linuxdebug/drivers/media/rc/ir-mce_kbd-decoder.c

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2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0-only
/* ir-mce_kbd-decoder.c - A decoder for the RC6-ish keyboard/mouse IR protocol
* used by the Microsoft Remote Keyboard for Windows Media Center Edition,
* referred to by Microsoft's Windows Media Center remote specification docs
* as "an internal protocol called MCIR-2".
*
* Copyright (C) 2011 by Jarod Wilson <jarod@redhat.com>
*/
#include <linux/module.h>
#include "rc-core-priv.h"
/*
* This decoder currently supports:
* - MCIR-2 29-bit IR signals used for mouse movement and buttons
* - MCIR-2 32-bit IR signals used for standard keyboard keys
*
* The media keys on the keyboard send RC-6 signals that are indistinguishable
* from the keys of the same name on the stock MCE remote, and will be handled
* by the standard RC-6 decoder, and be made available to the system via the
* input device for the remote, rather than the keyboard/mouse one.
*/
#define MCIR2_UNIT 333 /* us */
#define MCIR2_HEADER_NBITS 5
#define MCIR2_MOUSE_NBITS 29
#define MCIR2_KEYBOARD_NBITS 32
#define MCIR2_PREFIX_PULSE (8 * MCIR2_UNIT)
#define MCIR2_PREFIX_SPACE (1 * MCIR2_UNIT)
#define MCIR2_MAX_LEN (3 * MCIR2_UNIT)
#define MCIR2_BIT_START (1 * MCIR2_UNIT)
#define MCIR2_BIT_END (1 * MCIR2_UNIT)
#define MCIR2_BIT_0 (1 * MCIR2_UNIT)
#define MCIR2_BIT_SET (2 * MCIR2_UNIT)
#define MCIR2_MODE_MASK 0xf /* for the header bits */
#define MCIR2_KEYBOARD_HEADER 0x4
#define MCIR2_MOUSE_HEADER 0x1
#define MCIR2_MASK_KEYS_START 0xe0
enum mce_kbd_mode {
MCIR2_MODE_KEYBOARD,
MCIR2_MODE_MOUSE,
MCIR2_MODE_UNKNOWN,
};
enum mce_kbd_state {
STATE_INACTIVE,
STATE_HEADER_BIT_START,
STATE_HEADER_BIT_END,
STATE_BODY_BIT_START,
STATE_BODY_BIT_END,
STATE_FINISHED,
};
static unsigned char kbd_keycodes[256] = {
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_A,
KEY_B, KEY_C, KEY_D, KEY_E, KEY_F,
KEY_G, KEY_H, KEY_I, KEY_J, KEY_K,
KEY_L, KEY_M, KEY_N, KEY_O, KEY_P,
KEY_Q, KEY_R, KEY_S, KEY_T, KEY_U,
KEY_V, KEY_W, KEY_X, KEY_Y, KEY_Z,
KEY_1, KEY_2, KEY_3, KEY_4, KEY_5,
KEY_6, KEY_7, KEY_8, KEY_9, KEY_0,
KEY_ENTER, KEY_ESC, KEY_BACKSPACE, KEY_TAB, KEY_SPACE,
KEY_MINUS, KEY_EQUAL, KEY_LEFTBRACE, KEY_RIGHTBRACE, KEY_BACKSLASH,
KEY_BACKSLASH, KEY_SEMICOLON, KEY_APOSTROPHE, KEY_GRAVE, KEY_COMMA,
KEY_DOT, KEY_SLASH, KEY_CAPSLOCK, KEY_F1, KEY_F2,
KEY_F3, KEY_F4, KEY_F5, KEY_F6, KEY_F7,
KEY_F8, KEY_F9, KEY_F10, KEY_F11, KEY_F12,
KEY_SYSRQ, KEY_SCROLLLOCK, KEY_PAUSE, KEY_INSERT, KEY_HOME,
KEY_PAGEUP, KEY_DELETE, KEY_END, KEY_PAGEDOWN, KEY_RIGHT,
KEY_LEFT, KEY_DOWN, KEY_UP, KEY_NUMLOCK, KEY_KPSLASH,
KEY_KPASTERISK, KEY_KPMINUS, KEY_KPPLUS, KEY_KPENTER, KEY_KP1,
KEY_KP2, KEY_KP3, KEY_KP4, KEY_KP5, KEY_KP6,
KEY_KP7, KEY_KP8, KEY_KP9, KEY_KP0, KEY_KPDOT,
KEY_102ND, KEY_COMPOSE, KEY_POWER, KEY_KPEQUAL, KEY_F13,
KEY_F14, KEY_F15, KEY_F16, KEY_F17, KEY_F18,
