1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Freescale LINFlexD UART serial port driver 4 * 5 * Copyright 2012-2016 Freescale Semiconductor, Inc. 6 * Copyright 2017-2019 NXP 7 */ 8 9 #include <linux/console.h> 10 #include <linux/io.h> 11 #include <linux/irq.h> 12 #include <linux/module.h> 13 #include <linux/of.h> 14 #include <linux/platform_device.h> 15 #include <linux/serial_core.h> 16 #include <linux/slab.h> 17 #include <linux/tty_flip.h> 18 #include <linux/delay.h> 19 20 /* All registers are 32-bit width */ 21 22 #define LINCR1 0x0000 /* LIN control register */ 23 #define LINIER 0x0004 /* LIN interrupt enable register */ 24 #define LINSR 0x0008 /* LIN status register */ 25 #define LINESR 0x000C /* LIN error status register */ 26 #define UARTCR 0x0010 /* UART mode control register */ 27 #define UARTSR 0x0014 /* UART mode status register */ 28 #define LINTCSR 0x0018 /* LIN timeout control status register */ 29 #define LINOCR 0x001C /* LIN output compare register */ 30 #define LINTOCR 0x0020 /* LIN timeout control register */ 31 #define LINFBRR 0x0024 /* LIN fractional baud rate register */ 32 #define LINIBRR 0x0028 /* LIN integer baud rate register */ 33 #define LINCFR 0x002C /* LIN checksum field register */ 34 #define LINCR2 0x0030 /* LIN control register 2 */ 35 #define BIDR 0x0034 /* Buffer identifier register */ 36 #define BDRL 0x0038 /* Buffer data register least significant */ 37 #define BDRM 0x003C /* Buffer data register most significant */ 38 #define IFER 0x0040 /* Identifier filter enable register */ 39 #define IFMI 0x0044 /* Identifier filter match index */ 40 #define IFMR 0x0048 /* Identifier filter mode register */ 41 #define GCR 0x004C /* Global control register */ 42 #define UARTPTO 0x0050 /* UART preset timeout register */ 43 #define UARTCTO 0x0054 /* UART current timeout register */ 44 45 /* 46 * Register field definitions 47 */ 48 49 #define LINFLEXD_LINCR1_INIT BIT(0) 50 #define LINFLEXD_LINCR1_MME BIT(4) 51 #define LINFLEXD_LINCR1_BF BIT(7) 52 53 #define LINFLEXD_LINSR_LINS_INITMODE BIT(12) 54 #define LINFLEXD_LINSR_LINS_MASK (0xF << 12) 55 56 #define LINFLEXD_LINIER_SZIE BIT(15) 57 #define LINFLEXD_LINIER_OCIE BIT(14) 58 #define LINFLEXD_LINIER_BEIE BIT(13) 59 #define LINFLEXD_LINIER_CEIE BIT(12) 60 #define LINFLEXD_LINIER_HEIE BIT(11) 61 #define LINFLEXD_LINIER_FEIE BIT(8) 62 #define LINFLEXD_LINIER_BOIE BIT(7) 63 #define LINFLEXD_LINIER_LSIE BIT(6) 64 #define LINFLEXD_LINIER_WUIE BIT(5) 65 #define LINFLEXD_LINIER_DBFIE BIT(4) 66 #define LINFLEXD_LINIER_DBEIETOIE BIT(3) 67 #define LINFLEXD_LINIER_DRIE BIT(2) 68 #define LINFLEXD_LINIER_DTIE BIT(1) 69 #define LINFLEXD_LINIER_HRIE BIT(0) 70 71 #define LINFLEXD_UARTCR_OSR_MASK (0xF << 24) 72 #define LINFLEXD_UARTCR_OSR(uartcr) (((uartcr) \ 73 & LINFLEXD_UARTCR_OSR_MASK) >> 24) 74 75 #define LINFLEXD_UARTCR_ROSE BIT(23) 76 77 #define LINFLEXD_UARTCR_RFBM BIT(9) 78 #define LINFLEXD_UARTCR_TFBM BIT(8) 79 #define LINFLEXD_UARTCR_WL1 BIT(7) 80 #define LINFLEXD_UARTCR_PC1 BIT(6) 81 82 #define LINFLEXD_UARTCR_RXEN BIT(5) 83 #define LINFLEXD_UARTCR_TXEN BIT(4) 84 #define LINFLEXD_UARTCR_PC0 BIT(3) 85 86 #define LINFLEXD_UARTCR_PCE BIT(2) 87 #define LINFLEXD_UARTCR_WL0 BIT(1) 88 #define LINFLEXD_UARTCR_UART BIT(0) 89 90 #define LINFLEXD_UARTSR_SZF BIT(15) 91 #define LINFLEXD_UARTSR_OCF