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NetBSD/sys/dev/midivar.h

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/* $NetBSD: midivar.h,v 1.20 2014/12/22 07:02:22 mrg Exp $ */
/*
* Copyright (c) 1998, 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Lennart Augustsson (augustss@NetBSD.org) and (midi FST refactoring and
* Active Sense) Chapman Flack (chap@NetBSD.org).
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#ifndef _SYS_DEV_MIDIVAR_H_
#define _SYS_DEV_MIDIVAR_H_
#define MIDI_BUFSIZE 1024
#include <sys/callout.h>
#include <sys/cdefs.h>
#include <sys/device.h>
#include <sys/condvar.h>
#include <sys/mutex.h>
/*
* In both xmt and rcv direction, the midi_fst runs at the time data are
* buffered (midi_writebytes for xmt, midi_in for rcv) so what's in the
* buffer is always in canonical form (or compressed, on xmt, if the hw
* wants it that way). To preserve message boundaries for the buffer
* consumer, but allow transfers larger than one message, the buffer is
* split into a buf fork and an idx fork, where each byte of idx encodes
* the type and length of a message. Because messages are variable length,
* it is a guess how to set the relative sizes of idx and buf, or how many
* messages can be buffered before one or the other fills.
*
* The producer adds only complete messages to a buffer (except for SysEx
* messages, which have unpredictable length). A consumer serving byte-at-a-
* time hardware may partially consume a message, in which case it updates
* the length count at *idx_consumerp to reflect the remaining length of the
* message, only incrementing idx_consumerp when the message has been entirely
* consumed.
*
* The buffers are structured in the simple 1 reader 1 writer bounded buffer
* form, considered full when 1 unused byte remains. This should allow their
* use with minimal locking provided single pointer reads and writes can be
* assured atomic ... but then I chickened out on assuming that assurance, and
* added the extra locks to the code.
*
* Macros for manipulating the buffers:
*
* MIDI_BUF_DECLARE(frk) where frk is either buf or idx:
* declares the local variables frk_cur, frk_lim, frk_org, and frk_end.
*
* MIDI_BUF_CONSUMER_INIT(mb,frk)
* MIDI_BUF_PRODUCER_INIT(mb,frk)
* initializes frk_org and frk_end to the base and end (that is, address just
* past the last valid byte) of the buffer fork frk, frk_cur to the
* consumer's or producer's current position, respectively, and frk_lim to
* the current limit (for either consumer or producer, immediately following
* this macro, frk_lim-frk_cur gives the number of bytes to play with). That
* means frk_lim may actually point past the buffer; loops on the condition
* (frk_cur < frk_lim) must contain WRAP(frk) if proceeding byte-by-byte, or
* must explicitly handle wrapping around frk_end if doing anything clever.
* These are expression-shaped macros that have the value frk_lim. When used
* without locking--provided pointer reads and writes can be assumed atomic--
* these macros give a conservative estimate of what is available to consume
* or produce.
*
* MIDI_BUF_WRAP(frk)
* tests whether frk_cur == frk_end and, if so, wraps both frk_cur and
* frk_lim around the beginning of the buffer. Because the test is ==, it
* must be applied at each byte in a loop; if the loop is proceeding in
* bigger steps, the possibility of wrap must be coded for. This expression-
* shaped macro has the value of frk_cur after wrapping.
*
* MIDI_BUF_CONSUMER_REFRESH(mb,frk)
* MIDI_BUF_PRODUCER_REFRESH(mb,frk)
* refresh the local value frk_lim for a new snapshot of bytes available; an
* expression-shaped macro with the new value of frk_lim. Usually used after
* using up the first conservative estimate and obtaining a lock to get a
* final value. Used unlocked, just gives a more recent conservative estimate.
*
* MIDI_BUF_CONSUMER_WBACK(mb,frk)
* MIDI_BUF_PRODUCER_WBACK(mb,frk)
* write back the local copy of frk_cur to the buffer, after a barrier to
* ensure prior writes go first. Under the right atomicity conditions a
* producer could get away with using these unlocked, as long as the order
* is buf followed by idx. A consumer should update both in a critical
* section.
