/* The industrial I/O core, trigger handling functions
   *
   * Copyright (c) 2008 Jonathan Cameron
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published by
   * the Free Software Foundation.
   */
  #include <linux/irq.h>
  #include <linux/module.h>
  #include <linux/atomic.h>
  
  #ifndef _IIO_TRIGGER_H_
  #define _IIO_TRIGGER_H_
  
  #ifdef CONFIG_IIO_TRIGGER
  struct iio_subirq {
  	bool enabled;
  };
  
  /**
   * struct iio_trigger_ops - operations structure for an iio_trigger.
   * @owner:		used to monitor usage count of the trigger.
   * @set_trigger_state:	switch on/off the trigger on demand
   * @try_reenable:	function to reenable the trigger when the
   *			use count is zero (may be NULL)
   * @validate_device:	function to validate the device when the
   *			current trigger gets changed.
   *
   * This is typically static const within a driver and shared by
   * instances of a given device.
   **/
  struct iio_trigger_ops {
  	struct module *owner;
  	int (*set_trigger_state)(struct iio_trigger *trig, bool state);
  	int (*try_reenable)(struct iio_trigger *trig);
  	int (*validate_device)(struct iio_trigger *trig,
  			       struct iio_dev *indio_dev);
  };
  
  
  /**
   * struct iio_trigger - industrial I/O trigger device
   * @ops:		[DRIVER] operations structure
   * @id:			[INTERN] unique id number
   * @name:		[DRIVER] unique name
   * @dev:		[DRIVER] associated device (if relevant)
   * @list:		[INTERN] used in maintenance of global trigger list
   * @alloc_list:		[DRIVER] used for driver specific trigger list
   * @use_count:		use count for the trigger
   * @subirq_chip:	[INTERN] associate 'virtual' irq chip.
   * @subirq_base:	[INTERN] base number for irqs provided by trigger.
   * @subirqs:		[INTERN] information about the 'child' irqs.
   * @pool:		[INTERN] bitmap of irqs currently in use.
   * @pool_lock:		[INTERN] protection of the irq pool.
   **/
  struct iio_trigger {
  	const struct iio_trigger_ops	*ops;
  	int				id;
  	const char			*name;
  	struct device			dev;
  
  	struct list_head		list;
  	struct list_head		alloc_list;
  	atomic_t			use_count;
  
  	struct irq_chip			subirq_chip;
  	int				subirq_base;
  
  	struct iio_subirq subirqs[CONFIG_IIO_CONSUMERS_PER_TRIGGER];
  	unsigned long pool[BITS_TO_LONGS(CONFIG_IIO_CONSUMERS_PER_TRIGGER)];
  	struct mutex			pool_lock;
  };
  
  
  static inline struct iio_trigger *to_iio_trigger(struct device *d)
  {
  	return container_of(d, struct iio_trigger, dev);
  }
  
  static inline void iio_trigger_put(struct iio_trigger *trig)
  {
  	module_put(trig->ops->owner);
  	put_device(&trig->dev);
  }
  
  static inline struct iio_trigger *iio_trigger_get(struct iio_trigger *trig)
  {
  	get_device(&trig->dev);
  	__module_get(trig->ops->owner);
  
  	return trig;
  }
  
  /**
   * iio_device_set_drvdata() - Set trigger driver data
   * @trig: IIO trigger structure
   * @data: Driver specific data
   *
   * Allows to attach an arbitrary pointer to an IIO trigger, which can later be
   * retrieved by iio_trigger_get_drvdata().
   */
  static inline void iio_trigger_set_drvdata(struct iio_trigger *trig, void *data)
  {
  	dev_set_drvdata(&trig->dev, data);
  }
  
  /**
   * iio_trigger_get_drvdata() - Get trigger driver data
   * @trig: IIO trigger structure
   *
   * Returns the data previously set with iio_trigger_set_drvdata()
   */
  static inline void *iio_trigger_get_drvdata(struct iio_trigger *trig)
  {
  	return dev_get_drvdata(&trig->dev);
  }
  
  /**
   * iio_trigger_register() - register a trigger with the IIO core
   * @trig_info:	trigger to be registered
   **/
  int iio_trigger_register(struct iio_trigger *trig_info);
  
  /**
   * iio_trigger_unregister() - unregister a trigger from the core
   * @trig_info:	trigger to be unregistered
   **/
  void iio_trigger_unregister(struct iio_trigger *trig_info);
  
  /**
   * iio_trigger_poll() - called on a trigger occurring
   * @trig:	trigger which occurred
   * @time:	timestamp when trigger occurred
   *
   * Typically called in relevant hardware interrupt handler.
   **/
  void iio_trigger_poll(struct iio_trigger *trig, s64 time);
  void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time);
  
  irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private);
  
  __printf(1, 2) struct iio_trigger *iio_trigger_alloc(const char *fmt, ...);
  void iio_trigger_free(struct iio_trigger *trig);
  
  #else
  struct iio_trigger;
  struct iio_trigger_ops;
  #endif
  #endif /* _IIO_TRIGGER_H_ */