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c1dca562be
This abstracts the "gadget serial" driver TTY glue into a separate component, cleaning it up and disentangling it from connection state. It also changed some behaviors for the better: - Stops using "experimental" major #127, and switches over to having the TTY layer allocate the dev_t numbers. - Provides /sys/class/tty/ttyGS* nodes, thus mdev/udev support. (Note "mdev" hotplug bug in Busybox v1.7.2: /dev/ttyGS0 will be a *block* device without CONFIG_SYSFS_DEPRECATED_V2.) - The tty nodes no longer reject opens when there's no host. Now they can support normal getty configs in /etc/inttab... - Now implements RX throttling. When the line discipline says it doesn't want any more data, only packets in flight will be delivered (currently, max 1K/8K at full/high speeds) until it unthrottles the data. - Supports low_latency. This is a good policy for all USB serial adapters, since it eliminates scheduler overhead on RX paths. This also includes much cleanup including better comments, fixing memory leaks and other bugs (including some locking fixes), messaging cleanup, and an interface audit and tightening. This added up to a significant object code shrinkage, on the order of 20% (!) depending on CPU and compiler. A separate patch actually kicks in this new code, using the functions declared in this new header, and removes the previous glue. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
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| Kconfig | ||
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| README | ||
| usb-skeleton.c | ||
To understand all the Linux-USB framework, you'll use these resources:
* This source code. This is necessarily an evolving work, and
includes kerneldoc that should help you get a current overview.
("make pdfdocs", and then look at "usb.pdf" for host side and
"gadget.pdf" for peripheral side.) Also, Documentation/usb has
more information.
* The USB 2.0 specification (from www.usb.org), with supplements
such as those for USB OTG and the various device classes.
The USB specification has a good overview chapter, and USB
peripherals conform to the widely known "Chapter 9".
* Chip specifications for USB controllers. Examples include
host controllers (on PCs, servers, and more); peripheral
controllers (in devices with Linux firmware, like printers or
cell phones); and hard-wired peripherals like Ethernet adapters.
* Specifications for other protocols implemented by USB peripheral
functions. Some are vendor-specific; others are vendor-neutral
but just standardized outside of the www.usb.org team.
Here is a list of what each subdirectory here is, and what is contained in
them.
core/ - This is for the core USB host code, including the
usbfs files and the hub class driver ("khubd").
host/ - This is for USB host controller drivers. This
includes UHCI, OHCI, EHCI, and others that might
be used with more specialized "embedded" systems.
gadget/ - This is for USB peripheral controller drivers and
the various gadget drivers which talk to them.
Individual USB driver directories. A new driver should be added to the
first subdirectory in the list below that it fits into.
image/ - This is for still image drivers, like scanners or
digital cameras.
../input/ - This is for any driver that uses the input subsystem,
like keyboard, mice, touchscreens, tablets, etc.
../media/ - This is for multimedia drivers, like video cameras,
radios, and any other drivers that talk to the v4l
subsystem.
../net/ - This is for network drivers.
serial/ - This is for USB to serial drivers.
storage/ - This is for USB mass-storage drivers.
class/ - This is for all USB device drivers that do not fit
into any of the above categories, and work for a range
of USB Class specified devices.
misc/ - This is for all USB device drivers that do not fit
into any of the above categories.