1/* 2 * zs.c: Serial port driver for IOASIC DECstations. 3 * 4 * Derived from drivers/sbus/char/sunserial.c by Paul Mackerras. 5 * Derived from drivers/macintosh/macserial.c by Harald Koerfgen. 6 * 7 * DECstation changes 8 * Copyright (C) 1998-2000 Harald Koerfgen 9 * Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007 Maciej W. Rozycki 10 * 11 * For the rest of the code the original Copyright applies: 12 * Copyright (C) 1996 Paul Mackerras (Paul.Mackerras@cs.anu.edu.au) 13 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) 14 * 15 * 16 * Note: for IOASIC systems the wiring is as follows: 17 * 18 * mouse/keyboard: 19 * DIN-7 MJ-4 signal SCC 20 * 2 1 TxD <- A.TxD 21 * 3 4 RxD -> A.RxD 22 * 23 * EIA-232/EIA-423: 24 * DB-25 MMJ-6 signal SCC 25 * 2 2 TxD <- B.TxD 26 * 3 5 RxD -> B.RxD 27 * 4 RTS <- ~A.RTS 28 * 5 CTS -> ~B.CTS 29 * 6 6 DSR -> ~A.SYNC 30 * 8 CD -> ~B.DCD 31 * 12 DSRS(DCE) -> ~A.CTS (*) 32 * 15 TxC -> B.TxC 33 * 17 RxC -> B.RxC 34 * 20 1 DTR <- ~A.DTR 35 * 22 RI -> ~A.DCD 36 * 23 DSRS(DTE) <- ~B.RTS 37 * 38 * (*) EIA-232 defines the signal at this pin to be SCD, while DSRS(DCE) 39 * is shared with DSRS(DTE) at pin 23. 40 * 41 * As you can immediately notice the wiring of the RTS, DTR and DSR signals 42 * is a bit odd. This makes the handling of port B unnecessarily 43 * complicated and prevents the use of some automatic modes of operation. 44 */ 45 46#if defined(CONFIG_SERIAL_ZS_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) 47#define SUPPORT_SYSRQ 48#endif 49 50#include <linux/bug.h> 51#include <linux/console.h> 52#include <linux/delay.h> 53#include <linux/errno.h> 54#include <linux/init.h> 55#include <linux/interrupt.h> 56#include <linux/io.h> 57#include <linux/ioport.h> 58#include <linux/irqflags.h> 59#include <linux/kernel.h> 60#include <linux/major.h> 61#include <linux/serial.h> 62#include <linux/serial_core.h> 63#include <linux/spinlock.h> 64#include <linux/sysrq.h> 65#include <linux/tty.h> 66#include <linux/types.h> 67 68#include <asm/atomic.h> 69#include <asm/system.h> 70 71#include <asm/dec/interrupts.h> 72#include <asm/dec/ioasic_addrs.h> 73#include <asm/dec/system.h> 74 75#include "zs.h" 76 77 78MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>"); 79MODULE_DESCRIPTION("DECstation Z85C30 serial driver"); 80MODULE_LICENSE("GPL"); 81 82 83static char zs_name[] __initdata = "DECstation Z85C30 serial driver version "; 84static char zs_version[] __initdata = "0.10"; 85 86/* 87 * It would be nice to dynamically allocate everything that 88 * depends on ZS_NUM_SCCS, so we could support any number of 89 * Z85C30s, but for now... 90 */ 91#define ZS_NUM_SCCS 2 /* Max # of ZS chips supported. */ 92#define ZS_NUM_CHAN 2 /* 2 channels per chip. */ 93#define ZS_CHAN_A 0 /* Index of the channel A. */ 94#define ZS_CHAN_B 1 /* Index of the channel B. */ 95#define ZS_CHAN_IO_SIZE 8 /* IOMEM space size. */ 96#define ZS_CHAN_IO_STRIDE 4 /* Register alignment. */ 97#define ZS_CHAN_IO_OFFSET 1 /* The SCC resides on the high byte 98 of the 16-bit IOBUS. */ 99#define ZS_CLOCK 7372800 /* Z85C30 PCLK input clock rate. */ 100 101#define to_zport(uport) container_of(uport, struct zs_port, port) 102 103struct zs_parms { 104 resource_size_t scc[ZS_NUM_SCCS]; 105 int irq[ZS_NUM_SCCS]; 106}; 107 108static struct zs_scc zs_sccs[ZS_NUM_SCCS]; 109 110static u8 zs_init_regs[ZS_NUM_REGS] __initdata = { 111 0, /* write 0 */ 112 PAR_SPEC, /* write 1 */ 113 0, /* write 2 */ 114 0, /* write 3 */ 115 X16CLK | SB1, /* write 4 */ 116 0, /* write 5 */ 117 0, 0, 0, /* write 6, 7, 8 */ 118 MIE | DLC | NV, /* write 9 */ 119 NRZ, /* write 10 */ 120 TCBR | RCBR, /* write 11 */ 121 0, 0, /* BRG time constant, write 12 + 13 */ 122 BRSRC | BRENABL, /* write 14 */ 123 0, /* write 15 */ 124}; 125 126/* 127 * Debugging. 128 */ 129#undef ZS_DEBUG_REGS 130 131 132/* 133 * Reading and writing Z85C30 registers. 