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v5.14.15
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *   serial.c
   4 *   Copyright (c) by Jaroslav Kysela <perex@perex.cz>,
   5 *                    Isaku Yamahata <yamahata@private.email.ne.jp>,
   6 *		      George Hansper <ghansper@apana.org.au>,
   7 *		      Hannu Savolainen
   8 *
   9 *   This code is based on the code from ALSA 0.5.9, but heavily rewritten.
  10 *
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  11 * Sat Mar 31 17:27:57 PST 2001 tim.mann@compaq.com 
  12 *      Added support for the Midiator MS-124T and for the MS-124W in
  13 *      Single Addressed (S/A) or Multiple Burst (M/B) mode, with
  14 *      power derived either parasitically from the serial port or
  15 *      from a separate power supply.
  16 *
  17 *      More documentation can be found in serial-u16550.txt.
  18 */
  19
  20#include <linux/init.h>
  21#include <linux/interrupt.h>
  22#include <linux/err.h>
  23#include <linux/platform_device.h>
  24#include <linux/slab.h>
  25#include <linux/ioport.h>
  26#include <linux/module.h>
  27#include <linux/io.h>
  28#include <sound/core.h>
  29#include <sound/rawmidi.h>
  30#include <sound/initval.h>
  31
  32#include <linux/serial_reg.h>
  33#include <linux/jiffies.h>
  34
  35MODULE_DESCRIPTION("MIDI serial u16550");
  36MODULE_LICENSE("GPL");
 
  37
  38#define SNDRV_SERIAL_SOUNDCANVAS 0 /* Roland Soundcanvas; F5 NN selects part */
  39#define SNDRV_SERIAL_MS124T 1      /* Midiator MS-124T */
  40#define SNDRV_SERIAL_MS124W_SA 2   /* Midiator MS-124W in S/A mode */
  41#define SNDRV_SERIAL_MS124W_MB 3   /* Midiator MS-124W in M/B mode */
  42#define SNDRV_SERIAL_GENERIC 4     /* Generic Interface */
  43#define SNDRV_SERIAL_MAX_ADAPTOR SNDRV_SERIAL_GENERIC
  44static const char * const adaptor_names[] = {
  45	"Soundcanvas",
  46        "MS-124T",
  47	"MS-124W S/A",
  48	"MS-124W M/B",
  49	"Generic"
  50};
  51
  52#define SNDRV_SERIAL_NORMALBUFF 0 /* Normal blocking buffer operation */
  53#define SNDRV_SERIAL_DROPBUFF   1 /* Non-blocking discard operation */
  54
  55static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
  56static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
  57static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE; /* Enable this card */
  58static long port[SNDRV_CARDS] = SNDRV_DEFAULT_PORT; /* 0x3f8,0x2f8,0x3e8,0x2e8 */
  59static int irq[SNDRV_CARDS] = SNDRV_DEFAULT_IRQ; 	/* 3,4,5,7,9,10,11,14,15 */
  60static int speed[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 38400}; /* 9600,19200,38400,57600,115200 */
  61static int base[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 115200}; /* baud base */
  62static int outs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};	 /* 1 to 16 */
  63static int ins[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};	/* 1 to 16 */
  64static int adaptor[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = SNDRV_SERIAL_SOUNDCANVAS};
  65static bool droponfull[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS -1)] = SNDRV_SERIAL_NORMALBUFF };
  66
  67module_param_array(index, int, NULL, 0444);
  68MODULE_PARM_DESC(index, "Index value for Serial MIDI.");
  69module_param_array(id, charp, NULL, 0444);
  70MODULE_PARM_DESC(id, "ID string for Serial MIDI.");
  71module_param_array(enable, bool, NULL, 0444);
  72MODULE_PARM_DESC(enable, "Enable UART16550A chip.");
  73module_param_hw_array(port, long, ioport, NULL, 0444);
  74MODULE_PARM_DESC(port, "Port # for UART16550A chip.");
  75module_param_hw_array(irq, int, irq, NULL, 0444);
  76MODULE_PARM_DESC(irq, "IRQ # for UART16550A chip.");
  77module_param_array(speed, int, NULL, 0444);
  78MODULE_PARM_DESC(speed, "Speed in bauds.");
  79module_param_array(base, int, NULL, 0444);
  80MODULE_PARM_DESC(base, "Base for divisor in bauds.");
  81module_param_array(outs, int, NULL, 0444);
  82MODULE_PARM_DESC(outs, "Number of MIDI outputs.");
  83module_param_array(ins, int, NULL, 0444);
  84MODULE_PARM_DESC(ins, "Number of MIDI inputs.");
  85module_param_array(droponfull, bool, NULL, 0444);
  86MODULE_PARM_DESC(droponfull, "Flag to enable drop-on-full buffer mode");
  87
  88module_param_array(adaptor, int, NULL, 0444);
  89MODULE_PARM_DESC(adaptor, "Type of adaptor.");
  90
  91/*#define SNDRV_SERIAL_MS124W_MB_NOCOMBO 1*/  /* Address outs as 0-3 instead of bitmap */
  92
  93#define SNDRV_SERIAL_MAX_OUTS	16		/* max 64, min 16 */
  94#define SNDRV_SERIAL_MAX_INS	16		/* max 64, min 16 */
  95
  96#define TX_BUFF_SIZE		(1<<15)		/* Must be 2^n */
  97#define TX_BUFF_MASK		(TX_BUFF_SIZE - 1)
  98
  99#define SERIAL_MODE_NOT_OPENED 		(0)
 100#define SERIAL_MODE_INPUT_OPEN		(1 << 0)
 101#define SERIAL_MODE_OUTPUT_OPEN		(1 << 1)
 102#define SERIAL_MODE_INPUT_TRIGGERED	(1 << 2)
 103#define SERIAL_MODE_OUTPUT_TRIGGERED	(1 << 3)
 104
 105struct snd_uart16550 {
 106	struct snd_card *card;
 107	struct snd_rawmidi *rmidi;
 108	struct snd_rawmidi_substream *midi_output[SNDRV_SERIAL_MAX_OUTS];
 109	struct snd_rawmidi_substream *midi_input[SNDRV_SERIAL_MAX_INS];
 110
 111	int filemode;		/* open status of file */
 112
 113	spinlock_t open_lock;
 114
 115	int irq;
 116
 117	unsigned long base;
 118	struct resource *res_base;
 119
 120	unsigned int speed;
 121	unsigned int speed_base;
 122	unsigned char divisor;
 123
 124	unsigned char old_divisor_lsb;
 125	unsigned char old_divisor_msb;
 126	unsigned char old_line_ctrl_reg;
 127
 128	/* parameter for using of write loop */
 129	short int fifo_limit;	/* used in uart16550 */
 130        short int fifo_count;	/* used in uart16550 */
 131
 132	/* type of adaptor */
 133	int adaptor;
 134
 135	/* inputs */
 136	int prev_in;
 137	unsigned char rstatus;
 138
 139	/* outputs */
 140	int prev_out;
 141	unsigned char prev_status[SNDRV_SERIAL_MAX_OUTS];
 142
 143	/* write buffer and its writing/reading position */
 144	unsigned char tx_buff[TX_BUFF_SIZE];
 145	int buff_in_count;
 146        int buff_in;
 147        int buff_out;
 148        int drop_on_full;
 149
 150	/* wait timer */
 151	unsigned int timer_running:1;
 152	struct timer_list buffer_timer;
 153
 154};
 155
 156static struct platform_device *devices[SNDRV_CARDS];
 157
 158static inline void snd_uart16550_add_timer(struct snd_uart16550 *uart)
 159{
 160	if (!uart->timer_running) {
 161		/* timer 38600bps * 10bit * 16byte */
 162		mod_timer(&uart->buffer_timer, jiffies + (HZ + 255) / 256);
 163		uart->timer_running = 1;
 164	}
 165}
 166
 167static inline void snd_uart16550_del_timer(struct snd_uart16550 *uart)
 168{
 169	if (uart->timer_running) {
 170		del_timer(&uart->buffer_timer);
 171		uart->timer_running = 0;
 172	}
 173}
 174
 175/* This macro is only used in snd_uart16550_io_loop */
 176static inline void snd_uart16550_buffer_output(struct snd_uart16550 *uart)
 177{
 178	unsigned short buff_out = uart->buff_out;
 179	if (uart->buff_in_count > 0) {
 180		outb(uart->tx_buff[buff_out], uart->base + UART_TX);
 181		uart->fifo_count++;
 182		buff_out++;
 183		buff_out &= TX_BUFF_MASK;
 184		uart->buff_out = buff_out;
 185		uart->buff_in_count--;
 186	}
 187}
 188
 189/* This loop should be called with interrupts disabled
 190 * We don't want to interrupt this, 
 191 * as we're already handling an interrupt 
 192 */
 193static void snd_uart16550_io_loop(struct snd_uart16550 * uart)
 194{
 195	unsigned char c, status;
 196	int substream;
 197
 198	/* recall previous stream */
 199	substream = uart->prev_in;
 200
 201	/* Read Loop */
 202	while ((status = inb(uart->base + UART_LSR)) & UART_LSR_DR) {
 203		/* while receive data ready */
 204		c = inb(uart->base + UART_RX);
 205
 206		/* keep track of last status byte */
 207		if (c & 0x80)
 208			uart->rstatus = c;
 209
 210		/* handle stream switch */
 211		if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
 212			if (uart->rstatus == 0xf5) {
 213				if (c <= SNDRV_SERIAL_MAX_INS && c > 0)
 214					substream = c - 1;
 215				if (c != 0xf5)
 216					/* prevent future bytes from being
 217					   interpreted as streams */
 218					uart->rstatus = 0;
 219			} else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN)
 220				   && uart->midi_input[substream])
 221				snd_rawmidi_receive(uart->midi_input[substream],
 222						    &c, 1);
 223		} else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN) &&
 224			   uart->midi_input[substream])
 225			snd_rawmidi_receive(uart->midi_input[substream], &c, 1);
 226
 227		if (status & UART_LSR_OE)
 228			snd_printk(KERN_WARNING
 229				   "%s: Overrun on device at 0x%lx\n",
 230			       uart->rmidi->name, uart->base);
 231	}
 232
 233	/* remember the last stream */
 234	uart->prev_in = substream;
 235
 236	/* no need of check SERIAL_MODE_OUTPUT_OPEN because if not,
 237	   buffer is never filled. */
 238	/* Check write status */
 239	if (status & UART_LSR_THRE)
 240		uart->fifo_count = 0;
 241	if (uart->adaptor == SNDRV_SERIAL_MS124W_SA
 242	   || uart->adaptor == SNDRV_SERIAL_GENERIC) {
 243		/* Can't use FIFO, must send only when CTS is true */
 244		status = inb(uart->base + UART_MSR);
 245		while (uart->fifo_count == 0 && (status & UART_MSR_CTS) &&
 246		       uart->buff_in_count > 0) {
 247		       snd_uart16550_buffer_output(uart);
 248		       status = inb(uart->base + UART_MSR);
 249		}
 250	} else {
 251		/* Write loop */
 252		while (uart->fifo_count < uart->fifo_limit /* Can we write ? */
 253		       && uart->buff_in_count > 0)	/* Do we want to? */
 254			snd_uart16550_buffer_output(uart);
 255	}
 256	if (uart->irq < 0 && uart->buff_in_count > 0)
 257		snd_uart16550_add_timer(uart);
 258}
 259
 260/* NOTES ON SERVICING INTERUPTS
 261 * ---------------------------
 262 * After receiving a interrupt, it is important to indicate to the UART that
 263 * this has been done. 
