From sacadmin Mon Nov 20 11:34:37 2006 Received: from sfbaymail2sca.sfbay.sun.com (sfbaymail2sca.SFBay.Sun.COM [129.145.155.42]) by sac.sfbay.sun.com (8.13.6+Sun/8.13.6) with ESMTP id kAKJYat9003406 for ; Mon, 20 Nov 2006 11:34:36 -0800 (PST) Received: from nwk-ea-fw-1.sun.com (nwkes-gis-mail-2.SFBay.Sun.COM [10.4.134.6]) by sfbaymail2sca.sfbay.sun.com (8.13.6+Sun/8.12.10/ENSMAIL,v2.2) with ESMTP id kAKJYaTj023614 for ; Mon, 20 Nov 2006 11:34:36 -0800 (PST) Received: from d1-sfbay-10.sun.com ([192.18.39.120]) by nwk-ea-fw-1.sun.com (8.13.6+Sun/8.12.9) with ESMTP id kAKJYVTi004435 for ; Mon, 20 Nov 2006 11:34:31 -0800 (PST) Received: from conversion-daemon.d1-sfbay-10.sun.com by d1-sfbay-10.sun.com (Sun Java System Messaging Server 6.2-6.01 (built Apr 3 2006)) id <0J9100301NLGYU00@d1-sfbay-10.sun.com> (original mail from frits@sun.com) for PSARC@sac.sfbay.sun.com; Mon, 20 Nov 2006 11:34:31 -0800 (PST) Received: from [10.192.22.174] ([192.18.45.134]) by d1-sfbay-10.sun.com (Sun Java System Messaging Server 6.2-6.01 (built Apr 3 2006)) with ESMTPSA id <0J9100D0ONPINS65@d1-sfbay-10.sun.com>; Mon, 20 Nov 2006 11:34:31 -0800 (PST) Date: Mon, 20 Nov 2006 11:34:32 -0800 From: frits vanderlinden Subject: USB Interface Association support [PSARC/2006/649] Sender: Frits.Vanderlinden@sun.com To: PSARC@sac.sfbay.sun.com Cc: usb-tech , Tarl Neustaedter Message-id: <45620348.8050508@sun.com> MIME-version: 1.0 Content-type: multipart/mixed; boundary="Boundary_(ID_IbYjtq5PdL9yxWnX8RTZSg)" User-Agent: Thunderbird 1.5.0.8 (Macintosh/20061025) Status: RO Content-Length: 10025 This is a multi-part message in MIME format. --Boundary_(ID_IbYjtq5PdL9yxWnX8RTZSg) Content-type: text/plain; format=flowed; charset=ISO-8859-1 Content-transfer-encoding: 7BIT I am sponsoring this fasttrack for Gaopeng Chen. I believe this proposal qualifies for self-review and I am marking this case "closed approved automatic". Extensive discussions have taken place on updating the USB 1275 bindings with FWARC folks for Interface Associations and there appears to be agreement on the approach. I have deposited the draft update of the USB bindings in the case directory. In the unlikely case FWARC derails or requires a major change, this case will have to be reopened/updated. The reason I am submitting this case now is because 11/23 is my last day (I will retire). I wanted to wrap this up personally after working with the team for quite a while on this proposal. cheers fritS --Boundary_(ID_IbYjtq5PdL9yxWnX8RTZSg) Content-type: text/plain; name=proposal; x-mac-creator=0; x-mac-type=0 Content-transfer-encoding: 7BIT Content-disposition: inline; filename=proposal 1. Background ------------- USB IAD (Interface Association Descriptor) was introduced in a USB ECN doc in 2003 (refer to 2.1). It defines a new standard descriptor that lists multiple interfaces which are associated with one device function. This allows the OS to optionally bind one driver instance to a group of interfaces. IAD has already been included in audio class (after spec 1.7i), video class and the Wireless USB. New class drivers depend on the IAD feature. The project team is in the process of submitting a FWARC fasttrack to update the USB bindings. The new draft bindings are in the case directory. The original bindings can be found in: http://playground.sun.com/1275/home.html#OFDbusUSB. 2. References ------------- 2.1 "Interface Association Descriptor Engineering Change Notice (ECN)" http://www.usb.org/developers/docs 2.2 "USB Interface Association Descriptor Device Class Code and Use Model White Paper" http://www.usb.org/developers/whitepapers 2.3 USB video class spec (v1.1) (http://www.usb.org/developers/devclass_docs/USB_Video_Class_1_1.zip) 2.4 USB audio class spec (v2.0) (http://www.usb.org/developers/devclass_docs/Audio2.0_final.zip) 2.5 Wireless USB specs (http://www.usb.org/developers/wusb/) 2.6 FWARC/TBD update of USB bindings (in preparation) 2.7 PSARC/1998/111 Universal Serial Bus Framework Support 2.8 PSARC/2000/542 USB Architecture Update project 2.9 PSARC/2003/207 USBA2.0: adding USBA interfaces to the DDI 3. Solution ----------- This case proposes supporting the IAD in Solaris. It makes the devices work with either IA leaf drivers (in other words, a driver bound to an IA) or interface leaf drivers (children of the IA nexus driver). 3.1 Update of USBA framework ---------------------------- A new type of node, IA (Interface-Association) node is created for each IA descriptor. USBA allows users to bind a driver to a device, IA or interface node. If no driver is found for the device node, the generic multi interface driver (usb_mid(7D) will be bound. It creates interface and IA children. If no driver is found for an IA node, a generic nexus driver usb_ia will be bound. This driver creates child nodes for the set of interfaces belonging to the IA allowing interface drivers to attach. Example: A video device with IAD will have the following device tree. A new video driver is bound to video interface association. No driver is available for the audio IA, so usb_ia manages it and creates interface nodes for audio control and stream (these are drivers that are in Solaris today). device, instance # (usb_mid) interface, instance # (...) video, instance # (usb_video) <<<< interface association audio, instance # (usb_ia) <<<< interface association interface, instance # (usb_ac) interface, instance # (usb_as) Note that this approach allows using existing interface leaf drivers within an IA group but provides the option to write a new single audio driver which will be bound to the interface association node. 3.2 Update of node names and binding rules ------------------------------------------ The properties of an IA node are defined in [2.6]. The name of the node should be chosen from the following table, using the first name applicable: bFunction bFunctionSub bFunction Name Class Class Protocol __________________________________________________________ 0x01 any any audio 0x0E any any video 0xE0 0x02 0x02 device-wire-adapter 0xE0 any any wireless-controller any any any interface-association The new IA node will have the following compatible names for driver binding. "usb,ia" is appended to the tail for binding the default driver usb_ia. VID idVendor PID idProduct REV bcdDevice FN bFirstInterface FC bFunctionClass FSC bFunctionSubClass FPROTO bFunctionProtocol 1) usbiaVID,PID.REV.configCN.FN 2) usbiaVID,PID.configCN.FN 3) usbiaVID,classFC.FSC.FPROTO 4) usbiaVID,classFC.FSC 5) usbiaVID,classFC 6) usbia,classFC.FSC.FPROTO 7) usbia,classFC.FSC 8) usbia,classFC 9) usb,ia Refer to [2.6] for more details. 3.3 Update of USBA interfaces ----------------------------- 3.3.1 Changes in public header files A new type of descriptor IAD has been added to usbai.h. In addition, more class types are defined for the related USB classes (see interface table). 3.3.2 The change of USBA committed functions usb_set_alt_if() is the only interface that is affected by this project. The old function requires the driver to be bound to the entire device or the same interface to avoid contending with another driver for a different part of the device. Now the driver is allowed to be bound to the entire device, or the IA node which includes this alternative interface, or the corresponding interface. Therefore an IA driver can completely control the whole interface association. This change is backwards compatible. 3.4 Questions and Answers ------------------------- 3.4.1 Why create a new type of device node? This is a new USB feature and is also supported by Windows and new devices are appearing on the market. It allows a driver to be bound to a function which has multiple interfaces or leverage existing interface drivers. 3.4.2 Why is a nexus driver necessary? If there is no driver found for IA nodes, usb_ia can be bound to IA nodes and create children nodes for interfaces. It gives user two choices: to bind a driver to an IA or interface nodes. 3.4.3 What is the impact on the use of devices and existing drivers? No impact on devices without IAD. No impact on existing client drivers. Those devices that have an IAD and old class drivers are binary compatible and work well in the new USBA, such as audio 2.0 class devices. In other words, the existing devices and drivers are compatible with this approach. New class devices with IAD will work with the new driver bound to IA node, such as video class devices. 3.4.4 What is the benefit of IAD support? It provides a way to bind a single driver to multiple interfaces. It makes the development of complicated device drivers easier. A video class driver with IAD support will be released soon. And the upcoming Wireless USB drivers will depend on IA as well. 4. Documentation updates ------------------------ Draft man pages with changebars are in the case directory. Man page usba(7D), usb_mid(7D), usb_set_alt_if(9F) will be updated. usb_ia(7D) man page will be added for the new driver usb_ia. WDD (Write Device Drivers) guide will be updated. 5. Interface table ------------------ Com = Committed Interface Level Comments +------------------------------------------------------------------------------+ | Interface exported | +------------------------------------------------------------------------------+ usb_ia_descr_t | Com | Interface Association Descriptor ECN USB_DESCR_TYPE_IA | Com | Interface Association Descriptor ECN USB_CLASS_IMAGE | Com | Image interface class USB_CLASS_VIDEO | Com | Video interface class USB_CLASS_WIRELESS | Com | Wireless controller interface class USB_SUBCLS_VIDEO_CONTROL | Com | Video-control subclass USB_SUBCLS_VIDEO_STREAM | Com | Video-stream subclass USB_SUBCLS_VIDEO_COLLECTION | Com | Video collection subclass USB_SUBCLS_WUSB_1 | Com | Wireless subclass 1 USB_SUBCLS_WUSB_2 | Com | Wireless subclass 2 USB_PROTO_WUSB_HWA | Com | Wireless Host Wire Adapter protocol USB_PROTO_WUSB_DWA | Com | Wireless Device Wire Adapter protocol USB_PROTO_WUSB_DWA_ISO | Com | Wireless Device Wire Adapter isoc protocol usb_ia | Com | interface association driver name +------------------------------------------------------------------------------+ | Interface changed | +------------------------------------------------------------------------------+ usb_set_alt_if | Com | Set an alt iface to current iface +------------------------------------------------------------------------------+ 6. Release binding Patch/Update. --Boundary_(ID_IbYjtq5PdL9yxWnX8RTZSg)--