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 
97 	WARN_ONCE(list_empty(&trig->list),
98 		  "Getting non-registered iio trigger %s is prohibited\n",
99 		  trig->name);
100 
101 	__module_get(trig->owner);
102 
103 	return trig;
104 }
105 
106 /**
107  * iio_trigger_set_drvdata() - Set trigger driver data
108  * @trig: IIO trigger structure
109  * @data: Driver specific data
110  *
111  * Allows to attach an arbitrary pointer to an IIO trigger, which can later be
112  * retrieved by iio_trigger_get_drvdata().
113  */
iio_trigger_set_drvdata(struct iio_trigger * trig,void * data)114 static inline void iio_trigger_set_drvdata(struct iio_trigger *trig, void *data)
115 {
116 	dev_set_drvdata(&trig->dev, data);
117 }
118 
119 /**
120  * iio_trigger_get_drvdata() - Get trigger driver data
121  * @trig: IIO trigger structure
122  *
123  * Returns the data previously set with iio_trigger_set_drvdata()
124  */
iio_trigger_get_drvdata(struct iio_trigger * trig)125 static inline void *iio_trigger_get_drvdata(struct iio_trigger *trig)
126 {
127 	return dev_get_drvdata(&trig->dev);
128 }
129 
130 /**
131  * iio_trigger_register() - register a trigger with the IIO core
132  * @trig_info:	trigger to be registered
133  **/
134 int iio_trigger_register(struct iio_trigger *trig_info);
135 
136 int devm_iio_trigger_register(struct device *dev,
137 			      struct iio_trigger *trig_info);
138 
139 /**
140  * iio_trigger_unregister() - unregister a trigger from the core
141  * @trig_info:	trigger to be unregistered
142  **/
143 void iio_trigger_unregister(struct iio_trigger *trig_info);
144 
145 /**
146  * iio_trigger_set_immutable() - set an immutable trigger on destination
147  *
148  * @indio_dev: IIO device structure containing the device
149  * @trig: trigger to assign to device
150  *
151  **/
152 int iio_trigger_set_immutable(struct iio_dev *indio_dev, struct iio_trigger *trig);
153 
154 /**
155  * iio_trigger_poll() - called on a trigger occurring
156  * @trig:	trigger which occurred
157  *
158  * Typically called in relevant hardware interrupt handler.
159  **/
160 void iio_trigger_poll(struct iio_trigger *trig);
161 void iio_trigger_poll_chained(struct iio_trigger *trig);
162 
163 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private);
164 
165 #define iio_trigger_alloc(parent, fmt, ...) \
166 	__iio_trigger_alloc((parent), THIS_MODULE, (fmt), ##__VA_ARGS__)
167 
168 __printf(3, 4)
169 struct iio_trigger *__iio_trigger_alloc(struct device *parent,
170 					struct module *this_mod,
171 					const char *fmt, ...);
172 void iio_trigger_free(struct iio_trigger *trig);
173 
174 /**
175  * iio_trigger_using_own() - tells us if we use our own HW trigger ourselves
176  * @indio_dev:  device to check
177  */
178 bool iio_trigger_using_own(struct iio_dev *indio_dev);
179 
180 int iio_trigger_validate_own_device(struct iio_trigger *trig,
181 				     struct iio_dev *indio_dev);
182 
183 #else
184 struct iio_trigger;
185 struct iio_trigger_ops;
186 #endif
187 #endif /* _IIO_TRIGGER_H_ */
188