Sysfsgpio invert (active_low)

doc/configuration.rst

@@ -610,9 +610,11 @@ A :any:`SysfsGPIO` resource describes a GPIO line.
 
    SysfsGPIO:
      index: 12
+     invert: False
 
 Arguments:
   - index (int): index of the GPIO line
+  - invert (bool, default=False): optional, whether the logic level is inverted(active-low)
 
 Used by:
   - `GpioDigitalOutputDriver`_
@@ -636,6 +638,7 @@ USB based gpiochips.
        '@SUBSYSTEM': 'usb'
        '@ID_SERIAL_SHORT': 'D38EJ8LF'
      pin: 0
+     invert: False
 
 The example would search for a USB gpiochip with the key `ID_SERIAL_SHORT`
 and the value `D38EJ8LF` and use the pin 0 of this device.
@@ -644,6 +647,7 @@ The `ID_SERIAL_SHORT` property is set by the usb_id builtin helper program.
 Arguments:
   - match (dict): key and value pairs for a udev match, see `udev Matching`_
   - pin (int): gpio pin number within the matched gpiochip.
+  - invert (bool, default=False): optional, whether the logic level is inverted (active-low)
 
 Used by:
   - `GpioDigitalOutputDriver`_

examples/sysfsgpio/export-gpio.yaml

@@ -1,3 +1,4 @@
 desk:
-    GpioDigitalOutputDriver:
+    SysfsGPIO:
         index: 60
+        invert: False

examples/sysfsgpio/import-gpio.yaml

@@ -5,5 +5,3 @@ targets:
         name: gpio
     drivers:
       GpioDigitalOutputDriver: {}
-options:
-  coordinator_address: 'labgrid:20408'

examples/sysfsgpio/sysfsgpio.py

@@ -13,11 +13,12 @@
 StepLogger.start()
 
 t = Target("main")
-r = SysfsGPIO(t, name=None, index=60)
+r = SysfsGPIO(t, name=None, index=60, invert=True)
 d = GpioDigitalOutputDriver(t, name=None)
 
 p = t.get_driver("DigitalOutputProtocol")
 print(t.resources)
+print("Testing IO")
 p.set(True)
 print(p.get())
 time.sleep(2)

examples/sysfsgpio/sysfsgpio_remote.py

@@ -15,6 +15,7 @@
 
 p = t.get_driver("DigitalOutputProtocol")
 print(t.resources)
+print("Testing IO")
 p.set(True)
 print(p.get())
 time.sleep(2)

labgrid/driver/gpiodriver.py

@@ -37,9 +37,9 @@ def on_deactivate(self):
     @Driver.check_active
     @step(args=['status'])
     def set(self, status):
-        self.proxy.set(self.gpio.index, status)
+        self.proxy.set(self.gpio.index, self.gpio.invert, status)
 
     @Driver.check_active
     @step(result=True)
     def get(self):
-        return self.proxy.get(self.gpio.index)
+        return self.proxy.get(self.gpio.index, self.gpio.invert)

labgrid/remote/exporter.py

@@ -642,16 +642,19 @@ def _get_params(self):
         return {
             "host": self.host,
             "index": self.local.index,
+            "invert": self.local.invert,
         }
 
     def _get_start_params(self):
         return {
             "index": self.local.index,
+            "invert": self.local.invert,
         }
 
     def _start(self, start_params):
         """Start a GPIO export to userspace"""
         index = start_params["index"]
+        invert = start_params["invert"]  # pylint: disable=unused-variable
 
         if self.export_path.exists():
             self.system_exported = True

labgrid/resource/base.py

@@ -42,5 +42,7 @@ class SysfsGPIO(Resource):
     """The basic SysfsGPIO contains an index
 
     Args:
-        index (int): index of target gpio line."""
+        index (int): index of target gpio line.
+        invert (bool) : optional, whether the logic level is inverted (active-low)"""
     index = attr.ib(default=None, validator=attr.validators.instance_of(int))
+    invert = attr.ib(default=False,  validator=attr.validators.instance_of(bool))

labgrid/resource/remote.py

@@ -340,6 +340,7 @@ class NetworkSysfsGPIO(NetworkResource, ManagedResource):
 
