drivers/serial/serial.c

   1 /*
   2  * (C) Copyright 2004
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <environment.h>
  10 #include <serial.h>
  11 #include <stdio_dev.h>
  12 #include <post.h>
  13 #include <linux/compiler.h>
  14 #include <errno.h>
  15
  16 DECLARE_GLOBAL_DATA_PTR;
  17
  18 static struct serial_device *serial_devices;
  19 static struct serial_device *serial_current;
  20 /*
  21  * Table with supported baudrates (defined in config_xyz.h)
  22  */
  23 static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
  24
  25 /**
  26  * serial_null() - Void registration routine of a serial driver
  27  *
  28  * This routine implements a void registration routine of a serial
  29  * driver. The registration routine of a particular driver is aliased
  30  * to this empty function in case the driver is not compiled into
  31  * U-Boot.
  32  */
  33 static void serial_null(void)
  34 {
  35 }
  36
  37 /**
  38  * on_baudrate() - Update the actual baudrate when the env var changes
  39  *
  40  * This will check for a valid baudrate and only apply it if valid.
  41  */
  42 static int on_baudrate(const char *name, const char *value, enum env_op op,
  43         int flags)
  44 {
  45         int i;
  46         int baudrate;
  47
  48         switch (op) {
  49         case env_op_create:
  50         case env_op_overwrite:
  51                 /*
  52                  * Switch to new baudrate if new baudrate is supported
  53                  */
  54                 baudrate = simple_strtoul(value, NULL, 10);
  55
  56                 /* Not actually changing */
  57                 if (gd->baudrate == baudrate)
  58                         return 0;
  59
  60                 for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
  61                         if (baudrate == baudrate_table[i])
  62                                 break;
  63                 }
  64                 if (i == ARRAY_SIZE(baudrate_table)) {
  65                         if ((flags & H_FORCE) == 0)
  66                                 printf("## Baudrate %d bps not supported\n",
  67                                         baudrate);
  68                         return 1;
  69                 }
  70                 if ((flags & H_INTERACTIVE) != 0) {
  71                         printf("## Switch baudrate to %d"
  72                                 " bps and press ENTER ...\n", baudrate);
  73                         udelay(50000);
  74                 }
  75
  76                 gd->baudrate = baudrate;
  77
  78                 serial_setbrg();
  79
  80                 udelay(50000);
  81
  82                 if ((flags & H_INTERACTIVE) != 0)
  83                         while (1) {
  84                                 if (getc() == '\r')
  85                                         break;
  86                         }
  87
  88                 return 0;
  89         case env_op_delete:
  90                 printf("## Baudrate may not be deleted\n");
  91                 return 1;
  92         default:
  93                 return 0;
  94         }
  95 }
  96 U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
  97
  98 /**
  99  * serial_initfunc() - Forward declare of driver registration routine
 100  * @name:       Name of the real driver registration routine.
 101  *
 102  * This macro expands onto forward declaration of a driver registration
 103  * routine, which is then used below in serial_initialize() function.
 104  * The declaration is made weak and aliases to serial_null() so in case
 105  * the driver is not compiled in, the function is still declared and can
 106  * be used, but aliases to serial_null() and thus is optimized away.
