1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2004
4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 */
6
7 #include <common.h>
8 #include <env_internal.h>
9 #include <serial.h>
10 #include <stdio_dev.h>
11 #include <post.h>
12 #include <linux/compiler.h>
13 #include <errno.h>
14 #include <usb.h>
15
16 DECLARE_GLOBAL_DATA_PTR;
17
18 static struct serial_device *serial_devices;
19 static struct serial_device *serial_current;
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 /**
26 * serial_null() - Void registration routine of a serial driver
27 *
28 * This routine implements a void registration routine of a serial
29 * driver. The registration routine of a particular driver is aliased
30 * to this empty function in case the driver is not compiled into
31 * U-Boot.
32 */
serial_null(void)33 static void serial_null(void)
34 {
35 }
36
37 /**
38 * on_baudrate() - Update the actual baudrate when the env var changes
39 *
40 * @name: changed environment variable
41 * @value: new value of the environment variable
42 * @op: operation (create, overwrite, or delete)
43 * @flags: attributes of environment variable change,
44 * see flags H_* in include/search.h
45 *
46 * This will check for a valid baudrate and only apply it if valid.
47 *
48 * Return: 0 on success, 1 on error
49 */
on_baudrate(const char * name,const char * value,enum env_op op,int flags)50 static int on_baudrate(const char *name, const char *value, enum env_op op,
51 int flags)
52 {
53 int i;
54 int baudrate;
55
56 switch (op) {
57 case env_op_create:
58 case env_op_overwrite:
59 /*
60 * Switch to new baudrate if new baudrate is supported
61 */
62 baudrate = simple_strtoul(value, NULL, 10);
63
64 /* Not actually changing */
65 if (gd->baudrate == baudrate)
66 return 0;
67
68 for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
69 if (baudrate == baudrate_table[i])
70 break;
71 }
72 if (i == ARRAY_SIZE(baudrate_table)) {
73 if ((flags & H_FORCE) == 0)
74 printf("## Baudrate %d bps not supported\n",
75 baudrate);
76 return 1;
77 }
78 if ((flags & H_INTERACTIVE) != 0) {
79 printf("## Switch baudrate to %d"
80 " bps and press ENTER ...\n", baudrate);
81 udelay(50000);
82 }
83
84 gd->baudrate = baudrate;
85
86 serial_setbrg();
87
88 udelay(50000);
89
90 if ((flags & H_INTERACTIVE) != 0)
91 while (1) {
92 if (getc() == '\r')
93 break;
94 }
95
96 return 0;
97 case env_op_delete:
98 printf("## Baudrate may not be deleted\n");
99 return 1;
100 default:
101 return 0;
102 }
103 }
104 U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
105
106 /**
107 * serial_initfunc() - Forward declare of driver registration routine
108 * @name: Name of the real driver registration routine.
109 *
110 * This macro expands onto forward declaration of a driver registration
111 * routine, which is then used below in serial_initialize() function.
112 * The declaration is made weak and aliases to serial_null() so in case
113 * the driver is not compiled in, the function is still declared and can
114 * be used, but aliases to serial_null() and thus is optimized away.
115 */
116 #define serial_initfunc(name) \
117 void name(void) \
118 __attribute__((weak, alias("serial_null")));
119
120 serial_initfunc(atmel_serial_initialize);
121 serial_initfunc(mcf_serial_initialize);
122 serial_initfunc(mpc85xx_serial_initialize);
123 serial_initfunc(mxc_serial_initialize);
124 serial_initfunc(ns16550_serial_initialize);
125 serial_initfunc(pl01x_serial_initialize);
126 serial_initfunc(pxa_serial_initialize);
127 serial_initfunc(sh_serial_initialize);
128 serial_initfunc(mtk_serial_initialize);
129
130 /**
131 * serial_register() - Register serial driver with serial driver core
132 * @dev: Pointer to the serial driver structure
133 *
134 * This function registers the serial driver supplied via @dev with
135 * serial driver core, thus making U-Boot aware of it and making it
136 * available for U-Boot to use. On platforms that still require manual
137 * relocation of constant variables, relocation of the supplied structure
138 * is performed.
