linux/sound/drivers/serial-u16550.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

991 lines
30 KiB
C

/*
* serial.c
* Copyright (c) by Jaroslav Kysela <perex@suse.cz>,
* Isaku Yamahata <yamahata@private.email.ne.jp>,
* George Hansper <ghansper@apana.org.au>,
* Hannu Savolainen
*
* This code is based on the code from ALSA 0.5.9, but heavily rewritten.
*
* 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
*
* Sat Mar 31 17:27:57 PST 2001 tim.mann@compaq.com
* Added support for the Midiator MS-124T and for the MS-124W in
* Single Addressed (S/A) or Multiple Burst (M/B) mode, with
* power derived either parasitically from the serial port or
* from a separate power supply.
*
* More documentation can be found in serial-u16550.txt.
*/
#include <sound/driver.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/moduleparam.h>
#include <sound/core.h>
#include <sound/rawmidi.h>
#include <sound/initval.h>
#include <linux/serial_reg.h>
#include <asm/io.h>
MODULE_DESCRIPTION("MIDI serial u16550");
MODULE_LICENSE("GPL");
MODULE_SUPPORTED_DEVICE("{{ALSA, MIDI serial u16550}}");
#define SNDRV_SERIAL_SOUNDCANVAS 0 /* Roland Soundcanvas; F5 NN selects part */
#define SNDRV_SERIAL_MS124T 1 /* Midiator MS-124T */
#define SNDRV_SERIAL_MS124W_SA 2 /* Midiator MS-124W in S/A mode */
#define SNDRV_SERIAL_MS124W_MB 3 /* Midiator MS-124W in M/B mode */
#define SNDRV_SERIAL_GENERIC 4 /* Generic Interface */
#define SNDRV_SERIAL_MAX_ADAPTOR SNDRV_SERIAL_GENERIC
static char *adaptor_names[] = {
"Soundcanvas",
"MS-124T",
"MS-124W S/A",
"MS-124W M/B",
"Generic"
};
#define SNDRV_SERIAL_NORMALBUFF 0 /* Normal blocking buffer operation */
#define SNDRV_SERIAL_DROPBUFF 1 /* Non-blocking discard operation */
static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */
static int enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE; /* Enable this card */
static long port[SNDRV_CARDS] = SNDRV_DEFAULT_PORT; /* 0x3f8,0x2f8,0x3e8,0x2e8 */
static int irq[SNDRV_CARDS] = SNDRV_DEFAULT_IRQ; /* 3,4,5,7,9,10,11,14,15 */
static int speed[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 38400}; /* 9600,19200,38400,57600,115200 */
static int base[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 115200}; /* baud base */
static int outs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1}; /* 1 to 16 */
static int ins[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1}; /* 1 to 16 */
static int adaptor[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = SNDRV_SERIAL_SOUNDCANVAS};
static int droponfull[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS -1)] = SNDRV_SERIAL_NORMALBUFF };
module_param_array(index, int, NULL, 0444);
MODULE_PARM_DESC(index, "Index value for Serial MIDI.");
module_param_array(id, charp, NULL, 0444);
MODULE_PARM_DESC(id, "ID string for Serial MIDI.");
module_param_array(enable, bool, NULL, 0444);
MODULE_PARM_DESC(enable, "Enable UART16550A chip.");
module_param_array(port, long, NULL, 0444);
MODULE_PARM_DESC(port, "Port # for UART16550A chip.");
module_param_array(irq, int, NULL, 0444);
MODULE_PARM_DESC(irq, "IRQ # for UART16550A chip.");
module_param_array(speed, int, NULL, 0444);
MODULE_PARM_DESC(speed, "Speed in bauds.");
module_param_array(base, int, NULL, 0444);
MODULE_PARM_DESC(base, "Base for divisor in bauds.");
module_param_array(outs, int, NULL, 0444);
MODULE_PARM_DESC(outs, "Number of MIDI outputs.");
module_param_array(ins, int, NULL, 0444);
MODULE_PARM_DESC(ins, "Number of MIDI inputs.");
module_param_array(droponfull, bool, NULL, 0444);
MODULE_PARM_DESC(droponfull, "Flag to enable drop-on-full buffer mode");
module_param_array(adaptor, int, NULL, 0444);
MODULE_PARM_DESC(adaptor, "Type of adaptor.");
/*#define SNDRV_SERIAL_MS124W_MB_NOCOMBO 1*/ /* Address outs as 0-3 instead of bitmap */
#define SNDRV_SERIAL_MAX_OUTS 16 /* max 64, min 16 */
#define SNDRV_SERIAL_MAX_INS 16 /* max 64, min 16 */
#define TX_BUFF_SIZE (1<<15) /* Must be 2^n */
#define TX_BUFF_MASK (TX_BUFF_SIZE - 1)
#define SERIAL_MODE_NOT_OPENED (0)
#define SERIAL_MODE_INPUT_OPEN (1 << 0)
#define SERIAL_MODE_OUTPUT_OPEN (1 << 1)
