linux/drivers/tty/serial/bfin_sport_uart.c
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   1/*
   2 * Blackfin On-Chip Sport Emulated UART Driver
   3 *
   4 * Copyright 2006-2009 Analog Devices Inc.
   5 *
   6 * Enter bugs at http://blackfin.uclinux.org/
   7 *
   8 * Licensed under the GPL-2 or later.
   9 */
  10
  11/*
  12 * This driver and the hardware supported are in term of EE-191 of ADI.
  13 * http://www.analog.com/static/imported-files/application_notes/EE191.pdf 
  14 * This application note describe how to implement a UART on a Sharc DSP,
  15 * but this driver is implemented on Blackfin Processor.
  16 * Transmit Frame Sync is not used by this driver to transfer data out.
  17 */
  18
  19/* #define DEBUG */
  20
  21#define DRV_NAME "bfin-sport-uart"
  22#define DEVICE_NAME     "ttySS"
  23#define pr_fmt(fmt) DRV_NAME ": " fmt
  24
  25#include <linux/module.h>
  26#include <linux/ioport.h>
  27#include <linux/io.h>
  28#include <linux/init.h>
  29#include <linux/console.h>
  30#include <linux/sysrq.h>
  31#include <linux/slab.h>
  32#include <linux/platform_device.h>
  33#include <linux/tty.h>
  34#include <linux/tty_flip.h>
  35#include <linux/serial_core.h>
  36
  37#include <asm/bfin_sport.h>
  38#include <asm/delay.h>
  39#include <asm/portmux.h>
  40
  41#include "bfin_sport_uart.h"
  42
  43struct sport_uart_port {
  44        struct uart_port        port;
  45        int                     err_irq;
  46        unsigned short          csize;
  47        unsigned short          rxmask;
  48        unsigned short          txmask1;
  49        unsigned short          txmask2;
  50        unsigned char           stopb;
  51/*      unsigned char           parib; */
  52#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
  53        int cts_pin;
  54        int rts_pin;
  55#endif
  56};
  57
  58static int sport_uart_tx_chars(struct sport_uart_port *up);
  59static void sport_stop_tx(struct uart_port *port);
  60
  61static inline void tx_one_byte(struct sport_uart_port *up, unsigned int value)
  62{
  63        pr_debug("%s value:%x, mask1=0x%x, mask2=0x%x\n", __func__, value,
  64                up->txmask1, up->txmask2);
  65
  66        /* Place Start and Stop bits */
  67        __asm__ __volatile__ (
  68                "%[val] <<= 1;"
  69                "%[val] = %[val] & %[mask1];"
  70                "%[val] = %[val] | %[mask2];"
  71                : [val]"+d"(value)
  72                : [mask1]"d"(up->txmask1), [mask2]"d"(up->txmask2)
  73                : "ASTAT"
  74        );
  75        pr_debug("%s value:%x\n", __func__, value);
  76
  77        SPORT_PUT_TX(up, value);
  78}
  79
  80static inline unsigned char rx_one_byte(struct sport_uart_port *up)
  81{
  82        unsigned int value;
  83        unsigned char extract;
  84        u32 tmp_mask1, tmp_mask2, tmp_shift, tmp;
  85
  86        if ((up->csize + up->stopb) > 7)
  87                value = SPORT_GET_RX32(up);
  88        else
  89                value = SPORT_GET_RX(up);
  90
  91        pr_debug("%s value:%x, cs=%d, mask=0x%x\n", __func__, value,
  92                up->csize, up->rxmask);
  93
  94        /* Extract data */
  95        __asm__ __volatile__ (
  96                "%[extr] = 0;"
  97                "%[mask1] = %[rxmask];"
  98                "%[mask2] = 0x0200(Z);"
  99                "%[shift] = 0;"
 100                "LSETUP(.Lloop_s, .Lloop_e) LC0 = %[lc];"
 101                ".Lloop_s:"
 102                "%[tmp] = extract(%[val], %[mask1].L)(Z);"
 103                "%[tmp] <<= %[shift];"
 104                "%[extr] = %[extr] | %[tmp];"
 105                "%[mask1] = %[mask1] - %[mask2];"
 106                ".Lloop_e:"
 107                "%[shift] += 1;"
 108                : [extr]"=&d"(extract), [shift]"=&d"(tmp_shift), [tmp]"=&d"(tmp),
 109                  [mask1]"=&d"(tmp_mask1), [mask2]"=&d"(tmp_mask2)
 110                : [val]"d"(value), [rxmask]"d"(up->rxmask), [lc]"a"(up->csize)
 111                : "ASTAT", "LB0", "LC0", "LT0"
 112        );
 113
 114        pr_debug("      extract:%x\n", extract);
 115        return extract;
 116}
 117
 118static int sport_uart_setup(struct sport_uart_port *up, int size, int baud_rate)
 119{
 120        int tclkdiv, rclkdiv;
 121        unsigned int sclk = get_sclk();
 122
 123        /* Set TCR1 and TCR2, TFSR is not enabled for uart */
