drivers/tty/serial/bcm63xx_uart.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Derived from many drivers using generic_serial interface.
   4  *
   5  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
   6  *
   7  *  Serial driver for BCM63xx integrated UART.
   8  *
   9  * Hardware flow control was _not_ tested since I only have RX/TX on
  10  * my board.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/init.h>
  16 #include <linux/delay.h>
  17 #include <linux/module.h>
  18 #include <linux/console.h>
  19 #include <linux/clk.h>
  20 #include <linux/tty.h>
  21 #include <linux/tty_flip.h>
  22 #include <linux/sysrq.h>
  23 #include <linux/serial.h>
  24 #include <linux/serial_core.h>
  25 #include <linux/serial_bcm63xx.h>
  26 #include <linux/io.h>
  27 #include <linux/of.h>
  28
  29 #define BCM63XX_NR_UARTS        2
  30
  31 static struct uart_port ports[BCM63XX_NR_UARTS];
  32
  33 /*
  34  * rx interrupt mask / stat
  35  *
  36  * mask:
  37  *  - rx fifo full
  38  *  - rx fifo above threshold
  39  *  - rx fifo not empty for too long
  40  */
  41 #define UART_RX_INT_MASK        (UART_IR_MASK(UART_IR_RXOVER) |         \
  42                                 UART_IR_MASK(UART_IR_RXTHRESH) |        \
  43                                 UART_IR_MASK(UART_IR_RXTIMEOUT))
  44
  45 #define UART_RX_INT_STAT        (UART_IR_STAT(UART_IR_RXOVER) |         \
  46                                 UART_IR_STAT(UART_IR_RXTHRESH) |        \
  47                                 UART_IR_STAT(UART_IR_RXTIMEOUT))
  48
  49 /*
  50  * tx interrupt mask / stat
  51  *
  52  * mask:
  53  * - tx fifo empty
  54  * - tx fifo below threshold
  55  */
  56 #define UART_TX_INT_MASK        (UART_IR_MASK(UART_IR_TXEMPTY) |        \
  57                                 UART_IR_MASK(UART_IR_TXTRESH))
  58
  59 #define UART_TX_INT_STAT        (UART_IR_STAT(UART_IR_TXEMPTY) |        \
  60                                 UART_IR_STAT(UART_IR_TXTRESH))
  61
  62 /*
  63  * external input interrupt
  64  *
  65  * mask: any edge on CTS, DCD
  66  */
  67 #define UART_EXTINP_INT_MASK    (UART_EXTINP_IRMASK(UART_EXTINP_IR_CTS) | \
  68                                  UART_EXTINP_IRMASK(UART_EXTINP_IR_DCD))
  69
  70 /*
  71  * handy uart register accessor
  72  */
  73 static inline unsigned int bcm_uart_readl(struct uart_port *port,
  74                                          unsigned int offset)
  75 {
  76         return __raw_readl(port->membase + offset);
  77 }
  78
  79 static inline void bcm_uart_writel(struct uart_port *port,
  80                                   unsigned int value, unsigned int offset)
  81 {
  82         __raw_writel(value, port->membase + offset);
  83 }
  84
  85 /*
  86  * serial core request to check if uart tx fifo is empty
  87  */
  88 static unsigned int bcm_uart_tx_empty(struct uart_port *port)
  89 {
  90         unsigned int val;
  91
  92         val = bcm_uart_readl(port, UART_IR_REG);
  93         return (val & UART_IR_STAT(UART_IR_TXEMPTY)) ? 1 : 0;
  94 }
  95
  96 /*
  97  * serial core request to set RTS and DTR pin state and loopback mode
  98  */
  99 static void bcm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 100 {
 101         unsigned int val;
 102
 103         val = bcm_uart_readl(port, UART_MCTL_REG);
 104         val &= ~(UART_MCTL_DTR_MASK | UART_MCTL_RTS_MASK);
 105         /* invert of written value is reflected on the pin */
 106         if (!(mctrl & TIOCM_DTR))
 107                 val |= UART_MCTL_DTR_MASK;
 108         if (!(mctrl & TIOCM_RTS))
 109                 val |= UART_MCTL_RTS_MASK;
 110         bcm_uart_writel(port, val, UART_MCTL_REG);
 111
 112         val = bcm_uart_readl(port, UART_CTL_REG);
 113         if (mctrl & TIOCM_LOOP)
 114                 val |= UART_CTL_LOOPBACK_MASK;
 115         else
 116                 val &= ~UART_CTL_LOOPBACK_MASK;
 117         bcm_uart_writel(port, val, UART_CTL_REG);
 118 }
