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(amirix_serial_initialize);
 113 serial_initfunc(arc_serial_initialize);
 114 serial_initfunc(arm_dcc_initialize);
 115 serial_initfunc(asc_serial_initialize);
 116 serial_initfunc(atmel_serial_initialize);
 117 serial_initfunc(au1x00_serial_initialize);
 118 serial_initfunc(bfin_jtag_initialize);
 119 serial_initfunc(bfin_serial_initialize);
 120 serial_initfunc(bmw_serial_initialize);
 121 serial_initfunc(clps7111_serial_initialize);
 122 serial_initfunc(cogent_serial_initialize);
 123 serial_initfunc(cpci750_serial_initialize);
 124 serial_initfunc(evb64260_serial_initialize);
 125 serial_initfunc(imx_serial_initialize);
 126 serial_initfunc(iop480_serial_initialize);
 127 serial_initfunc(jz_serial_initialize);
 128 serial_initfunc(leon2_serial_initialize);
 129 serial_initfunc(leon3_serial_initialize);
 130 serial_initfunc(lh7a40x_serial_initialize);
 131 serial_initfunc(lpc32xx_serial_initialize);
 132 serial_initfunc(marvell_serial_initialize);
 133 serial_initfunc(max3100_serial_initialize);
 134 serial_initfunc(mcf_serial_initialize);
 135 serial_initfunc(ml2_serial_initialize);
 136 serial_initfunc(mpc85xx_serial_initialize);
 137 serial_initfunc(mpc8xx_serial_initialize);
 138 serial_initfunc(mxc_serial_initialize);
 139 serial_initfunc(mxs_auart_initialize);
 140 serial_initfunc(ns16550_serial_initialize);
 141 serial_initfunc(oc_serial_initialize);
 142 serial_initfunc(p3mx_serial_initialize);
 143 serial_initfunc(pl01x_serial_initialize);
 144 serial_initfunc(pxa_serial_initialize);
 145 serial_initfunc(s3c24xx_serial_initialize);
 146 serial_initfunc(s5p_serial_initialize);
 147 serial_initfunc(sa1100_serial_initialize);
 148 serial_initfunc(sandbox_serial_initialize);
 149 serial_initfunc(sconsole_serial_initialize);
 150 serial_initfunc(sh_serial_initialize);
 151 serial_initfunc(stm32_serial_initialize);
 152 serial_initfunc(uartlite_serial_initialize);
 153 serial_initfunc(zynq_serial_initialize);
 154
 155 /**
 156  * serial_register() - Register serial driver with serial driver core
 157  * @dev:        Pointer to the serial driver structure
 158  *
 159  * This function registers the serial driver supplied via @dev with
 160  * serial driver core, thus making U-Boot aware of it and making it
 161  * available for U-Boot to use. On platforms that still require manual
 162  * relocation of constant variables, relocation of the supplied structure
 163  * is performed.
 164  */
 165 void serial_register(struct serial_device *dev)
 166 {
 167 #ifdef CONFIG_NEEDS_MANUAL_RELOC
 168         if (dev->start)
 169                 dev->start += gd->reloc_off;
 170         if (dev->stop)
 171                 dev->stop += gd->reloc_off;
 172         if (dev->setbrg)
 173                 dev->setbrg += gd->reloc_off;
 174         if (dev->getc)
 175                 dev->getc += gd->reloc_off;
 176         if (dev->tstc)
 177                 dev->tstc += gd->reloc_off;
 178         if (dev->putc)
 179                 dev->putc += gd->reloc_off;
 180         if (dev->puts)
 181                 dev->puts += gd->reloc_off;
 182 #endif
 183
 184         dev->next = serial_devices;
 185         serial_devices = dev;
 186 }
 187
 188 /**
 189  * serial_initialize() - Register all compiled-in serial port drivers
 190  *
 191  * This function registers all serial port drivers that are compiled
 192  * into the U-Boot binary with the serial core, thus making them
 193  * available to U-Boot to use. Lastly, this function assigns a default
 194  * serial port to the serial core. That serial port is then used as a
 195  * default output.
