Initial import of sane-backends version 1.0.24-1.2

1 files changed, 1474 insertions, 0 deletions

diff --git a/backend/tamarack.c b/backend/tamarack.c
new file mode 100644
index 0000000..9baec51
--- /dev/null
+++ b/backend/tamarack.c
@@ -0,0 +1,1474 @@
+/* sane - Scanner Access Now Easy.
+   Copyright (C) 1996 David Mosberger-Tang
+   Copyright (C) 1997 R.E.Wolff@BitWizard.nl
+   This file is part of the SANE package.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+   MA 02111-1307, USA.
+
+   Note: The exception that is mentioned in the other source files is
+   not here. If a case arises where you need the rights that that
+   exception gives you, Please do contact me, and we'll work something
+   out.
+
+   R.E.Wolff@BitWizard.nl 
+   tel: +31-152137555 
+   fax: +31-152138217
+
+   This file implements a SANE backend for Tamarack flatbed scanners.  */
+
+/*
+   This driver was written initially by changing all occurances of
+   "mustek" to "tamarack". This actuall worked without modification
+   for the manufacturer detection code! :-)
+
+ */
+
+
+#include "../include/sane/config.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/time.h>
+
+#include "../include/_stdint.h"
+
+#include "../include/sane/sane.h"
+#include "../include/sane/sanei.h"
+#include "../include/sane/saneopts.h"
+#include "../include/sane/sanei_scsi.h"
+#include "../include/sane/sanei_thread.h"
+#include "../include/sane/sanei_config.h"
+
+/* For timeval... */
+#ifdef DEBUG
+#include <sys/time.h>
+#endif
+
+
+#define BACKEND_NAME	tamarack
+#include "../include/sane/sanei_backend.h"
+
+#include "tamarack.h"
+
+#ifndef PATH_MAX
+# define PATH_MAX	1024
+#endif
+
+#define TAMARACK_CONFIG_FILE "tamarack.conf"
+
+
+static int num_devices;
+static Tamarack_Device *first_dev;
+static Tamarack_Scanner *first_handle;
+
+static const SANE_String_Const mode_list[] =
+  {
+    SANE_VALUE_SCAN_MODE_LINEART,
+    SANE_VALUE_SCAN_MODE_HALFTONE,
+    SANE_VALUE_SCAN_MODE_GRAY,
+    SANE_VALUE_SCAN_MODE_COLOR,
+    0
+  };
+
+
+static const SANE_Range u8_range =
+  {
+      0,				/* minimum */
+    255,				/* maximum */
+      0				/* quantization */
+  };
+
+
+/* David used " 100 << SANE_FIXED_SCALE_SHIFT ". This assumes that
+ * it is implemented that way. I want to hide the datatype. 
+ */
+static const SANE_Range percentage_range =
+  {
+    SANE_FIX(-100),	/* minimum */
+    SANE_FIX( 100),	/* maximum */
+    SANE_FIX( 1  )	/* quantization */
+  };
+
+/* David used " 100 << SANE_FIXED_SCALE_SHIFT ". This assumes that
+ * it is implemented that way. I want to hide the datatype. 
+ */
+static const SANE_Range abs_percentage_range =
+  {
+    SANE_FIX( 0),	/* minimum */
+    SANE_FIX( 100),	/* maximum */
+    SANE_FIX( 1  )	/* quantization */
+  };
+
+
+#define INQ_LEN	0x60
+static const uint8_t inquiry[] =
+{
+  TAMARACK_SCSI_INQUIRY, 0x00, 0x00, 0x00, INQ_LEN, 0x00
+};
+
+static const uint8_t test_unit_ready[] =
+{
+  TAMARACK_SCSI_TEST_UNIT_READY, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+static const uint8_t stop[] =
+{
+  TAMARACK_SCSI_START_STOP, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+static const uint8_t get_status[] =
+{
+  TAMARACK_SCSI_GET_DATA_STATUS, 0x00, 0x00, 0x00, 0x00, 0x00, 
+                                       0x00, 0x00, 0x0c, 0x00
+};
+
+
+
+static SANE_Status
+wait_ready (int fd)
+{
+  SANE_Status status;
+  int i;
+
+  for (i = 0; i < 1000; ++i)
+    {
+      DBG(3, "wait_ready: sending TEST_UNIT_READY\n");
+      status = sanei_scsi_cmd (fd, test_unit_ready, sizeof (test_unit_ready),
+			       0, 0);
+      switch (status)
+	{
+	default:
+	  /* Ignore errors while waiting for scanner to become ready.
+	     Some SCSI drivers return EIO while the scanner is
+	     returning to the home position.  */
+	  DBG(1, "wait_ready: test unit ready failed (%s)\n",
+	      sane_strstatus (status));
+	  /* fall through */
+	case SANE_STATUS_DEVICE_BUSY:
+	  usleep (100000);	/* retry after 100ms */
+	  break;
+
+	case SANE_STATUS_GOOD:
+	  return status;
+	}
+    }
+  DBG(1, "wait_ready: timed out after %d attempts\n", i);
+  return SANE_STATUS_INVAL;
+}
+
+
+
+static SANE_Status
+sense_handler (int scsi_fd, u_char *result, void *arg)
+{
+  scsi_fd = scsi_fd;
+  arg = arg; /* silence compilation warnings */
+
+  switch (result[0])
+    {
+    case 0x00:
+      break;
+
+    default:
+      DBG(1, "sense_handler: got unknown sense code %02x\n", result[0]);
+      return SANE_STATUS_IO_ERROR;
+    }
+  return SANE_STATUS_GOOD;
+}
+
+
+/* XXX This might leak the memory to a TAMARACK string */
+
+static SANE_Status
+attach (const char *devname, Tamarack_Device **devp)
+{
+  char result[INQ_LEN];
+  int fd;
+  Tamarack_Device *dev;
+  SANE_Status status;
+  size_t size;
+  char *mfg, *model;
+  char *p;
+
+  for (dev = first_dev; dev; dev = dev->next)
+    if (strcmp (dev->sane.name, devname) == 0) {
+      if (devp)
+	*devp = dev;
+      return SANE_STATUS_GOOD;
+    }
+
+  DBG(3, "attach: opening %s\n", devname);
+  status = sanei_scsi_open (devname, &fd, sense_handler, 0);
+  if (status != SANE_STATUS_GOOD) {
+    DBG(1, "attach: open failed (%s)\n", sane_strstatus (status));
+    return SANE_STATUS_INVAL;
+  }
+
+  DBG(3, "attach: sending INQUIRY\n");
+  size = sizeof (result);
+  status = sanei_scsi_cmd (fd, inquiry, sizeof (inquiry), result, &size);
+  if (status != SANE_STATUS_GOOD || size != INQ_LEN) {
+    DBG(1, "attach: inquiry failed (%s)\n", sane_strstatus (status));
+    sanei_scsi_close (fd);
+    return status;
+  }
+
+  status = wait_ready (fd);