 264 * For a Rx interrupt, this is done by reading the received byte.
 265 * For a Tx interrupt this is done by either:
 266 * a) Writing a byte
 267 * b) Reading the IIR
 268 * It is particularly important to read the IIR if a Tx interrupt is received
 269 * when there is no data in tx_buff[], as in this case there no other
 270 * indication that the interrupt has been serviced, and it remains outstanding
 271 * indefinitely. This has the curious side effect that and no further interrupts
 272 * will be generated from this device AT ALL!!.
 273 * It is also desirable to clear outstanding interrupts when the device is
 274 * opened/closed.
 275 *
 276 *
 277 * Note that some devices need OUT2 to be set before they will generate
 278 * interrupts at all. (Possibly tied to an internal pull-up on CTS?)
 279 */
 280static irqreturn_t snd_uart16550_interrupt(int irq, void *dev_id)
 281{
 282	struct snd_uart16550 *uart;
 283
 284	uart = dev_id;
 285	spin_lock(&uart->open_lock);
 286	if (uart->filemode == SERIAL_MODE_NOT_OPENED) {
 287		spin_unlock(&uart->open_lock);
 288		return IRQ_NONE;
 289	}
 290	/* indicate to the UART that the interrupt has been serviced */
 291	inb(uart->base + UART_IIR);
 292	snd_uart16550_io_loop(uart);
 293	spin_unlock(&uart->open_lock);
 294	return IRQ_HANDLED;
 295}
 296
 297/* When the polling mode, this function calls snd_uart16550_io_loop. */
 298static void snd_uart16550_buffer_timer(struct timer_list *t)
 299{
 300	unsigned long flags;
 301	struct snd_uart16550 *uart;
 302
 303	uart = from_timer(uart, t, buffer_timer);
 304	spin_lock_irqsave(&uart->open_lock, flags);
 305	snd_uart16550_del_timer(uart);
 306	snd_uart16550_io_loop(uart);
 307	spin_unlock_irqrestore(&uart->open_lock, flags);
 308}
 309
 310/*
 311 *  this method probes, if an uart sits on given port
 312 *  return 0 if found
 313 *  return negative error if not found
 314 */
 315static int snd_uart16550_detect(struct snd_uart16550 *uart)
 316{
 317	unsigned long io_base = uart->base;
 318	int ok;
 319	unsigned char c;
 320
 321	/* Do some vague tests for the presence of the uart */
 322	if (io_base == 0 || io_base == SNDRV_AUTO_PORT) {
 323		return -ENODEV;	/* Not configured */
 324	}
 325
 326	uart->res_base = request_region(io_base, 8, "Serial MIDI");
 327	if (uart->res_base == NULL) {
 328		snd_printk(KERN_ERR "u16550: can't grab port 0x%lx\n", io_base);
 329		return -EBUSY;
 330	}
 331
 332	/* uart detected unless one of the following tests should fail */
 333	ok = 1;
 334	/* 8 data-bits, 1 stop-bit, parity off, DLAB = 0 */
 335	outb(UART_LCR_WLEN8, io_base + UART_LCR); /* Line Control Register */
 336	c = inb(io_base + UART_IER);
 337	/* The top four bits of the IER should always == 0 */
 338	if ((c & 0xf0) != 0)
 339		ok = 0;		/* failed */
 340
 341	outb(0xaa, io_base + UART_SCR);
 342	/* Write arbitrary data into the scratch reg */
 343	c = inb(io_base + UART_SCR);
 344	/* If it comes back, it's OK */
 345	if (c != 0xaa)
 346		ok = 0;		/* failed */
 347
 348	outb(0x55, io_base + UART_SCR);
 349	/* Write arbitrary data into the scratch reg */
 350	c = inb(io_base + UART_SCR);
 351	/* If it comes back, it's OK */
 352	if (c != 0x55)
 353		ok = 0;		/* failed */
 354
 355	return ok;
 356}
 357
 358static void snd_uart16550_do_open(struct snd_uart16550 * uart)
 359{
 360	char byte;
 361
 362	/* Initialize basic variables */
 363	uart->buff_in_count = 0;
 364	uart->buff_in = 0;
 365	uart->buff_out = 0;
 366	uart->fifo_limit = 1;
 367	uart->fifo_count = 0;
 368	uart->timer_running = 0;
 369
 370	outb(UART_FCR_ENABLE_FIFO	/* Enable FIFO's (if available) */
 371	     | UART_FCR_CLEAR_RCVR	/* Clear receiver FIFO */
 372	     | UART_FCR_CLEAR_XMIT	/* Clear transmitter FIFO */
 373	     | UART_FCR_TRIGGER_4	/* Set FIFO trigger at 4-bytes */
 374	/* NOTE: interrupt generated after T=(time)4-bytes
 375	 * if less than UART_FCR_TRIGGER bytes received
 376	 */
 377	     ,uart->base + UART_FCR);	/* FIFO Control Register */
 378
 379	if ((inb(uart->base + UART_IIR) & 0xf0) == 0xc0)
 380		uart->fifo_limit = 16;
 381	if (uart->divisor != 0) {
 382		uart->old_line_ctrl_reg = inb(uart->base + UART_LCR);
 383		outb(UART_LCR_DLAB	/* Divisor latch access bit */
 384		     ,uart->base + UART_LCR);	/* Line Control Register */
 385		uart->old_divisor_lsb = inb(uart->base + UART_DLL);
 386		uart->old_divisor_msb = inb(uart->base + UART_DLM);
 387
 388		outb(uart->divisor
 389		     ,uart->base + UART_DLL);	/* Divisor Latch Low */
 390		outb(0
 391		     ,uart->base + UART_DLM);	/* Divisor Latch High */
 392		/* DLAB is reset to 0 in next outb() */
 393	}
 394	/* Set serial parameters (parity off, etc) */
 395	outb(UART_LCR_WLEN8	/* 8 data-bits */
 396	     | 0		/* 1 stop-bit */
 397	     | 0		/* parity off */
 398	     | 0		/* DLAB = 0 */
 399	     ,uart->base + UART_LCR);	/* Line Control Register */
 400
 401	switch (uart->adaptor) {
 402	default:
 403		outb(UART_MCR_RTS	/* Set Request-To-Send line active */
 404		     | UART_MCR_DTR	/* Set Data-Terminal-Ready line active */
 405		     | UART_MCR_OUT2	/* Set OUT2 - not always required, but when
 406					 * it is, it is ESSENTIAL for enabling interrupts
 407				 */
 408		     ,uart->base + UART_MCR);	/* Modem Control Register */
 409		break;
 410	case SNDRV_SERIAL_MS124W_SA:
 411	case SNDRV_SERIAL_MS124W_MB:
 412		/* MS-124W can draw power from RTS and DTR if they
 413		   are in opposite states. */ 
 414		outb(UART_MCR_RTS | (0&UART_MCR_DTR) | UART_MCR_OUT2,
 415		     uart->base + UART_MCR);
 416		break;
 417	case SNDRV_SERIAL_MS124T:
 418		/* MS-124T can draw power from RTS and/or DTR (preferably
 419		   both) if they are both asserted. */
 420		outb(UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2,
 421		     uart->base + UART_MCR);
 422		break;
 423	}
 424
 425	if (uart->irq < 0) {
 426		byte = (0 & UART_IER_RDI)	/* Disable Receiver data interrupt */
 427		    |(0 & UART_IER_THRI)	/* Disable Transmitter holding register empty interrupt */
 428		    ;
 429	} else if (uart->adaptor == SNDRV_SERIAL_MS124W_SA) {
 430		byte = UART_IER_RDI	/* Enable Receiver data interrupt */
 431		    | UART_IER_MSI	/* Enable Modem status interrupt */
 432		    ;
 433	} else if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
 434		byte = UART_IER_RDI	/* Enable Receiver data interrupt */
 435		    | UART_IER_MSI	/* Enable Modem status interrupt */
 436		    | UART_IER_THRI	/* Enable Transmitter holding register empty interrupt */
 437		    ;
 438	} else {
 439		byte = UART_IER_RDI	/* Enable Receiver data interrupt */
 440		    | UART_IER_THRI	/* Enable Transmitter holding register empty interrupt */
 441		    ;
 442	}
 443	outb(byte, uart->base + UART_IER);	/* Interrupt enable Register */
 444
 445	inb(uart->base + UART_LSR);	/* Clear any pre-existing overrun indication */
 446	inb(uart->base + UART_IIR);	/* Clear any pre-existing transmit interrupt */
 447	inb(uart->base + UART_RX);	/* Clear any pre-existing receive interrupt */
 448}
 449
 450static void snd_uart16550_do_close(struct snd_uart16550 * uart)
 451{
 452	if (uart->irq < 0)
 453		snd_uart16550_del_timer(uart);
 454
 455	/* NOTE: may need to disable interrupts before de-registering out handler.
 456	 * For now, the consequences are harmless.
