1 /* 2 * QEMU 16550A UART emulation 3 * 4 * Copyright (c) 2003-2004 Fabrice Bellard 5 * Copyright (c) 2008 Citrix Systems, Inc. 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a copy 8 * of this software and associated documentation files (the "Software"), to deal 9 * in the Software without restriction, including without limitation the rights 10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 11 * copies of the Software, and to permit persons to whom the Software is 12 * furnished to do so, subject to the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be included in 15 * all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 23 * THE SOFTWARE. 24 */ 25 26 #include "qemu/osdep.h" 27 #include "hw/char/serial.h" 28 #include "chardev/char-serial.h" 29 #include "qapi/error.h" 30 #include "qemu/timer.h" 31 #include "qemu/error-report.h" 32 33 //#define DEBUG_SERIAL 34 35 #define UART_LCR_DLAB 0x80 /* Divisor latch access bit */ 36 37 #define UART_IER_MSI 0x08 /* Enable Modem status interrupt */ 38 #define UART_IER_RLSI 0x04 /* Enable receiver line status interrupt */ 39 #define UART_IER_THRI 0x02 /* Enable Transmitter holding register int. */ 40 #define UART_IER_RDI 0x01 /* Enable receiver data interrupt */ 41 42 #define UART_IIR_NO_INT 0x01 /* No interrupts pending */ 43 #define UART_IIR_ID 0x06 /* Mask for the interrupt ID */ 44 45 #define UART_IIR_MSI 0x00 /* Modem status interrupt */ 46 #define UART_IIR_THRI 0x02 /* Transmitter holding register empty */ 47 #define UART_IIR_RDI 0x04 /* Receiver data interrupt */ 48 #define UART_IIR_RLSI 0x06 /* Receiver line status interrupt */ 49 #define UART_IIR_CTI 0x0C /* Character Timeout Indication */ 50 51 #define UART_IIR_FENF 0x80 /* Fifo enabled, but not functionning */ 52 #define UART_IIR_FE 0xC0 /* Fifo enabled */ 53 54 /* 55 * These are the definitions for the Modem Control Register 56 */ 57 #define UART_MCR_LOOP 0x10 /* Enable loopback test mode */ 58 #define UART_MCR_OUT2 0x08 /* Out2 complement */ 59 #define UART_MCR_OUT1 0x04 /* Out1 complement */ 60 #define UART_MCR_RTS 0x02 /* RTS complement */ 61 #define UART_MCR_DTR 0x01 /* DTR complement */ 62 63 /* 64 * These are the definitions for the Modem Status Register 65 */ 66 #define UART_MSR_DCD 0x80 /* Data Carrier Detect */ 67 #define UART_MSR_RI 0x40 /* Ring Indicator */ 68 #define UART_MSR_DSR 0x20 /* Data Set Ready */ 69 #define UART_MSR_CTS 0x10 /* Clear to Send */ 70 #define UART_MSR_DDCD 0x08 /* Delta DCD */ 71 #define UART_MSR_TERI 0x04 /* Trailing edge ring indicator */ 72 #define UART_MSR_DDSR 0x02 /* Delta DSR */ 73 #define UART_MSR_DCTS 0x01 /* Delta CTS */ 74 #define UART_MSR_ANY_DELTA 0x0F /* Any of the delta bits! */ 75 76 #define UART_LSR_TEMT 0x40 /* Transmitter empty */ 77 #define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */ 78 #define UART_LSR_BI 0x10 /* Break interrupt indicator */ 79 #define UART_LSR_FE 0x08 /* Frame error indicator */ 80 #define UART_LSR_PE 0x04 /* Parity error indicator */ 81 #define UART_LSR_OE 0x02 /* Overrun error indicator */ 82 #define UART_LSR_DR 0x01 /* Receiver data ready */ 83 #define UART_LSR_INT_ANY 0x1E /* Any of the lsr-interrupt-triggering status bits */ 84 85 /* Interrupt trigger levels. The byte-counts are for 16550A - in newer UARTs the byte-count for each ITL is higher. */ 86 87 #define UART_FCR_ITL_1 0x00 /* 1 byte ITL */ 88 #define UART_FCR_ITL_2 0x40 /* 4 bytes ITL */ 89 #define UART_FCR_ITL_3 0x80 /* 8 bytes ITL */ 90 #define UART_FCR_ITL_4 0xC0 /* 14 bytes ITL */ 91 92 #define UART_FCR_DMS 0x08 /* DMA Mode Select */ 93 #define UART_FCR_XFR 0x04 /* XMIT Fifo Reset */ 94 #define UART_FCR_RFR 0x02 /* RCVR Fifo Reset */ 95 #define UART_FCR_FE 0x01 /* FIFO Enable */ 96 97 #define MAX_XMIT_RETRY 