+  sanei_scsi_close (fd);
+  if (status != SANE_STATUS_GOOD)
+    return status;
+
+  result[33]= '\0';
+  p = strchr(result+16,' ');
+  if (p) *p = '\0';
+  model = strdup (result+16);
+
+  result[16]= '\0';
+  p = strchr(result+8,' ');
+  if (p) *p = '\0';
+  mfg = strdup (result+8);
+
+  DBG(1, "attach: Inquiry gives mfg=%s, model=%s.\n", mfg, model);
+  
+  if (strcmp (mfg, "TAMARACK") != 0) {
+    DBG(1, "attach: device doesn't look like a Tamarack scanner "
+	   "(result[0]=%#02x)\n", result[0]);
+    return SANE_STATUS_INVAL;
+  }
+  
+  dev = malloc (sizeof (*dev));
+  if (!dev)
+    return SANE_STATUS_NO_MEM;
+  
+  memset (dev, 0, sizeof (*dev));
+
+  dev->sane.name   = strdup (devname);
+  dev->sane.vendor = "Tamarack";
+  dev->sane.model  = model;
+  dev->sane.type   = "flatbed scanner";
+
+  dev->x_range.min = 0;
+  dev->y_range.min = 0;
+  dev->x_range.quant = 0;
+  dev->y_range.quant = 0;
+  dev->dpi_range.min = SANE_FIX (1);
+  dev->dpi_range.quant = SANE_FIX (1);
+
+  dev->x_range.max = SANE_FIX (8.5 * MM_PER_INCH);
+  dev->y_range.max = SANE_FIX (11.0 * MM_PER_INCH);
+  dev->dpi_range.max = SANE_FIX (600);
+
+  DBG(3, "attach: found Tamarack scanner model %s (%s)\n",
+      dev->sane.model, dev->sane.type);
+
+  ++num_devices;
+  dev->next = first_dev;
+  first_dev = dev;
+
+  if (devp)
+    *devp = dev;
+  return SANE_STATUS_GOOD;
+}
+
+
+static size_t
+max_string_size (const SANE_String_Const strings[])
+{
+  size_t size, max_size = 0;
+  int i;
+
+  for (i = 0; strings[i]; ++i)
+    {
+      size = strlen (strings[i]) + 1;
+      if (size > max_size)
+	max_size = size;
+    }
+  return max_size;
+}
+
+
+static SANE_Status
+constrain_value (Tamarack_Scanner *s, SANE_Int option, void *value,
+		 SANE_Int *info)
+{
+  return sanei_constrain_value (s->opt + option, value, info);
+}
+
+
+static unsigned char sign_mag (double val)
+{
+  if (val >  100) val =  100;
+  if (val < -100) val = -100;
+  if (val >= 0) return ( val);
+  else          return ((unsigned char)(-val)) | 0x80;
+}
+
+
+
+static SANE_Status
+scan_area_and_windows (Tamarack_Scanner *s)
+{
+  struct def_win_par dwp;
+
+  memset (&dwp,'\0',sizeof (dwp));
+  dwp.dwph.opc = TAMARACK_SCSI_AREA_AND_WINDOWS;
+  set_triple (dwp.dwph.len,8 + sizeof (dwp.wdb)); 
+
+  set_double (dwp.wdh.wpll, sizeof (dwp.wdb));
+
+  dwp.wdb.winid = WINID;
+  set_double (dwp.wdb.xres, (int) SANE_UNFIX (s->val[OPT_RESOLUTION].w));
+  set_double (dwp.wdb.yres, (int) SANE_UNFIX (s->val[OPT_RESOLUTION].w));
+
+  set_quad (dwp.wdb.ulx, (int) (47.2 * SANE_UNFIX (s->val[OPT_TL_X].w)));
+  set_quad (dwp.wdb.uly, (int) (47.2 * SANE_UNFIX (s->val[OPT_TL_Y].w)));
+  set_quad (dwp.wdb.width, 
+     (int) (47.2 * SANE_UNFIX (s->val[OPT_BR_X].w - s->val[OPT_TL_X].w)));
+  set_quad (dwp.wdb.length,
+     (int) (47.2 * SANE_UNFIX (s->val[OPT_BR_Y].w - s->val[OPT_TL_Y].w)));
+
+  dwp.wdb.brightness = sign_mag (SANE_UNFIX (s->val[OPT_BRIGHTNESS].w));
+  dwp.wdb.contrast   = sign_mag (SANE_UNFIX (s->val[OPT_CONTRAST].w));
+  dwp.wdb.thresh     = 0x80;
+
+
+  switch (s->mode) {
+  case THRESHOLDED:
+    dwp.wdb.bpp = 1;
+    dwp.wdb.image_comp = 0;
+    dwp.wdb.thresh     = 1 + 2.55 * (SANE_UNFIX (s->val[OPT_THRESHOLD].w)); 
+    break;
+  case DITHERED:
+    dwp.wdb.bpp = 1;
+    dwp.wdb.image_comp = 1;
+    break;
+  case GREYSCALE:
+    dwp.wdb.bpp = 8;
+    dwp.wdb.image_comp = 2;
+    break;
+  case TRUECOLOR:
+    dwp.wdb.bpp = 8;
+    dwp.wdb.image_comp = 2;
+    break;
+  default:
+    DBG(1, "Invalid mode. %d\n", s->mode);
+    return SANE_STATUS_INVAL;
+  }
+  DBG(1, "bright, thresh, contrast = %d(%5.1f), %d, %d(%5.1f)\n", 
+      dwp.wdb.brightness, SANE_UNFIX (s->val[OPT_BRIGHTNESS].w),
+      dwp.wdb.thresh    ,
+      dwp.wdb.contrast  , SANE_UNFIX (s->val[OPT_CONTRAST].w));
+
+  set_double (dwp.wdb.halftone, 1); /* XXX What does this do again ? */
+  dwp.wdb.pad_type   = 3;           /* This is the only usable pad-type. */
+  dwp.wdb.exposure   = 0x6f;        /* XXX Option? */
+  dwp.wdb.compr_type = 0;
+
+  /* XXX Shouldn't this be sizeof (dwp) */
+  return sanei_scsi_cmd (s->fd, &dwp, (10+8+38), 0, 0);
+}
+
+
+static SANE_Status
+mode_select (Tamarack_Scanner *s)
+{
+  struct  {
+    struct command_header cmd;
+    struct page_header hdr;
+    struct tamarack_page page;
+  } c;
+
+  memset (&c, '\0', sizeof (c));  
+  c.cmd.opc = TAMARACK_SCSI_MODE_SELECT;
+  c.cmd.pad0[0] = 0x10;    /* Suddenly the pad bytes are no long pad... */
+  c.cmd.pad0[1] = 0;
+  c.cmd.len = sizeof (struct page_header) + sizeof (struct tamarack_page);
+  c.hdr.code = 0;
+  c.hdr.length = 6;
+  c.page.gamma = 2;
+  c.page.thresh = 0x80;    /* XXX Option? */
+  switch (s->mode) {
+  case THRESHOLDED:
+  case DITHERED:
+  case GREYSCALE:
+    c.page.masks = 0x80;   
+    break;
+  case TRUECOLOR:
+    c.page.masks = 0x40 >> s->pass;
+    break;
+  }
+  c.page.delay = 0x10;      /* XXX Option? */
+  c.page.features = (s->val[OPT_TRANS].w ? TAM_TRANS_ON:0) | 1;
+  return sanei_scsi_cmd (s->fd, &c, sizeof (c), 0, 0);
+}
+
+
+static SANE_Status
+start_scan (Tamarack_Scanner *s)
+{
+  struct  {
+    struct command_header cmd;
+    unsigned char winid[1];
+  } c;
+  
+  memset (&c,'\0',sizeof (c));
+  c.cmd.opc = TAMARACK_SCSI_START_STOP;
+  c.cmd.len = sizeof (c.winid);
+  c.winid[0] = WINID;
+  return sanei_scsi_cmd (s->fd, &c, sizeof (c), 0, 0);
+}
+
+
+static SANE_Status
+stop_scan (Tamarack_Scanner *s)
+{ 
+  /* XXX I don't think a TAMARACK can stop in mid-scan. Just stop
+     sending it requests for data.... 
