usb_gstrings_attach(9) [centos man page]

USB_GSTRINGS_ATTACH(9)					      Kernel Mode Gadget API					    USB_GSTRINGS_ATTACH(9)

NAME

       usb_gstrings_attach - attach gadget strings to a cdev and assign ids

SYNOPSIS

       struct usb_string * usb_gstrings_attach(struct usb_composite_dev * cdev, struct usb_gadget_strings ** sp, unsigned n_strings);

ARGUMENTS

       cdev
	   the device whose string descriptor IDs are being allocated and attached.

       sp
	   an array of usb_gadget_strings to attach.

       n_strings
	   number of entries in each usb_strings array (sp[]->strings)

DESCRIPTION

       This function will create a deep copy of usb_gadget_strings and usb_string and attach it to the cdev. The actual string (usb_string.s) will
       not be copied but only a referenced will be made. The struct usb_gadget_strings array may contain multiple languges and should be NULL
       terminated. The ->language pointer of each struct usb_gadget_strings has to contain the same amount of entries.

FOR INSTANCE

       sp[0] is en-US, sp[1] is es-ES. It is expected that the first usb_string entry of es-ES containts the translation of the first usb_string
       entry of en-US. Therefore both entries become the same id assign.

AUTHOR

       David Brownell <dbrownell@users.sourceforge.net>
	   Author.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						    USB_GSTRINGS_ATTACH(9)

STRUCT 
USB_CONFIGURA(9) 				      Kernel Mode Gadget API					   STRUCT USB_CONFIGURA(9)

NAME

       struct_usb_configuration - represents one gadget configuration

SYNOPSIS

       struct usb_configuration {
	 const char * label;
	 struct usb_gadget_strings ** strings;
	 const struct usb_descriptor_header ** descriptors;
	 int (* bind) (struct usb_configuration *);
	 void (* unbind) (struct usb_configuration *);
	 int (* setup) (struct usb_configuration *,const struct usb_ctrlrequest *);
	 u8 bConfigurationValue;
	 u8 iConfiguration;
	 u8 bmAttributes;
	 u8 bMaxPower;
	 struct usb_composite_dev * cdev;
       };

MEMBERS

       label
	   For diagnostics, describes the configuration.

       strings
	   Tables of strings, keyed by identifiers assigned during bind() and by language IDs provided in control requests.

       descriptors
	   Table of descriptors preceding all function descriptors. Examples include OTG and vendor-specific descriptors.

       bind
	   Called from usb_add_config() to allocate resources unique to this configuration and to call usb_add_function() for each function used.

       unbind
	   Reverses bind; called as a side effect of unregistering the driver which added this configuration.

       setup
	   Used to delegate control requests that aren't handled by standard device infrastructure or directed at a specific interface.

       bConfigurationValue
	   Copied into configuration descriptor.

       iConfiguration
	   Copied into configuration descriptor.

       bmAttributes
	   Copied into configuration descriptor.

       bMaxPower
	   Copied into configuration descriptor.

       cdev
	   assigned by usb_add_config() before calling bind(); this is the device associated with this configuration.

DESCRIPTION

       Configurations are building blocks for gadget drivers structured around function drivers. Simple USB gadgets require only one function and
       one configuration, and handle dual-speed hardware by always providing the same functionality. Slightly more complex gadgets may have more
       than one single-function configuration at a given speed; or have configurations that only work at one speed.

       Composite devices are, by definition, ones with configurations which include more than one function.

       The lifecycle of a usb_configuration includes allocation, initialization of the fields described above, and calling usb_add_config() to set
       up internal data and bind it to a specific device. The configuration's bind() method is then used to initialize all the functions and then
       call usb_add_function() for them.

       Those functions would normally be independant of each other, but that's not mandatory. CDC WMC devices are an example where functions often
       depend on other functions, with some functions subsidiary to others. Such interdependency may be managed in any way, so long as all of the
       descriptors complete by the time the composite driver returns from its bind routine.

AUTHOR

       David Brownell <dbrownell@users.sourceforge.net>
	   Author.

COPYRIGHT

Kernel Hackers Manual 2.6.					     July 2010						   STRUCT USB_CONFIGURA(9)