4 98 99 #ifdef DEBUG_SERIAL 100 #define DPRINTF(fmt, ...) \ 101 do { fprintf(stderr, "serial: " fmt , ## __VA_ARGS__); } while (0) 102 #else 103 #define DPRINTF(fmt, ...) \ 104 do {} while (0) 105 #endif 106 107 static void serial_receive1(void *opaque, const uint8_t *buf, int size); 108 static void serial_xmit(SerialState *s); 109 110 static inline void recv_fifo_put(SerialState *s, uint8_t chr) 111 { 112 /* Receive overruns do not overwrite FIFO contents. */ 113 if (!fifo8_is_full(&s->recv_fifo)) { 114 fifo8_push(&s->recv_fifo, chr); 115 } else { 116 s->lsr |= UART_LSR_OE; 117 } 118 } 119 120 static void serial_update_irq(SerialState *s) 121 { 122 uint8_t tmp_iir = UART_IIR_NO_INT; 123 124 if ((s->ier & UART_IER_RLSI) && (s->lsr & UART_LSR_INT_ANY)) { 125 tmp_iir = UART_IIR_RLSI; 126 } else if ((s->ier & UART_IER_RDI) && s->timeout_ipending) { 127 /* Note that(s->ier & UART_IER_RDI) can mask this interrupt, 128 * this is not in the specification but is observed on existing 129 * hardware. */ 130 tmp_iir = UART_IIR_CTI; 131 } else if ((s->ier & UART_IER_RDI) && (s->lsr & UART_LSR_DR) && 132 (!(s->fcr & UART_FCR_FE) || 133 s->recv_fifo.num >= s->recv_fifo_itl)) { 134 tmp_iir = UART_IIR_RDI; 135 } else if ((s->ier & UART_IER_THRI) && s->thr_ipending) { 136 tmp_iir = UART_IIR_THRI; 137 } else if ((s->ier & UART_IER_MSI) && (s->msr & UART_MSR_ANY_DELTA)) { 138 tmp_iir = UART_IIR_MSI; 139 } 140 141 s->iir = tmp_iir | (s->iir & 0xF0); 142 143 if (tmp_iir != UART_IIR_NO_INT) { 144 qemu_irq_raise(s->irq); 145 } else { 146 qemu_irq_lower(s->irq); 147 } 148 } 149 150 static void serial_update_parameters(SerialState *s) 151 { 152 int speed, parity, data_bits, stop_bits, frame_size; 153 QEMUSerialSetParams ssp; 154 155 if (s->divider == 0 || s->divider > s->baudbase) { 156 return; 157 } 158 159 /* Start bit. */ 160 frame_size = 1; 161 if (s->lcr & 0x08) { 162 /* Parity bit. */ 163 frame_size++; 164 if (s->lcr & 0x10) 165 parity = 'E'; 166 else 167 parity = 'O'; 168 } else { 169 parity = 'N'; 170 } 171 if (s->lcr & 0x04) 172 stop_bits = 2; 173 else 174 stop_bits = 1; 175 176 data_bits = (s->lcr & 0x03) + 5; 177 frame_size += data_bits + stop_bits; 178 speed = s->baudbase / s->divider; 179 ssp.speed = speed; 180 ssp.parity = parity; 181 ssp.data_bits = data_bits; 182 ssp.stop_bits = stop_bits; 183 s->char_transmit_time = (NANOSECONDS_PER_SECOND / speed) * frame_size; 184 qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp); 185 186 DPRINTF("speed=%d parity=%c data=%d stop=%d\n", 187 speed, parity, data_bits, stop_bits); 188 } 189 190 static void serial_update_msl(SerialState *s) 191 { 192 uint8_t omsr; 193 int flags; 194 195 timer_del(s->modem_status_poll); 196 197 if (qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_GET_TIOCM, 198 &flags) == -ENOTSUP) { 199 s->poll_msl = -1; 200 return; 201 } 202 203 omsr = s->msr; 204 205 s->msr = (flags & CHR_TIOCM_CTS) ? s->msr | UART_MSR_CTS : s->msr & ~UART_MSR_CTS; 206 s->msr = (flags & CHR_TIOCM_DSR) ? s->msr | UART_MSR_DSR : s->msr & ~UART_MSR_DSR; 207 s->msr = (flags & CHR_TIOCM_CAR) ? s->msr | UART_MSR_DCD : s->msr & ~UART_MSR_DCD; 208 s->msr = (flags & CHR_TIOCM_RI) ? s->msr | UART_MSR_RI : s->msr & ~UART_MSR_RI; 209 210 if (s->msr != omsr) { 211 /* Set delta bits */ 212 s->msr = s->msr | ((s->msr >> 4) ^ (omsr >> 4)); 213 /* UART_MSR_TERI only if change was from 1 -> 0 */ 214 if ((s->msr & UART_MSR_TERI) && !(omsr & UART_MSR_RI)) 215 s->msr &= ~UART_MSR_TERI; 216 serial_update_irq(s); 217 } 218 219 /* The real 16550A apparently has a 250ns response latency to line status changes. 