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 <sound/core.h>
  41#include <sound/rawmidi.h>
  42#include <sound/initval.h>
  43
  44#include <linux/serial_reg.h>
  45#include <linux/jiffies.h>
  46
  47#include <asm/io.h>
  48
  49MODULE_DESCRIPTION("MIDI serial u16550");
  50MODULE_LICENSE("GPL");
  51MODULE_SUPPORTED_DEVICE("{{ALSA, MIDI serial u16550}}");
  52
  53#define SNDRV_SERIAL_SOUNDCANVAS 0 /* Roland Soundcanvas; F5 NN selects part */
  54#define SNDRV_SERIAL_MS124T 1      /* Midiator MS-124T */
  55#define SNDRV_SERIAL_MS124W_SA 2   /* Midiator MS-124W in S/A mode */
  56#define SNDRV_SERIAL_MS124W_MB 3   /* Midiator MS-124W in M/B mode */
  57#define SNDRV_SERIAL_GENERIC 4     /* Generic Interface */
  58#define SNDRV_SERIAL_MAX_ADAPTOR SNDRV_SERIAL_GENERIC
  59static char *adaptor_names[] = {
  60        "Soundcanvas",
  61        "MS-124T",
  62        "MS-124W S/A",
  63        "MS-124W M/B",
  64        "Generic"
  65};
  66
  67#define SNDRV_SERIAL_NORMALBUFF 0 /* Normal blocking buffer operation */
  68#define SNDRV_SERIAL_DROPBUFF   1 /* Non-blocking discard operation */
  69
  70static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
  71static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
  72static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE; /* Enable this card */
  73static long port[SNDRV_CARDS] = SNDRV_DEFAULT_PORT; /* 0x3f8,0x2f8,0x3e8,0x2e8 */
  74static int irq[SNDRV_CARDS] = SNDRV_DEFAULT_IRQ;        /* 3,4,5,7,9,10,11,14,15 */
  75static int speed[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 38400}; /* 9600,19200,38400,57600,115200 */
  76static int base[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 115200}; /* baud base */
  77static int outs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};  /* 1 to 16 */
  78static int ins[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1};  /* 1 to 16 */
  79static int adaptor[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = SNDRV_SERIAL_SOUNDCANVAS};
  80static bool droponfull[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS -1)] = SNDRV_SERIAL_NORMALBUFF };
  81
  82module_param_array(index, int, NULL, 0444);
  83MODULE_PARM_DESC(index, "Index value for Serial MIDI.");
  84module_param_array(id, charp, NULL, 0444);
  85MODULE_PARM_DESC(id, "ID string for Serial MIDI.");
  86module_param_array(enable, bool, NULL, 0444);
  87MODULE_PARM_DESC(enable, "Enable UART16550A chip.");
  88module_param_array(port, long, NULL, 0444);
  89MODULE_PARM_DESC(port, "Port # for UART16550A chip.");
  90module_param_array(irq, int, NULL, 0444);
  91MODULE_PARM_DESC(irq, "IRQ # for UART16550A chip.");
  92module_param_array(speed, int, NULL, 0444);
  93MODULE_PARM_DESC(speed, "Speed in bauds.");
  94module_param_array(base, int, NULL, 0444);
  95MODULE_PARM_DESC(base, "Base for divisor in bauds.");
  96module_param_array(outs, int, NULL, 0444);
  97MODULE_PARM_DESC(outs, "Number of MIDI outputs.");
  98module_param_array(ins, int, NULL, 0444);
  99MODULE_PARM_DESC(ins, "Number of MIDI inputs.");
 100module_param_array(droponfull, bool, NULL, 0444);
 101MODULE_PARM_DESC(droponfull, "Flag to enable drop-on-full buffer mode");
 102
 103module_param_array(adaptor, int, NULL, 0444);
 104MODULE_PARM_DESC(adaptor, "Type of adaptor.");
 105
 106/*#define SNDRV_SERIAL_MS124W_MB_NOCOMBO 1*/  /* Address outs as 0-3 instead of bitmap */
 107
 108#define SNDRV_SERIAL_MAX_OUTS   16              /* max 64, min 16 */
 109#define SNDRV_SERIAL_MAX_INS    16              /* max 64, min 16 */
 110
 111#define TX_BUFF_SIZE            (1<<15)         /* Must be 2^n */
 112#define TX_BUFF_MASK            (TX_BUFF_SIZE - 1)
 113
 114#define SERIAL_MODE_NOT_OPENED          (0)
 115#define SERIAL_MODE_INPUT_OPEN          (1 << 0)
 116#define SERIAL_MODE_OUTPUT_OPEN         (1 << 1)
 117#define SERIAL_MODE_INPUT_TRIGGERED     (1 << 2)
 118#define SERIAL_MODE_OUTPUT_TRIGGERED    (1 << 3)
 119
 120struct snd_uart16550 {
 121        struct snd_card *card;
 122        struct snd_rawmidi *rmidi;
 123        struct snd_rawmidi_substream *midi_output[SNDRV_SERIAL_MAX_OUTS];
 124        struct snd_rawmidi_substream *midi_input[SNDRV_SERIAL_MAX_INS];
 125
 126        int filemode;           /* open status of file */
 127
 128        spinlock_t open_lock;
 129
 130        int irq;
 131
 132        unsigned long base;
 133        struct resource *res_base;
 134
 135        unsigned int speed;
 136        unsigned int speed_base;
 137        unsigned char divisor;
 138
 139        unsigned char old_divisor_lsb;
 140        unsigned char old_divisor_msb;
 141        unsigned char old_line_ctrl_reg;
 142
 143        /* parameter for using of write loop */
 144        short int fifo_limit;   /* used in uart16550 */
 145        short int fifo_count;   /* used in uart16550 */
 146
 147        /* type of adaptor */
 148        int adaptor;
 149
 150        /* inputs */
 151        int prev_in;
 152        unsigned char rstatus;
 153
 154        /* outputs */
 155        int prev_out;
 156        unsigned char prev_status[SNDRV_SERIAL_MAX_OUTS];
 157
