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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)
v6.8
  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
119	unsigned int speed;
120	unsigned int speed_base;
121	unsigned char divisor;
122
123	unsigned char old_divisor_lsb;
124	unsigned char old_divisor_msb;
125	unsigned char old_line_ctrl_reg;
126
127	/* parameter for using of write loop */
128	short int fifo_limit;	/* used in uart16550 */
129        short int fifo_count;	/* used in uart16550 */
130
131	/* type of adaptor */
132	int adaptor;
133
134	/* inputs */
135	int prev_in;
136	unsigned char rstatus;
137
138	/* outputs */
139	int prev_out;
140	unsigned char prev_status[SNDRV_SERIAL_MAX_OUTS];
141
142	/* write buffer and its writing/reading position */
143	unsigned char tx_buff[TX_BUFF_SIZE];
144	int buff_in_count;
145        int buff_in;
146        int buff_out;
147        int drop_on_full;
148
149	/* wait timer */
150	unsigned int timer_running:1;
151	struct timer_list buffer_timer;
152
153};
154
155static struct platform_device *devices[SNDRV_CARDS];
156
157static inline void snd_uart16550_add_timer(struct snd_uart16550 *uart)
158{
159	if (!uart->timer_running) {
160		/* timer 38600bps * 10bit * 16byte */
161		mod_timer(&uart->buffer_timer, jiffies + (HZ + 255) / 256);
162		uart->timer_running = 1;
163	}
164}
165
166static inline void snd_uart16550_del_timer(struct snd_uart16550 *uart)
167{
168	if (uart->timer_running) {
169		del_timer(&uart->buffer_timer);
170		uart->timer_running = 0;
171	}
172}
173
174/* This macro is only used in snd_uart16550_io_loop */
175static inline void snd_uart16550_buffer_output(struct snd_uart16550 *uart)
176{
177	unsigned short buff_out = uart->buff_out;
178	if (uart->buff_in_count > 0) {
179		outb(uart->tx_buff[buff_out], uart->base + UART_TX);
180		uart->fifo_count++;
181		buff_out++;
182		buff_out &= TX_BUFF_MASK;
183		uart->buff_out = buff_out;
184		uart->buff_in_count--;
185	}
186}
187
188/* This loop should be called with interrupts disabled
189 * We don't want to interrupt this, 
190 * as we're already handling an interrupt 
191 */
192static void snd_uart16550_io_loop(struct snd_uart16550 * uart)
193{
194	unsigned char c, status;
195	int substream;
196
197	/* recall previous stream */
198	substream = uart->prev_in;
199
200	/* Read Loop */
201	while ((status = inb(uart->base + UART_LSR)) & UART_LSR_DR) {
202		/* while receive data ready */
203		c = inb(uart->base + UART_RX);
204
205		/* keep track of last status byte */
206		if (c & 0x80)
207			uart->rstatus = c;
208
209		/* handle stream switch */
210		if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
211			if (uart->rstatus == 0xf5) {
212				if (c <= SNDRV_SERIAL_MAX_INS && c > 0)
213					substream = c - 1;
214				if (c != 0xf5)
215					/* prevent future bytes from being
216					   interpreted as streams */
217					uart->rstatus = 0;
218			} else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN)
219				   && uart->midi_input[substream])
220				snd_rawmidi_receive(uart->midi_input[substream],
221						    &c, 1);
222		} else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN) &&
223			   uart->midi_input[substream])
224			snd_rawmidi_receive(uart->midi_input[substream], &c, 1);
225
226		if (status & UART_LSR_OE)
227			snd_printk(KERN_WARNING
228				   "%s: Overrun on device at 0x%lx\n",
229			       uart->rmidi->name, uart->base);
230	}
231
232	/* remember the last stream */
233	uart->prev_in = substream;
234
235	/* no need of check SERIAL_MODE_OUTPUT_OPEN because if not,
236	   buffer is never filled. */
237	/* Check write status */
238	if (status & UART_LSR_THRE)
239		uart->fifo_count = 0;
240	if (uart->adaptor == SNDRV_SERIAL_MS124W_SA
241	   || uart->adaptor == SNDRV_SERIAL_GENERIC) {
242		/* Can't use FIFO, must send only when CTS is true */
243		status = inb(uart->base + UART_MSR);
244		while (uart->fifo_count == 0 && (status & UART_MSR_CTS) &&
245		       uart->buff_in_count > 0) {
246		       snd_uart16550_buffer_output(uart);
247		       status = inb(uart->base + UART_MSR);
248		}
249	} else {
250		/* Write loop */
251		while (uart->fifo_count < uart->fifo_limit /* Can we write ? */
252		       && uart->buff_in_count > 0)	/* Do we want to? */
253			snd_uart16550_buffer_output(uart);
254	}
255	if (uart->irq < 0 && uart->buff_in_count > 0)
256		snd_uart16550_add_timer(uart);
257}
258
259/* NOTES ON SERVICING INTERUPTS
260 * ---------------------------
261 * After receiving a interrupt, it is important to indicate to the UART that
262 * this has been done. 
