1 /* 2 * st-asc.c: ST Asynchronous serial controller (ASC) driver 3 * 4 * Copyright (C) 2003-2013 STMicroelectronics (R&D) Limited 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 as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 */ 12 13 #if defined(CONFIG_SERIAL_ST_ASC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) 14 #define SUPPORT_SYSRQ 15 #endif 16 17 #include <linux/module.h> 18 #include <linux/serial.h> 19 #include <linux/console.h> 20 #include <linux/sysrq.h> 21 #include <linux/platform_device.h> 22 #include <linux/io.h> 23 #include <linux/irq.h> 24 #include <linux/tty.h> 25 #include <linux/tty_flip.h> 26 #include <linux/delay.h> 27 #include <linux/spinlock.h> 28 #include <linux/pm_runtime.h> 29 #include <linux/of.h> 30 #include <linux/of_platform.h> 31 #include <linux/serial_core.h> 32 #include <linux/clk.h> 33 34 #define DRIVER_NAME "st-asc" 35 #define ASC_SERIAL_NAME "ttyAS" 36 #define ASC_FIFO_SIZE 16 37 #define ASC_MAX_PORTS 8 38 39 struct asc_port { 40 struct uart_port port; 41 struct clk *clk; 42 unsigned int hw_flow_control:1; 43 unsigned int force_m1:1; 44 }; 45 46 static struct asc_port asc_ports[ASC_MAX_PORTS]; 47 static struct uart_driver asc_uart_driver; 48 49 /*---- UART Register definitions ------------------------------*/ 50 51 /* Register offsets */ 52 53 #define ASC_BAUDRATE 0x00 54 #define ASC_TXBUF 0x04 55 #define ASC_RXBUF 0x08 56 #define ASC_CTL 0x0C 57 #define ASC_INTEN 0x10 58 #define ASC_STA 0x14 59 #define ASC_GUARDTIME 0x18 60 #define ASC_TIMEOUT 0x1C 61 #define ASC_TXRESET 0x20 62 #define ASC_RXRESET 0x24 63 #define ASC_RETRIES 0x28 64 65 /* ASC_RXBUF */ 66 #define ASC_RXBUF_PE 0x100 67 #define ASC_RXBUF_FE 0x200 68 /** 69 * Some of status comes from higher bits of the character and some come from 70 * the status register. Combining both of them in to single status using dummy 71 * bits. 72 */ 73 #define ASC_RXBUF_DUMMY_RX 0x10000 74 #define ASC_RXBUF_DUMMY_BE 0x20000 75 #define ASC_RXBUF_DUMMY_OE 0x40000 76 77 /* ASC_CTL */ 78 79 #define ASC_CTL_MODE_MSK 0x0007 80 #define ASC_CTL_MODE_8BIT 0x0001 81 #define ASC_CTL_MODE_7BIT_PAR 0x0003 82 #define ASC_CTL_MODE_9BIT 0x0004 83 #define ASC_CTL_MODE_8BIT_WKUP 0x0005 84 #define ASC_CTL_MODE_8BIT_PAR 0x0007 85 #define ASC_CTL_STOP_MSK 0x0018 86 #define ASC_CTL_STOP_HALFBIT 0x0000 87 #define ASC_CTL_STOP_1BIT 0x0008 88 #define ASC_CTL_STOP_1_HALFBIT 0x0010 89 #define ASC_CTL_STOP_2BIT 0x0018 90 #define ASC_CTL_PARITYODD 0x0020 91 #define ASC_CTL_LOOPBACK 0x0040 92 #define ASC_CTL_RUN 0x0080 93 #define ASC_CTL_RXENABLE 0x0100 94 #define ASC_CTL_SCENABLE 0x0200 95 #define ASC_CTL_FIFOENABLE 0x0400 96 #define ASC_CTL_CTSENABLE 0x0800 97 #define ASC_CTL_BAUDMODE 0x1000 98 99 /* ASC_GUARDTIME */ 100 101 #define ASC_GUARDTIME_MSK 0x00FF 102 103 /* ASC_INTEN */ 104 105 #define ASC_INTEN_RBE 0x0001 106 #define ASC_INTEN_TE 0x0002 107 #define ASC_INTEN_THE 0x0004 108 #define ASC_INTEN_PE 0x0008 109 #define ASC_INTEN_FE 0x0010 110 #define ASC_INTEN_OE 0x0020 111 #define ASC_INTEN_TNE 0x0040 112 #define ASC_INTEN_TOI 0x0080 113 #define ASC_INTEN_RHF 