diff -r 87b20532872b -r 5fe7df7f2433 master/fsm.c
--- a/master/fsm.c	Mon May 22 09:16:12 2006 +0000
+++ b/master/fsm.c	Fri May 26 14:26:57 2006 +0000
@@ -57,8 +57,14 @@
 /*****************************************************************************/
 
 void ec_fsm_master_start(ec_fsm_t *);
-void ec_fsm_master_wait(ec_fsm_t *);
+void ec_fsm_master_broadcast(ec_fsm_t *);
+void ec_fsm_master_proc_states(ec_fsm_t *);
 void ec_fsm_master_scan(ec_fsm_t *);
+void ec_fsm_master_states(ec_fsm_t *);
+void ec_fsm_master_validate_vendor(ec_fsm_t *);
+void ec_fsm_master_validate_product(ec_fsm_t *);
+void ec_fsm_master_reconfigure(ec_fsm_t *);
+void ec_fsm_master_address(ec_fsm_t *);
 void ec_fsm_master_conf(ec_fsm_t *);
 
 void ec_fsm_slave_start_reading(ec_fsm_t *);
@@ -69,7 +75,6 @@
 void ec_fsm_slave_read_sii(ec_fsm_t *);
 void ec_fsm_slave_category_header(ec_fsm_t *);
 void ec_fsm_slave_category_data(ec_fsm_t *);
-void ec_fsm_slave_conf(ec_fsm_t *);
 void ec_fsm_slave_end(ec_fsm_t *);
 
 void ec_fsm_slave_conf(ec_fsm_t *);
@@ -83,7 +88,7 @@
 void ec_fsm_sii_start_reading(ec_fsm_t *);
 void ec_fsm_sii_check(ec_fsm_t *);
 void ec_fsm_sii_fetch(ec_fsm_t *);
-void ec_fsm_sii_finished(ec_fsm_t *);
+void ec_fsm_sii_end(ec_fsm_t *);
 void ec_fsm_sii_error(ec_fsm_t *);
 
 void ec_fsm_change_start(ec_fsm_t *);
@@ -97,12 +102,19 @@
 
 /*****************************************************************************/
 
-int ec_fsm_init(ec_fsm_t *fsm, ec_master_t *master)
+/**
+   Constructor.
+*/
+
+int ec_fsm_init(ec_fsm_t *fsm, /**< finite state machine */
+                ec_master_t *master /**< EtherCAT master */
+                )
 {
     fsm->master = master;
     fsm->master_state = ec_fsm_master_start;
     fsm->master_slaves_responding = 0;
     fsm->master_slave_states = EC_SLAVE_STATE_UNKNOWN;
+    fsm->master_validation = 0;
     fsm->slave_cat_data = NULL;
 
     ec_command_init(&fsm->command);
@@ -116,7 +128,11 @@
 
 /*****************************************************************************/
 
-void ec_fsm_clear(ec_fsm_t *fsm)
+/**
+   Destructor.
+*/
+
+void ec_fsm_clear(ec_fsm_t *fsm /**< finite state machine */)
 {
     if (fsm->slave_cat_data) kfree(fsm->slave_cat_data);
     ec_command_clear(&fsm->command);
@@ -124,7 +140,11 @@
 
 /*****************************************************************************/
 
-void ec_fsm_reset(ec_fsm_t *fsm)
+/**
+   Resets the state machine.
+*/
+
+void ec_fsm_reset(ec_fsm_t *fsm /**< finite state machine */)
 {
     fsm->master_state = ec_fsm_master_start;
     fsm->master_slaves_responding = 0;
@@ -138,7 +158,11 @@
 
 /*****************************************************************************/
 
-void ec_fsm_execute(ec_fsm_t *fsm)
+/**
+   Executes the current state of the state machine.
+*/
+
+void ec_fsm_execute(ec_fsm_t *fsm /**< finite state machine */)
 {
     fsm->master_state(fsm);
 }
@@ -148,7 +172,7 @@
  *****************************************************************************/
 
 /**
-   State: Start.
+   Master state: START.
    Starts with getting slave count and slave states.
 */
 
@@ -156,153 +180,419 @@
 {
     ec_command_brd(&fsm->command, 0x0130, 2);
     ec_master_queue_command(fsm->master, &fsm->command);
-    fsm->master_state = ec_fsm_master_wait;
-}
-
-/*****************************************************************************/
-
-void ec_fsm_master_wait(ec_fsm_t *fsm)
-{
-    ec_command_t *command = &fsm->command;
-    unsigned int topology_change, i, eoe_slaves_active;
+    fsm->master_state = ec_fsm_master_broadcast;
+}
+
+/*****************************************************************************/
+
+/**
+   Master state: BROADCAST.
+   Processes the broadcast read slave count and slaves states.
+*/
+
+void ec_fsm_master_broadcast(ec_fsm_t *fsm /**< finite state machine */)
+{
+    ec_command_t *command = &fsm->command;
+    unsigned int topology_change, states_change, i;
     ec_slave_t *slave;
+    ec_master_t *master = fsm->master;
 
     if (command->state != EC_CMD_RECEIVED) {
-        if (!fsm->master->device->link_state)
-            // treat link down as topology change
+        if (!master->device->link_state) {
             fsm->master_slaves_responding = 0;
+            list_for_each_entry(slave, &master->slaves, list) {
+                slave->online = 0;
+            }
+        }
         fsm->master_state = ec_fsm_master_start;
         fsm->master_state(fsm); // execute immediately
         return;
     }
 