263 * For a Rx interrupt, this is done by reading the received byte.
264 * For a Tx interrupt this is done by either:
265 * a) Writing a byte
266 * b) Reading the IIR
267 * It is particularly important to read the IIR if a Tx interrupt is received
268 * when there is no data in tx_buff[], as in this case there no other
269 * indication that the interrupt has been serviced, and it remains outstanding
270 * indefinitely. This has the curious side effect that and no further interrupts
271 * will be generated from this device AT ALL!!.
272 * It is also desirable to clear outstanding interrupts when the device is
273 * opened/closed.
274 *
275 *
276 * Note that some devices need OUT2 to be set before they will generate
277 * interrupts at all. (Possibly tied to an internal pull-up on CTS?)
278 */
279static irqreturn_t snd_uart16550_interrupt(int irq, void *dev_id)
280{
281	struct snd_uart16550 *uart;
282
283	uart = dev_id;
284	spin_lock(&uart->open_lock);
285	if (uart->filemode == SERIAL_MODE_NOT_OPENED) {
286		spin_unlock(&uart->open_lock);
287		return IRQ_NONE;
288	}
289	/* indicate to the UART that the interrupt has been serviced */
290	inb(uart->base + UART_IIR);
291	snd_uart16550_io_loop(uart);
292	spin_unlock(&uart->open_lock);
293	return IRQ_HANDLED;
294}
295
296/* When the polling mode, this function calls snd_uart16550_io_loop. */
297static void snd_uart16550_buffer_timer(struct timer_list *t)
298{
299	unsigned long flags;
300	struct snd_uart16550 *uart;
301
302	uart = from_timer(uart, t, buffer_timer);
303	spin_lock_irqsave(&uart->open_lock, flags);
304	snd_uart16550_del_timer(uart);
305	snd_uart16550_io_loop(uart);
306	spin_unlock_irqrestore(&uart->open_lock, flags);
307}
308
309/*
310 *  this method probes, if an uart sits on given port
311 *  return 0 if found
312 *  return negative error if not found
313 */
314static int snd_uart16550_detect(struct snd_uart16550 *uart)
315{
316	unsigned long io_base = uart->base;
317	int ok;
318	unsigned char c;
319
320	/* Do some vague tests for the presence of the uart */
321	if (io_base == 0 || io_base == SNDRV_AUTO_PORT) {
322		return -ENODEV;	/* Not configured */
323	}
324
325	if (!devm_request_region(uart->card->dev, io_base, 8, "Serial MIDI")) {
 
326		snd_printk(KERN_ERR "u16550: can't grab port 0x%lx\n", io_base);
327		return -EBUSY;
328	}
329
330	/* uart detected unless one of the following tests should fail */
331	ok = 1;
332	/* 8 data-bits, 1 stop-bit, parity off, DLAB = 0 */
333	outb(UART_LCR_WLEN8, io_base + UART_LCR); /* Line Control Register */
334	c = inb(io_base + UART_IER);
335	/* The top four bits of the IER should always == 0 */
336	if ((c & 0xf0) != 0)
337		ok = 0;		/* failed */
338
339	outb(0xaa, io_base + UART_SCR);
340	/* Write arbitrary data into the scratch reg */
341	c = inb(io_base + UART_SCR);
342	/* If it comes back, it's OK */
343	if (c != 0xaa)
344		ok = 0;		/* failed */
345
346	outb(0x55, io_base + UART_SCR);
347	/* Write arbitrary data into the scratch reg */
348	c = inb(io_base + UART_SCR);
349	/* If it comes back, it's OK */
350	if (c != 0x55)
351		ok = 0;		/* failed */
352
353	return ok;
354}
355
356static void snd_uart16550_do_open(struct snd_uart16550 * uart)
357{
358	char byte;
359
360	/* Initialize basic variables */
361	uart->buff_in_count = 0;
362	uart->buff_in = 0;
363	uart->buff_out = 0;
364	uart->fifo_limit = 1;
365	uart->fifo_count = 0;
366	uart->timer_running = 0;
367
368	outb(UART_FCR_ENABLE_FIFO	/* Enable FIFO's (if available) */
