LXR uboot/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
  19DECLARE_GLOBAL_DATA_PTR;
  20
  21/*
  22 * Table with supported baudrates (defined in config_xyz.h)
  23 */
  24static 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
  30static 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
  73static void serial_find_console_or_panic(void)
  74{
  75        const void *blob = gd->fdt_blob;
  76        struct udevice *dev;
  77
  78        if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
  79                uclass_first_device(UCLASS_SERIAL, &dev);
  80                if (dev) {
  81                        gd->cur_serial_dev = dev;
  82                        return;
  83                }
  84        } else if (CONFIG_IS_ENABLED(OF_CONTROL) && blob) {
  85                /* Live tree has support for stdout */
  86                if (of_live_active()) {
  87                        struct device_node *np = of_get_stdout();
  88
  89                        if (np && !uclass_get_device_by_ofnode(UCLASS_SERIAL,
  90                                        np_to_ofnode(np), &dev)) {
  91                                gd->cur_serial_dev = dev;
  92                                return;
  93                        }
  94                } else {
  95                        if (!serial_check_stdout(blob, &dev)) {
  96                                gd->cur_serial_dev = dev;
  97                                return;
  98                        }
  99                }
 100        }
 101        if (!SPL_BUILD || !CONFIG_IS_ENABLED(OF_CONTROL) || !blob) {
 102                /*
 103                 * Try to use CONFIG_CONS_INDEX if available (it is numbered
 104                 * from 1!).
 105                 *
 106                 * Failing that, get the device with sequence number 0, or in
 107                 * extremis just the first serial device we can find. But we
 108                 * insist on having a console (even if it is silent).
 109                 */
 110#ifdef CONFIG_CONS_INDEX
 111#define INDEX (CONFIG_CONS_INDEX - 1)
 112#else
 113#define INDEX 0
 114#endif
 115                if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
 116                    !uclass_get_device(UCLASS_SERIAL, INDEX, &dev) ||
 117                    (!uclass_first_device(UCLASS_SERIAL, &dev) && dev)) {
 118                        gd->cur_serial_dev = dev;
 119                        return;
 120                }
 121#undef INDEX
 122        }
 123
 124#ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
 125        panic_str("No serial driver found");
 126#endif
 127}
 128
 129/* Called prior to relocation */
 130int serial_init(void)
 131{
 132        serial_find_console_or_panic();
 133        gd->flags |= GD_FLG_SERIAL_READY;
 134
 135        return 0;
 136}
 137
 138/* Called after relocation */
 139void serial_initialize(void)
 140{
 141        serial_init();
 142}
 143
 144static void _serial_putc(struct udevice *dev, char ch)
 145{
 146        struct dm_serial_ops *ops = serial_get_ops(dev);
 147        int err;
 148
 149        if (ch == '\n')
 150                _serial_putc(dev, '\r');
 151
 152        do {
 153                err = ops->putc(dev, ch);
 154        } while (err == -EAGAIN);
 155}
 156
 157static void _serial_puts(struct udevice *dev, const char *str)
 158{
 159        while (*str)
 160                _serial_putc(dev, *str++);
 161}
 162
 163static int __serial_getc(struct udevice *dev)
 164{
 165        struct dm_serial_ops *ops = serial_get_ops(dev);
 166        int err;
 167
 168        do {
 169                err = ops->getc(dev);
 170                if (err == -EAGAIN)
 171                        WATCHDOG_RESET();
 172        } while (err == -EAGAIN);
 173
 174        return err >= 0 ? err : 0;
 175}
 176
 177static int __serial_tstc(struct udevice *dev)
 178{
 179        struct dm_serial_ops *ops = serial_get_ops(dev);
 180
 181        if (ops->pending)
 182                return ops->pending(dev, true);
 183
 184        return 1;
 185}
 186
 187#if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
 188static int _serial_tstc(struct udevice *dev)
 189{
 190        struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
 191
 192        /* Read all available chars into the RX buffer */
 193        while (__serial_tstc(dev)) {
 194                upriv->buf[upriv->wr_ptr++] = __serial_getc(dev);
 195                upriv->wr_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
 196        }
 197
 198        return upriv->rd_ptr != upriv->wr_ptr ? 1 : 0;
 199}
 200
 201static int _serial_getc(struct udevice *dev)
 202{
 203        struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
 204        char val;
 205
 206        val = upriv->buf[upriv->rd_ptr++];
 207        upriv->rd_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
 208
 209        return val;
 210}
 211
 212#else /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
 213
 214static int _serial_getc(struct udevice *dev)
 215{
 216        return __serial_getc(dev);
 217}
 218
 219static int _serial_tstc(struct udevice *dev)
 220{
 221        return __serial_tstc(dev);
 222}
 223#endif /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
 224
 225void serial_putc(char ch)
 226{
 227        if (gd->cur_serial_dev)
 228                _serial_putc(gd->cur_serial_dev, ch);
 229}
 230
 231void serial_puts(const char *str)
 232{
 233        if (gd->cur_serial_dev)
 234                _serial_puts(gd->cur_serial_dev, str);
 235}
 236
 237int serial_getc(void)
 238{
 239        if (!gd->cur_serial_dev)
 240                return 0;
 241
 242        return _serial_getc(gd->cur_serial_dev);
 243}
 244
 245int serial_tstc(void)
 246{
 247        if (!gd->cur_serial_dev)
 248                return 0;
 249
 250        return _serial_tstc(gd->cur_serial_dev);
 251}
 252
 253void serial_setbrg(void)
 254{
 255        struct dm_serial_ops *ops;
 256
 257        if (!gd->cur_serial_dev)
 258                return;
 259
 260        ops = serial_get_ops(gd->cur_serial_dev);
 261        if (ops->setbrg)
 262                ops->setbrg(gd->cur_serial_dev, gd->baudrate);
 263}
 264
 265void serial_stdio_init(void)
 266{
 267}
 268
 269#if defined(CONFIG_DM_STDIO)
 270
 271#if CONFIG_IS_ENABLED(SERIAL_PRESENT)
 272static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
 273{
 274        _serial_putc(sdev->priv, ch);
 275}
 276#endif
 277
 278static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
 279{
 280        _serial_puts(sdev->priv, str);
 281}
 282
 283static int serial_stub_getc(struct stdio_dev *sdev)
 284{
 285        return _serial_getc(sdev->priv);
 286}
 287
 288static int serial_stub_tstc(struct stdio_dev *sdev)
 289{
 290        return _serial_tstc(sdev->priv);
 291}
 292#endif
 293
 294/**
 295 * on_baudrate() - Update the actual baudrate when the env var changes
 296 *
 297 * This will check for a valid baudrate and only apply it if valid.