-    if (command->working_counter == fsm->master_slaves_responding &&
-        command->data[0] == fsm->master_slave_states)
-    {
-        // check if any slaves are not in the state, they're supposed to be
-        list_for_each_entry(slave, &fsm->master->slaves, list) {
-            if (slave->state_error ||
-                slave->requested_state == EC_SLAVE_STATE_UNKNOWN ||
-                slave->current_state == slave->requested_state) continue;
-
-            EC_INFO("Changing state of slave %i from ", slave->ring_position);
-            ec_print_states(slave->current_state);
-            printk(" to ");
-            ec_print_states(slave->requested_state);
-            printk(".\n");
-
-            fsm->slave = slave;
-            fsm->slave_state = ec_fsm_slave_conf;
-
-            fsm->change_new = EC_SLAVE_STATE_INIT;
-            fsm->change_state = ec_fsm_change_start;
-
-            fsm->master_state = ec_fsm_master_conf;
+    topology_change = (command->working_counter !=
+                       fsm->master_slaves_responding);
+    states_change = (EC_READ_U8(command->data) != fsm->master_slave_states);
+
+    fsm->master_slave_states = EC_READ_U8(command->data);
+    fsm->master_slaves_responding = command->working_counter;
+
+    if (topology_change) {
+        if (fsm->master_slaves_responding == master->slave_count) {
+            EC_INFO("%i slave%s responding (VALID).\n",
+                    fsm->master_slaves_responding,
+                    fsm->master_slaves_responding == 1 ? "" : "s");
+            fsm->master_validation = 1; // start validation later
+        }
+        else {
+            EC_WARN("%i slave%s responding. Invalid slave count!\n",
+                    fsm->master_slaves_responding,
+                    fsm->master_slaves_responding == 1 ? "" : "s");
+        }
+    }
+
+    if (states_change) {
+        EC_INFO("Slave states: ");
+        ec_print_states(fsm->master_slave_states);
+        printk(".\n");
+    }
+
+    // topology change in free-run mode: clear all slaves and scan the bus
+    if (topology_change && master->mode == EC_MASTER_MODE_FREERUN) {
+        EC_INFO("Scanning bus.\n");
+
+        ec_master_eoe_stop(master);
+        ec_master_clear_slaves(master);
+
+        if (!fsm->master_slaves_responding) {
+            // no slaves present -> finish state machine.
+            fsm->master_state = ec_fsm_master_start;
             fsm->master_state(fsm); // execute immediately
             return;
         }
 
-        // nothing to configure...
-        eoe_slaves_active = 0;
-        list_for_each_entry(slave, &fsm->master->slaves, list) {
-            if (slave->sii_mailbox_protocols & EC_MBOX_EOE) {
-                eoe_slaves_active++;
+        // init slaves
+        for (i = 0; i < fsm->master_slaves_responding; i++) {
+            if (!(slave = (ec_slave_t *) kmalloc(sizeof(ec_slave_t),
+                                                 GFP_ATOMIC))) {
+                EC_ERR("Failed to allocate slave %i!\n", i);
+                fsm->master_state = ec_fsm_master_start;
+                fsm->master_state(fsm); // execute immediately
+                return;
+            }
+
+            if (ec_slave_init(slave, master, i, i + 1)) {
+                fsm->master_state = ec_fsm_master_start;
+                fsm->master_state(fsm); // execute immediately
+                return;
+            }
+
+            if (kobject_add(&slave->kobj)) {
+                EC_ERR("Failed to add kobject.\n");
+                kobject_put(&slave->kobj); // free
+                fsm->master_state = ec_fsm_master_start;
+                fsm->master_state(fsm); // execute immediately
+                return;
+            }
+
+            list_add_tail(&slave->list, &master->slaves);
+        }
+
+        // begin scanning of slaves
+        fsm->slave = list_entry(master->slaves.next, ec_slave_t, list);
+        fsm->slave_state = ec_fsm_slave_start_reading;
+        fsm->master_state = ec_fsm_master_scan;
+        fsm->master_state(fsm); // execute immediately
+        return;
+    }
+
+    // fetch state from each slave
+    fsm->slave = list_entry(master->slaves.next, ec_slave_t, list);
+    ec_command_nprd(&fsm->command, fsm->slave->station_address, 0x0130, 2);
+    ec_master_queue_command(master, &fsm->command);
+    fsm->master_state = ec_fsm_master_states;
+}
+
+/*****************************************************************************/
+
+/**
+   Master action: Get state of next slave.
+*/
+
+void ec_fsm_master_action_next_slave_state(ec_fsm_t *fsm
+                                           /**< finite state machine */)
+{
+    ec_master_t *master = fsm->master;
+    ec_slave_t *slave = fsm->slave;
+
+    // have all states been read?
+    if (slave->list.next == &master->slaves) {
+
+        // check, if a bus validation has to be done
+        if (fsm->master_validation) {
+            fsm->master_validation = 0;
+            list_for_each_entry(slave, &master->slaves, list) {
+                if (slave->online) continue;
+
+                // At least one slave is offline. validate!
+                EC_INFO("Validating bus.\n");
+                fsm->slave = list_entry(master->slaves.next, ec_slave_t, list);
+                fsm->master_state = ec_fsm_master_validate_vendor;
+                fsm->sii_offset = 0x0008; // vendor ID
+                fsm->sii_mode = 0;
+                fsm->sii_state = ec_fsm_sii_start_reading;
+                fsm->sii_state(fsm); // execute immediately
+                return;
             }
         }
 
-        if (eoe_slaves_active && !list_empty(&fsm->master->eoe_handlers))
-            ec_master_eoe_start(fsm->master);
-
+        fsm->master_state = ec_fsm_master_proc_states;
+        fsm->master_state(fsm); // execute immediately
+        return;
+    }
+
+    // process next slave
+    fsm->slave = list_entry(fsm->slave->list.next, ec_slave_t, list);
+    ec_command_nprd(&fsm->command, fsm->slave->station_address, 0x0130, 2);
+    ec_master_queue_command(master, &fsm->command);
+    fsm->master_state = ec_fsm_master_states;
+}
+
+/*****************************************************************************/
+
+/**
+   Master state: STATES.
+   Fetches the AL- and online state of a slave.
+*/
+
+void ec_fsm_master_states(ec_fsm_t *fsm /**< finite state machine */)
+{
+    ec_slave_t *slave = fsm->slave;
+    ec_command_t *command = &fsm->command;
+    uint8_t new_state;
+
+    if (command->state != EC_CMD_RECEIVED) {
         fsm->master_state = ec_fsm_master_start;
         fsm->master_state(fsm); // execute immediately
         return;
     }
 
