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 "hw/sysbus.h" 20 #include "sysemu/char.h" 21 #include "qemu/timer.h" 22 23 #ifdef CADENCE_UART_ERR_DEBUG 24 #define DB_PRINT(...) do { \ 25 fprintf(stderr, ": %s: ", __func__); \ 26 fprintf(stderr, ## __VA_ARGS__); \ 27 } while (0); 28 #else 29 #define DB_PRINT(...) 30 #endif 31 32 #define UART_SR_INTR_RTRIG 0x00000001 33 #define UART_SR_INTR_REMPTY 0x00000002 34 #define UART_SR_INTR_RFUL 0x00000004 35 #define UART_SR_INTR_TEMPTY 0x00000008 36 #define UART_SR_INTR_TFUL 0x00000010 37 /* bits fields in CSR that correlate to CISR. If any of these bits are set in 38 * SR, then the same bit in CISR is set high too */ 39 #define UART_SR_TO_CISR_MASK 0x0000001F 40 41 #define UART_INTR_ROVR 0x00000020 42 #define UART_INTR_FRAME 0x00000040 43 #define UART_INTR_PARE 0x00000080 44 #define UART_INTR_TIMEOUT 0x00000100 45 #define UART_INTR_DMSI 0x00000200 46 47 #define UART_SR_RACTIVE 0x00000400 48 #define UART_SR_TACTIVE 0x00000800 49 #define UART_SR_FDELT 0x00001000 50 51 #define UART_CR_RXRST 0x00000001 52 #define UART_CR_TXRST 0x00000002 53 #define UART_CR_RX_EN 0x00000004 54 #define UART_CR_RX_DIS 0x00000008 55 #define UART_CR_TX_EN 0x00000010 56 #define UART_CR_TX_DIS 0x00000020 57 #define UART_CR_RST_TO 0x00000040 58 #define UART_CR_STARTBRK 0x00000080 59 #define UART_CR_STOPBRK 0x00000100 60 61 #define UART_MR_CLKS 0x00000001 62 #define UART_MR_CHRL 0x00000006 63 #define UART_MR_CHRL_SH 1 64 #define UART_MR_PAR 0x00000038 65 #define UART_MR_PAR_SH 3 66 #define UART_MR_NBSTOP 0x000000C0 67 #define UART_MR_NBSTOP_SH 6 68 #define UART_MR_CHMODE 0x00000300 69 #define UART_MR_CHMODE_SH 8 70 #define UART_MR_UCLKEN 0x00000400 71 #define UART_MR_IRMODE 0x00000800 72 73 #define UART_DATA_BITS_6 (0x3 << UART_MR_CHRL_SH) 74 #define UART_DATA_BITS_7 (0x2 << UART_MR_CHRL_SH) 75 #define UART_PARITY_ODD (0x1 << UART_MR_PAR_SH) 76 #define UART_PARITY_EVEN (0x0 << UART_MR_PAR_SH) 77 #define UART_STOP_BITS_1 (0x3 << UART_MR_NBSTOP_SH) 78 #define UART_STOP_BITS_2 (0x2 << UART_MR_NBSTOP_SH) 79 #define NORMAL_MODE (0x0 << UART_MR_CHMODE_SH) 80 #define ECHO_MODE (0x1 << UART_MR_CHMODE_SH) 81 #define LOCAL_LOOPBACK (0x2 << UART_MR_CHMODE_SH) 82 #define REMOTE_LOOPBACK (0x3 << UART_MR_CHMODE_SH) 83 84 #define RX_FIFO_SIZE 16 85 #define TX_FIFO_SIZE 16 86 #define UART_INPUT_CLK 50000000 87 88 #define R_CR (0x00/4) 89 #define R_MR (0x04/4) 90 #define R_IER (0x08/4) 91 #define R_IDR (0x0C/4) 92 #define R_IMR (0x10/4) 93 #define R_CISR (0x14/4) 94 #define R_BRGR (0x18/4) 95 #define R_RTOR (0x1C/4) 96 #define R_RTRIG (0x20/4) 97 #define R_MCR (0x24/4) 98 #define R_MSR (0x28/4) 99 #define R_SR (0x2C/4) 100 #define R_TX_RX (0x30/4) 101 #define R_BDIV (0x34/4) 102 #define R_FDEL (0x38/4) 103 #define R_PMIN (0x3C/4) 104 #define R_PWID (0x40/4) 105 #define R_TTRIG (0x44/4) 106 107 #define R_MAX (R_TTRIG + 1) 108 109 #define TYPE_CADENCE_UART "cadence_uart" 110 #define CADENCE_UART(obj) OBJECT_CHECK(UartState, (obj), TYPE_CADENCE_UART) 111 112 typedef struct { 113 SysBusDevice parent_obj; 114 115 MemoryRegion iomem; 116 uint32_t r[R_MAX]; 117 uint8_t r_fifo[RX_FIFO_SIZE]; 118 uint32_t rx_wpos; 119 uint32_t rx_count; 120 uint64_t char_tx_time; 121 CharDriverState *chr; 122 qemu_irq irq; 123 struct QEMUTimer *fifo_trigger_handle; 124 struct QEMUTimer *tx_time_handle; 125 } UartState; 126 127 static void uart_update_status(UartState *s) 128 { 129 s->r[R_CISR] |= s->r[R_SR] & UART_SR_TO_CISR_MASK; 130 qemu_set_irq(s->irq, !!