1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Based on meson_uart.c, by AMLOGIC, INC. 4 * 5 * Copyright (C) 2014 Carlo Caione <carlo@caione.org> 6 */ 7 8 #include <linux/clk.h> 9 #include <linux/console.h> 10 #include <linux/delay.h> 11 #include <linux/init.h> 12 #include <linux/io.h> 13 #include <linux/iopoll.h> 14 #include <linux/module.h> 15 #include <linux/kernel.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 /* Register offsets */ 24 #define AML_UART_WFIFO 0x00 25 #define AML_UART_RFIFO 0x04 26 #define AML_UART_CONTROL 0x08 27 #define AML_UART_STATUS 0x0c 28 #define AML_UART_MISC 0x10 29 #define AML_UART_REG5 0x14 30 31 /* AML_UART_CONTROL bits */ 32 #define AML_UART_TX_EN BIT(12) 33 #define AML_UART_RX_EN BIT(13) 34 #define AML_UART_TWO_WIRE_EN BIT(15) 35 #define AML_UART_STOP_BIT_LEN_MASK (0x03 << 16) 36 #define AML_UART_STOP_BIT_1SB (0x00 << 16) 37 #define AML_UART_STOP_BIT_2SB (0x01 << 16) 38 #define AML_UART_PARITY_TYPE BIT(18) 39 #define AML_UART_PARITY_EN BIT(19) 40 #define AML_UART_TX_RST BIT(22) 41 #define AML_UART_RX_RST BIT(23) 42 #define AML_UART_CLEAR_ERR BIT(24) 43 #define AML_UART_RX_INT_EN BIT(27) 44 #define AML_UART_TX_INT_EN BIT(28) 45 #define AML_UART_DATA_LEN_MASK (0x03 << 20) 46 #define AML_UART_DATA_LEN_8BIT (0x00 << 20) 47 #define AML_UART_DATA_LEN_7BIT (0x01 << 20) 48 #define AML_UART_DATA_LEN_6BIT (0x02 << 20) 49 #define AML_UART_DATA_LEN_5BIT (0x03 << 20) 50 51 /* AML_UART_STATUS bits */ 52 #define AML_UART_PARITY_ERR BIT(16) 53 #define AML_UART_FRAME_ERR BIT(17) 54 #define AML_UART_TX_FIFO_WERR BIT(18) 55 #define AML_UART_RX_EMPTY BIT(20) 56 #define AML_UART_TX_FULL BIT(21) 57 #define AML_UART_TX_EMPTY BIT(22) 58 #define AML_UART_XMIT_BUSY BIT(25) 59 #define AML_UART_ERR (AML_UART_PARITY_ERR | \ 60 AML_UART_FRAME_ERR | \ 61 AML_UART_TX_FIFO_WERR) 62 63 /* AML_UART_MISC bits */ 64 #define AML_UART_XMIT_IRQ(c) (((c) & 0xff) << 8) 65 #define AML_UART_RECV_IRQ(c) ((c) & 0xff) 66 67 /* AML_UART_REG5 bits */ 68 #define AML_UART_BAUD_MASK 0x7fffff 69 #define AML_UART_BAUD_USE BIT(23) 70 #define AML_UART_BAUD_XTAL BIT(24) 71 #define AML_UART_BAUD_XTAL_DIV2 BIT(27) 72 73 #define AML_UART_PORT_NUM 12 74 #define AML_UART_PORT_OFFSET 6 75 76 #define AML_UART_POLL_USEC 5 77 #define AML_UART_TIMEOUT_USEC 10000 78 79 static struct uart_driver meson_uart_driver_ttyAML; 80 static struct uart_driver meson_uart_driver_ttyS; 81 82 static struct uart_port *meson_ports[AML_UART_PORT_NUM]; 83 84 struct meson_uart_data { 85 struct uart_driver *uart_driver; 86 bool has_xtal_div2; 87 }; 88 89 static void meson_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) 90 { 91 } 92 93 static unsigned int meson_uart_get_mctrl(struct uart_port *port) 94 { 95 return TIOCM_CTS; 96 } 97 98 static unsigned int meson_uart_tx_empty(struct uart_port *port) 99 { 100 u32 val; 101 102 val = readl(port->membase + AML_UART_STATUS); 103 val &= (AML_UART_TX_EMPTY | AML_UART_XMIT_BUSY); 104 return (val == AML_UART_TX_EMPTY) ? TIOCSER_TEMT : 0; 105 } 106 107 static void meson_uart_stop_tx(struct uart_port *port) 108 { 109 u32 val; 110 111 val = readl(port->membase + AML_UART_CONTROL); 112 val &= ~AML_UART_TX_INT_EN; 113 writel(val, port->membase + AML_UART_CONTROL); 114 } 115 116 static void meson_uart_stop_rx(struct uart_port *port) 117 { 118 u32 val; 119 120 val = readl(port->membase + AML_UART_CONTROL); 121 val &= ~AML_UART_RX_EN; 122 writel(val, port->membase + AML_UART_CONTROL); 123 } 124 125 static void meson_uart_shutdown(struct uart_port *port) 126 { 127 unsigned long flags; 128 u32 val; 129 130 free_irq(port->irq, port); 131 132 uart_port_lock_irqsave(port, &flags); 133 134 val = readl(port->membase + AML_UART_CONTROL); 135 val &= ~AML_UART_RX_EN; 136 val &= ~(AML_UART_RX_INT_EN | AML_UART_TX_INT_EN); 137 writel(val, port->membase + AML_UART_CONTROL); 138 139 uart_port_unlock_irqrestore(port, flags); 140 } 141 142 static void meson_uart_start_tx(struct uart_port *port) 143 { 144 struct tty_port *tport = &port->state->port; 145 unsigned char ch; 146 u32 val; 147 148 if (uart_tx_stopped(port)) { 149 meson_uart_stop_tx(port); 150 return; 151 } 152 153 while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_FULL)) { 154 if (port->x_char) { 155 writel(port->x_char, port->membase + AML_UART_WFIFO); 156 port->icount.tx++; 157 port->x_char = 0; 158 continue; 159 } 160 161 if (!uart_fifo_get(port, &ch)) 162 break; 163 164 writel(ch, port->membase + AML_UART_WFIFO); 165 } 166 167 if (!kfifo_is_empty(&tport->xmit_fifo)) { 168 val = readl(port->membase + AML_UART_CONTROL); 169 val |= AML_UART_TX_INT_EN; 170 writel(val, port->membase + AML_UART_CONTROL); 171 } 172 173 if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS) 174 uart_write_wakeup(port); 175 } 176 177 static void meson_receive_chars(struct uart_port *port) 178 { 179 struct tty_port *tport = &port->state->port; 180 char flag; 181 u32 ostatus, status, ch, mode; 182 183 do { 184 flag = TTY_NORMAL; 185 port->icount.rx++; 186 ostatus = status = readl(port->membase + AML_UART_STATUS); 187 188 if (status & AML_UART_ERR) { 189 if (status & AML_UART_TX_FIFO_WERR) 190 port->icount.overrun++; 191 else if (status & AML_UART_FRAME_ERR) 192 port->icount.frame++; 193 else if (status & AML_UART_PARITY_ERR) 194 port->icount.frame++; 195 196 mode = readl(port->membase + AML_UART_CONTROL); 197 mode |= AML_UART_CLEAR_ERR; 198 writel(mode, port->membase + AML_UART_CONTROL); 199 200 /* It doesn't clear to 0 automatically */ 201 mode &= ~AML_UART_CLEAR_ERR; 202 writel(mode, port->membase + AML_UART_CONTROL); 203 204 status &= port->read_status_mask; 205 if (status & AML_UART_FRAME_ERR) 206 flag = TTY_FRAME; 207 else if (status & AML_UART_PARITY_ERR) 208 flag = TTY_PARITY; 209 } 210 211 ch = readl(port->membase + AML_UART_RFIFO); 212 ch &= 0xff; 213 214 if ((ostatus & AML_UART_FRAME_ERR) && (ch == 0)) { 215 port->icount.brk++; 216 flag = TTY_BREAK; 217 if (uart_handle_break(port)) 