+# SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
"""
`usb_hid` - support for usb hid devices via usb_gadget driver
===========================================================
See `CircuitPython:usb_hid` in CircuitPython for more details.
For now using report ids in the descriptor
+# regarding usb_gadget see https://www.kernel.org/doc/Documentation/usb/gadget_configfs.txt
* Author(s): Björn Bösel
"""
from pathlib import Path
import os
import atexit
+import sys
-# https://www.kernel.org/doc/Documentation/usb/gadget_configfs.txt
+for module in ["dwc2", "libcomposite"]:
+ if Path("/proc/modules").read_text(encoding="utf-8").find(module) == -1:
+ raise Exception(
+ "%s module not present in your kernel. did you insmod it?" % module
+ )
+this = sys.modules[__name__]
-gadget_root = "/sys/kernel/config/usb_gadget/adafruit-blinka"
+this.gadget_root = "/sys/kernel/config/usb_gadget/adafruit-blinka"
+this.boot_device = 0
+this.devices = []
class Device:
- """HID Device specification: see https://github.com/adafruit/circuitpython/blob/main/shared-bindings/usb_hid/Device.c"""
+ """
+ HID Device specification: see
+ https://github.com/adafruit/circuitpython/blob/main/shared-bindings/usb_hid/Device.c
+ """
def __init__(
self,
self._last_received_report = None
def send_report(self, report: bytearray, report_id: int = None):
- device_path = self.gets_device_path(report_id)
+ """Send an HID report. If the device descriptor specifies zero or one report id's,
+ you can supply `None` (the default) as the value of ``report_id``.
+ Otherwise you must specify which report id to use when sending the report.
+ """
+ report_id = report_id or self.report_ids[0]
+ device_path = self.get_device_path(report_id)
with open(device_path, "rb+") as fd:
- fd.write(bytearray(report_id) + report)
+ if report_id > 0:
+ report = bytearray(report_id.to_bytes(1, "big")) + report
+ fd.write(report)
@property
def last_received_report(
self,
- ):
- device_path = self.gets_device_path(self.report_ids[0])
+ ) -> bytes:
+ """The HID OUT report as a `bytes` (read-only). `None` if nothing received.
+ Same as `get_last_received_report()` with no argument.
+
+ Deprecated: will be removed in CircutPython 8.0.0. Use `get_last_received_report()` instead.
+ """
+ return self.get_last_received_report()
+
+ def get_last_received_report(self, report_id=None) -> bytes:
+ """Get the last received HID OUT or feature report for the given report ID.
+ The report ID may be omitted if there is no report ID, or only one report ID.
+ Return `None` if nothing received.
+ """
+ device_path = self.get_device_path(report_id or self.report_ids[0])
with open(device_path, "rb+") as fd:
os.set_blocking(fd.fileno(), False)
report = fd.read(self.out_report_lengths[0])
self._last_received_report = report
return self._last_received_report
- def gets_device_path(self, report_id):
+ def get_device_path(self, report_id):
+ """
+ translates the /dev/hidg device from the report id
+ """
device = (
Path(
"%s/functions/hid.usb%s/dev"
- % (gadget_root, report_id or self.report_ids[0])
+ % (this.gadget_root, report_id or self.report_ids[0])
)
- .read_text()
+ .read_text(encoding="utf-8")
.strip()
.split(":")[1]
)
device_path = "/dev/hidg%s" % device
return device_path
+ KEYBOARD = None
+ MOUSE = None
+ CONSUMER_CONTROL = None
+
Device.KEYBOARD = Device(
descriptor=bytes(
0x29,
0x05, # usage maximum (kana)
0x91,
- 0x02, # output (data,var,abs,no wrap,linear,preferred state,no null position,non-volatile)
+ 0x02, # output
+ # (data,var,abs,no wrap,linear,preferred state,no null position,non-volatile)
0x95,
0x01, # report count (1)
0x75,
0x05, # report size (5)
0x91,
- 0x01, # output (const,array,abs,no wrap,linear,preferred state,no null position,non-volatile)
+ 0x01, # output
+ # (const,array,abs,no wrap,linear,preferred state,no null position,non-volatile)
0x95,
0x06, # report count (6)
0x75,
0xC0, # End Collection
)
),
- # Omitted for brevity.
usage_page=0x1,
usage=0x02,
- report_ids=[2],
+ report_ids=[0x02],
in_report_lengths=[4],
out_report_lengths=[0],
)
0xC0, # End Collection
)
),
- # Omitted for brevity.