 124        SPORT_PUT_TCR1(up, (LATFS | ITFS | TFSR | TLSBIT | ITCLK));
 125        SPORT_PUT_TCR2(up, size + 1);
 126        pr_debug("%s TCR1:%x, TCR2:%x\n", __func__, SPORT_GET_TCR1(up), SPORT_GET_TCR2(up));
 127
 128        /* Set RCR1 and RCR2 */
 129        SPORT_PUT_RCR1(up, (RCKFE | LARFS | LRFS | RFSR | IRCLK));
 130        SPORT_PUT_RCR2(up, (size + 1) * 2 - 1);
 131        pr_debug("%s RCR1:%x, RCR2:%x\n", __func__, SPORT_GET_RCR1(up), SPORT_GET_RCR2(up));
 132
 133        tclkdiv = sclk / (2 * baud_rate) - 1;
 134        /* The actual uart baud rate of devices vary between +/-2%. The sport
 135         * RX sample rate should be faster than the double of the worst case,
 136         * otherwise, wrong data are received. So, set sport RX clock to be
 137         * 3% faster.
 138         */
 139        rclkdiv = sclk / (2 * baud_rate * 2 * 97 / 100) - 1;
 140        SPORT_PUT_TCLKDIV(up, tclkdiv);
 141        SPORT_PUT_RCLKDIV(up, rclkdiv);
 142        SSYNC();
 143        pr_debug("%s sclk:%d, baud_rate:%d, tclkdiv:%d, rclkdiv:%d\n",
 144                        __func__, sclk, baud_rate, tclkdiv, rclkdiv);
 145
 146        return 0;
 147}
 148
 149static irqreturn_t sport_uart_rx_irq(int irq, void *dev_id)
 150{
 151        struct sport_uart_port *up = dev_id;
 152        struct tty_port *port = &up->port.state->port;
 153        unsigned int ch;
 154
 155        spin_lock(&up->port.lock);
 156
 157        while (SPORT_GET_STAT(up) & RXNE) {
 158                ch = rx_one_byte(up);
 159                up->port.icount.rx++;
 160
 161                if (!uart_handle_sysrq_char(&up->port, ch))
 162                        tty_insert_flip_char(port, ch, TTY_NORMAL);
 163        }
 164
 165        spin_unlock(&up->port.lock);
 166
 167        /* XXX this won't deadlock with lowlat? */
 168        tty_flip_buffer_push(port);
 169
 170        return IRQ_HANDLED;
 171}
 172
 173static irqreturn_t sport_uart_tx_irq(int irq, void *dev_id)
 174{
 175        struct sport_uart_port *up = dev_id;
 176
 177        spin_lock(&up->port.lock);
 178        sport_uart_tx_chars(up);
 179        spin_unlock(&up->port.lock);
 180
 181        return IRQ_HANDLED;
 182}
 183
 184static irqreturn_t sport_uart_err_irq(int irq, void *dev_id)
 185{
 186        struct sport_uart_port *up = dev_id;
 187        unsigned int stat = SPORT_GET_STAT(up);
 188
 189        spin_lock(&up->port.lock);
 190
 191        /* Overflow in RX FIFO */
 192        if (stat & ROVF) {
 193                up->port.icount.overrun++;
 194                tty_insert_flip_char(&up->port.state->port, 0, TTY_OVERRUN);
 195                SPORT_PUT_STAT(up, ROVF); /* Clear ROVF bit */
 196        }
 197        /* These should not happen */
 198        if (stat & (TOVF | TUVF | RUVF)) {
 199                pr_err("SPORT Error:%s %s %s\n",
 200                       (stat & TOVF) ? "TX overflow" : "",
 201                       (stat & TUVF) ? "TX underflow" : "",
 202                       (stat & RUVF) ? "RX underflow" : "");
 203                SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
 204                SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) & ~RSPEN);
 205        }
 206        SSYNC();
 207
 208        spin_unlock(&up->port.lock);
 209        /* XXX we don't push the overrun bit to TTY? */
 210
 211        return IRQ_HANDLED;
 212}
 213
 214#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
 215static unsigned int sport_get_mctrl(struct uart_port *port)
 216{
 217        struct sport_uart_port *up = (struct sport_uart_port *)port;
 218        if (up->cts_pin < 0)
 219                return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
 220
 221        /* CTS PIN is negative assertive. */
 222        if (SPORT_UART_GET_CTS(up))
 223                return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
 224        else
 225                return TIOCM_DSR | TIOCM_CAR;
 226}
 227
 228static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl)
 229{
 230        struct sport_uart_port *up = (struct sport_uart_port *)port;
 231        if (up->rts_pin < 0)
 232                return;
 233
 234        /* RTS PIN is negative assertive. */
 235        if (mctrl & TIOCM_RTS)
 236                SPORT_UART_ENABLE_RTS(up);
 237        else
 238                SPORT_UART_DISABLE_RTS(up);
 239}
 240
 241/*
 242 * Handle any change of modem status signal.
