1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (c) 2014 The Chromium OS Authors.
4 */
5
6 #include <common.h>
7 #include <dm.h>
8 #include <env_internal.h>
9 #include <errno.h>
10 #include <malloc.h>
11 #include <os.h>
12 #include <serial.h>
13 #include <stdio_dev.h>
14 #include <watchdog.h>
15 #include <asm/global_data.h>
16 #include <dm/lists.h>
17 #include <dm/device-internal.h>
18 #include <dm/of_access.h>
19 #include <linux/delay.h>
20
21 DECLARE_GLOBAL_DATA_PTR;
22
23 /*
24 * Table with supported baudrates (defined in config_xyz.h)
25 */
26 static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
27
28 #if !CONFIG_VAL(SYS_MALLOC_F_LEN)
29 #error "Serial is required before relocation - define CONFIG_$(SPL_)SYS_MALLOC_F_LEN to make this work"
30 #endif
31
32 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
serial_check_stdout(const void * blob,struct udevice ** devp)33 static int serial_check_stdout(const void *blob, struct udevice **devp)
34 {
35 int node = -1;
36 const char *str, *p, *name;
37 int namelen;
38
39 /* Check for a chosen console */
40 str = fdtdec_get_chosen_prop(blob, "stdout-path");
41 if (str) {
42 p = strchr(str, ':');
43 namelen = p ? p - str : strlen(str);
44 node = fdt_path_offset_namelen(blob, str, namelen);
45
46 if (node < 0) {
47 /*
48 * Deal with things like
49 * stdout-path = "serial0:115200n8";
50 *
51 * We need to look up the alias and then follow it to
52 * the correct node.
53 */
54 name = fdt_get_alias_namelen(blob, str, namelen);
55 if (name)
56 node = fdt_path_offset(blob, name);
57 }
58 }
59
60 if (node < 0)
61 node = fdt_path_offset(blob, "console");
62 if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, devp))
63 return 0;
64
65 /*
66 * If the console is not marked to be bound before relocation, bind it
67 * anyway.
68 */
69 if (node > 0 && !lists_bind_fdt(gd->dm_root, offset_to_ofnode(node),
70 devp, false)) {
71 if (!device_probe(*devp))
72 return 0;
73 }
74
75 return -ENODEV;
76 }
77
serial_find_console_or_panic(void)78 static void serial_find_console_or_panic(void)
79 {
80 const void *blob = gd->fdt_blob;
81 struct udevice *dev;
82 #ifdef CONFIG_SERIAL_SEARCH_ALL
83 int ret;
84 #endif
85
86 if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
87 uclass_first_device(UCLASS_SERIAL, &dev);
88 if (dev) {
89 gd->cur_serial_dev = dev;
90 return;
91 }
92 } else if (CONFIG_IS_ENABLED(OF_CONTROL) && blob) {
93 /* Live tree has support for stdout */
94 if (of_live_active()) {
95 struct device_node *np = of_get_stdout();
96
97 if (np && !uclass_get_device_by_ofnode(UCLASS_SERIAL,
98 np_to_ofnode(np), &dev)) {
99 gd->cur_serial_dev = dev;
100 return;
101 }
102 } else {
103 if (!serial_check_stdout(blob, &dev)) {
104 gd->cur_serial_dev = dev;
105 return;
106 }
107 }
108 }
109 if (!SPL_BUILD || !CONFIG_IS_ENABLED(OF_CONTROL) || !blob) {
110 /*
111 * Try to use CONFIG_CONS_INDEX if available (it is numbered
112 * from 1!).
113 *
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).