+   */
+  return sanei_scsi_cmd (s->fd, stop, sizeof (stop), 0, 0);
+}
+
+
+static SANE_Status
+do_eof (Tamarack_Scanner *s)
+{
+  if (s->pipe >= 0)
+    {
+      close (s->pipe);
+      s->pipe = -1;
+    }
+  return SANE_STATUS_EOF;
+}
+
+
+static SANE_Status
+do_cancel (Tamarack_Scanner *s)
+{
+  s->scanning = SANE_FALSE;
+  s->pass = 0;
+
+  do_eof (s);
+
+  if (s->reader_pid != -1)
+    {
+      int exit_status;
+
+      /* ensure child knows it's time to stop: */
+      sanei_thread_kill (s->reader_pid);
+      sanei_thread_waitpid (s->reader_pid, &exit_status);
+      s->reader_pid = -1;
+    }
+
+  if (s->fd >= 0)
+    {
+      stop_scan (s);
+      sanei_scsi_close (s->fd);
+      s->fd = -1;
+    }
+
+  return SANE_STATUS_CANCELLED;
+}
+
+
+static SANE_Status
+get_image_status (Tamarack_Scanner *s)
+{
+  uint8_t result[12];
+  SANE_Status status;
+  size_t len;
+  int busy;
+
+#if 1
+  do
+    {
+      len = sizeof (result);
+      status = sanei_scsi_cmd (s->fd, get_status, sizeof (get_status),
+			    result, &len);
+      if ((status != SANE_STATUS_GOOD) && (status != SANE_STATUS_DEVICE_BUSY))
+	return status;
+
+      busy = (result[2] != 8) || (status == SANE_STATUS_DEVICE_BUSY);
+      if (busy)
+	usleep (100000);
+
+      if (!s->scanning)
+	return do_cancel (s);
+    }
+  while (busy);
+#else
+  /* XXX Test if this works one day... */
+  wait_ready (s);
+#endif
+
+  len = sizeof (result);
+  status = sanei_scsi_cmd (s->fd, get_status, sizeof (get_status),
+			   result, &len);
+  if ((status != SANE_STATUS_GOOD) && (status != SANE_STATUS_DEVICE_BUSY))
+    return status;
+  
+  s->params.bytes_per_line = 
+    result[ 8] | (result[ 7] << 8) | (result[6] << 16);
+  s->params.lines = 
+    result[11] | (result[10] << 8) | (result[9] << 16);
+
+  switch (s->mode) {
+  case DITHERED:
+  case THRESHOLDED:
+    s->params.pixels_per_line = 8 * s->params.bytes_per_line;
+    break;
+  case GREYSCALE:
+  case TRUECOLOR:
+    s->params.pixels_per_line =     s->params.bytes_per_line;
+    break;
+  }
+
+
+  DBG(1, "get_image_status: bytes_per_line=%d, lines=%d\n",
+      s->params.bytes_per_line, s->params.lines);
+  return SANE_STATUS_GOOD;
+}
+
+
+static SANE_Status
+read_data (Tamarack_Scanner *s, SANE_Byte *buf, int lines, int bpl)
+{
+  struct command_header_10 cmd;
+  size_t nbytes;
+  SANE_Status status;
+#ifdef DEBUG
+  int dt;
+  struct timeval tv_start,tv_end;
+#endif
+
+  nbytes = bpl * lines;
+  memset (&cmd,'\0',sizeof (cmd));
+  cmd.opc = 0x28;
+  set_triple (cmd.len,nbytes);
+
+#ifdef DEBUG
+  if (verbose) DBG (1, "Doing read_data... \n");
+  gettimeofday (&tv_start,NULL);
+#endif
+
+  status = sanei_scsi_cmd (s->fd, &cmd, sizeof (cmd), buf, &nbytes);
+
+#ifdef DEBUG
+  gettimeofday (&tv_end,NULL);
+  dt =  tv_end.tv_usec - tv_start.tv_usec +
+       (tv_end.tv_sec  - tv_start.tv_sec) * 1000000;
+  if (verbose) DBG(1, "Read took %d.%06d seconds.",
+		   dt/1000000,dt%1000000);
+  dt = 1000000 * nbytes / dt;
+  if (verbose) DBG(1, "which is %d.%03d bytes per second.\n",dt,0);
+#endif
+  return status;
+}
+
+
+
+static SANE_Status
+init_options (Tamarack_Scanner *s)
+{
+  int i;
+
+  memset (s->opt, 0, sizeof (s->opt));
+  memset (s->val, 0, sizeof (s->val));
+
+  for (i = 0; i < NUM_OPTIONS; ++i) {
+    s->opt[i].size = sizeof (SANE_Word);
+    s->opt[i].cap = SANE_CAP_SOFT_SELECT | SANE_CAP_SOFT_DETECT;
+  }
+
+  s->opt[OPT_NUM_OPTS].title = SANE_TITLE_NUM_OPTIONS;
+  s->opt[OPT_NUM_OPTS].desc = SANE_DESC_NUM_OPTIONS;
+  s->opt[OPT_NUM_OPTS].type = SANE_TYPE_INT;
+  s->opt[OPT_NUM_OPTS].cap = SANE_CAP_SOFT_DETECT;
+  s->val[OPT_NUM_OPTS].w = NUM_OPTIONS;
+
+  /* "Mode" group: */
+  s->opt[OPT_MODE_GROUP].title = "Scan Mode";
+  s->opt[OPT_MODE_GROUP].desc = "";
+  s->opt[OPT_MODE_GROUP].type = SANE_TYPE_GROUP;
+  s->opt[OPT_MODE_GROUP].cap = 0;
+  s->opt[OPT_MODE_GROUP].constraint_type = SANE_CONSTRAINT_NONE;
+
+  /* scan mode */
+  s->opt[OPT_MODE].name = SANE_NAME_SCAN_MODE;
+  s->opt[OPT_MODE].title = SANE_TITLE_SCAN_MODE;
+  s->opt[OPT_MODE].desc = "Select the scan mode";
+  s->opt[OPT_MODE].type = SANE_TYPE_STRING;
+  s->opt[OPT_MODE].size = max_string_size (mode_list);
+  s->opt[OPT_MODE].constraint_type = SANE_CONSTRAINT_STRING_LIST;
+  s->opt[OPT_MODE].constraint.string_list = mode_list;
+  s->val[OPT_MODE].s = strdup (mode_list[OPT_MODE_DEFAULT]);
+
+  /* resolution */
+  s->opt[OPT_RESOLUTION].name = SANE_NAME_SCAN_RESOLUTION;
+  s->opt[OPT_RESOLUTION].title = SANE_TITLE_SCAN_RESOLUTION;
+  s->opt[OPT_RESOLUTION].desc = SANE_DESC_SCAN_RESOLUTION;
+  s->opt[OPT_RESOLUTION].type = SANE_TYPE_FIXED;
+  s->opt[OPT_RESOLUTION].unit = SANE_UNIT_DPI;
+  s->opt[OPT_RESOLUTION].constraint_type = SANE_CONSTRAINT_RANGE;