KEY_F19, KEY_F20, KEY_F21, KEY_F22, KEY_F23,
KEY_F24, KEY_OPEN, KEY_HELP, KEY_PROPS, KEY_FRONT,
KEY_STOP, KEY_AGAIN, KEY_UNDO, KEY_CUT, KEY_COPY,
KEY_PASTE, KEY_FIND, KEY_MUTE, KEY_VOLUMEUP, KEY_VOLUMEDOWN,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_KPCOMMA, KEY_RESERVED,
KEY_RO, KEY_KATAKANAHIRAGANA, KEY_YEN, KEY_HENKAN, KEY_MUHENKAN,
KEY_KPJPCOMMA, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_HANGUEL,
KEY_HANJA, KEY_KATAKANA, KEY_HIRAGANA, KEY_ZENKAKUHANKAKU, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED, KEY_LEFTCTRL,
KEY_LEFTSHIFT, KEY_LEFTALT, KEY_LEFTMETA, KEY_RIGHTCTRL, KEY_RIGHTSHIFT,
KEY_RIGHTALT, KEY_RIGHTMETA, KEY_PLAYPAUSE, KEY_STOPCD, KEY_PREVIOUSSONG,
KEY_NEXTSONG, KEY_EJECTCD, KEY_VOLUMEUP, KEY_VOLUMEDOWN, KEY_MUTE,
KEY_WWW, KEY_BACK, KEY_FORWARD, KEY_STOP, KEY_FIND,
KEY_SCROLLUP, KEY_SCROLLDOWN, KEY_EDIT, KEY_SLEEP, KEY_COFFEE,
KEY_REFRESH, KEY_CALC, KEY_RESERVED, KEY_RESERVED, KEY_RESERVED,
KEY_RESERVED
};
static void mce_kbd_rx_timeout(struct timer_list *t)
{
struct ir_raw_event_ctrl *raw = from_timer(raw, t, mce_kbd.rx_timeout);
unsigned char maskcode;
unsigned long flags;
int i;
dev_dbg(&raw->dev->dev, "timer callback clearing all keys\n");
spin_lock_irqsave(&raw->mce_kbd.keylock, flags);
if (time_is_before_eq_jiffies(raw->mce_kbd.rx_timeout.expires)) {
for (i = 0; i < 7; i++) {
maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i];
input_report_key(raw->dev->input_dev, maskcode, 0);
}
for (i = 0; i < MCIR2_MASK_KEYS_START; i++)
input_report_key(raw->dev->input_dev, kbd_keycodes[i],
0);
input_sync(raw->dev->input_dev);
}
spin_unlock_irqrestore(&raw->mce_kbd.keylock, flags);
}
static enum mce_kbd_mode mce_kbd_mode(struct mce_kbd_dec *data)
{
switch (data->header & MCIR2_MODE_MASK) {
case MCIR2_KEYBOARD_HEADER:
return MCIR2_MODE_KEYBOARD;
case MCIR2_MOUSE_HEADER:
return MCIR2_MODE_MOUSE;
default:
return MCIR2_MODE_UNKNOWN;
}
}
static void ir_mce_kbd_process_keyboard_data(struct rc_dev *dev, u32 scancode)
{
u8 keydata1 = (scancode >> 8) & 0xff;
u8 keydata2 = (scancode >> 16) & 0xff;
u8 shiftmask = scancode & 0xff;
unsigned char maskcode;
int i, keystate;
dev_dbg(&dev->dev, "keyboard: keydata2 = 0x%02x, keydata1 = 0x%02x, shiftmask = 0x%02x\n",
keydata2, keydata1, shiftmask);
for (i = 0; i < 7; i++) {
maskcode = kbd_keycodes[MCIR2_MASK_KEYS_START + i];
if (shiftmask & (1 << i))
keystate = 1;
else
keystate = 0;
input_report_key(dev->input_dev, maskcode, keystate);
}
if (keydata1)
input_report_key(dev->input_dev, kbd_keycodes[keydata1], 1);
if (keydata2)
input_report_key(dev->input_dev, kbd_keycodes[keydata2], 1);
if (!keydata1 && !keydata2) {
for (i = 0; i < MCIR2_MASK_KEYS_START; i++)
input_report_key(dev->input_dev, kbd_keycodes[i], 0);
}
}
static void ir_mce_kbd_process_mouse_data(struct rc_dev *dev, u32 scancode)
{
/* raw mouse coordinates */
u8 xdata = (scancode >> 7) & 0x7f;
