Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
msnd_midi.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) by Jaroslav Kysela <[email protected]>
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 
49 
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 
67 
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;
80  mpu->substream_input = NULL;
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) {
108  &mpu->mode))
109  snd_msndmidi_input_drop(mpu);
110  } else {
112  }
113  spin_unlock_irqrestore(&mpu->input_lock, flags);
114  if (up)
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 
131  &mpu->mode))
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 }
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 
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");
179  &snd_msndmidi_input);
181  return 0;
182 }