134 */ 135static void recovery_delay(void) 136{ 137 udelay(2); 138} 139 140static u8 read_zsreg(struct zs_port *zport, int reg) 141{ 142 void __iomem *control = zport->port.membase + ZS_CHAN_IO_OFFSET; 143 u8 retval; 144 145 if (reg != 0) { 146 writeb(reg & 0xf, control); 147 fast_iob(); 148 recovery_delay(); 149 } 150 retval = readb(control); 151 recovery_delay(); 152 return retval; 153} 154 155static void write_zsreg(struct zs_port *zport, int reg, u8 value) 156{ 157 void __iomem *control = zport->port.membase + ZS_CHAN_IO_OFFSET; 158 159 if (reg != 0) { 160 writeb(reg & 0xf, control); 161 fast_iob(); recovery_delay(); 162 } 163 writeb(value, control); 164 fast_iob(); 165 recovery_delay(); 166 return; 167} 168 169static u8 read_zsdata(struct zs_port *zport) 170{ 171 void __iomem *data = zport->port.membase + 172 ZS_CHAN_IO_STRIDE + ZS_CHAN_IO_OFFSET; 173 u8 retval; 174 175 retval = readb(data); 176 recovery_delay(); 177 return retval; 178} 179 180static void write_zsdata(struct zs_port *zport, u8 value) 181{ 182 void __iomem *data = zport->port.membase + 183 ZS_CHAN_IO_STRIDE + ZS_CHAN_IO_OFFSET; 184 185 writeb(value, data); 186 fast_iob(); 187 recovery_delay(); 188 return; 189} 190 191#ifdef ZS_DEBUG_REGS 192void zs_dump(void) 193{ 194 struct zs_port *zport; 195 int i, j; 196 197 for (i = 0; i < ZS_NUM_SCCS * ZS_NUM_CHAN; i++) { 198 zport = &zs_sccs[i / ZS_NUM_CHAN].zport[i % ZS_NUM_CHAN]; 199 200 if (!zport->scc) 201 continue; 202 203 for (j = 0; j < 16; j++) 204 printk("W%-2d = 0x%02x\t", j, zport->regs[j]); 205 printk("\n"); 206 for (j = 0; j < 16; j++) 207 printk("R%-2d = 0x%02x\t", j, read_zsreg(zport, j)); 208 printk("\n\n"); 209 } 210} 211#endif 212 213 214static void zs_spin_lock_cond_irq(spinlock_t *lock, int irq) 215{ 216 if (irq) 217 spin_lock_irq(lock); 218 else 219 spin_lock(lock); 220} 221 222static void zs_spin_unlock_cond_irq(spinlock_t *lock, int irq) 223{ 224 if (irq) 225 spin_unlock_irq(lock); 226 else 227 spin_unlock(lock); 228} 229 230static int zs_receive_drain(struct zs_port *zport) 231{ 232 int loops = 10000; 233 234 while ((read_zsreg(zport, R0) & Rx_CH_AV) && --loops) 235 read_zsdata(zport); 236 return loops; 237} 238 239static int zs_transmit_drain(struct zs_port *zport, int irq) 240{ 241 struct zs_scc *scc = zport->scc; 242 int loops = 10000; 243 244 while (!(read_zsreg(zport, R0) & Tx_BUF_EMP) && --loops) { 245 zs_spin_unlock_cond_irq(&scc->zlock, irq); 246 udelay(2); 247 zs_spin_lock_cond_irq(&scc->zlock, irq); 248 } 249 return loops; 250} 251 252static int zs_line_drain(struct zs_port *zport, int irq) 253{ 254 struct zs_scc *scc = zport->scc; 255 int loops = 10000; 256 257 while (!(read_zsreg(zport, R1) & ALL_SNT) && --loops) { 258 zs_spin_unlock_cond_irq(&scc->zlock, irq); 259 udelay(2); 260 zs_spin_lock_cond_irq(&scc->zlock, irq); 261 } 262 return loops; 263} 264 265 266static void load_zsregs(struct zs_port *zport, u8 *regs, int irq) 267{ 268 /* Let the current transmission finish. */ 269 zs_line_drain(zport, irq); 270 /* Load 'em up. */ 271 write_zsreg(zport, R3, regs[3] & ~RxENABLE); 272 write_zsreg(zport, R5, regs[5] & ~TxENAB); 273 write_zsreg(zport, R4, regs[4]); 274 write_zsreg(zport, R9, regs[9]); 275 write_zsreg(zport, R1, regs[1]); 276 write_zsreg(zport, R2, regs[2]); 277 write_zsreg(zport, R10, regs[10]); 278 write_zsreg(zport, R14, regs[14] & ~BRENABL); 279 write_zsreg(zport, R11, regs[11]); 280 write_zsreg(zport, R12, regs[12]); 281 write_zsreg(zport, R13, regs[13]); 282 write_zsreg(zport, R14, regs[14]); 283 write_zsreg(zport, R15, regs[15]); 284 if (regs[3] & RxENABLE) 285 write_zsreg(zport, R3, regs[3]); 286 if (regs[5] & TxENAB) 287 write_zsreg(zport, R5, regs[5]); 288 return; 289} 290 291 292/* 293 * Status handling routines. 294 */ 295 296/* 297 * zs_tx_empty() -- get the transmitter empty status 298 * 299 * Purpose: Let user call ioctl() to get info when the UART physically 300 * is emptied. On bus types like RS485, the transmitter must 301 * release the bus after transmitting. This must be done when 302 * the transmit shift register is empty, not be done when the 303 * transmit holding register is empty. This functionality 304 * allows an RS485 driver to be written in user space. 