diff --git a/backend/genesys/command_set.h b/backend/genesys/command_set.h
index e73a137fe..89f7e7160 100644
--- a/backend/genesys/command_set.h
+++ b/backend/genesys/command_set.h
@@ -76,6 +76,13 @@ public:
                                        Genesys_Register_Set& regs) const = 0;
     virtual void init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor& sensor) const = 0;
 
+    /** Set up registers for a scan. Similar to init_regs_for_scan except that the session is
+        already computed from the session
+    */
+    virtual void init_regs_for_scan_session(Genesys_Device* dev, const Genesys_Sensor& sensor,
+                                            Genesys_Register_Set* reg,
+                                            const ScanSession& session) const= 0;
+
     virtual void set_fe(Genesys_Device* dev, const Genesys_Sensor& sensor, std::uint8_t set) const = 0;
     virtual void set_powersaving(Genesys_Device* dev, int delay) const = 0;
     virtual void save_power(Genesys_Device* dev, bool enable) const = 0;
@@ -85,6 +92,7 @@ public:
     virtual void end_scan(Genesys_Device* dev, Genesys_Register_Set* regs,
                           bool check_stop) const = 0;
 
+
     /**
      * Send gamma tables to ASIC
      */
diff --git a/backend/genesys/gl124.cpp b/backend/genesys/gl124.cpp
index 49851ba6f..74946d093 100644
--- a/backend/genesys/gl124.cpp
+++ b/backend/genesys/gl124.cpp
@@ -863,12 +863,9 @@ static void gl124_init_optical_regs_scan(Genesys_Device* dev, const Genesys_Sens
     reg->set16(REG_DUMMY, sensor.dummy_pixel);
 }
 
-/** set up registers for an actual scan
- *
- * this function sets up the scanner to scan in normal or single line mode
- */
-static void gl124_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sensor,
-                                 Genesys_Register_Set* reg, const ScanSession& session)
+void CommandSetGl124::init_regs_for_scan_session(Genesys_Device* dev, const Genesys_Sensor& sensor,
+                                                 Genesys_Register_Set* reg,
+                                                 const ScanSession& session) const
 {
     DBG_HELPER(dbg);
     session.assert_computed();
@@ -1223,7 +1220,7 @@ void CommandSetGl124::slow_back_home(Genesys_Device* dev, bool wait_until_home)
                            ScanFlag::REVERSE;
     compute_session(dev, session, sensor);
 
-    gl124_init_scan_regs(dev, sensor, &local_reg, session);
+    init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     // clear scan and feed count
     dev->interface->write_register(REG_0x0D, REG_0x0D_CLRLNCNT | REG_0x0D_CLRMCNT);
@@ -1313,7 +1310,7 @@ static void gl124_feed(Genesys_Device* dev, unsigned int steps, int reverse)
     }
     compute_session(dev, session, sensor);
 
-    gl124_init_scan_regs(dev, sensor, &local_reg, session);
+    dev->cmd_set->init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     local_reg.set24(REG_EXPR, 0);
     local_reg.set24(REG_EXPG, 0);
@@ -1397,7 +1394,7 @@ void CommandSetGl124::search_start_position(Genesys_Device* dev) const
                            ScanFlag::DISABLE_BUFFER_FULL_MOVE;
     compute_session(dev, session, sensor);
 
-    gl124_init_scan_regs(dev, sensor, &local_reg, session);
+    init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     // send to scanner
     dev->interface->write_registers(local_reg);
@@ -1465,7 +1462,7 @@ void CommandSetGl124::init_regs_for_coarse_calibration(Genesys_Device* dev,
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl124_init_scan_regs(dev, sensor, &regs, session);
+    init_regs_for_scan_session(dev, sensor, &regs, session);
 
   sanei_genesys_set_motor_power(regs, false);
 
@@ -1532,7 +1529,7 @@ void CommandSetGl124::init_regs_for_shading(Genesys_Device* dev, const Genesys_S
     compute_session(dev, session, sensor);
 
     try {
-        gl124_init_scan_regs(dev, sensor, &regs, session);
+        init_regs_for_scan_session(dev, sensor, &regs, session);
     } catch (...) {
         catch_all_exceptions(__func__, [&](){ sanei_genesys_set_motor_power(regs, false); });
         throw;
@@ -1609,7 +1606,7 @@ void CommandSetGl124::init_regs_for_scan(Genesys_Device* dev, const Genesys_Sens
     session.params.flags = ScanFlag::NONE;
     compute_session(dev, session, sensor);
 