 119
 120 /*
 121  * serial core request to return RI, CTS, DCD and DSR pin state
 122  */
 123 static unsigned int bcm_uart_get_mctrl(struct uart_port *port)
 124 {
 125         unsigned int val, mctrl;
 126
 127         mctrl = 0;
 128         val = bcm_uart_readl(port, UART_EXTINP_REG);
 129         if (val & UART_EXTINP_RI_MASK)
 130                 mctrl |= TIOCM_RI;
 131         if (val & UART_EXTINP_CTS_MASK)
 132                 mctrl |= TIOCM_CTS;
 133         if (val & UART_EXTINP_DCD_MASK)
 134                 mctrl |= TIOCM_CD;
 135         if (val & UART_EXTINP_DSR_MASK)
 136                 mctrl |= TIOCM_DSR;
 137         return mctrl;
 138 }
 139
 140 /*
 141  * serial core request to disable tx ASAP (used for flow control)
 142  */
 143 static void bcm_uart_stop_tx(struct uart_port *port)
 144 {
 145         unsigned int val;
 146
 147         val = bcm_uart_readl(port, UART_CTL_REG);
 148         val &= ~(UART_CTL_TXEN_MASK);
 149         bcm_uart_writel(port, val, UART_CTL_REG);
 150
 151         val = bcm_uart_readl(port, UART_IR_REG);
 152         val &= ~UART_TX_INT_MASK;
 153         bcm_uart_writel(port, val, UART_IR_REG);
 154 }
 155
 156 /*
 157  * serial core request to (re)enable tx
 158  */
 159 static void bcm_uart_start_tx(struct uart_port *port)
 160 {
 161         unsigned int val;
 162
 163         val = bcm_uart_readl(port, UART_IR_REG);
 164         val |= UART_TX_INT_MASK;
 165         bcm_uart_writel(port, val, UART_IR_REG);
 166
 167         val = bcm_uart_readl(port, UART_CTL_REG);
 168         val |= UART_CTL_TXEN_MASK;
 169         bcm_uart_writel(port, val, UART_CTL_REG);
 170 }
 171
 172 /*
 173  * serial core request to stop rx, called before port shutdown
 174  */
 175 static void bcm_uart_stop_rx(struct uart_port *port)
 176 {
 177         unsigned int val;
 178
 179         val = bcm_uart_readl(port, UART_IR_REG);
 180         val &= ~UART_RX_INT_MASK;
 181         bcm_uart_writel(port, val, UART_IR_REG);
 182 }
 183
 184 /*
 185  * serial core request to enable modem status interrupt reporting
 186  */
 187 static void bcm_uart_enable_ms(struct uart_port *port)
 188 {
 189         unsigned int val;
 190
 191         val = bcm_uart_readl(port, UART_IR_REG);
 192         val |= UART_IR_MASK(UART_IR_EXTIP);
 193         bcm_uart_writel(port, val, UART_IR_REG);
 194 }
 195
 196 /*
 197  * serial core request to start/stop emitting break char
 198  */
 199 static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
 200 {
 201         unsigned long flags;
 202         unsigned int val;
 203
 204         uart_port_lock_irqsave(port, &flags);
 205
 206         val = bcm_uart_readl(port, UART_CTL_REG);
 207         if (ctl)
 208                 val |= UART_CTL_XMITBRK_MASK;
 209         else
 210                 val &= ~UART_CTL_XMITBRK_MASK;
 211         bcm_uart_writel(port, val, UART_CTL_REG);
 212
 213         uart_port_unlock_irqrestore(port, flags);
 214 }
 215
 216 /*
 217  * return port type in string format
 218  */
 219 static const char *bcm_uart_type(struct uart_port *port)
 220 {
 221         return (port->type == PORT_BCM63XX) ? "bcm63xx_uart" : NULL;
 222 }
 223
 224 /*
 225  * read all chars in rx fifo and send them to core
 226  */
 227 static void bcm_uart_do_rx(struct uart_port *port)
 228 {
 229         struct tty_port *tty_port = &port->state->port;
 230         unsigned int max_count;
 231
 232         /* limit number of char read in interrupt, should not be
 233          * higher than fifo size anyway since we're much faster than
 234          * serial port */
 235         max_count = 32;
 236         do {
 237                 unsigned int iestat, c, cstat;
 238                 char flag;
 239
 240                 /* get overrun/fifo empty information from ier
 241                  * register */
 242                 iestat = bcm_uart_readl(port, UART_IR_REG);
 243
 244                 if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
