USB Raw Gadget is a kernel module that provides a userspace interface for
the USB Gadget subsystem. Essentially it allows to emulate USB devices
from userspace. Enabled with CONFIG_USB_RAW_GADGET. Raw Gadget is
currently a strictly debugging feature and shouldn't be used in
production.

Raw Gadget is similar to GadgetFS, but provides a more low-level and
direct access to the USB Gadget layer for the userspace. The key
differences are:

1. Every USB request is passed to the userspace to get a response, while
   GadgetFS responds to some USB requests internally based on the provided
   descriptors. However note, that the UDC driver might respond to some
   requests on its own and never forward them to the Gadget layer.

2. GadgetFS performs some sanity checks on the provided USB descriptors,
   while Raw Gadget allows you to provide arbitrary data as responses to
   USB requests.

3. Raw Gadget provides a way to select a UDC device/driver to bind to,
   while GadgetFS currently binds to the first available UDC.

4. Raw Gadget uses predictable endpoint names (handles) across different
   UDCs (as long as UDCs have enough endpoints of each required transfer
   type).

5. Raw Gadget has ioctl-based interface instead of a filesystem-based one.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

It seems that some files were removed from USB documentation.

Update the links accordingly.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/00008303fde6b4e06d027d3b76ae7032614a7030.1580193653.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The Rio500 kernel driver has not been used by Rio500 owners since 2001
not long after the rio500 project added support for a user-space USB stack
through the very first versions of usbdevfs and then libusb.

Support for the kernel driver was removed from the upstream utilities
in 2008:
https://gitlab.freedesktop.org/hadess/rio500/commit/943f624ab721eb8281c287650fcc9e2026f6f5db

Cc: Cesar Miquel <miquel@df.uba.ar>
Signed-off-by: Bastien Nocera <hadess@hadess.net>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/6251c17584d220472ce882a3d9c199c401a51a71.camel@hadess.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The UWB and wusbcore code is long obsolete, so let us just move the code
out of the real part of the kernel and into the drivers/staging/
location with plans to remove it entirely in a few releases.

Link: https://lore.kernel.org/r/20190806101509.GA11280@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

While there are a mix of things here, most of the stuff
were written from Kernel developer's PoV. So, add them to
the driver-api book.

A follow up for this patch would be to move documents from
there that are specific to sysadmins, adding them to the
admin-guide.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Added the newly added limit and updated the text a bit

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Convert USB documents to ReST, in order to prepare for adding it
to the kernel API book, as most of the stuff there are driver or
subsystem-related.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

On Chrome OS we want to use USBguard to potentially limit access to USB
devices based on policy. We however to do not want to wait for userspace to
come up before initializing fixed USB devices to not regress our boot
times.

This patch adds option to instruct the kernel to only authorize devices
connected to the internal ports. Previously we could either authorize
all or none (or, by default, we'd only authorize wired devices).

The behavior is controlled via usbcore.authorized_default command line
option.

Signed-off-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix small typo authroized -> authorized in the authorization page.

Signed-off-by: Thiébaud Weksteen <tweek@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Johan writes:

USB-serial updates for v4.19-rc1

Here are the USB-serial updates for 4.19-rc1, including:

 - gpio support for CP2102N devices
 - improved line-speed handling for cp210x
 - conversion to spin_lock_irqsave() in completion handlers
 - dropped kl5kusb105 support from the kl5kusb105 driver (sic!)

Included are also various lower-priority fixes and clean ups.

All but the final commit have been in linux-next, and with no reported
issues.

Signed-off-by: Johan Hovold <johan@kernel.org>