Initial import of sane-backends version 1.0.24-1.2

1 files changed, 1825 insertions, 0 deletions

diff --git a/backend/pixma.c b/backend/pixma.c
new file mode 100644
index 0000000..6a2492e
--- /dev/null
+++ b/backend/pixma.c
@@ -0,0 +1,1825 @@
+/* SANE - Scanner Access Now Easy.
+
+   Copyright (C) 2007-2008 Nicolas Martin, <nicols-guest at alioth dot debian dot org>
+   Copyright (C) 2006-2007 Wittawat Yamwong <wittawat@web.de>
+   Copyright (C) 2011-2013 Rolf Bensch <rolf at bensch hyphen online dot de>
+
+   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.
+
+   As a special exception, the authors of SANE give permission for
+   additional uses of the libraries contained in this release of SANE.
+
+   The exception is that, if you link a SANE library with other files
+   to produce an executable, this does not by itself cause the
+   resulting executable to be covered by the GNU General Public
+   License.  Your use of that executable is in no way restricted on
+   account of linking the SANE library code into it.
+
+   This exception does not, however, invalidate any other reasons why
+   the executable file might be covered by the GNU General Public
+   License.
+
+   If you submit changes to SANE to the maintainers to be included in
+   a subsequent release, you agree by submitting the changes that
+   those changes may be distributed with this exception intact.
+
+   If you write modifications of your own for SANE, it is your choice
+   whether to permit this exception to apply to your modifications.
+   If you do not wish that, delete this exception notice.
+ */
+#include "../include/sane/config.h"
+
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#ifdef USE_PTHREAD
+# include <pthread.h>
+#endif
+#include <signal.h>		/* sigaction(POSIX) */
+#include <unistd.h>		/* POSIX: write read close pipe */
+#ifdef HAVE_FCNTL_H
+# include <fcntl.h>
+#endif
+
+#include "pixma_rename.h"
+#include "pixma.h"
+
+# define DEBUG_NOT_STATIC
+# include "../include/sane/sane.h"
+# include "../include/sane/sanei.h"
+# include "../include/sane/saneopts.h"
+# include "../include/sane/sanei_thread.h"
+# include "../include/sane/sanei_backend.h"
+# include "../include/sane/sanei_config.h"
+
+#ifdef NDEBUG
+# define PDBG(x)
+#else
+#  define PDBG(x) IF_DBG(x)
+#endif /* NDEBUG */
+
+#ifdef __GNUC__
+# define UNUSED(v) (void) v
+#else
+# define UNUSED(v)
+#endif
+
+#define DECL_CTX pixma_sane_t *ss = check_handle(h)
+#define OPT_IN_CTX ss->opt
+#define SOD(opt)  OPT_IN_CTX[opt].sod
+#define OVAL(opt) OPT_IN_CTX[opt].val
+#define AUTO_GAMMA 2.2
+
+/* pixma_sane_options.h generated by
+ * scripts/pixma_gen_options.py h < pixma.c > pixma_sane_options.h
+ */
+#include "pixma_sane_options.h"
+
+#define BUTTON_GROUP_SIZE ( opt_scan_resolution - opt_button_1 + 1 )
+#define BUTTON_GROUP_INDEX(x) ( x - opt_button_1 )
+
+typedef struct pixma_sane_t
+{
+  struct pixma_sane_t *next;
+  pixma_t *s;
+  pixma_scan_param_t sp;
+  SANE_Bool cancel;
+
+  /* valid states: idle, !idle && scanning, !idle && !scanning */
+  SANE_Bool idle;
+  SANE_Bool scanning;
+  SANE_Status last_read_status;	/* valid if !idle && !scanning */
+
+  option_descriptor_t opt[opt_last];
+  char button_option_is_cached[BUTTON_GROUP_SIZE];
+  SANE_Range xrange, yrange;
+  SANE_Word dpi_list[9];	/* up to 9600 dpi */
+  SANE_String_Const mode_list[6];
+  pixma_scan_mode_t mode_map[6];
+  uint8_t gamma_table[4096];
+  SANE_String_Const source_list[4];
+  pixma_paper_source_t source_map[4];
+
+  unsigned byte_pos_in_line, output_line_size;
+  uint64_t image_bytes_read;
+  unsigned page_count;		/* valid for ADF */
+
+  SANE_Pid reader_taskid;
+  int wpipe, rpipe;
+  SANE_Bool reader_stop;
+} pixma_sane_t;
+
+
+static const char vendor_str[] = "CANON";
+static const char type_str[] = "multi-function peripheral";
+
+static pixma_sane_t *first_scanner = NULL;
+static const SANE_Device **dev_list = NULL;
+static const char* conf_devices[MAX_CONF_DEVICES];
+
+static void mark_all_button_options_cached ( struct pixma_sane_t * ss )
+{
+  int i;
+  for (i = 0; i < (opt__group_5 - opt_button_1); i++ )
+      ss -> button_option_is_cached[i] = 1;
+}
+
+static SANE_Status config_attach_pixma(SANEI_Config * config, const char *devname)
+{
+  int i;
+  UNUSED(config);
+  for (i=0; i < (MAX_CONF_DEVICES -1); i++)
+    {
+      if(conf_devices[i] == NULL)
+        {
+          conf_devices[i] = strdup(devname);
+          return SANE_STATUS_GOOD;
+        }
+    }
+  return SANE_STATUS_INVAL;
+}
+
+static SANE_Status
+map_error (int error)
+{
+  if (error >= 0)
+    return SANE_STATUS_GOOD;
+
+  switch (error)
+    {
+    case PIXMA_ENOMEM:
+      return SANE_STATUS_NO_MEM;
+    case PIXMA_ECANCELED:
+      return SANE_STATUS_CANCELLED;
+    case PIXMA_EBUSY:
+      return SANE_STATUS_DEVICE_BUSY;
+    case PIXMA_EINVAL:
+      return SANE_STATUS_INVAL;
+    case PIXMA_EACCES:
+      return SANE_STATUS_ACCESS_DENIED;
+    case PIXMA_EPAPER_JAMMED:
+      return SANE_STATUS_JAMMED;
+    case PIXMA_ENO_PAPER:
+      return SANE_STATUS_NO_DOCS;
+    case PIXMA_ECOVER_OPEN:
+      return SANE_STATUS_COVER_OPEN;
+    case PIXMA_ENOTSUP:
+      return SANE_STATUS_UNSUPPORTED;
+    case PIXMA_EPROTO:
+    case PIXMA_ENODEV:
+    case PIXMA_EIO:
+    case PIXMA_ETIMEDOUT:
+      return SANE_STATUS_IO_ERROR;
+    }
+  PDBG (pixma_dbg (1, "BUG: unmapped error %d\n", error));
+  return SANE_STATUS_IO_ERROR;
+}
+
+static int
+getenv_atoi (const char *name, int def)
+{
+  const char *str = getenv (name);
+  return (str) ? atoi (str) : def;
+}
+
+#define CONST_CAST(t,x) (t)(x)
+
+static void
+free_block (const void * ptr)
+{
+  free (CONST_CAST (void *, ptr));
+}
+
+static void
+cleanup_device_list (void)
+{
+  if (dev_list)
+    {
+      int i;
+      for (i = 0; dev_list[i]; i++)
+        {
+          free_block ((const void *) dev_list[i]->name);
+          free_block ((const void *) dev_list[i]->model);
+          free_block ((const void *) dev_list[i]);
+        }
+    }
+  free (dev_list);
+  dev_list = NULL;
+}
+
+static void
+find_scanners (void)
+{
+  unsigned i, nscanners;
+
+  cleanup_device_list ();
+  nscanners = pixma_find_scanners (conf_devices);
+  PDBG (pixma_dbg (3, "pixma_find_scanners() found %u devices\n", nscanners));
