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