BIT(14) 92 #define LINFLEXD_UARTSR_PE3 BIT(13) 93 #define LINFLEXD_UARTSR_PE2 BIT(12) 94 #define LINFLEXD_UARTSR_PE1 BIT(11) 95 #define LINFLEXD_UARTSR_PE0 BIT(10) 96 #define LINFLEXD_UARTSR_RMB BIT(9) 97 #define LINFLEXD_UARTSR_FEF BIT(8) 98 #define LINFLEXD_UARTSR_BOF BIT(7) 99 #define LINFLEXD_UARTSR_RPS BIT(6) 100 #define LINFLEXD_UARTSR_WUF BIT(5) 101 #define LINFLEXD_UARTSR_4 BIT(4) 102 103 #define LINFLEXD_UARTSR_TO BIT(3) 104 105 #define LINFLEXD_UARTSR_DRFRFE BIT(2) 106 #define LINFLEXD_UARTSR_DTFTFF BIT(1) 107 #define LINFLEXD_UARTSR_NF BIT(0) 108 #define LINFLEXD_UARTSR_PE (LINFLEXD_UARTSR_PE0 |\ 109 LINFLEXD_UARTSR_PE1 |\ 110 LINFLEXD_UARTSR_PE2 |\ 111 LINFLEXD_UARTSR_PE3) 112 113 #define LINFLEX_LDIV_MULTIPLIER (16) 114 115 #define DRIVER_NAME "fsl-linflexuart" 116 #define DEV_NAME "ttyLF" 117 #define UART_NR 4 118 119 #define EARLYCON_BUFFER_INITIAL_CAP 8 120 121 #define PREINIT_DELAY 2000 /* us */ 122 123 static const struct of_device_id linflex_dt_ids[] = { 124 { 125 .compatible = "fsl,s32v234-linflexuart", 126 }, 127 { /* sentinel */ } 128 }; 129 MODULE_DEVICE_TABLE(of, linflex_dt_ids); 130 131 #ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE 132 static struct uart_port *earlycon_port; 133 static bool linflex_earlycon_same_instance; 134 static DEFINE_SPINLOCK(init_lock); 135 static bool during_init; 136 137 static struct { 138 char *content; 139 unsigned int len, cap; 140 } earlycon_buf; 141 #endif 142 linflex_stop_tx(struct uart_port * port)143 static void linflex_stop_tx(struct uart_port *port) 144 { 145 unsigned long ier; 146 147 ier = readl(port->membase + LINIER); 148 ier &= ~(LINFLEXD_LINIER_DTIE); 149 writel(ier, port->membase + LINIER); 150 } 151 linflex_stop_rx(struct uart_port * port)152 static void linflex_stop_rx(struct uart_port *port) 153 { 154 unsigned long ier; 155 156 ier = readl(port->membase + LINIER); 157 writel(ier & ~LINFLEXD_LINIER_DRIE, port->membase + LINIER); 158 } 159 linflex_put_char(struct uart_port * sport,unsigned char c)160 static void linflex_put_char(struct uart_port *sport, unsigned char c) 161 { 162 unsigned long status; 163 164 writeb(c, sport->membase + BDRL); 165 166 /* Waiting for data transmission completed. */ 167 while (((status = readl(sport->membase + UARTSR)) & 168 LINFLEXD_UARTSR_DTFTFF) != 169 LINFLEXD_UARTSR_DTFTFF) 170 ; 171 172 writel(status | LINFLEXD_UARTSR_DTFTFF, sport->membase + UARTSR); 173 } 174 linflex_transmit_buffer(struct uart_port * sport)175 static inline void linflex_transmit_buffer(struct uart_port *sport) 176 { 177 struct circ_buf *xmit = &sport->state->xmit; 178 179 while (!uart_circ_empty(xmit)) { 180 linflex_put_char(sport, xmit->buf[xmit->tail]); 181 uart_xmit_advance(sport, 1); 182 } 183 184 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) 185 uart_write_wakeup(sport); 186 187 if (uart_circ_empty(xmit)) 188 linflex_stop_tx(sport); 189 } 190 linflex_start_tx(struct uart_port * port)191 static void linflex_start_tx(struct uart_port *port) 192 { 193 unsigned long ier; 194 195 linflex_transmit_buffer(port); 196 ier = readl(port->membase + LINIER); 197 writel(ier | LINFLEXD_LINIER_DTIE, port->membase + LINIER); 198 } 199 linflex_txint(int irq,void * dev_id)200 static irqreturn_t linflex_txint(int irq, void *dev_id) 201 { 202 struct uart_port *sport = dev_id; 203 