NAME
slhci —
Cypress/ScanLogic SL811HS USB
Host Controller driver
SYNOPSIS
amiga
slhci* at zbus?
PCMCIA (CF) controllers
slhci* at pcmcia? function ?
usb* at slhci?
ISA controllers
slhci* at isa? port ? irq ?
usb* at slhci?
TURBOchannel controllers
tcu* at tc? slot ? offset ?
slhci* at tcu?
usb* at slhci?
x68k
slhci0 at intio0 addr 0xece380 intr 251
slhci1 at intio0 addr 0xeceb80 intr 250
usb* at slhci?
options SLHCI_TRY_LSVH
DESCRIPTION
The
slhci driver provides support for Cypress/ScanLogic
SL811HS USB Host Controller.
The driver supports control, bulk, and interrupt transfers but not isochronous
(audio), which cannot be supported by this chip without perfectly reliable 1ms
interrupts. USB is polled and this chip requires the driver to initiate all
transfers. The driver interrupts at least once every ms when a device is
attached even if no data is transferred. The driver polls the chip when the
transfer is expected to be completed soon; with maximum use of the bus, the
driver will not exit for most of each ms. Use of this driver can easily have a
significant performance impact on any system.
The chip is unreliable in some conditions, possibly due in part to difficulty
meeting timing restrictions (this is likely to be worse on multiprocessor
systems). Unexpected device behavior may trigger some problems; power cycling
externally powered devices may help resolve persistent problems. Detection of
invalid chip state will usually cause the driver to halt, however is
recommended that all data transfers be verified. Data corruption due to
controller error will not be detected automatically. Unmounting and remounting
a device is necessary to prevent use of cached data.
The driver currently will start the next incoming packet before copying in the
previous packet but will not copy the next outgoing packet before the previous
packet is transferred. Reading or writing the chip is about the same speed as
the USB bus, so this means that one outgoing transfer is half the speed of one
incoming transfer and two outgoing transfers are needed to use the full
available bandwidth.
All revisions of the SL811HS have trouble with low speed devices attached to
some (likely most) hubs. Low speed traffic via hub is not allowed by default,
but can be enabled with
options SLHCI_TRY_LSVH in the kernel
config file or by setting the
slhci_try_lsvh variable to
non-zero using
ddb(4) or
gdb(1).
Many USB keyboards have built in hubs and may be low speed devices. All USB mice
I have seen are low speed devices, however a serial mouse should be usable on
a hub with a full speed Serial-USB converter. A PS2-USB keyboard and mouse
converter is likely to be a single low speed device.
Some hardware using this chip does not provide the USB minimum 100mA current,
which could potentially cause problems even with externally powered hubs. The
system can allow excess power use in some other cases as well. Some signs of
excess power draw may cause the driver to halt, however this may not stop the
power draw. To be safe verify power use and availability before connecting any
device.
HARDWARE
Hardware supported by the
slhci driver includes:
- Ratoc CFU1U
- Nereid Ethernet/USB/Memory board
- Thylacine USB Host Controller
- flxd TC-USB
SEE ALSO
config(1),
isa(4),
pcmcia(4),
tc(4),
tcu(4),
usb(4)
Cypress SL811HS datasheet, errata, and
application note,
http://www.cypress.com.
HISTORY
The
slhci driver appeared in
NetBSD
2.0 and was rewritten in
NetBSD 5.0.
AUTHORS
Tetsuya Isaki ⟨isaki@NetBSD.org⟩
Matthew Orgass