1 /* 2 * ARC On-Chip(fpga) UART Driver 3 * 4 * Copyright (C) 2010-2012 Synopsys, Inc. (www.synopsys.com) 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * vineetg: July 10th 2012 11 * -Decoupled the driver from arch/arc 12 * +Using platform_get_resource() for irq/membase (thx to bfin_uart.c) 13 * +Using early_platform_xxx() for early console (thx to mach-shmobile/xxx) 14 * 15 * Vineetg: Aug 21st 2010 16 * -Is uart_tx_stopped() not done in tty write path as it has already been 17 * taken care of, in serial core 18 * 19 * Vineetg: Aug 18th 2010 20 * -New Serial Core based ARC UART driver 21 * -Derived largely from blackfin driver albiet with some major tweaks 22 * 23 * TODO: 24 * -check if sysreq works 25 */ 26 27 #if defined(CONFIG_SERIAL_ARC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) 28 #define SUPPORT_SYSRQ 29 #endif 30 31 #include <linux/module.h> 32 #include <linux/serial.h> 33 #include <linux/console.h> 34 #include <linux/sysrq.h> 35 #include <linux/platform_device.h> 36 #include <linux/tty.h> 37 #include <linux/tty_flip.h> 38 #include <linux/serial_core.h> 39 #include <linux/io.h> 40 #include <linux/of.h> 41 #include <linux/of_platform.h> 42 43 /************************************* 44 * ARC UART Hardware Specs 45 ************************************/ 46 #define ARC_UART_TX_FIFO_SIZE 1 47 48 /* 49 * UART Register set (this is not a Standards Compliant IP) 50 * Also each reg is Word aligned, but only 8 bits wide 51 */ 52 #define R_ID0 0 53 #define R_ID1 4 54 #define R_ID2 8 55 #define R_ID3 12 56 #define R_DATA 16 57 #define R_STS 20 58 #define R_BAUDL 24 59 #define R_BAUDH 28 60 61 /* Bits for UART Status Reg (R/W) */ 62 #define RXIENB 0x04 /* Receive Interrupt Enable */ 63 #define TXIENB 0x40 /* Transmit Interrupt Enable */ 64 65 #define RXEMPTY 0x20 /* Receive FIFO Empty: No char receivede */ 66 #define TXEMPTY 0x80 /* Transmit FIFO Empty, thus char can be written into */ 67 68 #define RXFULL 0x08 /* Receive FIFO full */ 69 #define RXFULL1 0x10 /* Receive FIFO has space for 1 char (tot space=4) */ 70 71 #define RXFERR 0x01 /* Frame Error: Stop Bit not detected */ 72 #define RXOERR 0x02 /* OverFlow Err: Char recv but RXFULL still set */ 73 74 /* Uart bit fiddling helpers: lowest level */ 75 #define RBASE(uart, reg) (uart->port.membase + reg) 76 #define UART_REG_SET(u, r, v) writeb((v), RBASE(u, r)) 77 #define UART_REG_GET(u, r) readb(RBASE(u, r)) 78 79 #define UART_REG_OR(u, r, v) UART_REG_SET(u, r, UART_REG_GET(u, r) | (v)) 80 #define UART_REG_CLR(u, r, v) UART_REG_SET(u, r, UART_REG_GET(u, r) & ~(v)) 81 82 /* Uart bit fiddling helpers: API level */ 83 #define UART_SET_DATA(uart, val) UART_REG_SET(uart, R_DATA, val) 84 #define UART_GET_DATA(uart) UART_REG_GET(uart, R_DATA) 85 86 #define UART_SET_BAUDH(uart, val) UART_REG_SET(uart, R_BAUDH, val) 87 #define UART_SET_BAUDL(uart, val) UART_REG_SET(uart, R_BAUDL, val) 88 89 #define UART_CLR_STATUS(uart, val) UART_REG_CLR(uart, R_STS, val) 90 #define UART_GET_STATUS(uart) UART_REG_GET(uart, R_STS) 91 92 #define UART_ALL_IRQ_DISABLE(uart) UART_REG_CLR(uart, R_STS, RXIENB|TXIENB) 93 #define UART_RX_IRQ_DISABLE(uart) UART_REG_CLR(uart, R_STS, RXIENB) 94 #define UART_TX_IRQ_DISABLE(uart) UART_REG_CLR(uart, R_STS, TXIENB) 95 96 #define