gpio wrapper

kvmd/kvmd/__init__.py

@@ -8,8 +8,6 @@ from typing import Set
 from typing import Callable
 from typing import Optional
 
-from RPi import GPIO
-
 import aiohttp
 
 from .application import init
@@ -17,6 +15,8 @@ from .application import init
 from .atx import Atx
 from .streamer import Streamer
 
+from . import gpio
+
 
 # =====
 _logger = logging.getLogger(__name__)
@@ -42,8 +42,6 @@ class _Application:
         self.__sockets: Set[aiohttp.web.WebSocketResponse] = set()
         self.__sockets_lock = asyncio.Lock()
 
-        GPIO.setmode(GPIO.BCM)
-
         self.__atx = Atx(
             power_led=self.__config["atx"]["leds"]["pinout"]["power"],
             hdd_led=self.__config["atx"]["leds"]["pinout"]["hdd"],
@@ -113,11 +111,6 @@ class _Application:
         if self.__streamer.is_running():
             await self.__streamer.stop()
 
-        _logger.info("Cleaning up GPIO ...")
-        GPIO.cleanup()
-
-        _logger.info("Bye-bye")
-
     @_system_task
     async def __stream_controller(self) -> None:
         prev = 0
@@ -189,4 +182,7 @@ class _Application:
 
 
 def main() -> None:
-    _Application(init()).run()
+    config = init()
+    with gpio.bcm():
+        _Application(config).run()
+    _logger.info("Bye-bye")

kvmd/kvmd/atx.py

@@ -3,7 +3,7 @@ import logging
 
 from typing import Tuple
 
-from RPi import GPIO
+from . import gpio
 
 
 # =====
@@ -21,29 +21,20 @@ class Atx:
         long_click_delay: float,
     ) -> None:
 
-        self.__power_led = self.__set_input_pin(power_led)
-        self.__hdd_led = self.__set_input_pin(hdd_led)
+        self.__power_led = gpio.set_input(power_led)
+        self.__hdd_led = gpio.set_input(hdd_led)
 
-        self.__power_switch = self.__set_output_pin(power_switch)
-        self.__reset_switch = self.__set_output_pin(reset_switch)
+        self.__power_switch = gpio.set_output_zeroed(power_switch)
+        self.__reset_switch = gpio.set_output_zeroed(reset_switch)
         self.__click_delay = click_delay
         self.__long_click_delay = long_click_delay
 
         self.__lock = asyncio.Lock()
 
-    def __set_input_pin(self, pin: int) -> int:
-        GPIO.setup(pin, GPIO.IN)
-        return pin
-
-    def __set_output_pin(self, pin: int) -> int:
-        GPIO.setup(pin, GPIO.OUT)
-        GPIO.output(pin, False)
-        return pin
-
     def get_leds(self) -> Tuple[bool, bool]:
         return (
-            not GPIO.input(self.__power_led),
-            not GPIO.input(self.__hdd_led),
+            not gpio.read(self.__power_led),
+            not gpio.read(self.__hdd_led),
         )
 
     async def click_power(self) -> None:
@@ -62,7 +53,7 @@ class Atx:
         if not self.__lock.locked():
             async with self.__lock:
                 for flag in (True, False):
-                    GPIO.output(pin, flag)
+                    gpio.write(pin, flag)
                     await asyncio.sleep(delay)
                     return True
         return False

kvmd/kvmd/extra/cleanup/__init__.py

@@ -1,9 +1,9 @@
 import logging
 
-from RPi import GPIO
-
 from ...application import init
 
+from ... import gpio
+
 
 # =====
 _logger = logging.getLogger(__name__)
@@ -12,12 +12,11 @@ _logger = logging.getLogger(__name__)
 def main() -> None:
     config = init()
     _logger.info("Cleaning up ...")
-    GPIO.setmode(GPIO.BCM)
-    for (key, pin) in [
-        *config["atx"]["switches"]["pinout"].items(),
-        *config["video"]["pinout"].items(),
-    ]:
-        _logger.info("Writing value=0 to pin=%d (%s)", pin, key)
-        GPIO.output(pin, False)
-    GPIO.cleanup()
-    _logger.info("Done!")
+    with gpio.bcm():
+        for (key, pin) in [
+            *config["atx"]["switches"]["pinout"].items(),
+            *config["video"]["pinout"].items(),
+        ]:
+            _logger.info("Writing value=0 to pin=%d (%s)", pin, key)
+            gpio.write(pin, False)
+    _logger.info("Bye-bye")

kvmd/kvmd/gpio.py

@@ -0,0 +1,38 @@
+import contextlib
+import logging
+
+from typing import Generator
+
+from RPi import GPIO
+
+
+# =====
+_logger = logging.getLogger(__name__)
+
+
+@contextlib.contextmanager
+def bcm() -> Generator[None, None, None]:
+    GPIO.setmode(GPIO.BCM)
+    _logger.info("Configured GPIO mode as BCM")
+    yield
+    GPIO.cleanup()
+    _logger.info("GPIO cleaned")
+
+
+def set_output_zeroed(pin: int) -> int:
+    GPIO.setup(pin, GPIO.OUT)
+    GPIO.output(pin, False)
+    return pin
+
+
+def set_input(pin: int) -> int:
+    GPIO.setup(pin, GPIO.IN)
+    return pin
+
+
+def read(pin: int) -> bool:
+    return bool(GPIO.input(pin))
+
+
+def write(pin: int, flag: bool) -> None:
+    GPIO.output(pin, flag)

kvmd/kvmd/streamer.py

@@ -5,7 +5,7 @@ import logging
 from typing import Dict
 from typing import Optional
 
-from RPi import GPIO
+from . import gpio
 
 
 # =====
@@ -22,8 +22,8 @@ class Streamer:  # pylint: disable=too-many-instance-attributes
         loop: asyncio.AbstractEventLoop,
     ) -> None:
 
-        self.__cap_power = self.__set_output_pin(cap_power)
-        self.__vga_power = self.__set_output_pin(vga_power)
+        self.__cap_power = gpio.set_output_zeroed(cap_power)
+        self.__vga_power = gpio.set_output_zeroed(vga_power)
         self.__sync_delay = sync_delay
 
         self.__cmd = (
@@ -36,11 +36,6 @@ class Streamer:  # pylint: disable=too-many-instance-attributes
 
         self.__proc_task: Optional[asyncio.Task] = None
 
-    def __set_output_pin(self, pin: int) -> int:
-        GPIO.setup(pin, GPIO.OUT)
-        GPIO.output(pin, False)
-        return pin
-
     async def start(self) -> None:
         assert not self.__proc_task
         _logger.info("Starting mjpg_streamer ...")
@@ -60,10 +55,10 @@ class Streamer:  # pylint: disable=too-many-instance-attributes
 
     async def __set_hw_enabled(self, enabled: bool) -> None:
         # XXX: This sequence is very important for enable
-        GPIO.output(self.__cap_power, enabled)
+        gpio.write(self.__cap_power, enabled)
         if enabled:
             await asyncio.sleep(self.__sync_delay)
-        GPIO.output(self.__vga_power, enabled)
+        gpio.write(self.__vga_power, enabled)
         await asyncio.sleep(self.__sync_delay)
 
     async def __process(self) -> None: