mirror of
https://github.com/hardkernel/linux.git
synced 2026-04-13 00:50:39 +09:00
e1b26377c7
This patch create host_testmode file in debugfs for USB HOST. It's useful for us to use a scope to verify signal integrity for USB2/USB3 HOST. For example, set testmodes for rk3328 board USB: 1. set test packet for the USB2 port of USB3 interface: echo test_packet > /sys/kernel/debug/usb.23/host_testmode 2. set compliance mode for the USB3 port of USB3 interface: echo test_u3 > /sys/kernel/debug/usb.23/host_testmode 3. check the testmode status: cat /sys/kernel/debug/usb.23/host_testmode The log maybe like this: U2: test_packet /* means that U2 in test mode */ U3: compliance mode /* means that U3 in test mode */ Change-Id: I6ddead14a7b78a011bbffcec6bf865df0632fe1b Signed-off-by: William Wu <wulf@rock-chips.com>
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 ("hub_wq").
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.