Imported Upstream version 1.0.25upstream/1.0.25

1 files changed, 1364 insertions, 0 deletions

diff --git a/backend/epsonds.c b/backend/epsonds.c
new file mode 100644
index 0000000..2f85312
--- /dev/null
+++ b/backend/epsonds.c
@@ -0,0 +1,1364 @@
+/*
+ * epsonds.c - Epson ESC/I-2 driver.
+ *
+ * Copyright (C) 2015 Tower Technologies
+ * Author: Alessandro Zummo <a.zummo@towertech.it>
+ *
+ * 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, version 2.
+ */
+
+#define EPSONDS_VERSION		1
+#define EPSONDS_REVISION	0
+#define EPSONDS_BUILD		35
+
+/* debugging levels:
+ *
+ *	32	eds_send
+ *	30	eds_recv
+ *	20	sane_read and related
+ *	18	sane_read and related
+ *	17	setvalue, getvalue, control_option
+ *	16
+ *	15	esci2_img
+ *	13	image_cb
+ *	12	eds_control
+ *	11	all received params
+ *	10	some received params
+ *	 9
+ *	 8	esci2_xxx
+ *	 7	open/close/attach
+ *	 6	print_params
+ *	 5	basic functions
+ *	 3	JPEG decompressor
+ *	 1	scanner info and capabilities
+ *	 0	errors
+ */
+
+#include "sane/config.h"
+
+#include <ctype.h>
+
+#include "sane/saneopts.h"
+#include "sane/sanei_config.h"
+
+#include "epsonds.h"
+#include "epsonds-usb.h"
+#include "epsonds-io.h"
+#include "epsonds-cmd.h"
+#include "epsonds-ops.h"
+#include "epsonds-jpeg.h"
+
+/*
+ * Definition of the mode_param struct, that is used to
+ * specify the valid parameters for the different scan modes.
+ *
+ * The depth variable gets updated when the bit depth is modified.
+ */
+
+struct mode_param mode_params[] = {
+	{0, 0x00, 0x30, 1},
+	{0, 0x00, 0x30, 8},
+	{1, 0x02, 0x00, 8},
+	{0, 0x00, 0x30, 1}
+};
+
+static SANE_String_Const mode_list[] = {
+	SANE_VALUE_SCAN_MODE_LINEART,
+	SANE_VALUE_SCAN_MODE_GRAY,
+	SANE_VALUE_SCAN_MODE_COLOR,
+	NULL
+};
+
+static const SANE_String_Const adf_mode_list[] = {
+	SANE_I18N("Simplex"),
+	SANE_I18N("Duplex"),
+	NULL
+};
+
+/* Define the different scan sources */
+
+#define FBF_STR	SANE_I18N("Flatbed")
+#define ADF_STR	SANE_I18N("Automatic Document Feeder")
+
+/* order will be fixed: fb, adf, tpu */
+SANE_String_Const source_list[] = {
+	NULL,
+	NULL,
+	NULL,
+	NULL
+};
+
+/*
+ * List of pointers to devices - will be dynamically allocated depending
+ * on the number of devices found.
+ */
+static const SANE_Device **devlist;
+
+/* Some utility functions */
+
+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 attach_one_usb(SANE_String_Const devname);
+
+static void
+print_params(const SANE_Parameters params)
+{
+	DBG(6, "params.format          = %d\n", params.format);
+	DBG(6, "params.last_frame      = %d\n", params.last_frame);
+	DBG(6, "params.bytes_per_line  = %d\n", params.bytes_per_line);
+	DBG(6, "params.pixels_per_line = %d\n", params.pixels_per_line);
+	DBG(6, "params.lines           = %d\n", params.lines);
+	DBG(6, "params.depth           = %d\n", params.depth);
+}
+
+static void
+close_scanner(epsonds_scanner *s)
+{
+	DBG(7, "%s: fd = %d\n", __func__, s->fd);
+
+	if (s->fd == -1)
+		goto free;
+
+	if (s->locked) {
+		DBG(7, " unlocking scanner\n");
+		esci2_fin(s);
+	}
+
+	if (s->hw->connection == SANE_EPSONDS_USB) {
+		sanei_usb_close(s->fd);
+	}
+
+free:
+
+	free(s->front.ring);
+	free(s->back.ring);
+	free(s->line_buffer);
+	free(s);
+
+	DBG(7, "%s: ZZZ\n", __func__);
+}
+
+static SANE_Status
+open_scanner(epsonds_scanner *s)
+{
+	SANE_Status status = SANE_STATUS_INVAL;
+
+	DBG(7, "%s: %s\n", __func__, s->hw->sane.name);
+
+	if (s->fd != -1) {
+		DBG(5, "scanner is already open: fd = %d\n", s->fd);
+		return SANE_STATUS_GOOD;	/* no need to open the scanner */
+	}
+
+	if (s->hw->connection == SANE_EPSONDS_USB) {
+
+		status = sanei_usb_open(s->hw->sane.name, &s->fd);
+		sanei_usb_set_timeout(USB_TIMEOUT);
+
+	} else {
+		DBG(1, "unknown connection type: %d\n", s->hw->connection);
+	}
+
+	if (status == SANE_STATUS_ACCESS_DENIED) {
+		DBG(1, "please check that you have permissions on the device.\n");
+		DBG(1, "if this is a multi-function device with a printer,\n");
+		DBG(1, "disable any conflicting driver (like usblp).\n");
+	}
+
+	if (status != SANE_STATUS_GOOD)
+		DBG(1, "%s open failed: %s\n",
