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