 107  */
 108 #define serial_initfunc(name)                                   \
 109         void name(void)                                         \
 110                 __attribute__((weak, alias("serial_null")));
 111
 112 serial_initfunc(mpc8xx_serial_initialize);
 113 serial_initfunc(ns16550_serial_initialize);
 114 serial_initfunc(pxa_serial_initialize);
 115 serial_initfunc(s3c24xx_serial_initialize);
 116 serial_initfunc(s5p_serial_initialize);
 117 serial_initfunc(zynq_serial_initialize);
 118 serial_initfunc(bfin_serial_initialize);
 119 serial_initfunc(bfin_jtag_initialize);
 120 serial_initfunc(mpc512x_serial_initialize);
 121 serial_initfunc(uartlite_serial_initialize);
 122 serial_initfunc(au1x00_serial_initialize);
 123 serial_initfunc(asc_serial_initialize);
 124 serial_initfunc(jz_serial_initialize);
 125 serial_initfunc(mpc5xx_serial_initialize);
 126 serial_initfunc(mpc8260_scc_serial_initialize);
 127 serial_initfunc(mpc8260_smc_serial_initialize);
 128 serial_initfunc(mpc85xx_serial_initialize);
 129 serial_initfunc(iop480_serial_initialize);
 130 serial_initfunc(leon2_serial_initialize);
 131 serial_initfunc(leon3_serial_initialize);
 132 serial_initfunc(marvell_serial_initialize);
 133 serial_initfunc(amirix_serial_initialize);
 134 serial_initfunc(bmw_serial_initialize);
 135 serial_initfunc(cogent_serial_initialize);
 136 serial_initfunc(cpci750_serial_initialize);
 137 serial_initfunc(evb64260_serial_initialize);
 138 serial_initfunc(ml2_serial_initialize);
 139 serial_initfunc(sconsole_serial_initialize);
 140 serial_initfunc(p3mx_serial_initialize);
 141 serial_initfunc(altera_jtag_serial_initialize);
 142 serial_initfunc(altera_serial_initialize);
 143 serial_initfunc(atmel_serial_initialize);
 144 serial_initfunc(lpc32xx_serial_initialize);
 145 serial_initfunc(mcf_serial_initialize);
 146 serial_initfunc(oc_serial_initialize);
 147 serial_initfunc(sandbox_serial_initialize);
 148 serial_initfunc(clps7111_serial_initialize);
 149 serial_initfunc(imx_serial_initialize);
 150 serial_initfunc(ks8695_serial_initialize);
 151 serial_initfunc(lh7a40x_serial_initialize);
 152 serial_initfunc(max3100_serial_initialize);
 153 serial_initfunc(mxc_serial_initialize);
 154 serial_initfunc(pl01x_serial_initialize);
 155 serial_initfunc(sa1100_serial_initialize);
 156 serial_initfunc(sh_serial_initialize);
 157 serial_initfunc(arm_dcc_initialize);
 158 serial_initfunc(mxs_auart_initialize);
 159 serial_initfunc(arc_serial_initialize);
 160
 161 /**
 162  * serial_register() - Register serial driver with serial driver core
 163  * @dev:        Pointer to the serial driver structure
 164  *
 165  * This function registers the serial driver supplied via @dev with
 166  * serial driver core, thus making U-Boot aware of it and making it
 167  * available for U-Boot to use. On platforms that still require manual
 168  * relocation of constant variables, relocation of the supplied structure
 169  * is performed.
 170  */
 171 void serial_register(struct serial_device *dev)
 172 {
 173 #ifdef CONFIG_NEEDS_MANUAL_RELOC
 174         if (dev->start)
 175                 dev->start += gd->reloc_off;
 176         if (dev->stop)
 177                 dev->stop += gd->reloc_off;
 178         if (dev->setbrg)
 179                 dev->setbrg += gd->reloc_off;
 180         if (dev->getc)
 181                 dev->getc += gd->reloc_off;
 182         if (dev->tstc)
 183                 dev->tstc += gd->reloc_off;
 184         if (dev->putc)
 185                 dev->putc += gd->reloc_off;
 186         if (dev->puts)
 187                 dev->puts += gd->reloc_off;
 188 #endif
 189
 190         dev->next = serial_devices;
 191         serial_devices = dev;
 192 }
 193
 194 /**
 195  * serial_initialize() - Register all compiled-in serial port drivers
 196  *
 197  * This function registers all serial port drivers that are compiled
 198  * into the U-Boot binary with the serial core, thus making them
 199  * available to U-Boot to use. Lastly, this function assigns a default
 200  * serial port to the serial core. That serial port is then used as a
 201  * default output.
