linux/drivers/tty/serial/lantiq.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
   4 *
   5 * Copyright (C) 2004 Infineon IFAP DC COM CPE
   6 * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
   7 * Copyright (C) 2007 John Crispin <john@phrozen.org>
   8 * Copyright (C) 2010 Thomas Langer, <thomas.langer@lantiq.com>
   9 */
  10
  11#include <linux/clk.h>
  12#include <linux/console.h>
  13#include <linux/device.h>
  14#include <linux/gpio.h>
  15#include <linux/init.h>
  16#include <linux/io.h>
  17#include <linux/ioport.h>
  18#include <linux/lantiq.h>
  19#include <linux/of_address.h>
  20#include <linux/of_irq.h>
  21#include <linux/of_platform.h>
  22#include <linux/serial.h>
  23#include <linux/serial_core.h>
  24#include <linux/slab.h>
  25#include <linux/sysrq.h>
  26#include <linux/tty.h>
  27#include <linux/tty_flip.h>
  28
  29#define PORT_LTQ_ASC            111
  30#define MAXPORTS                2
  31#define UART_DUMMY_UER_RX       1
  32#define DRVNAME                 "lantiq,asc"
  33#ifdef __BIG_ENDIAN
  34#define LTQ_ASC_TBUF            (0x0020 + 3)
  35#define LTQ_ASC_RBUF            (0x0024 + 3)
  36#else
  37#define LTQ_ASC_TBUF            0x0020
  38#define LTQ_ASC_RBUF            0x0024
  39#endif
  40#define LTQ_ASC_FSTAT           0x0048
  41#define LTQ_ASC_WHBSTATE        0x0018
  42#define LTQ_ASC_STATE           0x0014
  43#define LTQ_ASC_IRNCR           0x00F8
  44#define LTQ_ASC_CLC             0x0000
  45#define LTQ_ASC_ID              0x0008
  46#define LTQ_ASC_PISEL           0x0004
  47#define LTQ_ASC_TXFCON          0x0044
  48#define LTQ_ASC_RXFCON          0x0040
  49#define LTQ_ASC_CON             0x0010
  50#define LTQ_ASC_BG              0x0050
  51#define LTQ_ASC_IRNREN          0x00F4
  52
  53#define ASC_IRNREN_TX           0x1
  54#define ASC_IRNREN_RX           0x2
  55#define ASC_IRNREN_ERR          0x4
  56#define ASC_IRNREN_TX_BUF       0x8
  57#define ASC_IRNCR_TIR           0x1
  58#define ASC_IRNCR_RIR           0x2
  59#define ASC_IRNCR_EIR           0x4
  60
  61#define ASCOPT_CSIZE            0x3
  62#define TXFIFO_FL               1
  63#define RXFIFO_FL               1
  64#define ASCCLC_DISS             0x2
  65#define ASCCLC_RMCMASK          0x0000FF00
  66#define ASCCLC_RMCOFFSET        8
  67#define ASCCON_M_8ASYNC         0x0
  68#define ASCCON_M_7ASYNC         0x2
  69#define ASCCON_ODD              0x00000020
  70#define ASCCON_STP              0x00000080
  71#define ASCCON_BRS              0x00000100
  72#define ASCCON_FDE              0x00000200
  73#define ASCCON_R                0x00008000
  74#define ASCCON_FEN              0x00020000
  75#define ASCCON_ROEN             0x00080000
  76#define ASCCON_TOEN             0x00100000
  77#define ASCSTATE_PE             0x00010000
  78#define ASCSTATE_FE             0x00020000
  79#define ASCSTATE_ROE            0x00080000
  80#define ASCSTATE_ANY            (ASCSTATE_ROE|ASCSTATE_PE|ASCSTATE_FE)
  81#define ASCWHBSTATE_CLRREN      0x00000001
  82#define ASCWHBSTATE_SETREN      0x00000002
  83#define ASCWHBSTATE_CLRPE       0x00000004
  84#define ASCWHBSTATE_CLRFE       0x00000008
  85#define ASCWHBSTATE_CLRROE      0x00000020
  86#define ASCTXFCON_TXFEN         0x0001
  87#define ASCTXFCON_TXFFLU        0x0002
  88#define ASCTXFCON_TXFITLMASK    0x3F00
  89#define ASCTXFCON_TXFITLOFF     8
  90#define ASCRXFCON_RXFEN         0x0001
  91#define ASCRXFCON_RXFFLU        0x0002
  92#define ASCRXFCON_RXFITLMASK    0x3F00
  93#define ASCRXFCON_RXFITLOFF     8
  94#define ASCFSTAT_RXFFLMASK      0x003F
  95#define ASCFSTAT_TXFFLMASK      0x3F00
  96#define ASCFSTAT_TXFREEMASK     0x3F000000
  97#define ASCFSTAT_TXFREEOFF      24
  98
  99static void lqasc_tx_chars(struct uart_port *port);
 100static struct ltq_uart_port *lqasc_port[MAXPORTS];
 101static struct uart_driver lqasc_reg;
 102static DEFINE_SPINLOCK(ltq_asc_lock);
 103
