v4.19.13 snapshot.
diff --git a/sound/isa/msnd/msnd_midi.c b/sound/isa/msnd/msnd_midi.c
new file mode 100644
index 0000000..42876b0
--- /dev/null
+++ b/sound/isa/msnd/msnd_midi.c
@@ -0,0 +1,182 @@
+/*
+ * 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.
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#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;
+}