1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (c) 2014 The Chromium OS Authors.
8 #include <env_internal.h>
13 #include <stdio_dev.h>
16 #include <dm/device-internal.h>
17 #include <dm/of_access.h>
18 #include <linux/delay.h>
20 DECLARE_GLOBAL_DATA_PTR;
23 * Table with supported baudrates (defined in config_xyz.h)
25 static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
27 #if !CONFIG_VAL(SYS_MALLOC_F_LEN)
28 #error "Serial is required before relocation - define CONFIG_$(SPL_)SYS_MALLOC_F_LEN to make this work"
31 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
32 static int serial_check_stdout(const void *blob, struct udevice **devp)
35 const char *str, *p, *name;
38 /* Check for a chosen console */
39 str = fdtdec_get_chosen_prop(blob, "stdout-path");
42 namelen = p ? p - str : strlen(str);
43 node = fdt_path_offset_namelen(blob, str, namelen);
47 * Deal with things like
48 * stdout-path = "serial0:115200n8";
50 * We need to look up the alias and then follow it to
53 name = fdt_get_alias_namelen(blob, str, namelen);
55 node = fdt_path_offset(blob, name);
60 node = fdt_path_offset(blob, "console");
61 if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, devp))
65 * If the console is not marked to be bound before relocation, bind it
68 if (node > 0 && !lists_bind_fdt(gd->dm_root, offset_to_ofnode(node),
70 if (!device_probe(*devp))
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 (!SPL_BUILD || !CONFIG_IS_ENABLED(OF_CONTROL) || !blob) {
110 * Try to use CONFIG_CONS_INDEX if available (it is numbered
113 * Failing that, get the device with sequence number 0, or in
114 * extremis just the first working serial device we can find.
115 * But we insist on having a console (even if it is silent).
117 #ifdef CONFIG_CONS_INDEX
118 #define INDEX (CONFIG_CONS_INDEX - 1)
123 #ifdef CONFIG_SERIAL_SEARCH_ALL
124 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
125 !uclass_get_device(UCLASS_SERIAL, INDEX, &dev)) {
126 if (dev->flags & DM_FLAG_ACTIVATED) {
127 gd->cur_serial_dev = dev;
132 /* Search for any working device */
133 for (ret = uclass_first_device_check(UCLASS_SERIAL, &dev);
135 ret = uclass_next_device_check(&dev)) {
137 /* Device did succeed probing */
138 gd->cur_serial_dev = dev;
143 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
144 !uclass_get_device(UCLASS_SERIAL, INDEX, &dev) ||
145 (!uclass_first_device(UCLASS_SERIAL, &dev) && dev)) {
146 gd->cur_serial_dev = dev;
154 #ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
155 panic_str("No serial driver found");
158 #endif /* CONFIG_SERIAL_PRESENT */
160 /* Called prior to relocation */
161 int serial_init(void)
163 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
164 serial_find_console_or_panic();
165 gd->flags |= GD_FLG_SERIAL_READY;
172 /* Called after relocation */
173 int serial_initialize(void)
175 return serial_init();
178 static void _serial_putc(struct udevice *dev, char ch)
180 struct dm_serial_ops *ops = serial_get_ops(dev);
184 _serial_putc(dev, '\r');
187 err = ops->putc(dev, ch);
188 } while (err == -EAGAIN);
191 static void _serial_puts(struct udevice *dev, const char *str)
194 _serial_putc(dev, *str++);
197 static int __serial_getc(struct udevice *dev)
199 struct dm_serial_ops *ops = serial_get_ops(dev);
203 err = ops->getc(dev);
206 } while (err == -EAGAIN);
208 return err >= 0 ? err : 0;
211 static int __serial_tstc(struct udevice *dev)
213 struct dm_serial_ops *ops = serial_get_ops(dev);
216 return ops->pending(dev, true);
221 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
222 static int _serial_tstc(struct udevice *dev)
224 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
226 /* Read all available chars into the RX buffer */
227 while (__serial_tstc(dev)) {
228 upriv->buf[upriv->wr_ptr++] = __serial_getc(dev);
229 upriv->wr_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
232 return upriv->rd_ptr != upriv->wr_ptr ? 1 : 0;
235 static int _serial_getc(struct udevice *dev)
237 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
240 if (upriv->rd_ptr == upriv->wr_ptr)
241 return __serial_getc(dev);
243 val = upriv->buf[upriv->rd_ptr++];
244 upriv->rd_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
249 #else /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
251 static int _serial_getc(struct udevice *dev)
253 return __serial_getc(dev);
256 static int _serial_tstc(struct udevice *dev)
