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[] = CONFIG_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_probe(*devp))
76 static void serial_find_console_or_panic(void)
78 const void *blob = gd->fdt_blob;
80 #ifdef CONFIG_SERIAL_SEARCH_ALL
84 if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
85 uclass_first_device(UCLASS_SERIAL, &dev);
87 gd->cur_serial_dev = dev;
90 } else if (CONFIG_IS_ENABLED(OF_CONTROL) && blob) {
91 /* Live tree has support for stdout */
92 if (of_live_active()) {
93 struct device_node *np = of_get_stdout();
95 if (np && !uclass_get_device_by_ofnode(UCLASS_SERIAL,
96 np_to_ofnode(np), &dev)) {
97 gd->cur_serial_dev = dev;
101 if (!serial_check_stdout(blob, &dev)) {
102 gd->cur_serial_dev = dev;
107 if (!SPL_BUILD || !CONFIG_IS_ENABLED(OF_CONTROL) || !blob) {
109 * Try to use CONFIG_CONS_INDEX if available (it is numbered
112 * Failing that, get the device with sequence number 0, or in
113 * extremis just the first working serial device we can find.
114 * But we insist on having a console (even if it is silent).
116 #ifdef CONFIG_CONS_INDEX
117 #define INDEX (CONFIG_CONS_INDEX - 1)
122 #ifdef CONFIG_SERIAL_SEARCH_ALL
123 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
124 !uclass_get_device(UCLASS_SERIAL, INDEX, &dev)) {
125 if (dev_get_flags(dev) & DM_FLAG_ACTIVATED) {
126 gd->cur_serial_dev = dev;
131 /* Search for any working device */
132 for (ret = uclass_first_device_check(UCLASS_SERIAL, &dev);
134 ret = uclass_next_device_check(&dev)) {
136 /* Device did succeed probing */
137 gd->cur_serial_dev = dev;
142 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
143 !uclass_get_device(UCLASS_SERIAL, INDEX, &dev) ||
144 (!uclass_first_device(UCLASS_SERIAL, &dev) && dev)) {
145 gd->cur_serial_dev = dev;
153 #ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
154 panic_str("No serial driver found");
157 #endif /* CONFIG_SERIAL_PRESENT */
159 /* Called prior to relocation */
160 int serial_init(void)
162 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
163 serial_find_console_or_panic();
164 gd->flags |= GD_FLG_SERIAL_READY;
171 /* Called after relocation */
172 int serial_initialize(void)
174 /* Scanning uclass to probe devices */
175 if (IS_ENABLED(CONFIG_SERIAL_PROBE_ALL)) {
178 ret = uclass_probe_all(UCLASS_SERIAL);
183 return serial_init();
186 static void _serial_putc(struct udevice *dev, char ch)
188 struct dm_serial_ops *ops = serial_get_ops(dev);
192 _serial_putc(dev, '\r');
195 err = ops->putc(dev, ch);
196 } while (err == -EAGAIN);
199 static void _serial_puts(struct udevice *dev, const char *str)
202 _serial_putc(dev, *str++);
205 static int __serial_getc(struct udevice *dev)
207 struct dm_serial_ops *ops = serial_get_ops(dev);
211 err = ops->getc(dev);
214 } while (err == -EAGAIN);
216 return err >= 0 ? err : 0;
219 static int __serial_tstc(struct udevice *dev)
221 struct dm_serial_ops *ops = serial_get_ops(dev);
224 return ops->pending(dev, true);
229 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
230 static int _serial_tstc(struct udevice *dev)
232 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
234 /* Read all available chars into the RX buffer */
235 while (__serial_tstc(dev)) {
236 upriv->buf[upriv->wr_ptr++] = __serial_getc(dev);
237 upriv->wr_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
240 return upriv->rd_ptr != upriv->wr_ptr ? 1 : 0;
243 static int _serial_getc(struct udevice *dev)
245 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
248 if (upriv->rd_ptr == upriv->wr_ptr)
249 return __serial_getc(dev);
251 val = upriv->buf[upriv->rd_ptr++];
252 upriv->rd_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
257 #else /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
259 static int _serial_getc(struct udevice *dev)
261 return __serial_getc(dev);
264 static int _serial_tstc(struct udevice *dev)
266 return __serial_tstc(dev);
268 #endif /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
270 void serial_putc(char ch)
272 if (gd->cur_serial_dev)
273 _serial_putc(gd->cur_serial_dev, ch);
276 void serial_puts(const char *str)
278 if (gd->cur_serial_dev)
