1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * dz.c: Serial port driver for DECstations equipped 4 * with the DZ chipset. 5 * 6 * Copyright (C) 1998 Olivier A. D. Lebaillif 7 * 8 * Email: olivier.lebaillif@ifrsys.com 9 * 10 * Copyright (C) 2004, 2006, 2007 Maciej W. Rozycki 11 * 12 * [31-AUG-98] triemer 13 * Changed IRQ to use Harald's dec internals interrupts.h 14 * removed base_addr code - moving address assignment to setup.c 15 * Changed name of dz_init to rs_init to be consistent with tc code 16 * [13-NOV-98] triemer fixed code to receive characters 17 * after patches by harald to irq code. 18 * [09-JAN-99] triemer minor fix for schedule - due to removal of timeout 19 * field from "current" - somewhere between 2.1.121 and 2.1.131 20 Qua Jun 27 15:02:26 BRT 2001 21 * [27-JUN-2001] Arnaldo Carvalho de Melo <acme@conectiva.com.br> - cleanups 22 * 23 * Parts (C) 1999 David Airlie, airlied@linux.ie 24 * [07-SEP-99] Bugfixes 25 * 26 * [06-Jan-2002] Russell King <rmk@arm.linux.org.uk> 27 * Converted to new serial core 28 */ 29 30 #undef DEBUG_DZ 31 32 #include <linux/bitops.h> 33 #include <linux/compiler.h> 34 #include <linux/console.h> 35 #include <linux/delay.h> 36 #include <linux/errno.h> 37 #include <linux/init.h> 38 #include <linux/interrupt.h> 39 #include <linux/ioport.h> 40 #include <linux/kernel.h> 41 #include <linux/major.h> 42 #include <linux/module.h> 43 #include <linux/platform_device.h> 44 #include <linux/serial.h> 45 #include <linux/serial_core.h> 46 #include <linux/sysrq.h> 47 #include <linux/tty.h> 48 #include <linux/tty_flip.h> 49 50 #include <linux/atomic.h> 51 #include <linux/io.h> 52 53 #include "dz.h" 54 55 56 MODULE_DESCRIPTION("DECstation DZ serial driver"); 57 MODULE_LICENSE("GPL"); 58 59 60 static char dz_name[] __initdata = "DECstation DZ serial driver version "; 61 static char dz_version[] __initdata = "1.05"; 62 63 #define DZ_IO_SIZE 0x20 /* IOMEM space size. */ 64 65 struct dz_port { 66 struct dz_mux *mux; 67 struct uart_port port; 68 unsigned int cflag; 69 }; 70 71 struct dz_mux { 72 struct dz_port dport[DZ_NB_PORT]; 73 atomic_t map_guard; 74 atomic_t irq_guard; 75 int initialised; 76 }; 77 78 static struct dz_mux dz_mux; 79 static struct uart_driver dz_reg; 80 81 static inline struct dz_port *to_dport(struct uart_port *uport) 82 { 83 return container_of(uport, struct dz_port, port); 84 } 85 86 /* 87 * ------------------------------------------------------------ 88 * dz_in () and dz_out () 89 * 90 * These routines are used to access the registers of the DZ 91 * chip, hiding relocation differences between implementation. 92 * ------------------------------------------------------------ 93 */ 94 95 static u16 dz_in(struct dz_port *dport, unsigned offset) 96 { 97 void __iomem *addr = dport->port.membase + offset; 98 99 return readw(addr); 100 } 101 102 static void dz_out(struct dz_port *dport, unsigned offset, u16 value) 103 { 104 void __iomem *addr = dport->port.membase + offset; 105 106 writew(value, addr); 107 } 108 109 /* 110 * ------------------------------------------------------------ 111 * rs_stop () and rs_start () 112 * 113 * These routines are called before setting or resetting 114 * tty->flow.stopped. They enable or disable transmitter interrupts, 115 * as necessary. 