#define SERIAL_MODE_INPUT_TRIGGERED (1 << 2)
#define SERIAL_MODE_OUTPUT_TRIGGERED (1 << 3)
typedef struct _snd_uart16550 {
snd_card_t *card;
snd_rawmidi_t *rmidi;
snd_rawmidi_substream_t *midi_output[SNDRV_SERIAL_MAX_OUTS];
snd_rawmidi_substream_t *midi_input[SNDRV_SERIAL_MAX_INS];
int filemode; //open status of file
spinlock_t open_lock;
int irq;
unsigned long base;
struct resource *res_base;
unsigned int speed;
unsigned int speed_base;
unsigned char divisor;
unsigned char old_divisor_lsb;
unsigned char old_divisor_msb;
unsigned char old_line_ctrl_reg;
// parameter for using of write loop
short int fifo_limit; //used in uart16550
short int fifo_count; //used in uart16550
// type of adaptor
int adaptor;
// inputs
int prev_in;
unsigned char rstatus;
// outputs
int prev_out;
unsigned char prev_status[SNDRV_SERIAL_MAX_OUTS];
// write buffer and its writing/reading position
unsigned char tx_buff[TX_BUFF_SIZE];
int buff_in_count;
int buff_in;
int buff_out;
int drop_on_full;
// wait timer
unsigned int timer_running:1;
struct timer_list buffer_timer;
} snd_uart16550_t;
static snd_card_t *snd_serial_cards[SNDRV_CARDS] = SNDRV_DEFAULT_PTR;
inline static void snd_uart16550_add_timer(snd_uart16550_t *uart)
{
if (! uart->timer_running) {
/* timer 38600bps * 10bit * 16byte */
uart->buffer_timer.expires = jiffies + (HZ+255)/256;
uart->timer_running = 1;
add_timer(&uart->buffer_timer);
}
}
inline static void snd_uart16550_del_timer(snd_uart16550_t *uart)
{
if (uart->timer_running) {
del_timer(&uart->buffer_timer);
uart->timer_running = 0;
}
}
/* This macro is only used in snd_uart16550_io_loop */
inline static void snd_uart16550_buffer_output(snd_uart16550_t *uart)
{
unsigned short buff_out = uart->buff_out;
if( uart->buff_in_count > 0 ) {
outb(uart->tx_buff[buff_out], uart->base + UART_TX);
uart->fifo_count++;
buff_out++;
buff_out &= TX_BUFF_MASK;
uart->buff_out = buff_out;
uart->buff_in_count--;
}
}
/* This loop should be called with interrupts disabled
* We don't want to interrupt this,
* as we're already handling an interrupt
*/
static void snd_uart16550_io_loop(snd_uart16550_t * uart)
{
unsigned char c, status;
int substream;
/* recall previous stream */
substream = uart->prev_in;
/* Read Loop */
while ((status = inb(uart->base + UART_LSR)) & UART_LSR_DR) {
/* while receive data ready */
c = inb(uart->base + UART_RX);
/* keep track of last status byte */
if (c & 0x80) {
uart->rstatus = c;
}
/* handle stream switch */
if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
if (uart->rstatus == 0xf5) {
if (c <= SNDRV_SERIAL_MAX_INS && c > 0)
substream = c - 1;
if (c != 0xf5)
uart->rstatus = 0; /* prevent future bytes from being interpreted as streams */
}
else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN) && (uart->midi_input[substream] != NULL)) {
snd_rawmidi_receive(uart->midi_input[substream], &c, 1);
}
} else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN) && (uart->midi_input[substream] != NULL)) {
snd_rawmidi_receive(uart->midi_input[substream], &c, 1);
}
if (status & UART_LSR_OE)
snd_printk("%s: Overrun on device at 0x%lx\n",
uart->rmidi->name, uart->base);
}
/* remember the last stream */
uart->prev_in = substream;
/* no need of check SERIAL_MODE_OUTPUT_OPEN because if not,
buffer is never filled. */
/* Check write status */
if (status & UART_LSR_THRE) {
uart->fifo_count = 0;
}
if (uart->adaptor == SNDRV_SERIAL_MS124W_SA
|| uart->adaptor == SNDRV_SERIAL_GENERIC) {
/* Can't use FIFO, must send only when CTS is true */
status = inb(uart->base + UART_MSR);
while( (uart->fifo_count == 0) && (status & UART_MSR_CTS) &&
(uart->buff_in_count > 0) ) {
snd_uart16550_buffer_output(uart);
status = inb( uart->base + UART_MSR );
}
} else {
/* Write loop */
while (uart->fifo_count < uart->fifo_limit /* Can we write ? */
&& uart->buff_in_count > 0) /* Do we want to? */
snd_uart16550_buffer_output(uart);
}
if (uart->irq < 0 && uart->buff_in_count > 0)
snd_uart16550_add_timer(uart);
}
/* NOTES ON SERVICING INTERUPTS
* ---------------------------
* After receiving a interrupt, it is important to indicate to the UART that
* this has been done.