(s->r[R_IMR] & s->r[R_CISR])); 131 } 132 133 static void fifo_trigger_update(void *opaque) 134 { 135 UartState *s = (UartState *)opaque; 136 137 s->r[R_CISR] |= UART_INTR_TIMEOUT; 138 139 uart_update_status(s); 140 } 141 142 static void uart_tx_redo(UartState *s) 143 { 144 uint64_t new_tx_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); 145 146 timer_mod(s->tx_time_handle, new_tx_time + s->char_tx_time); 147 148 s->r[R_SR] |= UART_SR_INTR_TEMPTY; 149 150 uart_update_status(s); 151 } 152 153 static void uart_tx_write(void *opaque) 154 { 155 UartState *s = (UartState *)opaque; 156 157 uart_tx_redo(s); 158 } 159 160 static void uart_rx_reset(UartState *s) 161 { 162 s->rx_wpos = 0; 163 s->rx_count = 0; 164 if (s->chr) { 165 qemu_chr_accept_input(s->chr); 166 } 167 168 s->r[R_SR] |= UART_SR_INTR_REMPTY; 169 s->r[R_SR] &= ~UART_SR_INTR_RFUL; 170 } 171 172 static void uart_tx_reset(UartState *s) 173 { 174 s->r[R_SR] |= UART_SR_INTR_TEMPTY; 175 s->r[R_SR] &= ~UART_SR_INTR_TFUL; 176 } 177 178 static void uart_send_breaks(UartState *s) 179 { 180 int break_enabled = 1; 181 182 qemu_chr_fe_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_BREAK, 183 &break_enabled); 184 } 185 186 static void uart_parameters_setup(UartState *s) 187 { 188 QEMUSerialSetParams ssp; 189 unsigned int baud_rate, packet_size; 190 191 baud_rate = (s->r[R_MR] & UART_MR_CLKS) ? 192 UART_INPUT_CLK / 8 : UART_INPUT_CLK; 193 194 ssp.speed = baud_rate / (s->r[R_BRGR] * (s->r[R_BDIV] + 1)); 195 packet_size = 1; 196 197 switch (s->r[R_MR] & UART_MR_PAR) { 198 case UART_PARITY_EVEN: 199 ssp.parity = 'E'; 200 packet_size++; 201 break; 202 case UART_PARITY_ODD: 203 ssp.parity = 'O'; 204 packet_size++; 205 break; 206 default: 207 ssp.parity = 'N'; 208 break; 209 } 210 211 switch (s->r[R_MR] & UART_MR_CHRL) { 212 case UART_DATA_BITS_6: 213 ssp.data_bits = 6; 214 break; 215 case UART_DATA_BITS_7: 216 ssp.data_bits = 7; 217 break; 218 default: 219 ssp.data_bits = 8; 220 break; 221 } 222 223 switch (s->r[R_MR] & UART_MR_NBSTOP) { 224 case UART_STOP_BITS_1: 225 ssp.stop_bits = 1; 226 break; 227 default: 228 ssp.stop_bits = 2; 229 break; 230 } 231 232 packet_size += ssp.data_bits + ssp.stop_bits; 233 s->char_tx_time = (get_ticks_per_sec() / ssp.speed) * packet_size; 234 qemu_chr_fe_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp); 235 } 236 237 static int uart_can_receive(void *opaque) 238 { 239 UartState *s = (UartState *)opaque; 240 241 return RX_FIFO_SIZE - s->rx_count; 242 } 243 244 static void uart_ctrl_update(UartState *s) 245 { 246 if (s->r[R_CR] & UART_CR_TXRST) { 247 uart_tx_reset(s); 248 } 249 250 if (s->r[R_CR] & UART_CR_RXRST) { 251 uart_rx_reset(s); 252 } 253 254 s->r[R_CR] &= ~(UART_CR_TXRST | UART_CR_RXRST); 255 256 if ((s->r[R_CR] & UART_CR_TX_EN) && !(s->r[R_CR] & UART_CR_TX_DIS)) { 257 uart_tx_redo(s); 258 } 259 260 if (s->r[R_CR] & UART_CR_STARTBRK && !