 202  */
 203 void serial_initialize(void)
 204 {
 205         mpc8xx_serial_initialize();
 206         ns16550_serial_initialize();
 207         pxa_serial_initialize();
 208         s3c24xx_serial_initialize();
 209         s5p_serial_initialize();
 210         mpc512x_serial_initialize();
 211         bfin_serial_initialize();
 212         bfin_jtag_initialize();
 213         uartlite_serial_initialize();
 214         zynq_serial_initialize();
 215         au1x00_serial_initialize();
 216         asc_serial_initialize();
 217         jz_serial_initialize();
 218         mpc5xx_serial_initialize();
 219         mpc8260_scc_serial_initialize();
 220         mpc8260_smc_serial_initialize();
 221         mpc85xx_serial_initialize();
 222         iop480_serial_initialize();
 223         leon2_serial_initialize();
 224         leon3_serial_initialize();
 225         marvell_serial_initialize();
 226         amirix_serial_initialize();
 227         bmw_serial_initialize();
 228         cogent_serial_initialize();
 229         cpci750_serial_initialize();
 230         evb64260_serial_initialize();
 231         ml2_serial_initialize();
 232         sconsole_serial_initialize();
 233         p3mx_serial_initialize();
 234         altera_jtag_serial_initialize();
 235         altera_serial_initialize();
 236         atmel_serial_initialize();
 237         lpc32xx_serial_initialize();
 238         mcf_serial_initialize();
 239         oc_serial_initialize();
 240         sandbox_serial_initialize();
 241         clps7111_serial_initialize();
 242         imx_serial_initialize();
 243         ks8695_serial_initialize();
 244         lh7a40x_serial_initialize();
 245         max3100_serial_initialize();
 246         mxc_serial_initialize();
 247         pl01x_serial_initialize();
 248         sa1100_serial_initialize();
 249         sh_serial_initialize();
 250         arm_dcc_initialize();
 251         mxs_auart_initialize();
 252         arc_serial_initialize();
 253
 254         serial_assign(default_serial_console()->name);
 255 }
 256
 257 static int serial_stub_start(struct stdio_dev *sdev)
 258 {
 259         struct serial_device *dev = sdev->priv;
 260
 261         return dev->start();
 262 }
 263
 264 static int serial_stub_stop(struct stdio_dev *sdev)
 265 {
 266         struct serial_device *dev = sdev->priv;
 267
 268         return dev->stop();
 269 }
 270
 271 static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
 272 {
 273         struct serial_device *dev = sdev->priv;
 274
 275         dev->putc(ch);
 276 }
 277
 278 static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
 279 {
 280         struct serial_device *dev = sdev->priv;
 281
 282         dev->puts(str);
 283 }
 284
 285 int serial_stub_getc(struct stdio_dev *sdev)
 286 {
 287         struct serial_device *dev = sdev->priv;
 288
 289         return dev->getc();
 290 }
 291
 292 int serial_stub_tstc(struct stdio_dev *sdev)
 293 {
 294         struct serial_device *dev = sdev->priv;
 295
 296         return dev->tstc();
 297 }
 298
 299 /**
 300  * serial_stdio_init() - Register serial ports with STDIO core
 301  *
 302  * This function generates a proxy driver for each serial port driver.
 303  * These proxy drivers then register with the STDIO core, making the
 304  * serial drivers available as STDIO devices.
 305  */
 306 void serial_stdio_init(void)
 307 {
 308         struct stdio_dev dev;
 309         struct serial_device *s = serial_devices;
 310
 311         while (s) {
 312                 memset(&dev, 0, sizeof(dev));
 313
 314                 strcpy(dev.name, s->name);
 315                 dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT;
 316
 317                 dev.start = serial_stub_start;
 318                 dev.stop = serial_stub_stop;
 319                 dev.putc = serial_stub_putc;
 320                 dev.puts = serial_stub_puts;
 321                 dev.getc = serial_stub_getc;
 322                 dev.tstc = serial_stub_tstc;
 323                 dev.priv = s;
 324
 325                 stdio_register(&dev);
 326
 327                 s = s->next;
 328         }
 329 }
 330
 331 /**
 332  * serial_assign() - Select the serial output device by name
 333  * @name:       Name of the serial driver to be used as default output
 334  *
 335  * This function configures the serial output multiplexing by
 336  * selecting which serial device will be used as default. In case
 337  * the STDIO "serial" device is selected as stdin/stdout/stderr,
 338  * the serial device previously configured by this function will be
 339  * used for the particular operation.
 340  *
 341  * Returns 0 on success, negative on error.
 342  */
 343 int serial_assign(const char *name)
 344 {
 345         struct serial_device *s;
 346
 347         for (s = serial_devices; s; s = s->next) {
 348                 if (strcmp(s->name, name))
 349                         continue;
 350                 serial_current = s;
 351                 return 0;
 352         }
 353
 354         return -EINVAL;
 355 }
 356
 357 /**
 358  * serial_reinit_all() - Reinitialize all compiled-in serial ports
 359  *
 360  * This function reinitializes all serial ports that are compiled
 361  * into U-Boot by calling their serial_start() functions.