* For a Rx interrupt, this is done by reading the received byte.
* For a Tx interrupt this is done by either:
* a) Writing a byte
* b) Reading the IIR
* It is particularly important to read the IIR if a Tx interrupt is received
* when there is no data in tx_buff[], as in this case there no other
* indication that the interrupt has been serviced, and it remains outstanding
* indefinitely. This has the curious side effect that and no further interrupts
* will be generated from this device AT ALL!!.
* It is also desirable to clear outstanding interrupts when the device is
* opened/closed.
*
*
* Note that some devices need OUT2 to be set before they will generate
* interrupts at all. (Possibly tied to an internal pull-up on CTS?)
*/
static irqreturn_t snd_uart16550_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
snd_uart16550_t *uart;
uart = (snd_uart16550_t *) dev_id;
spin_lock(&uart->open_lock);
if (uart->filemode == SERIAL_MODE_NOT_OPENED) {
spin_unlock(&uart->open_lock);
return IRQ_NONE;
}
inb(uart->base + UART_IIR); /* indicate to the UART that the interrupt has been serviced */
snd_uart16550_io_loop(uart);
spin_unlock(&uart->open_lock);
return IRQ_HANDLED;
}
/* When the polling mode, this function calls snd_uart16550_io_loop. */
static void snd_uart16550_buffer_timer(unsigned long data)
{
unsigned long flags;
snd_uart16550_t *uart;
uart = (snd_uart16550_t *)data;
spin_lock_irqsave(&uart->open_lock, flags);
snd_uart16550_del_timer(uart);
snd_uart16550_io_loop(uart);
spin_unlock_irqrestore(&uart->open_lock, flags);
}
/*
* this method probes, if an uart sits on given port
* return 0 if found
* return negative error if not found
*/
static int __init snd_uart16550_detect(snd_uart16550_t *uart)
{
unsigned long io_base = uart->base;
int ok;
unsigned char c;
/* Do some vague tests for the presence of the uart */
if (io_base == 0 || io_base == SNDRV_AUTO_PORT) {
return -ENODEV; /* Not configured */
}
uart->res_base = request_region(io_base, 8, "Serial MIDI");
if (uart->res_base == NULL) {
snd_printk(KERN_ERR "u16550: can't grab port 0x%lx\n", io_base);
return -EBUSY;
}
ok = 1; /* uart detected unless one of the following tests should fail */
/* 8 data-bits, 1 stop-bit, parity off, DLAB = 0 */
outb(UART_LCR_WLEN8, io_base + UART_LCR); /* Line Control Register */
c = inb(io_base + UART_IER);
/* The top four bits of the IER should always == 0 */
if ((c & 0xf0) != 0)
ok = 0; /* failed */
outb(0xaa, io_base + UART_SCR);
/* Write arbitrary data into the scratch reg */
c = inb(io_base + UART_SCR);
/* If it comes back, it's OK */
if (c != 0xaa)
ok = 0; /* failed */
outb(0x55, io_base + UART_SCR);
/* Write arbitrary data into the scratch reg */
c = inb(io_base + UART_SCR);
/* If it comes back, it's OK */
if (c != 0x55)
ok = 0; /* failed */
return ok;
}
static void snd_uart16550_do_open(snd_uart16550_t * uart)
{
char byte;
/* Initialize basic variables */
uart->buff_in_count = 0;
uart->buff_in = 0;
uart->buff_out = 0;
uart->fifo_limit = 1;
uart->fifo_count = 0;
uart->timer_running = 0;
outb(UART_FCR_ENABLE_FIFO /* Enable FIFO's (if available) */
