Here is a list of all documented files with brief descriptions:

devices
ecdev.h	EtherCAT interface for EtherCAT device drivers
fake_lib
include
ecrt.h	EtherCAT master application interface
ectty.h	EtherCAT virtual TTY interface
master
cdev.c	EtherCAT master character device
cdev.h	EtherCAT master character device
coe_emerg_ring.c	EtherCAT CoE emergency ring buffer methods
coe_emerg_ring.h	EtherCAT CoE emergency ring buffer structure
datagram.c	Methods of an EtherCAT datagram
datagram.h	EtherCAT datagram structure
datagram_pair.c	EtherCAT datagram pair methods
datagram_pair.h	EtherCAT datagram pair structure
debug.c	Ethernet interface for debugging purposes
debug.h	Network interface for debugging purposes
device.c	EtherCAT device methods
device.h	EtherCAT device structure
domain.c	EtherCAT domain methods
domain.h	EtherCAT domain structure
doxygen.c	Doxygen mainpage only
eoe_request.c	Ethernet-over-EtherCAT request functions
eoe_request.h	EtherCAT EoE request structure
ethernet.c	Ethernet over EtherCAT (EoE)
ethernet.h	Ethernet over EtherCAT (EoE)
flag.c	Slave Configuration Feature Flag
flag.h	EtherCAT Slave Configuration Feature Flag
fmmu_config.c	EtherCAT FMMU configuration methods
fmmu_config.h	EtherCAT FMMU configuration structure
foe.h	FoE defines
foe_request.c	File-over-EtherCAT request functions
foe_request.h	EtherCAT FoE request structure
fsm_change.c	EtherCAT state change FSM
fsm_change.h	EtherCAT state change FSM
fsm_coe.c	EtherCAT CoE state machines
fsm_coe.h	EtherCAT CoE state machines
fsm_eoe.c	EtherCAT EoE state machines
fsm_eoe.h	EtherCAT EoE set IP parameter state machines
fsm_foe.c	EtherCAT FoE state machines
fsm_foe.h	EtherCAT FoE state machines
fsm_master.c	EtherCAT master state machine
fsm_master.h	EtherCAT master state machine
fsm_pdo.c	EtherCAT PDO configuration state machine
fsm_pdo.h	EtherCAT PDO configuration state machine structures
fsm_pdo_entry.c	EtherCAT PDO mapping state machine
fsm_pdo_entry.h	EtherCAT PDO entry configuration state machine structures
fsm_sii.c	EtherCAT slave information interface FSM
fsm_sii.h	EtherCAT slave information interface FSM structure
fsm_slave.c	EtherCAT slave (SDO) state machine
fsm_slave.h	EtherCAT slave request state machine
fsm_slave_config.c	EtherCAT slave configuration state machine
fsm_slave_config.h	EtherCAT slave configuration state machine
fsm_slave_scan.c	EtherCAT slave state machines
fsm_slave_scan.h	EtherCAT slave scanning state machine
fsm_soe.c	EtherCAT SoE state machines
fsm_soe.h	EtherCAT CoE state machines
globals.h	Global definitions and macros
ioctl.c	EtherCAT master character device
ioctl.h	EtherCAT master character device IOCTL commands
mailbox.c	Mailbox functionality
mailbox.h	Mailbox functionality
master.c	EtherCAT master methods
master.h	EtherCAT master structure
module.c	EtherCAT master driver module
pdo.c	EtherCAT process data object methods
pdo.h	EtherCAT Process data object structure
pdo_entry.c	EtherCAT process data object entry methods
pdo_entry.h	EtherCAT Process data object structure
pdo_list.c	EtherCAT PDO list methods
pdo_list.h	EtherCAT PDO list structure
reg_request.c	Register request functions
reg_request.h	EtherCAT register request structure
rt_locks.h	Abstract locks for realtime part of interface
rtdm-ioctl.c	EtherCAT master character device
rtdm.c	RTDM interface
rtdm.h	RTDM interface
rtdm_details.h
rtdm_xenomai_v3.c	RTDM interface
sdo.c	CANopen SDO functions
sdo.h	EtherCAT CANopen SDO structure
sdo_entry.c	CANopen over EtherCAT SDO entry functions
sdo_entry.h	EtherCAT CANopen SDO entry structure
sdo_request.c	Canopen over EtherCAT SDO request functions
sdo_request.h	EtherCAT CANopen SDO request structure
slave.c	EtherCAT slave methods
slave.h	EtherCAT slave structure
slave_config.c	EtherCAT slave configuration methods
slave_config.h	EtherCAT slave configuration structure
smp.h	Definitions of Kernel SMP macros
soe_errors.c	EtherCAT SoE errors
soe_request.c	Sercos-over-EtherCAT request functions
soe_request.h	EtherCAT SoE request structure
sync.c	EtherCAT sync manager methods
sync.h	EtherCAT sync manager
sync_config.c	EtherCAT sync manager configuration methods
sync_config.h	EtherCAT sync manager
voe_handler.c	Vendor specific over EtherCAT protocol handler functions
voe_handler.h	Vendor specific over EtherCAT protocol handler