1 /* 2 * Device model for Cadence UART 3 * 4 * Copyright (c) 2010 Xilinx Inc. 5 * Copyright (c) 2012 Peter A.G. Crosthwaite (peter.crosthwaite@petalogix.com) 6 * Copyright (c) 2012 PetaLogix Pty Ltd. 7 * Written by Haibing Ma 8 * M.Habib 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 * 15 * You should have received a copy of the GNU General Public License along 16 * with this program; if not, see <http://www.gnu.org/licenses/>. 17 */ 18 19 #include "qemu/osdep.h" 20 #include "hw/sysbus.h" 21 #include "sysemu/char.h" 22 #include "qemu/timer.h" 23 #include "qemu/log.h" 24 #include "hw/char/cadence_uart.h" 25 26 #ifdef CADENCE_UART_ERR_DEBUG 27 #define DB_PRINT(...) do { \ 28 fprintf(stderr, ": %s: ", __func__); \ 29 fprintf(stderr, ## __VA_ARGS__); \ 30 } while (0); 31 #else 32 #define DB_PRINT(...) 33 #endif 34 35 #define UART_SR_INTR_RTRIG 0x00000001 36 #define UART_SR_INTR_REMPTY 0x00000002 37 #define UART_SR_INTR_RFUL 0x00000004 38 #define UART_SR_INTR_TEMPTY 0x00000008 39 #define UART_SR_INTR_TFUL 0x00000010 40 /* somewhat awkwardly, TTRIG is misaligned between SR and ISR */ 41 #define UART_SR_TTRIG 0x00002000 42 #define UART_INTR_TTRIG 0x00000400 43 /* bits fields in CSR that correlate to CISR. If any of these bits are set in 44 * SR, then the same bit in CISR is set high too */ 45 #define UART_SR_TO_CISR_MASK 0x0000001F 46 47 #define UART_INTR_ROVR 0x00000020 48 #define UART_INTR_FRAME 0x00000040 49 #define UART_INTR_PARE 0x00000080 50 #define UART_INTR_TIMEOUT 0x00000100 51 #define UART_INTR_DMSI 0x00000200 52 #define UART_INTR_TOVR 0x00001000 53 54 #define UART_SR_RACTIVE 0x00000400 55 #define UART_SR_TACTIVE 0x00000800 56 #define UART_SR_FDELT 0x00001000 57 58 #define UART_CR_RXRST 0x00000001 59 #define UART_CR_TXRST 0x00000002 60 #define UART_CR_RX_EN 0x00000004 61 #define UART_CR_RX_DIS 0x00000008 62 #define UART_CR_TX_EN 0x00000010 63 #define UART_CR_TX_DIS 0x00000020 64 #define UART_CR_RST_TO 0x00000040 65 #define UART_CR_STARTBRK 0x00000080 66 #define UART_CR_STOPBRK 0x00000100 67 68 #define UART_MR_CLKS 0x00000001 69 #define UART_MR_CHRL 0x00000006 70 #define UART_MR_CHRL_SH 1 71 #define UART_MR_PAR 0x00000038 72 #define UART_MR_PAR_SH 3 73 #define UART_MR_NBSTOP 0x000000C0 74 #define UART_MR_NBSTOP_SH 6 75 #define UART_MR_CHMODE 0x00000300 76 #define UART_MR_CHMODE_SH 8 77 #define UART_MR_UCLKEN 0x00000400 78 #define UART_MR_IRMODE 0x00000800 79 80 #define UART_DATA_BITS_6 (0x3 << UART_MR_CHRL_SH) 81 #define UART_DATA_BITS_7 (0x2 << UART_MR_CHRL_SH) 82 #define UART_PARITY_ODD (0x1 << UART_MR_PAR_SH) 83 #define UART_PARITY_EVEN (0x0 << UART_MR_PAR_SH) 84 #define UART_STOP_BITS_1 (0x3 << UART_MR_NBSTOP_SH) 85 #define UART_STOP_BITS_2 (0x2 << UART_MR_NBSTOP_SH) 86 #define NORMAL_MODE (0x0 << UART_MR_CHMODE_SH) 87 #define ECHO_MODE (0x1 << UART_MR_CHMODE_SH) 88 #define LOCAL_LOOPBACK (0x2 << UART_MR_CHMODE_SH) 89 #define REMOTE_LOOPBACK (0x3 << UART_MR_CHMODE_SH) 90 91 #define UART_INPUT_CLK 50000000 92 93 #define R_CR (0x00/4) 94 #define R_MR (0x04/4) 95 #define R_IER (0x08/4) 96 #define R_IDR (0x0C/4) 97 #define R_IMR (0x10/4) 98 #define R_CISR (0x14/4) 99 #define R_BRGR (0x18/4) 100 #define R_RTOR (0x1C/4) 101 #define R_RTRIG (0x20/4) 102 #define R_MCR (0x24/4) 103 #define R_MSR (0x28/4) 104 #define R_SR (0x2C/4) 105 #define R_TX_RX (0x30/4) 106 #define R_BDIV (0x34/4) 107 #define R_FDEL (0x38/4) 108 #define R_PMIN (0x3C/4) 109 #define R_PWID (0x40/4) 110 #define R_TTRIG (0x44/4) 111 112 113 static void uart_update_status(CadenceUARTState *s) 114 { 115 s->r[R_SR] = 0; 116 117 s->r[R_SR] |= s->rx_count == CADENCE_UART_RX_FIFO_SIZE ? UART_SR_INTR_RFUL 118 : 0; 119 s->r[R_SR] |= !s->rx_count ? UART_SR_INTR_REMPTY : 0; 120 s->r[R_SR] |= s->rx_count >= s->r[R_RTRIG] ? UART_SR_INTR_RTRIG : 0; 121 122 s->r[R_SR] |= s->tx_count == CADENCE_UART_TX_FIFO_SIZE ? UART_SR_INTR_TFUL 123 : 0; 124 s->r[R_SR] |= !s->tx_count ? UART_SR_INTR_TEMPTY : 0; 125 s->r[R_SR] |= s->tx_count >= s->r[R_TTRIG] ? UART_SR_TTRIG : 0; 126 127 s->r[R_CISR] |= s->r[R_SR] & UART_SR_TO_CISR_MASK; 128 s->r[R_CISR] |= s->r[R_SR] & UART_SR_TTRIG ? UART_INTR_TTRIG : 0; 129 qemu_set_irq(s->irq, !!(s->r[R_IMR] & s->r[R_CISR])); 130 } 131 132 static void fifo_trigger_update(void *opaque) 133 { 134 CadenceUARTState *s = opaque; 135 136 s->r[R_CISR] |= UART_INTR_TIMEOUT; 137 138 uart_update_status(s); 139 } 140 141 static void uart_rx_reset(CadenceUARTState *s) 142 { 143 s->rx_wpos = 0; 144 s->rx_count = 0; 145 if (s->chr) { 146 qemu_chr_accept_input(s->chr); 147 } 148 } 149 150 static void uart_tx_reset(CadenceUARTState *s) 151 { 152 s->tx_count = 0; 153 } 154 155 static void uart_send_breaks(CadenceUARTState *s) 156 { 157 int break_enabled = 1; 158 159 if (s->chr) { 160 qemu_chr_fe_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_BREAK, 161 &break_enabled); 162 } 163 } 164 165 static void uart_parameters_setup(CadenceUARTState *s) 166 { 167 QEMUSerialSetParams ssp; 168 unsigned int baud_rate, packet_size; 169 170 baud_rate = (s->r[R_MR] & UART_MR_CLKS) ? 171 UART_INPUT_CLK / 8 : UART_INPUT_CLK; 172 173 ssp.speed = baud_rate / (s->r[R_BRGR] * (s->r[R_BDIV] + 1)); 174 packet_size = 1; 175 176 switch (s->r[R_MR] & UART_MR_PAR) { 177 case UART_PARITY_EVEN: 178 ssp.parity = 'E'; 179 packet_size++; 180 break; 181 case UART_PARITY_ODD: 182 ssp.parity = 'O'; 183 packet_size++; 184 break; 185 default: 186 ssp.parity = 'N'; 187 break; 188 } 189 190 switch (s->r[R_MR] & UART_MR_CHRL) { 191 case UART_DATA_BITS_6: 192 ssp.data_bits = 6; 193 break; 194 case UART_DATA_BITS_7: 195 ssp.data_bits = 7; 196 break; 197 default: 198 ssp.data_bits = 8; 199 break; 200 } 201 202 switch (s->r[R_MR] & UART_MR_NBSTOP) { 203 case UART_STOP_BITS_1: 204 ssp.stop_bits = 1; 205 break; 206 default: 207 ssp.stop_bits = 2; 208 break; 209 } 210 211 packet_size += ssp.data_bits + ssp.stop_bits; 