1 /*
2 * Copyright (c) 2014 The Chromium OS Authors.
3 *
4 * SPDX-License-Identifier: GPL-2.0+
5 */
6
7 #include <common.h>
8 #include <debug_uart.h>
9 #include <dm.h>
10 #include <environment.h>
11 #include <errno.h>
12 #include <os.h>
13 #include <serial.h>
14 #include <stdio_dev.h>
15 #include <watchdog.h>
16 #include <dm/lists.h>
17 #include <dm/device-internal.h>
18 #include <dm/of_access.h>
19
20 DECLARE_GLOBAL_DATA_PTR;
21
22 #if !CONFIG_VAL(SYS_MALLOC_F_LEN)
23 #error "Serial is required before relocation - define CONFIG_$(SPL_)SYS_MALLOC_F_LEN to make this work"
24 #endif
25
26 #ifndef CONFIG_DEBUG_UART_ALWAYS
27 /*
28 * Table with supported baudrates (defined in config_xyz.h)
29 */
30 static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
31
serial_check_stdout(const void * blob,struct udevice ** devp)32 static int serial_check_stdout(const void *blob, struct udevice **devp)
33 {
34 int node;
35
36 /* Check for a chosen console */
37 node = fdtdec_get_chosen_node(blob, "stdout-path");
38 if (node < 0) {
39 const char *str, *p, *name;
40
41 /*
42 * Deal with things like
43 * stdout-path = "serial0:115200n8";
44 *
45 * We need to look up the alias and then follow it to the
46 * correct node.
47 */
48 str = fdtdec_get_chosen_prop(blob, "stdout-path");
49 if (str) {
50 p = strchr(str, ':');
51 name = fdt_get_alias_namelen(blob, str,
52 p ? p - str : strlen(str));
53 if (name)
54 node = fdt_path_offset(blob, name);
55 }
56 }
57 if (node < 0)
58 node = fdt_path_offset(blob, "console");
59 if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, devp))
60 return 0;
61
62 /*
63 * If the console is not marked to be bound before relocation, bind it
64 * anyway.
65 */
66 if (node > 0 && !lists_bind_fdt(gd->dm_root, offset_to_ofnode(node),
67 devp)) {
68 if (!device_probe(*devp))
69 return 0;
70 }
71
72 return -ENODEV;
73 }
74
serial_find_console_or_panic(void)75 static void serial_find_console_or_panic(void)
76 {
77 const void *blob = gd->fdt_blob;
78 struct udevice *dev;
79
80 if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
81 uclass_first_device(UCLASS_SERIAL, &dev);
82 if (dev) {
83 gd->cur_serial_dev = dev;
84 return;
85 }
86 } else if (CONFIG_IS_ENABLED(OF_CONTROL) && blob) {
87 /* Live tree has support for stdout */
88 if (of_live_active()) {
89 struct device_node *np = of_get_stdout();
90
91 if (np && !uclass_get_device_by_ofnode(UCLASS_SERIAL,
92 np_to_ofnode(np), &dev)) {
93 gd->cur_serial_dev = dev;
94 return;
95 }
96 } else {
97 if (!serial_check_stdout(blob, &dev)) {
98 gd->cur_serial_dev = dev;
99 return;
100 }
101 }
102 }
103 if (!SPL_BUILD || !CONFIG_IS_ENABLED(OF_CONTROL) || !blob) {
104 /*
105 * Try to use CONFIG_CONS_INDEX if available (it is numbered
106 * from 1!).
107 *
108 * Failing that, get the device with sequence number 0, or in
109 * extremis just the first serial device we can find. But we
110 * insist on having a console (even if it is silent).