369	     | UART_FCR_CLEAR_RCVR	/* Clear receiver FIFO */
370	     | UART_FCR_CLEAR_XMIT	/* Clear transmitter FIFO */
371	     | UART_FCR_TRIGGER_4	/* Set FIFO trigger at 4-bytes */
372	/* NOTE: interrupt generated after T=(time)4-bytes
373	 * if less than UART_FCR_TRIGGER bytes received
374	 */
375	     ,uart->base + UART_FCR);	/* FIFO Control Register */
376
377	if ((inb(uart->base + UART_IIR) & 0xf0) == 0xc0)
378		uart->fifo_limit = 16;
379	if (uart->divisor != 0) {
380		uart->old_line_ctrl_reg = inb(uart->base + UART_LCR);
381		outb(UART_LCR_DLAB	/* Divisor latch access bit */
382		     ,uart->base + UART_LCR);	/* Line Control Register */
383		uart->old_divisor_lsb = inb(uart->base + UART_DLL);
384		uart->old_divisor_msb = inb(uart->base + UART_DLM);
385
386		outb(uart->divisor
387		     ,uart->base + UART_DLL);	/* Divisor Latch Low */
388		outb(0
389		     ,uart->base + UART_DLM);	/* Divisor Latch High */
390		/* DLAB is reset to 0 in next outb() */
391	}
392	/* Set serial parameters (parity off, etc) */
393	outb(UART_LCR_WLEN8	/* 8 data-bits */
394	     | 0		/* 1 stop-bit */
395	     | 0		/* parity off */
396	     | 0		/* DLAB = 0 */
397	     ,uart->base + UART_LCR);	/* Line Control Register */
398
399	switch (uart->adaptor) {
400	default:
401		outb(UART_MCR_RTS	/* Set Request-To-Send line active */
402		     | UART_MCR_DTR	/* Set Data-Terminal-Ready line active */
403		     | UART_MCR_OUT2	/* Set OUT2 - not always required, but when
404					 * it is, it is ESSENTIAL for enabling interrupts
405				 */
406		     ,uart->base + UART_MCR);	/* Modem Control Register */
407		break;
408	case SNDRV_SERIAL_MS124W_SA:
409	case SNDRV_SERIAL_MS124W_MB:
410		/* MS-124W can draw power from RTS and DTR if they
411		   are in opposite states. */ 
412		outb(UART_MCR_RTS | (0&UART_MCR_DTR) | UART_MCR_OUT2,
413		     uart->base + UART_MCR);
414		break;
415	case SNDRV_SERIAL_MS124T:
416		/* MS-124T can draw power from RTS and/or DTR (preferably
417		   both) if they are both asserted. */
418		outb(UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2,
419		     uart->base + UART_MCR);
420		break;
421	}
422
423	if (uart->irq < 0) {
424		byte = (0 & UART_IER_RDI)	/* Disable Receiver data interrupt */
425		    |(0 & UART_IER_THRI)	/* Disable Transmitter holding register empty interrupt */
426		    ;
427	} else if (uart->adaptor == SNDRV_SERIAL_MS124W_SA) {
428		byte = UART_IER_RDI	/* Enable Receiver data interrupt */
429		    | UART_IER_MSI	/* Enable Modem status interrupt */
430		    ;
431	} else if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
432		byte = UART_IER_RDI	/* Enable Receiver data interrupt */
433		    | UART_IER_MSI	/* Enable Modem status interrupt */
434		    | UART_IER_THRI	/* Enable Transmitter holding register empty interrupt */
435		    ;
436	} else {
437		byte = UART_IER_RDI	/* Enable Receiver data interrupt */
438		    | UART_IER_THRI	/* Enable Transmitter holding register empty interrupt */
439		    ;
440	}
441	outb(byte, uart->base + UART_IER);	/* Interrupt enable Register */
442
443	inb(uart->base + UART_LSR);	/* Clear any pre-existing overrun indication */
444	inb(uart->base + UART_IIR);	/* Clear any pre-existing transmit interrupt */
445	inb(uart->base + UART_RX);	/* Clear any pre-existing receive interrupt */
446}
447
448static void snd_uart16550_do_close(struct snd_uart16550 * uart)
449{
450	if (uart->irq < 0)
451		snd_uart16550_del_timer(uart);
452
453	/* NOTE: may need to disable interrupts before de-registering out handler.