 158        /* write buffer and its writing/reading position */
 159        unsigned char tx_buff[TX_BUFF_SIZE];
 160        int buff_in_count;
 161        int buff_in;
 162        int buff_out;
 163        int drop_on_full;
 164
 165        /* wait timer */
 166        unsigned int timer_running:1;
 167        struct timer_list buffer_timer;
 168
 169};
 170
 171static struct platform_device *devices[SNDRV_CARDS];
 172
 173static inline void snd_uart16550_add_timer(struct snd_uart16550 *uart)
 174{
 175        if (!uart->timer_running) {
 176                /* timer 38600bps * 10bit * 16byte */
 177                uart->buffer_timer.expires = jiffies + (HZ+255)/256;
 178                uart->timer_running = 1;
 179                add_timer(&uart->buffer_timer);
 180        }
 181}
 182
 183static inline void snd_uart16550_del_timer(struct snd_uart16550 *uart)
 184{
 185        if (uart->timer_running) {
 186                del_timer(&uart->buffer_timer);
 187                uart->timer_running = 0;
 188        }
 189}
 190
 191/* This macro is only used in snd_uart16550_io_loop */
 192static inline void snd_uart16550_buffer_output(struct snd_uart16550 *uart)
 193{
 194        unsigned short buff_out = uart->buff_out;
 195        if (uart->buff_in_count > 0) {
 196                outb(uart->tx_buff[buff_out], uart->base + UART_TX);
 197                uart->fifo_count++;
 198                buff_out++;
 199                buff_out &= TX_BUFF_MASK;
 200                uart->buff_out = buff_out;
 201                uart->buff_in_count--;
 202        }
 203}
 204
 205/* This loop should be called with interrupts disabled
 206 * We don't want to interrupt this, 
 207 * as we're already handling an interrupt 
 208 */
 209static void snd_uart16550_io_loop(struct snd_uart16550 * uart)
 210{
 211        unsigned char c, status;
 212        int substream;
 213
 214        /* recall previous stream */
 215        substream = uart->prev_in;
 216
 217        /* Read Loop */
 218        while ((status = inb(uart->base + UART_LSR)) & UART_LSR_DR) {
 219                /* while receive data ready */
 220                c = inb(uart->base + UART_RX);
 221
 222                /* keep track of last status byte */
 223                if (c & 0x80)
 224                        uart->rstatus = c;
 225
 226                /* handle stream switch */
 227                if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
 228                        if (uart->rstatus == 0xf5) {
 229                                if (c <= SNDRV_SERIAL_MAX_INS && c > 0)
 230                                        substream = c - 1;
 231                                if (c != 0xf5)
 232                                        /* prevent future bytes from being
 233                                           interpreted as streams */
 234                                        uart->rstatus = 0;
 235                        } else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN)
 236                                   && uart->midi_input[substream])
 237                                snd_rawmidi_receive(uart->midi_input[substream],
 238                                                    &c, 1);
 239                } else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN) &&
 240                           uart->midi_input[substream])
 241                        snd_rawmidi_receive(uart->midi_input[substream], &c, 1);
 242
 243                if (status & UART_LSR_OE)
 244                        snd_printk(KERN_WARNING
 245                                   "%s: Overrun on device at 0x%lx\n",
 246                               uart->rmidi->name, uart->base);
 247        }
 248
 249        /* remember the last stream */
 250        uart->prev_in = substream;
 251
 252        /* no need of check SERIAL_MODE_OUTPUT_OPEN because if not,
 253           buffer is never filled. */
 254        /* Check write status */
 255        if (status & UART_LSR_THRE)
 256                uart->fifo_count = 0;
 257        if (uart->adaptor == SNDRV_SERIAL_MS124W_SA
 258           || uart->adaptor == SNDRV_SERIAL_GENERIC) {
 259                /* Can't use FIFO, must send only when CTS is true */
 260                status = inb(uart->base + UART_MSR);
 261                while (uart->fifo_count == 0 && (status & UART_MSR_CTS) &&
 262                       uart->buff_in_count > 0) {
 263                       snd_uart16550_buffer_output(uart);
 264                       status = inb(uart->base + UART_MSR);
 265                }
 266        } else {
 267                /* Write loop */
 268                while (uart->fifo_count < uart->fifo_limit /* Can we write ? */
 269                       && uart->buff_in_count > 0)      /* Do we want to? */
 270                        snd_uart16550_buffer_output(uart);
 271        }
 272        if (uart->irq < 0 && uart->buff_in_count > 0)
 273                snd_uart16550_add_timer(uart);
 274}
 275
 276/* NOTES ON SERVICING INTERUPTS
 277 * ---------------------------
 278 * After receiving a interrupt, it is important to indicate to the UART that
 279 * this has been done. 
