+from typing import Sequence
+from pathlib import Path
+import atexit
+
+# https://www.kernel.org/doc/Documentation/usb/gadget_configfs.txt
+
+gadget_root = '/sys/kernel/config/usb_gadget/adafruit-blinka'
+
+
+class Device():
+ def __init__(self, *, descriptor: bytes, usage_page: int, usage: int, report_ids: Sequence[int],
+ in_report_lengths: Sequence[int], out_report_lengths: Sequence[int]) -> None:
+ self.out_report_lengths = out_report_lengths
+ self.in_report_lengths = in_report_lengths
+ self.report_ids = report_ids
+ self.usage = usage
+ self.usage_page = usage_page
+ self.descriptor = descriptor
+ self.handle = ''
+
+ def send_report(self, report: bytearray, report_id: int = None):
+ device = Path('%s/functions/hid.usb%s/dev' % (gadget_root, report_id or self.report_ids[0])).read_text().strip().split(':')[1]
+ with open('/dev/hidg%s' % device, 'rb+') as fd:
+ fd.write(report)
+
+
+Device.KEYBOARD = Device(
+ descriptor=bytes((
+ 0x05, 0x01, 0x09, 0x06, 0xa1, 0x01, 0x05, 0x07, 0x19, 0xe0, 0x29, 0xe7, 0x15, 0x00, 0x25, 0x01, 0x75, 0x01, 0x95, 0x08, 0x81, 0x02, 0x75, 0x08, 0x95, 0x01, 0x81, 0x01, 0x75, 0x01, 0x95, 0x03, 0x05, 0x08, 0x19, 0x01, 0x29, 0x03, 0x91, 0x02, 0x75, 0x01, 0x95, 0x05, 0x91, 0x01, 0x75, 0x08, 0x95, 0x06, 0x15, 0x00, 0x26, 0xff, 0x00, 0x05, 0x07, 0x19, 0x00, 0x2a, 0xff, 0x00, 0x81, 0x00, 0xc0
+ )),
+ usage_page=0x1,
+ usage=0x6,
+ report_ids=[1],
+ in_report_lengths=[8],
+ out_report_lengths=[1]
+)
+Device.MOUSE = Device(
+ descriptor=b"05010906a101050719e029e71500250175019508810275089501810175019503050819012903910275019505910175089506150026ff00050719002aff008100c0",
+ # Omitted for brevity.
+ usage_page=0x1,
+ usage=0x02,
+ report_ids=[2],
+ in_report_lengths=[8],
+ out_report_lengths=[1],
+)
+
+Device.CONSUMER_CONTROL = Device(
+ descriptor=b"05010906a101050719e029e71500250175019508810275089501810175019503050819012903910275019505910175089506150026ff00050719002aff008100c0",
+ # Omitted for brevity.
+ usage_page=0x0C,
+ usage=0x01,
+ report_ids=[3],
+ in_report_lengths=[1],
+ out_report_lengths=[8],
+)
+devices = [Device.KEYBOARD, Device.MOUSE, Device.CONSUMER_CONTROL]
+
+
+def disable() -> None:
+ try:
+ Path('%s/UDC' % gadget_root).write_text('')
+ except FileNotFoundError:
+ pass
+ for symlink in Path(gadget_root).glob('configs/**/hid.usb*'):
+ symlink.unlink()
+
+ for strings_file in Path(gadget_root).rglob('configs/*/strings/*/*'):
+ if strings_file.is_dir():
+ strings_file.rmdir()
+
+ for strings_file in Path(gadget_root).rglob('configs/*/strings/*'):
+ if strings_file.is_dir():
+ strings_file.rmdir()
+ for config_dir in Path(gadget_root).rglob('configs/*'):
+ if config_dir.is_dir():
+ config_dir.rmdir()
+ for function_dir in Path(gadget_root).rglob('functions/*'):
+ if function_dir.is_dir():
+ function_dir.rmdir()
+ try:
+ Path(gadget_root).rmdir()
+ except:
+ pass
+atexit.register(disable)
+
+def enable(devices: Sequence[Device], boot_device: int = 0) -> None:
+ if len(devices) == 0:
+ disable()
+ return
+ """
+ 1. Creating the gadgets
+ -----------------------
+
+ For each gadget to be created its corresponding directory must be created::
+
+ $ mkdir $CONFIGFS_HOME/usb_gadget/<gadget name>
+
+ e.g.::
+
+ $ mkdir $CONFIGFS_HOME/usb_gadget/g1
+
+ ...
+ ...
+ ...
+
+ $ cd $CONFIGFS_HOME/usb_gadget/g1
+
+ Each gadget needs to have its vendor id <VID> and product id <PID> specified::
+
+ $ echo <VID> > idVendor
+ $ echo <PID> > idProduct
+
+ A gadget also needs its serial number, manufacturer and product strings.