454	 * For now, the consequences are harmless.
455	 */
456
457	outb((0 & UART_IER_RDI)		/* Disable Receiver data interrupt */
458	     |(0 & UART_IER_THRI)	/* Disable Transmitter holding register empty interrupt */
459	     ,uart->base + UART_IER);	/* Interrupt enable Register */
460
461	switch (uart->adaptor) {
462	default:
463		outb((0 & UART_MCR_RTS)		/* Deactivate Request-To-Send line  */
464		     |(0 & UART_MCR_DTR)	/* Deactivate Data-Terminal-Ready line */
465		     |(0 & UART_MCR_OUT2)	/* Deactivate OUT2 */
466		     ,uart->base + UART_MCR);	/* Modem Control Register */
467	  break;
468	case SNDRV_SERIAL_MS124W_SA:
469	case SNDRV_SERIAL_MS124W_MB:
470		/* MS-124W can draw power from RTS and DTR if they
471		   are in opposite states; leave it powered. */ 
472		outb(UART_MCR_RTS | (0&UART_MCR_DTR) | (0&UART_MCR_OUT2),
473		     uart->base + UART_MCR);
474		break;
475	case SNDRV_SERIAL_MS124T:
476		/* MS-124T can draw power from RTS and/or DTR (preferably
477		   both) if they are both asserted; leave it powered. */
478		outb(UART_MCR_RTS | UART_MCR_DTR | (0&UART_MCR_OUT2),
479		     uart->base + UART_MCR);
480		break;
481	}
482
483	inb(uart->base + UART_IIR);	/* Clear any outstanding interrupts */
484
485	/* Restore old divisor */
486	if (uart->divisor != 0) {
487		outb(UART_LCR_DLAB		/* Divisor latch access bit */
488		     ,uart->base + UART_LCR);	/* Line Control Register */
489		outb(uart->old_divisor_lsb
490		     ,uart->base + UART_DLL);	/* Divisor Latch Low */
491		outb(uart->old_divisor_msb
492		     ,uart->base + UART_DLM);	/* Divisor Latch High */
493		/* Restore old LCR (data bits, stop bits, parity, DLAB) */
494		outb(uart->old_line_ctrl_reg
495		     ,uart->base + UART_LCR);	/* Line Control Register */
496	}
497}
498
499static int snd_uart16550_input_open(struct snd_rawmidi_substream *substream)
500{
501	unsigned long flags;
502	struct snd_uart16550 *uart = substream->rmidi->private_data;
503
504	spin_lock_irqsave(&uart->open_lock, flags);
505	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
506		snd_uart16550_do_open(uart);
507	uart->filemode |= SERIAL_MODE_INPUT_OPEN;
508	uart->midi_input[substream->number] = substream;
509	spin_unlock_irqrestore(&uart->open_lock, flags);
510	return 0;
511}
512
513static int snd_uart16550_input_close(struct snd_rawmidi_substream *substream)
514{
515	unsigned long flags;
516	struct snd_uart16550 *uart = substream->rmidi->private_data;
517
518	spin_lock_irqsave(&uart->open_lock, flags);
519	uart->filemode &= ~SERIAL_MODE_INPUT_OPEN;
520	uart->midi_input[substream->number] = NULL;
521	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
522		snd_uart16550_do_close(uart);
523	spin_unlock_irqrestore(&uart->open_lock, flags);
524	return 0;
525}
526
527static void snd_uart16550_input_trigger(struct snd_rawmidi_substream *substream,
528					int up)
529{
530	unsigned long flags;
531	struct snd_uart16550 *uart = substream->rmidi->private_data;
532
533	spin_lock_irqsave(&uart->open_lock, flags);
534	if (up)
535		uart->filemode |= SERIAL_MODE_INPUT_TRIGGERED;
536	else
537		uart->filemode &= ~SERIAL_MODE_INPUT_TRIGGERED;
538	spin_unlock_irqrestore(&uart->open_lock, flags);
539}
540
541static int snd_uart16550_output_open(struct snd_rawmidi_substream *substream)
542{
543	unsigned long flags;
544	struct snd_uart16550 *uart = substream->rmidi->private_data;
