Merge pull request #1339 from jeromebrunet/dev/matched

Resource: add udev based Sysfs GPIO support

Author: jluebbe

doc/configuration.rst

@@ -526,6 +526,48 @@ NetworkHIDRelay
 +++++++++++++++
 A :any:`NetworkHIDRelay` describes an `HIDRelay`_ exported over the network.
 
+SysfsGPIO
++++++++++
+
+A :any:`SysfsGPIO` resource describes a GPIO line.
+
+.. code-block:: yaml
+
+   SysfsGPIO:
+     index: 12
+
+Arguments:
+  - index (int): index of the GPIO line
+
+Used by:
+  - `GpioDigitalOutputDriver`_
+
+MatchedSysfsGpio
+++++++++++++++++
+A MatchedSysfsGpio resource describes a GPIO line, like a SysfsGPIO.
+The gpiochip is identified by matching udev properties. This allows
+identification through hot-plugging or rebooting for controllers like
+USB based gpiochips.
+
+.. code-block:: yaml
+
+   MatchedSysfsGpio:
+     match:
+       '@SUBSYSTEM': 'usb'
+       '@ID_SERIAL_SHORT': 'D38EJ8LF'
+     pin: 0
+
+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.
+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.
+
+Used by:
+  - `GpioDigitalOutputDriver`_
+
 NetworkService
 ~~~~~~~~~~~~~~
 A :any:`NetworkService` describes a remote SSH connection.
@@ -958,21 +1000,6 @@ Arguments:
 Used by:
   - `USBVideoDriver`_
 
-SysfsGPIO
-~~~~~~~~~
-A :any:`SysfsGPIO` resource describes a GPIO line.
-
-.. code-block:: yaml
-
-   SysfsGPIO:
-     index: 12
-
-Arguments:
-  - index (int): index of the GPIO line
-
-Used by:
-  - `GpioDigitalOutputDriver`_
-
 NetworkUSBVideo
 ~~~~~~~~~~~~~~~
 A :any:`NetworkUSBVideo` resource describes a `USBVideo`_ resource available
@@ -2142,6 +2169,7 @@ While the driver automatically exports the GPIO, it does not configure it in any
 Binds to:
   gpio:
     - `SysfsGPIO`_
+    - `MatchedSysfsGPIO`_
     - NetworkSysfsGPIO
 
 Implements:

labgrid/remote/exporter.py

@@ -579,11 +579,13 @@ class GPIOSysFSExport(ResourceExport):
 
     def __attrs_post_init__(self):
         super().__attrs_post_init__()
-        local_cls_name = self.cls
-        self.data['cls'] = f"Network{self.cls}"
-        from ..resource import base
-        local_cls = getattr(base, local_cls_name)
-        self.local = local_cls(target=None, name=None, **self.local_params)
+        if self.cls == "SysfsGPIO":
+            from ..resource.base import SysfsGPIO
+            self.local = SysfsGPIO(target=None, name=None, **self.local_params)
+        elif self.cls == "MatchedSysfsGPIO":
+            from ..resource.udev import MatchedSysfsGPIO
+            self.local = MatchedSysfsGPIO(target=None, name=None, **self.local_params)
+        self.data['cls'] = "NetworkSysfsGPIO"
         self.export_path = Path(GPIOSysFSExport._gpio_sysfs_path_prefix,
                                 f'gpio{self.local.index}')
         self.system_exported = False
@@ -624,6 +626,7 @@ def _stop(self, start_params):
             unexport.write(str(index).encode('utf-8'))
 
 exports["SysfsGPIO"] = GPIOSysFSExport
+exports["MatchedSysfsGPIO"] = GPIOSysFSExport
 
 
 @attr.s

labgrid/resource/__init__.py

@@ -15,6 +15,7 @@
     HIDRelay,
     IMXUSBLoader,
     LXAUSBMux,
+    MatchedSysfsGPIO,
     MXSUSBLoader,
     RKUSBLoader,
     SiSPMPowerPort,

labgrid/resource/suggest.py

@@ -23,6 +23,7 @@
     HIDRelay,
     USBDebugger,
     USBPowerPort,
+    MatchedSysfsGPIO
 )
 from ..util import dump
 
@@ -56,6 +57,7 @@ def __init__(self, args):
         self.resources.append(HIDRelay(**args))
         self.resources.append(USBDebugger(**args))
         self.resources.append(USBPowerPort(**args, index=0))
+        self.resources.append(MatchedSysfsGPIO(**args, pin=0))
 
     def suggest_callback(self, resource, meta, suggestions):
         cls = type(resource).__name__
@@ -84,6 +86,8 @@ def suggest_callback(self, resource, meta, suggestions):
             ))
             if cls == 'USBPowerPort':
                 print('    index: ?')
+            if cls == 'MatchedSysfsGPIO':
+                print('    pin: ?')
         print("  ---")
         print()
 

labgrid/resource/udev.py

@@ -718,3 +718,32 @@ def filter_match(self, device):
             return False
 
         return super().filter_match(device)
+
+@target_factory.reg_resource
+@attr.s(eq=False)
+class MatchedSysfsGPIO(USBResource):
+    """The MatchedSysfsGPIO described a SysfsGPIO matched by Udev
+
+    Args:
+        pin (int): gpio pin number within the matched gpiochip."""
+    pin = attr.ib(default=None, validator=attr.validators.instance_of(int))
+    index = None
+
+    def __attrs_post_init__(self):
+        self.match['SUBSYSTEM'] = 'gpio'
+        super().__attrs_post_init__()
+
+    def filter_match(self, device):
+        # Filter out the char device
+        if device.properties.get('DEVNAME') is not None:
+            return False
+        return super().filter_match(device)
+
+    def update(self):
+        super().update()
+        if self.device is not None:
+            if self.pin >= int(self.read_attr('ngpio')):
+                raise ValueError("MatchedSysfsGPIO pin out of bound")
+            self.index = int(self.read_attr('base')) + self.pin
+        else:
+            self.index = None