1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Actions Semi Owl family serial console 4 * 5 * Copyright 2013 Actions Semi Inc. 6 * Author: Actions Semi, Inc. 7 * 8 * Copyright (c) 2016-2017 Andreas Färber 9 */ 10 11 #include <linux/clk.h> 12 #include <linux/console.h> 13 #include <linux/delay.h> 14 #include <linux/io.h> 15 #include <linux/module.h> 16 #include <linux/of.h> 17 #include <linux/platform_device.h> 18 #include <linux/serial.h> 19 #include <linux/serial_core.h> 20 #include <linux/tty.h> 21 #include <linux/tty_flip.h> 22 23 #define OWL_UART_PORT_NUM 7 24 #define OWL_UART_DEV_NAME "ttyOWL" 25 26 #define OWL_UART_CTL 0x000 27 #define OWL_UART_RXDAT 0x004 28 #define OWL_UART_TXDAT 0x008 29 #define OWL_UART_STAT 0x00c 30 31 #define OWL_UART_CTL_DWLS_MASK GENMASK(1, 0) 32 #define OWL_UART_CTL_DWLS_5BITS (0x0 << 0) 33 #define OWL_UART_CTL_DWLS_6BITS (0x1 << 0) 34 #define OWL_UART_CTL_DWLS_7BITS (0x2 << 0) 35 #define OWL_UART_CTL_DWLS_8BITS (0x3 << 0) 36 #define OWL_UART_CTL_STPS_2BITS BIT(2) 37 #define OWL_UART_CTL_PRS_MASK GENMASK(6, 4) 38 #define OWL_UART_CTL_PRS_NONE (0x0 << 4) 39 #define OWL_UART_CTL_PRS_ODD (0x4 << 4) 40 #define OWL_UART_CTL_PRS_MARK (0x5 << 4) 41 #define OWL_UART_CTL_PRS_EVEN (0x6 << 4) 42 #define OWL_UART_CTL_PRS_SPACE (0x7 << 4) 43 #define OWL_UART_CTL_AFE BIT(12) 44 #define OWL_UART_CTL_TRFS_TX BIT(14) 45 #define OWL_UART_CTL_EN BIT(15) 46 #define OWL_UART_CTL_RXDE BIT(16) 47 #define OWL_UART_CTL_TXDE BIT(17) 48 #define OWL_UART_CTL_RXIE BIT(18) 49 #define OWL_UART_CTL_TXIE BIT(19) 50 #define OWL_UART_CTL_LBEN BIT(20) 51 52 #define OWL_UART_STAT_RIP BIT(0) 53 #define OWL_UART_STAT_TIP BIT(1) 54 #define OWL_UART_STAT_RXER BIT(2) 55 #define OWL_UART_STAT_TFER BIT(3) 56 #define OWL_UART_STAT_RXST BIT(4) 57 #define OWL_UART_STAT_RFEM BIT(5) 58 #define OWL_UART_STAT_TFFU BIT(6) 59 #define OWL_UART_STAT_CTSS BIT(7) 60 #define OWL_UART_STAT_RTSS BIT(8) 61 #define OWL_UART_STAT_TFES BIT(10) 62 #define OWL_UART_STAT_TRFL_MASK GENMASK(16, 11) 63 #define OWL_UART_STAT_UTBB BIT(17) 64 65 static struct uart_driver owl_uart_driver; 66 67 struct owl_uart_info { 68 unsigned int tx_fifosize; 69 }; 70 71 struct owl_uart_port { 72 struct uart_port port; 73 struct clk *clk; 74 }; 75 76 #define to_owl_uart_port(prt) container_of(prt, struct owl_uart_port, prt) 77 78 static struct owl_uart_port *owl_uart_ports[OWL_UART_PORT_NUM]; 79 80 static inline void owl_uart_write(struct uart_port *port, u32 val, unsigned int off) 81 { 82 writel(val, port->membase + off); 83 } 84 85 static inline u32 owl_uart_read(struct uart_port *port, unsigned int off) 86 { 87 return readl(port->membase + off); 88 } 89 90 static void owl_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) 91 { 92 u32 ctl; 93 94 ctl = owl_uart_read(port, OWL_UART_CTL); 95 96 if (mctrl & TIOCM_LOOP) 97 ctl |= OWL_UART_CTL_LBEN; 