 457	 */
 458
 459	outb((0 & UART_IER_RDI)		/* Disable Receiver data interrupt */
 460	     |(0 & UART_IER_THRI)	/* Disable Transmitter holding register empty interrupt */
 461	     ,uart->base + UART_IER);	/* Interrupt enable Register */
 462
 463	switch (uart->adaptor) {
 464	default:
 465		outb((0 & UART_MCR_RTS)		/* Deactivate Request-To-Send line  */
 466		     |(0 & UART_MCR_DTR)	/* Deactivate Data-Terminal-Ready line */
 467		     |(0 & UART_MCR_OUT2)	/* Deactivate OUT2 */
 468		     ,uart->base + UART_MCR);	/* Modem Control Register */
 469	  break;
 470	case SNDRV_SERIAL_MS124W_SA:
 471	case SNDRV_SERIAL_MS124W_MB:
 472		/* MS-124W can draw power from RTS and DTR if they
 473		   are in opposite states; leave it powered. */ 
 474		outb(UART_MCR_RTS | (0&UART_MCR_DTR) | (0&UART_MCR_OUT2),
 475		     uart->base + UART_MCR);
 476		break;
 477	case SNDRV_SERIAL_MS124T:
 478		/* MS-124T can draw power from RTS and/or DTR (preferably
 479		   both) if they are both asserted; leave it powered. */
 480		outb(UART_MCR_RTS | UART_MCR_DTR | (0&UART_MCR_OUT2),
 481		     uart->base + UART_MCR);
 482		break;
 483	}
 484
 485	inb(uart->base + UART_IIR);	/* Clear any outstanding interrupts */
 486
 487	/* Restore old divisor */
 488	if (uart->divisor != 0) {
 489		outb(UART_LCR_DLAB		/* Divisor latch access bit */
 490		     ,uart->base + UART_LCR);	/* Line Control Register */
 491		outb(uart->old_divisor_lsb
 492		     ,uart->base + UART_DLL);	/* Divisor Latch Low */
 493		outb(uart->old_divisor_msb
 494		     ,uart->base + UART_DLM);	/* Divisor Latch High */
 495		/* Restore old LCR (data bits, stop bits, parity, DLAB) */
 496		outb(uart->old_line_ctrl_reg
 497		     ,uart->base + UART_LCR);	/* Line Control Register */
 498	}
 499}
 500
 501static int snd_uart16550_input_open(struct snd_rawmidi_substream *substream)
 502{
 503	unsigned long flags;
 504	struct snd_uart16550 *uart = substream->rmidi->private_data;
 505
 506	spin_lock_irqsave(&uart->open_lock, flags);
 507	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
 508		snd_uart16550_do_open(uart);
 509	uart->filemode |= SERIAL_MODE_INPUT_OPEN;
 510	uart->midi_input[substream->number] = substream;
 511	spin_unlock_irqrestore(&uart->open_lock, flags);
 512	return 0;
 513}
 514
 515static int snd_uart16550_input_close(struct snd_rawmidi_substream *substream)
 516{
 517	unsigned long flags;
 518	struct snd_uart16550 *uart = substream->rmidi->private_data;
 519
 520	spin_lock_irqsave(&uart->open_lock, flags);
 521	uart->filemode &= ~SERIAL_MODE_INPUT_OPEN;
 522	uart->midi_input[substream->number] = NULL;
 523	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
 524		snd_uart16550_do_close(uart);
 525	spin_unlock_irqrestore(&uart->open_lock, flags);
 526	return 0;
 527}
 528
 529static void snd_uart16550_input_trigger(struct snd_rawmidi_substream *substream,
 530					int up)
 531{
 532	unsigned long flags;
 533	struct snd_uart16550 *uart = substream->rmidi->private_data;
 534
 535	spin_lock_irqsave(&uart->open_lock, flags);
 536	if (up)
 537		uart->filemode |= SERIAL_MODE_INPUT_TRIGGERED;
 538	else
 539		uart->filemode &= ~SERIAL_MODE_INPUT_TRIGGERED;
 540	spin_unlock_irqrestore(&uart->open_lock, flags);
 541}
 542
 543static int snd_uart16550_output_open(struct snd_rawmidi_substream *substream)
 544{
 545	unsigned long flags;
 546	struct snd_uart16550 *uart = substream->rmidi->private_data;
 547
 548	spin_lock_irqsave(&uart->open_lock, flags);
 549	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
 550		snd_uart16550_do_open(uart);
 551	uart->filemode |= SERIAL_MODE_OUTPUT_OPEN;
 552	uart->midi_output[substream->number] = substream;
 553	spin_unlock_irqrestore(&uart->open_lock, flags);
 554	return 0;
 555};
 556
 557static int snd_uart16550_output_close(struct snd_rawmidi_substream *substream)
 558{
 559	unsigned long flags;
 560	struct snd_uart16550 *uart = substream->rmidi->private_data;
 561
 562	spin_lock_irqsave(&uart->open_lock, flags);
 563	uart->filemode &= ~SERIAL_MODE_OUTPUT_OPEN;
 564	uart->midi_output[substream->number] = NULL;
 565	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
 566		snd_uart16550_do_close(uart);
 567	spin_unlock_irqrestore(&uart->open_lock, flags);
 568	return 0;
 569};
 570
 571static inline int snd_uart16550_buffer_can_write(struct snd_uart16550 *uart,
 572						 int Num)
 573{
 574	if (uart->buff_in_count + Num < TX_BUFF_SIZE)
 575		return 1;
 576	else
 577		return 0;
 578}
 579
 580static inline int snd_uart16550_write_buffer(struct snd_uart16550 *uart,
 581					     unsigned char byte)
 582{
 583	unsigned short buff_in = uart->buff_in;
 584	if (uart->buff_in_count < TX_BUFF_SIZE) {
 585		uart->tx_buff[buff_in] = byte;
 586		buff_in++;
 587		buff_in &= TX_BUFF_MASK;
 588		uart->buff_in = buff_in;
 589		uart->buff_in_count++;
 590		if (uart->irq < 0) /* polling mode */
 591			snd_uart16550_add_timer(uart);
 592		return 1;
 593	} else
 594		return 0;
 595}
 596
 597static int snd_uart16550_output_byte(struct snd_uart16550 *uart,
 598				     struct snd_rawmidi_substream *substream,
 599				     unsigned char midi_byte)
 600{
 601	if (uart->buff_in_count == 0                    /* Buffer empty? */
 602	    && ((uart->adaptor != SNDRV_SERIAL_MS124W_SA &&
 603	    uart->adaptor != SNDRV_SERIAL_GENERIC) ||
 604		(uart->fifo_count == 0                  /* FIFO empty? */
 605		 && (inb(uart->base + UART_MSR) & UART_MSR_CTS)))) { /* CTS? */
 606
 607	        /* Tx Buffer Empty - try to write immediately */
 608		if ((inb(uart->base + UART_LSR) & UART_LSR_THRE) != 0) {
 609		        /* Transmitter holding register (and Tx FIFO) empty */
 610		        uart->fifo_count = 1;
 611			outb(midi_byte, uart->base + UART_TX);
 612		} else {
 613		        if (uart->fifo_count < uart->fifo_limit) {
 614			        uart->fifo_count++;
 615				outb(midi_byte, uart->base + UART_TX);
 616			} else {
 617			        /* Cannot write (buffer empty) -
 618				 * put char in buffer */
 619				snd_uart16550_write_buffer(uart, midi_byte);
 620			}
 621		}
 622	} else {
 623		if (!snd_uart16550_write_buffer(uart, midi_byte)) {
 624			snd_printk(KERN_WARNING
 625				   "%s: Buffer overrun on device at 0x%lx\n",
 626				   uart->rmidi->name, uart->base);
 627			return 0;
 628		}
 629	}
 630
 631	return 1;
 632}
 633
 634static void snd_uart16550_output_write(struct snd_rawmidi_substream *substream)
 635{
 636	unsigned long flags;
 637	unsigned char midi_byte, addr_byte;
 638	struct snd_uart16550 *uart = substream->rmidi->private_data;
 639	char first;
 640	static unsigned long lasttime = 0;
 641	
 642	/* Interrupts are disabled during the updating of the tx_buff,
 643	 * since it is 'bad' to have two processes updating the same
 644	 * variables (ie buff_in & buff_out)
 645	 */
 646
 647	spin_lock_irqsave(&uart->open_lock, flags);
 648
 649	if (uart->irq < 0)	/* polling */
 650		snd_uart16550_io_loop(uart);
 651
 652	if (uart->adaptor == SNDRV_SERIAL_MS124W_MB) {
 653		while (1) {
 654			/* buffer full? */
 655			/* in this mode we need two bytes of space */
 656			if (uart->buff_in_count > TX_BUFF_SIZE - 2)
 657				break;
 658			if (snd_rawmidi_transmit(substream, &midi_byte, 1) != 1)
 659				break;
 660#ifdef SNDRV_SERIAL_MS124W_MB_NOCOMBO
 661			/* select exactly one of the four ports */
 662			addr_byte = (1 << (substream->number + 4)) | 0x08;
 663#else
 664			/* select any combination of the four ports */
 665			addr_byte = (substream->number << 4) | 0x08;
 666			/* ...except none */
 667			if (addr_byte == 0x08)
 668				addr_byte = 0xf8;
 669#endif
 670			snd_uart16550_output_byte(uart, substream, addr_byte);
 671			/* send midi byte */
 672			snd_uart16550_output_byte(uart, substream, midi_byte);
 673		}
 674	} else {
 675		first = 0;
 676		while (snd_rawmidi_transmit_peek(substream, &midi_byte, 1) == 1) {
 677			/* Also send F5 after 3 seconds with no data
 678			 * to handle device disconnect */
 679			if (first == 0 &&
 680			    (uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS ||
 681			     uart->adaptor == SNDRV_SERIAL_GENERIC) &&
 682			    (uart->prev_out != substream->number ||
 683			     time_after(jiffies, lasttime + 3*HZ))) {
 684
 685				if (snd_uart16550_buffer_can_write(uart, 3)) {
 686					/* Roland Soundcanvas part selection */
 687					/* If this substream of the data is
 688					 * different previous substream
 689					 * in this uart, send the change part
 690					 * event
 691					 */
 692					uart->prev_out = substream->number;
 693					/* change part */
 694					snd_uart16550_output_byte(uart, substream,
 695								  0xf5);
 696					/* data */
 697					snd_uart16550_output_byte(uart, substream,
 698								  uart->prev_out + 1);
 699					/* If midi_byte is a data byte,
 700					 * send the previous status byte */
 701					if (midi_byte < 0x80 &&
 702					    uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS)
 703						snd_uart16550_output_byte(uart, substream, uart->prev_status[uart->prev_out]);
 704				} else if (!uart->drop_on_full)
 705					break;
 706
 707			}
 708
 709			/* send midi byte */
 710			if (!snd_uart16550_output_byte(uart, substream, midi_byte) &&
 711			    !uart->drop_on_full )