116 * ------------------------------------------------------------ 117 */ 118 119 static void dz_stop_tx(struct uart_port *uport) 120 { 121 struct dz_port *dport = to_dport(uport); 122 u16 tmp, mask = 1 << dport->port.line; 123 124 tmp = dz_in(dport, DZ_TCR); /* read the TX flag */ 125 tmp &= ~mask; /* clear the TX flag */ 126 dz_out(dport, DZ_TCR, tmp); 127 } 128 129 static void dz_start_tx(struct uart_port *uport) 130 { 131 struct dz_port *dport = to_dport(uport); 132 u16 tmp, mask = 1 << dport->port.line; 133 134 tmp = dz_in(dport, DZ_TCR); /* read the TX flag */ 135 tmp |= mask; /* set the TX flag */ 136 dz_out(dport, DZ_TCR, tmp); 137 } 138 139 static void dz_stop_rx(struct uart_port *uport) 140 { 141 struct dz_port *dport = to_dport(uport); 142 143 dport->cflag &= ~DZ_RXENAB; 144 dz_out(dport, DZ_LPR, dport->cflag); 145 } 146 147 /* 148 * ------------------------------------------------------------ 149 * 150 * Here start the interrupt handling routines. All of the following 151 * subroutines are declared as inline and are folded into 152 * dz_interrupt. They were separated out for readability's sake. 153 * 154 * Note: dz_interrupt() is a "fast" interrupt, which means that it 155 * runs with interrupts turned off. People who may want to modify 156 * dz_interrupt() should try to keep the interrupt handler as fast as 157 * possible. After you are done making modifications, it is not a bad 158 * idea to do: 159 * 160 * make drivers/serial/dz.s 161 * 162 * and look at the resulting assemble code in dz.s. 163 * 164 * ------------------------------------------------------------ 165 */ 166 167 /* 168 * ------------------------------------------------------------ 169 * receive_char () 170 * 171 * This routine deals with inputs from any lines. 172 * ------------------------------------------------------------ 173 */ 174 static inline void dz_receive_chars(struct dz_mux *mux) 175 { 176 struct uart_port *uport; 177 struct dz_port *dport = &mux->dport[0]; 178 struct uart_icount *icount; 179 int lines_rx[DZ_NB_PORT] = { [0 ... DZ_NB_PORT - 1] = 0 }; 180 u16 status; 181 u8 ch, flag; 182 int i; 183 184 while ((status = dz_in(dport, DZ_RBUF)) & DZ_DVAL) { 185 dport = &mux->dport[LINE(status)]; 186 uport = &dport->port; 187 188 ch = UCHAR(status); /* grab the char */ 189 flag = TTY_NORMAL; 190 191 icount = &uport->icount; 192 icount->rx++; 193 194 if (unlikely(status & (DZ_OERR | DZ_FERR | DZ_PERR))) { 195 196 /* 197 * There is no separate BREAK status bit, so treat 198 * null characters with framing errors as BREAKs; 199 * normally, otherwise. For this move the Framing 200 * Error bit to a simulated BREAK bit. 201 */ 202 if (!ch) { 203 status |= (status & DZ_FERR) >> 204 (ffs(DZ_FERR) - ffs(DZ_BREAK)); 205 status &= ~DZ_FERR; 206 } 207 208 /* Handle SysRq/SAK & keep track of the statistics. */ 209 if (status & DZ_BREAK) { 210 icount->brk++; 211 if (uart_handle_break(uport)) 212 continue; 213 } else if (status & DZ_FERR) 214 icount->frame++; 215 else if (status & DZ_PERR) 216 icount->parity++; 217 if (status & DZ_OERR) 218 icount->overrun++; 219 220 status &= uport->read_status_mask; 221 if (status & DZ_BREAK) 222 flag = TTY_BREAK; 223 else if (status & DZ_FERR) 224 flag = TTY_FRAME; 225 else if (status & DZ_PERR) 226 flag = TTY_PARITY; 227 228 } 229 230 if (uart_handle_sysrq_char(uport, ch)) 231 continue; 232 233 uart_insert_char(uport, status, DZ_OERR, ch, flag); 234 lines_rx[LINE(status)] = 1; 235 } 236 for (i = 0; i < DZ_NB_PORT; i++) 237 if (lines_rx[i]) 238 tty_flip_buffer_push(&mux->dport[i].port.state->port); 239 } 240 241 /* 242 * ------------------------------------------------------------ 243 * transmit_char () 244 * 245 * This routine deals with outputs to any lines. 246 * ------------------------------------------------------------ 247 */ 248 static inline void dz_transmit_chars(struct dz_mux *mux) 249 { 250 struct dz_port *dport = &mux->dport[0]; 251 struct tty_port *tport; 252 unsigned char tmp; 253 u16 status; 254 255 status = dz_in(dport, DZ_CSR); 256 dport = &mux->dport[LINE(status)]; 257 tport = &dport->port.state->port; 258 259 if (dport->port.x_char) { /* XON/XOFF chars */ 260 dz_out(dport, DZ_TDR, dport->port.x_char); 261 dport->port.icount.tx++; 262 dport->port.x_char = 0; 263 return; 264 } 265 /* If nothing to do or stopped or hardware stopped. */ 266 if (uart_tx_stopped(&dport->port) || 267 !uart_fifo_get(&dport->port, &tmp)) { 268 uart_port_lock(&dport->port); 269 dz_stop_tx(&dport->port); 270 uart_port_unlock(&dport->port); 271 return; 272 } 273 274 /* 275 * If something to do... (remember the dz has no output fifo, 276 * so we go one char at a time) :-< 277 */ 278 dz_out(dport, DZ_TDR, tmp); 279 280 if (kfifo_len(&tport->xmit_fifo) < DZ_WAKEUP_CHARS) 281 uart_write_wakeup(&dport->port); 282 283 /* Are we are done. */ 284 if (kfifo_is_empty(&tport->xmit_fifo)) { 285 uart_port_lock(&dport->port); 286 dz_stop_tx(&dport->port); 287 uart_port_unlock(&dport->port); 288 } 289 } 290 291 /* 292 * ------------------------------------------------------------ 293 * check_modem_status() 294 * 295 * DS 3100 & 5100: Only valid for the MODEM line, duh! 296 * DS 5000/200: Valid for the MODEM and PRINTER line. 297 * ------------------------------------------------------------ 298 */ 299 static inline void check_modem_status(struct dz_port *dport) 300 { 301 /* 302 * FIXME: 303 * 1. No status change interrupt; use a timer. 304 * 2. Handle the 3100/5000 as appropriate. --macro 305 */ 306 u16 status; 307 308 /* If not the modem line just return. */ 309 if (dport->port.line != DZ_MODEM) 310 return; 311 312 status = dz_in(dport, DZ_MSR); 313 314 /* it's easy, since DSR2 is the only bit in the register */ 315 if (status) 316 dport->port.icount.dsr++; 317 } 318 319 /* 320 * ------------------------------------------------------------ 321 * dz_interrupt () 322 * 323 * this is the main interrupt routine for the DZ chip. 324 * It deals with the multiple ports. 325 * ------------------------------------------------------------ 326 */ 327 static irqreturn_t dz_interrupt(int irq, void *dev_id) 328 { 329 struct dz_mux *mux = dev_id; 330 struct dz_port *dport = &mux->dport[0]; 331 u16 status; 332 333 /* get the reason why we just got an irq */ 334 status = dz_in(dport, DZ_CSR); 335 336 if ((status & (DZ_RDONE | DZ_RIE)) == (DZ_RDONE | DZ_RIE)) 337 dz_receive_chars(mux); 338 339 if ((status & (DZ_TRDY | DZ_TIE)) == (DZ_TRDY | DZ_TIE)) 340 dz_transmit_chars(mux); 341 342 return IRQ_HANDLED; 343 } 344 345 /* 346 * ------------------------------------------------------------------- 347 * Here ends the DZ interrupt routines. 