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      1 /*	$NetBSD: midivar.h,v 1.20 2014/12/22 07:02:22 mrg Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1998, 2008 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Lennart Augustsson (augustss (at) NetBSD.org) and (midi FST refactoring and
      9  * Active Sense) Chapman Flack (chap (at) NetBSD.org).
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     30  * POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #ifndef _SYS_DEV_MIDIVAR_H_
     34 #define _SYS_DEV_MIDIVAR_H_
     35 
     36 #define MIDI_BUFSIZE 1024
     37 
     38 #include <sys/callout.h>
     39 #include <sys/cdefs.h>
     40 #include <sys/device.h>
     41 #include <sys/condvar.h>
     42 #include <sys/mutex.h>
     43 
     44 /*
     45  * In both xmt and rcv direction, the midi_fst runs at the time data are
     46  * buffered (midi_writebytes for xmt, midi_in for rcv) so what's in the
     47  * buffer is always in canonical form (or compressed, on xmt, if the hw
     48  * wants it that way). To preserve message boundaries for the buffer
     49  * consumer, but allow transfers larger than one message, the buffer is
     50  * split into a buf fork and an idx fork, where each byte of idx encodes
     51  * the type and length of a message. Because messages are variable length,
     52  * it is a guess how to set the relative sizes of idx and buf, or how many
     53  * messages can be buffered before one or the other fills.
     54  *
     55  * The producer adds only complete messages to a buffer (except for SysEx
     56  * messages, which have unpredictable length). A consumer serving byte-at-a-
     57  * time hardware may partially consume a message, in which case it updates
     58  * the length count at *idx_consumerp to reflect the remaining length of the
     59  * message, only incrementing idx_consumerp when the message has been entirely
     60  * consumed.
     61  *
     62  * The buffers are structured in the simple 1 reader 1 writer bounded buffer
     63  * form, considered full when 1 unused byte remains. This should allow their
     64  * use with minimal locking provided single pointer reads and writes can be
     65  * assured atomic ... but then I chickened out on assuming that assurance, and
     66  * added the extra locks to the code.
     67  *
     68  * Macros for manipulating the buffers:
     69  *
     70  * MIDI_BUF_DECLARE(frk) where frk is either buf or idx:
     71  *   declares the local variables frk_cur, frk_lim, frk_org, and frk_end.
     72  *
     73  * MIDI_BUF_CONSUMER_INIT(mb,frk)
     74  * MIDI_BUF_PRODUCER_INIT(mb,frk)
     75  *   initializes frk_org and frk_end to the base and end (that is, address just
     76  *   past the last valid byte) of the buffer fork frk, frk_cur to the
     77  *   consumer's or producer's current position, respectively, and frk_lim to
     78  *   the current limit (for either consumer or producer, immediately following
     79  *   this macro, frk_lim-frk_cur gives the number of bytes to play with). That
     80  *   means frk_lim may actually point past the buffer; loops on the condition
     81  *   (frk_cur < frk_lim) must contain WRAP(frk) if proceeding byte-by-byte, or
     82  *   must explicitly handle wrapping around frk_end if doing anything clever.
     83  *   These are expression-shaped macros that have the value frk_lim. When used
     84  *   without locking--provided pointer reads and writes can be assumed atomic--
     85  *   these macros give a conservative estimate of what is available to consume
     86  *   or produce.
     87  *
     88  * MIDI_BUF_WRAP(frk)
     89  *   tests whether frk_cur == frk_end and, if so, wraps both frk_cur and
     90  *   frk_lim around the beginning of the buffer. Because the test is ==, it
     91  *   must be applied at each byte in a loop; if the loop is proceeding in
     92  *   bigger steps, the possibility of wrap must be coded for. This expression-
     93  *   shaped macro has the value of frk_cur after wrapping.
     94  *
     95  * MIDI_BUF_CONSUMER_REFRESH(mb,frk)
     96  * MIDI_BUF_PRODUCER_REFRESH(mb,frk)
     97  *   refresh the local value frk_lim for a new snapshot of bytes available; an
     98  *   expression-shaped macro with the new value of frk_lim. Usually used after
     99  *   using up the first conservative estimate and obtaining a lock to get a
    100  *   final value. Used unlocked, just gives a more recent conservative estimate.