 245                         unsigned int val;
 246
 247                         /* fifo reset is required to clear
 248                          * interrupt */
 249                         val = bcm_uart_readl(port, UART_CTL_REG);
 250                         val |= UART_CTL_RSTRXFIFO_MASK;
 251                         bcm_uart_writel(port, val, UART_CTL_REG);
 252
 253                         port->icount.overrun++;
 254                         tty_insert_flip_char(tty_port, 0, TTY_OVERRUN);
 255                 }
 256
 257                 if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
 258                         break;
 259
 260                 cstat = c = bcm_uart_readl(port, UART_FIFO_REG);
 261                 port->icount.rx++;
 262                 flag = TTY_NORMAL;
 263                 c &= 0xff;
 264
 265                 if (unlikely((cstat & UART_FIFO_ANYERR_MASK))) {
 266                         /* do stats first */
 267                         if (cstat & UART_FIFO_BRKDET_MASK) {
 268                                 port->icount.brk++;
 269                                 if (uart_handle_break(port))
 270                                         continue;
 271                         }
 272
 273                         if (cstat & UART_FIFO_PARERR_MASK)
 274                                 port->icount.parity++;
 275                         if (cstat & UART_FIFO_FRAMEERR_MASK)
 276                                 port->icount.frame++;
 277
 278                         /* update flag wrt read_status_mask */
 279                         cstat &= port->read_status_mask;
 280                         if (cstat & UART_FIFO_BRKDET_MASK)
 281                                 flag = TTY_BREAK;
 282                         if (cstat & UART_FIFO_FRAMEERR_MASK)
 283                                 flag = TTY_FRAME;
 284                         if (cstat & UART_FIFO_PARERR_MASK)
 285                                 flag = TTY_PARITY;
 286                 }
 287
 288                 if (uart_prepare_sysrq_char(port, c))
 289                         continue;
 290
 291                 if ((cstat & port->ignore_status_mask) == 0)
 292                         tty_insert_flip_char(tty_port, c, flag);
 293
 294         } while (--max_count);
 295
 296         tty_flip_buffer_push(tty_port);
 297 }
 298
 299 /*
 300  * fill tx fifo with chars to send, stop when fifo is about to be full
 301  * or when all chars have been sent.
 302  */
 303 static void bcm_uart_do_tx(struct uart_port *port)
 304 {
 305         unsigned int val;
 306         bool pending;
 307         u8 ch;
 308
 309         val = bcm_uart_readl(port, UART_MCTL_REG);
 310         val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
 311         pending = uart_port_tx_limited_flags(port, ch, UART_TX_NOSTOP,
 312                 port->fifosize - val,
 313                 true,
 314                 bcm_uart_writel(port, ch, UART_FIFO_REG),
 315                 ({}));
 316         if (pending)
 317                 return;
 318
 319         /* nothing to send, disable transmit interrupt */
 320         val = bcm_uart_readl(port, UART_IR_REG);
 321         val &= ~UART_TX_INT_MASK;
 322         bcm_uart_writel(port, val, UART_IR_REG);
 323
 324         if (uart_tx_stopped(port))
 325                 bcm_uart_stop_tx(port);
 326 }
 327
 328 /*
 329  * process uart interrupt
 330  */
 331 static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
 332 {
 333         struct uart_port *port;
 334         unsigned int irqstat;
 335
 336         port = dev_id;
 337         uart_port_lock(port);
 338
 339         irqstat = bcm_uart_readl(port, UART_IR_REG);
 340         if (irqstat & UART_RX_INT_STAT)
 341                 bcm_uart_do_rx(port);
 342
 343         if (irqstat & UART_TX_INT_STAT)
 344                 bcm_uart_do_tx(port);
 345
 346         if (irqstat & UART_IR_MASK(UART_IR_EXTIP)) {
