struct_usb_composite_dev (9) Linux Manual Page

struct_usb_composite_dev – represents one composite usb gadget

Synopsis

struct usb_composite_dev {
    struct usb_gadget *gadget;
    struct usb_request *req;
    struct usb_request *os_desc_req;
    struct usb_configuration *config;
    u8 qw_sign[OS_STRING_QW_SIGN_LEN];
    u8 b_vendor_code;
    struct usb_configuration *os_desc_config;
    unsigned int use_os_string : 1;
};

Members

gadget

read-only, abstracts the gadget’s usb peripheral controller

req

used for control responses; buffer is pre-allocated

os_desc_req

used for OS descriptors responses; buffer is pre-allocated

config

the currently active configuration

qw_sign[OS_STRING_QW_SIGN_LEN]

qwSignature part of the OS string

b_vendor_code

bMS_VendorCode part of the OS string

os_desc_config

the configuration to be used with OS descriptors

use_os_string

false by default, interested gadgets set it

Description

One of these devices is allocated and initialized before the associated device driver’s bind is called.

OPEN ISSUE: it appears that some WUSB devices will need to be built by combining a normal (wired) gadget with a wireless one. This revision of the gadget framework should probably try to make sure doing that won’t hurt too much.

One notion for how to handle Wireless USB devices involves: (a) a second gadget here, discovery mechanism TBD, but likely needing separate “register/unregister WUSB gadget” calls; (b) updates to usb_gadget to include flags “is it wireless”, “is it wired”, plus (presumably in a wrapper structure) bandgroup and PHY info; (c) presumably a wireless_ep wrapping a usb_ep, and reporting wireless-specific parameters like maxburst and maxsequence; (d) configurations that are specific to wireless links; (e) function drivers that understand wireless configs and will support wireless for (additional) function instances; (f) a function to support association setup (like CBAF), not necessarily requiring a wireless adapter; (g) composite device setup that can create one or more wireless configs, including appropriate association setup support; (h) more, TBD.

Author

David Brownell <dbrownell [at] users.sourceforge.net>

Author.

Copyright