-    topology_change = command->working_counter !=
-        fsm->master_slaves_responding;
-
-    fsm->master_slaves_responding = command->working_counter;
-    fsm->master_slave_states = command->data[0];
-
-    EC_INFO("FSM: %i slave%s responding (", fsm->master_slaves_responding,
-            fsm->master_slaves_responding == 1 ? "" : "s");
-    ec_print_states(fsm->master_slave_states);
-    printk(")\n");
-
-    if (!topology_change || fsm->master->mode == EC_MASTER_MODE_RUNNING) {
+    // did the slave not respond to its station address?
+    if (command->working_counter != 1) {
+        if (slave->online) {
+            slave->online = 0;
+            EC_INFO("Slave %i: offline.\n", slave->ring_position);
+        }
+        ec_fsm_master_action_next_slave_state(fsm);
+        return;
+    }
+
+    // slave responded
+    new_state = EC_READ_U8(command->data);
+    if (!slave->online) { // slave was offline before
+        slave->online = 1;
+        slave->state_error = 0;
+        slave->current_state = new_state;
+        EC_INFO("Slave %i: online (", slave->ring_position);
+        ec_print_states(new_state);
+        printk(").\n");
+    }
+    else if (new_state != slave->current_state) {
+        EC_INFO("Slave %i: ", slave->ring_position);
+        ec_print_states(slave->current_state);
+        printk(" -> ");
+        ec_print_states(new_state);
+        printk(".\n");
+        slave->current_state = new_state;
+    }
+
+    ec_fsm_master_action_next_slave_state(fsm);
+}
+
+/*****************************************************************************/
+
+/**
+   Master state: PROC_STATES.
+   Processes the slave states.
+*/
+
+void ec_fsm_master_proc_states(ec_fsm_t *fsm /**< finite state machine */)
+{
+    ec_master_t *master = fsm->master;
+    ec_slave_t *slave;
+
+    // check if any slaves are not in the state, they're supposed to be
+    list_for_each_entry(slave, &master->slaves, list) {
+        if (slave->state_error || !slave->online ||
+            slave->requested_state == EC_SLAVE_STATE_UNKNOWN ||
+            slave->current_state == slave->requested_state) continue;
+
+        EC_INFO("Changing state of slave %i from ", slave->ring_position);
+        ec_print_states(slave->current_state);
+        printk(" to ");
+        ec_print_states(slave->requested_state);
+        printk(".\n");
+
+        fsm->slave = slave;
+        fsm->slave_state = ec_fsm_slave_conf;
+        fsm->change_new = EC_SLAVE_STATE_INIT;
+        fsm->change_state = ec_fsm_change_start;
+        fsm->master_state = ec_fsm_master_conf;
+        fsm->master_state(fsm); // execute immediately
+        return;
+    }
+
+    // nothing to configure. restart master state machine.
+    fsm->master_state = ec_fsm_master_start;
+    fsm->master_state(fsm); // execute immediately
+}
+
+/*****************************************************************************/
+
+/**
+   Master state: VALIDATE_VENDOR.
+   Validates the vendor ID of a slave.
+*/
+
+void ec_fsm_master_validate_vendor(ec_fsm_t *fsm /**< finite state machine */)
+{
+    ec_slave_t *slave = fsm->slave;
+
+    fsm->sii_state(fsm); // execute SII state machine
+
+    if (fsm->sii_state == ec_fsm_sii_error) {
+        EC_ERR("Failed to validate vendor ID of slave %i.\n",
+               slave->ring_position);
         fsm->master_state = ec_fsm_master_start;
         fsm->master_state(fsm); // execute immediately
         return;
     }
 
-    EC_INFO("Topology change detected - Scanning bus.\n");
-
-    ec_master_eoe_stop(fsm->master);
-    ec_master_clear_slaves(fsm->master);
-
-    if (!fsm->master_slaves_responding) {
-        // no slaves present -> finish state machine.
+    if (fsm->sii_state != ec_fsm_sii_end) return;
+
+    if (fsm->sii_result != slave->sii_vendor_id) {
+        EC_ERR("Slave %i: invalid vendor ID!\n", slave->ring_position);
         fsm->master_state = ec_fsm_master_start;
         fsm->master_state(fsm); // execute immediately
         return;
     }
 
