include/linux/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 #include <linux/atomic.h>
  12
  13 #ifndef _IIO_TRIGGER_H_
  14 #define _IIO_TRIGGER_H_
  15
  16 #ifdef CONFIG_IIO_TRIGGER
  17 struct iio_subirq {
  18         bool enabled;
  19 };
  20
  21 /**
  22  * struct iio_trigger_ops - operations structure for an iio_trigger.
  23  * @owner:              used to monitor usage count of the trigger.
  24  * @set_trigger_state:  switch on/off the trigger on demand
  25  * @try_reenable:       function to reenable the trigger when the
  26  *                      use count is zero (may be NULL)
  27  * @validate_device:    function to validate the device when the
  28  *                      current trigger gets changed.
  29  *
  30  * This is typically static const within a driver and shared by
  31  * instances of a given device.
  32  **/
  33 struct iio_trigger_ops {
  34         struct module *owner;
  35         int (*set_trigger_state)(struct iio_trigger *trig, bool state);
  36         int (*try_reenable)(struct iio_trigger *trig);
  37         int (*validate_device)(struct iio_trigger *trig,
  38                                struct iio_dev *indio_dev);
  39 };
  40
  41
  42 /**
  43  * struct iio_trigger - industrial I/O trigger device
  44  * @ops:                [DRIVER] operations structure
  45  * @id:                 [INTERN] unique id number
  46  * @name:               [DRIVER] unique name
  47  * @dev:                [DRIVER] associated device (if relevant)
  48  * @list:               [INTERN] used in maintenance of global trigger list
  49  * @alloc_list:         [DRIVER] used for driver specific trigger list
  50  * @use_count:          use count for the trigger
  51  * @subirq_chip:        [INTERN] associate 'virtual' irq chip.
  52  * @subirq_base:        [INTERN] base number for irqs provided by trigger.
  53  * @subirqs:            [INTERN] information about the 'child' irqs.
  54  * @pool:               [INTERN] bitmap of irqs currently in use.
  55  * @pool_lock:          [INTERN] protection of the irq pool.
  56  **/
  57 struct iio_trigger {
  58         const struct iio_trigger_ops    *ops;
  59         int                             id;
  60         const char                      *name;
  61         struct device                   dev;
  62
  63         struct list_head                list;
  64         struct list_head                alloc_list;
  65         atomic_t                        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_trigger_put(struct iio_trigger *trig)
  82 {
  83         module_put(trig->ops->owner);
  84         put_device(&trig->dev);
  85 }
  86
  87 static inline struct iio_trigger *iio_trigger_get(struct iio_trigger *trig)
  88 {
  89         get_device(&trig->dev);
  90         __module_get(trig->ops->owner);
  91
  92         return trig;
  93 }
  94
  95 /**
  96  * iio_device_set_drvdata() - Set trigger driver data
  97  * @trig: IIO trigger structure
  98  * @data: Driver specific data
  99  *
 100  * Allows to attach an arbitrary pointer to an IIO trigger, which can later be
 101  * retrieved by iio_trigger_get_drvdata().
 102  */
 103 static inline void iio_trigger_set_drvdata(struct iio_trigger *trig, void *data)
 104 {
 105         dev_set_drvdata(&trig->dev, data);
 106 }
 107
 108 /**
 109  * iio_trigger_get_drvdata() - Get trigger driver data
 110  * @trig: IIO trigger structure
 111  *
 112  * Returns the data previously set with iio_trigger_set_drvdata()
 113  */
 114 static inline void *iio_trigger_get_drvdata(struct iio_trigger *trig)
 115 {
 116         return dev_get_drvdata(&trig->dev);
 117 }
 118
 119 /**
 120  * iio_trigger_register() - register a trigger with the IIO core
 121  * @trig_info:  trigger to be registered
 122  **/
 123 int iio_trigger_register(struct iio_trigger *trig_info);
 124
 125 /**
 126  * iio_trigger_unregister() - unregister a trigger from the core
 127  * @trig_info:  trigger to be unregistered
 128  **/
 129 void iio_trigger_unregister(struct iio_trigger *trig_info);
 130
 131 /**
 132  * iio_trigger_poll() - called on a trigger occurring
 133  * @trig:       trigger which occurred
 134  *
 135  * Typically called in relevant hardware interrupt handler.
 136  **/
 137 void iio_trigger_poll(struct iio_trigger *trig);
 138 void iio_trigger_poll_chained(struct iio_trigger *trig);
 139
 140 irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private);
 141
 142 __printf(1, 2) struct iio_trigger *iio_trigger_alloc(const char *fmt, ...);
 143 void iio_trigger_free(struct iio_trigger *trig);
 144
 145 #else
 146 struct iio_trigger;
 147 struct iio_trigger_ops;
 148 #endif
 149 #endif /* _IIO_TRIGGER_H_ */