306 lines
9.6 KiB
Python
306 lines
9.6 KiB
Python
#!/usr/bin/env python3
|
||
# -*- coding: utf-8 -*-
|
||
"""DI 通道的底层读取后端。
|
||
|
||
每个后端只负责：open / close / read。
|
||
电平语义（0=低，1=高）由上层 DIChannel 统一处理。
|
||
|
||
后端类型：
|
||
- EventBackend：/dev/input/eventN，事件驱动，可 poll。SE5 的 IN1。
|
||
- SysfsBackend：/sys/.../gpio_status 或 /dev/tv_gpioin_N，轮询 + 抗抖。
|
||
SE9 的 IN1、所有设备的 IN2。
|
||
"""
|
||
|
||
import errno
|
||
import glob
|
||
import os
|
||
import struct
|
||
import time
|
||
|
||
from .config import (
|
||
EV_KEY, VALUE_RELEASE, VALUE_PRESS, VALUE_REPEAT,
|
||
DEFAULT_EVENT_DEVICE, GPIO_KEYS_NAME, DEFAULT_IN2_KEY,
|
||
DEBOUNCE, DEFAULT_INTERVAL,
|
||
find_status_file,
|
||
)
|
||
|
||
EVENT_STRUCT = struct.Struct("llHHi") # aarch64 / x86_64 都是 24 字节
|
||
|
||
|
||
# ---------------------------------------------------------------------------
|
||
# 基类
|
||
# ---------------------------------------------------------------------------
|
||
class Backend:
|
||
"""后端接口。"""
|
||
can_poll = False
|
||
|
||
def open(self):
|
||
raise NotImplementedError
|
||
|
||
def close(self):
|
||
raise NotImplementedError
|
||
|
||
def read(self):
|
||
"""非阻塞读一次，返回本批事件列表 [(level, ts), ...]；无事件返回 []。
|
||
|
||
level 是原始电平 0/1，尚未做 active_low 翻转。
|
||
同一批数据里的多个事件必须全部返回，不能只留最后一个，
|
||
否则快速抖动（一次 read 里按下+释放）会丢失中间跳变。
|
||
"""
|
||
raise NotImplementedError
|
||
|
||
@property
|
||
def name(self):
|
||
raise NotImplementedError
|
||
|
||
|
||
# ---------------------------------------------------------------------------
|
||
# /dev/input/eventN 后端（SE5 的 IN1）
|
||
# ---------------------------------------------------------------------------
|
||
class EventBackend(Backend):
|
||
"""基于 input 事件设备，事件驱动。
|
||
|
||
原始 value 语义：
|
||
VALUE_PRESS(1) -> 硬件“按下”
|
||
VALUE_RELEASE(0) -> 硬件“释放”
|
||
本后端返回原始 value，极性翻转留给 DIChannel。
|
||
"""
|
||
|
||
can_poll = True
|
||
|
||
def __init__(self, device=DEFAULT_EVENT_DEVICE, key=None,
|
||
find_by_name=GPIO_KEYS_NAME):
|
||
self.device = device
|
||
self.key = key
|
||
self.find_by_name = find_by_name
|
||
self.fd = None
|
||
self.buf = b""
|
||
|
||
# ---- 自动查找 ----
|
||
@staticmethod
|
||
def find_event_device(name=GPIO_KEYS_NAME):
|
||
"""按设备名找 eventN，找不到返回 None。"""
|
||
for path in sorted(glob.glob("/dev/input/event*")):
|
||
ev = path.rsplit("/", 1)[-1]
|
||
namefile = f"/sys/class/input/{ev}/device/name"
|
||
try:
|
||
with open(namefile) as f:
|
||
if f.read().strip() == name:
|
||
return path
|
||
except OSError:
|
||
continue
|
||
return None
|
||
|
||
def resolve_device(self):
|
||
if not self.device or self.device == "auto":
|
||
return self.find_event_device(self.find_by_name) or DEFAULT_EVENT_DEVICE
|
||
return self.device
|
||
|
||
@property
|
||
def name(self):
|
||
dev = self.device or "(auto)"
|
||
return f"event:{dev}"