-    // init slaves
-    for (i = 0; i < fsm->master_slaves_responding; i++) {
-        if (!(slave =
-              (ec_slave_t *) kmalloc(sizeof(ec_slave_t), GFP_ATOMIC))) {
-            EC_ERR("FSM failed to allocate slave %i!\n", i);
+    // vendor ID is ok. check product code.
+    fsm->master_state = ec_fsm_master_validate_product;
+    fsm->sii_offset = 0x000A; // product code
+    fsm->sii_mode = 0;
+    fsm->sii_state = ec_fsm_sii_start_reading;
+    fsm->sii_state(fsm); // execute immediately
+}
+
+/*****************************************************************************/
+
+/**
+   Master state: VALIDATE_PRODUCT.
+   Validates the product ID of a slave.
+*/
+
+void ec_fsm_master_validate_product(ec_fsm_t *fsm /**< finite state machine */)
+{
+    ec_slave_t *slave = fsm->slave;
+
+    fsm->sii_state(fsm); // execute SII state machine
+
+    if (fsm->sii_state == ec_fsm_sii_error) {
+        EC_ERR("Failed to validate product code of slave %i.\n",
+               slave->ring_position);
+        fsm->master_state = ec_fsm_master_start;
+        fsm->master_state(fsm); // execute immediately
+        return;
+    }
+
+    if (fsm->sii_state != ec_fsm_sii_end) return;
+
+    if (fsm->sii_result != slave->sii_product_code) {
+        EC_ERR("Slave %i: invalid product code!\n", slave->ring_position);
+        EC_ERR("expected 0x%08X, got 0x%08X.\n", slave->sii_product_code,
+               fsm->sii_result);
+        fsm->master_state = ec_fsm_master_start;
+        fsm->master_state(fsm); // execute immediately
+        return;
+    }
+
+    // have all states been validated?
+    if (slave->list.next == &fsm->master->slaves) {
+        fsm->slave = list_entry(fsm->master->slaves.next, ec_slave_t, list);
+        fsm->master_state = ec_fsm_master_reconfigure;
+        return;
+    }
+
+    // validate next slave
+    fsm->slave = list_entry(fsm->slave->list.next, ec_slave_t, list);
+    fsm->master_state = ec_fsm_master_validate_vendor;
+    fsm->sii_offset = 0x0008; // vendor ID
+    fsm->sii_mode = 0;
+    fsm->sii_state = ec_fsm_sii_start_reading;
+    fsm->sii_state(fsm); // execute immediately
+}
+
+/*****************************************************************************/
+
+/**
+   Master state: RECONFIGURE.
+   Looks for slave, that have lost their configuration and writes
+   their station address, so that they can be reconfigured later.
+*/
+
+void ec_fsm_master_reconfigure(ec_fsm_t *fsm /**< finite state machine */)
+{
+    ec_command_t *command = &fsm->command;
+
+    while (fsm->slave->online) {
+        if (fsm->slave->list.next == &fsm->master->slaves) { // last slave?
             fsm->master_state = ec_fsm_master_start;
+            fsm->master_state(fsm); // execute immediately
             return;
         }
-
-        if (ec_slave_init(slave, fsm->master, i, i + 1)) {
-            fsm->master_state = ec_fsm_master_start;
-            return;
-        }
-
-        if (kobject_add(&slave->kobj)) {
-            EC_ERR("FSM failed to add kobject.\n");
-            kobject_put(&slave->kobj); // free
-            fsm->master_state = ec_fsm_master_start;
-            return;
-        }
-
-        list_add_tail(&slave->list, &fsm->master->slaves);
-    }
-
-    // begin scanning of slaves
-    fsm->slave = list_entry(fsm->master->slaves.next, ec_slave_t, list);
-    fsm->slave_state = ec_fsm_slave_start_reading;
-
-    fsm->master_state = ec_fsm_master_scan;
+        // check next slave
+        fsm->slave = list_entry(fsm->slave->list.next, ec_slave_t, list);
+    }
+
+    EC_INFO("Reinitializing slave %i.\n", fsm->slave->ring_position);
+
+    // write station address
+    ec_command_apwr(command, fsm->slave->ring_position, 0x0010, 2);
+    EC_WRITE_U16(command->data, fsm->slave->station_address);
+    ec_master_queue_command(fsm->master, command);
+    fsm->master_state = ec_fsm_master_address;
+}
+
+/*****************************************************************************/
+
+/**
+   Master state: ADDRESS.
+   Checks, if the new station address has been written to the slave.
+*/
+
+void ec_fsm_master_address(ec_fsm_t *fsm /**< finite state machine */)
+{
+    ec_slave_t *slave = fsm->slave;
+    ec_command_t *command = &fsm->command;
+
+    if (command->state != EC_CMD_RECEIVED || command->working_counter != 1) {
+        EC_ERR("Failed to write station address on slave %i.\n",
+               slave->ring_position);
+    }
+
+    if (fsm->slave->list.next == &fsm->master->slaves) { // last slave?
+        fsm->master_state = ec_fsm_master_start;
+        fsm->master_state(fsm); // execute immediately
+        return;
+    }
+
+    // check next slave
+    fsm->slave = list_entry(fsm->slave->list.next, ec_slave_t, list);
+    fsm->master_state = ec_fsm_master_reconfigure;
     fsm->master_state(fsm); // execute immediately
 }
 
 /*****************************************************************************/
 
 /**
-   State: Get Slave.
-   Executes the sub-statemachine of a slave.
-*/
-
-void ec_fsm_master_scan(ec_fsm_t *fsm)
+   Master state: SCAN.
+   Executes the sub-statemachine for the scanning of a slave.
+*/
+
+void ec_fsm_master_scan(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_master_t *master = fsm->master;
     ec_slave_t *slave = fsm->slave;
+    uint16_t coupler_index, coupler_subindex;
+    uint16_t reverse_coupler_index, current_coupler_index;
+    ec_slave_ident_t *ident;
 
     fsm->slave_state(fsm); // execute slave state machine
 
     if (fsm->slave_state != ec_fsm_slave_end) return;
 
     // have all slaves been fetched?
-    if (slave->list.next == &master->slaves)
-    {
-        uint16_t coupler_index, coupler_subindex;
-        uint16_t reverse_coupler_index, current_coupler_index;
-        ec_slave_t *slave;
-        ec_slave_ident_t *ident;
-
+    if (slave->list.next == &master->slaves) {
         EC_INFO("Bus scanning completed.\n");
 
         // identify all slaves and calculate coupler addressing
@@ -352,6 +642,7 @@
                 else
                     slave->requested_state = EC_SLAVE_STATE_INIT;
             }
+            slave->state_error = 0;
 
             // calculate coupler-based slave address
             slave->coupler_index = current_coupler_index;
@@ -359,6 +650,11 @@
             coupler_subindex++;
         }
 
+        if (master->mode == EC_MASTER_MODE_FREERUN) {
+            // start EoE processing
+            ec_master_eoe_start(master);
+        }
+
         fsm->master_state = ec_fsm_master_start;
         fsm->master_state(fsm); // execute immediately
         return;
@@ -373,42 +669,15 @@
 /*****************************************************************************/
 
 /**
-   Free-Run state: Configure slaves.
-*/
-
-void ec_fsm_master_conf(ec_fsm_t *fsm)
-{
-    ec_master_t *master = fsm->master;
-    ec_slave_t *slave;
-
+   Master state: CONF.
+   Starts configuring a slave.
+*/
+
+void ec_fsm_master_conf(ec_fsm_t *fsm /**< finite state machine */)
+{
     fsm->slave_state(fsm); // execute slave's state machine
-
     if (fsm->slave_state != ec_fsm_slave_end) return;
-
-    // check if any slaves are not in the state, they're supposed to be
-    list_for_each_entry(slave, &master->slaves, list) {
-        if (slave->state_error ||
-            slave->requested_state == EC_SLAVE_STATE_UNKNOWN ||
-            slave->current_state == slave->requested_state) continue;
-
-        EC_INFO("Changing state of slave %i from ", slave->ring_position);
-        ec_print_states(slave->current_state);
-        printk(" to ");
-        ec_print_states(slave->requested_state);
-        printk(".\n");
-
-        fsm->slave = slave;
-        fsm->slave_state = ec_fsm_slave_conf;
-
-        fsm->change_new = EC_SLAVE_STATE_INIT;
-        fsm->change_state = ec_fsm_change_start;
-
-        fsm->master_state = ec_fsm_master_conf;
-        fsm->master_state(fsm); // execute immediately
-        return;
-    }
-
-    fsm->master_state = ec_fsm_master_start;
+    fsm->master_state = ec_fsm_master_proc_states;
     fsm->master_state(fsm); // execute immediately
 }
 