struct circ_buf *xmit = &sport->state->xmit; 204 unsigned long flags; 205 206 spin_lock_irqsave(&sport->lock, flags); 207 208 if (sport->x_char) { 209 linflex_put_char(sport, sport->x_char); 210 goto out; 211 } 212 213 if (uart_circ_empty(xmit) || uart_tx_stopped(sport)) { 214 linflex_stop_tx(sport); 215 goto out; 216 } 217 218 linflex_transmit_buffer(sport); 219 out: 220 spin_unlock_irqrestore(&sport->lock, flags); 221 return IRQ_HANDLED; 222 } 223 linflex_rxint(int irq,void * dev_id)224 static irqreturn_t linflex_rxint(int irq, void *dev_id) 225 { 226 struct uart_port *sport = dev_id; 227 unsigned int flg; 228 struct tty_port *port = &sport->state->port; 229 unsigned long flags, status; 230 unsigned char rx; 231 bool brk; 232 233 spin_lock_irqsave(&sport->lock, flags); 234 235 status = readl(sport->membase + UARTSR); 236 while (status & LINFLEXD_UARTSR_RMB) { 237 rx = readb(sport->membase + BDRM); 238 brk = false; 239 flg = TTY_NORMAL; 240 sport->icount.rx++; 241 242 if (status & (LINFLEXD_UARTSR_BOF | LINFLEXD_UARTSR_FEF | 243 LINFLEXD_UARTSR_PE)) { 244 if (status & LINFLEXD_UARTSR_BOF) 245 sport->icount.overrun++; 246 if (status & LINFLEXD_UARTSR_FEF) { 247 if (!rx) { 248 brk = true; 249 sport->icount.brk++; 250 } else 251 sport->icount.frame++; 252 } 253 if (status & LINFLEXD_UARTSR_PE) 254 sport->icount.parity++; 255 } 256 257 writel(status, sport->membase + UARTSR); 258 status = readl(sport->membase + UARTSR); 259 260 if (brk) { 261 uart_handle_break(sport); 262 } else { 263 if (uart_handle_sysrq_char(sport, (unsigned char)rx)) 264 continue; 265 tty_insert_flip_char(port, rx, flg); 266 } 267 } 268 269 spin_unlock_irqrestore(&sport->lock, flags); 270 271 tty_flip_buffer_push(port); 272 273 return IRQ_HANDLED; 274 } 275 linflex_int(int irq,void * dev_id)276 static irqreturn_t linflex_int(int irq, void *dev_id) 277 { 278 struct uart_port *sport = dev_id; 279 unsigned long status; 280 281 status = readl(sport->membase + UARTSR); 282 283 if (status & LINFLEXD_UARTSR_DRFRFE) 284 linflex_rxint(irq, dev_id); 285 if (status & LINFLEXD_UARTSR_DTFTFF) 286 linflex_txint(irq, dev_id); 287 288 return IRQ_HANDLED; 289 } 290 291 /* return TIOCSER_TEMT when transmitter is not busy */ linflex_tx_empty(struct uart_port * port)292 static unsigned int linflex_tx_empty(struct uart_port *port) 293 { 294 unsigned long status; 295 296 status = readl(port->membase + UARTSR) & LINFLEXD_UARTSR_DTFTFF; 297 298 return status ? TIOCSER_TEMT : 0; 299 } 300 linflex_get_mctrl(struct uart_port * port)301 static unsigned int linflex_get_mctrl(struct uart_port *port) 302 { 303 return 0; 304 } 305 linflex_set_mctrl(struct uart_port * port,unsigned int mctrl)306 static void linflex_set_mctrl(struct uart_port *port, unsigned int mctrl) 307 { 308 } 309 linflex_break_ctl(struct uart_port * port,int break_state)310 static void linflex_break_ctl(struct uart_port *port, int break_state) 311 { 312 } 313 linflex_setup_watermark(struct uart_port * sport)314 static void linflex_setup_watermark(struct uart_port *sport) 315 { 316 unsigned long cr, ier, cr1; 317 318 /* Disable transmission/reception */ 319 ier = readl(sport->membase + LINIER); 320 ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE); 321 writel(ier, sport->membase + LINIER); 322 323 cr = readl(sport->membase + UARTCR); 324 cr &= ~(LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN); 325 writel(cr, sport->membase + UARTCR); 326 327 /* Enter initialization mode by setting INIT bit */ 328 329 /* set the Linflex in master mode and activate by-pass filter */ 330 cr1 = LINFLEXD_LINCR1_BF | LINFLEXD_LINCR1_MME 331 | LINFLEXD_LINCR1_INIT; 332 writel(cr1, sport->membase + LINCR1); 333 334 /* wait for init mode entry */ 335 while ((readl(sport->membase + LINSR) 336 & LINFLEXD_LINSR_LINS_MASK) 337 != LINFLEXD_LINSR_LINS_INITMODE) 338 ; 339 340 /* 341 * UART = 0x1; - Linflex working in UART mode 342 * TXEN = 0x1; - Enable transmission of data now 343 * RXEn = 0x1; - Receiver enabled 344 * WL0 = 0x1; - 8 bit data 345 * PCE = 0x0; - No parity 346 */ 347 348 /* set UART bit to allow writing other bits */ 349 writel(LINFLEXD_UARTCR_UART, sport->membase + UARTCR); 350 351 cr = (LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN | 352 LINFLEXD_UARTCR_WL0 | LINFLEXD_UARTCR_UART); 353 354 writel(cr, sport->membase + UARTCR); 355 356 cr1 &= ~(LINFLEXD_LINCR1_INIT); 357 358 writel(cr1, sport->membase + LINCR1); 359 360 ier = readl(sport->membase + LINIER); 361 ier |= LINFLEXD_LINIER_DRIE; 362 ier |= LINFLEXD_LINIER_DTIE; 363 364 writel(ier, sport->membase + LINIER); 365 } 366 linflex_startup(struct uart_port * port)367 static int linflex_startup(struct uart_port *port) 368 { 369 int ret = 0; 370 unsigned long flags; 371 372 spin_lock_irqsave(&port->lock, flags); 373 374 linflex_setup_watermark(port); 375 376 spin_unlock_irqrestore(&port->lock, flags); 377 378 ret = devm_request_irq(port->dev, port->irq, linflex_int, 0, 379 DRIVER_NAME, port); 380 381 return ret; 382 } 383 linflex_shutdown(struct uart_port * port)384 static void linflex_shutdown(struct uart_port *port) 385 { 386 unsigned long ier; 387 unsigned long flags; 388 389 spin_lock_irqsave(&port->lock, flags); 390 391 /* disable interrupts */ 392 ier = readl(port->membase + LINIER); 393 ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE); 394 writel(ier, port->membase + LINIER); 395 396 spin_unlock_irqrestore(&port->lock, flags); 397 398 devm_free_irq(port->dev, port->irq, port); 399 } 400 401 static void linflex_set_termios(struct uart_port * port,struct ktermios * termios,const struct ktermios * old)402 linflex_set_termios(struct uart_port *port, struct ktermios *termios, 403 const struct ktermios *old) 404 { 405 unsigned long flags; 406 unsigned long cr, old_cr, cr1; 407 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8; 408 409 cr = readl(port->membase + UARTCR); 410 old_cr = cr; 411 412 /* Enter initialization mode by setting INIT bit */ 413 cr1 = readl(port->membase + LINCR1); 414 cr1 |= LINFLEXD_LINCR1_INIT; 415 writel(cr1, port->membase + LINCR1); 416 417 /* wait for init mode entry */ 418 while ((readl(port->membase + LINSR) 419 & LINFLEXD_LINSR_LINS_MASK) 420 != LINFLEXD_LINSR_LINS_INITMODE) 421 ; 422 423 /* 424 * only support CS8 and CS7, and for CS7 must enable PE. 425 * supported mode: 426 * - (7,e/o,1) 427 * - (8,n,1) 428 * - (8,e/o,1) 429 */ 430 /* enter the UART into configuration mode */ 431 432 while ((termios->c_cflag & CSIZE) != CS8 && 433 (termios->c_cflag & CSIZE) != CS7) { 434 termios->c_cflag &= ~CSIZE; 435 termios->c_cflag |= old_csize; 436 old_csize = CS8; 437 } 438 439 if ((termios->c_cflag & CSIZE) == CS7) { 