 243 */
 244static irqreturn_t sport_mctrl_cts_int(int irq, void *dev_id)
 245{
 246        struct sport_uart_port *up = (struct sport_uart_port *)dev_id;
 247        unsigned int status;
 248
 249        status = sport_get_mctrl(&up->port);
 250        uart_handle_cts_change(&up->port, status & TIOCM_CTS);
 251
 252        return IRQ_HANDLED;
 253}
 254#else
 255static unsigned int sport_get_mctrl(struct uart_port *port)
 256{
 257        pr_debug("%s enter\n", __func__);
 258        return TIOCM_CTS | TIOCM_CD | TIOCM_DSR;
 259}
 260
 261static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl)
 262{
 263        pr_debug("%s enter\n", __func__);
 264}
 265#endif
 266
 267/* Reqeust IRQ, Setup clock */
 268static int sport_startup(struct uart_port *port)
 269{
 270        struct sport_uart_port *up = (struct sport_uart_port *)port;
 271        int ret;
 272
 273        pr_debug("%s enter\n", __func__);
 274        ret = request_irq(up->port.irq, sport_uart_rx_irq, 0,
 275                "SPORT_UART_RX", up);
 276        if (ret) {
 277                dev_err(port->dev, "unable to request SPORT RX interrupt\n");
 278                return ret;
 279        }
 280
 281        ret = request_irq(up->port.irq+1, sport_uart_tx_irq, 0,
 282                "SPORT_UART_TX", up);
 283        if (ret) {
 284                dev_err(port->dev, "unable to request SPORT TX interrupt\n");
 285                goto fail1;
 286        }
 287
 288        ret = request_irq(up->err_irq, sport_uart_err_irq, 0,
 289                "SPORT_UART_STATUS", up);
 290        if (ret) {
 291                dev_err(port->dev, "unable to request SPORT status interrupt\n");
 292                goto fail2;
 293        }
 294
 295#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
 296        if (up->cts_pin >= 0) {
 297                if (request_irq(gpio_to_irq(up->cts_pin),
 298                        sport_mctrl_cts_int,
 299                        IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
 300                        0, "BFIN_SPORT_UART_CTS", up)) {
 301                        up->cts_pin = -1;
 302                        dev_info(port->dev, "Unable to attach BlackFin UART over SPORT CTS interrupt. So, disable it.\n");
 303                }
 304        }
 305        if (up->rts_pin >= 0) {
 306                if (gpio_request(up->rts_pin, DRV_NAME)) {
 307                        dev_info(port->dev, "fail to request RTS PIN at GPIO_%d\n", up->rts_pin);
 308                        up->rts_pin = -1;
 309                } else
 310                        gpio_direction_output(up->rts_pin, 0);
 311        }
 312#endif
 313
 314        return 0;
 315 fail2:
 316        free_irq(up->port.irq+1, up);
 317 fail1:
 318        free_irq(up->port.irq, up);
 319
 320        return ret;
 321}
 322
 323/*
 324 * sport_uart_tx_chars
 325 *
 326 * ret 1 means need to enable sport.