@@ -417,12 +686,12 @@
  *****************************************************************************/
 
 /**
-   Slave state: Start.
+   Slave state: START_READING.
    First state of the slave state machine. Writes the station address to the
    slave, according to its ring position.
 */
 
-void ec_fsm_slave_start_reading(ec_fsm_t *fsm)
+void ec_fsm_slave_start_reading(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
 
@@ -436,10 +705,10 @@
 /*****************************************************************************/
 
 /**
-   Slave state: Read status.
-*/
-
-void ec_fsm_slave_read_status(ec_fsm_t *fsm)
+   Slave state: READ_STATUS.
+*/
+
+void ec_fsm_slave_read_status(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
 
@@ -459,10 +728,10 @@
 /*****************************************************************************/
 
 /**
-   Slave state: Read base.
-*/
-
-void ec_fsm_slave_read_base(ec_fsm_t *fsm)
+   Slave state: READ_BASE.
+*/
+
+void ec_fsm_slave_read_base(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
     ec_slave_t *slave = fsm->slave;
@@ -490,10 +759,10 @@
 /*****************************************************************************/
 
 /**
-   Slave state: Read DL.
-*/
-
-void ec_fsm_slave_read_dl(ec_fsm_t *fsm)
+   Slave state: READ_DL.
+*/
+
+void ec_fsm_slave_read_dl(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
     ec_slave_t *slave = fsm->slave;
@@ -523,10 +792,10 @@
 /*****************************************************************************/
 
 /**
-   Slave state: Prepare SII.
-*/
-
-void ec_fsm_slave_prepare_sii(ec_fsm_t *fsm)
+   Slave state: PREPARE_SII.
+*/
+
+void ec_fsm_slave_prepare_sii(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
     ec_slave_t *slave = fsm->slave;
@@ -549,6 +818,7 @@
     }
 
     fsm->sii_offset = 0x0004;
+    fsm->sii_mode = 1;
     fsm->sii_state = ec_fsm_sii_start_reading;
     fsm->slave_sii_num = 0;
     fsm->slave_state = ec_fsm_slave_read_sii;
@@ -558,10 +828,10 @@
 /*****************************************************************************/
 
 /**
-   Slave state: Read SII.
-*/
-
-void ec_fsm_slave_read_sii(ec_fsm_t *fsm)
+   Slave state: READ_SII.
+*/
+
+void ec_fsm_slave_read_sii(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_slave_t *slave = fsm->slave;
 
@@ -575,7 +845,7 @@
         return;
     }
 
-    if (fsm->sii_state != ec_fsm_sii_finished) return;
+    if (fsm->sii_state != ec_fsm_sii_end) return;
 
     switch (fsm->slave_sii_num) {
         case 0:
@@ -643,11 +913,11 @@
 /*****************************************************************************/
 
 /**
-   Slave state: Read categories.
+   Slave state: CATEGORY_HEADER.
    Start reading categories.
 */
 
-void ec_fsm_slave_category_header(ec_fsm_t *fsm)
+void ec_fsm_slave_category_header(ec_fsm_t *fsm /**< finite state machine */)
 {
     // execute SII state machine
     fsm->sii_state(fsm);
@@ -661,7 +931,7 @@
         return;
     }
 
-    if (fsm->sii_state != ec_fsm_sii_finished) return;
+    if (fsm->sii_state != ec_fsm_sii_end) return;
 
     // last category?
     if ((fsm->sii_result & 0xFFFF) == 0xFFFF) {
@@ -685,6 +955,7 @@
     fsm->slave_cat_data_offset = 0;
     fsm->sii_offset = (fsm->slave_cat_offset + 2 +
                        fsm->slave_cat_data_offset);
+    fsm->sii_mode = 1;
     fsm->sii_state = ec_fsm_sii_start_reading;
     fsm->slave_state = ec_fsm_slave_category_data;
     fsm->slave_state(fsm); // execute state immediately
@@ -693,11 +964,11 @@
 /*****************************************************************************/
 
 /**
-   Slave state: Category data.
+   Slave state: CATEGORY_DATA.
    Reads category data.
 */
 
-void ec_fsm_slave_category_data(ec_fsm_t *fsm)
+void ec_fsm_slave_category_data(ec_fsm_t *fsm /**< finite state machine */)
 {
     // execute SII state machine
     fsm->sii_state(fsm);
@@ -712,7 +983,7 @@
         return;
     }
 
-    if (fsm->sii_state != ec_fsm_sii_finished) return;
+    if (fsm->sii_state != ec_fsm_sii_end) return;
 
     fsm->slave_cat_data[fsm->slave_cat_data_offset * 2] =
         fsm->sii_result & 0xFF;
@@ -733,6 +1004,7 @@
     if (fsm->slave_cat_data_offset < fsm->slave_cat_words) {
         fsm->sii_offset = (fsm->slave_cat_offset + 2 +
                            fsm->slave_cat_data_offset);
+        fsm->sii_mode = 1;
         fsm->sii_state = ec_fsm_sii_start_reading;
         fsm->slave_state = ec_fsm_slave_category_data;
         fsm->slave_state(fsm); // execute state immediately
@@ -777,6 +1049,7 @@
     // start reading next category header
     fsm->slave_cat_offset += 2 + fsm->slave_cat_words;
     fsm->sii_offset = fsm->slave_cat_offset;
+    fsm->sii_mode = 1;
     fsm->sii_state = ec_fsm_sii_start_reading;
     fsm->slave_state = ec_fsm_slave_category_header;
     fsm->slave_state(fsm); // execute state immediately
@@ -791,10 +1064,10 @@
 /*****************************************************************************/
 
