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 mpu = substream->rmidi->private_data;
46
47 mpu->substream_input = substream;
48
49 snd_msnd_enable_irq(mpu->dev);
50
51 snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_START);
52 set_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
53 return 0;
54 }
55
snd_msndmidi_input_close(struct snd_rawmidi_substream * substream)56 static int snd_msndmidi_input_close(struct snd_rawmidi_substream *substream)
57 {
58 struct snd_msndmidi *mpu;
59
60 mpu = substream->rmidi->private_data;
61 snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_STOP);
62 clear_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
63 mpu->substream_input = NULL;
64 snd_msnd_disable_irq(mpu->dev);
65 return 0;
66 }
67
snd_msndmidi_input_drop(struct snd_msndmidi * mpu)68 static void snd_msndmidi_input_drop(struct snd_msndmidi *mpu)
69 {
70 u16 tail;
71
72 tail = readw(mpu->dev->MIDQ + JQS_wTail);
73 writew(tail, mpu->dev->MIDQ + JQS_wHead);
74 }
75
76 /*
77 * trigger input
78 */
snd_msndmidi_input_trigger(struct snd_rawmidi_substream * substream,int up)79 static void snd_msndmidi_input_trigger(struct snd_rawmidi_substream *substream,
80 int up)
81 {
82 unsigned long flags;
83 struct snd_msndmidi *mpu;
84
85 mpu = substream->rmidi->private_data;
86 spin_lock_irqsave(&mpu->input_lock, flags);
87 if (up) {
88 if (!test_and_set_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER,
89 &mpu->mode))
90 snd_msndmidi_input_drop(mpu);
91 } else {
92 clear_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
93 }
94 spin_unlock_irqrestore(&mpu->input_lock, flags);
95 if (up)
96 snd_msndmidi_input_read(mpu);
97 }
98
snd_msndmidi_input_read(void * mpuv)99 void snd_msndmidi_input_read(void *mpuv)
100 {
101 unsigned long flags;
102 struct snd_msndmidi *mpu = mpuv;
103 void __iomem *pwMIDQData = mpu->dev->mappedbase + MIDQ_DATA_BUFF;
104 u16 head, tail, size;
105
106 spin_lock_irqsave(&mpu->input_lock, flags);
107 head = readw(mpu->dev->MIDQ + JQS_wHead);
108 tail = readw(mpu->dev->MIDQ + JQS_wTail);
109 size = readw(mpu->dev->MIDQ + JQS_wSize);
110 if (head > size || tail > size)
111 goto out;
112 while (head != tail) {
113 unsigned char val = readw(pwMIDQData + 2 * head);
114
115 if (test_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
116 snd_rawmidi_receive(mpu->substream_input, &val, 1);
117 if (++head > size)
118 head = 0;
119 writew(head, mpu->dev->MIDQ + JQS_wHead);
120 }
121 out:
122 spin_unlock_irqrestore(&mpu->input_lock, flags);
123 }
124 EXPORT_SYMBOL(snd_msndmidi_input_read);
125
126 static const struct snd_rawmidi_ops snd_msndmidi_input = {
127 .open = snd_msndmidi_input_open,
128 .close = snd_msndmidi_input_close,
129 .trigger = snd_msndmidi_input_trigger,
130 };
131
snd_msndmidi_free(struct snd_rawmidi * rmidi)132 static void snd_msndmidi_free(struct snd_rawmidi *rmidi)
133 {
134 struct snd_msndmidi *mpu = rmidi->private_data;
135 kfree(mpu);
136 }
137
snd_msndmidi_new(struct snd_card * card,int device)138 int snd_msndmidi_new(struct snd_card *card, int device)
139 {
140 struct snd_msnd *chip = card->private_data;
141 struct snd_msndmidi *mpu;
142 struct snd_rawmidi *rmidi;
143 int err;
144
145 err = snd_rawmidi_new(card, "MSND-MIDI", device, 1, 1, &rmidi);
146 if (err < 0)
147 return err;
148 mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
149 if (mpu == NULL) {
150 snd_device_free(card, rmidi);
151 return -ENOMEM;
152 }
153 mpu->dev = chip;
154 chip->msndmidi_mpu = mpu;
155 rmidi->private_data = mpu;
156 rmidi->private_free = snd_msndmidi_free;
157 spin_lock_init(&mpu->input_lock);
158 strcpy(rmidi->name, "MSND MIDI");
159 snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
160 &snd_msndmidi_input);
161 rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
162 return 0;
163 }
164