Adding upstream version 5.10.209.upstream/5.10.209

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

3 files changed, 889 insertions, 0 deletions

diff --git a/sound/drivers/mpu401/Makefile b/sound/drivers/mpu401/Makefile
new file mode 100644
index 000000000..3dfd5b374
--- /dev/null
+++ b/sound/drivers/mpu401/Makefile
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for ALSA
+# Copyright (c) 2001 by Jaroslav Kysela <perex@perex.cz>
+#
+
+snd-mpu401-objs := mpu401.o
+snd-mpu401-uart-objs := mpu401_uart.o
+
+obj-$(CONFIG_SND_MPU401_UART) += snd-mpu401-uart.o
+
+# Toplevel Module Dependency
+obj-$(CONFIG_SND_MPU401) += snd-mpu401.o
diff --git a/sound/drivers/mpu401/mpu401.c b/sound/drivers/mpu401/mpu401.c
new file mode 100644
index 000000000..8c552e258
--- /dev/null
+++ b/sound/drivers/mpu401/mpu401.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Driver for generic MPU-401 boards (UART mode only)
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ *  Copyright (c) 2004 by Castet Matthieu <castet.matthieu@free.fr>
+ */
+
+#include <linux/init.h>
+#include <linux/pnp.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <sound/core.h>
+#include <sound/mpu401.h>
+#include <sound/initval.h>
+
+MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
+MODULE_DESCRIPTION("MPU-401 UART");
+MODULE_LICENSE("GPL");
+
+static int index[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = -2}; /* exclude the first card */
+static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
+static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE;	/* Enable this card */
+#ifdef CONFIG_PNP
+static bool pnp[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};
+#endif
+static long port[SNDRV_CARDS] = SNDRV_DEFAULT_PORT;	/* MPU-401 port number */
+static int irq[SNDRV_CARDS] = SNDRV_DEFAULT_IRQ;	/* MPU-401 IRQ */
+static bool uart_enter[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};
+
+module_param_array(index, int, NULL, 0444);
+MODULE_PARM_DESC(index, "Index value for MPU-401 device.");
+module_param_array(id, charp, NULL, 0444);
+MODULE_PARM_DESC(id, "ID string for MPU-401 device.");
+module_param_array(enable, bool, NULL, 0444);
+MODULE_PARM_DESC(enable, "Enable MPU-401 device.");
+#ifdef CONFIG_PNP
+module_param_array(pnp, bool, NULL, 0444);
+MODULE_PARM_DESC(pnp, "PnP detection for MPU-401 device.");
+#endif
+module_param_hw_array(port, long, ioport, NULL, 0444);
+MODULE_PARM_DESC(port, "Port # for MPU-401 device.");
+module_param_hw_array(irq, int, irq, NULL, 0444);
+MODULE_PARM_DESC(irq, "IRQ # for MPU-401 device.");
+module_param_array(uart_enter, bool, NULL, 0444);
+MODULE_PARM_DESC(uart_enter, "Issue UART_ENTER command at open.");
+
+static struct platform_device *platform_devices[SNDRV_CARDS];
+static int pnp_registered;
+static unsigned int snd_mpu401_devices;
+
+static int snd_mpu401_create(struct device *devptr, int dev,