218 continue; 219 } 220 221 if (uart_prepare_sysrq_char(port, ch)) 222 continue; 223 224 if ((status & port->ignore_status_mask) == 0) 225 tty_insert_flip_char(tport, ch, flag); 226 227 if (status & AML_UART_TX_FIFO_WERR) 228 tty_insert_flip_char(tport, 0, TTY_OVERRUN); 229 230 } while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY)); 231 232 tty_flip_buffer_push(tport); 233 } 234 235 static irqreturn_t meson_uart_interrupt(int irq, void *dev_id) 236 { 237 struct uart_port *port = (struct uart_port *)dev_id; 238 239 uart_port_lock(port); 240 241 if (!(readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY)) 242 meson_receive_chars(port); 243 244 if (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_FULL)) { 245 if (readl(port->membase + AML_UART_CONTROL) & AML_UART_TX_INT_EN) 246 meson_uart_start_tx(port); 247 } 248 249 uart_unlock_and_check_sysrq(port); 250 251 return IRQ_HANDLED; 252 } 253 254 static const char *meson_uart_type(struct uart_port *port) 255 { 256 return (port->type == PORT_MESON) ? "meson_uart" : NULL; 257 } 258 259 /* 260 * This function is called only from probe() using a temporary io mapping 261 * in order to perform a reset before setting up the device. Since the 262 * temporarily mapped region was successfully requested, there can be no 263 * console on this port at this time. Hence it is not necessary for this 264 * function to acquire the port->lock. (Since there is no console on this 265 * port at this time, the port->lock is not initialized yet.) 266 */ 267 static void meson_uart_reset(struct uart_port *port) 268 { 269 u32 val; 270 271 val = readl(port->membase + AML_UART_CONTROL); 272 val |= (AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLEAR_ERR); 273 writel(val, port->membase + AML_UART_CONTROL); 274 275 val &= ~(AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLEAR_ERR); 276 writel(val, port->membase + AML_UART_CONTROL); 277 } 278 279 static int meson_uart_startup(struct uart_port *port) 280 { 281 unsigned long flags; 282 u32 val; 283 int ret = 0; 284 285 uart_port_lock_irqsave(port, &flags); 286 287 val = readl(port->membase + AML_UART_CONTROL); 288 val |= AML_UART_CLEAR_ERR; 289 writel(val, port->membase + AML_UART_CONTROL); 290 val &= ~AML_UART_CLEAR_ERR; 291 writel(val, port->membase + AML_UART_CONTROL); 292 293 val |= (AML_UART_RX_EN | AML_UART_TX_EN); 294 writel(val, port->membase + AML_UART_CONTROL); 295 296 val |= (AML_UART_RX_INT_EN | AML_UART_TX_INT_EN); 297 writel(val, port->membase + AML_UART_CONTROL); 298 299 val = (AML_UART_RECV_IRQ(1) | AML_UART_XMIT_IRQ(port->fifosize / 2)); 300 writel(val, port->membase + AML_UART_MISC); 301 302 uart_port_unlock_irqrestore(port, flags); 303 304 ret = request_irq(port->irq, meson_uart_interrupt, 0, 305 port->name, port); 306 307 return ret; 308 } 309 310 static void meson_uart_change_speed(struct uart_port *port, unsigned long baud) 311 { 312 const struct meson_uart_data *private_data = port->private_data; 313 u32 val = 0; 314 315 while (!meson_uart_tx_empty(port)) 316 cpu_relax(); 317 318 if (port->uartclk == 24000000) { 319 unsigned int xtal_div = 3; 320 321 if (private_data && private_data->has_xtal_div2) { 322 xtal_div = 2; 323 val |= AML_UART_BAUD_XTAL_DIV2; 324 } 325 val |= DIV_ROUND_CLOSEST(port->uartclk / xtal_div, baud) - 1; 326 val |= AML_UART_BAUD_XTAL; 327 } else { 328 val = DIV_ROUND_CLOSEST(port->uartclk / 4, baud) - 1; 329 } 330 val |= AML_UART_BAUD_USE; 331 writel(val, port->membase + AML_UART_REG5); 332 } 333 334 static void meson_uart_set_termios(struct uart_port *port, 335 struct ktermios *termios, 336 const struct ktermios *old) 337 { 338 unsigned int cflags, iflags, baud; 339 unsigned long flags; 340 u32 val; 341 342 uart_port_lock_irqsave(port, &flags); 343 344 cflags = termios->c_cflag; 345 iflags = termios->c_iflag; 346 347 val = readl(port->membase + AML_UART_CONTROL); 348 349 val &= ~AML_UART_DATA_LEN_MASK; 350 switch (cflags & CSIZE) { 351 case CS8: 352 val |= AML_UART_DATA_LEN_8BIT; 353 break; 354 case CS7: 355 val |= AML_UART_DATA_LEN_7BIT; 356 break; 357 case CS6: 358 val |= AML_UART_DATA_LEN_6BIT; 359 break; 360 case CS5: 361 val |= AML_UART_DATA_LEN_5BIT; 362 break; 363 } 364 365 if (cflags & PARENB) 366 val |= AML_UART_PARITY_EN; 367 else 368 val &= ~AML_UART_PARITY_EN; 369 370 if (cflags & PARODD) 371 val |= AML_UART_PARITY_TYPE; 372 else 373 val &= ~AML_UART_PARITY_TYPE; 374 375 val &= ~AML_UART_STOP_BIT_LEN_MASK; 376 if (cflags & CSTOPB) 377 val |= AML_UART_STOP_BIT_2SB; 378 else 379 val |= AML_UART_STOP_BIT_1SB; 380 381 if (cflags & CRTSCTS) { 382 if (port->flags & UPF_HARD_FLOW) 383 val &= ~AML_UART_TWO_WIRE_EN; 384 else 385 termios->c_cflag &= ~CRTSCTS; 386 } else { 387 val |= AML_UART_TWO_WIRE_EN; 388 } 389 390 writel(val, port->membase + AML_UART_CONTROL); 391 392 baud = uart_get_baud_rate(port, termios, old, 50, 4000000); 393 meson_uart_change_speed(port, baud); 394 395 port->read_status_mask = AML_UART_TX_FIFO_WERR; 396 if (iflags & INPCK) 397 port->read_status_mask |= AML_UART_PARITY_ERR | 398 AML_UART_FRAME_ERR; 399 400 port->ignore_status_mask = 0; 401 if (iflags & IGNPAR) 402 port->ignore_status_mask |= AML_UART_PARITY_ERR | 403 AML_UART_FRAME_ERR; 404 405 uart_update_timeout(port, termios->c_cflag, baud); 406 uart_port_unlock_irqrestore(port, flags); 407 } 408 409 static int meson_uart_verify_port(struct uart_port *port, 410 struct serial_struct *ser) 411 { 412 int ret = 0; 413 414 if (port->type != PORT_MESON) 415 ret = -EINVAL; 416 if (port->irq != ser->irq) 417 ret = -EINVAL; 418 if (ser->baud_base < 9600) 419 ret = -EINVAL; 420 return ret; 421 } 422 423 static void meson_uart_release_port(struct uart_port *port) 424 { 425 devm_iounmap(port->dev, port->membase); 426 port->membase = NULL; 427 devm_release_mem_region(port->dev, port->mapbase, port->mapsize); 428 } 429 430 static int meson_uart_request_port(struct uart_port *port) 431 { 432 if (!devm_request_mem_region(port->dev, port->mapbase, port->mapsize, 433 dev_name(port->dev))) { 434 dev_err(port->dev, "Memory region busy\n"); 435 return -EBUSY; 436 } 437 438 port->membase = devm_ioremap(port->dev, port->mapbase, 439 port->mapsize); 440 if (!port->membase) 441 return -ENOMEM; 442 443 return 0; 444 } 445 446 static void meson_uart_config_port(struct uart_port *port, int flags) 447 { 448 if (flags & UART_CONFIG_TYPE) { 449 port->type = PORT_MESON; 450 meson_uart_request_port(port); 451 } 452 } 453 454 #ifdef CONFIG_CONSOLE_POLL 455 /* 456 * Console polling routines for writing and reading from the uart while 457 * in an interrupt or debug context (i.e. kgdb). 458 */ 459 460 static int meson_uart_poll_get_char(struct uart_port *port) 461 { 462 u32 c; 463 unsigned long flags; 464 465 uart_port_lock_irqsave(port, &flags); 466 467 if (readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY) 468 c = NO_POLL_CHAR; 469 else 470 c = readl(port->membase + AML_UART_RFIFO); 471 472 uart_port_unlock_irqrestore(port, flags); 473 474 return c; 475 } 476 477 static void meson_uart_poll_put_char(struct uart_port *port, unsigned char c) 478 { 479 unsigned long flags; 480 u32 reg; 481 int ret; 482 483 uart_port_lock_irqsave(port, &flags); 484 485 /* Wait until FIFO is empty or timeout */ 486 ret = readl_poll_timeout_atomic(port->membase + AML_UART_STATUS, reg, 487 reg & AML_UART_TX_EMPTY, 488 AML_UART_POLL_USEC, 489 AML_UART_TIMEOUT_USEC); 490 if (ret == -ETIMEDOUT) { 491 dev_err(port->dev, "Timeout waiting for UART TX EMPTY\n"); 492 goto out; 493 } 494 495 /* Write the character */ 496 writel(c, port->membase + AML_UART_WFIFO); 497 498 /* Wait until FIFO is empty or timeout */ 499 ret = readl_poll_timeout_atomic(port->membase + AML_UART_STATUS, reg, 500 reg & AML_UART_TX_EMPTY, 501 AML_UART_POLL_USEC, 502 AML_UART_TIMEOUT_USEC); 503 if (ret == -ETIMEDOUT) 504 dev_err(port->dev, "Timeout waiting for UART TX EMPTY\n"); 505 506 out: 507 uart_port_unlock_irqrestore(port, flags); 508 } 509 510 #endif /* CONFIG_CONSOLE_POLL */ 511 512 static const struct uart_ops meson_uart_ops = { 513 .set_mctrl = meson_uart_set_mctrl, 514 .get_mctrl = meson_uart_get_mctrl, 515 .tx_empty = meson_uart_tx_empty, 516 .start_tx = meson_uart_start_tx, 517 .stop_tx = meson_uart_stop_tx, 518 .stop_rx = meson_uart_stop_rx, 519 .startup = meson_uart_startup, 520 .shutdown = meson_uart_shutdown, 521 .set_termios = meson_uart_set_termios, 522 .type = meson_uart_type, 523 .config_port = meson_uart_config_port, 524 .request_port = meson_uart_request_port, 525 .release_port = meson_uart_release_port, 526 .verify_port = meson_uart_verify_port, 527 #ifdef CONFIG_CONSOLE_POLL 528 .poll_get_char = meson_uart_poll_get_char, 529 .poll_put_char = meson_uart_poll_put_char, 530 #endif 531 }; 532 533 #ifdef CONFIG_SERIAL_MESON_CONSOLE 534 static void meson_uart_enable_tx_engine(struct uart_port *port) 535 { 536 u32 val; 537 538 val = readl(port->membase + AML_UART_CONTROL); 539 val |= AML_UART_TX_EN; 540 writel(val, port->membase + AML_UART_CONTROL); 541 } 542 543 static void meson_console_putchar(struct uart_port *port, unsigned char ch) 544 { 545 if (!port->membase) 546 return; 547 548 while (readl(port->membase + AML_UART_STATUS) & AML_UART_TX_FULL) 549 cpu_relax(); 550 writel(ch, port->membase + AML_UART_WFIFO); 551 } 552 553 static void meson_serial_port_write(struct uart_port *port, const char *s, 554 u_int count) 555 { 556 unsigned long flags; 557 int locked = 1; 558 u32 val, tmp; 559 560 if (oops_in_progress) 561 locked = uart_port_trylock_irqsave(port, &flags); 562 else 563 uart_port_lock_irqsave(port, &flags); 564 565 val = readl(port->membase + AML_UART_CONTROL); 566 tmp = val & ~(AML_UART_TX_INT_EN | AML_UART_RX_INT_EN); 567 writel(tmp, port->membase + AML_UART_CONTROL); 568 569 uart_console_write(port, s, count, meson_console_putchar); 570 writel(val, port->membase + AML_UART_CONTROL); 571 572 if (locked) 573 uart_port_unlock_irqrestore(port, flags); 574 } 575 576 static void meson_serial_console_write(struct console *co, const char *s, 577 u_int count) 578 { 579 struct uart_port *port; 580 581 port = meson_ports[co->index]; 582 if (!port) 583 return; 584 585 meson_serial_port_write(port, s, count); 586 } 587 588 static int meson_serial_console_setup(struct console *co, char *options) 589 { 590 struct uart_port *port; 591 int baud = 115200; 592 int bits = 8; 593 int parity = 'n'; 594 int flow = 'n'; 595 596 if (co->index < 0 || co->index >= AML_UART_PORT_NUM) 597 return -EINVAL; 598 599 port = meson_ports[co->index]; 600 if (!port || !port->membase) 601 return -ENODEV; 602 603 meson_uart_enable_tx_engine(port); 604 605 if (options) 606 uart_parse_options(options, &baud, &parity, &bits, &flow); 607 608 return uart_set_options(port, co, baud, parity, bits, flow); 609 } 610 611 #define MESON_SERIAL_CONSOLE(_devname) \ 612 static struct console meson_serial_console_##_devname = { \ 613 .name = __stringify(_devname), \ 614 .write = meson_serial_console_write, \ 615 .device = uart_console_device, \ 616 .setup = meson_serial_console_setup, \ 617 .flags = CON_PRINTBUFFER, \ 618 .index = -1, \ 619 .data = &meson_uart_driver_##_devname, \ 620 } 621 622 MESON_SERIAL_CONSOLE(ttyAML); 623 MESON_SERIAL_CONSOLE(ttyS); 624 625 static void meson_serial_early_console_write(struct console *co, 626 const char *s, 627 u_int count) 628 { 629 struct earlycon_device *dev = co->data; 630 631 meson_serial_port_write(&dev->port, s, count); 632 } 633 634 static int __init 635 meson_serial_early_console_setup(struct earlycon_device *device, const char *opt) 636 { 637 if (!device->port.membase) 638 return -ENODEV; 639 640 meson_uart_enable_tx_engine(&device->port); 641 device->con->write = meson_serial_early_console_write; 642 return 0; 643 } 644 645 OF_EARLYCON_DECLARE(meson, "amlogic,meson-ao-uart", meson_serial_early_console_setup); 646 