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 "qemu/bitops.h" 28 #include "hw/char/serial.h" 29 #include "hw/irq.h" 30 #include "migration/vmstate.h" 31 #include "chardev/char-serial.h" 32 #include "qapi/error.h" 33 #include "qemu/timer.h" 34 #include "sysemu/reset.h" 35 #include "sysemu/runstate.h" 36 #include "qemu/error-report.h" 37 #include "trace.h" 38 #include "hw/qdev-properties.h" 39 #include "hw/qdev-properties-system.h" 40 41 #define UART_LCR_DLAB 0x80 /* Divisor latch access bit */ 42 43 #define UART_IER_MSI 0x08 /* Enable Modem status interrupt */ 44 #define UART_IER_RLSI 0x04 /* Enable receiver line status interrupt */ 45 #define UART_IER_THRI 0x02 /* Enable Transmitter holding register int. */ 46 #define UART_IER_RDI 0x01 /* Enable receiver data interrupt */ 47 48 #define UART_IIR_NO_INT 0x01 /* No interrupts pending */ 49 #define UART_IIR_ID 0x06 /* Mask for the interrupt ID */ 50 51 #define UART_IIR_MSI 0x00 /* Modem status interrupt */ 52 #define UART_IIR_THRI 0x02 /* Transmitter holding register empty */ 53 #define UART_IIR_RDI 0x04 /* Receiver data interrupt */ 54 #define UART_IIR_RLSI 0x06 /* Receiver line status interrupt */ 55 #define UART_IIR_CTI 0x0C /* Character Timeout Indication */ 56 57 #define UART_IIR_FENF 0x80 /* Fifo enabled, but not functioning */ 58 #define UART_IIR_FE 0xC0 /* Fifo enabled */ 59 60 /* 61 * These are the definitions for the Modem Control Register 62 */ 63 #define UART_MCR_LOOP 0x10 /* Enable loopback test mode */ 64 #define UART_MCR_OUT2 0x08 /* Out2 complement */ 65 #define UART_MCR_OUT1 0x04 /* Out1 complement */ 66 #define UART_MCR_RTS 0x02 /* RTS complement */ 67 #define UART_MCR_DTR 0x01 /* DTR complement */ 68 69 /* 70 * These are the definitions for the Modem Status Register 71 */ 72 #define UART_MSR_DCD 0x80 /* Data Carrier Detect */ 73 #define UART_MSR_RI 0x40 /* Ring Indicator */ 74 #define UART_MSR_DSR 0x20 /* Data Set Ready */ 75 #define UART_MSR_CTS 0x10 /* Clear to Send */ 76 #define UART_MSR_DDCD 0x08 /* Delta DCD */ 77 #define UART_MSR_TERI 0x04 /* Trailing edge ring indicator */ 78 #define UART_MSR_DDSR 0x02 /* Delta DSR */ 79 #define UART_MSR_DCTS 0x01 /* Delta CTS */ 80 #define UART_MSR_ANY_DELTA 0x0F /* Any of the delta bits! */ 81 82 #define UART_LSR_TEMT 0x40 /* Transmitter empty */ 83 #define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */ 84 #define UART_LSR_BI 0x10 /* Break interrupt indicator */ 85 #define UART_LSR_FE 0x08 /* Frame error indicator */ 86 #define UART_LSR_PE 0x04 /* Parity error indicator */ 87 #define UART_LSR_OE 0x02 /* Overrun error indicator */ 88 #define UART_LSR_DR 0x01 /* Receiver data ready */ 89 #define UART_LSR_INT_ANY 0x1E /* Any of the lsr-interrupt-triggering status bits */ 90 91 /* Interrupt trigger levels. The byte-counts are for 16550A - in newer UARTs the byte-count for each ITL is higher. */ 92 93 #define UART_FCR_ITL_1 0x00 /* 1 byte ITL */ 94 #define UART_FCR_ITL_2 0x40 /* 4 bytes ITL */ 95 #define UART_FCR_ITL_3 0x80 /* 8 bytes ITL */ 96 #define UART_FCR_ITL_4 0xC0 /* 14 bytes ITL */ 97 98 #define UART_FCR_DMS 0x08 /* DMA Mode Select */ 99 #define UART_FCR_XFR 0x04 /* XMIT Fifo Reset */ 100 #define UART_FCR_RFR 0x02 /* RCVR Fifo Reset */ 101 #define UART_FCR_FE 0x01 /* FIFO Enable */ 102 103 #define MAX_XMIT_RETRY 4 104 105 static void serial_receive1(void *opaque, const uint8_t *buf, int size); 106 static void serial_xmit(SerialState *s); 107 108 static inline void recv_fifo_put(SerialState *s, uint8_t chr) 109 { 110 /* Receive overruns do not overwrite FIFO contents. */ 111 if (!fifo8_is_full(&s->recv_fifo)) { 112 fifo8_push(&s->recv_fifo, chr); 113 } else { 114 s->lsr |= UART_LSR_OE; 115 } 116 } 117 118 static void serial_update_irq(SerialState *s) 119 { 120 uint8_t tmp_iir = UART_IIR_NO_INT; 121 122 if ((s->ier & UART_IER_RLSI) && (s->lsr & UART_LSR_INT_ANY)) { 123 tmp_iir = UART_IIR_RLSI; 124 } else if ((s->ier & UART_IER_RDI) && s->timeout_ipending) { 125 /* Note that(s->ier & UART_IER_RDI) can mask this interrupt, 126 * this is not in the specification but is observed on existing 127 * hardware. */ 128 tmp_iir = UART_IIR_CTI; 129 } else if ((s->ier & UART_IER_RDI) && (s->lsr & UART_LSR_DR) && 130 (!(s->fcr & UART_FCR_FE) || 131 s->recv_fifo.num >= s->recv_fifo_itl)) { 132 tmp_iir = UART_IIR_RDI; 133 } else if ((s->ier & UART_IER_THRI) && s->thr_ipending) { 134 tmp_iir = UART_IIR_THRI; 135 } else if ((s->ier & UART_IER_MSI) && (s->msr & UART_MSR_ANY_DELTA)) { 136 tmp_iir = UART_IIR_MSI; 137 } 138 139 s->iir = tmp_iir | (s->iir & 0xF0); 140 141 if (tmp_iir != UART_IIR_NO_INT) { 142 qemu_irq_raise(s->irq); 143 } else { 144 qemu_irq_lower(s->irq); 145 } 146 } 147 148 static void serial_update_parameters(SerialState *s) 149 { 150 float speed; 151 int parity, data_bits, stop_bits, frame_size; 152 QEMUSerialSetParams ssp; 153 154 /* Start bit. */ 155 frame_size = 1; 156 if (s->lcr & 0x08) { 157 /* Parity bit. */ 158 frame_size++; 159 if (s->lcr & 0x10) 160 parity = 'E'; 161 else 162 parity = 'O'; 163 } else { 164 parity = 'N'; 165 } 166 if (s->lcr & 0x04) { 167 stop_bits = 2; 168 } else { 169 stop_bits = 1; 170 } 171 172 data_bits = (s->lcr & 0x03) + 5; 173 frame_size += data_bits + stop_bits; 174 /* Zero divisor should give about 3500 baud */ 175 speed = (s->divider == 0) ? 3500 : (float) s->baudbase / s->divider; 176 ssp.speed = speed; 177 ssp.parity = parity; 178 ssp.data_bits = data_bits; 179 ssp.stop_bits = stop_bits; 180 s->char_transmit_time = (NANOSECONDS_PER_SECOND / speed) * frame_size; 181 qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp); 182 trace_serial_update_parameters(speed, parity, data_bits, stop_bits); 183 } 184 185 static void serial_update_msl(SerialState *s) 186 { 187 uint8_t omsr; 188 int flags; 189 190 timer_del(s->modem_status_poll); 191 192 if (qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_GET_TIOCM, 193 &flags) == -ENOTSUP) { 194 s->poll_msl = -1; 195 return; 196 } 197 198 omsr = s->msr; 199 200 s->msr = (flags & CHR_TIOCM_CTS) ? s->msr | UART_MSR_CTS : s->msr & ~UART_MSR_CTS; 201 s->msr = (flags & CHR_TIOCM_DSR) ? s->msr | UART_MSR_DSR : s->msr & ~UART_MSR_DSR; 202 s->msr = (flags & CHR_TIOCM_CAR) ? s->msr | UART_MSR_DCD : s->msr & ~UART_MSR_DCD; 203 s->msr = (flags & CHR_TIOCM_RI) ? s->msr | UART_MSR_RI : s->msr & ~UART_MSR_RI; 204 205 if (s->msr != omsr) { 206 /* Set delta bits */ 207 s->msr = s->msr | ((s->msr >> 4) ^ (omsr >> 4)); 208 /* UART_MSR_TERI only if change was from 1 -> 0 */ 209 if ((s->msr & UART_MSR_TERI) && !