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/* 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.
*/
#ifndef _IIO_TRIGGER_H_
#define _IIO_TRIGGER_H_
#define IIO_TRIGGER_NAME_LENGTH 20
#define IIO_TRIGGER_ID_PREFIX "iio:trigger"
#define IIO_TRIGGER_ID_FORMAT IIO_TRIGGER_ID_PREFIX "%d"
/**
* struct iio_trigger - industrial I/O trigger device
*
* @id: [INTERN] unique id number
* @name: [DRIVER] unique name
* @dev: [DRIVER] associated device (if relevant)
* @private_data: [DRIVER] device specific data
* @list: [INTERN] used in maintenance of global trigger list
* @alloc_list: [DRIVER] used for driver specific trigger list
* @pollfunc_list_lock: [INTERN] protection of the polling function list
* @pollfunc_list: [INTERN] list of functions to run on trigger.
* @control_attrs: [DRIVER] sysfs attributes relevant to trigger type
* @timestamp: [INTERN] timestamp usesd by some trigs (e.g. datardy)
* @owner: [DRIVER] used to monitor usage count of the trigger.
* @use_count: use count for the trigger
* @set_trigger_state: [DRIVER] switch on/off the trigger on demand
* @try_reenable: function to reenable the trigger when the
* use count is zero (may be NULL)
**/
struct iio_trigger {
int id;
const char *name;
struct device dev;
void *private_data;
struct list_head list;
struct list_head alloc_list;
spinlock_t pollfunc_list_lock;
struct list_head pollfunc_list;
const struct attribute_group *control_attrs;
s64 timestamp;
struct module *owner;
int use_count;
int (*set_trigger_state)(struct iio_trigger *trig, bool state);
int (*try_reenable)(struct iio_trigger *trig);
};
static inline struct iio_trigger *to_iio_trigger(struct device *d)
{
return container_of(d, struct iio_trigger, dev);
};
static inline void iio_put_trigger(struct iio_trigger *trig)
{
put_device(&trig->dev);
module_put(trig->owner);
};
static inline void iio_get_trigger(struct iio_trigger *trig)
{
__module_get(trig->owner);
get_device(&trig->dev);
};
/**
* iio_trigger_read_name() - sysfs access function to get the trigger name
* @dev: the system device
* @attr: device attributes for the device
* @buf: output buffer to store the trigger name
**/
ssize_t iio_trigger_read_name(struct device *dev,
struct device_attribute *attr,
char *buf);
#define IIO_TRIGGER_NAME_ATTR DEVICE_ATTR(name, S_IRUGO, \
iio_trigger_read_name, \
NULL);
/**
* iio_trigger_find_by_name() - search global trigger list
* @name: trigger name to search for
* @len: trigger name string length to compare
**/
struct iio_trigger *iio_trigger_find_by_name(const char *name, size_t len);
/**
* 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_attach_poll_func() - add a function pair to be run on trigger
* @trig: trigger to which the function pair are being added
* @pf: poll function pair
**/
int iio_trigger_attach_poll_func(struct iio_trigger *trig,
struct iio_poll_func *pf);
/**
* iio_trigger_dettach_poll_func() - remove function pair from those to be
* run on trigger
* @trig: trigger from which the function is being removed
* @pf: poll function pair
**/
int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
struct iio_poll_func *pf);
/**
* iio_trigger_poll() - called on a trigger occurring
* @trig: trigger which occurred
*
* Typically called in relevant hardware interrupt handler.
**/
void iio_trigger_poll(struct iio_trigger *trig);
void iio_trigger_notify_done(struct iio_trigger *trig);
/**
* struct iio_poll_func - poll function pair
*
* @list: associate this with a triggers pollfunc_list
* @private_data: data specific to device (passed into poll func)
* @poll_func_immediate: function in here is run first. They should be
* extremely lightweight. Typically used for latch
* control on sensor supporting it.
* @poll_func_main: function in here is run after all immediates.
* Reading from sensor etc typically involves
* scheduling from here.
*
* The two stage approach used here is only important when multiple sensors are
* being triggered by a single trigger. This really comes into its own with
* simultaneous sampling devices where a simple latch command can be used to
* make the device store the values on all inputs.
**/
struct iio_poll_func {
struct list_head list;
void *private_data;
void (*poll_func_immediate)(struct iio_dev *indio_dev);
void (*poll_func_main)(struct iio_dev *private_data);
};
struct iio_trigger *iio_allocate_trigger(void);
void iio_free_trigger(struct iio_trigger *trig);
#endif /* _IIO_TRIGGER_H_ */