 362  */
 363 void serial_reinit_all(void)
 364 {
 365         struct serial_device *s;
 366
 367         for (s = serial_devices; s; s = s->next)
 368                 s->start();
 369 }
 370
 371 /**
 372  * get_current() - Return pointer to currently selected serial port
 373  *
 374  * This function returns a pointer to currently selected serial port.
 375  * The currently selected serial port is altered by serial_assign()
 376  * function.
 377  *
 378  * In case this function is called before relocation or before any serial
 379  * port is configured, this function calls default_serial_console() to
 380  * determine the serial port. Otherwise, the configured serial port is
 381  * returned.
 382  *
 383  * Returns pointer to the currently selected serial port on success,
 384  * NULL on error.
 385  */
 386 static struct serial_device *get_current(void)
 387 {
 388         struct serial_device *dev;
 389
 390         if (!(gd->flags & GD_FLG_RELOC))
 391                 dev = default_serial_console();
 392         else if (!serial_current)
 393                 dev = default_serial_console();
 394         else
 395                 dev = serial_current;
 396
 397         /* We must have a console device */
 398         if (!dev) {
 399 #ifdef CONFIG_SPL_BUILD
 400                 puts("Cannot find console\n");
 401                 hang();
 402 #else
 403                 panic("Cannot find console\n");
 404 #endif
 405         }
 406
 407         return dev;
 408 }
 409
 410 /**
 411  * serial_init() - Initialize currently selected serial port
 412  *
 413  * This function initializes the currently selected serial port. This
 414  * usually involves setting up the registers of that particular port,
 415  * enabling clock and such. This function uses the get_current() call
 416  * to determine which port is selected.
 417  *
 418  * Returns 0 on success, negative on error.
 419  */
 420 int serial_init(void)
 421 {
 422         gd->flags |= GD_FLG_SERIAL_READY;
 423         return get_current()->start();
 424 }
 425
 426 /**
 427  * serial_setbrg() - Configure baud-rate of currently selected serial port
 428  *
 429  * This function configures the baud-rate of the currently selected
 430  * serial port. The baud-rate is retrieved from global data within
 431  * the serial port driver. This function uses the get_current() call
 432  * to determine which port is selected.
 433  *
 434  * Returns 0 on success, negative on error.
 435  */
 436 void serial_setbrg(void)
 437 {
 438         get_current()->setbrg();
 439 }
 440
 441 /**
 442  * serial_getc() - Read character from currently selected serial port
 443  *
 444  * This function retrieves a character from currently selected serial
 445  * port. In case there is no character waiting on the serial port,
 446  * this function will block and wait for the character to appear. This
 447  * function uses the get_current() call to determine which port is
 448  * selected.
 449  *
 450  * Returns the character on success, negative on error.
 451  */
 452 int serial_getc(void)
 453 {
 454         return get_current()->getc();
 455 }
 456
 457 /**
 458  * serial_tstc() - Test if data is available on currently selected serial port
 459  *
 460  * This function tests if one or more characters are available on
 461  * currently selected serial port. This function never blocks. This
 462  * function uses the get_current() call to determine which port is
 463  * selected.
 464  *
 465  * Returns positive if character is available, zero otherwise.
 466  */
 467 int serial_tstc(void)
 468 {
 469         return get_current()->tstc();
 470 }
 471
 472 /**
 473  * serial_putc() - Output character via currently selected serial port
 474  * @c:  Single character to be output from the serial port.
 475  *
 476  * This function outputs a character via currently selected serial
 477  * port. This character is passed to the serial port driver responsible
 478  * for controlling the hardware. The hardware may still be in process
 479  * of transmitting another character, therefore this function may block
 480  * for a short amount of time. This function uses the get_current()
 481  * call to determine which port is selected.
 482  */
 483 void serial_putc(const char c)
 484 {
 485         get_current()->putc(c);
 486 }
 487
 488 /**
 489  * serial_puts() - Output string via currently selected serial port
 490  * @s:  Zero-terminated string to be output from the serial port.
 491  *
 492  * This function outputs a zero-terminated string via currently
 493  * selected serial port. This function behaves as an accelerator
 494  * in case the hardware can queue multiple characters for transfer.