440 /* Word length: WL1WL0:00 */ 441 cr = old_cr & ~LINFLEXD_UARTCR_WL1 & ~LINFLEXD_UARTCR_WL0; 442 } 443 444 if ((termios->c_cflag & CSIZE) == CS8) { 445 /* Word length: WL1WL0:01 */ 446 cr = (old_cr | LINFLEXD_UARTCR_WL0) & ~LINFLEXD_UARTCR_WL1; 447 } 448 449 if (termios->c_cflag & CMSPAR) { 450 if ((termios->c_cflag & CSIZE) != CS8) { 451 termios->c_cflag &= ~CSIZE; 452 termios->c_cflag |= CS8; 453 } 454 /* has a space/sticky bit */ 455 cr |= LINFLEXD_UARTCR_WL0; 456 } 457 458 if (termios->c_cflag & CSTOPB) 459 termios->c_cflag &= ~CSTOPB; 460 461 /* parity must be enabled when CS7 to match 8-bits format */ 462 if ((termios->c_cflag & CSIZE) == CS7) 463 termios->c_cflag |= PARENB; 464 465 if ((termios->c_cflag & PARENB)) { 466 cr |= LINFLEXD_UARTCR_PCE; 467 if (termios->c_cflag & PARODD) 468 cr = (cr | LINFLEXD_UARTCR_PC0) & 469 (~LINFLEXD_UARTCR_PC1); 470 else 471 cr = cr & (~LINFLEXD_UARTCR_PC1 & 472 ~LINFLEXD_UARTCR_PC0); 473 } else { 474 cr &= ~LINFLEXD_UARTCR_PCE; 475 } 476 477 spin_lock_irqsave(&port->lock, flags); 478 479 port->read_status_mask = 0; 480 481 if (termios->c_iflag & INPCK) 482 port->read_status_mask |= (LINFLEXD_UARTSR_FEF | 483 LINFLEXD_UARTSR_PE0 | 484 LINFLEXD_UARTSR_PE1 | 485 LINFLEXD_UARTSR_PE2 | 486 LINFLEXD_UARTSR_PE3); 487 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) 488 port->read_status_mask |= LINFLEXD_UARTSR_FEF; 489 490 /* characters to ignore */ 491 port->ignore_status_mask = 0; 492 if (termios->c_iflag & IGNPAR) 493 port->ignore_status_mask |= LINFLEXD_UARTSR_PE; 494 if (termios->c_iflag & IGNBRK) { 495 port->ignore_status_mask |= LINFLEXD_UARTSR_PE; 496 /* 497 * if we're ignoring parity and break indicators, 498 * ignore overruns too (for real raw support). 499 */ 500 if (termios->c_iflag & IGNPAR) 501 port->ignore_status_mask |= LINFLEXD_UARTSR_BOF; 502 } 503 504 writel(cr, port->membase + UARTCR); 505 506 cr1 &= ~(LINFLEXD_LINCR1_INIT); 507 508 writel(cr1, port->membase + LINCR1); 509 510 spin_unlock_irqrestore(&port->lock, flags); 511 } 512 linflex_type(struct uart_port * port)513 static const char *linflex_type(struct uart_port *port) 514 { 515 return "FSL_LINFLEX"; 516 } 517 linflex_release_port(struct uart_port * port)518 static void linflex_release_port(struct uart_port *port) 519 { 520 /* nothing to do */ 521 } 522 linflex_request_port(struct uart_port * port)523 static int linflex_request_port(struct uart_port *port) 524 { 525 return 0; 526 } 527 528 /* configure/auto-configure the port */ linflex_config_port(struct uart_port * port,int flags)529 static void linflex_config_port(struct uart_port *port, int flags) 530 { 531 if (flags & UART_CONFIG_TYPE) 532 port->type = PORT_LINFLEXUART; 533 } 534 535 static const struct uart_ops linflex_pops = { 536 .tx_empty = linflex_tx_empty, 537 .set_mctrl = linflex_set_mctrl, 538 .get_mctrl = linflex_get_mctrl, 539 .stop_tx = linflex_stop_tx, 540 .start_tx = linflex_start_tx, 541 .stop_rx = linflex_stop_rx, 542 .break_ctl = linflex_break_ctl, 543 .startup = linflex_startup, 544 .shutdown = linflex_shutdown, 545 .set_termios = linflex_set_termios, 546 .type = linflex_type, 547 .request_port = linflex_request_port, 548 .release_port = linflex_release_port, 549 .config_port = linflex_config_port, 550 }; 551 552 static struct uart_port *linflex_ports[UART_NR]; 553 554 #ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE linflex_console_putchar(struct uart_port * port,unsigned char ch)555 static void linflex_console_putchar(struct uart_port *port, unsigned char ch) 556 { 557 unsigned long cr; 558 559 cr = readl(port->membase + UARTCR); 560 561 writeb(ch, port->membase + BDRL); 562 563 if (!