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 <environment.h>
9 #include <errno.h>
10 #include <os.h>
11 #include <serial.h>
12 #include <stdio_dev.h>
13 #include <watchdog.h>
14 #include <dm/lists.h>
15 #include <dm/device-internal.h>
16 #include <dm/of_access.h>
17
18 DECLARE_GLOBAL_DATA_PTR;
19
20 /*
21 * Table with supported baudrates (defined in config_xyz.h)
22 */
23 static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
24
25 #if !CONFIG_VAL(SYS_MALLOC_F_LEN)
26 #error "Serial is required before relocation - define CONFIG_$(SPL_)SYS_MALLOC_F_LEN to make this work"
27 #endif
28
29 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
serial_check_stdout(const void * blob,struct udevice ** devp)30 static int serial_check_stdout(const void *blob, struct udevice **devp)
31 {
32 int node;
33
34 /* Check for a chosen console */
35 node = fdtdec_get_chosen_node(blob, "stdout-path");
36 if (node < 0) {
37 const char *str, *p, *name;
38
39 /*
40 * Deal with things like
41 * stdout-path = "serial0:115200n8";
42 *
43 * We need to look up the alias and then follow it to the
44 * correct node.
45 */
46 str = fdtdec_get_chosen_prop(blob, "stdout-path");
47 if (str) {
48 p = strchr(str, ':');
49 name = fdt_get_alias_namelen(blob, str,
50 p ? p - str : strlen(str));
51 if (name)
52 node = fdt_path_offset(blob, name);
53 }
54 }
55 if (node < 0)
56 node = fdt_path_offset(blob, "console");
57 if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, devp))
58 return 0;
59
60 /*
61 * If the console is not marked to be bound before relocation, bind it
62 * anyway.
63 */
64 if (node > 0 && !lists_bind_fdt(gd->dm_root, offset_to_ofnode(node),
65 devp, false)) {
66 if (!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 (!SPL_BUILD || !CONFIG_IS_ENABLED(OF_CONTROL) || !blob) {
105 /*
106 * Try to use CONFIG_CONS_INDEX if available (it is numbered
107 * from 1!).
108 *
109 * Failing that, get the device with sequence number 0, or in
110 * extremis just the first working serial device we can find.
111 * But we insist on having a console (even if it is silent).
112 */
113 #ifdef CONFIG_CONS_INDEX
114 #define INDEX (CONFIG_CONS_INDEX - 1)
115 #else
116 #define INDEX 0
117 #endif
118
119 #ifdef CONFIG_SERIAL_SEARCH_ALL
120 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
121 !uclass_get_device(UCLASS_SERIAL, INDEX, &dev)) {
122 if (dev->flags & DM_FLAG_ACTIVATED) {
123 gd->cur_serial_dev = dev;
124 return;
125 }
126 }
127
128 /* Search for any working device */
129 for (ret = uclass_first_device_check(UCLASS_SERIAL, &dev);
130 dev;
131 ret = uclass_next_device_check(&dev)) {
132 if (!ret) {
133 /* Device did succeed probing */
134 gd->cur_serial_dev = dev;
135 return;
136 }
137 }
138 #else
139 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
140 !uclass_get_device(UCLASS_SERIAL, INDEX, &dev) ||
141 (!uclass_first_device(UCLASS_SERIAL, &dev) && dev)) {
142 gd->cur_serial_dev = dev;
143 return;
144 }
145 #endif
146
147 #undef INDEX
148 }
149
150 #ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
151 panic_str("No serial driver found");
152 #endif
153 }
154 #endif /* CONFIG_SERIAL_PRESENT */
155
156 /* Called prior to relocation */
serial_init(void)157 int serial_init(void)
158 {
159 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
160 serial_find_console_or_panic();
161 gd->flags |= GD_FLG_SERIAL_READY;
162 #endif
163
164 return 0;
165 }
166
167 /* Called after relocation */
serial_initialize(void)168 void serial_initialize(void)
169 {
170 serial_init();
171 }
172
_serial_putc(struct udevice * dev,char ch)173 static void _serial_putc(struct udevice *dev, char ch)
174 {
175 struct dm_serial_ops *ops = serial_get_ops(dev);
176 int err;
177
178 if (ch == '\n')
179 _serial_putc(dev, '\r');
180
181 do {
182 err = ops->putc(dev, ch);
183 } while (err == -EAGAIN);
184 }
185
_serial_puts(struct udevice * dev,const char * str)186 static void _serial_puts(struct udevice *dev, const char *str)
187 {
188 while (*str)
189 _serial_putc(dev, *str++);
190 }
191
__serial_getc(struct udevice * dev)192 static int __serial_getc(struct udevice *dev)
193 {
194 struct dm_serial_ops *ops = serial_get_ops(dev);
195 int err;
196
197 do {
198 err = ops->getc(dev);
199 if (err == -EAGAIN)
200 WATCHDOG_RESET();
201 } while (err == -EAGAIN);
202