(s->r[R_CR] & UART_CR_STOPBRK)) { 261 uart_send_breaks(s); 262 } 263 } 264 265 static void uart_write_rx_fifo(void *opaque, const uint8_t *buf, int size) 266 { 267 UartState *s = (UartState *)opaque; 268 uint64_t new_rx_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); 269 int i; 270 271 if ((s->r[R_CR] & UART_CR_RX_DIS) || !(s->r[R_CR] & UART_CR_RX_EN)) { 272 return; 273 } 274 275 s->r[R_SR] &= ~UART_SR_INTR_REMPTY; 276 277 if (s->rx_count == RX_FIFO_SIZE) { 278 s->r[R_CISR] |= UART_INTR_ROVR; 279 } else { 280 for (i = 0; i < size; i++) { 281 s->r_fifo[s->rx_wpos] = buf[i]; 282 s->rx_wpos = (s->rx_wpos + 1) % RX_FIFO_SIZE; 283 s->rx_count++; 284 285 if (s->rx_count == RX_FIFO_SIZE) { 286 s->r[R_SR] |= UART_SR_INTR_RFUL; 287 break; 288 } 289 290 if (s->rx_count >= s->r[R_RTRIG]) { 291 s->r[R_SR] |= UART_SR_INTR_RTRIG; 292 } 293 } 294 timer_mod(s->fifo_trigger_handle, new_rx_time + 295 (s->char_tx_time * 4)); 296 } 297 uart_update_status(s); 298 } 299 300 static void uart_write_tx_fifo(UartState *s, const uint8_t *buf, int size) 301 { 302 if ((s->r[R_CR] & UART_CR_TX_DIS) || !(s->r[R_CR] & UART_CR_TX_EN)) { 303 return; 304 } 305 306 qemu_chr_fe_write_all(s->chr, buf, size); 307 } 308 309 static void uart_receive(void *opaque, const uint8_t *buf, int size) 310 { 311 UartState *s = (UartState *)opaque; 312 uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE; 313 314 if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) { 315 uart_write_rx_fifo(opaque, buf, size); 316 } 317 if (ch_mode == REMOTE_LOOPBACK || ch_mode == ECHO_MODE) { 318 uart_write_tx_fifo(s, buf, size); 319 } 320 } 321 322 static void uart_event(void *opaque, int event) 323 { 324 UartState *s = (UartState *)opaque; 325 uint8_t buf = '\0'; 326 327 if (event == CHR_EVENT_BREAK) { 328 uart_write_rx_fifo(opaque, &buf, 1); 329 } 330 331 uart_update_status(s); 332 } 333 334 static void uart_read_rx_fifo(UartState *s, uint32_t *c) 335 { 336 if ((s->r[R_CR] & UART_CR_RX_DIS) || !(s->r[R_CR] & UART_CR_RX_EN)) { 337 return; 338 } 339 340 s->r[R_SR] &= ~UART_SR_INTR_RFUL; 341 342 if (s->rx_count) { 343 uint32_t rx_rpos = 344 (RX_FIFO_SIZE + s->rx_wpos - s->rx_count) % RX_FIFO_SIZE; 345 *c = s->r_fifo[rx_rpos]; 346 s->rx_count--; 347 348 if (!s->rx_count) { 349 s->r[R_SR] |= UART_SR_INTR_REMPTY; 350 } 351 qemu_chr_accept_input(s->chr); 352 } else { 353 *c = 0; 354 s->r[R_SR] |= UART_SR_INTR_REMPTY; 355 } 356 357 if (s->rx_count < s->r[R_RTRIG]) { 358 s->r[R_SR] &= ~UART_SR_INTR_RTRIG; 359 } 360 uart_update_status(s); 361 } 362 363 static void uart_write(void *opaque, hwaddr offset, 364 uint64_t value, unsigned size) 365 { 366 UartState *s = (UartState *)opaque; 367 368 DB_PRINT(" offset:%x data:%08x\n", (unsigned)offset, (unsigned)value); 369 offset >>= 2; 370 switch (offset) { 371 case R_IER: /* ier (wts imr) */ 372 s->r[R_IMR] |= value; 373 break; 374 case R_IDR: /* idr (wtc imr) */ 375 s->r[R_IMR] &= ~value; 376 break; 377 case R_IMR: /* imr (read only) */ 378 break; 379 case R_CISR: /* cisr (wtc) */ 380 s->r[R_CISR] &= ~value; 381 break; 382 case R_TX_RX: /* UARTDR */ 383 switch (s->r[R_MR] & UART_MR_CHMODE) { 384 case NORMAL_MODE: 385 uart_write_tx_fifo(s, (uint8_t *) &value, 1); 386 break; 387 case LOCAL_LOOPBACK: 388 uart_write_rx_fifo(opaque, (uint8_t *) &value, 1); 389 break; 390 } 391 break; 392 default: 393 s->r[offset] = value; 394 } 395 396 switch (offset) { 397 case R_CR: 398 uart_ctrl_update(s); 399 break; 400 case R_MR: 401 uart_parameters_setup(s); 402 break; 403 } 404 } 405 406 static uint64_t uart_read(void *opaque, hwaddr offset, 407 unsigned size) 408 { 409 UartState *s = (UartState *)opaque; 410 uint32_t c = 0; 411 412 offset >>= 2; 413 if (offset >= R_MAX) { 414 c = 0; 415 } else if (offset == R_TX_RX) { 416 uart_read_rx_fifo(s, &c); 417 } else { 418 c = s->r[offset]; 419 } 420 421 DB_PRINT(" offset:%x data:%08x\n", (unsigned)(offset << 2), (unsigned)c); 422 return c; 423 } 424 425 static const MemoryRegionOps uart_ops = { 426 .read = uart_read, 427 .write = uart_write, 428 .endianness = DEVICE_NATIVE_ENDIAN, 429 }; 430 431 static void cadence_uart_reset(UartState *s) 432 { 433 s->r[R_CR] = 0x00000128; 434 s->r[R_IMR] = 0; 435 s->r[R_CISR] = 0; 436 s->r[R_RTRIG] = 0x00000020; 437 s->r[R_BRGR] = 0x0000000F; 438 s->r[R_TTRIG] = 0x00000020; 439 440 uart_rx_reset(s); 441 uart_tx_reset(s); 442 443 s->rx_count = 0; 444 s->rx_wpos = 0; 445 } 446 447 static int cadence_uart_init(SysBusDevice *dev) 448 { 449 UartState *s = CADENCE_UART(dev); 450 451 memory_region_init_io(&s->iomem, OBJECT(s), &uart_ops, s, "uart", 0x1000); 452 sysbus_init_mmio(dev, &s->iomem); 453 sysbus_init_irq(dev, &s->irq); 454 455 s->fifo_trigger_handle = timer_new_ns(QEMU_CLOCK_VIRTUAL, 456 (QEMUTimerCB *)fifo_trigger_update, s); 457 458 s->tx_time_handle = timer_new_ns(QEMU_CLOCK_VIRTUAL, 459 (QEMUTimerCB *)uart_tx_write, s); 460 461 s->char_tx_time = (get_ticks_per_sec() / 9600) * 10; 462 463 s->chr = qemu_char_get_next_serial(); 464 465 cadence_uart_reset(s); 466 467 if (s->chr) { 468 qemu_chr_add_handlers(s->chr, uart_can_receive, uart_receive, 469 uart_event, s); 470 } 471 472 return 0; 473 } 474 475 static int cadence_uart_post_load(void *opaque, int version_id) 476 { 477 UartState *s = opaque; 478 479 uart_parameters_setup(s); 480 uart_update_status(s); 481 return 0; 482 } 483 484 static const VMStateDescription vmstate_cadence_uart = { 485 .name = "cadence_uart", 486 .version_id = 1, 487 .minimum_version_id = 1, 488 .minimum_version_id_old = 1, 489 .post_load = cadence_uart_post_load, 490 .fields = (VMStateField[]) { 491 VMSTATE_UINT32_ARRAY(r, UartState, R_MAX), 492 VMSTATE_UINT8_ARRAY(r_fifo, UartState, RX_FIFO_SIZE), 493 VMSTATE_UINT32(rx_count, UartState), 494 VMSTATE_UINT32(rx_wpos, UartState), 495 VMSTATE_TIMER(fifo_trigger_handle, UartState), 496 VMSTATE_TIMER(tx_time_handle, UartState), 497 VMSTATE_END_OF_LIST() 498 } 499 }; 500 501 static void cadence_uart_class_init(ObjectClass *klass, void *data) 502 { 503 DeviceClass *dc = DEVICE_CLASS(klass); 504 SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass); 505 506 sdc->init = cadence_uart_init; 507 dc->vmsd = &vmstate_cadence_uart; 508 } 509 510 static const TypeInfo cadence_uart_info = { 511 .name = TYPE_CADENCE_UART, 512 .parent = TYPE_SYS_BUS_DEVICE, 513 .instance_size = sizeof(UartState), 514 .class_init = cadence_uart_class_init, 515 }; 516 517 static void cadence_uart_register_types(void) 518 { 519 type_register_static(&cadence_uart_info); 520 } 521 522 type_init(cadence_uart_register_types) 523