117 */
118 #ifdef CONFIG_CONS_INDEX
119 #define INDEX (CONFIG_CONS_INDEX - 1)
120 #else
121 #define INDEX 0
122 #endif
123
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;
129 return;
130 }
131 }
132
133 /* Search for any working device */
134 for (ret = uclass_first_device_check(UCLASS_SERIAL, &dev);
135 dev;
136 ret = uclass_next_device_check(&dev)) {
137 if (!ret) {
138 /* Device did succeed probing */
139 gd->cur_serial_dev = dev;
140 return;
141 }
142 }
143 #else
144 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
145 !uclass_get_device(UCLASS_SERIAL, INDEX, &dev) ||
146 (!uclass_first_device(UCLASS_SERIAL, &dev) && dev)) {
147 gd->cur_serial_dev = dev;
148 return;
149 }
150 #endif
151
152 #undef INDEX
153 }
154
155 #ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
156 panic_str("No serial driver found");
157 #endif
158 }
159 #endif /* CONFIG_SERIAL_PRESENT */
160
161 /* Called prior to relocation */
serial_init(void)162 int serial_init(void)
163 {
164 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
165 serial_find_console_or_panic();
166 gd->flags |= GD_FLG_SERIAL_READY;
167 serial_setbrg();
168 #endif
169
170 return 0;
171 }
172
173 /* Called after relocation */
serial_initialize(void)174 int serial_initialize(void)
175 {
176 /* Scanning uclass to probe devices */
177 if (IS_ENABLED(CONFIG_SERIAL_PROBE_ALL)) {
178 int ret;
179
180 ret = uclass_probe_all(UCLASS_SERIAL);
181 if (ret)
182 return ret;
183 }
184
185 return serial_init();
186 }
187
_serial_putc(struct udevice * dev,char ch)188 static void _serial_putc(struct udevice *dev, char ch)
189 {
190 struct dm_serial_ops *ops = serial_get_ops(dev);
191 int err;
192
193 if (ch == '\n')
194 _serial_putc(dev, '\r');
195
196 do {
197 err = ops->putc(dev, ch);
198 } while (err == -EAGAIN);
199 }
200
_serial_puts(struct udevice * dev,const char * str)201 static void _serial_puts(struct udevice *dev, const char *str)
202 {
203 while (*str)
204 _serial_putc(dev, *str++);
205 }
206
__serial_getc(struct udevice * dev)207 static int __serial_getc(struct udevice *dev)
208 {
209 struct dm_serial_ops *ops = serial_get_ops(dev);
210 int err;
211
212 do {
213 err = ops->getc(dev);
214 if (err == -EAGAIN)
215 WATCHDOG_RESET();
216 } while (err == -EAGAIN);
217
218 return err >= 0 ? err : 0;
219 }
220
__serial_tstc(struct udevice * dev)221 static int __serial_tstc(struct udevice *dev)
222 {
223 struct dm_serial_ops *ops = serial_get_ops(dev);
224
225 if (ops->pending)
226 return ops->pending(dev, true);
227
228 return 1;
229 }
230
231 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
_serial_tstc(struct udevice * dev)232 static int _serial_tstc(struct udevice *dev)
233 {
234 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
235
236 /* Read all available chars into the RX buffer */
237 while (__serial_tstc(dev)) {
238 upriv->buf[upriv->wr_ptr++] = __serial_getc(dev);
239 upriv->wr_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
240 }
241
242 return upriv->rd_ptr != upriv->wr_ptr ? 1 : 0;
243 }
244
_serial_getc(struct udevice * dev)245 static int _serial_getc(struct udevice *dev)
246 {
247 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
248 char val;
249
250 if (upriv->rd_ptr == upriv->wr_ptr)
251 return __serial_getc(dev);
252
253 val = upriv->buf[upriv->rd_ptr++];