220 We'll be lazy and poll only every 10ms, and only poll it at all if MSI interrupts are turned on */ 221 222 if (s->poll_msl) { 223 timer_mod(s->modem_status_poll, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 224 NANOSECONDS_PER_SECOND / 100); 225 } 226 } 227 228 static gboolean serial_watch_cb(GIOChannel *chan, GIOCondition cond, 229 void *opaque) 230 { 231 SerialState *s = opaque; 232 s->watch_tag = 0; 233 serial_xmit(s); 234 return FALSE; 235 } 236 237 static void serial_xmit(SerialState *s) 238 { 239 do { 240 assert(!(s->lsr & UART_LSR_TEMT)); 241 if (s->tsr_retry == 0) { 242 assert(!(s->lsr & UART_LSR_THRE)); 243 244 if (s->fcr & UART_FCR_FE) { 245 assert(!fifo8_is_empty(&s->xmit_fifo)); 246 s->tsr = fifo8_pop(&s->xmit_fifo); 247 if (!s->xmit_fifo.num) { 248 s->lsr |= UART_LSR_THRE; 249 } 250 } else { 251 s->tsr = s->thr; 252 s->lsr |= UART_LSR_THRE; 253 } 254 if ((s->lsr & UART_LSR_THRE) && !s->thr_ipending) { 255 s->thr_ipending = 1; 256 serial_update_irq(s); 257 } 258 } 259 260 if (s->mcr & UART_MCR_LOOP) { 261 /* in loopback mode, say that we just received a char */ 262 serial_receive1(s, &s->tsr, 1); 263 } else if (qemu_chr_fe_write(&s->chr, &s->tsr, 1) == 0 && 264 s->tsr_retry < MAX_XMIT_RETRY) { 265 assert(s->watch_tag == 0); 266 s->watch_tag = 267 qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP, 268 serial_watch_cb, s); 269 if (s->watch_tag > 0) { 270 s->tsr_retry++; 271 return; 272 } 273 } 274 s->tsr_retry = 0; 275 276 /* Transmit another byte if it is already available. It is only 277 possible when FIFO is enabled and not empty. */ 278 } while (!(s->lsr & UART_LSR_THRE)); 279 280 s->last_xmit_ts = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); 281 s->lsr |= UART_LSR_TEMT; 282 } 283 284 /* Setter for FCR. 285 is_load flag means, that value is set while loading VM state 286 and interrupt should not be invoked */ 287 static void serial_write_fcr(SerialState *s, uint8_t val) 288 { 289 /* Set fcr - val only has the bits that are supposed to "stick" */ 290 s->fcr = val; 291 292 if (val & UART_FCR_FE) { 293 s->iir |= UART_IIR_FE; 294 /* Set recv_fifo trigger Level */ 295 switch (val & 0xC0) { 296 case UART_FCR_ITL_1: 297 s->recv_fifo_itl = 1; 298 break; 299 case UART_FCR_ITL_2: 300 s->recv_fifo_itl = 4; 301 break; 302 case UART_FCR_ITL_3: 303 s->recv_fifo_itl = 8; 304 break; 305 case UART_FCR_ITL_4: 306 s->recv_fifo_itl = 14; 307 break; 308 } 309 } else { 310 s->iir &= ~UART_IIR_FE; 311 } 312 } 313 314 static void serial_update_tiocm(SerialState *s) 315 { 316 int flags; 317 318 qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_GET_TIOCM, &flags); 319 320 flags &= ~(CHR_TIOCM_RTS | CHR_TIOCM_DTR); 321 322 if (s->mcr & UART_MCR_RTS) { 323 flags |= CHR_TIOCM_RTS; 324 } 325 if (s->mcr & UART_MCR_DTR) { 326 flags |= CHR_TIOCM_DTR; 327 } 328 329 qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_TIOCM, &flags); 330 } 331 332 static void serial_ioport_write(void *opaque, hwaddr addr, uint64_t val, 333 unsigned size) 334 { 335 SerialState *s = opaque; 336 337 addr &= 7; 338 DPRINTF("write addr=0x%" HWADDR_PRIx " val=0x%" PRIx64 "\n", addr, val); 339 switch(addr) { 340 default: 341 case 0: 342 if (s->lcr & UART_LCR_DLAB) { 343 s->divider = (s->divider & 0xff00) | val; 344 serial_update_parameters(s); 345 } else { 346 s->thr = (uint8_t) val; 347 if(s->fcr & UART_FCR_FE) { 348 /* xmit overruns overwrite data, so make space if needed */ 349 if (fifo8_is_full(&s->xmit_fifo)) { 350 fifo8_pop(&s->xmit_fifo); 351 } 352 fifo8_push(&s->xmit_fifo, s->thr); 353 } 354 s->thr_ipending = 0; 355 s->lsr &= ~UART_LSR_THRE; 356 s->lsr &= ~UART_LSR_TEMT; 357 serial_update_irq(s); 358 if (s->tsr_retry == 0) { 359 serial_xmit(s); 360 } 361 } 362 break; 363 case 1: 364 if (s->lcr & UART_LCR_DLAB) { 365 s->divider = (s->divider & 0x00ff) | (val << 8); 366 serial_update_parameters(s); 367 } else { 368 uint8_t changed = (s->ier ^ val) & 0x0f; 369 s->ier = val & 0x0f; 370 /* If the backend device is a real serial port, turn polling of the modem 371 * status lines on physical port on or off depending on UART_IER_MSI state. 