OF_EARLYCON_DECLARE(meson, "amlogic,meson-s4-uart", meson_serial_early_console_setup); 647 648 #define MESON_SERIAL_CONSOLE_PTR(_devname) (&meson_serial_console_##_devname) 649 #else 650 #define MESON_SERIAL_CONSOLE_PTR(_devname) (NULL) 651 #endif 652 653 #define MESON_UART_DRIVER(_devname) \ 654 static struct uart_driver meson_uart_driver_##_devname = { \ 655 .owner = THIS_MODULE, \ 656 .driver_name = "meson_uart", \ 657 .dev_name = __stringify(_devname), \ 658 .nr = AML_UART_PORT_NUM, \ 659 .cons = MESON_SERIAL_CONSOLE_PTR(_devname), \ 660 } 661 662 MESON_UART_DRIVER(ttyAML); 663 MESON_UART_DRIVER(ttyS); 664 665 static int meson_uart_probe_clocks(struct platform_device *pdev, 666 struct uart_port *port) 667 { 668 struct clk *clk_xtal = NULL; 669 struct clk *clk_pclk = NULL; 670 struct clk *clk_baud = NULL; 671 672 clk_pclk = devm_clk_get_enabled(&pdev->dev, "pclk"); 673 if (IS_ERR(clk_pclk)) 674 return PTR_ERR(clk_pclk); 675 676 clk_xtal = devm_clk_get_enabled(&pdev->dev, "xtal"); 677 if (IS_ERR(clk_xtal)) 678 return PTR_ERR(clk_xtal); 679 680 clk_baud = devm_clk_get_enabled(&pdev->dev, "baud"); 681 if (IS_ERR(clk_baud)) 682 return PTR_ERR(clk_baud); 683 684 port->uartclk = clk_get_rate(clk_baud); 685 686 return 0; 687 } 688 689 static struct uart_driver *meson_uart_current(const struct meson_uart_data *pd) 690 { 691 return (pd && pd->uart_driver) ? 692 pd->uart_driver : &meson_uart_driver_ttyAML; 693 } 694 695 static int meson_uart_probe(struct platform_device *pdev) 696 { 697 const struct meson_uart_data *priv_data; 698 struct uart_driver *uart_driver; 699 struct resource *res_mem; 700 struct uart_port *port; 701 u32 fifosize = 64; /* Default is 64, 128 for EE UART_0 */ 702 int ret = 0; 703 int irq; 704 bool has_rtscts; 705 706 if (pdev->dev.of_node) 707 pdev->id = of_alias_get_id(pdev->dev.of_node, "serial"); 708 709 if (pdev->id < 0) { 710 int id; 711 712 for (id = AML_UART_PORT_OFFSET; id < AML_UART_PORT_NUM; id++) { 713 if (!meson_ports[id]) { 714 pdev->id = id; 715 break; 716 } 717 } 718 } 719 720 if (pdev->id < 0 || pdev->id >= AML_UART_PORT_NUM) 721 return -EINVAL; 722 723 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 724 if (!res_mem) 725 return -ENODEV; 726 727 irq = platform_get_irq(pdev, 0); 728 if (irq < 0) 729 return irq; 730 731 of_property_read_u32(pdev->dev.of_node, "fifo-size", &fifosize); 732 has_rtscts = of_property_read_bool(pdev->dev.of_node, "uart-has-rtscts"); 733 734 if (meson_ports[pdev->id]) { 735 return dev_err_probe(&pdev->dev, -EBUSY, 736 "port %d already allocated\n", pdev->id); 737 } 738 739 port = devm_kzalloc(&pdev->dev, sizeof(struct uart_port), GFP_KERNEL); 740 if (!port) 741 return -ENOMEM; 742 743 ret = meson_uart_probe_clocks(pdev, port); 744 if (ret) 745 return ret; 746 747 priv_data = device_get_match_data(&pdev->dev); 748 749 uart_driver = meson_uart_current(priv_data); 750 751 if (!uart_driver->state) { 752 ret = uart_register_driver(uart_driver); 753 if (ret) 754 return