+			     struct snd_card **rcard)
+{
+	struct snd_card *card;
+	int err;
+
+	if (!uart_enter[dev])
+		snd_printk(KERN_ERR "the uart_enter option is obsolete; remove it\n");
+
+	*rcard = NULL;
+	err = snd_card_new(devptr, index[dev], id[dev], THIS_MODULE,
+			   0, &card);
+	if (err < 0)
+		return err;
+	strcpy(card->driver, "MPU-401 UART");
+	strcpy(card->shortname, card->driver);
+	sprintf(card->longname, "%s at %#lx, ", card->shortname, port[dev]);
+	if (irq[dev] >= 0) {
+		sprintf(card->longname + strlen(card->longname), "irq %d", irq[dev]);
+	} else {
+		strcat(card->longname, "polled");
+	}
+
+	err = snd_mpu401_uart_new(card, 0, MPU401_HW_MPU401, port[dev], 0,
+				  irq[dev], NULL);
+	if (err < 0) {
+		printk(KERN_ERR "MPU401 not detected at 0x%lx\n", port[dev]);
+		goto _err;
+	}
+
+	*rcard = card;
+	return 0;
+
+ _err:
+	snd_card_free(card);
+	return err;
+}
+
+static int snd_mpu401_probe(struct platform_device *devptr)
+{
+	int dev = devptr->id;
+	int err;
+	struct snd_card *card;
+
+	if (port[dev] == SNDRV_AUTO_PORT) {
+		snd_printk(KERN_ERR "specify port\n");
+		return -EINVAL;
+	}
+	if (irq[dev] == SNDRV_AUTO_IRQ) {
+		snd_printk(KERN_ERR "specify or disable IRQ\n");
+		return -EINVAL;
+	}
+	err = snd_mpu401_create(&devptr->dev, dev, &card);
+	if (err < 0)
+		return err;
+	if ((err = snd_card_register(card)) < 0) {
+		snd_card_free(card);
+		return err;
+	}
+	platform_set_drvdata(devptr, card);
+	return 0;
+}
+
+static int snd_mpu401_remove(struct platform_device *devptr)
+{
+	snd_card_free(platform_get_drvdata(devptr));
+	return 0;
+}
+
+#define SND_MPU401_DRIVER	"snd_mpu401"
+
+static struct platform_driver snd_mpu401_driver = {
+	.probe		= snd_mpu401_probe,
+	.remove		= snd_mpu401_remove,
+	.driver		= {
+		.name	= SND_MPU401_DRIVER,
+	},
+};
+
+
+#ifdef CONFIG_PNP
+
+#define IO_EXTENT 2
+
+static const struct pnp_device_id snd_mpu401_pnpids[] = {
+	{ .id = "PNPb006" },
+	{ .id = "" }
+};
+
+MODULE_DEVICE_TABLE(pnp, snd_mpu401_pnpids);
+
+static int snd_mpu401_pnp(int dev, struct pnp_dev *device,
+			  const struct pnp_device_id *id)
+{
+	if (!pnp_port_valid(device, 0) ||
+	    pnp_port_flags(device, 0) & IORESOURCE_DISABLED) {
+		snd_printk(KERN_ERR "no PnP port\n");
+		return -ENODEV;
+	}
+	if (pnp_port_len(device, 0) < IO_EXTENT) {
+		snd_printk(KERN_ERR "PnP port length is %llu, expected %d\n",
+			   (unsigned long long)pnp_port_len(device, 0),
+			   IO_EXTENT);
+		return -ENODEV;
+	}
+	port[dev] = pnp_port_start(device, 0);
+
+	if (!pnp_irq_valid(device, 0) ||
+	    pnp_irq_flags(device, 0) & IORESOURCE_DISABLED) {
+		snd_printk(KERN_WARNING "no PnP irq, using polling\n");
+		irq[dev] = -1;
+	} else {
+		irq[dev] = pnp_irq(device, 0);
+	}
+	return 0;
+}
+
+static int snd_mpu401_pnp_probe(struct pnp_dev *pnp_dev,
+				const struct pnp_device_id *id)
+{
+	static int dev;