139 */
serial_register(struct serial_device * dev)140 void serial_register(struct serial_device *dev)
141 {
142 #ifdef CONFIG_NEEDS_MANUAL_RELOC
143 if (dev->start)
144 dev->start += gd->reloc_off;
145 if (dev->stop)
146 dev->stop += gd->reloc_off;
147 if (dev->setbrg)
148 dev->setbrg += gd->reloc_off;
149 if (dev->getc)
150 dev->getc += gd->reloc_off;
151 if (dev->tstc)
152 dev->tstc += gd->reloc_off;
153 if (dev->putc)
154 dev->putc += gd->reloc_off;
155 if (dev->puts)
156 dev->puts += gd->reloc_off;
157 #endif
158
159 dev->next = serial_devices;
160 serial_devices = dev;
161 }
162
163 /**
164 * serial_initialize() - Register all compiled-in serial port drivers
165 *
166 * This function registers all serial port drivers that are compiled
167 * into the U-Boot binary with the serial core, thus making them
168 * available to U-Boot to use. Lastly, this function assigns a default
169 * serial port to the serial core. That serial port is then used as a
170 * default output.
171 */
serial_initialize(void)172 void serial_initialize(void)
173 {
174 atmel_serial_initialize();
175 mcf_serial_initialize();
176 mpc85xx_serial_initialize();
177 mxc_serial_initialize();
178 ns16550_serial_initialize();
179 pl01x_serial_initialize();
180 pxa_serial_initialize();
181 sh_serial_initialize();
182 mtk_serial_initialize();
183
184 serial_assign(default_serial_console()->name);
185 }
186
serial_stub_start(struct stdio_dev * sdev)187 static int serial_stub_start(struct stdio_dev *sdev)
188 {
189 struct serial_device *dev = sdev->priv;
190
191 return dev->start();
192 }
193
serial_stub_stop(struct stdio_dev * sdev)194 static int serial_stub_stop(struct stdio_dev *sdev)
195 {
196 struct serial_device *dev = sdev->priv;
197
198 return dev->stop();
199 }
200
serial_stub_putc(struct stdio_dev * sdev,const char ch)201 static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
202 {
203 struct serial_device *dev = sdev->priv;
204
205 dev->putc(ch);
206 }
207
serial_stub_puts(struct stdio_dev * sdev,const char * str)208 static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
209 {
210 struct serial_device *dev = sdev->priv;
211
212 dev->puts(str);
213 }
214
serial_stub_getc(struct stdio_dev * sdev)215 static int serial_stub_getc(struct stdio_dev *sdev)
216 {
217 struct serial_device *dev = sdev->priv;
218
219 return dev->getc();
220 }
221
serial_stub_tstc(struct stdio_dev * sdev)222 static int serial_stub_tstc(struct stdio_dev *sdev)
223 {
224 struct serial_device *dev = sdev->priv;
225
226 return dev->tstc();
227 }
228
229 /**
230 * serial_stdio_init() - Register serial ports with STDIO core
231 *
232 * This function generates a proxy driver for each serial port driver.
233 * These proxy drivers then register with the STDIO core, making the
234 * serial drivers available as STDIO devices.
235 */
serial_stdio_init(void)236 void serial_stdio_init(void)
237 {
238 struct stdio_dev dev;
239 struct serial_device *s = serial_devices;
240
241 while (s) {
242 memset(&dev, 0, sizeof(dev));
243
244 strcpy(dev.name, s->name);
245 dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT;
246
247 dev.start = serial_stub_start;
248 dev.stop = serial_stub_stop;
249 dev.putc = serial_stub_putc;
250 dev.puts = serial_stub_puts;
251 dev.getc = serial_stub_getc;
252 dev.tstc = serial_stub_tstc;
253 dev.priv = s;
254
255 stdio_register(&dev);
256
257 s = s->next;
258 }
259 }
260
261 /**
262 * serial_assign() - Select the serial output device by name
263 * @name: Name of the serial driver to be used as default output
264 *
265 * This function configures the serial output multiplexing by
266 * selecting which serial device will be used as default. In case
267 * the STDIO "serial" device is selected as stdin/stdout/stderr,
268 * the serial device previously configured by this function will be
269 * used for the particular operation.
270 *
271 * Returns 0 on success, negative on error.