 327 * ret 0 means do nothing.
 328 */
 329static int sport_uart_tx_chars(struct sport_uart_port *up)
 330{
 331        struct circ_buf *xmit = &up->port.state->xmit;
 332
 333        if (SPORT_GET_STAT(up) & TXF)
 334                return 0;
 335
 336        if (up->port.x_char) {
 337                tx_one_byte(up, up->port.x_char);
 338                up->port.icount.tx++;
 339                up->port.x_char = 0;
 340                return 1;
 341        }
 342
 343        if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
 344                /* The waiting loop to stop SPORT TX from TX interrupt is
 345                 * too long. This may block SPORT RX interrupts and cause
 346                 * RX FIFO overflow. So, do stop sport TX only after the last
 347                 * char in TX FIFO is moved into the shift register.
 348                 */
 349                if (SPORT_GET_STAT(up) & TXHRE)
 350                        sport_stop_tx(&up->port);
 351                return 0;
 352        }
 353
 354        while(!(SPORT_GET_STAT(up) & TXF) && !uart_circ_empty(xmit)) {
 355                tx_one_byte(up, xmit->buf[xmit->tail]);
 356                xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE -1);
 357                up->port.icount.tx++;
 358        }
 359
 360        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 361                uart_write_wakeup(&up->port);
 362
 363        return 1;
 364}
 365
 366static unsigned int sport_tx_empty(struct uart_port *port)
 367{
 368        struct sport_uart_port *up = (struct sport_uart_port *)port;
 369        unsigned int stat;
 370
 371        stat = SPORT_GET_STAT(up);
 372        pr_debug("%s stat:%04x\n", __func__, stat);
 373        if (stat & TXHRE) {
 374                return TIOCSER_TEMT;
 375        } else
 376                return 0;
 377}
 378
 379static void sport_stop_tx(struct uart_port *port)
 380{
 381        struct sport_uart_port *up = (struct sport_uart_port *)port;
 382
 383        pr_debug("%s enter\n", __func__);
 384
 385        if (!(SPORT_GET_TCR1(up) & TSPEN))
 386                return;
 387
 388        /* Although the hold register is empty, last byte is still in shift
 389         * register and not sent out yet. So, put a dummy data into TX FIFO.
 390         * Then, sport tx stops when last byte is shift out and the dummy
 391         * data is moved into the shift register.
 392         */
 393        SPORT_PUT_TX(up, 0xffff);
 394        while (!(SPORT_GET_STAT(up) & TXHRE))
 395                cpu_relax();
 396
 397        SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
 398        SSYNC();
 399
 400        return;
 401}
 402
 403static void sport_start_tx(struct uart_port *port)
 404{
 405        struct sport_uart_port *up = (struct sport_uart_port *)port;
 406
 407        pr_debug("%s enter\n", __func__);
 408
 409        /* Write data into SPORT FIFO before enable SPROT to transmit */
 410        if (sport_uart_tx_chars(up)) {
 411                /* Enable transmit, then an interrupt will generated */
 412                SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
 413                SSYNC();
 414        }
 415
 416        pr_debug("%s exit\n", __func__);
 417}
 418
 419static void sport_stop_rx(struct uart_port *port)
 420{
 421        struct sport_uart_port *up = (struct sport_uart_port *)port;
 422
 423        pr_debug("%s enter\n", __func__);
 424        /* Disable sport to stop rx */
 425        SPORT_PUT_RCR1(up, (SPORT_GET_RCR1(up) & ~RSPEN));
 426        SSYNC();
 427}
 428
 429static void sport_enable_ms(struct uart_port *port)
 430{
 431        pr_debug("%s enter\n", __func__);
 432}
 433
 434static void sport_break_ctl(struct uart_port *port, int break_state)
 435{
 436        pr_debug("%s enter\n", __func__);
 437}
 438
 439static void sport_shutdown(struct uart_port *port)
 440{
 441        struct sport_uart_port *up = (struct sport_uart_port *)port;
 442
 443        dev_dbg(port->dev, "%s enter\n", __func__);
 444
 445        /* Disable sport */
