1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Derived from many drivers using generic_serial interface. 4 * 5 * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr> 6 * 7 * Serial driver for BCM63xx integrated UART. 8 * 9 * Hardware flow control was _not_ tested since I only have RX/TX on 10 * my board. 11 */ 12 13 #include <linux/kernel.h> 14 #include <linux/platform_device.h> 15 #include <linux/init.h> 16 #include <linux/delay.h> 17 #include <linux/module.h> 18 #include <linux/console.h> 19 #include <linux/clk.h> 20 #include <linux/tty.h> 21 #include <linux/tty_flip.h> 22 #include <linux/sysrq.h> 23 #include <linux/serial.h> 24 #include <linux/serial_core.h> 25 #include <linux/serial_bcm63xx.h> 26 #include <linux/io.h> 27 #include <linux/of.h> 28 29 #define BCM63XX_NR_UARTS 2 30 31 static struct uart_port ports[BCM63XX_NR_UARTS]; 32 33 /* 34 * rx interrupt mask / stat 35 * 36 * mask: 37 * - rx fifo full 38 * - rx fifo above threshold 39 * - rx fifo not empty for too long 40 */ 41 #define UART_RX_INT_MASK (UART_IR_MASK(UART_IR_RXOVER) | \ 42 UART_IR_MASK(UART_IR_RXTHRESH) | \ 43 UART_IR_MASK(UART_IR_RXTIMEOUT)) 44 45 #define UART_RX_INT_STAT (UART_IR_STAT(UART_IR_RXOVER) | \ 46 UART_IR_STAT(UART_IR_RXTHRESH) | \ 47 UART_IR_STAT(UART_IR_RXTIMEOUT)) 48 49 /* 50 * tx interrupt mask / stat 51 * 52 * mask: 53 * - tx fifo empty 54 * - tx fifo below threshold 55 */ 56 #define UART_TX_INT_MASK (UART_IR_MASK(UART_IR_TXEMPTY) | \ 57 UART_IR_MASK(UART_IR_TXTRESH)) 58 59 #define UART_TX_INT_STAT (UART_IR_STAT(UART_IR_TXEMPTY) | \ 60 UART_IR_STAT(UART_IR_TXTRESH)) 61 62 /* 63 * external input interrupt 64 * 65 * mask: any edge on CTS, DCD 66 */ 67 #define UART_EXTINP_INT_MASK (UART_EXTINP_IRMASK(UART_EXTINP_IR_CTS) | \ 68 UART_EXTINP_IRMASK(UART_EXTINP_IR_DCD)) 69 70 /* 71 * handy uart register accessor 72 */ 73 static inline unsigned int bcm_uart_readl(struct uart_port *port, 74 unsigned int offset) 75 { 76 return __raw_readl(port->membase + offset); 77 } 78 79 static inline void bcm_uart_writel(struct uart_port *port, 80 unsigned int value, unsigned int offset) 81 { 82 __raw_writel(value, port->membase + offset); 83 } 84 85 /* 86 * serial core request to check if uart tx fifo is empty 87 */ 88 static unsigned int bcm_uart_tx_empty(struct uart_port *port) 89 { 90 unsigned int val; 91 92 val = bcm_uart_readl(port, UART_IR_REG); 93 return (val & UART_IR_STAT(UART_IR_TXEMPTY)) ? 1 : 0; 94 } 95 96 /* 97 * serial core request to set RTS and DTR pin state and loopback mode 98 */ 99 static void bcm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) 100 { 101 unsigned int val; 102 103 val = bcm_uart_readl(port, UART_MCTL_REG); 104 val &= ~(UART_MCTL_DTR_MASK | UART_MCTL_RTS_MASK); 105 /* invert of written value is reflected on the pin */ 106 if (!(mctrl & TIOCM_DTR)) 107 val |= UART_MCTL_DTR_MASK; 108 if (!