(omsr & UART_MSR_RI)) 210 s->msr &= ~UART_MSR_TERI; 211 serial_update_irq(s); 212 } 213 214 /* The real 16550A apparently has a 250ns response latency to line status changes. 215 We'll be lazy and poll only every 10ms, and only poll it at all if MSI interrupts are turned on */ 216 217 if (s->poll_msl) { 218 timer_mod(s->modem_status_poll, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 219 NANOSECONDS_PER_SECOND / 100); 220 } 221 } 222 223 static gboolean serial_watch_cb(void *do_not_use, GIOCondition cond, 224 void *opaque) 225 { 226 SerialState *s = opaque; 227 s->watch_tag = 0; 228 serial_xmit(s); 229 return G_SOURCE_REMOVE; 230 } 231 232 static void serial_xmit(SerialState *s) 233 { 234 do { 235 assert(!(s->lsr & UART_LSR_TEMT)); 236 if (s->tsr_retry == 0) { 237 assert(!(s->lsr & UART_LSR_THRE)); 238 239 if (s->fcr & UART_FCR_FE) { 240 assert(!fifo8_is_empty(&s->xmit_fifo)); 241 s->tsr = fifo8_pop(&s->xmit_fifo); 242 if (!s->xmit_fifo.num) { 243 s->lsr |= UART_LSR_THRE; 244 } 245 } else { 246 s->tsr = s->thr; 247 s->lsr |= UART_LSR_THRE; 248 } 249 if ((s->lsr & UART_LSR_THRE) && !s->thr_ipending) { 250 s->thr_ipending = 1; 251 serial_update_irq(s); 252 } 253 } 254 255 if (s->mcr & UART_MCR_LOOP) { 256 /* in loopback mode, say that we just received a char */ 257 serial_receive1(s, &s->tsr, 1); 258 } else { 259 int rc = qemu_chr_fe_write(&s->chr, &s->tsr, 1); 260 261 if ((rc == 0 || 262 (rc == -1 && errno == EAGAIN)) && 263 s->tsr_retry < MAX_XMIT_RETRY) { 264 assert(s->watch_tag == 0); 265 s->watch_tag = 266 qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP, 267 serial_watch_cb, s); 268 if (s->watch_tag > 0) { 269 s->tsr_retry++; 270 return; 271 } 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 assert(size == 1 && addr < 8); 338 trace_serial_write(addr, val); 339 switch(addr) { 340 default: 341 case 0: 342 if (s->lcr & UART_LCR_DLAB) { 343 s->divider = deposit32(s->divider, 8 * addr, 8, 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 = deposit32(s->divider, 8 * addr, 8, val); 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 assert(size == 1 && addr < 8); 475 switch(addr) { 476 default: 477 case 0: 478 if (s->lcr & UART_LCR_DLAB) { 479 ret = extract16(s->divider, 8 * addr, 8); 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 = extract16(s->divider, 8 * addr, 8); 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 trace_serial_read(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, NULL); 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, QEMUChrEvent event) 625 { 626 SerialState *s = opaque; 627 if (event == CHR_EVENT_BREAK) 628 serial_receive_break(s); 629 } 630 631 static int serial_pre_save(void *opaque) 632 { 633 SerialState *s = opaque; 634 s->fcr_vmstate = s->fcr; 635 636 return 0; 637 } 638 639 static int serial_pre_load(void *opaque) 640 { 641 SerialState *s = opaque; 642 s->thr_ipending = -1; 643 s->poll_msl = -1; 644 return 0; 645 } 646 647 static int serial_post_load(void *opaque, int version_id) 648 { 649 SerialState *s = opaque; 650 651 if (version_id < 3) { 652 s->fcr_vmstate = 0; 653 } 654 if (s->thr_ipending == -1) { 655 s->thr_ipending = ((s->iir & UART_IIR_ID) == UART_IIR_THRI); 656 } 657 658 if (s->tsr_retry > 0) { 659 /* tsr_retry > 0 implies LSR.TEMT = 0 (transmitter not empty). */ 660 if (s->lsr & UART_LSR_TEMT) { 661 error_report("inconsistent state in serial device " 662 "(tsr empty, tsr_retry=%d", s->tsr_retry); 663 return -1; 664 } 665 666 if (s->tsr_retry > MAX_XMIT_RETRY) { 667 s->tsr_retry = MAX_XMIT_RETRY; 668 } 669 670 assert(s->watch_tag == 0); 671 s->watch_tag = qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP, 672 serial_watch_cb, s); 673 } else { 674 /* tsr_retry == 0 implies LSR.TEMT = 1 (transmitter empty). */ 675 if (!(s->lsr & UART_LSR_TEMT)) { 676 error_report("inconsistent state in serial device " 677 "(tsr not empty, tsr_retry=0"); 678 return -1; 679 } 680 } 681 682 s->last_break_enable = (s->lcr >> 6) & 1; 683 /* Initialize fcr via setter to perform essential side-effects */ 684 serial_write_fcr(s, s->fcr_vmstate); 685 serial_update_parameters(s); 686 return 0; 687 } 688 689 static bool serial_thr_ipending_needed(void *opaque) 690 { 691 SerialState *s = opaque; 692 693 if (s->ier & UART_IER_THRI) { 694 bool expected_value = ((s->iir & UART_IIR_ID) == UART_IIR_THRI); 695 return s->thr_ipending != expected_value; 696 } else { 697 /* LSR.THRE will be sampled again when the interrupt is 698 * enabled. thr_ipending is not used in this case, do 699 * not migrate it. 700 */ 701 return false; 702 } 703 } 704 705 static const VMStateDescription vmstate_serial_thr_ipending = { 706 .name = "serial/thr_ipending", 707 .version_id = 1, 708 .minimum_version_id = 1, 709 .needed = serial_thr_ipending_needed, 710 .fields = (const VMStateField[]) { 711 VMSTATE_INT32(thr_ipending, SerialState), 712 VMSTATE_END_OF_LIST() 713 } 714 }; 715 716 static bool serial_tsr_needed(void *opaque) 717 { 718 SerialState *s = (SerialState *)opaque; 719 return s->tsr_retry != 0; 720 } 721 722 static const VMStateDescription vmstate_serial_tsr = { 723 .name = "serial/tsr", 724 .version_id = 1, 725 .minimum_version_id = 1, 726 .needed = serial_tsr_needed, 727 .fields = (const VMStateField[]) { 728 VMSTATE_UINT32(tsr_retry, SerialState), 729 VMSTATE_UINT8(thr, SerialState), 730 VMSTATE_UINT8(tsr, SerialState), 731 VMSTATE_END_OF_LIST() 732 } 733 }; 734 735 static bool serial_recv_fifo_needed(void *opaque) 736 { 737 SerialState *s = (SerialState *)opaque; 738 return !fifo8_is_empty(&s->recv_fifo); 739 740 } 741 742 static const VMStateDescription vmstate_serial_recv_fifo = { 743 .name = "serial/recv_fifo", 744 .version_id = 1, 745 .minimum_version_id = 1, 746 .needed = serial_recv_fifo_needed, 747 .fields = (const VMStateField[]) { 748 VMSTATE_STRUCT(recv_fifo, SerialState, 1, vmstate_fifo8, Fifo8), 749 VMSTATE_END_OF_LIST() 750 } 751 }; 752 753 static bool serial_xmit_fifo_needed(void *opaque) 754 { 755 SerialState *s = (SerialState *)opaque; 756 return !fifo8_is_empty(&s->xmit_fifo); 757 } 758 759 static const VMStateDescription vmstate_serial_xmit_fifo = { 760 .name = "serial/xmit_fifo", 761 .version_id = 1, 762 .minimum_version_id = 1, 763 .needed = serial_xmit_fifo_needed, 764 .fields = (const VMStateField[]) { 765 VMSTATE_STRUCT(xmit_fifo, SerialState, 1, vmstate_fifo8, Fifo8), 766 VMSTATE_END_OF_LIST() 767 } 768 }; 769 