98 else 99 ctl &= ~OWL_UART_CTL_LBEN; 100 101 owl_uart_write(port, ctl, OWL_UART_CTL); 102 } 103 104 static unsigned int owl_uart_get_mctrl(struct uart_port *port) 105 { 106 unsigned int mctrl = TIOCM_CAR | TIOCM_DSR; 107 u32 stat, ctl; 108 109 ctl = owl_uart_read(port, OWL_UART_CTL); 110 stat = owl_uart_read(port, OWL_UART_STAT); 111 if (stat & OWL_UART_STAT_RTSS) 112 mctrl |= TIOCM_RTS; 113 if ((stat & OWL_UART_STAT_CTSS) || !(ctl & OWL_UART_CTL_AFE)) 114 mctrl |= TIOCM_CTS; 115 return mctrl; 116 } 117 118 static unsigned int owl_uart_tx_empty(struct uart_port *port) 119 { 120 unsigned long flags; 121 u32 val; 122 unsigned int ret; 123 124 spin_lock_irqsave(&port->lock, flags); 125 126 val = owl_uart_read(port, OWL_UART_STAT); 127 ret = (val & OWL_UART_STAT_TFES) ? TIOCSER_TEMT : 0; 128 129 spin_unlock_irqrestore(&port->lock, flags); 130 131 return ret; 132 } 133 134 static void owl_uart_stop_rx(struct uart_port *port) 135 { 136 u32 val; 137 138 val = owl_uart_read(port, OWL_UART_CTL); 139 val &= ~(OWL_UART_CTL_RXIE | OWL_UART_CTL_RXDE); 140 owl_uart_write(port, val, OWL_UART_CTL); 141 142 val = owl_uart_read(port, OWL_UART_STAT); 143 val |= OWL_UART_STAT_RIP; 144 owl_uart_write(port, val, OWL_UART_STAT); 145 } 146 147 static void owl_uart_stop_tx(struct uart_port *port) 148 { 149 u32 val; 150 151 val = owl_uart_read(port, OWL_UART_CTL); 152 val &= ~(OWL_UART_CTL_TXIE | OWL_UART_CTL_TXDE); 153 owl_uart_write(port, val, OWL_UART_CTL); 154 155 val = owl_uart_read(port, OWL_UART_STAT); 156 val |= OWL_UART_STAT_TIP; 157 owl_uart_write(port, val, OWL_UART_STAT); 158 } 159 160 static void owl_uart_start_tx(struct uart_port *port) 161 { 162 u32 val; 163 164 if (uart_tx_stopped(port)) { 165 owl_uart_stop_tx(port); 166 return; 167 } 168 169 val = owl_uart_read(port, OWL_UART_STAT); 170 val |= OWL_UART_STAT_TIP; 171 owl_uart_write(port, val, OWL_UART_STAT); 172 173 val = owl_uart_read(port, OWL_UART_CTL); 174 val |= OWL_UART_CTL_TXIE; 175 owl_uart_write(port, val, OWL_UART_CTL); 176 } 177 178 static void owl_uart_send_chars(struct uart_port *port) 179 { 180 struct circ_buf *xmit = &port->state->xmit; 181 unsigned int ch; 182 183 if (uart_tx_stopped(port)) 184 return; 185 186 if (port->x_char) { 187 while (!(owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU)) 188 cpu_relax(); 189 owl_uart_write(port, port->x_char, OWL_UART_TXDAT); 190 port->icount.tx++; 191 port->x_char = 0; 192 } 193 194 while (!(owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU)) { 195 if (uart_circ_empty(xmit)) 196 break; 197 198 ch = xmit->buf[xmit->tail]; 199 owl_uart_write(port, ch, OWL_UART_TXDAT); 200 xmit->tail = (xmit->tail + 1) & (SERIAL_XMIT_SIZE - 1); 201 port->icount.tx++; 202 } 203 204 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) 205 uart_write_wakeup(port); 206 207 if (uart_circ_empty(xmit)) 208 owl_uart_stop_tx(port); 209 } 210 211 static void owl_uart_receive_chars(struct uart_port *port) 212 { 213 u32 stat, val; 214 215 val = owl_uart_read(port, OWL_UART_CTL); 216 val &= ~OWL_UART_CTL_TRFS_TX; 217 owl_uart_write(port, val, OWL_UART_CTL); 218 219 stat = owl_uart_read(port, OWL_UART_STAT); 220 while (!