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ar933x_uart.c
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linux-6.19.14/drivers/tty/serial/ar933x_uart.c
1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Atheros AR933X SoC built-in UART driver 4 * 5 * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org> 6 * 7 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. 8 */ 9 10#include <linux/module.h> 11#include <linux/ioport.h> 12#include <linux/init.h> 13#include <linux/console.h> 14#include <linux/sysrq.h> 15#include <linux/delay.h> 16#include <linux/gpio/consumer.h> 17#include <linux/platform_device.h> 18#include <linux/of.h> 19#include <linux/of_platform.h> 20#include <linux/tty.h> 21#include <linux/tty_flip.h> 22#include <linux/serial_core.h> 23#include <linux/serial.h> 24#include <linux/slab.h> 25#include <linux/io.h> 26#include <linux/irq.h> 27#include <linux/clk.h> 28 29#include <asm/div64.h> 30 31#include <asm/mach-ath79/ar933x_uart.h> 32 33#include "serial_mctrl_gpio.h" 34 35#define DRIVER_NAME "ar933x-uart" 36 37#define AR933X_UART_MAX_SCALE 0xff 38#define AR933X_UART_MAX_STEP 0xffff 39 40#define AR933X_UART_MIN_BAUD 300 41#define AR933X_UART_MAX_BAUD 3000000 42 43#define AR933X_DUMMY_STATUS_RD 0x01 44 45static struct uart_driver ar933x_uart_driver; 46 47struct ar933x_uart_port { 48 struct uart_port port; 49 unsigned int ier; /* shadow Interrupt Enable Register */ 50 unsigned int min_baud; 51 unsigned int max_baud; 52 struct clk *clk; 53 struct mctrl_gpios *gpios; 54 struct gpio_desc *rts_gpiod; 55}; 56 57static inline unsigned int ar933x_uart_read(struct ar933x_uart_port *up, 58 int offset) 59{ 60 return readl(up->port.membase + offset); 61} 62 63static inline void ar933x_uart_write(struct ar933x_uart_port *up, 64 int offset, unsigned int value) 65{ 66 writel(value, up->port.membase + offset); 67} 68 69static inline void ar933x_uart_rmw(struct ar933x_uart_port *up, 70 unsigned int offset, 71 unsigned int mask, 72 unsigned int val) 73{ 74 unsigned int t; 75 76 t = ar933x_uart_read(up, offset); 77 t &= ~mask; 78 t |= val; 79 ar933x_uart_write(up, offset, t); 80} 81 82static inline void ar933x_uart_rmw_set(struct ar933x_uart_port *up, 83 unsigned int offset, 84 unsigned int val) 85{ 86 ar933x_uart_rmw(up, offset, 0, val); 87} 88 89static inline void ar933x_uart_rmw_clear(struct ar933x_uart_port *up, 90 unsigned int offset, 91 unsigned int val) 92{ 93 ar933x_uart_rmw(up, offset, val, 0); 94} 95 96static inline void ar933x_uart_start_tx_interrupt(struct ar933x_uart_port *up) 97{ 98 up->ier |= AR933X_UART_INT_TX_EMPTY; 99 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); 100} 101 102static inline void ar933x_uart_stop_tx_interrupt(struct ar933x_uart_port *up) 103{ 104 up->ier &= ~AR933X_UART_INT_TX_EMPTY; 105 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); 106} 107 108static inline void ar933x_uart_start_rx_interrupt(struct ar933x_uart_port *up) 109{ 110 up->ier |= AR933X_UART_INT_RX_VALID; 111 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); 112} 113 114static inline void ar933x_uart_stop_rx_interrupt(struct ar933x_uart_port *up) 115{ 116 up->ier &= ~AR933X_UART_INT_RX_VALID; 117 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); 