+			s->hw->sane.name,
+			sane_strstatus(status));
+	else
+		DBG(5, " opened correctly\n");
+
+	return status;
+}
+
+static int num_devices;			/* number of scanners attached to backend */
+static epsonds_device *first_dev;	/* first EPSON scanner in list */
+
+static struct epsonds_scanner *
+scanner_create(struct epsonds_device *dev, SANE_Status *status)
+{
+	struct epsonds_scanner *s;
+
+	s = malloc(sizeof(struct epsonds_scanner));
+	if (s == NULL) {
+		*status = SANE_STATUS_NO_MEM;
+		return NULL;
+	}
+
+	/* clear verything */
+	memset(s, 0x00, sizeof(struct epsonds_scanner));
+
+	s->fd = -1;
+	s->hw = dev;
+
+	return s;
+}
+
+static struct epsonds_scanner *
+device_detect(const char *name, int type, SANE_Status *status)
+{
+	struct epsonds_scanner *s;
+	struct epsonds_device *dev;
+
+	DBG(1, "%s\n", __func__);
+
+	/* try to find the device in our list */
+	for (dev = first_dev; dev; dev = dev->next) {
+		if (strcmp(dev->sane.name, name) == 0) {
+			DBG(1, " found cached device\n");
+			return scanner_create(dev, status);
+		}
+	}
+
+	/* not found, create new if valid */
+	if (type == SANE_EPSONDS_NODEV) {
+		*status = SANE_STATUS_INVAL;
+		return NULL;
+	}
+
+	/* alloc and clear our device structure */
+	dev = malloc(sizeof(*dev));
+	if (!dev) {
+		*status = SANE_STATUS_NO_MEM;
+		return NULL;
+	}
+	memset(dev, 0x00, sizeof(struct epsonds_device));
+
+	s = scanner_create(dev, status);
+	if (s == NULL)
+		return NULL;
+
+	dev->connection = type;
+	dev->model = strdup("(undetermined)");
+
+	dev->sane.name = name;
+	dev->sane.vendor = "Epson";
+	dev->sane.model = dev->model;
+	dev->sane.type = "ESC/I-2";
+
+	*status = open_scanner(s);
+	if (*status != SANE_STATUS_GOOD) {
+		free(s);
+		return NULL;
+	}
+
+	eds_dev_init(dev);
+
+	/* lock scanner */
+	*status = eds_lock(s);
+	if (*status != SANE_STATUS_GOOD) {
+		goto close;
+	}
+
+	/* discover capabilities */
+	*status = esci2_info(s);
+	if (*status != SANE_STATUS_GOOD)
+		goto close;
+
+	*status = esci2_capa(s);
+	if (*status != SANE_STATUS_GOOD)
+		goto close;
+
+	*status = esci2_resa(s);
+	if (*status != SANE_STATUS_GOOD)
+		goto close;
+
+	/* assume 1 and 8 bit are always supported */
+	eds_add_depth(s->hw, 1);
+	eds_add_depth(s->hw, 8);
+
+	/* setup area according to available options */
+	if (s->hw->has_fb) {
+
+		dev->x_range = &dev->fbf_x_range;
+		dev->y_range = &dev->fbf_y_range;
+		dev->alignment = dev->fbf_alignment;
+
+	} else if (s->hw->has_adf) {
+
+		dev->x_range = &dev->adf_x_range;
+		dev->y_range = &dev->adf_y_range;
+		dev->alignment = dev->adf_alignment;
+
+	} else {
+		DBG(0, "unable to lay on the flatbed or feed the feeder. is that a scanner??\n");
+	}
+
+	*status = eds_dev_post_init(dev);
+	if (*status != SANE_STATUS_GOOD)
+		goto close;
+
+	DBG(1, "scanner model: %s\n", dev->model);
+
+	/* add this scanner to the device list */
+
+	num_devices++;
+	dev->next = first_dev;
+	first_dev = dev;
+
+	return s;
+
+close:
+	DBG(1, " failed\n");
+
+	close_scanner(s);
+	return NULL;
+}
+
+
+static SANE_Status
+attach(const char *name, int type)
+{
+	SANE_Status status;
+	epsonds_scanner * s;
+
+	DBG(7, "%s: devname = %s, type = %d\n", __func__, name, type);
+
+	s = device_detect(name, type, &status);
+	if (s == NULL)
+		return status;
+
+	close_scanner(s);
+	return status;
+}
+
+SANE_Status
+attach_one_usb(const char *dev)
+{
+	DBG(7, "%s: dev = %s\n", __func__, dev);
+	return attach(dev, SANE_EPSONDS_USB);
+}
+
+static SANE_Status
+attach_one_config(SANEI_Config __sane_unused__ *config, const char *line)
+{
+	int vendor, product;
+
+	int len = strlen(line);
+
+	DBG(7, "%s: len = %d, line = %s\n", __func__, len, line);
+
+	if (sscanf(line, "usb %i %i", &vendor, &product) == 2) {
+
+		DBG(7, " user configured device\n");
+
+		if (vendor != SANE_EPSONDS_VENDOR_ID)
+			return SANE_STATUS_INVAL; /* this is not an Epson device */
+
+		sanei_usb_attach_matching_devices(line, attach_one_usb);
+
+	} else if (strncmp(line, "usb", 3) == 0 && len == 3) {
+
+		int i, numIds;
+
+		DBG(7, " probing usb devices\n");
+
+		numIds = epsonds_get_number_of_ids();
