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linux/sound/drivers/mpu401/mpu401_uart.c
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00

625 lines
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/*
* Copyright (c) by Jaroslav Kysela <perex@suse.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. 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
*
* 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 <sound/driver.h>
#include <asm/io.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <sound/core.h>
#include <sound/mpu401.h>
MODULE_AUTHOR("Jaroslav Kysela <perex@suse.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)) & 0x80))
#define snd_mpu401_output_ready(mpu) (!(mpu->read(mpu, MPU401C(mpu)) & 0x40))
#define MPU401_RESET 0xff
#define MPU401_ENTER_UART 0x3f
#define MPU401_ACK 0xfe
/* 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)
{
if (test_bit(MPU401_MODE_BIT_OUTPUT, &mpu->mode) &&
test_bit(MPU401_MODE_BIT_OUTPUT_TRIGGER, &mpu->mode)) {
spin_lock(&mpu->output_lock);
snd_mpu401_uart_output_write(mpu);
spin_unlock(&mpu->output_lock);
}
}
static void _snd_mpu401_uart_interrupt(struct snd_mpu401 *mpu)
{
if (mpu->info_flags & MPU401_INFO_INPUT) {
spin_lock(&mpu->input_lock);
if (test_bit(MPU401_MODE_BIT_INPUT, &mpu->mode))
snd_mpu401_uart_input_read(mpu);
else
snd_mpu401_uart_clear_rx(mpu);
spin_unlock(&mpu->input_lock);
}
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.
*/
irqreturn_t snd_mpu401_uart_interrupt(int irq, void *dev_id)
{
struct snd_mpu401 *mpu = dev_id;
if (mpu == NULL)
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.
*/
irqreturn_t snd_mpu401_uart_interrupt_tx(int irq, void *dev_id)
{
struct snd_mpu401 *mpu = dev_id;
if (mpu == NULL)
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(unsigned long data)
{
struct snd_mpu401 *mpu = (struct snd_mpu401 *)data;
unsigned long flags;
spin_lock_irqsave(&mpu->timer_lock, flags);
/*mpu->mode |= MPU401_MODE_TIMER;*/
mpu->timer.expires = 1 + jiffies;
add_timer(&mpu->timer);
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) {
init_timer(&mpu->timer);
mpu->timer.data = (unsigned long)mpu;
mpu->timer.function = snd_mpu401_uart_timer;
mpu->timer.expires = 1 + jiffies;
add_timer(&mpu->timer);
}
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) {
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;
}
/*
* 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_uart_cmd(mpu, MPU401_RESET, 1))
goto error_out;
if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1))
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_uart_cmd(mpu, MPU401_RESET, 1))
goto error_out;
if (snd_mpu401_uart_cmd(mpu, MPU401_ENTER_UART, 1))
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->irq < 0)
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->irq < 0)
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, timeout;
do {
if (snd_rawmidi_transmit_peek(mpu->substream_output,
&byte, 1) == 1) {
for (timeout = 100; timeout > 0; timeout--) {
if (snd_mpu401_output_ready(mpu))
break;
}
if (timeout == 0)
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 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 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_flags && 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 irq number, -1 if no interrupt for mpu
* @irq_flags: the irq request flags (SA_XXX), 0 if irq was already reserved.
* @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).
*
* Returns 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, int irq_flags,
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 == NULL) {
snd_printk(KERN_ERR "mpu401_uart: cannot allocate\n");
snd_device_free(card, rmidi);
return -ENOMEM;
}
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;
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 == NULL) {
snd_printk(KERN_ERR "mpu401_uart: "
"unable to grab port 0x%lx size %d\n",
port, res_size);
snd_device_free(card, rmidi);
return -EBUSY;
}
}
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 && irq_flags) {
if (request_irq(irq, snd_mpu401_uart_interrupt, irq_flags,
"MPU401 UART", (void *) mpu)) {
snd_printk(KERN_ERR "mpu401_uart: "
"unable to grab IRQ %d\n", irq);
snd_device_free(card, rmidi);
return -EBUSY;
}
}
mpu->info_flags = info_flags;
mpu->irq = irq;
mpu->irq_flags = irq_flags;
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;
}
EXPORT_SYMBOL(snd_mpu401_uart_new);
/*
* INIT part
*/
static int __init alsa_mpu401_uart_init(void)
{
return 0;
}
static void __exit alsa_mpu401_uart_exit(void)
{
}
module_init(alsa_mpu401_uart_init)
module_exit(alsa_mpu401_uart_exit)
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