(mctrl & TIOCM_RTS)) 109 val |= UART_MCTL_RTS_MASK; 110 bcm_uart_writel(port, val, UART_MCTL_REG); 111 112 val = bcm_uart_readl(port, UART_CTL_REG); 113 if (mctrl & TIOCM_LOOP) 114 val |= UART_CTL_LOOPBACK_MASK; 115 else 116 val &= ~UART_CTL_LOOPBACK_MASK; 117 bcm_uart_writel(port, val, UART_CTL_REG); 118 } 119 120 /* 121 * serial core request to return RI, CTS, DCD and DSR pin state 122 */ 123 static unsigned int bcm_uart_get_mctrl(struct uart_port *port) 124 { 125 unsigned int val, mctrl; 126 127 mctrl = 0; 128 val = bcm_uart_readl(port, UART_EXTINP_REG); 129 if (val & UART_EXTINP_RI_MASK) 130 mctrl |= TIOCM_RI; 131 if (val & UART_EXTINP_CTS_MASK) 132 mctrl |= TIOCM_CTS; 133 if (val & UART_EXTINP_DCD_MASK) 134 mctrl |= TIOCM_CD; 135 if (val & UART_EXTINP_DSR_MASK) 136 mctrl |= TIOCM_DSR; 137 return mctrl; 138 } 139 140 /* 141 * serial core request to disable tx ASAP (used for flow control) 142 */ 143 static void bcm_uart_stop_tx(struct uart_port *port) 144 { 145 unsigned int val; 146 147 val = bcm_uart_readl(port, UART_CTL_REG); 148 val &= ~(UART_CTL_TXEN_MASK); 149 bcm_uart_writel(port, val, UART_CTL_REG); 150 151 val = bcm_uart_readl(port, UART_IR_REG); 152 val &= ~UART_TX_INT_MASK; 153 bcm_uart_writel(port, val, UART_IR_REG); 154 } 155 156 /* 157 * serial core request to (re)enable tx 158 */ 159 static void bcm_uart_start_tx(struct uart_port *port) 160 { 161 unsigned int val; 162 163 val = bcm_uart_readl(port, UART_IR_REG); 164 val |= UART_TX_INT_MASK; 165 bcm_uart_writel(port, val, UART_IR_REG); 166 167 val = bcm_uart_readl(port, UART_CTL_REG); 168 val |= UART_CTL_TXEN_MASK; 169 bcm_uart_writel(port, val, UART_CTL_REG); 170 } 171 172 /* 173 * serial core request to stop rx, called before port shutdown 174 */ 175 static void bcm_uart_stop_rx(struct uart_port *port) 176 { 177 unsigned int val; 178 179 val = bcm_uart_readl(port, UART_IR_REG); 180 val &= ~UART_RX_INT_MASK; 181 bcm_uart_writel(port, val, UART_IR_REG); 182 } 183 184 /* 185 * serial core request to enable modem status interrupt reporting 186 */ 187 static void bcm_uart_enable_ms(struct uart_port *port) 188 { 189 unsigned int val; 190 191 val = bcm_uart_readl(port, UART_IR_REG); 192 val |= UART_IR_MASK(UART_IR_EXTIP); 193 bcm_uart_writel(port, val, UART_IR_REG); 194 } 195 196 /* 197 * serial core request to start/stop emitting break char 198 */ 199 static void bcm_uart_break_ctl(struct uart_port *port, int ctl) 200 { 201 unsigned long flags; 202 unsigned int val; 203 204 uart_port_lock_irqsave(port, &flags); 205 206 val = bcm_uart_readl(port, UART_CTL_REG); 207 if (ctl) 208 val |= UART_CTL_XMITBRK_MASK; 209 else 210 val &= ~UART_CTL_XMITBRK_MASK; 211 bcm_uart_writel(port, val, UART_CTL_REG); 212 213 uart_port_unlock_irqrestore(port, flags); 214 } 215 216 /* 217 * return port type in string format 218 */ 219 static const char *bcm_uart_type(struct uart_port *port) 220 { 221 return (port->type == PORT_BCM63XX) ? "bcm63xx_uart" : NULL; 222 } 223 224 /* 225 * read all chars in rx fifo and send them to core 226 */ 227 static void bcm_uart_do_rx(struct uart_port *port) 228 { 229 struct tty_port *tty_port = &port->state->port; 230 unsigned int max_count; 231 232 /* limit number of char read in interrupt, should not be 233 * higher than fifo size anyway since we're much faster