+
+		for (i = 0; i < numIds; i++) {
+			sanei_usb_find_devices(SANE_EPSONDS_VENDOR_ID,
+					epsonds_usb_product_ids[i], attach_one_usb);
+		}
+
+	} else {
+		DBG(0, "unable to parse config line: %s\n", line);
+	}
+
+	return SANE_STATUS_GOOD;
+}
+
+static void
+free_devices(void)
+{
+	epsonds_device *dev, *next;
+
+	for (dev = first_dev; dev; dev = next) {
+		next = dev->next;
+		free(dev->name);
+		free(dev->model);
+		free(dev);
+	}
+
+	free(devlist);
+	first_dev = NULL;
+}
+
+static void
+probe_devices(void)
+{
+	DBG(5, "%s\n", __func__);
+
+	free_devices();
+	sanei_configure_attach(EPSONDS_CONFIG_FILE, NULL, attach_one_config);
+}
+
+/**** SANE API ****/
+
+SANE_Status
+sane_init(SANE_Int *version_code, SANE_Auth_Callback __sane_unused__ authorize)
+{
+	DBG_INIT();
+	DBG(2, "%s: " PACKAGE " " VERSION "\n", __func__);
+
+	DBG(1, "epsonds backend, version %i.%i.%i\n",
+		EPSONDS_VERSION, EPSONDS_REVISION, EPSONDS_BUILD);
+
+	if (version_code != NULL)
+		*version_code = SANE_VERSION_CODE(SANE_CURRENT_MAJOR, V_MINOR,
+					  EPSONDS_BUILD);
+
+	sanei_usb_init();
+
+	return SANE_STATUS_GOOD;
+}
+
+void
+sane_exit(void)
+{
+	DBG(5, "** %s\n", __func__);
+	free_devices();
+}
+
+SANE_Status
+sane_get_devices(const SANE_Device ***device_list, SANE_Bool __sane_unused__ local_only)
+{
+	int i;
+	epsonds_device *dev;
+
+	DBG(5, "** %s\n", __func__);
+
+	probe_devices();
+
+	devlist = malloc((num_devices + 1) * sizeof(devlist[0]));
+	if (!devlist) {
+		DBG(1, "out of memory (line %d)\n", __LINE__);
+		return SANE_STATUS_NO_MEM;
+	}
+
+	DBG(5, "%s - results:\n", __func__);
+
+	for (i = 0, dev = first_dev; i < num_devices && dev; dev = dev->next, i++) {
+		DBG(1, " %d (%d): %s\n", i, dev->connection, dev->model);
+		devlist[i] = &dev->sane;
+	}
+
+	devlist[i] = NULL;
+
+	*device_list = devlist;
+
+	return SANE_STATUS_GOOD;
+}
+
+static SANE_Status
+init_options(epsonds_scanner *s)
+{
+	int i;
+
+	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;
+
+	/* "Scan Mode" group: */
+
+	s->opt[OPT_MODE_GROUP].title = SANE_I18N("Scan Mode");
+	s->opt[OPT_MODE_GROUP].desc = "";
+	s->opt[OPT_MODE_GROUP].type = SANE_TYPE_GROUP;
+	s->opt[OPT_MODE_GROUP].cap = 0;
+
+	/* 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 = SANE_DESC_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].w = 0;	/* Lineart */
+
+	/* bit depth */
+	s->opt[OPT_DEPTH].name = SANE_NAME_BIT_DEPTH;
+	s->opt[OPT_DEPTH].title = SANE_TITLE_BIT_DEPTH;
+	s->opt[OPT_DEPTH].desc = SANE_DESC_BIT_DEPTH;
+	s->opt[OPT_DEPTH].type = SANE_TYPE_INT;
+	s->opt[OPT_DEPTH].unit = SANE_UNIT_BIT;
+	s->opt[OPT_DEPTH].constraint_type = SANE_CONSTRAINT_WORD_LIST;
+	s->opt[OPT_DEPTH].constraint.word_list = s->hw->depth_list;
+	s->val[OPT_DEPTH].w = s->hw->depth_list[1];	/* the first "real" element is the default */
+
+	/* default is Lineart, disable depth selection */
+	s->opt[OPT_DEPTH].cap |= SANE_CAP_INACTIVE;
+
+	/* 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_INT;
+	s->opt[OPT_RESOLUTION].unit = SANE_UNIT_DPI;
+
+	/* range */
+	if (s->hw->dpi_range.quant) {
+		s->opt[OPT_RESOLUTION].constraint_type = SANE_CONSTRAINT_RANGE;
+		s->opt[OPT_RESOLUTION].constraint.range = &s->hw->dpi_range;
+		s->val[OPT_RESOLUTION].w = s->hw->dpi_range.min;
+	} else { /* list */
+		s->opt[OPT_RESOLUTION].constraint_type = SANE_CONSTRAINT_WORD_LIST;
+		s->opt[OPT_RESOLUTION].constraint.word_list = s->hw->res_list;
+		s->val[OPT_RESOLUTION].w = s->hw->res_list[1];
+	}
+
+	/* "Geometry" group: */
+	s->opt[OPT_GEOMETRY_GROUP].title = SANE_I18N("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;
+
+	/* 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;
+
+	/* "Optional equipment" group: */
+	s->opt[OPT_EQU_GROUP].title = SANE_I18N("Optional equipment");
+	s->opt[OPT_EQU_GROUP].desc = "";
+	s->opt[OPT_EQU_GROUP].type = SANE_TYPE_GROUP;
+	s->opt[OPT_EQU_GROUP].cap = SANE_CAP_ADVANCED;
+
+	/* source */
+	s->opt[OPT_SOURCE].name = SANE_NAME_SCAN_SOURCE;
+	s->opt[OPT_SOURCE].title = SANE_TITLE_SCAN_SOURCE;
+	s->opt[OPT_SOURCE].desc = SANE_DESC_SCAN_SOURCE;