372 */ 373 if ((changed & UART_IER_MSI) && s->poll_msl >= 0) { 374 if (s->ier & UART_IER_MSI) { 375 s->poll_msl = 1; 376 serial_update_msl(s); 377 } else { 378 timer_del(s->modem_status_poll); 379 s->poll_msl = 0; 380 } 381 } 382 383 /* Turning on the THRE interrupt on IER can trigger the interrupt 384 * if LSR.THRE=1, even if it had been masked before by reading IIR. 385 * This is not in the datasheet, but Windows relies on it. It is 386 * unclear if THRE has to be resampled every time THRI becomes 387 * 1, or only on the rising edge. Bochs does the latter, and Windows 388 * always toggles IER to all zeroes and back to all ones, so do the 389 * same. 390 * 391 * If IER.THRI is zero, thr_ipending is not used. Set it to zero 392 * so that the thr_ipending subsection is not migrated. 393 */ 394 if (changed & UART_IER_THRI) { 395 if ((s->ier & UART_IER_THRI) && (s->lsr & UART_LSR_THRE)) { 396 s->thr_ipending = 1; 397 } else { 398 s->thr_ipending = 0; 399 } 400 } 401 402 if (changed) { 403 serial_update_irq(s); 404 } 405 } 406 break; 407 case 2: 408 /* Did the enable/disable flag change? If so, make sure FIFOs get flushed */ 409 if ((val ^ s->fcr) & UART_FCR_FE) { 410 val |= UART_FCR_XFR | UART_FCR_RFR; 411 } 412 413 /* FIFO clear */ 414 415 if (val & UART_FCR_RFR) { 416 s->lsr &= ~(UART_LSR_DR | UART_LSR_BI); 417 timer_del(s->fifo_timeout_timer); 418 s->timeout_ipending = 0; 419 fifo8_reset(&s->recv_fifo); 420 } 421 422 if (val & UART_FCR_XFR) { 423 s->lsr |= UART_LSR_THRE; 424 s->thr_ipending = 1; 425 fifo8_reset(&s->xmit_fifo); 426 } 427 428 serial_write_fcr(s, val & 0xC9); 429 serial_update_irq(s); 430 break; 431 case 3: 432 { 433 int break_enable; 434 s->lcr = val; 435 serial_update_parameters(s); 436 break_enable = (val >> 6) & 1; 437 if (break_enable != s->last_break_enable) { 438 s->last_break_enable = break_enable; 439 qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_BREAK, 440 &break_enable); 441 } 442 } 443 break; 444 case 4: 445 { 446 int old_mcr = s->mcr; 447 s->mcr = val & 0x1f; 448 if (val & UART_MCR_LOOP) 449 break; 450 451 if (s->poll_msl >= 0 && old_mcr != s->mcr) { 452 serial_update_tiocm(s); 453 /* Update the modem status after a one-character-send wait-time, since there may be a response 454 from the device/computer at the other end of the serial line */ 455 timer_mod(s->modem_status_poll, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->char_transmit_time); 456 } 457 } 458 break; 459 case 5: 460 break; 461 case 6: 462 break; 463 case 7: 464 s->scr = val; 465 break; 466 } 467 } 468 469 static uint64_t serial_ioport_read(void *opaque, hwaddr addr, unsigned size) 470 { 471 SerialState *s = opaque; 472 uint32_t ret; 473 474 addr &= 7; 475 switch(addr) { 476 default: 477 case 0: 478 if (s->lcr & UART_LCR_DLAB) { 479 ret = s->divider & 0xff; 480 } else { 481 if(s->fcr & UART_FCR_FE) { 482 ret = fifo8_is_empty(&s->recv_fifo) ? 483 0 : fifo8_pop(&s->recv_fifo); 484 if (s->recv_fifo.num == 0) { 485 s->lsr &= ~(UART_LSR_DR | UART_LSR_BI); 486 } else { 487 timer_mod(s->fifo_timeout_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->char_transmit_time * 4); 488 } 489 s->timeout_ipending = 0; 490 } else { 491 ret = s->rbr; 492 s->lsr &= ~(UART_LSR_DR | UART_LSR_BI); 493 } 494 serial_update_irq(s); 495 if (!