 196  */
 197 void serial_initialize(void)
 198 {
 199         amirix_serial_initialize();
 200         arc_serial_initialize();
 201         arm_dcc_initialize();
 202         asc_serial_initialize();
 203         atmel_serial_initialize();
 204         au1x00_serial_initialize();
 205         bfin_jtag_initialize();
 206         bfin_serial_initialize();
 207         bmw_serial_initialize();
 208         clps7111_serial_initialize();
 209         cogent_serial_initialize();
 210         cpci750_serial_initialize();
 211         evb64260_serial_initialize();
 212         imx_serial_initialize();
 213         iop480_serial_initialize();
 214         jz_serial_initialize();
 215         leon2_serial_initialize();
 216         leon3_serial_initialize();
 217         lh7a40x_serial_initialize();
 218         lpc32xx_serial_initialize();
 219         marvell_serial_initialize();
 220         max3100_serial_initialize();
 221         mcf_serial_initialize();
 222         ml2_serial_initialize();
 223         mpc85xx_serial_initialize();
 224         mpc8xx_serial_initialize();
 225         mxc_serial_initialize();
 226         mxs_auart_initialize();
 227         ns16550_serial_initialize();
 228         oc_serial_initialize();
 229         p3mx_serial_initialize();
 230         pl01x_serial_initialize();
 231         pxa_serial_initialize();
 232         s3c24xx_serial_initialize();
 233         s5p_serial_initialize();
 234         sa1100_serial_initialize();
 235         sandbox_serial_initialize();
 236         sconsole_serial_initialize();
 237         sh_serial_initialize();
 238         stm32_serial_initialize();
 239         uartlite_serial_initialize();
 240         zynq_serial_initialize();
 241
 242         serial_assign(default_serial_console()->name);
 243 }
 244
 245 static int serial_stub_start(struct stdio_dev *sdev)
 246 {
 247         struct serial_device *dev = sdev->priv;
 248
 249         return dev->start();
 250 }
 251
 252 static int serial_stub_stop(struct stdio_dev *sdev)
 253 {
 254         struct serial_device *dev = sdev->priv;
 255
 256         return dev->stop();
 257 }
 258
 259 static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
 260 {
 261         struct serial_device *dev = sdev->priv;
 262
 263         dev->putc(ch);
 264 }
 265
 266 static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
 267 {
 268         struct serial_device *dev = sdev->priv;
 269
 270         dev->puts(str);
 271 }
 272
 273 static int serial_stub_getc(struct stdio_dev *sdev)
 274 {
 275         struct serial_device *dev = sdev->priv;
 276
 277         return dev->getc();
 278 }
 279
 280 static int serial_stub_tstc(struct stdio_dev *sdev)
 281 {
 282         struct serial_device *dev = sdev->priv;
 283
 284         return dev->tstc();
 285 }
 286
 287 /**
 288  * serial_stdio_init() - Register serial ports with STDIO core
 289  *
 290  * This function generates a proxy driver for each serial port driver.
 291  * These proxy drivers then register with the STDIO core, making the
 292  * serial drivers available as STDIO devices.
 293  */
 294 void serial_stdio_init(void)
 295 {
 296         struct stdio_dev dev;
 297         struct serial_device *s = serial_devices;
 298
 299         while (s) {
 300                 memset(&dev, 0, sizeof(dev));
 301
 302                 strcpy(dev.name, s->name);
 303                 dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT;
 304
 305                 dev.start = serial_stub_start;
 306                 dev.stop = serial_stub_stop;
 307                 dev.putc = serial_stub_putc;
 308                 dev.puts = serial_stub_puts;
 309                 dev.getc = serial_stub_getc;
 310                 dev.tstc = serial_stub_tstc;
 311                 dev.priv = s;
 312
 313                 stdio_register(&dev);
 314
 315                 s = s->next;
 316         }
 317 }
 318
 319 /**
 320  * serial_assign() - Select the serial output device by name
 321  * @name:       Name of the serial driver to be used as default output
 322  *
 323  * This function configures the serial output multiplexing by
 324  * selecting which serial device will be used as default. In case
 325  * the STDIO "serial" device is selected as stdin/stdout/stderr,
 326  * the serial device previously configured by this function will be
 327  * used for the particular operation.
 328  *
 329  * Returns 0 on success, negative on error.
 330  */
 331 int serial_assign(const char *name)
 332 {
 333         struct serial_device *s;
 334
 335         for (s = serial_devices; s; s = s->next) {
 336                 if (strcmp(s->name, name))
 337                         continue;
 338                 serial_current = s;
 339                 return 0;
 340         }
 341
 342         return -EINVAL;
 343 }
 344
 345 /**
 346  * serial_reinit_all() - Reinitialize all compiled-in serial ports
 347  *
 348  * This function reinitializes all serial ports that are compiled
 349  * into U-Boot by calling their serial_start() functions.