0x0100 114 115 /* ASC_RETRIES */ 116 117 #define ASC_RETRIES_MSK 0x00FF 118 119 /* ASC_RXBUF */ 120 121 #define ASC_RXBUF_MSK 0x03FF 122 123 /* ASC_STA */ 124 125 #define ASC_STA_RBF 0x0001 126 #define ASC_STA_TE 0x0002 127 #define ASC_STA_THE 0x0004 128 #define ASC_STA_PE 0x0008 129 #define ASC_STA_FE 0x0010 130 #define ASC_STA_OE 0x0020 131 #define ASC_STA_TNE 0x0040 132 #define ASC_STA_TOI 0x0080 133 #define ASC_STA_RHF 0x0100 134 #define ASC_STA_TF 0x0200 135 #define ASC_STA_NKD 0x0400 136 137 /* ASC_TIMEOUT */ 138 139 #define ASC_TIMEOUT_MSK 0x00FF 140 141 /* ASC_TXBUF */ 142 143 #define ASC_TXBUF_MSK 0x01FF 144 145 /*---- Inline function definitions ---------------------------*/ 146 147 static inline struct asc_port *to_asc_port(struct uart_port *port) 148 { 149 return container_of(port, struct asc_port, port); 150 } 151 152 static inline u32 asc_in(struct uart_port *port, u32 offset) 153 { 154 #ifdef readl_relaxed 155 return readl_relaxed(port->membase + offset); 156 #else 157 return readl(port->membase + offset); 158 #endif 159 } 160 161 static inline void asc_out(struct uart_port *port, u32 offset, u32 value) 162 { 163 #ifdef writel_relaxed 164 writel_relaxed(value, port->membase + offset); 165 #else 166 writel(value, port->membase + offset); 167 #endif 168 } 169 170 /* 171 * Some simple utility functions to enable and disable interrupts. 172 * Note that these need to be called with interrupts disabled. 173 */ 174 static inline void asc_disable_tx_interrupts(struct uart_port *port) 175 { 176 u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_THE; 177 asc_out(port, ASC_INTEN, intenable); 178 (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */ 179 } 180 181 static inline void asc_enable_tx_interrupts(struct uart_port *port) 182 { 183 u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_THE; 184 asc_out(port, ASC_INTEN, intenable); 185 } 186 187 static inline void asc_disable_rx_interrupts(struct uart_port *port) 188 { 189 u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_RBE; 190 asc_out(port, ASC_INTEN, intenable); 191 (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */ 192 } 193 194 static inline void asc_enable_rx_interrupts(struct uart_port *port) 195 { 196 u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_RBE; 197 asc_out(port, ASC_INTEN, intenable); 198 } 199 200 static inline u32 asc_txfifo_is_empty(struct uart_port *port) 201 { 202 return asc_in(port, ASC_STA) & ASC_STA_TE; 203 } 204 205 static inline u32 asc_txfifo_is_half_empty(struct uart_port *port) 206 { 207 return asc_in(port, ASC_STA) & ASC_STA_THE; 208 } 209 210 static inline const char *asc_port_name(struct uart_port *port) 211 { 212 return to_platform_device(port->dev)->name; 213 } 214 215 /*----------------------------------------------------------------------*/ 216 217 /* 218 * This section contains code to support the use of the ASC as a 219 * generic serial port. 220 */ 221 222 static inline unsigned asc_hw_txroom(struct uart_port *port) 223 { 224 u32 status = asc_in(port, ASC_STA); 225 226 if (status & ASC_STA_THE) 227 return port->fifosize / 2; 228 else if (!