770 static bool serial_fifo_timeout_timer_needed(void *opaque) 771 { 772 SerialState *s = (SerialState *)opaque; 773 return timer_pending(s->fifo_timeout_timer); 774 } 775 776 static const VMStateDescription vmstate_serial_fifo_timeout_timer = { 777 .name = "serial/fifo_timeout_timer", 778 .version_id = 1, 779 .minimum_version_id = 1, 780 .needed = serial_fifo_timeout_timer_needed, 781 .fields = (const VMStateField[]) { 782 VMSTATE_TIMER_PTR(fifo_timeout_timer, SerialState), 783 VMSTATE_END_OF_LIST() 784 } 785 }; 786 787 static bool serial_timeout_ipending_needed(void *opaque) 788 { 789 SerialState *s = (SerialState *)opaque; 790 return s->timeout_ipending != 0; 791 } 792 793 static const VMStateDescription vmstate_serial_timeout_ipending = { 794 .name = "serial/timeout_ipending", 795 .version_id = 1, 796 .minimum_version_id = 1, 797 .needed = serial_timeout_ipending_needed, 798 .fields = (const VMStateField[]) { 799 VMSTATE_INT32(timeout_ipending, SerialState), 800 VMSTATE_END_OF_LIST() 801 } 802 }; 803 804 static bool serial_poll_needed(void *opaque) 805 { 806 SerialState *s = (SerialState *)opaque; 807 return s->poll_msl >= 0; 808 } 809 810 static const VMStateDescription vmstate_serial_poll = { 811 .name = "serial/poll", 812 .version_id = 1, 813 .needed = serial_poll_needed, 814 .minimum_version_id = 1, 815 .fields = (const VMStateField[]) { 816 VMSTATE_INT32(poll_msl, SerialState), 817 VMSTATE_TIMER_PTR(modem_status_poll, SerialState), 818 VMSTATE_END_OF_LIST() 819 } 820 }; 821 822 const VMStateDescription vmstate_serial = { 823 .name = "serial", 824 .version_id = 3, 825 .minimum_version_id = 2, 826 .pre_save = serial_pre_save, 827 .pre_load = serial_pre_load, 828 .post_load = serial_post_load, 829 .fields = (const VMStateField[]) { 830 VMSTATE_UINT16_V(divider, SerialState, 2), 831 VMSTATE_UINT8(rbr, SerialState), 832 VMSTATE_UINT8(ier, SerialState), 833 VMSTATE_UINT8(iir, SerialState), 834 VMSTATE_UINT8(lcr, SerialState), 835 VMSTATE_UINT8(mcr, SerialState), 836 VMSTATE_UINT8(lsr, SerialState), 837 VMSTATE_UINT8(msr, SerialState), 838 VMSTATE_UINT8(scr, SerialState), 839 VMSTATE_UINT8_V(fcr_vmstate, SerialState, 3), 840 VMSTATE_END_OF_LIST() 841 }, 842 .subsections = (const VMStateDescription * const []) { 843 &vmstate_serial_thr_ipending, 844 &vmstate_serial_tsr, 845 &vmstate_serial_recv_fifo, 846 &vmstate_serial_xmit_fifo, 847 &vmstate_serial_fifo_timeout_timer, 848 &vmstate_serial_timeout_ipending, 849 &vmstate_serial_poll, 850 NULL 851 } 852 }; 853 854 static void serial_reset(void *opaque) 855 { 856 SerialState *s = opaque; 857 858 if (s->watch_tag > 0) { 859 g_source_remove(s->watch_tag); 860 s->watch_tag = 0; 861 } 862 863 s->rbr = 0; 864 s->ier = 0; 865 s->iir = UART_IIR_NO_INT; 866 s->lcr = 0; 867 s->lsr = UART_LSR_TEMT | UART_LSR_THRE; 868 s->msr = UART_MSR_DCD | UART_MSR_DSR | UART_MSR_CTS; 869 /* Default to 9600 baud, 1 start bit, 8 data bits, 1 stop bit, no parity. */ 870 s->divider = 0x0C; 871 s->mcr = UART_MCR_OUT2; 872 s->scr = 0; 873 s->tsr_retry = 0; 874 s->char_transmit_time = (NANOSECONDS_PER_SECOND / 9600) * 10; 875 s->poll_msl = 0; 876 877 s->timeout_ipending = 0; 878 timer_del(s->fifo_timeout_timer); 879 timer_del(s->modem_status_poll); 880 