118} 119 120static inline void ar933x_uart_putc(struct ar933x_uart_port *up, int ch) 121{ 122 unsigned int rdata; 123 124 rdata = ch & AR933X_UART_DATA_TX_RX_MASK; 125 rdata |= AR933X_UART_DATA_TX_CSR; 126 ar933x_uart_write(up, AR933X_UART_DATA_REG, rdata); 127} 128 129static unsigned int ar933x_uart_tx_empty(struct uart_port *port) 130{ 131 struct ar933x_uart_port *up = 132 container_of(port, struct ar933x_uart_port, port); 133 unsigned long flags; 134 unsigned int rdata; 135 136 uart_port_lock_irqsave(&up->port, &flags); 137 rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG); 138 uart_port_unlock_irqrestore(&up->port, flags); 139 140 return (rdata & AR933X_UART_DATA_TX_CSR) ? 0 : TIOCSER_TEMT; 141} 142 143static unsigned int ar933x_uart_get_mctrl(struct uart_port *port) 144{ 145 struct ar933x_uart_port *up = 146 container_of(port, struct ar933x_uart_port, port); 147 int ret = TIOCM_CTS | TIOCM_DSR | TIOCM_CAR; 148 149 mctrl_gpio_get(up->gpios, &ret); 150 151 return ret; 152} 153 154static void ar933x_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) 155{ 156 struct ar933x_uart_port *up = 157 container_of(port, struct ar933x_uart_port, port); 158 159 mctrl_gpio_set(up->gpios, mctrl); 160} 161 162static void ar933x_uart_start_tx(struct uart_port *port) 163{ 164 struct ar933x_uart_port *up = 165 container_of(port, struct ar933x_uart_port, port); 166 167 ar933x_uart_start_tx_interrupt(up); 168} 169 170static void ar933x_uart_wait_tx_complete(struct ar933x_uart_port *up) 171{ 172 unsigned int status; 173 unsigned int timeout = 60000; 174 175 /* Wait up to 60ms for the character(s) to be sent. */ 176 do { 177 status = ar933x_uart_read(up, AR933X_UART_CS_REG); 178 if (--timeout == 0) 179 break; 180 udelay(1); 181 } while (status & AR933X_UART_CS_TX_BUSY); 182 183 if (timeout == 0) 184 dev_err(up->port.dev, "waiting for TX timed out\n"); 185} 186 187static void ar933x_uart_rx_flush(struct ar933x_uart_port *up) 188{ 189 unsigned int status; 190 191 /* clear RX_VALID interrupt */ 192 ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_RX_VALID); 193 194 /* remove characters from the RX FIFO */ 195 do { 196 ar933x_uart_write(up, AR933X_UART_DATA_REG, AR933X_UART_DATA_RX_CSR); 197 status = ar933x_uart_read(up, AR933X_UART_DATA_REG); 198 } while (status & AR933X_UART_DATA_RX_CSR); 199} 200 201static void ar933x_uart_stop_tx(struct uart_port *port) 202{ 203 struct ar933x_uart_port *up = 204 container_of(port, struct ar933x_uart_port, port); 205 206 ar933x_uart_stop_tx_interrupt(up); 207} 208 209static void ar933x_uart_stop_rx(struct uart_port *port) 210{ 211 struct ar933x_uart_port *up = 212 container_of(port, struct ar933x_uart_port, port); 213 214 ar933x_uart_stop_rx_interrupt(up); 215} 216 217static void ar933x_uart_break_ctl(struct uart_port *port, int break_state) 218{ 219 struct ar933x_uart_port *up = 220 container_of(port, struct ar933x_uart_port, port); 221 unsigned long flags; 222 223 uart_port_lock_irqsave(&up->port, &flags); 224 if (break_state == -1) 225 ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, 226 AR933X_UART_CS_TX_BREAK); 227 else 228 ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG, 229 AR933X_UART_CS_TX_BREAK); 230 