uboot/drivers/serial/serial.c
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   1/*
   2 * (C) Copyright 2004
   3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4 *
   5 * See file CREDITS for list of people who contributed to this
   6 * project.
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License as
  10 * published by the Free Software Foundation; either version 2 of
  11 * the License, or (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program; if not, write to the Free Software
  20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21 * MA 02111-1307 USA
  22 */
  23
  24#include <common.h>
  25#include <environment.h>
  26#include <serial.h>
  27#include <stdio_dev.h>
  28#include <post.h>
  29#include <linux/compiler.h>
  30#include <errno.h>
  31
  32DECLARE_GLOBAL_DATA_PTR;
  33
  34static struct serial_device *serial_devices;
  35static struct serial_device *serial_current;
  36/*
  37 * Table with supported baudrates (defined in config_xyz.h)
  38 */
  39static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
  40#define N_BAUDRATES (sizeof(baudrate_table) / sizeof(baudrate_table[0]))
  41
  42/**
  43 * serial_null() - Void registration routine of a serial driver
  44 *
  45 * This routine implements a void registration routine of a serial
  46 * driver. The registration routine of a particular driver is aliased
  47 * to this empty function in case the driver is not compiled into
  48 * U-Boot.
  49 */
  50static void serial_null(void)
  51{
  52}
  53
  54/**
  55 * on_baudrate() - Update the actual baudrate when the env var changes
  56 *
  57 * This will check for a valid baudrate and only apply it if valid.
  58 */
  59static int on_baudrate(const char *name, const char *value, enum env_op op,
  60        int flags)
  61{
  62        int i;
  63        int baudrate;
  64
  65        switch (op) {
  66        case env_op_create:
  67        case env_op_overwrite:
  68                /*
  69                 * Switch to new baudrate if new baudrate is supported
  70                 */
  71                baudrate = simple_strtoul(value, NULL, 10);
  72
  73                /* Not actually changing */
  74                if (gd->baudrate == baudrate)
  75                        return 0;
  76
  77                for (i = 0; i < N_BAUDRATES; ++i) {
  78                        if (baudrate == baudrate_table[i])
  79                                break;
  80                }
  81                if (i == N_BAUDRATES) {
  82                        if ((flags & H_FORCE) == 0)
  83                                printf("## Baudrate %d bps not supported\n",
  84                                        baudrate);
  85                        return 1;
  86                }
  87                if ((flags & H_INTERACTIVE) != 0) {
  88                        printf("## Switch baudrate to %d"
  89                                " bps and press ENTER ...\n", baudrate);
  90                        udelay(50000);
  91                }
  92
  93                gd->baudrate = baudrate;
  94#if defined(CONFIG_PPC) || defined(CONFIG_MCF52x2)
  95                gd->bd->bi_baudrate = baudrate;
  96#endif
  97
  98                serial_setbrg();
  99
 100                udelay(50000);
 101
 102                if ((flags & H_INTERACTIVE) != 0)
 103                        while (1) {
 104                                if (getc() == '\r')
 105                                        break;
 106                        }
 107
 108                return 0;
 109        case env_op_delete:
 110                printf("## Baudrate may not be deleted\n");
 111                return 1;
 112        default:
 113                return 0;
 114        }
 115}
 116U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
 117
 118/**
 119 * serial_initfunc() - Forward declare of driver registration routine
 120 * @name:       Name of the real driver registration routine.
 121 *
 122 * This macro expands onto forward declaration of a driver registration
 123 * routine, which is then used below in serial_initialize() function.
 124 * The declaration is made weak and aliases to serial_null() so in case
 125 * the driver is not compiled in, the function is still declared and can
 126 * be used, but aliases to serial_null() and thus is optimized away.