279 _serial_puts(gd->cur_serial_dev, str);
282 int serial_getc(void)
284 if (!gd->cur_serial_dev)
287 return _serial_getc(gd->cur_serial_dev);
290 int serial_tstc(void)
292 if (!gd->cur_serial_dev)
295 return _serial_tstc(gd->cur_serial_dev);
298 void serial_setbrg(void)
300 struct dm_serial_ops *ops;
302 if (!gd->cur_serial_dev)
305 ops = serial_get_ops(gd->cur_serial_dev);
307 ops->setbrg(gd->cur_serial_dev, gd->baudrate);
310 int serial_getconfig(struct udevice *dev, uint *config)
312 struct dm_serial_ops *ops;
314 ops = serial_get_ops(dev);
316 return ops->getconfig(dev, config);
321 int serial_setconfig(struct udevice *dev, uint config)
323 struct dm_serial_ops *ops;
325 ops = serial_get_ops(dev);
327 return ops->setconfig(dev, config);
332 int serial_getinfo(struct udevice *dev, struct serial_device_info *info)
334 struct dm_serial_ops *ops;
339 info->baudrate = gd->baudrate;
341 ops = serial_get_ops(dev);
343 return ops->getinfo(dev, info);
348 void serial_stdio_init(void)
352 #if defined(CONFIG_DM_STDIO)
354 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
355 static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
357 _serial_putc(sdev->priv, ch);
361 static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
363 _serial_puts(sdev->priv, str);
366 static int serial_stub_getc(struct stdio_dev *sdev)
368 return _serial_getc(sdev->priv);
371 static int serial_stub_tstc(struct stdio_dev *sdev)
373 return _serial_tstc(sdev->priv);
378 * on_baudrate() - Update the actual baudrate when the env var changes
380 * This will check for a valid baudrate and only apply it if valid.
382 static int on_baudrate(const char *name, const char *value, enum env_op op,
390 case env_op_overwrite:
392 * Switch to new baudrate if new baudrate is supported
394 baudrate = dectoul(value, NULL);
396 /* Not actually changing */
397 if (gd->baudrate == baudrate)
400 for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
401 if (baudrate == baudrate_table[i])
404 if (i == ARRAY_SIZE(baudrate_table)) {
405 if ((flags & H_FORCE) == 0)
406 printf("## Baudrate %d bps not supported\n",
410 if ((flags & H_INTERACTIVE) != 0) {
411 printf("## Switch baudrate to %d bps and press ENTER ...\n",
416 gd->baudrate = baudrate;
422 if ((flags & H_INTERACTIVE) != 0)
424 if (getchar() == '\r')
430 printf("## Baudrate may not be deleted\n");
436 U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
438 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
439 static int serial_post_probe(struct udevice *dev)
441 struct dm_serial_ops *ops = serial_get_ops(dev);
442 #ifdef CONFIG_DM_STDIO
443 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
444 struct stdio_dev sdev;
448 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
450 ops->setbrg += gd->reloc_off;
452 ops->getc += gd->reloc_off;
454 ops->putc += gd->reloc_off;
456 ops->pending += gd->reloc_off;
458 ops->clear += gd->reloc_off;
460 ops->getconfig += gd->reloc_off;
462 ops->setconfig += gd->reloc_off;
463 #if CONFIG_POST & CONFIG_SYS_POST_UART
465 ops->loop += gd->reloc_off;
468 ops->getinfo += gd->reloc_off;
470 /* Set the baud rate */
472 ret = ops->setbrg(dev, gd->baudrate);
477 #ifdef CONFIG_DM_STDIO
478 if (!(gd->flags & GD_FLG_RELOC))
480 memset(&sdev, '\0', sizeof(sdev));
482 strncpy(sdev.name, dev->name, sizeof(sdev.name));
483 sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT | DEV_FLAGS_DM;
485 sdev.putc = serial_stub_putc;
486 sdev.puts = serial_stub_puts;
487 sdev.getc = serial_stub_getc;
488 sdev.tstc = serial_stub_tstc;
490 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
491 /* Allocate the RX buffer */
492 upriv->buf = malloc(CONFIG_SERIAL_RX_BUFFER_SIZE);
495 stdio_register_dev(&sdev, &upriv->sdev);
500 static int serial_pre_remove(struct udevice *dev)
502 #if CONFIG_IS_ENABLED(SYS_STDIO_DEREGISTER)
503 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
505 if (stdio_deregister_dev(upriv->sdev, true))
512 UCLASS_DRIVER(serial) = {
515 .flags = DM_UC_FLAG_SEQ_ALIAS,
516 .post_probe = serial_post_probe,
517 .pre_remove = serial_pre_remove,
518 .per_device_auto = sizeof(struct serial_dev_priv),