UART_ALL_IRQ_ENABLE(uart) UART_REG_OR(uart, R_STS, RXIENB|TXIENB) 97 #define UART_RX_IRQ_ENABLE(uart) UART_REG_OR(uart, R_STS, RXIENB) 98 #define UART_TX_IRQ_ENABLE(uart) UART_REG_OR(uart, R_STS, TXIENB) 99 100 #define ARC_SERIAL_DEV_NAME "ttyARC" 101 102 struct arc_uart_port { 103 struct uart_port port; 104 unsigned long baud; 105 int is_emulated; /* H/w vs. Instruction Set Simulator */ 106 }; 107 108 #define to_arc_port(uport) container_of(uport, struct arc_uart_port, port) 109 110 static struct arc_uart_port arc_uart_ports[CONFIG_SERIAL_ARC_NR_PORTS]; 111 112 #ifdef CONFIG_SERIAL_ARC_CONSOLE 113 static struct console arc_console; 114 #endif 115 116 #define DRIVER_NAME "arc-uart" 117 118 static struct uart_driver arc_uart_driver = { 119 .owner = THIS_MODULE, 120 .driver_name = DRIVER_NAME, 121 .dev_name = ARC_SERIAL_DEV_NAME, 122 .major = 0, 123 .minor = 0, 124 .nr = CONFIG_SERIAL_ARC_NR_PORTS, 125 #ifdef CONFIG_SERIAL_ARC_CONSOLE 126 .cons = &arc_console, 127 #endif 128 }; 129 130 static void arc_serial_stop_rx(struct uart_port *port) 131 { 132 struct arc_uart_port *uart = to_arc_port(port); 133 134 UART_RX_IRQ_DISABLE(uart); 135 } 136 137 static void arc_serial_stop_tx(struct uart_port *port) 138 { 139 struct arc_uart_port *uart = to_arc_port(port); 140 141 while (!(UART_GET_STATUS(uart) & TXEMPTY)) 142 cpu_relax(); 143 144 UART_TX_IRQ_DISABLE(uart); 145 } 146 147 /* 148 * Return TIOCSER_TEMT when transmitter is not busy. 149 */ 150 static unsigned int arc_serial_tx_empty(struct uart_port *port) 151 { 152 struct arc_uart_port *uart = to_arc_port(port); 153 unsigned int stat; 154 155 stat = UART_GET_STATUS(uart); 156 if (stat & TXEMPTY) 157 return TIOCSER_TEMT; 158 159 return 0; 160 } 161 162 /* 163 * Driver internal routine, used by both tty(serial core) as well as tx-isr 164 * -Called under spinlock in either cases 165 * -also tty->stopped has already been checked 166 * = by uart_start( ) before calling us 167 * = tx_ist checks that too before calling 168 */ 169 static void arc_serial_tx_chars(struct arc_uart_port *uart) 170 { 171 struct circ_buf *xmit = &uart->port.state->xmit; 172 int sent = 0; 173 unsigned char ch; 174 175 if (unlikely(uart->port.x_char)) { 176 UART_SET_DATA(uart, uart->port.x_char); 177 uart->port.icount.tx++; 178 uart->port.x_char = 0; 179 sent = 1; 180 } else if (xmit->tail != xmit->head) { /* TODO: uart_circ_empty */ 181 ch = xmit->buf[xmit->tail]; 182 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); 183 uart->port.icount.tx++; 184 while (!(UART_GET_STATUS(uart) & TXEMPTY)) 185 cpu_relax(); 186 UART_SET_DATA(uart, ch); 187 sent = 1; 188 } 189 190 /* 191 * If num chars in xmit buffer are too few, ask tty layer for more. 192 * By Hard ISR to schedule processing in software interrupt part 193 */ 194 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) 195 uart_write_wakeup(&uart->port); 196 197 if (sent) 198 UART_TX_IRQ_ENABLE(uart); 199 } 200 201 /* 202 * port is locked and interrupts are disabled 203 * uart_start( ) calls us under the port spinlock irqsave 204 */ 205 static void arc_serial_start_tx(struct uart_port *port) 206 { 207 struct arc_uart_port *uart = to_arc_port(port); 208 209 arc_serial_tx_chars(uart); 210 } 211 212 static void arc_serial_rx_chars(struct arc_uart_port *uart, unsigned int status) 213 { 214 unsigned int ch, flg = 0; 215 216 /* 217 * UART has 4 deep RX-FIFO. Driver's recongnition of this fact 218 * is very subtle. Here's how ... 