203 return err >= 0 ? err : 0;
204 }
205
__serial_tstc(struct udevice * dev)206 static int __serial_tstc(struct udevice *dev)
207 {
208 struct dm_serial_ops *ops = serial_get_ops(dev);
209
210 if (ops->pending)
211 return ops->pending(dev, true);
212
213 return 1;
214 }
215
216 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
_serial_tstc(struct udevice * dev)217 static int _serial_tstc(struct udevice *dev)
218 {
219 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
220
221 /* Read all available chars into the RX buffer */
222 while (__serial_tstc(dev)) {
223 upriv->buf[upriv->wr_ptr++] = __serial_getc(dev);
224 upriv->wr_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
225 }
226
227 return upriv->rd_ptr != upriv->wr_ptr ? 1 : 0;
228 }
229
_serial_getc(struct udevice * dev)230 static int _serial_getc(struct udevice *dev)
231 {
232 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
233 char val;
234
235 if (upriv->rd_ptr == upriv->wr_ptr)
236 return __serial_getc(dev);
237
238 val = upriv->buf[upriv->rd_ptr++];
239 upriv->rd_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
240
241 return val;
242 }
243
244 #else /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
245
_serial_getc(struct udevice * dev)246 static int _serial_getc(struct udevice *dev)
247 {
248 return __serial_getc(dev);
249 }
250
_serial_tstc(struct udevice * dev)251 static int _serial_tstc(struct udevice *dev)
252 {
253 return __serial_tstc(dev);
254 }
255 #endif /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
256
serial_putc(char ch)257 void serial_putc(char ch)
258 {
259 if (gd->cur_serial_dev)
260 _serial_putc(gd->cur_serial_dev, ch);
261 }
262
serial_puts(const char * str)263 void serial_puts(const char *str)
264 {
265 if (gd->cur_serial_dev)
266 _serial_puts(gd->cur_serial_dev, str);
267 }
268
serial_getc(void)269 int serial_getc(void)
270 {
271 if (!gd->cur_serial_dev)
272 return 0;
273
274 return _serial_getc(gd->cur_serial_dev);
275 }
276
serial_tstc(void)277 int serial_tstc(void)
278 {
279 if (!gd->cur_serial_dev)
280 return 0;
281
282 return _serial_tstc(gd->cur_serial_dev);
283 }
284
serial_setbrg(void)285 void serial_setbrg(void)
286 {
287 struct dm_serial_ops *ops;
288
289 if (!gd->cur_serial_dev)
290 return;
291
292 ops = serial_get_ops(gd->cur_serial_dev);
293 if (ops->setbrg)
294 ops->setbrg(gd->cur_serial_dev, gd->baudrate);
295 }
296
serial_getconfig(struct udevice * dev,uint * config)297 int serial_getconfig(struct udevice *dev, uint *config)
298 {
299 struct dm_serial_ops *ops;
300
301 ops = serial_get_ops(dev);
302 if (ops->getconfig)
303 return ops->getconfig(dev, config);
304
305 return 0;
306 }
307
serial_setconfig(struct udevice * dev,uint config)308 int serial_setconfig(struct udevice *dev, uint config)
309 {
310 struct dm_serial_ops *ops;
311
312 ops = serial_get_ops(dev);
313 if (ops->setconfig)
314 return ops->setconfig(dev, config);
315
316 return 0;
317 }
318
serial_getinfo(struct udevice * dev,struct serial_device_info * info)319 int serial_getinfo(struct udevice *dev, struct serial_device_info *info)
320 {
321 struct dm_serial_ops *ops;
322
323 if (!info)
324 return -EINVAL;
325
326 info->baudrate = gd->baudrate;
327
328 ops = serial_get_ops(dev);
329 if (ops->getinfo)
330 return ops->getinfo(dev, info);
331
332 return -EINVAL;
333 }
334
serial_stdio_init(void)335 void serial_stdio_init(void)
336 {
337 }
338
339 #if defined(CONFIG_DM_STDIO)
340
341 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
serial_stub_putc(struct stdio_dev * sdev,const char ch)342 static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
343 {
344 _serial_putc(sdev->priv, ch);
345 }
346 #endif
347
serial_stub_puts(struct stdio_dev * sdev,const char * str)348 static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
349 {
350 _serial_puts(sdev->priv, str);
351 }
352
serial_stub_getc(struct stdio_dev * sdev)353 static int serial_stub_getc(struct stdio_dev *sdev)
354 {
355 return _serial_getc(sdev->priv);
356 }
357
serial_stub_tstc(struct stdio_dev * sdev)358 static int serial_stub_tstc(struct stdio_dev *sdev)
359 {
360 return _serial_tstc(sdev->priv);
361 }
362 #endif
363
364 /**
365 * on_baudrate() - Update the actual baudrate when the env var changes
366 *
367 * This will check for a valid baudrate and only apply it if valid.