 104struct ltq_uart_port {
 105        struct uart_port        port;
 106        /* clock used to derive divider */
 107        struct clk              *freqclk;
 108        /* clock gating of the ASC core */
 109        struct clk              *clk;
 110        unsigned int            tx_irq;
 111        unsigned int            rx_irq;
 112        unsigned int            err_irq;
 113};
 114
 115static inline void asc_update_bits(u32 clear, u32 set, void __iomem *reg)
 116{
 117        u32 tmp = __raw_readl(reg);
 118
 119        __raw_writel((tmp & ~clear) | set, reg);
 120}
 121
 122static inline struct
 123ltq_uart_port *to_ltq_uart_port(struct uart_port *port)
 124{
 125        return container_of(port, struct ltq_uart_port, port);
 126}
 127
 128static void
 129lqasc_stop_tx(struct uart_port *port)
 130{
 131        return;
 132}
 133
 134static void
 135lqasc_start_tx(struct uart_port *port)
 136{
 137        unsigned long flags;
 138        spin_lock_irqsave(&ltq_asc_lock, flags);
 139        lqasc_tx_chars(port);
 140        spin_unlock_irqrestore(&ltq_asc_lock, flags);
 141        return;
 142}
 143
 144static void
 145lqasc_stop_rx(struct uart_port *port)
 146{
 147        __raw_writel(ASCWHBSTATE_CLRREN, port->membase + LTQ_ASC_WHBSTATE);
 148}
 149
 150static int
 151lqasc_rx_chars(struct uart_port *port)
 152{
 153        struct tty_port *tport = &port->state->port;
 154        unsigned int ch = 0, rsr = 0, fifocnt;
 155
 156        fifocnt = __raw_readl(port->membase + LTQ_ASC_FSTAT) &
 157                  ASCFSTAT_RXFFLMASK;
 158        while (fifocnt--) {
 159                u8 flag = TTY_NORMAL;
 160                ch = readb(port->membase + LTQ_ASC_RBUF);
 161                rsr = (__raw_readl(port->membase + LTQ_ASC_STATE)
 162                        & ASCSTATE_ANY) | UART_DUMMY_UER_RX;
 163                tty_flip_buffer_push(tport);
 164                port->icount.rx++;
 165
 166                /*
 167                 * Note that the error handling code is
 168                 * out of the main execution path
 169                 */
 170                if (rsr & ASCSTATE_ANY) {
 171                        if (rsr & ASCSTATE_PE) {
 172                                port->icount.parity++;
 173                                asc_update_bits(0, ASCWHBSTATE_CLRPE,
 174                                        port->membase + LTQ_ASC_WHBSTATE);
 175                        } else if (rsr & ASCSTATE_FE) {
 176                                port->icount.frame++;
 177                                asc_update_bits(0, ASCWHBSTATE_CLRFE,
 178                                        port->membase + LTQ_ASC_WHBSTATE);
 179                        }
 180                        if (rsr & ASCSTATE_ROE) {
 181                                port->icount.overrun++;
 182                                asc_update_bits(0, ASCWHBSTATE_CLRROE,
 183                                        port->membase + LTQ_ASC_WHBSTATE);
 184                        }
 185
 186                        rsr &= port->read_status_mask;
 187
 188                        if (rsr & ASCSTATE_PE)
 189                                flag = TTY_PARITY;
 190                        else if (rsr & ASCSTATE_FE)
 191                                flag = TTY_FRAME;
 192                }
 193
 194                if ((rsr & port->ignore_status_mask) == 0)
 195                        tty_insert_flip_char(tport, ch, flag);
 196
 197                if (rsr & ASCSTATE_ROE)
 198                        /*
 199                         * Overrun is special, since it's reported
 200                         * immediately, and doesn't affect the current
 201                         * character
 202                         */
 203                        tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 204        }
 205
 206        if (ch != 0)
 207                tty_flip_buffer_push(tport);
 208
 209        return 0;