-    gl124_init_scan_regs(dev, sensor, &dev->reg, session);
+    init_regs_for_scan_session(dev, sensor, &dev->reg, session);
 }
 
 /**
@@ -1753,7 +1750,7 @@ static void move_to_calibration_area(Genesys_Device* dev, const Genesys_Sensor&
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl124_init_scan_regs(dev, sensor, &regs, session);
+    dev->cmd_set->init_regs_for_scan_session(dev, sensor, &regs, session);
 
   size = pixels * 3;
   std::vector<uint8_t> line(size);
@@ -1836,7 +1833,7 @@ SensorExposure CommandSetGl124::led_calibration(Genesys_Device* dev, const Genes
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl124_init_scan_regs(dev, sensor, &regs, session);
+    init_regs_for_scan_session(dev, sensor, &regs, session);
 
     total_size = num_pixels * channels * (session.params.depth / 8) * 1;
   std::vector<uint8_t> line(total_size);
@@ -2011,7 +2008,7 @@ void CommandSetGl124::offset_calibration(Genesys_Device* dev, const Genesys_Sens
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl124_init_scan_regs(dev, sensor, &regs, session);
+    init_regs_for_scan_session(dev, sensor, &regs, session);
 
   sanei_genesys_set_motor_power(regs, false);
 
@@ -2172,7 +2169,7 @@ void CommandSetGl124::coarse_gain_calibration(Genesys_Device* dev, const Genesys
     compute_session(dev, session, sensor);
 
     try {
-        gl124_init_scan_regs(dev, sensor, &regs, session);
+        init_regs_for_scan_session(dev, sensor, &regs, session);
     } catch (...) {
         catch_all_exceptions(__func__, [&](){ sanei_genesys_set_motor_power(regs, false); });
         throw;
@@ -2287,7 +2284,7 @@ void CommandSetGl124::init_regs_for_warmup(Genesys_Device* dev, const Genesys_Se
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl124_init_scan_regs(dev, sensor, reg, session);
+    init_regs_for_scan_session(dev, sensor, reg, session);
 
     num_pixels = session.output_pixels;
 
diff --git a/backend/genesys/gl124.h b/backend/genesys/gl124.h
index c1c6fe2cc..711ba067f 100644
--- a/backend/genesys/gl124.h
+++ b/backend/genesys/gl124.h
@@ -137,6 +137,10 @@ public:
 
     void init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor& sensor) const override;
 
+    void init_regs_for_scan_session(Genesys_Device* dev, const Genesys_Sensor& sensor,
+                                    Genesys_Register_Set* reg,
+                                    const ScanSession& session) const override;
+
     void set_fe(Genesys_Device* dev, const Genesys_Sensor& sensor, uint8_t set) const override;
     void set_powersaving(Genesys_Device* dev, int delay) const override;
     void save_power(Genesys_Device* dev, bool enable) const override;
diff --git a/backend/genesys/gl646.cpp b/backend/genesys/gl646.cpp
index a88280939..eb583206f 100644
--- a/backend/genesys/gl646.cpp
+++ b/backend/genesys/gl646.cpp
@@ -166,22 +166,9 @@ static int get_cksel(SensorId sensor_id, int required, unsigned channels)
   return 1;
 }
 
-/**
- * Setup register and motor tables for a scan at the
- * given resolution and color mode. TODO try to not use any filed from
- * the device.
- * @param dev          pointer to a struct describing the device
- * @param regs         register set to fill
- * @param slope_table1 first motor table to fill
- * @param slope_table2 second motor table to fill
- * @note No harcoded SENSOR or MOTOR 'names' should be present and
- * registers are set from settings tables and flags related
- * to the hardware capabilities.
- * */
-static void gl646_setup_registers(Genesys_Device* dev,
-                                  const Genesys_Sensor& sensor,
-                                  Genesys_Register_Set* regs,
-                                  const ScanSession& session)
+void CommandSetGl646::init_regs_for_scan_session(Genesys_Device* dev, const Genesys_Sensor& sensor,
+                                                 Genesys_Register_Set* regs,
+                                                 const ScanSession& session) const
 {
     DBG_HELPER(dbg);
     session.assert_computed();
@@ -1535,8 +1522,7 @@ void CommandSetGl646::slow_back_home(Genesys_Device* dev, bool wait_until_home)
     }
     compute_session(dev, session, sensor);
 