 /**
-   Slave state: Start configuring.
-*/
-
-void ec_fsm_slave_conf(ec_fsm_t *fsm)
+   Slave state: CONF.
+*/
+
+void ec_fsm_slave_conf(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_slave_t *slave = fsm->slave;
     ec_master_t *master = fsm->master;
@@ -840,10 +1113,11 @@
 /*****************************************************************************/
 
 /**
-   Slave state: Configure sync managers.
-*/
-
-void ec_fsm_slave_sync(ec_fsm_t *fsm)
+   Slave state: SYNC.
+   Configure sync managers.
+*/
+
+void ec_fsm_slave_sync(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
     ec_slave_t *slave = fsm->slave;
@@ -852,8 +1126,9 @@
     ec_eeprom_sync_t *eeprom_sync, mbox_sync;
 
     if (command->state != EC_CMD_RECEIVED || command->working_counter != 1) {
-        EC_ERR("FSM failed to reset FMMUs of slave %i.\n",
+        EC_ERR("Failed to reset FMMUs of slave %i.\n",
                slave->ring_position);
+        slave->state_error = 1;
         fsm->slave_state = ec_fsm_slave_end;
         return;
     }
@@ -923,36 +1198,37 @@
 /*****************************************************************************/
 
 /**
-   Slave state: Change slave state to PREOP.
-*/
-
-void ec_fsm_slave_preop(ec_fsm_t *fsm)
+   Slave state: PREOP.
+   Change slave state to PREOP.
+*/
+
+void ec_fsm_slave_preop(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
     ec_slave_t *slave = fsm->slave;
 
     if (command->state != EC_CMD_RECEIVED || command->working_counter != 1) {
-        EC_ERR("FSM failed to set sync managers on slave %i.\n",
+        EC_ERR("Failed to set sync managers on slave %i.\n",
                slave->ring_position);
+        slave->state_error = 1;
         fsm->slave_state = ec_fsm_slave_end;
         return;
     }
 
     fsm->change_new = EC_SLAVE_STATE_PREOP;
     fsm->change_state = ec_fsm_change_start;
-
     fsm->slave_state = ec_fsm_slave_fmmu;
-
     fsm->change_state(fsm); // execute immediately
 }
 
 /*****************************************************************************/
 
 /**
-   Slave state: Configure FMMUs.
-*/
-
-void ec_fsm_slave_fmmu(ec_fsm_t *fsm)
+   Slave state: FMMU.
+   Configure FMMUs.
+*/
+
+void ec_fsm_slave_fmmu(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_slave_t *slave = fsm->slave;
     ec_master_t *master = fsm->master;
@@ -980,16 +1256,6 @@
         return;
     }
 
-#if 0
-    // slaves that are not registered are only brought into PREOP
-    // state -> nice blinking and mailbox communication possible
-    if (!slave->registered && !slave->type->special) {
-        EC_WARN("Slave %i was not registered!\n", slave->ring_position);
-        fsm->slave_state = ec_fsm_slave_end;
-        return;
-    }
-#endif
-
     if (!slave->base_fmmu_count) {
         fsm->slave_state = ec_fsm_slave_saveop;
         fsm->slave_state(fsm); // execute immediately
@@ -1011,10 +1277,11 @@
 /*****************************************************************************/
 
 /**
-   Slave state: Set slave state to SAVEOP.
-*/
-
-void ec_fsm_slave_saveop(ec_fsm_t *fsm)
+   Slave state: SAVEOP.
+   Set slave state to SAVEOP.
+*/
+
+void ec_fsm_slave_saveop(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
 
@@ -1022,6 +1289,7 @@
                                         command->working_counter != 1)) {
         EC_ERR("FSM failed to set FMMUs on slave %i.\n",
                fsm->slave->ring_position);
+        fsm->slave->state_error = 1;
         fsm->slave_state = ec_fsm_slave_end;
         return;
     }
@@ -1036,10 +1304,11 @@
 /*****************************************************************************/
 
 /**
-   Slave state: Set slave state to OP.
-*/
-
-void ec_fsm_slave_op(ec_fsm_t *fsm)
+   Slave state: OP.
+   Set slave state to OP.
+*/
+
+void ec_fsm_slave_op(ec_fsm_t *fsm /**< finite state machine */)
 {
     fsm->change_state(fsm); // execute state change state machine
 
@@ -1066,10 +1335,11 @@
 /*****************************************************************************/
 
 /**
-   Slave state: Set slave state to OP.
-*/
-
-void ec_fsm_slave_op2(ec_fsm_t *fsm)
+   Slave state: OP2
+   Executes the change state machine, until the OP state is set.
+*/
+
+void ec_fsm_slave_op2(ec_fsm_t *fsm /**< finite state machine */)
 {
     fsm->change_state(fsm); // execute state change state machine
 
@@ -1087,11 +1357,11 @@
 /*****************************************************************************/
 
 /**
-   Slave state: End.
+   Slave state: END.
    End state of the slave state machine.
 */
 
-void ec_fsm_slave_end(ec_fsm_t *fsm)
+void ec_fsm_slave_end(ec_fsm_t *fsm /**< finite state machine */)
 {
 }
 
@@ -1100,19 +1370,25 @@
  *****************************************************************************/
 
 /**
-   Slave SII state: Start reading.
+   SII state: START_READING.
    Starts reading the slave information interface.
 */
 
-void ec_fsm_sii_start_reading(ec_fsm_t *fsm)
+void ec_fsm_sii_start_reading(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
 
