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)
34 const char *str, *p, *name;
37 /* Check for a chosen console */
38 str = fdtdec_get_chosen_prop(blob, "stdout-path");
41 namelen = p ? p - str : strlen(str);
42 node = fdt_path_offset_namelen(blob, str, namelen);
46 * Deal with things like
47 * stdout-path = "serial0:115200n8";
49 * We need to look up the alias and then follow it to
52 name = fdt_get_alias_namelen(blob, str, namelen);
54 node = fdt_path_offset(blob, name);
59 node = fdt_path_offset(blob, "console");
60 if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, devp))
64 * If the console is not marked to be bound before relocation, bind it
67 if (node > 0 && !lists_bind_fdt(gd->dm_root, offset_to_ofnode(node),
69 if (device_get_uclass_id(*devp) == UCLASS_SERIAL &&
77 static void serial_find_console_or_panic(void)
79 const void *blob = gd->fdt_blob;
81 #ifdef CONFIG_SERIAL_SEARCH_ALL
85 if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
86 uclass_first_device(UCLASS_SERIAL, &dev);
88 gd->cur_serial_dev = dev;
91 } else if (CONFIG_IS_ENABLED(OF_CONTROL) && blob) {
92 /* Live tree has support for stdout */
93 if (of_live_active()) {
94 struct device_node *np = of_get_stdout();
96 if (np && !uclass_get_device_by_ofnode(UCLASS_SERIAL,
97 np_to_ofnode(np), &dev)) {
98 gd->cur_serial_dev = dev;
102 if (!serial_check_stdout(blob, &dev)) {
103 gd->cur_serial_dev = dev;
108 if (!IS_ENABLED(CONFIG_SPL_BUILD) || !CONFIG_IS_ENABLED(OF_CONTROL) ||
111 * Try to use CONFIG_CONS_INDEX if available (it is numbered
114 * Failing that, get the device with sequence number 0, or in
115 * extremis just the first working serial device we can find.
116 * But we insist on having a console (even if it is silent).
118 #ifdef CONFIG_CONS_INDEX
119 #define INDEX (CONFIG_CONS_INDEX - 1)
124 #ifdef CONFIG_SERIAL_SEARCH_ALL
125 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
126 !uclass_get_device(UCLASS_SERIAL, INDEX, &dev)) {
127 if (dev_get_flags(dev) & DM_FLAG_ACTIVATED) {
128 gd->cur_serial_dev = dev;
133 /* Search for any working device */
134 for (ret = uclass_first_device_check(UCLASS_SERIAL, &dev);
136 ret = uclass_next_device_check(&dev)) {
138 /* Device did succeed probing */
139 gd->cur_serial_dev = dev;
144 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
145 !uclass_get_device(UCLASS_SERIAL, INDEX, &dev) ||
146 !uclass_first_device_err(UCLASS_SERIAL, &dev)) {
147 gd->cur_serial_dev = dev;
155 #ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
156 panic_str("No serial driver found");
159 #endif /* CONFIG_SERIAL_PRESENT */
161 /* Called prior to relocation */
162 int serial_init(void)
164 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
165 serial_find_console_or_panic();
166 gd->flags |= GD_FLG_SERIAL_READY;
173 /* Called after relocation */
174 int serial_initialize(void)
176 /* Scanning uclass to probe devices */
177 if (IS_ENABLED(CONFIG_SERIAL_PROBE_ALL)) {
180 ret = uclass_probe_all(UCLASS_SERIAL);
185 return serial_init();
188 static void _serial_putc(struct udevice *dev, char ch)
190 struct dm_serial_ops *ops = serial_get_ops(dev);
194 _serial_putc(dev, '\r');
197 err = ops->putc(dev, ch);
198 } while (err == -EAGAIN);
201 static int __serial_puts(struct udevice *dev, const char *str, size_t len)
203 struct dm_serial_ops *ops = serial_get_ops(dev);
206 ssize_t written = ops->puts(dev, str, len);
217 static void _serial_puts(struct udevice *dev, const char *str)
219 struct dm_serial_ops *ops = serial_get_ops(dev);
221 if (!CONFIG_IS_ENABLED(SERIAL_PUTS) || !ops->puts) {
223 _serial_putc(dev, *str++);
228 const char *newline = strchrnul(str, '\n');
229 size_t len = newline - str;
231 if (__serial_puts(dev, str, len))
234 if (*newline && __serial_puts(dev, "\r\n", 2))
237 str += len + !!*newline;
241 #ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
242 static void _serial_flush(struct udevice *dev)
244 struct dm_serial_ops *ops = serial_get_ops(dev);
248 while (ops->pending(dev, false) > 0)
253 static int __serial_getc(struct udevice *dev)
255 struct dm_serial_ops *ops = serial_get_ops(dev);
259 err = ops->getc(dev);
262 } while (err == -EAGAIN);
264 return err >= 0 ? err : 0;
267 static int __serial_tstc(struct udevice *dev)
269 struct dm_serial_ops *ops = serial_get_ops(dev);
272 return ops->pending(dev, true);
277 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
278 static int _serial_tstc(struct udevice *dev)
280 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
282 /* Read all available chars into the RX buffer */
283 while (__serial_tstc(dev)) {
284 upriv->buf[upriv->wr_ptr++] = __serial_getc(dev);
285 upriv->wr_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
288 return upriv->rd_ptr != upriv->wr_ptr ? 1 : 0;
291 static int _serial_getc(struct udevice *dev)
293 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
296 if (upriv->rd_ptr == upriv->wr_ptr)
297 return __serial_getc(dev);
299 val = upriv->buf[upriv->rd_ptr++];