+	s->opt[OPT_SOURCE].type = SANE_TYPE_STRING;
+	s->opt[OPT_SOURCE].size = max_string_size(source_list);
+	s->opt[OPT_SOURCE].constraint_type = SANE_CONSTRAINT_STRING_LIST;
+	s->opt[OPT_SOURCE].constraint.string_list = source_list;
+	s->val[OPT_SOURCE].w = 0;
+
+	s->opt[OPT_EJECT].name = "eject";
+	s->opt[OPT_EJECT].title = SANE_I18N("Eject");
+	s->opt[OPT_EJECT].desc = SANE_I18N("Eject the sheet in the ADF");
+	s->opt[OPT_EJECT].type = SANE_TYPE_BUTTON;
+
+	if (!s->hw->adf_has_eject)
+		s->opt[OPT_EJECT].cap |= SANE_CAP_INACTIVE;
+
+	s->opt[OPT_LOAD].name = "load";
+	s->opt[OPT_LOAD].title = SANE_I18N("Load");
+	s->opt[OPT_LOAD].desc = SANE_I18N("Load a sheet in the ADF");
+	s->opt[OPT_LOAD].type = SANE_TYPE_BUTTON;
+
+	if (!s->hw->adf_has_load)
+		s->opt[OPT_LOAD].cap |= SANE_CAP_INACTIVE;
+
+	s->opt[OPT_ADF_MODE].name = "adf-mode";
+	s->opt[OPT_ADF_MODE].title = SANE_I18N("ADF Mode");
+	s->opt[OPT_ADF_MODE].desc =
+		SANE_I18N("Selects the ADF mode (simplex/duplex)");
+	s->opt[OPT_ADF_MODE].type = SANE_TYPE_STRING;
+	s->opt[OPT_ADF_MODE].size = max_string_size(adf_mode_list);
+	s->opt[OPT_ADF_MODE].constraint_type = SANE_CONSTRAINT_STRING_LIST;
+	s->opt[OPT_ADF_MODE].constraint.string_list = adf_mode_list;
+	s->val[OPT_ADF_MODE].w = 0; /* simplex */
+
+	if (!s->hw->adf_is_duplex)
+		s->opt[OPT_ADF_MODE].cap |= SANE_CAP_INACTIVE;
+
+	s->opt[OPT_ADF_SKEW].name = "adf-skew";
+	s->opt[OPT_ADF_SKEW].title = SANE_I18N("ADF Skew Correction");
+	s->opt[OPT_ADF_SKEW].desc =
+		SANE_I18N("Enables ADF skew correction");
+	s->opt[OPT_ADF_SKEW].type = SANE_TYPE_BOOL;
+	s->val[OPT_ADF_SKEW].w = 0;
+
+	if (!s->hw->adf_has_skew)
+		s->opt[OPT_ADF_SKEW].cap |= SANE_CAP_INACTIVE;
+
+	return SANE_STATUS_GOOD;
+}
+
+SANE_Status
+sane_open(SANE_String_Const name, SANE_Handle *handle)
+{
+	SANE_Status status;
+	epsonds_scanner *s = NULL;
+
+	DBG(7, "** %s: name = '%s'\n", __func__, name);
+
+	/* probe if empty device name provided */
+	if (name[0] == '\0') {
+
+		probe_devices();
+
+		if (first_dev == NULL) {
+			DBG(1, "no devices detected\n");
+			return SANE_STATUS_INVAL;
+		}
+
+		s = device_detect(first_dev->sane.name, first_dev->connection,
+					&status);
+		if (s == NULL) {
+			DBG(1, "cannot open a perfectly valid device (%s),"
+				" please report to the authors\n", name);
+			return SANE_STATUS_INVAL;
+		}
+
+	} else {
+
+		if (strncmp(name, "libusb:", 7) == 0) {
+			s = device_detect(name, SANE_EPSONDS_USB, &status);
+			if (s == NULL)
+				return status;
+		} else {
+			DBG(1, "invalid device name: %s\n", name);
+			return SANE_STATUS_INVAL;
+		}
+	}
+
+	/* s is always valid here */
+
+	DBG(5, "%s: handle obtained\n", __func__);
+
+	init_options(s);
+
+	*handle = (SANE_Handle)s;
+
+	status = open_scanner(s);
+	if (status != SANE_STATUS_GOOD) {
+		free(s);
+		return status;
+	}
+
+	/* lock scanner if required */
+	if (!s->locked) {
+		status = eds_lock(s);
+	}
+
+	return status;
+}
+
+void
+sane_close(SANE_Handle handle)
+{
+	epsonds_scanner *s = (epsonds_scanner *)handle;
+
+	DBG(1, "** %s\n", __func__);
+
+	close_scanner(s);
+}
+
+const SANE_Option_Descriptor *
+sane_get_option_descriptor(SANE_Handle handle, SANE_Int option)
+{
+	epsonds_scanner *s = (epsonds_scanner *) handle;
+
+	if (option < 0 || option >= NUM_OPTIONS)
+		return NULL;
+
+	return s->opt + option;
+}
+
+static const SANE_String_Const *
+search_string_list(const SANE_String_Const *list, SANE_String value)
+{
+	while (*list != NULL && strcmp(value, *list) != 0)
+		list++;
+
+	return ((*list == NULL) ? NULL : list);
+}
+
+static void
+activateOption(epsonds_scanner *s, SANE_Int option, SANE_Bool *change)
+{
+	if (!SANE_OPTION_IS_ACTIVE(s->opt[option].cap)) {
+		s->opt[option].cap &= ~SANE_CAP_INACTIVE;
+		*change = SANE_TRUE;
+	}
+}
+
+static void
+deactivateOption(epsonds_scanner *s, SANE_Int option, SANE_Bool *change)
+{
+	if (SANE_OPTION_IS_ACTIVE(s->opt[option].cap)) {
+		s->opt[option].cap |= SANE_CAP_INACTIVE;
+		*change = SANE_TRUE;
+	}
+}
+
+/*
+ * Handles setting the source (flatbed, transparency adapter (TPU),
+ * or auto document feeder (ADF)).