 127 */
 128#define serial_initfunc(name)                                   \
 129        void name(void)                                         \
 130                __attribute__((weak, alias("serial_null")));
 131
 132serial_initfunc(mpc8xx_serial_initialize);
 133serial_initfunc(ns16550_serial_initialize);
 134serial_initfunc(pxa_serial_initialize);
 135serial_initfunc(s3c24xx_serial_initialize);
 136serial_initfunc(s5p_serial_initialize);
 137serial_initfunc(zynq_serial_initalize);
 138serial_initfunc(bfin_serial_initialize);
 139serial_initfunc(bfin_jtag_initialize);
 140serial_initfunc(mpc512x_serial_initialize);
 141serial_initfunc(uartlite_serial_initialize);
 142serial_initfunc(au1x00_serial_initialize);
 143serial_initfunc(asc_serial_initialize);
 144serial_initfunc(jz_serial_initialize);
 145serial_initfunc(mpc5xx_serial_initialize);
 146serial_initfunc(mpc8220_serial_initialize);
 147serial_initfunc(mpc8260_scc_serial_initialize);
 148serial_initfunc(mpc8260_smc_serial_initialize);
 149serial_initfunc(mpc85xx_serial_initialize);
 150serial_initfunc(iop480_serial_initialize);
 151serial_initfunc(leon2_serial_initialize);
 152serial_initfunc(leon3_serial_initialize);
 153serial_initfunc(marvell_serial_initialize);
 154serial_initfunc(amirix_serial_initialize);
 155serial_initfunc(bmw_serial_initialize);
 156serial_initfunc(cogent_serial_initialize);
 157serial_initfunc(cpci750_serial_initialize);
 158serial_initfunc(evb64260_serial_initialize);
 159serial_initfunc(ml2_serial_initialize);
 160serial_initfunc(sconsole_serial_initialize);
 161serial_initfunc(p3mx_serial_initialize);
 162serial_initfunc(altera_jtag_serial_initialize);
 163serial_initfunc(altera_serial_initialize);
 164serial_initfunc(atmel_serial_initialize);
 165serial_initfunc(lpc32xx_serial_initialize);
 166serial_initfunc(mcf_serial_initialize);
 167serial_initfunc(ns9750_serial_initialize);
 168serial_initfunc(oc_serial_initialize);
 169serial_initfunc(s3c64xx_serial_initialize);
 170serial_initfunc(sandbox_serial_initialize);
 171serial_initfunc(clps7111_serial_initialize);
 172serial_initfunc(imx_serial_initialize);
 173serial_initfunc(ixp_serial_initialize);
 174serial_initfunc(ks8695_serial_initialize);
 175serial_initfunc(lh7a40x_serial_initialize);
 176serial_initfunc(max3100_serial_initialize);
 177serial_initfunc(mxc_serial_initialize);
 178serial_initfunc(pl01x_serial_initialize);
 179serial_initfunc(s3c44b0_serial_initialize);
 180serial_initfunc(sa1100_serial_initialize);
 181serial_initfunc(sh_serial_initialize);
 182
 183/**
 184 * serial_register() - Register serial driver with serial driver core
 185 * @dev:        Pointer to the serial driver structure
 186 *
 187 * This function registers the serial driver supplied via @dev with
 188 * serial driver core, thus making U-Boot aware of it and making it
 189 * available for U-Boot to use. On platforms that still require manual
 190 * relocation of constant variables, relocation of the supplied structure
 191 * is performed.
 192 */
 193void serial_register(struct serial_device *dev)
 194{
 195#ifdef CONFIG_NEEDS_MANUAL_RELOC
 196        if (dev->start)
 197                dev->start += gd->reloc_off;
 198        if (dev->stop)
 199                dev->stop += gd->reloc_off;
 200        if (dev->setbrg)
 201                dev->setbrg += gd->reloc_off;
 202        if (dev->getc)
 203                dev->getc += gd->reloc_off;
 204        if (dev->tstc)
 205                dev->tstc += gd->reloc_off;
 206        if (dev->putc)
 207                dev->putc += gd->reloc_off;
 208        if (dev->puts)
 209                dev->puts += gd->reloc_off;
 210#endif
 211
 212        dev->next = serial_devices;
 213        serial_devices = dev;
 214}
 215
 216/**
 217 * serial_initialize() - Register all compiled-in serial port drivers
 218 *
 219 * This function registers all serial port drivers that are compiled
 220 * into the U-Boot binary with the serial core, thus making them
 221 * available to U-Boot to use. Lastly, this function assigns a default
 222 * serial port to the serial core. That serial port is then used as a
 223 * default output.
