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
  11 #ifndef _IIO_TRIGGER_H_
  12 #define _IIO_TRIGGER_H_
  13
  14 struct iio_subirq {
  15         bool enabled;
  16 };
  17
  18 /**
  19  * struct iio_trigger_ops - operations structure for an iio_trigger.
  20  * @owner:              used to monitor usage count of the trigger.
  21  * @set_trigger_state:  switch on/off the trigger on demand
  22  * @try_reenable:       function to reenable the trigger when the
  23  *                      use count is zero (may be NULL)
  24  * @validate_device:    function to validate the device when the
  25  *                      current trigger gets changed.
  26  *
  27  * This is typically static const within a driver and shared by
  28  * instances of a given device.
  29  **/
  30 struct iio_trigger_ops {
  31         struct module                   *owner;
  32         int (*set_trigger_state)(struct iio_trigger *trig, bool state);
  33         int (*try_reenable)(struct iio_trigger *trig);
  34         int (*validate_device)(struct iio_trigger *trig,
  35                                struct iio_dev *indio_dev);
  36 };
  37
  38
  39 /**
  40  * struct iio_trigger - industrial I/O trigger device
  41  *
  42  * @id:                 [INTERN] unique id number
  43  * @name:               [DRIVER] unique name
  44  * @dev:                [DRIVER] associated device (if relevant)
  45  * @private_data:       [DRIVER] device specific data
  46  * @list:               [INTERN] used in maintenance of global trigger list
  47  * @alloc_list:         [DRIVER] used for driver specific trigger list
  48  * @owner:              [DRIVER] used to monitor usage count of the trigger.
  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         struct module                   *owner;
  66         int use_count;
  67
  68         struct irq_chip                 subirq_chip;
  69         int                             subirq_base;
  70
  71         struct iio_subirq subirqs[CONFIG_IIO_CONSUMERS_PER_TRIGGER];
  72         unsigned long pool[BITS_TO_LONGS(CONFIG_IIO_CONSUMERS_PER_TRIGGER)];
  73         struct mutex                    pool_lock;
  74 };
  75
  76
  77 static inline struct iio_trigger *to_iio_trigger(struct device *d)
  78 {
  79         return container_of(d, struct iio_trigger, dev);
  80 };
  81
  82 static inline void iio_put_trigger(struct iio_trigger *trig)
  83 {
  84         module_put(trig->ops->owner);
  85         put_device(&trig->dev);
  86 };
  87
  88 static inline void iio_get_trigger(struct iio_trigger *trig)
  89 {
  90         get_device(&trig->dev);
  91         __module_get(trig->ops->owner);
  92 };
  93
  94 /**
  95  * iio_trigger_register() - register a trigger with the IIO core
  96  * @trig_info:  trigger to be registered
  97  **/
  98 int iio_trigger_register(struct iio_trigger *trig_info);
  99
 100 /**
 101  * iio_trigger_unregister() - unregister a trigger from the core
 102  * @trig_info:  trigger to be unregistered
 103  **/
 104 void iio_trigger_unregister(struct iio_trigger *trig_info);
 105
 106 /**
 107  * iio_trigger_attach_poll_func() - add a function pair to be run on trigger
 108  * @trig:       trigger to which the function pair are being added
 109  * @pf:         poll function pair
 110  **/
 111 int iio_trigger_attach_poll_func(struct iio_trigger *trig,
 112                                  struct iio_poll_func *pf);
 113
 114 /**
 115  * iio_trigger_dettach_poll_func() -    remove function pair from those to be
 116  *                                      run on trigger
 117  * @trig:       trigger from which the function is being removed
 118  * @pf:         poll function pair
 119  **/
 120 int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
 121                                   struct iio_poll_func *pf);
 122
 123 /**
 124  * iio_trigger_poll() - called on a trigger occurring
 125  * @trig: trigger which occurred
 126  *
 127  * Typically called in relevant hardware interrupt handler.
 128  **/
 129 void iio_trigger_poll(struct iio_trigger *trig, s64 time);
 130 void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time);
 131
 132
 133 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private);
 134
 135 static inline int iio_trigger_get_irq(struct iio_trigger *trig)
 136 {
 137         int ret;
 138         mutex_lock(&trig->pool_lock);
 139         ret = bitmap_find_free_region(trig->pool,
 140                                       CONFIG_IIO_CONSUMERS_PER_TRIGGER,
 141                                       ilog2(1));
 142         mutex_unlock(&trig->pool_lock);
 143         if (ret >= 0)
 144                 ret += trig->subirq_base;
 145
 146         return ret;
 147 };
 148
 149 static inline void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
 150 {
 151         mutex_lock(&trig->pool_lock);
 152         clear_bit(irq - trig->subirq_base, trig->pool);
 153         mutex_unlock(&trig->pool_lock);
 154 };
 155
 156 struct iio_trigger *iio_allocate_trigger(const char *fmt, ...)
 157         __attribute__((format(printf, 1, 2)));
 158 void iio_free_trigger(struct iio_trigger *trig);
 159
 160 #endif /* _IIO_TRIGGER_H_ */