xref: /openbmc/u-boot/drivers/serial/serial.c (revision 73286d87)
1 /*
2  * (C) Copyright 2004
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23 
24 #include <common.h>
25 #include <serial.h>
26 #include <stdio_dev.h>
27 #include <post.h>
28 #include <linux/compiler.h>
29 #include <errno.h>
30 
31 DECLARE_GLOBAL_DATA_PTR;
32 
33 static struct serial_device *serial_devices;
34 static struct serial_device *serial_current;
35 
36 /**
37  * serial_null() - Void registration routine of a serial driver
38  *
39  * This routine implements a void registration routine of a serial
40  * driver. The registration routine of a particular driver is aliased
41  * to this empty function in case the driver is not compiled into
42  * U-Boot.
43  */
44 static void serial_null(void)
45 {
46 }
47 
48 /**
49  * serial_initfunc() - Forward declare of driver registration routine
50  * @name:	Name of the real driver registration routine.
51  *
52  * This macro expands onto forward declaration of a driver registration
53  * routine, which is then used below in serial_initialize() function.
54  * The declaration is made weak and aliases to serial_null() so in case
55  * the driver is not compiled in, the function is still declared and can
56  * be used, but aliases to serial_null() and thus is optimized away.
57  */
58 #define serial_initfunc(name)					\
59 	void name(void)						\
60 		__attribute__((weak, alias("serial_null")));
61 
62 serial_initfunc(mpc8xx_serial_initialize);
63 serial_initfunc(ns16550_serial_initialize);
64 serial_initfunc(pxa_serial_initialize);
65 serial_initfunc(s3c24xx_serial_initialize);
66 serial_initfunc(s5p_serial_initialize);
67 serial_initfunc(zynq_serial_initalize);
68 serial_initfunc(bfin_serial_initialize);
69 serial_initfunc(bfin_jtag_initialize);
70 serial_initfunc(mpc512x_serial_initialize);
71 serial_initfunc(uartlite_serial_initialize);
72 serial_initfunc(au1x00_serial_initialize);
73 serial_initfunc(asc_serial_initialize);
74 serial_initfunc(jz_serial_initialize);
75 serial_initfunc(mpc5xx_serial_initialize);
76 serial_initfunc(mpc8220_serial_initialize);
77 serial_initfunc(mpc8260_scc_serial_initialize);
78 serial_initfunc(mpc8260_smc_serial_initialize);
79 serial_initfunc(mpc85xx_serial_initialize);
80 serial_initfunc(iop480_serial_initialize);
81 serial_initfunc(leon2_serial_initialize);
82 serial_initfunc(leon3_serial_initialize);
83 serial_initfunc(marvell_serial_initialize);
84 serial_initfunc(amirix_serial_initialize);
85 serial_initfunc(bmw_serial_initialize);
86 serial_initfunc(cogent_serial_initialize);
87 serial_initfunc(cpci750_serial_initialize);
88 serial_initfunc(evb64260_serial_initialize);
89 serial_initfunc(ml2_serial_initialize);
90 serial_initfunc(sconsole_serial_initialize);
91 serial_initfunc(p3mx_serial_initialize);
92 serial_initfunc(altera_jtag_serial_initialize);
93 serial_initfunc(altera_serial_initialize);
94 serial_initfunc(atmel_serial_initialize);
95 serial_initfunc(lpc32xx_serial_initialize);
96 serial_initfunc(mcf_serial_initialize);
97 serial_initfunc(ns9750_serial_initialize);
98 serial_initfunc(oc_serial_initialize);
99 serial_initfunc(s3c64xx_serial_initialize);
100 serial_initfunc(sandbox_serial_initialize);
101 serial_initfunc(clps7111_serial_initialize);
102 serial_initfunc(imx_serial_initialize);
103 serial_initfunc(ixp_serial_initialize);
104 serial_initfunc(ks8695_serial_initialize);
105 serial_initfunc(lh7a40x_serial_initialize);
106 serial_initfunc(max3100_serial_initialize);
107 serial_initfunc(mxc_serial_initialize);
108 serial_initfunc(pl01x_serial_initialize);
109 serial_initfunc(s3c44b0_serial_initialize);
110 serial_initfunc(sa1100_serial_initialize);
111 serial_initfunc(sh_serial_initialize);
112 
113 /**
114  * serial_register() - Register serial driver with serial driver core
115  * @dev:	Pointer to the serial driver structure
116  *
117  * This function registers the serial driver supplied via @dev with
118  * serial driver core, thus making U-Boot aware of it and making it
119  * available for U-Boot to use. On platforms that still require manual
120  * relocation of constant variables, relocation of the supplied structure
121  * is performed.