545
546	spin_lock_irqsave(&uart->open_lock, flags);
547	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
548		snd_uart16550_do_open(uart);
549	uart->filemode |= SERIAL_MODE_OUTPUT_OPEN;
550	uart->midi_output[substream->number] = substream;
551	spin_unlock_irqrestore(&uart->open_lock, flags);
552	return 0;
553};
554
555static int snd_uart16550_output_close(struct snd_rawmidi_substream *substream)
556{
557	unsigned long flags;
558	struct snd_uart16550 *uart = substream->rmidi->private_data;
559
560	spin_lock_irqsave(&uart->open_lock, flags);
561	uart->filemode &= ~SERIAL_MODE_OUTPUT_OPEN;
562	uart->midi_output[substream->number] = NULL;
563	if (uart->filemode == SERIAL_MODE_NOT_OPENED)
564		snd_uart16550_do_close(uart);
565	spin_unlock_irqrestore(&uart->open_lock, flags);
566	return 0;
567};
568
569static inline int snd_uart16550_buffer_can_write(struct snd_uart16550 *uart,
570						 int Num)
571{
572	if (uart->buff_in_count + Num < TX_BUFF_SIZE)
573		return 1;
574	else
575		return 0;
576}
577
578static inline int snd_uart16550_write_buffer(struct snd_uart16550 *uart,
579					     unsigned char byte)
580{
581	unsigned short buff_in = uart->buff_in;
582	if (uart->buff_in_count < TX_BUFF_SIZE) {
583		uart->tx_buff[buff_in] = byte;
584		buff_in++;
585		buff_in &= TX_BUFF_MASK;
586		uart->buff_in = buff_in;
587		uart->buff_in_count++;
588		if (uart->irq < 0) /* polling mode */
589			snd_uart16550_add_timer(uart);
590		return 1;
591	} else
592		return 0;
593}
594
595static int snd_uart16550_output_byte(struct snd_uart16550 *uart,
596				     struct snd_rawmidi_substream *substream,
597				     unsigned char midi_byte)
598{
599	if (uart->buff_in_count == 0                    /* Buffer empty? */
600	    && ((uart->adaptor != SNDRV_SERIAL_MS124W_SA &&
601	    uart->adaptor != SNDRV_SERIAL_GENERIC) ||
602		(uart->fifo_count == 0                  /* FIFO empty? */
603		 && (inb(uart->base + UART_MSR) & UART_MSR_CTS)))) { /* CTS? */
604
605	        /* Tx Buffer Empty - try to write immediately */
606		if ((inb(uart->base + UART_LSR) & UART_LSR_THRE) != 0) {
607		        /* Transmitter holding register (and Tx FIFO) empty */
608		        uart->fifo_count = 1;
609			outb(midi_byte, uart->base + UART_TX);
610		} else {
611		        if (uart->fifo_count < uart->fifo_limit) {
612			        uart->fifo_count++;
613				outb(midi_byte, uart->base + UART_TX);
614			} else {
615			        /* Cannot write (buffer empty) -
616				 * put char in buffer */
617				snd_uart16550_write_buffer(uart, midi_byte);
618			}
619		}
620	} else {
621		if (!snd_uart16550_write_buffer(uart, midi_byte)) {
622			snd_printk(KERN_WARNING
623				   "%s: Buffer overrun on device at 0x%lx\n",
624				   uart->rmidi->name, uart->base);
625			return 0;
626		}
627	}
628
629	return 1;
630}
631
632static void snd_uart16550_output_write(struct snd_rawmidi_substream *substream)
633{
634	unsigned long flags;
635	unsigned char midi_byte, addr_byte;
636	struct snd_uart16550 *uart = substream->rmidi->private_data;
637	char first;
638	static unsigned long lasttime = 0;
639	
640	/* Interrupts are disabled during the updating of the tx_buff,
641	 * since it is 'bad' to have two processes updating the same
642	 * variables (ie buff_in & buff_out)
643	 */
644
645	spin_lock_irqsave(&uart->open_lock, flags);
646
