epson2: add autofocus

Enable autofocus support on my Epson 12000XL. The middle of the scan
area will be used as the focus point. An arbitrary X,Y is possible but
not implemented yet

Signed-off-by: Wolfram Sang <wsa@kernel.org>

backend/epson2.c

@@ -1339,6 +1339,14 @@ init_options(Epson_Scanner *s)
 	s->opt[OPT_FOCUS_GROUP].type = SANE_TYPE_GROUP;
 	s->opt[OPT_FOCUS_GROUP].cap = SANE_CAP_ADVANCED;
 
+	/* autofocus */
+	s->opt[OPT_AUTOFOCUS].name = SANE_NAME_AUTOFOCUS;
+	s->opt[OPT_AUTOFOCUS].title = SANE_TITLE_AUTOFOCUS;
+	s->opt[OPT_AUTOFOCUS].desc = SANE_DESC_AUTOFOCUS;
+	s->opt[OPT_AUTOFOCUS].type = SANE_TYPE_BOOL;
+	s->val[OPT_AUTOFOCUS].w = SANE_FALSE;
+	s->opt[OPT_AUTOFOCUS].cap |= SANE_CAP_ADVANCED;
+
 	/* focus position */
 	s->opt[OPT_FOCUS_POS].name = SANE_NAME_FOCUS;
 	s->opt[OPT_FOCUS_POS].title = SANE_TITLE_FOCUS;
@@ -1350,10 +1358,13 @@ init_options(Epson_Scanner *s)
 	s->val[OPT_FOCUS_POS].w = FOCUS_ON_GLASS;
 	s->opt[OPT_FOCUS_POS].cap |= SANE_CAP_ADVANCED;
 
-	if (s->hw->focusSupport == SANE_TRUE)
+	if (s->hw->focusSupport == SANE_TRUE) {
 		s->opt[OPT_FOCUS_POS].cap &= ~SANE_CAP_INACTIVE;
-	else
+		s->opt[OPT_AUTOFOCUS].cap &= ~SANE_CAP_INACTIVE;
+	} else {
 		s->opt[OPT_FOCUS_POS].cap |= SANE_CAP_INACTIVE;
+		s->opt[OPT_AUTOFOCUS].cap |= SANE_CAP_INACTIVE;
+	}
 
 	/* "Optional equipment" group: */
 	s->opt[OPT_EQU_GROUP].title = SANE_I18N("Optional equipment");
@@ -1649,6 +1660,7 @@ getvalue(SANE_Handle handle, SANE_Int option, void *value)
 	case OPT_THRESHOLD:
 	case OPT_BIT_DEPTH:
 	case OPT_WAIT_FOR_BUTTON:
+	case OPT_AUTOFOCUS:
 	case OPT_FOCUS_POS:
 		*((SANE_Word *) value) = sval->w;
 		break;
@@ -1979,6 +1991,11 @@ setvalue(SANE_Handle handle, SANE_Int option, void *value, SANE_Int *info)
 		break;
 	}
 
+	case OPT_AUTOFOCUS:
+		sval->w = *((SANE_Word *) value);
+		setOptionState(s, !sval->w, OPT_FOCUS_POS, &reload);
+		break;
+
 	case OPT_MIRROR:
 	case OPT_AAS:
 	case OPT_PREVIEW:	/* needed? */
@@ -2112,16 +2129,6 @@ sane_start(SANE_Handle handle)
 			return status;
 	}
 
-	if (s->hw->focusSupport == SANE_TRUE) {
-		DBG(1, "setting focus to %u\n", s->val[OPT_FOCUS_POS].w);
-		status = esci_set_focus_position(s, s->val[OPT_FOCUS_POS].w);
-
-		if (status != SANE_STATUS_GOOD) {
-			DBG(1, "setting focus failed\n");
-			return status;
-		}
-	}
-
 	/* set scanning parameters */
 	if (dev->extended_commands)
 		status = e2_set_extended_scanning_parameters(s);
@@ -2131,6 +2138,27 @@ sane_start(SANE_Handle handle)
 	if (status != SANE_STATUS_GOOD)
 		return status;
 
+	/*
+	 * set focus after we set scanning parameters because the scanner will
+	 * use the middle of the scanning area for autofocus. If we want to
+	 * support a defined x,y position for autofocus, we'd need to send
+	 * specific scanning paramters just for autofocus.
+	 */
+	if (s->hw->focusSupport == SANE_TRUE) {
+		if (s->val[OPT_AUTOFOCUS].w) {
+			DBG(1, "setting autofocus\n");
+			status = esci_set_focus_position(s, 0xff);
+		} else {
+			DBG(1, "setting focus to %u\n", s->val[OPT_FOCUS_POS].w);
+			status = esci_set_focus_position(s, s->val[OPT_FOCUS_POS].w);
+		}
+
+		if (status != SANE_STATUS_GOOD) {
+			DBG(1, "setting focus failed\n");
+			return status;
+		}
+	}
+
 	/* ESC z, user defined gamma table */
 	if (dev->cmd->set_gamma_table
 	    && gamma_userdefined[s->val[OPT_GAMMA_CORRECTION].w]) {
@@ -2236,6 +2264,12 @@ sane_start(SANE_Handle handle)
 	if (status != SANE_STATUS_GOOD)
 		return status;
 
+	if (s->hw->focusSupport == SANE_TRUE && s->val[OPT_AUTOFOCUS].w) {
+		status = esci_request_focus_position(s, &s->currentFocusPosition);
+		if (status == SANE_STATUS_GOOD)
+			s->val[OPT_FOCUS_POS].w = s->currentFocusPosition;
+	}
+
 	/* start scanning */
 	DBG(1, "%s: scanning...\n", __func__);
 

backend/epson2.h

@@ -257,6 +257,7 @@ enum {
 	OPT_BR_X,
 	OPT_BR_Y,
 	OPT_FOCUS_GROUP,
+	OPT_AUTOFOCUS,
 	OPT_FOCUS_POS,
 	OPT_EQU_GROUP,
 	OPT_SOURCE,