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Diffstat (limited to 'Documentation/usb/WUSB-Design-overview.txt')
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1 files changed, 37 insertions, 19 deletions
diff --git a/Documentation/usb/WUSB-Design-overview.txt b/Documentation/usb/WUSB-Design-overview.txt index fdb47637720e..dc5e21609bb5 100644 --- a/Documentation/usb/WUSB-Design-overview.txt +++ b/Documentation/usb/WUSB-Design-overview.txt @@ -1,7 +1,9 @@ - +================================ Linux UWB + Wireless USB + WiNET +================================ + + Copyright (C) 2005-2006 Intel Corporation - (C) 2005-2006 Intel Corporation Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> This program is free software; you can redistribute it and/or @@ -29,6 +31,7 @@ drivers for the USB based UWB radio controllers defined in the Wireless USB 1.0 specification (including Wireless USB host controller and an Intel WiNET controller). +.. Contents 1. Introduction 1. HWA: Host Wire adapters, your Wireless USB dongle @@ -51,7 +54,8 @@ and an Intel WiNET controller). 4. Glossary - Introduction +Introduction +============ UWB is a wide-band communication protocol that is to serve also as the low-level protocol for others (much like TCP sits on IP). Currently @@ -93,7 +97,8 @@ The different logical parts of this driver are: do the actual WUSB. - HWA: Host Wire adapters, your Wireless USB dongle +HWA: Host Wire adapters, your Wireless USB dongle +------------------------------------------------- WUSB also defines a device called a Host Wire Adaptor (HWA), which in mere terms is a USB dongle that enables your PC to have UWB and Wireless @@ -125,7 +130,8 @@ The HWA itself is broken in two or three main interfaces: their type and kick into gear. - DWA: Device Wired Adaptor, a Wireless USB hub for wired devices +DWA: Device Wired Adaptor, a Wireless USB hub for wired devices +--------------------------------------------------------------- These are the complement to HWAs. They are a USB host for connecting wired devices, but it is connected to your PC connected via Wireless @@ -137,7 +143,8 @@ code with the HWA-RC driver; there is a bunch of factorization work that has been done to support that in upcoming releases. - WHCI: Wireless Host Controller Interface, the PCI WUSB host adapter +WHCI: Wireless Host Controller Interface, the PCI WUSB host adapter +------------------------------------------------------------------- This is your usual PCI device that implements WHCI. Similar in concept to EHCI, it allows your wireless USB devices (including DWAs) to connect @@ -148,7 +155,8 @@ There is still no driver support for this, but will be in upcoming releases. - The UWB stack +The UWB stack +============= The main mission of the UWB stack is to keep a tally of which devices are in radio proximity to allow drivers to connect to them. As well, it @@ -156,7 +164,8 @@ provides an API for controlling the local radio controllers (RCs from now on), such as to start/stop beaconing, scan, allocate bandwidth, etc. - Devices and hosts: the basic structure +Devices and hosts: the basic structure +-------------------------------------- The main building block here is the UWB device (struct uwb_dev). For each device that pops up in radio presence (ie: the UWB host receives a @@ -187,7 +196,8 @@ the USB connected HWA. Eventually, drivers/whci-rc.c will do the same for the PCI connected WHCI controller. - Host Controller life cycle +Host Controller life cycle +-------------------------- So let's say we connect a dongle to the system: it is detected and firmware uploaded if needed [for Intel's i1480 @@ -209,7 +219,8 @@ When a dongle is disconnected, /drivers/uwb/hwa-rc.c:hwarc_disconnect()/ takes time of tearing everything down safely (or not...). - On the air: beacons and enumerating the radio neighborhood +On the air: beacons and enumerating the radio neighborhood +---------------------------------------------------------- So assuming we have devices and we have agreed for a channel to connect on (let's say 9), we put the new RC to beacon: @@ -235,12 +246,14 @@ are received in some time, the device is considered gone and wiped out the beacon cache of dead devices]. - Device lists +Device lists +------------ All UWB devices are kept in the list of the struct bus_type uwb_bus_type. - Bandwidth allocation +Bandwidth allocation +-------------------- The UWB stack maintains a local copy of DRP availability through processing of incoming *DRP Availability Change* notifications. This @@ -260,7 +273,8 @@ completion. [Note: The bandwidth reservation work is in progress and subject to change.] - Wireless USB Host Controller drivers +Wireless USB Host Controller drivers +==================================== *WARNING* This section needs a lot of work! @@ -296,7 +310,8 @@ starts sending MMCs. Now it all depends on external stimuli. -*New device connection* +New device connection +--------------------- A new device pops up, it scans the radio looking for MMCs that give out the existence of Wireless USB channels. Once one (or more) are found, @@ -322,7 +337,8 @@ has seen the port status changes, as we have been toggling them. It will start enumerating and doing transfers through usb_hcd->urb_enqueue() to read descriptors and move our data. -*Device life cycle and keep alives* +Device life cycle and keep alives +--------------------------------- Every time there is a successful transfer to/from a device, we update a per-device activity timestamp. If not, every now and then we check and @@ -340,7 +356,8 @@ device list looking for whom needs refreshing. If the device wants to disconnect, it will either die (ugly) or send a /DN_Disconnect/ that will prompt a disconnection from the system. -*Sending and receiving data* +Sending and receiving data +-------------------------- Data is sent and received through /Remote Pipes/ (rpipes). An rpipe is /aimed/ at an endpoint in a WUSB device. This is the same for HWAs and @@ -394,7 +411,8 @@ finalize the transfer. For IN xfers, we only issue URBs for the segments we want to read and then wait for the xfer result data. -*URB mapping into xfers* +URB mapping into xfers +^^^^^^^^^^^^^^^^^^^^^^ This is done by hwahc_op_urb_[en|de]queue(). In enqueue() we aim an rpipe to the endpoint where we have to transmit, create a transfer @@ -407,7 +425,8 @@ and not yet done and when all that is done, the xfer callback will be called--this will call the URB callback. - Glossary +Glossary +======== *DWA* -- Device Wire Adapter @@ -436,4 +455,3 @@ the host. Design-overview.txt-1.8 (last edited 2006-11-04 12:22:24 by InakyPerezGonzalez) - |