647	if (uart->irq < 0)	/* polling */
648		snd_uart16550_io_loop(uart);
649
650	if (uart->adaptor == SNDRV_SERIAL_MS124W_MB) {
651		while (1) {
652			/* buffer full? */
653			/* in this mode we need two bytes of space */
654			if (uart->buff_in_count > TX_BUFF_SIZE - 2)
655				break;
656			if (snd_rawmidi_transmit(substream, &midi_byte, 1) != 1)
657				break;
658#ifdef SNDRV_SERIAL_MS124W_MB_NOCOMBO
659			/* select exactly one of the four ports */
660			addr_byte = (1 << (substream->number + 4)) | 0x08;
661#else
662			/* select any combination of the four ports */
663			addr_byte = (substream->number << 4) | 0x08;
664			/* ...except none */
665			if (addr_byte == 0x08)
666				addr_byte = 0xf8;
667#endif
668			snd_uart16550_output_byte(uart, substream, addr_byte);
669			/* send midi byte */
670			snd_uart16550_output_byte(uart, substream, midi_byte);
671		}
672	} else {
673		first = 0;
674		while (snd_rawmidi_transmit_peek(substream, &midi_byte, 1) == 1) {
675			/* Also send F5 after 3 seconds with no data
676			 * to handle device disconnect */
677			if (first == 0 &&
678			    (uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS ||
679			     uart->adaptor == SNDRV_SERIAL_GENERIC) &&
680			    (uart->prev_out != substream->number ||
681			     time_after(jiffies, lasttime + 3*HZ))) {
682
683				if (snd_uart16550_buffer_can_write(uart, 3)) {
684					/* Roland Soundcanvas part selection */
685					/* If this substream of the data is
686					 * different previous substream
687					 * in this uart, send the change part
688					 * event
689					 */
690					uart->prev_out = substream->number;
691					/* change part */
692					snd_uart16550_output_byte(uart, substream,
693								  0xf5);
694					/* data */
695					snd_uart16550_output_byte(uart, substream,
696								  uart->prev_out + 1);
697					/* If midi_byte is a data byte,
698					 * send the previous status byte */
699					if (midi_byte < 0x80 &&
700					    uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS)
701						snd_uart16550_output_byte(uart, substream, uart->prev_status[uart->prev_out]);
702				} else if (!uart->drop_on_full)
703					break;
704
705			}
706
707			/* send midi byte */
708			if (!snd_uart16550_output_byte(uart, substream, midi_byte) &&
709			    !uart->drop_on_full )
710				break;
711
712			if (midi_byte >= 0x80 && midi_byte < 0xf0)
713				uart->prev_status[uart->prev_out] = midi_byte;
714			first = 1;
715
716			snd_rawmidi_transmit_ack( substream, 1 );
717		}
718		lasttime = jiffies;
719	}
720	spin_unlock_irqrestore(&uart->open_lock, flags);
721}
722
723static void snd_uart16550_output_trigger(struct snd_rawmidi_substream *substream,
724					 int up)
725{
726	unsigned long flags;
727	struct snd_uart16550 *uart = substream->rmidi->private_data;
728
729	spin_lock_irqsave(&uart->open_lock, flags);
730	if (up)
731		uart->filemode |= SERIAL_MODE_OUTPUT_TRIGGERED;
732	else
733		uart->filemode &= ~SERIAL_MODE_OUTPUT_TRIGGERED;
734	spin_unlock_irqrestore(&uart->open_lock, flags);
735	if (up)
736		snd_uart16550_output_write(substream);
737}
738
739static const struct snd_rawmidi_ops snd_uart16550_output =
740{
741	.open =		snd_uart16550_output_open,
742	.close =	snd_uart16550_output_close,
743	.trigger =	snd_uart16550_output_trigger,
744};
745
746static const struct snd_rawmidi_ops snd_uart16550_input =
747{