usage_page=0x0C,
usage=0x01,
report_ids=[3],
in_report_lengths=[2],
out_report_lengths=[0],
)
-devices = [Device.KEYBOARD, Device.MOUSE, Device.CONSUMER_CONTROL]
+
+Device.BOOT_KEYBOARD = Device(
+ descriptor=bytes(
+ (
+ 0x05,
+ 0x01, # usage page (generic desktop ctrls)
+ 0x09,
+ 0x06, # usage (keyboard)
+ 0xA1,
+ 0x01, # collection (application)
+ 0x05,
+ 0x07, # usage page (kbrd/keypad)
+ 0x19,
+ 0xE0, # usage minimum (0xe0)
+ 0x29,
+ 0xE7, # usage maximum (0xe7)
+ 0x15,
+ 0x00, # logical minimum (0)
+ 0x25,
+ 0x01, # logical maximum (1)
+ 0x75,
+ 0x01, # report size (1)
+ 0x95,
+ 0x08, # report count (8)
+ 0x81,
+ 0x02, # input (data,var,abs,no wrap,linear,preferred state,no null position)
+ 0x95,
+ 0x01, # report count (1)
+ 0x75,
+ 0x08, # report size (8)
+ 0x81,
+ 0x01, # input (const,array,abs,no wrap,linear,preferred state,no null position)
+ 0x95,
+ 0x03, # report count (3)
+ 0x75,
+ 0x01, # report size (1)
+ 0x05,
+ 0x08, # usage page (leds)
+ 0x19,
+ 0x01, # usage minimum (num lock)
+ 0x29,
+ 0x05, # usage maximum (kana)
+ 0x91,
+ 0x02, # output
+ # (data,var,abs,no wrap,linear,preferred state,no null position,non-volatile)
+ 0x95,
+ 0x01, # report count (1)
+ 0x75,
+ 0x05, # report size (5)
+ 0x91,
+ 0x01, # output
+ # (const,array,abs,no wrap,linear,preferred state,no null position,non-volatile)
+ 0x95,
+ 0x06, # report count (6)
+ 0x75,
+ 0x08, # report size (8)
+ 0x15,
+ 0x00, # logical minimum (0)
+ 0x26,
+ 0xFF,
+ 0x00, # logical maximum (255)
+ 0x05,
+ 0x07, # usage page (kbrd/keypad)
+ 0x19,
+ 0x00, # usage minimum (0x00)
+ 0x2A,
+ 0xFF,
+ 0x00, # usage maximum (0xff)
+ 0x81,
+ 0x00, # input (data,array,abs,no wrap,linear,preferred state,no null position)
+ 0xC0, # end collection
+ )
+ ),
+ usage_page=0x1,
+ usage=0x6,
+ report_ids=[0x0],
+ in_report_lengths=[8],
+ out_report_lengths=[1],
+)
+Device.BOOT_MOUSE = Device(
+ descriptor=bytes(
+ (
+ 0x05,
+ 0x01, # Usage Page (Generic Desktop Ctrls)
+ 0x09,
+ 0x02, # Usage (Mouse)
+ 0xA1,
+ 0x01, # Collection (Application)
+ 0x09,
+ 0x01, # Usage (Pointer)
+ 0xA1,
+ 0x00, # Collection (Physical)
+ 0x05,
+ 0x09, # Usage Page (Button)
+ 0x19,
+ 0x01, # Usage Minimum (0x01)
+ 0x29,
+ 0x05, # Usage Maximum (0x05)
+ 0x15,
+ 0x00, # Logical Minimum (0)
+ 0x25,
+ 0x01, # Logical Maximum (1)
+ 0x95,
+ 0x05, # Report Count (5)
+ 0x75,
+ 0x01, # Report Size (1)
+ 0x81,
+ 0x02, # Input (Data,Var,Abs,No Wrap,Linear,Preferred State,No Null Position)
+ 0x95,
+ 0x01, # Report Count (1)
+ 0x75,
+ 0x03, # Report Size (3)
+ 0x81,
+ 0x01, # Input (Const,Array,Abs,No Wrap,Linear,Preferred State,No Null Position)
+ 0x05,
+ 0x01, # Usage Page (Generic Desktop Ctrls)
+ 0x09,
+ 0x30, # Usage (X)
+ 0x09,
+ 0x31, # Usage (Y)
+ 0x15,
+ 0x81, # Logical Minimum (-127)
+ 0x25,
+ 0x7F, # Logical Maximum (127)
+ 0x75,
+ 0x08, # Report Size (8)
+ 0x95,
+ 0x02, # Report Count (2)
+ 0x81,
+ 0x06, # Input (Data,Var,Rel,No Wrap,Linear,Preferred State,No Null Position)
+ 0x09,
+ 0x38, # Usage (Wheel)
+ 0x15,
+ 0x81, # Logical Minimum (-127)
+ 0x25,
+ 0x7F, # Logical Maximum (127)
+ 0x75,
+ 0x08, # Report Size (8)
+ 0x95,
+ 0x01, # Report Count (1)
+ 0x81,
+ 0x06, # Input (Data,Var,Rel,No Wrap,Linear,Preferred State,No Null Position)
+ 0xC0, # End Collection
+ 0xC0, # End Collection
+ )
+ ),
+ usage_page=0x1,
+ usage=0x02,
+ report_ids=[0],
+ in_report_lengths=[4],
+ out_report_lengths=[0],
+)
def disable() -> None:
+ """Do not present any USB HID devices to the host computer.