219 * Upon getting a RX-Intr, such that RX-EMPTY=0, meaning data available, 220 * driver reads the DATA Reg and keeps doing that in a loop, until 221 * RX-EMPTY=1. Multiple chars being avail, with a single Interrupt, 222 * before RX-EMPTY=0, implies some sort of buffering going on in the 223 * controller, which is indeed the Rx-FIFO. 224 */ 225 do { 226 /* 227 * This could be an Rx Intr for err (no data), 228 * so check err and clear that Intr first 229 */ 230 if (unlikely(status & (RXOERR | RXFERR))) { 231 if (status & RXOERR) { 232 uart->port.icount.overrun++; 233 flg = TTY_OVERRUN; 234 UART_CLR_STATUS(uart, RXOERR); 235 } 236 237 if (status & RXFERR) { 238 uart->port.icount.frame++; 239 flg = TTY_FRAME; 240 UART_CLR_STATUS(uart, RXFERR); 241 } 242 } else 243 flg = TTY_NORMAL; 244 245 if (status & RXEMPTY) 246 continue; 247 248 ch = UART_GET_DATA(uart); 249 uart->port.icount.rx++; 250 251 if (!(uart_handle_sysrq_char(&uart->port, ch))) 252 uart_insert_char(&uart->port, status, RXOERR, ch, flg); 253 254 spin_unlock(&uart->port.lock); 255 tty_flip_buffer_push(&uart->port.state->port); 256 spin_lock(&uart->port.lock); 257 } while (!((status = UART_GET_STATUS(uart)) & RXEMPTY)); 258 } 259 260 /* 261 * A note on the Interrupt handling state machine of this driver 262 * 263 * kernel printk writes funnel thru the console driver framework and in order 264 * to keep things simple as well as efficient, it writes to UART in polled 265 * mode, in one shot, and exits. 266 * 267 * OTOH, Userland output (via tty layer), uses interrupt based writes as there 268 * can be undeterministic delay between char writes. 269 * 270 * Thus Rx-interrupts are always enabled, while tx-interrupts are by default 271 * disabled. 272 * 273 * When tty has some data to send out, serial core calls driver's start_tx 274 * which 275 * -checks-if-tty-buffer-has-char-to-send 276 * -writes-data-to-uart 277 * -enable-tx-intr 278 * 279 * Once data bits are pushed out, controller raises the Tx-room-avail-Interrupt. 280 * The first thing Tx ISR does is disable further Tx interrupts (as this could 281 * be the last char to send, before settling down into the quiet polled mode). 282 * It then calls the exact routine used by tty layer write to send out any 283 * more char in tty buffer. In case of sending, it re-enables Tx-intr. In case 284 * of no data, it remains disabled. 285 * This is how the transmit state machine is dynamically switched on/off 286 */ 287 288 static irqreturn_t arc_serial_isr(int irq, void *dev_id) 289 { 290 struct arc_uart_port *uart = dev_id; 291 unsigned int status; 292 293 status = UART_GET_STATUS(uart); 294 295 /* 296 * Single IRQ for both Rx (data available) Tx (room available) Interrupt 297 * notifications from the UART Controller. 298 * To demultiplex between the two, we check the relevant bits 299 */ 300 if (status & RXIENB) { 301 302 /* already in ISR, no need of xx_irqsave */ 303 spin_lock(&uart->port.lock); 304 arc_serial_rx_chars(uart, status); 305 spin_unlock(&uart->port.lock); 306 } 307 308 if ((status & TXIENB) && (status & TXEMPTY)) { 309 310 /* Unconditionally disable further Tx-Interrupts. 