+  s->opt[OPT_RESOLUTION].constraint.range = &s->hw->dpi_range;
+  s->val[OPT_RESOLUTION].w = SANE_FIX (OPT_RESOLUTION_DEFAULT);
+
+  /* preview */
+  s->opt[OPT_PREVIEW].name = SANE_NAME_PREVIEW;
+  s->opt[OPT_PREVIEW].title = SANE_TITLE_PREVIEW;
+  s->opt[OPT_PREVIEW].desc = SANE_DESC_PREVIEW;
+  s->opt[OPT_PREVIEW].cap = SANE_CAP_SOFT_DETECT | SANE_CAP_SOFT_SELECT;
+  s->val[OPT_PREVIEW].w = 0;
+
+  /* gray preview */
+  s->opt[OPT_GRAY_PREVIEW].name = SANE_NAME_GRAY_PREVIEW;
+  s->opt[OPT_GRAY_PREVIEW].title = SANE_TITLE_GRAY_PREVIEW;
+  s->opt[OPT_GRAY_PREVIEW].desc = SANE_DESC_GRAY_PREVIEW;
+  s->opt[OPT_GRAY_PREVIEW].type = SANE_TYPE_BOOL;
+  s->val[OPT_GRAY_PREVIEW].w = SANE_FALSE;
+
+  /* "Geometry" group: */
+  s->opt[OPT_GEOMETRY_GROUP].title = "Geometry";
+  s->opt[OPT_GEOMETRY_GROUP].desc = "";
+  s->opt[OPT_GEOMETRY_GROUP].type = SANE_TYPE_GROUP;
+  s->opt[OPT_GEOMETRY_GROUP].cap = SANE_CAP_ADVANCED;
+  s->opt[OPT_GEOMETRY_GROUP].constraint_type = SANE_CONSTRAINT_NONE;
+
+  /* top-left x */
+  s->opt[OPT_TL_X].name = SANE_NAME_SCAN_TL_X;
+  s->opt[OPT_TL_X].title = SANE_TITLE_SCAN_TL_X;
+  s->opt[OPT_TL_X].desc = SANE_DESC_SCAN_TL_X;
+  s->opt[OPT_TL_X].type = SANE_TYPE_FIXED;
+  s->opt[OPT_TL_X].unit = SANE_UNIT_MM;
+  s->opt[OPT_TL_X].constraint_type = SANE_CONSTRAINT_RANGE;
+  s->opt[OPT_TL_X].constraint.range = &s->hw->x_range;
+  s->val[OPT_TL_X].w = 0;
+
+  /* top-left y */
+  s->opt[OPT_TL_Y].name = SANE_NAME_SCAN_TL_Y;
+  s->opt[OPT_TL_Y].title = SANE_TITLE_SCAN_TL_Y;
+  s->opt[OPT_TL_Y].desc = SANE_DESC_SCAN_TL_Y;
+  s->opt[OPT_TL_Y].type = SANE_TYPE_FIXED;
+  s->opt[OPT_TL_Y].unit = SANE_UNIT_MM;
+  s->opt[OPT_TL_Y].constraint_type = SANE_CONSTRAINT_RANGE;
+  s->opt[OPT_TL_Y].constraint.range = &s->hw->y_range;
+  s->val[OPT_TL_Y].w = 0;
+
+  /* bottom-right x */
+  s->opt[OPT_BR_X].name = SANE_NAME_SCAN_BR_X;
+  s->opt[OPT_BR_X].title = SANE_TITLE_SCAN_BR_X;
+  s->opt[OPT_BR_X].desc = SANE_DESC_SCAN_BR_X;
+  s->opt[OPT_BR_X].type = SANE_TYPE_FIXED;
+  s->opt[OPT_BR_X].unit = SANE_UNIT_MM;
+  s->opt[OPT_BR_X].constraint_type = SANE_CONSTRAINT_RANGE;
+  s->opt[OPT_BR_X].constraint.range = &s->hw->x_range;
+  s->val[OPT_BR_X].w = s->hw->x_range.max;
+
+  /* bottom-right y */
+  s->opt[OPT_BR_Y].name = SANE_NAME_SCAN_BR_Y;
+  s->opt[OPT_BR_Y].title = SANE_TITLE_SCAN_BR_Y;
+  s->opt[OPT_BR_Y].desc = SANE_DESC_SCAN_BR_Y;
+  s->opt[OPT_BR_Y].type = SANE_TYPE_FIXED;
+  s->opt[OPT_BR_Y].unit = SANE_UNIT_MM;
+  s->opt[OPT_BR_Y].constraint_type = SANE_CONSTRAINT_RANGE;
+  s->opt[OPT_BR_Y].constraint.range = &s->hw->y_range;
+  s->val[OPT_BR_Y].w = s->hw->y_range.max;
+
+  /* "Enhancement" group: */
+  s->opt[OPT_ENHANCEMENT_GROUP].title = "Enhancement";
+  s->opt[OPT_ENHANCEMENT_GROUP].desc = "";
+  s->opt[OPT_ENHANCEMENT_GROUP].type = SANE_TYPE_GROUP;
+  s->opt[OPT_ENHANCEMENT_GROUP].cap = 0;
+  s->opt[OPT_ENHANCEMENT_GROUP].constraint_type = SANE_CONSTRAINT_NONE;
+
+  /* transparency adapter. */
+  s->opt[OPT_TRANS].name = "transparency";
+  s->opt[OPT_TRANS].title = "transparency";
+  s->opt[OPT_TRANS].desc = "Turn on the transparency adapter.";
+  s->opt[OPT_TRANS].type = SANE_TYPE_BOOL;
+  s->opt[OPT_TRANS].unit = SANE_UNIT_NONE;
+  s->val[OPT_TRANS].w = SANE_FALSE;
+
+  /* brightness */
+  s->opt[OPT_BRIGHTNESS].name = SANE_NAME_BRIGHTNESS;
+  s->opt[OPT_BRIGHTNESS].title = SANE_TITLE_BRIGHTNESS;
+  s->opt[OPT_BRIGHTNESS].desc = SANE_DESC_BRIGHTNESS
+    "  This option is active for lineart/halftone modes only.  "
+    "For multibit modes (grey/color) use the gamma-table(s).";
+  s->opt[OPT_BRIGHTNESS].type = SANE_TYPE_FIXED;
+  s->opt[OPT_BRIGHTNESS].unit = SANE_UNIT_PERCENT;
+  s->opt[OPT_BRIGHTNESS].constraint_type = SANE_CONSTRAINT_RANGE;
+  s->opt[OPT_BRIGHTNESS].constraint.range = &percentage_range;
+  s->val[OPT_BRIGHTNESS].w = SANE_FIX(0);
+
+  /* contrast */
+  s->opt[OPT_CONTRAST].name = SANE_NAME_CONTRAST;
+  s->opt[OPT_CONTRAST].title = SANE_TITLE_CONTRAST;
+  s->opt[OPT_CONTRAST].desc = SANE_DESC_CONTRAST
+    "  This option is active for lineart/halftone modes only.  "
+    "For multibit modes (grey/color) use the gamma-table(s).";
+  s->opt[OPT_CONTRAST].type = SANE_TYPE_FIXED;
+  s->opt[OPT_CONTRAST].unit = SANE_UNIT_PERCENT;
+  s->opt[OPT_CONTRAST].constraint_type = SANE_CONSTRAINT_RANGE;
+  s->opt[OPT_CONTRAST].constraint.range = &percentage_range;
+  s->val[OPT_CONTRAST].w = SANE_FIX(0);
+
+  /* Threshold */
+  s->opt[OPT_THRESHOLD].name = "Threshold";
+  s->opt[OPT_THRESHOLD].title = "Threshold";
+  s->opt[OPT_THRESHOLD].desc = "Threshold: below this level is black, above is white"
+    "  This option is active for bitmap modes only.  ";
+  s->opt[OPT_THRESHOLD].type = SANE_TYPE_FIXED;
+  s->opt[OPT_THRESHOLD].unit = SANE_UNIT_PERCENT;