+  dev_list =
+    (const SANE_Device **) calloc (nscanners + 1, sizeof (*dev_list));
+  if (!dev_list)
+    return;
+  for (i = 0; i != nscanners; i++)
+    {
+      SANE_Device *sdev = (SANE_Device *) calloc (1, sizeof (*sdev));
+      char *name, *model;
+      if (!sdev)
+        goto nomem;
+      name = strdup (pixma_get_device_id (i));
+      model = strdup (pixma_get_device_model (i));
+      if (!name || !model)
+        {
+          free (name);
+          free (model);
+          free (sdev);
+          goto nomem;
+        }
+      sdev->name = name;
+      sdev->model = model;
+      sdev->vendor = vendor_str;
+      sdev->type = type_str;
+      dev_list[i] = sdev;
+    }
+  /* dev_list is already NULL terminated by calloc(). */
+  return;
+
+nomem:
+  PDBG (pixma_dbg (1, "WARNING:not enough memory for device list\n"));
+  return;
+}
+
+static pixma_sane_t *
+check_handle (SANE_Handle h)
+{
+  pixma_sane_t *p;
+
+  for (p = first_scanner; p && (SANE_Handle) p != h; p = p->next)
+    {
+    }
+  return p;
+}
+
+static void
+update_button_state (pixma_sane_t * ss, SANE_Int * info)
+{
+  SANE_Int b1 = OVAL (opt_button_1).w;
+  SANE_Int b2 = OVAL (opt_button_2).w;
+  uint32_t ev = pixma_wait_event (ss->s, 300);
+  switch (ev & ~PIXMA_EV_ACTION_MASK)
+    {
+    case PIXMA_EV_BUTTON1:
+      b1 = 1;
+      break;
+    case PIXMA_EV_BUTTON2:
+      b2 = 1;
+      break;
+    }
+
+  if (b1 != OVAL (opt_button_1).w || b2 != OVAL (opt_button_2).w)
+    { 
+    *info |= SANE_INFO_RELOAD_OPTIONS;
+    OVAL (opt_button_1).w = b1;
+    OVAL (opt_button_2).w = b2;
+    OVAL (opt_original).w = GET_EV_ORIGINAL(ev);
+    OVAL (opt_target).w = GET_EV_TARGET(ev);
+    OVAL (opt_scan_resolution).w = GET_EV_DPI(ev);
+    }
+  mark_all_button_options_cached(ss);
+}
+
+static SANE_Bool
+enable_option (pixma_sane_t * ss, SANE_Int o, SANE_Bool enable)
+{
+  SANE_Word save = SOD (o).cap;
+  if (enable)
+    SOD (o).cap &= ~SANE_CAP_INACTIVE;
+  else
+    SOD (o).cap |= SANE_CAP_INACTIVE;
+  return (save != SOD (o).cap);
+}
+
+static void
+clamp_value (pixma_sane_t * ss, SANE_Int n, void *v, SANE_Int * info)
+{
+  SANE_Option_Descriptor *sod = &SOD (n);
+  SANE_Word *va = (SANE_Word *) v;
+  const SANE_Range *range = sod->constraint.range;
+  int i, nmemb;
+
+  nmemb = sod->size / sizeof (SANE_Word);
+  for (i = 0; i < nmemb; i++)
+    {
+      SANE_Word value = va[i];
+      if (value < range->min)
+        {
+          value = range->min;
+        }
+      else if (value > range->max)
+        {
+          value = range->max;
+        }
+      if (range->quant != 0)
+        {
+          value = (value - range->min + range->quant / 2) /
+            range->quant * range->quant;
+        }
+      if (value != va[i])
+        {
+          va[i] = value;
+          *info |= SANE_INFO_INEXACT;
+        }
+    }
+}
+
+/* create dynamic mode_list
+ * ss:      scanner device
+ * tpu = 0: flatbed or ADF mode
+ *          1 bit lineart, 8 bit grayscale and 24 bit color scans
+ * tpu = 1: TPU mode
+ *          16 bit grayscale and 48 bit color scans */
+static void
+create_mode_list (pixma_sane_t * ss)
+{
+  SANE_Bool tpu;
+  const pixma_config_t *cfg;
+  int i;
+
+  cfg = pixma_get_config (ss->s);
+  tpu = (ss->source_map[OVAL (opt_source).w] == PIXMA_SOURCE_TPU);
+
+  /* setup available mode */
+  i = 0;
+  ss->mode_list[i] = SANE_VALUE_SCAN_MODE_COLOR;
+  ss->mode_map[i] = PIXMA_SCAN_MODE_COLOR;
+  i++;
+  if (cfg->cap & PIXMA_CAP_GRAY)
+    {
+      ss->mode_list[i] = SANE_VALUE_SCAN_MODE_GRAY;
+      ss->mode_map[i] = PIXMA_SCAN_MODE_GRAY;
+      i++;
+    }
+  if (tpu && (cfg->cap & PIXMA_CAP_NEGATIVE))
+    {
+      ss->mode_list[i] = SANE_I18N ("Negative color");
+      ss->mode_map[i] = PIXMA_SCAN_MODE_NEGATIVE_COLOR;
+      i++;
+      if (cfg->cap & PIXMA_CAP_GRAY)
+        {
+          ss->mode_list[i] = SANE_I18N ("Negative gray");
+          ss->mode_map[i] = PIXMA_SCAN_MODE_NEGATIVE_GRAY;
+          i++;
+        }
+    }
+  if (tpu && (cfg->cap & PIXMA_CAP_TPUIR) == PIXMA_CAP_TPUIR)
+    {
+      ss->mode_list[i] = SANE_I18N ("Infrared");
+      ss->mode_map[i] = PIXMA_SCAN_MODE_TPUIR;
+      i++;
+    }
+  if (!tpu && (cfg->cap & PIXMA_CAP_48BIT))
+    {
+      ss->mode_list[i] = SANE_I18N ("48 bits color");
+      ss->mode_map[i] = PIXMA_SCAN_MODE_COLOR_48;
+      i++;
+      if (cfg->cap & PIXMA_CAP_GRAY)
+        {
+          ss->mode_list[i] = SANE_I18N ("16 bits gray");
+          ss->mode_map[i] = PIXMA_SCAN_MODE_GRAY_16;
+          i++;
+        }
+    }
+  if (!tpu && (cfg->cap & PIXMA_CAP_LINEART))
+    {
+      ss->mode_list[i] = SANE_VALUE_SCAN_MODE_LINEART;
+      ss->mode_map[i] = PIXMA_SCAN_MODE_LINEART;
+      i++;
+    }
+  /* terminate mode_list and mode_map */
+  ss->mode_list[i] = 0;
+  ss->mode_map[i] = 0;
+}
+
+/* create dynamic dpi_list
+ * ss: scanner device */
+static void
+create_dpi_list (pixma_sane_t * ss)
+{
+  const pixma_config_t *cfg;
+  int i, j;
+  int min;
+  unsigned min_dpi;
+  unsigned max_dpi;
+
+  cfg = pixma_get_config (ss->s);
+
+  /* get min/max dpi */
+  max_dpi = cfg->xdpi;
+  min_dpi = 75;
+  if (ss->source_map[OVAL (opt_source).w] == PIXMA_SOURCE_TPU
+      && ss->mode_map[OVAL (opt_mode).w] == PIXMA_SCAN_MODE_TPUIR)
+  { /* IR mode */
+    /*PDBG (pixma_dbg (4, "*create_dpi_list***** TPUIR mode\n"));*/
+    min_dpi = (cfg->tpuir_min_dpi) ? cfg->tpuir_min_dpi : 75;
+    max_dpi = (cfg->tpuir_max_dpi) ? cfg->tpuir_max_dpi : cfg->xdpi;
+  }
+  else if (ss->source_map[OVAL (opt_source).w] == PIXMA_SOURCE_TPU
+            || ss->source_map[OVAL (opt_source).w] == PIXMA_SOURCE_ADF
+            || ss->source_map[OVAL (opt_source).w] == PIXMA_SOURCE_ADFDUP)
+  { /* ADF / TPU mode */
+    /*PDBG (pixma_dbg (4, "*create_dpi_list***** ADF/TPU mode\n"));*/
+    min_dpi = (cfg->adftpu_min_dpi) ? cfg->adftpu_min_dpi : 75;
+    max_dpi = (cfg->adftpu_max_dpi) ? cfg->adftpu_max_dpi : cfg->xdpi;
+  }
+  else if (ss->source_map[OVAL (opt_source).w] == PIXMA_SOURCE_FLATBED
+            && (ss->mode_map[OVAL (opt_mode).w] == PIXMA_SCAN_MODE_COLOR_48
+                || ss->mode_map[OVAL (opt_mode).w] == PIXMA_SCAN_MODE_GRAY_16))
+  { /* 48 bits flatbed */
+    /*PDBG (pixma_dbg (4, "*create_dpi_list***** 48 bits flatbed mode\n"));*/
+    min_dpi = 150;