212 s->char_tx_time = (NANOSECONDS_PER_SECOND / ssp.speed) * packet_size; 213 if (s->chr) { 214 qemu_chr_fe_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp); 215 } 216 } 217 218 static int uart_can_receive(void *opaque) 219 { 220 CadenceUARTState *s = opaque; 221 int ret = MAX(CADENCE_UART_RX_FIFO_SIZE, CADENCE_UART_TX_FIFO_SIZE); 222 uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE; 223 224 if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) { 225 ret = MIN(ret, CADENCE_UART_RX_FIFO_SIZE - s->rx_count); 226 } 227 if (ch_mode == REMOTE_LOOPBACK || ch_mode == ECHO_MODE) { 228 ret = MIN(ret, CADENCE_UART_TX_FIFO_SIZE - s->tx_count); 229 } 230 return ret; 231 } 232 233 static void uart_ctrl_update(CadenceUARTState *s) 234 { 235 if (s->r[R_CR] & UART_CR_TXRST) { 236 uart_tx_reset(s); 237 } 238 239 if (s->r[R_CR] & UART_CR_RXRST) { 240 uart_rx_reset(s); 241 } 242 243 s->r[R_CR] &= ~(UART_CR_TXRST | UART_CR_RXRST); 244 245 if (s->r[R_CR] & UART_CR_STARTBRK && !(s->r[R_CR] & UART_CR_STOPBRK)) { 246 uart_send_breaks(s); 247 } 248 } 249 250 static void uart_write_rx_fifo(void *opaque, const uint8_t *buf, int size) 251 { 252 CadenceUARTState *s = opaque; 253 uint64_t new_rx_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); 254 int i; 255 256 if ((s->r[R_CR] & UART_CR_RX_DIS) || !(s->r[R_CR] & UART_CR_RX_EN)) { 257 return; 258 } 259 260 if (s->rx_count == CADENCE_UART_RX_FIFO_SIZE) { 261 s->r[R_CISR] |= UART_INTR_ROVR; 262 } else { 263 for (i = 0; i < size; i++) { 264 s->rx_fifo[s->rx_wpos] = buf[i]; 265 s->rx_wpos = (s->rx_wpos + 1) % CADENCE_UART_RX_FIFO_SIZE; 266 s->rx_count++; 267 } 268 timer_mod(s->fifo_trigger_handle, new_rx_time + 269 (s->char_tx_time * 4)); 270 } 271 uart_update_status(s); 272 } 273 274 static gboolean cadence_uart_xmit(GIOChannel *chan, GIOCondition cond, 275 void *opaque) 276 { 277 CadenceUARTState *s = opaque; 278 int ret; 279 280 /* instant drain the fifo when there's no back-end */ 281 if (!s->chr) { 282 s->tx_count = 0; 283 return FALSE; 284 } 285 286 if (!s->tx_count) { 287 return FALSE; 288 } 289 290 ret = qemu_chr_fe_write(s->chr, s->tx_fifo, s->tx_count); 291 292 if (ret >= 0) { 293 s->tx_count -= ret; 294 memmove(s->tx_fifo, s->tx_fifo + ret, s->tx_count); 295 } 296 297 if (s->tx_count) { 298 int r = qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP, 299 cadence_uart_xmit, s); 300 assert(r); 301 } 302 303 uart_update_status(s); 304 return FALSE; 305 } 306 307 static void uart_write_tx_fifo(CadenceUARTState *s, const uint8_t *buf, 308 int size) 309 { 310 if ((s->r[R_CR] & UART_CR_TX_DIS) || !