348 * ------------------------------------------------------------------- 349 */ 350 351 static unsigned int dz_get_mctrl(struct uart_port *uport) 352 { 353 /* 354 * FIXME: Handle the 3100/5000 as appropriate. --macro 355 */ 356 struct dz_port *dport = to_dport(uport); 357 unsigned int mctrl = TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; 358 359 if (dport->port.line == DZ_MODEM) { 360 if (dz_in(dport, DZ_MSR) & DZ_MODEM_DSR) 361 mctrl &= ~TIOCM_DSR; 362 } 363 364 return mctrl; 365 } 366 367 static void dz_set_mctrl(struct uart_port *uport, unsigned int mctrl) 368 { 369 /* 370 * FIXME: Handle the 3100/5000 as appropriate. --macro 371 */ 372 struct dz_port *dport = to_dport(uport); 373 u16 tmp; 374 375 if (dport->port.line == DZ_MODEM) { 376 tmp = dz_in(dport, DZ_TCR); 377 if (mctrl & TIOCM_DTR) 378 tmp &= ~DZ_MODEM_DTR; 379 else 380 tmp |= DZ_MODEM_DTR; 381 dz_out(dport, DZ_TCR, tmp); 382 } 383 } 384 385 /* 386 * ------------------------------------------------------------------- 387 * startup () 388 * 389 * various initialization tasks 390 * ------------------------------------------------------------------- 391 */ 392 static int dz_startup(struct uart_port *uport) 393 { 394 struct dz_port *dport = to_dport(uport); 395 struct dz_mux *mux = dport->mux; 396 unsigned long flags; 397 int irq_guard; 398 int ret; 399 u16 tmp; 400 401 irq_guard = atomic_add_return(1, &mux->irq_guard); 402 if (irq_guard != 1) 403 return 0; 404 405 ret = request_irq(dport->port.irq, dz_interrupt, 406 IRQF_SHARED, "dz", mux); 407 if (ret) { 408 atomic_add(-1, &mux->irq_guard); 409 printk(KERN_ERR "dz: Cannot get IRQ %d!\n", dport->port.irq); 410 return ret; 411 } 412 413 uart_port_lock_irqsave(&dport->port, &flags); 414 415 /* Enable interrupts. */ 416 tmp = dz_in(dport, DZ_CSR); 417 tmp |= DZ_RIE | DZ_TIE; 418 dz_out(dport, DZ_CSR, tmp); 419 420 uart_port_unlock_irqrestore(&dport->port, flags); 421 422 return 0; 423 } 424 425 /* 426 * ------------------------------------------------------------------- 427 * shutdown () 428 * 429 * This routine will shutdown a serial port; interrupts are disabled, and 430 * DTR is dropped if the hangup on close termio flag is on. 431 * ------------------------------------------------------------------- 432 */ 433 static void dz_shutdown(struct uart_port *uport) 434 { 435 struct dz_port *dport = to_dport(uport); 436 struct dz_mux *mux = dport->mux; 437 unsigned long flags; 438 int irq_guard; 439 u16 tmp; 440 441 uart_port_lock_irqsave(&dport->port, &flags); 442 dz_stop_tx(&dport->port); 443 uart_port_unlock_irqrestore(&dport->port, flags); 444 445 irq_guard = atomic_add_return(-1, &mux->irq_guard); 446 if (!irq_guard) { 447 /* Disable interrupts. */ 448 tmp = dz_in(dport, DZ_CSR); 449 tmp &= ~(DZ_RIE | DZ_TIE); 450 dz_out(dport, DZ_CSR, tmp); 451 452 free_irq(dport->port.irq, mux); 453 } 454 } 455 456 /* 457 * ------------------------------------------------------------------- 458 * dz_tx_empty() -- get the transmitter empty status 459 * 460 * Purpose: Let user call ioctl() to get info when the UART physically 461 * is emptied. On bus types like RS485, the transmitter must 462 * release the bus after transmitting. This must be done when 463 * the transmit shift register is empty, not be done when the 464 * transmit holding register is empty. This functionality 465 * allows an RS485 driver to be written in user space. 