305 */ 306static unsigned int zs_tx_empty(struct uart_port *uport) 307{ 308 struct zs_port *zport = to_zport(uport); 309 struct zs_scc *scc = zport->scc; 310 unsigned long flags; 311 u8 status; 312 313 spin_lock_irqsave(&scc->zlock, flags); 314 status = read_zsreg(zport, R1); 315 spin_unlock_irqrestore(&scc->zlock, flags); 316 317 return status & ALL_SNT ? TIOCSER_TEMT : 0; 318} 319 320static unsigned int zs_raw_get_ab_mctrl(struct zs_port *zport_a, 321 struct zs_port *zport_b) 322{ 323 u8 status_a, status_b; 324 unsigned int mctrl; 325 326 status_a = read_zsreg(zport_a, R0); 327 status_b = read_zsreg(zport_b, R0); 328 329 mctrl = ((status_b & CTS) ? TIOCM_CTS : 0) | 330 ((status_b & DCD) ? TIOCM_CAR : 0) | 331 ((status_a & DCD) ? TIOCM_RNG : 0) | 332 ((status_a & SYNC_HUNT) ? TIOCM_DSR : 0); 333 334 return mctrl; 335} 336 337static unsigned int zs_raw_get_mctrl(struct zs_port *zport) 338{ 339 struct zs_port *zport_a = &zport->scc->zport[ZS_CHAN_A]; 340 341 return zport != zport_a ? zs_raw_get_ab_mctrl(zport_a, zport) : 0; 342} 343 344static unsigned int zs_raw_xor_mctrl(struct zs_port *zport) 345{ 346 struct zs_port *zport_a = &zport->scc->zport[ZS_CHAN_A]; 347 unsigned int mmask, mctrl, delta; 348 u8 mask_a, mask_b; 349 350 if (zport == zport_a) 351 return 0; 352 353 mask_a = zport_a->regs[15]; 354 mask_b = zport->regs[15]; 355 356 mmask = ((mask_b & CTSIE) ? TIOCM_CTS : 0) | 357 ((mask_b & DCDIE) ? TIOCM_CAR : 0) | 358 ((mask_a & DCDIE) ? TIOCM_RNG : 0) | 359 ((mask_a & SYNCIE) ? TIOCM_DSR : 0); 360 361 mctrl = zport->mctrl; 362 if (mmask) { 363 mctrl &= ~mmask; 364 mctrl |= zs_raw_get_ab_mctrl(zport_a, zport) & mmask; 365 } 366 367 delta = mctrl ^ zport->mctrl; 368 if (delta) 369 zport->mctrl = mctrl; 370 371 return delta; 372} 373 374static unsigned int zs_get_mctrl(struct uart_port *uport) 375{ 376 struct zs_port *zport = to_zport(uport); 377 struct zs_scc *scc = zport->scc; 378 unsigned int mctrl; 379 380 spin_lock(&scc->zlock); 381 mctrl = zs_raw_get_mctrl(zport); 382 spin_unlock(&scc->zlock); 383 384 return mctrl; 385} 386 387static void zs_set_mctrl(struct uart_port *uport, unsigned int mctrl) 388{ 389 struct zs_port *zport = to_zport(uport); 390 struct zs_scc *scc = zport->scc; 391 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A]; 392 u8 oldloop, newloop; 393 394 spin_lock(&scc->zlock); 395 if (zport != zport_a) { 396 if (mctrl & TIOCM_DTR) 397 zport_a->regs[5] |= DTR; 398 else 399 zport_a->regs[5] &= ~DTR; 400 if (mctrl & TIOCM_RTS) 401 zport_a->regs[5] |= RTS; 402 else 403 zport_a->regs[5] &= ~RTS; 404 write_zsreg(zport_a, R5, zport_a->regs[5]); 405 } 406 407 /* Rarely modified, so don't poke at hardware unless necessary. */ 408 oldloop = zport->regs[14]; 409 newloop = oldloop; 410 if (mctrl & TIOCM_LOOP) 411 newloop |= LOOPBAK; 412 else 413 newloop &= ~LOOPBAK; 414 if (newloop != oldloop) { 415 zport->regs[14] = newloop; 416 write_zsreg(zport, R14, zport->regs[14]); 417 } 418 spin_unlock(&scc->zlock); 419} 420 421static void zs_raw_stop_tx(struct zs_port *zport) 422{ 423 write_zsreg(zport, R0, RES_Tx_P); 424 zport->tx_stopped = 1; 425} 426 427static void zs_stop_tx(struct uart_port *uport) 428{ 429 struct zs_port *zport = to_zport(uport); 430 struct zs_scc *scc = zport->scc; 431 432 spin_lock(&scc->zlock); 433 zs_raw_stop_tx(zport); 434 spin_unlock(&scc->zlock); 435} 436 437static void zs_raw_transmit_chars(struct zs_port *); 438 439static void zs_start_tx(struct uart_port *uport) 440{ 441 struct zs_port *zport = to_zport(uport); 442 struct zs_scc *scc = zport->scc; 443 444 spin_lock(&scc->zlock); 445 if (zport->tx_stopped) { 446 zs_transmit_drain(zport, 0); 447 zport->tx_stopped = 0; 448 zs_raw_transmit_chars(zport); 449 } 450 spin_unlock(&scc->zlock); 451} 452 453static void zs_stop_rx(struct uart_port *uport) 454{ 455 struct zs_port *zport = to_zport(uport); 456 struct zs_scc *scc = zport->scc; 457 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A]; 458 459 spin_lock(&scc->zlock); 460 zport->regs[15] &= ~BRKIE; 461 zport->regs[1] &= ~(RxINT_MASK | TxINT_ENAB); 462 zport->regs[1] |= RxINT_DISAB; 463 464 if (zport != zport_a) { 465 /* A-side DCD tracks RI and SYNC tracks DSR. */ 466 zport_a->regs[15] &= ~(DCDIE | SYNCIE); 467 write_zsreg(zport_a, R15, zport_a->regs[15]); 468 if (!(zport_a->regs[15] & BRKIE)) { 469 zport_a->regs[1] &= ~EXT_INT_ENAB; 470 write_zsreg(zport_a, R1, zport_a->regs[1]); 471 } 472 473 /* This-side DCD tracks DCD and CTS tracks CTS. */ 474 zport->regs[15] &= ~(DCDIE | CTSIE); 475 zport->regs[1] &= ~EXT_INT_ENAB; 476 } else { 477 /* DCD tracks RI and SYNC tracks DSR for the B side. */ 478 if (!