+  }
+
+  /* set j for min. dpi
+   *  75 dpi: j = 0
+   * 150 dpi: j = 1 \
+   * 300 dpi: j = 2 |--> from cfg->adftpu_min_dpi or cfg->tpuir_min_dpi
+   * 600 dpi: j = 3 /
+   * */
+  j = -1;
+  min = min_dpi / 75;
+  do
+  {
+    j++;
+    min >>= 1;
+  }
+  while (min > 0);
+
+  /* create dpi_list
+   * use j for min. dpi */
+  i = 0;
+  do
+    {
+      i++; j++;
+      ss->dpi_list[i] = 75 * (1 << (j - 1));    /* 75 x 2^(j-1) */
+    }
+  while ((unsigned) ss->dpi_list[i] < max_dpi);
+  ss->dpi_list[0] = i;
+  /*PDBG (pixma_dbg (4, "*create_dpi_list***** min_dpi = %d, max_dpi = %d\n", min_dpi, max_dpi));*/
+}
+
+static void
+select_value_from_list (pixma_sane_t * ss, SANE_Int n, void *v,
+			SANE_Int * info)
+{
+  SANE_Option_Descriptor *sod = &SOD (n);
+  SANE_Word *va = (SANE_Word *) v;
+  const SANE_Word *list = sod->constraint.word_list;
+  int i, j, nmemb;
+
+  nmemb = sod->size / sizeof (SANE_Word);
+  for (i = 0; i < nmemb; i++)
+    {
+      SANE_Word value = va[i];
+      SANE_Word mindelta = abs (value - list[1]);
+      SANE_Word nearest = list[1];
+      for (j = 2; j <= list[0]; j++)
+        {
+          SANE_Word delta = abs (value - list[j]);
+          if (delta < mindelta)
+            {
+              mindelta = delta;
+              nearest = list[j];
+            }
+          if (mindelta == 0)
+            break;
+        }
+      if (va[i] != nearest)
+        {
+          va[i] = nearest;
+          *info |= SANE_INFO_INEXACT;
+        }
+    }
+}
+
+static SANE_Status
+control_scalar_option (pixma_sane_t * ss, SANE_Int n, SANE_Action a, void *v,
+		       SANE_Int * info)
+{
+  option_descriptor_t *opt = &(OPT_IN_CTX[n]);
+  SANE_Word val;
+
+  switch (a)
+    {
+    case SANE_ACTION_GET_VALUE:
+      switch (opt->sod.type)
+        {
+        case SANE_TYPE_BOOL:
+        case SANE_TYPE_INT:
+        case SANE_TYPE_FIXED:
+          *(SANE_Word *) v = opt->val.w;
+          break;
+        default:
+          return SANE_STATUS_UNSUPPORTED;
+        }
+      return SANE_STATUS_GOOD;
+
+    case SANE_ACTION_SET_VALUE:
+      switch (opt->sod.type)
+        {
+        case SANE_TYPE_BOOL:
+          val = *(SANE_Word *) v;
+          if (val != SANE_TRUE && val != SANE_FALSE)
+            return SANE_STATUS_INVAL;
+          opt->val.w = val;
+          break;
+        case SANE_TYPE_INT:
+        case SANE_TYPE_FIXED:
+          if (opt->sod.constraint_type == SANE_CONSTRAINT_RANGE)
+            clamp_value (ss, n, v, info);
+          else if (opt->sod.constraint_type == SANE_CONSTRAINT_WORD_LIST)
+            select_value_from_list (ss, n, v, info);
+          opt->val.w = *(SANE_Word *) v;
+          break;
+        default:
+          return SANE_STATUS_UNSUPPORTED;
+        }
+      *info |= opt->info;
+      return SANE_STATUS_GOOD;
+
+    case SANE_ACTION_SET_AUTO:
+      switch (opt->sod.type)
+        {
+        case SANE_TYPE_BOOL:
+        case SANE_TYPE_INT:
+        case SANE_TYPE_FIXED:
+          opt->val.w = opt->def.w;
+          break;
+        default:
+          return SANE_STATUS_UNSUPPORTED;
+        }
+      *info |= opt->info;
+      return SANE_STATUS_GOOD;
+    }
+  return SANE_STATUS_UNSUPPORTED;
+}
+
+static SANE_Status
+control_string_option (pixma_sane_t * ss, SANE_Int n, SANE_Action a, void *v,
+		       SANE_Int * info)
+{
+  option_descriptor_t *opt = &(OPT_IN_CTX[n]);
+  const SANE_String_Const *slist = opt->sod.constraint.string_list;
+  SANE_String str = (SANE_String) v;
+
+  if (opt->sod.constraint_type == SANE_CONSTRAINT_NONE)
+    {
+      switch (a)
+        {
+        case SANE_ACTION_GET_VALUE:
+          strcpy (str, opt->val.s);
+          break;
+        case SANE_ACTION_SET_AUTO:
+          str = opt->def.s;
+          /* fall through */
+        case SANE_ACTION_SET_VALUE:
+          strncpy (opt->val.s, str, opt->sod.size - 1);
+          *info |= opt->info;
+          break;
+        }
+      return SANE_STATUS_GOOD;
+    }
+  else
+    {
+      int i;
+
+      switch (a)
+        {
+        case SANE_ACTION_GET_VALUE:
+          strcpy (str, slist[opt->val.w]);
+          break;
+        case SANE_ACTION_SET_AUTO:
+          str = opt->def.ptr;
+          /* fall through */
+        case SANE_ACTION_SET_VALUE:
+          i = 0;
+          while (slist[i] && strcasecmp (str, slist[i]) != 0)
+            i++;
+          if (!slist[i])
+            return SANE_STATUS_INVAL;
+          if (strcmp (slist[i], str) != 0)
+            {
+              strcpy (str, slist[i]);
+              *info |= SANE_INFO_INEXACT;
+            }
+          opt->val.w = i;
+          *info |= opt->info;
+          break;
+        }
+      return SANE_STATUS_GOOD;
+    }
+}
+
+static SANE_Status
+control_option (pixma_sane_t * ss, SANE_Int n,
+		SANE_Action a, void *v, SANE_Int * info)
+{
+  int result, i;
+  const pixma_config_t *cfg;
+  SANE_Int dummy;
+
+  /* info may be null, better to set a dummy here then test everywhere */
+  if (info == NULL) 
+    info = &dummy;
+  
+  cfg = pixma_get_config (ss->s);
+
+  /* PDBG (pixma_dbg (4, "*control_option***** n = %u, a = %u\n", n, a)); */
+
+  /* first deal with options that require special treatment */
+  result = SANE_STATUS_UNSUPPORTED;
+  switch (n)
+    {
+      case opt_gamma_table:
+        switch (a)
+          {
+          case SANE_ACTION_SET_VALUE:
+            clamp_value (ss, n, v, info);
+            for (i = 0; i != 4096; i++)
+              ss->gamma_table[i] = *((SANE_Int *) v + i);
+            break;
+          case SANE_ACTION_GET_VALUE:
+            for (i = 0; i != 4096; i++)
+              *((SANE_Int *) v + i) = ss->gamma_table[i];
+            break;
+          case SANE_ACTION_SET_AUTO:
+            pixma_fill_gamma_table (AUTO_GAMMA, ss->gamma_table,
+                  sizeof (ss->gamma_table));
+            break;
+          default:
+            return SANE_STATUS_UNSUPPORTED;
+          }
+        return SANE_STATUS_GOOD;
+
+      case opt_button_update:
+        if (a == SANE_ACTION_SET_VALUE)
+          {
+            update_button_state (ss, info);
+            return SANE_STATUS_GOOD;
+          }
+        else
+          {
+            return SANE_STATUS_INVAL;
+          }
+        break;
+      case opt_button_1:
+      case opt_button_2:
+      case opt_original:
+      case opt_target:
+      case opt_scan_resolution:
+        /* poll scanner if option is not cached */
+        if (! ss->button_option_is_cached[ BUTTON_GROUP_INDEX(n) ] )
+          update_button_state (ss, info);
+        /* mark this option as read */
+        ss->button_option_is_cached[  BUTTON_GROUP_INDEX(n) ] = 0;
+    }
+
+  /* now deal with getting and setting of options */ 
+  switch (SOD (n).type)
+    {
+    case SANE_TYPE_BOOL:
+    case SANE_TYPE_INT:
+    case SANE_TYPE_FIXED:
+      result = control_scalar_option (ss, n, a, v, info);
+      break;
+    case SANE_TYPE_STRING:
+      result = control_string_option (ss, n, a, v, info);
+      break;
+    case SANE_TYPE_BUTTON:
+    case SANE_TYPE_GROUP:
+      PDBG (pixma_dbg (1, "BUG:control_option():Unhandled option\n"));
+      result = SANE_STATUS_INVAL;
+      break;
+    }
+  if (result != SANE_STATUS_GOOD)
+    return result;
+
+  /* deal with dependencies between options */
+  switch (n)
+    {
+    case opt_custom_gamma:
+      if (a == SANE_ACTION_SET_VALUE || a == SANE_ACTION_SET_AUTO)
+        {
+          if (enable_option (ss, opt_gamma_table, OVAL (opt_custom_gamma).b))
+            *info |= SANE_INFO_RELOAD_OPTIONS;
+        }
+      break;
+    case opt_gamma:
+      if (a == SANE_ACTION_SET_VALUE || a == SANE_ACTION_SET_AUTO)
+        {
+          /* PDBG (pixma_dbg (4, "*control_option***** gamma = %f *\n",
+                           SANE_UNFIX (OVAL (opt_gamma).w))); */
+          pixma_fill_gamma_table (SANE_UNFIX (OVAL (opt_gamma).w),
+                                  ss->gamma_table, sizeof (ss->gamma_table));
+        }
+      break;
+    case opt_mode:
+      if (cfg->cap & (PIXMA_CAP_48BIT|PIXMA_CAP_LINEART|PIXMA_CAP_TPUIR)
+          && (a == SANE_ACTION_SET_VALUE || a == SANE_ACTION_SET_AUTO))
+        { /* new mode selected: Color, Gray, ... */
+          /* PDBG (pixma_dbg (4, "*control_option***** mode = %u *\n",
+                           ss->mode_map[OVAL (opt_mode).w])); */
+          /* recreate dynamic lists */
+          create_dpi_list (ss);
+          if (ss->mode_map[OVAL (opt_mode).w] == PIXMA_SCAN_MODE_LINEART)
+            { /* lineart */
+              enable_option (ss, opt_threshold, SANE_TRUE);
+              enable_option (ss, opt_threshold_curve, SANE_TRUE);
+            }
+          else
+            { /* all other modes */
+              enable_option (ss, opt_threshold, SANE_FALSE);
+              enable_option (ss, opt_threshold_curve, SANE_FALSE);
+            }
+          *info |= SANE_INFO_RELOAD_OPTIONS;
+        }
+      break;
+    case opt_source:
+      if ((cfg->cap & (PIXMA_CAP_ADF|PIXMA_CAP_ADFDUP|PIXMA_CAP_TPU))
+          && (a == SANE_ACTION_SET_VALUE || a == SANE_ACTION_SET_AUTO))
+        { /* new source selected: flatbed, ADF, TPU, ... */
+          /* to avoid fatal errors,
+           * select first entry of dynamic mode_list
+           * identifiers are unknown here */
+          OVAL (opt_mode).w = ss->mode_map[0];
+          /* recreate dynamic lists */
+          create_mode_list (ss);
+          create_dpi_list (ss);
+          /* to avoid fatal errors,
+           * select first entry of dynamic dpi_list
+           * identifiers are unknown here */
+          OVAL (opt_resolution).w = ss->dpi_list[1];
+          if (ss->mode_map[OVAL (opt_mode).w] == PIXMA_SCAN_MODE_LINEART)
+            { /* lineart */
+              enable_option (ss, opt_threshold, SANE_TRUE);
+              enable_option (ss, opt_threshold_curve, SANE_TRUE);
+            }
+          else
+            { /* all other modes */
+              enable_option (ss, opt_threshold, SANE_FALSE);
+              enable_option (ss, opt_threshold_curve, SANE_FALSE);
+            }
+          *info |= SANE_INFO_RELOAD_OPTIONS;
+        }
+      break;
+    }
+
+  return result;
+}
+
+#ifndef NDEBUG
+static void
+print_scan_param (int level, const pixma_scan_param_t * sp)
+{
+  pixma_dbg (level, "Scan parameters\n");
+  pixma_dbg (level, "  line_size=%"PRIu64" image_size=%"PRIu64" channels=%u depth=%u\n",
+	     sp->line_size, sp->image_size, sp->channels, sp->depth);
+  pixma_dbg (level, "  dpi=%ux%u offset=(%u,%u) dimension=%ux%u\n",
+	     sp->xdpi, sp->ydpi, sp->x, sp->y, sp->w, sp->h);
+  pixma_dbg (level, "  gamma_table=%p source=%d\n", sp->gamma_table,
+	     sp->source);
+}
+#endif
+
+static int
+calc_scan_param (pixma_sane_t * ss, pixma_scan_param_t * sp)
+{
+  int x1, y1, x2, y2;
+  int error;
+
+  memset (sp, 0, sizeof (*sp));
+
+  sp->channels = (OVAL (opt_mode).w == 0) ? 3 : 1;
+  sp->depth = (OVAL (opt_mode).w == 2) ? 1 : 8;
+  sp->xdpi = sp->ydpi = OVAL (opt_resolution).w;
+
+#define PIXEL(x,dpi) (int)((SANE_UNFIX(x) / 25.4 * (dpi)) + 0.5)
+  x1 = PIXEL (OVAL (opt_tl_x).w, sp->xdpi);
+  x2 = PIXEL (OVAL (opt_br_x).w, sp->xdpi);
+  if (x2 < x1)
+    {
+      int temp = x1;
+      x1 = x2;
+      x2 = temp;
+    }
+  y1 = PIXEL (OVAL (opt_tl_y).w, sp->ydpi);
+  y2 = PIXEL (OVAL (opt_br_y).w, sp->ydpi);
+  if (y2 < y1)
+    {
+      int temp = y1;
+      y1 = y2;
+      y2 = temp;
+    }
+#undef PIXEL
+  sp->x = x1;
+  sp->y = y1;
+  sp->w = x2 - x1;
+  sp->h = y2 - y1;
+  if (sp->w == 0)
+    sp->w = 1;
+  if (sp->h == 0)
+    sp->h = 1;
+  sp->tpu_offset_added = 0;
+
+  sp->gamma_table = (OVAL (opt_custom_gamma).b) ? ss->gamma_table : NULL;
+  sp->source = ss->source_map[OVAL (opt_source).w];
+  sp->mode = ss->mode_map[OVAL (opt_mode).w];
+  sp->adf_pageid = ss->page_count;
+  sp->threshold = 2.55 * OVAL (opt_threshold).w;
+  sp->threshold_curve = OVAL (opt_threshold_curve).w;
+
+  error = pixma_check_scan_param (ss->s, sp);
+  if (error < 0)
+    {
+      PDBG (pixma_dbg (1, "BUG:calc_scan_param() failed %d\n", error));
+      PDBG (print_scan_param (1, sp));
+    }
+  return error;
+}
+
+static void
+init_option_descriptors (pixma_sane_t * ss)
+{
+  const pixma_config_t *cfg;
+  int i;
+
+  cfg = pixma_get_config (ss->s);
+
+  /* setup range for the scan area. */
+  ss->xrange.min = SANE_FIX (0);
+  ss->xrange.max = SANE_FIX (cfg->width / 75.0 * 25.4);
+  ss->xrange.quant = SANE_FIX (0);
+
+  ss->yrange.min = SANE_FIX (0);
+  ss->yrange.max = SANE_FIX (cfg->height / 75.0 * 25.4);