 712				break;
 713
 714			if (midi_byte >= 0x80 && midi_byte < 0xf0)
 715				uart->prev_status[uart->prev_out] = midi_byte;
 716			first = 1;
 717
 718			snd_rawmidi_transmit_ack( substream, 1 );
 719		}
 720		lasttime = jiffies;
 721	}
 722	spin_unlock_irqrestore(&uart->open_lock, flags);
 723}
 724
 725static void snd_uart16550_output_trigger(struct snd_rawmidi_substream *substream,
 726					 int up)
 727{
 728	unsigned long flags;
 729	struct snd_uart16550 *uart = substream->rmidi->private_data;
 730
 731	spin_lock_irqsave(&uart->open_lock, flags);
 732	if (up)
 733		uart->filemode |= SERIAL_MODE_OUTPUT_TRIGGERED;
 734	else
 735		uart->filemode &= ~SERIAL_MODE_OUTPUT_TRIGGERED;
 736	spin_unlock_irqrestore(&uart->open_lock, flags);
 737	if (up)
 738		snd_uart16550_output_write(substream);
 739}
 740
 741static const struct snd_rawmidi_ops snd_uart16550_output =
 742{
 743	.open =		snd_uart16550_output_open,
 744	.close =	snd_uart16550_output_close,
 745	.trigger =	snd_uart16550_output_trigger,
 746};
 747
 748static const struct snd_rawmidi_ops snd_uart16550_input =
 749{
 750	.open =		snd_uart16550_input_open,
 751	.close =	snd_uart16550_input_close,
 752	.trigger =	snd_uart16550_input_trigger,
 753};
 754
 755static int snd_uart16550_free(struct snd_uart16550 *uart)
 756{
 757	if (uart->irq >= 0)
 758		free_irq(uart->irq, uart);
 759	release_and_free_resource(uart->res_base);
 760	kfree(uart);
 761	return 0;
 762};
 763
 764static int snd_uart16550_dev_free(struct snd_device *device)
 765{
 766	struct snd_uart16550 *uart = device->device_data;
 767	return snd_uart16550_free(uart);
 768}
 769
 770static int snd_uart16550_create(struct snd_card *card,
 771				unsigned long iobase,
 772				int irq,
 773				unsigned int speed,
 774				unsigned int base,
 775				int adaptor,
 776				int droponfull,
 777				struct snd_uart16550 **ruart)
 778{
 779	static const struct snd_device_ops ops = {
 780		.dev_free =	snd_uart16550_dev_free,
 781	};
 782	struct snd_uart16550 *uart;
 783	int err;
 784
 785
 786	uart = kzalloc(sizeof(*uart), GFP_KERNEL);
 787	if (!uart)
 788		return -ENOMEM;
 789	uart->adaptor = adaptor;
 790	uart->card = card;
 791	spin_lock_init(&uart->open_lock);
 792	uart->irq = -1;
 793	uart->base = iobase;
 794	uart->drop_on_full = droponfull;
 795
 796	err = snd_uart16550_detect(uart);
 797	if (err <= 0) {
 798		printk(KERN_ERR "no UART detected at 0x%lx\n", iobase);
 799		snd_uart16550_free(uart);
 800		return -ENODEV;
 801	}
 802
 803	if (irq >= 0 && irq != SNDRV_AUTO_IRQ) {
 804		if (request_irq(irq, snd_uart16550_interrupt,
 805				0, "Serial MIDI", uart)) {
 806			snd_printk(KERN_WARNING
 807				   "irq %d busy. Using Polling.\n", irq);
 808		} else {
 809			uart->irq = irq;
 810		}
 811	}
 812	uart->divisor = base / speed;
 813	uart->speed = base / (unsigned int)uart->divisor;
 814	uart->speed_base = base;
 815	uart->prev_out = -1;
 816	uart->prev_in = 0;
 817	uart->rstatus = 0;
 818	memset(uart->prev_status, 0x80, sizeof(unsigned char) * SNDRV_SERIAL_MAX_OUTS);
 819	timer_setup(&uart->buffer_timer, snd_uart16550_buffer_timer, 0);
 
 820	uart->timer_running = 0;
 821
 822	/* Register device */
 823	err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, uart, &ops);
 824	if (err < 0) {
 825		snd_uart16550_free(uart);
 826		return err;
 827	}
 828
 829	switch (uart->adaptor) {
 830	case SNDRV_SERIAL_MS124W_SA:
 831	case SNDRV_SERIAL_MS124W_MB:
 832		/* MS-124W can draw power from RTS and DTR if they
 833		   are in opposite states. */ 
 834		outb(UART_MCR_RTS | (0&UART_MCR_DTR), uart->base + UART_MCR);
 835		break;
 836	case SNDRV_SERIAL_MS124T:
 837		/* MS-124T can draw power from RTS and/or DTR (preferably
 838		   both) if they are asserted. */
 839		outb(UART_MCR_RTS | UART_MCR_DTR, uart->base + UART_MCR);
 840		break;
 841	default:
 842		break;
 843	}
 844
 845	if (ruart)
 846		*ruart = uart;
 847
 848	return 0;
 849}
 850
 851static void snd_uart16550_substreams(struct snd_rawmidi_str *stream)
 852{
 853	struct snd_rawmidi_substream *substream;
 854
 855	list_for_each_entry(substream, &stream->substreams, list) {
 856		sprintf(substream->name, "Serial MIDI %d", substream->number + 1);
 857	}
 858}
 859
 860static int snd_uart16550_rmidi(struct snd_uart16550 *uart, int device,
 861			       int outs, int ins,
 862			       struct snd_rawmidi **rmidi)
 863{
 864	struct snd_rawmidi *rrawmidi;
 865	int err;
 866
 867	err = snd_rawmidi_new(uart->card, "UART Serial MIDI", device,
 868			      outs, ins, &rrawmidi);
 869	if (err < 0)
 870		return err;
 871	snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 872			    &snd_uart16550_input);
 873	snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 874			    &snd_uart16550_output);
 875	strcpy(rrawmidi->name, "Serial MIDI");
 876	snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT]);
 877	snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT]);
 878	rrawmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
 879			       SNDRV_RAWMIDI_INFO_INPUT |
 880			       SNDRV_RAWMIDI_INFO_DUPLEX;
 881	rrawmidi->private_data = uart;
 882	if (rmidi)
 883		*rmidi = rrawmidi;
 884	return 0;
 885}
 886
 887static int snd_serial_probe(struct platform_device *devptr)
 888{
 889	struct snd_card *card;
 890	struct snd_uart16550 *uart;
 891	int err;
 892	int dev = devptr->id;
 893
 894	switch (adaptor[dev]) {
 895	case SNDRV_SERIAL_SOUNDCANVAS:
 896		ins[dev] = 1;
 897		break;
 898	case SNDRV_SERIAL_MS124T:
 899	case SNDRV_SERIAL_MS124W_SA:
 900		outs[dev] = 1;
 901		ins[dev] = 1;
 902		break;
 903	case SNDRV_SERIAL_MS124W_MB:
 904		outs[dev] = 16;
 905		ins[dev] = 1;
 906		break;
 907	case SNDRV_SERIAL_GENERIC:
 908		break;
 909	default:
 910		snd_printk(KERN_ERR
 911			   "Adaptor type is out of range 0-%d (%d)\n",
 912			   SNDRV_SERIAL_MAX_ADAPTOR, adaptor[dev]);
 913		return -ENODEV;
 914	}
 915
 916	if (outs[dev] < 1 || outs[dev] > SNDRV_SERIAL_MAX_OUTS) {
 917		snd_printk(KERN_ERR
 918			   "Count of outputs is out of range 1-%d (%d)\n",
 919			   SNDRV_SERIAL_MAX_OUTS, outs[dev]);
 920		return -ENODEV;
 921	}
 922
 923	if (ins[dev] < 1 || ins[dev] > SNDRV_SERIAL_MAX_INS) {
 924		snd_printk(KERN_ERR
 925			   "Count of inputs is out of range 1-%d (%d)\n",
 926			   SNDRV_SERIAL_MAX_INS, ins[dev]);
 927		return -ENODEV;
 928	}
 929
 930	err  = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
 931			    0, &card);
 932	if (err < 0)
 933		return err;
 934
 935	strcpy(card->driver, "Serial");
 936	strcpy(card->shortname, "Serial MIDI (UART16550A)");
 937
 938	err = snd_uart16550_create(card, port[dev], irq[dev], speed[dev],
 939				   base[dev], adaptor[dev], droponfull[dev],
 940				   &uart);
 941	if (err < 0)
 
 
 
 
 942		goto _err;
 943
 944	err = snd_uart16550_rmidi(uart, 0, outs[dev], ins[dev], &uart->rmidi);
 945	if (err < 0)
 946		goto _err;
 947
 948	sprintf(card->longname, "%s [%s] at %#lx, irq %d",
 949		card->shortname,
 950		adaptor_names[uart->adaptor],
 951		uart->base,
 952		uart->irq);
 953
 954	err = snd_card_register(card);
 955	if (err < 0)
 956		goto _err;
 957
 958	platform_set_drvdata(devptr, card);
 959	return 0;
 960
 961 _err:
 962	snd_card_free(card);
 963	return err;
 964}
 965
 966static int snd_serial_remove(struct platform_device *devptr)
 967{
 968	snd_card_free(platform_get_drvdata(devptr));
 969	return 0;
 970}
 971
 972#define SND_SERIAL_DRIVER	"snd_serial_u16550"
 973
 974static struct platform_driver snd_serial_driver = {
 975	.probe		= snd_serial_probe,
 976	.remove		=  snd_serial_remove,
 977	.driver		= {
 978		.name	= SND_SERIAL_DRIVER,
 979	},
 980};
 981
 982static void snd_serial_unregister_all(void)
 983{
 984	int i;
 985
 986	for (i = 0; i < ARRAY_SIZE(devices); ++i)
 987		platform_device_unregister(devices[i]);
 988	platform_driver_unregister(&snd_serial_driver);
 989}
 990
 991static int __init alsa_card_serial_init(void)
 992{
 993	int i, cards, err;
 994
 995	err = platform_driver_register(&snd_serial_driver);
 996	if (err < 0)
 997		return err;
 998
 999	cards = 0;
1000	for (i = 0; i < SNDRV_CARDS; i++) {
1001		struct platform_device *device;
1002		if (! enable[i])
1003			continue;
1004		device = platform_device_register_simple(SND_SERIAL_DRIVER,
1005							 i, NULL, 0);
1006		if (IS_ERR(device))
1007			continue;
1008		if (!platform_get_drvdata(device)) {
1009			platform_device_unregister(device);
1010			continue;
1011		}
1012		devices[i] = device;
1013		cards++;
1014	}
1015	if (! cards) {
1016#ifdef MODULE
1017		printk(KERN_ERR "serial midi soundcard not found or device busy\n");
1018#endif
1019		snd_serial_unregister_all();
1020		return -ENODEV;
1021	}
1022	return 0;
1023}
1024
1025static void __exit alsa_card_serial_exit(void)
1026{
1027	snd_serial_unregister_all();
1028}
1029
1030module_init(alsa_card_serial_init)
1031module_exit(alsa_card_serial_exit)
v4.6
 
   1/*
   2 *   serial.c
   3 *   Copyright (c) by Jaroslav Kysela <perex@perex.cz>,
   4 *                    Isaku Yamahata <yamahata@private.email.ne.jp>,
   5 *		      George Hansper <ghansper@apana.org.au>,
   6 *		      Hannu Savolainen
   7 *
   8 *   This code is based on the code from ALSA 0.5.9, but heavily rewritten.