300 upriv->rd_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
305 #else /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
307 static int _serial_getc(struct udevice *dev)
309 return __serial_getc(dev);
312 static int _serial_tstc(struct udevice *dev)
314 return __serial_tstc(dev);
316 #endif /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
318 void serial_putc(char ch)
320 if (gd->cur_serial_dev)
321 _serial_putc(gd->cur_serial_dev, ch);
324 void serial_puts(const char *str)
326 if (gd->cur_serial_dev)
327 _serial_puts(gd->cur_serial_dev, str);
330 #ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
331 void serial_flush(void)
333 if (!gd->cur_serial_dev)
336 _serial_flush(gd->cur_serial_dev);
340 int serial_getc(void)
342 if (!gd->cur_serial_dev)
345 return _serial_getc(gd->cur_serial_dev);
348 int serial_tstc(void)
350 if (!gd->cur_serial_dev)
353 return _serial_tstc(gd->cur_serial_dev);
356 void serial_setbrg(void)
358 struct dm_serial_ops *ops;
360 if (!gd->cur_serial_dev)
363 ops = serial_get_ops(gd->cur_serial_dev);
365 ops->setbrg(gd->cur_serial_dev, gd->baudrate);
368 int serial_getconfig(struct udevice *dev, uint *config)
370 struct dm_serial_ops *ops;
372 ops = serial_get_ops(dev);
374 return ops->getconfig(dev, config);
379 int serial_setconfig(struct udevice *dev, uint config)
381 struct dm_serial_ops *ops;
383 ops = serial_get_ops(dev);
385 return ops->setconfig(dev, config);
390 int serial_getinfo(struct udevice *dev, struct serial_device_info *info)
392 struct dm_serial_ops *ops;
397 info->baudrate = gd->baudrate;
399 ops = serial_get_ops(dev);
401 return ops->getinfo(dev, info);
406 void serial_stdio_init(void)
410 #if defined(CONFIG_DM_STDIO)
412 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
413 static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
415 _serial_putc(sdev->priv, ch);
418 static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
420 _serial_puts(sdev->priv, str);
423 #ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
424 static void serial_stub_flush(struct stdio_dev *sdev)
426 _serial_flush(sdev->priv);
430 static int serial_stub_getc(struct stdio_dev *sdev)
432 return _serial_getc(sdev->priv);
435 static int serial_stub_tstc(struct stdio_dev *sdev)
437 return _serial_tstc(sdev->priv);
443 * on_baudrate() - Update the actual baudrate when the env var changes
445 * This will check for a valid baudrate and only apply it if valid.
447 static int on_baudrate(const char *name, const char *value, enum env_op op,
455 case env_op_overwrite:
457 * Switch to new baudrate if new baudrate is supported
459 baudrate = dectoul(value, NULL);
461 /* Not actually changing */
462 if (gd->baudrate == baudrate)
465 for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
466 if (baudrate == baudrate_table[i])
469 if (i == ARRAY_SIZE(baudrate_table)) {
470 if ((flags & H_FORCE) == 0)
471 printf("## Baudrate %d bps not supported\n",
475 if ((flags & H_INTERACTIVE) != 0) {
476 printf("## Switch baudrate to %d bps and press ENTER ...\n",
482 gd->baudrate = baudrate;
488 if ((flags & H_INTERACTIVE) != 0)
490 if (getchar() == '\r')
496 printf("## Baudrate may not be deleted\n");
502 U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
504 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
505 static int serial_post_probe(struct udevice *dev)
507 struct dm_serial_ops *ops = serial_get_ops(dev);
508 #ifdef CONFIG_DM_STDIO
509 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
510 struct stdio_dev sdev;
514 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
516 ops->setbrg += gd->reloc_off;
518 ops->getc += gd->reloc_off;
520 ops->putc += gd->reloc_off;
522 ops->pending += gd->reloc_off;
524 ops->clear += gd->reloc_off;
526 ops->getconfig += gd->reloc_off;
528 ops->setconfig += gd->reloc_off;
529 #if CONFIG_POST & CONFIG_SYS_POST_UART
531 ops->loop += gd->reloc_off;
534 ops->getinfo += gd->reloc_off;
536 /* Set the baud rate */
538 ret = ops->setbrg(dev, gd->baudrate);
543 #ifdef CONFIG_DM_STDIO
544 if (!(gd->flags & GD_FLG_RELOC))
546 memset(&sdev, '\0', sizeof(sdev));
548 strncpy(sdev.name, dev->name, sizeof(sdev.name));
549 sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT | DEV_FLAGS_DM;
551 sdev.putc = serial_stub_putc;
552 sdev.puts = serial_stub_puts;
553 STDIO_DEV_ASSIGN_FLUSH(&sdev, serial_stub_flush);
554 sdev.getc = serial_stub_getc;
555 sdev.tstc = serial_stub_tstc;
557 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
558 /* Allocate the RX buffer */
559 upriv->buf = malloc(CONFIG_SERIAL_RX_BUFFER_SIZE);
562 stdio_register_dev(&sdev, &upriv->sdev);
567 static int serial_pre_remove(struct udevice *dev)
569 #if CONFIG_IS_ENABLED(SYS_STDIO_DEREGISTER)
570 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
572 if (stdio_deregister_dev(upriv->sdev, true))
579 UCLASS_DRIVER(serial) = {
582 .flags = DM_UC_FLAG_SEQ_ALIAS,
583 .post_probe = serial_post_probe,
584 .pre_remove = serial_pre_remove,
585 .per_device_auto = sizeof(struct serial_dev_priv),