xref: /openbmc/linux/sound/isa/msnd/msnd_midi.c (revision bc5aa3a0)
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 <linux/export.h>
33 #include <sound/core.h>
34 #include <sound/rawmidi.h>
35 
36 #include "msnd.h"
37 
38 #define MSNDMIDI_MODE_BIT_INPUT		0
39 #define MSNDMIDI_MODE_BIT_OUTPUT		1
40 #define MSNDMIDI_MODE_BIT_INPUT_TRIGGER	2
41 #define MSNDMIDI_MODE_BIT_OUTPUT_TRIGGER	3
42 
43 struct snd_msndmidi {
44 	struct snd_msnd *dev;
45 
46 	unsigned long mode;		/* MSNDMIDI_MODE_XXXX */
47 
48 	struct snd_rawmidi_substream *substream_input;
49 
50 	spinlock_t input_lock;
51 };
52 
53 /*
54  * input/output open/close - protected by open_mutex in rawmidi.c
55  */
56 static int snd_msndmidi_input_open(struct snd_rawmidi_substream *substream)
57 {
58 	struct snd_msndmidi *mpu;
59 
60 	snd_printdd("snd_msndmidi_input_open()\n");
61 
62 	mpu = substream->rmidi->private_data;
63 
64 	mpu->substream_input = substream;
65 
66 	snd_msnd_enable_irq(mpu->dev);
67 
68 	snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_START);
69 	set_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
70 	return 0;
71 }
72 
73 static int snd_msndmidi_input_close(struct snd_rawmidi_substream *substream)
74 {
75 	struct snd_msndmidi *mpu;
76 
77 	mpu = substream->rmidi->private_data;
78 	snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_STOP);
79 	clear_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
80 	mpu->substream_input = NULL;
81 	snd_msnd_disable_irq(mpu->dev);
82 	return 0;
83 }
84 
85 static void snd_msndmidi_input_drop(struct snd_msndmidi *mpu)
86 {
87 	u16 tail;
88 
89 	tail = readw(mpu->dev->MIDQ + JQS_wTail);
90 	writew(tail, mpu->dev->MIDQ + JQS_wHead);
91 }
92 
93 /*
94  * trigger input
95  */
96 static void snd_msndmidi_input_trigger(struct snd_rawmidi_substream *substream,
97 					int up)
98 {
99 	unsigned long flags;
100 	struct snd_msndmidi *mpu;
101 
102 	snd_printdd("snd_msndmidi_input_trigger(, %i)\n", up);
103 
104 	mpu = substream->rmidi->private_data;
105 	spin_lock_irqsave(&mpu->input_lock, flags);
106 	if (up) {
107 		if (!test_and_set_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER,
108 				      &mpu->mode))
109 			snd_msndmidi_input_drop(mpu);
110 	} else {
111 		clear_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
112 	}
113 	spin_unlock_irqrestore(&mpu->input_lock, flags);
114 	if (up)
115 		snd_msndmidi_input_read(mpu);
116 }
117 
118 void snd_msndmidi_input_read(void *mpuv)
119 {
120 	unsigned long flags;
121 	struct snd_msndmidi *mpu = mpuv;
122 	void *pwMIDQData = mpu->dev->mappedbase + MIDQ_DATA_BUFF;
123 
124 	spin_lock_irqsave(&mpu->input_lock, flags);
125 	while (readw(mpu->dev->MIDQ + JQS_wTail) !=
126 	       readw(mpu->dev->MIDQ + JQS_wHead)) {
127 		u16 wTmp, val;
128 		val = readw(pwMIDQData + 2 * readw(mpu->dev->MIDQ + JQS_wHead));
129 
130 			if (test_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER,
131 				     &mpu->mode))
132 				snd_rawmidi_receive(mpu->substream_input,
133 						    (unsigned char *)&val, 1);
134 
135 		wTmp = readw(mpu->dev->MIDQ + JQS_wHead) + 1;
136 		if (wTmp > readw(mpu->dev->MIDQ + JQS_wSize))
137 			writew(0,  mpu->dev->MIDQ + JQS_wHead);
138 		else
139 			writew(wTmp,  mpu->dev->MIDQ + JQS_wHead);
140 	}
141 	spin_unlock_irqrestore(&mpu->input_lock, flags);
142 }
143 EXPORT_SYMBOL(snd_msndmidi_input_read);
144 
145 static struct snd_rawmidi_ops snd_msndmidi_input = {
146 	.open =		snd_msndmidi_input_open,
147 	.close =	snd_msndmidi_input_close,
148 	.trigger =	snd_msndmidi_input_trigger,
149 };
150 
151 static void snd_msndmidi_free(struct snd_rawmidi *rmidi)
152 {
153 	struct snd_msndmidi *mpu = rmidi->private_data;
154 	kfree(mpu);
155 }
156 
157 int snd_msndmidi_new(struct snd_card *card, int device)
158 {
159 	struct snd_msnd *chip = card->private_data;
160 	struct snd_msndmidi *mpu;
161 	struct snd_rawmidi *rmidi;
162 	int err;
163 
164 	err = snd_rawmidi_new(card, "MSND-MIDI", device, 1, 1, &rmidi);
165 	if (err < 0)
166 		return err;
167 	mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
168 	if (mpu == NULL) {
169 		snd_device_free(card, rmidi);
170 		return -ENOMEM;
171 	}
172 	mpu->dev = chip;
173 	chip->msndmidi_mpu = mpu;
174 	rmidi->private_data = mpu;
175 	rmidi->private_free = snd_msndmidi_free;
176 	spin_lock_init(&mpu->input_lock);
177 	strcpy(rmidi->name, "MSND MIDI");
178 	snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
179 			    &snd_msndmidi_input);
180 	rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
181 	return 0;
182 }
183