linux/drivers/media/rc/ir-imon-decoder.c

// SPDX-License-Identifier: GPL-2.0+
// ir-imon-decoder.c - handle iMon protocol
//
// Copyright (C) 2018 by Sean Young <[email protected]>

#define pr_fmt(fmt) …

#include <linux/module.h>
#include "rc-core-priv.h"

#define IMON_UNIT …
#define IMON_BITS …
#define IMON_CHKBITS …

/*
 * This protocol has 30 bits. The format is one IMON_UNIT header pulse,
 * followed by 30 bits. Each bit is one IMON_UNIT check field, and then
 * one IMON_UNIT field with the actual bit (1=space, 0=pulse).
 * The check field is always space for some bits, for others it is pulse if
 * both the preceding and current bit are zero, else space. IMON_CHKBITS
 * defines which bits are of type check.
 *
 * There is no way to distinguish an incomplete message from one where
 * the lower bits are all set, iow. the last pulse is for the lowest
 * bit which is 0.
 */
enum imon_state { … };

static void ir_imon_decode_scancode(struct rc_dev *dev)
{ … }

/**
 * ir_imon_decode() - Decode one iMON pulse or space
 * @dev:	the struct rc_dev descriptor of the device
 * @ev:		the struct ir_raw_event descriptor of the pulse/space
 *
 * This function returns -EINVAL if the pulse violates the state machine
 */
static int ir_imon_decode(struct rc_dev *dev, struct ir_raw_event ev)
{ … }

/**
 * ir_imon_encode() - Encode a scancode as a stream of raw events
 *
 * @protocol:	protocol to encode
 * @scancode:	scancode to encode
 * @events:	array of raw ir events to write into
 * @max:	maximum size of @events
 *
 * Returns:	The number of events written.
 *		-ENOBUFS if there isn't enough space in the array to fit the
 *		encoding. In this case all @max events will have been written.
 */
static int ir_imon_encode(enum rc_proto protocol, u32 scancode,
			  struct ir_raw_event *events, unsigned int max)
{ … }

static int ir_imon_register(struct rc_dev *dev)
{ … }

static struct ir_raw_handler imon_handler = …;

static int __init ir_imon_decode_init(void)
{ … }

static void __exit ir_imon_decode_exit(void)
{ … }

module_init(…) …;
module_exit(ir_imon_decode_exit);

MODULE_LICENSE(…) …;
MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;