 210}
 211
 212static void
 213lqasc_tx_chars(struct uart_port *port)
 214{
 215        struct circ_buf *xmit = &port->state->xmit;
 216        if (uart_tx_stopped(port)) {
 217                lqasc_stop_tx(port);
 218                return;
 219        }
 220
 221        while (((__raw_readl(port->membase + LTQ_ASC_FSTAT) &
 222                ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF) != 0) {
 223                if (port->x_char) {
 224                        writeb(port->x_char, port->membase + LTQ_ASC_TBUF);
 225                        port->icount.tx++;
 226                        port->x_char = 0;
 227                        continue;
 228                }
 229
 230                if (uart_circ_empty(xmit))
 231                        break;
 232
 233                writeb(port->state->xmit.buf[port->state->xmit.tail],
 234                        port->membase + LTQ_ASC_TBUF);
 235                xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 236                port->icount.tx++;
 237        }
 238
 239        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 240                uart_write_wakeup(port);
 241}
 242
 243static irqreturn_t
 244lqasc_tx_int(int irq, void *_port)
 245{
 246        unsigned long flags;
 247        struct uart_port *port = (struct uart_port *)_port;
 248        spin_lock_irqsave(&ltq_asc_lock, flags);
 249        __raw_writel(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);
 250        spin_unlock_irqrestore(&ltq_asc_lock, flags);
 251        lqasc_start_tx(port);
 252        return IRQ_HANDLED;
 253}
 254
 255static irqreturn_t
 256lqasc_err_int(int irq, void *_port)
 257{
 258        unsigned long flags;
 259        struct uart_port *port = (struct uart_port *)_port;
 260        spin_lock_irqsave(&ltq_asc_lock, flags);
 261        /* clear any pending interrupts */
 262        asc_update_bits(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |
 263                ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE);
 264        spin_unlock_irqrestore(&ltq_asc_lock, flags);
 265        return IRQ_HANDLED;
 266}
 267
 268static irqreturn_t
 269lqasc_rx_int(int irq, void *_port)
 270{
 271        unsigned long flags;
 272        struct uart_port *port = (struct uart_port *)_port;
 273        spin_lock_irqsave(&ltq_asc_lock, flags);
 274        __raw_writel(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);
 275        lqasc_rx_chars(port);
 276        spin_unlock_irqrestore(&ltq_asc_lock, flags);
 277        return IRQ_HANDLED;
 278}
 279
 280static unsigned int
 281lqasc_tx_empty(struct uart_port *port)
 282{
 283        int status;
 284        status = __raw_readl(port->membase + LTQ_ASC_FSTAT) &
 285                 ASCFSTAT_TXFFLMASK;
 286        return status ? 0 : TIOCSER_TEMT;
 287}
 288
 289static unsigned int
 290lqasc_get_mctrl(struct uart_port *port)
 291{
 292        return TIOCM_CTS | TIOCM_CAR | TIOCM_DSR;
 293}
 294
 295static void
 296lqasc_set_mctrl(struct uart_port *port, u_int mctrl)
 297{
 298}
 299
 300static void
 301lqasc_break_ctl(struct uart_port *port, int break_state)
 302{
 303}
 304
 305static int
 306lqasc_startup(struct uart_port *port)
 307{
 308        struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
 309        int retval;
 310
 311        if (!IS_ERR(ltq_port->clk))
 312                clk_prepare_enable(ltq_port->clk);
 313        port->uartclk = clk_get_rate(ltq_port->freqclk);
 314
 315        asc_update_bits(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),
 316                port->membase + LTQ_ASC_CLC);
 317
 318        __raw_writel(0, port->membase + LTQ_ASC_PISEL);
 319        __raw_writel(
 320                ((TXFIFO_FL << ASCTXFCON_TXFITLOFF) & ASCTXFCON_TXFITLMASK) |
 321                ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU,
 322                port->membase + LTQ_ASC_TXFCON);
 323        __raw_writel(