+  s->opt[OPT_THRESHOLD].constraint_type = SANE_CONSTRAINT_RANGE;
+  s->opt[OPT_THRESHOLD].constraint.range = &abs_percentage_range;
+  s->val[OPT_THRESHOLD].w = SANE_FIX(50);
+  s->opt[OPT_THRESHOLD].cap  |= SANE_CAP_INACTIVE;
+
+#if 0
+  /* custom-gamma table */
+  s->opt[OPT_CUSTOM_GAMMA].name = SANE_NAME_CUSTOM_GAMMA;
+  s->opt[OPT_CUSTOM_GAMMA].title = SANE_TITLE_CUSTOM_GAMMA;
+  s->opt[OPT_CUSTOM_GAMMA].desc = SANE_DESC_CUSTOM_GAMMA;
+  s->opt[OPT_CUSTOM_GAMMA].type = SANE_TYPE_BOOL;
+  s->opt[OPT_CUSTOM_GAMMA].cap |= SANE_CAP_INACTIVE;
+  s->val[OPT_CUSTOM_GAMMA].w = SANE_FALSE;
+
+  /* grayscale gamma vector */
+  s->opt[OPT_GAMMA_VECTOR].name = SANE_NAME_GAMMA_VECTOR;
+  s->opt[OPT_GAMMA_VECTOR].title = SANE_TITLE_GAMMA_VECTOR;
+  s->opt[OPT_GAMMA_VECTOR].desc = SANE_DESC_GAMMA_VECTOR;
+  s->opt[OPT_GAMMA_VECTOR].type = SANE_TYPE_INT;
+  s->opt[OPT_GAMMA_VECTOR].cap |= SANE_CAP_INACTIVE;
+  s->opt[OPT_GAMMA_VECTOR].unit = SANE_UNIT_NONE;
+  s->opt[OPT_GAMMA_VECTOR].size = 256 * sizeof (SANE_Word);
+  s->opt[OPT_GAMMA_VECTOR].constraint_type = SANE_CONSTRAINT_RANGE;
+  s->opt[OPT_GAMMA_VECTOR].constraint.range = &u8_range;
+  s->val[OPT_GAMMA_VECTOR].wa = &s->gamma_table[0][0];
+
+  /* red gamma vector */
+  s->opt[OPT_GAMMA_VECTOR_R].name = SANE_NAME_GAMMA_VECTOR_R;
+  s->opt[OPT_GAMMA_VECTOR_R].title = SANE_TITLE_GAMMA_VECTOR_R;
+  s->opt[OPT_GAMMA_VECTOR_R].desc = SANE_DESC_GAMMA_VECTOR_R;
+  s->opt[OPT_GAMMA_VECTOR_R].type = SANE_TYPE_INT;
+  s->opt[OPT_GAMMA_VECTOR_R].cap |= SANE_CAP_INACTIVE;
+  s->opt[OPT_GAMMA_VECTOR_R].unit = SANE_UNIT_NONE;
+  s->opt[OPT_GAMMA_VECTOR_R].size = 256 * sizeof (SANE_Word);
+  s->opt[OPT_GAMMA_VECTOR_R].constraint_type = SANE_CONSTRAINT_RANGE;
+  s->opt[OPT_GAMMA_VECTOR_R].constraint.range = &u8_range;
+  s->val[OPT_GAMMA_VECTOR_R].wa = &s->gamma_table[1][0];
+
+  /* green gamma vector */
+  s->opt[OPT_GAMMA_VECTOR_G].name = SANE_NAME_GAMMA_VECTOR_G;
+  s->opt[OPT_GAMMA_VECTOR_G].title = SANE_TITLE_GAMMA_VECTOR_G;
+  s->opt[OPT_GAMMA_VECTOR_G].desc = SANE_DESC_GAMMA_VECTOR_G;
+  s->opt[OPT_GAMMA_VECTOR_G].type = SANE_TYPE_INT;
+  s->opt[OPT_GAMMA_VECTOR_G].cap |= SANE_CAP_INACTIVE;
+  s->opt[OPT_GAMMA_VECTOR_G].unit = SANE_UNIT_NONE;
+  s->opt[OPT_GAMMA_VECTOR_G].size = 256 * sizeof (SANE_Word);
+  s->opt[OPT_GAMMA_VECTOR_G].constraint_type = SANE_CONSTRAINT_RANGE;
+  s->opt[OPT_GAMMA_VECTOR_G].constraint.range = &u8_range;
+  s->val[OPT_GAMMA_VECTOR_G].wa = &s->gamma_table[2][0];
+
+  /* blue gamma vector */
+  s->opt[OPT_GAMMA_VECTOR_B].name = SANE_NAME_GAMMA_VECTOR_B;
+  s->opt[OPT_GAMMA_VECTOR_B].title = SANE_TITLE_GAMMA_VECTOR_B;
+  s->opt[OPT_GAMMA_VECTOR_B].desc = SANE_DESC_GAMMA_VECTOR_B;
+  s->opt[OPT_GAMMA_VECTOR_B].type = SANE_TYPE_INT;
+  s->opt[OPT_GAMMA_VECTOR_B].cap |= SANE_CAP_INACTIVE;
+  s->opt[OPT_GAMMA_VECTOR_B].unit = SANE_UNIT_NONE;
+  s->opt[OPT_GAMMA_VECTOR_B].size = 256 * sizeof (SANE_Word);
+  s->opt[OPT_GAMMA_VECTOR_B].constraint_type = SANE_CONSTRAINT_RANGE;
+  s->opt[OPT_GAMMA_VECTOR_B].constraint.range = &u8_range;
+  s->val[OPT_GAMMA_VECTOR_B].wa = &s->gamma_table[3][0];
+#endif
+  return SANE_STATUS_GOOD;
+}
+
+
+/* This function is executed as a child process.  The reason this is
+   executed as a subprocess is because some (most?) generic SCSI
+   interfaces block a SCSI request until it has completed.  With a
+   subprocess, we can let it block waiting for the request to finish
+   while the main process can go about to do more important things
+   (such as recognizing when the user presses a cancel button).
+
+   WARNING: Since this is executed as a subprocess, it's NOT possible
+   to update any of the variables in the main process (in particular
+   the scanner state cannot be updated).  */
+static int
+reader_process (void *scanner)
+{
+  Tamarack_Scanner *s = (Tamarack_Scanner *) scanner;
+  int fd = s->reader_pipe;
+
+  SANE_Byte *data;
+  int lines_per_buffer, bpl;
+  SANE_Status status;
+  sigset_t sigterm_set;
+  sigset_t ignore_set;
+  struct SIGACTION act;
+  FILE *fp;
+
+  if (sanei_thread_is_forked()) close (s->pipe);
+
+  sigfillset (&ignore_set);
+  sigdelset (&ignore_set, SIGTERM);
+#if defined (__APPLE__) && defined (__MACH__)
+  sigdelset (&ignore_set, SIGUSR2);
+#endif
+  sigprocmask (SIG_SETMASK, &ignore_set, 0);
+
+  memset (&act, 0, sizeof (act));
+  sigaction (SIGTERM, &act, 0);
+
+  sigemptyset (&sigterm_set);
+  sigaddset (&sigterm_set, SIGTERM);
+
+  fp = fdopen (fd, "w");
+  if (!fp)
+    return 1;
+
+  bpl = s->params.bytes_per_line;
+
+  lines_per_buffer = sanei_scsi_max_request_size / bpl;
+  if (!lines_per_buffer)
+    return 2;			/* resolution is too high */
+
+  /* Limit the size of a single transfer to one inch. 
