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