linux/include/uapi/linux/counter.h

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
 * Userspace ABI for Counter character devices
 * Copyright (C) 2020 William Breathitt Gray
 */
#ifndef _UAPI_COUNTER_H_
#define _UAPI_COUNTER_H_

#include <linux/ioctl.h>
#include <linux/types.h>

/* Component type definitions */
enum counter_component_type { … };

/* Component scope definitions */
enum counter_scope { … };

/**
 * struct counter_component - Counter component identification
 * @type: component type (one of enum counter_component_type)
 * @scope: component scope (one of enum counter_scope)
 * @parent: parent ID (matching the ID suffix of the respective parent sysfs
 *          path as described by the ABI documentation file
 *          Documentation/ABI/testing/sysfs-bus-counter)
 * @id: component ID (matching the ID provided by the respective *_component_id
 *      sysfs attribute of the desired component)
 *
 * For example, if the Count 2 ceiling extension of Counter device 4 is desired,
 * set type equal to COUNTER_COMPONENT_EXTENSION, scope equal to
 * COUNTER_SCOPE_COUNT, parent equal to 2, and id equal to the value provided by
 * the respective /sys/bus/counter/devices/counter4/count2/ceiling_component_id
 * sysfs attribute.
 */
struct counter_component { … };

/* Event type definitions */
enum counter_event_type { … };

/**
 * struct counter_watch - Counter component watch configuration
 * @component: component to watch when event triggers
 * @event: event that triggers (one of enum counter_event_type)
 * @channel: event channel (typically 0 unless the device supports concurrent
 *	     events of the same type)
 */
struct counter_watch { … };

/*
 * Queues a Counter watch for the specified event.
 *
 * The queued watches will not be applied until COUNTER_ENABLE_EVENTS_IOCTL is
 * called.
 */
#define COUNTER_ADD_WATCH_IOCTL …
/*
 * Enables monitoring the events specified by the Counter watches that were
 * queued by COUNTER_ADD_WATCH_IOCTL.
 *
 * If events are already enabled, the new set of watches replaces the old one.
 * Calling this ioctl also has the effect of clearing the queue of watches added
 * by COUNTER_ADD_WATCH_IOCTL.
 */
#define COUNTER_ENABLE_EVENTS_IOCTL …
/*
 * Stops monitoring the previously enabled events.
 */
#define COUNTER_DISABLE_EVENTS_IOCTL …

/**
 * struct counter_event - Counter event data
 * @timestamp: best estimate of time of event occurrence, in nanoseconds
 * @value: component value
 * @watch: component watch configuration
 * @status: return status (system error number)
 */
struct counter_event { … };

/* Count direction values */
enum counter_count_direction { … };

/* Count mode values */
enum counter_count_mode { … };

/* Count function values */
enum counter_function { … };

/* Signal values */
enum counter_signal_level { … };

/* Action mode values */
enum counter_synapse_action { … };

/* Signal polarity values */
enum counter_signal_polarity { … };

#endif /* _UAPI_COUNTER_H_ */