xref: /linux/sound/isa/msnd/msnd_midi.c (revision d524dac9279b6a41ffdf7ff7958c577f2e387db6)
1 /*
2  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
3  *  Copyright (c) 2009 by Krzysztof Helt
4  *  Routines for control of MPU-401 in UART mode
5  *
6  *  MPU-401 supports UART mode which is not capable generate transmit
7  *  interrupts thus output is done via polling. Also, if irq < 0, then
8  *  input is done also via polling. Do not expect good performance.
9  *
10  *
11  *   This program is free software; you can redistribute it and/or modify
12  *   it under the terms of the GNU General Public License as published by
13  *   the Free Software Foundation; either version 2 of the License, or
14  *   (at your option) any later version.
15  *
16  *   This program is distributed in the hope that it will be useful,
17  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
18  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  *   GNU General Public License for more details.
20  *
21  *   You should have received a copy of the GNU General Public License
22  *   along with this program; if not, write to the Free Software
23  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
24  *
25  */
26 
27 #include <linux/io.h>
28 #include <linux/slab.h>
29 #include <linux/delay.h>
30 #include <linux/ioport.h>
31 #include <linux/errno.h>
32 #include <sound/core.h>
33 #include <sound/rawmidi.h>
34 
35 #include "msnd.h"
36 
37 #define MSNDMIDI_MODE_BIT_INPUT		0
38 #define MSNDMIDI_MODE_BIT_OUTPUT		1
39 #define MSNDMIDI_MODE_BIT_INPUT_TRIGGER	2
40 #define MSNDMIDI_MODE_BIT_OUTPUT_TRIGGER	3
41 
42 struct snd_msndmidi {
43 	struct snd_msnd *dev;
44 
45 	unsigned long mode;		/* MSNDMIDI_MODE_XXXX */
46 
47 	struct snd_rawmidi_substream *substream_input;
48 
49 	spinlock_t input_lock;
50 };
51 
52 /*
53  * input/output open/close - protected by open_mutex in rawmidi.c
54  */
55 static int snd_msndmidi_input_open(struct snd_rawmidi_substream *substream)
56 {
57 	struct snd_msndmidi *mpu;
58 
59 	snd_printdd("snd_msndmidi_input_open()\n");
60 
61 	mpu = substream->rmidi->private_data;
62 
63 	mpu->substream_input = substream;
64 
65 	snd_msnd_enable_irq(mpu->dev);
66 
67 	snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_START);
68 	set_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
69 	return 0;
70 }
71 
72 static int snd_msndmidi_input_close(struct snd_rawmidi_substream *substream)
73 {
74 	struct snd_msndmidi *mpu;
75 
76 	mpu = substream->rmidi->private_data;
77 	snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_STOP);
78 	clear_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
79 	mpu->substream_input = NULL;
80 	snd_msnd_disable_irq(mpu->dev);
81 	return 0;
82 }
83 
84 static void snd_msndmidi_input_drop(struct snd_msndmidi *mpu)
85 {
86 	u16 tail;
87 
88 	tail = readw(mpu->dev->MIDQ + JQS_wTail);
89 	writew(tail, mpu->dev->MIDQ + JQS_wHead);
90 }
91 
92 /*
93  * trigger input
94  */
95 static void snd_msndmidi_input_trigger(struct snd_rawmidi_substream *substream,
96 					int up)
97 {
98 	unsigned long flags;
99 	struct snd_msndmidi *mpu;
100 
101 	snd_printdd("snd_msndmidi_input_trigger(, %i)\n", up);
102 
103 	mpu = substream->rmidi->private_data;
104 	spin_lock_irqsave(&mpu->input_lock, flags);
105 	if (up) {
106 		if (!test_and_set_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER,
107 				      &mpu->mode))
108 			snd_msndmidi_input_drop(mpu);
109 	} else {
110 		clear_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
111 	}
112 	spin_unlock_irqrestore(&mpu->input_lock, flags);
113 	if (up)
114 		snd_msndmidi_input_read(mpu);
115 }
116 
117 void snd_msndmidi_input_read(void *mpuv)
118 {
119 	unsigned long flags;
120 	struct snd_msndmidi *mpu = mpuv;
121 	void *pwMIDQData = mpu->dev->mappedbase + MIDQ_DATA_BUFF;
122 
123 	spin_lock_irqsave(&mpu->input_lock, flags);
124 	while (readw(mpu->dev->MIDQ + JQS_wTail) !=
125 	       readw(mpu->dev->MIDQ + JQS_wHead)) {
126 		u16 wTmp, val;
127 		val = readw(pwMIDQData + 2 * readw(mpu->dev->MIDQ + JQS_wHead));
128 
129 			if (test_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER,
130 				     &mpu->mode))
131 				snd_rawmidi_receive(mpu->substream_input,
132 						    (unsigned char *)&val, 1);
133 
134 		wTmp = readw(mpu->dev->MIDQ + JQS_wHead) + 1;
135 		if (wTmp > readw(mpu->dev->MIDQ + JQS_wSize))
136 			writew(0,  mpu->dev->MIDQ + JQS_wHead);
137 		else
138 			writew(wTmp,  mpu->dev->MIDQ + JQS_wHead);
139 	}
140 	spin_unlock_irqrestore(&mpu->input_lock, flags);
141 }
142 EXPORT_SYMBOL(snd_msndmidi_input_read);
143 
144 static struct snd_rawmidi_ops snd_msndmidi_input = {
145 	.open =		snd_msndmidi_input_open,
146 	.close =	snd_msndmidi_input_close,
147 	.trigger =	snd_msndmidi_input_trigger,
148 };
149 
150 static void snd_msndmidi_free(struct snd_rawmidi *rmidi)
151 {
152 	struct snd_msndmidi *mpu = rmidi->private_data;
153 	kfree(mpu);
154 }
155 
156 int snd_msndmidi_new(struct snd_card *card, int device)
157 {
158 	struct snd_msnd *chip = card->private_data;
159 	struct snd_msndmidi *mpu;
160 	struct snd_rawmidi *rmidi;
161 	int err;
162 
163 	err = snd_rawmidi_new(card, "MSND-MIDI", device, 1, 1, &rmidi);
164 	if (err < 0)
165 		return err;
166 	mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
167 	if (mpu == NULL) {
168 		snd_device_free(card, rmidi);
169 		return -ENOMEM;
170 	}
171 	mpu->dev = chip;
172 	chip->msndmidi_mpu = mpu;
173 	rmidi->private_data = mpu;
174 	rmidi->private_free = snd_msndmidi_free;
175 	spin_lock_init(&mpu->input_lock);
176 	strcpy(rmidi->name, "MSND MIDI");
177 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
178 			    &snd_msndmidi_input);
179 	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
180 	return 0;
181 }
182