 446        SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
 447        SPORT_PUT_RCR1(up, (SPORT_GET_RCR1(up) & ~RSPEN));
 448        SSYNC();
 449
 450        free_irq(up->port.irq, up);
 451        free_irq(up->port.irq+1, up);
 452        free_irq(up->err_irq, up);
 453#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
 454        if (up->cts_pin >= 0)
 455                free_irq(gpio_to_irq(up->cts_pin), up);
 456        if (up->rts_pin >= 0)
 457                gpio_free(up->rts_pin);
 458#endif
 459}
 460
 461static const char *sport_type(struct uart_port *port)
 462{
 463        struct sport_uart_port *up = (struct sport_uart_port *)port;
 464
 465        pr_debug("%s enter\n", __func__);
 466        return up->port.type == PORT_BFIN_SPORT ? "BFIN-SPORT-UART" : NULL;
 467}
 468
 469static void sport_release_port(struct uart_port *port)
 470{
 471        pr_debug("%s enter\n", __func__);
 472}
 473
 474static int sport_request_port(struct uart_port *port)
 475{
 476        pr_debug("%s enter\n", __func__);
 477        return 0;
 478}
 479
 480static void sport_config_port(struct uart_port *port, int flags)
 481{
 482        struct sport_uart_port *up = (struct sport_uart_port *)port;
 483
 484        pr_debug("%s enter\n", __func__);
 485        up->port.type = PORT_BFIN_SPORT;
 486}
 487
 488static int sport_verify_port(struct uart_port *port, struct serial_struct *ser)
 489{
 490        pr_debug("%s enter\n", __func__);
 491        return 0;
 492}
 493
 494static void sport_set_termios(struct uart_port *port,
 495                struct ktermios *termios, struct ktermios *old)
 496{
 497        struct sport_uart_port *up = (struct sport_uart_port *)port;
 498        unsigned long flags;
 499        int i;
 500
 501        pr_debug("%s enter, c_cflag:%08x\n", __func__, termios->c_cflag);
 502
 503        switch (termios->c_cflag & CSIZE) {
 504        case CS8:
 505                up->csize = 8;
 506                break;
 507        case CS7:
 508                up->csize = 7;
 509                break;
 510        case CS6:
 511                up->csize = 6;
 512                break;
 513        case CS5:
 514                up->csize = 5;
 515                break;
 516        default:
 517                pr_warning("requested word length not supported\n");
 518        }
 519
 520        if (termios->c_cflag & CSTOPB) {
 521                up->stopb = 1;
 522        }
 523        if (termios->c_cflag & PARENB) {
 524                pr_warning("PAREN bits is not supported yet\n");
 525                /* up->parib = 1; */
 526        }
 527
 528        spin_lock_irqsave(&up->port.lock, flags);
 529
 530        port->read_status_mask = 0;
 531
 532        /*
 533         * Characters to ignore
 534         */
 535        port->ignore_status_mask = 0;
 536
 537        /* RX extract mask */
 538        up->rxmask = 0x01 | (((up->csize + up->stopb) * 2 - 1) << 0x8);
 539        /* TX masks, 8 bit data and 1 bit stop for example:
 540         * mask1 = b#0111111110
 541         * mask2 = b#1000000000
 542         */
 543        for (i = 0, up->txmask1 = 0; i < up->csize; i++)
 544                up->txmask1 |= (1<<i);
 545        up->txmask2 = (1<<i);
 546        if (up->stopb) {
 547                ++i;
 548                up->txmask2 |= (1<<i);
 549        }
 550        up->txmask1 <<= 1;
 551        up->txmask2 <<= 1;
 552        /* uart baud rate */
 553        port->uartclk = uart_get_baud_rate(port, termios, old, 0, get_sclk()/16);
 554
 555        /* Disable UART */
 556        SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
 557        SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) & ~RSPEN);
 558
 559        sport_uart_setup(up, up->csize + up->stopb, port->uartclk);
 560
 561        /* driver TX line high after config, one dummy data is
 562         * necessary to stop sport after shift one byte
 563         */
 564        SPORT_PUT_TX(up, 0xffff);
 565        SPORT_PUT_TX(up, 0xffff);
 566        SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