 324                ((RXFIFO_FL << ASCRXFCON_RXFITLOFF) & ASCRXFCON_RXFITLMASK)
 325                | ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU,
 326                port->membase + LTQ_ASC_RXFCON);
 327        /* make sure other settings are written to hardware before
 328         * setting enable bits
 329         */
 330        wmb();
 331        asc_update_bits(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN |
 332                ASCCON_ROEN, port->membase + LTQ_ASC_CON);
 333
 334        retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,
 335                0, "asc_tx", port);
 336        if (retval) {
 337                pr_err("failed to request lqasc_tx_int\n");
 338                return retval;
 339        }
 340
 341        retval = request_irq(ltq_port->rx_irq, lqasc_rx_int,
 342                0, "asc_rx", port);
 343        if (retval) {
 344                pr_err("failed to request lqasc_rx_int\n");
 345                goto err1;
 346        }
 347
 348        retval = request_irq(ltq_port->err_irq, lqasc_err_int,
 349                0, "asc_err", port);
 350        if (retval) {
 351                pr_err("failed to request lqasc_err_int\n");
 352                goto err2;
 353        }
 354
 355        __raw_writel(ASC_IRNREN_RX | ASC_IRNREN_ERR | ASC_IRNREN_TX,
 356                port->membase + LTQ_ASC_IRNREN);
 357        return 0;
 358
 359err2:
 360        free_irq(ltq_port->rx_irq, port);
 361err1:
 362        free_irq(ltq_port->tx_irq, port);
 363        return retval;
 364}
 365
 366static void
 367lqasc_shutdown(struct uart_port *port)
 368{
 369        struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
 370        free_irq(ltq_port->tx_irq, port);
 371        free_irq(ltq_port->rx_irq, port);
 372        free_irq(ltq_port->err_irq, port);
 373
 374        __raw_writel(0, port->membase + LTQ_ASC_CON);
 375        asc_update_bits(ASCRXFCON_RXFEN, ASCRXFCON_RXFFLU,
 376                port->membase + LTQ_ASC_RXFCON);
 377        asc_update_bits(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU,
 378                port->membase + LTQ_ASC_TXFCON);
 379        if (!IS_ERR(ltq_port->clk))
 380                clk_disable_unprepare(ltq_port->clk);
 381}
 382
 383static void
 384lqasc_set_termios(struct uart_port *port,
 385        struct ktermios *new, struct ktermios *old)
 386{
 387        unsigned int cflag;
 388        unsigned int iflag;
 389        unsigned int divisor;
 390        unsigned int baud;
 391        unsigned int con = 0;
 392        unsigned long flags;
 393
 394        cflag = new->c_cflag;
 395        iflag = new->c_iflag;
 396
 397        switch (cflag & CSIZE) {
 398        case CS7:
 399                con = ASCCON_M_7ASYNC;
 400                break;
 401
 402        case CS5:
 403        case CS6:
 404        default:
 405                new->c_cflag &= ~ CSIZE;
 406                new->c_cflag |= CS8;
 407                con = ASCCON_M_8ASYNC;
 408                break;
 409        }
 410
 411        cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
 412
 413        if (cflag & CSTOPB)
 414                con |= ASCCON_STP;
 415
 416        if (cflag & PARENB) {
 417                if (!(cflag & PARODD))
 418                        con &= ~ASCCON_ODD;
 419                else
 420                        con |= ASCCON_ODD;
 421        }
 422
 423        port->read_status_mask = ASCSTATE_ROE;
 424        if (iflag & INPCK)
 425                port->read_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
 426
 427        port->ignore_status_mask = 0;
 428        if (iflag & IGNPAR)
 429                port->ignore_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
 430
 431        if (iflag & IGNBRK) {
 432                /*
 433                 * If we're ignoring parity and break indicators,
 434                 * ignore overruns too (for real raw support).
