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use std::io::Read;
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::Arc;
use log::{debug, info, warn};
use crate::device::input::EV_KEY;
// A single physical power press on the Kobo emits repeated EV_KEY press (val=1)
// events. Without debouncing, those bounce events toggle sleep/wake in rapid
// succession — the multi-frame cover<->book flicker on wake. Ignore presses
// within this window of the last accepted press.
const POWER_DEBOUNCE_MS: u64 = 300;
pub fn spawn_power_monitor(pressed: Arc<AtomicBool>, exit: Arc<AtomicBool>, power_dev: &str) {
let power_dev = power_dev.to_string();
std::thread::spawn(move || {
use std::os::unix::io::AsRawFd;
info!("power: thread started on {} (blocking)", power_dev);
'outer: loop {
if exit.load(Ordering::SeqCst) {
break;
}
let mut dev = match std::fs::OpenOptions::new().read(true).open(&power_dev) {
Ok(d) => d,
Err(e) => {
warn!("power: open {} failed: {} (retry in 500ms)", power_dev, e);
std::thread::sleep(std::time::Duration::from_millis(500));
continue;
}
};
let fd = dev.as_raw_fd();
// SAFETY: fd is a valid, owned File descriptor (dev is alive on this stack frame,
// not closed). F_GETFL/F_SETFL take/return an int flags value; clearing O_NONBLOCK
// on our own fd is sound and only affects this descriptor's blocking mode.
unsafe {
let flags = libc::fcntl(fd, libc::F_GETFL);
libc::fcntl(fd, libc::F_SETFL, flags & !libc::O_NONBLOCK);
}
let mut buf = [0u8; 24];
let mut last_press: Option<std::time::Instant> = None;
// Track key down/up state. On most kernels the power key emits val=1
// (press) then val=0 (release); state-tracking gives a clean single
// press. Some Kobo GPIO drivers only emit val=1 with autorepeat, so a
// time-based debounce remains as a backstop.
let mut key_down = false;
loop {
if exit.load(Ordering::SeqCst) {
drop(dev);
break 'outer;
}
match dev.read(&mut buf) {
Ok(n) if n >= 16 => {
let typ = u16::from_le_bytes([buf[8], buf[9]]);
let code = u16::from_le_bytes([buf[10], buf[11]]);
let val = i32::from_le_bytes([buf[12], buf[13], buf[14], buf[15]]);
if typ == EV_KEY {
debug!(
"power: raw event typ={} code={} val={} n={} down={}",
typ, code, val, n, key_down
);
}
if typ == EV_KEY {
if val == 0 {
key_down = false;
} else if val == 1 {
let now = std::time::Instant::now();
let since_last =
last_press.map(|t| now.duration_since(t).as_millis());
let debounce_ok = since_last
.map(|ms| ms >= POWER_DEBOUNCE_MS as u128)
.unwrap_or(true);
if !key_down || debounce_ok {
if key_down {
info!(
"power: press accepted via debounce ({}ms since last)",
since_last.unwrap_or(0)
);
} else {
info!("power: press accepted (clean key-down)");
}
pressed.store(true, Ordering::SeqCst);
last_press = Some(now);
} else {
debug!(
"power: press suppressed (held, {}ms < {}ms debounce)",
since_last.unwrap_or(0),
POWER_DEBOUNCE_MS
);
}
key_down = true;
}
}
}
Ok(_) => {}
Err(_) => {
std::thread::sleep(std::time::Duration::from_millis(500));
continue 'outer;
}
}
}
}
});
}
/// Pure decision: does a press→release pair count as a wake swipe-up?
/// Extracted from poll_touch_for_wake so the threshold is unit-testable (§11).
/// Requires a long, deliberate swipe: it must start in the bottom ~40% of the
/// screen, travel upward at least ~40% of the screen height, and be more
/// vertical than horizontal — so a short accidental flick won't unlock.