| UART_FCR_CLEAR_RCVR /* Clear receiver FIFO */
| UART_FCR_CLEAR_XMIT /* Clear transmitter FIFO */
| UART_FCR_TRIGGER_4 /* Set FIFO trigger at 4-bytes */
/* NOTE: interrupt generated after T=(time)4-bytes
* if less than UART_FCR_TRIGGER bytes received
*/
,uart->base + UART_FCR); /* FIFO Control Register */
if ((inb(uart->base + UART_IIR) & 0xf0) == 0xc0)
uart->fifo_limit = 16;
if (uart->divisor != 0) {
uart->old_line_ctrl_reg = inb(uart->base + UART_LCR);
outb(UART_LCR_DLAB /* Divisor latch access bit */
,uart->base + UART_LCR); /* Line Control Register */
uart->old_divisor_lsb = inb(uart->base + UART_DLL);
uart->old_divisor_msb = inb(uart->base + UART_DLM);
outb(uart->divisor
,uart->base + UART_DLL); /* Divisor Latch Low */
outb(0
,uart->base + UART_DLM); /* Divisor Latch High */
/* DLAB is reset to 0 in next outb() */
}
/* Set serial parameters (parity off, etc) */
outb(UART_LCR_WLEN8 /* 8 data-bits */
| 0 /* 1 stop-bit */
| 0 /* parity off */
| 0 /* DLAB = 0 */
,uart->base + UART_LCR); /* Line Control Register */
switch (uart->adaptor) {
default:
outb(UART_MCR_RTS /* Set Request-To-Send line active */
| UART_MCR_DTR /* Set Data-Terminal-Ready line active */
| UART_MCR_OUT2 /* Set OUT2 - not always required, but when
* it is, it is ESSENTIAL for enabling interrupts
*/
,uart->base + UART_MCR); /* Modem Control Register */
break;
case SNDRV_SERIAL_MS124W_SA:
case SNDRV_SERIAL_MS124W_MB:
/* MS-124W can draw power from RTS and DTR if they
are in opposite states. */
outb(UART_MCR_RTS | (0&UART_MCR_DTR) | UART_MCR_OUT2,
uart->base + UART_MCR);
break;
case SNDRV_SERIAL_MS124T:
/* MS-124T can draw power from RTS and/or DTR (preferably
both) if they are both asserted. */
outb(UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2,
uart->base + UART_MCR);
break;
}
if (uart->irq < 0) {
byte = (0 & UART_IER_RDI) /* Disable Receiver data interrupt */
|(0 & UART_IER_THRI) /* Disable Transmitter holding register empty interrupt */
;
} else if (uart->adaptor == SNDRV_SERIAL_MS124W_SA) {
byte = UART_IER_RDI /* Enable Receiver data interrupt */
| UART_IER_MSI /* Enable Modem status interrupt */
;
} else if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
byte = UART_IER_RDI /* Enable Receiver data interrupt */
| UART_IER_MSI /* Enable Modem status interrupt */
| UART_IER_THRI /* Enable Transmitter holding register empty interrupt */
;
} else {
byte = UART_IER_RDI /* Enable Receiver data interrupt */
| UART_IER_THRI /* Enable Transmitter holding register empty interrupt */
;
}
outb(byte, uart->base + UART_IER); /* Interupt enable Register */
inb(uart->base + UART_LSR); /* Clear any pre-existing overrun indication */
inb(uart->base + UART_IIR); /* Clear any pre-existing transmit interrupt */
inb(uart->base + UART_RX); /* Clear any pre-existing receive interrupt */
}
static void snd_uart16550_do_close(snd_uart16550_t * uart)
{
if (uart->irq < 0)
snd_uart16550_del_timer(uart);
/* NOTE: may need to disable interrupts before de-registering out handler.
* For now, the consequences are harmless.