748	.open =		snd_uart16550_input_open,
749	.close =	snd_uart16550_input_close,
750	.trigger =	snd_uart16550_input_trigger,
751};
752
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
753static int snd_uart16550_create(struct snd_card *card,
754				unsigned long iobase,
755				int irq,
756				unsigned int speed,
757				unsigned int base,
758				int adaptor,
759				int droponfull,
760				struct snd_uart16550 **ruart)
761{
 
 
 
762	struct snd_uart16550 *uart;
763	int err;
764
765
766	uart = devm_kzalloc(card->dev, sizeof(*uart), GFP_KERNEL);
767	if (!uart)
768		return -ENOMEM;
769	uart->adaptor = adaptor;
770	uart->card = card;
771	spin_lock_init(&uart->open_lock);
772	uart->irq = -1;
773	uart->base = iobase;
774	uart->drop_on_full = droponfull;
775
776	err = snd_uart16550_detect(uart);
777	if (err <= 0) {
778		printk(KERN_ERR "no UART detected at 0x%lx\n", iobase);
 
779		return -ENODEV;
780	}
781
782	if (irq >= 0 && irq != SNDRV_AUTO_IRQ) {
783		if (devm_request_irq(card->dev, irq, snd_uart16550_interrupt,
784				     0, "Serial MIDI", uart)) {
785			snd_printk(KERN_WARNING
786				   "irq %d busy. Using Polling.\n", irq);
787		} else {
788			uart->irq = irq;
789		}
790	}
791	uart->divisor = base / speed;
792	uart->speed = base / (unsigned int)uart->divisor;
793	uart->speed_base = base;
794	uart->prev_out = -1;
795	uart->prev_in = 0;
796	uart->rstatus = 0;
797	memset(uart->prev_status, 0x80, sizeof(unsigned char) * SNDRV_SERIAL_MAX_OUTS);
798	timer_setup(&uart->buffer_timer, snd_uart16550_buffer_timer, 0);
799	uart->timer_running = 0;
800
 
 
 
 
 
 
 
801	switch (uart->adaptor) {
802	case SNDRV_SERIAL_MS124W_SA:
803	case SNDRV_SERIAL_MS124W_MB:
804		/* MS-124W can draw power from RTS and DTR if they
805		   are in opposite states. */ 
806		outb(UART_MCR_RTS | (0&UART_MCR_DTR), uart->base + UART_MCR);
807		break;
808	case SNDRV_SERIAL_MS124T:
809		/* MS-124T can draw power from RTS and/or DTR (preferably
810		   both) if they are asserted. */
811		outb(UART_MCR_RTS | UART_MCR_DTR, uart->base + UART_MCR);
812		break;
813	default:
814		break;
815	}
816
817	if (ruart)
818		*ruart = uart;
819
820	return 0;
821}
822
823static void snd_uart16550_substreams(struct snd_rawmidi_str *stream)
824{
825	struct snd_rawmidi_substream *substream;
826
827	list_for_each_entry(substream, &stream->substreams, list) {
828		sprintf(substream->name, "Serial MIDI %d", substream->number + 1);
829	}
830}
831
832static int snd_uart16550_rmidi(struct snd_uart16550 *uart, int device,
833			       int outs, int ins,
834			       struct snd_rawmidi **rmidi)
835{
836	struct snd_rawmidi *rrawmidi;
837	int err;
838
839	err = snd_rawmidi_new(uart->card, "UART Serial MIDI", device,
840			      outs, ins, &rrawmidi);
841	if (err < 0)
842		return err;
843	snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_INPUT,
844			    &snd_uart16550_input);
845	snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
846			    &snd_uart16550_output);
847	strcpy(rrawmidi->name, "Serial MIDI");
848	snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT]);
849	snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT]);
850	rrawmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
851			       SNDRV_RAWMIDI_INFO_INPUT |
852			       SNDRV_RAWMIDI_INFO_DUPLEX;
853	rrawmidi->private_data = uart;
854	if (rmidi)
855		*rmidi = rrawmidi;
856	return 0;
