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serial-u16550.c
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linux-6.19.14/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 35MODULE_DESCRIPTION("MIDI serial u16550"); 36MODULE_LICENSE("GPL"); 37 38#define SNDRV_SERIAL_SOUNDCANVAS 0 /* Roland Soundcanvas; F5 NN selects part */ 39#define SNDRV_SERIAL_MS124T 1 /* Midiator MS-124T */ 40#define SNDRV_SERIAL_MS124W_SA 2 /* Midiator MS-124W in S/A mode */ 41#define SNDRV_SERIAL_MS124W_MB 3 /* Midiator MS-124W in M/B mode */ 42#define SNDRV_SERIAL_GENERIC 4 /* Generic Interface */ 43#define SNDRV_SERIAL_MAX_ADAPTOR SNDRV_SERIAL_GENERIC 44static const char * const adaptor_names[] = { 45 "Soundcanvas", 46 "MS-124T", 47 "MS-124W S/A", 48 "MS-124W M/B", 49 "Generic" 50}; 51 52#define SNDRV_SERIAL_NORMALBUFF 0 /* Normal blocking buffer operation */ 53#define SNDRV_SERIAL_DROPBUFF 1 /* Non-blocking discard operation */ 54 55static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */ 56static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */ 57static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE; /* Enable this card */ 58static long port[SNDRV_CARDS] = SNDRV_DEFAULT_PORT; /* 0x3f8,0x2f8,0x3e8,0x2e8 */ 59static int irq[SNDRV_CARDS] = SNDRV_DEFAULT_IRQ; /* 3,4,5,7,9,10,11,14,15 */ 60static int speed[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 38400}; /* 9600,19200,38400,57600,115200 */ 61static int base[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 115200}; /* baud base */ 62static int outs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1}; /* 1 to 16 */ 63static int ins[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1}; /* 1 to 16 */ 64static int adaptor[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = SNDRV_SERIAL_SOUNDCANVAS}; 65static bool droponfull[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS -1)] = SNDRV_SERIAL_NORMALBUFF }; 66 67module_param_array(index, int, NULL, 0444); 68MODULE_PARM_DESC(index, "Index value for Serial MIDI."); 69module_param_array(id, charp, NULL, 0444); 70MODULE_PARM_DESC(id, "ID string for Serial MIDI."); 71module_param_array(enable, bool, NULL, 0444); 72MODULE_PARM_DESC(enable, "Enable UART16550A chip."); 73module_param_hw_array(port, long, ioport, NULL, 0444); 74MODULE_PARM_DESC(port, "Port # for UART16550A chip."); 75module_param_hw_array(irq, int, irq, NULL, 0444); 76MODULE_PARM_DESC(irq, "IRQ # for UART16550A chip."); 77module_param_array(speed, int, NULL, 0444); 78MODULE_PARM_DESC(speed, "Speed in bauds."); 79module_param_array(base, int, NULL, 0444); 80MODULE_PARM_DESC(base, "Base for divisor in bauds."); 81module_param_array(outs, int, NULL, 0444); 82MODULE_PARM_DESC(outs, "Number of MIDI outputs."); 83module_param_array(ins, int, NULL, 0444); 84MODULE_PARM_DESC(ins, "Number of MIDI inputs."); 85module_param_array(droponfull, bool, NULL, 0444); 86MODULE_PARM_DESC(droponfull, "Flag to enable drop-on-full buffer mode"); 87 88module_param_array(adaptor, int, NULL, 0444); 89MODULE_PARM_DESC(adaptor, "Type of adaptor."); 90 91/*#define SNDRV_SERIAL_MS124W_MB_NOCOMBO 1*/ /* Address outs as 0-3 instead of bitmap */ 92 93#define SNDRV_SERIAL_MAX_OUTS 16 /* max 64, min 16 */ 94#define SNDRV_SERIAL_MAX_INS 16 /* max 64, min 16 */ 95 96#define TX_BUFF_SIZE (1<<15) /* Must be 2^n */ 97#define TX_BUFF_MASK (TX_BUFF_SIZE - 1) 98 99#define SERIAL_MODE_NOT_OPENED (0) 100#define SERIAL_MODE_INPUT_OPEN (1 << 0) 101#define SERIAL_MODE_OUTPUT_OPEN (1 << 1) 102#define SERIAL_MODE_INPUT_TRIGGERED (1 << 2) 103#define SERIAL_MODE_OUTPUT_TRIGGERED (1 << 3) 104 105struct snd_uart16550 { 106 struct snd_card *card; 107 struct snd_rawmidi *rmidi; 108 struct snd_rawmidi_substream *midi_output[SNDRV_SERIAL_MAX_OUTS]; 109 struct