122  */
123 void serial_register(struct serial_device *dev)
124 {
125 #ifdef CONFIG_NEEDS_MANUAL_RELOC
126 	if (dev->start)
127 		dev->start += gd->reloc_off;
128 	if (dev->stop)
129 		dev->stop += gd->reloc_off;
130 	if (dev->setbrg)
131 		dev->setbrg += gd->reloc_off;
132 	if (dev->getc)
133 		dev->getc += gd->reloc_off;
134 	if (dev->tstc)
135 		dev->tstc += gd->reloc_off;
136 	if (dev->putc)
137 		dev->putc += gd->reloc_off;
138 	if (dev->puts)
139 		dev->puts += gd->reloc_off;
140 #endif
141 
142 	dev->next = serial_devices;
143 	serial_devices = dev;
144 }
145 
146 /**
147  * serial_initialize() - Register all compiled-in serial port drivers
148  *
149  * This function registers all serial port drivers that are compiled
150  * into the U-Boot binary with the serial core, thus making them
151  * available to U-Boot to use. Lastly, this function assigns a default
152  * serial port to the serial core. That serial port is then used as a
153  * default output.
154  */
155 void serial_initialize(void)
156 {
157 	mpc8xx_serial_initialize();
158 	ns16550_serial_initialize();
159 	pxa_serial_initialize();
160 	s3c24xx_serial_initialize();
161 	s5p_serial_initialize();
162 	mpc512x_serial_initialize();
163 	bfin_serial_initialize();
164 	bfin_jtag_initialize();
165 	uartlite_serial_initialize();
166 	zynq_serial_initalize();
167 	au1x00_serial_initialize();
168 	asc_serial_initialize();
169 	jz_serial_initialize();
170 	mpc5xx_serial_initialize();
171 	mpc8220_serial_initialize();
172 	mpc8260_scc_serial_initialize();
173 	mpc8260_smc_serial_initialize();
174 	mpc85xx_serial_initialize();
175 	iop480_serial_initialize();
176 	leon2_serial_initialize();
177 	leon3_serial_initialize();
178 	marvell_serial_initialize();
179 	amirix_serial_initialize();
180 	bmw_serial_initialize();
181 	cogent_serial_initialize();
182 	cpci750_serial_initialize();
183 	evb64260_serial_initialize();
184 	ml2_serial_initialize();
185 	sconsole_serial_initialize();
186 	p3mx_serial_initialize();
187 	altera_jtag_serial_initialize();
188 	altera_serial_initialize();
189 	atmel_serial_initialize();
190 	lpc32xx_serial_initialize();
191 	mcf_serial_initialize();
192 	ns9750_serial_initialize();
193 	oc_serial_initialize();
194 	s3c64xx_serial_initialize();
195 	sandbox_serial_initialize();
196 	clps7111_serial_initialize();
197 	imx_serial_initialize();
198 	ixp_serial_initialize();
199 	ks8695_serial_initialize();
200 	lh7a40x_serial_initialize();
201 	max3100_serial_initialize();
202 	mxc_serial_initialize();
203 	pl01x_serial_initialize();
204 	s3c44b0_serial_initialize();
205 	sa1100_serial_initialize();
206 	sh_serial_initialize();
207 
208 	serial_assign(default_serial_console()->name);
209 }
210 
211 /**
212  * serial_stdio_init() - Register serial ports with STDIO core
213  *
214  * This function generates a proxy driver for each serial port driver.
215  * These proxy drivers then register with the STDIO core, making the
216  * serial drivers available as STDIO devices.
217  */
218 void serial_stdio_init(void)
219 {
220 	struct stdio_dev dev;
221 	struct serial_device *s = serial_devices;
222 
223 	while (s) {
224 		memset(&dev, 0, sizeof(dev));
225 
226 		strcpy(dev.name, s->name);
227 		dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT;
228 
229 		dev.start = s->start;
230 		dev.stop = s->stop;
231 		dev.putc = s->putc;
232 		dev.puts = s->puts;
233 		dev.getc = s->getc;
234 		dev.tstc = s->tstc;
235 
236 		stdio_register(&dev);
237 
238 		s = s->next;
239 	}
240 }
241 
242 /**
243  * serial_assign() - Select the serial output device by name
244  * @name:	Name of the serial driver to be used as default output
245  *
246  * This function configures the serial output multiplexing by
247  * selecting which serial device will be used as default. In case
248  * the STDIO "serial" device is selected as stdin/stdout/stderr,
249  * the serial device previously configured by this function will be
250  * used for the particular operation.
251  *
252  * Returns 0 on success, negative on error.
253  */
254 int serial_assign(const char *name)
255 {
256 	struct serial_device *s;
257 
258 	for (s = serial_devices; s; s = s->next) {
259 		if (strcmp(s->name, name))
260 			continue;
261 		serial_current = s;
262 		return 0;
263 	}
264 
265 	return -EINVAL;
266 }
267 
268 /**
269  * serial_reinit_all() - Reinitialize all compiled-in serial ports
270  *
271  * This function reinitializes all serial ports that are compiled
272  * into U-Boot by calling their serial_start() functions.