311 * will be enabled by tx_chars() if needed. 312 */ 313 UART_TX_IRQ_DISABLE(uart); 314 315 spin_lock(&uart->port.lock); 316 317 if (!uart_tx_stopped(&uart->port)) 318 arc_serial_tx_chars(uart); 319 320 spin_unlock(&uart->port.lock); 321 } 322 323 return IRQ_HANDLED; 324 } 325 326 static unsigned int arc_serial_get_mctrl(struct uart_port *port) 327 { 328 /* 329 * Pretend we have a Modem status reg and following bits are 330 * always set, to satify the serial core state machine 331 * (DSR) Data Set Ready 332 * (CTS) Clear To Send 333 * (CAR) Carrier Detect 334 */ 335 return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR; 336 } 337 338 static void arc_serial_set_mctrl(struct uart_port *port, unsigned int mctrl) 339 { 340 /* MCR not present */ 341 } 342 343 /* Enable Modem Status Interrupts */ 344 345 static void arc_serial_enable_ms(struct uart_port *port) 346 { 347 /* MSR not present */ 348 } 349 350 static void arc_serial_break_ctl(struct uart_port *port, int break_state) 351 { 352 /* ARC UART doesn't support sending Break signal */ 353 } 354 355 static int arc_serial_startup(struct uart_port *port) 356 { 357 struct arc_uart_port *uart = to_arc_port(port); 358 359 /* Before we hook up the ISR, Disable all UART Interrupts */ 360 UART_ALL_IRQ_DISABLE(uart); 361 362 if (request_irq(uart->port.irq, arc_serial_isr, 0, "arc uart rx-tx", 363 uart)) { 364 dev_warn(uart->port.dev, "Unable to attach ARC UART intr\n"); 365 return -EBUSY; 366 } 367 368 UART_RX_IRQ_ENABLE(uart); /* Only Rx IRQ enabled to begin with */ 369 370 return 0; 371 } 372 373 /* This is not really needed */ 374 static void arc_serial_shutdown(struct uart_port *port) 375 { 376 struct arc_uart_port *uart = to_arc_port(port); 377 free_irq(uart->port.irq, uart); 378 } 379 380 static void 381 arc_serial_set_termios(struct uart_port *port, struct ktermios *new, 382 struct ktermios *old) 383 { 384 struct arc_uart_port *uart = to_arc_port(port); 385 unsigned int baud, uartl, uarth, hw_val; 386 unsigned long flags; 387 388 /* 389 * Use the generic handler so that any specially encoded baud rates 390 * such as SPD_xx flags or "%B0" can be handled 391 * Max Baud I suppose will not be more than current 115K * 4 392 * Formula for ARC UART is: hw-val = ((CLK/(BAUD*4)) -1) 393 * spread over two 8-bit registers 394 */ 395 baud = uart_get_baud_rate(port, new, old, 0, 460800); 396 397 hw_val = port->uartclk / (uart->baud * 4) - 1; 398 uartl = hw_val & 0xFF; 399 uarth = (hw_val >> 8) & 0xFF; 400 401 /* 402 * UART ISS(Instruction Set simulator) emulation has a subtle bug: 403 * A existing value of Baudh = 0 is used as a indication to startup 404 * it's internal state machine. 405 * Thus if baudh is set to 0, 2 times, it chokes. 