table of contents
| USB_ALTNUM_TO_ALTSET(9) | USB Core APIs | USB_ALTNUM_TO_ALTSET(9) |
NAME¶
usb_altnum_to_altsetting - get the altsetting structure with a given alternate setting number.
SYNOPSIS¶
struct usb_host_interface * usb_altnum_to_altsetting(const struct usb_interface * intf, unsigned int altnum);
ARGUMENTS¶
intf
the interface containing the altsetting in question
altnum
the desired alternate setting number
DESCRIPTION¶
This searches the altsetting array of the specified interface for an entry with the correct bAlternateSetting value and returns a pointer to that entry, or null.
Note that altsettings need not be stored sequentially by number, so it would be incorrect to assume that the first altsetting entry in the array corresponds to altsetting zero. This routine helps device drivers avoid such mistakes.
Don´t call this function unless you are bound to the intf interface or you have locked the device!
COPYRIGHT¶
| May 2024 | Kernel Hackers Manual 2.6. |