(s->mcr & UART_MCR_LOOP)) { 496 /* in loopback mode, don't receive any data */ 497 qemu_chr_fe_accept_input(&s->chr); 498 } 499 } 500 break; 501 case 1: 502 if (s->lcr & UART_LCR_DLAB) { 503 ret = (s->divider >> 8) & 0xff; 504 } else { 505 ret = s->ier; 506 } 507 break; 508 case 2: 509 ret = s->iir; 510 if ((ret & UART_IIR_ID) == UART_IIR_THRI) { 511 s->thr_ipending = 0; 512 serial_update_irq(s); 513 } 514 break; 515 case 3: 516 ret = s->lcr; 517 break; 518 case 4: 519 ret = s->mcr; 520 break; 521 case 5: 522 ret = s->lsr; 523 /* Clear break and overrun interrupts */ 524 if (s->lsr & (UART_LSR_BI|UART_LSR_OE)) { 525 s->lsr &= ~(UART_LSR_BI|UART_LSR_OE); 526 serial_update_irq(s); 527 } 528 break; 529 case 6: 530 if (s->mcr & UART_MCR_LOOP) { 531 /* in loopback, the modem output pins are connected to the 532 inputs */ 533 ret = (s->mcr & 0x0c) << 4; 534 ret |= (s->mcr & 0x02) << 3; 535 ret |= (s->mcr & 0x01) << 5; 536 } else { 537 if (s->poll_msl >= 0) 538 serial_update_msl(s); 539 ret = s->msr; 540 /* Clear delta bits & msr int after read, if they were set */ 541 if (s->msr & UART_MSR_ANY_DELTA) { 542 s->msr &= 0xF0; 543 serial_update_irq(s); 544 } 545 } 546 break; 547 case 7: 548 ret = s->scr; 549 break; 550 } 551 DPRINTF("read addr=0x%" HWADDR_PRIx " val=0x%02x\n", addr, ret); 552 return ret; 553 } 554 555 static int serial_can_receive(SerialState *s) 556 { 557 if(s->fcr & UART_FCR_FE) { 558 if (s->recv_fifo.num < UART_FIFO_LENGTH) { 559 /* 560 * Advertise (fifo.itl - fifo.count) bytes when count < ITL, and 1 561 * if above. If UART_FIFO_LENGTH - fifo.count is advertised the 562 * effect will be to almost always fill the fifo completely before 563 * the guest has a chance to respond, effectively overriding the ITL 564 * that the guest has set. 565 */ 566 return (s->recv_fifo.num <= s->recv_fifo_itl) ? 567 s->recv_fifo_itl - s->recv_fifo.num : 1; 568 } else { 569 return 0; 570 } 571 } else { 572 return !(s->lsr & UART_LSR_DR); 573 } 574 } 575 576 static void serial_receive_break(SerialState *s) 577 { 578 s->rbr = 0; 579 /* When the LSR_DR is set a null byte is pushed into the fifo */ 580 recv_fifo_put(s, '\0'); 581 s->lsr |= UART_LSR_BI | UART_LSR_DR; 582 serial_update_irq(s); 583 } 584 585 /* There's data in recv_fifo and s->rbr has not been read for 4 char transmit times */ 586 static void fifo_timeout_int (void *opaque) { 587 SerialState *s = opaque; 588 if (s->recv_fifo.num) { 589 s->timeout_ipending = 1; 590 serial_update_irq(s); 591 } 592 } 593 594 static int serial_can_receive1(void *opaque) 595 { 596 SerialState *s = opaque; 597 return serial_can_receive(s); 598 } 599 600 static void serial_receive1(void *opaque, const uint8_t *buf, int size) 601 { 602 SerialState *s = opaque; 603 604 if (s->wakeup) { 605 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); 606 } 607 if(s->fcr & UART_FCR_FE) { 608 int i; 609 for (i = 0; i < size; i++) { 610 recv_fifo_put(s, buf[i]); 611 } 612 s->lsr |= UART_LSR_DR; 613 /* call the timeout receive callback in 4 char transmit time */ 614 timer_mod(s->fifo_timeout_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->char_transmit_time * 4); 615 } else { 616 if (s->lsr & UART_LSR_DR) 617 s->lsr |= UART_LSR_OE; 618 s->rbr = buf[0]; 619 s->lsr |= UART_LSR_DR; 620 } 621 serial_update_irq(s); 622 } 623 624 static void serial_event(void *opaque, int event) 625 { 626 SerialState *s = opaque; 627 DPRINTF("event %x\n", event); 628 if (event == CHR_EVENT_BREAK) 629 serial_receive_break(s); 630 } 631 632 static int serial_pre_save(void *opaque) 633 { 634 SerialState *s = opaque; 635 s->fcr_vmstate = s->fcr; 636 637 return 0; 638 } 639 640 static int serial_pre_load(void *opaque) 641 { 642 SerialState *s = opaque; 643 s->thr_ipending = -1; 644 s->poll_msl = -1; 645 return 0; 646 } 647 648 static int serial_post_load(void *opaque, int version_id) 649 { 650 SerialState *s = opaque; 651 652 if (version_id < 3) { 653 s->fcr_vmstate = 0; 654 } 655 if (s->thr_ipending == -1) { 656 s->thr_ipending = ((s->iir & UART_IIR_ID) == UART_IIR_THRI); 657 } 658 659 if (s->tsr_retry > 0) { 660 /* tsr_retry > 0 implies LSR.TEMT = 0 (transmitter not empty). */ 661 if (s->lsr & UART_LSR_TEMT) { 662 error_report("inconsistent state in serial device " 663 "(tsr empty, tsr_retry=%d", s->tsr_retry); 664 return -1; 665 } 666 667 if (s->tsr_retry > MAX_XMIT_RETRY) { 668 s->tsr_retry = MAX_XMIT_RETRY; 669 } 670 671 assert(s->watch_tag == 0); 672 s->watch_tag = qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP, 673 serial_watch_cb, s); 674 } else { 675 /* tsr_retry == 0 implies LSR.TEMT = 1 (transmitter empty). */ 676 if (!(s->lsr & UART_LSR_TEMT)) { 677 error_report("inconsistent state in serial device " 678 "(tsr not empty, tsr_retry=0"); 679 return -1; 680 } 681 } 682 683 s->last_break_enable = (s->lcr >> 6) & 1; 684 /* Initialize fcr via setter to perform essential side-effects */ 685 serial_write_fcr(s, s->fcr_vmstate); 686 serial_update_parameters(s); 687 return 0; 688 } 689 690 static bool serial_thr_ipending_needed(void *opaque) 691 { 692 SerialState *s = opaque; 693 694 if (s->ier & UART_IER_THRI) { 695 bool expected_value = ((s->iir & UART_IIR_ID) == UART_IIR_THRI); 696 return s->thr_ipending != expected_value; 697 } else { 698 /* LSR.THRE will be sampled again when the interrupt is 699 * enabled. thr_ipending is not used in this case, do 700 * not migrate it. 701 */ 702 return false; 703 } 704 } 705 706 static const VMStateDescription vmstate_serial_thr_ipending = { 707 .name = "serial/thr_ipending", 708 .version_id = 1, 709 .minimum_version_id = 1, 710 .needed = serial_thr_ipending_needed, 711 .fields = (VMStateField[]) { 712 VMSTATE_INT32(thr_ipending, SerialState), 713 VMSTATE_END_OF_LIST() 714 } 715 }; 716 717 static bool serial_tsr_needed(void *opaque) 718 { 719 SerialState *s = (SerialState *)opaque; 720 return s->tsr_retry != 0; 721 } 722 723 static const VMStateDescription vmstate_serial_tsr = { 724 .name = "serial/tsr", 725 .version_id = 1, 726 .minimum_version_id = 1, 727 .needed = serial_tsr_needed, 728 .fields = (VMStateField[]) { 729 VMSTATE_UINT32(tsr_retry, SerialState), 730 VMSTATE_UINT8(thr, SerialState), 731 VMSTATE_UINT8(tsr, SerialState), 732 VMSTATE_END_OF_LIST() 733 } 734 }; 735 736 static bool serial_recv_fifo_needed(void *opaque) 737 { 738 SerialState *s = (SerialState *)opaque; 739 return !fifo8_is_empty(&s->recv_fifo); 740 741 } 742 743 static const VMStateDescription vmstate_serial_recv_fifo = { 744 .name = "serial/recv_fifo", 745 .version_id = 1, 746 .minimum_version_id = 1, 747 .needed = serial_recv_fifo_needed, 748 .fields = (VMStateField[]) { 749 VMSTATE_STRUCT(recv_fifo, SerialState, 1, vmstate_fifo8, Fifo8), 750 VMSTATE_END_OF_LIST() 751 } 752 }; 753 754 static bool serial_xmit_fifo_needed(void *opaque) 755 { 756 SerialState *s = (SerialState *)opaque; 757 return !fifo8_is_empty(&s->xmit_fifo); 758 } 759 760 static const VMStateDescription vmstate_serial_xmit_fifo = { 761 .name = "serial/xmit_fifo", 762 .version_id = 1, 763 .minimum_version_id = 1, 764 .needed = serial_xmit_fifo_needed, 765 .fields = (VMStateField[]) { 766 VMSTATE_STRUCT(xmit_fifo, SerialState, 1, vmstate_fifo8, Fifo8), 767 VMSTATE_END_OF_LIST() 768 } 769 }; 770 771 static bool serial_fifo_timeout_timer_needed(void *opaque) 772 { 773 SerialState *s = (SerialState *)opaque; 774 return timer_pending(s->fifo_timeout_timer); 775 } 776 777 static const VMStateDescription vmstate_serial_fifo_timeout_timer = { 778 .name = "serial/fifo_timeout_timer", 779 .version_id = 1, 780 .minimum_version_id = 1, 781 .needed = serial_fifo_timeout_timer_needed, 782 .fields = (VMStateField[]) { 783 VMSTATE_TIMER_PTR(fifo_timeout_timer, SerialState), 784 