1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (c) 2014 The Chromium OS Authors.
4 */
5
6 #define LOG_CATEGORY UCLASS_SERIAL
7
8 #include <common.h>
9 #include <dm.h>
10 #include <env_internal.h>
11 #include <errno.h>
12 #include <malloc.h>
13 #include <os.h>
14 #include <serial.h>
15 #include <stdio_dev.h>
16 #include <watchdog.h>
17 #include <asm/global_data.h>
18 #include <dm/lists.h>
19 #include <dm/device-internal.h>
20 #include <dm/of_access.h>
21 #include <linux/delay.h>
22
23 DECLARE_GLOBAL_DATA_PTR;
24
25 /*
26 * Table with supported baudrates (defined in config_xyz.h)
27 */
28 static const unsigned long baudrate_table[] = CFG_SYS_BAUDRATE_TABLE;
29
30 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
serial_check_stdout(const void * blob,struct udevice ** devp)31 static int serial_check_stdout(const void *blob, struct udevice **devp)
32 {
33 int node = -1;
34 const char *str, *p;
35 int namelen;
36
37 /* Check for a chosen console */
38 str = fdtdec_get_chosen_prop(blob, "stdout-path");
39 if (str) {
40 p = strchr(str, ':');
41 namelen = p ? p - str : strlen(str);
42 /*
43 * This also deals with things like
44 *
45 * stdout-path = "serial0:115200n8";
46 *
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.
50 */
51 node = fdt_path_offset_namelen(blob, str, namelen);
52 }
53
54 if (node < 0)
55 node = fdt_path_offset(blob, "console");
56 if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, devp))
57 return 0;
58
59 /*
60 * If the console is not marked to be bound before relocation, bind it
61 * anyway.
62 */
63 if (node > 0 && !lists_bind_fdt(gd->dm_root, offset_to_ofnode(node),
64 devp, NULL, false)) {
65 if (device_get_uclass_id(*devp) == UCLASS_SERIAL &&
66 !device_probe(*devp))
67 return 0;
68 }
69
70 return -ENODEV;
71 }
72
serial_find_console_or_panic(void)73 static void serial_find_console_or_panic(void)
74 {
75 const void *blob = gd->fdt_blob;
76 struct udevice *dev;
77 #ifdef CONFIG_SERIAL_SEARCH_ALL
78 int ret;
79 #endif
80
81 if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
82 uclass_first_device(UCLASS_SERIAL, &dev);
83 if (dev) {
84 gd->cur_serial_dev = dev;
85 return;
86 }
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();
91
92 if (np && !uclass_get_device_by_ofnode(UCLASS_SERIAL,
93 np_to_ofnode(np), &dev)) {
94 gd->cur_serial_dev = dev;
95 return;
96 }
97 } else {
98 if (!serial_check_stdout(blob, &dev)) {
99 gd->cur_serial_dev = dev;
100 return;
101 }
102 }
103 }
104 if (!IS_ENABLED(CONFIG_SPL_BUILD) || !CONFIG_IS_ENABLED(OF_CONTROL) ||
105 !blob) {
106 /*
107 * Try to use CONFIG_CONS_INDEX if available (it is numbered
108 * from 1!).
109 *
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).