 298 */
 299static int on_baudrate(const char *name, const char *value, enum env_op op,
 300        int flags)
 301{
 302        int i;
 303        int baudrate;
 304
 305        switch (op) {
 306        case env_op_create:
 307        case env_op_overwrite:
 308                /*
 309                 * Switch to new baudrate if new baudrate is supported
 310                 */
 311                baudrate = simple_strtoul(value, NULL, 10);
 312
 313                /* Not actually changing */
 314                if (gd->baudrate == baudrate)
 315                        return 0;
 316
 317                for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
 318                        if (baudrate == baudrate_table[i])
 319                                break;
 320                }
 321                if (i == ARRAY_SIZE(baudrate_table)) {
 322                        if ((flags & H_FORCE) == 0)
 323                                printf("## Baudrate %d bps not supported\n",
 324                                       baudrate);
 325                        return 1;
 326                }
 327                if ((flags & H_INTERACTIVE) != 0) {
 328                        printf("## Switch baudrate to %d bps and press ENTER ...\n",
 329                               baudrate);
 330                        udelay(50000);
 331                }
 332
 333                gd->baudrate = baudrate;
 334
 335                serial_setbrg();
 336
 337                udelay(50000);
 338
 339                if ((flags & H_INTERACTIVE) != 0)
 340                        while (1) {
 341                                if (getc() == '\r')
 342                                        break;
 343                        }
 344
 345                return 0;
 346        case env_op_delete:
 347                printf("## Baudrate may not be deleted\n");
 348                return 1;
 349        default:
 350                return 0;
 351        }
 352}
 353U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
 354
 355#if CONFIG_IS_ENABLED(SERIAL_PRESENT)
 356static int serial_post_probe(struct udevice *dev)
 357{
 358        struct dm_serial_ops *ops = serial_get_ops(dev);
 359#ifdef CONFIG_DM_STDIO
 360        struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
 361        struct stdio_dev sdev;
 362#endif
 363        int ret;
 364
 365#if defined(CONFIG_NEEDS_MANUAL_RELOC)
 366        if (ops->setbrg)
 367                ops->setbrg += gd->reloc_off;
 368        if (ops->getc)
 369                ops->getc += gd->reloc_off;
 370        if (ops->putc)
 371                ops->putc += gd->reloc_off;
 372        if (ops->pending)
 373                ops->pending += gd->reloc_off;
 374        if (ops->clear)
 375                ops->clear += gd->reloc_off;
 376#if CONFIG_POST & CONFIG_SYS_POST_UART
 377        if (ops->loop)
 378                ops->loop += gd->reloc_off
 379#endif
 380#endif
 381        /* Set the baud rate */
 382        if (ops->setbrg) {
 383                ret = ops->setbrg(dev, gd->baudrate);
 384                if (ret)
 385                        return ret;
 386        }
 387
 388#ifdef CONFIG_DM_STDIO
 389        if (!(gd->flags & GD_FLG_RELOC))
 390                return 0;
 391        memset(&sdev, '\0', sizeof(sdev));
 392
 393        strncpy(sdev.name, dev->name, sizeof(sdev.name));
 394        sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT | DEV_FLAGS_DM;
 395        sdev.priv = dev;
 396        sdev.putc = serial_stub_putc;
 397        sdev.puts = serial_stub_puts;
 398        sdev.getc = serial_stub_getc;
 399        sdev.tstc = serial_stub_tstc;
 400
 401#if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
 402        /* Allocate the RX buffer */
 403        upriv->buf = malloc(CONFIG_SERIAL_RX_BUFFER_SIZE);
 404#endif
 405
 406        stdio_register_dev(&sdev, &upriv->sdev);
 407#endif
 408        return 0;
 409}
 410
 411static int serial_pre_remove(struct udevice *dev)
 412{
 413#if CONFIG_IS_ENABLED(SYS_STDIO_DEREGISTER)
 414        struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
 415
 416        if (stdio_deregister_dev(upriv->sdev, true))
 417                return -EPERM;
 418#endif
 419
 420        return 0;
 421}
 422
 423UCLASS_DRIVER(serial) = {
 424        .id             = UCLASS_SERIAL,
 425        .name           = "serial",
 426        .flags          = DM_UC_FLAG_SEQ_ALIAS,
 427        .post_probe     = serial_post_probe,
 428        .pre_remove     = serial_pre_remove,
 429        .per_device_auto_alloc_size = sizeof(struct serial_dev_priv),
 430};
 431#endif
 432