+  ss->yrange.quant = SANE_FIX (0);
+
+  /* mode_list and source_list were already NULL-terminated,
+   * because the whole pixma_sane_t was cleared during allocation. */
+
+  /* setup available mode. */
+  create_mode_list (ss);
+
+  /* setup dpi up to the value supported by the scanner. */
+  create_dpi_list (ss);
+
+  /* setup paper source */
+  i = 0;
+  ss->source_list[i] = SANE_I18N ("Flatbed");
+  ss->source_map[i] = PIXMA_SOURCE_FLATBED;
+  i++;
+  if (cfg->cap & PIXMA_CAP_ADF)
+    {
+      ss->source_list[i] = SANE_I18N ("Automatic Document Feeder");
+      ss->source_map[i] = PIXMA_SOURCE_ADF;
+      i++;
+    }
+  if ((cfg->cap & PIXMA_CAP_ADFDUP) == PIXMA_CAP_ADFDUP)
+    {
+      ss->source_list[i] = SANE_I18N ("ADF Duplex");
+      ss->source_map[i] = PIXMA_SOURCE_ADFDUP;
+      i++;
+    }
+  if (cfg->cap & PIXMA_CAP_TPU)
+    {
+      ss->source_list[i] = SANE_I18N ("Transparency Unit");
+      ss->source_map[i] = PIXMA_SOURCE_TPU;
+      i++;
+    }
+
+  build_option_descriptors (ss);
+
+  /* Enable options that are available only in some scanners. */
+  if (cfg->cap & PIXMA_CAP_GAMMA_TABLE)
+    {
+      enable_option (ss, opt_gamma, SANE_TRUE);
+      enable_option (ss, opt_custom_gamma, SANE_TRUE);
+      sane_control_option (ss, opt_custom_gamma, SANE_ACTION_SET_AUTO,
+			   NULL, NULL);
+      pixma_fill_gamma_table (AUTO_GAMMA, ss->gamma_table, 4096);
+    }
+  enable_option (ss, opt_button_controlled,
+		 ((cfg->cap & PIXMA_CAP_EVENTS) != 0));
+}
+
+/* Writing to reader_ss outside reader_process() is a BUG! */
+static pixma_sane_t *reader_ss = NULL;
+
+static RETSIGTYPE
+reader_signal_handler (int sig)
+{
+  if (reader_ss)
+    {
+      reader_ss->reader_stop = SANE_TRUE;
+      /* reader process is ended by SIGTERM, so no cancel in this case */
+      if (sig != SIGTERM)
+        pixma_cancel (reader_ss->s);
+    }
+}
+
+static int
+write_all (pixma_sane_t * ss, void *buf_, size_t size)
+{
+  uint8_t *buf = (uint8_t *) buf_;
+  int count;
+
+  while (size != 0 && !ss->reader_stop)
+    {
+      count = write (ss->wpipe, buf, size);
+      if (count == -1 && errno != EINTR)
+	break;
+      if (count == -1 && errno == EINTR)
+	continue;
+      buf += count;
+      size -= count;
+    }
+  return buf - (uint8_t *) buf_;
+}
+
+/* NOTE: reader_loop() runs either in a separate thread or process. */
+static SANE_Status
+reader_loop (pixma_sane_t * ss)
+{
+  void *buf;
+  unsigned bufsize;
+  int count = 0;
+
+  PDBG (pixma_dbg (3, "Reader task started\n"));
+  /*bufsize = ss->sp.line_size + 1;*/	/* XXX: "odd" bufsize for testing pixma_read_image() */
+  bufsize = ss->sp.line_size;   /* bufsize EVEN needed by Xsane for 48 bits depth */
+  buf = malloc (bufsize);
+  if (!buf)
+    {
+      count = PIXMA_ENOMEM;
+      goto done;
+    }
+
+  count = pixma_activate_connection (ss->s);
+  if (count < 0)
+    goto done;
+
+  pixma_enable_background (ss->s, 1);
+  if (OVAL (opt_button_controlled).b && ss->page_count == 0)
+    {
+      int start = 0;
+#ifndef NDEBUG
+      pixma_dbg (1, "==== Button-controlled scan mode is enabled.\n");
+      pixma_dbg (1, "==== To proceed, press 'SCAN' or 'COLOR' button. "
+		 "To cancel, press 'GRAY' or 'END' button.\n");
+#endif
+      while (pixma_wait_event (ss->s, 10) != 0)
+        {
+        }
+      while (!start)
+        {
+          uint32_t events;
+          if (ss->reader_stop)
+            {
+              count = PIXMA_ECANCELED;
+              goto done;
+            }
+          events = pixma_wait_event (ss->s, 1000);
+          switch (events & ~PIXMA_EV_ACTION_MASK)
+            {
+            case PIXMA_EV_BUTTON1:
+              start = 1;
+              break;
+            case PIXMA_EV_BUTTON2:
+              count = PIXMA_ECANCELED;
+              goto done;
+            }
+        }
+    }
+  count = pixma_scan (ss->s, &ss->sp);
+  if (count >= 0)
+    {
+      while ((count = pixma_read_image (ss->s, buf, bufsize)) > 0)
+        {
+          if (write_all (ss, buf, count) != count)
+            pixma_cancel (ss->s);
+        }
+    }
+
+done:
+  pixma_enable_background (ss->s, 0);
+  pixma_deactivate_connection (ss->s);
+  free (buf);
+  close (ss->wpipe);
+  ss->wpipe = -1;
+  if (count >= 0)
+    {
+      PDBG (pixma_dbg (3, "Reader task terminated\n"));
+    }
+  else
+    {
+      PDBG (pixma_dbg
+	    (2, "Reader task terminated: %s\n", pixma_strerror (count)));
+    }
+  return map_error (count);
+}
+
+static int
+reader_process (void *arg)
+{
+  pixma_sane_t *ss = (pixma_sane_t *) arg;
+  struct SIGACTION sa;
+
+  reader_ss = ss;
+  memset (&sa, 0, sizeof (sa));
+  sigemptyset (&sa.sa_mask);
+  sa.sa_handler = reader_signal_handler;
+  /* FIXME: which signal else? */
+  sigaction (SIGHUP, &sa, NULL);
+  sigaction (SIGINT, &sa, NULL);
+  sigaction (SIGPIPE, &sa, NULL);
+  sigaction (SIGTERM, &sa, NULL);
+  close (ss->rpipe);
+  ss->rpipe = -1;
+  return reader_loop (ss);
+}
+
+static int
+reader_thread (void *arg)
+{
+  pixma_sane_t *ss = (pixma_sane_t *) arg;
+#ifdef USE_PTHREAD
+  /* Block SIGPIPE. We will handle this in reader_loop() by checking
+     ss->reader_stop and the return value from write(). */
+  sigset_t sigs;
+  sigemptyset (&sigs);
+  sigaddset (&sigs, SIGPIPE);
+  pthread_sigmask (SIG_BLOCK, &sigs, NULL);
+#endif /* USE_PTHREAD */
+  return reader_loop (ss);
+}
+
+static SANE_Pid
+terminate_reader_task (pixma_sane_t * ss, int *exit_code)
+{
+  SANE_Pid result, pid;
+  int status = 0;
+
+  pid = ss->reader_taskid;
+  if (pid == -1)
+    return -1;
+  if (sanei_thread_is_forked ())
+    {
+      sanei_thread_kill (pid);
+    }
+  else
+    {
+      ss->reader_stop = SANE_TRUE;
+/*      pixma_cancel (ss->s);   What is this for ? Makes end-of-scan buggy => removing */
+    }
+  result = sanei_thread_waitpid (pid, &status);
+  ss->reader_taskid = -1;
+
+  if (ss->sp.source != PIXMA_SOURCE_ADF && ss->sp.source != PIXMA_SOURCE_ADFDUP)
+    ss->idle = SANE_TRUE;
+
+  if (result == pid)
+    {
+      if (exit_code)
+	      *exit_code = status;
+      return pid;
+    }
+  else
+    {
+      PDBG (pixma_dbg (1, "WARNING:waitpid() failed %s\n", strerror (errno)));
+      return -1;
+    }
+}
+
+static int
+start_reader_task (pixma_sane_t * ss)
+{
+  int fds[2];
+  SANE_Pid pid;