113 */
114 #ifdef CONFIG_CONS_INDEX
115 #define INDEX (CONFIG_CONS_INDEX - 1)
116 #else
117 #define INDEX 0
118 #endif
119
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;
125 return;
126 }
127 }
128
129 /* Search for any working device */
130 for (ret = uclass_first_device_check(UCLASS_SERIAL, &dev);
131 dev;
132 ret = uclass_next_device_check(&dev)) {
133 if (!ret) {
134 /* Device did succeed probing */
135 gd->cur_serial_dev = dev;
136 return;
137 }
138 }
139 #else
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;
144 return;
145 }
146 #endif
147
148 #undef INDEX
149 }
150
151 #ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
152 panic_str("No serial driver found");
153 #endif
154 }
155 #endif /* CONFIG_SERIAL_PRESENT */
156
157 /* Called prior to relocation */
serial_init(void)158 int serial_init(void)
159 {
160 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
161 serial_find_console_or_panic();
162 gd->flags |= GD_FLG_SERIAL_READY;
163 serial_setbrg();
164 #endif
165
166 return 0;
167 }
168
169 /* Called after relocation */
serial_initialize(void)170 int serial_initialize(void)
171 {
172 /* Scanning uclass to probe devices */
173 if (IS_ENABLED(CONFIG_SERIAL_PROBE_ALL)) {
174 int ret;
175
176 ret = uclass_probe_all(UCLASS_SERIAL);
177 if (ret)
178 return ret;
179 }
180
181 return serial_init();
182 }
183
_serial_putc(struct udevice * dev,char ch)184 static void _serial_putc(struct udevice *dev, char ch)
185 {
186 struct dm_serial_ops *ops = serial_get_ops(dev);
187 int err;
188
189 if (ch == '\n')
190 _serial_putc(dev, '\r');
191
192 do {
193 err = ops->putc(dev, ch);
194 } while (err == -EAGAIN);
195 }
196
__serial_puts(struct udevice * dev,const char * str,size_t len)197 static int __serial_puts(struct udevice *dev, const char *str, size_t len)
198 {
199 struct dm_serial_ops *ops = serial_get_ops(dev);
200
201 do {
202 ssize_t written = ops->puts(dev, str, len);
203
204 if (written < 0)
205 return written;
206 str += written;
207 len -= written;
208 } while (len);
209
210 return 0;
211 }
212
_serial_puts(struct udevice * dev,const char * str)213 static void _serial_puts(struct udevice *dev, const char *str)
214 {
215 struct dm_serial_ops *ops = serial_get_ops(dev);
216
217 if (!CONFIG_IS_ENABLED(SERIAL_PUTS) || !ops->puts) {
218 while (*str)
219 _serial_putc(dev, *str++);
220 return;
221 }
222
223 do {
224 const char *newline = strchrnul(str, '\n');
225 size_t len = newline - str;
226
227 if (__serial_puts(dev, str, len))
228 return;
229
230 if (*newline && __serial_puts(dev, "\r\n", 2))
231 return;
232
233 str += len + !!*newline;
234 } while (*str);
235 }
236
237 #ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
_serial_flush(struct udevice * dev)238 static void _serial_flush(struct udevice *dev)
239 {
240 struct dm_serial_ops *ops = serial_get_ops(dev);
241
242 if (!ops->pending)
243 return;
244 while (ops->pending(dev, false) > 0)
245 ;
246 }
247 #endif
248
__serial_getc(struct udevice * dev)249 static int __serial_getc(struct udevice *dev)
250 {
251 struct dm_serial_ops *ops = serial_get_ops(dev);
252 int err;
253
254 do {
255 err = ops->getc(dev);
256 if (err == -EAGAIN)
257 schedule();
258 } while (err == -EAGAIN);
259
260 return err >= 0 ? err : 0;
261 }
262
__serial_tstc(struct udevice * dev)263 static int __serial_tstc(struct udevice *dev)
264 {
265 struct dm_serial_ops *ops = serial_get_ops(dev);
266
267 if (ops->pending)
268 return ops->pending(dev, true);
269
270 return 1;
271 }
272
273 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
_serial_tstc(struct udevice * dev)274 static int _serial_tstc(struct udevice *dev)
275 {
276 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
277
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;
282 }
283
284 return upriv->rd_ptr != upriv->wr_ptr ? 1 : 0;
285 }
286
_serial_getc(struct udevice * dev)287 static int _serial_getc(struct udevice *dev)