254 upriv->rd_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
255
256 return val;
257 }
258
259 #else /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
260
_serial_getc(struct udevice * dev)261 static int _serial_getc(struct udevice *dev)
262 {
263 return __serial_getc(dev);
264 }
265
_serial_tstc(struct udevice * dev)266 static int _serial_tstc(struct udevice *dev)
267 {
268 return __serial_tstc(dev);
269 }
270 #endif /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
271
serial_putc(char ch)272 void serial_putc(char ch)
273 {
274 if (gd->cur_serial_dev)
275 _serial_putc(gd->cur_serial_dev, ch);
276 }
277
serial_puts(const char * str)278 void serial_puts(const char *str)
279 {
280 if (gd->cur_serial_dev)
281 _serial_puts(gd->cur_serial_dev, str);
282 }
283
serial_getc(void)284 int serial_getc(void)
285 {
286 if (!gd->cur_serial_dev)
287 return 0;
288
289 return _serial_getc(gd->cur_serial_dev);
290 }
291
serial_tstc(void)292 int serial_tstc(void)
293 {
294 if (!gd->cur_serial_dev)
295 return 0;
296
297 return _serial_tstc(gd->cur_serial_dev);
298 }
299
serial_setbrg(void)300 void serial_setbrg(void)
301 {
302 struct dm_serial_ops *ops;
303
304 if (!gd->cur_serial_dev)
305 return;
306
307 ops = serial_get_ops(gd->cur_serial_dev);
308 if (ops->setbrg)
309 ops->setbrg(gd->cur_serial_dev, gd->baudrate);
310 }
311
serial_getconfig(struct udevice * dev,uint * config)312 int serial_getconfig(struct udevice *dev, uint *config)
313 {
314 struct dm_serial_ops *ops;
315
316 ops = serial_get_ops(dev);
317 if (ops->getconfig)
318 return ops->getconfig(dev, config);
319
320 return 0;
321 }
322
serial_setconfig(struct udevice * dev,uint config)323 int serial_setconfig(struct udevice *dev, uint config)
324 {
325 struct dm_serial_ops *ops;
326
327 ops = serial_get_ops(dev);
328 if (ops->setconfig)
329 return ops->setconfig(dev, config);
330
331 return 0;
332 }
333
serial_getinfo(struct udevice * dev,struct serial_device_info * info)334 int serial_getinfo(struct udevice *dev, struct serial_device_info *info)
335 {
336 struct dm_serial_ops *ops;
337
338 if (!info)
339 return -EINVAL;
340
341 info->baudrate = gd->baudrate;
342
343 ops = serial_get_ops(dev);
344 if (ops->getinfo)
345 return ops->getinfo(dev, info);
346
347 return -EINVAL;
348 }
349
serial_stdio_init(void)350 void serial_stdio_init(void)
351 {
352 }
353
354 #if defined(CONFIG_DM_STDIO)
355
356 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
serial_stub_putc(struct stdio_dev * sdev,const char ch)357 static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
358 {
359 _serial_putc(sdev->priv, ch);
360 }
361 #endif
362
serial_stub_puts(struct stdio_dev * sdev,const char * str)363 static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
364 {
365 _serial_puts(sdev->priv, str);
366 }
367
serial_stub_getc(struct stdio_dev * sdev)368 static int serial_stub_getc(struct stdio_dev *sdev)
369 {
370 return _serial_getc(sdev->priv);
371 }
372
serial_stub_tstc(struct stdio_dev * sdev)373 static int serial_stub_tstc(struct stdio_dev *sdev)
374 {
375 return _serial_tstc(sdev->priv);
376 }
377 #endif
378
379 /**
380 * on_baudrate() - Update the actual baudrate when the env var changes
381 *
382 * This will check for a valid baudrate and only apply it if valid.
