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linux/sound/drivers/serial-u16550.c
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* serial.c
* Copyright (c) by Jaroslav Kysela <perex@perex.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.
*
* 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 <linux/init.h>
#include <linux/interrupt.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/io.h>
#include <sound/core.h>
#include <sound/rawmidi.h>
#include <sound/initval.h>
#include <linux/serial_reg.h>
#include <linux/jiffies.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 bool 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 bool 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_hw_array(port, long, ioport, NULL, 0444);
MODULE_PARM_DESC(port, "Port # for UART16550A chip.");
module_param_hw_array(irq, int, irq, 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)
struct snd_uart16550 {
struct snd_card *card;
struct snd_rawmidi *rmidi;
struct snd_rawmidi_substream *midi_output[SNDRV_SERIAL_MAX_OUTS];
struct snd_rawmidi_substream *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;
};
static struct platform_device *devices[SNDRV_CARDS];
static inline void snd_uart16550_add_timer(struct snd_uart16550 *uart)
{
if (!uart->timer_running) {
/* timer 38600bps * 10bit * 16byte */
mod_timer(&uart->buffer_timer, jiffies + (HZ + 255) / 256);
uart->timer_running = 1;
}
}
static inline void snd_uart16550_del_timer(struct snd_uart16550 *uart)
{
if (uart->timer_running) {
del_timer(&uart->buffer_timer);
uart->timer_running = 0;
}
}
/* This macro is only used in snd_uart16550_io_loop */
static inline void snd_uart16550_buffer_output(struct snd_uart16550 *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(struct snd_uart16550 * 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)
/* prevent future bytes from being
interpreted as streams */
uart->rstatus = 0;
} else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN)
&& uart->midi_input[substream])
snd_rawmidi_receive(uart->midi_input[substream],
&c, 1);
} else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN) &&
uart->midi_input[substream])
snd_rawmidi_receive(uart->midi_input[substream], &c, 1);
if (status & UART_LSR_OE)
snd_printk(KERN_WARNING
"%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 snd_uart16550 *uart;
uart = dev_id;
spin_lock(&uart->open_lock);
if (uart->filemode == SERIAL_MODE_NOT_OPENED) {
spin_unlock(&uart->open_lock);
return IRQ_NONE;
}
/* indicate to the UART that the interrupt has been serviced */
inb(uart->base + UART_IIR);
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(struct timer_list *t)
{
unsigned long flags;
struct snd_uart16550 *uart;
uart = from_timer(uart, t, buffer_timer);
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 snd_uart16550_detect(struct snd_uart16550 *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;
}
/* uart detected unless one of the following tests should fail */
ok = 1;
/* 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(struct snd_uart16550 * 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); /* Interrupt 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(struct snd_uart16550 * 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); /* Interrupt 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(struct snd_rawmidi_substream *substream)
{
unsigned long flags;
struct snd_uart16550 *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(struct snd_rawmidi_substream *substream)
{
unsigned long flags;
struct snd_uart16550 *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(struct snd_rawmidi_substream *substream,
int up)
{
unsigned long flags;
struct snd_uart16550 *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(struct snd_rawmidi_substream *substream)
{
unsigned long flags;
struct snd_uart16550 *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(struct snd_rawmidi_substream *substream)
{
unsigned long flags;
struct snd_uart16550 *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;
};
static inline int snd_uart16550_buffer_can_write(struct snd_uart16550 *uart,
int Num)
{
if (uart->buff_in_count + Num < TX_BUFF_SIZE)
return 1;
else
return 0;
}
static inline int snd_uart16550_write_buffer(struct snd_uart16550 *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(struct snd_uart16550 *uart,
struct snd_rawmidi_substream *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(KERN_WARNING
"%s: Buffer overrun on device at 0x%lx\n",
uart->rmidi->name, uart->base);
return 0;
}
}
return 1;
}
static void snd_uart16550_output_write(struct snd_rawmidi_substream *substream)
{
unsigned long flags;
unsigned char midi_byte, addr_byte;