(s->r[R_CR] & UART_CR_TX_EN)) { 311 return; 312 } 313 314 if (size > CADENCE_UART_TX_FIFO_SIZE - s->tx_count) { 315 size = CADENCE_UART_TX_FIFO_SIZE - s->tx_count; 316 /* 317 * This can only be a guest error via a bad tx fifo register push, 318 * as can_receive() should stop remote loop and echo modes ever getting 319 * us to here. 320 */ 321 qemu_log_mask(LOG_GUEST_ERROR, "cadence_uart: TxFIFO overflow"); 322 s->r[R_CISR] |= UART_INTR_ROVR; 323 } 324 325 memcpy(s->tx_fifo + s->tx_count, buf, size); 326 s->tx_count += size; 327 328 cadence_uart_xmit(NULL, G_IO_OUT, s); 329 } 330 331 static void uart_receive(void *opaque, const uint8_t *buf, int size) 332 { 333 CadenceUARTState *s = opaque; 334 uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE; 335 336 if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) { 337 uart_write_rx_fifo(opaque, buf, size); 338 } 339 if (ch_mode == REMOTE_LOOPBACK || ch_mode == ECHO_MODE) { 340 uart_write_tx_fifo(s, buf, size); 341 } 342 } 343 344 static void uart_event(void *opaque, int event) 345 { 346 CadenceUARTState *s = opaque; 347 uint8_t buf = '\0'; 348 349 if (event == CHR_EVENT_BREAK) { 350 uart_write_rx_fifo(opaque, &buf, 1); 351 } 352 353 uart_update_status(s); 354 } 355 356 static void uart_read_rx_fifo(CadenceUARTState *s, uint32_t *c) 357 { 358 if ((s->r[R_CR] & UART_CR_RX_DIS) || !(s->r[R_CR] & UART_CR_RX_EN)) { 359 return; 360 } 361 362 if (s->rx_count) { 363 uint32_t rx_rpos = (CADENCE_UART_RX_FIFO_SIZE + s->rx_wpos - 364 s->rx_count) % CADENCE_UART_RX_FIFO_SIZE; 365 *c = s->rx_fifo[rx_rpos]; 366 s->rx_count--; 367 368 if (s->chr) { 369 qemu_chr_accept_input(s->chr); 370 } 371 } else { 372 *c = 0; 373 } 374 375 uart_update_status(s); 376 } 377 378 static void uart_write(void *opaque, hwaddr offset, 379 uint64_t value, unsigned size) 380 { 381 CadenceUARTState *s = opaque; 382 383 DB_PRINT(" offset:%x data:%08x\n", (unsigned)offset, (unsigned)value); 384 offset >>= 2; 385 if (offset >= CADENCE_UART_R_MAX) { 386 return; 387 } 388 switch (offset) { 389 case R_IER: /* ier (wts imr) */ 390 s->r[R_IMR] |= value; 391 break; 392 case R_IDR: /* idr (wtc imr) */ 393 s->r[R_IMR] &= ~value; 394 break; 395 case R_IMR: /* imr (read only) */ 396 break; 397 case R_CISR: /* cisr (wtc) */ 398 s->r[R_CISR] &= ~value; 399 break; 400 case R_TX_RX: /* UARTDR */ 401 switch (s->r[R_MR] & UART_MR_CHMODE) { 402 case NORMAL_MODE: 403 uart_write_tx_fifo(s, (uint8_t *) &value, 1); 404 break; 405 case LOCAL_LOOPBACK: 406 uart_write_rx_fifo(opaque, (uint8_t *) &value, 1); 407 break; 408 } 409 break; 410 default: 411 s->r[offset] = value; 412 } 413 414 switch (offset) { 415 case R_CR: 416 uart_ctrl_update(s); 417 break; 418 case R_MR: 419 uart_parameters_setup(s); 420 break; 421 } 422 uart_update_status(s); 423 } 424 425 static uint64_t uart_read(void *opaque, hwaddr offset, 426 unsigned size) 427 { 428 CadenceUARTState *s = opaque; 429 uint32_t c = 0; 430 431 offset >>= 2; 432 if (offset >= CADENCE_UART_R_MAX) { 433 c = 0; 434 } else if (offset == R_TX_RX) { 435 uart_read_rx_fifo(s, &c); 436 } else { 437 c = s->r[offset]; 438 } 439 440 DB_PRINT(" offset:%x data:%08x\n", (unsigned)(offset << 2), (unsigned)c); 441 return c; 442 } 443 444 static const MemoryRegionOps