    101  *
    102  * MIDI_BUF_CONSUMER_WBACK(mb,frk)
    103  * MIDI_BUF_PRODUCER_WBACK(mb,frk)
    104  *   write back the local copy of frk_cur to the buffer, after a barrier to
    105  *   ensure prior writes go first. Under the right atomicity conditions a
    106  *   producer could get away with using these unlocked, as long as the order
    107  *   is buf followed by idx. A consumer should update both in a critical
    108  *   section.
    109  */
    110 struct midi_buffer {
    111 	u_char * __volatile idx_producerp;
    112 	u_char * __volatile idx_consumerp;
    113 	u_char * __volatile buf_producerp;
    114 	u_char * __volatile buf_consumerp;
    115 	u_char idx[MIDI_BUFSIZE/3];
    116 	u_char buf[MIDI_BUFSIZE-MIDI_BUFSIZE/3];
    117 };
    118 #define MIDI_BUF_DECLARE(frk) \
    119 u_char *__CONCAT(frk,_cur); \
    120 u_char *__CONCAT(frk,_lim); \
    121 u_char *__CONCAT(frk,_org); \
    122 u_char *__CONCAT(frk,_end)
    123 
    124 #define MIDI_BUF_CONSUMER_REFRESH(mb,frk) \
    125 ((__CONCAT(frk,_lim)=(mb)->__CONCAT(frk,_producerp)), \
    126 __CONCAT(frk,_lim) < __CONCAT(frk,_cur) ? \
    127 (__CONCAT(frk,_lim) += sizeof (mb)->frk) : __CONCAT(frk,_lim))
    128 
    129 #define MIDI_BUF_PRODUCER_REFRESH(mb,frk) \
    130 ((__CONCAT(frk,_lim)=(mb)->__CONCAT(frk,_consumerp)-1), \
    131 __CONCAT(frk,_lim) < __CONCAT(frk,_cur) ? \
    132 (__CONCAT(frk,_lim) += sizeof (mb)->frk) : __CONCAT(frk,_lim))
    133 
    134 #define MIDI_BUF_EXTENT_INIT(mb,frk) \
    135 ((__CONCAT(frk,_org)=(mb)->frk), \
    136 (__CONCAT(frk,_end)=__CONCAT(frk,_org)+sizeof (mb)->frk))
    137 
    138 #define MIDI_BUF_CONSUMER_INIT(mb,frk) \
    139 (MIDI_BUF_EXTENT_INIT((mb),frk), \
    140 (__CONCAT(frk,_cur)=(mb)->__CONCAT(frk,_consumerp)), \
    141 MIDI_BUF_CONSUMER_REFRESH((mb),frk))
    142 
    143 #define MIDI_BUF_PRODUCER_INIT(mb,frk) \
    144 (MIDI_BUF_EXTENT_INIT((mb),frk), \
    145 (__CONCAT(frk,_cur)=(mb)->__CONCAT(frk,_producerp)), \
    146 MIDI_BUF_PRODUCER_REFRESH((mb),frk))
    147 
    148 #define MIDI_BUF_WRAP(frk) \
    149 (__predict_false(__CONCAT(frk,_cur)==__CONCAT(frk,_end)) ? (\
    150 (__CONCAT(frk,_lim)-=__CONCAT(frk,_end)-__CONCAT(frk,_org)), \
    151 (__CONCAT(frk,_cur)=__CONCAT(frk,_org))) : __CONCAT(frk,_cur))
    152 
    153 #define MIDI_BUF_CONSUMER_WBACK(mb,frk) do { \
    154 __insn_barrier(); \
    155 (mb)->__CONCAT(frk,_consumerp)=__CONCAT(frk,_cur); \
    156 } while (/*CONSTCOND*/0)
    157 
    158 #define MIDI_BUF_PRODUCER_WBACK(mb,frk) do { \
    159 __insn_barrier(); \
    160 (mb)->__CONCAT(frk,_producerp)=__CONCAT(frk,_cur); \
    161 } while (/*CONSTCOND*/0)
    162 
    163 
    164 #define MIDI_MAX_WRITE 32	/* max bytes written with busy wait */
    165 #define MIDI_WAIT 10000		/* microseconds to wait after busy wait */
    166 
    167 struct midi_state {
    168 	struct  evcnt bytesDiscarded;
    169 	struct  evcnt incompleteMessages;