288 {
289 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
290 char val;
291
292 if (upriv->rd_ptr == upriv->wr_ptr)
293 return __serial_getc(dev);
294
295 val = upriv->buf[upriv->rd_ptr++];
296 upriv->rd_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
297
298 return val;
299 }
300
301 #else /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
302
_serial_getc(struct udevice * dev)303 static int _serial_getc(struct udevice *dev)
304 {
305 return __serial_getc(dev);
306 }
307
_serial_tstc(struct udevice * dev)308 static int _serial_tstc(struct udevice *dev)
309 {
310 return __serial_tstc(dev);
311 }
312 #endif /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
313
serial_putc(char ch)314 void serial_putc(char ch)
315 {
316 if (gd->cur_serial_dev)
317 _serial_putc(gd->cur_serial_dev, ch);
318 }
319
serial_puts(const char * str)320 void serial_puts(const char *str)
321 {
322 if (gd->cur_serial_dev)
323 _serial_puts(gd->cur_serial_dev, str);
324 }
325
326 #ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
serial_flush(void)327 void serial_flush(void)
328 {
329 if (!gd->cur_serial_dev)
330 return;
331
332 _serial_flush(gd->cur_serial_dev);
333 }
334 #endif
335
serial_getc(void)336 int serial_getc(void)
337 {
338 if (!gd->cur_serial_dev)
339 return 0;
340
341 return _serial_getc(gd->cur_serial_dev);
342 }
343
serial_tstc(void)344 int serial_tstc(void)
345 {
346 if (!gd->cur_serial_dev)
347 return 0;
348
349 return _serial_tstc(gd->cur_serial_dev);
350 }
351
serial_setbrg(void)352 void serial_setbrg(void)
353 {
354 struct dm_serial_ops *ops;
355
356 if (!gd->cur_serial_dev)
357 return;
358
359 ops = serial_get_ops(gd->cur_serial_dev);
360 if (ops->setbrg)
361 ops->setbrg(gd->cur_serial_dev, gd->baudrate);
362 }
363
serial_getconfig(struct udevice * dev,uint * config)364 int serial_getconfig(struct udevice *dev, uint *config)
365 {
366 struct dm_serial_ops *ops;
367
368 ops = serial_get_ops(dev);
369 if (ops->getconfig)
370 return ops->getconfig(dev, config);
371
372 return 0;
373 }
374
serial_setconfig(struct udevice * dev,uint config)375 int serial_setconfig(struct udevice *dev, uint config)
376 {
377 struct dm_serial_ops *ops;
378
379 ops = serial_get_ops(dev);
380 if (ops->setconfig)
381 return ops->setconfig(dev, config);
382
383 return 0;
384 }
385
serial_getinfo(struct udevice * dev,struct serial_device_info * info)386 int serial_getinfo(struct udevice *dev, struct serial_device_info *info)
387 {
388 struct dm_serial_ops *ops;
389
390 if (!info)
391 return -EINVAL;
392
393 info->baudrate = gd->baudrate;
394
395 ops = serial_get_ops(dev);
396 if (ops->getinfo)
397 return ops->getinfo(dev, info);
398
399 return -EINVAL;
400 }
401
serial_stdio_init(void)402 void serial_stdio_init(void)
403 {
404 }
405
406 #if CONFIG_IS_ENABLED(DM_STDIO)
407
408 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
serial_stub_putc(struct stdio_dev * sdev,const char ch)409 static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
410 {
411 _serial_putc(sdev->priv, ch);
412 }
413
serial_stub_puts(struct stdio_dev * sdev,const char * str)414 static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
415 {
416 _serial_puts(sdev->priv, str);
417 }
418
419 #ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
serial_stub_flush(struct stdio_dev * sdev)420 static void serial_stub_flush(struct stdio_dev *sdev)
421 {
422 _serial_flush(sdev->priv);
423 }
424 #endif
425
serial_stub_getc(struct stdio_dev * sdev)426 static int serial_stub_getc(struct stdio_dev *sdev)
427 {
428 return _serial_getc(sdev->priv);
429 }
430
serial_stub_tstc(struct stdio_dev * sdev)431 static int serial_stub_tstc(struct stdio_dev *sdev)
432 {
433 return _serial_tstc(sdev->priv);
434 }
435 #endif
436 #endif
437
438 /**
439 * on_baudrate() - Update the actual baudrate when the env var changes
440 *
441 * This will check for a valid baudrate and only apply it if valid.
