support/usb: enable/disable USB functions on power events

Re-create USB functions that are needed from target_on() and
uninstall all of them from target_off().

Closes: #214
Signed-off-by: Cedric Hombourger <[email protected]>

mtda/main.py

@@ -33,6 +33,7 @@
 import mtda.video.controller
 import mtda.utils
 from mtda import __version__
+from mtda.support.usb import Composite
 
 try:
     www_support = True
@@ -131,6 +132,33 @@ def command(self, args, session=None):
         self.mtda.debug(3, "main.command(): %s" % str(result))
         return result
 
+    def _composite_start(self):
+        self.mtda.debug(3, "main._composite_start()")
+
+        result = True
+        storage = self.storage_controller
+        if storage is not None and storage.variant == 'usbf':
+            status, _, _ = self.storage_status()
+            enabled = status == CONSTS.STORAGE.ON_TARGET
+            self.mtda.debug(3, "main._composite_start(): "
+                               "with storage? {}".format(enabled))
+            Composite.storage_toggle(enabled)
+            result = Composite.install()
+
+        self.mtda.debug(3, "main._composite_start(): {}".format(result))
+        return result
+
+    def _composite_stop(self):
+        self.mtda.debug(3, "main._composite_stop()")
+
+        result = None
+        storage = self.storage_controller
+        if storage is not None and storage.variant == 'usbf':
+            Composite.remove()
+
+        self.mtda.debug(3, "main._composite_stop(): {}".format(result))
+        return result
+
     def config_set_power_timeout(self, timeout, session=None):
         self.mtda.debug(3, "main.config_set_power_timeout()")
 
@@ -846,7 +874,14 @@ def _target_on(self, session=None):
 
         result = False
         if self.power_locked(session) is False:
-            result = self.power_controller.on()
+            # Toggle the mass storage functions of the usbf controller
+            result = self._composite_start()
+
+            # Turn the DUT on
+            if result is True:
+                result = self.power_controller.on()
+
+            # Resume logging
             if result is True:
                 if self.console_logger is not None:
                     self.console_logger.resume()
@@ -922,6 +957,7 @@ def _target_off(self, session=None):
         result = True
         if self.power_controller is not None:
             result = self.power_controller.off()
+        self._composite_stop()
         self._power_event(CONSTS.POWER.OFF)
 
         self.mtda.debug(3, "main._target_off(): {}".format(result))
@@ -1315,6 +1351,7 @@ def load_storage_config(self, parser):
             mod = importlib.import_module("mtda.storage." + variant)
             factory = getattr(mod, 'instantiate')
             self.storage_controller = factory(self)
+            self.storage_controller.variant = variant
             self._writer = AsyncImageWriter(self, self.storage_controller)
             # Configure the storage controller
             self.storage_controller.configure(dict(parser.items('storage')))

mtda/storage/usbf.py

@@ -80,7 +80,7 @@ def probe(self):
                                        "device!".format(self.device))
         if self.file is not None:
             if os.path.exists(self.file) is True:
-                result = Composite.install()
+                result = True
             else:
                 self.mtda.debug(1, "storage.usbf.probe(): "
                                    "{} not found!".format(self.file))

mtda/support/usb.py

@@ -27,15 +27,14 @@ class Composite:
     _storage = None
     _installed = False
 
-    functions = []
     path = "/sys/kernel/config/usb_gadget/" + product.lower().replace(" ", "_")
 
     def debug(level, msg):
         if Composite.mtda is not None:
             Composite.mtda.debug(level, msg)
 
     def configure(what, conf):
-        Composite.debug(3, "composite.configure()")
+        Composite.debug(3, "composite.configure('{}')".format(what))
 
         with Composite.lock:
             result = Composite._configure(what, conf)
@@ -45,18 +44,18 @@ def configure(what, conf):
 
     def _configure(what, conf):
         result = True
-        if what == 'console':
-            Composite.functions.append(Composite.console_function)
-        elif what == 'monitor':
-            Composite.functions.append(Composite.monitor_function)
-        elif what == 'keyboard':
-            Composite.functions.append(Composite.hid_function)
-        elif what == 'storage':
-            if 'file' in conf:
-                Composite._storage = conf['file']
-                Composite.functions.append(Composite.ms_function)
+        if what == 'storage' and 'file' in conf:
+            Composite._storage = conf['file']
+        if what in Composite.functions:
+            Composite.functions[what]['configured'] = True
+            Composite.functions[what]['enabled'] = True
+            Composite.debug(2, "composite.configure(): "
+                               "{} configured & enabled".format(what))
         else:
+            Composite.debug(1, "composite.configure(): "
+                               "not supported")
             result = False
+
         return result
 
     def _enable():
@@ -86,6 +85,18 @@ def _install():
 
         Composite._remove()
 
+        enabled = False
+        for function in Composite.functions.values():
+            if function['enabled'] is True:
+                enabled = True
+                break
+
+        if enabled is False:
+            # Nothing to install
+            Composite.debug(2, "composite.install(): "
+                               "no functions were enabled")
+            return True
+
         atexit.register(Composite.remove)
         path = Composite.path
         create_dirs(path)
@@ -106,13 +117,17 @@ def _install():
 
         Composite._create_functions()
 
-        if Composite._storage is not None:
+        if Composite.functions['storage']['enabled'] is True:
             lun = path + "/functions/mass_storage.usb0/lun.0/"
+            file = Composite._storage
             write(lun + "cdrom", "0")
             write(lun + "ro", "0")
             write(lun + "nofua", "0")
-            write(lun + "file", Composite._storage)
+            write(lun + "file", file)
+            Composite.debug(2, "composite.install(): "
+                               "storage device/file: {}".format(file))
         Composite._installed = Composite._enable()
+        return Composite._installed
 
     def remove():
         Composite.debug(3, "composite.remove()")
@@ -145,9 +160,12 @@ def _remove():
         Composite._installed = False
 
     def _create_functions():
-        functions = Composite.functions
-        for function in functions:
+        for function in Composite.functions.values():
             name = function['name']
+            if function['configured'] is False:
+                continue
+            if function['enabled'] is False:
+                continue
             Composite.debug(2, "composite._create_functions: "
                                "registering {}".format(name))
             path = Composite.path + "/functions/" + name
@@ -165,8 +183,15 @@ def _create_functions():
             if not os.path.exists(config):
                 os.symlink(path, config, True)
 
+    def storage_toggle(enabled):
+        with Composite.lock:
+            if Composite.functions['storage']['configured'] is True:
+                Composite.functions['storage']['enabled'] = enabled
+
     hid_function = {
         "name": "hid.usb0",
+        "configured": False,
+        "enabled": False,
         "protocol": "1",
         "subclass": "1",
         "report_length": "8",
@@ -207,15 +232,28 @@ def _create_functions():
     }
 
     console_function = {
-        "name": "acm.GS0"
+        "name": "acm.GS0",
+        "configured": False,
+        "enabled": False
     }
 
     monitor_function = {
-        "name": "acm.GS1"
+        "name": "acm.GS1",
+        "configured": False,
+        "enabled": False
     }
 
     ms_function = {
-        "name": "mass_storage.usb0"
+        "name": "mass_storage.usb0",
+        "configured": False,
+        "enabled": False
+    }
+
+    functions = {
+        "console": console_function,
+        "monitor": monitor_function,
+        "keyboard": hid_function,
+        "storage": ms_function
     }