+     XXX Add a stripsize option. */
+  if (lines_per_buffer > SANE_UNFIX (s->val[OPT_RESOLUTION].w))
+      lines_per_buffer = SANE_UNFIX (s->val[OPT_RESOLUTION].w);
+
+  DBG(3, "lines_per_buffer=%d, bytes_per_line=%d\n", lines_per_buffer, bpl);
+
+  data = malloc (lines_per_buffer * bpl);
+
+  for (s->line = 0; s->line < s->params.lines; s->line += lines_per_buffer) {
+    if (s->line + lines_per_buffer > s->params.lines)
+      /* do the last few lines: */
+      lines_per_buffer = s->params.lines - s->line;
+
+    sigprocmask (SIG_BLOCK, &sigterm_set, 0);
+    status = read_data (s, data, lines_per_buffer, bpl);
+    sigprocmask (SIG_UNBLOCK, &sigterm_set, 0);
+    if (status != SANE_STATUS_GOOD) {
+      DBG(1, "reader_process: read_data failed with status=%d\n", status);
+      return 3;
+    }
+    DBG(3, "reader_process: read %d lines\n", lines_per_buffer);
+    
+    if ((s->mode == TRUECOLOR) || (s->mode == GREYSCALE)) {
+      fwrite (data, lines_per_buffer, bpl, fp);
+    } else {
+      /* in singlebit mode, the scanner returns 1 for black. ;-( --DM */
+      /* Hah! Same for Tamarack... -- REW */
+      int i;
+      
+      for (i = 0; i < lines_per_buffer * bpl; ++i)
+	fputc (~data[i], fp);
+    }
+  }
+  fclose (fp);
+  return 0;
+}
+
+
+static SANE_Status
+attach_one (const char *dev)
+{
+  attach (dev, 0);
+  return SANE_STATUS_GOOD;
+}
+
+
+SANE_Status
+sane_init (SANE_Int *version_code, SANE_Auth_Callback authorize)
+{
+  char dev_name[PATH_MAX];
+  size_t len;
+  FILE *fp;
+
+  authorize = authorize; /* silence compilation warnings */
+
+  DBG_INIT();
+
+  sanei_thread_init();
+
+  if (version_code)
+    *version_code = SANE_VERSION_CODE (SANE_CURRENT_MAJOR, V_MINOR, 0);
+
+  fp = sanei_config_open (TAMARACK_CONFIG_FILE);
+  if (!fp) {
+    /* default to /dev/scanner instead of insisting on config file */
+    attach ("/dev/scanner", 0);
+    return SANE_STATUS_GOOD;
+  }
+
+  while (sanei_config_read (dev_name, sizeof (dev_name), fp)) {
+    if (dev_name[0] == '#')		/* ignore line comments */
+      continue;
+    len = strlen (dev_name);
+    
+    if (!len)
+      continue;			/* ignore empty lines */
+    
+    sanei_config_attach_matching_devices (dev_name, attach_one);
+  }
+  fclose (fp);
+  return SANE_STATUS_GOOD;
+}
+
+
+void
+sane_exit (void)
+{
+  Tamarack_Device *dev, *next;
+
+  for (dev = first_dev; dev; dev = next) {
+    next = dev->next;
+    free ((void *) dev->sane.name);
+    free ((void *) dev->sane.model);
+    free (dev);
+  }
+}
+
+SANE_Status
+sane_get_devices (const SANE_Device ***device_list, SANE_Bool local_only)
+{
+  static const SANE_Device **devlist = 0;
+  Tamarack_Device *dev;
+  int i;
+
+  local_only = local_only; /* silence compilation warnings */
+
+  if (devlist)
+    free (devlist);
+
+  devlist = malloc ((num_devices + 1) * sizeof (devlist[0]));
+  if (!devlist)
+    return SANE_STATUS_NO_MEM;
+
+  i = 0;
+  for (dev = first_dev; i < num_devices; dev = dev->next)
+    devlist[i++] = &dev->sane;
+  devlist[i++] = 0;
+
+  *device_list = devlist;
+  return SANE_STATUS_GOOD;
+}
+
+
+SANE_Status
+sane_open (SANE_String_Const devicename, SANE_Handle *handle)
+{
+  Tamarack_Device *dev;
+  SANE_Status status;
+  Tamarack_Scanner *s;
+  int i, j;
+
+  if (devicename[0]) {
+    for (dev = first_dev; dev; dev = dev->next)
+      if (strcmp (dev->sane.name, devicename) == 0)
+	break;
+
+    if (!dev) {
+      status = attach (devicename, &dev);
+      if (status != SANE_STATUS_GOOD)
+	return status;
+    }
+  } else {
+    /* empty devicname -> use first device */
+    dev = first_dev;
+  }
+
+  if (!dev)
+    return SANE_STATUS_INVAL;
+
+  s = malloc (sizeof (*s));
+  if (!s)
+    return SANE_STATUS_NO_MEM;
+  memset (s, 0, sizeof (*s));
+  s->fd = -1;
+  s->pipe = -1;
+  s->hw = dev;
+  for (i = 0; i < 4; ++i)
+    for (j = 0; j < 256; ++j)
+      s->gamma_table[i][j] = j;
+
+  init_options (s);
+
+  /* insert newly opened handle into list of open handles: */
+  s->next = first_handle;
+  first_handle = s;
+
+  *handle = s;
+  return SANE_STATUS_GOOD;
+}
+
+
+void
+sane_close (SANE_Handle handle)
+{
+  Tamarack_Scanner *prev, *s;
+
+  /* remove handle from list of open handles: */
+  prev = 0;
+  for (s = first_handle; s; s = s->next) {
+    if (s == handle)
+      break;
+    prev = s;
+  }
+
+  if (!s) {
+    DBG(1, "close: invalid handle %p\n", handle);
+    return;		/* oops, not a handle we know about */
+  }
+
+  if (s->scanning)
+    do_cancel (handle);
+
+  if (prev)
+    prev->next = s->next;
+  else
+    first_handle = s->next;
+
+  free (handle);
+}
+
+
+const SANE_Option_Descriptor *
+sane_get_option_descriptor (SANE_Handle handle, SANE_Int option)
+{
+  Tamarack_Scanner *s = handle;
+  
+  if ((unsigned) option >= NUM_OPTIONS)
+    return 0;
+  return s->opt + option;
+}
+
+
+
+static int make_mode (char *mode)
+{
+    if (strcmp (mode, SANE_VALUE_SCAN_MODE_LINEART) == 0)
+      return THRESHOLDED;
+    if (strcmp (mode, SANE_VALUE_SCAN_MODE_HALFTONE) == 0)
+      return DITHERED;
+    else if (strcmp (mode, SANE_VALUE_SCAN_MODE_GRAY) == 0)
+      return GREYSCALE;
+    else if (strcmp (mode, SANE_VALUE_SCAN_MODE_COLOR) == 0)