466 * ------------------------------------------------------------------- 467 */ 468 static unsigned int dz_tx_empty(struct uart_port *uport) 469 { 470 struct dz_port *dport = to_dport(uport); 471 unsigned short tmp, mask = 1 << dport->port.line; 472 473 tmp = dz_in(dport, DZ_TCR); 474 tmp &= mask; 475 476 return tmp ? 0 : TIOCSER_TEMT; 477 } 478 479 static void dz_break_ctl(struct uart_port *uport, int break_state) 480 { 481 /* 482 * FIXME: Can't access BREAK bits in TDR easily; 483 * reuse the code for polled TX. --macro 484 */ 485 struct dz_port *dport = to_dport(uport); 486 unsigned long flags; 487 unsigned short tmp, mask = 1 << dport->port.line; 488 489 uart_port_lock_irqsave(uport, &flags); 490 tmp = dz_in(dport, DZ_TCR); 491 if (break_state) 492 tmp |= mask; 493 else 494 tmp &= ~mask; 495 dz_out(dport, DZ_TCR, tmp); 496 uart_port_unlock_irqrestore(uport, flags); 497 } 498 499 static int dz_encode_baud_rate(unsigned int baud) 500 { 501 switch (baud) { 502 case 50: 503 return DZ_B50; 504 case 75: 505 return DZ_B75; 506 case 110: 507 return DZ_B110; 508 case 134: 509 return DZ_B134; 510 case 150: 511 return DZ_B150; 512 case 300: 513 return DZ_B300; 514 case 600: 515 return DZ_B600; 516 case 1200: 517 return DZ_B1200; 518 case 1800: 519 return DZ_B1800; 520 case 2000: 521 return DZ_B2000; 522 case 2400: 523 return DZ_B2400; 524 case 3600: 525 return DZ_B3600; 526 case 4800: 527 return DZ_B4800; 528 case 7200: 529 return DZ_B7200; 530 case 9600: 531 return DZ_B9600; 532 default: 533 return -1; 534 } 535 } 536 537 538 static void dz_reset(struct dz_port *dport) 539 { 540 struct dz_mux *mux = dport->mux; 541 unsigned short tcr; 542 int loops = 10000; 543 544 if (mux->initialised) 545 return; 546 547 tcr = dz_in(dport, DZ_TCR); 548 549 /* Do not disturb any ongoing transmissions. */ 550 if (dz_in(dport, DZ_CSR) & DZ_MSE) { 551 unsigned short csr, mask; 552 553 mask = tcr; 554 while ((mask & DZ_LNENB) && loops--) { 555 csr = dz_in(dport, DZ_CSR); 556 if (!(csr & DZ_TRDY)) 557 continue; 558 mask &= ~(1 << ((csr & DZ_TLINE) >> 8)); 559 dz_out(dport, DZ_TCR, mask); 560 iob(); 561 udelay(2); /* 1.4us TRDY recovery. */ 562 } 563 fsleep(1200); /* Transmitter drain. */ 564 } 565 566 dz_out(dport, DZ_CSR, DZ_CLR); 567 while (dz_in(dport, DZ_CSR) & DZ_CLR); 568 iob(); 569 570 /* 571 * Set parameters across all lines such as not to interfere 572 * with the initial PROM-based console. Otherwise any output 573 * produced before the console handover would cause the system 574 * firmware to produce rubbish. 