struct snd_uart16550 *uart = substream->rmidi->private_data;
char first;
static unsigned long lasttime = 0;
/* Interrupts 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 (snd_rawmidi_transmit_peek(substream, &midi_byte, 1) == 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 ||
time_after(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(struct snd_rawmidi_substream *substream,
int up)
{
unsigned long flags;
struct snd_uart16550 *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 const struct snd_rawmidi_ops snd_uart16550_output =
{
.open = snd_uart16550_output_open,
.close = snd_uart16550_output_close,
.trigger = snd_uart16550_output_trigger,
};
static const struct snd_rawmidi_ops snd_uart16550_input =
{
.open = snd_uart16550_input_open,
.close = snd_uart16550_input_close,
.trigger = snd_uart16550_input_trigger,
};
static int snd_uart16550_free(struct snd_uart16550 *uart)
{
if (uart->irq >= 0)
free_irq(uart->irq, uart);
release_and_free_resource(uart->res_base);
kfree(uart);
return 0;
};
static int snd_uart16550_dev_free(struct snd_device *device)
{
struct snd_uart16550 *uart = device->device_data;
return snd_uart16550_free(uart);
}
static int snd_uart16550_create(struct snd_card *card,
unsigned long iobase,
int irq,
unsigned int speed,
unsigned int base,
int adaptor,
int droponfull,
struct snd_uart16550 **ruart)
{
static struct snd_device_ops ops = {
.dev_free = snd_uart16550_dev_free,
};
struct snd_uart16550 *uart;
int err;
if ((uart = kzalloc(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);
snd_uart16550_free(uart);
return -ENODEV;
}
if (irq >= 0 && irq != SNDRV_AUTO_IRQ) {
if (request_irq(irq, snd_uart16550_interrupt,
0, "Serial MIDI", uart)) {
snd_printk(KERN_WARNING
"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);
timer_setup(&uart->buffer_timer, snd_uart16550_buffer_timer, 0);
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 snd_uart16550_substreams(struct snd_rawmidi_str *stream)
{
struct snd_rawmidi_substream *substream;
list_for_each_entry(substream, &stream->substreams, list) {
sprintf(substream->name, "Serial MIDI %d", substream->number + 1);
}
}
static int snd_uart16550_rmidi(struct snd_uart16550 *uart, int device,
int outs, int ins,
struct snd_rawmidi **rmidi)
{
struct snd_rawmidi *rrawmidi;
int err;
err = snd_rawmidi_new(uart->card, "UART Serial MIDI", device,
outs, ins, &rrawmidi);
if (err < 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 snd_serial_probe(struct platform_device *devptr)
{
struct snd_card *card;
struct snd_uart16550 *uart;
int err;
int dev = devptr->id;
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(KERN_ERR
"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(KERN_ERR
"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(KERN_ERR
"Count of inputs is out of range 1-%d (%d)\n",
SNDRV_SERIAL_MAX_INS, ins[dev]);
return -ENODEV;
}
err = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
0, &card);
if (err < 0)
return err;
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)
goto _err;
err = snd_uart16550_rmidi(uart, 0, outs[dev], ins[dev], &uart->rmidi);
if (err < 0)
goto _err;
sprintf(card->longname, "%s [%s] at %#lx, irq %d",
card->shortname,
adaptor_names[uart->adaptor],
uart->base,
uart->irq);
if ((err = snd_card_register(card)) < 0)
goto _err;
platform_set_drvdata(devptr, card);
return 0;
_err:
snd_card_free(card);
return err;
}
static int snd_serial_remove(struct platform_device *devptr)
{
snd_card_free(platform_get_drvdata(devptr));
return 0;
}
#define SND_SERIAL_DRIVER "snd_serial_u16550"
static struct platform_driver snd_serial_driver = {
.probe = snd_serial_probe,
.remove = snd_serial_remove,
.driver = {
.name = SND_SERIAL_DRIVER,
},
};
static void snd_serial_unregister_all(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(devices); ++i)
platform_device_unregister(devices[i]);
platform_driver_unregister(&snd_serial_driver);
}
static int __init alsa_card_serial_init(void)
{
int i, cards, err;
if ((err = platform_driver_register(&snd_serial_driver)) < 0)
return err;
cards = 0;
for (i = 0; i < SNDRV_CARDS; i++) {
struct platform_device *device;
if (! enable[i])
continue;
device = platform_device_register_simple(SND_SERIAL_DRIVER,
i, NULL, 0);
if (IS_ERR(device))
continue;
if (!platform_get_drvdata(device)) {
platform_device_unregister(device);
continue;
}
devices[i] = device;
cards++;
}
if (! cards) {
#ifdef MODULE
printk(KERN_ERR "serial midi soundcard not found or device busy\n");
#endif
snd_serial_unregister_all();
return -ENODEV;
}
return 0;
}
static void __exit alsa_card_serial_exit(void)
{
snd_serial_unregister_all();
}
module_init(alsa_card_serial_init)
module_exit(alsa_card_serial_exit)
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