1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (c) 2014 The Chromium OS Authors.
6 #define LOG_CATEGORY UCLASS_SERIAL
10 #include <env_internal.h>
15 #include <stdio_dev.h>
17 #include <asm/global_data.h>
19 #include <dm/device-internal.h>
20 #include <dm/of_access.h>
21 #include <linux/delay.h>
23 DECLARE_GLOBAL_DATA_PTR;
26 * Table with supported baudrates (defined in config_xyz.h)
28 static const unsigned long baudrate_table[] = CFG_SYS_BAUDRATE_TABLE;
30 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
31 static int serial_check_stdout(const void *blob, struct udevice **devp)
37 /* Check for a chosen console */
38 str = fdtdec_get_chosen_prop(blob, "stdout-path");
41 namelen = p ? p - str : strlen(str);
43 * This also deals with things like
45 * stdout-path = "serial0:115200n8";
47 * since fdt_path_offset_namelen() treats a str not
48 * beginning with '/' as an alias and thus applies
49 * fdt_get_alias_namelen() to it.
51 node = fdt_path_offset_namelen(blob, str, namelen);
55 node = fdt_path_offset(blob, "console");
56 if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, devp))
60 * If the console is not marked to be bound before relocation, bind it
63 if (node > 0 && !lists_bind_fdt(gd->dm_root, offset_to_ofnode(node),
65 if (device_get_uclass_id(*devp) == UCLASS_SERIAL &&
73 static void serial_find_console_or_panic(void)
75 const void *blob = gd->fdt_blob;
77 #ifdef CONFIG_SERIAL_SEARCH_ALL
81 if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
82 uclass_first_device(UCLASS_SERIAL, &dev);
84 gd->cur_serial_dev = dev;
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();
92 if (np && !uclass_get_device_by_ofnode(UCLASS_SERIAL,
93 np_to_ofnode(np), &dev)) {
94 gd->cur_serial_dev = dev;
98 if (!serial_check_stdout(blob, &dev)) {
99 gd->cur_serial_dev = dev;
104 if (!IS_ENABLED(CONFIG_SPL_BUILD) || !CONFIG_IS_ENABLED(OF_CONTROL) ||
107 * Try to use CONFIG_CONS_INDEX if available (it is numbered
110 * Failing that, get the device with sequence number 0, or in
111 * extremis just the first working serial device we can find.
112 * But we insist on having a console (even if it is silent).
114 #ifdef CONFIG_CONS_INDEX
115 #define INDEX (CONFIG_CONS_INDEX - 1)
120 #ifdef CONFIG_SERIAL_SEARCH_ALL
121 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
122 !uclass_get_device(UCLASS_SERIAL, INDEX, &dev)) {
123 if (dev_get_flags(dev) & DM_FLAG_ACTIVATED) {
124 gd->cur_serial_dev = dev;
129 /* Search for any working device */
130 for (ret = uclass_first_device_check(UCLASS_SERIAL, &dev);
132 ret = uclass_next_device_check(&dev)) {
134 /* Device did succeed probing */
135 gd->cur_serial_dev = dev;
140 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
141 !uclass_get_device(UCLASS_SERIAL, INDEX, &dev) ||
142 !uclass_first_device_err(UCLASS_SERIAL, &dev)) {
143 gd->cur_serial_dev = dev;
151 #ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
152 panic_str("No serial driver found");
155 #endif /* CONFIG_SERIAL_PRESENT */
157 /* Called prior to relocation */
158 int serial_init(void)
160 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
161 serial_find_console_or_panic();
162 gd->flags |= GD_FLG_SERIAL_READY;
169 /* Called after relocation */
170 int serial_initialize(void)
172 /* Scanning uclass to probe devices */
173 if (IS_ENABLED(CONFIG_SERIAL_PROBE_ALL)) {
176 ret = uclass_probe_all(UCLASS_SERIAL);
181 return serial_init();
184 static void _serial_putc(struct udevice *dev, char ch)
186 struct dm_serial_ops *ops = serial_get_ops(dev);
190 _serial_putc(dev, '\r');
193 err = ops->putc(dev, ch);
194 } while (err == -EAGAIN);
197 static int __serial_puts(struct udevice *dev, const char *str, size_t len)
199 struct dm_serial_ops *ops = serial_get_ops(dev);
202 ssize_t written = ops->puts(dev, str, len);
213 static void _serial_puts(struct udevice *dev, const char *str)
215 struct dm_serial_ops *ops = serial_get_ops(dev);