575 */ 576 for (int line = 0; line < DZ_NB_PORT; line++) 577 dz_out(dport, DZ_LPR, DZ_B9600 | DZ_CS8 | line); 578 579 /* Re-enable transmission for the initial PROM-based console. */ 580 dz_out(dport, DZ_TCR, tcr); 581 582 /* Enable scanning. */ 583 dz_out(dport, DZ_CSR, DZ_MSE); 584 585 mux->initialised = 1; 586 } 587 588 static void dz_set_termios(struct uart_port *uport, struct ktermios *termios, 589 const struct ktermios *old_termios) 590 { 591 struct dz_port *dport = to_dport(uport); 592 unsigned long flags; 593 unsigned int cflag, baud; 594 int bflag; 595 596 cflag = dport->port.line; 597 598 switch (termios->c_cflag & CSIZE) { 599 case CS5: 600 cflag |= DZ_CS5; 601 break; 602 case CS6: 603 cflag |= DZ_CS6; 604 break; 605 case CS7: 606 cflag |= DZ_CS7; 607 break; 608 case CS8: 609 default: 610 cflag |= DZ_CS8; 611 } 612 613 if (termios->c_cflag & CSTOPB) 614 cflag |= DZ_CSTOPB; 615 if (termios->c_cflag & PARENB) 616 cflag |= DZ_PARENB; 617 if (termios->c_cflag & PARODD) 618 cflag |= DZ_PARODD; 619 620 baud = uart_get_baud_rate(uport, termios, old_termios, 50, 9600); 621 bflag = dz_encode_baud_rate(baud); 622 if (bflag < 0) { 623 if (old_termios) { 624 /* Keep unchanged. */ 625 baud = tty_termios_baud_rate(old_termios); 626 bflag = dz_encode_baud_rate(baud); 627 } 628 if (bflag < 0) { /* Resort to 9600. */ 629 baud = 9600; 630 bflag = DZ_B9600; 631 } 632 tty_termios_encode_baud_rate(termios, baud, baud); 633 } 634 cflag |= bflag; 635 636 if (termios->c_cflag & CREAD) 637 cflag |= DZ_RXENAB; 638 639 uart_port_lock_irqsave(&dport->port, &flags); 640 641 uart_update_timeout(uport, termios->c_cflag, baud); 642 643 dz_out(dport, DZ_LPR, cflag); 644 dport->cflag = cflag; 645 646 /* setup accept flag */ 647 dport->port.read_status_mask = DZ_OERR; 648 if (termios->c_iflag & INPCK) 649 dport->port.read_status_mask |= DZ_FERR | DZ_PERR; 650 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) 651 dport->port.read_status_mask |= DZ_BREAK; 652 653 /* characters to ignore */ 654 uport->ignore_status_mask = 0; 655 if ((termios->c_iflag & (IGNPAR | IGNBRK)) == (IGNPAR | IGNBRK)) 656 dport->port.ignore_status_mask |= DZ_OERR; 657 if (termios->c_iflag & IGNPAR) 658 dport->port.ignore_status_mask |= DZ_FERR | DZ_PERR; 659 if (termios->c_iflag & IGNBRK) 660 dport->port.ignore_status_mask |= DZ_BREAK; 661 662 uart_port_unlock_irqrestore(&dport->port, flags); 663 } 664 665 static const char *dz_type(struct uart_port *uport) 666 { 667 return "DZ"; 668 } 669 670 static void dz_release_port(struct uart_port *uport) 671 { 672 struct dz_mux *mux = to_dport(uport)->mux; 673 int map_guard; 674 675 iounmap(uport->membase); 676 uport->membase = NULL; 677 678 map_guard = atomic_add_return(-1, &mux->map_guard); 679 if (!map_guard) 680 release_mem_region(uport->mapbase, DZ_IO_SIZE); 681 } 682 683 static int dz_map_port(struct uart_port *uport) 684 { 685 if (!uport->membase) 686 uport->membase = ioremap(uport->mapbase, DZ_IO_SIZE); 687 if (!uport->membase) { 688 printk(KERN_ERR "dz: Cannot map MMIO\n"); 689 return -ENOMEM; 690 } 691 return 0; 692 } 693 694 static int dz_request_port(struct uart_port *uport) 695 { 696 struct dz_mux *mux = to_dport(uport)->mux; 697 int map_guard; 698 int ret; 699 700 map_guard = atomic_add_return(1, &mux->map_guard); 701 if (map_guard == 1) { 702 if (!request_mem_region(uport->mapbase, DZ_IO_SIZE, "dz")) { 703 atomic_add(-1, &mux->map_guard); 704 printk(KERN_ERR 705 "dz: Unable to reserve MMIO resource\n"); 706 return -EBUSY; 707 } 708 } 709 ret = dz_map_port(uport); 710 if (ret) { 711 map_guard = atomic_add_return(-1, &mux->map_guard); 712 if (!map_guard) 713 release_mem_region(uport->mapbase, DZ_IO_SIZE); 714 return ret; 715 } 716 return 0; 717 } 718 719 static void dz_config_port(struct uart_port *uport, int flags) 720 { 721 struct dz_port *dport = to_dport(uport); 722 723 if (flags & UART_CONFIG_TYPE) { 724 if (dz_request_port(uport)) 725 return; 726 727 uport->type = PORT_DZ; 728 729 dz_reset(dport); 730 } 731 } 732 733 /* 734 * Verify the new serial_struct (for TIOCSSERIAL). 