1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /* The industrial I/O core, trigger handling functions
3  *
4  * Copyright (c) 2008 Jonathan Cameron
5  */
6 #include <linux/irq.h>
7 #include <linux/module.h>
8 #include <linux/atomic.h>
9 
10 #ifndef _IIO_TRIGGER_H_
11 #define _IIO_TRIGGER_H_
12 
13 #ifdef CONFIG_IIO_TRIGGER
14 struct iio_subirq {
15 	bool enabled;
16 };
17 
18 struct iio_dev;
19 struct iio_trigger;
20 
21 /**
22  * struct iio_trigger_ops - operations structure for an iio_trigger.
23  * @set_trigger_state:	switch on/off the trigger on demand
24  * @reenable:		function to reenable the trigger when the
25  *			use count is zero (may be NULL)
26  * @validate_device:	function to validate the device when the
27  *			current trigger gets changed.
28  *
29  * This is typically static const within a driver and shared by
30  * instances of a given device.
31  **/
32 struct iio_trigger_ops {
33 	int (*set_trigger_state)(struct iio_trigger *trig, bool state);
34 	void (*reenable)(struct iio_trigger *trig);
35 	int (*validate_device)(struct iio_trigger *trig,
36 			       struct iio_dev *indio_dev);
37 };
38 
39 
40 /**
41  * struct iio_trigger - industrial I/O trigger device
42  * @ops:		[DRIVER] operations structure
43  * @owner:		[INTERN] owner of this driver module
44  * @id:			[INTERN] unique id number
45  * @name:		[DRIVER] unique name
46  * @dev:		[DRIVER] associated device (if relevant)
47  * @list:		[INTERN] used in maintenance of global trigger list
48  * @alloc_list:		[DRIVER] used for driver specific trigger list
49  * @use_count:		[INTERN] 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  * @attached_own_device:[INTERN] if we are using our own device as trigger,
56  *			i.e. if we registered a poll function to the same
57  *			device as the one providing the trigger.
58  * @reenable_work:	[INTERN] work item used to ensure reenable can sleep.
59  **/
60 struct iio_trigger {
61 	const struct iio_trigger_ops	*ops;
62 	struct module			*owner;
63 	int				id;
64 	const char			*name;
65 	struct device			dev;
66 
67 	struct list_head		list;
68 	struct list_head		alloc_list;
69 	atomic_t			use_count;
70 
71 	struct irq_chip			subirq_chip;
72 	int				subirq_base;
73 
74 	struct iio_subirq subirqs[CONFIG_IIO_CONSUMERS_PER_TRIGGER];
75 	unsigned long pool[BITS_TO_LONGS(CONFIG_IIO_CONSUMERS_PER_TRIGGER)];
76 	struct mutex			pool_lock;
77 	bool				attached_own_device;
78 	struct work_struct		reenable_work;
79 };
80 
81 
to_iio_trigger(struct device * d)82 static inline struct iio_trigger *to_iio_trigger(struct device *d)
83 {
84 	return container_of(d, struct iio_trigger, dev);
85 }
86 
iio_trigger_put(struct iio_trigger * trig)87 static inline void iio_trigger_put(struct iio_trigger *trig)
88 {
89 	module_put(trig->owner);
90 	put_device(&trig->dev);
91 }
92 
iio_trigger_get(struct iio_trigger * trig)93 static inline struct iio_trigger *iio_trigger_get(struct iio_trigger *trig)
94 {
95 	get_device(&trig->dev);
96 	__module_get(trig->owner);
97 
98 	return trig;
99 }
100 
101 /**
102  * iio_trigger_set_drvdata() - Set trigger driver data
103  * @trig: IIO trigger structure
104  * @data: Driver specific data
105  *
106  * Allows to attach an arbitrary pointer to an IIO trigger, which can later be
107  * retrieved by iio_trigger_get_drvdata().
108  */
iio_trigger_set_drvdata(struct iio_trigger * trig,void * data)109 static inline void iio_trigger_set_drvdata(struct iio_trigger *trig, void *data)
110 {
111 	dev_set_drvdata(&trig->dev, data);
112 }
113 
114 /**
115  * iio_trigger_get_drvdata() - Get trigger driver data
116  * @trig: IIO trigger structure
117  *
118  * Returns the data previously set with iio_trigger_set_drvdata()
119  */
iio_trigger_get_drvdata(struct iio_trigger * trig)120 static inline void *iio_trigger_get_drvdata(struct iio_trigger *trig)
121 {
122 	return dev_get_drvdata(&trig->dev);
123 }
124 
125 /**
126  * iio_trigger_register() - register a trigger with the IIO core
127  * @trig_info:	trigger to be registered
128  **/
129 #define iio_trigger_register(trig_info) \
130 	__iio_trigger_register((trig_info), THIS_MODULE)
131 int __iio_trigger_register(struct iio_trigger *trig_info,
132 			   struct module *this_mod);
133 
134 #define devm_iio_trigger_register(dev, trig_info) \
135 	__devm_iio_trigger_register((dev), (trig_info), THIS_MODULE)
136 int __devm_iio_trigger_register(struct device *dev,
137 				struct iio_trigger *trig_info,
138 				struct module *this_mod);
139 
140 /**
141  * iio_trigger_unregister() - unregister a trigger from the core
142  * @trig_info:	trigger to be unregistered
143  **/
144 void iio_trigger_unregister(struct iio_trigger *trig_info);
145 
146 /**
147  * iio_trigger_set_immutable() - set an immutable trigger on destination
148  *
149  * @indio_dev: IIO device structure containing the device
150  * @trig: trigger to assign to device
151  *
152  **/
153 int iio_trigger_set_immutable(struct iio_dev *indio_dev, struct iio_trigger *trig);
154 
155 /**
156  * iio_trigger_poll() - called on a trigger occurring
157  * @trig:	trigger which occurred
158  *
159  * Typically called in relevant hardware interrupt handler.
160  **/
161 void iio_trigger_poll(struct iio_trigger *trig);
162 void iio_trigger_poll_chained(struct iio_trigger *trig);
163 
164 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private);
165 
166 __printf(2, 3)
167 struct iio_trigger *iio_trigger_alloc(struct device *parent, const char *fmt, ...);
168 void iio_trigger_free(struct iio_trigger *trig);
169 
170 /**
171  * iio_trigger_using_own() - tells us if we use our own HW trigger ourselves
172  * @indio_dev:  device to check
173  */
174 bool iio_trigger_using_own(struct iio_dev *indio_dev);
175 
176 int iio_trigger_validate_own_device(struct iio_trigger *trig,
177 				     struct iio_dev *indio_dev);
178 
179 #else
180 struct iio_trigger;
181 struct iio_trigger_ops;
182 #endif
183 #endif /* _IIO_TRIGGER_H_ */
184