*/
outb((0 & UART_IER_RDI) /* Disable Receiver data interrupt */
|(0 & UART_IER_THRI) /* Disable Transmitter holding register empty interrupt */
,uart->base + UART_IER); /* Interupt enable Register */
switch (uart->adaptor) {
default:
outb((0 & UART_MCR_RTS) /* Deactivate Request-To-Send line */
|(0 & UART_MCR_DTR) /* Deactivate Data-Terminal-Ready line */
|(0 & UART_MCR_OUT2) /* Deactivate OUT2 */
,uart->base + UART_MCR); /* Modem Control Register */
break;
case SNDRV_SERIAL_MS124W_SA:
case SNDRV_SERIAL_MS124W_MB:
/* MS-124W can draw power from RTS and DTR if they
are in opposite states; leave it powered. */
outb(UART_MCR_RTS | (0&UART_MCR_DTR) | (0&UART_MCR_OUT2),
uart->base + UART_MCR);
break;
case SNDRV_SERIAL_MS124T:
/* MS-124T can draw power from RTS and/or DTR (preferably
both) if they are both asserted; leave it powered. */
outb(UART_MCR_RTS | UART_MCR_DTR | (0&UART_MCR_OUT2),
uart->base + UART_MCR);
break;
}
inb(uart->base + UART_IIR); /* Clear any outstanding interrupts */
/* Restore old divisor */
if (uart->divisor != 0) {
outb(UART_LCR_DLAB /* Divisor latch access bit */
,uart->base + UART_LCR); /* Line Control Register */
outb(uart->old_divisor_lsb
,uart->base + UART_DLL); /* Divisor Latch Low */
outb(uart->old_divisor_msb
,uart->base + UART_DLM); /* Divisor Latch High */
/* Restore old LCR (data bits, stop bits, parity, DLAB) */
outb(uart->old_line_ctrl_reg
,uart->base + UART_LCR); /* Line Control Register */
}
}
static int snd_uart16550_input_open(snd_rawmidi_substream_t * substream)
{
unsigned long flags;
snd_uart16550_t *uart = substream->rmidi->private_data;
spin_lock_irqsave(&uart->open_lock, flags);
if (uart->filemode == SERIAL_MODE_NOT_OPENED)
snd_uart16550_do_open(uart);
uart->filemode |= SERIAL_MODE_INPUT_OPEN;
uart->midi_input[substream->number] = substream;
spin_unlock_irqrestore(&uart->open_lock, flags);
return 0;
}
static int snd_uart16550_input_close(snd_rawmidi_substream_t * substream)
{
unsigned long flags;
snd_uart16550_t *uart = substream->rmidi->private_data;
spin_lock_irqsave(&uart->open_lock, flags);
uart->filemode &= ~SERIAL_MODE_INPUT_OPEN;
uart->midi_input[substream->number] = NULL;
if (uart->filemode == SERIAL_MODE_NOT_OPENED)
snd_uart16550_do_close(uart);
spin_unlock_irqrestore(&uart->open_lock, flags);
return 0;
}
static void snd_uart16550_input_trigger(snd_rawmidi_substream_t * substream, int up)
{
unsigned long flags;
snd_uart16550_t *uart = substream->rmidi->private_data;
spin_lock_irqsave(&uart->open_lock, flags);
if (up) {
uart->filemode |= SERIAL_MODE_INPUT_TRIGGERED;
} else {
uart->filemode &= ~SERIAL_MODE_INPUT_TRIGGERED;
}
spin_unlock_irqrestore(&uart->open_lock, flags);
}
static int snd_uart16550_output_open(snd_rawmidi_substream_t * substream)
{
unsigned long flags;
snd_uart16550_t *uart = substream->rmidi->private_data;
spin_lock_irqsave(&uart->open_lock, flags);
if (uart->filemode == SERIAL_MODE_NOT_OPENED)
snd_uart16550_do_open(uart);
uart->filemode |= SERIAL_MODE_OUTPUT_OPEN;
uart->midi_output[substream->number] = substream;
spin_unlock_irqrestore(&uart->open_lock, flags);
return 0;
};
static int snd_uart16550_output_close(snd_rawmidi_substream_t * substream)
{
unsigned long flags;
snd_uart16550_t *uart = substream->rmidi->private_data;
spin_lock_irqsave(&uart->open_lock, flags);
uart->filemode &= ~SERIAL_MODE_OUTPUT_OPEN;
uart->midi_output[substream->number] = NULL;
if (uart->filemode == SERIAL_MODE_NOT_OPENED)
snd_uart16550_do_close(uart);