(cr & LINFLEXD_UARTCR_TFBM)) 564 while ((readl(port->membase + UARTSR) & 565 LINFLEXD_UARTSR_DTFTFF) 566 != LINFLEXD_UARTSR_DTFTFF) 567 ; 568 else 569 while (readl(port->membase + UARTSR) & 570 LINFLEXD_UARTSR_DTFTFF) 571 ; 572 573 if (!(cr & LINFLEXD_UARTCR_TFBM)) { 574 writel((readl(port->membase + UARTSR) | 575 LINFLEXD_UARTSR_DTFTFF), 576 port->membase + UARTSR); 577 } 578 } 579 linflex_earlycon_putchar(struct uart_port * port,unsigned char ch)580 static void linflex_earlycon_putchar(struct uart_port *port, unsigned char ch) 581 { 582 unsigned long flags; 583 char *ret; 584 585 if (!linflex_earlycon_same_instance) { 586 linflex_console_putchar(port, ch); 587 return; 588 } 589 590 spin_lock_irqsave(&init_lock, flags); 591 if (!during_init) 592 goto outside_init; 593 594 if (earlycon_buf.len >= 1 << CONFIG_LOG_BUF_SHIFT) 595 goto init_release; 596 597 if (!earlycon_buf.cap) { 598 earlycon_buf.content = kmalloc(EARLYCON_BUFFER_INITIAL_CAP, 599 GFP_ATOMIC); 600 earlycon_buf.cap = earlycon_buf.content ? 601 EARLYCON_BUFFER_INITIAL_CAP : 0; 602 } else if (earlycon_buf.len == earlycon_buf.cap) { 603 ret = krealloc(earlycon_buf.content, earlycon_buf.cap << 1, 604 GFP_ATOMIC); 605 if (ret) { 606 earlycon_buf.content = ret; 607 earlycon_buf.cap <<= 1; 608 } 609 } 610 611 if (earlycon_buf.len < earlycon_buf.cap) 612 earlycon_buf.content[earlycon_buf.len++] = ch; 613 614 goto init_release; 615 616 outside_init: 617 linflex_console_putchar(port, ch); 618 init_release: 619 spin_unlock_irqrestore(&init_lock, flags); 620 } 621 linflex_string_write(struct uart_port * sport,const char * s,unsigned int count)622 static void linflex_string_write(struct uart_port *sport, const char *s, 623 unsigned int count) 624 { 625 unsigned long cr, ier = 0; 626 627 ier = readl(sport->membase + LINIER); 628 linflex_stop_tx(sport); 629 630 cr = readl(sport->membase + UARTCR); 631 cr |= (LINFLEXD_UARTCR_TXEN); 632 writel(cr, sport->membase + UARTCR); 633 634 uart_console_write(sport, s, count, linflex_console_putchar); 635 636 writel(ier, sport->membase + LINIER); 637 } 638 639 static void linflex_console_write(struct console * co,const char * s,unsigned int count)640 linflex_console_write(struct console *co, const char *s, unsigned int count) 641 { 642 struct uart_port *sport = linflex_ports[co->index]; 643 unsigned long flags; 644 int locked = 1; 645 646 if (sport->sysrq) 647 locked = 0; 648 else if (oops_in_progress) 649 locked = spin_trylock_irqsave(&sport->lock, flags); 650 else 651 spin_lock_irqsave(&sport->lock, flags); 652 653 linflex_string_write(sport, s, count); 654 655 if (locked) 656 spin_unlock_irqrestore(&sport->lock, flags); 657 } 658 659 /* 660 * if the port was already initialised (eg, by a boot loader), 661 * try to determine the current setup. 