uart_ops = { 445 .read = uart_read, 446 .write = uart_write, 447 .endianness = DEVICE_NATIVE_ENDIAN, 448 }; 449 450 static void cadence_uart_reset(DeviceState *dev) 451 { 452 CadenceUARTState *s = CADENCE_UART(dev); 453 454 s->r[R_CR] = 0x00000128; 455 s->r[R_IMR] = 0; 456 s->r[R_CISR] = 0; 457 s->r[R_RTRIG] = 0x00000020; 458 s->r[R_BRGR] = 0x0000000F; 459 s->r[R_TTRIG] = 0x00000020; 460 461 uart_rx_reset(s); 462 uart_tx_reset(s); 463 464 uart_update_status(s); 465 } 466 467 static void cadence_uart_realize(DeviceState *dev, Error **errp) 468 { 469 CadenceUARTState *s = CADENCE_UART(dev); 470 471 s->fifo_trigger_handle = timer_new_ns(QEMU_CLOCK_VIRTUAL, 472 fifo_trigger_update, s); 473 474 if (s->chr) { 475 qemu_chr_add_handlers(s->chr, uart_can_receive, uart_receive, 476 uart_event, s); 477 } 478 } 479 480 static void cadence_uart_init(Object *obj) 481 { 482 SysBusDevice *sbd = SYS_BUS_DEVICE(obj); 483 CadenceUARTState *s = CADENCE_UART(obj); 484 485 memory_region_init_io(&s->iomem, obj, &uart_ops, s, "uart", 0x1000); 486 sysbus_init_mmio(sbd, &s->iomem); 487 sysbus_init_irq(sbd, &s->irq); 488 489 s->char_tx_time = (NANOSECONDS_PER_SECOND / 9600) * 10; 490 } 491 492 static int cadence_uart_post_load(void *opaque, int version_id) 493 { 494 CadenceUARTState *s = opaque; 495 496 uart_parameters_setup(s); 497 uart_update_status(s); 498 return 0; 499 } 500 501 static const VMStateDescription vmstate_cadence_uart = { 502 .name = "cadence_uart", 503 .version_id = 2, 504 .minimum_version_id = 2, 505 .post_load = cadence_uart_post_load, 506 .fields = (VMStateField[]) { 507 VMSTATE_UINT32_ARRAY(r, CadenceUARTState, CADENCE_UART_R_MAX), 508 VMSTATE_UINT8_ARRAY(rx_fifo, CadenceUARTState, 509 CADENCE_UART_RX_FIFO_SIZE), 510 VMSTATE_UINT8_ARRAY(tx_fifo, CadenceUARTState, 511 CADENCE_UART_TX_FIFO_SIZE), 512 VMSTATE_UINT32(rx_count, CadenceUARTState), 513 VMSTATE_UINT32(tx_count, CadenceUARTState), 514 VMSTATE_UINT32(rx_wpos, CadenceUARTState), 515 VMSTATE_TIMER_PTR(fifo_trigger_handle, CadenceUARTState), 516 VMSTATE_END_OF_LIST() 517 } 518 }; 519 520 static Property cadence_uart_properties[] = { 521 DEFINE_PROP_CHR("chardev", CadenceUARTState, chr), 522 DEFINE_PROP_END_OF_LIST(), 523 }; 524 525 static void cadence_uart_class_init(ObjectClass *klass, void *data) 526 { 527 DeviceClass *dc = DEVICE_CLASS(klass); 528 529 dc->realize = cadence_uart_realize; 530 dc->vmsd = &vmstate_cadence_uart; 531 dc->reset = cadence_uart_reset; 532 dc->props = cadence_uart_properties; 533 } 534 535 static const TypeInfo cadence_uart_info = { 536 .name = TYPE_CADENCE_UART, 537 .parent = TYPE_SYS_BUS_DEVICE, 538 .instance_size = sizeof(CadenceUARTState), 539 .instance_init = cadence_uart_init, 540 .class_init = cadence_uart_class_init, 541 }; 542 543 static void cadence_uart_register_types(void) 544 { 545 type_register_static(&cadence_uart_info); 546 } 547 548 type_init(cadence_uart_register_types) 549