 280 * For a Rx interrupt, this is done by reading the received byte.
 281 * For a Tx interrupt this is done by either:
 282 * a) Writing a byte
 283 * b) Reading the IIR
 284 * It is particularly important to read the IIR if a Tx interrupt is received
 285 * when there is no data in tx_buff[], as in this case there no other
 286 * indication that the interrupt has been serviced, and it remains outstanding
 287 * indefinitely. This has the curious side effect that and no further interrupts
 288 * will be generated from this device AT ALL!!.
 289 * It is also desirable to clear outstanding interrupts when the device is
 290 * opened/closed.
 291 *
 292 *
 293 * Note that some devices need OUT2 to be set before they will generate
 294 * interrupts at all. (Possibly tied to an internal pull-up on CTS?)
 295 */
 296static irqreturn_t snd_uart16550_interrupt(int irq, void *dev_id)
 297{
 298        struct snd_uart16550 *uart;
 299
 300        uart = dev_id;
 301        spin_lock(&uart->open_lock);
 302        if (uart->filemode == SERIAL_MODE_NOT_OPENED) {
 303                spin_unlock(&uart->open_lock);
 304                return IRQ_NONE;
 305        }
 306        /* indicate to the UART that the interrupt has been serviced */
 307        inb(uart->base + UART_IIR);
 308        snd_uart16550_io_loop(uart);
 309        spin_unlock(&uart->open_lock);
 310        return IRQ_HANDLED;
 311}
 312
 313/* When the polling mode, this function calls snd_uart16550_io_loop. */
 314static void snd_uart16550_buffer_timer(unsigned long data)
 315{
 316        unsigned long flags;
 317        struct snd_uart16550 *uart;
 318
 319        uart = (struct snd_uart16550 *)data;
 320        spin_lock_irqsave(&uart->open_lock, flags);
 321        snd_uart16550_del_timer(uart);
 322        snd_uart16550_io_loop(uart);
 323        spin_unlock_irqrestore(&uart->open_lock, flags);
 324}
 325
 326/*
 327 *  this method probes, if an uart sits on given port
 328 *  return 0 if found
 329 *  return negative error if not found
 330 */
 331static int __devinit snd_uart16550_detect(struct snd_uart16550 *uart)
 332{
 333        unsigned long io_base = uart->base;
 334        int ok;
 335        unsigned char c;
 336
 337        /* Do some vague tests for the presence of the uart */
 338        if (io_base == 0 || io_base == SNDRV_AUTO_PORT) {
 339                return -ENODEV; /* Not configured */
 340        }
 341
 342        uart->res_base = request_region(io_base, 8, "Serial MIDI");
 343        if (uart->res_base == NULL) {
 344                snd_printk(KERN_ERR "u16550: can't grab port 0x%lx\n", io_base);
 345                return -EBUSY;
 346        }
 347
 348        /* uart detected unless one of the following tests should fail */
 349        ok = 1;
 350        /* 8 data-bits, 1 stop-bit, parity off, DLAB = 0 */
 351        outb(UART_LCR_WLEN8, io_base + UART_LCR); /* Line Control Register */
 352        c = inb(io_base + UART_IER);
 353        /* The top four bits of the IER should always == 0 */
 354        if ((c & 0xf0) != 0)
 355                ok = 0;         /* failed */
 356
 357        outb(0xaa, io_base + UART_SCR);
 358        /* Write arbitrary data into the scratch reg */
 359        c = inb(io_base + UART_SCR);
 360        /* If it comes back, it's OK */
 361        if (c != 0xaa)
 362                ok = 0;         /* failed */
 363
 364        outb(0x55, io_base + UART_SCR);
 365        /* Write arbitrary data into the scratch reg */
 366        c = inb(io_base + UART_SCR);
 367        /* If it comes back, it's OK */
 368        if (c != 0x55)
 369                ok = 0;         /* failed */
 370
 371        return ok;
 372}
 373
 374static void snd_uart16550_do_open(struct snd_uart16550 * uart)
 375{
 376        char byte;
 377
 378        /* Initialize basic variables */
 379        uart->buff_in_count = 0;
 380        uart->buff_in = 0;
 381        uart->buff_out = 0;
 382        uart->fifo_limit = 1;
 383        uart->fifo_count = 0;
 384        uart->timer_running = 0;
 385
 386        outb(UART_FCR_ENABLE_FIFO       /* Enable FIFO's (if available) */
 387             | UART_FCR_CLEAR_RCVR      /* Clear receiver FIFO */
 388             | UART_FCR_CLEAR_XMIT      /* Clear transmitter FIFO */
 389             | UART_FCR_TRIGGER_4       /* Set FIFO trigger at 4-bytes */
 390        /* NOTE: interrupt generated after T=(time)4-bytes
 391         * if less than UART_FCR_TRIGGER bytes received
 392         */
 393             ,uart->base + UART_FCR);   /* FIFO Control Register */
 394
 395        if ((inb(uart->base + UART_IIR) & 0xf0) == 0xc0)
 396                uart->fifo_limit = 16;
 397        if (uart->divisor != 0) {
 398                uart->old_line_ctrl_reg = inb(uart->base + UART_LCR);
 399                outb(UART_LCR_DLAB      /* Divisor latch access bit */
 400                     ,uart->base + UART_LCR);   /* Line Control Register */
 401                uart->old_divisor_lsb = inb(uart->base + UART_DLL);
 402                uart->old_divisor_msb = inb(uart->base + UART_DLM);
 403
 404                outb(uart->divisor
 405                     ,uart->base + UART_DLL);   /* Divisor Latch Low */
 406                outb(0
 407                     ,uart->base + UART_DLM);   /* Divisor Latch High */
 408                /* DLAB is reset to 0 in next outb() */
 409        }
 410        /* Set serial parameters (parity off, etc) */
 411        outb(UART_LCR_WLEN8     /* 8 data-bits */
 412             | 0                /* 1 stop-bit */