   9 *
  10 *   This program is free software; you can redistribute it and/or modify
  11 *   it under the terms of the GNU General Public License as published by
  12 *   the Free Software Foundation; either version 2 of the License, or
  13 *   (at your option) any later version.
  14 *
  15 *   This program is distributed in the hope that it will be useful,
  16 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 *   GNU General Public License for more details.
  19 *
  20 *   You should have received a copy of the GNU General Public License
  21 *   along with this program; if not, write to the Free Software
  22 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  23 *
  24 * Sat Mar 31 17:27:57 PST 2001 tim.mann@compaq.com 
  25 *      Added support for the Midiator MS-124T and for the MS-124W in
  26 *      Single Addressed (S/A) or Multiple Burst (M/B) mode, with
  27 *      power derived either parasitically from the serial port or
  28 *      from a separate power supply.
  29 *
  30 *      More documentation can be found in serial-u16550.txt.
  31 */
  32
  33#include <linux/init.h>
  34#include <linux/interrupt.h>
  35#include <linux/err.h>
  36#include <linux/platform_device.h>
  37#include <linux/slab.h>
  38#include <linux/ioport.h>
  39#include <linux/module.h>
  40#include <linux/io.h>
  41#include <sound/core.h>
  42#include <sound/rawmidi.h>
  43#include <sound/initval.h>
  44
  45#include <linux/serial_reg.h>
  46#include <linux/jiffies.h>
  47
  48MODULE_DESCRIPTION("MIDI serial u16550");
  49MODULE_LICENSE("GPL");
  50MODULE_SUPPORTED_DEVICE("{{ALSA, MIDI serial u16550}}");
  51
  52#define SNDRV_SERIAL_SOUNDCANVAS 0 /* Roland Soundcanvas; F5 NN selects part */
  53#define SNDRV_SERIAL_MS124T 1      /* Midiator MS-124T */
  54#define SNDRV_SERIAL_MS124W_SA 2   /* Midiator MS-124W in S/A mode */
  55#define SNDRV_SERIAL_MS124W_MB 3   /* Midiator MS-124W in M/B mode */
  56#define SNDRV_SERIAL_GENERIC 4     /* Generic Interface */
  57#define SNDRV_SERIAL_MAX_ADAPTOR SNDRV_SERIAL_GENERIC
  58static char *adaptor_names[] = {
  59	"Soundcanvas",
  60        "MS-124T",
  61	"MS-124W S/A",
  62	"MS-124W M/B",
  63	"Generic"
  64};
  65
  66#define SNDRV_SERIAL_NORMALBUFF 0 /* Normal blocking buffer operation */
  67#define SNDRV_SERIAL_DROPBUFF   1 /* Non-blocking discard operation */
  68
  69static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
  70static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
  71static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE; /* Enable this card */
  72static long port[SNDRV_CARDS] = SNDRV_DEFAULT_PORT; /* 0x3f8,0x2f8,0x3e8,0x2e8 */
  73static int irq[SNDRV_CARDS] = SNDRV_DEFAULT_IRQ; 	/* 3,4,5,7,9,10,11,14,15 */
  74static int speed[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 38400}; /* 9600,19200,38400,57600,115200 */
  75static int base[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 115200}; /* baud base */
  76static int outs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};	 /* 1 to 16 */
  77static int ins[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};	/* 1 to 16 */
  78static int adaptor[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = SNDRV_SERIAL_SOUNDCANVAS};
  79static bool droponfull[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS -1)] = SNDRV_SERIAL_NORMALBUFF };
  80
  81module_param_array(index, int, NULL, 0444);
  82MODULE_PARM_DESC(index, "Index value for Serial MIDI.");
  83module_param_array(id, charp, NULL, 0444);
  84MODULE_PARM_DESC(id, "ID string for Serial MIDI.");
  85module_param_array(enable, bool, NULL, 0444);
  86MODULE_PARM_DESC(enable, "Enable UART16550A chip.");
  87module_param_array(port, long, NULL, 0444);
  88MODULE_PARM_DESC(port, "Port # for UART16550A chip.");
  89module_param_array(irq, int, NULL, 0444);
  90MODULE_PARM_DESC(irq, "IRQ # for UART16550A chip.");
  91module_param_array(speed, int, NULL, 0444);
  92MODULE_PARM_DESC(speed, "Speed in bauds.");
  93module_param_array(base, int, NULL, 0444);
  94MODULE_PARM_DESC(base, "Base for divisor in bauds.");
  95module_param_array(outs, int, NULL, 0444);
  96MODULE_PARM_DESC(outs, "Number of MIDI outputs.");
  97module_param_array(ins, int, NULL, 0444);
  98MODULE_PARM_DESC(ins, "Number of MIDI inputs.");
  99module_param_array(droponfull, bool, NULL, 0444);
 100MODULE_PARM_DESC(droponfull, "Flag to enable drop-on-full buffer mode");
 101
 102module_param_array(adaptor, int, NULL, 0444);
 103MODULE_PARM_DESC(adaptor, "Type of adaptor.");
 104
 105/*#define SNDRV_SERIAL_MS124W_MB_NOCOMBO 1*/  /* Address outs as 0-3 instead of bitmap */
 106
 107#define SNDRV_SERIAL_MAX_OUTS	16		/* max 64, min 16 */
 108#define SNDRV_SERIAL_MAX_INS	16		/* max 64, min 16 */
 109
 110#define TX_BUFF_SIZE		(1<<15)		/* Must be 2^n */
 111#define TX_BUFF_MASK		(TX_BUFF_SIZE - 1)
 112
 113#define SERIAL_MODE_NOT_OPENED 		(0)
 114#define SERIAL_MODE_INPUT_OPEN		(1 << 0)
 115#define SERIAL_MODE_OUTPUT_OPEN		(1 << 1)
 116#define SERIAL_MODE_INPUT_TRIGGERED	(1 << 2)
 117#define SERIAL_MODE_OUTPUT_TRIGGERED	(1 << 3)
 118
 119struct snd_uart16550 {
 120	struct snd_card *card;
 121	struct snd_rawmidi *rmidi;
 122	struct snd_rawmidi_substream *midi_output[SNDRV_SERIAL_MAX_OUTS];
 123	struct snd_rawmidi_substream *midi_input[SNDRV_SERIAL_MAX_INS];
 124
 125	int filemode;		/* open status of file */
 126
 127	spinlock_t open_lock;
 128
 129	int irq;
 130
 131	unsigned long base;
 132	struct resource *res_base;
 133
 134	unsigned int speed;
 135	unsigned int speed_base;
 136	unsigned char divisor;
 137
 138	unsigned char old_divisor_lsb;
 139	unsigned char old_divisor_msb;
 140	unsigned char old_line_ctrl_reg;
 141
 142	/* parameter for using of write loop */
 143	short int fifo_limit;	/* used in uart16550 */
 144        short int fifo_count;	/* used in uart16550 */
 145
 146	/* type of adaptor */
 147	int adaptor;
 148
 149	/* inputs */
 150	int prev_in;
 151	unsigned char rstatus;
 152
 153	/* outputs */
 154	int prev_out;
 155	unsigned char prev_status[SNDRV_SERIAL_MAX_OUTS];
 156
 157	/* write buffer and its writing/reading position */
 158	unsigned char tx_buff[TX_BUFF_SIZE];
 159	int buff_in_count;
 160        int buff_in;
 161        int buff_out;
 162        int drop_on_full;
 163
 164	/* wait timer */
 165	unsigned int timer_running:1;
 166	struct timer_list buffer_timer;
 167
 168};
 169
 170static struct platform_device *devices[SNDRV_CARDS];
 171
 172static inline void snd_uart16550_add_timer(struct snd_uart16550 *uart)
 173{
 174	if (!uart->timer_running) {
 175		/* timer 38600bps * 10bit * 16byte */
 176		mod_timer(&uart->buffer_timer, jiffies + (HZ + 255) / 256);
 177		uart->timer_running = 1;
 178	}
 179}
 180
 181static inline void snd_uart16550_del_timer(struct snd_uart16550 *uart)
 182{
 183	if (uart->timer_running) {
 184		del_timer(&uart->buffer_timer);
 185		uart->timer_running = 0;
 186	}
 187}
 188
 189/* This macro is only used in snd_uart16550_io_loop */
 190static inline void snd_uart16550_buffer_output(struct snd_uart16550 *uart)
 191{
 192	unsigned short buff_out = uart->buff_out;
 193	if (uart->buff_in_count > 0) {
 194		outb(uart->tx_buff[buff_out], uart->base + UART_TX);
 195		uart->fifo_count++;
 196		buff_out++;
 197		buff_out &= TX_BUFF_MASK;
 198		uart->buff_out = buff_out;
 199		uart->buff_in_count--;
 200	}
 201}
 202
 203/* This loop should be called with interrupts disabled
 204 * We don't want to interrupt this, 
 205 * as we're already handling an interrupt 
 206 */
 207static void snd_uart16550_io_loop(struct snd_uart16550 * uart)
 208{
 209	unsigned char c, status;
 210	int substream;
 211
 212	/* recall previous stream */
 213	substream = uart->prev_in;
 214
 215	/* Read Loop */
 216	while ((status = inb(uart->base + UART_LSR)) & UART_LSR_DR) {
 217		/* while receive data ready */
 218		c = inb(uart->base + UART_RX);
 219
 220		/* keep track of last status byte */
 221		if (c & 0x80)
 222			uart->rstatus = c;
 223
 224		/* handle stream switch */
 225		if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
 226			if (uart->rstatus == 0xf5) {
 227				if (c <= SNDRV_SERIAL_MAX_INS && c > 0)
 228					substream = c - 1;
 229				if (c != 0xf5)
 230					/* prevent future bytes from being
 231					   interpreted as streams */
 232					uart->rstatus = 0;
 233			} else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN)
 234				   && uart->midi_input[substream])
 235				snd_rawmidi_receive(uart->midi_input[substream],
 236						    &c, 1);
 237		} else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN) &&
 238			   uart->midi_input[substream])
 239			snd_rawmidi_receive(uart->midi_input[substream], &c, 1);
 240
 241		if (status & UART_LSR_OE)
 242			snd_printk(KERN_WARNING
 243				   "%s: Overrun on device at 0x%lx\n",
 244			       uart->rmidi->name, uart->base);
 245	}
 246
 247	/* remember the last stream */
 248	uart->prev_in = substream;
 249
 250	/* no need of check SERIAL_MODE_OUTPUT_OPEN because if not,
 251	   buffer is never filled. */
 252	/* Check write status */
 253	if (status & UART_LSR_THRE)
 254		uart->fifo_count = 0;
 255	if (uart->adaptor == SNDRV_SERIAL_MS124W_SA
 256	   || uart->adaptor == SNDRV_SERIAL_GENERIC) {
 257		/* Can't use FIFO, must send only when CTS is true */
 258		status = inb(uart->base + UART_MSR);
 259		while (uart->fifo_count == 0 && (status & UART_MSR_CTS) &&
 260		       uart->buff_in_count > 0) {
 261		       snd_uart16550_buffer_output(uart);
 262		       status = inb(uart->base + UART_MSR);
 263		}
 264	} else {
 265		/* Write loop */
 266		while (uart->fifo_count < uart->fifo_limit /* Can we write ? */
 267		       && uart->buff_in_count > 0)	/* Do we want to? */
 268			snd_uart16550_buffer_output(uart);
 269	}
 270	if (uart->irq < 0 && uart->buff_in_count > 0)
 271		snd_uart16550_add_timer(uart);
 272}
 273
 274/* NOTES ON SERVICING INTERUPTS
 275 * ---------------------------
 276 * After receiving a interrupt, it is important to indicate to the UART that
 277 * this has been done. 