dev_err_probe(&pdev->dev, ret, 755 "can't register uart driver\n"); 756 } 757 758 port->iotype = UPIO_MEM; 759 port->mapbase = res_mem->start; 760 port->mapsize = resource_size(res_mem); 761 port->irq = irq; 762 port->flags = UPF_BOOT_AUTOCONF | UPF_LOW_LATENCY; 763 if (has_rtscts) 764 port->flags |= UPF_HARD_FLOW; 765 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MESON_CONSOLE); 766 port->dev = &pdev->dev; 767 port->line = pdev->id; 768 port->type = PORT_MESON; 769 port->x_char = 0; 770 port->ops = &meson_uart_ops; 771 port->fifosize = fifosize; 772 port->private_data = (void *)priv_data; 773 774 meson_ports[pdev->id] = port; 775 platform_set_drvdata(pdev, port); 776 777 /* reset port before registering (and possibly registering console) */ 778 if (meson_uart_request_port(port) >= 0) { 779 meson_uart_reset(port); 780 meson_uart_release_port(port); 781 } 782 783 ret = uart_add_one_port(uart_driver, port); 784 if (ret) 785 meson_ports[pdev->id] = NULL; 786 787 return ret; 788 } 789 790 static void meson_uart_remove(struct platform_device *pdev) 791 { 792 struct uart_driver *uart_driver; 793 struct uart_port *port; 794 795 port = platform_get_drvdata(pdev); 796 uart_driver = meson_uart_current(port->private_data); 797 uart_remove_one_port(uart_driver, port); 798 meson_ports[pdev->id] = NULL; 799 800 for (int id = 0; id < AML_UART_PORT_NUM; id++) 801 if (meson_ports[id]) 802 return; 803 804 /* No more available uart ports, unregister uart driver */ 805 uart_unregister_driver(uart_driver); 806 } 807 808 static struct meson_uart_data meson_g12a_uart_data = { 809 .has_xtal_div2 = true, 810 }; 811 812 static struct meson_uart_data meson_a1_uart_data = { 813 .uart_driver = &meson_uart_driver_ttyS, 814 .has_xtal_div2 = false, 815 }; 816 817 static struct meson_uart_data meson_s4_uart_data = { 818 .uart_driver = &meson_uart_driver_ttyS, 819 .has_xtal_div2 = true, 820 }; 821 822 static const struct of_device_id meson_uart_dt_match[] = { 823 { .compatible = "amlogic,meson6-uart" }, 824 { .compatible = "amlogic,meson8-uart" }, 825 { .compatible = "amlogic,meson8b-uart" }, 826 { .compatible = "amlogic,meson-gx-uart" }, 827 { 828 .compatible = "amlogic,meson-g12a-uart", 829 .data = (void *)&meson_g12a_uart_data, 830 }, 831 { 832 .compatible = "amlogic,meson-s4-uart", 833 .data = (void *)&meson_s4_uart_data, 834 }, 835 { 836 .compatible = "amlogic,meson-a1-uart", 837 .data = (void *)&meson_a1_uart_data, 838 }, 839 { /* sentinel */ }, 840 }; 841 MODULE_DEVICE_TABLE(of, meson_uart_dt_match); 842 843 static struct platform_driver meson_uart_platform_driver = { 844 .probe = meson_uart_probe, 845 .remove = meson_uart_remove, 846 .driver = { 847 .name = "meson_uart", 848 .of_match_table = meson_uart_dt_match, 849 }, 850 }; 851 852 module_platform_driver(meson_uart_platform_driver); 853 854 MODULE_AUTHOR("Carlo Caione <carlo@caione.org>"); 855 MODULE_DESCRIPTION("Amlogic Meson serial port driver"); 856 MODULE_LICENSE("GPL v2"); 857