than 234 * serial port */ 235 max_count = 32; 236 do { 237 unsigned int iestat, c, cstat; 238 char flag; 239 240 /* get overrun/fifo empty information from ier 241 * register */ 242 iestat = bcm_uart_readl(port, UART_IR_REG); 243 244 if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) { 245 unsigned int val; 246 247 /* fifo reset is required to clear 248 * interrupt */ 249 val = bcm_uart_readl(port, UART_CTL_REG); 250 val |= UART_CTL_RSTRXFIFO_MASK; 251 bcm_uart_writel(port, val, UART_CTL_REG); 252 253 port->icount.overrun++; 254 tty_insert_flip_char(tty_port, 0, TTY_OVERRUN); 255 } 256 257 if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY))) 258 break; 259 260 cstat = c = bcm_uart_readl(port, UART_FIFO_REG); 261 port->icount.rx++; 262 flag = TTY_NORMAL; 263 c &= 0xff; 264 265 if (unlikely((cstat & UART_FIFO_ANYERR_MASK))) { 266 /* do stats first */ 267 if (cstat & UART_FIFO_BRKDET_MASK) { 268 port->icount.brk++; 269 if (uart_handle_break(port)) 270 continue; 271 } 272 273 if (cstat & UART_FIFO_PARERR_MASK) 274 port->icount.parity++; 275 if (cstat & UART_FIFO_FRAMEERR_MASK) 276 port->icount.frame++; 277 278 /* update flag wrt read_status_mask */ 279 cstat &= port->read_status_mask; 280 if (cstat & UART_FIFO_BRKDET_MASK) 281 flag = TTY_BREAK; 282 if (cstat & UART_FIFO_FRAMEERR_MASK) 283 flag = TTY_FRAME; 284 if (cstat & UART_FIFO_PARERR_MASK) 285 flag = TTY_PARITY; 286 } 287 288 if (uart_prepare_sysrq_char(port, c)) 289 continue; 290 291 if ((cstat & port->ignore_status_mask) == 0) 292 tty_insert_flip_char(tty_port, c, flag); 293 294 } while (--max_count); 295 296 tty_flip_buffer_push(tty_port); 297 } 298 299 /* 300 * fill tx fifo with chars to send, stop when fifo is about to be full 301 * or when all chars have been sent. 302 */ 303 static void bcm_uart_do_tx(struct uart_port *port) 304 { 305 unsigned int val; 306 bool pending; 307 u8 ch; 308 309 val = bcm_uart_readl(port, UART_MCTL_REG); 310 val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT; 311 pending = uart_port_tx_limited_flags(port, ch, UART_TX_NOSTOP, 312 port->fifosize - val, 313 true, 314 bcm_uart_writel(port, ch, UART_FIFO_REG), 315 ({})); 316 if (pending) 317 return; 318 319 /* nothing to send, disable transmit interrupt */ 320 val = bcm_uart_readl(port, UART_IR_REG); 321 val &= ~UART_TX_INT_MASK; 322 bcm_uart_writel(port, val, UART_IR_REG); 323 324 if (uart_tx_stopped(port)) 325 bcm_uart_stop_tx(port); 326 } 327 328 /* 329 * process uart interrupt 330 */ 331 static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id) 332 { 333 struct uart_port *port; 334 unsigned int irqstat; 335 336 port = dev_id; 337 uart_port_lock(port); 338 339 irqstat = bcm_uart_readl(port, UART_IR_REG); 340 if (irqstat & UART_RX_INT_STAT) 341 bcm_uart_do_rx(port); 342 343 if (irqstat & UART_TX_INT_STAT) 344 bcm_uart_do_tx(port); 345 346 if (irqstat & UART_IR_MASK(UART_IR_EXTIP)) { 347 unsigned int estat; 348 349 estat = bcm_uart_readl(port, UART_EXTINP_REG); 350 if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_CTS)) 351 uart_handle_cts_change(port, 352 