 347                 unsigned int estat;
 348
 349                 estat = bcm_uart_readl(port, UART_EXTINP_REG);
 350                 if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_CTS))
 351                         uart_handle_cts_change(port,
 352                                                estat & UART_EXTINP_CTS_MASK);
 353                 if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_DCD))
 354                         uart_handle_dcd_change(port,
 355                                                estat & UART_EXTINP_DCD_MASK);
 356         }
 357
 358         uart_unlock_and_check_sysrq(port);
 359         return IRQ_HANDLED;
 360 }
 361
 362 /*
 363  * enable rx & tx operation on uart
 364  */
 365 static void bcm_uart_enable(struct uart_port *port)
 366 {
 367         unsigned int val;
 368
 369         val = bcm_uart_readl(port, UART_CTL_REG);
 370         val |= (UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
 371         bcm_uart_writel(port, val, UART_CTL_REG);
 372 }
 373
 374 /*
 375  * disable rx & tx operation on uart
 376  */
 377 static void bcm_uart_disable(struct uart_port *port)
 378 {
 379         unsigned int val;
 380
 381         val = bcm_uart_readl(port, UART_CTL_REG);
 382         val &= ~(UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK |
 383                  UART_CTL_RXEN_MASK);
 384         bcm_uart_writel(port, val, UART_CTL_REG);
 385 }
 386
 387 /*
 388  * clear all unread data in rx fifo and unsent data in tx fifo
 389  */
 390 static void bcm_uart_flush(struct uart_port *port)
 391 {
 392         unsigned int val;
 393
 394         /* empty rx and tx fifo */
 395         val = bcm_uart_readl(port, UART_CTL_REG);
 396         val |= UART_CTL_RSTRXFIFO_MASK | UART_CTL_RSTTXFIFO_MASK;
 397         bcm_uart_writel(port, val, UART_CTL_REG);
 398
 399         /* read any pending char to make sure all irq status are
 400          * cleared */
 401         (void)bcm_uart_readl(port, UART_FIFO_REG);
 402 }
 403
 404 /*
 405  * serial core request to initialize uart and start rx operation
 406  */
 407 static int bcm_uart_startup(struct uart_port *port)
 408 {
 409         unsigned int val;
 410         int ret;
 411
 412         /* mask all irq and flush port */
 413         bcm_uart_disable(port);
 414         bcm_uart_writel(port, 0, UART_IR_REG);
 415         bcm_uart_flush(port);
 416
 417         /* clear any pending external input interrupt */
 418         (void)bcm_uart_readl(port, UART_EXTINP_REG);
 419
 420         /* set rx/tx fifo thresh to fifo half size */
 421         val = bcm_uart_readl(port, UART_MCTL_REG);
 422         val &= ~(UART_MCTL_RXFIFOTHRESH_MASK | UART_MCTL_TXFIFOTHRESH_MASK);
 423         val |= (port->fifosize / 2) << UART_MCTL_RXFIFOTHRESH_SHIFT;
 424         val |= (port->fifosize / 2) << UART_MCTL_TXFIFOTHRESH_SHIFT;
 425         bcm_uart_writel(port, val, UART_MCTL_REG);
 426
 427         /* set rx fifo timeout to 1 char time */
 428         val = bcm_uart_readl(port, UART_CTL_REG);
 429         val &= ~UART_CTL_RXTMOUTCNT_MASK;
 430         val |= 1 << UART_CTL_RXTMOUTCNT_SHIFT;
 431         bcm_uart_writel(port, val, UART_CTL_REG);
 432
 433         /* report any edge on dcd and cts */
 434         val = UART_EXTINP_INT_MASK;
 435         val |= UART_EXTINP_DCD_NOSENSE_MASK;
 436         val |= UART_EXTINP_CTS_NOSENSE_MASK;
 437         bcm_uart_writel(port, val, UART_EXTINP_REG);
 438
 439         /* register irq and enable rx interrupts */
 440         ret = request_irq(port->irq, bcm_uart_interrupt, 0,
 441                           dev_name(port->dev), port);
 442         if (ret)
 443                 return ret;
 444         bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG);
 445         bcm_uart_enable(port);
 446         return 0;
 447 }
 448
 449 /*
 450  * serial core request to flush & disable uart
 451  */
 452 static void bcm_uart_shutdown(struct uart_port *port)
 453 {