111 */
112 #ifdef CONFIG_CONS_INDEX
113 #define INDEX (CONFIG_CONS_INDEX - 1)
114 #else
115 #define INDEX 0
116 #endif
117 if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
118 !uclass_get_device(UCLASS_SERIAL, INDEX, &dev) ||
119 (!uclass_first_device(UCLASS_SERIAL, &dev) && dev)) {
120 gd->cur_serial_dev = dev;
121 return;
122 }
123 #undef INDEX
124 }
125
126 #ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
127 panic_str("No serial driver found");
128 #endif
129 }
130
131 /* Called prior to relocation */
serial_init(void)132 int serial_init(void)
133 {
134 serial_find_console_or_panic();
135 gd->flags |= GD_FLG_SERIAL_READY;
136
137 return 0;
138 }
139 #else
serial_init(void)140 int serial_init(void) { return 0; }
141 #endif
142
143 /* Called after relocation */
serial_initialize(void)144 void serial_initialize(void)
145 {
146 serial_init();
147 }
148
_serial_putc(struct udevice * dev,char ch)149 static void _serial_putc(struct udevice *dev, char ch)
150 {
151 struct dm_serial_ops *ops = serial_get_ops(dev);
152 int err;
153
154 if (ch == '\n')
155 _serial_putc(dev, '\r');
156
157 do {
158 err = ops->putc(dev, ch);
159 } while (err == -EAGAIN);
160 }
161
_serial_puts(struct udevice * dev,const char * str)162 static void _serial_puts(struct udevice *dev, const char *str)
163 {
164 while (*str)
165 _serial_putc(dev, *str++);
166 }
167
__serial_getc(struct udevice * dev)168 static int __serial_getc(struct udevice *dev)
169 {
170 struct dm_serial_ops *ops = serial_get_ops(dev);
171 int err;
172
173 do {
174 err = ops->getc(dev);
175 if (err == -EAGAIN)
176 WATCHDOG_RESET();
177 } while (err == -EAGAIN);
178
179 return err >= 0 ? err : 0;
180 }
181
__serial_tstc(struct udevice * dev)182 static int __serial_tstc(struct udevice *dev)
183 {
184 struct dm_serial_ops *ops = serial_get_ops(dev);
185
186 if (ops->pending)
187 return ops->pending(dev, true);
188
189 return 1;
190 }
191
__serial_clear(struct udevice * dev)192 static void __serial_clear(struct udevice *dev)
193 {
194 struct dm_serial_ops *ops = serial_get_ops(dev);
195
196 if (ops->clear)
197 ops->clear(dev);
198 }
199
200 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
_serial_tstc(struct udevice * dev)201 static int _serial_tstc(struct udevice *dev)
202 {
203 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
204
205 /* Read all available chars into the RX buffer */
206 while (__serial_tstc(dev)) {
207 upriv->buf[upriv->wr_ptr++] = __serial_getc(dev);
208 upriv->wr_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
209 }
210
211 return upriv->rd_ptr != upriv->wr_ptr ? 1 : 0;
212 }
213
_serial_getc(struct udevice * dev)214 static int _serial_getc(struct udevice *dev)
215 {
216 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
217 char val;
218
219 val = upriv->buf[upriv->rd_ptr++];
220 upriv->rd_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
221
222 return val;
223 }
224
225 #else /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
226
_serial_getc(struct udevice * dev)227 static int _serial_getc(struct udevice *dev)
228 {
229 return __serial_getc(dev);
230 }
231
_serial_tstc(struct udevice * dev)232 static int _serial_tstc(struct udevice *dev)
233 {
234 return __serial_tstc(dev);
235 }
236 #endif /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */
237
serial_putc(char ch)238 void serial_putc(char ch)
239 {
240 if (gd->cur_serial_dev)
241 _serial_putc(gd->cur_serial_dev, ch);
242 else
243 printch(ch);
244 }
245
serial_puts(const char * str)246 void serial_puts(const char *str)
247 {
248 if (gd->cur_serial_dev)
249 _serial_puts(gd->cur_serial_dev, str);
250 else
251 printascii(str);
252 }
253
serial_getc(void)254 int serial_getc(void)
255 {
256 if (gd->cur_serial_dev)
257 return _serial_getc(gd->cur_serial_dev);
258 else
259 return debug_uart_getc();
260 }
261
serial_tstc(void)262 int serial_tstc(void)
263 {
264 if (gd->cur_serial_dev)
265 return _serial_tstc(gd->cur_serial_dev);
266 else
267 return debug_uart_tstc();
268 }
269
serial_setbrg(void)270 void serial_setbrg(void)
271 {
272 struct dm_serial_ops *ops;
273
274 if (!gd->cur_serial_dev) {
275 debug_uart_setbrg();
276 return;
277 }
278
279 ops = serial_get_ops(gd->cur_serial_dev);
280 if (ops->setbrg)
281 ops->setbrg(gd->cur_serial_dev, gd->baudrate);
282 }
283
serial_clear(void)284 void serial_clear(void)
285 {
286 if (gd->cur_serial_dev)
287 __serial_clear(gd->cur_serial_dev);
288 else
289 debug_uart_clrc();
290 }
291
serial_dev_putc(struct udevice * dev,char ch)292 void serial_dev_putc(struct udevice *dev, char ch)
293 {
294 if (!dev)
295 return;
296
297 _serial_putc(dev, ch);
298 }
299
serial_dev_puts(struct udevice * dev,const char * str)300 void serial_dev_puts(struct udevice *dev, const char *str)
301 {
302 if (!dev)
303 return;
304
305 _serial_puts(dev, str);
306 }
307
serial_dev_getc(struct udevice * dev)308 int serial_dev_getc(struct udevice *dev)
309 {
310 if (!dev)
311 return 0;
312
313 return _serial_getc(dev);
314 }
315
serial_dev_tstc(struct udevice * dev)316 int serial_dev_tstc(struct udevice *dev)
317 {
318 if (!dev)
319 return 0;
320
321 return _serial_tstc(dev);
322 }
323
serial_dev_setbrg(struct udevice * dev,int baudrate)324 void serial_dev_setbrg(struct udevice *dev, int baudrate)
325 {
326 struct dm_serial_ops *ops;
327
328 if (!dev)
329 return;
330
331 ops = serial_get_ops(dev);
332 if (ops->setbrg)
333 ops->setbrg(dev, baudrate);
334 }
335
serial_dev_clear(struct udevice * dev)336 void serial_dev_clear(struct udevice *dev)
337 {
338 if (!dev)
339 return;
340
341 __serial_clear(dev);
342 }
343
serial_stdio_init(void)344 void serial_stdio_init(void)
345 {
346 }
347
348 #if defined(CONFIG_DM_STDIO)
349
350 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
serial_stub_putc(struct stdio_dev * sdev,const char ch)351 static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
352 {
353 _serial_putc(sdev->priv, ch);
354 }
355 #endif
356
serial_stub_puts(struct stdio_dev * sdev,const char * str)357 static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
358 {
359 _serial_puts(sdev->priv, str);
360 }
361
serial_stub_getc(struct stdio_dev * sdev)362 static int serial_stub_getc(struct stdio_dev *sdev)
363 {
364 return _serial_getc(sdev->priv);
365 }
366
serial_stub_tstc(struct stdio_dev * sdev)367 static int serial_stub_tstc(struct stdio_dev *sdev)
368 {
369 return _serial_tstc(sdev->priv);
370 }
371 #endif
372
373 #ifndef CONFIG_DEBUG_UART_ALWAYS
374 /**
375 * on_baudrate() - Update the actual baudrate when the env var changes
376 *
377 * This will check for a valid baudrate and only apply it if valid.