 278 * For a Rx interrupt, this is done by reading the received byte.
 279 * For a Tx interrupt this is done by either:
 280 * a) Writing a byte
 281 * b) Reading the IIR
 282 * It is particularly important to read the IIR if a Tx interrupt is received
 283 * when there is no data in tx_buff[], as in this case there no other
 284 * indication that the interrupt has been serviced, and it remains outstanding
 285 * indefinitely. This has the curious side effect that and no further interrupts
 286 * will be generated from this device AT ALL!!.
 287 * It is also desirable to clear outstanding interrupts when the device is
 288 * opened/closed.
 289 *
 290 *
 291 * Note that some devices need OUT2 to be set before they will generate
 292 * interrupts at all. (Possibly tied to an internal pull-up on CTS?)
 293 */
 294static irqreturn_t snd_uart16550_interrupt(int irq, void *dev_id)
 295{
 296	struct snd_uart16550 *uart;
 297
 298	uart = dev_id;
 299	spin_lock(&uart->open_lock);
 300	if (uart->filemode == SERIAL_MODE_NOT_OPENED) {
 301		spin_unlock(&uart->open_lock);
 302		return IRQ_NONE;
 303	}
 304	/* indicate to the UART that the interrupt has been serviced */
 305	inb(uart->base + UART_IIR);
 306	snd_uart16550_io_loop(uart);
 307	spin_unlock(&uart->open_lock);
 308	return IRQ_HANDLED;
 309}
 310
 311/* When the polling mode, this function calls snd_uart16550_io_loop. */
 312static void snd_uart16550_buffer_timer(unsigned long data)
 313{
 314	unsigned long flags;
 315	struct snd_uart16550 *uart;
 316
 317	uart = (struct snd_uart16550 *)data;
 318	spin_lock_irqsave(&uart->open_lock, flags);
 319	snd_uart16550_del_timer(uart);
 320	snd_uart16550_io_loop(uart);
 321	spin_unlock_irqrestore(&uart->open_lock, flags);
 322}
 323
 324/*
 325 *  this method probes, if an uart sits on given port
 326 *  return 0 if found
 327 *  return negative error if not found
 328 */
 329static int snd_uart16550_detect(struct snd_uart16550 *uart)
 330{
 331	unsigned long io_base = uart->base;
 332	int ok;
 333	unsigned char c;
 334
 335	/* Do some vague tests for the presence of the uart */
 336	if (io_base == 0 || io_base == SNDRV_AUTO_PORT) {
 337		return -ENODEV;	/* Not configured */
 338	}
 339
 340	uart->res_base = request_region(io_base, 8, "Serial MIDI");
 341	if (uart->res_base == NULL) {
 342		snd_printk(KERN_ERR "u16550: can't grab port 0x%lx\n", io_base);
 343		return -EBUSY;
 344	}
 345
 346	/* uart detected unless one of the following tests should fail */
 347	ok = 1;
 348	/* 8 data-bits, 1 stop-bit, parity off, DLAB = 0 */
 349	outb(UART_LCR_WLEN8, io_base + UART_LCR); /* Line Control Register */
 350	c = inb(io_base + UART_IER);
 351	/* The top four bits of the IER should always == 0 */
 352	if ((c & 0xf0) != 0)
 353		ok = 0;		/* failed */
 354
 355	outb(0xaa, io_base + UART_SCR);
 356	/* Write arbitrary data into the scratch reg */
 357	c = inb(io_base + UART_SCR);
 358	/* If it comes back, it's OK */
 359	if (c != 0xaa)
 360		ok = 0;		/* failed */
 361
 362	outb(0x55, io_base + UART_SCR);
 363	/* Write arbitrary data into the scratch reg */
 364	c = inb(io_base + UART_SCR);
 365	/* If it comes back, it's OK */
 366	if (c != 0x55)
 367		ok = 0;		/* failed */
 368
 369	return ok;
 370}
 371
 372static void snd_uart16550_do_open(struct snd_uart16550 * uart)
 373{
 374	char byte;
 375
 376	/* Initialize basic variables */
 377	uart->buff_in_count = 0;
 378	uart->buff_in = 0;
 379	uart->buff_out = 0;
 380	uart->fifo_limit = 1;
 381	uart->fifo_count = 0;
 382	uart->timer_running = 0;
 383
 384	outb(UART_FCR_ENABLE_FIFO	/* Enable FIFO's (if available) */
 385	     | UART_FCR_CLEAR_RCVR	/* Clear receiver FIFO */
 386	     | UART_FCR_CLEAR_XMIT	/* Clear transmitter FIFO */
 387	     | UART_FCR_TRIGGER_4	/* Set FIFO trigger at 4-bytes */
 388	/* NOTE: interrupt generated after T=(time)4-bytes
 389	 * if less than UART_FCR_TRIGGER bytes received
 390	 */
 391	     ,uart->base + UART_FCR);	/* FIFO Control Register */
 392
 393	if ((inb(uart->base + UART_IIR) & 0xf0) == 0xc0)
 394		uart->fifo_limit = 16;
 395	if (uart->divisor != 0) {
 396		uart->old_line_ctrl_reg = inb(uart->base + UART_LCR);
 397		outb(UART_LCR_DLAB	/* Divisor latch access bit */
 398		     ,uart->base + UART_LCR);	/* Line Control Register */
 399		uart->old_divisor_lsb = inb(uart->base + UART_DLL);
 400		uart->old_divisor_msb = inb(uart->base + UART_DLM);
 401
 402		outb(uart->divisor
 403		     ,uart->base + UART_DLL);	/* Divisor Latch Low */
 404		outb(0
 405		     ,uart->base + UART_DLM);	/* Divisor Latch High */
 406		/* DLAB is reset to 0 in next outb() */
 407	}
 408	/* Set serial parameters (parity off, etc) */
 409	outb(UART_LCR_WLEN8	/* 8 data-bits */
 410	     | 0		/* 1 stop-bit */
 411	     | 0		/* parity off */
 412	     | 0		/* DLAB = 0 */
 413	     ,uart->base + UART_LCR);	/* Line Control Register */
 414
 415	switch (uart->adaptor) {
 416	default:
 417		outb(UART_MCR_RTS	/* Set Request-To-Send line active */
 418		     | UART_MCR_DTR	/* Set Data-Terminal-Ready line active */
 419		     | UART_MCR_OUT2	/* Set OUT2 - not always required, but when
 420					 * it is, it is ESSENTIAL for enabling interrupts
 421				 */
 422		     ,uart->base + UART_MCR);	/* Modem Control Register */
 423		break;
 424	case SNDRV_SERIAL_MS124W_SA:
 425	case SNDRV_SERIAL_MS124W_MB:
 426		/* MS-124W can draw power from RTS and DTR if they
 427		   are in opposite states. */ 
 428		outb(UART_MCR_RTS | (0&UART_MCR_DTR) | UART_MCR_OUT2,
 429		     uart->base + UART_MCR);
 430		break;
 431	case SNDRV_SERIAL_MS124T:
 432		/* MS-124T can draw power from RTS and/or DTR (preferably
 433		   both) if they are both asserted. */
 434		outb(UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2,
 435		     uart->base + UART_MCR);
 436		break;
 437	}
 438
 439	if (uart->irq < 0) {
 440		byte = (0 & UART_IER_RDI)	/* Disable Receiver data interrupt */
 441		    |(0 & UART_IER_THRI)	/* Disable Transmitter holding register empty interrupt */
 442		    ;
 443	} else if (uart->adaptor == SNDRV_SERIAL_MS124W_SA) {
 444		byte = UART_IER_RDI	/* Enable Receiver data interrupt */
 445		    | UART_IER_MSI	/* Enable Modem status interrupt */
 446		    ;
 447	} else if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
 448		byte = UART_IER_RDI	/* Enable Receiver data interrupt */
 449		    | UART_IER_MSI	/* Enable Modem status interrupt */
 450		    | UART_IER_THRI	/* Enable Transmitter holding register empty interrupt */
 451		    ;
 452	} else {
 453		byte = UART_IER_RDI	/* Enable Receiver data interrupt */
 454		    | UART_IER_THRI	/* Enable Transmitter holding register empty interrupt */
 455		    ;
 456	}
 457	outb(byte, uart->base + UART_IER);	/* Interrupt enable Register */
 458
 459	inb(uart->base + UART_LSR);	/* Clear any pre-existing overrun indication */
 460	inb(uart->base + UART_IIR);	/* Clear any pre-existing transmit interrupt */
 461	inb(uart->base + UART_RX);	/* Clear any pre-existing receive interrupt */
 462}
 463
 464static void snd_uart16550_do_close(struct snd_uart16550 * uart)
 465{
 466	if (uart->irq < 0)
 467		snd_uart16550_del_timer(uart);
 468
 469	/* NOTE: may need to disable interrupts before de-registering out handler.
 470	 * For now, the consequences are harmless.
