dummy_cs.4

pcmcia source code

.\" Copyright (C) 1998 David A. Hinds -- [e-mail]
.\" dummy_cs.4 1.7 2000/06/12 21:24:47
.\"
.TH DUMMY_CS 4 "2000/06/12 21:24:47" "pcmcia-cs"
.SH NAME
dummy_cs \- PCMCIA dummy device driver
.SH SYNOPSIS
.B insmod dummy_cs.o
.RB [ pc_debug=\c
.IR n ]
.RB [ free_ports=\c
.IR n ]
.RB [ irq_list=\c
.IR i,j,... ]
.SH DESCRIPTION
The
.B dummy_cs
module has two purposes.  It is intended as a demonstration of how to
write the PCMCIA interface code for a client driver, and the source
code is heavily commented.  It is also written to function as a sort
of generic ``point enabler'': when bound to any PCMCIA IO card, it
will read the card's Configuration Information Structure, and
configure the card appropriately.  The configuration includes setting
up IO and memory windows, configuring the card for interrupts, and
initializing the card's PCMCIA configuration registers.
.PP
It turns out that many cards report incomplete or inaccurate
configuration information, due to vendor carelessness and the
complexity of the data format.  A vendor driver can generally take
for granted many configuration details, so there is not much incentive
for vendors to ensure that the on-card information is complete.  Thus,
the
.B dummy_cs
module is limited by its generality: since it makes no assumptions
about card types, it is forced to rely on the card information, for
better or worse.
.SH PARAMETERS
.TP
.BI pc_debug= n
Selects the PCMCIA debugging level.  This parameter is only available
if the module is compiled with debugging enabled.  A non-zero value
enables debugging.
.TP
.BI free_ports= n
A flag indicating if the IO ports allocated for the card should be
freed from the kernel resource maps.  This is useful if the dummy
driver is being used to configure a card in preparation for loading a
specific PCMCIA-unaware driver.  The default is 0 (false).
.TP
.BI irq_list= i,j,...
Specifies the set of interrupts that may be allocated by this driver.
.SH AUTHOR
David Hinds \- [e-mail]
.SH "SEE ALSO"
cardmgr(8), pcmcia(5).