378 */
on_baudrate(const char * name,const char * value,enum env_op op,int flags)379 static int on_baudrate(const char *name, const char *value, enum env_op op,
380 int flags)
381 {
382 int i;
383 int baudrate;
384
385 switch (op) {
386 case env_op_create:
387 case env_op_overwrite:
388 /*
389 * Switch to new baudrate if new baudrate is supported
390 */
391 baudrate = simple_strtoul(value, NULL, 10);
392
393 /* Not actually changing */
394 if (gd->baudrate == baudrate)
395 return 0;
396
397 for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
398 if (baudrate == baudrate_table[i])
399 break;
400 }
401 if (i == ARRAY_SIZE(baudrate_table)) {
402 if ((flags & H_FORCE) == 0)
403 printf("## Baudrate %d bps not supported\n",
404 baudrate);
405 return 1;
406 }
407 if ((flags & H_INTERACTIVE) != 0) {
408 printf("## Switch baudrate to %d bps and press ENTER ...\n",
409 baudrate);
410 udelay(50000);
411 }
412
413 gd->baudrate = baudrate;
414
415 serial_setbrg();
416
417 udelay(50000);
418
419 if ((flags & H_INTERACTIVE) != 0)
420 while (1) {
421 if (getc() == '\r')
422 break;
423 }
424
425 return 0;
426 case env_op_delete:
427 printf("## Baudrate may not be deleted\n");
428 return 1;
429 default:
430 return 0;
431 }
432 }
433 U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
434 #endif
435
436 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
serial_post_probe(struct udevice * dev)437 static int serial_post_probe(struct udevice *dev)
438 {
439 struct dm_serial_ops *ops = serial_get_ops(dev);
440 #ifdef CONFIG_DM_STDIO
441 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
442 struct stdio_dev sdev;
443 #endif
444 int ret;
445
446 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
447 if (ops->setbrg)
448 ops->setbrg += gd->reloc_off;
449 if (ops->getc)
450 ops->getc += gd->reloc_off;
451 if (ops->putc)
452 ops->putc += gd->reloc_off;
453 if (ops->pending)
454 ops->pending += gd->reloc_off;
455 if (ops->clear)
456 ops->clear += gd->reloc_off;
457 #if CONFIG_POST & CONFIG_SYS_POST_UART
458 if (ops->loop)
459 ops->loop += gd->reloc_off
460 #endif
461 #endif
462 /* Set the baud rate */
463 if (ops->setbrg) {
464 ret = ops->setbrg(dev, gd->baudrate);
465 if (ret)
466 return ret;
467 }
468
469 #ifdef CONFIG_DM_STDIO
470 if (!(gd->flags & GD_FLG_RELOC))
471 return 0;
472 memset(&sdev, '\0', sizeof(sdev));
473
474 strncpy(sdev.name, dev->name, sizeof(sdev.name));
475 sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT | DEV_FLAGS_DM;
476 sdev.priv = dev;
477 sdev.putc = serial_stub_putc;
478 sdev.puts = serial_stub_puts;
479 sdev.getc = serial_stub_getc;
480 sdev.tstc = serial_stub_tstc;
481
482 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
483 /* Allocate the RX buffer */
484 upriv->buf = malloc(CONFIG_SERIAL_RX_BUFFER_SIZE);
485 #endif
486
487 stdio_register_dev(&sdev, &upriv->sdev);
488 #endif
489 return 0;
490 }
491
serial_pre_remove(struct udevice * dev)492 static int serial_pre_remove(struct udevice *dev)
493 {
494 #if CONFIG_IS_ENABLED(SYS_STDIO_DEREGISTER)
495 struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
496
497 if (stdio_deregister_dev(upriv->sdev, true))
498 return -EPERM;
499 #endif
500
501 return 0;
502 }
503
504 UCLASS_DRIVER(serial) = {
505 .id = UCLASS_SERIAL,
506 .name = "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),
511 };
512 #endif
513