268 строки
6.5 KiB
C
268 строки
6.5 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
// ir-imon-decoder.c - handle iMon protocol
|
|
//
|
|
// Copyright (C) 2018 by Sean Young <sean@mess.org>
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/module.h>
|
|
#include "rc-core-priv.h"
|
|
|
|
#define IMON_UNIT 416 /* us */
|
|
#define IMON_BITS 30
|
|
#define IMON_CHKBITS (BIT(30) | BIT(25) | BIT(24) | BIT(22) | \
|
|
BIT(21) | BIT(20) | BIT(19) | BIT(18) | \
|
|
BIT(17) | BIT(16) | BIT(14) | BIT(13) | \
|
|
BIT(12) | BIT(11) | BIT(10) | BIT(9))
|
|
|
|
/*
|
|
* 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 {
|
|
STATE_INACTIVE,
|
|
STATE_BIT_CHK,
|
|
STATE_BIT_START,
|
|
STATE_FINISHED,
|
|
STATE_ERROR,
|
|
};
|
|
|
|
static void ir_imon_decode_scancode(struct rc_dev *dev)
|
|
{
|
|
struct imon_dec *imon = &dev->raw->imon;
|
|
|
|
/* Keyboard/Mouse toggle */
|
|
if (imon->bits == 0x299115b7)
|
|
imon->stick_keyboard = !imon->stick_keyboard;
|
|
|
|
if ((imon->bits & 0xfc0000ff) == 0x680000b7) {
|
|
int rel_x, rel_y;
|
|
u8 buf;
|
|
|
|
buf = imon->bits >> 16;
|
|
rel_x = (buf & 0x08) | (buf & 0x10) >> 2 |
|
|
(buf & 0x20) >> 4 | (buf & 0x40) >> 6;
|
|
if (imon->bits & 0x02000000)
|
|
rel_x |= ~0x0f;
|
|
buf = imon->bits >> 8;
|
|
rel_y = (buf & 0x08) | (buf & 0x10) >> 2 |
|
|
(buf & 0x20) >> 4 | (buf & 0x40) >> 6;
|
|
if (imon->bits & 0x01000000)
|
|
rel_y |= ~0x0f;
|
|
|
|
if (rel_x && rel_y && imon->stick_keyboard) {
|
|
if (abs(rel_y) > abs(rel_x))
|
|
imon->bits = rel_y > 0 ?
|
|
0x289515b7 : /* KEY_DOWN */
|
|
0x2aa515b7; /* KEY_UP */
|
|
else
|
|
imon->bits = rel_x > 0 ?
|
|
0x2ba515b7 : /* KEY_RIGHT */
|
|
0x29a515b7; /* KEY_LEFT */
|
|
}
|
|
|
|
if (!imon->stick_keyboard) {
|
|
input_report_rel(dev->input_dev, REL_X, rel_x);
|
|
input_report_rel(dev->input_dev, REL_Y, rel_y);
|
|
|
|
input_report_key(dev->input_dev, BTN_LEFT,
|
|
(imon->bits & 0x00010000) != 0);
|
|
input_report_key(dev->input_dev, BTN_RIGHT,
|
|
(imon->bits & 0x00040000) != 0);
|
|
}
|
|
}
|
|
|
|
rc_keydown(dev, RC_PROTO_IMON, imon->bits, 0);
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
struct imon_dec *data = &dev->raw->imon;
|
|
|
|
if (!is_timing_event(ev)) {
|
|
if (ev.overflow)
|
|
data->state = STATE_INACTIVE;
|
|
return 0;
|
|
}
|
|
|
|
dev_dbg(&dev->dev,
|
|
"iMON decode started at state %d bitno %d (%uus %s)\n",
|
|
data->state, data->count, ev.duration, TO_STR(ev.pulse));
|
|
|
|
/*
|
|
* Since iMON protocol is a series of bits, if at any point
|
|
* we encounter an error, make sure that any remaining bits
|
|
* aren't parsed as a scancode made up of less bits.
|
|
*
|
|
* Note that if the stick is held, then the remote repeats
|
|
* the scancode with about 12ms between them. So, make sure
|
|
* we have at least 10ms of space after an error. That way,
|
|
* we're at a new scancode.
