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 - industrial I/O trigger device
  20  *
  21  * @id:                 [INTERN] unique id number
  22  * @name:               [DRIVER] unique name
  23  * @dev:                [DRIVER] associated device (if relevant)
  24  * @private_data:       [DRIVER] device specific data
  25  * @list:               [INTERN] used in maintenance of global trigger list
  26  * @alloc_list:         [DRIVER] used for driver specific trigger list
  27  * @owner:              [DRIVER] used to monitor usage count of the trigger.
  28  * @use_count:          use count for the trigger
  29  * @set_trigger_state:  [DRIVER] switch on/off the trigger on demand
  30  * @try_reenable:       function to reenable the trigger when the
  31  *                      use count is zero (may be NULL)
  32  * @subirq_chip:        [INTERN] associate 'virtual' irq chip.
  33  * @subirq_base:        [INTERN] base number for irqs provided by trigger.
  34  * @subirqs:            [INTERN] information about the 'child' irqs.
  35  * @pool:               [INTERN] bitmap of irqs currently in use.
  36  * @pool_lock:          [INTERN] protection of the irq pool.
  37  **/
  38 struct iio_trigger {
  39         int                             id;
  40         const char                      *name;
  41         struct device                   dev;
  42
  43         void                            *private_data;
  44         struct list_head                list;
  45         struct list_head                alloc_list;
  46         struct module                   *owner;
  47         int use_count;
  48
  49         int (*set_trigger_state)(struct iio_trigger *trig, bool state);
  50         int (*try_reenable)(struct iio_trigger *trig);
  51
  52         struct irq_chip                 subirq_chip;
  53         int                             subirq_base;
  54
  55         struct iio_subirq subirqs[CONFIG_IIO_CONSUMERS_PER_TRIGGER];
  56         unsigned long pool[BITS_TO_LONGS(CONFIG_IIO_CONSUMERS_PER_TRIGGER)];
  57         struct mutex                    pool_lock;
  58 };
  59
  60 static inline struct iio_trigger *to_iio_trigger(struct device *d)
  61 {
  62         return container_of(d, struct iio_trigger, dev);
  63 };
  64
  65 static inline void iio_put_trigger(struct iio_trigger *trig)
  66 {
  67         put_device(&trig->dev);
  68         module_put(trig->owner);
  69 };
  70
  71 static inline void iio_get_trigger(struct iio_trigger *trig)
  72 {
  73         __module_get(trig->owner);
  74         get_device(&trig->dev);
  75 };
  76
  77 /**
  78  * iio_trigger_register() - register a trigger with the IIO core
  79  * @trig_info:  trigger to be registered
  80  **/
  81 int iio_trigger_register(struct iio_trigger *trig_info);
  82
  83 /**
  84  * iio_trigger_unregister() - unregister a trigger from the core
  85  * @trig_info:  trigger to be unregistered
  86  **/
  87 void iio_trigger_unregister(struct iio_trigger *trig_info);
  88
  89 /**
  90  * iio_trigger_attach_poll_func() - add a function pair to be run on trigger
  91  * @trig:       trigger to which the function pair are being added
  92  * @pf:         poll function pair
  93  **/
  94 int iio_trigger_attach_poll_func(struct iio_trigger *trig,
  95                                  struct iio_poll_func *pf);
  96
  97 /**
  98  * iio_trigger_dettach_poll_func() -    remove function pair from those to be
  99  *                                      run on trigger
 100  * @trig:       trigger from which the function is being removed
 101  * @pf:         poll function pair
 102  **/
 103 int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
 104                                   struct iio_poll_func *pf);
 105
 106 /**
 107  * iio_trigger_poll() - called on a trigger occurring
 108  * @trig: trigger which occurred
 109  *
 110  * Typically called in relevant hardware interrupt handler.
 111  **/
 112 void iio_trigger_poll(struct iio_trigger *trig, s64 time);
 113 void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time);
 114 void iio_trigger_notify_done(struct iio_trigger *trig);
 115
 116 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private);
 117
 118 static inline int iio_trigger_get_irq(struct iio_trigger *trig)
 119 {
 120         int ret;
 121         mutex_lock(&trig->pool_lock);
 122         ret = bitmap_find_free_region(trig->pool,
 123                                       CONFIG_IIO_CONSUMERS_PER_TRIGGER,
 124                                       ilog2(1));
 125         mutex_unlock(&trig->pool_lock);
 126         if (ret >= 0)
 127                 ret += trig->subirq_base;
 128
 129         return ret;
 130 };
 131
 132 static inline void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
 133 {
 134         mutex_lock(&trig->pool_lock);
 135         clear_bit(irq - trig->subirq_base, trig->pool);
 136         mutex_unlock(&trig->pool_lock);
 137 };
 138
 139 /**
 140  * struct iio_poll_func - poll function pair
 141  *
 142  * @private_data:               data specific to device (passed into poll func)
 143  * @h:                          the function that is actually run on trigger
 144  * @thread:                     threaded interrupt part
 145  * @type:                       the type of interrupt (basically if oneshot)
 146  * @name:                       name used to identify the trigger consumer.
 147  * @irq:                        the corresponding irq as allocated from the
 148  *                              trigger pool
 149  * @timestamp:                  some devices need a timestamp grabbed as soon
 150  *                              as possible after the trigger - hence handler
 151  *                              passes it via here.
 152  **/
 153 struct iio_poll_func {
 154         void                            *private_data;
 155         irqreturn_t (*h)(int irq, void *p);
 156         irqreturn_t (*thread)(int irq, void *p);
 157         int type;
 158         char *name;
 159         int irq;
 160         s64 timestamp;
 161 };
 162
 163 irqreturn_t iio_pollfunc_store_time(int irq, void *p);
 164
 165 /*
 166  * Two functions for common case where all that happens is a pollfunc
 167  * is attached and detached from a trigger
 168  */
 169 int iio_triggered_ring_postenable(struct iio_dev *indio_dev);
 170 int iio_triggered_ring_predisable(struct iio_dev *indio_dev);
 171
 172 struct iio_trigger *iio_allocate_trigger(const char *fmt, ...)
 173         __attribute__((format(printf, 1, 2)));
 174 void iio_free_trigger(struct iio_trigger *trig);
 175
 176 #endif /* _IIO_TRIGGER_H_ */