-    // set up correct values for scan (gamma and shading enabled)
-    gl646_setup_registers(dev, sensor, &dev->reg, session);
+    init_regs_for_scan_session(dev, sensor, &dev->reg, session);
 
   /* backward , no actual data scanned TODO more setup flags to avoid this register manipulations ? */
     dev->reg.find_reg(0x01).value &= ~REG_0x01_SCAN;
@@ -1776,8 +1762,7 @@ void CommandSetGl646::init_regs_for_scan(Genesys_Device* dev, const Genesys_Sens
 
     ScanSession session = calculate_scan_session(dev, sensor, dev->settings);
 
-    // set up correct values for scan (gamma and shading enabled)
-    gl646_setup_registers(dev, sensor, &dev->reg, session);
+    init_regs_for_scan_session(dev, sensor, &dev->reg, session);
 
   /* gamma is only enabled at final scan time */
     if (dev->settings.depth < 16) {
@@ -1865,8 +1850,7 @@ static void setup_for_scan(Genesys_Device* dev,
     }
     compute_session(dev, session, sensor);
 
-    // set up correct values for scan (gamma and shading enabled)
-    gl646_setup_registers(dev, sensor, regs, session);
+    dev->cmd_set->init_regs_for_scan_session(dev, sensor, regs, session);
 }
 
 /**
diff --git a/backend/genesys/gl646.h b/backend/genesys/gl646.h
index 1ba01fa79..7e93bbb06 100644
--- a/backend/genesys/gl646.h
+++ b/backend/genesys/gl646.h
@@ -254,6 +254,10 @@ public:
 
     void init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor& sensor) const override;
 
+    void init_regs_for_scan_session(Genesys_Device* dev, const Genesys_Sensor& sensor,
+                                    Genesys_Register_Set* reg,
+                                    const ScanSession& session) const override;
+
     void set_fe(Genesys_Device* dev, const Genesys_Sensor& sensor, uint8_t set) const override;
     void set_powersaving(Genesys_Device* dev, int delay) const override;
     void save_power(Genesys_Device* dev, bool enable) const override;
diff --git a/backend/genesys/gl841.cpp b/backend/genesys/gl841.cpp
index 1c97d9305..152cbb49b 100644
--- a/backend/genesys/gl841.cpp
+++ b/backend/genesys/gl841.cpp
@@ -1533,10 +1533,9 @@ static StepType gl841_scan_step_type(Genesys_Device *dev, int yres)
     return type;
 }
 
-// set up registers for an actual scan this function sets up the scanner to scan in normal or single
-// line mode
-static void gl841_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sensor,
-                                 Genesys_Register_Set* reg, const ScanSession& session)
+void CommandSetGl841::init_regs_for_scan_session(Genesys_Device* dev, const Genesys_Sensor& sensor,
+                                                 Genesys_Register_Set* reg,
+                                                 const ScanSession& session) const
 {
     DBG_HELPER(dbg);
     session.assert_computed();
@@ -2364,7 +2363,7 @@ void CommandSetGl841::search_start_position(Genesys_Device* dev) const
                            ScanFlag::DISABLE_BUFFER_FULL_MOVE;
     compute_session(dev, session, sensor);
 
-    gl841_init_scan_regs(dev, sensor, &local_reg, session);
+    init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     // send to scanner
     dev->interface->write_registers(local_reg);
@@ -2431,7 +2430,7 @@ void CommandSetGl841::init_regs_for_coarse_calibration(Genesys_Device* dev,
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl841_init_scan_regs(dev, sensor, &regs, session);
+    init_regs_for_scan_session(dev, sensor, &regs, session);
 
   DBG(DBG_info, "%s: optical sensor res: %d dpi, actual res: %d\n", __func__,
       sensor.optical_res / sensor.ccd_pixels_per_system_pixel(), dev->settings.xres);
@@ -2503,7 +2502,7 @@ void CommandSetGl841::init_regs_for_shading(Genesys_Device* dev, const Genesys_S
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, calib_sensor);
 
-    gl841_init_scan_regs(dev, calib_sensor, &regs, session);
+    init_regs_for_scan_session(dev, calib_sensor, &regs, session);
 
   dev->scanhead_position_in_steps += dev->calib_lines + starty;
 