 350  */
 351 void serial_reinit_all(void)
 352 {
 353         struct serial_device *s;
 354
 355         for (s = serial_devices; s; s = s->next)
 356                 s->start();
 357 }
 358
 359 /**
 360  * get_current() - Return pointer to currently selected serial port
 361  *
 362  * This function returns a pointer to currently selected serial port.
 363  * The currently selected serial port is altered by serial_assign()
 364  * function.
 365  *
 366  * In case this function is called before relocation or before any serial
 367  * port is configured, this function calls default_serial_console() to
 368  * determine the serial port. Otherwise, the configured serial port is
 369  * returned.
 370  *
 371  * Returns pointer to the currently selected serial port on success,
 372  * NULL on error.
 373  */
 374 static struct serial_device *get_current(void)
 375 {
 376         struct serial_device *dev;
 377
 378         if (!(gd->flags & GD_FLG_RELOC))
 379                 dev = default_serial_console();
 380         else if (!serial_current)
 381                 dev = default_serial_console();
 382         else
 383                 dev = serial_current;
 384
 385         /* We must have a console device */
 386         if (!dev) {
 387 #ifdef CONFIG_SPL_BUILD
 388                 puts("Cannot find console\n");
 389                 hang();
 390 #else
 391                 panic("Cannot find console\n");
 392 #endif
 393         }
 394
 395         return dev;
 396 }
 397
 398 /**
 399  * serial_init() - Initialize currently selected serial port
 400  *
 401  * This function initializes the currently selected serial port. This
 402  * usually involves setting up the registers of that particular port,
 403  * enabling clock and such. This function uses the get_current() call
 404  * to determine which port is selected.
 405  *
 406  * Returns 0 on success, negative on error.
 407  */
 408 int serial_init(void)
 409 {
 410         gd->flags |= GD_FLG_SERIAL_READY;
 411         return get_current()->start();
 412 }
 413
 414 /**
 415  * serial_setbrg() - Configure baud-rate of currently selected serial port
 416  *
 417  * This function configures the baud-rate of the currently selected
 418  * serial port. The baud-rate is retrieved from global data within
 419  * the serial port driver. This function uses the get_current() call
 420  * to determine which port is selected.
 421  *
 422  * Returns 0 on success, negative on error.
 423  */
 424 void serial_setbrg(void)
 425 {
 426         get_current()->setbrg();
 427 }
 428
 429 /**
 430  * serial_getc() - Read character from currently selected serial port
 431  *
 432  * This function retrieves a character from currently selected serial
 433  * port. In case there is no character waiting on the serial port,
 434  * this function will block and wait for the character to appear. This
 435  * function uses the get_current() call to determine which port is
 436  * selected.
 437  *
 438  * Returns the character on success, negative on error.
 439  */
 440 int serial_getc(void)
 441 {
 442         return get_current()->getc();
 443 }
 444
 445 /**
 446  * serial_tstc() - Test if data is available on currently selected serial port
 447  *
 448  * This function tests if one or more characters are available on
 449  * currently selected serial port. This function never blocks. This
 450  * function uses the get_current() call to determine which port is
 451  * selected.
 452  *
 453  * Returns positive if character is available, zero otherwise.
 454  */
 455 int serial_tstc(void)
 456 {
 457         return get_current()->tstc();
 458 }
 459
 460 /**
 461  * serial_putc() - Output character via currently selected serial port
 462  * @c:  Single character to be output from the serial port.
 463  *
 464  * This function outputs a character via currently selected serial
 465  * port. This character is passed to the serial port driver responsible
 466  * for controlling the hardware. The hardware may still be in process
 467  * of transmitting another character, therefore this function may block
 468  * for a short amount of time. This function uses the get_current()
 469  * call to determine which port is selected.
 470  */
 471 void serial_putc(const char c)
 472 {
 473         get_current()->putc(c);
 474 }
 475
 476 /**
 477  * serial_puts() - Output string via currently selected serial port
 478  * @s:  Zero-terminated string to be output from the serial port.