 495  * The whole string that is to be output is available to the function
 496  * implementing the hardware manipulation. Transmitting the whole
 497  * string may take some time, thus this function may block for some
 498  * amount of time. This function uses the get_current() call to
 499  * determine which port is selected.
 500  */
 501 void serial_puts(const char *s)
 502 {
 503         get_current()->puts(s);
 504 }
 505
 506 /**
 507  * default_serial_puts() - Output string by calling serial_putc() in loop
 508  * @s:  Zero-terminated string to be output from the serial port.
 509  *
 510  * This function outputs a zero-terminated string by calling serial_putc()
 511  * in a loop. Most drivers do not support queueing more than one byte for
 512  * transfer, thus this function precisely implements their serial_puts().
 513  *
 514  * To optimize the number of get_current() calls, this function only
 515  * calls get_current() once and then directly accesses the putc() call
 516  * of the &struct serial_device .
 517  */
 518 void default_serial_puts(const char *s)
 519 {
 520         struct serial_device *dev = get_current();
 521         while (*s)
 522                 dev->putc(*s++);
 523 }
 524
 525 #if CONFIG_POST & CONFIG_SYS_POST_UART
 526 static const int bauds[] = CONFIG_SYS_BAUDRATE_TABLE;
 527
 528 /**
 529  * uart_post_test() - Test the currently selected serial port using POST
 530  * @flags:      POST framework flags
 531  *
 532  * Do a loopback test of the currently selected serial port. This
 533  * function is only useful in the context of the POST testing framwork.
 534  * The serial port is firstly configured into loopback mode and then
 535  * characters are sent through it.
 536  *
 537  * Returns 0 on success, value otherwise.
 538  */
 539 /* Mark weak until post/cpu/.../uart.c migrate over */
 540 __weak
 541 int uart_post_test(int flags)
 542 {
 543         unsigned char c;
 544         int ret, saved_baud, b;
 545         struct serial_device *saved_dev, *s;
 546
 547         /* Save current serial state */
 548         ret = 0;
 549         saved_dev = serial_current;
 550         saved_baud = gd->baudrate;
 551
 552         for (s = serial_devices; s; s = s->next) {
 553                 /* If this driver doesn't support loop back, skip it */
 554                 if (!s->loop)
 555                         continue;
 556
 557                 /* Test the next device */
 558                 serial_current = s;
 559
 560                 ret = serial_init();
 561                 if (ret)
 562                         goto done;
 563
 564                 /* Consume anything that happens to be queued */
 565                 while (serial_tstc())
 566                         serial_getc();
 567
 568                 /* Enable loop back */
 569                 s->loop(1);
 570
 571                 /* Test every available baud rate */
 572                 for (b = 0; b < ARRAY_SIZE(bauds); ++b) {
 573                         gd->baudrate = bauds[b];
 574                         serial_setbrg();
 575
 576                         /*
 577                          * Stick to printable chars to avoid issues:
 578                          *  - terminal corruption
 579                          *  - serial program reacting to sequences and sending
 580                          *    back random extra data
 581                          *  - most serial drivers add in extra chars (like \r\n)
 582                          */
 583                         for (c = 0x20; c < 0x7f; ++c) {
 584                                 /* Send it out */
 585                                 serial_putc(c);
 586
 587                                 /* Make sure it's the same one */
 588                                 ret = (c != serial_getc());
 589                                 if (ret) {
 590                                         s->loop(0);
 591                                         goto done;
 592                                 }
 593
 594                                 /* Clean up the output in case it was sent */
 595                                 serial_putc('\b');
 596                                 ret = ('\b' != serial_getc());
 597                                 if (ret) {
 598                                         s->loop(0);
 599                                         goto done;
 600                                 }
 601                         }
 602                 }
 603
 604                 /* Disable loop back */
 605                 s->loop(0);
 606
 607                 /* XXX: There is no serial_stop() !? */
 608                 if (s->stop)
 609                         s->stop();
 610         }
 611
 612  done:
 613         /* Restore previous serial state */
 614         serial_current = saved_dev;
 615         gd->baudrate = saved_baud;
 616         serial_reinit_all();
 617         serial_setbrg();
 618
 619         return ret;
 620 }
 621 #endif