 454         unsigned long flags;
 455
 456         uart_port_lock_irqsave(port, &flags);
 457         bcm_uart_writel(port, 0, UART_IR_REG);
 458         uart_port_unlock_irqrestore(port, flags);
 459
 460         bcm_uart_disable(port);
 461         bcm_uart_flush(port);
 462         free_irq(port->irq, port);
 463 }
 464
 465 /*
 466  * serial core request to change current uart setting
 467  */
 468 static void bcm_uart_set_termios(struct uart_port *port, struct ktermios *new,
 469                                  const struct ktermios *old)
 470 {
 471         unsigned int ctl, baud, quot, ier;
 472         unsigned long flags;
 473         int tries;
 474
 475         uart_port_lock_irqsave(port, &flags);
 476
 477         /* Drain the hot tub fully before we power it off for the winter. */
 478         for (tries = 3; !bcm_uart_tx_empty(port) && tries; tries--)
 479                 mdelay(10);
 480
 481         /* disable uart while changing speed */
 482         bcm_uart_disable(port);
 483         bcm_uart_flush(port);
 484
 485         /* update Control register */
 486         ctl = bcm_uart_readl(port, UART_CTL_REG);
 487         ctl &= ~UART_CTL_BITSPERSYM_MASK;
 488
 489         switch (new->c_cflag & CSIZE) {
 490         case CS5:
 491                 ctl |= (0 << UART_CTL_BITSPERSYM_SHIFT);
 492                 break;
 493         case CS6:
 494                 ctl |= (1 << UART_CTL_BITSPERSYM_SHIFT);
 495                 break;
 496         case CS7:
 497                 ctl |= (2 << UART_CTL_BITSPERSYM_SHIFT);
 498                 break;
 499         default:
 500                 ctl |= (3 << UART_CTL_BITSPERSYM_SHIFT);
 501                 break;
 502         }
 503
 504         ctl &= ~UART_CTL_STOPBITS_MASK;
 505         if (new->c_cflag & CSTOPB)
 506                 ctl |= UART_CTL_STOPBITS_2;
 507         else
 508                 ctl |= UART_CTL_STOPBITS_1;
 509
 510         ctl &= ~(UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
 511         if (new->c_cflag & PARENB)
 512                 ctl |= (UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
 513         ctl &= ~(UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
 514         if (new->c_cflag & PARODD)
 515                 ctl |= (UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
 516         bcm_uart_writel(port, ctl, UART_CTL_REG);
 517
 518         /* update Baudword register */
 519         baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
 520         quot = uart_get_divisor(port, baud) - 1;
 521         bcm_uart_writel(port, quot, UART_BAUD_REG);
 522
 523         /* update Interrupt register */
 524         ier = bcm_uart_readl(port, UART_IR_REG);
 525
 526         ier &= ~UART_IR_MASK(UART_IR_EXTIP);
 527         if (UART_ENABLE_MS(port, new->c_cflag))
 528                 ier |= UART_IR_MASK(UART_IR_EXTIP);
 529
 530         bcm_uart_writel(port, ier, UART_IR_REG);
 531
 532         /* update read/ignore mask */
 533         port->read_status_mask = UART_FIFO_VALID_MASK;
 534         if (new->c_iflag & INPCK) {
 535                 port->read_status_mask |= UART_FIFO_FRAMEERR_MASK;
 536                 port->read_status_mask |= UART_FIFO_PARERR_MASK;
 537         }
 538         if (new->c_iflag & (IGNBRK | BRKINT))
 539                 port->read_status_mask |= UART_FIFO_BRKDET_MASK;
 540
 541         port->ignore_status_mask = 0;
 542         if (new->c_iflag & IGNPAR)
 543                 port->ignore_status_mask |= UART_FIFO_PARERR_MASK;
 544         if (new->c_iflag & IGNBRK)
 545                 port->ignore_status_mask |= UART_FIFO_BRKDET_MASK;
 546         if (!(new->c_cflag & CREAD))
 547                 port->ignore_status_mask |= UART_FIFO_VALID_MASK;
 548
 549         uart_update_timeout(port, new->c_cflag, baud);
 550         bcm_uart_enable(port);
 551         uart_port_unlock_irqrestore(port, flags);
 552 }
 553
 554 /*
 555  * serial core request to claim uart iomem