(stat & OWL_UART_STAT_RFEM)) { 221 char flag = TTY_NORMAL; 222 223 if (stat & OWL_UART_STAT_RXER) 224 port->icount.overrun++; 225 226 if (stat & OWL_UART_STAT_RXST) { 227 /* We are not able to distinguish the error type. */ 228 port->icount.brk++; 229 port->icount.frame++; 230 231 stat &= port->read_status_mask; 232 if (stat & OWL_UART_STAT_RXST) 233 flag = TTY_PARITY; 234 } else 235 port->icount.rx++; 236 237 val = owl_uart_read(port, OWL_UART_RXDAT); 238 val &= 0xff; 239 240 if ((stat & port->ignore_status_mask) == 0) 241 tty_insert_flip_char(&port->state->port, val, flag); 242 243 stat = owl_uart_read(port, OWL_UART_STAT); 244 } 245 246 spin_unlock(&port->lock); 247 tty_flip_buffer_push(&port->state->port); 248 spin_lock(&port->lock); 249 } 250 251 static irqreturn_t owl_uart_irq(int irq, void *dev_id) 252 { 253 struct uart_port *port = dev_id; 254 unsigned long flags; 255 u32 stat; 256 257 spin_lock_irqsave(&port->lock, flags); 258 259 stat = owl_uart_read(port, OWL_UART_STAT); 260 261 if (stat & OWL_UART_STAT_RIP) 262 owl_uart_receive_chars(port); 263 264 if (stat & OWL_UART_STAT_TIP) 265 owl_uart_send_chars(port); 266 267 stat = owl_uart_read(port, OWL_UART_STAT); 268 stat |= OWL_UART_STAT_RIP | OWL_UART_STAT_TIP; 269 owl_uart_write(port, stat, OWL_UART_STAT); 270 271 spin_unlock_irqrestore(&port->lock, flags); 272 273 return IRQ_HANDLED; 274 } 275 276 static void owl_uart_shutdown(struct uart_port *port) 277 { 278 u32 val; 279 unsigned long flags; 280 281 spin_lock_irqsave(&port->lock, flags); 282 283 val = owl_uart_read(port, OWL_UART_CTL); 284 val &= ~(OWL_UART_CTL_TXIE | OWL_UART_CTL_RXIE 285 | OWL_UART_CTL_TXDE | OWL_UART_CTL_RXDE | OWL_UART_CTL_EN); 286 owl_uart_write(port, val, OWL_UART_CTL); 287 288 spin_unlock_irqrestore(&port->lock, flags); 289 290 free_irq(port->irq, port); 291 } 292 293 static int owl_uart_startup(struct uart_port *port) 294 { 295 u32 val; 296 unsigned long flags; 297 int ret; 298 299 ret = request_irq(port->irq, owl_uart_irq, IRQF_TRIGGER_HIGH, 300 "owl-uart", port); 301 if (ret) 302 return ret; 303 304 spin_lock_irqsave(&port->lock, flags); 305 306 val = owl_uart_read(port, OWL_UART_STAT); 307 val |= OWL_UART_STAT_RIP | OWL_UART_STAT_TIP 308 | OWL_UART_STAT_RXER | OWL_UART_STAT_TFER | OWL_UART_STAT_RXST; 309 owl_uart_write(port, val, OWL_UART_STAT); 310 311 val = owl_uart_read(port, OWL_UART_CTL); 312 val |= OWL_UART_CTL_RXIE | OWL_UART_CTL_TXIE; 313 val |= OWL_UART_CTL_EN; 314 owl_uart_write(port, val, OWL_UART_CTL); 315 316 