 435                 */
 436                if (iflag & IGNPAR)
 437                        port->ignore_status_mask |= ASCSTATE_ROE;
 438        }
 439
 440        if ((cflag & CREAD) == 0)
 441                port->ignore_status_mask |= UART_DUMMY_UER_RX;
 442
 443        /* set error signals  - framing, parity  and overrun, enable receiver */
 444        con |= ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN;
 445
 446        spin_lock_irqsave(&ltq_asc_lock, flags);
 447
 448        /* set up CON */
 449        asc_update_bits(0, con, port->membase + LTQ_ASC_CON);
 450
 451        /* Set baud rate - take a divider of 2 into account */
 452        baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
 453        divisor = uart_get_divisor(port, baud);
 454        divisor = divisor / 2 - 1;
 455
 456        /* disable the baudrate generator */
 457        asc_update_bits(ASCCON_R, 0, port->membase + LTQ_ASC_CON);
 458
 459        /* make sure the fractional divider is off */
 460        asc_update_bits(ASCCON_FDE, 0, port->membase + LTQ_ASC_CON);
 461
 462        /* set up to use divisor of 2 */
 463        asc_update_bits(ASCCON_BRS, 0, port->membase + LTQ_ASC_CON);
 464
 465        /* now we can write the new baudrate into the register */
 466        __raw_writel(divisor, port->membase + LTQ_ASC_BG);
 467
 468        /* turn the baudrate generator back on */
 469        asc_update_bits(0, ASCCON_R, port->membase + LTQ_ASC_CON);
 470
 471        /* enable rx */
 472        __raw_writel(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE);
 473
 474        spin_unlock_irqrestore(&ltq_asc_lock, flags);
 475
 476        /* Don't rewrite B0 */
 477        if (tty_termios_baud_rate(new))
 478                tty_termios_encode_baud_rate(new, baud, baud);
 479
 480        uart_update_timeout(port, cflag, baud);
 481}
 482
 483static const char*
 484lqasc_type(struct uart_port *port)
 485{
 486        if (port->type == PORT_LTQ_ASC)
 487                return DRVNAME;
 488        else
 489                return NULL;
 490}
 491
 492static void
 493lqasc_release_port(struct uart_port *port)
 494{
 495        struct platform_device *pdev = to_platform_device(port->dev);
 496
 497        if (port->flags & UPF_IOREMAP) {
 498                devm_iounmap(&pdev->dev, port->membase);
 499                port->membase = NULL;
 500        }
 501}
 502
 503static int
 504lqasc_request_port(struct uart_port *port)
 505{
 506        struct platform_device *pdev = to_platform_device(port->dev);
 507        struct resource *res;
 508        int size;
 509
 510        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 511        if (!res) {
 512                dev_err(&pdev->dev, "cannot obtain I/O memory region");
 513                return -ENODEV;
 514        }
 515        size = resource_size(res);
 516
 517        res = devm_request_mem_region(&pdev->dev, res->start,
 518                size, dev_name(&pdev->dev));
 519        if (!res) {
 520                dev_err(&pdev->dev, "cannot request I/O memory region");
 521                return -EBUSY;
 522        }
 523
 524        if (port->flags & UPF_IOREMAP) {
 525                port->membase = devm_ioremap_nocache(&pdev->dev,
 526                        port->mapbase, size);
 527                if (port->membase == NULL)
 528                        return -ENOMEM;
 529        }
 530        return 0;
 531}
 532
 533static void
 534lqasc_config_port(struct uart_port *port, int flags)
 535{
 536        if (flags & UART_CONFIG_TYPE) {
 537                port->type = PORT_LTQ_ASC;
 538                lqasc_request_port(port);
 539        }
 540}
 541
 542static int
 543lqasc_verify_port(struct uart_port *port,
 544        struct serial_struct *ser)
 545{
 546        int ret = 0;
 547        if (ser->type != PORT_UNKNOWN && ser->type != PORT_LTQ_ASC)
 548                ret = -EINVAL;
 549        if (ser->irq < 0 || ser->irq >= NR_IRQS)
 550                ret = -EINVAL;
 551        if (ser->baud_base < 9600)
 552                ret = -EINVAL;
 553        return ret;
 554}
 555
 556static const struct uart_ops lqasc_pops = {