+	struct snd_card *card;
+	int err;
+
+	for ( ; dev < SNDRV_CARDS; ++dev) {
+		if (!enable[dev] || !pnp[dev])
+			continue;
+		err = snd_mpu401_pnp(dev, pnp_dev, id);
+		if (err < 0)
+			return err;
+		err = snd_mpu401_create(&pnp_dev->dev, dev, &card);
+		if (err < 0)
+			return err;
+		if ((err = snd_card_register(card)) < 0) {
+			snd_card_free(card);
+			return err;
+		}
+		pnp_set_drvdata(pnp_dev, card);
+		snd_mpu401_devices++;
+		++dev;
+		return 0;
+	}
+	return -ENODEV;
+}
+
+static void snd_mpu401_pnp_remove(struct pnp_dev *dev)
+{
+	struct snd_card *card = (struct snd_card *) pnp_get_drvdata(dev);
+
+	snd_card_disconnect(card);
+	snd_card_free_when_closed(card);
+}
+
+static struct pnp_driver snd_mpu401_pnp_driver = {
+	.name = "mpu401",
+	.id_table = snd_mpu401_pnpids,
+	.probe = snd_mpu401_pnp_probe,
+	.remove = snd_mpu401_pnp_remove,
+};
+#else
+static struct pnp_driver snd_mpu401_pnp_driver;
+#endif
+
+static void snd_mpu401_unregister_all(void)
+{
+	int i;
+
+	if (pnp_registered)
+		pnp_unregister_driver(&snd_mpu401_pnp_driver);
+	for (i = 0; i < ARRAY_SIZE(platform_devices); ++i)
+		platform_device_unregister(platform_devices[i]);
+	platform_driver_unregister(&snd_mpu401_driver);
+}
+
+static int __init alsa_card_mpu401_init(void)
+{
+	int i, err;
+
+	if ((err = platform_driver_register(&snd_mpu401_driver)) < 0)
+		return err;
+
+	for (i = 0; i < SNDRV_CARDS; i++) {
+		struct platform_device *device;
+		if (! enable[i])
+			continue;
+#ifdef CONFIG_PNP
+		if (pnp[i])
+			continue;
+#endif
+		device = platform_device_register_simple(SND_MPU401_DRIVER,
+							 i, NULL, 0);
+		if (IS_ERR(device))
+			continue;
+		if (!platform_get_drvdata(device)) {
+			platform_device_unregister(device);
+			continue;
+		}
+		platform_devices[i] = device;
+		snd_mpu401_devices++;
+	}
+	err = pnp_register_driver(&snd_mpu401_pnp_driver);
+	if (!err)
+		pnp_registered = 1;
+
+	if (!snd_mpu401_devices) {
+#ifdef MODULE
+		printk(KERN_ERR "MPU-401 device not found or device busy\n");
+#endif
+		snd_mpu401_unregister_all();
+		return -ENODEV;
+	}
+	return 0;
+}
+
+static void __exit alsa_card_mpu401_exit(void)
+{
+	snd_mpu401_unregister_all();
+}
+
+module_init(alsa_card_mpu401_init)
+module_exit(alsa_card_mpu401_exit)
diff --git a/sound/drivers/mpu401/mpu401_uart.c b/sound/drivers/mpu401/mpu401_uart.c
new file mode 100644
index 000000000..65982d6ba
--- /dev/null
+++ b/sound/drivers/mpu401/mpu401_uart.c
@@ -0,0 +1,604 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ *  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. Without interrupt,
+ *  input is done also via polling. Do not expect good performance.
+ *
+ *   13-03-2003:
+ *      Added support for different kind of hardware I/O. Build in choices
+ *      are port and mmio. For other kind of I/O, set mpu->read and
+ *      mpu->write to your own I/O functions.