snd_rawmidi_substream *midi_input[SNDRV_SERIAL_MAX_INS]; 110 111 int filemode; /* open status of file */ 112 113 spinlock_t open_lock; 114 115 int irq; 116 117 unsigned long base; 118 119 unsigned int speed; 120 unsigned int speed_base; 121 unsigned char divisor; 122 123 unsigned char old_divisor_lsb; 124 unsigned char old_divisor_msb; 125 unsigned char old_line_ctrl_reg; 126 127 /* parameter for using of write loop */ 128 short int fifo_limit; /* used in uart16550 */ 129 short int fifo_count; /* used in uart16550 */ 130 131 /* type of adaptor */ 132 int adaptor; 133 134 /* inputs */ 135 int prev_in; 136 unsigned char rstatus; 137 138 /* outputs */ 139 int prev_out; 140 unsigned char prev_status[SNDRV_SERIAL_MAX_OUTS]; 141 142 /* write buffer and its writing/reading position */ 143 unsigned char tx_buff[TX_BUFF_SIZE]; 144 int buff_in_count; 145 int buff_in; 146 int buff_out; 147 int drop_on_full; 148 149 /* wait timer */ 150 unsigned int timer_running:1; 151 struct timer_list buffer_timer; 152 153}; 154 155static struct platform_device *devices[SNDRV_CARDS]; 156 157static inline void snd_uart16550_add_timer(struct snd_uart16550 *uart) 158{ 159 if (!uart->timer_running) { 160 /* timer 38600bps * 10bit * 16byte */ 161 mod_timer(&uart->buffer_timer, jiffies + (HZ + 255) / 256); 162 uart->timer_running = 1; 163 } 164} 165 166static inline void snd_uart16550_del_timer(struct snd_uart16550 *uart) 167{ 168 if (uart->timer_running) { 169 timer_delete(&uart->buffer_timer); 170 uart->timer_running = 0; 171 } 172} 173 174/* This macro is only used in snd_uart16550_io_loop */ 175static inline void snd_uart16550_buffer_output(struct snd_uart16550 *uart) 176{ 177 unsigned short buff_out = uart->buff_out; 178 if (uart->buff_in_count > 0) { 179 outb(uart->tx_buff[buff_out], uart->base + UART_TX); 180 uart->fifo_count++; 181 buff_out++; 182 buff_out &= TX_BUFF_MASK; 183 uart->buff_out = buff_out; 184 uart->buff_in_count--; 185 } 186} 187 188/* This loop should be called with interrupts disabled 189 * We don't want to interrupt this, 190 * as we're already handling an interrupt 191 */ 192static void snd_uart16550_io_loop(struct snd_uart16550 * uart) 193{ 194 unsigned char c, status; 195 int substream; 196 197 /* recall previous stream */ 198 substream = uart->prev_in; 199 200 /* Read Loop */ 201 while ((status = inb(uart->base + UART_LSR)) & UART_LSR_DR) { 202 /* while receive data ready */ 203 c = inb(uart->base + UART_RX); 204 205 /* keep track of last status byte */ 206 if (c & 0x80) 207 uart->rstatus = c; 208 209 /* handle stream switch */ 210 if (uart->adaptor == SNDRV_SERIAL_GENERIC) { 211 if (uart->rstatus == 0xf5) { 212 if (c <= SNDRV_SERIAL_MAX_INS && c > 0) 213 substream = c - 1; 214 if (c != 0xf5) 215 /* prevent future bytes from being 216 interpreted as streams */ 217 uart->rstatus = 0; 218 } else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN) 219 && uart->midi_input[substream]) 220 snd_rawmidi_receive(uart->midi_input[substream], 221 &c, 1); 222 } else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN) && 223 uart->midi_input[substream]) 224 snd_rawmidi_receive(uart->midi_input[substream], &c, 1); 225 226 if (status & UART_LSR_OE) 227 dev_warn(uart->card->dev, 228 "%s: Overrun on device at 0x%lx\n", 229 uart->rmidi->name, uart->base); 230 } 231 232 /* remember the last stream */ 233 uart->prev_in = substream; 234 235 /* no need of check SERIAL_MODE_OUTPUT_OPEN because if not, 236 buffer is never filled. */ 237 /* Check write status */ 238 if (status & UART_LSR_THRE) 239 uart->fifo_count = 0; 240 if (uart->adaptor == SNDRV_SERIAL_MS124W_SA 241 || uart->adaptor == SNDRV_SERIAL_GENERIC) { 242 /* Can't use FIFO, must send only when CTS is true */ 243 status = inb(uart->base + UART_MSR); 244 while (uart->fifo_count == 0 && (status & UART_MSR_CTS) && 245 uart->buff_in_count > 0) { 246 snd_uart16550_buffer_output(uart); 247 status = inb(uart->base + UART_MSR); 248 } 249 } else { 250 /* Write loop */ 251 while (uart->fifo_count < uart->fifo_limit /* Can we write ? */ 252 && uart->buff_in_count > 0) /* Do we want to? */ 253 snd_uart16550_buffer_output(uart); 254 } 255 if (uart->irq < 0 && uart->buff_in_count > 0) 256 snd_uart16550_add_timer(uart); 257} 258 259/* NOTES ON SERVICING INTERUPTS 260 * --------------------------- 261 * After receiving a interrupt, it is important to indicate to the UART that 262 * this has been done. 263 * For a Rx interrupt, this is done by reading the received byte. 264 * For a Tx interrupt this is done by either: 265 * a) Writing a byte 266 * b) Reading the IIR 267 * It is particularly important to read the IIR if a Tx interrupt is received 268 * when there is no data in tx_buff[], as in this case there no other 269 * indication that the interrupt has been serviced, and it remains outstanding 270 * indefinitely. This has the curious side effect that and no further interrupts 271 * will be generated from this device AT ALL!!. 272 * It is also desirable to clear outstanding interrupts when the device is 273 * opened/closed. 274 * 275 * 276 * Note that some devices need OUT2 to be set before they will generate 277 * interrupts at all. (Possibly tied to an internal pull-up on CTS?) 278 */ 279static irqreturn_t snd_uart16550_interrupt(int irq, void *dev_id) 280{ 281 struct snd_uart16550 *uart; 282 283 uart = dev_id; 284 guard(spinlock)(&uart->open_lock); 285 if (uart->filemode == SERIAL_MODE_NOT_OPENED) 286 return IRQ_NONE; 287 /* indicate to the UART that the interrupt has been serviced */ 288 inb(uart->base + UART_IIR); 289 snd_uart16550_io_loop(uart); 290 return IRQ_HANDLED; 291} 292 293/* When the polling mode, this function calls snd_uart16550_io_loop. */ 294static void snd_uart16550_buffer_timer(struct timer_list *t) 295{ 296 struct snd_uart16550 *uart; 297 298 uart = timer_container_of(uart, t, buffer_timer); 299 guard(spinlock_irqsave)(&uart->open_lock); 300 snd_uart16550_del_timer(uart); 301 snd_uart16550_io_loop(uart); 302} 303 304/* 305 * this method probes, if an uart sits on given port 306 * return 0 if found 307 * return negative error if not found 308 */ 309static int snd_uart16550_detect(struct snd_uart16550 *uart) 310{ 311 unsigned long io_base = uart->base; 312 int ok; 313 unsigned char c; 314 315 /* Do some vague tests for the presence of the uart */ 316 if (io_base == 0 || io_base == SNDRV_AUTO_PORT) { 317 return -ENODEV; /* Not configured */ 318 } 319 320 if (!devm_request_region(uart->card->dev, io_base, 8, "Serial MIDI")) { 321 dev_err(uart->card->dev, 322 "u16550: can't grab port 0x%lx\n", io_base); 323 return -EBUSY; 324 } 325 326 /* uart detected unless one of the following tests should fail */ 327 ok = 1; 328 /* 8 data-bits, 1 stop-bit, parity off, DLAB = 0 */ 329 outb(UART_LCR_WLEN8, io_base + UART_LCR); /* Line Control Register */ 330 c = inb(io_base + UART_IER); 331 /* The top four bits of the IER should always == 0 */ 332 if ((c & 0xf0) != 0) 333 ok = 0; /* failed */ 334 335 outb(0xaa, io_base + UART_SCR); 336 /* Write arbitrary data into the scratch reg */ 337 c = inb(io_base + UART_SCR); 338 /* If it comes back, it's OK */ 339 if (c != 0xaa) 340 ok = 0; /* failed */ 341 342 outb(0x55, 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 != 0x55) 347 ok = 0; /* failed */ 348 349 return ok; 350} 351 352static void snd_uart16550_do_open(struct snd_uart16550 * uart) 353{ 354 char byte; 355 356 /* Initialize basic variables */ 357 uart->buff_in_count = 0; 358 uart->buff_in = 0; 359 uart->buff_out = 0; 360 uart->fifo_limit = 1; 361 uart->fifo_count = 0; 362 uart->timer_running = 0; 363 364 outb(UART_FCR_ENABLE_FIFO /* Enable FIFO's (if available) */ 365 | UART_FCR_CLEAR_RCVR /* Clear receiver FIFO */ 366 | UART_FCR_CLEAR_XMIT /* Clear transmitter FIFO */ 367 | UART_FCR_TRIGGER_4 /* Set FIFO trigger at 4-bytes */ 368 /* NOTE: interrupt generated after T=(time)4-bytes 369 * if less than UART_FCR_TRIGGER bytes received 370 */ 371 ,uart->base + UART_FCR); /* FIFO Control Register */ 372 373 if ((inb(uart->base + UART_IIR) & 0xf0) == 0xc0) 374 uart->fifo_limit = 16; 375 if (uart->divisor != 0) { 376 uart->old_line_ctrl_reg = inb(uart->base + UART_LCR); 377 outb(UART_LCR_DLAB /* Divisor latch access bit */ 378 ,uart->base + UART_LCR); /* Line Control Register */ 379 uart->old_divisor_lsb = inb(uart->base + UART_DLL); 380 uart->old_divisor_msb = inb(uart->base + UART_DLM); 381 382 outb(uart->divisor 383 ,uart->base + UART_DLL); /* Divisor Latch Low */ 384 outb(0 385 ,uart->base + UART_DLM); /* Divisor Latch High */ 386 /* DLAB is reset to 0 in next outb() */ 387 } 388 /* Set serial parameters (parity off, etc) */ 389 outb(UART_LCR_WLEN8 /* 8 data-bits */ 390 | 0 /* 1 stop-bit */ 391 | 0 /* parity off */ 392 | 0 /* DLAB = 0 */ 393 ,uart->base + UART_LCR); /* Line Control Register */ 394 395 switch (uart->adaptor) { 396 default: 397 outb(UART_MCR_RTS /* Set Request-To-Send line active */ 398 | UART_MCR_DTR /* Set Data-Terminal-Ready line active */ 399 | UART_MCR_OUT2 /* Set OUT2 - not always required, but when 400 * it is, it is ESSENTIAL for enabling interrupts 401 */ 402 ,uart->base + UART_MCR); /* Modem Control Register */ 403 break; 404 case SNDRV_SERIAL_MS124W_SA: 405 case SNDRV_SERIAL_MS124W_MB: 406 /* MS-124W can draw power from RTS and DTR if they 407 are in opposite states. */ 408 outb(UART_MCR_RTS | (0&UART_MCR_DTR) | UART_MCR_OUT2, 409 uart->base + UART_MCR); 410 break; 411 case SNDRV_SERIAL_MS124T: 412 /* MS-124T can draw power from RTS and/or DTR (preferably 413 both) if they are both asserted. */ 414 outb(UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2, 415 uart->base + UART_MCR); 416 break; 417 } 418 419 if (uart->irq < 0) { 420 byte = (0 & UART_IER_RDI) /* Disable Receiver data interrupt */ 421 |(0 & UART_IER_THRI) /* Disable Transmitter holding register empty interrupt */ 422 ; 423 } else if (uart->adaptor == SNDRV_SERIAL_MS124W_SA) { 424 byte = UART_IER_RDI /* Enable Receiver data interrupt */ 425 | UART_IER_MSI /* Enable Modem status interrupt */ 426 ; 427 } else if (uart->adaptor == SNDRV_SERIAL_GENERIC) { 428 byte = UART_IER_RDI /* Enable Receiver data interrupt */ 429 | UART_IER_MSI /* Enable Modem status interrupt */ 430 | UART_IER_THRI /* Enable Transmitter holding register empty interrupt */ 431 ; 432 } else { 433 byte = UART_IER_RDI /* Enable Receiver data interrupt */ 434 | UART_IER_THRI /* Enable Transmitter holding register empty interrupt */ 435 ; 436 } 437 outb(byte, uart->base + UART_IER); /* Interrupt enable Register */ 438 439 inb(uart->base + UART_LSR); /* Clear any pre-existing overrun indication */ 440 inb(uart->base + UART_IIR); /* Clear any pre-existing transmit interrupt */ 441 inb(uart->base + UART_RX); /* Clear any pre-existing receive interrupt */ 442} 443 444static void snd_uart16550_do_close(struct snd_uart16550 * uart) 445{ 446 if (uart->irq < 0) 447 snd_uart16550_del_timer(uart); 448 449 /* NOTE: may need to disable interrupts before de-registering out handler. 450 * For now, the consequences are harmless. 