|
||
|
||
# ---- 生命周期 ----
|
||
def open(self):
|
||
if self.fd is None:
|
||
dev = self.resolve_device()
|
||
if not dev or not os.path.exists(dev):
|
||
raise FileNotFoundError(
|
||
errno.ENOENT,
|
||
f"event 设备不存在：{dev}",
|
||
dev,
|
||
)
|
||
self.device = dev
|
||
self.fd = os.open(dev, os.O_RDONLY | os.O_NONBLOCK)
|
||
|
||
def close(self):
|
||
if self.fd is not None:
|
||
try:
|
||
os.close(self.fd)
|
||
finally:
|
||
self.fd = None
|
||
|
||
def fileno(self):
|
||
return self.fd
|
||
|
||
# ---- 读取 ----
|
||
def read(self):
|
||
"""返回 [(level, ts), ...]；只汇报关心的 key，批内事件按序全部返回。"""
|
||
if self.fd is None:
|
||
return []
|
||
try:
|
||
data = os.read(self.fd, EVENT_STRUCT.size * 64)
|
||
except OSError:
|
||
return []
|
||
self.buf += data
|
||
events = []
|
||
while len(self.buf) >= EVENT_STRUCT.size:
|
||
chunk = self.buf[:EVENT_STRUCT.size]
|
||
self.buf = self.buf[EVENT_STRUCT.size:]
|
||
sec, usec, etype, code, value = EVENT_STRUCT.unpack(chunk)
|
||
if etype != EV_KEY:
|
||
continue
|
||
if self.key is not None and code != self.key:
|
||
continue
|
||
if value == VALUE_REPEAT:
|
||
continue
|
||
if value not in (VALUE_RELEASE, VALUE_PRESS):
|
||
continue
|
||
ts = sec + usec / 1e6
|
||
events.append((value, ts))
|
||
return events
|
||
|
||
|
||
# ---------------------------------------------------------------------------
|
||
# sysfs 状态文件后端（SE9 的 IN1、所有 IN2）
|
||
# ---------------------------------------------------------------------------
|
||
class SysfsBackend(Backend):
|
||
"""基于 /sys/.../gpio_status 或 /dev/tv_gpioin_N，轮询采样 + 抗抖。"""
|
||
|
||
can_poll = False
|
||
|
||
def __init__(self, path, debounce=DEBOUNCE, interval=DEFAULT_INTERVAL):
|
||
self.path = path
|
||
self.debounce = max(1, int(debounce))
|
||
self.interval = interval
|
||
self._cand = None
|
||
self._cand_n = 0
|
||
self._reported = None # 上次上报的稳定值（跳变只报一次）
|
||
|
||
@property
|
||
def name(self):
|
||
return f"sysfs:{self.path}"
|
||
|
||
def open(self):
|
||
if not os.access(self.path, os.R_OK):
|
||
raise FileNotFoundError(
|
||
errno.ENOENT,
|
||
f"状态文件不可读：{self.path}",
|
||
self.path,
|
||
)
|
||
|
||
def close(self):
|
||
pass
|
||
|
||
# ---- 原始电平 ----
|
||
def read_raw(self):
|
||
try:
|
||
with open(self.path, "r") as f:
|
||
v = f.read()
|
||
except OSError:
|
||
return None
|
||
v = v.strip().strip("\t\r\n ")
|
||
return v if v in ("0", "1") else None
|
||
|
||
# ---- 带抗抖的读取 ----
|
||
def read(self):
|
||
"""返回 [(level, ts)]；抗抖未确认或电平未变化时返回 []。
|
||
|
||
连续 debounce 次采样一致才确认稳定值；确认值与上次上报不同
|
||
（真实跳变）才上报一次，避免稳态期间每个抗抖周期重复产出事件。
|
||
"""
|
||
v = self.read_raw()
|
||
if v is None:
|
||
return []
|
||
ts = time.time()
|
||
|
||
if self._cand is None or v == self._cand:
|
||
self._cand = v
|
||
self._cand_n += 1
|
||
else:
|
||
self._cand = v
|
||