     // initiate read operation
-    ec_command_npwr(command, fsm->slave->station_address, 0x502, 6);
+    if (fsm->sii_mode) {
+        ec_command_npwr(command, fsm->slave->station_address, 0x502, 4);
+    }
+    else {
+        ec_command_apwr(command, fsm->slave->ring_position, 0x502, 4);
+    }
+
     EC_WRITE_U8 (command->data,     0x00); // read-only access
     EC_WRITE_U8 (command->data + 1, 0x01); // request read operation
-    EC_WRITE_U32(command->data + 2, fsm->sii_offset);
+    EC_WRITE_U16(command->data + 2, fsm->sii_offset);
     ec_master_queue_command(fsm->master, command);
     fsm->sii_state = ec_fsm_sii_check;
 }
@@ -1120,21 +1396,30 @@
 /*****************************************************************************/
 
 /**
-   Slave SII state: Check.
+   SII state: CHECK.
    Checks, if the SII-read-command has been sent and issues a fetch command.
 */
 
-void ec_fsm_sii_check(ec_fsm_t *fsm)
+void ec_fsm_sii_check(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
 
     if (command->state != EC_CMD_RECEIVED || command->working_counter != 1) {
-        EC_ERR("FSM SII: Reception of check command failed.\n");
+        EC_ERR("SII: Reception of read command failed.\n");
         fsm->sii_state = ec_fsm_sii_error;
         return;
     }
 
-    ec_command_nprd(command, fsm->slave->station_address, 0x502, 10);
+    fsm->sii_start = get_cycles();
+
+    // issue check/fetch command
+    if (fsm->sii_mode) {
+        ec_command_nprd(command, fsm->slave->station_address, 0x502, 10);
+    }
+    else {
+        ec_command_aprd(command, fsm->slave->ring_position, 0x502, 10);
+    }
+
     ec_master_queue_command(fsm->master, command);
     fsm->sii_state = ec_fsm_sii_fetch;
 }
@@ -1142,46 +1427,78 @@
 /*****************************************************************************/
 
 /**
-   Slave SII state: Fetch.
+   SII state: FETCH.
    Fetches the result of an SII-read command.
 */
 
-void ec_fsm_sii_fetch(ec_fsm_t *fsm)
+void ec_fsm_sii_fetch(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
 
     if (command->state != EC_CMD_RECEIVED || command->working_counter != 1) {
-        EC_ERR("FSM SII: Reception of fetch command failed.\n");
+        EC_ERR("SII: Reception of check/fetch command failed.\n");
         fsm->sii_state = ec_fsm_sii_error;
         return;
     }
 
     // check "busy bit"
-    if (likely((EC_READ_U8(command->data + 1) & 0x81) == 0)) {
-        fsm->sii_result = EC_READ_U32(command->data + 6);
-        fsm->sii_state = ec_fsm_sii_finished;
-    }
-}
-
-/*****************************************************************************/
-
-/**
-   Slave SII state: Finished.
+    if (EC_READ_U8(command->data + 1) & 0x81) {
+        // still busy... timeout?
+        if (get_cycles() - fsm->sii_start >= (cycles_t) 10 * cpu_khz) {
+            EC_ERR("SII: Timeout.\n");
+            fsm->sii_state = ec_fsm_sii_error;
+#if 0
+            EC_DBG("SII busy: %02X %02X %02X %02X\n",
+                   EC_READ_U8(command->data + 0),
+                   EC_READ_U8(command->data + 1),
+                   EC_READ_U8(command->data + 2),
+                   EC_READ_U8(command->data + 3));
+#endif
+        }
+
+        // issue check/fetch command again
+        if (fsm->sii_mode) {
+            ec_command_nprd(command, fsm->slave->station_address, 0x502, 10);
+        }
+        else {
+            ec_command_aprd(command, fsm->slave->ring_position, 0x502, 10);
+        }
+        ec_master_queue_command(fsm->master, command);
+        return;
+    }
+
+#if 0
+    EC_DBG("SII rec: %02X %02X %02X %02X - %02X %02X %02X %02X\n",
+           EC_READ_U8(command->data + 0), EC_READ_U8(command->data + 1),
+           EC_READ_U8(command->data + 2), EC_READ_U8(command->data + 3),
+           EC_READ_U8(command->data + 6), EC_READ_U8(command->data + 7),
+           EC_READ_U8(command->data + 8), EC_READ_U8(command->data + 9));
+#endif
+
+    // SII value received.
+    fsm->sii_result = EC_READ_U32(command->data + 6);
+    fsm->sii_state = ec_fsm_sii_end;
+}
+
+/*****************************************************************************/
+
+/**
+   SII state: END.
    End state of the slave SII state machine.
 */
 
-void ec_fsm_sii_finished(ec_fsm_t *fsm)
-{
-}
-
-/*****************************************************************************/
-
-/**
-   Slave SII state: Error.
+void ec_fsm_sii_end(ec_fsm_t *fsm /**< finite state machine */)
+{
+}
+
+/*****************************************************************************/
+
+/**
+   SII state: ERROR.
    End state of the slave SII state machine.
 */
 
-void ec_fsm_sii_error(ec_fsm_t *fsm)
+void ec_fsm_sii_error(ec_fsm_t *fsm /**< finite state machine */)
 {
 }
 
@@ -1190,10 +1507,10 @@
  *****************************************************************************/
 
 /**
-   State change state: Start.
-*/
-
-void ec_fsm_change_start(ec_fsm_t *fsm)
+   Change state: START.
+*/
+
+void ec_fsm_change_start(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
     ec_slave_t *slave = fsm->slave;
@@ -1208,23 +1525,31 @@
 /*****************************************************************************/
 
 /**
-   State change state: Check.
-*/
-
-void ec_fsm_change_check(ec_fsm_t *fsm)
-{
-    ec_command_t *command = &fsm->command;
-    ec_slave_t *slave = fsm->slave;
-
-    if (command->state != EC_CMD_RECEIVED || command->working_counter != 1) {
-        EC_ERR("FSM: Reception of state command failed.\n");
+   Change state: CHECK.
+*/
+
+void ec_fsm_change_check(ec_fsm_t *fsm /**< finite state machine */)
+{
+    ec_command_t *command = &fsm->command;
+    ec_slave_t *slave = fsm->slave;
+
+    if (command->state != EC_CMD_RECEIVED) {
+        EC_ERR("Failed to send state command to slave %i!\n",
+               fsm->slave->ring_position);
         slave->state_error = 1;
         fsm->change_state = ec_fsm_change_error;
         return;
     }
 
