https://github.com/torvalds/linux
Tip revision: b9bbe6ed63b2b9f2c9ee5cbd0f2c946a2723f4ce authored by Linus Torvalds on 17 May 2020, 23:48:37 UTC
Linux 5.7-rc6
Linux 5.7-rc6
Tip revision: b9bbe6e
msnd_midi.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
* Copyright (c) 2009 by Krzysztof Helt
* Routines for control of MPU-401 in UART mode
*
* MPU-401 supports UART mode which is not capable generate transmit
* interrupts thus output is done via polling. Also, if irq < 0, then
* input is done also via polling. Do not expect good performance.
*/
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/rawmidi.h>
#include "msnd.h"
#define MSNDMIDI_MODE_BIT_INPUT 0
#define MSNDMIDI_MODE_BIT_OUTPUT 1
#define MSNDMIDI_MODE_BIT_INPUT_TRIGGER 2
#define MSNDMIDI_MODE_BIT_OUTPUT_TRIGGER 3
struct snd_msndmidi {
struct snd_msnd *dev;
unsigned long mode; /* MSNDMIDI_MODE_XXXX */
struct snd_rawmidi_substream *substream_input;
spinlock_t input_lock;
};
/*
* input/output open/close - protected by open_mutex in rawmidi.c
*/
static int snd_msndmidi_input_open(struct snd_rawmidi_substream *substream)
{
struct snd_msndmidi *mpu;
snd_printdd("snd_msndmidi_input_open()\n");
mpu = substream->rmidi->private_data;
mpu->substream_input = substream;
snd_msnd_enable_irq(mpu->dev);
snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_START);
set_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
return 0;
}
static int snd_msndmidi_input_close(struct snd_rawmidi_substream *substream)
{
struct snd_msndmidi *mpu;
mpu = substream->rmidi->private_data;
snd_msnd_send_dsp_cmd(mpu->dev, HDEX_MIDI_IN_STOP);
clear_bit(MSNDMIDI_MODE_BIT_INPUT, &mpu->mode);
mpu->substream_input = NULL;
snd_msnd_disable_irq(mpu->dev);
return 0;
}
static void snd_msndmidi_input_drop(struct snd_msndmidi *mpu)
{
u16 tail;
tail = readw(mpu->dev->MIDQ + JQS_wTail);
writew(tail, mpu->dev->MIDQ + JQS_wHead);
}
/*
* trigger input
*/
static void snd_msndmidi_input_trigger(struct snd_rawmidi_substream *substream,
int up)
{
unsigned long flags;
struct snd_msndmidi *mpu;
snd_printdd("snd_msndmidi_input_trigger(, %i)\n", up);
mpu = substream->rmidi->private_data;
spin_lock_irqsave(&mpu->input_lock, flags);
if (up) {
if (!test_and_set_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER,
&mpu->mode))
snd_msndmidi_input_drop(mpu);
} else {
clear_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
}
spin_unlock_irqrestore(&mpu->input_lock, flags);
if (up)
snd_msndmidi_input_read(mpu);
}
void snd_msndmidi_input_read(void *mpuv)
{
unsigned long flags;
struct snd_msndmidi *mpu = mpuv;
void __iomem *pwMIDQData = mpu->dev->mappedbase + MIDQ_DATA_BUFF;
u16 head, tail, size;
spin_lock_irqsave(&mpu->input_lock, flags);
head = readw(mpu->dev->MIDQ + JQS_wHead);
tail = readw(mpu->dev->MIDQ + JQS_wTail);
size = readw(mpu->dev->MIDQ + JQS_wSize);
if (head > size || tail > size)
goto out;
while (head != tail) {
unsigned char val = readw(pwMIDQData + 2 * head);
if (test_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
snd_rawmidi_receive(mpu->substream_input, &val, 1);
if (++head > size)
head = 0;
writew(head, mpu->dev->MIDQ + JQS_wHead);
}
out:
spin_unlock_irqrestore(&mpu->input_lock, flags);
}
EXPORT_SYMBOL(snd_msndmidi_input_read);
static const struct snd_rawmidi_ops snd_msndmidi_input = {
.open = snd_msndmidi_input_open,
.close = snd_msndmidi_input_close,
.trigger = snd_msndmidi_input_trigger,
};
static void snd_msndmidi_free(struct snd_rawmidi *rmidi)
{
struct snd_msndmidi *mpu = rmidi->private_data;
kfree(mpu);
}
int snd_msndmidi_new(struct snd_card *card, int device)
{
struct snd_msnd *chip = card->private_data;
struct snd_msndmidi *mpu;
struct snd_rawmidi *rmidi;
int err;
err = snd_rawmidi_new(card, "MSND-MIDI", device, 1, 1, &rmidi);
if (err < 0)
return err;
mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
if (mpu == NULL) {
snd_device_free(card, rmidi);
return -ENOMEM;
}
mpu->dev = chip;
chip->msndmidi_mpu = mpu;
rmidi->private_data = mpu;
rmidi->private_free = snd_msndmidi_free;
spin_lock_init(&mpu->input_lock);
strcpy(rmidi->name, "MSND MIDI");
snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
&snd_msndmidi_input);
rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
return 0;
}