trig->pool,
163				      CONFIG_IIO_CONSUMERS_PER_TRIGGER,
164				      ilog2(1));
165	mutex_unlock(&trig->pool_lock);
166	if (ret >= 0)
167		ret += trig->subirq_base;
168
169	return ret;
170};
171
172static inline void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
173{
174	mutex_lock(&trig->pool_lock);
175	clear_bit(irq - trig->subirq_base, trig->pool);
176	mutex_unlock(&trig->pool_lock);
177};
178
179struct iio_poll_func
180*iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
181		    irqreturn_t (*thread)(int irq, void *p),
182		    int type,
183		    struct iio_dev *indio_dev,
184		    const char *fmt,
185		    ...);
186void iio_dealloc_pollfunc(struct iio_poll_func *pf);
187irqreturn_t iio_pollfunc_store_time(int irq, void *p);
188
189/*
190 * Two functions for common case where all that happens is a pollfunc
191 * is attached and detached from a trigger
192 */
193int iio_triggered_ring_postenable(struct iio_dev *indio_dev);
194int iio_triggered_ring_predisable(struct iio_dev *indio_dev);
195
196struct iio_trigger *iio_allocate_trigger(const char *fmt, ...)
197	__attribute__((format(printf, 1, 2)));
198void iio_free_trigger(struct iio_trigger *trig);
199
200#endif /* _IIO_TRIGGER_H_ */
201