+  int is_forked;
+
+  if (ss->rpipe != -1 || ss->wpipe != -1)
+    {
+      PDBG (pixma_dbg
+	    (1, "BUG:rpipe = %d, wpipe = %d\n", ss->rpipe, ss->wpipe));
+      close (ss->rpipe);
+      close (ss->wpipe);
+      ss->rpipe = -1;
+      ss->wpipe = -1;
+    }
+  if (ss->reader_taskid != -1)
+    {
+      PDBG (pixma_dbg
+	    (1, "BUG:reader_taskid(%ld) != -1\n", (long) ss->reader_taskid));
+      terminate_reader_task (ss, NULL);
+    }
+  if (pipe (fds) == -1)
+    {
+      PDBG (pixma_dbg (1, "ERROR:start_reader_task():pipe() failed %s\n",
+		       strerror (errno)));
+      return PIXMA_ENOMEM;
+    }
+  ss->rpipe = fds[0];
+  ss->wpipe = fds[1];
+  ss->reader_stop = SANE_FALSE;
+
+  is_forked = sanei_thread_is_forked ();
+  if (is_forked)
+    {
+      pid = sanei_thread_begin (reader_process, ss);
+      if (pid > 0)
+        {
+          close (ss->wpipe);
+          ss->wpipe = -1;
+        }
+    }
+  else
+    {
+      pid = sanei_thread_begin (reader_thread, ss);
+    }
+  if (pid == -1)
+    {
+      close (ss->wpipe);
+      close (ss->rpipe);
+      ss->wpipe = -1;
+      ss->rpipe = -1;
+      PDBG (pixma_dbg (1, "ERROR:unable to start reader task\n"));
+      return PIXMA_ENOMEM;
+    }
+  PDBG (pixma_dbg (3, "Reader task id=%ld (%s)\n", (long) pid,
+		   (is_forked) ? "forked" : "threaded"));
+  ss->reader_taskid = pid;
+  return 0;
+}
+
+static SANE_Status
+read_image (pixma_sane_t * ss, void *buf, unsigned size, int *readlen)
+{
+  int count, status;
+
+  if (readlen)
+    *readlen = 0;
+  if (ss->image_bytes_read >= ss->sp.image_size)
+    return SANE_STATUS_EOF;
+
+  do
+    {
+      if (ss->cancel)
+        /* ss->rpipe has already been closed by sane_cancel(). */
+        return SANE_STATUS_CANCELLED;
+      count = read (ss->rpipe, buf, size);
+    }
+  while (count == -1 && errno == EINTR);
+
+  if (count == -1)
+    {
+      if (errno == EAGAIN)
+        return SANE_STATUS_GOOD;
+      if (!ss->cancel)
+        {
+          PDBG (pixma_dbg (1, "WARNING:read_image():read() failed %s\n",
+               strerror (errno)));
+        }
+      close (ss->rpipe);
+      ss->rpipe = -1;
+      terminate_reader_task (ss, NULL);
+      return SANE_STATUS_IO_ERROR;
+    }
+
+  /* here count >= 0 */
+  ss->image_bytes_read += count;
+  if (ss->image_bytes_read > ss->sp.image_size)
+    {
+      PDBG (pixma_dbg (1, "BUG:ss->image_bytes_read > ss->sp.image_size\n"));
+    }
+  if (ss->image_bytes_read >= ss->sp.image_size)
+    {
+      close (ss->rpipe);
+      ss->rpipe = -1;
+      terminate_reader_task (ss, NULL);
+    }
+  else if (count == 0)
+    {
+      PDBG (pixma_dbg (3, "read_image():reader task closed the pipe:%"
+		       PRIu64" bytes received, %"PRIu64" bytes expected\n",
+		       ss->image_bytes_read, ss->sp.image_size));
+      close (ss->rpipe);
+      ss->rpipe = -1;
+      if (terminate_reader_task (ss, &status) != -1
+      	  && status != SANE_STATUS_GOOD)
+        {
+          return status;
+        }
+      else
+        {
+          /* either terminate_reader_task failed or
+             rpipe was closed but we expect more data */
+          return SANE_STATUS_IO_ERROR;
+        }
+    }
+  if (readlen)
+    *readlen = count;
+  return SANE_STATUS_GOOD;
+}
+
+
+/*******************************************************************
+ ** SANE API
+ *******************************************************************/
+SANE_Status
+sane_init (SANE_Int * version_code, SANE_Auth_Callback authorize)
+{
+  int status, myversion, i;
+  SANEI_Config config;
+
+  UNUSED (authorize);
+
+  if (!version_code)
+    return SANE_STATUS_INVAL;
+  myversion = 100 * PIXMA_VERSION_MAJOR + PIXMA_VERSION_MINOR;
+  *version_code = SANE_VERSION_CODE (SANE_CURRENT_MAJOR, V_MINOR, myversion);
+  DBG_INIT ();
+  sanei_thread_init ();
+  pixma_set_debug_level (DBG_LEVEL);
+
+  PDBG(pixma_dbg(2, "pixma is compiled %s pthread support.\n",
+                   (sanei_thread_is_forked () ? "without" : "with")));
+
+  for (i = 0; i < MAX_CONF_DEVICES; i++)
+    conf_devices[i] = NULL;
+
+  config.count = 0;
+  config.descriptors = NULL;
+  config.values = NULL;
+
+  if (sanei_configure_attach(PIXMA_CONFIG_FILE, &config, config_attach_pixma) !=
+       SANE_STATUS_GOOD)
+    PDBG(pixma_dbg(2, "Could not read pixma configuration file: %s\n",
+                   PIXMA_CONFIG_FILE));
+
+  status = pixma_init ();
+  if (status < 0)
+    {
+      PDBG (pixma_dbg (2, "pixma_init() failed %s\n", pixma_strerror (status)));
+    }
+  return map_error (status);
+}
+
+void
+sane_exit (void)
+{
+  while (first_scanner)
+    sane_close (first_scanner);
+  cleanup_device_list ();
+  pixma_cleanup ();
+}
+
+SANE_Status
+sane_get_devices (const SANE_Device *** device_list, SANE_Bool local_only)
+{
+  UNUSED (local_only);
+
+  if (!device_list)
+    return SANE_STATUS_INVAL;
+  find_scanners ();
+  *device_list = dev_list;
+  return (dev_list) ? SANE_STATUS_GOOD : SANE_STATUS_NO_MEM;
+}
+
+SANE_Status
+sane_open (SANE_String_Const name, SANE_Handle * h)
+{
+  unsigned i, j, nscanners;
+  int error = 0;
+  pixma_sane_t *ss = NULL;
+  const pixma_config_t *cfg;
+
+  if (!name || !h)
+    return SANE_STATUS_INVAL;
+
+  *h = NULL;
+  nscanners = pixma_find_scanners (conf_devices);
+  if (nscanners == 0)
+    return SANE_STATUS_INVAL;
+  if (name[0] == '\0')
+    name = pixma_get_device_id (0);
+
+  /* Have we already opened the scanner? */
+  for (ss = first_scanner; ss; ss = ss->next)
+    {
+      if (strcmp (pixma_get_string (ss->s, PIXMA_STRING_ID), name) == 0)
+        {
+          /* We have already opened it! */
+          return SANE_STATUS_DEVICE_BUSY;
+        }
+    }
+
+  i = 0;
+  while (strcmp (pixma_get_device_id (i), name) != 0)
+    {
+      if (++i >= nscanners)
+	      return SANE_STATUS_INVAL;
+    }
+  cfg = pixma_get_device_config (i);
+  if ((cfg->cap & PIXMA_CAP_EXPERIMENT) != 0)
+    {
+#ifndef NDEBUG
+      pixma_dbg (1, "WARNING:"
+		 "Experimental backend CAN DAMAGE your hardware!\n");
+      if (getenv_atoi ("PIXMA_EXPERIMENT", 0) == 0)
+        {
+          pixma_dbg (1, "Experimental SANE backend for %s is disabled "
+               "by default.\n", pixma_get_device_model (i));
+          pixma_dbg (1, "To enable it, set the environment variable "
