/*  $Id: usb_libusb.c,v 1.10 2004/03/21 10:13:11 jmuelmen Exp $  */ 

/* This file implements the USB-level functionality of libsurf on
 * systems that have libusb.  On systems that don't, there are other
 * files (called usb_*.c) that do the same thing. */

/* Note that at this level we're dealing with a device handle and
 * channel number.  Turning module/board name into device handle and
 * channel number is done in module.c and board.c. */

#ifdef HAVE_LIBUSB

#include "libsurf.h"
#include "surf_int.h"
#include "surf_drv.h"

#define INIT if (!_init) surflib_init()
static int _init = 0;

int surf_find_boards ();
struct surf_t *surf_search (const char *);

int surflib_init ()
{
     usb_init();
     usb_set_debug(0);
     _init = 1;
     
     return 0;
}

int surf_write_ep (struct surf_t *b, int ep, char *buf, int count)
{
     /* do the USB sending stuff; if it fails, call surf_find_boards()
        to see if the SuRF board is just hiding somewhere because of a
        re-enumeration. */
     int n, i;
     usb_dev_handle *dev;

     INIT;

     i = 5; /* five tries to write to the damn thing should be enough */
     while (i--) {
	  /* try to write to the board */
	  dev = surft_get_dev(b);
	  
	  if (ep) 
	       n = usb_bulk_write(dev, ep, buf, count, SURF_TO);
	  else n = usb_control_msg(dev, buf[0], buf[1],
				   (buf[2] << 8) + buf[3], 
				   (buf[4] << 8) + buf[5], buf + 6,
				   count - 6, SURF_TO); 
	  
	  if (n >= 0) /* we succeeded; we're happy. */
	       return n;

	  /* if we didn't succeed, we have to see if the bus changed */
	  surft_make_stale(b);
	  if (surf_find_boards())
	       /* something bad happened on the bus.  errno is already
                  set. */
	       return -1;

	  /* if the board is still stale (i.e. we can't talk to the
	     device), then it's time to give up.  Probably some
	     tourist took the board as a souvenir. */
	  if (surft_stale(b)) {
	       surf_errno = ENOBOARD;
	       return -1;
	  }

	  /* otherwise, we just try again.  It should work on the
	     second try unless someone changed the bus in the
	     meantime.  Then it'll work on the third try unless... */
     }

     /* we failed.  No board to be had. */
     surf_errno = ENOBOARD;
     return -1;
}

int surf_read_ep (struct surf_t *b, int ep, char *buf, int count)
{
     /* do the USB receiving stuff; if it fails, call surf_find_boards()
        to see if the SuRF board is just hiding somewhere because of a
        re-enumeration. */
     int n, i;
     usb_dev_handle *dev;

     INIT;

     i = 5; /* five tries to read from the damn thing should be enough */
     while (i--) {
	  /* try to read from the board */
	  dev = surft_get_dev(b);
     
	  if (ep) 
	       n = usb_bulk_read(dev, ep, buf, count, SURF_TO);
	  else n = usb_control_msg(dev, USB_ENDPOINT_OUT, buf[0], 
				   (buf[1] << 8) + buf[2], 
				   (buf[3] << 8) + buf[4], buf + 5,
				   count - 5, SURF_TO); 
     
	  if (n >= 0) /* we succeeded; we're happy. */
	       return n;

	  /* if we didn't succeed, we have to see if the bus changed */
	  surft_make_stale(b);
	  if (surf_find_boards())
	       /* something bad happened on the bus.  errno is already
                  set. */
	       return -1;

	  /* if the board is still stale (i.e. we can't talk to the
	     device), then it's time to give up.  Probably some
	     tourist took the board as a souvenir. */
	  if (surft_stale(b)) {
	       surf_errno = ENOBOARD;
	       return -1;
	  }

	  /* otherwise, we just try again.  It should work on the
	     second try unless someone changed the bus in the
	     meantime.  Then it'll work on the third try unless... */

	  /* fix me!  There should be a provision for resetting the endpoint
	     before giving up. */
     }

     /* we failed.  No board to be had. */
     surf_errno = ENOBOARD;
     return -1;
}

static void convert_unicode (const char *unicode, char *ascii, int len)
{
     int i;
/*       printf("Unicode string (length %x) is", len); */
/*       for (i = 0; i < len; ++i)  */
/*  	  printf(" %x", unicode[i]); */
/*       printf("\n"); */
     for (i = 0; i < len / 2 - 1; ++i) 
	  ascii[i] = unicode[2 * i + 2];
     ascii[i] = 0;
}

/* Go through the list of existing boards; check which ones are still
    connected and update the device handles as necessary */
int surf_find_boards ()
{
     /* go through the USB; 
	get the SuRF device's serial number; 
	check if it's in the list of boards already (binary search);
	if it is in the list, update the device handle if necessary;
	if it's not in the list, add it at the end;
	if there have been additions to the list, remember to qsort at the end!
     */

     struct usb_bus *bus;
     struct usb_device *dev;
     
     INIT;
     usb_find_busses();
     usb_find_devices();

     for (bus = usb_busses; bus; bus = bus->next) {
	  for (dev = bus->devices; dev; dev = dev->next) {
	       int ret;
	       char b_name[256], b_name_uc[256];
	       char rev[256], rev_uc[256];
	       usb_dev_handle *udev;
	       struct surf_t *surf;
	       
	       /*  check that this is a SuRF board */
	       if (dev->descriptor.idVendor != SURF_VEND ||
		   dev->descriptor.idProduct != SURF_PROD)
		    continue;
	       
	       /*  check that we can open the device  */
	       if (!(udev = usb_open(dev))) {
		    surf_errno = ESURFDEV;
		    SURF_LOG(LOGSURF_ERROR, "Can't open device\n");
		    return -1;
	       }
	       
	       ret = usb_get_string(udev, dev->descriptor.iSerialNumber, 
				    0x03, b_name_uc, sizeof(b_name_uc));
	       if (ret <= 0) {
		    surf_errno = ESURFDEV;
		    SURF_LOG(LOGSURF_ERROR, "Can't get board serial number\n");
  		    return -1; 
	       } else convert_unicode(b_name_uc, b_name, ret);

	       SURF_LOG(LOGSURF_LOUD, "Serial Number: %s\n", b_name);

	       ret = usb_get_string(udev, SURF_FIRM_REV, 0x03, rev_uc, 
				    sizeof(rev_uc));
	       if (ret <= 0) {
		    surf_errno = ESURFDEV;
		    SURF_LOG(LOGSURF_ERROR, "Can't get board firmware "
			     "revision\n");
		    return -1;
	       } else convert_unicode(rev_uc, rev, ret);
	       SURF_LOG(LOGSURF_LOUD, "Revision: %02x.%02x.%02x\n", 
			rev[0], rev[1], rev[2]);

	       /* see if the board is already in the list */
	       if (!(surf = surf_search(b_name))) {
		    if (!(surf = surft_create(b_name))) 
			 /* something failed.  Errno already got set.
                             Just get out. */
			 return -1;
	       } else {
		    /* else just close the old device */
		    usb_close(surft_get_dev(surf));
	       }

	       surft_set_dev(surf, udev);
	       /* board is fresh again */
	       surft_make_fresh(surf);
	       surft_set_rev(surf, rev[0], rev[1], rev[2]);
	  }
     }

     return 0;
}

#endif /* ifdef HAVE_LIBUSB */