1 // SPDX-License-Identifier: GPL-2.0-or-later
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
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.
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>
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
31 unsigned long mode
; /* MSNDMIDI_MODE_XXXX */
33 struct snd_rawmidi_substream
*substream_input
;
35 spinlock_t input_lock
;
39 * input/output open/close - protected by open_mutex in rawmidi.c
41 static int snd_msndmidi_input_open(struct snd_rawmidi_substream
*substream
)
43 struct snd_msndmidi
*mpu
;
45 snd_printdd("snd_msndmidi_input_open()\n");
47 mpu
= substream
->rmidi
->private_data
;
49 mpu
->substream_input
= substream
;
51 snd_msnd_enable_irq(mpu
->dev
);
53 snd_msnd_send_dsp_cmd(mpu
->dev
, HDEX_MIDI_IN_START
);
54 set_bit(MSNDMIDI_MODE_BIT_INPUT
, &mpu
->mode
);
58 static int snd_msndmidi_input_close(struct snd_rawmidi_substream
*substream
)
60 struct snd_msndmidi
*mpu
;
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
);
70 static void snd_msndmidi_input_drop(struct snd_msndmidi
*mpu
)
74 tail
= readw(mpu
->dev
->MIDQ
+ JQS_wTail
);
75 writew(tail
, mpu
->dev
->MIDQ
+ JQS_wHead
);
81 static void snd_msndmidi_input_trigger(struct snd_rawmidi_substream
*substream
,
85 struct snd_msndmidi
*mpu
;
87 snd_printdd("snd_msndmidi_input_trigger(, %i)\n", up
);
89 mpu
= substream
->rmidi
->private_data
;
90 spin_lock_irqsave(&mpu
->input_lock
, flags
);
92 if (!test_and_set_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER
,
94 snd_msndmidi_input_drop(mpu
);
96 clear_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER
, &mpu
->mode
);
98 spin_unlock_irqrestore(&mpu
->input_lock
, flags
);
100 snd_msndmidi_input_read(mpu
);
103 void snd_msndmidi_input_read(void *mpuv
)
106 struct snd_msndmidi
*mpu
= mpuv
;
107 void __iomem
*pwMIDQData
= mpu
->dev
->mappedbase
+ MIDQ_DATA_BUFF
;
108 u16 head
, tail
, size
;
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
)
116 while (head
!= tail
) {
117 unsigned char val
= readw(pwMIDQData
+ 2 * head
);
119 if (test_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER
, &mpu
->mode
))
120 snd_rawmidi_receive(mpu
->substream_input
, &val
, 1);
123 writew(head
, mpu
->dev
->MIDQ
+ JQS_wHead
);
126 spin_unlock_irqrestore(&mpu
->input_lock
, flags
);
128 EXPORT_SYMBOL(snd_msndmidi_input_read
);
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
,
136 static void snd_msndmidi_free(struct snd_rawmidi
*rmidi
)
138 struct snd_msndmidi
*mpu
= rmidi
->private_data
;
142 int snd_msndmidi_new(struct snd_card
*card
, int device
)
144 struct snd_msnd
*chip
= card
->private_data
;
145 struct snd_msndmidi
*mpu
;
146 struct snd_rawmidi
*rmidi
;
149 err
= snd_rawmidi_new(card
, "MSND-MIDI", device
, 1, 1, &rmidi
);
152 mpu
= kzalloc(sizeof(*mpu
), GFP_KERNEL
);
154 snd_device_free(card
, rmidi
);
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
;