+ */
+
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <sound/core.h>
+#include <sound/mpu401.h>
+
+MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
+MODULE_DESCRIPTION("Routines for control of MPU-401 in UART mode");
+MODULE_LICENSE("GPL");
+
+static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu);
+static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu);
+
+/*
+
+ */
+
+#define snd_mpu401_input_avail(mpu) \
+	(!(mpu->read(mpu, MPU401C(mpu)) & MPU401_RX_EMPTY))
+#define snd_mpu401_output_ready(mpu) \
+	(!(mpu->read(mpu, MPU401C(mpu)) & MPU401_TX_FULL))
+
+/* Build in lowlevel io */
+static void mpu401_write_port(struct snd_mpu401 *mpu, unsigned char data,
+			      unsigned long addr)
+{
+	outb(data, addr);
+}
+
+static unsigned char mpu401_read_port(struct snd_mpu401 *mpu,
+				      unsigned long addr)
+{
+	return inb(addr);
+}
+
+static void mpu401_write_mmio(struct snd_mpu401 *mpu, unsigned char data,
+			      unsigned long addr)
+{
+	writeb(data, (void __iomem *)addr);
+}
+
+static unsigned char mpu401_read_mmio(struct snd_mpu401 *mpu,
+				      unsigned long addr)
+{
+	return readb((void __iomem *)addr);
+}
+/*  */
+
+static void snd_mpu401_uart_clear_rx(struct snd_mpu401 *mpu)
+{
+	int timeout = 100000;
+	for (; timeout > 0 && snd_mpu401_input_avail(mpu); timeout--)
+		mpu->read(mpu, MPU401D(mpu));
+#ifdef CONFIG_SND_DEBUG
+	if (timeout <= 0)
+		snd_printk(KERN_ERR "cmd: clear rx timeout (status = 0x%x)\n",
+			   mpu->read(mpu, MPU401C(mpu)));
+#endif
+}
+
+static void uart_interrupt_tx(struct snd_mpu401 *mpu)
+{
+	unsigned long flags;
+
+	if (test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode) &&
+	    test_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode)) {
+		spin_lock_irqsave(&mpu->output_lock, flags);
+		snd_mpu401_uart_output_write(mpu);
+		spin_unlock_irqrestore(&mpu->output_lock, flags);
+	}
+}
+
+static void _snd_mpu401_uart_interrupt(struct snd_mpu401 *mpu)
+{
+	unsigned long flags;
+
+	if (mpu->info_flags & MPU401_INFO_INPUT) {
+		spin_lock_irqsave(&mpu->input_lock, flags);
+		if (test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
+			snd_mpu401_uart_input_read(mpu);
+		else
+			snd_mpu401_uart_clear_rx(mpu);
+		spin_unlock_irqrestore(&mpu->input_lock, flags);
+	}
+	if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
+		/* ok. for better Tx performance try do some output
+		   when input is done */
+		uart_interrupt_tx(mpu);
+}
+
+/**
+ * snd_mpu401_uart_interrupt - generic MPU401-UART interrupt handler
+ * @irq: the irq number
+ * @dev_id: mpu401 instance
+ *
+ * Processes the interrupt for MPU401-UART i/o.
+ *
+ * Return: %IRQ_HANDLED if the interrupt was handled. %IRQ_NONE otherwise.
+ */
+irqreturn_t snd_mpu401_uart_interrupt(int irq, void *dev_id)
+{
+	struct snd_mpu401 *mpu = dev_id;
+	
+	if (!mpu)
+		return IRQ_NONE;
+	_snd_mpu401_uart_interrupt(mpu);
+	return IRQ_HANDLED;
+}
+
+EXPORT_SYMBOL(snd_mpu401_uart_interrupt);
+
+/**
+ * snd_mpu401_uart_interrupt_tx - generic MPU401-UART transmit irq handler
+ * @irq: the irq number
+ * @dev_id: mpu401 instance
+ *
+ * Processes the interrupt for MPU401-UART output.
+ *
+ * Return: %IRQ_HANDLED if the interrupt was handled. %IRQ_NONE otherwise.