662 */ 663 static void __init linflex_console_get_options(struct uart_port * sport,int * parity,int * bits)664 linflex_console_get_options(struct uart_port *sport, int *parity, int *bits) 665 { 666 unsigned long cr; 667 668 cr = readl(sport->membase + UARTCR); 669 cr &= LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN; 670 671 if (!cr) 672 return; 673 674 /* ok, the port was enabled */ 675 676 *parity = 'n'; 677 if (cr & LINFLEXD_UARTCR_PCE) { 678 if (cr & LINFLEXD_UARTCR_PC0) 679 *parity = 'o'; 680 else 681 *parity = 'e'; 682 } 683 684 if ((cr & LINFLEXD_UARTCR_WL0) && ((cr & LINFLEXD_UARTCR_WL1) == 0)) { 685 if (cr & LINFLEXD_UARTCR_PCE) 686 *bits = 9; 687 else 688 *bits = 8; 689 } 690 } 691 linflex_console_setup(struct console * co,char * options)692 static int __init linflex_console_setup(struct console *co, char *options) 693 { 694 struct uart_port *sport; 695 int baud = 115200; 696 int bits = 8; 697 int parity = 'n'; 698 int flow = 'n'; 699 int ret; 700 int i; 701 unsigned long flags; 702 /* 703 * check whether an invalid uart number has been specified, and 704 * if so, search for the first available port that does have 705 * console support. 706 */ 707 if (co->index == -1 || co->index >= ARRAY_SIZE(linflex_ports)) 708 co->index = 0; 709 710 sport = linflex_ports[co->index]; 711 if (!sport) 712 return -ENODEV; 713 714 if (options) 715 uart_parse_options(options, &baud, &parity, &bits, &flow); 716 else 717 linflex_console_get_options(sport, &parity, &bits); 718 719 if (earlycon_port && sport->mapbase == earlycon_port->mapbase) { 720 linflex_earlycon_same_instance = true; 721 722 spin_lock_irqsave(&init_lock, flags); 723 during_init = true; 724 spin_unlock_irqrestore(&init_lock, flags); 725 726 /* Workaround for character loss or output of many invalid 727 * characters, when INIT mode is entered shortly after a 728 * character has just been printed. 729 */ 730 udelay(PREINIT_DELAY); 731 } 732 733 linflex_setup_watermark(sport); 734 735 ret = uart_set_options(sport, co, baud, parity, bits, flow); 736 737 if (!linflex_earlycon_same_instance) 738 goto done; 739 740 spin_lock_irqsave(&init_lock, flags); 741 742 /* Emptying buffer */ 743 if (earlycon_buf.len) { 744 for (i = 0; i < earlycon_buf.len; i++) 745 linflex_console_putchar(earlycon_port, 746 earlycon_buf.content[i]); 747 748 kfree(earlycon_buf.content); 749 earlycon_buf.len = 0; 750 } 751 752 during_init = false; 753 spin_unlock_irqrestore(&init_lock, flags); 754 755 done: 756 return ret; 757 } 758 759 static struct uart_driver linflex_reg; 760 static struct console linflex_console = { 761 .name = DEV_NAME, 762 .write = linflex_console_write, 763 .device = uart_console_device, 764 .setup = linflex_console_setup, 765 .flags = CON_PRINTBUFFER, 766 .index = -1, 767 .data = &linflex_reg, 768 }; 769 linflex_earlycon_write(struct console * con,const char * s,unsigned int n)770 static void linflex_earlycon_write(struct console *con, const char *s, 771 unsigned int n) 772 { 773 struct earlycon_device *dev = con->data; 774 775 uart_console_write(&dev->port, s, n, linflex_earlycon_putchar); 776 } 777 linflex_early_console_setup(struct earlycon_device * device,const char * options)778 static int __init linflex_early_console_setup(struct earlycon_device *device, 779 const char *options) 780 { 781 if (!device->port.membase) 782 return -ENODEV; 783 784 device->con->write = linflex_earlycon_write; 785 earlycon_port = &device->port; 786 787 return 0; 788 } 789 790 OF_EARLYCON_DECLARE(linflex, "fsl,s32v234-linflexuart", 