 471	 */
 472
 473	outb((0 & UART_IER_RDI)		/* Disable Receiver data interrupt */
 474	     |(0 & UART_IER_THRI)	/* Disable Transmitter holding register empty interrupt */
 475	     ,uart->base + UART_IER);	/* Interrupt enable Register */
 476
 477	switch (uart->adaptor) {
 478	default:
 479		outb((0 & UART_MCR_RTS)		/* Deactivate Request-To-Send line  */
 480		     |(0 & UART_MCR_DTR)	/* Deactivate Data-Terminal-Ready line */
 481		     |(0 & UART_MCR_OUT2)	/* Deactivate OUT2 */
 482		     ,uart->base + UART_MCR);	/* Modem Control Register */
 483	  break;
 484	case SNDRV_SERIAL_MS124W_SA:
 485	case SNDRV_SERIAL_MS124W_MB:
 486		/* MS-124W can draw power from RTS and DTR if they
 487		   are in opposite states; leave it powered. */ 
 488		outb(UART_MCR_RTS | (0&UART_MCR_DTR) | (0&UART_MCR_OUT2),
 489		     uart->base + UART_MCR);
 490		break;
 491	case SNDRV_SERIAL_MS124T:
 492		/* MS-124T can draw power from RTS and/or DTR (preferably
 493		   both) if they are both asserted; leave it powered. */
 494		outb(UART_MCR_RTS | UART_MCR_DTR | (0&UART_MCR_OUT2),
 495		     uart->base + UART_MCR);
 496		break;
 497	}
 498
 499	inb(uart->base + UART_IIR);	/* Clear any outstanding interrupts */
 500
 501	/* Restore old divisor */
 502	if (uart->divisor != 0) {
 503		outb(UART_LCR_DLAB		/* Divisor latch access bit */
 504		     ,uart->base + UART_LCR);	/* Line Control Register */
 505		outb(uart->old_divisor_lsb
 506		     ,uart->base + UART_DLL);	/* Divisor Latch Low */
 507		outb(uart->old_divisor_msb
 508		     ,uart->base + UART_DLM);	/* Divisor Latch High */
 509		/* Restore old LCR (data bits, stop bits, parity, DLAB) */
 510		outb(uart->old_line_ctrl_reg
 511		     ,uart->base + UART_LCR);	/* Line Control Register */
 512	}
 513}
 514
 515static int snd_uart16550_input_open(struct snd_rawmidi_substream *substream)
 516{
 517	unsigned long flags;
 518	struct snd_uart16550 *uart = substream->rmidi->private_data;
 519
 520	spin_lock_irqsave(&uart->open_lock, flags);
 521	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
 522		snd_uart16550_do_open(uart);
 523	uart->filemode |= SERIAL_MODE_INPUT_OPEN;
 524	uart->midi_input[substream->number] = substream;
 525	spin_unlock_irqrestore(&uart->open_lock, flags);
 526	return 0;
 527}
 528
 529static int snd_uart16550_input_close(struct snd_rawmidi_substream *substream)
 530{
 531	unsigned long flags;
 532	struct snd_uart16550 *uart = substream->rmidi->private_data;
 533
 534	spin_lock_irqsave(&uart->open_lock, flags);
 535	uart->filemode &= ~SERIAL_MODE_INPUT_OPEN;
 536	uart->midi_input[substream->number] = NULL;
 537	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
 538		snd_uart16550_do_close(uart);
 539	spin_unlock_irqrestore(&uart->open_lock, flags);
 540	return 0;
 541}
 542
 543static void snd_uart16550_input_trigger(struct snd_rawmidi_substream *substream,
 544					int up)
 545{
 546	unsigned long flags;
 547	struct snd_uart16550 *uart = substream->rmidi->private_data;
 548
 549	spin_lock_irqsave(&uart->open_lock, flags);
 550	if (up)
 551		uart->filemode |= SERIAL_MODE_INPUT_TRIGGERED;
 552	else
 553		uart->filemode &= ~SERIAL_MODE_INPUT_TRIGGERED;
 554	spin_unlock_irqrestore(&uart->open_lock, flags);
 555}
 556
 557static int snd_uart16550_output_open(struct snd_rawmidi_substream *substream)
 558{
 559	unsigned long flags;
 560	struct snd_uart16550 *uart = substream->rmidi->private_data;
 561
 562	spin_lock_irqsave(&uart->open_lock, flags);
 563	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
 564		snd_uart16550_do_open(uart);
 565	uart->filemode |= SERIAL_MODE_OUTPUT_OPEN;
 566	uart->midi_output[substream->number] = substream;
 567	spin_unlock_irqrestore(&uart->open_lock, flags);
 568	return 0;
 569};
 570
 571static int snd_uart16550_output_close(struct snd_rawmidi_substream *substream)
 572{
 573	unsigned long flags;
 574	struct snd_uart16550 *uart = substream->rmidi->private_data;
 575
 576	spin_lock_irqsave(&uart->open_lock, flags);
 577	uart->filemode &= ~SERIAL_MODE_OUTPUT_OPEN;
 578	uart->midi_output[substream->number] = NULL;
 579	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
 580		snd_uart16550_do_close(uart);
 581	spin_unlock_irqrestore(&uart->open_lock, flags);
 582	return 0;
 583};
 584
 585static inline int snd_uart16550_buffer_can_write(struct snd_uart16550 *uart,
 586						 int Num)
 587{
 588	if (uart->buff_in_count + Num < TX_BUFF_SIZE)
 589		return 1;
 590	else
 591		return 0;
 592}
 593
 594static inline int snd_uart16550_write_buffer(struct snd_uart16550 *uart,
 595					     unsigned char byte)
 596{
 597	unsigned short buff_in = uart->buff_in;
 598	if (uart->buff_in_count < TX_BUFF_SIZE) {
 599		uart->tx_buff[buff_in] = byte;
 600		buff_in++;
 601		buff_in &= TX_BUFF_MASK;
 602		uart->buff_in = buff_in;
 603		uart->buff_in_count++;
 604		if (uart->irq < 0) /* polling mode */
 605			snd_uart16550_add_timer(uart);
 606		return 1;
 607	} else
 608		return 0;
 609}
 610
 611static int snd_uart16550_output_byte(struct snd_uart16550 *uart,
 612				     struct snd_rawmidi_substream *substream,
 613				     unsigned char midi_byte)
 614{
 615	if (uart->buff_in_count == 0                    /* Buffer empty? */
 616	    && ((uart->adaptor != SNDRV_SERIAL_MS124W_SA &&
 617	    uart->adaptor != SNDRV_SERIAL_GENERIC) ||
 618		(uart->fifo_count == 0                  /* FIFO empty? */
 619		 && (inb(uart->base + UART_MSR) & UART_MSR_CTS)))) { /* CTS? */
 620
 621	        /* Tx Buffer Empty - try to write immediately */
 622		if ((inb(uart->base + UART_LSR) & UART_LSR_THRE) != 0) {
 623		        /* Transmitter holding register (and Tx FIFO) empty */
 624		        uart->fifo_count = 1;
 625			outb(midi_byte, uart->base + UART_TX);
 626		} else {
 627		        if (uart->fifo_count < uart->fifo_limit) {
 628			        uart->fifo_count++;
 629				outb(midi_byte, uart->base + UART_TX);
 630			} else {
 631			        /* Cannot write (buffer empty) -
 632				 * put char in buffer */
 633				snd_uart16550_write_buffer(uart, midi_byte);
 634			}
 635		}
 636	} else {
 637		if (!snd_uart16550_write_buffer(uart, midi_byte)) {
 638			snd_printk(KERN_WARNING
 639				   "%s: Buffer overrun on device at 0x%lx\n",
 640				   uart->rmidi->name, uart->base);
 641			return 0;
 642		}
 643	}
 644
 645	return 1;
 646}
 647
 648static void snd_uart16550_output_write(struct snd_rawmidi_substream *substream)
 649{
 650	unsigned long flags;
 651	unsigned char midi_byte, addr_byte;
 652	struct snd_uart16550 *uart = substream->rmidi->private_data;
 653	char first;
 654	static unsigned long lasttime = 0;
 655	
 656	/* Interrupts are disabled during the updating of the tx_buff,
 657	 * since it is 'bad' to have two processes updating the same
 658	 * variables (ie buff_in & buff_out)
 659	 */
 660
 661	spin_lock_irqsave(&uart->open_lock, flags);
 662
 663	if (uart->irq < 0)	/* polling */
 664		snd_uart16550_io_loop(uart);
 665
 666	if (uart->adaptor == SNDRV_SERIAL_MS124W_MB) {
 667		while (1) {
 668			/* buffer full? */
 669			/* in this mode we need two bytes of space */
 670			if (uart->buff_in_count > TX_BUFF_SIZE - 2)
 671				break;
 672			if (snd_rawmidi_transmit(substream, &midi_byte, 1) != 1)
 673				break;
 674#ifdef SNDRV_SERIAL_MS124W_MB_NOCOMBO
 675			/* select exactly one of the four ports */
 676			addr_byte = (1 << (substream->number + 4)) | 0x08;
 677#else
 678			/* select any combination of the four ports */
 679			addr_byte = (substream->number << 4) | 0x08;
 680			/* ...except none */
 681			if (addr_byte == 0x08)
 682				addr_byte = 0xf8;
 683#endif
 684			snd_uart16550_output_byte(uart, substream, addr_byte);
 685			/* send midi byte */
 686			snd_uart16550_output_byte(uart, substream, midi_byte);
 687		}
 688	} else {
 689		first = 0;
 690		while (snd_rawmidi_transmit_peek(substream, &midi_byte, 1) == 1) {
 691			/* Also send F5 after 3 seconds with no data
 692			 * to handle device disconnect */
 693			if (first == 0 &&
 694			    (uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS ||
 695			     uart->adaptor == SNDRV_SERIAL_GENERIC) &&
 696			    (uart->prev_out != substream->number ||
 697			     time_after(jiffies, lasttime + 3*HZ))) {
 698
 699				if (snd_uart16550_buffer_can_write(uart, 3)) {
 700					/* Roland Soundcanvas part selection */
 701					/* If this substream of the data is
 702					 * different previous substream
 703					 * in this uart, send the change part
 704					 * event
 705					 */
 706					uart->prev_out = substream->number;
 707					/* change part */
 708					snd_uart16550_output_byte(uart, substream,
 709								  0xf5);
 710					/* data */
 711					snd_uart16550_output_byte(uart, substream,
 712								  uart->prev_out + 1);
 713					/* If midi_byte is a data byte,
 714					 * send the previous status byte */
 715					if (midi_byte < 0x80 &&
 716					    uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS)
 717						snd_uart16550_output_byte(uart, substream, uart->prev_status[uart->prev_out]);
 718				} else if (!uart->drop_on_full)
