279 строки
6.9 KiB
C
279 строки
6.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
// ir-nec-decoder.c - handle NEC IR Pulse/Space protocol
|
|
//
|
|
// Copyright (C) 2010 by Mauro Carvalho Chehab
|
|
|
|
#include <linux/bitrev.h>
|
|
#include <linux/module.h>
|
|
#include "rc-core-priv.h"
|
|
|
|
#define NEC_NBITS 32
|
|
#define NEC_UNIT 563 /* us */
|
|
#define NEC_HEADER_PULSE (16 * NEC_UNIT)
|
|
#define NECX_HEADER_PULSE (8 * NEC_UNIT) /* Less common NEC variant */
|
|
#define NEC_HEADER_SPACE (8 * NEC_UNIT)
|
|
#define NEC_REPEAT_SPACE (4 * NEC_UNIT)
|
|
#define NEC_BIT_PULSE (1 * NEC_UNIT)
|
|
#define NEC_BIT_0_SPACE (1 * NEC_UNIT)
|
|
#define NEC_BIT_1_SPACE (3 * NEC_UNIT)
|
|
#define NEC_TRAILER_PULSE (1 * NEC_UNIT)
|
|
#define NEC_TRAILER_SPACE (10 * NEC_UNIT) /* even longer in reality */
|
|
#define NECX_REPEAT_BITS 1
|
|
|
|
enum nec_state {
|
|
STATE_INACTIVE,
|
|
STATE_HEADER_SPACE,
|
|
STATE_BIT_PULSE,
|
|
STATE_BIT_SPACE,
|
|
STATE_TRAILER_PULSE,
|
|
STATE_TRAILER_SPACE,
|
|
};
|
|
|
|
/**
|
|
* ir_nec_decode() - Decode one NEC 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_nec_decode(struct rc_dev *dev, struct ir_raw_event ev)
|
|
{
|
|
struct nec_dec *data = &dev->raw->nec;
|
|
u32 scancode;
|
|
enum rc_proto rc_proto;
|
|
u8 address, not_address, command, not_command;
|
|
|
|
if (!is_timing_event(ev)) {
|
|
if (ev.reset)
|
|
data->state = STATE_INACTIVE;
|
|
return 0;
|
|
}
|
|
|
|
dev_dbg(&dev->dev, "NEC decode started at state %d (%uus %s)\n",
|
|
data->state, ev.duration, TO_STR(ev.pulse));
|
|
|
|
switch (data->state) {
|
|
|
|
case STATE_INACTIVE:
|
|
if (!ev.pulse)
|
|
break;
|
|
|
|
if (eq_margin(ev.duration, NEC_HEADER_PULSE, NEC_UNIT * 2)) {
|
|
data->is_nec_x = false;
|
|
data->necx_repeat = false;
|
|
} else if (eq_margin(ev.duration, NECX_HEADER_PULSE, NEC_UNIT / 2))
|
|
data->is_nec_x = true;
|
|
else
|
|
break;
|
|
|
|
data->count = 0;
|
|
data->state = STATE_HEADER_SPACE;
|
|
return 0;
|
|
|
|
case STATE_HEADER_SPACE:
|
|
if (ev.pulse)
|
|
break;
|
|
|
|
if (eq_margin(ev.duration, NEC_HEADER_SPACE, NEC_UNIT)) {
|
|
data->state = STATE_BIT_PULSE;
|
|
return 0;
|
|
} else if (eq_margin(ev.duration, NEC_REPEAT_SPACE, NEC_UNIT / 2)) {
|
|
data->state = STATE_TRAILER_PULSE;
|
|
return 0;
|
|
}
|
|
|
|
break;
|
|
|
|
case STATE_BIT_PULSE:
|
|
if (!ev.pulse)
|
|
break;
|
|
|
|
if (!eq_margin(ev.duration, NEC_BIT_PULSE, NEC_UNIT / 2))
|
|
break;
|
|
|
|
data->state = STATE_BIT_SPACE;
|
|
return 0;
|
|
|
|
case STATE_BIT_SPACE:
|
|
if (ev.pulse)
|
|
break;
|
|
|
|
if (data->necx_repeat && data->count == NECX_REPEAT_BITS &&
|
|
geq_margin(ev.duration, NEC_TRAILER_SPACE, NEC_UNIT / 2)) {
|
|
dev_dbg(&dev->dev, "Repeat last key\n");
|
|
rc_repeat(dev);
|
|
data->state = STATE_INACTIVE;
|
|
return 0;
|
|
} else if (data->count > NECX_REPEAT_BITS)
|
|
data->necx_repeat = false;
|
|
|
|
data->bits <<= 1;
|
|
if (eq_margin(ev.duration, NEC_BIT_1_SPACE, NEC_UNIT / 2))
|
|
data->bits |= 1;
|
|
else if (!eq_margin(ev.duration, NEC_BIT_0_SPACE, NEC_UNIT / 2))
|
|
break;
|
|
data->count++;
|
|
|
|
if (data->count == NEC_NBITS)
|
|
data->state = STATE_TRAILER_PULSE;
|
|
else
|
|
data->state = STATE_BIT_PULSE;
|
|
|
|
return 0;
|
|
|
|
case STATE_TRAILER_PULSE:
|
|
if (!ev.pulse)
|
|
break;
|
|
|
|
if (!eq_margin(ev.duration, NEC_TRAILER_PULSE, NEC_UNIT / 2))
|
|
break;
|
|
|
|
data->state = STATE_TRAILER_SPACE;
|
|
return 0;
|
|
|
|
case STATE_TRAILER_SPACE:
|
|
if (ev.pulse)
|
|
break;
|
|
|
|
if (!geq_margin(ev.duration, NEC_TRAILER_SPACE, NEC_UNIT / 2))
|
|
break;
|
|
|
|
if (data->count == NEC_NBITS) {
|
|
address = bitrev8((data->bits >> 24) & 0xff);
|
|
not_address = bitrev8((data->bits >> 16) & 0xff);
|
|
command = bitrev8((data->bits >> 8) & 0xff);
|
|
not_command = bitrev8((data->bits >> 0) & 0xff);
|
|
|
|
scancode = ir_nec_bytes_to_scancode(address,
|
|
not_address,
|
|
command,
|
|
not_command,
|
|
&rc_proto);
|
|
|
|
if (data->is_nec_x)
|
|
data->necx_repeat = true;
|
|
|
|
rc_keydown(dev, rc_proto, scancode, 0);
|
|
} else {
|
|
rc_repeat(dev);
|
|
}
|
|
|
|
data->state = STATE_INACTIVE;
|
|
return 0;
|
|
}
|
|
|
|
dev_dbg(&dev->dev, "NEC decode failed at count %d state %d (%uus %s)\n",
|
|
data->count, data->state, ev.duration, TO_STR(ev.pulse));
|
|
data->state = STATE_INACTIVE;
|
|
return -EINVAL;
|
|
}
|
|
|
|
/**
|
|
* ir_nec_scancode_to_raw() - encode an NEC scancode ready for modulation.