 556  */
 557 static int bcm_uart_request_port(struct uart_port *port)
 558 {
 559         /* UARTs always present */
 560         return 0;
 561 }
 562
 563 /*
 564  * serial core request to release uart iomem
 565  */
 566 static void bcm_uart_release_port(struct uart_port *port)
 567 {
 568         /* Nothing to release ... */
 569 }
 570
 571 /*
 572  * serial core request to do any port required autoconfiguration
 573  */
 574 static void bcm_uart_config_port(struct uart_port *port, int flags)
 575 {
 576         if (flags & UART_CONFIG_TYPE) {
 577                 if (bcm_uart_request_port(port))
 578                         return;
 579                 port->type = PORT_BCM63XX;
 580         }
 581 }
 582
 583 /*
 584  * serial core request to check that port information in serinfo are
 585  * suitable
 586  */
 587 static int bcm_uart_verify_port(struct uart_port *port,
 588                                 struct serial_struct *serinfo)
 589 {
 590         if (port->type != PORT_BCM63XX)
 591                 return -EINVAL;
 592         if (port->irq != serinfo->irq)
 593                 return -EINVAL;
 594         if (port->iotype != serinfo->io_type)
 595                 return -EINVAL;
 596         if (port->mapbase != (unsigned long)serinfo->iomem_base)
 597                 return -EINVAL;
 598         return 0;
 599 }
 600
 601 #ifdef CONFIG_CONSOLE_POLL
 602 /*
 603  * return true when outstanding tx equals fifo size
 604  */
 605 static bool bcm_uart_tx_full(struct uart_port *port)
 606 {
 607         unsigned int val;
 608
 609         val = bcm_uart_readl(port, UART_MCTL_REG);
 610         val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
 611         return !(port->fifosize - val);
 612 }
 613
 614 static int bcm_uart_poll_get_char(struct uart_port *port)
 615 {
 616         unsigned int iestat;
 617
 618         iestat = bcm_uart_readl(port, UART_IR_REG);
 619         if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
 620                 return NO_POLL_CHAR;
 621
 622         return bcm_uart_readl(port, UART_FIFO_REG);
 623 }
 624
 625 static void bcm_uart_poll_put_char(struct uart_port *port, unsigned char c)
 626 {
 627         while (bcm_uart_tx_full(port)) {
 628                 cpu_relax();
 629         }
 630
 631         bcm_uart_writel(port, c, UART_FIFO_REG);
 632 }
 633 #endif
 634
 635 /* serial core callbacks */
 636 static const struct uart_ops bcm_uart_ops = {
 637         .tx_empty       = bcm_uart_tx_empty,
 638         .get_mctrl      = bcm_uart_get_mctrl,
 639         .set_mctrl      = bcm_uart_set_mctrl,
 640         .start_tx       = bcm_uart_start_tx,
 641         .stop_tx        = bcm_uart_stop_tx,
 642         .stop_rx        = bcm_uart_stop_rx,
 643         .enable_ms      = bcm_uart_enable_ms,
 644         .break_ctl      = bcm_uart_break_ctl,
 645         .startup        = bcm_uart_startup,
 646         .shutdown       = bcm_uart_shutdown,
 647         .set_termios    = bcm_uart_set_termios,
 648         .type           = bcm_uart_type,
 649         .release_port   = bcm_uart_release_port,
 650         .request_port   = bcm_uart_request_port,
 651         .config_port    = bcm_uart_config_port,
 652         .verify_port    = bcm_uart_verify_port,
 653 #ifdef CONFIG_CONSOLE_POLL
 654         .poll_get_char  = bcm_uart_poll_get_char,
 655         .poll_put_char  = bcm_uart_poll_put_char,
 656 #endif
 657 };
 658
 659
 660
 661 #ifdef CONFIG_SERIAL_BCM63XX_CONSOLE
 662 static void wait_for_xmitr(struct uart_port *port)
 663 {
 664         unsigned int tmout;
 665
 666         /* Wait up to 10ms for the character(s) to be sent. */
 667         tmout = 10000;
 668         while (--tmout) {
 669                 unsigned int val;
 670
 671                 val = bcm_uart_readl(port, UART_IR_REG);
 672                 if (val & UART_IR_STAT(UART_IR_TXEMPTY))
 673                         break;
 674                 udelay(1);
 675         }
