Lines Matching +full:display +full:- +full:hub
1 .. _usb-hostside-api:
4 The Linux-USB Host Side API
18 That master/slave asymmetry was designed-in for a number of reasons, one
22 distributed auto-configuration since the pre-designated master node
37 USB Host-Side API Model
40 Host-side drivers for USB devices talk to the "usbcore" APIs. There are
41 two. One is intended for *general-purpose* drivers (exposed through
43 core*. Such core drivers include the *hub* driver (which manages trees
49 - USB supports four kinds of data transfers (control, bulk, interrupt,
54 - The device description model includes one or more "configurations"
60 - From USB 3.0 on configurations have one or more "functions", which
64 - Configurations or functions have one or more "interfaces", each of which may have
74 - Interfaces have one or more "endpoints", each of which supports one
79 - Data transfer on USB is packetized; each endpoint has a maximum
84 - The Linux USB API supports synchronous calls for control and bulk
94 The only host-side drivers that actually touch hardware (reading/writing
101 faults (including software-induced ones like unlinking an URB) isn't yet
105 well as to make sure they aren't relying on some HCD-specific behavior.
109 USB-Standard Types
120 .. kernel-doc:: drivers/usb/common/common.c
128 Host-Side Data Types and Macros
136 .. kernel-doc:: include/linux/usb.h
148 per-packet fault reports). Built on top of that is synchronous API
151 wrappers for single-buffer control and bulk transfers (which are awkward
161 .. kernel-doc:: drivers/usb/core/urb.c
164 .. kernel-doc:: drivers/usb/core/message.c
167 .. kernel-doc:: drivers/usb/core/file.c
170 .. kernel-doc:: drivers/usb/core/driver.c
173 .. kernel-doc:: drivers/usb/core/usb.c
176 .. kernel-doc:: drivers/usb/core/hub.c
193 based controllers (and a few non-PCI based ones) use one of those
203 significantly reduce hcd-specific behaviors.
205 .. kernel-doc:: drivers/usb/core/hcd.c
208 .. kernel-doc:: drivers/usb/core/hcd-pci.c
211 .. kernel-doc:: drivers/usb/core/buffer.c
223 - `libusb <http://libusb.sourceforge.net>`__ for C/C++, and
224 - `jUSB <http://jUSB.sourceforge.net>`__ for Java.
228 at http://www.linux-usb.org/
232 - They were used to be implemented via *usbfs*, but this is not part of
235 - This particular documentation is incomplete, especially with respect
237 (new) documentation need to be cross-reviewed.
240 -----------------------------
244 - ``/dev/bus/usb/BBB/DDD`` ... magic files exposing the each device's
252 always leave the devices plugged in to the same hub port. *Don't even
260 --------------------
264 - *They can be read,* producing first the device descriptor (18 bytes) and
269 the BCD-encoded fields, and the vendor and product IDs) will be
274 - *Perform USB operations* using *ioctl()* requests to make endpoint I/O
288 it's relatively common for devices to re-enumerate while they are
289 still connected (perhaps someone jostled their power supply, hub,
295 configuration of the device. Multi-byte fields in the device descriptor
303 These files may also be used to write user-level drivers for the USB
320 -------------------------------
339 (An example might be software using vendor-specific control requests for
343 More likely, you need a more complex style driver: one using non-control
352 Your user-mode driver should never need to worry about cleaning up
357 --------------------
374 :ref:`usb-error-codes`).
379 hub_wq (in the kernel) setting a device-wide *configuration* that
446 * 'request' becomes the driver->ioctl() 'code' parameter.
448 * is copied to or from the driver->ioctl() 'buf' parameter.
467 devices what device special file should be used. Two pre-defined
543 returning ``-EPIPE`` status to a data transfer request. Do not issue
630 (It's usually a pointer to per-request data.) Flags can modify requests
689 - ``/sys/kernel/debug/usb/devices`` ... a text file showing each of the USB
694 -----------------------------
698 (including class and vendor status) is available from device-specific
711 poll(&pfd, 1, -1);
719 udev or HAL to initialize a device or start a user-mode helper program,
730 Each line is tagged with a one-character ID for that line::
842 | version and the driver which provides this hub emulation.
874 rather differently. For example, a bus-powered configuration
875 might be much less capable than one that is self-powered. Only
904 of bus bandwidth, drivers must select a non-default altsetting.
928 the per-microframe data transfer size. For "high bandwidth"
932 With the Linux-USB stack, periodic bandwidth reservations use the
942 ``grep -i ^[tdp]: /sys/kernel/debug/usb/devices`` can be used to list
945 script, it can display any selected lines (for example, only T, D,
952 of the USB devices on a system's root hub. (See more below
963 Here's an example, from a system which has a UHCI root hub,
964 an external hub connected to the root hub, and a mouse and
965 a serial converter connected to the external hub.
971 D: Ver= 1.00 Cls=09(hub ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1
973 S: Product=USB UHCI Root Hub
976 I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
980 D: Ver= 1.00 Cls=09(hub ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1
983 I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
1012 I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub
1021 +------------------+
1023 +------------------+ (nn) is Mbps.
1025 +------------------+
1028 +-----------------------+
1029 Level 1 | Dev#2: 4-port hub (12)|
1030 +-----------------------+
1032 +-----------------------+
1036 +--------------------+ +--------------------+
1038 +--------------------+ +--------------------+
1042 Or, in a more tree-like structure (ports [Connectors] without
1045 PC: Dev# 1, root hub, 2 ports, 12 Mbps
1046 |_ CN.0: Dev# 2, hub, 4 ports, 12 Mbps