summaryrefslogtreecommitdiff
path: root/doc
diff options
context:
space:
mode:
Diffstat (limited to 'doc')
-rw-r--r--doc/README.generic_usb_ohci43
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 0000000..017c69a
--- /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.
+
+
+
+