spin_unlock_irqrestore(&port->lock, flags); 317 318 return 0; 319 } 320 321 static void owl_uart_change_baudrate(struct owl_uart_port *owl_port, 322 unsigned long baud) 323 { 324 clk_set_rate(owl_port->clk, baud * 8); 325 } 326 327 static void owl_uart_set_termios(struct uart_port *port, 328 struct ktermios *termios, 329 struct ktermios *old) 330 { 331 struct owl_uart_port *owl_port = to_owl_uart_port(port); 332 unsigned int baud; 333 u32 ctl; 334 unsigned long flags; 335 336 spin_lock_irqsave(&port->lock, flags); 337 338 ctl = owl_uart_read(port, OWL_UART_CTL); 339 340 ctl &= ~OWL_UART_CTL_DWLS_MASK; 341 switch (termios->c_cflag & CSIZE) { 342 case CS5: 343 ctl |= OWL_UART_CTL_DWLS_5BITS; 344 break; 345 case CS6: 346 ctl |= OWL_UART_CTL_DWLS_6BITS; 347 break; 348 case CS7: 349 ctl |= OWL_UART_CTL_DWLS_7BITS; 350 break; 351 case CS8: 352 default: 353 ctl |= OWL_UART_CTL_DWLS_8BITS; 354 break; 355 } 356 357 if (termios->c_cflag & CSTOPB) 358 ctl |= OWL_UART_CTL_STPS_2BITS; 359 else 360 ctl &= ~OWL_UART_CTL_STPS_2BITS; 361 362 ctl &= ~OWL_UART_CTL_PRS_MASK; 363 if (termios->c_cflag & PARENB) { 364 if (termios->c_cflag & CMSPAR) { 365 if (termios->c_cflag & PARODD) 366 ctl |= OWL_UART_CTL_PRS_MARK; 367 else 368 ctl |= OWL_UART_CTL_PRS_SPACE; 369 } else if (termios->c_cflag & PARODD) 370 ctl |= OWL_UART_CTL_PRS_ODD; 371 else 372 ctl |= OWL_UART_CTL_PRS_EVEN; 373 } else 374 ctl |= OWL_UART_CTL_PRS_NONE; 375 376 if (termios->c_cflag & CRTSCTS) 377 ctl |= OWL_UART_CTL_AFE; 378 else 379 ctl &= ~OWL_UART_CTL_AFE; 380 381 owl_uart_write(port, ctl, OWL_UART_CTL); 382 383 baud = uart_get_baud_rate(port, termios, old, 9600, 3200000); 384 owl_uart_change_baudrate(owl_port, baud); 385 386 /* Don't rewrite B0 */ 387 if (tty_termios_baud_rate(termios)) 388 tty_termios_encode_baud_rate(termios, baud, baud); 389 390 port->read_status_mask |= OWL_UART_STAT_RXER; 391 if (termios->c_iflag & INPCK) 392 port->read_status_mask |= OWL_UART_STAT_RXST; 393 394 uart_update_timeout(port, termios->c_cflag, baud); 395 396 spin_unlock_irqrestore(&port->lock, flags); 397 } 398 399 static void owl_uart_release_port(struct uart_port *port) 400 { 401 struct platform_device *pdev = to_platform_device(port->dev); 402 struct resource *res; 403 404 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 405 if (!res) 406 return; 407 408 if (port->flags & UPF_IOREMAP) { 409 devm_release_mem_region(port->dev, port->mapbase, 410 resource_size(res)); 411 devm_iounmap(port->dev, port->membase); 412 port->membase = NULL; 413 } 414 } 415 416 static int owl_uart_request_port(struct uart_port *port) 417 { 418 struct platform_device *pdev = to_platform_device(port->dev); 419 struct resource *res; 420 421 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 422 if (!res) 423 return -ENXIO; 424 425 if (!devm_request_mem_region(port->dev, port->mapbase, 426 