    170 	struct {
    171 		uint32_t bytesDiscarded;
    172 		uint32_t incompleteMessages;
    173 	}	atOpen,
    174 		atQuery;
    175 	int     state;
    176 	u_char *pos;
    177 	u_char *end;
    178 	u_char  msg[3];
    179 };
    180 
    181 struct midi_softc {
    182 	device_t dev;		/* Hardware device struct */
    183 	void	*hw_hdl;	/* Hardware driver handle */
    184 	const struct	midi_hw_if *hw_if; /* Hardware interface */
    185 	const struct	midi_hw_if_ext *hw_if_ext; /* see midi_if.h */
    186 	int	isopen;		/* Open indicator */
    187 	int	flags;		/* Open flags */
    188 	int	dying;
    189 	struct	midi_buffer outbuf;
    190 	struct	midi_buffer inbuf;
    191 	int	props;
    192 	int	refcnt;
    193 	kcondvar_t detach_cv;
    194 	kcondvar_t rchan;
    195 	kcondvar_t wchan;
    196 	kmutex_t *lock;
    197 	int	pbus;
    198 	int	rcv_expect_asense;
    199 	int	rcv_quiescent;
    200 	int	rcv_eof;
    201 	struct	selinfo wsel;	/* write selector */
    202 	struct	selinfo rsel;	/* read selector */
    203 	pid_t	async;	/* process who wants audio SIGIO */
    204 	void	*sih;
    205 
    206 	struct callout xmt_asense_co;
    207 	struct callout rcv_asense_co;
    208 
    209 	/* MIDI input state machine; states are *s of 4 to allow | CAT bits */
    210 	struct midi_state rcv;
    211 	struct midi_state xmt;
    212 #define MIDI_IN_START	0
    213 #define MIDI_IN_RUN0_1	4
    214 #define MIDI_IN_RUN1_1	8
    215 #define MIDI_IN_RUN0_2 12
    216 #define MIDI_IN_RUN1_2 16
    217 #define MIDI_IN_RUN2_2 20
    218 #define MIDI_IN_COM0_1 24
    219 #define MIDI_IN_COM0_2 28
    220 #define MIDI_IN_COM1_2 32
    221 #define MIDI_IN_SYX1_3 36
    222 #define MIDI_IN_SYX2_3 40
    223 #define MIDI_IN_SYX0_3 44
    224 #define MIDI_IN_RNX0_1 48
    225 #define MIDI_IN_RNX0_2 52
    226 #define MIDI_IN_RNX1_2 56
    227 #define MIDI_IN_RNY1_2 60 /* not needed except for accurate error counts */
    228 /*
    229  * Four more states are needed to model the equivalence of NoteOff vel. 64
    230  * and NoteOn vel. 0 for canonicalization or compression. In each of these 4
    231  * states, we know the last message input and output was a NoteOn or a NoteOff.
    232  */
    233 #define MIDI_IN_RXX2_2 64 /* last output == msg[0] != last input */
    234 #define MIDI_IN_RXX0_2 68 /* last output != msg[0] == this input */
    235 #define MIDI_IN_RXX1_2 72 /* " */
    236 #define MIDI_IN_RXY1_2 76 /* variant of RXX1_2 needed for error count only */
    237 
    238 #define MIDI_CAT_DATA 0
    239 #define MIDI_CAT_STATUS1 1
    240 #define MIDI_CAT_STATUS2 2
    241 #define MIDI_CAT_COMMON 3
    242 
    243 	/* Synthesizer emulation stuff */
    244 	int	seqopen;
    245 	struct	midi_dev *seq_md; /* structure that links us with the seq. */
    246 };
    247 
    248 #define MIDIUNIT(d) ((d) & 0xff)
    249 
    250 #endif /* _SYS_DEV_MIDIVAR_H_ */
    251