uart_port_unlock_irqrestore(&up->port, flags); 231} 232 233/* 234 * baudrate = (clk / (scale + 1)) * (step * (1 / 2^17)) 235 */ 236static unsigned long ar933x_uart_get_baud(unsigned int clk, 237 unsigned int scale, 238 unsigned int step) 239{ 240 u64 t; 241 u32 div; 242 243 div = (2 << 16) * (scale + 1); 244 t = clk; 245 t *= step; 246 t += (div / 2); 247 do_div(t, div); 248 249 return t; 250} 251 252static void ar933x_uart_get_scale_step(unsigned int clk, 253 unsigned int baud, 254 unsigned int *scale, 255 unsigned int *step) 256{ 257 unsigned int tscale; 258 long min_diff; 259 260 *scale = 0; 261 *step = 0; 262 263 min_diff = baud; 264 for (tscale = 0; tscale < AR933X_UART_MAX_SCALE; tscale++) { 265 u64 tstep; 266 int diff; 267 268 tstep = baud * (tscale + 1); 269 tstep *= (2 << 16); 270 do_div(tstep, clk); 271 272 if (tstep > AR933X_UART_MAX_STEP) 273 break; 274 275 diff = abs(ar933x_uart_get_baud(clk, tscale, tstep) - baud); 276 if (diff < min_diff) { 277 min_diff = diff; 278 *scale = tscale; 279 *step = tstep; 280 } 281 } 282} 283 284static void ar933x_uart_set_termios(struct uart_port *port, 285 struct ktermios *new, 286 const struct ktermios *old) 287{ 288 struct ar933x_uart_port *up = 289 container_of(port, struct ar933x_uart_port, port); 290 unsigned int cs; 291 unsigned long flags; 292 unsigned int baud, scale, step; 293 294 /* Only CS8 is supported */ 295 new->c_cflag &= ~CSIZE; 296 new->c_cflag |= CS8; 297 298 /* Only one stop bit is supported */ 299 new->c_cflag &= ~CSTOPB; 300 301 cs = 0; 302 if (new->c_cflag & PARENB) { 303 if (!(new->c_cflag & PARODD)) 304 cs |= AR933X_UART_CS_PARITY_EVEN; 305 else 306 cs |= AR933X_UART_CS_PARITY_ODD; 307 } else { 308 cs |= AR933X_UART_CS_PARITY_NONE; 309 } 310 311 /* Mark/space parity is not supported */ 312 new->c_cflag &= ~CMSPAR; 313 314 baud = uart_get_baud_rate(port, new, old, up->min_baud, up->max_baud); 315 ar933x_uart_get_scale_step(port->uartclk, baud, &scale, &step); 316 317 /* 318 * Ok, we're now changing the port state. Do it with 319 * interrupts disabled. 320 */ 321 uart_port_lock_irqsave(&up->port, &flags); 322 323 /* disable the UART */ 324 ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG, 325 AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S); 326 327 /* Update the per-port timeout. */ 328 uart_update_timeout(port, new->c_cflag, baud); 329 330 up->port.ignore_status_mask = 0; 331 332 /* ignore all characters if CREAD is not set */ 333 if ((new->c_cflag & CREAD) == 0) 334 up->port.ignore_status_mask |= AR933X_DUMMY_STATUS_RD; 335 336 ar933x_uart_write(up, AR933X_UART_CLOCK_REG, 337 scale << AR933X_UART_CLOCK_SCALE_S | step); 338 339 /* setup configuration register */ 340 ar933x_uart_rmw(up, AR933X_UART_CS_REG, AR933X_UART_CS_PARITY_M, cs); 341 342 /* enable host interrupt */ 343 ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, 344 AR933X_UART_CS_HOST_INT_EN); 345 346 /* enable RX and TX ready overide */ 347 ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, 348 AR933X_UART_CS_TX_READY_ORIDE | AR933X_UART_CS_RX_READY_ORIDE); 349 350 /* reenable the UART */ 351 ar933x_uart_rmw(up, AR933X_UART_CS_REG, 352 AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S, 353 AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S); 354 355 uart_port_unlock_irqrestore(&up->port, flags); 356 357 if (tty_termios_baud_rate(new)) 358 tty_termios_encode_baud_rate(new, baud, baud); 359} 360 361static void ar933x_uart_rx_chars(struct ar933x_uart_port *up) 362{ 363 struct tty_port *port = &up->port.state->port; 364 int max_count = 256; 365 366 do { 367 unsigned int rdata; 368 unsigned char ch; 369 370 rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG); 371 if ((rdata & AR933X_UART_DATA_RX_CSR) == 0) 372 break; 373 374 /* remove the character from the FIFO */ 375 ar933x_uart_write(up, AR933X_UART_DATA_REG, 376 AR933X_UART_DATA_RX_CSR); 377 378 up->port.icount.rx++; 379 ch = rdata & AR933X_UART_DATA_TX_RX_MASK; 380 381 if (uart_prepare_sysrq_char(&up->port, ch)) 382 continue; 383 384 if ((up->port.ignore_status_mask & AR933X_DUMMY_STATUS_RD) == 0) 385 tty_insert_flip_char(port, ch, TTY_NORMAL); 386 } while (max_count-- > 0); 387 388 tty_flip_buffer_push(port); 389} 390 391static void ar933x_uart_tx_chars(struct ar933x_uart_port *up) 392{ 393 struct tty_port *tport = &up->port.state->port; 394 struct serial_rs485 *rs485conf = &up->port.rs485; 395 int count; 396 bool half_duplex_send = false; 397 398 if (uart_tx_stopped(&up->port)) 399 return; 400 401 if ((rs485conf->flags & SER_RS485_ENABLED) && 402 (up->port.x_char || !kfifo_is_empty(&tport->xmit_fifo))) { 403 ar933x_uart_stop_rx_interrupt(up); 404 gpiod_set_value(up->rts_gpiod, !!(rs485conf->flags & SER_RS485_RTS_ON_SEND)); 405 half_duplex_send = true; 406 } 407 408 count = up->port.fifosize; 409 do { 410 unsigned int rdata; 411 unsigned char c; 412 413 rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG); 414 if ((rdata & AR933X_UART_DATA_TX_CSR) == 0) 415 break; 416 417 if (up->port.x_char) { 418 ar933x_uart_putc(up, up->port.x_char); 419 up->port.icount.tx++; 420 up->port.x_char = 0; 421 continue; 422 } 423 424 if (!uart_fifo_get(&up->port, &c)) 425 break; 426 427 ar933x_uart_putc(up, c); 428 } while (--count > 0); 429 430 if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS) 431 uart_write_wakeup(&up->port); 432 433 if (!kfifo_is_empty(&tport->xmit_fifo)) { 434 ar933x_uart_start_tx_interrupt(up); 435 } else if (half_duplex_send) { 436 ar933x_uart_wait_tx_complete(up); 437 ar933x_uart_rx_flush(up); 438 ar933x_uart_start_rx_interrupt(up); 439 gpiod_set_value(up->rts_gpiod, !!(rs485conf->flags & SER_RS485_RTS_AFTER_SEND)); 440 } 441} 442 443static irqreturn_t ar933x_uart_interrupt(int irq, void *dev_id) 444{ 445 struct ar933x_uart_port *up = dev_id; 446 unsigned int status; 447 448 status = ar933x_uart_read(up, AR933X_UART_CS_REG); 449 if ((status & AR933X_UART_CS_HOST_INT) == 0) 450 return IRQ_NONE; 451 452 uart_port_lock(&up->port); 453 454 status = ar933x_uart_read(up, AR933X_UART_INT_REG); 455 status &= ar933x_uart_read(up, AR933X_UART_INT_EN_REG); 456 457 if (status & AR933X_UART_INT_RX_VALID) { 458 ar933x_uart_write(up, AR933X_UART_INT_REG, 459 AR933X_UART_INT_RX_VALID); 460 ar933x_uart_rx_chars(up); 461 } 462 463 if (status & AR933X_UART_INT_TX_EMPTY) { 464 ar933x_uart_write(up, AR933X_UART_INT_REG, 465 AR933X_UART_INT_TX_EMPTY); 466 ar933x_uart_stop_tx_interrupt(up); 467 ar933x_uart_tx_chars(up); 