217 if (!CONFIG_IS_ENABLED(SERIAL_PUTS) || !ops->puts) {
219 _serial_putc(dev, *str++);
224 const char *newline = strchrnul(str, '\n');
225 size_t len = newline - str;
227 if (__serial_puts(dev, str, len))
230 if (*newline && __serial_puts(dev, "\r\n", 2))
233 str += len + !!*newline;
237 #ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
238 static void _serial_flush(struct udevice *dev)
240 struct dm_serial_ops *ops = serial_get_ops(dev);
244 while (ops->pending(dev, false) > 0)
249 static int __serial_getc(struct udevice *dev)
251 struct dm_serial_ops *ops = serial_get_ops(dev);
255 err = ops->getc(dev);
258 } while (err == -EAGAIN);
260 return err >= 0 ? err : 0;
263 static int __serial_tstc(struct udevice *dev)
265 struct dm_serial_ops *ops = serial_get_ops(dev);
268 return ops->pending(dev, true);
273 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
274 static int _serial_tstc(struct udevice *dev)
276 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
278 /* Read all available chars into the RX buffer */
279 while (__serial_tstc(dev)) {
280 upriv->buf[upriv->wr_ptr++] = __serial_getc(dev);
281 upriv->wr_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
284 return upriv->rd_ptr != upriv->wr_ptr ? 1 : 0;
287 static int _serial_getc(struct udevice *dev)
289 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
292 if (upriv->rd_ptr == upriv->wr_ptr)
293 return __serial_getc(dev);
295 val = upriv->buf[upriv->rd_ptr++];
296 upriv->rd_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
301 #else /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
303 static int _serial_getc(struct udevice *dev)
305 return __serial_getc(dev);
308 static int _serial_tstc(struct udevice *dev)
310 return __serial_tstc(dev);
312 #endif /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
314 void serial_putc(char ch)
316 if (gd->cur_serial_dev)
317 _serial_putc(gd->cur_serial_dev, ch);
320 void serial_puts(const char *str)
322 if (gd->cur_serial_dev)
323 _serial_puts(gd->cur_serial_dev, str);
326 #ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
327 void serial_flush(void)
329 if (!gd->cur_serial_dev)
332 _serial_flush(gd->cur_serial_dev);
336 int serial_getc(void)
338 if (!gd->cur_serial_dev)
341 return _serial_getc(gd->cur_serial_dev);
344 int serial_tstc(void)
346 if (!gd->cur_serial_dev)
349 return _serial_tstc(gd->cur_serial_dev);
352 void serial_setbrg(void)
354 struct dm_serial_ops *ops;
356 if (!gd->cur_serial_dev)
359 ops = serial_get_ops(gd->cur_serial_dev);
361 ops->setbrg(gd->cur_serial_dev, gd->baudrate);
364 int serial_getconfig(struct udevice *dev, uint *config)
366 struct dm_serial_ops *ops;
368 ops = serial_get_ops(dev);
370 return ops->getconfig(dev, config);
375 int serial_setconfig(struct udevice *dev, uint config)
377 struct dm_serial_ops *ops;
379 ops = serial_get_ops(dev);
381 return ops->setconfig(dev, config);
386 int serial_getinfo(struct udevice *dev, struct serial_device_info *info)
388 struct dm_serial_ops *ops;
393 info->baudrate = gd->baudrate;
395 ops = serial_get_ops(dev);
397 return ops->getinfo(dev, info);
402 void serial_stdio_init(void)
406 #if CONFIG_IS_ENABLED(DM_STDIO)
408 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
409 static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
411 _serial_putc(sdev->priv, ch);
414 static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
416 _serial_puts(sdev->priv, str);
419 #ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
420 static void serial_stub_flush(struct stdio_dev *sdev)
422 _serial_flush(sdev->priv);
426 static int serial_stub_getc(struct stdio_dev *sdev)
428 return _serial_getc(sdev->priv);
431 static int serial_stub_tstc(struct stdio_dev *sdev)
433 return _serial_tstc(sdev->priv);
439 * on_baudrate() - Update the actual baudrate when the env var changes
441 * This will check for a valid baudrate and only apply it if valid.