(status & ASC_STA_TF)) 229 return 1; 230 231 return 0; 232 } 233 234 /* 235 * Start transmitting chars. 236 * This is called from both interrupt and task level. 237 * Either way interrupts are disabled. 238 */ 239 static void asc_transmit_chars(struct uart_port *port) 240 { 241 struct circ_buf *xmit = &port->state->xmit; 242 int txroom; 243 unsigned char c; 244 245 txroom = asc_hw_txroom(port); 246 247 if ((txroom != 0) && port->x_char) { 248 c = port->x_char; 249 port->x_char = 0; 250 asc_out(port, ASC_TXBUF, c); 251 port->icount.tx++; 252 txroom = asc_hw_txroom(port); 253 } 254 255 if (uart_tx_stopped(port)) { 256 /* 257 * We should try and stop the hardware here, but I 258 * don't think the ASC has any way to do that. 259 */ 260 asc_disable_tx_interrupts(port); 261 return; 262 } 263 264 if (uart_circ_empty(xmit)) { 265 asc_disable_tx_interrupts(port); 266 return; 267 } 268 269 if (txroom == 0) 270 return; 271 272 do { 273 c = xmit->buf[xmit->tail]; 274 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); 275 asc_out(port, ASC_TXBUF, c); 276 port->icount.tx++; 277 txroom--; 278 } while ((txroom > 0) && (!uart_circ_empty(xmit))); 279 280 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) 281 uart_write_wakeup(port); 282 283 if (uart_circ_empty(xmit)) 284 asc_disable_tx_interrupts(port); 285 } 286 287 static void asc_receive_chars(struct uart_port *port) 288 { 289 struct tty_port *tport = &port->state->port; 290 unsigned long status; 291 unsigned long c = 0; 292 char flag; 293 294 if (port->irq_wake) 295 pm_wakeup_event(tport->tty->dev, 0); 296 297 while ((status = asc_in(port, ASC_STA)) & ASC_STA_RBF) { 298 c = asc_in(port, ASC_RXBUF) | ASC_RXBUF_DUMMY_RX; 299 flag = TTY_NORMAL; 300 port->icount.rx++; 301 302 if ((c & (ASC_RXBUF_FE | ASC_RXBUF_PE)) || 303 status & ASC_STA_OE) { 304 305 if (c & ASC_RXBUF_FE) { 306 if (c == (ASC_RXBUF_FE | ASC_RXBUF_DUMMY_RX)) { 307 port->icount.brk++; 308 if (uart_handle_break(port)) 309 continue; 310 c |= ASC_RXBUF_DUMMY_BE; 311 } else { 312 port->icount.frame++; 313 } 314 } else if (c & ASC_RXBUF_PE) { 315 port->icount.parity++; 316 } 317 /* 318 * Reading any data from the RX FIFO clears the 319 * overflow error condition. 320 */ 321 if (status & ASC_STA_OE) { 322 port->icount.overrun++; 323 c |= ASC_RXBUF_DUMMY_OE; 324 } 325 326 c &= port->read_status_mask; 327 328 if (c & ASC_RXBUF_DUMMY_BE) 329 flag = TTY_BREAK; 330 else if (c & ASC_RXBUF_PE) 331 flag = TTY_PARITY; 332 else if (c & ASC_RXBUF_FE) 333 flag = TTY_FRAME; 334 } 335 336 if (uart_handle_sysrq_char(port, c & 0xff)) 337 continue; 338 339 uart_insert_char(port, c, ASC_RXBUF_DUMMY_OE, c & 0xff, flag); 340 } 341 342 /* Tell the rest of the system the news. New characters! */ 343 tty_flip_buffer_push(tport); 344 } 345 346 static irqreturn_t asc_interrupt(int irq, void *ptr) 347 { 348 struct uart_port *port = ptr; 349 u32 status; 350 351 spin_lock(&port->lock); 352 353 status = asc_in(port, ASC_STA); 354 355 if (status & ASC_STA_RBF) { 356 /* Receive FIFO not empty */ 357 asc_receive_chars(port); 358 } 359 360 if ((status & ASC_STA_THE) && 361 (asc_in(port, ASC_INTEN) & ASC_INTEN_THE)) { 362 /* Transmitter FIFO at least half empty */ 363 asc_transmit_chars(port); 364 } 365 366 spin_unlock(&port->lock); 367 368 return IRQ_HANDLED; 369 } 370 371 /*----------------------------------------------------------------------*/ 372 373 /* 374 * UART Functions 375 */ 376 377 static unsigned int asc_tx_empty(struct uart_port *port) 378 { 379 return asc_txfifo_is_empty(port) ? TIOCSER_TEMT : 0; 380 } 381 382 static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl) 383 { 384 /* 385 * This routine is used for seting signals of: DTR, DCD, CTS/RTS 386 * We use ASC's hardware for CTS/RTS, so don't need any for that. 387 * Some boards have DTR and DCD implemented using PIO pins, 388 * code to do this should be hooked in here. 389 */ 390 } 391 392 static unsigned int asc_get_mctrl(struct uart_port *port) 393 { 394 /* 395 * This routine is used for geting signals of: DTR, DCD, DSR, RI, 396 * and CTS/RTS 397 */ 398 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; 399 } 400 401 /* There are probably characters waiting to be transmitted. */ 402 static void asc_start_tx(struct uart_port *port) 403 { 404 struct circ_buf *xmit = &port->state->xmit; 405 406 if (!uart_circ_empty(xmit)) 407 asc_enable_tx_interrupts(port); 408 } 409 410 /* Transmit stop */ 411 static void asc_stop_tx(struct uart_port *port) 412 { 413 asc_disable_tx_interrupts(port); 414 } 415 416 /* Receive stop */ 417 static void asc_stop_rx(struct uart_port *port) 418 { 419 asc_disable_rx_interrupts(port); 420 } 421 422 /* Handle breaks - ignored by us */ 423 static void asc_break_ctl(struct uart_port *port, int break_state) 424 { 425 /* Nothing here yet .. */ 426 } 427 428 /* 429 * Enable port for reception. 430 */ 431 static int asc_startup(struct uart_port *port) 432 { 433 if (request_irq(port->irq, asc_interrupt, IRQF_NO_SUSPEND, 434 asc_port_name(port), port)) { 435 dev_err(port->dev, "cannot allocate irq.\n"); 436 return -ENODEV; 437 } 438 439 asc_transmit_chars(port); 440 asc_enable_rx_interrupts(port); 441 442 return 0; 443 } 444 445 static void asc_shutdown(struct uart_port *port) 446 { 447 asc_disable_tx_interrupts(port); 448 asc_disable_rx_interrupts(port); 449 free_irq(port->irq, port); 450 } 451 452 static void asc_pm(struct uart_port *port, unsigned int state, 453 unsigned int oldstate) 454 { 455 struct asc_port *ascport = to_asc_port(port); 456 unsigned long flags = 0; 457 u32 ctl; 458 459 switch (state) { 460 case UART_PM_STATE_ON: 461 clk_prepare_enable(ascport->clk); 462 break; 463 case UART_PM_STATE_OFF: 464 /* 465 * Disable the ASC baud rate generator, which is as close as 466 * we can come to turning it off. Note this is not called with 467 * the port spinlock held. 468 */ 469 spin_lock_irqsave(&port->lock, flags); 470 ctl = asc_in(port, ASC_CTL) & ~ASC_CTL_RUN; 471 asc_out(port, ASC_CTL, ctl); 472 spin_unlock_irqrestore(&port->lock, flags); 473 clk_disable_unprepare(ascport->clk); 474 break; 475 } 476 } 477 478 static void asc_set_termios(struct uart_port *port, struct ktermios *termios, 479 struct ktermios *old) 480 { 481 struct asc_port *ascport = to_asc_port(port); 482 unsigned int baud; 483 u32 ctrl_val; 484 tcflag_t cflag; 485 unsigned long flags; 486 487 /* Update termios to reflect hardware capabilities */ 488 termios->c_cflag &= ~(CMSPAR | 489 (ascport->hw_flow_control ? 