 413             | 0                /* parity off */
 414             | 0                /* DLAB = 0 */
 415             ,uart->base + UART_LCR);   /* Line Control Register */
 416
 417        switch (uart->adaptor) {
 418        default:
 419                outb(UART_MCR_RTS       /* Set Request-To-Send line active */
 420                     | UART_MCR_DTR     /* Set Data-Terminal-Ready line active */
 421                     | UART_MCR_OUT2    /* Set OUT2 - not always required, but when
 422                                         * it is, it is ESSENTIAL for enabling interrupts
 423                                 */
 424                     ,uart->base + UART_MCR);   /* Modem Control Register */
 425                break;
 426        case SNDRV_SERIAL_MS124W_SA:
 427        case SNDRV_SERIAL_MS124W_MB:
 428                /* MS-124W can draw power from RTS and DTR if they
 429                   are in opposite states. */ 
 430                outb(UART_MCR_RTS | (0&UART_MCR_DTR) | UART_MCR_OUT2,
 431                     uart->base + UART_MCR);
 432                break;
 433        case SNDRV_SERIAL_MS124T:
 434                /* MS-124T can draw power from RTS and/or DTR (preferably
 435                   both) if they are both asserted. */
 436                outb(UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2,
 437                     uart->base + UART_MCR);
 438                break;
 439        }
 440
 441        if (uart->irq < 0) {
 442                byte = (0 & UART_IER_RDI)       /* Disable Receiver data interrupt */
 443                    |(0 & UART_IER_THRI)        /* Disable Transmitter holding register empty interrupt */
 444                    ;
 445        } else if (uart->adaptor == SNDRV_SERIAL_MS124W_SA) {
 446                byte = UART_IER_RDI     /* Enable Receiver data interrupt */
 447                    | UART_IER_MSI      /* Enable Modem status interrupt */
 448                    ;
 449        } else if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
 450                byte = UART_IER_RDI     /* Enable Receiver data interrupt */
 451                    | UART_IER_MSI      /* Enable Modem status interrupt */
 452                    | UART_IER_THRI     /* Enable Transmitter holding register empty interrupt */
 453                    ;
 454        } else {
 455                byte = UART_IER_RDI     /* Enable Receiver data interrupt */
 456                    | UART_IER_THRI     /* Enable Transmitter holding register empty interrupt */
 457                    ;
 458        }
 459        outb(byte, uart->base + UART_IER);      /* Interrupt enable Register */
 460
 461        inb(uart->base + UART_LSR);     /* Clear any pre-existing overrun indication */
 462        inb(uart->base + UART_IIR);     /* Clear any pre-existing transmit interrupt */
 463        inb(uart->base + UART_RX);      /* Clear any pre-existing receive interrupt */
 464}
 465
 466static void snd_uart16550_do_close(struct snd_uart16550 * uart)
 467{
 468        if (uart->irq < 0)
 469                snd_uart16550_del_timer(uart);
 470
 471        /* NOTE: may need to disable interrupts before de-registering out handler.
 472         * For now, the consequences are harmless.
 473         */
 474
 475        outb((0 & UART_IER_RDI)         /* Disable Receiver data interrupt */
 476             |(0 & UART_IER_THRI)       /* Disable Transmitter holding register empty interrupt */
 477             ,uart->base + UART_IER);   /* Interrupt enable Register */
 478
 479        switch (uart->adaptor) {
 480        default:
 481                outb((0 & UART_MCR_RTS)         /* Deactivate Request-To-Send line  */
 482                     |(0 & UART_MCR_DTR)        /* Deactivate Data-Terminal-Ready line */
 483                     |(0 & UART_MCR_OUT2)       /* Deactivate OUT2 */
 484                     ,uart->base + UART_MCR);   /* Modem Control Register */
 485          break;
 486        case SNDRV_SERIAL_MS124W_SA:
 487        case SNDRV_SERIAL_MS124W_MB:
 488                /* MS-124W can draw power from RTS and DTR if they
 489                   are in opposite states; leave it powered. */ 
 490                outb(UART_MCR_RTS | (0&UART_MCR_DTR) | (0&UART_MCR_OUT2),
 491                     uart->base + UART_MCR);
 492                break;
 493        case SNDRV_SERIAL_MS124T:
 494                /* MS-124T can draw power from RTS and/or DTR (preferably
 495                   both) if they are both asserted; leave it powered. */
 496                outb(UART_MCR_RTS | UART_MCR_DTR | (0&UART_MCR_OUT2),
 497                     uart->base + UART_MCR);
 498                break;
 499        }
 500
 501        inb(uart->base + UART_IIR);     /* Clear any outstanding interrupts */
 502
 503        /* Restore old divisor */
 504        if (uart->divisor != 0) {
 505                outb(UART_LCR_DLAB              /* Divisor latch access bit */
 506                     ,uart->base + UART_LCR);   /* Line Control Register */
 507                outb(uart->old_divisor_lsb
 508                     ,uart->base + UART_DLL);   /* Divisor Latch Low */
 509                outb(uart->old_divisor_msb
 510                     ,uart->base + UART_DLM);   /* Divisor Latch High */
 511                /* Restore old LCR (data bits, stop bits, parity, DLAB) */
 512                outb(uart->old_line_ctrl_reg
 513                     ,uart->base + UART_LCR);   /* Line Control Register */
 514        }
 515}
 516
 517static int snd_uart16550_input_open(struct snd_rawmidi_substream *substream)