451 */ 452 453 outb((0 & UART_IER_RDI) /* Disable Receiver data interrupt */ 454 |(0 & UART_IER_THRI) /* Disable Transmitter holding register empty interrupt */ 455 ,uart->base + UART_IER); /* Interrupt enable Register */ 456 457 switch (uart->adaptor) { 458 default: 459 outb((0 & UART_MCR_RTS) /* Deactivate Request-To-Send line */ 460 |(0 & UART_MCR_DTR) /* Deactivate Data-Terminal-Ready line */ 461 |(0 & UART_MCR_OUT2) /* Deactivate OUT2 */ 462 ,uart->base + UART_MCR); /* Modem Control Register */ 463 break; 464 case SNDRV_SERIAL_MS124W_SA: 465 case SNDRV_SERIAL_MS124W_MB: 466 /* MS-124W can draw power from RTS and DTR if they 467 are in opposite states; leave it powered. */ 468 outb(UART_MCR_RTS | (0&UART_MCR_DTR) | (0&UART_MCR_OUT2), 469 uart->base + UART_MCR); 470 break; 471 case SNDRV_SERIAL_MS124T: 472 /* MS-124T can draw power from RTS and/or DTR (preferably 473 both) if they are both asserted; leave it powered. */ 474 outb(UART_MCR_RTS | UART_MCR_DTR | (0&UART_MCR_OUT2), 475 uart->base + UART_MCR); 476 break; 477 } 478 479 inb(uart->base + UART_IIR); /* Clear any outstanding interrupts */ 480 481 /* Restore old divisor */ 482 if (uart->divisor != 0) { 483 outb(UART_LCR_DLAB /* Divisor latch access bit */ 484 ,uart->base + UART_LCR); /* Line Control Register */ 485 outb(uart->old_divisor_lsb 486 ,uart->base + UART_DLL); /* Divisor Latch Low */ 487 outb(uart->old_divisor_msb 488 ,uart->base + UART_DLM); /* Divisor Latch High */ 489 /* Restore old LCR (data bits, stop bits, parity, DLAB) */ 490 outb(uart->old_line_ctrl_reg 491 ,uart->base + UART_LCR); /* Line Control Register */ 492 } 493} 494 495static int snd_uart16550_input_open(struct snd_rawmidi_substream *substream) 496{ 497 struct snd_uart16550 *uart = substream->rmidi->private_data; 498 499 guard(spinlock_irqsave)(&uart->open_lock); 500 if (uart->filemode == SERIAL_MODE_NOT_OPENED) 501 snd_uart16550_do_open(uart); 502 uart->filemode |= SERIAL_MODE_INPUT_OPEN; 503 uart->midi_input[substream->number] = substream; 504 return 0; 505} 506 507static int snd_uart16550_input_close(struct snd_rawmidi_substream *substream) 508{ 509 struct snd_uart16550 *uart = substream->rmidi->private_data; 510 511 guard(spinlock_irqsave)(&uart->open_lock); 512 uart->filemode &= ~SERIAL_MODE_INPUT_OPEN; 513 uart->midi_input[substream->number] = NULL; 514 if (uart->filemode == SERIAL_MODE_NOT_OPENED) 515 snd_uart16550_do_close(uart); 516 return 0; 517} 518 519static void snd_uart16550_input_trigger(struct snd_rawmidi_substream *substream, 520 int up) 521{ 522 struct snd_uart16550 *uart = substream->rmidi->private_data; 523 524 guard(spinlock_irqsave)(&uart->open_lock); 525 if (up) 526 uart->filemode |= SERIAL_MODE_INPUT_TRIGGERED; 527 else 528 uart->filemode &= ~SERIAL_MODE_INPUT_TRIGGERED; 529} 530 531static int snd_uart16550_output_open(struct snd_rawmidi_substream *substream) 532{ 533 struct snd_uart16550 *uart = substream->rmidi->private_data; 534 535 guard(spinlock_irqsave)(&uart->open_lock); 536 if (uart->filemode == SERIAL_MODE_NOT_OPENED) 537 snd_uart16550_do_open(uart); 538 uart->filemode |= SERIAL_MODE_OUTPUT_OPEN; 539 uart->midi_output[substream->number] = substream; 540 return 0; 541}; 542 543static int snd_uart16550_output_close(struct snd_rawmidi_substream *substream) 544{ 545 struct snd_uart16550 *uart = substream->rmidi->private_data; 546 547 guard(spinlock_irqsave)(&uart->open_lock); 548 uart->filemode &= ~SERIAL_MODE_OUTPUT_OPEN; 549 uart->midi_output[substream->number] = NULL; 550 if (uart->filemode == SERIAL_MODE_NOT_OPENED) 551 snd_uart16550_do_close(uart); 552 return 0; 553}; 554 555static inline int snd_uart16550_buffer_can_write(struct snd_uart16550 *uart, 556 int Num) 557{ 558 if (uart->buff_in_count + Num < TX_BUFF_SIZE) 559 return 1; 560 else 561 return 0; 562} 563 564static inline int snd_uart16550_write_buffer(struct snd_uart16550 *uart, 565 unsigned char byte) 566{ 567 unsigned short buff_in = uart->buff_in; 568 if (uart->buff_in_count < TX_BUFF_SIZE) { 569 uart->tx_buff[buff_in] = byte; 570 buff_in++; 571 buff_in &= TX_BUFF_MASK; 572 uart->buff_in = buff_in; 573 uart->buff_in_count++; 574 if (uart->irq < 0) /* polling mode */ 575 snd_uart16550_add_timer(uart); 576 return 1; 577 } else 578 return 0; 579} 580 581static int snd_uart16550_output_byte(struct snd_uart16550 *uart, 582 struct snd_rawmidi_substream *substream, 583 unsigned char midi_byte) 584{ 585 if (uart->buff_in_count == 0 /* Buffer empty? */ 586 && ((uart->adaptor != SNDRV_SERIAL_MS124W_SA && 587 uart->adaptor != SNDRV_SERIAL_GENERIC) || 588 (uart->fifo_count == 0 /* FIFO empty? */ 589 && (inb(uart->base + UART_MSR) & UART_MSR_CTS)))) { /* CTS? */ 590 591 /* Tx Buffer Empty - try to write immediately */ 592 if ((inb(uart->base + UART_LSR) & UART_LSR_THRE) != 0) { 593 /* Transmitter holding register (and Tx FIFO) empty */ 594 uart->fifo_count = 1; 595 outb(midi_byte, uart->base + UART_TX); 596 } else { 597 if (uart->fifo_count < uart->fifo_limit) { 598 uart->fifo_count++; 599 outb(midi_byte, uart->base + UART_TX); 600 } else { 601 /* Cannot write (buffer empty) - 602 * put char in buffer */ 603 snd_uart16550_write_buffer(uart, midi_byte); 604 } 605 } 606 } else { 607 if (!snd_uart16550_write_buffer(uart, midi_byte)) { 608 dev_warn(uart->card->dev, 609 "%s: Buffer overrun on device at 0x%lx\n", 610 uart->rmidi->name, uart->base); 611 return 0; 612 } 613 } 614 615 return 1; 616} 617 618static void snd_uart16550_output_write(struct snd_rawmidi_substream *substream) 619{ 620 unsigned char midi_byte, addr_byte; 621 struct snd_uart16550 *uart = substream->rmidi->private_data; 622 char first; 623 static unsigned long lasttime = 0; 624 625 /* Interrupts are disabled during the updating of the tx_buff, 626 * since it is 'bad' to have two processes updating the same 627 * variables (ie buff_in & buff_out) 628 */ 629 630 guard(spinlock_irqsave)(&uart->open_lock); 631 632 if (uart->irq < 0) /* polling */ 633 snd_uart16550_io_loop(uart); 634 635 if (uart->adaptor == SNDRV_SERIAL_MS124W_MB) { 636 while (1) { 637 /* buffer full? */ 638 /* in this mode we need two bytes of space */ 639 if (uart->buff_in_count > TX_BUFF_SIZE - 2) 640 break; 641 if (snd_rawmidi_transmit(substream, &midi_byte, 1) != 1) 642 break; 643#ifdef SNDRV_SERIAL_MS124W_MB_NOCOMBO 644 /* select exactly one of the four ports */ 645 addr_byte = (1 << (substream->number + 4)) | 0x08; 646#else 647 /* select any combination of the four ports */ 648 addr_byte = (substream->number << 4) | 0x08; 649 /* ...except none */ 650 if (addr_byte == 0x08) 651 addr_byte = 0xf8; 652#endif 653 snd_uart16550_output_byte(uart, substream, addr_byte); 654 /* send midi byte */ 655 snd_uart16550_output_byte(uart, substream, midi_byte); 656 } 657 } else { 658 first = 0; 659 while (snd_rawmidi_transmit_peek(substream, &midi_byte, 1) == 1) { 660 /* Also send F5 after 3 seconds with no data 661 * to handle device disconnect */ 662 if (first == 0 && 663 (uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS || 664 uart->adaptor == SNDRV_SERIAL_GENERIC) && 665 (uart->prev_out != substream->number || 666 time_after(jiffies, lasttime + 3*HZ))) { 667 668 if (snd_uart16550_buffer_can_write(uart, 3)) { 669 /* Roland Soundcanvas part selection */ 670 /* If this substream of the data is 671 * different previous substream 672 * in this uart, send the change part 673 * event 674 */ 675 uart->prev_out = substream->number; 676 /* change part */ 677 snd_uart16550_output_byte(uart, substream, 678 0xf5); 679 /* data */ 680 snd_uart16550_output_byte(uart, substream, 681 uart->prev_out + 1); 682 /* If midi_byte is a data byte, 683 * send the previous status byte */ 684 if (midi_byte < 0x80 && 685 uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS) 686 snd_uart16550_output_byte(uart, substream, uart->prev_status[uart->prev_out]); 687 } else if (!uart->drop_on_full) 688 break; 689 690 } 691 692 /* send midi byte */ 693 if (!snd_uart16550_output_byte(uart, substream, midi_byte) && 694 !uart->drop_on_full ) 695 break; 696 697 if (midi_byte >= 0x80 && midi_byte < 0xf0) 698 uart->prev_status[uart->prev_out] = midi_byte; 699 first = 1; 700 701 snd_rawmidi_transmit_ack( substream, 1 ); 702 } 703 lasttime = jiffies; 704 } 705} 706 707static void snd_uart16550_output_trigger(struct snd_rawmidi_substream *substream, 708 int up) 709{ 710 struct snd_uart16550 *uart = substream->rmidi->private_data; 711 712 scoped_guard(spinlock_irqsave, &uart->open_lock) { 713 if (up) 714 uart->filemode |= SERIAL_MODE_OUTPUT_TRIGGERED; 715 else 716 uart->filemode &= ~SERIAL_MODE_OUTPUT_TRIGGERED; 717 } 718 if (up) 719 snd_uart16550_output_write(substream); 720} 721 722static const struct snd_rawmidi_ops snd_uart16550_output = 723{ 724 .open = snd_uart16550_output_open, 725 .close = snd_uart16550_output_close, 726 .trigger = snd_uart16550_output_trigger, 727}; 728 729static const struct snd_rawmidi_ops snd_uart16550_input = 730{ 731 .open = snd_uart16550_input_open, 732 .close = snd_uart16550_input_close, 733 .trigger = snd_uart16550_input_trigger, 734}; 735 736static int snd_uart16550_create(struct snd_card *card, 737 unsigned long iobase, 738 int irq, 739 unsigned int speed, 740 unsigned int base, 741 int adaptor, 742 int droponfull, 743 struct snd_uart16550 **ruart) 744{ 745 struct snd_uart16550 *uart; 746 int err; 747 748 749 uart = devm_kzalloc(card->dev, sizeof(*uart), GFP_KERNEL); 750 if (!uart) 751 return -ENOMEM; 752 uart->adaptor = adaptor; 753 uart->card = card; 754 spin_lock_init(&uart->open_lock); 755 uart->irq = -1; 756 uart->base = iobase; 757 uart->drop_on_full = droponfull; 758 759 err = snd_uart16550_detect(uart); 760 if (err <= 0) { 761 dev_err(card->dev, "no UART detected at 0x%lx\n", iobase); 762 return -ENODEV; 763 } 764 765 if (irq >= 0 && irq != SNDRV_AUTO_IRQ) { 766 if (devm_request_irq(card->dev, irq, snd_uart16550_interrupt, 767 0, "Serial MIDI", uart)) { 768 dev_warn(card->dev, 769 "irq %d busy. Using Polling.\n", irq); 770 } else { 771 uart->irq = irq; 772 } 773 } 774 uart->divisor = base / speed; 775 uart->speed = base / (unsigned int)uart->divisor; 776 uart->speed_base = base; 777 uart->prev_out = -1; 778 uart->prev_in = 0; 779 uart->rstatus = 0; 780 memset(uart->prev_status, 0x80, sizeof(unsigned char) * SNDRV_SERIAL_MAX_OUTS); 781 timer_setup(&uart->buffer_timer, snd_uart16550_buffer_timer, 0); 782 uart->timer_running = 0; 783 784 switch (uart->adaptor) { 785 case SNDRV_SERIAL_MS124W_SA: 786 case SNDRV_SERIAL_MS124W_MB: 787 /* MS-124W can draw power from RTS and DTR if they 788 are in opposite states. */ 789 outb(UART_MCR_RTS | (0&UART_MCR_DTR), uart->base + UART_MCR); 790 break; 791 case SNDRV_SERIAL_MS124T: 792 /* MS-124T can draw power from RTS and/or DTR (preferably 793 both) if they are asserted. */ 794 outb(UART_MCR_RTS | UART_MCR_DTR, uart->base + UART_MCR); 795 break; 796 default: 797 break; 798 } 799 800 if (ruart) 801 *ruart = uart; 802 803 return 0; 804} 805 806static void snd_uart16550_substreams(struct snd_rawmidi_str *stream) 807{ 808 struct snd_rawmidi_substream *substream; 809 810 list_for_each_entry(substream, &stream->substreams, list) { 811 sprintf(substream->name, "Serial MIDI %d", substream->number + 1); 812 } 813} 814 815static int snd_uart16550_rmidi(struct snd_uart16550 *uart, int device, 816 int outs, int ins, 817 struct snd_rawmidi **rmidi) 818{ 819 struct snd_rawmidi *rrawmidi; 820 int err; 821 822 err = snd_rawmidi_new(uart->card, "UART Serial MIDI", device, 823 outs, ins, &rrawmidi); 824 if (err < 0) 825 return err; 826 snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_INPUT, 827 &snd_uart16550_input); 