442 */
on_baudrate(const char * name,const char * value,enum env_op op,int flags)443 static int on_baudrate(const char *name, const char *value, enum env_op op,
444 int flags)
445 {
446 int i;
447 int baudrate;
448
449 switch (op) {
450 case env_op_create:
451 case env_op_overwrite:
452 /*
453 * Switch to new baudrate if new baudrate is supported
454 */
455 baudrate = dectoul(value, NULL);
456
457 /* Not actually changing */
458 if (gd->baudrate == baudrate)
459 return 0;
460
461 for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
462 if (baudrate == baudrate_table[i])
463 break;
464 }
465 if (i == ARRAY_SIZE(baudrate_table)) {
466 if ((flags & H_FORCE) == 0)
467 printf("## Baudrate %d bps not supported\n",
468 baudrate);
469 return 1;
470 }
471 if ((flags & H_INTERACTIVE) != 0) {
472 printf("## Switch baudrate to %d bps and press ENTER ...\n",
473 baudrate);
474 udelay(50000);
475 flush();
476 }
477
478 gd->baudrate = baudrate;
479
480 serial_setbrg();
481
482 udelay(50000);
483
484 if ((flags & H_INTERACTIVE) != 0)
485 while (1) {
486 if (getchar() == '\r')
487 break;
488 }
489
490 return 0;
491 case env_op_delete:
492 printf("## Baudrate may not be deleted\n");
493 return 1;
494 default:
495 return 0;
496 }
497 }
498 U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
499
500 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
serial_post_probe(struct udevice * dev)501 static int serial_post_probe(struct udevice *dev)
502 {
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;
507 #endif
508 int ret;
509
510 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
511 if (ops->setbrg)
512 ops->setbrg += gd->reloc_off;
513 if (ops->getc)
514 ops->getc += gd->reloc_off;
515 if (ops->putc)
516 ops->putc += gd->reloc_off;
517 if (ops->pending)
518 ops->pending += gd->reloc_off;
519 if (ops->clear)
520 ops->clear += gd->reloc_off;
521 if (ops->getconfig)
522 ops->getconfig += gd->reloc_off;
523 if (ops->setconfig)
524 ops->setconfig += gd->reloc_off;
525 #if CFG_POST & CFG_SYS_POST_UART
526 if (ops->loop)
527 ops->loop += gd->reloc_off;
528 #endif
529 if (ops->getinfo)
530 ops->getinfo += gd->reloc_off;
531 #endif
532 /* Set the baud rate */
533 if (ops->setbrg) {
534 ret = ops->setbrg(dev, gd->baudrate);
535 if (ret)
536 return ret;
537 }
538
539 #if CONFIG_IS_ENABLED(DM_STDIO)
540 if (!(gd->flags & GD_FLG_RELOC))
541 return 0;
542 memset(&sdev, '\0', sizeof(sdev));
543
544 strncpy(sdev.name, dev->name, sizeof(sdev.name));
545 sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT | DEV_FLAGS_DM;
546 sdev.priv = dev;
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;
552
553 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
554 /* Allocate the RX buffer */
555 upriv->buf = malloc(CONFIG_SERIAL_RX_BUFFER_SIZE);
556 #endif
557
558 stdio_register_dev(&sdev, &upriv->sdev);
559 #endif
560 return 0;
561 }
562
serial_pre_remove(struct udevice * dev)563 static int serial_pre_remove(struct udevice *dev)
564 {
565 #if CONFIG_IS_ENABLED(SYS_STDIO_DEREGISTER)
566 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
567
568 if (stdio_deregister_dev(upriv->sdev, true))
569 return -EPERM;
570 #endif
571
572 return 0;
573 }
574
575 UCLASS_DRIVER(serial) = {
576 .id = UCLASS_SERIAL,
577 .name = "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),
582 };
583 #endif
584