u8 ydata = (scancode >> 14) & 0x7f;
int x, y;
/* mouse buttons */
bool right = scancode & 0x40;
bool left = scancode & 0x20;
if (xdata & 0x40)
x = -((~xdata & 0x7f) + 1);
else
x = xdata;
if (ydata & 0x40)
y = -((~ydata & 0x7f) + 1);
else
y = ydata;
dev_dbg(&dev->dev, "mouse: x = %d, y = %d, btns = %s%s\n",
x, y, left ? "L" : "", right ? "R" : "");
input_report_rel(dev->input_dev, REL_X, x);
input_report_rel(dev->input_dev, REL_Y, y);
input_report_key(dev->input_dev, BTN_LEFT, left);
input_report_key(dev->input_dev, BTN_RIGHT, right);
}
/**
* ir_mce_kbd_decode() - Decode one mce_kbd 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_mce_kbd_decode(struct rc_dev *dev, struct ir_raw_event ev)
{
struct mce_kbd_dec *data = &dev->raw->mce_kbd;
u32 scancode;
unsigned long delay;
struct lirc_scancode lsc = {};
if (!is_timing_event(ev)) {
if (ev.overflow)
data->state = STATE_INACTIVE;
return 0;
}
if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2))
goto out;
again:
dev_dbg(&dev->dev, "started at state %i (%uus %s)\n",
data->state, ev.duration, TO_STR(ev.pulse));
if (!geq_margin(ev.duration, MCIR2_UNIT, MCIR2_UNIT / 2))
return 0;
switch (data->state) {
case STATE_INACTIVE:
if (!ev.pulse)
break;
/* Note: larger margin on first pulse since each MCIR2_UNIT
is quite short and some hardware takes some time to
adjust to the signal */
if (!eq_margin(ev.duration, MCIR2_PREFIX_PULSE, MCIR2_UNIT))
break;
data->state = STATE_HEADER_BIT_START;
data->count = 0;
data->header = 0;
return 0;
case STATE_HEADER_BIT_START:
if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2))
break;
data->header <<= 1;
if (ev.pulse)
data->header |= 1;
data->count++;
data->state = STATE_HEADER_BIT_END;
return 0;
case STATE_HEADER_BIT_END:
decrease_duration(&ev, MCIR2_BIT_END);
if (data->count != MCIR2_HEADER_NBITS) {
data->state = STATE_HEADER_BIT_START;
goto again;
}
switch (mce_kbd_mode(data)) {
case MCIR2_MODE_KEYBOARD:
data->wanted_bits = MCIR2_KEYBOARD_NBITS;
break;
case MCIR2_MODE_MOUSE:
data->wanted_bits = MCIR2_MOUSE_NBITS;
break;
default:
dev_dbg(&dev->dev, "not keyboard or mouse data\n");
goto out;
}
data->count = 0;
data->body = 0;
data->state = STATE_BODY_BIT_START;
goto again;
case STATE_BODY_BIT_START:
if (geq_margin(ev.duration, MCIR2_MAX_LEN, MCIR2_UNIT / 2))
break;
data->body <<= 1;
if (ev.pulse)
data->body |= 1;
data->count++;
data->state = STATE_BODY_BIT_END;
return 0;
case STATE_BODY_BIT_END:
if (data->count == data->wanted_bits)
data->state = STATE_FINISHED;
else
data->state = STATE_BODY_BIT_START;
decrease_duration(&ev, MCIR2_BIT_END);
goto again;
case STATE_FINISHED:
if (ev.pulse)
break;
switch (data->wanted_bits) {
case MCIR2_KEYBOARD_NBITS:
scancode = data->body & 0xffffff;
dev_dbg(&dev->dev, "keyboard data 0x%08x\n",
data->body);
spin_lock(&data->keylock);
if (scancode) {
delay = usecs_to_jiffies(dev->timeout) +
msecs_to_jiffies(100);