+               "PIXMA_EXPERIMENT to non-zero.\n");
+          return SANE_STATUS_UNSUPPORTED;
+        }
+#else
+      return SANE_STATUS_UNSUPPORTED;
+#endif
+    }
+
+  ss = (pixma_sane_t *) calloc (1, sizeof (*ss));
+  if (!ss)
+    return SANE_STATUS_NO_MEM;
+  ss->next = first_scanner;
+  first_scanner = ss;
+  ss->reader_taskid = -1;
+  ss->wpipe = -1;
+  ss->rpipe = -1;
+  ss->idle = SANE_TRUE;
+  ss->scanning = SANE_FALSE;
+  for (j=0; j < BUTTON_GROUP_SIZE; j++)
+    ss->button_option_is_cached[j] = 0;
+  error = pixma_open (i, &ss->s);
+  if (error < 0)
+    {
+      sane_close (ss);
+      return map_error (error);
+    }
+  pixma_enable_background (ss->s, 0);
+  init_option_descriptors (ss);
+  *h = ss;
+  return SANE_STATUS_GOOD;
+}
+
+void
+sane_close (SANE_Handle h)
+{
+  pixma_sane_t **p, *ss;
+
+  for (p = &first_scanner; *p && *p != (pixma_sane_t *) h; p = &((*p)->next))
+    {
+    }
+  if (!(*p))
+    return;
+  ss = *p;
+  sane_cancel (ss);
+  pixma_close (ss->s);
+  *p = ss->next;
+  free (ss);
+}
+
+const SANE_Option_Descriptor *
+sane_get_option_descriptor (SANE_Handle h, SANE_Int n)
+{
+  DECL_CTX;
+
+  if (ss && 0 <= n && n < opt_last)
+    return &SOD (n);
+  return NULL;
+}
+
+SANE_Status
+sane_control_option (SANE_Handle h, SANE_Int n,
+		     SANE_Action a, void *v, SANE_Int * i)
+{
+  DECL_CTX;
+  SANE_Int info = 0;
+  int error;
+  option_descriptor_t *opt;
+
+  if (i)
+    *i = 0;
+  if (!ss)
+    return SANE_STATUS_INVAL;
+  if (n < 0 || n >= opt_last)
+    return SANE_STATUS_UNSUPPORTED;
+  if (!ss->idle && a != SANE_ACTION_GET_VALUE)
+    {
+      PDBG (pixma_dbg (3, "Warning: !idle && !SANE_ACTION_GET_VALUE\n"));
+      if (ss->sp.source != PIXMA_SOURCE_ADF && ss->sp.source != PIXMA_SOURCE_ADFDUP) 
+        return SANE_STATUS_INVAL;
+    }
+
+  opt = &(OPT_IN_CTX[n]);
+  if (!SANE_OPTION_IS_ACTIVE (opt->sod.cap))
+    return SANE_STATUS_INVAL;
+  switch (a)
+    {
+    case SANE_ACTION_SET_VALUE:
+      if ((opt->sod.type != SANE_TYPE_BUTTON && !v) ||
+          !SANE_OPTION_IS_SETTABLE (opt->sod.cap))
+        return SANE_STATUS_INVAL;	/* or _UNSUPPORTED? */
+        break;
+    case SANE_ACTION_SET_AUTO:
+      if (!(opt->sod.cap & SANE_CAP_AUTOMATIC) ||
+          !SANE_OPTION_IS_SETTABLE (opt->sod.cap))
+        return SANE_STATUS_INVAL;	/* or _UNSUPPORTED? */
+        break;
+    case SANE_ACTION_GET_VALUE:
+      if (!v || !(opt->sod.cap & SANE_CAP_SOFT_DETECT))
+        return SANE_STATUS_INVAL;	/* or _UNSUPPORTED? */
+        break;
+    default:
+      return SANE_STATUS_UNSUPPORTED;
+    }
+
+  error = control_option (ss, n, a, v, &info);
+  if (error == SANE_STATUS_GOOD && i)
+    *i = info;
+  return error;
+}
+
+SANE_Status
+sane_get_parameters (SANE_Handle h, SANE_Parameters * p)
+{
+  DECL_CTX;
+  pixma_scan_param_t temp, *sp;
+
+  if (!ss || !p)
+    return SANE_STATUS_INVAL;
+
+  if (!ss->idle)
+    {
+      sp = &ss->sp;		/* sp is calculated in sane_start() */
+    }
+  else
+    {
+      calc_scan_param (ss, &temp);
+      sp = &temp;
+    }
+  p->format = (sp->channels == 3) ? SANE_FRAME_RGB : SANE_FRAME_GRAY;
+  p->last_frame = SANE_TRUE;
+  p->lines = sp->h;
+  p->depth = sp->depth;
+  p->pixels_per_line = sp->w;
+  /* p->bytes_per_line = sp->line_size; NOTE: It should work this way, but it doesn't. No SANE frontend can cope with this. */
+  p->bytes_per_line = (sp->w * sp->channels * sp->depth) / 8;
+  return SANE_STATUS_GOOD;
+}
+
+SANE_Status
+sane_start (SANE_Handle h)
+{
+  DECL_CTX;
+  int error = 0;
+
+  if (!ss)
+    return SANE_STATUS_INVAL;
+  if (!ss->idle && ss->scanning)
+    {
+      PDBG (pixma_dbg (3, "Warning in Sane_start: !idle && scanning. idle=%d, ss->scanning=%d\n",
+                       ss->idle, ss->scanning));
+      if (ss->sp.source != PIXMA_SOURCE_ADF && ss->sp.source != PIXMA_SOURCE_ADFDUP)
+        return SANE_STATUS_INVAL;
+    }
+
+  ss->cancel = SANE_FALSE;
+  if (ss->idle ||
+      ss->source_map[OVAL (opt_source).w] == PIXMA_SOURCE_FLATBED ||
+      ss->source_map[OVAL (opt_source).w] == PIXMA_SOURCE_TPU)
+    ss->page_count = 0;	/* start from idle state or scan from flatbed or TPU */
+  else
+    ss->page_count++;
+  if (calc_scan_param (ss, &ss->sp) < 0)
+    return SANE_STATUS_INVAL;
+  ss->image_bytes_read = 0;
+  /* TODO: Check paper here in sane_start(). A function like
+     pixma_get_status() is needed. */
+  error = start_reader_task (ss);
+  if (error >= 0)
+    {
+      ss->output_line_size = (ss->sp.w * ss->sp.channels * ss->sp.depth) / 8;
+      ss->byte_pos_in_line = 0;
+      ss->last_read_status = SANE_STATUS_GOOD;
+      ss->scanning = SANE_TRUE;
+      ss->idle = SANE_FALSE;
+    }
+  return map_error (error);
+}
+
+SANE_Status
+sane_read (SANE_Handle h, SANE_Byte * buf, SANE_Int maxlen, SANE_Int * len)
+{
+  DECL_CTX;
+  int sum, n;
+  /* Due to 32 pixels alignment, sizeof(temp) is to be greater than:
+   * max(nchannels) * max (sp.line_size - output_line_size)
+   * so currently: 3 * 32 = 96  for better end line cropping efficiency */
+  SANE_Byte temp[100];
+  SANE_Status status;
+
+  if (len)
+    *len = 0;
+  if (!ss || !buf || !len)
+    return SANE_STATUS_INVAL;
+  if (ss->cancel)
+    return SANE_STATUS_CANCELLED;
+  if ((ss->idle)
+      && (ss->sp.source == PIXMA_SOURCE_ADF || ss->sp.source == PIXMA_SOURCE_ADFDUP))
+    return SANE_STATUS_INVAL;
+  if (!ss->scanning)
+    return ss->last_read_status;
+
+  status = SANE_STATUS_GOOD;
+  /* CCD scanners use software lineart
+   * the scanner must scan 24 bit color or 8 bit grayscale for one bit lineart */
+  if ((ss->sp.line_size - ((ss->sp.software_lineart == 1) ? (ss->output_line_size * 8) : ss->output_line_size)) == 0)
+    {
+      status = read_image (ss, buf, maxlen, &sum);
+    }
+  else
+    {
+      /* FIXME: Because there is no frontend that can cope with padding at
+         the end of line, we've to remove it here in the backend! */
+      PDBG (pixma_dbg (1, "*sane_read***** Warning: padding may cause incomplete scan results\n"));
+      sum = 0;
+      while (sum < maxlen)
+        {
+          if (ss->byte_pos_in_line < ss->output_line_size)
+            {
+              n = ss->output_line_size - ss->byte_pos_in_line;
+              if ((maxlen - sum) < n)
+                n = maxlen - sum;
