drivers/serial/serial-uclass.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2014 The Chromium OS Authors.
   4  */
   5
   6 #include <common.h>
   7 #include <dm.h>
   8 #include <env_internal.h>
   9 #include <errno.h>
  10 #include <malloc.h>
  11 #include <os.h>
  12 #include <serial.h>
  13 #include <stdio_dev.h>
  14 #include <watchdog.h>
  15 #include <dm/lists.h>
  16 #include <dm/device-internal.h>
  17 #include <dm/of_access.h>
  18
  19 DECLARE_GLOBAL_DATA_PTR;
  20
  21 /*
  22  * Table with supported baudrates (defined in config_xyz.h)
  23  */
  24 static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
  25
  26 #if !CONFIG_VAL(SYS_MALLOC_F_LEN)
  27 #error "Serial is required before relocation - define CONFIG_$(SPL_)SYS_MALLOC_F_LEN to make this work"
  28 #endif
  29
  30 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
  31 static int serial_check_stdout(const void *blob, struct udevice **devp)
  32 {
  33         int node = -1;
  34         const char *str, *p, *name;
  35         int namelen;
  36
  37         /* Check for a chosen console */
  38         str = fdtdec_get_chosen_prop(blob, "stdout-path");
  39         if (str) {
  40                 p = strchr(str, ':');
  41                 namelen = p ? p - str : strlen(str);
  42                 node = fdt_path_offset_namelen(blob, str, namelen);
  43
  44                 if (node < 0) {
  45                         /*
  46                          * Deal with things like
  47                          *      stdout-path = "serial0:115200n8";
  48                          *
  49                          * We need to look up the alias and then follow it to
  50                          * the correct node.
  51                          */
  52                         name = fdt_get_alias_namelen(blob, str, namelen);
  53                         if (name)
  54                                 node = fdt_path_offset(blob, name);
  55                 }
  56         }
  57
  58         if (node < 0)
  59                 node = fdt_path_offset(blob, "console");
  60         if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, devp))
  61                 return 0;
  62
  63         /*
  64          * If the console is not marked to be bound before relocation, bind it
  65          * anyway.
  66          */
  67         if (node > 0 && !lists_bind_fdt(gd->dm_root, offset_to_ofnode(node),
  68                                         devp, false)) {
  69                 if (!device_probe(*devp))
  70                         return 0;
  71         }
  72
  73         return -ENODEV;
  74 }
  75
  76 static void serial_find_console_or_panic(void)
  77 {
  78         const void *blob = gd->fdt_blob;
  79         struct udevice *dev;
  80 #ifdef CONFIG_SERIAL_SEARCH_ALL
  81         int ret;
  82 #endif
  83
  84         if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
  85                 uclass_first_device(UCLASS_SERIAL, &dev);
  86                 if (dev) {
  87                         gd->cur_serial_dev = dev;
  88                         return;
  89                 }
  90         } else if (CONFIG_IS_ENABLED(OF_CONTROL) && blob) {
  91                 /* Live tree has support for stdout */
  92                 if (of_live_active()) {
  93                         struct device_node *np = of_get_stdout();
  94
  95                         if (np && !uclass_get_device_by_ofnode(UCLASS_SERIAL,
  96                                         np_to_ofnode(np), &dev)) {
  97                                 gd->cur_serial_dev = dev;
  98                                 return;
  99                         }
 100                 } else {
 101                         if (!serial_check_stdout(blob, &dev)) {
 102                                 gd->cur_serial_dev = dev;
 103                                 return;
 104                         }
 105                 }
 106         }
 107         if (!SPL_BUILD || !CONFIG_IS_ENABLED(OF_CONTROL) || !blob) {
 108                 /*
 109                  * Try to use CONFIG_CONS_INDEX if available (it is numbered
 110                  * from 1!).
 111                  *
 112                  * Failing that, get the device with sequence number 0, or in
 113                  * extremis just the first working serial device we can find.
 114                  * But we insist on having a console (even if it is silent).