resource_size(res), dev_name(port->dev))) 427 return -EBUSY; 428 429 if (port->flags & UPF_IOREMAP) { 430 port->membase = devm_ioremap_nocache(port->dev, port->mapbase, 431 resource_size(res)); 432 if (!port->membase) 433 return -EBUSY; 434 } 435 436 return 0; 437 } 438 439 static const char *owl_uart_type(struct uart_port *port) 440 { 441 return (port->type == PORT_OWL) ? "owl-uart" : NULL; 442 } 443 444 static int owl_uart_verify_port(struct uart_port *port, 445 struct serial_struct *ser) 446 { 447 if (port->type != PORT_OWL) 448 return -EINVAL; 449 450 if (port->irq != ser->irq) 451 return -EINVAL; 452 453 return 0; 454 } 455 456 static void owl_uart_config_port(struct uart_port *port, int flags) 457 { 458 if (flags & UART_CONFIG_TYPE) { 459 port->type = PORT_OWL; 460 owl_uart_request_port(port); 461 } 462 } 463 464 static const struct uart_ops owl_uart_ops = { 465 .set_mctrl = owl_uart_set_mctrl, 466 .get_mctrl = owl_uart_get_mctrl, 467 .tx_empty = owl_uart_tx_empty, 468 .start_tx = owl_uart_start_tx, 469 .stop_rx = owl_uart_stop_rx, 470 .stop_tx = owl_uart_stop_tx, 471 .startup = owl_uart_startup, 472 .shutdown = owl_uart_shutdown, 473 .set_termios = owl_uart_set_termios, 474 .type = owl_uart_type, 475 .config_port = owl_uart_config_port, 476 .request_port = owl_uart_request_port, 477 .release_port = owl_uart_release_port, 478 .verify_port = owl_uart_verify_port, 479 }; 480 481 #ifdef CONFIG_SERIAL_OWL_CONSOLE 482 483 static void owl_console_putchar(struct uart_port *port, int ch) 484 { 485 if (!port->membase) 486 return; 487 488 while (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU) 489 cpu_relax(); 490 491 owl_uart_write(port, ch, OWL_UART_TXDAT); 492 } 493 494 static void owl_uart_port_write(struct uart_port *port, const char *s, 495 u_int count) 496 { 497 u32 old_ctl, val; 498 unsigned long flags; 499 int locked; 500 501 local_irq_save(flags); 502 503 if (port->sysrq) 504 locked = 0; 505 else if (oops_in_progress) 506 locked = spin_trylock(&port->lock); 507 else { 508 spin_lock(&port->lock); 509 locked = 1; 510 } 511 512 old_ctl = owl_uart_read(port, OWL_UART_CTL); 513 val = old_ctl | OWL_UART_CTL_TRFS_TX; 514 /* disable IRQ */ 515 val &= ~(OWL_UART_CTL_RXIE | OWL_UART_CTL_TXIE); 516 owl_uart_write(port, val, OWL_UART_CTL); 517 518 uart_console_write(port, s, count, owl_console_putchar); 519 520 /* wait until all contents have been sent out */ 521 while (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TRFL_MASK) 522 cpu_relax(); 523 524 /* clear IRQ pending */ 525 val = owl_uart_read(port, OWL_UART_STAT); 526 val |= OWL_UART_STAT_TIP | OWL_UART_STAT_RIP; 527 owl_uart_write(port, val, OWL_UART_STAT); 528 529 owl_uart_write(port, old_ctl, OWL_UART_CTL); 530 531 if (locked) 532 spin_unlock(&port->lock); 533 534 local_irq_restore(flags); 535 } 536 537 static void owl_uart_console_write(struct