258 return __serial_tstc(dev);
260 #endif /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
262 void serial_putc(char ch)
264 if (gd->cur_serial_dev)
265 _serial_putc(gd->cur_serial_dev, ch);
268 void serial_puts(const char *str)
270 if (gd->cur_serial_dev)
271 _serial_puts(gd->cur_serial_dev, str);
274 int serial_getc(void)
276 if (!gd->cur_serial_dev)
279 return _serial_getc(gd->cur_serial_dev);
282 int serial_tstc(void)
284 if (!gd->cur_serial_dev)
287 return _serial_tstc(gd->cur_serial_dev);
290 void serial_setbrg(void)
292 struct dm_serial_ops *ops;
294 if (!gd->cur_serial_dev)
297 ops = serial_get_ops(gd->cur_serial_dev);
299 ops->setbrg(gd->cur_serial_dev, gd->baudrate);
302 int serial_getconfig(struct udevice *dev, uint *config)
304 struct dm_serial_ops *ops;
306 ops = serial_get_ops(dev);
308 return ops->getconfig(dev, config);
313 int serial_setconfig(struct udevice *dev, uint config)
315 struct dm_serial_ops *ops;
317 ops = serial_get_ops(dev);
319 return ops->setconfig(dev, config);
324 int serial_getinfo(struct udevice *dev, struct serial_device_info *info)
326 struct dm_serial_ops *ops;
331 info->baudrate = gd->baudrate;
333 ops = serial_get_ops(dev);
335 return ops->getinfo(dev, info);
340 void serial_stdio_init(void)
344 #if defined(CONFIG_DM_STDIO)
346 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
347 static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
349 _serial_putc(sdev->priv, ch);
353 static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
355 _serial_puts(sdev->priv, str);
358 static int serial_stub_getc(struct stdio_dev *sdev)
360 return _serial_getc(sdev->priv);
363 static int serial_stub_tstc(struct stdio_dev *sdev)
365 return _serial_tstc(sdev->priv);
370 * on_baudrate() - Update the actual baudrate when the env var changes
372 * This will check for a valid baudrate and only apply it if valid.
374 static int on_baudrate(const char *name, const char *value, enum env_op op,
382 case env_op_overwrite:
384 * Switch to new baudrate if new baudrate is supported
386 baudrate = simple_strtoul(value, NULL, 10);
388 /* Not actually changing */
389 if (gd->baudrate == baudrate)
392 for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
393 if (baudrate == baudrate_table[i])
396 if (i == ARRAY_SIZE(baudrate_table)) {
397 if ((flags & H_FORCE) == 0)
398 printf("## Baudrate %d bps not supported\n",
402 if ((flags & H_INTERACTIVE) != 0) {
403 printf("## Switch baudrate to %d bps and press ENTER ...\n",
408 gd->baudrate = baudrate;
414 if ((flags & H_INTERACTIVE) != 0)
422 printf("## Baudrate may not be deleted\n");
428 U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
430 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
431 static int serial_post_probe(struct udevice *dev)
433 struct dm_serial_ops *ops = serial_get_ops(dev);
434 #ifdef CONFIG_DM_STDIO
435 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
436 struct stdio_dev sdev;
440 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
442 ops->setbrg += gd->reloc_off;
444 ops->getc += gd->reloc_off;
446 ops->putc += gd->reloc_off;
448 ops->pending += gd->reloc_off;
450 ops->clear += gd->reloc_off;
452 ops->getconfig += gd->reloc_off;
454 ops->setconfig += gd->reloc_off;
455 #if CONFIG_POST & CONFIG_SYS_POST_UART
457 ops->loop += gd->reloc_off;
460 ops->getinfo += gd->reloc_off;
462 /* Set the baud rate */
464 ret = ops->setbrg(dev, gd->baudrate);
469 #ifdef CONFIG_DM_STDIO
470 if (!(gd->flags & GD_FLG_RELOC))
472 memset(&sdev, '\0', sizeof(sdev));
474 strncpy(sdev.name, dev->name, sizeof(sdev.name));
475 sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT | DEV_FLAGS_DM;
477 sdev.putc = serial_stub_putc;
478 sdev.puts = serial_stub_puts;
479 sdev.getc = serial_stub_getc;
480 sdev.tstc = serial_stub_tstc;
482 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
483 /* Allocate the RX buffer */
484 upriv->buf = malloc(CONFIG_SERIAL_RX_BUFFER_SIZE);
487 stdio_register_dev(&sdev, &upriv->sdev);
492 static int serial_pre_remove(struct udevice *dev)
494 #if CONFIG_IS_ENABLED(SYS_STDIO_DEREGISTER)
495 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
497 if (stdio_deregister_dev(upriv->sdev, true))
504 UCLASS_DRIVER(serial) = {
507 .flags = DM_UC_FLAG_SEQ_ALIAS,
508 .post_probe = serial_post_probe,
509 .pre_remove = serial_pre_remove,
510 .per_device_auto_alloc_size = sizeof(struct serial_dev_priv),