+ *
+ * For newer scanners it also sets the focus according to the
+ * glass / TPU settings.
+ */
+
+static void
+change_source(epsonds_scanner *s, SANE_Int optindex, char *value)
+{
+	int force_max = SANE_FALSE;
+	SANE_Bool dummy;
+
+	DBG(1, "%s: optindex = %d, source = '%s'\n", __func__, optindex,
+	    value);
+
+	s->val[OPT_SOURCE].w = optindex;
+
+	/* if current selected area is the maximum available,
+	 * keep this setting on the new source.
+	 */
+	if (s->val[OPT_TL_X].w == s->hw->x_range->min
+	    && s->val[OPT_TL_Y].w == s->hw->y_range->min
+	    && s->val[OPT_BR_X].w == s->hw->x_range->max
+	    && s->val[OPT_BR_Y].w == s->hw->y_range->max) {
+		force_max = SANE_TRUE;
+	}
+
+	if (strcmp(ADF_STR, value) == 0) {
+
+		s->hw->x_range = &s->hw->adf_x_range;
+		s->hw->y_range = &s->hw->adf_y_range;
+		s->hw->alignment = s->hw->adf_alignment;
+
+		if (s->hw->adf_is_duplex) {
+			activateOption(s, OPT_ADF_MODE, &dummy);
+		} else {
+			deactivateOption(s, OPT_ADF_MODE, &dummy);
+			s->val[OPT_ADF_MODE].w = 0;
+		}
+
+	} else if (strcmp(TPU_STR, value) == 0) {
+
+		s->hw->x_range = &s->hw->tpu_x_range;
+		s->hw->y_range = &s->hw->tpu_y_range;
+
+		deactivateOption(s, OPT_ADF_MODE, &dummy);
+
+	} else {
+
+		/* neither ADF nor TPU active, assume FB */
+		s->hw->x_range = &s->hw->fbf_x_range;
+		s->hw->y_range = &s->hw->fbf_y_range;
+		s->hw->alignment = s->hw->fbf_alignment;
+	}
+
+	s->opt[OPT_BR_X].constraint.range = s->hw->x_range;
+	s->opt[OPT_BR_Y].constraint.range = s->hw->y_range;
+
+	if (s->val[OPT_TL_X].w < s->hw->x_range->min || force_max)
+		s->val[OPT_TL_X].w = s->hw->x_range->min;
+
+	if (s->val[OPT_TL_Y].w < s->hw->y_range->min || force_max)
+		s->val[OPT_TL_Y].w = s->hw->y_range->min;
+
+	if (s->val[OPT_BR_X].w > s->hw->x_range->max || force_max)
+		s->val[OPT_BR_X].w = s->hw->x_range->max;
+
+	if (s->val[OPT_BR_Y].w > s->hw->y_range->max || force_max)
+		s->val[OPT_BR_Y].w = s->hw->y_range->max;
+}
+
+static SANE_Status
+getvalue(SANE_Handle handle, SANE_Int option, void *value)
+{
+	epsonds_scanner *s = (epsonds_scanner *)handle;
+	SANE_Option_Descriptor *sopt = &(s->opt[option]);
+	Option_Value *sval = &(s->val[option]);
+
+	DBG(17, "%s: option = %d\n", __func__, option);
+
+	switch (option) {
+
+	case OPT_NUM_OPTS:
+	case OPT_RESOLUTION:
+	case OPT_TL_X:
+	case OPT_TL_Y:
+	case OPT_BR_X:
+	case OPT_BR_Y:
+	case OPT_DEPTH:
+	case OPT_ADF_SKEW:
+		*((SANE_Word *) value) = sval->w;
+		break;
+
+	case OPT_MODE:
+	case OPT_ADF_MODE:
+	case OPT_SOURCE:
+		strcpy((char *) value, sopt->constraint.string_list[sval->w]);
+		break;
+
+	default:
+		return SANE_STATUS_INVAL;
+	}
+
+	return SANE_STATUS_GOOD;
+}
+
+static SANE_Status
+setvalue(SANE_Handle handle, SANE_Int option, void *value, SANE_Int *info)
+{
+	epsonds_scanner *s = (epsonds_scanner *) handle;
+	SANE_Option_Descriptor *sopt = &(s->opt[option]);
+	Option_Value *sval = &(s->val[option]);
+
+	SANE_Status status;
+	const SANE_String_Const *optval = NULL;
+	int optindex = 0;
+	SANE_Bool reload = SANE_FALSE;
+
+	DBG(17, "** %s: option = %d, value = %p\n", __func__, option, value);
+
+	status = sanei_constrain_value(sopt, value, info);
+	if (status != SANE_STATUS_GOOD)
+		return status;
+
+	if (info && value && (*info & SANE_INFO_INEXACT)
+	    && sopt->type == SANE_TYPE_INT)
+		DBG(17, " constrained val = %d\n", *(SANE_Word *) value);
+
+	if (sopt->constraint_type == SANE_CONSTRAINT_STRING_LIST) {