 224 */
 225void serial_initialize(void)
 226{
 227        mpc8xx_serial_initialize();
 228        ns16550_serial_initialize();
 229        pxa_serial_initialize();
 230        s3c24xx_serial_initialize();
 231        s5p_serial_initialize();
 232        mpc512x_serial_initialize();
 233        bfin_serial_initialize();
 234        bfin_jtag_initialize();
 235        uartlite_serial_initialize();
 236        zynq_serial_initalize();
 237        au1x00_serial_initialize();
 238        asc_serial_initialize();
 239        jz_serial_initialize();
 240        mpc5xx_serial_initialize();
 241        mpc8220_serial_initialize();
 242        mpc8260_scc_serial_initialize();
 243        mpc8260_smc_serial_initialize();
 244        mpc85xx_serial_initialize();
 245        iop480_serial_initialize();
 246        leon2_serial_initialize();
 247        leon3_serial_initialize();
 248        marvell_serial_initialize();
 249        amirix_serial_initialize();
 250        bmw_serial_initialize();
 251        cogent_serial_initialize();
 252        cpci750_serial_initialize();
 253        evb64260_serial_initialize();
 254        ml2_serial_initialize();
 255        sconsole_serial_initialize();
 256        p3mx_serial_initialize();
 257        altera_jtag_serial_initialize();
 258        altera_serial_initialize();
 259        atmel_serial_initialize();
 260        lpc32xx_serial_initialize();
 261        mcf_serial_initialize();
 262        ns9750_serial_initialize();
 263        oc_serial_initialize();
 264        s3c64xx_serial_initialize();
 265        sandbox_serial_initialize();
 266        clps7111_serial_initialize();
 267        imx_serial_initialize();
 268        ixp_serial_initialize();
 269        ks8695_serial_initialize();
 270        lh7a40x_serial_initialize();
 271        max3100_serial_initialize();
 272        mxc_serial_initialize();
 273        pl01x_serial_initialize();
 274        s3c44b0_serial_initialize();
 275        sa1100_serial_initialize();
 276        sh_serial_initialize();
 277
 278        serial_assign(default_serial_console()->name);
 279}
 280
 281/**
 282 * serial_stdio_init() - Register serial ports with STDIO core
 283 *
 284 * This function generates a proxy driver for each serial port driver.
 285 * These proxy drivers then register with the STDIO core, making the
 286 * serial drivers available as STDIO devices.
 287 */
 288void serial_stdio_init(void)
 289{
 290        struct stdio_dev dev;
 291        struct serial_device *s = serial_devices;
 292
 293        while (s) {
 294                memset(&dev, 0, sizeof(dev));
 295
 296                strcpy(dev.name, s->name);
 297                dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT;
 298
 299                dev.start = s->start;
 300                dev.stop = s->stop;
 301                dev.putc = s->putc;
 302                dev.puts = s->puts;
 303                dev.getc = s->getc;
 304                dev.tstc = s->tstc;
 305
 306                stdio_register(&dev);
 307
 308                s = s->next;
 309        }
 310}
 311
 312/**
 313 * serial_assign() - Select the serial output device by name
 314 * @name:       Name of the serial driver to be used as default output
 315 *
 316 * This function configures the serial output multiplexing by
 317 * selecting which serial device will be used as default. In case
 318 * the STDIO "serial" device is selected as stdin/stdout/stderr,
 319 * the serial device previously configured by this function will be
 320 * used for the particular operation.
 321 *
 322 * Returns 0 on success, negative on error.
 323 */
 324int serial_assign(const char *name)
 325{
 326        struct serial_device *s;
 327
 328        for (s = serial_devices; s; s = s->next) {
 329                if (strcmp(s->name, name))
 330                        continue;
 331                serial_current = s;
 332                return 0;
 333        }
 334
 335        return -EINVAL;
 336}
 337
 338/**
 339 * serial_reinit_all() - Reinitialize all compiled-in serial ports
 340 *
 341 * This function reinitializes all serial ports that are compiled
 342 * into U-Boot by calling their serial_start() functions.