 557        .tx_empty =     lqasc_tx_empty,
 558        .set_mctrl =    lqasc_set_mctrl,
 559        .get_mctrl =    lqasc_get_mctrl,
 560        .stop_tx =      lqasc_stop_tx,
 561        .start_tx =     lqasc_start_tx,
 562        .stop_rx =      lqasc_stop_rx,
 563        .break_ctl =    lqasc_break_ctl,
 564        .startup =      lqasc_startup,
 565        .shutdown =     lqasc_shutdown,
 566        .set_termios =  lqasc_set_termios,
 567        .type =         lqasc_type,
 568        .release_port = lqasc_release_port,
 569        .request_port = lqasc_request_port,
 570        .config_port =  lqasc_config_port,
 571        .verify_port =  lqasc_verify_port,
 572};
 573
 574static void
 575lqasc_console_putchar(struct uart_port *port, int ch)
 576{
 577        int fifofree;
 578
 579        if (!port->membase)
 580                return;
 581
 582        do {
 583                fifofree = (__raw_readl(port->membase + LTQ_ASC_FSTAT)
 584                        & ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF;
 585        } while (fifofree == 0);
 586        writeb(ch, port->membase + LTQ_ASC_TBUF);
 587}
 588
 589static void lqasc_serial_port_write(struct uart_port *port, const char *s,
 590                                    u_int count)
 591{
 592        unsigned long flags;
 593
 594        spin_lock_irqsave(&ltq_asc_lock, flags);
 595        uart_console_write(port, s, count, lqasc_console_putchar);
 596        spin_unlock_irqrestore(&ltq_asc_lock, flags);
 597}
 598
 599static void
 600lqasc_console_write(struct console *co, const char *s, u_int count)
 601{
 602        struct ltq_uart_port *ltq_port;
 603
 604        if (co->index >= MAXPORTS)
 605                return;
 606
 607        ltq_port = lqasc_port[co->index];
 608        if (!ltq_port)
 609                return;
 610
 611        lqasc_serial_port_write(&ltq_port->port, s, count);
 612}
 613
 614static int __init
 615lqasc_console_setup(struct console *co, char *options)
 616{
 617        struct ltq_uart_port *ltq_port;
 618        struct uart_port *port;
 619        int baud = 115200;
 620        int bits = 8;
 621        int parity = 'n';
 622        int flow = 'n';
 623
 624        if (co->index >= MAXPORTS)
 625                return -ENODEV;
 626
 627        ltq_port = lqasc_port[co->index];
 628        if (!ltq_port)
 629                return -ENODEV;
 630
 631        port = &ltq_port->port;
 632
 633        if (!IS_ERR(ltq_port->clk))
 634                clk_prepare_enable(ltq_port->clk);
 635
 636        port->uartclk = clk_get_rate(ltq_port->freqclk);
 637
 638        if (options)
 639                uart_parse_options(options, &baud, &parity, &bits, &flow);
 640        return uart_set_options(port, co, baud, parity, bits, flow);
 641}
 642
 643static struct console lqasc_console = {
 644        .name =         "ttyLTQ",
 645        .write =        lqasc_console_write,
 646        .device =       uart_console_device,
 647        .setup =        lqasc_console_setup,
 648        .flags =        CON_PRINTBUFFER,
 649        .index =        -1,
 650        .data =         &lqasc_reg,
 651};
 652
 653static int __init
 654lqasc_console_init(void)
 655{
 656        register_console(&lqasc_console);
 657        return 0;
 658}
 659console_initcall(lqasc_console_init);
 660
 661static void lqasc_serial_early_console_write(struct console *co,
 662                                             const char *s,
 663                                             u_int count)
 664{
 665        struct earlycon_device *dev = co->data;
 666
 667        lqasc_serial_port_write(&dev->port, s, count);
 668}
 669
 670static int __init
 671lqasc_serial_early_console_setup(struct earlycon_device *device,
 672                                 const char *opt)
 673{
 674        if (!device->port.membase)
 675                return -ENODEV;
 676
 677        device->con->write = lqasc_serial_early_console_write;
 678        return 0;
 679}
 680OF_EARLYCON_DECLARE(lantiq, DRVNAME, lqasc_serial_early_console_setup);
 681
 682static struct uart_driver lqasc_reg = {
 683        .owner =        THIS_MODULE,