*/
struct midi_buffer {
u_char * __volatile idx_producerp;
u_char * __volatile idx_consumerp;
u_char * __volatile buf_producerp;
u_char * __volatile buf_consumerp;
u_char idx[MIDI_BUFSIZE/3];
u_char buf[MIDI_BUFSIZE-MIDI_BUFSIZE/3];
};
#define MIDI_BUF_DECLARE(frk) \
u_char *__CONCAT(frk,_cur); \
u_char *__CONCAT(frk,_lim); \
u_char *__CONCAT(frk,_org); \
u_char *__CONCAT(frk,_end)
#define MIDI_BUF_CONSUMER_REFRESH(mb,frk) \
((__CONCAT(frk,_lim)=(mb)->__CONCAT(frk,_producerp)), \
__CONCAT(frk,_lim) < __CONCAT(frk,_cur) ? \
(__CONCAT(frk,_lim) += sizeof (mb)->frk) : __CONCAT(frk,_lim))
#define MIDI_BUF_PRODUCER_REFRESH(mb,frk) \
((__CONCAT(frk,_lim)=(mb)->__CONCAT(frk,_consumerp)-1), \
__CONCAT(frk,_lim) < __CONCAT(frk,_cur) ? \
(__CONCAT(frk,_lim) += sizeof (mb)->frk) : __CONCAT(frk,_lim))
#define MIDI_BUF_EXTENT_INIT(mb,frk) \
((__CONCAT(frk,_org)=(mb)->frk), \
(__CONCAT(frk,_end)=__CONCAT(frk,_org)+sizeof (mb)->frk))
#define MIDI_BUF_CONSUMER_INIT(mb,frk) \
(MIDI_BUF_EXTENT_INIT((mb),frk), \
(__CONCAT(frk,_cur)=(mb)->__CONCAT(frk,_consumerp)), \
MIDI_BUF_CONSUMER_REFRESH((mb),frk))
#define MIDI_BUF_PRODUCER_INIT(mb,frk) \
(MIDI_BUF_EXTENT_INIT((mb),frk), \
(__CONCAT(frk,_cur)=(mb)->__CONCAT(frk,_producerp)), \
MIDI_BUF_PRODUCER_REFRESH((mb),frk))
#define MIDI_BUF_WRAP(frk) \
(__predict_false(__CONCAT(frk,_cur)==__CONCAT(frk,_end)) ? (\
(__CONCAT(frk,_lim)-=__CONCAT(frk,_end)-__CONCAT(frk,_org)), \
(__CONCAT(frk,_cur)=__CONCAT(frk,_org))) : __CONCAT(frk,_cur))
#define MIDI_BUF_CONSUMER_WBACK(mb,frk) do { \
__insn_barrier(); \
(mb)->__CONCAT(frk,_consumerp)=__CONCAT(frk,_cur); \
} while (/*CONSTCOND*/0)
#define MIDI_BUF_PRODUCER_WBACK(mb,frk) do { \
__insn_barrier(); \
(mb)->__CONCAT(frk,_producerp)=__CONCAT(frk,_cur); \
} while (/*CONSTCOND*/0)
#define MIDI_MAX_WRITE 32 /* max bytes written with busy wait */
#define MIDI_WAIT 10000 /* microseconds to wait after busy wait */
struct midi_state {
struct evcnt bytesDiscarded;
struct evcnt incompleteMessages;
struct {
uint32_t bytesDiscarded;
uint32_t incompleteMessages;
} atOpen,
atQuery;
int state;
u_char *pos;
u_char *end;
u_char msg[3];
};
struct midi_softc {
device_t dev; /* Hardware device struct */
void *hw_hdl; /* Hardware driver handle */
const struct midi_hw_if *hw_if; /* Hardware interface */
const struct midi_hw_if_ext *hw_if_ext; /* see midi_if.h */
int isopen; /* Open indicator */
int flags; /* Open flags */
int dying;
struct midi_buffer outbuf;
struct midi_buffer inbuf;
int props;
int refcnt;
kcondvar_t detach_cv;
kcondvar_t rchan;
kcondvar_t wchan;
kmutex_t *lock;
int pbus;
int rcv_expect_asense;
int rcv_quiescent;
int rcv_eof;
struct selinfo wsel; /* write selector */
struct selinfo rsel; /* read selector */
pid_t async; /* process who wants audio SIGIO */
void *sih;
struct callout xmt_asense_co;
struct callout rcv_asense_co;
/* MIDI input state machine; states are *s of 4 to allow | CAT bits */
struct midi_state rcv;
struct midi_state xmt;
#define MIDI_IN_START 0
#define MIDI_IN_RUN0_1 4
#define MIDI_IN_RUN1_1 8
#define MIDI_IN_RUN0_2 12
#define MIDI_IN_RUN1_2 16
#define MIDI_IN_RUN2_2 20
#define MIDI_IN_COM0_1 24
#define MIDI_IN_COM0_2 28
#define MIDI_IN_COM1_2 32
#define MIDI_IN_SYX1_3 36
#define MIDI_IN_SYX2_3 40
#define MIDI_IN_SYX0_3 44
#define MIDI_IN_RNX0_1 48
#define MIDI_IN_RNX0_2 52
#define MIDI_IN_RNX1_2 56
#define MIDI_IN_RNY1_2 60 /* not needed except for accurate error counts */
/*
* Four more states are needed to model the equivalence of NoteOff vel. 64
* and NoteOn vel. 0 for canonicalization or compression. In each of these 4
* states, we know the last message input and output was a NoteOn or a NoteOff.
*/
#define MIDI_IN_RXX2_2 64 /* last output == msg[0] != last input */
#define MIDI_IN_RXX0_2 68 /* last output != msg[0] == this input */
#define MIDI_IN_RXX1_2 72 /* " */
#define MIDI_IN_RXY1_2 76 /* variant of RXX1_2 needed for error count only */
#define MIDI_CAT_DATA 0
#define MIDI_CAT_STATUS1 1
#define MIDI_CAT_STATUS2 2
#define MIDI_CAT_COMMON 3
/* Synthesizer emulation stuff */
int seqopen;
struct midi_dev *seq_md; /* structure that links us with the seq. */
};
#define MIDIUNIT(d) ((d) & 0xff)
#endif /* _SYS_DEV_MIDIVAR_H_ */
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