 567        SSYNC();
 568        while (!(SPORT_GET_STAT(up) & TXHRE))
 569                cpu_relax();
 570        SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
 571        SSYNC();
 572
 573        /* Port speed changed, update the per-port timeout. */
 574        uart_update_timeout(port, termios->c_cflag, port->uartclk);
 575
 576        /* Enable sport rx */
 577        SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) | RSPEN);
 578        SSYNC();
 579
 580        spin_unlock_irqrestore(&up->port.lock, flags);
 581}
 582
 583struct uart_ops sport_uart_ops = {
 584        .tx_empty       = sport_tx_empty,
 585        .set_mctrl      = sport_set_mctrl,
 586        .get_mctrl      = sport_get_mctrl,
 587        .stop_tx        = sport_stop_tx,
 588        .start_tx       = sport_start_tx,
 589        .stop_rx        = sport_stop_rx,
 590        .enable_ms      = sport_enable_ms,
 591        .break_ctl      = sport_break_ctl,
 592        .startup        = sport_startup,
 593        .shutdown       = sport_shutdown,
 594        .set_termios    = sport_set_termios,
 595        .type           = sport_type,
 596        .release_port   = sport_release_port,
 597        .request_port   = sport_request_port,
 598        .config_port    = sport_config_port,
 599        .verify_port    = sport_verify_port,
 600};
 601
 602#define BFIN_SPORT_UART_MAX_PORTS 4
 603
 604static struct sport_uart_port *bfin_sport_uart_ports[BFIN_SPORT_UART_MAX_PORTS];
 605
 606#ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
 607#define CLASS_BFIN_SPORT_CONSOLE        "bfin-sport-console"
 608
 609static int __init
 610sport_uart_console_setup(struct console *co, char *options)
 611{
 612        struct sport_uart_port *up;
 613        int baud = 57600;
 614        int bits = 8;
 615        int parity = 'n';
 616# ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
 617        int flow = 'r';
 618# else
 619        int flow = 'n';
 620# endif
 621
 622        /* Check whether an invalid uart number has been specified */
 623        if (co->index < 0 || co->index >= BFIN_SPORT_UART_MAX_PORTS)
 624                return -ENODEV;
 625
 626        up = bfin_sport_uart_ports[co->index];
 627        if (!up)
 628                return -ENODEV;
 629
 630        if (options)
 631                uart_parse_options(options, &baud, &parity, &bits, &flow);
 632
 633        return uart_set_options(&up->port, co, baud, parity, bits, flow);
 634}
 635
 636static void sport_uart_console_putchar(struct uart_port *port, int ch)
 637{
 638        struct sport_uart_port *up = (struct sport_uart_port *)port;
 639
 640        while (SPORT_GET_STAT(up) & TXF)
 641                barrier();
 642
 643        tx_one_byte(up, ch);
 644}
 645
 646/*
 647 * Interrupts are disabled on entering
 648 */
 649static void
 650sport_uart_console_write(struct console *co, const char *s, unsigned int count)
 651{
 652        struct sport_uart_port *up = bfin_sport_uart_ports[co->index];
 653        unsigned long flags;
 654
 655        spin_lock_irqsave(&up->port.lock, flags);
 656
 657        if (SPORT_GET_TCR1(up) & TSPEN)
 658                uart_console_write(&up->port, s, count, sport_uart_console_putchar);
 659        else {
 660                /* dummy data to start sport */
 661                while (SPORT_GET_STAT(up) & TXF)
 662                        barrier();
 663                SPORT_PUT_TX(up, 0xffff);
 664                /* Enable transmit, then an interrupt will generated */
 665                SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
 666                SSYNC();
 667
 668                uart_console_write(&up->port, s, count, sport_uart_console_putchar);
 669
 670                /* Although the hold register is empty, last byte is still in shift
 671                 * register and not sent out yet. So, put a dummy data into TX FIFO.
 672                 * Then, sport tx stops when last byte is shift out and the dummy
 673                 * data is moved into the shift register.