+ */
+irqreturn_t snd_mpu401_uart_interrupt_tx(int irq, void *dev_id)
+{
+	struct snd_mpu401 *mpu = dev_id;
+	
+	if (!mpu)
+		return IRQ_NONE;
+	uart_interrupt_tx(mpu);
+	return IRQ_HANDLED;
+}
+
+EXPORT_SYMBOL(snd_mpu401_uart_interrupt_tx);
+
+/*
+ * timer callback
+ * reprogram the timer and call the interrupt job
+ */
+static void snd_mpu401_uart_timer(struct timer_list *t)
+{
+	struct snd_mpu401 *mpu = from_timer(mpu, t, timer);
+	unsigned long flags;
+
+	spin_lock_irqsave(&mpu->timer_lock, flags);
+	/*mpu->mode |= MPU401_MODE_TIMER;*/
+	mod_timer(&mpu->timer,  1 + jiffies);
+	spin_unlock_irqrestore(&mpu->timer_lock, flags);
+	if (mpu->rmidi)
+		_snd_mpu401_uart_interrupt(mpu);
+}
+
+/*
+ * initialize the timer callback if not programmed yet
+ */
+static void snd_mpu401_uart_add_timer (struct snd_mpu401 *mpu, int input)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave (&mpu->timer_lock, flags);
+	if (mpu->timer_invoked == 0) {
+		timer_setup(&mpu->timer, snd_mpu401_uart_timer, 0);
+		mod_timer(&mpu->timer, 1 + jiffies);
+	} 
+	mpu->timer_invoked |= input ? MPU401_MODE_INPUT_TIMER :
+		MPU401_MODE_OUTPUT_TIMER;
+	spin_unlock_irqrestore (&mpu->timer_lock, flags);
+}
+
+/*
+ * remove the timer callback if still active
+ */
+static void snd_mpu401_uart_remove_timer (struct snd_mpu401 *mpu, int input)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave (&mpu->timer_lock, flags);
+	if (mpu->timer_invoked) {
+		mpu->timer_invoked &= input ? ~MPU401_MODE_INPUT_TIMER :
+			~MPU401_MODE_OUTPUT_TIMER;
+		if (! mpu->timer_invoked)
+			del_timer(&mpu->timer);
+	}
+	spin_unlock_irqrestore (&mpu->timer_lock, flags);
+}
+
+/*
+ * send a UART command
+ * return zero if successful, non-zero for some errors
+ */
+
+static int snd_mpu401_uart_cmd(struct snd_mpu401 * mpu, unsigned char cmd,
+			       int ack)
+{
+	unsigned long flags;
+	int timeout, ok;
+
+	spin_lock_irqsave(&mpu->input_lock, flags);
+	if (mpu->hardware != MPU401_HW_TRID4DWAVE) {
+		mpu->write(mpu, 0x00, MPU401D(mpu));
+		/*snd_mpu401_uart_clear_rx(mpu);*/
+	}
+	/* ok. standard MPU-401 initialization */
+	if (mpu->hardware != MPU401_HW_SB) {
+		for (timeout = 1000; timeout > 0 &&
+			     !snd_mpu401_output_ready(mpu); timeout--)
+			udelay(10);
+#ifdef CONFIG_SND_DEBUG
+		if (!timeout)
+			snd_printk(KERN_ERR "cmd: tx timeout (status = 0x%x)\n",
+				   mpu->read(mpu, MPU401C(mpu)));
+#endif
+	}
+	mpu->write(mpu, cmd, MPU401C(mpu));
+	if (ack && !(mpu->info_flags & MPU401_INFO_NO_ACK)) {
+		ok = 0;
+		timeout = 10000;
+		while (!ok && timeout-- > 0) {
+			if (snd_mpu401_input_avail(mpu)) {
+				if (mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
+					ok = 1;
+			}
+		}
+		if (!ok && mpu->read(mpu, MPU401D(mpu)) == MPU401_ACK)
+			ok = 1;
+	} else
+		ok = 1;
+	spin_unlock_irqrestore(&mpu->input_lock, flags);
+	if (!ok) {
+		snd_printk(KERN_ERR "cmd: 0x%x failed at 0x%lx "
+			   "(status = 0x%x, data = 0x%x)\n", cmd, mpu->port,
+			   mpu->read(mpu, MPU401C(mpu)),
+			   mpu->read(mpu, MPU401D(mpu)));
+		return 1;
+	}
+	return 0;
+}
+
+static int snd_mpu401_do_reset(struct snd_mpu401 *mpu)
+{
+	if (snd_mpu401_uart_cmd(mpu, MPU401_RESET, 1))
+		return -EIO;
+	if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 0))
+		return -EIO;
+	return 0;
+}
+
+/*
+ * input/output open/close - protected by open_mutex in rawmidi.c
+ */
+static int snd_mpu401_uart_input_open(struct snd_rawmidi_substream *substream)
+{
+	struct snd_mpu401 *mpu;
+	int err;
+
+	mpu = substream->rmidi->private_data;
+	if (mpu->open_input && (err = mpu->open_input(mpu)) < 0)
+		return err;
+	if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode)) {
+		if (snd_mpu401_do_reset(mpu) < 0)