+      return TRUECOLOR;
+
+    return -1;
+}
+
+
+SANE_Status
+sane_control_option (SANE_Handle handle, SANE_Int option,
+		     SANE_Action action, void *val, SANE_Int *info)
+{
+  Tamarack_Scanner *s = handle;
+  SANE_Status status;
+  SANE_Word cap;
+
+  if (info)
+    *info = 0;
+
+  if (s->scanning)
+    return SANE_STATUS_DEVICE_BUSY;
+
+  if (option >= NUM_OPTIONS)
+    return SANE_STATUS_INVAL;
+
+  cap = s->opt[option].cap;
+
+  if (!SANE_OPTION_IS_ACTIVE (cap))
+    return SANE_STATUS_INVAL;
+
+  if (action == SANE_ACTION_GET_VALUE) {
+    switch (option) {
+      /* word options: */
+    case OPT_PREVIEW:
+    case OPT_GRAY_PREVIEW:
+    case OPT_RESOLUTION:
+    case OPT_TL_X:
+    case OPT_TL_Y:
+    case OPT_BR_X:
+    case OPT_BR_Y:
+    case OPT_NUM_OPTS:
+    case OPT_TRANS:
+    case OPT_BRIGHTNESS:
+    case OPT_CONTRAST:
+    case OPT_THRESHOLD:
+#if 0
+    case OPT_CUSTOM_GAMMA:
+#endif
+      *(SANE_Word *) val = s->val[option].w;
+      return SANE_STATUS_GOOD;
+
+#if 0
+      /* word-array options: */
+    case OPT_GAMMA_VECTOR:
+    case OPT_GAMMA_VECTOR_R:
+    case OPT_GAMMA_VECTOR_G:
+    case OPT_GAMMA_VECTOR_B:
+      memcpy (val, s->val[option].wa, s->opt[option].size);
+      return SANE_STATUS_GOOD;
+#endif
+
+      /* string options: */
+    case OPT_MODE:
+      strcpy (val, s->val[option].s);
+      return SANE_STATUS_GOOD;
+    }
+  } else if (action == SANE_ACTION_SET_VALUE) {
+    if (!SANE_OPTION_IS_SETTABLE (cap))
+      return SANE_STATUS_INVAL;
+
+    status = constrain_value (s, option, val, info);
+    if (status != SANE_STATUS_GOOD)
+      return status;
+    
+    switch (option)
+      {
+	/* (mostly) side-effect-free word options: */
+      case OPT_RESOLUTION:
+      case OPT_TL_X:
+      case OPT_TL_Y:
+      case OPT_BR_X:
+      case OPT_BR_Y:
+	if (info)
+	  *info |= SANE_INFO_RELOAD_PARAMS;
+	/* fall through */
+      case OPT_PREVIEW:
+      case OPT_GRAY_PREVIEW:
+      case OPT_BRIGHTNESS:
+      case OPT_CONTRAST:
+      case OPT_THRESHOLD:
+      case OPT_TRANS:
+	s->val[option].w = *(SANE_Word *) val;
+	return SANE_STATUS_GOOD;
+
+#if 0
+	/* side-effect-free word-array options: */
+      case OPT_GAMMA_VECTOR:
+      case OPT_GAMMA_VECTOR_R:
+      case OPT_GAMMA_VECTOR_G:
+      case OPT_GAMMA_VECTOR_B:
+	memcpy (s->val[option].wa, val, s->opt[option].size);
+	return SANE_STATUS_GOOD;
+
+	/* options with side-effects: */
+
+      case OPT_CUSTOM_GAMMA:
+	w = *(SANE_Word *) val;
+	if (w == s->val[OPT_CUSTOM_GAMMA].w)
+	  return SANE_STATUS_GOOD;		/* no change */
+
+	s->val[OPT_CUSTOM_GAMMA].w = w;
+	if (w) {
+	  s->mode = make_mode (s->val[OPT_MODE].s);
+
+	  if (s->mode == GREYSCALE) {
+	    s->opt[OPT_GAMMA_VECTOR].cap &= ~SANE_CAP_INACTIVE;
+	  } else if (s->mode == TRUECOLOR) {
+	    s->opt[OPT_GAMMA_VECTOR].cap   &= ~SANE_CAP_INACTIVE;
+	    s->opt[OPT_GAMMA_VECTOR_R].cap &= ~SANE_CAP_INACTIVE;
+	    s->opt[OPT_GAMMA_VECTOR_G].cap &= ~SANE_CAP_INACTIVE;
+	    s->opt[OPT_GAMMA_VECTOR_B].cap &= ~SANE_CAP_INACTIVE;
+	  }
+	} else {
+	  s->opt[OPT_GAMMA_VECTOR].cap   |= SANE_CAP_INACTIVE;
+	  s->opt[OPT_GAMMA_VECTOR_R].cap |= SANE_CAP_INACTIVE;
+	  s->opt[OPT_GAMMA_VECTOR_G].cap |= SANE_CAP_INACTIVE;
+	  s->opt[OPT_GAMMA_VECTOR_B].cap |= SANE_CAP_INACTIVE;
+	}
+	if (info)
+	  *info |= SANE_INFO_RELOAD_OPTIONS;
+	return SANE_STATUS_GOOD;
+#endif
+
+      case OPT_MODE:
+	{
+
+	  if (s->val[option].s)
+	    free (s->val[option].s);
+	  s->val[option].s = strdup (val);
+
+	  s->mode = make_mode (s->val[OPT_MODE].s);
+
+	  if (info)
+	    *info |= SANE_INFO_RELOAD_OPTIONS | SANE_INFO_RELOAD_PARAMS;
+
+	  s->opt[OPT_BRIGHTNESS].cap |= SANE_CAP_INACTIVE;
+	  s->opt[OPT_CONTRAST].cap   |= SANE_CAP_INACTIVE;
+	  s->opt[OPT_THRESHOLD].cap  |= SANE_CAP_INACTIVE;
+#if 0
+	  s->opt[OPT_CUSTOM_GAMMA].cap |= SANE_CAP_INACTIVE;
+	  s->opt[OPT_GAMMA_VECTOR].cap |= SANE_CAP_INACTIVE;
+	  s->opt[OPT_GAMMA_VECTOR_R].cap |= SANE_CAP_INACTIVE;
+	  s->opt[OPT_GAMMA_VECTOR_G].cap |= SANE_CAP_INACTIVE;
+	  s->opt[OPT_GAMMA_VECTOR_B].cap |= SANE_CAP_INACTIVE;
+#endif
+
+
+	  if (strcmp (val, SANE_VALUE_SCAN_MODE_LINEART) == 0) 
+	    s->opt[OPT_THRESHOLD].cap  &= ~SANE_CAP_INACTIVE;
+	  else {
+	    s->opt[OPT_BRIGHTNESS].cap &= ~SANE_CAP_INACTIVE;
+	    s->opt[OPT_CONTRAST].cap   &= ~SANE_CAP_INACTIVE;
+	  }
+#if 0
+	  if (!binary)
+	    s->opt[OPT_CUSTOM_GAMMA].cap &= ~SANE_CAP_INACTIVE;
+
+	  if (s->val[OPT_CUSTOM_GAMMA].w) {
+	    if (strcmp (val, SANE_VALUE_SCAN_MODE_GRAY) == 0)
+	      s->opt[OPT_GAMMA_VECTOR].cap &= ~SANE_CAP_INACTIVE;
+	    else if (strcmp (val, SANE_VALUE_SCAN_MODE_COLOR) == 0) {
+	      s->opt[OPT_GAMMA_VECTOR].cap   &= ~SANE_CAP_INACTIVE;
+	      s->opt[OPT_GAMMA_VECTOR_R].cap &= ~SANE_CAP_INACTIVE;
+	      s->opt[OPT_GAMMA_VECTOR_G].cap &= ~SANE_CAP_INACTIVE;
+	      s->opt[OPT_GAMMA_VECTOR_B].cap &= ~SANE_CAP_INACTIVE;
+	    }
+	  }
+#endif
+	  return SANE_STATUS_GOOD;
+	}
+      }
+    }
+  return SANE_STATUS_INVAL;
+}
+
+
+SANE_Status
+sane_get_parameters (SANE_Handle handle, SANE_Parameters *params)
+{
+  Tamarack_Scanner *s = handle;
+
+  if (!s->scanning) {
+    double width, height, dpi;
