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 - industrial I/O trigger device
  21  *
  22  * @id:                 [INTERN] unique id number
  23  * @name:               [DRIVER] unique name
  24  * @dev:                [DRIVER] associated device (if relevant)
  25  * @private_data:       [DRIVER] device specific data
  26  * @list:               [INTERN] used in maintenance of global trigger list
  27  * @alloc_list:         [DRIVER] used for driver specific trigger list
  28  * @owner:              [DRIVER] used to monitor usage count of the trigger.
  29  * @use_count:          use count for the trigger
  30  * @set_trigger_state:  [DRIVER] switch on/off the trigger on demand
  31  * @try_reenable:       function to reenable the trigger when the
  32  *                      use count is zero (may be NULL)
  33  * @validate_device:    function to validate the device when the
  34  *                      current trigger gets changed.
  35  * @subirq_chip:        [INTERN] associate 'virtual' irq chip.
  36  * @subirq_base:        [INTERN] base number for irqs provided by trigger.
  37  * @subirqs:            [INTERN] information about the 'child' irqs.
  38  * @pool:               [INTERN] bitmap of irqs currently in use.
  39  * @pool_lock:          [INTERN] protection of the irq pool.
  40  **/
  41 struct iio_trigger {
  42         int                             id;
  43         const char                      *name;
  44         struct device                   dev;
  45
  46         void                            *private_data;
  47         struct list_head                list;
  48         struct list_head                alloc_list;
  49         struct module                   *owner;
  50         int use_count;
  51
  52         int (*set_trigger_state)(struct iio_trigger *trig, bool state);
  53         int (*try_reenable)(struct iio_trigger *trig);
  54         int (*validate_device)(struct iio_trigger *trig,
  55                                struct iio_dev *indio_dev);
  56
  57         struct irq_chip                 subirq_chip;
  58         int                             subirq_base;
  59
  60         struct iio_subirq subirqs[CONFIG_IIO_CONSUMERS_PER_TRIGGER];
  61         unsigned long pool[BITS_TO_LONGS(CONFIG_IIO_CONSUMERS_PER_TRIGGER)];
  62         struct mutex                    pool_lock;
  63 };
  64
  65 /**
  66  * struct iio_poll_func - poll function pair
  67  *
  68  * @private_data:               data specific to device (passed into poll func)
  69  * @h:                          the function that is actually run on trigger
  70  * @thread:                     threaded interrupt part
  71  * @type:                       the type of interrupt (basically if oneshot)
  72  * @name:                       name used to identify the trigger consumer.
  73  * @irq:                        the corresponding irq as allocated from the
  74  *                              trigger pool
  75  * @timestamp:                  some devices need a timestamp grabbed as soon
  76  *                              as possible after the trigger - hence handler
  77  *                              passes it via here.
  78  **/
  79 struct iio_poll_func {
  80         void                            *private_data;
  81         irqreturn_t (*h)(int irq, void *p);
  82         irqreturn_t (*thread)(int irq, void *p);
  83         int type;
  84         char *name;
  85         int irq;
  86         s64 timestamp;
  87 };
  88
  89 static inline struct iio_trigger *to_iio_trigger(struct device *d)
  90 {
  91         return container_of(d, struct iio_trigger, dev);
  92 };
  93
  94 static inline void iio_put_trigger(struct iio_trigger *trig)
  95 {
  96         put_device(&trig->dev);
  97         module_put(trig->owner);
  98 };
  99
 100 static inline void iio_get_trigger(struct iio_trigger *trig)
 101 {
 102         __module_get(trig->owner);
 103         get_device(&trig->dev);
 104 };
 105
 106 /**
 107  * iio_trigger_register() - register a trigger with the IIO core
 108  * @trig_info:  trigger to be registered
 109  **/
 110 int iio_trigger_register(struct iio_trigger *trig_info);
 111
 112 /**
 113  * iio_trigger_unregister() - unregister a trigger from the core
 114  * @trig_info:  trigger to be unregistered
 115  **/
 116 void iio_trigger_unregister(struct iio_trigger *trig_info);
 117
 118 /**
 119  * iio_trigger_attach_poll_func() - add a function pair to be run on trigger
 120  * @trig:       trigger to which the function pair are being added
 121  * @pf:         poll function pair
 122  **/
 123 int iio_trigger_attach_poll_func(struct iio_trigger *trig,
 124                                  struct iio_poll_func *pf);
 125
 126 /**
 127  * iio_trigger_dettach_poll_func() -    remove function pair from those to be
 128  *                                      run on trigger
 129  * @trig:       trigger from which the function is being removed
 130  * @pf:         poll function pair
 131  **/
 132 int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
 133                                   struct iio_poll_func *pf);
 134
 135 /**
 136  * iio_trigger_poll() - called on a trigger occurring
 137  * @trig: trigger which occurred
 138  *
 139  * Typically called in relevant hardware interrupt handler.
 140  **/
 141 void iio_trigger_poll(struct iio_trigger *trig, s64 time);
 142 void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time);
 143 void iio_trigger_notify_done(struct iio_trigger *trig);
 144
 145 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private);
 146
 147 static inline int iio_trigger_get_irq(struct iio_trigger *trig)
 148 {
 149         int ret;
 150         mutex_lock(&trig->pool_lock);
 151         ret = bitmap_find_free_region(trig->pool,
 152                                       CONFIG_IIO_CONSUMERS_PER_TRIGGER,
 153                                       ilog2(1));
 154         mutex_unlock(&trig->pool_lock);
 155         if (ret >= 0)
 156                 ret += trig->subirq_base;
 157
 158         return ret;
 159 };
 160
 161 static inline void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
 162 {
 163         mutex_lock(&trig->pool_lock);
 164         clear_bit(irq - trig->subirq_base, trig->pool);
 165         mutex_unlock(&trig->pool_lock);
 166 };
 167
 168 struct iio_poll_func
 169 *iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
 170                     irqreturn_t (*thread)(int irq, void *p),
 171                     int type,
 172                     void *private,
 173                     const char *fmt,
 174                     ...);
 175 void iio_dealloc_pollfunc(struct iio_poll_func *pf);
 176 irqreturn_t iio_pollfunc_store_time(int irq, void *p);
 177
 178 /*
 179  * Two functions for common case where all that happens is a pollfunc
 180  * is attached and detached from a trigger
 181  */
 182 int iio_triggered_ring_postenable(struct iio_dev *indio_dev);
 183 int iio_triggered_ring_predisable(struct iio_dev *indio_dev);
 184
 185 struct iio_trigger *iio_allocate_trigger(const char *fmt, ...)
 186         __attribute__((format(printf, 1, 2)));
 187 void iio_free_trigger(struct iio_trigger *trig);
 188
 189 #endif /* _IIO_TRIGGER_H_ */