mpu401_uart.c
/*
* 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.
*
*
* 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
*
* 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);