+              status = read_image (ss, buf, n, &n);
+              if (n == 0)
+                break;
+              sum += n;
+              buf += n;
+              ss->byte_pos_in_line += n;
+            }
+          else
+            {
+              /* skip padding */
+              n = ss->sp.line_size - ss->byte_pos_in_line;
+              if (n > (int) sizeof (temp))
+                {
+                  PDBG (pixma_dbg (3, "Inefficient skip buffer. Should be %d\n", n));
+                  n = sizeof (temp);
+                }
+              status = read_image (ss, temp, n, &n);
+              if (n == 0)
+                break;
+              ss->byte_pos_in_line += n;
+              if (ss->byte_pos_in_line == ss->sp.line_size)
+                ss->byte_pos_in_line = 0;
+             }
+        }
+    }
+  if (ss->cancel)
+    status = SANE_STATUS_CANCELLED;
+  else if ((status == SANE_STATUS_GOOD || status == SANE_STATUS_EOF) &&
+	   sum > 0)
+    {
+      *len = sum;
+      status = SANE_STATUS_GOOD;
+    }
+  ss->scanning = (status == SANE_STATUS_GOOD);
+  ss->last_read_status = status;
+  return status;
+}
+
+void
+sane_cancel (SANE_Handle h)
+{
+  DECL_CTX;
+
+  if (!ss)
+    return;
+  ss->cancel = SANE_TRUE;
+  if (ss->idle)
+    return;
+  close (ss->rpipe);
+  ss->rpipe = -1;
+  terminate_reader_task (ss, NULL);
+  ss->idle = SANE_TRUE;
+}
+
+SANE_Status
+sane_set_io_mode (SANE_Handle h, SANE_Bool m)
+{
+  DECL_CTX;
+
+  if (!ss || ss->idle || ss->rpipe == -1)
+    return SANE_STATUS_INVAL;
+#ifdef HAVE_FCNTL_H
+  PDBG (pixma_dbg (2, "Setting %sblocking mode\n", (m) ? "non-" : ""));
+  if (fcntl (ss->rpipe, F_SETFL, (m) ? O_NONBLOCK : 0) == -1)
+    {
+      PDBG (pixma_dbg
+	    (1, "WARNING:fcntl(F_SETFL) failed %s\n", strerror (errno)));
+      return SANE_STATUS_UNSUPPORTED;
+    }
+  return SANE_STATUS_GOOD;
+#else
+  return (m) ? SANE_STATUS_UNSUPPORTED : SANE_STATUS_GOOD;
+#endif
+}
+
+SANE_Status
+sane_get_select_fd (SANE_Handle h, SANE_Int * fd)
+{
+  DECL_CTX;
+
+  *fd = -1;
+  if (!ss || !fd || ss->idle || ss->rpipe == -1)
+    return SANE_STATUS_INVAL;
+  *fd = ss->rpipe;
+  return SANE_STATUS_GOOD;
+}
+
+/*
+BEGIN SANE_Option_Descriptor
+
+rem -------------------------------------------
+type group
+  title Scan mode
+
+type int resolution
+  unit dpi
+  constraint @word_list = ss->dpi_list
+  default 75
+  title @SANE_TITLE_SCAN_RESOLUTION
+  desc  @SANE_DESC_SCAN_RESOLUTION
+  cap soft_select soft_detect automatic
+  info reload_params
+
+type string mode[30]
+  constraint @string_list = ss->mode_list
+  default @s = SANE_VALUE_SCAN_MODE_COLOR
+  title @SANE_TITLE_SCAN_MODE
+  desc  @SANE_DESC_SCAN_MODE
+  cap soft_select soft_detect automatic
+  info reload_params
+
+type string source[30]
+  constraint @string_list = ss->source_list
+  title @SANE_TITLE_SCAN_SOURCE
+  desc  Selects the scan source (such as a document-feeder). Set source before mode and resolution. Resets mode and resolution to auto values.
+  default Flatbed
+  cap soft_select soft_detect
+
+type bool button-controlled
+  title Button-controlled scan
+  desc When enabled, scan process will not start immediately. To proceed, press \"SCAN\" button (for MP150) or \"COLOR\" button (for other models). To cancel, press \"GRAY\" button.
+  default SANE_FALSE
+  cap soft_select soft_detect inactive
+
+rem -------------------------------------------
+type group
+  title Gamma
+
+type bool custom-gamma
+  default SANE_TRUE
+  title @SANE_TITLE_CUSTOM_GAMMA
+  desc  @SANE_DESC_CUSTOM_GAMMA
+  cap soft_select soft_detect automatic inactive
+
+type int gamma-table[4096]
+  constraint (0,255,0)
+  title @SANE_TITLE_GAMMA_VECTOR
+  desc  @SANE_DESC_GAMMA_VECTOR
+  cap soft_select soft_detect automatic inactive
+
+type fixed gamma
+  default AUTO_GAMMA
+  constraint (0.3,5,0)
+  title Gamma function exponent
+  desc  Changes intensity of midtones
+  cap soft_select soft_detect automatic inactive
+
+rem -------------------------------------------
+type group
+  title Geometry
+
+type fixed tl-x
+  unit mm
+  default 0
+  constraint @range = &ss->xrange
+  title @SANE_TITLE_SCAN_TL_X
+  desc  @SANE_DESC_SCAN_TL_X
+  cap soft_select soft_detect automatic
+  info reload_params
+
+type fixed tl-y
+  unit mm
+  default 0
+  constraint @range = &ss->yrange
+  title @SANE_TITLE_SCAN_TL_Y
+  desc  @SANE_DESC_SCAN_TL_Y
+  cap soft_select soft_detect automatic
+  info reload_params
+
+type fixed br-x
+  unit mm
+  default _MAX
+  constraint @range = &ss->xrange
+  title @SANE_TITLE_SCAN_BR_X
+  desc  @SANE_DESC_SCAN_BR_X
+  cap soft_select soft_detect automatic
+  info reload_params
+
+type fixed br-y
+  unit mm
+  default _MAX
+  constraint @range = &ss->yrange
+  title @SANE_TITLE_SCAN_BR_Y
+  desc  @SANE_DESC_SCAN_BR_Y
+  cap soft_select soft_detect automatic
+  info reload_params
+
+rem -------------------------------------------
+type group
+  title Buttons
+
+type button button-update
+  title Update button state
+  cap soft_select soft_detect advanced
+
+type int button-1
+  default 0
+  title Button 1
+  cap soft_detect advanced
+
+type int button-2
+  default 0
+  title Button 2
+  cap soft_detect advanced
+
+type int original
+  default 0
+  title Type of original to scan
+  cap soft_detect advanced
+
+type int target
+  default 0
+  title Target operation type
+  cap soft_detect advanced 
+
+type int scan-resolution
+  default 0
+  title Scan resolution
+  cap soft_detect advanced
+
+rem -------------------------------------------
+type group
+  title Extras
+
+type int threshold
+  unit PERCENT
+  default 50
+  constraint (0,100,1)
+  title @SANE_TITLE_THRESHOLD
+  desc  @SANE_DESC_THRESHOLD
+  cap soft_select soft_detect automatic inactive
+
+type int threshold-curve
+  constraint (0,127,1)
+  title Threshold curve
+  desc  Dynamic threshold curve, from light to dark, normally 50-65
+  cap soft_select soft_detect automatic inactive
+
+rem -------------------------------------------
+END SANE_Option_Descriptor
+*/
+
+/* pixma_sane_options.c generated by
+ * scripts/pixma_gen_options.py < pixma.c > pixma_sane_options.c
+ *
+ * pixma_sane_options.h generated by
+ * scripts/pixma_gen_options.py h < pixma.c > pixma_sane_options.h
+ */
+#include "pixma_sane_options.c"