u-boot/doc/README.generic_usb_ohci
Tom Rini dea25842ab usb: ohci-hcd: Remove some unused legacy code
At this point, the only user of ohci-hcd that also uses PCI is using DM,
so we can drop CONFIG_PCI_OHCI* usage.  No platforms set either of
CONFIG_SYS_USB_OHCI_BOARD_INIT or CONFIG_SYS_USB_OHCI_CPU_INIT so those
hooks can be removed as well.

Signed-off-by: Tom Rini <trini@konsulko.com>
2022-07-07 09:29:08 -04:00

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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
CONFIG_SYS_USB_OHCI_REGS_BASE: defines the base address of the OHCI
registers
CONFIG_SYS_USB_OHCI_SLOT_NAME: slot name
CONFIG_SYS_USB_OHCI_MAX_ROOT_PORTS: maximal number of ports of the
root hub.
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.