 518{
 519        unsigned long flags;
 520        struct snd_uart16550 *uart = substream->rmidi->private_data;
 521
 522        spin_lock_irqsave(&uart->open_lock, flags);
 523        if (uart->filemode == SERIAL_MODE_NOT_OPENED)
 524                snd_uart16550_do_open(uart);
 525        uart->filemode |= SERIAL_MODE_INPUT_OPEN;
 526        uart->midi_input[substream->number] = substream;
 527        spin_unlock_irqrestore(&uart->open_lock, flags);
 528        return 0;
 529}
 530
 531static int snd_uart16550_input_close(struct snd_rawmidi_substream *substream)
 532{
 533        unsigned long flags;
 534        struct snd_uart16550 *uart = substream->rmidi->private_data;
 535
 536        spin_lock_irqsave(&uart->open_lock, flags);
 537        uart->filemode &= ~SERIAL_MODE_INPUT_OPEN;
 538        uart->midi_input[substream->number] = NULL;
 539        if (uart->filemode == SERIAL_MODE_NOT_OPENED)
 540                snd_uart16550_do_close(uart);
 541        spin_unlock_irqrestore(&uart->open_lock, flags);
 542        return 0;
 543}
 544
 545static void snd_uart16550_input_trigger(struct snd_rawmidi_substream *substream,
 546                                        int up)
 547{
 548        unsigned long flags;
 549        struct snd_uart16550 *uart = substream->rmidi->private_data;
 550
 551        spin_lock_irqsave(&uart->open_lock, flags);
 552        if (up)
 553                uart->filemode |= SERIAL_MODE_INPUT_TRIGGERED;
 554        else
 555                uart->filemode &= ~SERIAL_MODE_INPUT_TRIGGERED;
 556        spin_unlock_irqrestore(&uart->open_lock, flags);
 557}
 558
 559static int snd_uart16550_output_open(struct snd_rawmidi_substream *substream)
 560{
 561        unsigned long flags;
 562        struct snd_uart16550 *uart = substream->rmidi->private_data;
 563
 564        spin_lock_irqsave(&uart->open_lock, flags);
 565        if (uart->filemode == SERIAL_MODE_NOT_OPENED)
 566                snd_uart16550_do_open(uart);
 567        uart->filemode |= SERIAL_MODE_OUTPUT_OPEN;
 568        uart->midi_output[substream->number] = substream;
 569        spin_unlock_irqrestore(&uart->open_lock, flags);
 570        return 0;
 571};
 572
 573static int snd_uart16550_output_close(struct snd_rawmidi_substream *substream)
 574{
 575        unsigned long flags;
 576        struct snd_uart16550 *uart = substream->rmidi->private_data;
 577
 578        spin_lock_irqsave(&uart->open_lock, flags);
 579        uart->filemode &= ~SERIAL_MODE_OUTPUT_OPEN;
 580        uart->midi_output[substream->number] = NULL;
 581        if (uart->filemode == SERIAL_MODE_NOT_OPENED)
 582                snd_uart16550_do_close(uart);
 583        spin_unlock_irqrestore(&uart->open_lock, flags);
 584        return 0;
 585};
 586
 587static inline int snd_uart16550_buffer_can_write(struct snd_uart16550 *uart,
 588                                                 int Num)
 589{
 590        if (uart->buff_in_count + Num < TX_BUFF_SIZE)
 591                return 1;
 592        else
 593                return 0;
 594}
 595
 596static inline int snd_uart16550_write_buffer(struct snd_uart16550 *uart,
 597                                             unsigned char byte)
 598{
 599        unsigned short buff_in = uart->buff_in;
 600        if (uart->buff_in_count < TX_BUFF_SIZE) {
 601                uart->tx_buff[buff_in] = byte;
 602                buff_in++;
 603                buff_in &= TX_BUFF_MASK;
 604                uart->buff_in = buff_in;
 605                uart->buff_in_count++;
 606                if (uart->irq < 0) /* polling mode */
 607                        snd_uart16550_add_timer(uart);
 608                return 1;
 609        } else
 610                return 0;
 611}
 612
 613static int snd_uart16550_output_byte(struct snd_uart16550 *uart,
 614                                     struct snd_rawmidi_substream *substream,
 615                                     unsigned char midi_byte)
 616{
 617        if (uart->buff_in_count == 0                    /* Buffer empty? */
 618            && ((uart->adaptor != SNDRV_SERIAL_MS124W_SA &&
 619            uart->adaptor != SNDRV_SERIAL_GENERIC) ||
 620                (uart->fifo_count == 0                  /* FIFO empty? */
 621                 && (inb(uart->base + UART_MSR) & UART_MSR_CTS)))) { /* CTS? */
 622
 623                /* Tx Buffer Empty - try to write immediately */
 624                if ((inb(uart->base + UART_LSR) & UART_LSR_THRE) != 0) {
 625                        /* Transmitter holding register (and Tx FIFO) empty */
 626                        uart->fifo_count = 1;
 627                        outb(midi_byte, uart->base + UART_TX);
 628                } else {
 629                        if (uart->fifo_count < uart->fifo_limit) {
 630                                uart->fifo_count++;
 631                                outb(midi_byte, uart->base + UART_TX);
 632                        } else {
 633                                /* Cannot write (buffer empty) -
 634                                 * put char in buffer */
 635                                snd_uart16550_write_buffer(uart, midi_byte);
 636                        }
 637                }
 638        } else {
 639                if (!snd_uart16550_write_buffer(uart, midi_byte)) {
 640                        snd_printk(KERN_WARNING
 641                                   "%s: Buffer overrun on device at 0x%lx\n",
 642                                   uart->rmidi->name, uart->base);
 643                        return 0;