468 } 469 470 uart_unlock_and_check_sysrq(&up->port); 471 472 return IRQ_HANDLED; 473} 474 475static int ar933x_uart_startup(struct uart_port *port) 476{ 477 struct ar933x_uart_port *up = 478 container_of(port, struct ar933x_uart_port, port); 479 unsigned long flags; 480 int ret; 481 482 ret = request_irq(up->port.irq, ar933x_uart_interrupt, 483 up->port.irqflags, dev_name(up->port.dev), up); 484 if (ret) 485 return ret; 486 487 uart_port_lock_irqsave(&up->port, &flags); 488 489 /* Enable HOST interrupts */ 490 ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, 491 AR933X_UART_CS_HOST_INT_EN); 492 493 /* enable RX and TX ready overide */ 494 ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, 495 AR933X_UART_CS_TX_READY_ORIDE | AR933X_UART_CS_RX_READY_ORIDE); 496 497 /* Enable RX interrupts */ 498 ar933x_uart_start_rx_interrupt(up); 499 500 uart_port_unlock_irqrestore(&up->port, flags); 501 502 return 0; 503} 504 505static void ar933x_uart_shutdown(struct uart_port *port) 506{ 507 struct ar933x_uart_port *up = 508 container_of(port, struct ar933x_uart_port, port); 509 510 /* Disable all interrupts */ 511 up->ier = 0; 512 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier); 513 514 /* Disable break condition */ 515 ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG, 516 AR933X_UART_CS_TX_BREAK); 517 518 free_irq(up->port.irq, up); 519} 520 521static const char *ar933x_uart_type(struct uart_port *port) 522{ 523 return (port->type == PORT_AR933X) ? "AR933X UART" : NULL; 524} 525 526static void ar933x_uart_release_port(struct uart_port *port) 527{ 528 /* Nothing to release ... */ 529} 530 531static int ar933x_uart_request_port(struct uart_port *port) 532{ 533 /* UARTs always present */ 534 return 0; 535} 536 537static void ar933x_uart_config_port(struct uart_port *port, int flags) 538{ 539 if (flags & UART_CONFIG_TYPE) 540 port->type = PORT_AR933X; 541} 542 543static int ar933x_uart_verify_port(struct uart_port *port, 544 struct serial_struct *ser) 545{ 546 struct ar933x_uart_port *up = 547 container_of(port, struct ar933x_uart_port, port); 548 549 if (ser->type != PORT_UNKNOWN && 550 ser->type != PORT_AR933X) 551 return -EINVAL; 552 553 if (ser->irq < 0 || ser->irq >= NR_IRQS) 554 return -EINVAL; 555 556 if (ser->baud_base < up->min_baud || 557 ser->baud_base > up->max_baud) 558 return -EINVAL; 559 560 return 0; 561} 562 563#ifdef CONFIG_CONSOLE_POLL 564static int ar933x_poll_get_char(struct uart_port *port) 565{ 566 struct ar933x_uart_port *up = 567 container_of(port, struct ar933x_uart_port, port); 568 unsigned int rdata; 569 unsigned char ch; 570 u32 imr; 571 572 /* Disable all interrupts */ 573 imr = ar933x_uart_read(up, AR933X_UART_INT_EN_REG); 574 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, 0); 575 576 rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG); 577 if ((rdata & AR933X_UART_DATA_RX_CSR) == 0) { 578 /* Enable interrupts */ 579 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, imr); 580 return NO_POLL_CHAR; 581 } 582 583 /* remove the character from the FIFO */ 584 ar933x_uart_write(up, AR933X_UART_DATA_REG, 585 AR933X_UART_DATA_RX_CSR); 586 587 ch = rdata & AR933X_UART_DATA_TX_RX_MASK; 588 589 /* Enable interrupts */ 590 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, imr); 591 592 return ch; 593} 594 595static void ar933x_poll_put_char(struct uart_port *port, unsigned char c) 596{ 597 struct ar933x_uart_port *up = 598 container_of(port, struct ar933x_uart_port, port); 599 u32 imr; 600 601 /* Disable all interrupts */ 602 imr = ar933x_uart_read(up, AR933X_UART_INT_EN_REG); 603 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, 0); 604 605 /* Wait until FIFO is empty */ 606 while (!(ar933x_uart_read(up, AR933X_UART_DATA_REG) & AR933X_UART_DATA_TX_CSR)) 607 cpu_relax(); 608 609 /* Write a character */ 610 ar933x_uart_putc(up, c); 611 612 /* Wait until FIFO is empty */ 613 while (!(ar933x_uart_read(up, AR933X_UART_DATA_REG) & AR933X_UART_DATA_TX_CSR)) 614 cpu_relax(); 615 616 /* Enable interrupts */ 617 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, imr); 618} 619#endif 620 621static const struct uart_ops ar933x_uart_ops = { 622 .tx_empty = ar933x_uart_tx_empty, 623 .set_mctrl = ar933x_uart_set_mctrl, 624 .get_mctrl = ar933x_uart_get_mctrl, 625 .stop_tx = ar933x_uart_stop_tx, 626 .start_tx = ar933x_uart_start_tx, 627 .stop_rx = ar933x_uart_stop_rx, 628 .break_ctl = ar933x_uart_break_ctl, 629 .startup = ar933x_uart_startup, 630 .shutdown = ar933x_uart_shutdown, 631 .set_termios = ar933x_uart_set_termios, 632 .type = ar933x_uart_type, 633 .release_port = ar933x_uart_release_port, 634 .request_port = ar933x_uart_request_port, 635 .config_port = ar933x_uart_config_port, 636 .verify_port = ar933x_uart_verify_port, 637#ifdef CONFIG_CONSOLE_POLL 638 .poll_get_char = ar933x_poll_get_char, 639 .poll_put_char = ar933x_poll_put_char, 640#endif 641}; 642 643static int ar933x_config_rs485(struct uart_port *port, struct ktermios *termios, 644 struct serial_rs485 *rs485conf) 645{ 646 struct ar933x_uart_port *up = 647 container_of(port, struct ar933x_uart_port, port); 648 649 if (port->rs485.flags & SER_RS485_ENABLED) 650 gpiod_set_value(up->rts_gpiod, 651 !!(rs485conf->flags & SER_RS485_RTS_AFTER_SEND)); 652 653 return 0; 654} 655 656#ifdef CONFIG_SERIAL_AR933X_CONSOLE 657static struct ar933x_uart_port * 658ar933x_console_ports[CONFIG_SERIAL_AR933X_NR_UARTS]; 659 660static void ar933x_uart_wait_xmitr(struct ar933x_uart_port *up) 661{ 662 unsigned int status; 663 unsigned int timeout = 60000; 664 665 /* Wait up to 60ms for the character(s) to be sent. */ 666 do { 667 status = ar933x_uart_read(up, AR933X_UART_DATA_REG); 668 if (--timeout == 0) 669 break; 670 udelay(1); 671 } while ((status & AR933X_UART_DATA_TX_CSR) == 0); 672} 673 674static void ar933x_uart_console_putchar(struct uart_port *port, unsigned char ch) 675{ 676 struct ar933x_uart_port *up = 677 container_of(port, struct ar933x_uart_port, port); 678 679 ar933x_uart_wait_xmitr(up); 680 ar933x_uart_putc(up, ch); 681} 682 683static void ar933x_uart_console_write(struct console *co, const char *s, 684 unsigned int count) 685{ 686 struct ar933x_uart_port *up = ar933x_console_ports[co->index]; 687 unsigned long flags; 688 unsigned int int_en; 689 int locked = 1; 690 691 if (oops_in_progress) 692 locked = uart_port_trylock_irqsave(&up->port, &flags); 693 else 694 uart_port_lock_irqsave(&up->port, &flags); 695 696 /* 697 * First save the IER then disable the interrupts 698 */ 699 int_en = ar933x_uart_read(up, AR933X_UART_INT_EN_REG); 700 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, 0); 701 702 uart_console_write(&up->port, s, count, ar933x_uart_console_putchar); 703 704 /* 705 * Finally, wait for transmitter to become empty 706 * and restore the IER 707 */ 708 ar933x_uart_wait_xmitr(up); 709 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, int_en); 710 711 ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_ALLINTS); 712 713 if (locked) 714 uart_port_unlock_irqrestore(&up->port, flags); 715} 716 717static int ar933x_uart_console_setup(struct console *co, char *options) 718{ 719 struct ar933x_uart_port *up; 720 int baud = 115200; 721 int bits = 8; 722 int parity = 'n'; 723 int flow = 'n'; 724 725 if (co->index < 0 || co->index >= CONFIG_SERIAL_AR933X_NR_UARTS) 726 return -EINVAL; 727 728 up = ar933x_console_ports[co->index]; 729 if (!up) 730 return -ENODEV; 731 732 if (options) 733 uart_parse_options(options, &baud, &parity, &bits, &flow); 734 735 return uart_set_options(&up->port, co, baud, parity, bits, flow); 736} 737 738static struct console ar933x_uart_console = { 739 .name = "ttyATH", 740 .write = ar933x_uart_console_write, 741 .device = uart_console_device, 742 .setup = ar933x_uart_console_setup, 743 .flags = CON_PRINTBUFFER, 744 .index = -1, 745 .data = &ar933x_uart_driver, 746}; 747#endif /* CONFIG_SERIAL_AR933X_CONSOLE */ 748 749static struct uart_driver ar933x_uart_driver = { 750 .owner = THIS_MODULE, 751 .driver_name = DRIVER_NAME, 752 .dev_name = "ttyATH", 753 .nr = CONFIG_SERIAL_AR933X_NR_UARTS, 754 .cons = NULL, /* filled in runtime */ 755}; 756 757static const struct serial_rs485 ar933x_rs485_supported = { 758 .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND, 759}; 760 761static int ar933x_uart_probe(struct platform_device *pdev) 762{ 763 struct ar933x_uart_port *up; 764 struct uart_port *port; 765 struct resource *mem_res; 766 struct device_node *np; 767 unsigned int baud; 768 int id; 769 int ret; 770 int irq; 771 772 np = pdev->dev.of_node; 773 if (IS_ENABLED(CONFIG_OF) && np) { 774 id = of_alias_get_id(np, "serial"); 775 if (id < 0) { 776 dev_err(&pdev->dev, "unable to get alias id, err=%d\n", 777 id); 778 return id; 779 } 780 } else { 781 id = pdev->id; 782 if (id == -1) 783 id = 0; 784 } 785 786 if (id >= CONFIG_SERIAL_AR933X_NR_UARTS) 787 return -EINVAL; 788 789 irq = platform_get_irq(pdev, 0); 790 if (irq < 0) 791 return irq; 792 793 up = devm_kzalloc(&pdev->dev, sizeof(struct ar933x_uart_port), 794 GFP_KERNEL); 795 if (!up) 796 return -ENOMEM; 797 798 up->clk = devm_clk_get(&pdev->dev, "uart"); 799 if (IS_ERR(up->clk)) { 800 dev_err(&pdev->dev, "unable to get UART clock\n"); 801 return PTR_ERR(up->clk); 802 } 803 804 port = &up->port; 805 806 port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &mem_res); 807 if (IS_ERR(port->membase)) 808 return PTR_ERR(port->membase); 809 810 ret = clk_prepare_enable(up->clk); 811 if (ret) 812 return ret; 813 814 port->uartclk = clk_get_rate(up->clk); 815 if (!port->uartclk) { 816 ret = -EINVAL; 817 goto err_disable_clk; 818 } 819 820 port->mapbase = mem_res->start; 821 port->line = id; 822 port->irq = irq; 823 port->dev = &pdev->dev; 824 port->type = PORT_AR933X; 825 port->iotype = UPIO_MEM32; 826 827 port->regshift = 2; 828 port->fifosize = AR933X_UART_FIFO_SIZE; 829 port->ops = &ar933x_uart_ops; 830 port->rs485_config = ar933x_config_rs485; 831 port->rs485_supported = ar933x_rs485_supported; 832 833 baud = ar933x_uart_get_baud(port->uartclk, AR933X_UART_MAX_SCALE, 1); 834 up->min_baud = max_t(unsigned int, baud, AR933X_UART_MIN_BAUD); 835 836 baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP); 837 up->max_baud = min_t(unsigned int, baud, AR933X_UART_MAX_BAUD); 838 839 ret = uart_get_rs485_mode(port); 840 if (ret) 841 goto err_disable_clk; 842 843 up->gpios = mctrl_gpio_init(port, 0); 844 if (IS_ERR(up->gpios) && PTR_ERR(up->gpios) != -ENOSYS) { 845 ret = PTR_ERR(up->gpios); 846 goto err_disable_clk; 847 } 848 849 up->rts_gpiod = mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_RTS); 850 851 if (!up->rts_gpiod) { 852 port->rs485_supported.flags &= ~SER_RS485_ENABLED; 853 if (port->rs485.flags & SER_RS485_ENABLED) { 854 dev_err(&pdev->dev, "lacking rts-gpio, disabling RS485\n"); 855 port->rs485.flags &= ~SER_RS485_ENABLED; 856 } 857 } 858 859#ifdef CONFIG_SERIAL_AR933X_CONSOLE 860 ar933x_console_ports[up->port.line] = up; 861#endif 862 863 ret = uart_add_one_port(&ar933x_uart_driver, &up->port); 864 if (ret) 865 goto err_disable_clk; 866 867 platform_set_drvdata(pdev, up); 868 return 0; 869 870err_disable_clk: 871 clk_disable_unprepare(up->clk); 872 return ret; 873} 874 875static void ar933x_uart_remove(struct platform_device *pdev) 876{ 877 struct ar933x_uart_port *up; 878 879 up = platform_get_drvdata(pdev); 880 881 if (up) { 882 uart_remove_one_port(&ar933x_uart_driver, &up->port); 883 clk_disable_unprepare(up->clk); 884 } 885} 886 887#ifdef CONFIG_OF 888static const struct of_device_id ar933x_uart_of_ids[] = { 889 { .compatible = "qca,ar9330-uart" }, 890 {}, 891}; 892MODULE_DEVICE_TABLE(of, ar933x_uart_of_ids); 893#endif 894 895static struct platform_driver ar933x_uart_platform_driver = { 896 .probe = ar933x_uart_probe, 897 .remove = ar933x_uart_remove, 898 .driver = { 899 .name = DRIVER_NAME, 900 .of_match_table = of_match_ptr(ar933x_uart_of_ids), 901 }, 902}; 903 904static int __init ar933x_uart_init(void) 905{ 906 int ret; 907 908#ifdef CONFIG_SERIAL_AR933X_CONSOLE 909 ar933x_uart_driver.cons = &ar933x_uart_console; 910#endif 911 912 ret = uart_register_driver(&ar933x_uart_driver); 913 if (ret) 914 goto err_out; 915 916 ret = platform_driver_register(&ar933x_uart_platform_driver); 917 if (ret) 918 goto err_unregister_uart_driver; 919 920 return 0; 921 922err_unregister_uart_driver: 923 uart_unregister_driver(&ar933x_uart_driver); 924err_out: 925 return ret; 926} 927 928static void __exit ar933x_uart_exit(void) 929{ 930 platform_driver_unregister(&ar933x_uart_platform_driver); 931 uart_unregister_driver(&ar933x_uart_driver); 932} 933 934module_init(ar933x_uart_init); 935module_exit(ar933x_uart_exit); 936 937MODULE_DESCRIPTION("Atheros AR933X UART driver"); 938MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>"); 939MODULE_LICENSE("GPL v2"); 940MODULE_ALIAS("platform:" DRIVER_NAME);
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