|
|
* @protocol: specific protocol to use
|
|
* @scancode: a single NEC scancode.
|
|
*/
|
|
static u32 ir_nec_scancode_to_raw(enum rc_proto protocol, u32 scancode)
|
|
{
|
|
unsigned int addr, addr_inv, data, data_inv;
|
|
|
|
data = scancode & 0xff;
|
|
|
|
if (protocol == RC_PROTO_NEC32) {
|
|
/* 32-bit NEC (used by Apple and TiVo remotes) */
|
|
/* scan encoding: aaAAddDD */
|
|
addr_inv = (scancode >> 24) & 0xff;
|
|
addr = (scancode >> 16) & 0xff;
|
|
data_inv = (scancode >> 8) & 0xff;
|
|
} else if (protocol == RC_PROTO_NECX) {
|
|
/* Extended NEC */
|
|
/* scan encoding AAaaDD */
|
|
addr = (scancode >> 16) & 0xff;
|
|
addr_inv = (scancode >> 8) & 0xff;
|
|
data_inv = data ^ 0xff;
|
|
} else {
|
|
/* Normal NEC */
|
|
/* scan encoding: AADD */
|
|
addr = (scancode >> 8) & 0xff;
|
|
addr_inv = addr ^ 0xff;
|
|
data_inv = data ^ 0xff;
|
|
}
|
|
|
|
/* raw encoding: ddDDaaAA */
|
|
return data_inv << 24 |
|
|
data << 16 |
|
|
addr_inv << 8 |
|
|
addr;
|
|
}
|
|
|
|
static const struct ir_raw_timings_pd ir_nec_timings = {
|
|
.header_pulse = NEC_HEADER_PULSE,
|
|
.header_space = NEC_HEADER_SPACE,
|
|
.bit_pulse = NEC_BIT_PULSE,
|
|
.bit_space[0] = NEC_BIT_0_SPACE,
|
|
.bit_space[1] = NEC_BIT_1_SPACE,
|
|
.trailer_pulse = NEC_TRAILER_PULSE,
|
|
.trailer_space = NEC_TRAILER_SPACE,
|
|
.msb_first = 0,
|
|
};
|
|
|
|
/**
|
|
* ir_nec_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_nec_encode(enum rc_proto protocol, u32 scancode,
|
|
struct ir_raw_event *events, unsigned int max)
|
|
{
|
|
struct ir_raw_event *e = events;
|
|
int ret;
|
|
u32 raw;
|
|
|
|
/* Convert a NEC scancode to raw NEC data */
|
|
raw = ir_nec_scancode_to_raw(protocol, scancode);
|
|
|
|
/* Modulate the raw data using a pulse distance modulation */
|
|
ret = ir_raw_gen_pd(&e, max, &ir_nec_timings, NEC_NBITS, raw);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
return e - events;
|
|
}
|
|
|
|
static struct ir_raw_handler nec_handler = {
|
|
.protocols = RC_PROTO_BIT_NEC | RC_PROTO_BIT_NECX |
|
|
RC_PROTO_BIT_NEC32,
|
|
.decode = ir_nec_decode,
|
|
.encode = ir_nec_encode,
|
|
.carrier = 38000,
|
|
.min_timeout = NEC_TRAILER_SPACE,
|
|
};
|
|
|
|
static int __init ir_nec_decode_init(void)
|
|
{
|
|
ir_raw_handler_register(&nec_handler);
|
|
|
|
printk(KERN_INFO "IR NEC protocol handler initialized\n");
|
|
return 0;
|
|
}
|
|
|
|
static void __exit ir_nec_decode_exit(void)
|
|
{
|
|
ir_raw_handler_unregister(&nec_handler);
|
|
}
|
|
|
|
module_init(ir_nec_decode_init);
|
|
module_exit(ir_nec_decode_exit);
|
|
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_AUTHOR("Mauro Carvalho Chehab");
|
|
MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
|
|
MODULE_DESCRIPTION("NEC IR protocol decoder");
|