@@ -2594,7 +2593,7 @@ void CommandSetGl841::init_regs_for_scan(Genesys_Device* dev, const Genesys_Sens
     session.params.flags = flags;
     compute_session(dev, session, sensor);
 
-    gl841_init_scan_regs(dev, sensor, &dev->reg, session);
+    init_regs_for_scan_session(dev, sensor, &dev->reg, session);
 }
 
 
@@ -2675,7 +2674,7 @@ SensorExposure CommandSetGl841::led_calibration(Genesys_Device* dev, const Genes
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, calib_sensor_base);
 
-    gl841_init_scan_regs(dev, calib_sensor_base, &regs, session);
+    init_regs_for_scan_session(dev, calib_sensor_base, &regs, session);
 
     dev->interface->write_registers(regs);
 
@@ -2886,7 +2885,7 @@ static void ad_fe_offset_calibration(Genesys_Device* dev, const Genesys_Sensor&
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, calib_sensor);
 
-    gl841_init_scan_regs(dev, calib_sensor, &regs, session);
+    dev->cmd_set->init_regs_for_scan_session(dev, calib_sensor, &regs, session);
 
   total_size = num_pixels * 3 * 2 * 1;
 
@@ -3016,7 +3015,7 @@ void CommandSetGl841::offset_calibration(Genesys_Device* dev, const Genesys_Sens
                            ScanFlag::DISABLE_LAMP;
     compute_session(dev, session, calib_sensor);
 
-    gl841_init_scan_regs(dev, calib_sensor, &regs, session);
+    init_regs_for_scan_session(dev, calib_sensor, &regs, session);
 
   total_size = num_pixels * channels * 2 * 1;	/* colors * bytes_per_color * scan lines */
 
@@ -3386,7 +3385,7 @@ void CommandSetGl841::coarse_gain_calibration(Genesys_Device* dev, const Genesys
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, calib_sensor);
 
-    gl841_init_scan_regs(dev, calib_sensor, &regs, session);
+    init_regs_for_scan_session(dev, calib_sensor, &regs, session);
 
     dev->interface->write_registers(regs);
 
@@ -3539,7 +3538,7 @@ void CommandSetGl841::init_regs_for_warmup(Genesys_Device* dev, const Genesys_Se
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl841_init_scan_regs(dev, sensor, local_reg, session);
+    init_regs_for_scan_session(dev, sensor, local_reg, session);
 
     num_pixels = session.output_pixels;
 
@@ -3657,7 +3656,7 @@ void CommandSetGl841::init(Genesys_Device* dev) const
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, calib_sensor);
 
-    gl841_init_scan_regs(dev, calib_sensor, &regs, session);
+    init_regs_for_scan_session(dev, calib_sensor, &regs, session);
 
     dev->interface->write_registers(regs);
 
@@ -3787,7 +3786,7 @@ void CommandSetGl841::search_strip(Genesys_Device* dev, const Genesys_Sensor& se
     size = pixels * channels * lines * (session.params.depth / 8);
     std::vector<uint8_t> data(size);
 
-    gl841_init_scan_regs(dev, sensor, &local_reg, session);
+    init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
   /* set up for reverse or forward */
   r = sanei_genesys_get_address(&local_reg, 0x02);
diff --git a/backend/genesys/gl841.h b/backend/genesys/gl841.h
index 3c9a4ab4b..dd3b1e0bd 100644
--- a/backend/genesys/gl841.h
+++ b/backend/genesys/gl841.h
@@ -71,6 +71,10 @@ public:
 
     void init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor& sensor) const override;
 
+    void init_regs_for_scan_session(Genesys_Device* dev, const Genesys_Sensor& sensor,
+                                    Genesys_Register_Set* reg,
+                                    const ScanSession& session) const override;
+
     void set_fe(Genesys_Device* dev, const Genesys_Sensor& sensor, uint8_t set) const override;
     void set_powersaving(Genesys_Device* dev, int delay) const override;
     void save_power(Genesys_Device* dev, bool enable) const override;
diff --git a/backend/genesys/gl843.cpp b/backend/genesys/gl843.cpp
index e532f95fe..753b4d7ef 100644
--- a/backend/genesys/gl843.cpp
+++ b/backend/genesys/gl843.cpp
@@ -1160,10 +1160,9 @@ static void gl843_init_optical_regs_scan(Genesys_Device* dev, const Genesys_Sens
   r->value = sensor.dummy_pixel;
 }
 