 115                  */
 116 #ifdef CONFIG_CONS_INDEX
 117 #define INDEX (CONFIG_CONS_INDEX - 1)
 118 #else
 119 #define INDEX 0
 120 #endif
 121
 122 #ifdef CONFIG_SERIAL_SEARCH_ALL
 123                 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
 124                     !uclass_get_device(UCLASS_SERIAL, INDEX, &dev)) {
 125                         if (dev->flags & DM_FLAG_ACTIVATED) {
 126                                 gd->cur_serial_dev = dev;
 127                                 return;
 128                         }
 129                 }
 130
 131                 /* Search for any working device */
 132                 for (ret = uclass_first_device_check(UCLASS_SERIAL, &dev);
 133                      dev;
 134                      ret = uclass_next_device_check(&dev)) {
 135                         if (!ret) {
 136                                 /* Device did succeed probing */
 137                                 gd->cur_serial_dev = dev;
 138                                 return;
 139                         }
 140                 }
 141 #else
 142                 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
 143                     !uclass_get_device(UCLASS_SERIAL, INDEX, &dev) ||
 144                     (!uclass_first_device(UCLASS_SERIAL, &dev) && dev)) {
 145                         gd->cur_serial_dev = dev;
 146                         return;
 147                 }
 148 #endif
 149
 150 #undef INDEX
 151         }
 152
 153 #ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
 154         panic_str("No serial driver found");
 155 #endif
 156 }
 157 #endif /* CONFIG_SERIAL_PRESENT */
 158
 159 /* Called prior to relocation */
 160 int serial_init(void)
 161 {
 162 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
 163         serial_find_console_or_panic();
 164         gd->flags |= GD_FLG_SERIAL_READY;
 165 #endif
 166
 167         return 0;
 168 }
 169
 170 /* Called after relocation */
 171 void serial_initialize(void)
 172 {
 173         serial_init();
 174 }
 175
 176 static void _serial_putc(struct udevice *dev, char ch)
 177 {
 178         struct dm_serial_ops *ops = serial_get_ops(dev);
 179         int err;
 180
 181         if (ch == '\n')
 182                 _serial_putc(dev, '\r');
 183
 184         do {
 185                 err = ops->putc(dev, ch);
 186         } while (err == -EAGAIN);
 187 }
 188
 189 static void _serial_puts(struct udevice *dev, const char *str)
 190 {
 191         while (*str)
 192                 _serial_putc(dev, *str++);
 193 }
 194
 195 static int __serial_getc(struct udevice *dev)
 196 {
 197         struct dm_serial_ops *ops = serial_get_ops(dev);
 198         int err;
 199
 200         do {
 201                 err = ops->getc(dev);
 202                 if (err == -EAGAIN)
 203                         WATCHDOG_RESET();
 204         } while (err == -EAGAIN);
 205
 206         return err >= 0 ? err : 0;
 207 }
 208
 209 static int __serial_tstc(struct udevice *dev)
 210 {
 211         struct dm_serial_ops *ops = serial_get_ops(dev);
 212
 213         if (ops->pending)
 214                 return ops->pending(dev, true);
 215
 216         return 1;
 217 }
 218
 219 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
 220 static int _serial_tstc(struct udevice *dev)
 221 {
 222         struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
 223
 224         /* Read all available chars into the RX buffer */
 225         while (__serial_tstc(dev)) {
 226                 upriv->buf[upriv->wr_ptr++] = __serial_getc(dev);
 227                 upriv->wr_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