(zport->regs[15] & (DCDIE | SYNCIE))) 479 zport->regs[1] &= ~EXT_INT_ENAB; 480 } 481 482 write_zsreg(zport, R15, zport->regs[15]); 483 write_zsreg(zport, R1, zport->regs[1]); 484 spin_unlock(&scc->zlock); 485} 486 487static void zs_enable_ms(struct uart_port *uport) 488{ 489 struct zs_port *zport = to_zport(uport); 490 struct zs_scc *scc = zport->scc; 491 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A]; 492 493 if (zport == zport_a) 494 return; 495 496 spin_lock(&scc->zlock); 497 498 /* Clear Ext interrupts if not being handled already. */ 499 if (!(zport_a->regs[1] & EXT_INT_ENAB)) 500 write_zsreg(zport_a, R0, RES_EXT_INT); 501 502 /* A-side DCD tracks RI and SYNC tracks DSR. */ 503 zport_a->regs[1] |= EXT_INT_ENAB; 504 zport_a->regs[15] |= DCDIE | SYNCIE; 505 506 /* This-side DCD tracks DCD and CTS tracks CTS. */ 507 zport->regs[15] |= DCDIE | CTSIE; 508 509 zs_raw_xor_mctrl(zport); 510 511 write_zsreg(zport_a, R1, zport_a->regs[1]); 512 write_zsreg(zport_a, R15, zport_a->regs[15]); 513 write_zsreg(zport, R15, zport->regs[15]); 514 spin_unlock(&scc->zlock); 515} 516 517static void zs_break_ctl(struct uart_port *uport, int break_state) 518{ 519 struct zs_port *zport = to_zport(uport); 520 struct zs_scc *scc = zport->scc; 521 unsigned long flags; 522 523 spin_lock_irqsave(&scc->zlock, flags); 524 if (break_state == -1) 525 zport->regs[5] |= SND_BRK; 526 else 527 zport->regs[5] &= ~SND_BRK; 528 write_zsreg(zport, R5, zport->regs[5]); 529 spin_unlock_irqrestore(&scc->zlock, flags); 530} 531 532 533/* 534 * Interrupt handling routines. 535 */ 536#define Rx_BRK 0x0100 /* BREAK event software flag. */ 537#define Rx_SYS 0x0200 /* SysRq event software flag. */ 538 539static void zs_receive_chars(struct zs_port *zport) 540{ 541 struct uart_port *uport = &zport->port; 542 struct zs_scc *scc = zport->scc; 543 struct uart_icount *icount; 544 unsigned int avail, status, ch, flag; 545 int count; 546 547 for (count = 16; count; count--) { 548 spin_lock(&scc->zlock); 549 avail = read_zsreg(zport, R0) & Rx_CH_AV; 550 spin_unlock(&scc->zlock); 551 if (!avail) 552 break; 553 554 spin_lock(&scc->zlock); 555 status = read_zsreg(zport, R1) & (Rx_OVR | FRM_ERR | PAR_ERR); 556 ch = read_zsdata(zport); 557 spin_unlock(&scc->zlock); 558 559 flag = TTY_NORMAL; 560 561 icount = &uport->icount; 562 icount->rx++; 563 564 /* Handle the null char got when BREAK is removed. */ 565 if (!ch) 566 status |= zport->tty_break; 567 if (unlikely(status & 568 (Rx_OVR | FRM_ERR | PAR_ERR | Rx_SYS | Rx_BRK))) { 569 zport->tty_break = 0; 570 571 /* Reset the error indication. */ 572 if (status & (Rx_OVR | FRM_ERR | PAR_ERR)) { 573 spin_lock(&scc->zlock); 574 write_zsreg(zport, R0, ERR_RES); 575 spin_unlock(&scc->zlock); 576 } 577 578 if (status & (Rx_SYS | Rx_BRK)) { 579 icount->brk++; 580 /* SysRq discards the null char. */ 581 if (status & Rx_SYS) 582 continue; 583 } else if (status & FRM_ERR) 584 icount->frame++; 585 else if (status & PAR_ERR) 586 icount->parity++; 587 if (status & Rx_OVR) 588 icount->overrun++; 589 590 status &= uport->read_status_mask; 591 if (status & Rx_BRK) 592 flag = TTY_BREAK; 593 else if (status & FRM_ERR) 594 flag = TTY_FRAME; 595 else if (status & PAR_ERR) 596 flag = TTY_PARITY; 597 } 598 599 if (uart_handle_sysrq_char(uport, ch)) 600 continue; 601 602 uart_insert_char(uport, status, Rx_OVR, ch, flag); 603 } 604 605 tty_flip_buffer_push(uport->state->port.tty); 606} 607 608static void zs_raw_transmit_chars(struct zs_port *zport) 609{ 610 struct circ_buf *xmit = &zport->port.state->xmit; 611 612 /* XON/XOFF chars. */ 613 if (zport->port.x_char) { 614 write_zsdata(zport, zport->port.x_char); 615 zport->port.icount.tx++; 616 zport->port.x_char = 0; 617 return; 618 } 619 620 /* If nothing to do or stopped or hardware stopped. */ 621 if (uart_circ_empty(xmit) || uart_tx_stopped(&zport->port)) { 622 zs_raw_stop_tx(zport); 623 return; 624 } 625 626 /* Send char. */ 627 write_zsdata(zport, xmit->buf[xmit->tail]); 628 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); 629 zport->port.icount.tx++; 630 631 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) 632 uart_write_wakeup(&zport->port); 633 634 /* Are we are done? */ 635 if (uart_circ_empty(xmit)) 636 zs_raw_stop_tx(zport); 637} 638 639static void zs_transmit_chars(struct zs_port *zport) 640{ 641 struct zs_scc *scc = zport->scc; 642 643 spin_lock(&scc->zlock); 644 zs_raw_transmit_chars(zport); 645 spin_unlock(&scc->zlock); 646} 647 648static void zs_status_handle(struct zs_port *zport, struct zs_port *zport_a) 649{ 