-// set up registers for an actual scan this function sets up the scanner to scan in normal or single
-// line mode
-static void gl843_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sensor,
-                                 Genesys_Register_Set* reg, const ScanSession& session)
+void CommandSetGl843::init_regs_for_scan_session(Genesys_Device* dev, const Genesys_Sensor& sensor,
+                                                 Genesys_Register_Set* reg,
+                                                 const ScanSession& session) const
 {
     DBG_HELPER(dbg);
     session.assert_computed();
@@ -1831,7 +1830,7 @@ void CommandSetGl843::slow_back_home(Genesys_Device* dev, bool wait_until_home)
                             ScanFlag::REVERSE;
     compute_session(dev, session, sensor);
 
-    gl843_init_scan_regs(dev, sensor, &local_reg, session);
+    init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     // clear scan and feed count
     dev->interface->write_register(REG_0x0D, REG_0x0D_CLRLNCNT | REG_0x0D_CLRMCNT);
@@ -1921,7 +1920,7 @@ void CommandSetGl843::search_start_position(Genesys_Device* dev) const
                             ScanFlag::DISABLE_BUFFER_FULL_MOVE;
     compute_session(dev, session, sensor);
 
-    gl843_init_scan_regs(dev, sensor, &local_reg, session);
+    init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     // send to scanner
     dev->interface->write_registers(local_reg);
@@ -1992,7 +1991,7 @@ void CommandSetGl843::init_regs_for_coarse_calibration(Genesys_Device* dev,
     session.params.flags = flags;
     compute_session(dev, session, sensor);
 
-    gl843_init_scan_regs(dev, sensor, &regs, session);
+    init_regs_for_scan_session(dev, sensor, &regs, session);
 
   sanei_genesys_set_motor_power(regs, false);
 
@@ -2038,7 +2037,7 @@ static void gl843_feed(Genesys_Device* dev, unsigned int steps)
                             ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl843_init_scan_regs(dev, sensor, &local_reg, session);
+    dev->cmd_set->init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     // clear scan and feed count
     dev->interface->write_register(REG_0x0D, REG_0x0D_CLRLNCNT);
@@ -2163,7 +2162,7 @@ void CommandSetGl843::init_regs_for_shading(Genesys_Device* dev, const Genesys_S
     session.params.flags = flags;
     compute_session(dev, session, calib_sensor);
 
-    gl843_init_scan_regs(dev, calib_sensor, &regs, session);
+    init_regs_for_scan_session(dev, calib_sensor, &regs, session);
 
      // the pixel number may be updated to conform to scanner constraints
     dev->calib_pixels = session.output_pixels;
@@ -2249,7 +2248,7 @@ void CommandSetGl843::init_regs_for_scan(Genesys_Device* dev, const Genesys_Sens
     session.params.flags = flags;
     compute_session(dev, session, sensor);
 
-    gl843_init_scan_regs(dev, sensor, &dev->reg, session);
+    init_regs_for_scan_session(dev, sensor, &dev->reg, session);
 }
 
 /**
@@ -2328,7 +2327,7 @@ SensorExposure CommandSetGl843::led_calibration(Genesys_Device* dev, const Genes
                             ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, calib_sensor);
 
-    gl843_init_scan_regs(dev, calib_sensor, &regs, session);
+    init_regs_for_scan_session(dev, calib_sensor, &regs, session);
 
     dev->interface->write_registers(regs);
 
@@ -2554,7 +2553,7 @@ void CommandSetGl843::offset_calibration(Genesys_Device* dev, const Genesys_Sens
     DBG(DBG_io, "%s: resolution  =%d\n", __func__, resolution);
     DBG(DBG_io, "%s: pixels      =%d\n", __func__, pixels);
     DBG(DBG_io, "%s: black_pixels=%d\n", __func__, black_pixels);
-    gl843_init_scan_regs(dev, calib_sensor, &regs, session);
+    init_regs_for_scan_session(dev, calib_sensor, &regs, session);
 
   sanei_genesys_set_motor_power(regs, false);
 
@@ -2773,7 +2772,7 @@ void CommandSetGl843::coarse_gain_calibration(Genesys_Device* dev, const Genesys
     std::size_t pixels = session.output_pixels;
 
     try {
-        gl843_init_scan_regs(dev, calib_sensor, &regs, session);
+        init_regs_for_scan_session(dev, calib_sensor, &regs, session);
     } catch (...) {
         catch_all_exceptions(__func__, [&](){ sanei_genesys_set_motor_power(regs, false); });
         throw;
@@ -2890,7 +2889,7 @@ void CommandSetGl843::init_regs_for_warmup(Genesys_Device* dev, const Genesys_Se
                             ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, calib_sensor);
 