735 */ 736 static int dz_verify_port(struct uart_port *uport, struct serial_struct *ser) 737 { 738 int ret = 0; 739 740 if (ser->type != PORT_UNKNOWN && ser->type != PORT_DZ) 741 ret = -EINVAL; 742 if (ser->irq != uport->irq) 743 ret = -EINVAL; 744 return ret; 745 } 746 747 static const struct uart_ops dz_ops = { 748 .tx_empty = dz_tx_empty, 749 .get_mctrl = dz_get_mctrl, 750 .set_mctrl = dz_set_mctrl, 751 .stop_tx = dz_stop_tx, 752 .start_tx = dz_start_tx, 753 .stop_rx = dz_stop_rx, 754 .break_ctl = dz_break_ctl, 755 .startup = dz_startup, 756 .shutdown = dz_shutdown, 757 .set_termios = dz_set_termios, 758 .type = dz_type, 759 .release_port = dz_release_port, 760 .request_port = dz_request_port, 761 .config_port = dz_config_port, 762 .verify_port = dz_verify_port, 763 }; 764 765 static int __init dz_probe(struct platform_device *pdev) 766 { 767 struct resource *mem_resource, *irq_resource; 768 int line; 769 770 mem_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); 771 irq_resource = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 772 if (!mem_resource || !irq_resource) 773 return -ENODEV; 774 775 for (line = 0; line < DZ_NB_PORT; line++) { 776 struct dz_port *dport = &dz_mux.dport[line]; 777 struct uart_port *uport = &dport->port; 778 779 dport->mux = &dz_mux; 780 781 uport->dev = &pdev->dev; 782 uport->irq = irq_resource->start; 783 uport->fifosize = 1; 784 uport->iotype = UPIO_MEM; 785 uport->flags = UPF_BOOT_AUTOCONF; 786 uport->ops = &dz_ops; 787 uport->line = line; 788 uport->mapbase = mem_resource->start; 789 uport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_DZ_CONSOLE); 790 791 if (uart_add_one_port(&dz_reg, uport)) 792 uport->dev = NULL; 793 } 794 795 return 0; 796 } 797 798 static void __exit dz_remove(struct platform_device *pdev) 799 { 800 int line; 801 802 for (line = DZ_NB_PORT - 1; line >= 0; line--) { 803 struct dz_port *dport = &dz_mux.dport[line]; 804 struct uart_port *uport = &dport->port; 805 806 if (uport->dev) 807 uart_remove_one_port(&dz_reg, uport); 808 } 809 } 810 811 #ifdef CONFIG_SERIAL_DZ_CONSOLE 812 /* 813 * ------------------------------------------------------------------- 814 * dz_console_putchar() -- transmit a character 815 * 816 * Polled transmission. This is tricky. We need to mask transmit 817 * interrupts so that they do not interfere, enable the transmitter 818 * for the line requested and then wait till the transmit scanner 819 * requests data for this line. But it may request data for another 820 * line first, in which case we have to disable its transmitter and 821 * repeat waiting till our line pops up. Only then the character may 822 * be transmitted. Finally, the state of the transmitter mask is 823 * restored. Welcome to the world of PDP-11! 