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  * @validate_device:    function to validate the device when the
  33  *                      current trigger gets changed.
  34  * @subirq_chip:        [INTERN] associate 'virtual' irq chip.
  35  * @subirq_base:        [INTERN] base number for irqs provided by trigger.
  36  * @subirqs:            [INTERN] information about the 'child' irqs.
  37  * @pool:               [INTERN] bitmap of irqs currently in use.
  38  * @pool_lock:          [INTERN] protection of the irq pool.
  39  **/
  40 struct iio_trigger {
  41         int                             id;
  42         const char                      *name;
  43         struct device                   dev;
  44
  45         void                            *private_data;
  46         struct list_head                list;
  47         struct list_head                alloc_list;
  48         struct module                   *owner;
  49         int use_count;
  50
  51         int (*set_trigger_state)(struct iio_trigger *trig, bool state);
  52         int (*try_reenable)(struct iio_trigger *trig);
  53         int (*validate_device)(struct iio_trigger *trig,
  54                                struct iio_dev *indio_dev);
  55
  56         struct irq_chip                 subirq_chip;
  57         int                             subirq_base;
  58
  59         struct iio_subirq subirqs[CONFIG_IIO_CONSUMERS_PER_TRIGGER];
  60         unsigned long pool[BITS_TO_LONGS(CONFIG_IIO_CONSUMERS_PER_TRIGGER)];
  61         struct mutex                    pool_lock;
  62 };
  63
  64 /**
  65  * struct iio_poll_func - poll function pair
  66  *
  67  * @private_data:               data specific to device (passed into poll func)
  68  * @h:                          the function that is actually run on trigger
  69  * @thread:                     threaded interrupt part
  70  * @type:                       the type of interrupt (basically if oneshot)
  71  * @name:                       name used to identify the trigger consumer.
  72  * @irq:                        the corresponding irq as allocated from the
  73  *                              trigger pool
  74  * @timestamp:                  some devices need a timestamp grabbed as soon
  75  *                              as possible after the trigger - hence handler
  76  *                              passes it via here.
  77  **/
  78 struct iio_poll_func {
  79         void                            *private_data;
  80         irqreturn_t (*h)(int irq, void *p);
  81         irqreturn_t (*thread)(int irq, void *p);
  82         int type;
  83         char *name;
  84         int irq;
  85         s64 timestamp;
  86 };
  87
  88 static inline struct iio_trigger *to_iio_trigger(struct device *d)
  89 {
  90         return container_of(d, struct iio_trigger, dev);
  91 };
  92
  93 static inline void iio_put_trigger(struct iio_trigger *trig)
  94 {
  95         put_device(&trig->dev);
  96         module_put(trig->owner);
  97 };
  98
  99 static inline void iio_get_trigger(struct iio_trigger *trig)
 100 {
 101         __module_get(trig->owner);
 102         get_device(&trig->dev);
 103 };
 104
 105 /**
 106  * iio_trigger_register() - register a trigger with the IIO core
 107  * @trig_info:  trigger to be registered
 108  **/
 109 int iio_trigger_register(struct iio_trigger *trig_info);
 110
 111 /**
 112  * iio_trigger_unregister() - unregister a trigger from the core
 113  * @trig_info:  trigger to be unregistered
 114  **/
 115 void iio_trigger_unregister(struct iio_trigger *trig_info);
 116
 117 /**
 118  * iio_trigger_attach_poll_func() - add a function pair to be run on trigger
 119  * @trig:       trigger to which the function pair are being added
 120  * @pf:         poll function pair
 121  **/
 122 int iio_trigger_attach_poll_func(struct iio_trigger *trig,
 123                                  struct iio_poll_func *pf);
 124
 125 /**
 126  * iio_trigger_dettach_poll_func() -    remove function pair from those to be
 127  *                                      run on trigger
 128  * @trig:       trigger from which the function is being removed
 129  * @pf:         poll function pair
 130  **/
 131 int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
 132                                   struct iio_poll_func *pf);
 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, s64 time);
 141 void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time);
 142 void iio_trigger_notify_done(struct iio_trigger *trig);
 143
 144 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private);
 145
 146 static inline int iio_trigger_get_irq(struct iio_trigger *trig)
 147 {
 148         int ret;
 149         mutex_lock(&trig->pool_lock);
 150         ret = bitmap_find_free_region(trig->pool,
 151                                       CONFIG_IIO_CONSUMERS_PER_TRIGGER,
 152                                       ilog2(1));
 153         mutex_unlock(&trig->pool_lock);
 154         if (ret >= 0)
 155                 ret += trig->subirq_base;
 156
 157         return ret;
 158 };
 159
 160 static inline void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
 161 {
 162         mutex_lock(&trig->pool_lock);
 163         clear_bit(irq - trig->subirq_base, trig->pool);
 164         mutex_unlock(&trig->pool_lock);
 165 };
 166
 167 struct iio_poll_func
 168 *iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
 169                     irqreturn_t (*thread)(int irq, void *p),
 170                     int type,
 171                     void *private,
 172                     const char *fmt,
 173                     ...);
 174 void iio_dealloc_pollfunc(struct iio_poll_func *pf);
 175 irqreturn_t iio_pollfunc_store_time(int irq, void *p);
 176
 177 /*
 178  * Two functions for common case where all that happens is a pollfunc
 179  * is attached and detached from a trigger
 180  */
 181 int iio_triggered_ring_postenable(struct iio_dev *indio_dev);
 182 int iio_triggered_ring_predisable(struct iio_dev *indio_dev);
 183
 184 struct iio_trigger *iio_allocate_trigger(const char *fmt, ...)
 185         __attribute__((format(printf, 1, 2)));
 186 void iio_free_trigger(struct iio_trigger *trig);
 187
 188 #endif /* _IIO_TRIGGER_H_ */