VMSTATE_END_OF_LIST() 785 } 786 }; 787 788 static bool serial_timeout_ipending_needed(void *opaque) 789 { 790 SerialState *s = (SerialState *)opaque; 791 return s->timeout_ipending != 0; 792 } 793 794 static const VMStateDescription vmstate_serial_timeout_ipending = { 795 .name = "serial/timeout_ipending", 796 .version_id = 1, 797 .minimum_version_id = 1, 798 .needed = serial_timeout_ipending_needed, 799 .fields = (VMStateField[]) { 800 VMSTATE_INT32(timeout_ipending, SerialState), 801 VMSTATE_END_OF_LIST() 802 } 803 }; 804 805 static bool serial_poll_needed(void *opaque) 806 { 807 SerialState *s = (SerialState *)opaque; 808 return s->poll_msl >= 0; 809 } 810 811 static const VMStateDescription vmstate_serial_poll = { 812 .name = "serial/poll", 813 .version_id = 1, 814 .needed = serial_poll_needed, 815 .minimum_version_id = 1, 816 .fields = (VMStateField[]) { 817 VMSTATE_INT32(poll_msl, SerialState), 818 VMSTATE_TIMER_PTR(modem_status_poll, SerialState), 819 VMSTATE_END_OF_LIST() 820 } 821 }; 822 823 const VMStateDescription vmstate_serial = { 824 .name = "serial", 825 .version_id = 3, 826 .minimum_version_id = 2, 827 .pre_save = serial_pre_save, 828 .pre_load = serial_pre_load, 829 .post_load = serial_post_load, 830 .fields = (VMStateField[]) { 831 VMSTATE_UINT16_V(divider, SerialState, 2), 832 VMSTATE_UINT8(rbr, SerialState), 833 VMSTATE_UINT8(ier, SerialState), 834 VMSTATE_UINT8(iir, SerialState), 835 VMSTATE_UINT8(lcr, SerialState), 836 VMSTATE_UINT8(mcr, SerialState), 837 VMSTATE_UINT8(lsr, SerialState), 838 VMSTATE_UINT8(msr, SerialState), 839 VMSTATE_UINT8(scr, SerialState), 840 VMSTATE_UINT8_V(fcr_vmstate, SerialState, 3), 841 VMSTATE_END_OF_LIST() 842 }, 843 .subsections = (const VMStateDescription*[]) { 844 &vmstate_serial_thr_ipending, 845 &vmstate_serial_tsr, 846 &vmstate_serial_recv_fifo, 847 &vmstate_serial_xmit_fifo, 848 &vmstate_serial_fifo_timeout_timer, 849 &vmstate_serial_timeout_ipending, 850 &vmstate_serial_poll, 851 NULL 852 } 853 }; 854 855 static void serial_reset(void *opaque) 856 { 857 SerialState *s = opaque; 858 859 if (s->watch_tag > 0) { 860 g_source_remove(s->watch_tag); 861 s->watch_tag = 0; 862 } 863 864 s->rbr = 0; 865 s->ier = 0; 866 s->iir = UART_IIR_NO_INT; 867 s->lcr = 0; 868 s->lsr = UART_LSR_TEMT | UART_LSR_THRE; 869 s->msr = UART_MSR_DCD | UART_MSR_DSR | UART_MSR_CTS; 870 /* Default to 9600 baud, 1 start bit, 8 data bits, 1 stop bit, no parity. */ 871 s->divider = 0x0C; 872 s->mcr = UART_MCR_OUT2; 873 s->scr = 0; 874 s->tsr_retry = 0; 875 s->char_transmit_time = (NANOSECONDS_PER_SECOND / 9600) * 10; 876 s->poll_msl = 0; 877 878 s->timeout_ipending = 0; 879 timer_del(s->fifo_timeout_timer); 880 timer_del(s->modem_status_poll); 881 882 fifo8_reset(&s->recv_fifo); 883 fifo8_reset(&s->xmit_fifo); 884 885 s->last_xmit_ts = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); 886 887 s->thr_ipending = 0; 888 s->last_break_enable = 0; 889 qemu_irq_lower(s->irq); 890 891 serial_update_msl(s); 892 s->msr &= ~UART_MSR_ANY_DELTA; 893 } 894 895 static int serial_be_change(void *opaque) 896 { 897 SerialState *s = opaque; 898 899 qemu_chr_fe_set_handlers(&s->chr, serial_can_receive1, serial_receive1, 900 serial_event, serial_be_change, s, NULL, true); 901 902 serial_update_parameters(s); 903 904 qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_BREAK, 905 &s->last_break_enable); 906 907 s->poll_msl = (s->ier & UART_IER_MSI) ? 1 : 0; 908 serial_update_msl(s); 909 910 if (s->poll_msl >= 0 && !