+			goto error_out;
+	}
+	mpu->substream_input = substream;
+	set_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
+	return 0;
+
+error_out:
+	if (mpu->open_input && mpu->close_input)
+		mpu->close_input(mpu);
+	return -EIO;
+}
+
+static int snd_mpu401_uart_output_open(struct snd_rawmidi_substream *substream)
+{
+	struct snd_mpu401 *mpu;
+	int err;
+
+	mpu = substream->rmidi->private_data;
+	if (mpu->open_output && (err = mpu->open_output(mpu)) < 0)
+		return err;
+	if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode)) {
+		if (snd_mpu401_do_reset(mpu) < 0)
+			goto error_out;
+	}
+	mpu->substream_output = substream;
+	set_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
+	return 0;
+
+error_out:
+	if (mpu->open_output && mpu->close_output)
+		mpu->close_output(mpu);
+	return -EIO;
+}
+
+static int snd_mpu401_uart_input_close(struct snd_rawmidi_substream *substream)
+{
+	struct snd_mpu401 *mpu;
+	int err = 0;
+
+	mpu = substream->rmidi->private_data;
+	clear_bit(MPU401_MODE_BIT_INPUT, &mpu->mode);
+	mpu->substream_input = NULL;
+	if (! test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode))
+		err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
+	if (mpu->close_input)
+		mpu->close_input(mpu);
+	if (err)
+		return -EIO;
+	return 0;
+}
+
+static int snd_mpu401_uart_output_close(struct snd_rawmidi_substream *substream)
+{
+	struct snd_mpu401 *mpu;
+	int err = 0;
+
+	mpu = substream->rmidi->private_data;
+	clear_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode);
+	mpu->substream_output = NULL;
+	if (! test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
+		err = snd_mpu401_uart_cmd(mpu, MPU401_RESET, 0);
+	if (mpu->close_output)
+		mpu->close_output(mpu);
+	if (err)
+		return -EIO;
+	return 0;
+}
+
+/*
+ * trigger input callback
+ */
+static void
+snd_mpu401_uart_input_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+	unsigned long flags;
+	struct snd_mpu401 *mpu;
+	int max = 64;
+
+	mpu = substream->rmidi->private_data;
+	if (up) {
+		if (! test_and_set_bit(MPU401_MODE_BIT_INPUT_TRIGGER,
+				       &mpu->mode)) {
+			/* first time - flush FIFO */
+			while (max-- > 0)
+				mpu->read(mpu, MPU401D(mpu));
+			if (mpu->info_flags & MPU401_INFO_USE_TIMER)
+				snd_mpu401_uart_add_timer(mpu, 1);
+		}
+		
+		/* read data in advance */
+		spin_lock_irqsave(&mpu->input_lock, flags);
+		snd_mpu401_uart_input_read(mpu);
+		spin_unlock_irqrestore(&mpu->input_lock, flags);
+	} else {
+		if (mpu->info_flags & MPU401_INFO_USE_TIMER)
+			snd_mpu401_uart_remove_timer(mpu, 1);
+		clear_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode);
+	}
+
+}
+
+/*
+ * transfer input pending data
+ * call with input_lock spinlock held
+ */
+static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu)
+{
+	int max = 128;
+	unsigned char byte;
+
+	while (max-- > 0) {
+		if (! snd_mpu401_input_avail(mpu))
+			break; /* input not available */
+		byte = mpu->read(mpu, MPU401D(mpu));
+		if (test_bit(MPU401_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
+			snd_rawmidi_receive(mpu->substream_input, &byte, 1);
+	}
+}
+
+/*
+ *  Tx FIFO sizes:
+ *    CS4237B			- 16 bytes
+ *    AudioDrive ES1688         - 12 bytes
+ *    S3 SonicVibes             -  8 bytes
+ *    SoundBlaster AWE 64       -  2 bytes (ugly hardware)
+ */
+
+/*
+ * write output pending bytes
+ * call with output_lock spinlock held
+ */
+static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu)
+{
+	unsigned char byte;
+	int max = 256;
+
+	do {
+		if (snd_rawmidi_transmit_peek(mpu->substream_output,
+					      &byte, 1) == 1) {
+			/*
+			 * Try twice because there is hardware that insists on
+			 * setting the output busy bit after each write.