-    gl843_init_scan_regs(dev, calib_sensor, reg, session);
+    init_regs_for_scan_session(dev, calib_sensor, reg, session);
 
   sanei_genesys_set_motor_power(*reg, false);
     dev->interface->write_registers(*reg);
@@ -3136,7 +3135,7 @@ void CommandSetGl843::search_strip(Genesys_Device* dev, const Genesys_Sensor& se
     }
     compute_session(dev, session, calib_sensor);
 
-    gl843_init_scan_regs(dev, calib_sensor, &local_reg, session);
+    init_regs_for_scan_session(dev, calib_sensor, &local_reg, session);
 
     dev->interface->write_registers(local_reg);
 
diff --git a/backend/genesys/gl843.h b/backend/genesys/gl843.h
index 6d7bd3330..5912b50a9 100644
--- a/backend/genesys/gl843.h
+++ b/backend/genesys/gl843.h
@@ -71,6 +71,10 @@ public:
 
     void init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor& sensor) const override;
 
+    void init_regs_for_scan_session(Genesys_Device* dev, const Genesys_Sensor& sensor,
+                                    Genesys_Register_Set* reg,
+                                    const ScanSession& session) const override;
+
     void set_fe(Genesys_Device* dev, const Genesys_Sensor& sensor, uint8_t set) const override;
     void set_powersaving(Genesys_Device* dev, int delay) const override;
     void save_power(Genesys_Device* dev, bool enable) const override;
diff --git a/backend/genesys/gl846.cpp b/backend/genesys/gl846.cpp
index bbffc0bed..11c38f7c4 100644
--- a/backend/genesys/gl846.cpp
+++ b/backend/genesys/gl846.cpp
@@ -715,10 +715,9 @@ static void gl846_init_optical_regs_scan(Genesys_Device* dev, const Genesys_Sens
   r->value = sensor.dummy_pixel;
 }
 
-// set up registers for an actual scan this function sets up the scanner to scan in normal or single
-// line mode
-static void gl846_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sensor,
-                                 Genesys_Register_Set* reg, const ScanSession& session)
+void CommandSetGl846::init_regs_for_scan_session(Genesys_Device* dev, const Genesys_Sensor& sensor,
+                                                 Genesys_Register_Set* reg,
+                                                 const ScanSession& session) const
 {
     DBG_HELPER(dbg);
     session.assert_computed();
@@ -972,7 +971,7 @@ void CommandSetGl846::slow_back_home(Genesys_Device* dev, bool wait_until_home)
                            ScanFlag::REVERSE;
     compute_session(dev, session, sensor);
 
-    gl846_init_scan_regs(dev, sensor, &local_reg, session);
+    init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     // clear scan and feed count
     dev->interface->write_register(REG_0x0D, REG_0x0D_CLRLNCNT | REG_0x0D_CLRMCNT);
@@ -1061,7 +1060,7 @@ void CommandSetGl846::search_start_position(Genesys_Device* dev) const
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl846_init_scan_regs(dev, sensor, &local_reg, session);
+    init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     // send to scanner
     dev->interface->write_registers(local_reg);
@@ -1130,7 +1129,7 @@ void CommandSetGl846::init_regs_for_coarse_calibration(Genesys_Device* dev,
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl846_init_scan_regs(dev, sensor, &regs, session);
+    init_regs_for_scan_session(dev, sensor, &regs, session);
 
     DBG(DBG_info, "%s: optical sensor res: %d dpi, actual res: %d\n", __func__,
         sensor.optical_res / sensor.ccd_pixels_per_system_pixel(), dev->settings.xres);
@@ -1172,7 +1171,7 @@ static void gl846_feed(Genesys_Device* dev, unsigned int steps)
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl846_init_scan_regs(dev, sensor, &local_reg, session);
+    dev->cmd_set->init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     local_reg.set24(REG_EXPR, 0);
     local_reg.set24(REG_EXPG, 0);
@@ -1267,7 +1266,7 @@ void CommandSetGl846::init_regs_for_shading(Genesys_Device* dev, const Genesys_S
                    ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl846_init_scan_regs(dev, sensor, &regs, session);
+    init_regs_for_scan_session(dev, sensor, &regs, session);
 
     dev->interface->write_registers(regs);
 