 644                }
 645        }
 646
 647        return 1;
 648}
 649
 650static void snd_uart16550_output_write(struct snd_rawmidi_substream *substream)
 651{
 652        unsigned long flags;
 653        unsigned char midi_byte, addr_byte;
 654        struct snd_uart16550 *uart = substream->rmidi->private_data;
 655        char first;
 656        static unsigned long lasttime = 0;
 657        
 658        /* Interrupts are disabled during the updating of the tx_buff,
 659         * since it is 'bad' to have two processes updating the same
 660         * variables (ie buff_in & buff_out)
 661         */
 662
 663        spin_lock_irqsave(&uart->open_lock, flags);
 664
 665        if (uart->irq < 0)      /* polling */
 666                snd_uart16550_io_loop(uart);
 667
 668        if (uart->adaptor == SNDRV_SERIAL_MS124W_MB) {
 669                while (1) {
 670                        /* buffer full? */
 671                        /* in this mode we need two bytes of space */
 672                        if (uart->buff_in_count > TX_BUFF_SIZE - 2)
 673                                break;
 674                        if (snd_rawmidi_transmit(substream, &midi_byte, 1) != 1)
 675                                break;
 676#ifdef SNDRV_SERIAL_MS124W_MB_NOCOMBO
 677                        /* select exactly one of the four ports */
 678                        addr_byte = (1 << (substream->number + 4)) | 0x08;
 679#else
 680                        /* select any combination of the four ports */
 681                        addr_byte = (substream->number << 4) | 0x08;
 682                        /* ...except none */
 683                        if (addr_byte == 0x08)
 684                                addr_byte = 0xf8;
 685#endif
 686                        snd_uart16550_output_byte(uart, substream, addr_byte);
 687                        /* send midi byte */
 688                        snd_uart16550_output_byte(uart, substream, midi_byte);
 689                }
 690        } else {
 691                first = 0;
 692                while (snd_rawmidi_transmit_peek(substream, &midi_byte, 1) == 1) {
 693                        /* Also send F5 after 3 seconds with no data
 694                         * to handle device disconnect */
 695                        if (first == 0 &&
 696                            (uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS ||
 697                             uart->adaptor == SNDRV_SERIAL_GENERIC) &&
 698                            (uart->prev_out != substream->number ||
 699                             time_after(jiffies, lasttime + 3*HZ))) {
 700
 701                                if (snd_uart16550_buffer_can_write(uart, 3)) {
 702                                        /* Roland Soundcanvas part selection */
 703                                        /* If this substream of the data is
 704                                         * different previous substream
 705                                         * in this uart, send the change part
 706                                         * event
 707                                         */
 708                                        uart->prev_out = substream->number;
 709                                        /* change part */
 710                                        snd_uart16550_output_byte(uart, substream,
 711                                                                  0xf5);
 712                                        /* data */
 713                                        snd_uart16550_output_byte(uart, substream,
 714                                                                  uart->prev_out + 1);
 715                                        /* If midi_byte is a data byte,
 716                                         * send the previous status byte */
 717                                        if (midi_byte < 0x80 &&
 718                                            uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS)
 719                                                snd_uart16550_output_byte(uart, substream, uart->prev_status[uart->prev_out]);
 720                                } else if (!uart->drop_on_full)
 721                                        break;
 722
 723                        }
 724
 725                        /* send midi byte */
 726                        if (!snd_uart16550_output_byte(uart, substream, midi_byte) &&
 727                            !uart->drop_on_full )
 728                                break;
 729
 730                        if (midi_byte >= 0x80 && midi_byte < 0xf0)
 731                                uart->prev_status[uart->prev_out] = midi_byte;
 732                        first = 1;
 733
 734                        snd_rawmidi_transmit_ack( substream, 1 );
 735                }
 736                lasttime = jiffies;
 737        }
 738        spin_unlock_irqrestore(&uart->open_lock, flags);
 739}
 740
 741static void snd_uart16550_output_trigger(struct snd_rawmidi_substream *substream,
 742                                         int up)
 743{
 744        unsigned long flags;
 745        struct snd_uart16550 *uart = substream->rmidi->private_data;
 746
 747        spin_lock_irqsave(&uart->open_lock, flags);
 748        if (up)
 749                uart->filemode |= SERIAL_MODE_OUTPUT_TRIGGERED;
 750        else
 751                uart->filemode &= ~SERIAL_MODE_OUTPUT_TRIGGERED;
 752        spin_unlock_irqrestore(&uart->open_lock, flags);
 753        if (up)