406 * This happens with BAUD=115200 and the formaula above 407 * Until that is fixed, when running on ISS, we will set baudh to !0 408 */ 409 if (uart->is_emulated) 410 uarth = 1; 411 412 spin_lock_irqsave(&port->lock, flags); 413 414 UART_ALL_IRQ_DISABLE(uart); 415 416 UART_SET_BAUDL(uart, uartl); 417 UART_SET_BAUDH(uart, uarth); 418 419 UART_RX_IRQ_ENABLE(uart); 420 421 /* 422 * UART doesn't support Parity/Hardware Flow Control; 423 * Only supports 8N1 character size 424 */ 425 new->c_cflag &= ~(CMSPAR|CRTSCTS|CSIZE); 426 new->c_cflag |= CS8; 427 428 if (old) 429 tty_termios_copy_hw(new, old); 430 431 /* Don't rewrite B0 */ 432 if (tty_termios_baud_rate(new)) 433 tty_termios_encode_baud_rate(new, baud, baud); 434 435 uart_update_timeout(port, new->c_cflag, baud); 436 437 spin_unlock_irqrestore(&port->lock, flags); 438 } 439 440 static const char *arc_serial_type(struct uart_port *port) 441 { 442 struct arc_uart_port *uart = to_arc_port(port); 443 444 return uart->port.type == PORT_ARC ? DRIVER_NAME : NULL; 445 } 446 447 static void arc_serial_release_port(struct uart_port *port) 448 { 449 } 450 451 static int arc_serial_request_port(struct uart_port *port) 452 { 453 return 0; 454 } 455 456 /* 457 * Verify the new serial_struct (for TIOCSSERIAL). 458 */ 459 static int 460 arc_serial_verify_port(struct uart_port *port, struct serial_struct *ser) 461 { 462 if (port->type != PORT_UNKNOWN && ser->type != PORT_ARC) 463 return -EINVAL; 464 465 return 0; 466 } 467 468 /* 469 * Configure/autoconfigure the port. 470 */ 471 static void arc_serial_config_port(struct uart_port *port, int flags) 472 { 473 struct arc_uart_port *uart = to_arc_port(port); 474 475 if (flags & UART_CONFIG_TYPE) 476 uart->port.type = PORT_ARC; 477 } 478 479 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_ARC_CONSOLE) 480 481 static void arc_serial_poll_putchar(struct uart_port *port, unsigned char chr) 482 { 483 struct arc_uart_port *uart = to_arc_port(port); 484 485 while (!(UART_GET_STATUS(uart) & TXEMPTY)) 486 cpu_relax(); 487 488 UART_SET_DATA(uart, chr); 489 } 490 #endif 491 492 #ifdef CONFIG_CONSOLE_POLL 493 static int arc_serial_poll_getchar(struct uart_port *port) 494 { 495 struct arc_uart_port *uart = to_arc_port(port); 496 unsigned char chr; 497 498 while (!(UART_GET_STATUS(uart) & RXEMPTY)) 499 cpu_relax(); 500 501 chr = UART_GET_DATA(uart); 502 return chr; 503 } 504 #endif 505 506 static struct uart_ops arc_serial_pops = { 507 .tx_empty = arc_serial_tx_empty, 508 .set_mctrl = arc_serial_set_mctrl, 509 .get_mctrl = arc_serial_get_mctrl, 510 .stop_tx = arc_serial_stop_tx, 511 .start_tx = arc_serial_start_tx, 512 .stop_rx = arc_serial_stop_rx, 513 .enable_ms = arc_serial_enable_ms, 514 .break_ctl = arc_serial_break_ctl, 515 .startup = arc_serial_startup, 516 .shutdown = arc_serial_shutdown, 517 .set_termios = arc_serial_set_termios, 518 .type = arc_serial_type, 519 .release_port = arc_serial_release_port, 520 .request_port = arc_serial_request_port, 521 .config_port = arc_serial_config_port, 522 .verify_port = arc_serial_verify_port, 523 #ifdef CONFIG_CONSOLE_POLL 524 .poll_put_char = arc_serial_poll_putchar, 525 .poll_get_char = arc_serial_poll_getchar, 526 #endif 527 }; 528 529 static int 530 arc_uart_init_one(struct platform_device *pdev, int dev_id) 531 { 532 struct resource *res, *res2; 533 unsigned long *plat_data; 534 struct arc_uart_port *uart = &arc_uart_ports[dev_id]; 535 536 plat_data = (unsigned long *)dev_get_platdata(&pdev->dev); 537 if (!plat_data) 538 return -ENODEV; 539 540 uart->is_emulated = !!plat_data[0]; /* workaround ISS bug */ 541 542 if (is_early_platform_device(pdev)) { 543 uart->port.uartclk = plat_data[1]; 544 uart->baud = plat_data[2]; 