|
|
*/
|
|
if (data->state == STATE_ERROR) {
|
|
if (!ev.pulse && ev.duration > MS_TO_US(10))
|
|
data->state = STATE_INACTIVE;
|
|
return 0;
|
|
}
|
|
|
|
for (;;) {
|
|
if (!geq_margin(ev.duration, IMON_UNIT, IMON_UNIT / 2))
|
|
return 0;
|
|
|
|
decrease_duration(&ev, IMON_UNIT);
|
|
|
|
switch (data->state) {
|
|
case STATE_INACTIVE:
|
|
if (ev.pulse) {
|
|
data->state = STATE_BIT_CHK;
|
|
data->bits = 0;
|
|
data->count = IMON_BITS;
|
|
}
|
|
break;
|
|
case STATE_BIT_CHK:
|
|
if (IMON_CHKBITS & BIT(data->count))
|
|
data->last_chk = ev.pulse;
|
|
else if (ev.pulse)
|
|
goto err_out;
|
|
data->state = STATE_BIT_START;
|
|
break;
|
|
case STATE_BIT_START:
|
|
data->bits <<= 1;
|
|
if (!ev.pulse)
|
|
data->bits |= 1;
|
|
|
|
if (IMON_CHKBITS & BIT(data->count)) {
|
|
if (data->last_chk != !(data->bits & 3))
|
|
goto err_out;
|
|
}
|
|
|
|
if (!data->count--)
|
|
data->state = STATE_FINISHED;
|
|
else
|
|
data->state = STATE_BIT_CHK;
|
|
break;
|
|
case STATE_FINISHED:
|
|
if (ev.pulse)
|
|
goto err_out;
|
|
ir_imon_decode_scancode(dev);
|
|
data->state = STATE_INACTIVE;
|
|
break;
|
|
}
|
|
}
|
|
|
|
err_out:
|
|
dev_dbg(&dev->dev,
|
|
"iMON decode failed at state %d bitno %d (%uus %s)\n",
|
|
data->state, data->count, ev.duration, TO_STR(ev.pulse));
|
|
|
|
data->state = STATE_ERROR;
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
struct ir_raw_event *e = events;
|
|
int i, pulse;
|
|
|
|
if (!max--)
|
|
return -ENOBUFS;
|
|
init_ir_raw_event_duration(e, 1, IMON_UNIT);
|
|
|
|
for (i = IMON_BITS; i >= 0; i--) {
|
|
if (BIT(i) & IMON_CHKBITS)
|
|
pulse = !(scancode & (BIT(i) | BIT(i + 1)));
|
|
else
|
|
pulse = 0;
|
|
|
|
if (pulse == e->pulse) {
|
|
e->duration += IMON_UNIT;
|
|
} else {
|
|
if (!max--)
|
|
return -ENOBUFS;
|
|
init_ir_raw_event_duration(++e, pulse, IMON_UNIT);
|
|
}
|
|
|
|
pulse = !(scancode & BIT(i));
|
|
|
|
if (pulse == e->pulse) {
|
|
e->duration += IMON_UNIT;
|
|
} else {
|
|
if (!max--)
|
|
return -ENOBUFS;
|
|
init_ir_raw_event_duration(++e, pulse, IMON_UNIT);
|
|
}
|
|
}
|
|
|
|
if (e->pulse)
|
|
e++;
|
|
|
|
return e - events;
|
|
}
|
|
|
|
static int ir_imon_register(struct rc_dev *dev)
|
|
{
|
|
struct imon_dec *imon = &dev->raw->imon;
|
|
|
|
imon->stick_keyboard = false;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct ir_raw_handler imon_handler = {
|
|
.protocols = RC_PROTO_BIT_IMON,
|
|
.decode = ir_imon_decode,
|
|
.encode = ir_imon_encode,
|
|
.carrier = 38000,
|
|
.raw_register = ir_imon_register,
|
|
.min_timeout = IMON_UNIT * IMON_BITS * 2,
|
|
};
|
|
|
|
static int __init ir_imon_decode_init(void)
|
|
{
|
|
ir_raw_handler_register(&imon_handler);
|
|
|
|
pr_info("IR iMON protocol handler initialized\n");
|
|
return 0;
|
|
}
|
|
|
|
static void __exit ir_imon_decode_exit(void)
|
|
{
|
|
ir_raw_handler_unregister(&imon_handler);
|
|
}
|
|
|
|
module_init(ir_imon_decode_init);
|
|
module_exit(ir_imon_decode_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Sean Young <sean@mess.org>");
|
|
MODULE_DESCRIPTION("iMON IR protocol decoder");
|