SLHCI(4)						   BSD Kernel Interfaces Manual 						  SLHCI(4)

NAME

     slhci -- Cypress/ScanLogic SL811HS USB Host Controller driver

SYNOPSIS

   PCMCIA (CF) controllers
     slhci*   at pcmcia? function ?
     usb*     at slhci?

   ISA controllers
     slhci*   at isa? port ? irq ?
     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 per-
     fectly 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 com-
     pleted 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 mul-
     tiprocessor systems).  Unexpected device behavior may trigger some problems;  power cycling externally powered devices may help resolve per-
     sistent 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 outgo-
     ing 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

SEE ALSO

     config(1), isa(4), pcmcia(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

BSD
								  April 24, 2007							       BSD