spin_unlock_irqrestore(&uart->open_lock, flags);
return 0;
};
inline static int snd_uart16550_buffer_can_write( snd_uart16550_t *uart, int Num )
{
if( uart->buff_in_count + Num < TX_BUFF_SIZE )
return 1;
else
return 0;
}
inline static int snd_uart16550_write_buffer(snd_uart16550_t *uart, unsigned char byte)
{
unsigned short buff_in = uart->buff_in;
if( uart->buff_in_count < TX_BUFF_SIZE ) {
uart->tx_buff[buff_in] = byte;
buff_in++;
buff_in &= TX_BUFF_MASK;
uart->buff_in = buff_in;
uart->buff_in_count++;
if (uart->irq < 0) /* polling mode */
snd_uart16550_add_timer(uart);
return 1;
} else
return 0;
}
static int snd_uart16550_output_byte(snd_uart16550_t *uart, snd_rawmidi_substream_t * substream, unsigned char midi_byte)
{
if (uart->buff_in_count == 0 /* Buffer empty? */
&& ((uart->adaptor != SNDRV_SERIAL_MS124W_SA &&
uart->adaptor != SNDRV_SERIAL_GENERIC) ||
(uart->fifo_count == 0 /* FIFO empty? */
&& (inb(uart->base + UART_MSR) & UART_MSR_CTS)))) { /* CTS? */
/* Tx Buffer Empty - try to write immediately */
if ((inb(uart->base + UART_LSR) & UART_LSR_THRE) != 0) {
/* Transmitter holding register (and Tx FIFO) empty */
uart->fifo_count = 1;
outb(midi_byte, uart->base + UART_TX);
} else {
if (uart->fifo_count < uart->fifo_limit) {
uart->fifo_count++;
outb(midi_byte, uart->base + UART_TX);
} else {
/* Cannot write (buffer empty) - put char in buffer */
snd_uart16550_write_buffer(uart, midi_byte);
}
}
} else {
if( !snd_uart16550_write_buffer(uart, midi_byte) ) {
snd_printk("%s: Buffer overrun on device at 0x%lx\n",
uart->rmidi->name, uart->base);
return 0;
}
}
return 1;
}
static void snd_uart16550_output_write(snd_rawmidi_substream_t * substream)
{
unsigned long flags;
unsigned char midi_byte, addr_byte;
snd_uart16550_t *uart = substream->rmidi->private_data;
char first;
static unsigned long lasttime=0;
/* Interupts are disabled during the updating of the tx_buff,
* since it is 'bad' to have two processes updating the same
* variables (ie buff_in & buff_out)
*/
spin_lock_irqsave(&uart->open_lock, flags);
if (uart->irq < 0) //polling
snd_uart16550_io_loop(uart);
if (uart->adaptor == SNDRV_SERIAL_MS124W_MB) {
while (1) {
/* buffer full? */
/* in this mode we need two bytes of space */
if (uart->buff_in_count > TX_BUFF_SIZE - 2)
break;
if (snd_rawmidi_transmit(substream, &midi_byte, 1) != 1)
break;
#ifdef SNDRV_SERIAL_MS124W_MB_NOCOMBO
/* select exactly one of the four ports */
addr_byte = (1 << (substream->number + 4)) | 0x08;
#else
/* select any combination of the four ports */
addr_byte = (substream->number << 4) | 0x08;
/* ...except none */
if (addr_byte == 0x08) addr_byte = 0xf8;
#endif
snd_uart16550_output_byte(uart, substream, addr_byte);
/* send midi byte */
snd_uart16550_output_byte(uart, substream, midi_byte);
}
} else {
first = 0;
while( 1 == snd_rawmidi_transmit_peek(substream, &midi_byte, 1) ) {
/* Also send F5 after 3 seconds with no data to handle device disconnect */
if (first == 0 && (uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS ||
uart->adaptor == SNDRV_SERIAL_GENERIC) &&
(uart->prev_out != substream->number || jiffies-lasttime > 3*HZ)) {
if( snd_uart16550_buffer_can_write( uart, 3 ) ) {
/* Roland Soundcanvas part selection */
/* If this substream of the data is different previous
substream in this uart, send the change part event */
uart->prev_out = substream->number;
/* change part */
snd_uart16550_output_byte(uart, substream, 0xf5);
/* data */