estat & UART_EXTINP_CTS_MASK); 353 if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_DCD)) 354 uart_handle_dcd_change(port, 355 estat & UART_EXTINP_DCD_MASK); 356 } 357 358 uart_unlock_and_check_sysrq(port); 359 return IRQ_HANDLED; 360 } 361 362 /* 363 * enable rx & tx operation on uart 364 */ 365 static void bcm_uart_enable(struct uart_port *port) 366 { 367 unsigned int val; 368 369 val = bcm_uart_readl(port, UART_CTL_REG); 370 val |= (UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK); 371 bcm_uart_writel(port, val, UART_CTL_REG); 372 } 373 374 /* 375 * disable rx & tx operation on uart 376 */ 377 static void bcm_uart_disable(struct uart_port *port) 378 { 379 unsigned int val; 380 381 val = bcm_uart_readl(port, UART_CTL_REG); 382 val &= ~(UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | 383 UART_CTL_RXEN_MASK); 384 bcm_uart_writel(port, val, UART_CTL_REG); 385 } 386 387 /* 388 * clear all unread data in rx fifo and unsent data in tx fifo 389 */ 390 static void bcm_uart_flush(struct uart_port *port) 391 { 392 unsigned int val; 393 394 /* empty rx and tx fifo */ 395 val = bcm_uart_readl(port, UART_CTL_REG); 396 val |= UART_CTL_RSTRXFIFO_MASK | UART_CTL_RSTTXFIFO_MASK; 397 bcm_uart_writel(port, val, UART_CTL_REG); 398 399 /* read any pending char to make sure all irq status are 400 * cleared */ 401 (void)bcm_uart_readl(port, UART_FIFO_REG); 402 } 403 404 /* 405 * serial core request to initialize uart and start rx operation 406 */ 407 static int bcm_uart_startup(struct uart_port *port) 408 { 409 unsigned int val; 410 int ret; 411 412 /* mask all irq and flush port */ 413 bcm_uart_disable(port); 414 bcm_uart_writel(port, 0, UART_IR_REG); 415 bcm_uart_flush(port); 416 417 /* clear any pending external input interrupt */ 418 (void)bcm_uart_readl(port, UART_EXTINP_REG); 419 420 /* set rx/tx fifo thresh to fifo half size */ 421 val = bcm_uart_readl(port, UART_MCTL_REG); 422 val &= ~(UART_MCTL_RXFIFOTHRESH_MASK | UART_MCTL_TXFIFOTHRESH_MASK); 423 val |= (port->fifosize / 2) << UART_MCTL_RXFIFOTHRESH_SHIFT; 424 val |= (port->fifosize / 2) << UART_MCTL_TXFIFOTHRESH_SHIFT; 425 bcm_uart_writel(port, val, UART_MCTL_REG); 426 427 /* set rx fifo timeout to 1 char time */ 428 val = bcm_uart_readl(port, UART_CTL_REG); 429 val &= ~UART_CTL_RXTMOUTCNT_MASK; 430 val |= 1 << UART_CTL_RXTMOUTCNT_SHIFT; 431 bcm_uart_writel(port, val, UART_CTL_REG); 432 433 /* report any edge on dcd and cts */ 434 val = UART_EXTINP_INT_MASK; 435 val |= UART_EXTINP_DCD_NOSENSE_MASK; 436 val |= UART_EXTINP_CTS_NOSENSE_MASK; 437 bcm_uart_writel(port, val, UART_EXTINP_REG); 438 439 /* register irq and enable rx interrupts */ 440 ret = request_irq(port->irq, bcm_uart_interrupt, 0, 441 dev_name(port->dev), port); 442 if (ret) 443 return ret; 444 bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG); 445 bcm_uart_enable(port); 446 return 0; 447 } 448 449 /* 450 * serial core request to flush & disable uart 451 */ 452 static void bcm_uart_shutdown(struct uart_port *port) 453 { 454 unsigned long flags; 455 456 uart_port_lock_irqsave(port, &flags); 