443 static int on_baudrate(const char *name, const char *value, enum env_op op,
451 case env_op_overwrite:
453 * Switch to new baudrate if new baudrate is supported
455 baudrate = dectoul(value, NULL);
457 /* Not actually changing */
458 if (gd->baudrate == baudrate)
461 for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
462 if (baudrate == baudrate_table[i])
465 if (i == ARRAY_SIZE(baudrate_table)) {
466 if ((flags & H_FORCE) == 0)
467 printf("## Baudrate %d bps not supported\n",
471 if ((flags & H_INTERACTIVE) != 0) {
472 printf("## Switch baudrate to %d bps and press ENTER ...\n",
478 gd->baudrate = baudrate;
484 if ((flags & H_INTERACTIVE) != 0)
486 if (getchar() == '\r')
492 printf("## Baudrate may not be deleted\n");
498 U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
500 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
501 static int serial_post_probe(struct udevice *dev)
503 struct dm_serial_ops *ops = serial_get_ops(dev);
504 #if CONFIG_IS_ENABLED(DM_STDIO)
505 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
506 struct stdio_dev sdev;
510 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
512 ops->setbrg += gd->reloc_off;
514 ops->getc += gd->reloc_off;
516 ops->putc += gd->reloc_off;
518 ops->pending += gd->reloc_off;
520 ops->clear += gd->reloc_off;
522 ops->getconfig += gd->reloc_off;
524 ops->setconfig += gd->reloc_off;
525 #if CFG_POST & CFG_SYS_POST_UART
527 ops->loop += gd->reloc_off;
530 ops->getinfo += gd->reloc_off;
532 /* Set the baud rate */
534 ret = ops->setbrg(dev, gd->baudrate);
539 #if CONFIG_IS_ENABLED(DM_STDIO)
540 if (!(gd->flags & GD_FLG_RELOC))
542 memset(&sdev, '\0', sizeof(sdev));
544 strncpy(sdev.name, dev->name, sizeof(sdev.name));
545 sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT | DEV_FLAGS_DM;
547 sdev.putc = serial_stub_putc;
548 sdev.puts = serial_stub_puts;
549 STDIO_DEV_ASSIGN_FLUSH(&sdev, serial_stub_flush);
550 sdev.getc = serial_stub_getc;
551 sdev.tstc = serial_stub_tstc;
553 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
554 /* Allocate the RX buffer */
555 upriv->buf = malloc(CONFIG_SERIAL_RX_BUFFER_SIZE);
558 stdio_register_dev(&sdev, &upriv->sdev);
563 static int serial_pre_remove(struct udevice *dev)
565 #if CONFIG_IS_ENABLED(SYS_STDIO_DEREGISTER)
566 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
568 if (stdio_deregister_dev(upriv->sdev, true))
575 UCLASS_DRIVER(serial) = {
578 .flags = DM_UC_FLAG_SEQ_ALIAS,
579 .post_probe = serial_post_probe,
580 .pre_remove = serial_pre_remove,
581 .per_device_auto = sizeof(struct serial_dev_priv),