snd_uart16550_output_byte(uart, substream, uart->prev_out + 1);
/* If midi_byte is a data byte, send the previous status byte */
if ((midi_byte < 0x80) && (uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS))
snd_uart16550_output_byte(uart, substream, uart->prev_status[uart->prev_out]);
} else if( !uart->drop_on_full )
break;
}
/* send midi byte */
if( !snd_uart16550_output_byte(uart, substream, midi_byte) && !uart->drop_on_full )
break;
if (midi_byte >= 0x80 && midi_byte < 0xf0)
uart->prev_status[uart->prev_out] = midi_byte;
first = 1;
snd_rawmidi_transmit_ack( substream, 1 );
}
lasttime = jiffies;
}
spin_unlock_irqrestore(&uart->open_lock, flags);
}
static void snd_uart16550_output_trigger(snd_rawmidi_substream_t * substream, int up)
{
unsigned long flags;
snd_uart16550_t *uart = substream->rmidi->private_data;
spin_lock_irqsave(&uart->open_lock, flags);
if (up) {
uart->filemode |= SERIAL_MODE_OUTPUT_TRIGGERED;
} else {
uart->filemode &= ~SERIAL_MODE_OUTPUT_TRIGGERED;
}
spin_unlock_irqrestore(&uart->open_lock, flags);
if (up)
snd_uart16550_output_write(substream);
}
static snd_rawmidi_ops_t snd_uart16550_output =
{
.open = snd_uart16550_output_open,
.close = snd_uart16550_output_close,
.trigger = snd_uart16550_output_trigger,
};
static snd_rawmidi_ops_t snd_uart16550_input =
{
.open = snd_uart16550_input_open,
.close = snd_uart16550_input_close,
.trigger = snd_uart16550_input_trigger,
};
static int snd_uart16550_free(snd_uart16550_t *uart)
{
if (uart->irq >= 0)
free_irq(uart->irq, (void *)uart);
if (uart->res_base) {
release_resource(uart->res_base);
kfree_nocheck(uart->res_base);
}
kfree(uart);
return 0;
};
static int snd_uart16550_dev_free(snd_device_t *device)
{
snd_uart16550_t *uart = device->device_data;
return snd_uart16550_free(uart);
}
static int __init snd_uart16550_create(snd_card_t * card,
unsigned long iobase,
int irq,
unsigned int speed,
unsigned int base,
int adaptor,
int droponfull,
snd_uart16550_t **ruart)
{
static snd_device_ops_t ops = {
.dev_free = snd_uart16550_dev_free,
};
snd_uart16550_t *uart;
int err;
if ((uart = kcalloc(1, sizeof(*uart), GFP_KERNEL)) == NULL)
return -ENOMEM;
uart->adaptor = adaptor;
uart->card = card;
spin_lock_init(&uart->open_lock);
uart->irq = -1;
uart->base = iobase;
uart->drop_on_full = droponfull;
if ((err = snd_uart16550_detect(uart)) <= 0) {
printk(KERN_ERR "no UART detected at 0x%lx\n", iobase);
return err;
}
if (irq >= 0 && irq != SNDRV_AUTO_IRQ) {
if (request_irq(irq, snd_uart16550_interrupt,
SA_INTERRUPT, "Serial MIDI", (void *) uart)) {
snd_printk("irq %d busy. Using Polling.\n", irq);
} else {
uart->irq = irq;
}
}
uart->divisor = base / speed;
uart->speed = base / (unsigned int)uart->divisor;
uart->speed_base = base;
uart->prev_out = -1;
uart->prev_in = 0;
uart->rstatus = 0;
memset(uart->prev_status, 0x80, sizeof(unsigned char) * SNDRV_SERIAL_MAX_OUTS);
init_timer(&uart->buffer_timer);
uart->buffer_timer.function = snd_uart16550_buffer_timer;
uart->buffer_timer.data = (unsigned long)uart;
uart->timer_running = 0;
/* Register device */
if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, uart, &ops)) < 0) {
snd_uart16550_free(uart);
return err;
}
switch (uart->adaptor) {
case SNDRV_SERIAL_MS124W_SA:
case SNDRV_SERIAL_MS124W_MB:
/* MS-124W can draw power from RTS and DTR if they
are in opposite states. */
outb(UART_MCR_RTS | (0&UART_MCR_DTR), uart->base + UART_MCR);
break;
case SNDRV_SERIAL_MS124T:
/* MS-124T can draw power from RTS and/or DTR (preferably
