freebsd-skq/share/man/man9/microseq.9

119 lines
3.6 KiB
Groff
Raw Normal View History

.\" Copyright (c) 1998, Nicolas Souchu
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"
.Dd June 6, 1998
.Dt MICROSEQ 9
.Os FreeBSD
.Sh NAME
.Nm microseq
.Nd
ppbus microseqencer developer's guide
.Sh SYNOPSIS
.Fd "#include <dev/ppbus/ppb_msq.h>"
.Sh DESCRIPTION
See
.Xr ppbus 4
for ppbus description and general info about the microsequencer.
.Pp
The purpose of this document is to encourage developers to use the
microsequencer mechanism in order to have:
.Bl -enum -offset indent
.It
a uniform programming model
.It
efficient code
.El
.Sh INTERFACE
.Ss C structures
.Bd -literal
union ppb_insarg {
int i;
char c;
void *p;
int (* f)(void *, char *);
};
.Ed
.Bd -literal
struct ppb_microseq {
int opcode; /* microins. opcode */
union ppb_insarg arg[PPB_MS_MAXARGS]; /* arguments */
};
.Ed
.Ss Using microsequences
.Pp
To instanciate a microsequence, just declare an array of ppb_microseq
structures and initialize it as needed. You may either use defined macros
or code directly your microinstructions according to the ppb_microseq
definition. For example,
.Bd -literal
struct ppb_microseq select_microseq[] = {
/* parameter list
*/
#define SELECT_TARGET MS_PARAM(0, 1, MS_TYP_INT)
#define SELECT_INITIATOR MS_PARAM(3, 1, MS_TYP_INT)
/* send the select command to the drive */
MS_DASS(MS_UNKNOWN),
MS_CASS(H_nAUTO | H_nSELIN | H_INIT | H_STROBE),
MS_CASS( H_AUTO | H_nSELIN | H_INIT | H_STROBE),
MS_DASS(MS_UNKNOWN),
MS_CASS( H_AUTO | H_nSELIN | H_nINIT | H_STROBE),
/* now, wait until the drive is ready */
MS_SET(VP0_SELTMO),
/* loop: */ MS_BRSET(H_ACK, 3 /* ready */),
MS_DBRA(-1 /* loop */),
/* error: */ MS_RET(1),
/* ready: */ MS_RET(0)
};
.Ed
.Pp
Here, some parameters are undefined and must be filled before executing
the microsequence. In order to initialize seach a microsequence, one should
use the ppb_MS_init_msq() function like this:
.Bd -literal
ppb_MS_init_msq(select_microseq, 2,
SELECT_TARGET, 1 << target,
SELECT_INITIATOR, 1 << initiator);
.Ed
.Pp
and then execute the microsequence.
.Ss The microsequencer
The microsequencer is executed either at ppbus or adapter level (see
.Xr ppbus 4
for info about ppbus system layers).
.Sh SEE ALSO
.Xr ppbus 4
.Sh HISTORY
The
.Nm
manual page first appeared in
.Fx 3.0 .
.Sh AUTHOR
This
manual page was written by
.An Nicolas Souchu .