857}
858
859static int snd_serial_probe(struct platform_device *devptr)
860{
861	struct snd_card *card;
862	struct snd_uart16550 *uart;
863	int err;
864	int dev = devptr->id;
865
866	switch (adaptor[dev]) {
867	case SNDRV_SERIAL_SOUNDCANVAS:
868		ins[dev] = 1;
869		break;
870	case SNDRV_SERIAL_MS124T:
871	case SNDRV_SERIAL_MS124W_SA:
872		outs[dev] = 1;
873		ins[dev] = 1;
874		break;
875	case SNDRV_SERIAL_MS124W_MB:
876		outs[dev] = 16;
877		ins[dev] = 1;
878		break;
879	case SNDRV_SERIAL_GENERIC:
880		break;
881	default:
882		snd_printk(KERN_ERR
883			   "Adaptor type is out of range 0-%d (%d)\n",
884			   SNDRV_SERIAL_MAX_ADAPTOR, adaptor[dev]);
885		return -ENODEV;
886	}
887
888	if (outs[dev] < 1 || outs[dev] > SNDRV_SERIAL_MAX_OUTS) {
889		snd_printk(KERN_ERR
890			   "Count of outputs is out of range 1-%d (%d)\n",
891			   SNDRV_SERIAL_MAX_OUTS, outs[dev]);
892		return -ENODEV;
893	}
894
895	if (ins[dev] < 1 || ins[dev] > SNDRV_SERIAL_MAX_INS) {
896		snd_printk(KERN_ERR
897			   "Count of inputs is out of range 1-%d (%d)\n",
898			   SNDRV_SERIAL_MAX_INS, ins[dev]);
899		return -ENODEV;
900	}
901
902	err  = snd_devm_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE,
903				 0, &card);
904	if (err < 0)
905		return err;
906
907	strcpy(card->driver, "Serial");
908	strcpy(card->shortname, "Serial MIDI (UART16550A)");
909
910	err = snd_uart16550_create(card, port[dev], irq[dev], speed[dev],
911				   base[dev], adaptor[dev], droponfull[dev],
912				   &uart);
913	if (err < 0)
914		return err;
915
916	err = snd_uart16550_rmidi(uart, 0, outs[dev], ins[dev], &uart->rmidi);
917	if (err < 0)
918		return err;
919
920	sprintf(card->longname, "%s [%s] at %#lx, irq %d",
921		card->shortname,
922		adaptor_names[uart->adaptor],
923		uart->base,
924		uart->irq);
925
926	err = snd_card_register(card);
927	if (err < 0)
928		return err;
929
930	platform_set_drvdata(devptr, card);
931	return 0;
 
 
 
 
 
 
 
 
 
 
932}
933
934#define SND_SERIAL_DRIVER	"snd_serial_u16550"
935
936static struct platform_driver snd_serial_driver = {
937	.probe		= snd_serial_probe,
 
938	.driver		= {
939		.name	= SND_SERIAL_DRIVER,
940	},
941};
942
943static void snd_serial_unregister_all(void)
944{
945	int i;
946
947	for (i = 0; i < ARRAY_SIZE(devices); ++i)
948		platform_device_unregister(devices[i]);
949	platform_driver_unregister(&snd_serial_driver);
950}
951
952static int __init alsa_card_serial_init(void)
953{
954	int i, cards, err;
955
956	err = platform_driver_register(&snd_serial_driver);
957	if (err < 0)
958		return err;
959
960	cards = 0;
961	for (i = 0; i < SNDRV_CARDS; i++) {
962		struct platform_device *device;
963		if (! enable[i])
964			continue;
965		device = platform_device_register_simple(SND_SERIAL_DRIVER,
966							 i, NULL, 0);
967		if (IS_ERR(device))
968			continue;
969		if (!platform_get_drvdata(device)) {
970			platform_device_unregister(device);
971			continue;
972		}
973		devices[i] = device;
974		cards++;
975	}
976	if (! cards) {
977#ifdef MODULE
978		printk(KERN_ERR "serial midi soundcard not found or device busy\n");
979#endif
980		snd_serial_unregister_all();
981		return -ENODEV;
982	}
983	return 0;
984}
985
986static void __exit alsa_card_serial_exit(void)
987{
988	snd_serial_unregister_all();
989}
990
991module_init(alsa_card_serial_init)
992module_exit(alsa_card_serial_exit)