 479  *
 480  * This function outputs a zero-terminated string via currently
 481  * selected serial port. This function behaves as an accelerator
 482  * in case the hardware can queue multiple characters for transfer.
 483  * The whole string that is to be output is available to the function
 484  * implementing the hardware manipulation. Transmitting the whole
 485  * string may take some time, thus this function may block for some
 486  * amount of time. This function uses the get_current() call to
 487  * determine which port is selected.
 488  */
 489 void serial_puts(const char *s)
 490 {
 491         get_current()->puts(s);
 492 }
 493
 494 /**
 495  * default_serial_puts() - Output string by calling serial_putc() in loop
 496  * @s:  Zero-terminated string to be output from the serial port.
 497  *
 498  * This function outputs a zero-terminated string by calling serial_putc()
 499  * in a loop. Most drivers do not support queueing more than one byte for
 500  * transfer, thus this function precisely implements their serial_puts().
 501  *
 502  * To optimize the number of get_current() calls, this function only
 503  * calls get_current() once and then directly accesses the putc() call
 504  * of the &struct serial_device .
 505  */
 506 void default_serial_puts(const char *s)
 507 {
 508         struct serial_device *dev = get_current();
 509         while (*s)
 510                 dev->putc(*s++);
 511 }
 512
 513 #if CONFIG_POST & CONFIG_SYS_POST_UART
 514 static const int bauds[] = CONFIG_SYS_BAUDRATE_TABLE;
 515
 516 /**
 517  * uart_post_test() - Test the currently selected serial port using POST
 518  * @flags:      POST framework flags
 519  *
 520  * Do a loopback test of the currently selected serial port. This
 521  * function is only useful in the context of the POST testing framwork.
 522  * The serial port is first configured into loopback mode and then
 523  * characters are sent through it.
 524  *
 525  * Returns 0 on success, value otherwise.
 526  */
 527 /* Mark weak until post/cpu/.../uart.c migrate over */
 528 __weak
 529 int uart_post_test(int flags)
 530 {
 531         unsigned char c;
 532         int ret, saved_baud, b;
 533         struct serial_device *saved_dev, *s;
 534
 535         /* Save current serial state */
 536         ret = 0;
 537         saved_dev = serial_current;
 538         saved_baud = gd->baudrate;
 539
 540         for (s = serial_devices; s; s = s->next) {
 541                 /* If this driver doesn't support loop back, skip it */
 542                 if (!s->loop)
 543                         continue;
 544
 545                 /* Test the next device */
 546                 serial_current = s;
 547
 548                 ret = serial_init();
 549                 if (ret)
 550                         goto done;
 551
 552                 /* Consume anything that happens to be queued */
 553                 while (serial_tstc())
 554                         serial_getc();
 555
 556                 /* Enable loop back */
 557                 s->loop(1);
 558
 559                 /* Test every available baud rate */
 560                 for (b = 0; b < ARRAY_SIZE(bauds); ++b) {
 561                         gd->baudrate = bauds[b];
 562                         serial_setbrg();
 563
 564                         /*
 565                          * Stick to printable chars to avoid issues:
 566                          *  - terminal corruption
 567                          *  - serial program reacting to sequences and sending
 568                          *    back random extra data
 569                          *  - most serial drivers add in extra chars (like \r\n)
 570                          */
 571                         for (c = 0x20; c < 0x7f; ++c) {
 572                                 /* Send it out */
 573                                 serial_putc(c);
 574
 575                                 /* Make sure it's the same one */
 576                                 ret = (c != serial_getc());
 577                                 if (ret) {
 578                                         s->loop(0);
 579                                         goto done;
 580                                 }
 581
 582                                 /* Clean up the output in case it was sent */
 583                                 serial_putc('\b');
 584                                 ret = ('\b' != serial_getc());
 585                                 if (ret) {
 586                                         s->loop(0);
 587                                         goto done;
 588                                 }
 589                         }
 590                 }
 591
 592                 /* Disable loop back */
 593                 s->loop(0);
 594
 595                 /* XXX: There is no serial_stop() !? */
 596                 if (s->stop)
 597                         s->stop();
 598         }
 599
 600  done:
 601         /* Restore previous serial state */
 602         serial_current = saved_dev;
 603         gd->baudrate = saved_baud;
 604         serial_reinit_all();
 605         serial_setbrg();
 606
 607         return ret;
 608 }
 609 #endif