+		optval = search_string_list(sopt->constraint.string_list,
+					    (char *) value);
+		if (optval == NULL)
+			return SANE_STATUS_INVAL;
+		optindex = optval - sopt->constraint.string_list;
+	}
+
+	/* block faulty frontends */
+	if (sopt->cap & SANE_CAP_INACTIVE) {
+		DBG(1, " tried to modify a disabled parameter");
+		return SANE_STATUS_INVAL;
+	}
+
+	switch (option) {
+
+	case OPT_ADF_MODE: /* simple lists */
+		sval->w = optindex;
+		break;
+
+	case OPT_ADF_SKEW:
+	case OPT_RESOLUTION:
+		sval->w = *((SANE_Word *) value);
+		reload = SANE_TRUE;
+		break;
+
+	case OPT_BR_X:
+	case OPT_BR_Y:
+		sval->w = *((SANE_Word *) value);
+		if (SANE_UNFIX(sval->w) == 0) {
+			DBG(17, " invalid br-x or br-y\n");
+			return SANE_STATUS_INVAL;
+		}
+		/* passthru */
+	case OPT_TL_X:
+	case OPT_TL_Y:
+		sval->w = *((SANE_Word *) value);
+		if (NULL != info)
+			*info |= SANE_INFO_RELOAD_PARAMS;
+		break;
+
+	case OPT_SOURCE:
+		change_source(s, optindex, (char *) value);
+		reload = SANE_TRUE;
+		break;
+
+	case OPT_MODE:
+	{
+		/* use JPEG mode if RAW is not available when bpp > 1 */
+		if (optindex > 0 && !s->hw->has_raw) {
+			s->mode_jpeg = 1;
+		} else {
+			s->mode_jpeg = 0;
+		}
+
+		sval->w = optindex;
+
+		/* if binary, then disable the bit depth selection */
+		if (optindex == 0) {
+			s->opt[OPT_DEPTH].cap |= SANE_CAP_INACTIVE;
+		} else {
+			if (s->hw->depth_list[0] == 1)
+				s->opt[OPT_DEPTH].cap |= SANE_CAP_INACTIVE;
+			else {
+				s->opt[OPT_DEPTH].cap &= ~SANE_CAP_INACTIVE;
+				s->val[OPT_DEPTH].w =
+					mode_params[optindex].depth;
+			}
+		}
+
+		reload = SANE_TRUE;
+		break;
+	}
+
+	case OPT_DEPTH:
+		sval->w = *((SANE_Word *) value);
+		mode_params[s->val[OPT_MODE].w].depth = sval->w;
+		reload = SANE_TRUE;
+		break;
+
+	case OPT_LOAD:
+		esci2_mech(s, "#ADFLOAD");
+		break;
+
+	case OPT_EJECT:
+		esci2_mech(s, "#ADFEJCT");
+		break;
+
+	default:
+		return SANE_STATUS_INVAL;
+	}
+
+	if (reload && info != NULL)
+		*info |= SANE_INFO_RELOAD_OPTIONS | SANE_INFO_RELOAD_PARAMS;
+
+	return SANE_STATUS_GOOD;
+}
+
+SANE_Status
+sane_control_option(SANE_Handle handle, SANE_Int option, SANE_Action action,
+		    void *value, SANE_Int *info)
+{
+	DBG(17, "** %s: action = %x, option = %d\n", __func__, action, option);
+
+	if (option < 0 || option >= NUM_OPTIONS)
+		return SANE_STATUS_INVAL;
+
+	if (info != NULL)
+		*info = 0;
+
+	switch (action) {
+	case SANE_ACTION_GET_VALUE:
+		return getvalue(handle, option, value);
+
+	case SANE_ACTION_SET_VALUE:
+		return setvalue(handle, option, value, info);
+
+	default:
+		return SANE_STATUS_INVAL;
+	}
+
+	return SANE_STATUS_INVAL;
+}
+
+SANE_Status
+sane_get_parameters(SANE_Handle handle, SANE_Parameters *params)
+{
+	epsonds_scanner *s = (epsonds_scanner *)handle;
+
+	DBG(5, "** %s\n", __func__);
+
+	if (params == NULL)
+		DBG(1, "%s: params is NULL\n", __func__);
+
+	/*
+	 * If sane_start was already called, then just retrieve the parameters
+	 * from the scanner data structure
+	 */
+	if (s->scanning) {
+		DBG(5, "scan in progress, returning saved params structure\n");
+	} else {
+		/* otherwise initialize the params structure */
+		eds_init_parameters(s);
+	}
+
+	if (params != NULL)
+		*params = s->params;
+
+	print_params(s->params);
+
+	return SANE_STATUS_GOOD;
+}
+
+/*
+ * This function is part of the SANE API and gets called from the front end to
+ * start the scan process.
