On Fri, 2005-05-20 at 16:36 -0500, Steven Palm wrote: > On May 14, 2005, at 7:18 AM, Henning Meier-Geinitz wrote: > >> Any notes on how to go about (or general guidelines for) converting a > >> driver to support libusb? > > > > You shouldn't use libusb directly but the sanei_usb functions. AFAIK > > the avision backend has been changed to use direct USB access instead > > of using the kernel driver hpusbscsi so you may want to have a look at > > its code. > > I'm running into a few issues that are beyond the scope of my > ignorance... :-) (Well, the scope of my ignorance is pretty large in > this area, so maybe I should say beyond the scope of my understanding.) > > A few things seem to be different between the avision and microtek2 > that are complicating my efforts. > > 1) The avision does a status read on an interrupt endpoint, the > microtek2 USB config has none. Not a big deal, I just do a bulk_read > and it seems to catch it OK. > > 2) The microtek has three endpoints, one output and two input. > Using the sanei_open() and related functions I see this happening: > > [sanei_usb] sanei_usb_open: trying to open device `libusb: > 003:002-05da-00a3-ff-03' > usb_os_open: 05da:00a3 > usb_set_configuration: called for config 1 > usb_claim_interface: called for interface 0 > Interface 0 of device is 0x000011cf > claim_interface: Interface 0 of device from QueryInterface is 0x303c80 > libusb/darwin.c get_endpoints: building table of endpoints. > get_endpoints: Pipe 1: DIR: 0 number: 1 > get_endpoints: Pipe 2: DIR: 1 number: 2 > get_endpoints: Pipe 3: DIR: 1 number: 3 > libusb/darwin.c get_endpoints: complete. > [sanei_usb] sanei_usb_open: configuration nr: 0 > [sanei_usb] sanei_usb_open: interface nr: 0 > [sanei_usb] sanei_usb_open: alt_setting nr: 0 > [sanei_usb] sanei_usb_open:num: 0 endpoint: 0x304260 > [sanei_usb] sanei_usb_open: direction: 0) > [sanei_usb] sanei_usb_open: address: 1 transfertype: 2 > [sanei_usb] sanei_usb_open: found bulk-out endpoint (address 0x01) > [sanei_usb] sanei_usb_open:num: 1 endpoint: 0x304274 > [sanei_usb] sanei_usb_open: direction: 128) > [sanei_usb] sanei_usb_open: address: 2 transfertype: 2 > [sanei_usb] sanei_usb_open: found bulk-in endpoint (address 0x02) > [sanei_usb] sanei_usb_open:num: 2 endpoint: 0x304288 > [sanei_usb] sanei_usb_open: direction: 128) > [sanei_usb] sanei_usb_open: address: 3 transfertype: 2 > [sanei_usb] sanei_usb_open: found bulk-in endpoint (address 0x03) > [sanei_usb] sanei_usb_open: we already have a bulk-in endpoint > (address: 0x82), ignoring the new one > [sanei_usb] sanei_usb_open: opened usb device `libusb: > 003:002-05da-00a3-ff-03' (*dn=0) > > The trouble is, I can't have it throwing away the other endpoint, > because apparently the microtek scanner sends command responses back > on endpoint 2, but scan data comes back on endpoint 3. <sigh> Anyway > to get this type of behavior out of the sanei_ routines? > > FWIW, I gleaned this little bit of info from the microtek linux > kernel driver code: > > * The X6 USB has three bulk endpoints, one output (0x1) down which > * commands and outgoing data are sent, and two input: 0x82 from which > * normal data is read from the scanner (in packets of maximum 32 > * bytes) and from which the status byte is read, and 0x83 from which > * the results of a scan (or preview) are read in up to 64 * 1024 byte > * chunks by the Windows driver. We don't know how much it is possible > * to read at a time from 0x83. > * > * It seems possible to read (with URB transfers) everything from 0x82 > * in one go, without bothering to read in 32 byte chunks. > * > * There seems to be an optimisation of a further READ implicit if > * you simply read from 0x83. > > > (MY NOTE: I have no clue what that last bit means... Anyone? :-) > > * > * Guessed protocol: > * > * Send raw SCSI command to EP 0x1 > * > * If there is data to receive: > * If the command was READ datatype=image: > * Read a lot of data from EP 0x83 > * Else: > * Read data from EP 0x82 > * Else: > * If there is data to transmit: > * Write it to EP 0x1 > * > * Read status byte from EP 0x82 > > > So far, it is talking to the scanner anyway, sending some commands > and getting data back right up until it calls the READ microtek > opcode and times out on waiting for response, my guess is that this > response needs to be obtained over the other endpoint. THe above > said READ datatype=image, and in this case the READ is type=system > status. > > Thanks! > > Steve >
Advantage for a bulk endpoint with a greater size should be that its faster. To select in SANE in the same configuration (conf 0, interface 0 and altsetting ) a different endpoint is not possible yet. It can be done by adding a a sanei_usb_read_bulk_ep routine (at least thats how i called it) if needed. For some example see this page and the sanei_usb.c and .h files. I have not added these routines to SANE CVS because i used them for testing but didn't needed them at this moment. http://gkall.hobby.nl/downloads.html -- -------- m.vr.gr. Gerard Klaver