(s->mcr & UART_MCR_LOOP)) { 911 serial_update_tiocm(s); 912 } 913 914 if (s->watch_tag > 0) { 915 g_source_remove(s->watch_tag); 916 s->watch_tag = qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP, 917 serial_watch_cb, s); 918 } 919 920 return 0; 921 } 922 923 void serial_realize_core(SerialState *s, Error **errp) 924 { 925 s->modem_status_poll = timer_new_ns(QEMU_CLOCK_VIRTUAL, (QEMUTimerCB *) serial_update_msl, s); 926 927 s->fifo_timeout_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, (QEMUTimerCB *) fifo_timeout_int, s); 928 qemu_register_reset(serial_reset, s); 929 930 qemu_chr_fe_set_handlers(&s->chr, serial_can_receive1, serial_receive1, 931 serial_event, serial_be_change, s, NULL, true); 932 fifo8_create(&s->recv_fifo, UART_FIFO_LENGTH); 933 fifo8_create(&s->xmit_fifo, UART_FIFO_LENGTH); 934 serial_reset(s); 935 } 936 937 void serial_exit_core(SerialState *s) 938 { 939 qemu_chr_fe_deinit(&s->chr, false); 940 941 timer_del(s->modem_status_poll); 942 timer_free(s->modem_status_poll); 943 944 timer_del(s->fifo_timeout_timer); 945 timer_free(s->fifo_timeout_timer); 946 947 fifo8_destroy(&s->recv_fifo); 948 fifo8_destroy(&s->xmit_fifo); 949 950 qemu_unregister_reset(serial_reset, s); 951 } 952 953 /* Change the main reference oscillator frequency. */ 954 void serial_set_frequency(SerialState *s, uint32_t frequency) 955 { 956 s->baudbase = frequency; 957 serial_update_parameters(s); 958 } 959 960 const MemoryRegionOps serial_io_ops = { 961 .read = serial_ioport_read, 962 .write = serial_ioport_write, 963 .impl = { 964 .min_access_size = 1, 965 .max_access_size = 1, 966 }, 967 .endianness = DEVICE_LITTLE_ENDIAN, 968 }; 969 970 SerialState *serial_init(int base, qemu_irq irq, int baudbase, 971 Chardev *chr, MemoryRegion *system_io) 972 { 973 SerialState *s; 974 975 s = g_malloc0(sizeof(SerialState)); 976 977 s->irq = irq; 978 s->baudbase = baudbase; 979 qemu_chr_fe_init(&s->chr, chr, &error_abort); 980 serial_realize_core(s, &error_fatal); 981 982 vmstate_register(NULL, base, &vmstate_serial, s); 983 984 memory_region_init_io(&s->io, NULL, &serial_io_ops, s, "serial", 8); 985 memory_region_add_subregion(system_io, base, &s->io); 986 987 return s; 988 } 989 990 /* Memory mapped interface */ 991 static uint64_t serial_mm_read(void *opaque, hwaddr addr, 992 unsigned size) 993 { 994 SerialState *s = opaque; 995 return serial_ioport_read(s, addr >> s->it_shift, 1); 996 } 997 998 static void serial_mm_write(void *opaque, hwaddr addr, 999 uint64_t value, unsigned size) 1000 { 1001 SerialState *s = opaque; 1002 value &= 255; 1003 serial_ioport_write(s, addr >> s->it_shift, value, 1); 1004 } 1005 1006 static const MemoryRegionOps serial_mm_ops[3] = { 1007 [DEVICE_NATIVE_ENDIAN] = { 1008 .read = serial_mm_read, 1009 .write = serial_mm_write, 1010 .endianness = DEVICE_NATIVE_ENDIAN, 1011 .valid.max_access_size = 8, 1012 .impl.max_access_size = 8, 1013 }, 1014 [DEVICE_LITTLE_ENDIAN] = { 1015 .read = serial_mm_read, 1016 .write = serial_mm_write, 1017 .endianness = DEVICE_LITTLE_ENDIAN, 1018 .valid.max_access_size = 8, 1019 .impl.max_access_size = 8, 1020 }, 1021 [DEVICE_BIG_ENDIAN] = { 1022 .read = serial_mm_read, 1023 .write = serial_mm_write, 1024 .endianness = DEVICE_BIG_ENDIAN, 1025 .valid.max_access_size = 8, 1026 .impl.max_access_size = 8, 1027 }, 1028 }; 1029 1030 SerialState *serial_mm_init(MemoryRegion *address_space, 1031 hwaddr base, int it_shift, 1032 qemu_irq irq, int baudbase, 1033 Chardev *chr, enum device_endian end) 1034 { 1035 SerialState *s; 1036 1037 s = g_malloc0(sizeof(SerialState)); 1038 1039 s->it_shift = it_shift; 1040 s->irq = irq; 1041 s->baudbase = baudbase; 1042 qemu_chr_fe_init(&s->chr, chr, &error_abort); 1043 1044 serial_realize_core(s, &error_fatal); 1045 vmstate_register(NULL, base, &vmstate_serial, s); 1046 1047 memory_region_init_io(&s->io, NULL, &serial_mm_ops[end], s, 1048 "serial", 8 << it_shift); 1049 memory_region_add_subregion(address_space, base, &s->io); 1050 return s; 1051 } 1052