+ */
+
+SANE_Status
+sane_start(SANE_Handle handle)
+{
+	epsonds_scanner *s = (epsonds_scanner *)handle;
+	char buf[64];
+	char cmd[100]; /* take care not to overflow */
+	SANE_Status status = 0;
+
+	s->pages++;
+
+	DBG(5, "** %s, pages = %d, scanning = %d, backside = %d, front fill: %d, back fill: %d\n",
+		__func__, s->pages, s->scanning, s->backside,
+		eds_ring_avail(&s->front),
+		eds_ring_avail(&s->back));
+
+	s->eof = 0;
+	s->canceling = 0;
+
+	if ((s->pages % 2) == 1) {
+		s->current = &s->front;
+		eds_ring_flush(s->current);
+	} else if (eds_ring_avail(&s->back)) {
+		DBG(5, "back side\n");
+		s->current = &s->back;
+	}
+
+	/* prepare the JPEG decompressor */
+	if (s->mode_jpeg) {
+		status = eds_jpeg_start(s);
+		if (status != SANE_STATUS_GOOD) {
+			goto end;
+	}	}
+
+	/* scan already in progress? (one pass adf) */
+	if (s->scanning) {
+		DBG(5, " scan in progress, returning early\n");
+		return SANE_STATUS_GOOD;
+	}
+
+	/* calc scanning parameters */
+	status = eds_init_parameters(s);
+	if (status != SANE_STATUS_GOOD) {
+		DBG(1, " parameters initialization failed\n");
+		return status;
+	}
+
+	/* allocate line buffer */
+	s->line_buffer = realloc(s->line_buffer, s->params.bytes_per_line);
+	if (s->line_buffer == NULL)
+		return SANE_STATUS_NO_MEM;
+
+	/* ring buffer for front page, twice bsz */
+	/* XXX read value from scanner */
+	status = eds_ring_init(&s->front, (65536 * 4) * 2);
+	if (status != SANE_STATUS_GOOD) {
+		return status;
+	}
+
+	/* transfer buffer, bsz */
+	/* XXX read value from scanner */
+	s->buf = realloc(s->buf, 65536 * 4);
+	if (s->buf == NULL)
+		return SANE_STATUS_NO_MEM;
+
+	print_params(s->params);
+
+	/* set scanning parameters */
+
+	/* document source */
+	if (strcmp(source_list[s->val[OPT_SOURCE].w], ADF_STR) == 0) {
+
+		sprintf(buf, "#ADF%s%s",
+			s->val[OPT_ADF_MODE].w ? "DPLX" : "",
+			s->val[OPT_ADF_SKEW].w ? "SKEW" : "");
+
+		if (s->hw->adf_has_dfd == 2) {
+			strcat(buf, "DFL2");
+		} else if (s->hw->adf_has_dfd == 1) {
+			strcat(buf, "DFL1");
+		}
+
+	} else if (strcmp(source_list[s->val[OPT_SOURCE].w], FBF_STR) == 0) {
+
+		strcpy(buf, "#FB ");
+
+	} else {
+		/* XXX */
+	}
+
+	strcpy(cmd, buf);
+
+	if (s->params.format == SANE_FRAME_GRAY) {
+		sprintf(buf, "#COLM%03d", s->params.depth);
+	} else if (s->params.format == SANE_FRAME_RGB) {
+		sprintf(buf, "#COLC%03d", s->params.depth * 3);
+	}
+
+	strcat(cmd, buf);
+
+	/* image transfer format */
+	if (!s->mode_jpeg) {
+		if (s->params.depth > 1 || s->hw->has_raw) {
+			strcat(cmd, "#FMTRAW ");
+		}
+	} else {
+		strcat(cmd, "#FMTJPG #JPGd090");
+	}
+
+	/* resolution (RSMi not always supported) */
+
+	if (s->val[OPT_RESOLUTION].w > 999) {
+		sprintf(buf, "#RSMi%07d", s->val[OPT_RESOLUTION].w);
+	} else {
+		sprintf(buf, "#RSMd%03d", s->val[OPT_RESOLUTION].w);
+	}
+
+	strcat(cmd, buf);
+
+	/* scanning area */
+	sprintf(buf, "#ACQi%07di%07di%07di%07d",
+		s->left, s->top, s->params.pixels_per_line, s->params.lines);
+
+	strcat(cmd, buf);
+
+	status = esci2_para(s, cmd);
+	if (status != SANE_STATUS_GOOD) {
+		goto end;
+	}
+
+	/* start scanning */
+	DBG(1, "%s: scanning...\n", __func__);
+
+	/* switch to data state */
+	status = esci2_trdt(s);
+	if (status != SANE_STATUS_GOOD) {
+		goto end;
+	}
+
+	/* first page is page 1 */
+	s->pages = 1;
+	s->scanning = 1;
+
+end:
+	if (status != SANE_STATUS_GOOD) {
+		DBG(1, "%s: start failed: %s\n", __func__, sane_strstatus(status));
+	}
+
+	return status;
+}
+
+/* this moves data from our buffers to SANE */
+
+SANE_Status
+sane_read(SANE_Handle handle, SANE_Byte *data, SANE_Int max_length,
+	  SANE_Int *length)
+{
+	SANE_Int read = 0, tries = 3;
+	SANE_Int available;
+	SANE_Status status = 0;