650 struct uart_port *uport = &zport->port; 651 struct zs_scc *scc = zport->scc; 652 unsigned int delta; 653 u8 status, brk; 654 655 spin_lock(&scc->zlock); 656 657 /* Get status from Read Register 0. */ 658 status = read_zsreg(zport, R0); 659 660 if (zport->regs[15] & BRKIE) { 661 brk = status & BRK_ABRT; 662 if (brk && !zport->brk) { 663 spin_unlock(&scc->zlock); 664 if (uart_handle_break(uport)) 665 zport->tty_break = Rx_SYS; 666 else 667 zport->tty_break = Rx_BRK; 668 spin_lock(&scc->zlock); 669 } 670 zport->brk = brk; 671 } 672 673 if (zport != zport_a) { 674 delta = zs_raw_xor_mctrl(zport); 675 spin_unlock(&scc->zlock); 676 677 if (delta & TIOCM_CTS) 678 uart_handle_cts_change(uport, 679 zport->mctrl & TIOCM_CTS); 680 if (delta & TIOCM_CAR) 681 uart_handle_dcd_change(uport, 682 zport->mctrl & TIOCM_CAR); 683 if (delta & TIOCM_RNG) 684 uport->icount.dsr++; 685 if (delta & TIOCM_DSR) 686 uport->icount.rng++; 687 688 if (delta) 689 wake_up_interruptible(&uport->state->port.delta_msr_wait); 690 691 spin_lock(&scc->zlock); 692 } 693 694 /* Clear the status condition... */ 695 write_zsreg(zport, R0, RES_EXT_INT); 696 697 spin_unlock(&scc->zlock); 698} 699 700/* 701 * This is the Z85C30 driver's generic interrupt routine. 702 */ 703static irqreturn_t zs_interrupt(int irq, void *dev_id) 704{ 705 struct zs_scc *scc = dev_id; 706 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A]; 707 struct zs_port *zport_b = &scc->zport[ZS_CHAN_B]; 708 irqreturn_t status = IRQ_NONE; 709 u8 zs_intreg; 710 int count; 711 712 /* 713 * NOTE: The read register 3, which holds the irq status, 714 * does so for both channels on each chip. Although 715 * the status value itself must be read from the A 716 * channel and is only valid when read from channel A. 717 * Yes... broken hardware... 718 */ 719 for (count = 16; count; count--) { 720 spin_lock(&scc->zlock); 721 zs_intreg = read_zsreg(zport_a, R3); 722 spin_unlock(&scc->zlock); 723 if (!zs_intreg) 724 break; 725 726 /* 727 * We do not like losing characters, so we prioritise 728 * interrupt sources a little bit differently than 729 * the SCC would, was it allowed to. 730 */ 731 if (zs_intreg & CHBRxIP) 732 zs_receive_chars(zport_b); 733 if (zs_intreg & CHARxIP) 734 zs_receive_chars(zport_a); 735 if (zs_intreg & CHBEXT) 736 zs_status_handle(zport_b, zport_a); 737 if (zs_intreg & CHAEXT) 738 zs_status_handle(zport_a, zport_a); 739 if (zs_intreg & CHBTxIP) 740 zs_transmit_chars(zport_b); 741 if (zs_intreg & CHATxIP) 742 zs_transmit_chars(zport_a); 743 744 status = IRQ_HANDLED; 745 } 746 747 return status; 748} 749 750 751/* 752 * Finally, routines used to initialize the serial port. 753 */ 754static int zs_startup(struct uart_port *uport) 755{ 756 struct zs_port *zport = to_zport(uport); 757 struct zs_scc *scc = zport->scc; 758 unsigned long flags; 759 int irq_guard; 760 int ret; 761 762 irq_guard = atomic_add_return(1, &scc->irq_guard); 763 if (irq_guard == 1) { 764 ret = request_irq(zport->port.irq, zs_interrupt, 765 IRQF_SHARED, "scc", scc); 766 if (ret) { 767 atomic_add(-1, &scc->irq_guard); 768 printk(KERN_ERR "zs: can't get irq %d\n", 769 zport->port.irq); 770 return ret; 771 } 772 } 773 774 spin_lock_irqsave(&scc->zlock, flags); 775 776 /* Clear the receive FIFO. */ 777 zs_receive_drain(zport); 778 779 /* Clear the interrupt registers. */ 780 write_zsreg(zport, R0, ERR_RES); 781 write_zsreg(zport, R0, RES_Tx_P); 782 /* But Ext only if not being handled already. */ 783 if (!(zport->regs[1] & EXT_INT_ENAB)) 784 write_zsreg(zport, R0, RES_EXT_INT); 785 786 /* Finally, enable sequencing and interrupts. */ 787 zport->regs[1] &= ~RxINT_MASK; 788 zport->regs[1] |= RxINT_ALL | TxINT_ENAB | EXT_INT_ENAB; 789 zport->regs[3] |= RxENABLE; 790 zport->regs[15] |= BRKIE; 791 write_zsreg(zport, R1, zport->regs[1]); 792 write_zsreg(zport, R3, zport->regs[3]); 793 write_zsreg(zport, R5, zport->regs[5]); 794 write_zsreg(zport, R15, zport->regs[15]); 795 796 /* Record the current state of RR0. */ 797 zport->mctrl = zs_raw_get_mctrl(zport); 798 zport->brk = read_zsreg(zport, R0) & BRK_ABRT; 799 800 zport->tx_stopped = 1; 801 802 spin_unlock_irqrestore(&scc->zlock, flags); 803 804 return 0; 805} 806 807static void zs_shutdown(struct uart_port *uport) 808{ 809 struct zs_port *zport = to_zport(uport); 810 struct zs_scc *scc = zport->scc; 811 unsigned long flags; 812 int irq_guard; 813 814 spin_lock_irqsave(&scc->zlock, flags); 815 816 zport->regs[3] &= ~RxENABLE; 817 write_zsreg(zport, R5, zport->regs[5]); 818 write_zsreg(zport, R3, zport->regs[3]); 819 820 spin_unlock_irqrestore(&scc->zlock, flags); 821 822 irq_guard = atomic_add_return(-1, &scc->irq_guard); 823 if (!irq_guard) 824 free_irq(zport->port.irq, scc); 825} 826 827 828static void zs_reset(struct zs_port *zport) 829{ 830 struct zs_scc *scc = zport->scc; 831 int irq; 832 unsigned long flags; 833 834 spin_lock_irqsave(&scc->zlock, flags); 835 irq = !irqs_disabled_flags(flags); 836 if (!scc->initialised) { 837 /* Reset the pointer first, just in case... */ 838 read_zsreg(zport, R0); 839 /* And let the current transmission finish. */ 840 zs_line_drain(zport, irq); 841 write_zsreg(zport, R9, FHWRES); 842 udelay(10); 843 write_zsreg(zport, R9, 0); 844 scc->initialised = 1; 845 } 846 load_zsregs(zport, zport->regs, irq); 847 spin_unlock_irqrestore(&scc->zlock, flags); 848} 849 850static void zs_set_termios(struct uart_port *uport, struct ktermios *termios, 851 struct ktermios *old_termios) 852{ 853 struct zs_port *zport = to_zport(uport); 854 struct zs_scc *scc = zport->scc; 855 struct zs_port *zport_a = &scc->zport[ZS_CHAN_A]; 856 int irq; 857 unsigned int baud, brg; 858 unsigned long flags; 859 860 spin_lock_irqsave(&scc->zlock, flags); 861 irq = !irqs_disabled_flags(flags); 862 863 /* Byte size. */ 864 zport->regs[3] &= ~RxNBITS_MASK; 865 zport->regs[5] &= ~TxNBITS_MASK; 866 switch (termios->c_cflag & CSIZE) { 867 case CS5: 868 zport->regs[3] |= Rx5; 869 zport->regs[5] |= Tx5; 870 break; 871 case CS6: 872 zport->regs[3] |= Rx6; 873 zport->regs[5] |= Tx6; 874 break; 875 case CS7: 876 zport->regs[3] |= Rx7; 877 zport->regs[5] |= Tx7; 878 break; 879 case CS8: 880 default: 881 zport->regs[3] |= Rx8; 882 zport->regs[5] |= Tx8; 883 break; 884 } 885 886 /* Parity and stop bits. */ 887 zport->regs[4] &= ~(XCLK_MASK | SB_MASK | PAR_ENA | PAR_EVEN); 888 if (termios->c_cflag & CSTOPB) 889 zport->regs[4] |= SB2; 890 else 891 zport->regs[4] |= SB1; 892 if (termios->c_cflag & PARENB) 893 zport->regs[4] |= PAR_ENA; 894 if (!(termios->c_cflag & PARODD)) 895 zport->regs[4] |= PAR_EVEN; 896 switch (zport->clk_mode) { 897 case 64: 898 zport->regs[4] |= X64CLK; 899 break; 900 case 32: 901 zport->regs[4] |= X32CLK; 902 break; 903 case 16: 904 zport->regs[4] |= X16CLK; 905 break; 906 case 1: 907 zport->regs[4] |= X1CLK; 908 break; 909 default: 910 BUG(); 911 } 912 913 baud = uart_get_baud_rate(uport, termios, old_termios, 0, 914 uport->uartclk / zport->clk_mode / 4); 915 916 brg = ZS_BPS_TO_BRG(baud, uport->uartclk / zport->clk_mode); 917 zport->regs[12] = brg & 0xff; 918 zport->regs[13] = (brg >> 8) & 0xff; 919 920 uart_update_timeout(uport, termios->c_cflag, baud); 921 922 uport->read_status_mask = Rx_OVR; 923 if (termios->c_iflag & INPCK) 924 uport->read_status_mask |= FRM_ERR | PAR_ERR; 925 if (termios->c_iflag & (BRKINT | PARMRK)) 926 uport->read_status_mask |= Rx_BRK; 927 928 uport->ignore_status_mask = 0; 929 if (termios->c_iflag & IGNPAR) 930 uport->ignore_status_mask |= FRM_ERR | PAR_ERR; 931 if (termios->c_iflag & IGNBRK) { 932 uport->ignore_status_mask |= Rx_BRK; 933 if (termios->c_iflag & IGNPAR) 934 uport->ignore_status_mask |= Rx_OVR; 935 } 936 937 if (termios->c_cflag & CREAD) 938 zport->regs[3] |= RxENABLE; 939 else 940 zport->regs[3] &= ~RxENABLE; 941 942 if (zport != zport_a) { 943 if (!(termios->c_cflag & CLOCAL)) { 944 zport->regs[15] |= DCDIE; 945 } else 946 zport->regs[15] &= ~DCDIE; 947 if (termios->c_cflag & CRTSCTS) { 948 zport->regs[15] |= CTSIE; 949 } else 950 zport->regs[15] &= ~CTSIE; 951 zs_raw_xor_mctrl(zport); 952 } 953 954 /* Load up the new values. */ 955 load_zsregs(zport, zport->regs, irq); 956 957 spin_unlock_irqrestore(&scc->zlock, flags); 958} 959 960/* 961 * Hack alert! 