828 snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, 829 &snd_uart16550_output); 830 strscpy(rrawmidi->name, "Serial MIDI"); 831 snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT]); 832 snd_uart16550_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT]); 833 rrawmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT | 834 SNDRV_RAWMIDI_INFO_INPUT | 835 SNDRV_RAWMIDI_INFO_DUPLEX; 836 rrawmidi->private_data = uart; 837 if (rmidi) 838 *rmidi = rrawmidi; 839 return 0; 840} 841 842static int snd_serial_probe(struct platform_device *devptr) 843{ 844 struct snd_card *card; 845 struct snd_uart16550 *uart; 846 int err; 847 int dev = devptr->id; 848 849 switch (adaptor[dev]) { 850 case SNDRV_SERIAL_SOUNDCANVAS: 851 ins[dev] = 1; 852 break; 853 case SNDRV_SERIAL_MS124T: 854 case SNDRV_SERIAL_MS124W_SA: 855 outs[dev] = 1; 856 ins[dev] = 1; 857 break; 858 case SNDRV_SERIAL_MS124W_MB: 859 outs[dev] = 16; 860 ins[dev] = 1; 861 break; 862 case SNDRV_SERIAL_GENERIC: 863 break; 864 default: 865 dev_err(&devptr->dev, 866 "Adaptor type is out of range 0-%d (%d)\n", 867 SNDRV_SERIAL_MAX_ADAPTOR, adaptor[dev]); 868 return -ENODEV; 869 } 870 871 if (outs[dev] < 1 || outs[dev] > SNDRV_SERIAL_MAX_OUTS) { 872 dev_err(&devptr->dev, 873 "Count of outputs is out of range 1-%d (%d)\n", 874 SNDRV_SERIAL_MAX_OUTS, outs[dev]); 875 return -ENODEV; 876 } 877 878 if (ins[dev] < 1 || ins[dev] > SNDRV_SERIAL_MAX_INS) { 879 dev_err(&devptr->dev, 880 "Count of inputs is out of range 1-%d (%d)\n", 881 SNDRV_SERIAL_MAX_INS, ins[dev]); 882 return -ENODEV; 883 } 884 885 err = snd_devm_card_new(&devptr->dev, index[dev], id[dev], THIS_MODULE, 886 0, &card); 887 if (err < 0) 888 return err; 889 890 strscpy(card->driver, "Serial"); 891 strscpy(card->shortname, "Serial MIDI (UART16550A)"); 892 893 err = snd_uart16550_create(card, port[dev], irq[dev], speed[dev], 894 base[dev], adaptor[dev], droponfull[dev], 895 &uart); 896 if (err < 0) 897 return err; 898 899 err = snd_uart16550_rmidi(uart, 0, outs[dev], ins[dev], &uart->rmidi); 900 if (err < 0) 901 return err; 902 903 sprintf(card->longname, "%s [%s] at %#lx, irq %d", 904 card->shortname, 905 adaptor_names[uart->adaptor], 906 uart->base, 907 uart->irq); 908 909 err = snd_card_register(card); 910 if (err < 0) 911 return err; 912 913 platform_set_drvdata(devptr, card); 914 return 0; 915} 916 917#define SND_SERIAL_DRIVER "snd_serial_u16550" 918 919static struct platform_driver snd_serial_driver = { 920 .probe = snd_serial_probe, 921 .driver = { 922 .name = SND_SERIAL_DRIVER, 923 }, 924}; 925 926static void snd_serial_unregister_all(void) 927{ 928 int i; 929 930 for (i = 0; i < ARRAY_SIZE(devices); ++i) 931 platform_device_unregister(devices[i]); 932 platform_driver_unregister(&snd_serial_driver); 933} 934 935static int __init alsa_card_serial_init(void) 936{ 937 int i, cards, err; 938 939 err = platform_driver_register(&snd_serial_driver); 940 if (err < 0) 941 return err; 942 943 cards = 0; 944 for (i = 0; i < SNDRV_CARDS; i++) { 945 struct platform_device *device; 946 if (! enable[i]) 947 continue; 948 device = platform_device_register_simple(SND_SERIAL_DRIVER, 949 i, NULL, 0); 950 if (IS_ERR(device)) 951 continue; 952 if (!platform_get_drvdata(device)) { 953 platform_device_unregister(device); 954 continue; 955 } 956 devices[i] = device; 957 cards++; 958 } 959 if (! cards) { 960#ifdef MODULE 961 pr_err("serial midi soundcard not found or device busy\n"); 962#endif 963 snd_serial_unregister_all(); 964 return -ENODEV; 965 } 966 return 0; 967} 968 969static void __exit alsa_card_serial_exit(void) 970{ 971 snd_serial_unregister_all(); 972} 973 974module_init(alsa_card_serial_init) 975module_exit(alsa_card_serial_exit)
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