drivers/staging/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
  12 #ifndef _IIO_TRIGGER_H_
  13 #define _IIO_TRIGGER_H_
  14
  15 struct iio_subirq {
  16         bool enabled;
  17 };
  18
  19 /**
  20  * struct iio_trigger_ops - operations structure for an iio_trigger.
  21  * @owner:              used to monitor usage count of the trigger.
  22  * @set_trigger_state:  switch on/off the trigger on demand
  23  * @try_reenable:       function to reenable the trigger when the
  24  *                      use count is zero (may be NULL)
  25  * @validate_device:    function to validate the device when the
  26  *                      current trigger gets changed.
  27  *
  28  * This is typically static const within a driver and shared by
  29  * instances of a given device.
  30  **/
  31 struct iio_trigger_ops {
  32         struct module                   *owner;
  33         int (*set_trigger_state)(struct iio_trigger *trig, bool state);
  34         int (*try_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  *
  43  * @id:                 [INTERN] unique id number
  44  * @name:               [DRIVER] unique name
  45  * @dev:                [DRIVER] associated device (if relevant)
  46  * @private_data:       [DRIVER] device specific data
  47  * @list:               [INTERN] used in maintenance of global trigger list
  48  * @alloc_list:         [DRIVER] used for driver specific trigger list
  49  * @owner:              [DRIVER] used to monitor usage count of the trigger.
  50  * @use_count:          use count for the trigger
  51  * @subirq_chip:        [INTERN] associate 'virtual' irq chip.
  52  * @subirq_base:        [INTERN] base number for irqs provided by trigger.
  53  * @subirqs:            [INTERN] information about the 'child' irqs.
  54  * @pool:               [INTERN] bitmap of irqs currently in use.
  55  * @pool_lock:          [INTERN] protection of the irq pool.
  56  **/
  57 struct iio_trigger {
  58         const struct iio_trigger_ops    *ops;
  59         int                             id;
  60         const char                      *name;
  61         struct device                   dev;
  62
  63         void                            *private_data;
  64         struct list_head                list;
  65         struct list_head                alloc_list;
  66         struct module                   *owner;
  67         int use_count;
  68
  69         struct irq_chip                 subirq_chip;
  70         int                             subirq_base;
  71
  72         struct iio_subirq subirqs[CONFIG_IIO_CONSUMERS_PER_TRIGGER];
  73         unsigned long pool[BITS_TO_LONGS(CONFIG_IIO_CONSUMERS_PER_TRIGGER)];
  74         struct mutex                    pool_lock;
  75 };
  76
  77
  78 static inline struct iio_trigger *to_iio_trigger(struct device *d)
  79 {
  80         return container_of(d, struct iio_trigger, dev);
  81 };
  82
  83 static inline void iio_put_trigger(struct iio_trigger *trig)
  84 {
  85         module_put(trig->ops->owner);
  86         put_device(&trig->dev);
  87 };
  88
  89 static inline void iio_get_trigger(struct iio_trigger *trig)
  90 {
  91         get_device(&trig->dev);
  92         __module_get(trig->ops->owner);
  93 };
  94
  95 /**
  96  * iio_trigger_register() - register a trigger with the IIO core
  97  * @trig_info:  trigger to be registered
  98  **/
  99 int iio_trigger_register(struct iio_trigger *trig_info);
 100
 101 /**
 102  * iio_trigger_unregister() - unregister a trigger from the core
 103  * @trig_info:  trigger to be unregistered
 104  **/
 105 void iio_trigger_unregister(struct iio_trigger *trig_info);
 106
 107 /**
 108  * iio_trigger_poll() - called on a trigger occurring
 109  * @trig: trigger which occurred
 110  *
 111  * Typically called in relevant hardware interrupt handler.
 112  **/
 113 void iio_trigger_poll(struct iio_trigger *trig, s64 time);
 114 void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time);
 115
 116 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private);
 117
 118 struct iio_trigger *iio_allocate_trigger(const char *fmt, ...)
 119         __attribute__((format(printf, 1, 2)));
 120 void iio_free_trigger(struct iio_trigger *trig);
 121
 122 #endif /* _IIO_TRIGGER_H_ */