- move bus scanning for device to a new sanei_usb_scan_devices
- call this new function from sanei_usb_init to preserve current behaviour
- split bus device scanning into several smaller functions on a per scanning method
method basis
Since we now have the possibility to change the endpoint used for a particular USB communication type,
we also need a way to retrieve the current endpoint, so that one can e.g. reset the endpoint to the
old value after a single usb operation on a different endpoint.
Added
void sanei_usb_set_endpoint (SANE_Int dn, SANE_Int ep_type, SANE_Int ep);
This function allows the user to set the endpoint to use on
the given device for the given endpoint type (e.g. bulk in).
Some scanners have multiple bulk in/out endpoints but use
only one for communication (not the one detected during auto-detection),
so one call to the new function will change the used endpoint.
Some scanners use two different endpoint for different purposes,
so in that case each read/write call needs to be preceeded
by a call to that function to set the proper endpoint.
ep_type is a bitmask and is usually of the form
(USB_DIR_IN|USB_ENDPOINT_TYPE_BULK)
/** Initiate a interrupt transfer read.
*
* Read up to size bytes from the interrupt endpoint from the device to
* buffer. After the read, size contains the number of bytes actually read.
*
* @param dn device number
* @param buffer buffer to store read data in
* @param size size of the data
*
* @return
* - SANE_STATUS_GOOD - on succes
* - SANE_STATUS_EOF - if zero bytes have been read
* - SANE_STATUS_IO_ERROR - if an error occured during the read
* - SANE_STATUS_INVAL - on every other error
*
*/
usb_find_busses only once. Make sure that already opened devices aren't opened
again. Exit libusb scan loop if one device is found. Make error values more
expressive. Check for missing config descriptors before using them to avoid
segfaults.
Henning Meier-Geinitz <henning@meier-geinitz.de>
Povilas Kanapickas