+	epsonds_scanner *s = (epsonds_scanner *)handle;
+
+	*length = read = 0;
+
+	DBG(20, "** %s: backside = %d\n", __func__, s->backside);
+
+	/* sane_read called before sane_start? */
+	if (s->current == NULL) {
+		DBG(0, "%s: buffer is NULL", __func__);
+		return SANE_STATUS_INVAL;
+	}
+
+	/* anything in the buffer? pass it to the frontend */
+	available = eds_ring_avail(s->current);
+	if (available) {
+
+		DBG(18, "reading from ring buffer, %d left\n", available);
+
+		if (s->mode_jpeg && !s->jpeg_header_seen) {
+
+			status = eds_jpeg_read_header(s);
+			if (status != SANE_STATUS_GOOD && --tries) {
+				goto read_again;
+			}
+		}
+
+		if (s->mode_jpeg) {
+			eds_jpeg_read(handle, data, max_length, &read);
+		} else {
+			eds_copy_image_from_ring(s, data, max_length, &read);
+		}
+
+		if (read == 0) {
+			goto read_again;
+		}
+
+		*length = read;
+
+		return SANE_STATUS_GOOD;
+
+
+	} else if (s->current == &s->back) {
+
+		/* finished reading the back page, next
+		 * command should give us the EOF
+		 */
+		DBG(18, "back side ring buffer empty\n");
+	}
+
+	/* read until data or error */
+
+read_again:
+
+	status = esci2_img(s, &read);
+	if (status != SANE_STATUS_GOOD) {
+		DBG(20, "read: %d, eof: %d, backside: %d, status: %d\n", read, s->eof, s->backside, status);
+	}
+
+	/* just got a back side page, alloc ring buffer if necessary
+	 * we didn't before because dummy was not known
+	 */
+	if (s->backside) {
+
+		int required = s->params.lines * (s->params.bytes_per_line + s->dummy);
+
+		if (s->back.size < required) {
+
+			DBG(20, "allocating buffer for the back side\n");
+
+			status = eds_ring_init(&s->back, required);
+			if (status != SANE_STATUS_GOOD) {
+				return status;
+			}
+		}
+	}
+
+	/* abort scanning when appropriate */
+	if (status == SANE_STATUS_CANCELLED) {
+		esci2_can(s);
+		return status;
+	}
+
+	if (s->eof && s->backside) {
+		DBG(18, "back side scan finished\n");
+	}
+
+	/* read again if no error and no data */
+	if (read == 0 && status == SANE_STATUS_GOOD) {
+		goto read_again;
+	}
+
+	/* got something, write to ring */
+	if (read) {
+
+		DBG(20, " %d bytes read, %d lines, eof: %d, canceling: %d, status: %d, backside: %d\n",
+			read, read / (s->params.bytes_per_line + s->dummy),
+			s->canceling, s->eof, status, s->backside);
+
+		/* move data to the appropriate ring */
+		status = eds_ring_write(s->backside ? &s->back : &s->front, s->buf, read);
+
+		if (0 && s->mode_jpeg && !s->jpeg_header_seen
+			&& status == SANE_STATUS_GOOD) {
+
+			status = eds_jpeg_read_header(s);
+			if (status != SANE_STATUS_GOOD && --tries) {
+				goto read_again;
+			}
+		}
+	}
+
+	/* continue reading if appropriate */
+	if (status == SANE_STATUS_GOOD)
+		return status;
+
+	/* cleanup */
+	DBG(5, "** %s: cleaning up\n", __func__);
+
+	if (s->mode_jpeg) {
+		eds_jpeg_finish(s);
+	}
+
+	eds_ring_flush(s->current);
+
+	return status;
+}
+
+/*
+ * void sane_cancel(SANE_Handle handle)
+ *
+ * Set the cancel flag to true. The next time the backend requests data
+ * from the scanner the CAN message will be sent.
+ */
+
+void
+sane_cancel(SANE_Handle handle)
+{
+	DBG(1, "** %s\n", __func__);
+	((epsonds_scanner *)handle)->canceling = SANE_TRUE;
+}
+
+/*
+ * SANE_Status sane_set_io_mode()
+ *
+ * not supported - for asynchronous I/O
+ */
+
+SANE_Status
+sane_set_io_mode(SANE_Handle __sane_unused__ handle,
+	SANE_Bool __sane_unused__ non_blocking)
+{
+	return SANE_STATUS_UNSUPPORTED;
+}
+
+/*
+ * SANE_Status sane_get_select_fd()
+ *
+ * not supported - for asynchronous I/O
+ */
+
+SANE_Status
+sane_get_select_fd(SANE_Handle __sane_unused__ handle,
+	SANE_Int __sane_unused__ *fd)
+{
+	return SANE_STATUS_UNSUPPORTED;
+}