 674                 */
 675                while (SPORT_GET_STAT(up) & TXF)
 676                        barrier();
 677                SPORT_PUT_TX(up, 0xffff);
 678                while (!(SPORT_GET_STAT(up) & TXHRE))
 679                        barrier();
 680
 681                /* Stop sport tx transfer */
 682                SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
 683                SSYNC();
 684        }
 685
 686        spin_unlock_irqrestore(&up->port.lock, flags);
 687}
 688
 689static struct uart_driver sport_uart_reg;
 690
 691static struct console sport_uart_console = {
 692        .name           = DEVICE_NAME,
 693        .write          = sport_uart_console_write,
 694        .device         = uart_console_device,
 695        .setup          = sport_uart_console_setup,
 696        .flags          = CON_PRINTBUFFER,
 697        .index          = -1,
 698        .data           = &sport_uart_reg,
 699};
 700
 701#define SPORT_UART_CONSOLE      (&sport_uart_console)
 702#else
 703#define SPORT_UART_CONSOLE      NULL
 704#endif /* CONFIG_SERIAL_BFIN_SPORT_CONSOLE */
 705
 706
 707static struct uart_driver sport_uart_reg = {
 708        .owner          = THIS_MODULE,
 709        .driver_name    = DRV_NAME,
 710        .dev_name       = DEVICE_NAME,
 711        .major          = 204,
 712        .minor          = 84,
 713        .nr             = BFIN_SPORT_UART_MAX_PORTS,
 714        .cons           = SPORT_UART_CONSOLE,
 715};
 716
 717#ifdef CONFIG_PM
 718static int sport_uart_suspend(struct device *dev)
 719{
 720        struct sport_uart_port *sport = dev_get_drvdata(dev);
 721
 722        dev_dbg(dev, "%s enter\n", __func__);
 723        if (sport)
 724                uart_suspend_port(&sport_uart_reg, &sport->port);
 725
 726        return 0;
 727}
 728
 729static int sport_uart_resume(struct device *dev)
 730{
 731        struct sport_uart_port *sport = dev_get_drvdata(dev);
 732
 733        dev_dbg(dev, "%s enter\n", __func__);
 734        if (sport)
 735                uart_resume_port(&sport_uart_reg, &sport->port);
 736
 737        return 0;
 738}
 739
 740static struct dev_pm_ops bfin_sport_uart_dev_pm_ops = {
 741        .suspend        = sport_uart_suspend,
 742        .resume         = sport_uart_resume,
 743};
 744#endif
 745
 746static int sport_uart_probe(struct platform_device *pdev)
 747{
 748        struct resource *res;
 749        struct sport_uart_port *sport;
 750        int ret = 0;
 751
 752        dev_dbg(&pdev->dev, "%s enter\n", __func__);
 753
 754        if (pdev->id < 0 || pdev->id >= BFIN_SPORT_UART_MAX_PORTS) {
 755                dev_err(&pdev->dev, "Wrong sport uart platform device id.\n");
 756                return -ENOENT;
 757        }
 758
 759        if (bfin_sport_uart_ports[pdev->id] == NULL) {
 760                bfin_sport_uart_ports[pdev->id] =
 761                        kzalloc(sizeof(struct sport_uart_port), GFP_KERNEL);
 762                sport = bfin_sport_uart_ports[pdev->id];
 763                if (!sport) {
 764                        dev_err(&pdev->dev,
 765                                "Fail to malloc sport_uart_port\n");
 766                        return -ENOMEM;
 767                }
 768
 769                ret = peripheral_request_list(dev_get_platdata(&pdev->dev),
 770                                                DRV_NAME);
 771                if (ret) {
 772                        dev_err(&pdev->dev,
 773                                "Fail to request SPORT peripherals\n");
 774                        goto out_error_free_mem;
 775                }
 776
 777                spin_lock_init(&sport->port.lock);
 778                sport->port.fifosize  = SPORT_TX_FIFO_SIZE,
 779                sport->port.ops       = &sport_uart_ops;
 780                sport->port.line      = pdev->id;
 781                sport->port.iotype    = UPIO_MEM;
 782                sport->port.flags     = UPF_BOOT_AUTOCONF;
 783
 784                res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 785                if (res == NULL) {
 786                        dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
 787                        ret = -ENOENT;
 788                        goto out_error_free_peripherals;
 789                }
 790
 791                sport->port.membase = ioremap(res->start, resource_size(res));
 792                if (!sport->port.membase) {
 793                        dev_err(&pdev->dev, "Cannot map sport IO\n");
 794                        ret = -ENXIO;
 795                        goto out_error_free_peripherals;
 796                }
 797                sport->port.mapbase = res->start;
 798
 799                sport->port.irq = platform_get_irq(pdev, 0);
 800                if ((int)sport->port.irq < 0) {