 228         }
 229
 230         return upriv->rd_ptr != upriv->wr_ptr ? 1 : 0;
 231 }
 232
 233 static int _serial_getc(struct udevice *dev)
 234 {
 235         struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
 236         char val;
 237
 238         if (upriv->rd_ptr == upriv->wr_ptr)
 239                 return __serial_getc(dev);
 240
 241         val = upriv->buf[upriv->rd_ptr++];
 242         upriv->rd_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
 243
 244         return val;
 245 }
 246
 247 #else /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
 248
 249 static int _serial_getc(struct udevice *dev)
 250 {
 251         return __serial_getc(dev);
 252 }
 253
 254 static int _serial_tstc(struct udevice *dev)
 255 {
 256         return __serial_tstc(dev);
 257 }
 258 #endif /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
 259
 260 void serial_putc(char ch)
 261 {
 262         if (gd->cur_serial_dev)
 263                 _serial_putc(gd->cur_serial_dev, ch);
 264 }
 265
 266 void serial_puts(const char *str)
 267 {
 268         if (gd->cur_serial_dev)
 269                 _serial_puts(gd->cur_serial_dev, str);
 270 }
 271
 272 int serial_getc(void)
 273 {
 274         if (!gd->cur_serial_dev)
 275                 return 0;
 276
 277         return _serial_getc(gd->cur_serial_dev);
 278 }
 279
 280 int serial_tstc(void)
 281 {
 282         if (!gd->cur_serial_dev)
 283                 return 0;
 284
 285         return _serial_tstc(gd->cur_serial_dev);
 286 }
 287
 288 void serial_setbrg(void)
 289 {
 290         struct dm_serial_ops *ops;
 291
 292         if (!gd->cur_serial_dev)
 293                 return;
 294
 295         ops = serial_get_ops(gd->cur_serial_dev);
 296         if (ops->setbrg)
 297                 ops->setbrg(gd->cur_serial_dev, gd->baudrate);
 298 }
 299
 300 int serial_getconfig(struct udevice *dev, uint *config)
 301 {
 302         struct dm_serial_ops *ops;
 303
 304         ops = serial_get_ops(dev);
 305         if (ops->getconfig)
 306                 return ops->getconfig(dev, config);
 307
 308         return 0;
 309 }
 310
 311 int serial_setconfig(struct udevice *dev, uint config)
 312 {
 313         struct dm_serial_ops *ops;
 314
 315         ops = serial_get_ops(dev);
 316         if (ops->setconfig)
 317                 return ops->setconfig(dev, config);
 318
 319         return 0;
 320 }
 321
 322 int serial_getinfo(struct udevice *dev, struct serial_device_info *info)
 323 {
 324         struct dm_serial_ops *ops;
 325
 326         if (!info)
 327                 return -EINVAL;
 328
 329         info->baudrate = gd->baudrate;
 330
 331         ops = serial_get_ops(dev);
 332         if (ops->getinfo)
 333                 return ops->getinfo(dev, info);
 334
 335         return -EINVAL;
 336 }
 337
 338 void serial_stdio_init(void)
 339 {
 340 }
 341
 342 #if defined(CONFIG_DM_STDIO)
 343
 344 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
 345 static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
 346 {
 347         _serial_putc(sdev->priv, ch);
 348 }
 349 #endif
 350
 351 static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
 352 {
 353         _serial_puts(sdev->priv, str);
 354 }
 355
 356 static int serial_stub_getc(struct stdio_dev *sdev)
 357 {
 358         return _serial_getc(sdev->priv);
 359 }
 360
 361 static int serial_stub_tstc(struct stdio_dev *sdev)
 362 {
 363         return _serial_tstc(sdev->priv);
 364 }
 365 #endif
 366
 367 /**
 368  * on_baudrate() - Update the actual baudrate when the env var changes
 369  *
 370  * This will check for a valid baudrate and only apply it if valid.