545 } else { 546 struct device_node *np = pdev->dev.of_node; 547 u32 val; 548 549 if (of_property_read_u32(np, "clock-frequency", &val)) { 550 dev_err(&pdev->dev, "clock-frequency property NOTset\n"); 551 return -EINVAL; 552 } 553 uart->port.uartclk = val; 554 555 if (of_property_read_u32(np, "current-speed", &val)) { 556 dev_err(&pdev->dev, "current-speed property NOT set\n"); 557 return -EINVAL; 558 } 559 uart->baud = val; 560 } 561 562 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 563 if (!res) 564 return -ENODEV; 565 566 res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 567 if (!res2) 568 return -ENODEV; 569 570 uart->port.mapbase = res->start; 571 uart->port.membase = ioremap_nocache(res->start, resource_size(res)); 572 if (!uart->port.membase) 573 /* No point of dev_err since UART itself is hosed here */ 574 return -ENXIO; 575 576 uart->port.irq = res2->start; 577 uart->port.dev = &pdev->dev; 578 uart->port.iotype = UPIO_MEM; 579 uart->port.flags = UPF_BOOT_AUTOCONF; 580 uart->port.line = dev_id; 581 uart->port.ops = &arc_serial_pops; 582 583 uart->port.fifosize = ARC_UART_TX_FIFO_SIZE; 584 585 /* 586 * uart_insert_char( ) uses it in decideding whether to ignore a 587 * char or not. Explicitly setting it here, removes the subtelty 588 */ 589 uart->port.ignore_status_mask = 0; 590 591 return 0; 592 } 593 594 #ifdef CONFIG_SERIAL_ARC_CONSOLE 595 596 static int arc_serial_console_setup(struct console *co, char *options) 597 { 598 struct uart_port *port; 599 int baud = 115200; 600 int bits = 8; 601 int parity = 'n'; 602 int flow = 'n'; 603 604 if (co->index < 0 || co->index >= CONFIG_SERIAL_ARC_NR_PORTS) 605 return -ENODEV; 606 607 /* 608 * The uart port backing the console (e.g. ttyARC1) might not have been 609 * init yet. If so, defer the console setup to after the port. 610 */ 611 port = &arc_uart_ports[co->index].port; 612 if (!port->membase) 613 return -ENODEV; 614 615 if (options) 616 uart_parse_options(options, &baud, &parity, &bits, &flow); 617 618 /* 619 * Serial core will call port->ops->set_termios( ) 620 * which will set the baud reg 621 */ 622 return uart_set_options(port, co, baud, parity, bits, flow); 623 } 624 625 static void arc_serial_console_putchar(struct uart_port *port, int ch) 626 { 627 arc_serial_poll_putchar(port, (unsigned char)ch); 628 } 629 630 /* 631 * Interrupts are disabled on entering 632 */ 633 static void arc_serial_console_write(struct console *co, const char *s, 634 unsigned int count) 635 { 636 struct uart_port *port = &arc_uart_ports[co->index].port; 637 unsigned long flags; 638 639 spin_lock_irqsave(&port->lock, flags); 640 uart_console_write(port, s, count, arc_serial_console_putchar); 641 spin_unlock_irqrestore(&port->lock, flags); 642 } 643 644 static struct console arc_console = { 645 .name = ARC_SERIAL_DEV_NAME, 646 .write = arc_serial_console_write, 647 .device = uart_console_device, 648 .setup = arc_serial_console_setup, 649 .flags = CON_PRINTBUFFER, 650 .index = -1, 651 .data = &arc_uart_driver 652 }; 653 654 static __init void early_serial_write(struct console *con, const char *s, 655 unsigned int n) 656 { 657 struct uart_port *port = &arc_uart_ports[con->index].port; 658 unsigned int i; 659 660 for (i = 0; i < n; i++, s++) { 661 if (*s == '\n') 662 arc_serial_poll_putchar(port, '\r'); 663 arc_serial_poll_putchar(port, *s); 664 } 665 } 666 667 static struct console arc_early_serial_console __initdata = { 668 .name = "early_ARCuart", 669 .write = early_serial_write, 670 .flags = CON_PRINTBUFFER | CON_BOOT, 671 .index = -1 672 }; 673 674 static int __init arc_serial_probe_earlyprintk(struct platform_device *pdev) 675 { 676 int dev_id = pdev->id < 0 ? 