 754                snd_uart16550_output_write(substream);
 755}
 756
 757static struct snd_rawmidi_ops snd_uart16550_output =
 758{
 759        .open =         snd_uart16550_output_open,
 760        .close =        snd_uart16550_output_close,
 761        .trigger =      snd_uart16550_output_trigger,
 762};
 763
 764static struct snd_rawmidi_ops snd_uart16550_input =
 765{
 766        .open =         snd_uart16550_input_open,
 767        .close =        snd_uart16550_input_close,
 768        .trigger =      snd_uart16550_input_trigger,
 769};
 770
 771static int snd_uart16550_free(struct snd_uart16550 *uart)
 772{
 773        if (uart->irq >= 0)
 774                free_irq(uart->irq, uart);
 775        release_and_free_resource(uart->res_base);
 776        kfree(uart);
 777        return 0;
 778};
 779
 780static int snd_uart16550_dev_free(struct snd_device *device)
 781{
 782        struct snd_uart16550 *uart = device->device_data;
 783        return snd_uart16550_free(uart);
 784}
 785
 786static int __devinit snd_uart16550_create(struct snd_card *card,
 787                                       unsigned long iobase,
 788                                       int irq,
 789                                       unsigned int speed,
 790                                       unsigned int base,
 791                                       int adaptor,
 792                                       int droponfull,
 793                                       struct snd_uart16550 **ruart)
 794{
 795        static struct snd_device_ops ops = {
 796                .dev_free =     snd_uart16550_dev_free,
 797        };
 798        struct snd_uart16550 *uart;
 799        int err;
 800
 801
 802        if ((uart = kzalloc(sizeof(*uart), GFP_KERNEL)) == NULL)
 803                return -ENOMEM;
 804        uart->adaptor = adaptor;
 805        uart->card = card;
 806        spin_lock_init(&uart->open_lock);
 807        uart->irq = -1;
 808        uart->base = iobase;
 809        uart->drop_on_full = droponfull;
 810
 811        if ((err = snd_uart16550_detect(uart)) <= 0) {
 812                printk(KERN_ERR "no UART detected at 0x%lx\n", iobase);
 813                snd_uart16550_free(uart);
 814                return -ENODEV;
 815        }
 816
 817        if (irq >= 0 && irq != SNDRV_AUTO_IRQ) {
 818                if (request_irq(irq, snd_uart16550_interrupt,
 819                                0, "Serial MIDI", uart)) {
 820                        snd_printk(KERN_WARNING
 821                                   "irq %d busy. Using Polling.\n", irq);
 822                } else {
 823                        uart->irq = irq;
 824                }
 825        }
 826        uart->divisor = base / speed;
 827        uart->speed = base / (unsigned int)uart->divisor;
 828        uart->speed_base = base;
 829        uart->prev_out = -1;
 830        uart->prev_in = 0;
 831        uart->rstatus = 0;
 832        memset(uart->prev_status, 0x80, sizeof(unsigned char) * SNDRV_SERIAL_MAX_OUTS);
 833        init_timer(&uart->buffer_timer);
 834        uart->buffer_timer.function = snd_uart16550_buffer_timer;
 835        uart->buffer_timer.data = (unsigned long)uart;
 836        uart->timer_running = 0;
 837
 838        /* Register device */
 839        if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, uart, &ops)) < 0) {
 840                snd_uart16550_free(uart);
 841                return err;
 842        }
 843
 844        switch (uart->adaptor) {
 845        case SNDRV_SERIAL_MS124W_SA:
 846        case SNDRV_SERIAL_MS124W_MB:
 847                /* MS-124W can draw power from RTS and DTR if they
 848                   are in opposite states. */ 
 849                outb(UART_MCR_RTS | (0&UART_MCR_DTR), uart->base + UART_MCR);
 850                break;
 851        case SNDRV_SERIAL_MS124T:
 852                /* MS-124T can draw power from RTS and/or DTR (preferably
 853                   both) if they are asserted. */
 854                outb(UART_MCR_RTS | UART_MCR_DTR, uart->base + UART_MCR);
 855                break;
 856        default:
 857                break;
 858        }
 859
 860        if (ruart)
 861                *ruart = uart;
 862
 863        return 0;
 864}
 865
 866static void __devinit snd_uart16550_substreams(struct snd_rawmidi_str *stream)
 867{
 868        struct snd_rawmidi_substream *substream;
 869
 870        list_for_each_entry(substream, &stream->substreams, list) {
 871                sprintf(substream->name, "Serial MIDI %d", substream->number + 1);
 872        }
 873}
 874
 875static int __devinit snd_uart16550_rmidi(struct snd_uart16550 *uart, int device,
 876                                      int outs, int ins,
 877                                      struct snd_rawmidi **rmidi)
 878{
 879        struct snd_rawmidi *rrawmidi;
 880        int err;
 881
 882        err = snd_rawmidi_new(uart->card, "UART Serial MIDI", device,
 883                              outs, ins, &rrawmidi);
 884        if (err < 0)
 885                return err;
 886        snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_INPUT,
 887                            &snd_uart16550_input);
 888        snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
 889                            &snd_uart16550_output);
 890        strcpy(rrawmidi->name, "Serial MIDI");
 891        snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT]);
 892        snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT]);
 893        rrawmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