457 bcm_uart_writel(port, 0, UART_IR_REG); 458 uart_port_unlock_irqrestore(port, flags); 459 460 bcm_uart_disable(port); 461 bcm_uart_flush(port); 462 free_irq(port->irq, port); 463 } 464 465 /* 466 * serial core request to change current uart setting 467 */ 468 static void bcm_uart_set_termios(struct uart_port *port, struct ktermios *new, 469 const struct ktermios *old) 470 { 471 unsigned int ctl, baud, quot, ier; 472 unsigned long flags; 473 int tries; 474 475 uart_port_lock_irqsave(port, &flags); 476 477 /* Drain the hot tub fully before we power it off for the winter. */ 478 for (tries = 3; !bcm_uart_tx_empty(port) && tries; tries--) 479 mdelay(10); 480 481 /* disable uart while changing speed */ 482 bcm_uart_disable(port); 483 bcm_uart_flush(port); 484 485 /* update Control register */ 486 ctl = bcm_uart_readl(port, UART_CTL_REG); 487 ctl &= ~UART_CTL_BITSPERSYM_MASK; 488 489 switch (new->c_cflag & CSIZE) { 490 case CS5: 491 ctl |= (0 << UART_CTL_BITSPERSYM_SHIFT); 492 break; 493 case CS6: 494 ctl |= (1 << UART_CTL_BITSPERSYM_SHIFT); 495 break; 496 case CS7: 497 ctl |= (2 << UART_CTL_BITSPERSYM_SHIFT); 498 break; 499 default: 500 ctl |= (3 << UART_CTL_BITSPERSYM_SHIFT); 501 break; 502 } 503 504 ctl &= ~UART_CTL_STOPBITS_MASK; 505 if (new->c_cflag & CSTOPB) 506 ctl |= UART_CTL_STOPBITS_2; 507 else 508 ctl |= UART_CTL_STOPBITS_1; 509 510 ctl &= ~(UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK); 511 if (new->c_cflag & PARENB) 512 ctl |= (UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK); 513 ctl &= ~(UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK); 514 if (new->c_cflag & PARODD) 515 ctl |= (UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK); 516 bcm_uart_writel(port, ctl, UART_CTL_REG); 517 518 /* update Baudword register */ 519 baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16); 520 quot = uart_get_divisor(port, baud) - 1; 521 bcm_uart_writel(port, quot, UART_BAUD_REG); 522 523 /* update Interrupt register */ 524 ier = bcm_uart_readl(port, UART_IR_REG); 525 526 ier &= ~UART_IR_MASK(UART_IR_EXTIP); 527 if (UART_ENABLE_MS(port, new->c_cflag)) 528 ier |= UART_IR_MASK(UART_IR_EXTIP); 529 530 bcm_uart_writel(port, ier, UART_IR_REG); 531 532 /* update read/ignore mask */ 533 port->read_status_mask = UART_FIFO_VALID_MASK; 534 if (new->c_iflag & INPCK) { 535 port->read_status_mask |= UART_FIFO_FRAMEERR_MASK; 536 port->read_status_mask |= UART_FIFO_PARERR_MASK; 537 } 538 if (new->c_iflag & (IGNBRK | BRKINT)) 539 port->read_status_mask |= UART_FIFO_BRKDET_MASK; 540 541 port->ignore_status_mask = 0; 542 if (new->c_iflag & IGNPAR) 543 port->ignore_status_mask |= UART_FIFO_PARERR_MASK; 544 if (new->c_iflag & IGNBRK) 545 port->ignore_status_mask |= UART_FIFO_BRKDET_MASK; 546 if (!