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usb_get_string_descr (9)

>> usb_get_string_descr (9) ( Solaris man: Ядро )

NAME

usb_get_string_descr - Get string descriptor from
device

SYNOPSIS

#include <sys/usb/usba.h>



int usb_get_string_descr(dev_info_t *dip, 
    uint16_t langid, uint8_t index,
    char *buf, size_t buflen);

INTERFACE LEVEL

Solaris DDI specific (Solaris DDI)

PARAMETERS

dip

: Pointer to the device's dev_info structure.

langid

: Language ID. Currently only USB_LANG_ID (English ascii) is valid.

index

: String index indicating descriptor to retrieve.

buf

: Address into which the string descriptor is placed.

buflen

: Size of buf in bytes.

DESCRIPTION

The usb_get_string_descr() function retrieves a parsed string descriptor from a device. dip specifies the device, while index indicates which descriptor to return.

String descriptors provide information about other descriptors, or information that is encoded in other descriptors, in readable form. Many descriptor types have one or more index fields which identify string descriptors. (See Sections 9.5 and 9.6 of the USB 2.0 specification.) For example, a configuration descriptor's seventh byte contains the string descriptor index describing a specific configuration.

Retrieved descriptors that do not fit into buflen bytes are truncated. All returned descriptors are null-terminated.

RETURN VALUES

USB_SUCCESS

: String descriptor is returned in buf.

USB_INVALID_ARGS

: dip or buf are NULL, or index or buflen is 0.

USB_FAILURE

: Descriptor cannot be retrieved.

CONTEXT

May be called from user or kernel context.

EXAMPLES

   /* Get the first string descriptor. */

   char buf[SIZE];

   if (usb_get_string_descr(
       dip, USB_LANG_ID, 0, buf, SIZE) == USB_SUCCESS) {
           cmn_err (CE_NOTE, "%s%d: %s",
               ddi_driver_name(dip), ddi_get_instance(dip), buf);
   }