mod_timer(&data->rx_timeout, jiffies + delay);
} else {
del_timer(&data->rx_timeout);
}
/* Pass data to keyboard buffer parser */
ir_mce_kbd_process_keyboard_data(dev, scancode);
spin_unlock(&data->keylock);
lsc.rc_proto = RC_PROTO_MCIR2_KBD;
break;
case MCIR2_MOUSE_NBITS:
scancode = data->body & 0x1fffff;
dev_dbg(&dev->dev, "mouse data 0x%06x\n", scancode);
/* Pass data to mouse buffer parser */
ir_mce_kbd_process_mouse_data(dev, scancode);
lsc.rc_proto = RC_PROTO_MCIR2_MSE;
break;
default:
dev_dbg(&dev->dev, "not keyboard or mouse data\n");
goto out;
}
lsc.scancode = scancode;
lirc_scancode_event(dev, &lsc);
data->state = STATE_INACTIVE;
input_event(dev->input_dev, EV_MSC, MSC_SCAN, scancode);
input_sync(dev->input_dev);
return 0;
}
out:
dev_dbg(&dev->dev, "failed at state %i (%uus %s)\n",
data->state, ev.duration, TO_STR(ev.pulse));
data->state = STATE_INACTIVE;
return -EINVAL;
}
static int ir_mce_kbd_register(struct rc_dev *dev)
{
struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd;
timer_setup(&mce_kbd->rx_timeout, mce_kbd_rx_timeout, 0);
spin_lock_init(&mce_kbd->keylock);
return 0;
}
static int ir_mce_kbd_unregister(struct rc_dev *dev)
{
struct mce_kbd_dec *mce_kbd = &dev->raw->mce_kbd;
del_timer_sync(&mce_kbd->rx_timeout);
return 0;
}
static const struct ir_raw_timings_manchester ir_mce_kbd_timings = {
.leader_pulse = MCIR2_PREFIX_PULSE,
.invert = 1,
.clock = MCIR2_UNIT,
.trailer_space = MCIR2_UNIT * 10,
};
/**
* ir_mce_kbd_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_mce_kbd_encode(enum rc_proto protocol, u32 scancode,
struct ir_raw_event *events, unsigned int max)
{
struct ir_raw_event *e = events;
int len, ret;
u64 raw;
if (protocol == RC_PROTO_MCIR2_KBD) {
raw = scancode |
((u64)MCIR2_KEYBOARD_HEADER << MCIR2_KEYBOARD_NBITS);
len = MCIR2_KEYBOARD_NBITS + MCIR2_HEADER_NBITS;
} else {
raw = scancode |
((u64)MCIR2_MOUSE_HEADER << MCIR2_MOUSE_NBITS);
len = MCIR2_MOUSE_NBITS + MCIR2_HEADER_NBITS;
}
ret = ir_raw_gen_manchester(&e, max, &ir_mce_kbd_timings, len, raw);
if (ret < 0)
return ret;
return e - events;
}
static struct ir_raw_handler mce_kbd_handler = {
.protocols = RC_PROTO_BIT_MCIR2_KBD | RC_PROTO_BIT_MCIR2_MSE,
.decode = ir_mce_kbd_decode,
.encode = ir_mce_kbd_encode,
.raw_register = ir_mce_kbd_register,
.raw_unregister = ir_mce_kbd_unregister,
.carrier = 36000,
.min_timeout = MCIR2_MAX_LEN + MCIR2_UNIT / 2,
};
static int __init ir_mce_kbd_decode_init(void)
{
ir_raw_handler_register(&mce_kbd_handler);
printk(KERN_INFO "IR MCE Keyboard/mouse protocol handler initialized\n");
return 0;
}
static void __exit ir_mce_kbd_decode_exit(void)
{
ir_raw_handler_unregister(&mce_kbd_handler);
}
module_init(ir_mce_kbd_decode_init);
module_exit(ir_mce_kbd_decode_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jarod Wilson <jarod@redhat.com>");
MODULE_DESCRIPTION("MCE Keyboard/mouse IR protocol decoder");