-    //start = get_cycles();
-    //timeout = (cycles_t) 10 * cpu_khz; // 10ms
+    if (command->working_counter != 1) {
+        EC_ERR("Failed to set state 0x%02X on slave %i: Slave did not"
+               " respond.\n", fsm->change_new, fsm->slave->ring_position);
+        slave->state_error = 1;
+        fsm->change_state = ec_fsm_change_error;
+        return;
+    }
+
+    fsm->change_start = get_cycles();
 
     // read AL status from slave
     ec_command_nprd(command, slave->station_address, 0x0130, 2);
@@ -1235,16 +1560,17 @@
 /*****************************************************************************/
 
 /**
-   State change state: Status.
-*/
-
-void ec_fsm_change_status(ec_fsm_t *fsm)
+   Change state: STATUS.
+*/
+
+void ec_fsm_change_status(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
     ec_slave_t *slave = fsm->slave;
 
     if (command->state != EC_CMD_RECEIVED || command->working_counter != 1) {
-        EC_ERR("FSM: Reception of state check command failed.\n");
+        EC_ERR("Failed to check state 0x%02X on slave %i.\n",
+               fsm->change_new, slave->ring_position);
         slave->state_error = 1;
         fsm->change_state = ec_fsm_change_error;
         return;
@@ -1252,13 +1578,18 @@
 
     slave->current_state = EC_READ_U8(command->data);
 
-    if (slave->current_state & 0x10) { // state change error
+    if (slave->current_state == fsm->change_new) {
+        // state has been set successfully
+        fsm->change_state = ec_fsm_change_end;
+        return;
+    }
+
+    if (slave->current_state & 0x10) {
+        // state change error
+        fsm->change_new = slave->current_state & 0x0F;
         EC_ERR("Failed to set state 0x%02X - Slave %i refused state change"
                " (code 0x%02X)!\n", fsm->change_new, slave->ring_position,
                slave->current_state);
-
-        fsm->change_new = slave->current_state & 0x0F;
-
         // fetch AL status error code
         ec_command_nprd(command, slave->station_address, 0x0134, 2);
         ec_master_queue_command(fsm->master, command);
@@ -1266,24 +1597,27 @@
         return;
     }
 
-    if (slave->current_state == fsm->change_new) {
-        fsm->change_state = ec_fsm_change_end;
-        return;
-    }
-
-    EC_ERR("Failed to check state 0x%02X of slave %i - Timeout!\n",
-           fsm->change_new, slave->ring_position);
-    slave->state_error = 1;
-    fsm->change_state = ec_fsm_change_error;
-}
-
-/*****************************************************************************/
-
-/**
-   State change state: Code.
-*/
-
-void ec_fsm_change_code(ec_fsm_t *fsm)
+    if (get_cycles() - fsm->change_start >= (cycles_t) 10 * cpu_khz) {
+        // timeout while checking
+        slave->state_error = 1;
+        fsm->change_state = ec_fsm_change_error;
+        EC_ERR("Timeout while setting state 0x%02X on slave %i.\n",
+               fsm->change_new, slave->ring_position);
+        return;
+    }
+
+    // still old state: check again
+    ec_command_nprd(command, slave->station_address, 0x0130, 2);
+    ec_master_queue_command(fsm->master, command);
+}
+
+/*****************************************************************************/
+
+/**
+   Change state: CODE.
+*/
+
+void ec_fsm_change_code(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
     ec_slave_t *slave = fsm->slave;
@@ -1291,7 +1625,7 @@
     const ec_code_msg_t *al_msg;
 
     if (command->state != EC_CMD_RECEIVED || command->working_counter != 1) {
-        EC_ERR("FSM: Reception of AL status code command failed.\n");
+        EC_ERR("Reception of AL status code command failed.\n");
         slave->state_error = 1;
         fsm->change_state = ec_fsm_change_error;
         return;
@@ -1318,16 +1652,16 @@
 /*****************************************************************************/
 
 /**
-   State change state: Acknowledge.
-*/
-
-void ec_fsm_change_ack(ec_fsm_t *fsm)
+   Change state: ACK.
+*/
+
+void ec_fsm_change_ack(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
     ec_slave_t *slave = fsm->slave;
 
     if (command->state != EC_CMD_RECEIVED || command->working_counter != 1) {
-        EC_ERR("FSM: Reception of state ack command failed.\n");
+        EC_ERR("Reception of state ack command failed.\n");
         slave->state_error = 1;
         fsm->change_state = ec_fsm_change_error;
         return;
@@ -1342,16 +1676,17 @@
 /*****************************************************************************/
 
 /**
-   State change state: Acknowledge 2.
-*/
-
-void ec_fsm_change_ack2(ec_fsm_t *fsm)
+   Change state: ACK.
+   Acknowledge 2.
+*/
+
+void ec_fsm_change_ack2(ec_fsm_t *fsm /**< finite state machine */)
 {
     ec_command_t *command = &fsm->command;
     ec_slave_t *slave = fsm->slave;
 
     if (command->state != EC_CMD_RECEIVED || command->working_counter != 1) {
-        EC_ERR("FSM: Reception of state ack check command failed.\n");
+        EC_ERR("Reception of state ack check command failed.\n");
         slave->state_error = 1;
         fsm->change_state = ec_fsm_change_error;
         return;
@@ -1376,20 +1711,20 @@
 /*****************************************************************************/
 
 /**
-   State change state: End.
-*/
-
-void ec_fsm_change_end(ec_fsm_t *fsm)
-{
-}
-
-/*****************************************************************************/
-
-/**
-   State change state: Error.
-*/
-
-void ec_fsm_change_error(ec_fsm_t *fsm)
+   Change state: END.
+*/
+
+void ec_fsm_change_end(ec_fsm_t *fsm /**< finite state machine */)
+{
+}
+
+/*****************************************************************************/
+
+/**
+   Change state: ERROR.
+*/
+
+void ec_fsm_change_error(ec_fsm_t *fsm /**< finite state machine */)
 {
 }