console *co, const char *s, 538 u_int count) 539 { 540 struct owl_uart_port *owl_port; 541 542 owl_port = owl_uart_ports[co->index]; 543 if (!owl_port) 544 return; 545 546 owl_uart_port_write(&owl_port->port, s, count); 547 } 548 549 static int owl_uart_console_setup(struct console *co, char *options) 550 { 551 struct owl_uart_port *owl_port; 552 int baud = 115200; 553 int bits = 8; 554 int parity = 'n'; 555 int flow = 'n'; 556 557 if (co->index < 0 || co->index >= OWL_UART_PORT_NUM) 558 return -EINVAL; 559 560 owl_port = owl_uart_ports[co->index]; 561 if (!owl_port || !owl_port->port.membase) 562 return -ENODEV; 563 564 if (options) 565 uart_parse_options(options, &baud, &parity, &bits, &flow); 566 567 return uart_set_options(&owl_port->port, co, baud, parity, bits, flow); 568 } 569 570 static struct console owl_uart_console = { 571 .name = OWL_UART_DEV_NAME, 572 .write = owl_uart_console_write, 573 .device = uart_console_device, 574 .setup = owl_uart_console_setup, 575 .flags = CON_PRINTBUFFER, 576 .index = -1, 577 .data = &owl_uart_driver, 578 }; 579 580 static int __init owl_uart_console_init(void) 581 { 582 register_console(&owl_uart_console); 583 584 return 0; 585 } 586 console_initcall(owl_uart_console_init); 587 588 static void owl_uart_early_console_write(struct console *co, 589 const char *s, 590 u_int count) 591 { 592 struct earlycon_device *dev = co->data; 593 594 owl_uart_port_write(&dev->port, s, count); 595 } 596 597 static int __init 598 owl_uart_early_console_setup(struct earlycon_device *device, const char *opt) 599 { 600 if (!device->port.membase) 601 return -ENODEV; 602 603 device->con->write = owl_uart_early_console_write; 604 605 return 0; 606 } 607 OF_EARLYCON_DECLARE(owl, "actions,owl-uart", 608 owl_uart_early_console_setup); 609 610 #define OWL_UART_CONSOLE (&owl_uart_console) 611 #else 612 #define OWL_UART_CONSOLE NULL 613 #endif 614 615 static struct uart_driver owl_uart_driver = { 616 .owner = THIS_MODULE, 617 .driver_name = "owl-uart", 618 .dev_name = OWL_UART_DEV_NAME, 619 .nr = OWL_UART_PORT_NUM, 620 .cons = OWL_UART_CONSOLE, 621 }; 622 623 static const struct owl_uart_info owl_s500_info = { 624 .tx_fifosize = 16, 625 }; 626 627 static const struct owl_uart_info owl_s900_info = { 628 .tx_fifosize = 32, 629 }; 630 631 static const struct of_device_id owl_uart_dt_matches[] = { 632 { .compatible = "actions,s500-uart", .data = &owl_s500_info }, 633 { .compatible = "actions,s900-uart", .data = &owl_s900_info }, 634 { } 635 }; 636 MODULE_DEVICE_TABLE(of, owl_uart_dt_matches); 637 638 static int owl_uart_probe(struct platform_device *pdev) 639 { 640 const struct of_device_id *match; 641 const struct owl_uart_info *info = NULL; 642 struct resource *res_mem; 643 struct owl_uart_port *owl_port; 644 int ret, irq; 645 646 if (pdev->dev.of_node) { 647 pdev->id = of_alias_get_id(pdev->dev.of_node, "serial"); 648 match = of_match_node(owl_uart_dt_matches, pdev->dev.of_node); 649 if (match) 650 info = match->data; 651 } 652 653 if (pdev->id < 0 || pdev->id >= OWL_UART_PORT_NUM) { 654 dev_err(&pdev->dev, "id %d out of range\n", pdev->id); 655 return -EINVAL; 656 } 657 658 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 659 if (!res_mem) { 660 dev_err(&pdev->dev, "could not get mem\n"); 661 return -ENODEV; 662 } 663 664 irq = platform_get_irq(pdev, 0); 665 if (irq < 0) 666 return irq; 667 668 if (owl_uart_ports[pdev->id]) { 669 dev_err(&pdev->dev, "port %d already allocated\n", pdev->id); 670 return -EBUSY; 671 } 672 673 owl_port = devm_kzalloc(&pdev->dev, sizeof(*owl_port), GFP_KERNEL); 674 if (!owl_port) 675 return -ENOMEM; 676 677 owl_port->clk = devm_clk_get(&pdev->dev, NULL); 678 if (IS_ERR(owl_port->clk)) { 679 dev_err(&pdev->dev, "could not get clk\n"); 680 return PTR_ERR(owl_port->clk); 681 } 682 683 owl_port->port.dev = &pdev->dev; 684 owl_port->port.line = pdev->id; 685 owl_port->port.type = PORT_OWL; 686 owl_port->port.iotype = UPIO_MEM; 687 owl_port->port.mapbase = res_mem->start; 688 owl_port->port.irq = irq; 689 owl_port->port.uartclk = clk_get_rate(owl_port->clk); 690 if (owl_port->port.uartclk == 0) { 691 dev_err(&pdev->dev, "clock rate is zero\n"); 692 return -EINVAL; 693 } 694 owl_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP | UPF_LOW_LATENCY; 695 owl_port->port.x_char = 0; 696 owl_port->port.fifosize = (info) ? info->tx_fifosize : 16; 697 owl_port->port.ops = &owl_uart_ops; 698 699 owl_uart_ports[pdev->id] = owl_port; 700 platform_set_drvdata(pdev, owl_port); 701 702 ret = uart_add_one_port(&owl_uart_driver, &owl_port->port); 703 if (ret) 704 owl_uart_ports[pdev->id] = NULL; 705 706 return ret; 707 } 708 709 static int owl_uart_remove(struct platform_device *pdev) 710 { 711 struct owl_uart_port *owl_port = platform_get_drvdata(pdev); 712 713 uart_remove_one_port(&owl_uart_driver, &owl_port->port); 714 owl_uart_ports[pdev->id] = NULL; 715 716 return 0; 717 } 718 719 static struct platform_driver owl_uart_platform_driver = { 720 .probe = owl_uart_probe, 721 .remove = owl_uart_remove, 722 .driver = { 723 .name = "owl-uart", 724 .of_match_table = owl_uart_dt_matches, 725 }, 726 }; 727 728 static int __init owl_uart_init(void) 729 { 730 int ret; 731 732 ret = uart_register_driver(&owl_uart_driver); 733 if (ret) 734 return ret; 735 736 ret = platform_driver_register(&owl_uart_platform_driver); 737 if (ret) 738 uart_unregister_driver(&owl_uart_driver); 739 740 return ret; 741 } 742 743 static void __init owl_uart_exit(void) 744 { 745 platform_driver_unregister(&owl_uart_platform_driver); 746 uart_unregister_driver(&owl_uart_driver); 747 } 748 749 module_init(owl_uart_init); 750 module_exit(owl_uart_exit); 751 752 MODULE_LICENSE("GPL"); 753