[J-u-boot.git] / doc / README.generic_usb_ohci

Notes on the the generic USB-OHCI driver
========================================

This driver (drivers/usb/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_SYS_USB_OHCI_REGS_BASE: defines the base address of the OHCI
				registers

	CONFIG_SYS_USB_OHCI_SLOT_NAME: slot name

Endianness issues
------------------

The USB bus operates in little endian, but unfortunately there are
OHCI controllers that operate in big endian such as ppc4xx. For these the
config option

	CONFIG_SYS_OHCI_BE_CONTROLLER

needs to be defined.
Commit	Line	Data
58b48577 MK	1	Notes on the the generic USB-OHCI driver
	2	========================================
	3
7817cb20	4	This driver (drivers/usb/usb_ohci.[ch]) is the result of the merge of
58b48577 MK	5	various existing OHCI drivers that were basically identical beside
	6	cpu/board dependant initalization. This initalization has been moved
	7	into cpu/board directories and are called via the hooks below.
	8
	9	Configuration options
	10	----------------------
	11
fc43be47	12	CONFIG_USB_OHCI_NEW: enable the new OHCI driver
58b48577	13
65cc0e2a	14	CFG_SYS_USB_OHCI_REGS_BASE: defines the base address of the OHCI
fc43be47	15	registers
58b48577	16
6d0f6bcf	17	CONFIG_SYS_USB_OHCI_SLOT_NAME: slot name
58b48577	18
58b48577 MK	19	Endianness issues
	20	------------------
	21
fc43be47	22	The USB bus operates in little endian, but unfortunately there are
064b55cf HS	23	OHCI controllers that operate in big endian such as ppc4xx. For these the
064b55cf HS	24	config option
58b48577	25
6d0f6bcf	26	CONFIG_SYS_OHCI_BE_CONTROLLER
fc43be47	27
be5d72d1	28	needs to be defined.
fc43be47	29