@@ -1349,7 +1348,7 @@ void CommandSetGl846::init_regs_for_scan(Genesys_Device* dev, const Genesys_Sens
     session.params.flags = ScanFlag::DISABLE_BUFFER_FULL_MOVE;
     compute_session(dev, session, sensor);
 
-    gl846_init_scan_regs(dev, sensor, &dev->reg, session);
+    init_regs_for_scan_session(dev, sensor, &dev->reg, session);
 }
 
 
@@ -1485,7 +1484,7 @@ SensorExposure CommandSetGl846::led_calibration(Genesys_Device* dev, const Genes
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl846_init_scan_regs(dev, sensor, &regs, session);
+    init_regs_for_scan_session(dev, sensor, &regs, session);
 
     total_size = num_pixels * channels * (session.params.depth / 8) * 1;
   std::vector<uint8_t> line(total_size);
@@ -1828,7 +1827,7 @@ void CommandSetGl846::search_strip(Genesys_Device* dev, const Genesys_Sensor& se
     }
     compute_session(dev, session, sensor);
 
-    gl846_init_scan_regs(dev, sensor, &local_reg, session);
+    init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     size = pixels * channels * lines * (session.params.depth / 8);
     std::vector<uint8_t> data(size);
@@ -2049,7 +2048,7 @@ void CommandSetGl846::offset_calibration(Genesys_Device* dev, const Genesys_Sens
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl846_init_scan_regs(dev, sensor, &regs, session);
+    init_regs_for_scan_session(dev, sensor, &regs, session);
 
   sanei_genesys_set_motor_power(regs, false);
 
@@ -2204,7 +2203,7 @@ void CommandSetGl846::coarse_gain_calibration(Genesys_Device* dev, const Genesys
     compute_session(dev, session, sensor);
 
     try {
-        gl846_init_scan_regs(dev, sensor, &regs, session);
+        init_regs_for_scan_session(dev, sensor, &regs, session);
     } catch (...) {
         catch_all_exceptions(__func__, [&](){ sanei_genesys_set_motor_power(regs, false); });
         throw;
diff --git a/backend/genesys/gl846.h b/backend/genesys/gl846.h
index f2bee5f92..04ab01467 100644
--- a/backend/genesys/gl846.h
+++ b/backend/genesys/gl846.h
@@ -156,6 +156,10 @@ public:
 
     void init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor& sensor) const override;
 
+    void init_regs_for_scan_session(Genesys_Device* dev, const Genesys_Sensor& sensor,
+                                    Genesys_Register_Set* reg,
+                                    const ScanSession& session) const override;
+
     void set_fe(Genesys_Device* dev, const Genesys_Sensor& sensor, uint8_t set) const override;
     void set_powersaving(Genesys_Device* dev, int delay) const override;
     void save_power(Genesys_Device* dev, bool enable) const override;
diff --git a/backend/genesys/gl847.cpp b/backend/genesys/gl847.cpp
index 252a30080..7a03049a8 100644
--- a/backend/genesys/gl847.cpp
+++ b/backend/genesys/gl847.cpp
@@ -724,10 +724,9 @@ static void gl847_init_optical_regs_scan(Genesys_Device* dev, const Genesys_Sens
   r->value = sensor.dummy_pixel;
 }
 
-// set up registers for an actual scan this function sets up the scanner to scan in normal or single
-// line mode
-static void gl847_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sensor,
-                                 Genesys_Register_Set* reg, const ScanSession& session)
+void CommandSetGl847::init_regs_for_scan_session(Genesys_Device* dev, const Genesys_Sensor& sensor,
+                                                 Genesys_Register_Set* reg,
+                                                 const ScanSession& session) const
 {
     DBG_HELPER(dbg);
     session.assert_computed();
@@ -1017,7 +1016,7 @@ void CommandSetGl847::slow_back_home(Genesys_Device* dev, bool wait_until_home)
                            ScanFlag::REVERSE;
     compute_session(dev, session, sensor);
 