+ Can be called in ``boot.py``, before USB is connected.
+ The HID composite device is normally enabled by default,
+ but on some boards with limited endpoints, including STM32F4,
+ it is disabled by default. You must turn off another USB device such
+ as `usb_cdc` or `storage` to free up endpoints for use by `usb_hid`.
+ """
try:
- Path("%s/UDC" % gadget_root).write_text("")
+ Path("%s/UDC" % this.gadget_root).write_text("", encoding="utf-8")
except FileNotFoundError:
pass
- for symlink in Path(gadget_root).glob("configs/**/hid.usb*"):
+ for symlink in Path(this.gadget_root).glob("configs/**/hid.usb*"):
symlink.unlink()
- for strings_file in Path(gadget_root).rglob("configs/*/strings/*/*"):
+ for strings_file in Path(this.gadget_root).rglob("configs/*/strings/*/*"):
if strings_file.is_dir():
strings_file.rmdir()
- for strings_file in Path(gadget_root).rglob("configs/*/strings/*"):
+ for strings_file in Path(this.gadget_root).rglob("configs/*/strings/*"):
if strings_file.is_dir():
strings_file.rmdir()
- for config_dir in Path(gadget_root).rglob("configs/*"):
+ for config_dir in Path(this.gadget_root).rglob("configs/*"):
if config_dir.is_dir():
config_dir.rmdir()
- for function_dir in Path(gadget_root).rglob("functions/*"):
+ for function_dir in Path(this.gadget_root).rglob("functions/*"):
if function_dir.is_dir():
function_dir.rmdir()
try:
- Path(gadget_root).rmdir()
- except:
+ Path(this.gadget_root).rmdir()
+ except FileNotFoundError:
pass
+ this.devices = []
-# atexit.register(disable)
-
+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::
+def enable(requested_devices: Sequence[Device], boot_device: int = 0) -> None:
+ """Specify which USB HID devices that will be available.
+ Can be called in ``boot.py``, before USB is connected.
- $ mkdir $CONFIGFS_HOME/usb_gadget/<gadget name>
+ :param Sequence devices: `Device` objects.
+ If `devices` is empty, HID is disabled. The order of the ``Devices``
+ may matter to the host. For instance, for MacOS, put the mouse device
+ before any Gamepad or Digitizer HID device or else it will not work.
+ :param int boot_device: If non-zero, inform the host that support for a
+ a boot HID device is available.
+ If ``boot_device=1``, a boot keyboard is available.
+ If ``boot_device=2``, a boot mouse is available. No other values are allowed.
+ See below.
- e.g.::
+ If you enable too many devices at once, you will run out of USB endpoints.
+ The number of available endpoints varies by microcontroller.
+ CircuitPython will go into safe mode after running ``boot.py`` to inform you if
+ not enough endpoints are available.
- $ mkdir $CONFIGFS_HOME/usb_gadget/g1
+ **Boot Devices**
- ...
- ...
- ...
+ Boot devices implement a fixed, predefined report descriptor, defined in
+ https://www.usb.org/sites/default/files/hid1_12.pdf, Appendix B. A USB host
+ can request to use the boot device if the USB device says it is available.
+ Usually only a BIOS or other kind of limited-functionality
+ host needs boot keyboard support.
- $ cd $CONFIGFS_HOME/usb_gadget/g1
+ For example, to make a boot keyboard available, you can use this code::
- Each gadget needs to have its vendor id <VID> and product id <PID> specified::
+ usb_hid.enable((Device.KEYBOARD), boot_device=1) # 1 for a keyboard
- $ echo <VID> > idVendor
- $ echo <PID> > idProduct
+ If the host requests the boot keyboard, the report descriptor provided by `Device.KEYBOARD`
+ will be ignored, and the predefined report descriptor will be used.