+ In order to have a place to store them, a strings subdirectory must be created
+ for each language, e.g.::
+
+ $ mkdir strings/0x409
+
+ Then the strings can be specified::
+
+ $ echo <serial number> > strings/0x409/serialnumber
+ $ echo <manufacturer> > strings/0x409/manufacturer
+ $ echo <product> > strings/0x409/product
+ """
+ Path('%s/functions' % gadget_root).mkdir(parents=True, exist_ok=True)
+ Path('%s/configs' % gadget_root).mkdir(parents=True, exist_ok=True)
+ Path('%s/bcdDevice' % gadget_root).write_text('%s' % 1) # Version 1.0.0
+ Path('%s/bcdUSB' % gadget_root).write_text('%s' % 0x0200) # USB 2.0
+ Path('%s/bDeviceClass' % gadget_root).write_text('%s' % 0xEF) # multipurpose i guess?
+ Path('%s/bDeviceProtocol' % gadget_root).write_text('%s' % 0x01)
+ Path('%s/bDeviceSubClass' % gadget_root).write_text('%s' % 0x02)
+ Path('%s/bMaxPacketSize0' % gadget_root).write_text('%s' % 0x08)
+ Path('%s/idProduct' % gadget_root).write_text('%s' % 0x0104) # Multifunction Composite Gadget
+ Path('%s/idVendor' % gadget_root).write_text('%s' % 0x1d6b) # Linux Foundation
+ """
+ 2. Creating the configurations
+ ------------------------------
+
+ Each gadget will consist of a number of configurations, their corresponding
+ directories must be created:
+
+ $ mkdir configs/<name>.<number>
+
+ where <name> can be any string which is legal in a filesystem and the
+ <number> is the configuration's number, e.g.::
+
+ $ mkdir configs/c.1
+
+ ...
+ ...
+ ...
+
+ Each configuration also needs its strings, so a subdirectory must be created
+ for each language, e.g.::
+
+ $ mkdir configs/c.1/strings/0x409
+
+ Then the configuration string can be specified::
+
+ $ echo <configuration> > configs/c.1/strings/0x409/configuration
+
+ Some attributes can also be set for a configuration, e.g.::
+
+ $ echo 120 > configs/c.1/MaxPower
+ """
+
+ for i, device in enumerate(devices):
+ config_root = '%s/configs/device.%s' % (gadget_root, i + 1)
+ Path('%s/' % config_root).mkdir(parents=True, exist_ok=True)
+ Path('%s/strings/0x409' % config_root).mkdir(parents=True, exist_ok=True)
+ Path('%s/strings/0x409/configuration' % config_root).write_text('my configuration')
+ Path('%s/MaxPower' % config_root).write_text('150')
+ Path('%s/bmAttributes' % config_root).write_text('%s' % 0x080)
+
+ """
+ 3. Creating the functions
+ -------------------------
+
+ The gadget will provide some functions, for each function its corresponding
+ directory must be created::
+
+ $ mkdir functions/<name>.<instance name>
+
+ where <name> corresponds to one of allowed function names and instance name
+ is an arbitrary string allowed in a filesystem, e.g.::
+
+ $ mkdir functions/ncm.usb0 # usb_f_ncm.ko gets loaded with request_module()
+
+ ...
+ ...
+ ...
+
+ Each function provides its specific set of attributes, with either read-only
+ or read-write access. Where applicable they need to be written to as
+ appropriate.
+ Please refer to Documentation/ABI/*/configfs-usb-gadget* for more information.
+
+ """
+
+ # create functions
+ for report_index, report_id in enumerate(device.report_ids):
+ function_root = '%s/functions/hid.usb%s' % (gadget_root, report_id)
+ try:
+ Path('%s/' % function_root).mkdir(parents=True)
+ except FileExistsError:
+ continue
+ Path('%s/protocol' % function_root).write_text('%s' % 1)
+ Path('%s/report_length' % function_root).write_text('%s' % device.in_report_lengths[report_index])
+ Path('%s/subclass' % function_root).write_text('%s' % 1)
+ Path('%s/report_desc' % function_root).write_bytes(device.descriptor)
+ """
+ 4. Associating the functions with their configurations
+ ------------------------------------------------------
+
+ At this moment a number of gadgets is created, each of which has a number of
+ configurations specified and a number of functions available. What remains
+ is specifying which function is available in which configuration (the same
+ function can be used in multiple configurations). This is achieved with
+ creating symbolic links::
+
+ $ ln -s functions/<name>.<instance name> configs/<name>.<number>
+
+ e.g.::
+
+ $ ln -s functions/ncm.usb0 configs/c.1
+ """
+
+ Path('%s/hid.usb%s' % (config_root, report_id)).symlink_to(function_root)
+ """
+ 5. Enabling the gadget
+ ----------------------
+ Such a gadget must be finally enabled so that the USB host can enumerate it.
+
+ In order to enable the gadget it must be bound to a UDC (USB Device
+ Controller)::
+
+ $ echo <udc name> > UDC
+
+ where <udc name> is one of those found in /sys/class/udc/*
+ e.g.::
+
+ $ echo s3c-hsotg > UDC
+
+ """
+ udc = next(Path('/sys/class/udc/').glob('*'))
+ Path('%s/UDC' % gadget_root).write_text('%s' % udc.name)
projects / Adafruit_Blinka-hackapet.git / blobdiff