(new->c_cflag & CREAD)) 547 port->ignore_status_mask |= UART_FIFO_VALID_MASK; 548 549 uart_update_timeout(port, new->c_cflag, baud); 550 bcm_uart_enable(port); 551 uart_port_unlock_irqrestore(port, flags); 552 } 553 554 /* 555 * serial core request to claim uart iomem 556 */ 557 static int bcm_uart_request_port(struct uart_port *port) 558 { 559 /* UARTs always present */ 560 return 0; 561 } 562 563 /* 564 * serial core request to release uart iomem 565 */ 566 static void bcm_uart_release_port(struct uart_port *port) 567 { 568 /* Nothing to release ... */ 569 } 570 571 /* 572 * serial core request to do any port required autoconfiguration 573 */ 574 static void bcm_uart_config_port(struct uart_port *port, int flags) 575 { 576 if (flags & UART_CONFIG_TYPE) { 577 if (bcm_uart_request_port(port)) 578 return; 579 port->type = PORT_BCM63XX; 580 } 581 } 582 583 /* 584 * serial core request to check that port information in serinfo are 585 * suitable 586 */ 587 static int bcm_uart_verify_port(struct uart_port *port, 588 struct serial_struct *serinfo) 589 { 590 if (port->type != PORT_BCM63XX) 591 return -EINVAL; 592 if (port->irq != serinfo->irq) 593 return -EINVAL; 594 if (port->iotype != serinfo->io_type) 595 return -EINVAL; 596 if (port->mapbase != (unsigned long)serinfo->iomem_base) 597 return -EINVAL; 598 return 0; 599 } 600 601 #ifdef CONFIG_CONSOLE_POLL 602 /* 603 * return true when outstanding tx equals fifo size 604 */ 605 static bool bcm_uart_tx_full(struct uart_port *port) 606 { 607 unsigned int val; 608 609 val = bcm_uart_readl(port, UART_MCTL_REG); 610 val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT; 611 return !(port->fifosize - val); 612 } 613 614 static int bcm_uart_poll_get_char(struct uart_port *port) 615 { 616 unsigned int iestat; 617 618 iestat = bcm_uart_readl(port, UART_IR_REG); 619 if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY))) 620 return NO_POLL_CHAR; 621 622 return bcm_uart_readl(port, UART_FIFO_REG); 623 } 624 625 static void bcm_uart_poll_put_char(struct uart_port *port, unsigned char c) 626 { 627 while (bcm_uart_tx_full(port)) { 628 cpu_relax(); 629 } 630 631 bcm_uart_writel(port, c, UART_FIFO_REG); 632 } 633 #endif 634 635 /* serial core callbacks */ 636 static const struct uart_ops bcm_uart_ops = { 637 .tx_empty = bcm_uart_tx_empty, 638 .get_mctrl = bcm_uart_get_mctrl, 639 .set_mctrl = bcm_uart_set_mctrl, 640 .start_tx = bcm_uart_start_tx, 641 .stop_tx = bcm_uart_stop_tx, 642 .stop_rx = bcm_uart_stop_rx, 643 .enable_ms = bcm_uart_enable_ms, 644 .break_ctl = bcm_uart_break_ctl, 645 .startup = bcm_uart_startup, 646 .shutdown = bcm_uart_shutdown, 647 .set_termios = bcm_uart_set_termios, 648 .type = bcm_uart_type, 649 .release_port = bcm_uart_release_port, 650 .request_port = bcm_uart_request_port, 651 .config_port = bcm_uart_config_port, 652 .verify_port = bcm_uart_verify_port, 653 #ifdef CONFIG_CONSOLE_POLL 654 .poll_get_char = bcm_uart_poll_get_char, 655 .poll_put_char = bcm_uart_poll_put_char, 656 #endif 657 }; 658 659 660 661 #ifdef CONFIG_SERIAL_BCM63XX_CONSOLE 662 static void wait_for_xmitr(struct uart_port *port) 663 { 664 unsigned int tmout; 665 666 /* Wait up to 10ms for the character(s) to be sent. */ 667 tmout = 10000; 668 while (--tmout) { 669 unsigned int val; 670 671 val = bcm_uart_readl(port, UART_IR_REG); 672 if (val & UART_IR_STAT(UART_IR_TXEMPTY)) 673 break; 674 udelay(1); 