include/linux/iio/trigger.h

   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
  79 static inline struct iio_trigger *to_iio_trigger(struct device *d)
  80 {
  81         return container_of(d, struct iio_trigger, dev);
  82 }
  83
  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
  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  */
 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  */
 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_ */