 371  */
 372 static int on_baudrate(const char *name, const char *value, enum env_op op,
 373         int flags)
 374 {
 375         int i;
 376         int baudrate;
 377
 378         switch (op) {
 379         case env_op_create:
 380         case env_op_overwrite:
 381                 /*
 382                  * Switch to new baudrate if new baudrate is supported
 383                  */
 384                 baudrate = simple_strtoul(value, NULL, 10);
 385
 386                 /* Not actually changing */
 387                 if (gd->baudrate == baudrate)
 388                         return 0;
 389
 390                 for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
 391                         if (baudrate == baudrate_table[i])
 392                                 break;
 393                 }
 394                 if (i == ARRAY_SIZE(baudrate_table)) {
 395                         if ((flags & H_FORCE) == 0)
 396                                 printf("## Baudrate %d bps not supported\n",
 397                                        baudrate);
 398                         return 1;
 399                 }
 400                 if ((flags & H_INTERACTIVE) != 0) {
 401                         printf("## Switch baudrate to %d bps and press ENTER ...\n",
 402                                baudrate);
 403                         udelay(50000);
 404                 }
 405
 406                 gd->baudrate = baudrate;
 407
 408                 serial_setbrg();
 409
 410                 udelay(50000);
 411
 412                 if ((flags & H_INTERACTIVE) != 0)
 413                         while (1) {
 414                                 if (getc() == '\r')
 415                                         break;
 416                         }
 417
 418                 return 0;
 419         case env_op_delete:
 420                 printf("## Baudrate may not be deleted\n");
 421                 return 1;
 422         default:
 423                 return 0;
 424         }
 425 }
 426 U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
 427
 428 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
 429 static int serial_post_probe(struct udevice *dev)
 430 {
 431         struct dm_serial_ops *ops = serial_get_ops(dev);
 432 #ifdef CONFIG_DM_STDIO
 433         struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
 434         struct stdio_dev sdev;
 435 #endif
 436         int ret;
 437
 438 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
 439         if (ops->setbrg)
 440                 ops->setbrg += gd->reloc_off;
 441         if (ops->getc)
 442                 ops->getc += gd->reloc_off;
 443         if (ops->putc)
 444                 ops->putc += gd->reloc_off;
 445         if (ops->pending)
 446                 ops->pending += gd->reloc_off;
 447         if (ops->clear)
 448                 ops->clear += gd->reloc_off;
 449         if (ops->getconfig)
 450                 ops->getconfig += gd->reloc_off;
 451         if (ops->setconfig)
 452                 ops->setconfig += gd->reloc_off;
 453 #if CONFIG_POST & CONFIG_SYS_POST_UART
 454         if (ops->loop)
 455                 ops->loop += gd->reloc_off;
 456 #endif
 457         if (ops->getinfo)
 458                 ops->getinfo += gd->reloc_off;
 459 #endif
 460         /* Set the baud rate */
 461         if (ops->setbrg) {
 462                 ret = ops->setbrg(dev, gd->baudrate);
 463                 if (ret)
 464                         return ret;
 465         }
 466
 467 #ifdef CONFIG_DM_STDIO
 468         if (!(gd->flags & GD_FLG_RELOC))
 469                 return 0;
 470         memset(&sdev, '\0', sizeof(sdev));
 471
 472         strncpy(sdev.name, dev->name, sizeof(sdev.name));
 473         sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT | DEV_FLAGS_DM;
 474         sdev.priv = dev;
 475         sdev.putc = serial_stub_putc;
 476         sdev.puts = serial_stub_puts;
 477         sdev.getc = serial_stub_getc;
 478         sdev.tstc = serial_stub_tstc;
 479
 480 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
 481         /* Allocate the RX buffer */
 482         upriv->buf = malloc(CONFIG_SERIAL_RX_BUFFER_SIZE);
 483 #endif
 484
 485         stdio_register_dev(&sdev, &upriv->sdev);
 486 #endif
 487         return 0;
 488 }
 489
 490 static int serial_pre_remove(struct udevice *dev)
 491 {
 492 #if CONFIG_IS_ENABLED(SYS_STDIO_DEREGISTER)
 493         struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
 494
 495         if (stdio_deregister_dev(upriv->sdev, true))
 496                 return -EPERM;
 497 #endif
 498
 499         return 0;
 500 }
 501
 502 UCLASS_DRIVER(serial) = {
 503         .id             = UCLASS_SERIAL,
 504         .name           = "serial",
 505         .flags          = DM_UC_FLAG_SEQ_ALIAS,
 506         .post_probe     = serial_post_probe,
 507         .pre_remove     = serial_pre_remove,
 508         .per_device_auto_alloc_size = sizeof(struct serial_dev_priv),
 509 };
 510 #endif