 894                               SNDRV_RAWMIDI_INFO_INPUT |
 895                               SNDRV_RAWMIDI_INFO_DUPLEX;
 896        rrawmidi->private_data = uart;
 897        if (rmidi)
 898                *rmidi = rrawmidi;
 899        return 0;
 900}
 901
 902static int __devinit snd_serial_probe(struct platform_device *devptr)
 903{
 904        struct snd_card *card;
 905        struct snd_uart16550 *uart;
 906        int err;
 907        int dev = devptr->id;
 908
 909        switch (adaptor[dev]) {
 910        case SNDRV_SERIAL_SOUNDCANVAS:
 911                ins[dev] = 1;
 912                break;
 913        case SNDRV_SERIAL_MS124T:
 914        case SNDRV_SERIAL_MS124W_SA:
 915                outs[dev] = 1;
 916                ins[dev] = 1;
 917                break;
 918        case SNDRV_SERIAL_MS124W_MB:
 919                outs[dev] = 16;
 920                ins[dev] = 1;
 921                break;
 922        case SNDRV_SERIAL_GENERIC:
 923                break;
 924        default:
 925                snd_printk(KERN_ERR
 926                           "Adaptor type is out of range 0-%d (%d)\n",
 927                           SNDRV_SERIAL_MAX_ADAPTOR, adaptor[dev]);
 928                return -ENODEV;
 929        }
 930
 931        if (outs[dev] < 1 || outs[dev] > SNDRV_SERIAL_MAX_OUTS) {
 932                snd_printk(KERN_ERR
 933                           "Count of outputs is out of range 1-%d (%d)\n",
 934                           SNDRV_SERIAL_MAX_OUTS, outs[dev]);
 935                return -ENODEV;
 936        }
 937
 938        if (ins[dev] < 1 || ins[dev] > SNDRV_SERIAL_MAX_INS) {
 939                snd_printk(KERN_ERR
 940                           "Count of inputs is out of range 1-%d (%d)\n",
 941                           SNDRV_SERIAL_MAX_INS, ins[dev]);
 942                return -ENODEV;
 943        }
 944
 945        err  = snd_card_create(index[dev], id[dev], THIS_MODULE, 0, &card);
 946        if (err < 0)
 947                return err;
 948
 949        strcpy(card->driver, "Serial");
 950        strcpy(card->shortname, "Serial MIDI (UART16550A)");
 951
 952        if ((err = snd_uart16550_create(card,
 953                                        port[dev],
 954                                        irq[dev],
 955                                        speed[dev],
 956                                        base[dev],
 957                                        adaptor[dev],
 958                                        droponfull[dev],
 959                                        &uart)) < 0)
 960                goto _err;
 961
 962        err = snd_uart16550_rmidi(uart, 0, outs[dev], ins[dev], &uart->rmidi);
 963        if (err < 0)
 964                goto _err;
 965
 966        sprintf(card->longname, "%s [%s] at %#lx, irq %d",
 967                card->shortname,
 968                adaptor_names[uart->adaptor],
 969                uart->base,
 970                uart->irq);
 971
 972        snd_card_set_dev(card, &devptr->dev);
 973
 974        if ((err = snd_card_register(card)) < 0)
 975                goto _err;
 976
 977        platform_set_drvdata(devptr, card);
 978        return 0;
 979
 980 _err:
 981        snd_card_free(card);
 982        return err;
 983}
 984
 985static int __devexit snd_serial_remove(struct platform_device *devptr)
 986{
 987        snd_card_free(platform_get_drvdata(devptr));
 988        platform_set_drvdata(devptr, NULL);
 989        return 0;
 990}
 991
 992#define SND_SERIAL_DRIVER       "snd_serial_u16550"
 993
 994static struct platform_driver snd_serial_driver = {
 995        .probe          = snd_serial_probe,
 996        .remove         = __devexit_p( snd_serial_remove),
 997        .driver         = {
 998                .name   = SND_SERIAL_DRIVER,
 999                .owner  = THIS_MODULE,
1000        },
1001};
1002
1003static void snd_serial_unregister_all(void)
1004{
1005        int i;
1006
1007        for (i = 0; i < ARRAY_SIZE(devices); ++i)
1008                platform_device_unregister(devices[i]);
1009        platform_driver_unregister(&snd_serial_driver);
1010}
1011
1012static int __init alsa_card_serial_init(void)
1013{
1014        int i, cards, err;
1015
1016        if ((err = platform_driver_register(&snd_serial_driver)) < 0)
1017                return err;
1018
1019        cards = 0;
1020        for (i = 0; i < SNDRV_CARDS; i++) {
1021                struct platform_device *device;
1022                if (! enable[i])
1023                        continue;
1024                device = platform_device_register_simple(SND_SERIAL_DRIVER,
1025                                                         i, NULL, 0);
1026                if (IS_ERR(device))
1027                        continue;
1028                if (!platform_get_drvdata(device)) {
1029                        platform_device_unregister(device);
1030                        continue;
1031                }
1032                devices[i] = device;
1033                cards++;
1034        }
1035        if (! cards) {
1036#ifdef MODULE
1037                printk(KERN_ERR "serial midi soundcard not found or device busy\n");
1038#endif
1039                snd_serial_unregister_all();
1040                return -ENODEV;
1041        }
1042        return 0;
1043}
1044
1045static void __exit alsa_card_serial_exit(void)
1046{
1047        snd_serial_unregister_all();
1048}
1049
1050module_init(alsa_card_serial_init)
1051module_exit(alsa_card_serial_exit)
1052
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