+ But if the host does not request the boot keyboard,
+ the descriptor provided by `Device.KEYBOARD` will be used.
- 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
+ The HID boot device must usually be the first or only device presented by CircuitPython.
+ The HID device will be USB interface number 0.
+ To make sure it is the first device, disable other USB devices, including CDC and MSC
+ (CIRCUITPY).
+ If you specify a non-zero ``boot_device``, and it is not the first device, CircuitPython
+ will enter safe mode to report this error.
+ """
+ this.boot_device = boot_device
- Then the strings can be specified::
+ if len(requested_devices) == 0:
+ disable()
+ return
- $ 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" % 0x00
+ if boot_device == 1:
+ requested_devices = [Device.BOOT_KEYBOARD]
+ if boot_device == 2:
+ requested_devices = [Device.BOOT_MOUSE]
+
+ # """
+ # 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" % this.gadget_root).mkdir(parents=True, exist_ok=True)
+ Path("%s/configs" % this.gadget_root).mkdir(parents=True, exist_ok=True)
+ Path("%s/bcdDevice" % this.gadget_root).write_text(
+ "%s" % 1, encoding="utf-8"
+ ) # Version 1.0.0
+ Path("%s/bcdUSB" % this.gadget_root).write_text(
+ "%s" % 0x0200, encoding="utf-8"
+ ) # USB 2.0
+ Path("%s/bDeviceClass" % this.gadget_root).write_text(
+ "%s" % 0x00, encoding="utf-8"
) # multipurpose i guess?
- Path("%s/bDeviceProtocol" % gadget_root).write_text("%s" % 0x00)
- Path("%s/bDeviceSubClass" % gadget_root).write_text("%s" % 0x00)
- Path("%s/bMaxPacketSize0" % gadget_root).write_text("%s" % 0x08)
- Path("%s/idProduct" % gadget_root).write_text(
- "%s" % 0x0104
+ Path("%s/bDeviceProtocol" % this.gadget_root).write_text(
+ "%s" % 0x00, encoding="utf-8"
+ )
+ Path("%s/bDeviceSubClass" % this.gadget_root).write_text(
+ "%s" % 0x00, encoding="utf-8"
+ )
+ Path("%s/bMaxPacketSize0" % this.gadget_root).write_text(
+ "%s" % 0x08, encoding="utf-8"
+ )
+ Path("%s/idProduct" % this.gadget_root).write_text(
+ "%s" % 0x0104, encoding="utf-8"
) # 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, 1)
+ Path("%s/idVendor" % this.gadget_root).write_text(
+ "%s" % 0x1D6B, encoding="utf-8"
+ ) # 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 device in requested_devices:
+ config_root = "%s/configs/device.1" % this.gadget_root
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"
+ "my configuration", encoding="utf-8"
)
- 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
+ Path("%s/MaxPower" % config_root).write_text("150", encoding="utf-8")
+ Path("%s/bmAttributes" % config_root).write_text("%s" % 0x080, encoding="utf-8")
+ this.devices.append(device)
+ # """
+ # 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. """
for report_index, report_id in enumerate(device.report_ids):
- function_root = "%s/functions/hid.usb%s" % (gadget_root, report_id)
+ function_root = "%s/functions/hid.usb%s" % (this.gadget_root, report_id)
try:
Path("%s/" % function_root).mkdir(parents=True)
except FileExistsError:
continue
- Path("%s/protocol" % function_root).write_text("%s" % report_id)
+ Path("%s/protocol" % function_root).write_text(
+ "%s" % report_id, encoding="utf-8"
+ )
Path("%s/report_length" % function_root).write_text(
- "%s" % device.in_report_lengths[report_index]
+ "%s" % device.in_report_lengths[report_index], encoding="utf-8"
)
- Path("%s/subclass" % function_root).write_text("%s" % 1)
+ Path("%s/subclass" % function_root).write_text("%s" % 1, encoding="utf-8")
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
-
- """
+ # """
+ # 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 """
+ try:
+ Path("%s/hid.usb%s" % (config_root, report_id)).symlink_to(
+ function_root
+ )
+ except FileNotFoundError:
+ pass
+ # """ 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)
+ Path("%s/UDC" % this.gadget_root).write_text("%s" % udc.name, encoding="utf-8")
projects / Adafruit_Blinka-hackapet.git / blobdiff