 684        .driver_name =  DRVNAME,
 685        .dev_name =     "ttyLTQ",
 686        .major =        0,
 687        .minor =        0,
 688        .nr =           MAXPORTS,
 689        .cons =         &lqasc_console,
 690};
 691
 692static int __init
 693lqasc_probe(struct platform_device *pdev)
 694{
 695        struct device_node *node = pdev->dev.of_node;
 696        struct ltq_uart_port *ltq_port;
 697        struct uart_port *port;
 698        struct resource *mmres, irqres[3];
 699        int line;
 700        int ret;
 701
 702        mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 703        ret = of_irq_to_resource_table(node, irqres, 3);
 704        if (!mmres || (ret != 3)) {
 705                dev_err(&pdev->dev,
 706                        "failed to get memory/irq for serial port\n");
 707                return -ENODEV;
 708        }
 709
 710        /* get serial id */
 711        line = of_alias_get_id(node, "serial");
 712        if (line < 0) {
 713                if (IS_ENABLED(CONFIG_LANTIQ)) {
 714                        if (mmres->start == CPHYSADDR(LTQ_EARLY_ASC))
 715                                line = 0;
 716                        else
 717                                line = 1;
 718                } else {
 719                        dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
 720                                line);
 721                        return line;
 722                }
 723        }
 724
 725        if (lqasc_port[line]) {
 726                dev_err(&pdev->dev, "port %d already allocated\n", line);
 727                return -EBUSY;
 728        }
 729
 730        ltq_port = devm_kzalloc(&pdev->dev, sizeof(struct ltq_uart_port),
 731                        GFP_KERNEL);
 732        if (!ltq_port)
 733                return -ENOMEM;
 734
 735        port = &ltq_port->port;
 736
 737        port->iotype    = SERIAL_IO_MEM;
 738        port->flags     = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
 739        port->ops       = &lqasc_pops;
 740        port->fifosize  = 16;
 741        port->type      = PORT_LTQ_ASC,
 742        port->line      = line;
 743        port->dev       = &pdev->dev;
 744        /* unused, just to be backward-compatible */
 745        port->irq       = irqres[0].start;
 746        port->mapbase   = mmres->start;
 747
 748        if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
 749                ltq_port->freqclk = clk_get_fpi();
 750        else
 751                ltq_port->freqclk = devm_clk_get(&pdev->dev, "freq");
 752
 753
 754        if (IS_ERR(ltq_port->freqclk)) {
 755                pr_err("failed to get fpi clk\n");
 756                return -ENOENT;
 757        }
 758
 759        /* not all asc ports have clock gates, lets ignore the return code */
 760        if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
 761                ltq_port->clk = clk_get(&pdev->dev, NULL);
 762        else
 763                ltq_port->clk = devm_clk_get(&pdev->dev, "asc");
 764
 765        ltq_port->tx_irq = irqres[0].start;
 766        ltq_port->rx_irq = irqres[1].start;
 767        ltq_port->err_irq = irqres[2].start;
 768
 769        lqasc_port[line] = ltq_port;
 770        platform_set_drvdata(pdev, ltq_port);
 771
 772        ret = uart_add_one_port(&lqasc_reg, port);
 773
 774        return ret;
 775}
 776
 777static const struct of_device_id ltq_asc_match[] = {
 778        { .compatible = DRVNAME },
 779        {},
 780};
 781
 782static struct platform_driver lqasc_driver = {
 783        .driver         = {
 784                .name   = DRVNAME,
 785                .of_match_table = ltq_asc_match,
 786        },
 787};
 788
 789static int __init
 790init_lqasc(void)
 791{
 792        int ret;
 793
 794        ret = uart_register_driver(&lqasc_reg);
 795        if (ret != 0)
 796                return ret;
 797
 798        ret = platform_driver_probe(&lqasc_driver, lqasc_probe);
 799        if (ret != 0)
 800                uart_unregister_driver(&lqasc_reg);
 801
 802        return ret;
 803}
 804device_initcall(init_lqasc);
 805