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  * @use_count:          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  **/
  56 struct iio_trigger {
  57         const struct iio_trigger_ops    *ops;
  58         int                             id;
  59         const char                      *name;
  60         struct device                   dev;
  61
  62         void                            *private_data;
  63         struct list_head                list;
  64         struct list_head                alloc_list;
  65         int use_count;
  66
  67         struct irq_chip                 subirq_chip;
  68         int                             subirq_base;
  69
  70         struct iio_subirq subirqs[CONFIG_IIO_CONSUMERS_PER_TRIGGER];
  71         unsigned long pool[BITS_TO_LONGS(CONFIG_IIO_CONSUMERS_PER_TRIGGER)];
  72         struct mutex                    pool_lock;
  73 };
  74
  75
  76 static inline struct iio_trigger *to_iio_trigger(struct device *d)
  77 {
  78         return container_of(d, struct iio_trigger, dev);
  79 };
  80
  81 static inline void iio_put_trigger(struct iio_trigger *trig)
  82 {
  83         module_put(trig->ops->owner);
  84         put_device(&trig->dev);
  85 };
  86
  87 static inline void iio_get_trigger(struct iio_trigger *trig)
  88 {
  89         get_device(&trig->dev);
  90         __module_get(trig->ops->owner);
  91 };
  92
  93 /**
  94  * iio_trigger_register() - register a trigger with the IIO core
  95  * @trig_info:  trigger to be registered
  96  **/
  97 int iio_trigger_register(struct iio_trigger *trig_info);
  98
  99 /**
 100  * iio_trigger_unregister() - unregister a trigger from the core
 101  * @trig_info:  trigger to be unregistered
 102  **/
 103 void iio_trigger_unregister(struct iio_trigger *trig_info);
 104
 105 /**
 106  * iio_trigger_poll() - called on a trigger occurring
 107  * @trig: trigger which occurred
 108  *
 109  * Typically called in relevant hardware interrupt handler.
 110  **/
 111 void iio_trigger_poll(struct iio_trigger *trig, s64 time);
 112 void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time);
 113
 114 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private);
 115
 116 __printf(1, 2) struct iio_trigger *iio_allocate_trigger(const char *fmt, ...);
 117 void iio_free_trigger(struct iio_trigger *trig);
 118
 119 #endif /* _IIO_TRIGGER_H_ */