 676
 677         /* Wait up to 1s for flow control if necessary */
 678         if (port->flags & UPF_CONS_FLOW) {
 679                 tmout = 1000000;
 680                 while (--tmout) {
 681                         unsigned int val;
 682
 683                         val = bcm_uart_readl(port, UART_EXTINP_REG);
 684                         if (val & UART_EXTINP_CTS_MASK)
 685                                 break;
 686                         udelay(1);
 687                 }
 688         }
 689 }
 690
 691 /*
 692  * output given char
 693  */
 694 static void bcm_console_putchar(struct uart_port *port, unsigned char ch)
 695 {
 696         wait_for_xmitr(port);
 697         bcm_uart_writel(port, ch, UART_FIFO_REG);
 698 }
 699
 700 /*
 701  * console core request to output given string
 702  */
 703 static void bcm_console_write(struct console *co, const char *s,
 704                               unsigned int count)
 705 {
 706         struct uart_port *port;
 707         unsigned long flags;
 708         int locked = 1;
 709
 710         port = &ports[co->index];
 711
 712         if (oops_in_progress)
 713                 locked = uart_port_trylock_irqsave(port, &flags);
 714         else
 715                 uart_port_lock_irqsave(port, &flags);
 716
 717         /* call helper to deal with \r\n */
 718         uart_console_write(port, s, count, bcm_console_putchar);
 719
 720         /* and wait for char to be transmitted */
 721         wait_for_xmitr(port);
 722
 723         if (locked)
 724                 uart_port_unlock_irqrestore(port, flags);
 725 }
 726
 727 /*
 728  * console core request to setup given console, find matching uart
 729  * port and setup it.
 730  */
 731 static int bcm_console_setup(struct console *co, char *options)
 732 {
 733         struct uart_port *port;
 734         int baud = 9600;
 735         int bits = 8;
 736         int parity = 'n';
 737         int flow = 'n';
 738
 739         if (co->index < 0 || co->index >= BCM63XX_NR_UARTS)
 740                 return -EINVAL;
 741         port = &ports[co->index];
 742         if (!port->membase)
 743                 return -ENODEV;
 744         if (options)
 745                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 746
 747         return uart_set_options(port, co, baud, parity, bits, flow);
 748 }
 749
 750 static struct uart_driver bcm_uart_driver;
 751
 752 static struct console bcm63xx_console = {
 753         .name           = "ttyS",
 754         .write          = bcm_console_write,
 755         .device         = uart_console_device,
 756         .setup          = bcm_console_setup,
 757         .flags          = CON_PRINTBUFFER,
 758         .index          = -1,
 759         .data           = &bcm_uart_driver,
 760 };
 761
 762 static int __init bcm63xx_console_init(void)
 763 {
 764         register_console(&bcm63xx_console);
 765         return 0;
 766 }
 767
 768 console_initcall(bcm63xx_console_init);
 769
 770 static void bcm_early_write(struct console *con, const char *s, unsigned n)
 771 {
 772         struct earlycon_device *dev = con->data;
 773
 774         uart_console_write(&dev->port, s, n, bcm_console_putchar);
 775         wait_for_xmitr(&dev->port);
 776 }
 777
 778 static int __init bcm_early_console_setup(struct earlycon_device *device,
 779                                           const char *opt)
 780 {
 781         if (!device->port.membase)
 782                 return -ENODEV;
 783
 784         device->con->write = bcm_early_write;
 785         return 0;
 786 }
 787
 788 OF_EARLYCON_DECLARE(bcm63xx_uart, "brcm,bcm6345-uart", bcm_early_console_setup);
 789
 790 #define BCM63XX_CONSOLE (&bcm63xx_console)
 791 #else
 792 #define BCM63XX_CONSOLE NULL
 793 #endif /* CONFIG_SERIAL_BCM63XX_CONSOLE */
 794
 795 static struct uart_driver bcm_uart_driver = {
 796         .owner          = THIS_MODULE,
 797         .driver_name    = "bcm63xx_uart",