 719					break;
 720
 721			}
 722
 723			/* send midi byte */
 724			if (!snd_uart16550_output_byte(uart, substream, midi_byte) &&
 725			    !uart->drop_on_full )
 726				break;
 727
 728			if (midi_byte >= 0x80 && midi_byte < 0xf0)
 729				uart->prev_status[uart->prev_out] = midi_byte;
 730			first = 1;
 731
 732			snd_rawmidi_transmit_ack( substream, 1 );
 733		}
 734		lasttime = jiffies;
 735	}
 736	spin_unlock_irqrestore(&uart->open_lock, flags);
 737}
 738
 739static void snd_uart16550_output_trigger(struct snd_rawmidi_substream *substream,
 740					 int up)
 741{
 742	unsigned long flags;
 743	struct snd_uart16550 *uart = substream->rmidi->private_data;
 744
 745	spin_lock_irqsave(&uart->open_lock, flags);
 746	if (up)
 747		uart->filemode |= SERIAL_MODE_OUTPUT_TRIGGERED;
 748	else
 749		uart->filemode &= ~SERIAL_MODE_OUTPUT_TRIGGERED;
 750	spin_unlock_irqrestore(&uart->open_lock, flags);
 751	if (up)
 752		snd_uart16550_output_write(substream);
 753}
 754
 755static struct snd_rawmidi_ops snd_uart16550_output =
 756{
 757	.open =		snd_uart16550_output_open,
 758	.close =	snd_uart16550_output_close,
 759	.trigger =	snd_uart16550_output_trigger,
 760};
 761
 762static struct snd_rawmidi_ops snd_uart16550_input =
 763{
 764	.open =		snd_uart16550_input_open,
 765	.close =	snd_uart16550_input_close,
 766	.trigger =	snd_uart16550_input_trigger,
 767};
 768
 769static int snd_uart16550_free(struct snd_uart16550 *uart)
 770{
 771	if (uart->irq >= 0)
 772		free_irq(uart->irq, uart);
 773	release_and_free_resource(uart->res_base);
 774	kfree(uart);
 775	return 0;
 776};
 777
 778static int snd_uart16550_dev_free(struct snd_device *device)
 779{
 780	struct snd_uart16550 *uart = device->device_data;
 781	return snd_uart16550_free(uart);
 782}
 783
 784static int snd_uart16550_create(struct snd_card *card,
 785				unsigned long iobase,
 786				int irq,
 787				unsigned int speed,
 788				unsigned int base,
 789				int adaptor,
 790				int droponfull,
 791				struct snd_uart16550 **ruart)
 792{
 793	static struct snd_device_ops ops = {
 794		.dev_free =	snd_uart16550_dev_free,
 795	};
 796	struct snd_uart16550 *uart;
 797	int err;
 798
 799
 800	if ((uart = kzalloc(sizeof(*uart), GFP_KERNEL)) == NULL)
 
 801		return -ENOMEM;
 802	uart->adaptor = adaptor;
 803	uart->card = card;
 804	spin_lock_init(&uart->open_lock);
 805	uart->irq = -1;
 806	uart->base = iobase;
 807	uart->drop_on_full = droponfull;
 808
 809	if ((err = snd_uart16550_detect(uart)) <= 0) {
 
 810		printk(KERN_ERR "no UART detected at 0x%lx\n", iobase);
 811		snd_uart16550_free(uart);
 812		return -ENODEV;
 813	}
 814
 815	if (irq >= 0 && irq != SNDRV_AUTO_IRQ) {
 816		if (request_irq(irq, snd_uart16550_interrupt,
 817				0, "Serial MIDI", uart)) {
 818			snd_printk(KERN_WARNING
 819				   "irq %d busy. Using Polling.\n", irq);
 820		} else {
 821			uart->irq = irq;
 822		}
 823	}
 824	uart->divisor = base / speed;
 825	uart->speed = base / (unsigned int)uart->divisor;
 826	uart->speed_base = base;
 827	uart->prev_out = -1;
 828	uart->prev_in = 0;
 829	uart->rstatus = 0;
 830	memset(uart->prev_status, 0x80, sizeof(unsigned char) * SNDRV_SERIAL_MAX_OUTS);
 831	setup_timer(&uart->buffer_timer, snd_uart16550_buffer_timer,
 832		    (unsigned long)uart);
 833	uart->timer_running = 0;
 834
 835	/* Register device */
 836	if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, uart, &ops)) < 0) {
 
 837		snd_uart16550_free(uart);
 838		return err;
 839	}
 840
 841	switch (uart->adaptor) {
 842	case SNDRV_SERIAL_MS124W_SA:
 843	case SNDRV_SERIAL_MS124W_MB:
 844		/* MS-124W can draw power from RTS and DTR if they
 845		   are in opposite states. */ 
 846		outb(UART_MCR_RTS | (0&UART_MCR_DTR), uart->base + UART_MCR);
 847		break;
 848	case SNDRV_SERIAL_MS124T:
 849		/* MS-124T can draw power from RTS and/or DTR (preferably
 850		   both) if they are asserted. */
 851		outb(UART_MCR_RTS | UART_MCR_DTR, uart->base + UART_MCR);
 852		break;
 853	default:
 854		break;
 855	}
 856
 857	if (ruart)
 858		*ruart = uart;
 859
 860	return 0;
 861}
 862
 863static void snd_uart16550_substreams(struct snd_rawmidi_str *stream)
 864{
 865	struct snd_rawmidi_substream *substream;
 866
 867	list_for_each_entry(substream, &stream->substreams, list) {
 868		sprintf(substream->name, "Serial MIDI %d", substream->number + 1);
 869	}
 870}
 871
 872static int snd_uart16550_rmidi(struct snd_uart16550 *uart, int device,
 873			       int outs, int ins,
 874			       struct snd_rawmidi **rmidi)
 875{
 876	struct snd_rawmidi *rrawmidi;
 877	int err;
 878
 879	err = snd_rawmidi_new(uart->card, "UART Serial MIDI", device,
 880			      outs, ins, &rrawmidi);
 881	if (err < 0)
 882		return err;
 883	snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 884			    &snd_uart16550_input);
 885	snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 886			    &snd_uart16550_output);
 887	strcpy(rrawmidi->name, "Serial MIDI");
 888	snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT]);
 889	snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT]);
 890	rrawmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
 891			       SNDRV_RAWMIDI_INFO_INPUT |
 892			       SNDRV_RAWMIDI_INFO_DUPLEX;
 893	rrawmidi->private_data = uart;
 894	if (rmidi)
 895		*rmidi = rrawmidi;
 896	return 0;
 897}
 898
 899static int snd_serial_probe(struct platform_device *devptr)
 900{
 901	struct snd_card *card;
 902	struct snd_uart16550 *uart;
 903	int err;
 904	int dev = devptr->id;
 905
 906	switch (adaptor[dev]) {
 907	case SNDRV_SERIAL_SOUNDCANVAS:
 908		ins[dev] = 1;
 909		break;
 910	case SNDRV_SERIAL_MS124T:
 911	case SNDRV_SERIAL_MS124W_SA:
 912		outs[dev] = 1;
 913		ins[dev] = 1;
 914		break;
 915	case SNDRV_SERIAL_MS124W_MB:
 916		outs[dev] = 16;
 917		ins[dev] = 1;
 918		break;
 919	case SNDRV_SERIAL_GENERIC:
 920		break;
 921	default:
 922		snd_printk(KERN_ERR
 923			   "Adaptor type is out of range 0-%d (%d)\n",
 924			   SNDRV_SERIAL_MAX_ADAPTOR, adaptor[dev]);
 925		return -ENODEV;
 926	}
 927
 928	if (outs[dev] < 1 || outs[dev] > SNDRV_SERIAL_MAX_OUTS) {
 929		snd_printk(KERN_ERR
 930			   "Count of outputs is out of range 1-%d (%d)\n",
 931			   SNDRV_SERIAL_MAX_OUTS, outs[dev]);
 932		return -ENODEV;
 933	}
 934
 935	if (ins[dev] < 1 || ins[dev] > SNDRV_SERIAL_MAX_INS) {
 936		snd_printk(KERN_ERR
 937			   "Count of inputs is out of range 1-%d (%d)\n",
 938			   SNDRV_SERIAL_MAX_INS, ins[dev]);
 939		return -ENODEV;
 940	}
 941
 942	err  = snd_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
 943			    0, &card);
 944	if (err < 0)
 945		return err;
 946
 947	strcpy(card->driver, "Serial");
 948	strcpy(card->shortname, "Serial MIDI (UART16550A)");
 949
 950	if ((err = snd_uart16550_create(card,
 951					port[dev],
 952					irq[dev],
 953					speed[dev],
 954					base[dev],
 955					adaptor[dev],
 956					droponfull[dev],
 957					&uart)) < 0)
 958		goto _err;
 959
 960	err = snd_uart16550_rmidi(uart, 0, outs[dev], ins[dev], &uart->rmidi);
 961	if (err < 0)
 962		goto _err;
 963
 964	sprintf(card->longname, "%s [%s] at %#lx, irq %d",
 965		card->shortname,
 966		adaptor_names[uart->adaptor],
 967		uart->base,
 968		uart->irq);
 969
 970	if ((err = snd_card_register(card)) < 0)
 
 971		goto _err;
 972
 973	platform_set_drvdata(devptr, card);
 974	return 0;
 975
 976 _err:
 977	snd_card_free(card);
 978	return err;
 979}
 980
 981static int snd_serial_remove(struct platform_device *devptr)
 982{
 983	snd_card_free(platform_get_drvdata(devptr));
 984	return 0;
 985}
 986
 987#define SND_SERIAL_DRIVER	"snd_serial_u16550"
 988
 989static struct platform_driver snd_serial_driver = {
 990	.probe		= snd_serial_probe,
 991	.remove		=  snd_serial_remove,
 992	.driver		= {
 993		.name	= SND_SERIAL_DRIVER,
 994	},
 995};
 996
 997static void snd_serial_unregister_all(void)
 998{
 999	int i;
1000
1001	for (i = 0; i < ARRAY_SIZE(devices); ++i)
1002		platform_device_unregister(devices[i]);
1003	platform_driver_unregister(&snd_serial_driver);
1004}
1005
1006static int __init alsa_card_serial_init(void)
1007{
1008	int i, cards, err;
1009
1010	if ((err = platform_driver_register(&snd_serial_driver)) < 0)
 
1011		return err;
1012
1013	cards = 0;
1014	for (i = 0; i < SNDRV_CARDS; i++) {
1015		struct platform_device *device;
1016		if (! enable[i])
1017			continue;
1018		device = platform_device_register_simple(SND_SERIAL_DRIVER,
1019							 i, NULL, 0);
1020		if (IS_ERR(device))
1021			continue;
1022		if (!platform_get_drvdata(device)) {
1023			platform_device_unregister(device);
1024			continue;
1025		}
1026		devices[i] = device;
1027		cards++;
1028	}
1029	if (! cards) {
1030#ifdef MODULE
1031		printk(KERN_ERR "serial midi soundcard not found or device busy\n");
1032#endif
1033		snd_serial_unregister_all();
1034		return -ENODEV;
1035	}
1036	return 0;
1037}
1038
1039static void __exit alsa_card_serial_exit(void)
1040{
1041	snd_serial_unregister_all();
1042}
1043
1044module_init(alsa_card_serial_init)
1045module_exit(alsa_card_serial_exit)