sound/drivers/serial-u16550.c

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