0 : CRTSCTS)); 490 491 port->uartclk = clk_get_rate(ascport->clk); 492 493 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); 494 cflag = termios->c_cflag; 495 496 spin_lock_irqsave(&port->lock, flags); 497 498 /* read control register */ 499 ctrl_val = asc_in(port, ASC_CTL); 500 501 /* stop serial port and reset value */ 502 asc_out(port, ASC_CTL, (ctrl_val & ~ASC_CTL_RUN)); 503 ctrl_val = ASC_CTL_RXENABLE | ASC_CTL_FIFOENABLE; 504 505 /* reset fifo rx & tx */ 506 asc_out(port, ASC_TXRESET, 1); 507 asc_out(port, ASC_RXRESET, 1); 508 509 /* set character length */ 510 if ((cflag & CSIZE) == CS7) { 511 ctrl_val |= ASC_CTL_MODE_7BIT_PAR; 512 } else { 513 ctrl_val |= (cflag & PARENB) ? ASC_CTL_MODE_8BIT_PAR : 514 ASC_CTL_MODE_8BIT; 515 } 516 517 /* set stop bit */ 518 ctrl_val |= (cflag & CSTOPB) ? ASC_CTL_STOP_2BIT : ASC_CTL_STOP_1BIT; 519 520 /* odd parity */ 521 if (cflag & PARODD) 522 ctrl_val |= ASC_CTL_PARITYODD; 523 524 /* hardware flow control */ 525 if ((cflag & CRTSCTS)) 526 ctrl_val |= ASC_CTL_CTSENABLE; 527 528 if ((baud < 19200) && !ascport->force_m1) { 529 asc_out(port, ASC_BAUDRATE, (port->uartclk / (16 * baud))); 530 } else { 531 /* 532 * MODE 1: recommended for high bit rates (above 19.2K) 533 * 534 * baudrate * 16 * 2^16 535 * ASCBaudRate = ------------------------ 536 * inputclock 537 * 538 * To keep maths inside 64bits, we divide inputclock by 16. 539 */ 540 u64 dividend = (u64)baud * (1 << 16); 541 542 do_div(dividend, port->uartclk / 16); 543 asc_out(port, ASC_BAUDRATE, dividend); 544 ctrl_val |= ASC_CTL_BAUDMODE; 545 } 546 547 uart_update_timeout(port, cflag, baud); 548 549 ascport->port.read_status_mask = ASC_RXBUF_DUMMY_OE; 550 if (termios->c_iflag & INPCK) 551 ascport->port.read_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE; 552 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) 553 ascport->port.read_status_mask |= ASC_RXBUF_DUMMY_BE; 554 555 /* 556 * Characters to ignore 557 */ 558 ascport->port.ignore_status_mask = 0; 559 if (termios->c_iflag & IGNPAR) 560 ascport->port.ignore_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE; 561 if (termios->c_iflag & IGNBRK) { 562 ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_BE; 563 /* 564 * If we're ignoring parity and break indicators, 565 * ignore overruns too (for real raw support). 566 */ 567 if (termios->c_iflag & IGNPAR) 568 ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_OE; 569 } 570 571 /* 572 * Ignore all characters if CREAD is not set. 573 */ 574 if (!