Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 257 insertions, 0 deletions

diff --git a/sound/usb/line6/midibuf.c b/sound/usb/line6/midibuf.c
new file mode 100644
index 000000000..e7f830f75
--- /dev/null
+++ b/sound/usb/line6/midibuf.c
@@ -0,0 +1,257 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Line 6 Linux USB driver
+ *
+ * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
+ */
+
+#include <linux/slab.h>
+
+#include "midibuf.h"
+
+
+static int midibuf_message_length(unsigned char code)
+{
+	int message_length;
+
+	if (code < 0x80)
+		message_length = -1;
+	else if (code < 0xf0) {
+		static const int length[] = { 3, 3, 3, 3, 2, 2, 3 };
+
+		message_length = length[(code >> 4) - 8];
+	} else {
+		static const int length[] = { -1, 2, 2, 2, -1, -1, 1, 1, 1, -1,
+			1, 1, 1, -1, 1, 1
+		};
+		message_length = length[code & 0x0f];
+	}
+
+	return message_length;
+}
+
+static int midibuf_is_empty(struct midi_buffer *this)
+{
+	return (this->pos_read == this->pos_write) && !this->full;
+}
+
+static int midibuf_is_full(struct midi_buffer *this)
+{
+	return this->full;
+}
+
+void line6_midibuf_reset(struct midi_buffer *this)
+{
+	this->pos_read = this->pos_write = this->full = 0;
+	this->command_prev = -1;
+}
+
+int line6_midibuf_init(struct midi_buffer *this, int size, int split)
+{
+	this->buf = kmalloc(size, GFP_KERNEL);
+
+	if (this->buf == NULL)
+		return -ENOMEM;
+
+	this->size = size;
+	this->split = split;
+	line6_midibuf_reset(this);
+	return 0;
+}
+
+int line6_midibuf_bytes_free(struct midi_buffer *this)
+{
+	return
+	    midibuf_is_full(this) ?
+	    0 :
+	    (this->pos_read - this->pos_write + this->size - 1) % this->size +
+	    1;
+}
+
+int line6_midibuf_bytes_used(struct midi_buffer *this)
+{
+	return
+	    midibuf_is_empty(this) ?
+	    0 :
+	    (this->pos_write - this->pos_read + this->size - 1) % this->size +
+	    1;
+}
+
+int line6_midibuf_write(struct midi_buffer *this, unsigned char *data,
+			int length)
+{
+	int bytes_free;
+	int length1, length2;
+	int skip_active_sense = 0;
+
+	if (midibuf_is_full(this) || (length <= 0))
+		return 0;
+
+	/* skip trailing active sense */
+	if (data[length - 1] == 0xfe) {
+		--length;
+		skip_active_sense = 1;
+	}
+
+	bytes_free = line6_midibuf_bytes_free(this);
+
+	if (length > bytes_free)
+		length = bytes_free;
+
+	if (length > 0) {
+		length1 = this->size - this->pos_write;
+
+		if (length < length1) {
+			/* no buffer wraparound */
+			memcpy(this->buf + this->pos_write, data, length);
+			this->pos_write += length;
+		} else {
+			/* buffer wraparound */
+			length2 = length - length1;
+			memcpy(this->buf + this->pos_write, data, length1);
+			memcpy(this->buf, data + length1, length2);
+			this->pos_write = length2;
+		}
+
+		if (this->pos_write == this->pos_read)
+			this->full = 1;
+	}
+
+	return length + skip_active_sense;
+}
+
+int line6_midibuf_read(struct midi_buffer *this, unsigned char *data,
+		       int length, int read_type)
+{
+	int bytes_used;
+	int length1, length2;
+	int command;
+	int midi_length;
+	int repeat = 0;
+	int i;
+
+	/* we need to be able to store at least a 3 byte MIDI message */
+	if (length < 3)
+		return -EINVAL;
+
+	if (midibuf_is_empty(this))
+		return 0;
+
+	bytes_used = line6_midibuf_bytes_used(this);
+
+	if (length > bytes_used)
+		length = bytes_used;
+
+	length1 = this->size - this->pos_read;
+
+	command = this->buf[this->pos_read];
+	/*
+	   PODxt always has status byte lower nibble set to 0010,
+	   when it means to send 0000, so we correct if here so
+	   that control/program changes come on channel 1 and
+	   sysex message status byte is correct
+	 */
+	if (read_type == LINE6_MIDIBUF_READ_RX) {
+		if (command == 0xb2 || command == 0xc2 || command == 0xf2) {
+			unsigned char fixed = command & 0xf0;
+			this->buf[this->pos_read] = fixed;
+			command = fixed;
+		}
+	}
+
+	/* check MIDI command length */
+	if (command & 0x80) {
+		midi_length = midibuf_message_length(command);
+		this->command_prev = command;
+	} else {
+		if (this->command_prev > 0) {
+			int midi_length_prev =
+			    midibuf_message_length(this->command_prev);
+
+			if (midi_length_prev > 1) {
+				midi_length = midi_length_prev - 1;
+				repeat = 1;
+			} else
+				midi_length = -1;
+		} else
+			midi_length = -1;
+	}
+
+	if (midi_length < 0) {
+		/* search for end of message */
+		if (length < length1) {
+			/* no buffer wraparound */
+			for (i = 1; i < length; ++i)
+				if (this->buf[this->pos_read + i] & 0x80)
+					break;
+
+			midi_length = i;
+		} else {
+			/* buffer wraparound */
+			length2 = length - length1;
+
+			for (i = 1; i < length1; ++i)
+				if (this->buf[this->pos_read + i] & 0x80)
+					break;
+
+			if (i < length1)
+				midi_length = i;
+			else {
+				for (i = 0; i < length2; ++i)
+					if (this->buf[i] & 0x80)
+						break;
+
+				midi_length = length1 + i;
+			}
+		}
+
+		if (midi_length == length)
+			midi_length = -1;	/* end of message not found */
+	}
+
+	if (midi_length < 0) {
+		if (!this->split)
+			return 0;	/* command is not yet complete */
+	} else {
+		if (length < midi_length)
+			return 0;	/* command is not yet complete */
+
+		length = midi_length;
+	}
+
+	if (length < length1) {
+		/* no buffer wraparound */
+		memcpy(data + repeat, this->buf + this->pos_read, length);
+		this->pos_read += length;
+	} else {
+		/* buffer wraparound */
+		length2 = length - length1;
+		memcpy(data + repeat, this->buf + this->pos_read, length1);
+		memcpy(data + repeat + length1, this->buf, length2);
+		this->pos_read = length2;
+	}
+
+	if (repeat)
+		data[0] = this->command_prev;
+
+	this->full = 0;
+	return length + repeat;
+}
+
+int line6_midibuf_ignore(struct midi_buffer *this, int length)
+{
+	int bytes_used = line6_midibuf_bytes_used(this);
+
+	if (length > bytes_used)
+		length = bytes_used;
+
+	this->pos_read = (this->pos_read + length) % this->size;
+	this->full = 0;
+	return length;
+}
+
+void line6_midibuf_destroy(struct midi_buffer *this)
+{
+	kfree(this->buf);
+	this->buf = NULL;
+}