 343 */
 344void serial_reinit_all(void)
 345{
 346        struct serial_device *s;
 347
 348        for (s = serial_devices; s; s = s->next)
 349                s->start();
 350}
 351
 352/**
 353 * get_current() - Return pointer to currently selected serial port
 354 *
 355 * This function returns a pointer to currently selected serial port.
 356 * The currently selected serial port is altered by serial_assign()
 357 * function.
 358 *
 359 * In case this function is called before relocation or before any serial
 360 * port is configured, this function calls default_serial_console() to
 361 * determine the serial port. Otherwise, the configured serial port is
 362 * returned.
 363 *
 364 * Returns pointer to the currently selected serial port on success,
 365 * NULL on error.
 366 */
 367static struct serial_device *get_current(void)
 368{
 369        struct serial_device *dev;
 370
 371        if (!(gd->flags & GD_FLG_RELOC))
 372                dev = default_serial_console();
 373        else if (!serial_current)
 374                dev = default_serial_console();
 375        else
 376                dev = serial_current;
 377
 378        /* We must have a console device */
 379        if (!dev) {
 380#ifdef CONFIG_SPL_BUILD
 381                puts("Cannot find console\n");
 382                hang();
 383#else
 384                panic("Cannot find console\n");
 385#endif
 386        }
 387
 388        return dev;
 389}
 390
 391/**
 392 * serial_init() - Initialize currently selected serial port
 393 *
 394 * This function initializes the currently selected serial port. This
 395 * usually involves setting up the registers of that particular port,
 396 * enabling clock and such. This function uses the get_current() call
 397 * to determine which port is selected.
 398 *
 399 * Returns 0 on success, negative on error.
 400 */
 401int serial_init(void)
 402{
 403        return get_current()->start();
 404}
 405
 406/**
 407 * serial_setbrg() - Configure baud-rate of currently selected serial port
 408 *
 409 * This function configures the baud-rate of the currently selected
 410 * serial port. The baud-rate is retrieved from global data within
 411 * the serial port driver. This function uses the get_current() call
 412 * to determine which port is selected.
 413 *
 414 * Returns 0 on success, negative on error.
 415 */
 416void serial_setbrg(void)
 417{
 418        get_current()->setbrg();
 419}
 420
 421/**
 422 * serial_getc() - Read character from currently selected serial port
 423 *
 424 * This function retrieves a character from currently selected serial
 425 * port. In case there is no character waiting on the serial port,
 426 * this function will block and wait for the character to appear. This
 427 * function uses the get_current() call to determine which port is
 428 * selected.
 429 *
 430 * Returns the character on success, negative on error.
 431 */
 432int serial_getc(void)
 433{
 434        return get_current()->getc();
 435}
 436
 437/**
 438 * serial_tstc() - Test if data is available on currently selected serial port
 439 *
 440 * This function tests if one or more characters are available on
 441 * currently selected serial port. This function never blocks. This
 442 * function uses the get_current() call to determine which port is
 443 * selected.
 444 *
 445 * Returns positive if character is available, zero otherwise.
 446 */
 447int serial_tstc(void)
 448{
 449        return get_current()->tstc();
 450}
 451
 452/**
 453 * serial_putc() - Output character via currently selected serial port
 454 * @c:  Single character to be output from the serial port.
 455 *
 456 * This function outputs a character via currently selected serial
 457 * port. This character is passed to the serial port driver responsible
 458 * for controlling the hardware. The hardware may still be in process
 459 * of transmitting another character, therefore this function may block
 460 * for a short amount of time. This function uses the get_current()
 461 * call to determine which port is selected.
 462 */
 463void serial_putc(const char c)
 464{
 465        get_current()->putc(c);
 466}
 467
 468/**
 469 * serial_puts() - Output string via currently selected serial port
 470 * @s:  Zero-terminated string to be output from the serial port.
 471 *
 472 * This function outputs a zero-terminated string via currently
 473 * selected serial port. This function behaves as an accelerator
 474 * in case the hardware can queue multiple characters for transfer.