both) if they are asserted. */
outb(UART_MCR_RTS | UART_MCR_DTR, uart->base + UART_MCR);
break;
default:
break;
}
if (ruart)
*ruart = uart;
return 0;
}
static void __init snd_uart16550_substreams(snd_rawmidi_str_t *stream)
{
struct list_head *list;
list_for_each(list, &stream->substreams) {
snd_rawmidi_substream_t *substream = list_entry(list, snd_rawmidi_substream_t, list);
sprintf(substream->name, "Serial MIDI %d", substream->number + 1);
}
}
static int __init snd_uart16550_rmidi(snd_uart16550_t *uart, int device, int outs, int ins, snd_rawmidi_t **rmidi)
{
snd_rawmidi_t *rrawmidi;
int err;
if ((err = snd_rawmidi_new(uart->card, "UART Serial MIDI", device, outs, ins, &rrawmidi)) < 0)
return err;
snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_INPUT, &snd_uart16550_input);
snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &snd_uart16550_output);
strcpy(rrawmidi->name, "Serial MIDI");
snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT]);
snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT]);
rrawmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
SNDRV_RAWMIDI_INFO_INPUT |
SNDRV_RAWMIDI_INFO_DUPLEX;
rrawmidi->private_data = uart;
if (rmidi)
*rmidi = rrawmidi;
return 0;
}
static int __init snd_serial_probe(int dev)
{
snd_card_t *card;
snd_uart16550_t *uart;
int err;
if (!enable[dev])
return -ENOENT;
switch (adaptor[dev]) {
case SNDRV_SERIAL_SOUNDCANVAS:
ins[dev] = 1;
break;
case SNDRV_SERIAL_MS124T:
case SNDRV_SERIAL_MS124W_SA:
outs[dev] = 1;
ins[dev] = 1;
break;
case SNDRV_SERIAL_MS124W_MB:
outs[dev] = 16;
ins[dev] = 1;
break;
case SNDRV_SERIAL_GENERIC:
break;
default:
snd_printk("Adaptor type is out of range 0-%d (%d)\n",
SNDRV_SERIAL_MAX_ADAPTOR, adaptor[dev]);
return -ENODEV;
}
if (outs[dev] < 1 || outs[dev] > SNDRV_SERIAL_MAX_OUTS) {
snd_printk("Count of outputs is out of range 1-%d (%d)\n",
SNDRV_SERIAL_MAX_OUTS, outs[dev]);
return -ENODEV;
}
if (ins[dev] < 1 || ins[dev] > SNDRV_SERIAL_MAX_INS) {
snd_printk("Count of inputs is out of range 1-%d (%d)\n",
SNDRV_SERIAL_MAX_INS, ins[dev]);
return -ENODEV;
}
card = snd_card_new(index[dev], id[dev], THIS_MODULE, 0);
if (card == NULL)
return -ENOMEM;
strcpy(card->driver, "Serial");
strcpy(card->shortname, "Serial MIDI (UART16550A)");
if ((err = snd_uart16550_create(card,
port[dev],
irq[dev],
speed[dev],
base[dev],
adaptor[dev],
droponfull[dev],
&uart)) < 0) {
snd_card_free(card);
return err;
}
if ((err = snd_uart16550_rmidi(uart, 0, outs[dev], ins[dev], &uart->rmidi)) < 0) {
snd_card_free(card);
return err;
}
sprintf(card->longname, "%s at 0x%lx, irq %d speed %d div %d outs %d ins %d adaptor %s droponfull %d",
card->shortname,
uart->base,
uart->irq,
uart->speed,
(int)uart->divisor,
outs[dev],
ins[dev],
adaptor_names[uart->adaptor],
uart->drop_on_full);
if ((err = snd_card_register(card)) < 0) {
snd_card_free(card);
return err;
}
snd_serial_cards[dev] = card;
return 0;
}
static int __init alsa_card_serial_init(void)
{
int dev = 0;
int cards = 0;
for (dev = 0; dev < SNDRV_CARDS; dev++) {
if (snd_serial_probe(dev) == 0)
cards++;
}
if (cards == 0) {
#ifdef MODULE
printk(KERN_ERR "serial midi soundcard not found or device busy\n");
#endif
return -ENODEV;
}
return 0;
}
static void __exit alsa_card_serial_exit(void)
{
int dev;
for (dev = 0; dev < SNDRV_CARDS; dev++) {
if (snd_serial_cards[dev] != NULL)
snd_card_free(snd_serial_cards[dev]);
}
}
module_init(alsa_card_serial_init)
module_exit(alsa_card_serial_exit)