+			 */
+			if (!snd_mpu401_output_ready(mpu) &&
+			    !snd_mpu401_output_ready(mpu))
+				break;	/* Tx FIFO full - try again later */
+			mpu->write(mpu, byte, MPU401D(mpu));
+			snd_rawmidi_transmit_ack(mpu->substream_output, 1);
+		} else {
+			snd_mpu401_uart_remove_timer (mpu, 0);
+			break;	/* no other data - leave the tx loop */
+		}
+	} while (--max > 0);
+}
+
+/*
+ * output trigger callback
+ */
+static void
+snd_mpu401_uart_output_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+	unsigned long flags;
+	struct snd_mpu401 *mpu;
+
+	mpu = substream->rmidi->private_data;
+	if (up) {
+		set_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
+
+		/* try to add the timer at each output trigger,
+		 * since the output timer might have been removed in
+		 * snd_mpu401_uart_output_write().
+		 */
+		if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
+			snd_mpu401_uart_add_timer(mpu, 0);
+
+		/* output pending data */
+		spin_lock_irqsave(&mpu->output_lock, flags);
+		snd_mpu401_uart_output_write(mpu);
+		spin_unlock_irqrestore(&mpu->output_lock, flags);
+	} else {
+		if (! (mpu->info_flags & MPU401_INFO_TX_IRQ))
+			snd_mpu401_uart_remove_timer(mpu, 0);
+		clear_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode);
+	}
+}
+
+/*
+
+ */
+
+static const struct snd_rawmidi_ops snd_mpu401_uart_output =
+{
+	.open =		snd_mpu401_uart_output_open,
+	.close =	snd_mpu401_uart_output_close,
+	.trigger =	snd_mpu401_uart_output_trigger,
+};
+
+static const struct snd_rawmidi_ops snd_mpu401_uart_input =
+{
+	.open =		snd_mpu401_uart_input_open,
+	.close =	snd_mpu401_uart_input_close,
+	.trigger =	snd_mpu401_uart_input_trigger,
+};
+
+static void snd_mpu401_uart_free(struct snd_rawmidi *rmidi)
+{
+	struct snd_mpu401 *mpu = rmidi->private_data;
+	if (mpu->irq >= 0)
+		free_irq(mpu->irq, (void *) mpu);
+	release_and_free_resource(mpu->res);
+	kfree(mpu);
+}
+
+/**
+ * snd_mpu401_uart_new - create an MPU401-UART instance
+ * @card: the card instance
+ * @device: the device index, zero-based
+ * @hardware: the hardware type, MPU401_HW_XXXX
+ * @port: the base address of MPU401 port
+ * @info_flags: bitflags MPU401_INFO_XXX
+ * @irq: the ISA irq number, -1 if not to be allocated
+ * @rrawmidi: the pointer to store the new rawmidi instance
+ *
+ * Creates a new MPU-401 instance.
+ *
+ * Note that the rawmidi instance is returned on the rrawmidi argument,
+ * not the mpu401 instance itself.  To access to the mpu401 instance,
+ * cast from rawmidi->private_data (with struct snd_mpu401 magic-cast).
+ *
+ * Return: Zero if successful, or a negative error code.