0 : pdev->id; 677 int rc; 678 679 arc_early_serial_console.index = dev_id; 680 681 rc = arc_uart_init_one(pdev, dev_id); 682 if (rc) 683 panic("early console init failed\n"); 684 685 arc_serial_console_setup(&arc_early_serial_console, NULL); 686 687 register_console(&arc_early_serial_console); 688 return 0; 689 } 690 #endif /* CONFIG_SERIAL_ARC_CONSOLE */ 691 692 static int arc_serial_probe(struct platform_device *pdev) 693 { 694 int rc, dev_id; 695 struct device_node *np = pdev->dev.of_node; 696 697 /* no device tree device */ 698 if (!np) 699 return -ENODEV; 700 701 dev_id = of_alias_get_id(np, "serial"); 702 if (dev_id < 0) 703 dev_id = 0; 704 705 rc = arc_uart_init_one(pdev, dev_id); 706 if (rc) 707 return rc; 708 709 rc = uart_add_one_port(&arc_uart_driver, &arc_uart_ports[dev_id].port); 710 return rc; 711 } 712 713 static int arc_serial_remove(struct platform_device *pdev) 714 { 715 /* This will never be called */ 716 return 0; 717 } 718 719 static const struct of_device_id arc_uart_dt_ids[] = { 720 { .compatible = "snps,arc-uart" }, 721 { /* Sentinel */ } 722 }; 723 MODULE_DEVICE_TABLE(of, arc_uart_dt_ids); 724 725 static struct platform_driver arc_platform_driver = { 726 .probe = arc_serial_probe, 727 .remove = arc_serial_remove, 728 .driver = { 729 .name = DRIVER_NAME, 730 .owner = THIS_MODULE, 731 .of_match_table = arc_uart_dt_ids, 732 }, 733 }; 734 735 #ifdef CONFIG_SERIAL_ARC_CONSOLE 736 737 static struct platform_driver early_arc_platform_driver __initdata = { 738 .probe = arc_serial_probe_earlyprintk, 739 .remove = arc_serial_remove, 740 .driver = { 741 .name = DRIVER_NAME, 742 .owner = THIS_MODULE, 743 }, 744 }; 745 /* 746 * Register an early platform driver of "earlyprintk" class. 747 * ARCH platform code installs the driver and probes the early devices 748 * The installation could rely on user specifying earlyprintk=xyx in cmd line 749 * or it could be done independently, for all "earlyprintk" class drivers. 750 * [see arch/arc/plat-arcfpga/platform.c] 751 */ 752 early_platform_init("earlyprintk", &early_arc_platform_driver); 753 754 #endif /* CONFIG_SERIAL_ARC_CONSOLE */ 755 756 static int __init arc_serial_init(void) 757 { 758 int ret; 759 760 ret = uart_register_driver(&arc_uart_driver); 761 if (ret) 762 return ret; 763 764 ret = platform_driver_register(&arc_platform_driver); 765 if (ret) 766 uart_unregister_driver(&arc_uart_driver); 767 768 return ret; 769 } 770 771 static void __exit arc_serial_exit(void) 772 { 773 platform_driver_unregister(&arc_platform_driver); 774 uart_unregister_driver(&arc_uart_driver); 775 } 776 777 module_init(arc_serial_init); 778 module_exit(arc_serial_exit); 779 780 MODULE_LICENSE("GPL"); 781 MODULE_ALIAS("platform:" DRIVER_NAME); 782 MODULE_AUTHOR("Vineet Gupta"); 783 MODULE_DESCRIPTION("ARC(Synopsys) On-Chip(fpga) serial driver"); 784