driver/host/Kconfig:

config USB_EHCI_ARC
 bool "Support for Freescale controller"
 depends on USB_EHCI_HCD && (ARCH_MXC || ARCH_STMP3XXX || ARCH_MXS)
 select USB_OTG_UTILS
 ---help---
    Some Freescale processors have an integrated High Speed
    USBOTG controller, which supports EHCI host mode.

    Say "y" here to add support for this controller
    to the EHCI HCD driver.

實際上.config:

CONFIG_USB_EHCI_HCD=y
CONFIG_USB_EHCI_ARC=y
CONFIG_USB_EHCI_ARC_OTG=y
CONFIG_USB_EHCI_FSL_UTMI=y
CONFIG_USB_EHCI_ROOT_HUB_TT=y

---

然後在 driver/usb/host...

然後 CONFIG_USB_EHCI_HCD::

drivers/usb/host/Makefile:obj-$(CONFIG_USB_EHCI_HCD) += ehci-hcd.o

CONFIG_USB_EHCI_ARC, _OTG 的：

arch/arm/mach-mx5/usb_h1.c:#ifdef CONFIG_USB_EHCI_ARC
arch/arm/mach-mx5/usb_dr.c:#ifdef CONFIG_USB_EHCI_ARC_OTG
arch/arm/mach-mx5/usb_dr.c:#endif /* CONFIG_USB_EHCI_ARC_OTG */
arch/arm/mach-mx5/usb_dr.c:#ifdef CONFIG_USB_EHCI_ARC_OTG
arch/arm/mach-mx5/usb_h2.c:#ifdef CONFIG_USB_EHCI_ARC
drivers/usb/host/ehci-hcd.c:#ifdef CONFIG_USB_EHCI_ARC
drivers/usb/otg/fsl_otg.c:  "CONFIG_USB_EHCI_ARC_OTG\n"

---

所以主要的好像就只有 driver/usb/host/ehci-hcd.c

然後這個 source include 很多其他的 .c

#include "ehci-dbg.c"
#include "ehci-hub.c"
#include "ehci-sched.c"
#include "ehci-arc.c"
#define PLATFORM_DRIVER  ehci_fsl_driver

以上就是實際compile 的 source code.