drivers/serial/serial-uclass.c

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