962 * Required solely so that the initial PROM-based console 963 * works undisturbed in parallel with this one. 964 */ 965static void zs_pm(struct uart_port *uport, unsigned int state, 966 unsigned int oldstate) 967{ 968 struct zs_port *zport = to_zport(uport); 969 970 if (state < 3) 971 zport->regs[5] |= TxENAB; 972 else 973 zport->regs[5] &= ~TxENAB; 974 write_zsreg(zport, R5, zport->regs[5]); 975} 976 977 978static const char *zs_type(struct uart_port *uport) 979{ 980 return "Z85C30 SCC"; 981} 982 983static void zs_release_port(struct uart_port *uport) 984{ 985 iounmap(uport->membase); 986 uport->membase = 0; 987 release_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE); 988} 989 990static int zs_map_port(struct uart_port *uport) 991{ 992 if (!uport->membase) 993 uport->membase = ioremap_nocache(uport->mapbase, 994 ZS_CHAN_IO_SIZE); 995 if (!uport->membase) { 996 printk(KERN_ERR "zs: Cannot map MMIO\n"); 997 return -ENOMEM; 998 } 999 return 0; 1000} 1001 1002static int zs_request_port(struct uart_port *uport) 1003{ 1004 int ret; 1005 1006 if (!request_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE, "scc")) { 1007 printk(KERN_ERR "zs: Unable to reserve MMIO resource\n"); 1008 return -EBUSY; 1009 } 1010 ret = zs_map_port(uport); 1011 if (ret) { 1012 release_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE); 1013 return ret; 1014 } 1015 return 0; 1016} 1017 1018static void zs_config_port(struct uart_port *uport, int flags) 1019{ 1020 struct zs_port *zport = to_zport(uport); 1021 1022 if (flags & UART_CONFIG_TYPE) { 1023 if (zs_request_port(uport)) 1024 return; 1025 1026 uport->type = PORT_ZS; 1027 1028 zs_reset(zport); 1029 } 1030} 1031 1032static int zs_verify_port(struct uart_port *uport, struct serial_struct *ser) 1033{ 1034 struct zs_port *zport = to_zport(uport); 1035 int ret = 0; 1036 1037 if (ser->type != PORT_UNKNOWN && ser->type != PORT_ZS) 1038 ret = -EINVAL; 1039 if (ser->irq != uport->irq) 1040 ret = -EINVAL; 1041 if (ser->baud_base != uport->uartclk / zport->clk_mode / 4) 1042 ret = -EINVAL; 1043 return ret; 1044} 1045 1046 1047static struct uart_ops zs_ops = { 1048 .tx_empty = zs_tx_empty, 1049 .set_mctrl = zs_set_mctrl, 1050 .get_mctrl = zs_get_mctrl, 1051 .stop_tx = zs_stop_tx, 1052 .start_tx = zs_start_tx, 1053 .stop_rx = zs_stop_rx, 1054 .enable_ms = zs_enable_ms, 1055 .break_ctl = zs_break_ctl, 1056 .startup = zs_startup, 1057 .shutdown = zs_shutdown, 1058 .set_termios = zs_set_termios, 1059 .pm = zs_pm, 1060 .type = zs_type, 1061 .release_port = zs_release_port, 1062 .request_port = zs_request_port, 1063 .config_port = zs_config_port, 1064 .verify_port = zs_verify_port, 1065}; 1066 1067/* 1068 * Initialize Z85C30 port structures. 1069 */ 1070static int __init zs_probe_sccs(void) 1071{ 1072 static int probed; 1073 struct zs_parms zs_parms; 1074 int chip, side, irq; 1075 int n_chips = 0; 1076 int i; 1077 1078 if (probed) 1079 return 0; 1080 1081 irq = dec_interrupt[DEC_IRQ_SCC0]; 1082 if (irq >= 0) { 1083 zs_parms.scc[n_chips] = IOASIC_SCC0; 1084 zs_parms.irq[n_chips] = dec_interrupt[DEC_IRQ_SCC0]; 1085 n_chips++; 1086 } 1087 irq = dec_interrupt[DEC_IRQ_SCC1]; 1088 if (irq >= 0) { 1089 zs_parms.scc[n_chips] = IOASIC_SCC1; 1090 zs_parms.irq[n_chips] = dec_interrupt[DEC_IRQ_SCC1]; 1091 n_chips++; 1092 } 1093 if (!n_chips) 1094 return -ENXIO; 1095 1096 probed = 1; 1097 1098 for (chip = 0; chip < n_chips; chip++) { 1099 spin_lock_init(&zs_sccs[chip].zlock); 1100 for (side = 0; side < ZS_NUM_CHAN; side++) { 1101 struct zs_port *zport = &zs_sccs[chip].zport[side]; 1102 struct uart_port *uport = &zport->port; 1103 1104 zport->scc = &zs_sccs[chip]; 1105 zport->clk_mode = 16; 1106 1107 uport->irq = zs_parms.irq[chip]; 1108 uport->uartclk = ZS_CLOCK; 1109 uport->fifosize = 1; 1110 uport->iotype = UPIO_MEM; 1111 uport->flags = UPF_BOOT_AUTOCONF; 1112 uport->ops = &zs_ops; 1113 uport->line = chip * ZS_NUM_CHAN + side; 1114 uport->mapbase = dec_kn_slot_base + 1115 zs_parms.scc[chip] + 1116 (side ^ ZS_CHAN_B) * ZS_CHAN_IO_SIZE; 1117 1118 for (i = 0; i < ZS_NUM_REGS; i++) 1119 zport->regs[i] = zs_init_regs[i]; 1120 } 1121 } 1122 1123 return 0; 1124} 1125 1126 1127#ifdef CONFIG_SERIAL_ZS_CONSOLE 1128static void zs_console_putchar(struct uart_port *uport, int ch) 1129{ 1130 struct zs_port *zport = to_zport(uport); 1131 struct zs_scc *scc = zport->scc; 1132 int irq; 1133 unsigned long flags; 1134 1135 spin_lock_irqsave(&scc->zlock, flags); 1136 irq = !irqs_disabled_flags(flags); 1137 if (zs_transmit_drain(zport, irq)) 1138 write_zsdata(zport, ch); 1139 spin_unlock_irqrestore(&scc->zlock, flags); 1140} 1141 1142/* 1143 * Print a string to the serial port trying not to disturb 1144 * any possible real use of the port... 1145 */ 1146static void zs_console_write(struct console *co, const char *s, 1147 unsigned int count) 1148{ 1149 int chip = co->index / ZS_NUM_CHAN, side = co->index % ZS_NUM_CHAN; 1150 struct zs_port *zport = &zs_sccs[chip].zport[side]; 1151 struct zs_scc *scc = zport->scc; 1152 unsigned long flags; 1153 u8 txint, txenb; 1154 int irq; 1155 1156 /* Disable transmit interrupts and enable the transmitter. */ 1157 spin_lock_irqsave(&scc->zlock, flags); 1158 txint = zport->regs[1]; 1159 txenb = zport->regs[5]; 1160 if (txint & TxINT_ENAB) { 1161 zport->regs[1] = txint & ~TxINT_ENAB; 1162 write_zsreg(zport, R1, zport->regs[1]); 1163 } 1164 if (!