272 */
serial_assign(const char * name)273 int serial_assign(const char *name)
274 {
275 struct serial_device *s;
276
277 for (s = serial_devices; s; s = s->next) {
278 if (strcmp(s->name, name))
279 continue;
280 serial_current = s;
281 return 0;
282 }
283
284 return -EINVAL;
285 }
286
287 /**
288 * serial_reinit_all() - Reinitialize all compiled-in serial ports
289 *
290 * This function reinitializes all serial ports that are compiled
291 * into U-Boot by calling their serial_start() functions.
292 */
serial_reinit_all(void)293 void serial_reinit_all(void)
294 {
295 struct serial_device *s;
296
297 for (s = serial_devices; s; s = s->next)
298 s->start();
299 }
300
301 /**
302 * get_current() - Return pointer to currently selected serial port
303 *
304 * This function returns a pointer to currently selected serial port.
305 * The currently selected serial port is altered by serial_assign()
306 * function.
307 *
308 * In case this function is called before relocation or before any serial
309 * port is configured, this function calls default_serial_console() to
310 * determine the serial port. Otherwise, the configured serial port is
311 * returned.
312 *
313 * Returns pointer to the currently selected serial port on success,
314 * NULL on error.
315 */
get_current(void)316 static struct serial_device *get_current(void)
317 {
318 struct serial_device *dev;
319
320 if (!(gd->flags & GD_FLG_RELOC))
321 dev = default_serial_console();
322 else if (!serial_current)
323 dev = default_serial_console();
324 else
325 dev = serial_current;
326
327 /* We must have a console device */
328 if (!dev) {
329 #ifdef CONFIG_SPL_BUILD
330 puts("Cannot find console\n");
331 hang();
332 #else
333 panic("Cannot find console\n");
334 #endif
335 }
336
337 return dev;
338 }
339
340 /**
341 * serial_init() - Initialize currently selected serial port
342 *
343 * This function initializes the currently selected serial port. This
344 * usually involves setting up the registers of that particular port,
345 * enabling clock and such. This function uses the get_current() call
346 * to determine which port is selected.
347 *
348 * Returns 0 on success, negative on error.
349 */
serial_init(void)350 int serial_init(void)
351 {
352 gd->flags |= GD_FLG_SERIAL_READY;
353 return get_current()->start();
354 }
355
356 /**
357 * serial_setbrg() - Configure baud-rate of currently selected serial port
358 *
359 * This function configures the baud-rate of the currently selected
360 * serial port. The baud-rate is retrieved from global data within
361 * the serial port driver. This function uses the get_current() call
362 * to determine which port is selected.
363 *
364 * Returns 0 on success, negative on error.
365 */
serial_setbrg(void)366 void serial_setbrg(void)
367 {
368 get_current()->setbrg();
369 }
370
371 /**
372 * serial_getc() - Read character from currently selected serial port
373 *
374 * This function retrieves a character from currently selected serial
375 * port. In case there is no character waiting on the serial port,
376 * this function will block and wait for the character to appear. This
377 * function uses the get_current() call to determine which port is
378 * selected.
379 *
380 * Returns the character on success, negative on error.
381 */
serial_getc(void)382 int serial_getc(void)
383 {
384 return get_current()->getc();
385 }
386
387 /**
388 * serial_tstc() - Test if data is available on currently selected serial port
389 *
390 * This function tests if one or more characters are available on
391 * currently selected serial port. This function never blocks. This
392 * function uses the get_current() call to determine which port is
393 * selected.
394 *
395 * Returns positive if character is available, zero otherwise.
396 */
serial_tstc(void)397 int serial_tstc(void)
398 {
399 return get_current()->tstc();
400 }
401
402 /**
403 * serial_putc() - Output character via currently selected serial port
404 * @c: Single character to be output from the serial port.
405 *
406 * This function outputs a character via currently selected serial
407 * port. This character is passed to the serial port driver responsible
408 * for controlling the hardware. The hardware may still be in process
409 * of transmitting another character, therefore this function may block
410 * for a short amount of time. This function uses the get_current()
411 * call to determine which port is selected.
