1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
4 * Copyright (c) 2009 by Krzysztof Helt
5 * Routines for control of MPU-401 in UART mode
6 *
7 * MPU-401 supports UART mode which is not capable generate transmit
8 * interrupts thus output is done via polling. Also, if irq < 0, then
9 * input is done also via polling. Do not expect good performance.
10 */
11
12 #include <linux/io.h>
13 #include <linux/slab.h>
14 #include <linux/delay.h>
15 #include <linux/ioport.h>
16 #include <linux/errno.h>
17 #include <linux/export.h>
18 #include <sound/core.h>
19 #include <sound/rawmidi.h>
20
21 #include "msnd.h"
22
23 #define MSNDMIDI_MODE_BIT_INPUT 0
24 #define MSNDMIDI_MODE_BIT_OUTPUT 1
25 #define MSNDMIDI_MODE_BIT_INPUT_TRIGGER 2
26 #define MSNDMIDI_MODE_BIT_OUTPUT_TRIGGER 3
27
28 struct snd_msndmidi {
29 struct snd_msnd *dev;
30
31 unsigned long mode; /* MSNDMIDI_MODE_XXXX */
32
33 struct snd_rawmidi_substream *substream_input;
34
35 spinlock_t input_lock;
36 };
37
38 /*
39 * input/output open/close - protected by open_mutex in rawmidi.c
40 */
snd_msndmidi_input_open(struct snd_rawmidi_substream * substream)41 static int snd_msndmidi_input_open(struct snd_rawmidi_substream *substream)
42 {
43 struct snd_msndmidi *mpu;
44
45 snd_printdd("snd_msndmidi_input_open()\n");
46
47 mpu = substream->rmidi->private_data;
48
49 mpu->substream_input = substream;
50
51 snd_msnd_enable_irq(mpu->dev);
52
53 snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_START);
54 set_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
55 return 0;
56 }
57
snd_msndmidi_input_close(struct snd_rawmidi_substream * substream)58 static int snd_msndmidi_input_close(struct snd_rawmidi_substream *substream)
59 {
60 struct snd_msndmidi *mpu;
61
62 mpu = substream->rmidi->private_data;
63 snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_STOP);
64 clear_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
65 mpu->substream_input = NULL;
66 snd_msnd_disable_irq(mpu->dev);
67 return 0;
68 }
69
snd_msndmidi_input_drop(struct snd_msndmidi * mpu)70 static void snd_msndmidi_input_drop(struct snd_msndmidi *mpu)
71 {
72 u16 tail;
73
74 tail = readw(mpu->dev->MIDQ + JQS_wTail);
75 writew(tail, mpu->dev->MIDQ + JQS_wHead);
76 }
77
78 /*
79 * trigger input
80 */
snd_msndmidi_input_trigger(struct snd_rawmidi_substream * substream,int up)81 static void snd_msndmidi_input_trigger(struct snd_rawmidi_substream *substream,
82 int up)
83 {
84 unsigned long flags;
85 struct snd_msndmidi *mpu;
86
87 snd_printdd("snd_msndmidi_input_trigger(, %i)\n", up);
88
89 mpu = substream->rmidi->private_data;
90 spin_lock_irqsave(&mpu->input_lock, flags);
91 if (up) {
92 if (!test_and_set_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER,
93 &mpu->mode))
94 snd_msndmidi_input_drop(mpu);
95 } else {
96 clear_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
97 }
98 spin_unlock_irqrestore(&mpu->input_lock, flags);
99 if (up)
100 snd_msndmidi_input_read(mpu);
101 }
102
snd_msndmidi_input_read(void * mpuv)103 void snd_msndmidi_input_read(void *mpuv)
104 {
105 unsigned long flags;
106 struct snd_msndmidi *mpu = mpuv;
107 void __iomem *pwMIDQData = mpu->dev->mappedbase + MIDQ_DATA_BUFF;
108 u16 head, tail, size;
109
110 spin_lock_irqsave(&mpu->input_lock, flags);
111 head = readw(mpu->dev->MIDQ + JQS_wHead);
112 tail = readw(mpu->dev->MIDQ + JQS_wTail);
113 size = readw(mpu->dev->MIDQ + JQS_wSize);
114 if (head > size || tail > size)
115 goto out;
116 while (head != tail) {
117 unsigned char val = readw(pwMIDQData + 2 * head);
118
119 if (test_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
120 snd_rawmidi_receive(mpu->substream_input, &val, 1);
121 if (++head > size)
122 head = 0;
123 writew(head, mpu->dev->MIDQ + JQS_wHead);
124 }
125 out:
126 spin_unlock_irqrestore(&mpu->input_lock, flags);
127 }
128 EXPORT_SYMBOL(snd_msndmidi_input_read);
129
130 static const struct snd_rawmidi_ops snd_msndmidi_input = {
131 .open = snd_msndmidi_input_open,
132 .close = snd_msndmidi_input_close,
133 .trigger = snd_msndmidi_input_trigger,
134 };
135
snd_msndmidi_free(struct snd_rawmidi * rmidi)136 static void snd_msndmidi_free(struct snd_rawmidi *rmidi)
137 {
138 struct snd_msndmidi *mpu = rmidi->private_data;
139 kfree(mpu);
140 }
141
snd_msndmidi_new(struct snd_card * card,int device)142 int snd_msndmidi_new(struct snd_card *card, int device)
143 {
144 struct snd_msnd *chip = card->private_data;
145 struct snd_msndmidi *mpu;
146 struct snd_rawmidi *rmidi;
147 int err;
148
149 err = snd_rawmidi_new(card, "MSND-MIDI", device, 1, 1, &rmidi);
150 if (err < 0)
151 return err;
152 mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
153 if (mpu == NULL) {
154 snd_device_free(card, rmidi);
155 return -ENOMEM;
156 }
157 mpu->dev = chip;
158 chip->msndmidi_mpu = mpu;
159 rmidi->private_data = mpu;
160 rmidi->private_free = snd_msndmidi_free;
161 spin_lock_init(&mpu->input_lock);
162 strcpy(rmidi->name, "MSND MIDI");
163 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
164 &snd_msndmidi_input);
165 rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
166 return 0;
167 }
168