+    
+
+    memset (&s->params, 0, sizeof (s->params));
+    
+    width  = SANE_UNFIX (s->val[OPT_BR_X].w - s->val[OPT_TL_X].w);
+    height = SANE_UNFIX (s->val[OPT_BR_Y].w - s->val[OPT_TL_Y].w);
+    dpi    = SANE_UNFIX (s->val[OPT_RESOLUTION].w);
+    s->mode = make_mode (s->val[OPT_MODE].s);
+    DBG(1, "got mode '%s' -> %d.\n", s->val[OPT_MODE].s, s->mode);
+    /* make best-effort guess at what parameters will look like once
+       scanning starts.  */
+    if (dpi > 0.0 && width > 0.0 && height > 0.0) {
+      double dots_per_mm = dpi / MM_PER_INCH;
+      
+      s->params.pixels_per_line = width * dots_per_mm;
+      s->params.lines = height * dots_per_mm;
+    }
+    if ((s->mode == THRESHOLDED) || (s->mode == DITHERED)) {
+      s->params.format = SANE_FRAME_GRAY;
+      s->params.bytes_per_line = (s->params.pixels_per_line + 7) / 8;
+      s->params.depth = 1;
+    } else if (s->mode == GREYSCALE) {
+      s->params.format = SANE_FRAME_GRAY;
+      s->params.bytes_per_line = s->params.pixels_per_line;
+      s->params.depth = 8;
+    } else {
+      s->params.format = SANE_FRAME_RED + s->pass;
+      s->params.bytes_per_line = s->params.pixels_per_line;
+      s->params.depth = 8;
+    }
+    s->pass = 0;
+  } else {
+    if (s->mode == TRUECOLOR)
+      s->params.format = SANE_FRAME_RED + s->pass;
+  }
+
+  s->params.last_frame =  (s->mode != TRUECOLOR) || (s->pass == 2);
+  
+  if (params)
+    *params = s->params;
+
+  DBG(1, "Got parameters: format:%d, ppl: %d, bpl:%d, depth:%d, "
+	   "last %d pass %d\n", 
+	   s->params.format, s->params.pixels_per_line, 
+	   s->params.bytes_per_line, s->params.depth, 
+	   s->params.last_frame, s->pass);
+  return SANE_STATUS_GOOD;
+}
+
+
+SANE_Status
+sane_start (SANE_Handle handle)
+{
+  Tamarack_Scanner *s = handle;
+  SANE_Status status;
+  int fds[2];
+
+  /* First make sure we have a current parameter set.  Some of the
+     parameters will be overwritten below, but that's OK.  */
+  status = sane_get_parameters (s, 0);
+
+  if (status != SANE_STATUS_GOOD)
+      return status;
+
+  if (s->fd < 0) {
+    /* translate options into s->mode for convenient access: */
+    s->mode = make_mode (s->val[OPT_MODE].s);
+
+    if (s->mode == TRUECOLOR)
+      {
+	if (s->val[OPT_PREVIEW].w && s->val[OPT_GRAY_PREVIEW].w) {
+	  /* Force gray-scale mode when previewing.  */
+	  s->mode = GREYSCALE;
+	  s->params.format = SANE_FRAME_GRAY;
+	  s->params.bytes_per_line = s->params.pixels_per_line;
+	  s->params.last_frame = SANE_TRUE;
+	}
+      }
+    
+    status = sanei_scsi_open (s->hw->sane.name, &s->fd, sense_handler, 0);
+    if (status != SANE_STATUS_GOOD) {
+      DBG(1, "open: open of %s failed: %s\n",
+	  s->hw->sane.name, sane_strstatus (status));
+      return status;
+    }
+  }
+
+  status = wait_ready (s->fd);
+  if (status != SANE_STATUS_GOOD) {
+    DBG(1, "open: wait_ready() failed: %s\n", sane_strstatus (status));
+    goto stop_scanner_and_return;
+  }
+
+  status = scan_area_and_windows (s);
+  if (status != SANE_STATUS_GOOD) {
+    DBG(1, "open: set scan area command failed: %s\n",
+	sane_strstatus (status));
+    goto stop_scanner_and_return;
+  }
+
+  status = mode_select (s);
+  if (status != SANE_STATUS_GOOD)
+    goto stop_scanner_and_return;
+    
+  s->scanning = SANE_TRUE;
+
+  status = start_scan (s);
+  if (status != SANE_STATUS_GOOD)
+    goto stop_scanner_and_return;
+
+  status = get_image_status (s);
+  if (status != SANE_STATUS_GOOD)
+    goto stop_scanner_and_return;
+
+  s->line = 0;
+
+  if (pipe (fds) < 0)
+    return SANE_STATUS_IO_ERROR;
+
+  s->pipe = fds[0];
+  s->reader_pipe = fds[1];
+  s->reader_pid = sanei_thread_begin (reader_process, (void *) s);
+
+  if (sanei_thread_is_forked()) close (s->reader_pipe);
+
+  return SANE_STATUS_GOOD;
+
+stop_scanner_and_return:
+  do_cancel (s);
+  return status;
+}
+
+
+SANE_Status
+sane_read (SANE_Handle handle, SANE_Byte *buf, SANE_Int max_len, SANE_Int *len)
+{
+  Tamarack_Scanner *s = handle;
+  ssize_t nread;
+
+  *len = 0;
+
+  nread = read (s->pipe, buf, max_len);
+  DBG(3, "read %ld bytes\n", (long) nread);
+
+  if (!s->scanning)
+    return do_cancel (s);
+  
+  if (nread < 0) {
+    if (errno == EAGAIN) {
+      return SANE_STATUS_GOOD;
+    } else {
+      do_cancel (s);
+      return SANE_STATUS_IO_ERROR;
+    }
+  }
+
+  *len = nread;
+
+  if (nread == 0) {
+    s->pass++;
+    return do_eof (s);
+  }
+  return SANE_STATUS_GOOD;
+}
+
+
+void
+sane_cancel (SANE_Handle handle)
+{
+  Tamarack_Scanner *s = handle;
+
+  if (s->reader_pid != -1)
+    sanei_thread_kill (s->reader_pid);
+  s->scanning = SANE_FALSE;
+}
+
+
+SANE_Status
+sane_set_io_mode (SANE_Handle handle, SANE_Bool non_blocking)
+{
+  Tamarack_Scanner *s = handle;
+
+  if (!s->scanning)
+    return SANE_STATUS_INVAL;
+
+  if (fcntl (s->pipe, F_SETFL, non_blocking ? O_NONBLOCK : 0) < 0)
+    return SANE_STATUS_IO_ERROR;
+
+  return SANE_STATUS_GOOD;
+}
+
+
+SANE_Status
+sane_get_select_fd (SANE_Handle handle, SANE_Int *fd)
+{
+  Tamarack_Scanner *s = handle;
+
+  if (!s->scanning)
+    return SANE_STATUS_INVAL;
+
+  *fd = s->pipe;
+  return SANE_STATUS_GOOD;
+}
+