412 */
serial_putc(const char c)413 void serial_putc(const char c)
414 {
415 get_current()->putc(c);
416 }
417
418 /**
419 * serial_puts() - Output string via currently selected serial port
420 * @s: Zero-terminated string to be output from the serial port.
421 *
422 * This function outputs a zero-terminated string via currently
423 * selected serial port. This function behaves as an accelerator
424 * in case the hardware can queue multiple characters for transfer.
425 * The whole string that is to be output is available to the function
426 * implementing the hardware manipulation. Transmitting the whole
427 * string may take some time, thus this function may block for some
428 * amount of time. This function uses the get_current() call to
429 * determine which port is selected.
430 */
serial_puts(const char * s)431 void serial_puts(const char *s)
432 {
433 get_current()->puts(s);
434 }
435
436 /**
437 * default_serial_puts() - Output string by calling serial_putc() in loop
438 * @s: Zero-terminated string to be output from the serial port.
439 *
440 * This function outputs a zero-terminated string by calling serial_putc()
441 * in a loop. Most drivers do not support queueing more than one byte for
442 * transfer, thus this function precisely implements their serial_puts().
443 *
444 * To optimize the number of get_current() calls, this function only
445 * calls get_current() once and then directly accesses the putc() call
446 * of the &struct serial_device .
447 */
default_serial_puts(const char * s)448 void default_serial_puts(const char *s)
449 {
450 #ifndef CONFIG_MINI_BOOT
451 udc_puts(s);
452 #endif
453 struct serial_device *dev = get_current();
454 while (*s)
455 dev->putc(*s++);
456 }
457
458 #if CONFIG_POST & CONFIG_SYS_POST_UART
459 static const int bauds[] = CONFIG_SYS_BAUDRATE_TABLE;
460
461 /**
462 * uart_post_test() - Test the currently selected serial port using POST
463 * @flags: POST framework flags
464 *
465 * Do a loopback test of the currently selected serial port. This
466 * function is only useful in the context of the POST testing framwork.
467 * The serial port is first configured into loopback mode and then
468 * characters are sent through it.
469 *
470 * Returns 0 on success, value otherwise.
471 */
472 /* Mark weak until post/cpu/.../uart.c migrate over */
473 __weak
uart_post_test(int flags)474 int uart_post_test(int flags)
475 {
476 unsigned char c;
477 int ret, saved_baud, b;
478 struct serial_device *saved_dev, *s;
479
480 /* Save current serial state */
481 ret = 0;
482 saved_dev = serial_current;
483 saved_baud = gd->baudrate;
484
485 for (s = serial_devices; s; s = s->next) {
486 /* If this driver doesn't support loop back, skip it */
487 if (!s->loop)
488 continue;
489
490 /* Test the next device */
491 serial_current = s;
492
493 ret = serial_init();
494 if (ret)
495 goto done;
496
497 /* Consume anything that happens to be queued */
498 while (serial_tstc())
499 serial_getc();
500
501 /* Enable loop back */
502 s->loop(1);
503
504 /* Test every available baud rate */
505 for (b = 0; b < ARRAY_SIZE(bauds); ++b) {
506 gd->baudrate = bauds[b];
507 serial_setbrg();
508
509 /*
510 * Stick to printable chars to avoid issues:
511 * - terminal corruption
512 * - serial program reacting to sequences and sending
513 * back random extra data
514 * - most serial drivers add in extra chars (like \r\n)
515 */
516 for (c = 0x20; c < 0x7f; ++c) {
517 /* Send it out */
518 serial_putc(c);
519
520 /* Make sure it's the same one */
521 ret = (c != serial_getc());
522 if (ret) {
523 s->loop(0);
524 goto done;
525 }
526
527 /* Clean up the output in case it was sent */
528 serial_putc('\b');
529 ret = ('\b' != serial_getc());
530 if (ret) {
531 s->loop(0);
532 goto done;
533 }
534 }
535 }
536
537 /* Disable loop back */
538 s->loop(0);
539
540 /* XXX: There is no serial_stop() !? */
541 if (s->stop)
542 s->stop();
543 }
544
545 done:
546 /* Restore previous serial state */
547 serial_current = saved_dev;
548 gd->baudrate = saved_baud;
549 serial_reinit_all();
550 serial_setbrg();
551
552 return ret;
553 }
554 #endif
555