+ */
+int snd_mpu401_uart_new(struct snd_card *card, int device,
+			unsigned short hardware,
+			unsigned long port,
+			unsigned int info_flags,
+			int irq,
+			struct snd_rawmidi ** rrawmidi)
+{
+	struct snd_mpu401 *mpu;
+	struct snd_rawmidi *rmidi;
+	int in_enable, out_enable;
+	int err;
+
+	if (rrawmidi)
+		*rrawmidi = NULL;
+	if (! (info_flags & (MPU401_INFO_INPUT | MPU401_INFO_OUTPUT)))
+		info_flags |= MPU401_INFO_INPUT | MPU401_INFO_OUTPUT;
+	in_enable = (info_flags & MPU401_INFO_INPUT) ? 1 : 0;
+	out_enable = (info_flags & MPU401_INFO_OUTPUT) ? 1 : 0;
+	if ((err = snd_rawmidi_new(card, "MPU-401U", device,
+				   out_enable, in_enable, &rmidi)) < 0)
+		return err;
+	mpu = kzalloc(sizeof(*mpu), GFP_KERNEL);
+	if (!mpu) {
+		err = -ENOMEM;
+		goto free_device;
+	}
+	rmidi->private_data = mpu;
+	rmidi->private_free = snd_mpu401_uart_free;
+	spin_lock_init(&mpu->input_lock);
+	spin_lock_init(&mpu->output_lock);
+	spin_lock_init(&mpu->timer_lock);
+	mpu->hardware = hardware;
+	mpu->irq = -1;
+	if (! (info_flags & MPU401_INFO_INTEGRATED)) {
+		int res_size = hardware == MPU401_HW_PC98II ? 4 : 2;
+		mpu->res = request_region(port, res_size, "MPU401 UART");
+		if (!mpu->res) {
+			snd_printk(KERN_ERR "mpu401_uart: "
+				   "unable to grab port 0x%lx size %d\n",
+				   port, res_size);
+			err = -EBUSY;
+			goto free_device;
+		}
+	}
+	if (info_flags & MPU401_INFO_MMIO) {
+		mpu->write = mpu401_write_mmio;
+		mpu->read = mpu401_read_mmio;
+	} else {
+		mpu->write = mpu401_write_port;
+		mpu->read = mpu401_read_port;
+	}
+	mpu->port = port;
+	if (hardware == MPU401_HW_PC98II)
+		mpu->cport = port + 2;
+	else
+		mpu->cport = port + 1;
+	if (irq >= 0) {
+		if (request_irq(irq, snd_mpu401_uart_interrupt, 0,
+				"MPU401 UART", (void *) mpu)) {
+			snd_printk(KERN_ERR "mpu401_uart: "
+				   "unable to grab IRQ %d\n", irq);
+			err = -EBUSY;
+			goto free_device;
+		}
+	}
+	if (irq < 0 && !(info_flags & MPU401_INFO_IRQ_HOOK))
+		info_flags |= MPU401_INFO_USE_TIMER;
+	mpu->info_flags = info_flags;
+	mpu->irq = irq;
+	if (card->shortname[0])
+		snprintf(rmidi->name, sizeof(rmidi->name), "%s MIDI",
+			 card->shortname);
+	else
+		sprintf(rmidi->name, "MPU-401 MIDI %d-%d",card->number, device);
+	if (out_enable) {
+		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
+				    &snd_mpu401_uart_output);
+		rmidi->info_flags |= SNDRV_RAWMIDI_INFO_OUTPUT;
+	}
+	if (in_enable) {
+		snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT,
+				    &snd_mpu401_uart_input);
+		rmidi->info_flags |= SNDRV_RAWMIDI_INFO_INPUT;
+		if (out_enable)
+			rmidi->info_flags |= SNDRV_RAWMIDI_INFO_DUPLEX;
+	}
+	mpu->rmidi = rmidi;
+	if (rrawmidi)
+		*rrawmidi = rmidi;
+	return 0;
+free_device:
+	snd_device_free(card, rmidi);
+	return err;
+}
+
+EXPORT_SYMBOL(snd_mpu401_uart_new);