-    gl847_init_scan_regs(dev, sensor, &local_reg, session);
+    init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     // clear scan and feed count
     dev->interface->write_register(REG_0x0D, REG_0x0D_CLRLNCNT | REG_0x0D_CLRMCNT);
@@ -1104,7 +1103,7 @@ void CommandSetGl847::search_start_position(Genesys_Device* dev) const
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl847_init_scan_regs(dev, sensor, &local_reg, session);
+    init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     // send to scanner
     dev->interface->write_registers(local_reg);
@@ -1173,7 +1172,7 @@ void CommandSetGl847::init_regs_for_coarse_calibration(Genesys_Device* dev,
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl847_init_scan_regs(dev, sensor, &regs, session);
+    init_regs_for_scan_session(dev, sensor, &regs, session);
 
   DBG(DBG_info, "%s: optical sensor res: %d dpi, actual res: %d\n", __func__,
       sensor.optical_res / sensor.ccd_pixels_per_system_pixel(), dev->settings.xres);
@@ -1214,7 +1213,7 @@ static void gl847_feed(Genesys_Device* dev, unsigned int steps)
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl847_init_scan_regs(dev, sensor, &local_reg, session);
+    dev->cmd_set->init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     // set exposure to zero
     local_reg.set24(REG_EXPR,0);
@@ -1299,7 +1298,7 @@ void CommandSetGl847::init_regs_for_shading(Genesys_Device* dev, const Genesys_S
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl847_init_scan_regs(dev, sensor, &regs, session);
+    init_regs_for_scan_session(dev, sensor, &regs, session);
 
     dev->interface->write_registers(regs);
 
@@ -1380,7 +1379,7 @@ void CommandSetGl847::init_regs_for_scan(Genesys_Device* dev, const Genesys_Sens
     session.params.flags = ScanFlag::DISABLE_BUFFER_FULL_MOVE;
     compute_session(dev, session, sensor);
 
-    gl847_init_scan_regs(dev, sensor, &dev->reg, session);
+    init_regs_for_scan_session(dev, sensor, &dev->reg, session);
 }
 
 
@@ -1517,7 +1516,7 @@ SensorExposure CommandSetGl847::led_calibration(Genesys_Device* dev, const Genes
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl847_init_scan_regs(dev, sensor, &regs, session);
+    init_regs_for_scan_session(dev, sensor, &regs, session);
 
     total_size = num_pixels * channels * (session.params.depth/8) * 1;
   std::vector<uint8_t> line(total_size);
@@ -1899,7 +1898,7 @@ void CommandSetGl847::search_strip(Genesys_Device* dev, const Genesys_Sensor& se
     size = pixels * channels * lines * (session.params.depth / 8);
     std::vector<uint8_t> data(size);
 
-    gl847_init_scan_regs(dev, sensor, &local_reg, session);
+    init_regs_for_scan_session(dev, sensor, &local_reg, session);
 
     dev->interface->write_registers(local_reg);
 
@@ -2118,7 +2117,7 @@ void CommandSetGl847::offset_calibration(Genesys_Device* dev, const Genesys_Sens
                            ScanFlag::IGNORE_LINE_DISTANCE;
     compute_session(dev, session, sensor);
 
-    gl847_init_scan_regs(dev, sensor, &regs, session);
+    init_regs_for_scan_session(dev, sensor, &regs, session);
 
   sanei_genesys_set_motor_power(regs, false);
 
@@ -2272,7 +2271,7 @@ void CommandSetGl847::coarse_gain_calibration(Genesys_Device* dev, const Genesys
     compute_session(dev, session, sensor);
 
     try {
-        gl847_init_scan_regs(dev, sensor, &regs, session);
+        init_regs_for_scan_session(dev, sensor, &regs, session);
     } catch (...) {
         catch_all_exceptions(__func__, [&](){ sanei_genesys_set_motor_power(regs, false); });
         throw;
diff --git a/backend/genesys/gl847.h b/backend/genesys/gl847.h
index c9798aac9..6e1db2178 100644
--- a/backend/genesys/gl847.h
+++ b/backend/genesys/gl847.h
@@ -140,6 +140,10 @@ public:
 
     void init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor& sensor) const override;
 
+    void init_regs_for_scan_session(Genesys_Device* dev, const Genesys_Sensor& sensor,
+                                    Genesys_Register_Set* reg,
+                                    const ScanSession& session) const override;
+
     void set_fe(Genesys_Device* dev, const Genesys_Sensor& sensor, uint8_t set) const override;
     void set_powersaving(Genesys_Device* dev, int delay) const override;
     void save_power(Genesys_Device* dev, bool enable) const override;