 475 * The whole string that is to be output is available to the function
 476 * implementing the hardware manipulation. Transmitting the whole
 477 * string may take some time, thus this function may block for some
 478 * amount of time. This function uses the get_current() call to
 479 * determine which port is selected.
 480 */
 481void serial_puts(const char *s)
 482{
 483        get_current()->puts(s);
 484}
 485
 486/**
 487 * default_serial_puts() - Output string by calling serial_putc() in loop
 488 * @s:  Zero-terminated string to be output from the serial port.
 489 *
 490 * This function outputs a zero-terminated string by calling serial_putc()
 491 * in a loop. Most drivers do not support queueing more than one byte for
 492 * transfer, thus this function precisely implements their serial_puts().
 493 *
 494 * To optimize the number of get_current() calls, this function only
 495 * calls get_current() once and then directly accesses the putc() call
 496 * of the &struct serial_device .
 497 */
 498void default_serial_puts(const char *s)
 499{
 500        struct serial_device *dev = get_current();
 501        while (*s)
 502                dev->putc(*s++);
 503}
 504
 505#if CONFIG_POST & CONFIG_SYS_POST_UART
 506static const int bauds[] = CONFIG_SYS_BAUDRATE_TABLE;
 507
 508/**
 509 * uart_post_test() - Test the currently selected serial port using POST
 510 * @flags:      POST framework flags
 511 *
 512 * Do a loopback test of the currently selected serial port. This
 513 * function is only useful in the context of the POST testing framwork.
 514 * The serial port is firstly configured into loopback mode and then
 515 * characters are sent through it.
 516 *
 517 * Returns 0 on success, value otherwise.
 518 */
 519/* Mark weak until post/cpu/.../uart.c migrate over */
 520__weak
 521int uart_post_test(int flags)
 522{
 523        unsigned char c;
 524        int ret, saved_baud, b;
 525        struct serial_device *saved_dev, *s;
 526        bd_t *bd = gd->bd;
 527
 528        /* Save current serial state */
 529        ret = 0;
 530        saved_dev = serial_current;
 531        saved_baud = bd->bi_baudrate;
 532
 533        for (s = serial_devices; s; s = s->next) {
 534                /* If this driver doesn't support loop back, skip it */
 535                if (!s->loop)
 536                        continue;
 537
 538                /* Test the next device */
 539                serial_current = s;
 540
 541                ret = serial_init();
 542                if (ret)
 543                        goto done;
 544
 545                /* Consume anything that happens to be queued */
 546                while (serial_tstc())
 547                        serial_getc();
 548
 549                /* Enable loop back */
 550                s->loop(1);
 551
 552                /* Test every available baud rate */
 553                for (b = 0; b < ARRAY_SIZE(bauds); ++b) {
 554                        bd->bi_baudrate = bauds[b];
 555                        serial_setbrg();
 556
 557                        /*
 558                         * Stick to printable chars to avoid issues:
 559                         *  - terminal corruption
 560                         *  - serial program reacting to sequences and sending
 561                         *    back random extra data
 562                         *  - most serial drivers add in extra chars (like \r\n)
 563                         */
 564                        for (c = 0x20; c < 0x7f; ++c) {
 565                                /* Send it out */
 566                                serial_putc(c);
 567
 568                                /* Make sure it's the same one */
 569                                ret = (c != serial_getc());
 570                                if (ret) {
 571                                        s->loop(0);
 572                                        goto done;
 573                                }
 574
 575                                /* Clean up the output in case it was sent */
 576                                serial_putc('\b');
 577                                ret = ('\b' != serial_getc());
 578                                if (ret) {
 579                                        s->loop(0);
 580                                        goto done;
 581                                }
 582                        }
 583                }
 584
 585                /* Disable loop back */
 586                s->loop(0);
 587
 588                /* XXX: There is no serial_stop() !? */
 589                if (s->stop)
 590                        s->stop();
 591        }
 592
 593 done:
 594        /* Restore previous serial state */
 595        serial_current = saved_dev;
 596        bd->bi_baudrate = saved_baud;
 597        serial_reinit_all();
 598        serial_setbrg();
 599
 600        return ret;
 601}
 602#endif
 603