 801                        dev_err(&pdev->dev, "No sport RX/TX IRQ specified\n");
 802                        ret = -ENOENT;
 803                        goto out_error_unmap;
 804                }
 805
 806                sport->err_irq = platform_get_irq(pdev, 1);
 807                if (sport->err_irq < 0) {
 808                        dev_err(&pdev->dev, "No sport status IRQ specified\n");
 809                        ret = -ENOENT;
 810                        goto out_error_unmap;
 811                }
 812#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
 813                res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 814                if (res == NULL)
 815                        sport->cts_pin = -1;
 816                else {
 817                        sport->cts_pin = res->start;
 818                        sport->port.flags |= ASYNC_CTS_FLOW;
 819                }
 820
 821                res = platform_get_resource(pdev, IORESOURCE_IO, 1);
 822                if (res == NULL)
 823                        sport->rts_pin = -1;
 824                else
 825                        sport->rts_pin = res->start;
 826#endif
 827        }
 828
 829#ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
 830        if (!is_early_platform_device(pdev)) {
 831#endif
 832                sport = bfin_sport_uart_ports[pdev->id];
 833                sport->port.dev = &pdev->dev;
 834                dev_set_drvdata(&pdev->dev, sport);
 835                ret = uart_add_one_port(&sport_uart_reg, &sport->port);
 836#ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
 837        }
 838#endif
 839        if (!ret)
 840                return 0;
 841
 842        if (sport) {
 843out_error_unmap:
 844                iounmap(sport->port.membase);
 845out_error_free_peripherals:
 846                peripheral_free_list(dev_get_platdata(&pdev->dev));
 847out_error_free_mem:
 848                kfree(sport);
 849                bfin_sport_uart_ports[pdev->id] = NULL;
 850        }
 851
 852        return ret;
 853}
 854
 855static int sport_uart_remove(struct platform_device *pdev)
 856{
 857        struct sport_uart_port *sport = platform_get_drvdata(pdev);
 858
 859        dev_dbg(&pdev->dev, "%s enter\n", __func__);
 860        dev_set_drvdata(&pdev->dev, NULL);
 861
 862        if (sport) {
 863                uart_remove_one_port(&sport_uart_reg, &sport->port);
 864                iounmap(sport->port.membase);
 865                peripheral_free_list(dev_get_platdata(&pdev->dev));
 866                kfree(sport);
 867                bfin_sport_uart_ports[pdev->id] = NULL;
 868        }
 869
 870        return 0;
 871}
 872
 873static struct platform_driver sport_uart_driver = {
 874        .probe          = sport_uart_probe,
 875        .remove         = sport_uart_remove,
 876        .driver         = {
 877                .name   = DRV_NAME,
 878#ifdef CONFIG_PM
 879                .pm     = &bfin_sport_uart_dev_pm_ops,
 880#endif
 881        },
 882};
 883
 884#ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
 885static struct early_platform_driver early_sport_uart_driver __initdata = {
 886        .class_str = CLASS_BFIN_SPORT_CONSOLE,
 887        .pdrv = &sport_uart_driver,
 888        .requested_id = EARLY_PLATFORM_ID_UNSET,
 889};
 890
 891static int __init sport_uart_rs_console_init(void)
 892{
 893        early_platform_driver_register(&early_sport_uart_driver, DRV_NAME);
 894
 895        early_platform_driver_probe(CLASS_BFIN_SPORT_CONSOLE,
 896                BFIN_SPORT_UART_MAX_PORTS, 0);
 897
 898        register_console(&sport_uart_console);
 899
 900        return 0;
 901}
 902console_initcall(sport_uart_rs_console_init);
 903#endif
 904
 905static int __init sport_uart_init(void)
 906{
 907        int ret;
 908
 909        pr_info("Blackfin uart over sport driver\n");
 910
 911        ret = uart_register_driver(&sport_uart_reg);
 912        if (ret) {
 913                pr_err("failed to register %s:%d\n",
 914                                sport_uart_reg.driver_name, ret);
 915                return ret;
 916        }
 917
 918        ret = platform_driver_register(&sport_uart_driver);
 919        if (ret) {
 920                pr_err("failed to register sport uart driver:%d\n", ret);
 921                uart_unregister_driver(&sport_uart_reg);
 922        }
 923
 924        return ret;
 925}
 926module_init(sport_uart_init);
 927
 928static void __exit sport_uart_exit(void)
 929{
 930        platform_driver_unregister(&sport_uart_driver);
 931        uart_unregister_driver(&sport_uart_reg);
 932}
 933module_exit(sport_uart_exit);
 934
 935MODULE_AUTHOR("Sonic Zhang, Roy Huang");
 936MODULE_DESCRIPTION("Blackfin serial over SPORT driver");
 937MODULE_LICENSE("GPL");
 938