383 */
on_baudrate(const char * name,const char * value,enum env_op op,int flags)384 static int on_baudrate(const char *name, const char *value, enum env_op op,
385 int flags)
386 {
387 int i;
388 int baudrate;
389
390 switch (op) {
391 case env_op_create:
392 case env_op_overwrite:
393 /*
394 * Switch to new baudrate if new baudrate is supported
395 */
396 baudrate = simple_strtoul(value, NULL, 10);
397
398 /* Not actually changing */
399 if (gd->baudrate == baudrate)
400 return 0;
401
402 for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
403 if (baudrate == baudrate_table[i])
404 break;
405 }
406 if (i == ARRAY_SIZE(baudrate_table)) {
407 if ((flags & H_FORCE) == 0)
408 printf("## Baudrate %d bps not supported\n",
409 baudrate);
410 return 1;
411 }
412 if ((flags & H_INTERACTIVE) != 0) {
413 printf("## Switch baudrate to %d bps and press ENTER ...\n",
414 baudrate);
415 udelay(50000);
416 }
417
418 gd->baudrate = baudrate;
419
420 serial_setbrg();
421
422 udelay(50000);
423
424 if ((flags & H_INTERACTIVE) != 0)
425 while (1) {
426 if (getchar() == '\r')
427 break;
428 }
429
430 return 0;
431 case env_op_delete:
432 printf("## Baudrate may not be deleted\n");
433 return 1;
434 default:
435 return 0;
436 }
437 }
438 U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
439
440 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
serial_post_probe(struct udevice * dev)441 static int serial_post_probe(struct udevice *dev)
442 {
443 struct dm_serial_ops *ops = serial_get_ops(dev);
444 #ifdef CONFIG_DM_STDIO
445 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
446 struct stdio_dev sdev;
447 #endif
448 int ret;
449
450 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
451 if (ops->setbrg)
452 ops->setbrg += gd->reloc_off;
453 if (ops->getc)
454 ops->getc += gd->reloc_off;
455 if (ops->putc)
456 ops->putc += gd->reloc_off;
457 if (ops->pending)
458 ops->pending += gd->reloc_off;
459 if (ops->clear)
460 ops->clear += gd->reloc_off;
461 if (ops->getconfig)
462 ops->getconfig += gd->reloc_off;
463 if (ops->setconfig)
464 ops->setconfig += gd->reloc_off;
465 #if CONFIG_POST & CONFIG_SYS_POST_UART
466 if (ops->loop)
467 ops->loop += gd->reloc_off;
468 #endif
469 if (ops->getinfo)
470 ops->getinfo += gd->reloc_off;
471 #endif
472 /* Set the baud rate */
473 if (ops->setbrg) {
474 ret = ops->setbrg(dev, gd->baudrate);
475 if (ret)
476 return ret;
477 }
478
479 #ifdef CONFIG_DM_STDIO
480 if (!(gd->flags & GD_FLG_RELOC))
481 return 0;
482 memset(&sdev, '\0', sizeof(sdev));
483
484 strncpy(sdev.name, dev->name, sizeof(sdev.name));
485 sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT | DEV_FLAGS_DM;
486 sdev.priv = dev;
487 sdev.putc = serial_stub_putc;
488 sdev.puts = serial_stub_puts;
489 sdev.getc = serial_stub_getc;
490 sdev.tstc = serial_stub_tstc;
491
492 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
493 /* Allocate the RX buffer */
494 upriv->buf = malloc(CONFIG_SERIAL_RX_BUFFER_SIZE);
495 #endif
496
497 stdio_register_dev(&sdev, &upriv->sdev);
498 #endif
499 return 0;
500 }
501
serial_pre_remove(struct udevice * dev)502 static int serial_pre_remove(struct udevice *dev)
503 {
504 #if CONFIG_IS_ENABLED(SYS_STDIO_DEREGISTER)
505 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
506
507 if (stdio_deregister_dev(upriv->sdev, true))
508 return -EPERM;
509 #endif
510
511 return 0;
512 }
513
514 UCLASS_DRIVER(serial) = {
515 .id = UCLASS_SERIAL,
516 .name = "serial",
517 .flags = DM_UC_FLAG_SEQ_ALIAS,
518 .post_probe = serial_post_probe,
519 .pre_remove = serial_pre_remove,
520 .per_device_auto = sizeof(struct serial_dev_priv),
521 };
522 #endif
523