usb_get_string_descr(9f)

1usb_get_string_descr(9F) Kernel Functions for Drivers usb_get_string_descr(9F)
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NAME

6       usb_get_string_descr - Get string descriptor from device
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SYNOPSIS

9       #include <sys/usb/usba.h>
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13       int usb_get_string_descr(dev_info_t *dip,
14            uint16_t langid, uint8_t index,
15            char *buf, size_t buflen);
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INTERFACE LEVEL

19       Solaris DDI specific (Solaris DDI)
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PARAMETERS

22       dip       Pointer to the device's dev_info structure.
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25       langid    Language  ID.  Currently  only USB_LANG_ID (English ascii) is
26                 valid.
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29       index     String index indicating descriptor to retrieve.
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32       buf       Address into which the string descriptor is placed.
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35       buflen    Size of buf in bytes.
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DESCRIPTION

39       The usb_get_string_descr() function retrieves a parsed string  descrip‐
40       tor  from  a  device.  dip  specifies the device, while index indicates
41       which descriptor to return.
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44       String descriptors provide  information  about  other  descriptors,  or
45       information  that  is  encoded  in other descriptors, in readable form.
46       Many descriptor types have one or  more  index  fields  which  identify
47       string descriptors.  (See  Sections 9.5 and 9.6 of the USB 2.0 specifi‐
48       cation.) For example, a configuration descriptor's  seventh  byte  con‐
49       tains the string descriptor index describing a specific configuration.
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52       Retrieved  descriptors that do not fit into buflen bytes are truncated.
53       All returned descriptors are null-terminated.
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RETURN VALUES

56       USB_SUCCESS         String descriptor is returned in buf.
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59       USB_INVALID_ARGS    dip or buf are NULL, or index or buflen is 0.
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62       USB_FAILURE         Descriptor cannot be retrieved.
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CONTEXT

66       May be called from user or kernel context.
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EXAMPLES

69            /* Get the first string descriptor. */
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71             char buf[SIZE];
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73             if (usb_get_string_descr(
74                 dip, USB_LANG_ID, 0, buf, SIZE) == USB_SUCCESS) {
75                     cmn_err (CE_NOTE, "%s%d: %s",
76                         ddi_driver_name(dip), ddi_get_instance(dip), buf);
77             }
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ATTRIBUTES

81       See attributes(5) for descriptions of the following attributes:
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86       ┌─────────────────────────────┬─────────────────────────────┐
87       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
88       ├─────────────────────────────┼─────────────────────────────┤
89       │Architecture                 │PCI-based systems            │
90       ├─────────────────────────────┼─────────────────────────────┤
91       │Interface stability          │Committed                    │
92       ├─────────────────────────────┼─────────────────────────────┤
93       │Availability                 │SUNWusb                      │
94       └─────────────────────────────┴─────────────────────────────┘
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