824 * ------------------------------------------------------------------- 825 */ 826 static void dz_console_putchar(struct uart_port *uport, unsigned char ch) 827 { 828 struct dz_port *dport = to_dport(uport); 829 unsigned long flags; 830 unsigned short csr, tcr, trdy, mask; 831 int loops = 10000; 832 833 uart_port_lock_irqsave(&dport->port, &flags); 834 csr = dz_in(dport, DZ_CSR); 835 dz_out(dport, DZ_CSR, csr & ~DZ_TIE); 836 tcr = dz_in(dport, DZ_TCR); 837 tcr |= 1 << dport->port.line; 838 mask = tcr; 839 dz_out(dport, DZ_TCR, mask); 840 iob(); 841 uart_port_unlock_irqrestore(&dport->port, flags); 842 843 do { 844 trdy = dz_in(dport, DZ_CSR); 845 if (!(trdy & DZ_TRDY)) 846 continue; 847 trdy = (trdy & DZ_TLINE) >> 8; 848 if (trdy == dport->port.line) 849 break; 850 mask &= ~(1 << trdy); 851 dz_out(dport, DZ_TCR, mask); 852 iob(); 853 udelay(2); 854 } while (--loops); 855 856 if (loops) /* Cannot send otherwise. */ 857 dz_out(dport, DZ_TDR, ch); 858 859 dz_out(dport, DZ_TCR, tcr); 860 dz_out(dport, DZ_CSR, csr); 861 } 862 863 /* 864 * ------------------------------------------------------------------- 865 * dz_console_print () 866 * 867 * dz_console_print is registered for printk. 868 * The console must be locked when we get here. 869 * ------------------------------------------------------------------- 870 */ 871 static void dz_console_print(struct console *co, 872 const char *str, 873 unsigned int count) 874 { 875 struct dz_port *dport = &dz_mux.dport[co->index]; 876 #ifdef DEBUG_DZ 877 prom_printf((char *) str); 878 #endif 879 uart_console_write(&dport->port, str, count, dz_console_putchar); 880 } 881 882 static int __init dz_console_setup(struct console *co, char *options) 883 { 884 struct dz_port *dport = &dz_mux.dport[co->index]; 885 struct uart_port *uport = &dport->port; 886 int baud = 9600; 887 int bits = 8; 888 int parity = 'n'; 889 int flow = 'n'; 890 891 if (!dport->mux) 892 return -ENODEV; 893 if (options) 894 uart_parse_options(options, &baud, &parity, &bits, &flow); 895 return uart_set_options(uport, co, baud, parity, bits, flow); 896 } 897 898 static struct console dz_console = { 899 .name = "ttyS", 900 .write = dz_console_print, 901 .device = uart_console_device, 902 .setup = dz_console_setup, 903 .flags = CON_PRINTBUFFER, 904 .index = -1, 905 .data = &dz_reg, 906 }; 907 908 #define SERIAL_DZ_CONSOLE &dz_console 909 #else 910 #define SERIAL_DZ_CONSOLE NULL 911 #endif /* CONFIG_SERIAL_DZ_CONSOLE */ 912 913 static struct uart_driver dz_reg = { 914 .owner = THIS_MODULE, 915 .driver_name = "serial_dz", 916 .dev_name = "ttyS", 917 .major = TTY_MAJOR, 918 .minor = 64, 919 .nr = DZ_NB_PORT, 920 .cons = SERIAL_DZ_CONSOLE, 921 }; 922 923 static struct platform_driver dz_driver = { 924 .remove = __exit_p(dz_remove), 925 .driver = { .name = "dz" }, 926 }; 927 928 static int __init dz_init(void) 929 { 930 int ret; 931 932 printk("%s%s\n", dz_name, dz_version); 933 934 ret = uart_register_driver(&dz_reg); 935 if (ret) 936 return ret; 937 ret = platform_driver_probe(&dz_driver, dz_probe); 938 if (ret) 939 uart_unregister_driver(&dz_reg); 940 941 return ret; 942 } 943 944 static void __exit dz_exit(void) 945 { 946 platform_driver_unregister(&dz_driver); 947 uart_unregister_driver(&dz_reg); 948 } 949 950 module_init(dz_init); 951 module_exit(dz_exit); 952