881 fifo8_reset(&s->recv_fifo); 882 fifo8_reset(&s->xmit_fifo); 883 884 s->last_xmit_ts = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); 885 886 s->thr_ipending = 0; 887 s->last_break_enable = 0; 888 qemu_irq_lower(s->irq); 889 890 serial_update_msl(s); 891 s->msr &= ~UART_MSR_ANY_DELTA; 892 } 893 894 static int serial_be_change(void *opaque) 895 { 896 SerialState *s = opaque; 897 898 qemu_chr_fe_set_handlers(&s->chr, serial_can_receive1, serial_receive1, 899 serial_event, serial_be_change, s, NULL, true); 900 901 serial_update_parameters(s); 902 903 qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_BREAK, 904 &s->last_break_enable); 905 906 s->poll_msl = (s->ier & UART_IER_MSI) ? 1 : 0; 907 serial_update_msl(s); 908 909 if (s->poll_msl >= 0 && !(s->mcr & UART_MCR_LOOP)) { 910 serial_update_tiocm(s); 911 } 912 913 if (s->watch_tag > 0) { 914 g_source_remove(s->watch_tag); 915 s->watch_tag = qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP, 916 serial_watch_cb, s); 917 } 918 919 return 0; 920 } 921 922 static void serial_realize(DeviceState *dev, Error **errp) 923 { 924 SerialState *s = SERIAL(dev); 925 926 s->modem_status_poll = timer_new_ns(QEMU_CLOCK_VIRTUAL, (QEMUTimerCB *) serial_update_msl, s); 927 928 s->fifo_timeout_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, (QEMUTimerCB *) fifo_timeout_int, s); 929 qemu_register_reset(serial_reset, s); 930 931 qemu_chr_fe_set_handlers(&s->chr, serial_can_receive1, serial_receive1, 932 serial_event, serial_be_change, s, NULL, true); 933 fifo8_create(&s->recv_fifo, UART_FIFO_LENGTH); 934 fifo8_create(&s->xmit_fifo, UART_FIFO_LENGTH); 935 serial_reset(s); 936 } 937 938 static void serial_unrealize(DeviceState *dev) 939 { 940 SerialState *s = SERIAL(dev); 941 942 qemu_chr_fe_deinit(&s->chr, false); 943 944 timer_free(s->modem_status_poll); 945 946 timer_free(s->fifo_timeout_timer); 947 948 fifo8_destroy(&s->recv_fifo); 949 fifo8_destroy(&s->xmit_fifo); 950 951 qemu_unregister_reset(serial_reset, s); 952 } 953 954 const MemoryRegionOps serial_io_ops = { 955 .read = serial_ioport_read, 956 .write = serial_ioport_write, 957 .valid = { 958 .unaligned = 1, 959 }, 960 .impl = { 961 .min_access_size = 1, 962 .max_access_size = 1, 963 }, 964 .endianness = DEVICE_LITTLE_ENDIAN, 965 }; 966 967 static Property serial_properties[] = { 968 DEFINE_PROP_CHR("chardev", SerialState, chr), 969 DEFINE_PROP_UINT32("baudbase", SerialState, baudbase, 115200), 970 DEFINE_PROP_BOOL("wakeup", SerialState, wakeup, false), 971 DEFINE_PROP_END_OF_LIST(), 972 }; 973 974 static void serial_class_init(ObjectClass *klass, void* data) 975 { 976 DeviceClass *dc = DEVICE_CLASS(klass); 977 978 /* internal device for serialio/serialmm, not user-creatable */ 979 dc->user_creatable = false; 980 dc->realize = serial_realize; 981 dc->unrealize = serial_unrealize; 982 device_class_set_props(dc, serial_properties); 983 } 984 985 static const TypeInfo serial_info = { 986 .name = TYPE_SERIAL, 987 .parent = TYPE_DEVICE, 988 .instance_size = sizeof(SerialState), 989 .class_init = serial_class_init, 990 }; 991 992 static void serial_register_types(void) 993 { 994 type_register_static(&serial_info); 995 } 996 997 type_init(serial_register_types) 998