(termios->c_cflag & CREAD)) 575 ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_RX; 576 577 /* Set the timeout */ 578 asc_out(port, ASC_TIMEOUT, 20); 579 580 /* write final value and enable port */ 581 asc_out(port, ASC_CTL, (ctrl_val | ASC_CTL_RUN)); 582 583 spin_unlock_irqrestore(&port->lock, flags); 584 } 585 586 static const char *asc_type(struct uart_port *port) 587 { 588 return (port->type == PORT_ASC) ? DRIVER_NAME : NULL; 589 } 590 591 static void asc_release_port(struct uart_port *port) 592 { 593 } 594 595 static int asc_request_port(struct uart_port *port) 596 { 597 return 0; 598 } 599 600 /* 601 * Called when the port is opened, and UPF_BOOT_AUTOCONF flag is set 602 * Set type field if successful 603 */ 604 static void asc_config_port(struct uart_port *port, int flags) 605 { 606 if ((flags & UART_CONFIG_TYPE)) 607 port->type = PORT_ASC; 608 } 609 610 static int 611 asc_verify_port(struct uart_port *port, struct serial_struct *ser) 612 { 613 /* No user changeable parameters */ 614 return -EINVAL; 615 } 616 617 #ifdef CONFIG_CONSOLE_POLL 618 /* 619 * Console polling routines for writing and reading from the uart while 620 * in an interrupt or debug context (i.e. kgdb). 621 */ 622 623 static int asc_get_poll_char(struct uart_port *port) 624 { 625 if (!(asc_in(port, ASC_STA) & ASC_STA_RBF)) 626 return NO_POLL_CHAR; 627 628 return asc_in(port, ASC_RXBUF); 629 } 630 631 static void asc_put_poll_char(struct uart_port *port, unsigned char c) 632 { 633 while (!asc_txfifo_is_half_empty(port)) 634 cpu_relax(); 635 asc_out(port, ASC_TXBUF, c); 636 } 637 638 #endif /* CONFIG_CONSOLE_POLL */ 639 640 /*---------------------------------------------------------------------*/ 641 642 static struct uart_ops asc_uart_ops = { 643 .tx_empty = asc_tx_empty, 644 .set_mctrl = asc_set_mctrl, 645 .get_mctrl = asc_get_mctrl, 646 .start_tx = asc_start_tx, 647 .stop_tx = asc_stop_tx, 648 .stop_rx = asc_stop_rx, 649 .break_ctl = asc_break_ctl, 650 .startup = asc_startup, 651 .shutdown = asc_shutdown, 652 .set_termios = asc_set_termios, 653 .type = asc_type, 654 .release_port = asc_release_port, 655 .request_port = asc_request_port, 656 .config_port = asc_config_port, 657 .verify_port = asc_verify_port, 658 .pm = asc_pm, 659 #ifdef CONFIG_CONSOLE_POLL 660 .poll_get_char = asc_get_poll_char, 661 .poll_put_char = asc_put_poll_char, 662 #endif /* CONFIG_CONSOLE_POLL */ 663 }; 664 665 static int asc_init_port(struct asc_port *ascport, 666 struct platform_device *pdev) 667 { 668 struct uart_port *port = &ascport->port; 669 struct resource *res; 670 671 port->iotype = UPIO_MEM; 672 port->flags = UPF_BOOT_AUTOCONF; 673 port->ops = &asc_uart_ops; 674 port->fifosize = ASC_FIFO_SIZE; 675 port->dev = &pdev->dev; 676 port->irq = platform_get_irq(pdev, 0); 677 678 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 679 port->membase = devm_ioremap_resource(&pdev->dev, res); 680 if (IS_ERR(port->membase)) 681 return PTR_ERR(port->membase); 682 port->mapbase = res->start; 683 684 spin_lock_init(&port->lock); 685 686 ascport->clk = devm_clk_get(&pdev->dev, NULL); 687 688 if (WARN_ON(IS_ERR(ascport->clk))) 689 return -EINVAL; 690 /* ensure that clk rate is correct by enabling the clk */ 691 clk_prepare_enable(ascport->clk); 692 ascport->port.uartclk = clk_get_rate(ascport->clk); 693 WARN_ON(ascport->port.uartclk == 0); 694 clk_disable_unprepare(ascport->clk); 