diff options
| author | Markus Klotzbuecher <mk@denx.de> | 2007-06-06 11:49:35 +0200 |
|---|---|---|
| committer | Markus Klotzbuecher <mk@pollux.denx.de> | 2007-06-06 11:49:35 +0200 |
| commit | fc43be478f2aa37ce38acd85355038866e4162af (patch) | |
| tree | d80b73493a6b6c59439601715025f8e7a275b9fa /doc | |
| parent | 18135125f909948b85d1d6881ab4ac0efb4a1c58 (diff) | |
USB/OHCI: endianness cleanup in the generic ohci driver
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.generic_usb_ohci | 49 |
1 files changed, 33 insertions, 16 deletions
diff --git a/doc/README.generic_usb_ohci b/doc/README.generic_usb_ohci index 017c69ab079..c343dfdf90a 100644 --- a/doc/README.generic_usb_ohci +++ b/doc/README.generic_usb_ohci @@ -9,35 +9,52 @@ into cpu/board directories and are called via the hooks below. Configuration options ---------------------- -CONFIG_USB_OHCI_NEW: enable the new OHCI driver + CONFIG_USB_OHCI_NEW: enable the new OHCI driver -CFG_USB_OHCI_BOARD_INIT: call the board dependant hooks: + 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); + - 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: + 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); + - 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_REGS_BASE: defines the base address of the OHCI + registers -CFG_USB_OHCI_SLOT_NAME: slot name + CFG_USB_OHCI_SLOT_NAME: slot name -CFG_USB_OHCI_MAX_ROOT_PORTS: maximal number of ports of the root hub. + 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. +The USB bus operates in little endian, but unfortunately there are +OHCI controllers that operate in big endian such as ppc4xx and +mpc5xxx. For these the config option + CFG_OHCI_BE_CONTROLLER + +needs to be defined. + + +PCI Controllers +---------------- + +You'll need to define + + CONFIG_PCI_OHCI + +PCI Controllers need to do byte swapping on register accesses, so they +should to define: + + CFG_OHCI_SWAP_REG_ACCESS |