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Diffstat (limited to 'doc/README.generic_usb_ohci')
| -rw-r--r-- | doc/README.generic_usb_ohci | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/doc/README.generic_usb_ohci b/doc/README.generic_usb_ohci new file mode 100644 index 0000000000..017c69ab07 --- /dev/null +++ b/doc/README.generic_usb_ohci @@ -0,0 +1,43 @@ +Notes on the the generic USB-OHCI driver +======================================== + +This driver (drivers/usb_ohci.[ch]) is the result of the merge of +various existing OHCI drivers that were basically identical beside +cpu/board dependant initalization. This initalization has been moved +into cpu/board directories and are called via the hooks below. + +Configuration options +---------------------- + +CONFIG_USB_OHCI_NEW: enable the new OHCI driver + +CFG_USB_OHCI_BOARD_INIT: call the board dependant hooks: + + - extern int usb_board_init(void); + - extern int usb_board_stop(void); + - extern int usb_cpu_init_fail(void); + +CFG_USB_OHCI_CPU_INIT: call the cpu dependant hooks: + + - extern int usb_cpu_init(void); + - extern int usb_cpu_stop(void); + - extern int usb_cpu_init_fail(void); + +CFG_USB_OHCI_REGS_BASE: defines the base address of the OHCI registers + +CFG_USB_OHCI_SLOT_NAME: slot name + +CFG_USB_OHCI_MAX_ROOT_PORTS: maximal number of ports of the root hub. + + +Endianness issues +------------------ + +The LITTLEENDIAN #define determines if the 'swap_16' and 'swap_32' +macros do byte swapping or not. But some cpus OHCI-controllers such as +ppc4xx and mpc5xxx operate in little endian mode, so some extra ifdefs +were necessary to make this work. + + + + |