fn is_wake_swipe(
press_x: f32,
press_y: f32,
release_x: f32,
release_y: f32,
screen_h: f32,
) -> bool {
const START_BAND: f32 = 0.6;
const MIN_SWIPE_FRAC: f32 = 0.40;
let dy = press_y - release_y;
let dx = (release_x - press_x).abs();
press_y > screen_h * START_BAND && dy > screen_h * MIN_SWIPE_FRAC && dy > dx
}
pub fn poll_touch_for_wake(
touch_dev: &mut std::fs::File,
touch_fd: libc::c_int,
pressed: Arc<AtomicBool>,
cfg: &crate::device::touch::TouchConfig,
) {
use crate::device::input::{
ABS_MT_POSITION_X, ABS_MT_POSITION_Y, BTN_TOUCH_CODE, EV_ABS, EV_KEY, EV_SYN, SYN_REPORT,
};
use crate::device::touch::to_display;
info!(
"WAKE: poll_touch_for_wake started (screen {}x{}, switch={}, mirror=({},{}))",
cfg.screen_w, cfg.screen_h, cfg.switch_xy, cfg.mirrored_x, cfg.mirrored_y
);
let screen_h = cfg.screen_h as f32;
let mut touch_rec: [u8; 16] = [0; 16];
let mut frame_x: i32 = 0;
let mut frame_y: i32 = 0;
let mut frame_down = false;
let mut prev_down = false;
let mut press_raw: Option<(i32, i32)> = None;
loop {
if pressed.load(Ordering::SeqCst) {
info!("WAKE (power button)");
break;
}
let mut pfd = libc::pollfd {
fd: touch_fd,
events: libc::POLLIN,
revents: 0,
};
// SAFETY: poll takes a single initialized `pollfd` pointing at our stack `pfd` and a
// valid touch_fd (caller-owned, nonblocking). It only writes `revents` back into pfd
// (no other aliasing) and returns an int count; 500ms timeout bounds the wait.
let n = unsafe { libc::poll(&mut pfd, 1, 500) };
if n > 0 {
while touch_dev.read(&mut touch_rec).is_ok() {
let typ = u16::from_le_bytes([touch_rec[8], touch_rec[9]]);
let code = u16::from_le_bytes([touch_rec[10], touch_rec[11]]);
let val = i32::from_le_bytes([
touch_rec[12],
touch_rec[13],
touch_rec[14],
touch_rec[15],
]);
match (typ, code) {
(EV_KEY, BTN_TOUCH_CODE) => frame_down = val == 1,
(EV_ABS, ABS_MT_POSITION_X) => frame_x = val,
(EV_ABS, ABS_MT_POSITION_Y) => frame_y = val,
(EV_SYN, SYN_REPORT) => {
if frame_down && !prev_down {
press_raw = Some((frame_x, frame_y));
}
if !frame_down && prev_down {
if let Some(pr) = press_raw {
let (press_x, press_y) = to_display(pr.0, pr.1, cfg);
let (release_x, release_y) = to_display(frame_x, frame_y, cfg);
if is_wake_swipe(press_x, press_y, release_x, release_y, screen_h) {
info!(
"WAKE: swipe-up press=({:.0},{:.0}) release=({:.0},{:.0}) dy={:.0}",
press_x, press_y, release_x, release_y, press_y - release_y
);
pressed.store(true, Ordering::SeqCst);
info!("WAKE (swipe-up from bottom)");
break;
}
}
press_raw = None;
}
prev_down = frame_down;
}
_ => {}
}
}
if pressed.load(Ordering::SeqCst) {
break;
}
}
}
}
#[cfg(test)]
mod tests {
use super::*;
const SCREEN_H: f32 = 1448.0;
#[test]
fn wake_swipe_long_upward_from_bottom_wakes() {
assert!(is_wake_swipe(500.0, 1300.0, 500.0, 600.0, SCREEN_H));
}
#[test]
fn wake_swipe_short_flick_does_not_wake() {
assert!(!is_wake_swipe(500.0, 1300.0, 500.0, 1150.0, SCREEN_H));
}
#[test]
fn wake_swipe_barely_meeting_threshold_wakes() {
assert!(is_wake_swipe(500.0, 1300.0, 500.0, 700.0, SCREEN_H));
}
#[test]
fn wake_swipe_starting_too_high_does_not_wake() {
assert!(!is_wake_swipe(500.0, 400.0, 500.0, 100.0, SCREEN_H));
}
#[test]
fn wake_swipe_horizontal_does_not_wake() {
assert!(!is_wake_swipe(100.0, 1300.0, 1100.0, 1000.0, SCREEN_H));
}
#[test]
fn wake_swipe_downward_does_not_wake() {
assert!(!is_wake_swipe(500.0, 900.0, 500.0, 1300.0, SCREEN_H));
}
}