791 linflex_early_console_setup); 792 793 #define LINFLEX_CONSOLE (&linflex_console) 794 #else 795 #define LINFLEX_CONSOLE NULL 796 #endif 797 798 static struct uart_driver linflex_reg = { 799 .owner = THIS_MODULE, 800 .driver_name = DRIVER_NAME, 801 .dev_name = DEV_NAME, 802 .nr = ARRAY_SIZE(linflex_ports), 803 .cons = LINFLEX_CONSOLE, 804 }; 805 linflex_probe(struct platform_device * pdev)806 static int linflex_probe(struct platform_device *pdev) 807 { 808 struct device_node *np = pdev->dev.of_node; 809 struct uart_port *sport; 810 struct resource *res; 811 int ret; 812 813 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); 814 if (!sport) 815 return -ENOMEM; 816 817 ret = of_alias_get_id(np, "serial"); 818 if (ret < 0) { 819 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret); 820 return ret; 821 } 822 if (ret >= UART_NR) { 823 dev_err(&pdev->dev, "driver limited to %d serial ports\n", 824 UART_NR); 825 return -ENOMEM; 826 } 827 828 sport->line = ret; 829 830 sport->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res); 831 if (IS_ERR(sport->membase)) 832 return PTR_ERR(sport->membase); 833 sport->mapbase = res->start; 834 835 sport->dev = &pdev->dev; 836 sport->type = PORT_LINFLEXUART; 837 sport->iotype = UPIO_MEM; 838 sport->irq = platform_get_irq(pdev, 0); 839 sport->ops = &linflex_pops; 840 sport->flags = UPF_BOOT_AUTOCONF; 841 sport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE); 842 843 linflex_ports[sport->line] = sport; 844 845 platform_set_drvdata(pdev, sport); 846 847 return uart_add_one_port(&linflex_reg, sport); 848 } 849 linflex_remove(struct platform_device * pdev)850 static int linflex_remove(struct platform_device *pdev) 851 { 852 struct uart_port *sport = platform_get_drvdata(pdev); 853 854 uart_remove_one_port(&linflex_reg, sport); 855 856 return 0; 857 } 858 859 #ifdef CONFIG_PM_SLEEP linflex_suspend(struct device * dev)860 static int linflex_suspend(struct device *dev) 861 { 862 struct uart_port *sport = dev_get_drvdata(dev); 863 864 uart_suspend_port(&linflex_reg, sport); 865 866 return 0; 867 } 868 linflex_resume(struct device * dev)869 static int linflex_resume(struct device *dev) 870 { 871 struct uart_port *sport = dev_get_drvdata(dev); 872 873 uart_resume_port(&linflex_reg, sport); 874 875 return 0; 876 } 877 #endif 878 879 static SIMPLE_DEV_PM_OPS(linflex_pm_ops, linflex_suspend, linflex_resume); 880 881 static struct platform_driver linflex_driver = { 882 .probe = linflex_probe, 883 .remove = linflex_remove, 884 .driver = { 885 .name = DRIVER_NAME, 886 .of_match_table = linflex_dt_ids, 887 .pm = &linflex_pm_ops, 888 }, 889 }; 890 linflex_serial_init(void)891 static int __init linflex_serial_init(void) 892 { 893 int ret; 894 895 ret = uart_register_driver(&linflex_reg); 896 if (ret) 897 return ret; 898 899 ret = platform_driver_register(&linflex_driver); 900 if (ret) 901 uart_unregister_driver(&linflex_reg); 902 903 return ret; 904 } 905 linflex_serial_exit(void)906 static void __exit linflex_serial_exit(void) 907 { 908 platform_driver_unregister(&linflex_driver); 909 uart_unregister_driver(&linflex_reg); 910 } 911 912 module_init(linflex_serial_init); 913 module_exit(linflex_serial_exit); 914 915 MODULE_DESCRIPTION("Freescale LINFlexD serial port driver"); 916 MODULE_LICENSE("GPL v2"); 917