695 696 return 0; 697 } 698 699 static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev) 700 { 701 struct device_node *np = pdev->dev.of_node; 702 int id; 703 704 if (!np) 705 return NULL; 706 707 id = of_alias_get_id(np, ASC_SERIAL_NAME); 708 709 if (id < 0) 710 id = 0; 711 712 if (WARN_ON(id >= ASC_MAX_PORTS)) 713 return NULL; 714 715 asc_ports[id].hw_flow_control = of_property_read_bool(np, 716 "st,hw-flow-control"); 717 asc_ports[id].force_m1 = of_property_read_bool(np, "st,force_m1"); 718 asc_ports[id].port.line = id; 719 return &asc_ports[id]; 720 } 721 722 #ifdef CONFIG_OF 723 static struct of_device_id asc_match[] = { 724 { .compatible = "st,asc", }, 725 {}, 726 }; 727 728 MODULE_DEVICE_TABLE(of, asc_match); 729 #endif 730 731 static int asc_serial_probe(struct platform_device *pdev) 732 { 733 int ret; 734 struct asc_port *ascport; 735 736 ascport = asc_of_get_asc_port(pdev); 737 if (!ascport) 738 return -ENODEV; 739 740 ret = asc_init_port(ascport, pdev); 741 if (ret) 742 return ret; 743 744 ret = uart_add_one_port(&asc_uart_driver, &ascport->port); 745 if (ret) 746 return ret; 747 748 platform_set_drvdata(pdev, &ascport->port); 749 750 return 0; 751 } 752 753 static int asc_serial_remove(struct platform_device *pdev) 754 { 755 struct uart_port *port = platform_get_drvdata(pdev); 756 757 return uart_remove_one_port(&asc_uart_driver, port); 758 } 759 760 #ifdef CONFIG_PM_SLEEP 761 static int asc_serial_suspend(struct device *dev) 762 { 763 struct platform_device *pdev = to_platform_device(dev); 764 struct uart_port *port = platform_get_drvdata(pdev); 765 766 return uart_suspend_port(&asc_uart_driver, port); 767 } 768 769 static int asc_serial_resume(struct device *dev) 770 { 771 struct platform_device *pdev = to_platform_device(dev); 772 struct uart_port *port = platform_get_drvdata(pdev); 773 774 return uart_resume_port(&asc_uart_driver, port); 775 } 776 777 #endif /* CONFIG_PM_SLEEP */ 778 779 /*----------------------------------------------------------------------*/ 780 781 #ifdef CONFIG_SERIAL_ST_ASC_CONSOLE 782 static void asc_console_putchar(struct uart_port *port, int ch) 783 { 784 unsigned int timeout = 1000000; 785 786 /* Wait for upto 1 second in case flow control is stopping us. */ 787 while (--timeout && !asc_txfifo_is_half_empty(port)) 788 udelay(1); 789 790 asc_out(port, ASC_TXBUF, ch); 791 } 792 793 /* 794 * Print a string to the serial port trying not to disturb 795 * any possible real use of the port... 796 */ 797 798 static void asc_console_write(struct console *co, const char *s, unsigned count) 799 { 800 struct uart_port *port = &asc_ports[co->index].port; 801 unsigned long flags; 802 unsigned long timeout = 1000000; 803 int locked = 1; 804 u32 intenable; 805 806 local_irq_save(flags); 807 if (port->sysrq) 808 locked = 0; /* asc_interrupt has already claimed the lock */ 809 else if (oops_in_progress) 810 locked = spin_trylock(&port->lock); 811 else 812 spin_lock(&port->lock); 813 814 /* 815 * Disable interrupts so we don't get the IRQ line bouncing 816 * up and down while interrupts are disabled. 