linux/sound/drivers/serial-u16550.c
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   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)
1046