(txenb & TxENAB)) { 1165 zport->regs[5] = txenb | TxENAB; 1166 write_zsreg(zport, R5, zport->regs[5]); 1167 } 1168 spin_unlock_irqrestore(&scc->zlock, flags); 1169 1170 uart_console_write(&zport->port, s, count, zs_console_putchar); 1171 1172 /* Restore transmit interrupts and the transmitter enable. */ 1173 spin_lock_irqsave(&scc->zlock, flags); 1174 irq = !irqs_disabled_flags(flags); 1175 zs_line_drain(zport, irq); 1176 if (!(txenb & TxENAB)) { 1177 zport->regs[5] &= ~TxENAB; 1178 write_zsreg(zport, R5, zport->regs[5]); 1179 } 1180 if (txint & TxINT_ENAB) { 1181 zport->regs[1] |= TxINT_ENAB; 1182 write_zsreg(zport, R1, zport->regs[1]); 1183 } 1184 spin_unlock_irqrestore(&scc->zlock, flags); 1185} 1186 1187/* 1188 * Setup serial console baud/bits/parity. We do two things here: 1189 * - construct a cflag setting for the first uart_open() 1190 * - initialise the serial port 1191 * Return non-zero if we didn't find a serial port. 1192 */ 1193static int __init zs_console_setup(struct console *co, char *options) 1194{ 1195 int chip = co->index / ZS_NUM_CHAN, side = co->index % ZS_NUM_CHAN; 1196 struct zs_port *zport = &zs_sccs[chip].zport[side]; 1197 struct uart_port *uport = &zport->port; 1198 int baud = 9600; 1199 int bits = 8; 1200 int parity = 'n'; 1201 int flow = 'n'; 1202 int ret; 1203 1204 ret = zs_map_port(uport); 1205 if (ret) 1206 return ret; 1207 1208 zs_reset(zport); 1209 zs_pm(uport, 0, -1); 1210 1211 if (options) 1212 uart_parse_options(options, &baud, &parity, &bits, &flow); 1213 return uart_set_options(uport, co, baud, parity, bits, flow); 1214} 1215 1216static struct uart_driver zs_reg; 1217static struct console zs_console = { 1218 .name = "ttyS", 1219 .write = zs_console_write, 1220 .device = uart_console_device, 1221 .setup = zs_console_setup, 1222 .flags = CON_PRINTBUFFER, 1223 .index = -1, 1224 .data = &zs_reg, 1225}; 1226 1227/* 1228 * Register console. 1229 */ 1230static int __init zs_serial_console_init(void) 1231{ 1232 int ret; 1233 1234 ret = zs_probe_sccs(); 1235 if (ret) 1236 return ret; 1237 register_console(&zs_console); 1238 1239 return 0; 1240} 1241 1242console_initcall(zs_serial_console_init); 1243 1244#define SERIAL_ZS_CONSOLE &zs_console 1245#else 1246#define SERIAL_ZS_CONSOLE NULL 1247#endif /* CONFIG_SERIAL_ZS_CONSOLE */ 1248 1249static struct uart_driver zs_reg = { 1250 .owner = THIS_MODULE, 1251 .driver_name = "serial", 1252 .dev_name = "ttyS", 1253 .major = TTY_MAJOR, 1254 .minor = 64, 1255 .nr = ZS_NUM_SCCS * ZS_NUM_CHAN, 1256 .cons = SERIAL_ZS_CONSOLE, 1257}; 1258 1259/* zs_init inits the driver. */ 1260static int __init zs_init(void) 1261{ 1262 int i, ret; 1263 1264 pr_info("%s%s\n", zs_name, zs_version); 1265 1266 /* Find out how many Z85C30 SCCs we have. */ 1267 ret = zs_probe_sccs(); 1268 if (ret) 1269 return ret; 1270 1271 ret = uart_register_driver(&zs_reg); 1272 if (ret) 1273 return ret; 1274 1275 for (i = 0; i < ZS_NUM_SCCS * ZS_NUM_CHAN; i++) { 1276 struct zs_scc *scc = &zs_sccs[i / ZS_NUM_CHAN]; 1277 struct zs_port *zport = &scc->zport[i % ZS_NUM_CHAN]; 1278 struct uart_port *uport = &zport->port; 1279 1280 if (zport->scc) 1281 uart_add_one_port(&zs_reg, uport); 1282 } 1283 1284 return 0; 1285} 1286 1287static void __exit zs_exit(void) 1288{ 1289 int i; 1290 1291 for (i = ZS_NUM_SCCS * ZS_NUM_CHAN - 1; i >= 0; i--) { 1292 struct zs_scc *scc = &zs_sccs[i / ZS_NUM_CHAN]; 1293 struct zs_port *zport = &scc->zport[i % ZS_NUM_CHAN]; 1294 struct uart_port *uport = &zport->port; 1295 1296 if (zport->scc) 1297 uart_remove_one_port(&zs_reg, uport); 1298 } 1299 1300 uart_unregister_driver(&zs_reg); 1301} 1302 1303module_init(zs_init); 1304module_exit(zs_exit); 1305