     """The NetworkSysfsGPIO describes a remotely accessible gpio line"""
     index = attr.ib(validator=attr.validators.optional(attr.validators.instance_of(int)))
+    invert = attr.ib(default=False, validator=attr.validators.instance_of(bool))
     def __attrs_post_init__(self):
         self.timeout = 10.0
         super().__attrs_post_init__()

labgrid/resource/udev.py

@@ -778,8 +778,10 @@ class MatchedSysfsGPIO(USBResource):
     """The MatchedSysfsGPIO described a SysfsGPIO matched by Udev
 
     Args:
-        pin (int): gpio pin number within the matched gpiochip."""
+        pin (int): gpio pin number within the matched gpiochip.
+        invert (bool): optional, whether the logic level is inverted (active-low)"""
     pin = attr.ib(default=None, validator=attr.validators.instance_of(int))
+    invert = attr.ib(default=False, validator=attr.validators.instance_of(bool))
     index = None
 
     def __attrs_post_init__(self):

labgrid/util/agents/sysfsgpio.py

@@ -2,6 +2,7 @@
 This module implements switching GPIOs via sysfs GPIO kernel interface.
 
 Takes an integer property 'index' which refers to the already exported GPIO device.
+Takes a boolean property 'invert' which inverts logical values if set to True (active-low)
 
 """
 import logging
@@ -23,7 +24,7 @@ def _assert_gpio_line_is_exported(index):
         if not os.path.exists(gpio_sysfs_path):
             raise ValueError("Device not found")
 
-    def __init__(self, index):
+    def __init__(self, index, invert):
         self.gpio_sysfs_value_fd = None
         self._logger = logging.getLogger("Device: ")
         GpioDigitalOutput._assert_gpio_line_is_exported(index)
@@ -41,6 +42,10 @@ def __init__(self, index):
         gpio_sysfs_value_path = os.path.join(gpio_sysfs_path, 'value')
         self.gpio_sysfs_value_fd = os.open(gpio_sysfs_value_path, flags=(os.O_RDWR | os.O_SYNC))
 
+        gpio_sysfs_active_low_path = os.path.join(gpio_sysfs_path, 'active_low')
+        with open(gpio_sysfs_active_low_path, 'w') as active_low_fd:
+            active_low_fd.write(str(int(invert)))
+
     def __del__(self):
         if self.gpio_sysfs_value_fd:
             os.close(self.gpio_sysfs_value_fd)
@@ -68,24 +73,22 @@ def set(self, status):
 
         os.write(self.gpio_sysfs_value_fd, binary_value)
 
-
 _gpios = {}
 
-def _get_gpio_line(index):
+def _get_gpio_line(index, invert):
     if index not in _gpios:
-        _gpios[index] = GpioDigitalOutput(index=index)
+        _gpios[index] = GpioDigitalOutput(index=index, invert=invert)
     return _gpios[index]
 
-def handle_set(index, status):
-    gpio_line = _get_gpio_line(index)
+def handle_set(index, invert, status):
+    gpio_line = _get_gpio_line(index, invert)
     gpio_line.set(status)
 
 
-def handle_get(index):
-    gpio_line = _get_gpio_line(index)
+def handle_get(index, invert):
+    gpio_line = _get_gpio_line(index, invert)
     return gpio_line.get()
 
-
 methods = {
     'set': handle_set,
     'get': handle_get,

tests/test_sysfsgpioagent.py

@@ -36,11 +36,11 @@ def set(self, val):
             super().set(val)
 
     def test_instantiation(self):
-        gpio_line = TestGpioAgent.GpioDigitalOutputMock(index=13)
+        gpio_line = TestGpioAgent.GpioDigitalOutputMock(index=13, invert=False)
         assert isinstance(gpio_line, GpioDigitalOutput)
 
     def test_set(self):
-        gpio_line = TestGpioAgent.GpioDigitalOutputMock(index=13)
+        gpio_line = TestGpioAgent.GpioDigitalOutputMock(index=13, invert=False)
         for val in [True, False, True, False]:
             gpio_line.set(val)
             assert gpio_line.get() == val