self._cand_n = 1
|
||
|
||
if self._cand_n < self.debounce:
|
||
return []
|
||
confirmed = int(v)
|
||
if self._reported == confirmed:
|
||
return []
|
||
self._reported = confirmed
|
||
return [(confirmed, ts)]
|
||
|
||
|
||
# ---------------------------------------------------------------------------
|
||
# 工厂
|
||
# ---------------------------------------------------------------------------
|
||
def make_backend(kind: str, **kwargs):
|
||
"""kind = 'event' | 'sysfs'。"""
|
||
if kind == "event":
|
||
return EventBackend(**kwargs)
|
||
if kind == "sysfs":
|
||
return SysfsBackend(**kwargs)
|
||
raise ValueError(f"未知后端类型：{kind}")
|
||
|
||
|
||
def make_in1_backend(device=None, key=None, in_index=1):
|
||
"""自动为 IN1 选择后端，适配 SE5 / SE9。
|
||
|
||
优先级：
|
||
1) 显式 device（非 auto） -> EventBackend
|
||
2) 自动查找 gpio-keys 的 event 设备 -> EventBackend
|
||
3) 查找 gpio-in-<in_index> 的状态文件 -> SysfsBackend
|
||
4) 都找不到 -> 返回 EventBackend（open 时抛出可诊断的错误）
|
||
"""
|
||
# 1) 显式指定
|
||
if device and device != "auto":
|
||
return EventBackend(device, key=key)
|
||
|
||
# 2) 自动查找 gpio-keys
|
||
ev = EventBackend.find_event_device(GPIO_KEYS_NAME)
|
||
if ev:
|
||
return EventBackend(ev, key=key)
|
||
|
||
# 3) 回退到 sysfs 状态文件
|
||
status = find_status_file(in_index)
|
||
if status:
|
||
return SysfsBackend(status)
|
||
|
||
# 4) 都找不到，返回一个 open 时会报错的 EventBackend
|
||
return EventBackend(DEFAULT_EVENT_DEVICE, key=key)
|
||
|
||
|
||
def make_in2_backend(device=None, key=None, in_index=2,
|
||
interval=DEFAULT_INTERVAL, debounce=DEBOUNCE):
|
||
"""自动为 IN2 选择后端：优先 sysfs（SE9），回退 gpio-keys event（SE5）。
|
||
|
||
SE5 无 gpio-in-2 状态文件，IN2 与 IN1 同走 gpio-keys 事件设备（不同键码）。
|
||
|
||
优先级：
|
||
1) 显式 device（event 设备路径） -> EventBackend
|
||
2) 查找 gpio-in-<in_index> 的状态文件 -> SysfsBackend
|
||
3) 自动查找 gpio-keys 的 event 设备 -> EventBackend（key 缺省 DEFAULT_IN2_KEY）
|
||
4) 都找不到 -> 返回 None（由调用方给出可诊断错误）
|
||
"""
|
||
# 1) 显式指定 event 设备
|
||
if device and device != "auto":
|
||
return EventBackend(device, key=key if key is not None else DEFAULT_IN2_KEY)
|
||
|
||
# 2) sysfs 状态文件（SE9）
|
||
status = find_status_file(in_index)
|
||
if status:
|
||
return SysfsBackend(status, debounce=debounce, interval=interval)
|
||
|
||
# 3) 回退到 gpio-keys 事件设备（SE5）
|
||
ev = EventBackend.find_event_device(GPIO_KEYS_NAME)
|
||
if ev:
|
||
return EventBackend(ev, key=key if key is not None else DEFAULT_IN2_KEY)
|
||
|
||
# 4) 都找不到
|
||
return None
|
||
|
||
def find_event_device(name=GPIO_KEYS_NAME):
|
||
"""模块级别别名，等价于 EventBackend.find_event_device."""
|
||
return EventBackend.find_event_device(name)
|
||
|
||
__all__ = [
|
||
"Backend",
|
||
"EventBackend",
|
||
"SysfsBackend",
|
||
"make_backend",
|
||
"make_in1_backend",
|
||
"make_in2_backend",
|
||
"find_status_file",
|
||
"find_event_device",
|
||
]
|