817 */ 818 intenable = asc_in(port, ASC_INTEN); 819 asc_out(port, ASC_INTEN, 0); 820 (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */ 821 822 uart_console_write(port, s, count, asc_console_putchar); 823 824 while (--timeout && !asc_txfifo_is_empty(port)) 825 udelay(1); 826 827 asc_out(port, ASC_INTEN, intenable); 828 829 if (locked) 830 spin_unlock(&port->lock); 831 local_irq_restore(flags); 832 } 833 834 static int asc_console_setup(struct console *co, char *options) 835 { 836 struct asc_port *ascport; 837 int baud = 9600; 838 int bits = 8; 839 int parity = 'n'; 840 int flow = 'n'; 841 842 if (co->index >= ASC_MAX_PORTS) 843 return -ENODEV; 844 845 ascport = &asc_ports[co->index]; 846 847 /* 848 * This driver does not support early console initialization 849 * (use ARM early printk support instead), so we only expect 850 * this to be called during the uart port registration when the 851 * driver gets probed and the port should be mapped at that point. 852 */ 853 if (ascport->port.mapbase == 0 || ascport->port.membase == NULL) 854 return -ENXIO; 855 856 if (options) 857 uart_parse_options(options, &baud, &parity, &bits, &flow); 858 859 return uart_set_options(&ascport->port, co, baud, parity, bits, flow); 860 } 861 862 static struct console asc_console = { 863 .name = ASC_SERIAL_NAME, 864 .device = uart_console_device, 865 .write = asc_console_write, 866 .setup = asc_console_setup, 867 .flags = CON_PRINTBUFFER, 868 .index = -1, 869 .data = &asc_uart_driver, 870 }; 871 872 #define ASC_SERIAL_CONSOLE (&asc_console) 873 874 #else 875 #define ASC_SERIAL_CONSOLE NULL 876 #endif /* CONFIG_SERIAL_ST_ASC_CONSOLE */ 877 878 static struct uart_driver asc_uart_driver = { 879 .owner = THIS_MODULE, 880 .driver_name = DRIVER_NAME, 881 .dev_name = ASC_SERIAL_NAME, 882 .major = 0, 883 .minor = 0, 884 .nr = ASC_MAX_PORTS, 885 .cons = ASC_SERIAL_CONSOLE, 886 }; 887 888 static const struct dev_pm_ops asc_serial_pm_ops = { 889 SET_SYSTEM_SLEEP_PM_OPS(asc_serial_suspend, asc_serial_resume) 890 }; 891 892 static struct platform_driver asc_serial_driver = { 893 .probe = asc_serial_probe, 894 .remove = asc_serial_remove, 895 .driver = { 896 .name = DRIVER_NAME, 897 .pm = &asc_serial_pm_ops, 898 .of_match_table = of_match_ptr(asc_match), 899 }, 900 }; 901 902 static int __init asc_init(void) 903 { 904 int ret; 905 static char banner[] __initdata = 906 KERN_INFO "STMicroelectronics ASC driver initialized\n"; 907 908 printk(banner); 909 910 ret = uart_register_driver(&asc_uart_driver); 911 if (ret) 912 return ret; 913 914 ret = platform_driver_register(&asc_serial_driver); 915 if (ret) 916 uart_unregister_driver(&asc_uart_driver); 917 918 return ret; 919 } 920 921 static void __exit asc_exit(void) 922 { 923 platform_driver_unregister(&asc_serial_driver); 924 uart_unregister_driver(&asc_uart_driver); 925 } 926 927 module_init(asc_init); 928 module_exit(asc_exit); 929 930 MODULE_ALIAS("platform:" DRIVER_NAME); 931 MODULE_AUTHOR("STMicroelectronics (R&D) Limited"); 932 MODULE_DESCRIPTION("STMicroelectronics ASC serial port driver"); 933 MODULE_LICENSE("GPL"); 934