 798         .dev_name       = "ttyS",
 799         .major          = TTY_MAJOR,
 800         .minor          = 64,
 801         .nr             = BCM63XX_NR_UARTS,
 802         .cons           = BCM63XX_CONSOLE,
 803 };
 804
 805 /*
 806  * platform driver probe/remove callback
 807  */
 808 static int bcm_uart_probe(struct platform_device *pdev)
 809 {
 810         struct resource *res_mem;
 811         struct uart_port *port;
 812         struct clk *clk;
 813         int ret;
 814
 815         if (pdev->dev.of_node) {
 816                 pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
 817
 818                 if (pdev->id < 0)
 819                         pdev->id = of_alias_get_id(pdev->dev.of_node, "uart");
 820         }
 821
 822         if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS)
 823                 return -EINVAL;
 824
 825         port = &ports[pdev->id];
 826         if (port->membase)
 827                 return -EBUSY;
 828         memset(port, 0, sizeof(*port));
 829
 830         port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res_mem);
 831         if (IS_ERR(port->membase))
 832                 return PTR_ERR(port->membase);
 833         port->mapbase = res_mem->start;
 834
 835         ret = platform_get_irq(pdev, 0);
 836         if (ret < 0)
 837                 return ret;
 838         port->irq = ret;
 839
 840         clk = clk_get(&pdev->dev, "refclk");
 841         if (IS_ERR(clk) && pdev->dev.of_node)
 842                 clk = of_clk_get(pdev->dev.of_node, 0);
 843
 844         if (IS_ERR(clk))
 845                 return -ENODEV;
 846
 847         port->iotype = UPIO_MEM;
 848         port->ops = &bcm_uart_ops;
 849         port->flags = UPF_BOOT_AUTOCONF;
 850         port->dev = &pdev->dev;
 851         port->fifosize = 16;
 852         port->uartclk = clk_get_rate(clk) / 2;
 853         port->line = pdev->id;
 854         port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_BCM63XX_CONSOLE);
 855         clk_put(clk);
 856
 857         ret = uart_add_one_port(&bcm_uart_driver, port);
 858         if (ret) {
 859                 ports[pdev->id].membase = NULL;
 860                 return ret;
 861         }
 862         platform_set_drvdata(pdev, port);
 863         return 0;
 864 }
 865
 866 static void bcm_uart_remove(struct platform_device *pdev)
 867 {
 868         struct uart_port *port;
 869
 870         port = platform_get_drvdata(pdev);
 871         uart_remove_one_port(&bcm_uart_driver, port);
 872         /* mark port as free */
 873         ports[pdev->id].membase = NULL;
 874 }
 875
 876 static const struct of_device_id bcm63xx_of_match[] = {
 877         { .compatible = "brcm,bcm6345-uart" },
 878         { /* sentinel */ }
 879 };
 880 MODULE_DEVICE_TABLE(of, bcm63xx_of_match);
 881
 882 /*
 883  * platform driver stuff
 884  */
 885 static struct platform_driver bcm_uart_platform_driver = {
 886         .probe  = bcm_uart_probe,
 887         .remove = bcm_uart_remove,
 888         .driver = {
 889                 .name  = "bcm63xx_uart",
 890                 .of_match_table = bcm63xx_of_match,
 891         },
 892 };
 893
 894 static int __init bcm_uart_init(void)
 895 {
 896         int ret;
 897
 898         ret = uart_register_driver(&bcm_uart_driver);
 899         if (ret)
 900                 return ret;
 901
 902         ret = platform_driver_register(&bcm_uart_platform_driver);
 903         if (ret)
 904                 uart_unregister_driver(&bcm_uart_driver);
 905
 906         return ret;
 907 }
 908
 909 static void __exit bcm_uart_exit(void)
 910 {
 911         platform_driver_unregister(&bcm_uart_platform_driver);
 912         uart_unregister_driver(&bcm_uart_driver);
 913 }
 914
 915 module_init(bcm_uart_init);
 916 module_exit(bcm_uart_exit);
 917
 918 MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
 919 MODULE_DESCRIPTION("Broadcom 63xx integrated uart driver");
 920 MODULE_LICENSE("GPL");