368 */
on_baudrate(const char * name,const char * value,enum env_op op,int flags)369 static int on_baudrate(const char *name, const char *value, enum env_op op,
370 int flags)
371 {
372 int i;
373 int baudrate;
374
375 switch (op) {
376 case env_op_create:
377 case env_op_overwrite:
378 /*
379 * Switch to new baudrate if new baudrate is supported
380 */
381 baudrate = simple_strtoul(value, NULL, 10);
382
383 /* Not actually changing */
384 if (gd->baudrate == baudrate)
385 return 0;
386
387 for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
388 if (baudrate == baudrate_table[i])
389 break;
390 }
391 if (i == ARRAY_SIZE(baudrate_table)) {
392 if ((flags & H_FORCE) == 0)
393 printf("## Baudrate %d bps not supported\n",
394 baudrate);
395 return 1;
396 }
397 if ((flags & H_INTERACTIVE) != 0) {
398 printf("## Switch baudrate to %d bps and press ENTER ...\n",
399 baudrate);
400 udelay(50000);
401 }
402
403 gd->baudrate = baudrate;
404
405 serial_setbrg();
406
407 udelay(50000);
408
409 if ((flags & H_INTERACTIVE) != 0)
410 while (1) {
411 if (getc() == '\r')
412 break;
413 }
414
415 return 0;
416 case env_op_delete:
417 printf("## Baudrate may not be deleted\n");
418 return 1;
419 default:
420 return 0;
421 }
422 }
423 U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
424
425 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
serial_post_probe(struct udevice * dev)426 static int serial_post_probe(struct udevice *dev)
427 {
428 struct dm_serial_ops *ops = serial_get_ops(dev);
429 #ifdef CONFIG_DM_STDIO
430 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
431 struct stdio_dev sdev;
432 #endif
433 int ret;
434
435 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
436 if (ops->setbrg)
437 ops->setbrg += gd->reloc_off;
438 if (ops->getc)
439 ops->getc += gd->reloc_off;
440 if (ops->putc)
441 ops->putc += gd->reloc_off;
442 if (ops->pending)
443 ops->pending += gd->reloc_off;
444 if (ops->clear)
445 ops->clear += gd->reloc_off;
446 if (ops->getconfig)
447 ops->getconfig += gd->reloc_off;
448 if (ops->setconfig)
449 ops->setconfig += gd->reloc_off;
450 #if CONFIG_POST & CONFIG_SYS_POST_UART
451 if (ops->loop)
452 ops->loop += gd->reloc_off;
453 #endif
454 if (ops->getinfo)
455 ops->getinfo += gd->reloc_off;
456 #endif
457 /* Set the baud rate */
458 if (ops->setbrg) {
459 ret = ops->setbrg(dev, gd->baudrate);
460 if (ret)
461 return ret;
462 }
463
464 #ifdef CONFIG_DM_STDIO
465 if (!(gd->flags & GD_FLG_RELOC))
466 return 0;
467 memset(&sdev, '\0', sizeof(sdev));
468
469 strncpy(sdev.name, dev->name, sizeof(sdev.name));
470 sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT | DEV_FLAGS_DM;
471 sdev.priv = dev;
472 sdev.putc = serial_stub_putc;
473 sdev.puts = serial_stub_puts;
474 sdev.getc = serial_stub_getc;
475 sdev.tstc = serial_stub_tstc;
476
477 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
478 /* Allocate the RX buffer */
479 upriv->buf = malloc(CONFIG_SERIAL_RX_BUFFER_SIZE);
480 #endif
481
482 stdio_register_dev(&sdev, &upriv->sdev);
483 #endif
484 return 0;
485 }
486
serial_pre_remove(struct udevice * dev)487 static int serial_pre_remove(struct udevice *dev)
488 {
489 #if CONFIG_IS_ENABLED(SYS_STDIO_DEREGISTER)
490 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
491
492 if (stdio_deregister_dev(upriv->sdev, true))
493 return -EPERM;
494 #endif
495
496 return 0;
497 }
498
499 UCLASS_DRIVER(serial) = {
500 .id = UCLASS_SERIAL,
501 .name = "serial",
502 .flags = DM_UC_FLAG_SEQ_ALIAS,
503 .post_probe = serial_post_probe,
504 .pre_remove = serial_pre_remove,
505 .per_device_auto_alloc_size = sizeof(struct serial_dev_priv),
506 };
507 #endif
508