675 } 676 677 /* Wait up to 1s for flow control if necessary */ 678 if (port->flags & UPF_CONS_FLOW) { 679 tmout = 1000000; 680 while (--tmout) { 681 unsigned int val; 682 683 val = bcm_uart_readl(port, UART_EXTINP_REG); 684 if (val & UART_EXTINP_CTS_MASK) 685 break; 686 udelay(1); 687 } 688 } 689 } 690 691 /* 692 * output given char 693 */ 694 static void bcm_console_putchar(struct uart_port *port, unsigned char ch) 695 { 696 wait_for_xmitr(port); 697 bcm_uart_writel(port, ch, UART_FIFO_REG); 698 } 699 700 /* 701 * console core request to output given string 702 */ 703 static void bcm_console_write(struct console *co, const char *s, 704 unsigned int count) 705 { 706 struct uart_port *port; 707 unsigned long flags; 708 int locked = 1; 709 710 port = &ports[co->index]; 711 712 if (oops_in_progress) 713 locked = uart_port_trylock_irqsave(port, &flags); 714 else 715 uart_port_lock_irqsave(port, &flags); 716 717 /* call helper to deal with \r\n */ 718 uart_console_write(port, s, count, bcm_console_putchar); 719 720 /* and wait for char to be transmitted */ 721 wait_for_xmitr(port); 722 723 if (locked) 724 uart_port_unlock_irqrestore(port, flags); 725 } 726 727 /* 728 * console core request to setup given console, find matching uart 729 * port and setup it. 730 */ 731 static int bcm_console_setup(struct console *co, char *options) 732 { 733 struct uart_port *port; 734 int baud = 9600; 735 int bits = 8; 736 int parity = 'n'; 737 int flow = 'n'; 738 739 if (co->index < 0 || co->index >= BCM63XX_NR_UARTS) 740 return -EINVAL; 741 port = &ports[co->index]; 742 if (!port->membase) 743 return -ENODEV; 744 if (options) 745 uart_parse_options(options, &baud, &parity, &bits, &flow); 746 747 return uart_set_options(port, co, baud, parity, bits, flow); 748 } 749 750 static struct uart_driver bcm_uart_driver; 751 752 static struct console bcm63xx_console = { 753 .name = "ttyS", 754 .write = bcm_console_write, 755 .device = uart_console_device, 756 .setup = bcm_console_setup, 757 .flags = CON_PRINTBUFFER, 758 .index = -1, 759 .data = &bcm_uart_driver, 760 }; 761 762 static int __init bcm63xx_console_init(void) 763 { 764 register_console(&bcm63xx_console); 765 return 0; 766 } 767 768 console_initcall(bcm63xx_console_init); 769 770 static void bcm_early_write(struct console *con, const char *s, unsigned n) 771 { 772 struct earlycon_device *dev = con->data; 773 774 uart_console_write(&dev->port, s, n, bcm_console_putchar); 775 wait_for_xmitr(&dev->port); 776 } 777 778 static int __init bcm_early_console_setup(struct earlycon_device *device, 779 const char *opt) 780 { 781 if (!device->port.membase) 782 return -ENODEV; 783 784 device->con->write = bcm_early_write; 785 return 0; 786 } 787 788 OF_EARLYCON_DECLARE(bcm63xx_uart, "brcm,bcm6345-uart", bcm_early_console_setup); 789 790 #define BCM63XX_CONSOLE (&bcm63xx_console) 791 #else 792 #define BCM63XX_CONSOLE NULL 793 #endif /* CONFIG_SERIAL_BCM63XX_CONSOLE */ 794 795 static struct uart_driver bcm_uart_driver = { 796 .owner = THIS_MODULE, 797 .driver_name = "bcm63xx_uart", 798 .dev_name = "ttyS", 799 .major = TTY_MAJOR, 800 .minor = 64, 801 .nr = BCM63XX_NR_UARTS, 802 .cons = BCM63XX_CONSOLE, 803 }; 804 805 /* 806 * platform driver probe/remove callback 807 */ 808 static int bcm_uart_probe(struct platform_device *pdev) 809 { 810 struct resource *res_mem; 811 struct uart_port *port; 812 struct clk *clk; 813 int ret; 814 815 if (pdev->dev.of_node) { 816 pdev->id = of_alias_get_id(pdev->dev.of_node, "serial"); 817 818 if (pdev->id < 0) 819 pdev->id = of_alias_get_id(pdev->dev.of_node, "uart"); 820 } 821 822 if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS) 823 return -EINVAL; 824 825 port = &ports[pdev->id]; 826 if (port->membase) 827 return -EBUSY; 828 memset(port, 0, sizeof(*port)); 829 830 port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res_mem); 831 if (IS_ERR(port->membase)) 832 return PTR_ERR(port->membase); 833 port->mapbase = res_mem->start; 834 835 ret = platform_get_irq(pdev, 0); 836 if (ret < 0) 837 return ret; 838 port->irq = ret; 839 840 clk = clk_get(&pdev->dev, "refclk"); 841 if (IS_ERR(clk) && pdev->dev.of_node) 842 clk = of_clk_get(pdev->dev.of_node, 0); 843 844 if (IS_ERR(clk)) 845 return -ENODEV; 846 847 port->iotype = UPIO_MEM; 848 port->ops = &bcm_uart_ops; 849 port->flags = UPF_BOOT_AUTOCONF; 850 port->dev = &pdev->dev; 851 port->fifosize = 16; 852 port->uartclk = clk_get_rate(clk) / 2; 853 port->line = pdev->id; 854 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_BCM63XX_CONSOLE); 855 clk_put(clk); 856 857 ret = uart_add_one_port(&bcm_uart_driver, port); 858 if (ret) { 859 ports[pdev->id].membase = NULL; 860 return ret; 861 } 862 platform_set_drvdata(pdev, port); 863 return 0; 864 } 865 866 static void bcm_uart_remove(struct platform_device *pdev) 867 { 868 struct uart_port *port; 869 870 port = platform_get_drvdata(pdev); 871 uart_remove_one_port(&bcm_uart_driver, port); 872 /* mark port as free */ 873 ports[pdev->id].membase = NULL; 874 } 875 876 static const struct of_device_id bcm63xx_of_match[] = { 877 { .compatible = "brcm,bcm6345-uart" }, 878 { /* sentinel */ } 879 }; 880 MODULE_DEVICE_TABLE(of, bcm63xx_of_match); 881 882 /* 883 * platform driver stuff 884 */ 885 static struct platform_driver bcm_uart_platform_driver = { 886 .probe = bcm_uart_probe, 887 .remove = bcm_uart_remove, 888 .driver = { 889 .name = "bcm63xx_uart", 890 .of_match_table = bcm63xx_of_match, 891 }, 892 }; 893 894 static int __init bcm_uart_init(void) 895 { 896 int ret; 897 898 ret = uart_register_driver(&bcm_uart_driver); 899 if (ret) 900 return ret; 901 902 ret = platform_driver_register(&bcm_uart_platform_driver); 903 if (ret) 904 uart_unregister_driver(&bcm_uart_driver); 905 906 return ret; 907 } 908 909 static void __exit bcm_uart_exit(void) 910 { 911 platform_driver_unregister(&bcm_uart_platform_driver); 912 uart_unregister_driver(&bcm_uart_driver); 913 } 914 915 module_init(bcm_uart_init); 916 module_exit(bcm_uart_exit); 917 918 MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>"); 919 MODULE_DESCRIPTION("Broadcom 63xx integrated uart driver"); 920 MODULE_LICENSE("GPL"); 921