273  */
274 void serial_reinit_all(void)
275 {
276 	struct serial_device *s;
277 
278 	for (s = serial_devices; s; s = s->next)
279 		s->start();
280 }
281 
282 /**
283  * get_current() - Return pointer to currently selected serial port
284  *
285  * This function returns a pointer to currently selected serial port.
286  * The currently selected serial port is altered by serial_assign()
287  * function.
288  *
289  * In case this function is called before relocation or before any serial
290  * port is configured, this function calls default_serial_console() to
291  * determine the serial port. Otherwise, the configured serial port is
292  * returned.
293  *
294  * Returns pointer to the currently selected serial port on success,
295  * NULL on error.
296  */
297 static struct serial_device *get_current(void)
298 {
299 	struct serial_device *dev;
300 
301 	if (!(gd->flags & GD_FLG_RELOC))
302 		dev = default_serial_console();
303 	else if (!serial_current)
304 		dev = default_serial_console();
305 	else
306 		dev = serial_current;
307 
308 	/* We must have a console device */
309 	if (!dev) {
310 #ifdef CONFIG_SPL_BUILD
311 		puts("Cannot find console\n");
312 		hang();
313 #else
314 		panic("Cannot find console\n");
315 #endif
316 	}
317 
318 	return dev;
319 }
320 
321 /**
322  * serial_init() - Initialize currently selected serial port
323  *
324  * This function initializes the currently selected serial port. This
325  * usually involves setting up the registers of that particular port,
326  * enabling clock and such. This function uses the get_current() call
327  * to determine which port is selected.
328  *
329  * Returns 0 on success, negative on error.
330  */
331 int serial_init(void)
332 {
333 	return get_current()->start();
334 }
335 
336 /**
337  * serial_setbrg() - Configure baud-rate of currently selected serial port
338  *
339  * This function configures the baud-rate of the currently selected
340  * serial port. The baud-rate is retrieved from global data within
341  * the serial port driver. This function uses the get_current() call
342  * to determine which port is selected.
343  *
344  * Returns 0 on success, negative on error.
345  */
346 void serial_setbrg(void)
347 {
348 	get_current()->setbrg();
349 }
350 
351 /**
352  * serial_getc() - Read character from currently selected serial port
353  *
354  * This function retrieves a character from currently selected serial
355  * port. In case there is no character waiting on the serial port,
356  * this function will block and wait for the character to appear. This
357  * function uses the get_current() call to determine which port is
358  * selected.
359  *
360  * Returns the character on success, negative on error.
361  */
362 int serial_getc(void)
363 {
364 	return get_current()->getc();
365 }
366 
367 /**
368  * serial_tstc() - Test if data is available on currently selected serial port
369  *
370  * This function tests if one or more characters are available on
371  * currently selected serial port. This function never blocks. This
372  * function uses the get_current() call to determine which port is
373  * selected.
374  *
375  * Returns positive if character is available, zero otherwise.
376  */
377 int serial_tstc(void)
378 {
379 	return get_current()->tstc();
380 }
381 
382 /**
383  * serial_putc() - Output character via currently selected serial port
384  * @c:	Single character to be output from the serial port.
385  *
386  * This function outputs a character via currently selected serial
387  * port. This character is passed to the serial port driver responsible
388  * for controlling the hardware. The hardware may still be in process
389  * of transmitting another character, therefore this function may block
390  * for a short amount of time. This function uses the get_current()
391  * call to determine which port is selected.
392  */
393 void serial_putc(const char c)
394 {
395 	get_current()->putc(c);
396 }
397 
398 /**
399  * serial_puts() - Output string via currently selected serial port
400  * @s:	Zero-terminated string to be output from the serial port.
401  *
402  * This function outputs a zero-terminated string via currently
403  * selected serial port. This function behaves as an accelerator
404  * in case the hardware can queue multiple characters for transfer.
405  * The whole string that is to be output is available to the function
406  * implementing the hardware manipulation. Transmitting the whole
407  * string may take some time, thus this function may block for some
408  * amount of time. This function uses the get_current() call to
409  * determine which port is selected.
410  */
411 void serial_puts(const char *s)
412 {
413 	get_current()->puts(s);
414 }
415 
416 /**
417  * default_serial_puts() - Output string by calling serial_putc() in loop
418  * @s:	Zero-terminated string to be output from the serial port.
419  *
420  * This function outputs a zero-terminated string by calling serial_putc()
421  * in a loop. Most drivers do not support queueing more than one byte for
422  * transfer, thus this function precisely implements their serial_puts().
423  *
424  * To optimize the number of get_current() calls, this function only
425  * calls get_current() once and then directly accesses the putc() call
426  * of the &struct serial_device .
427  */
428 void default_serial_puts(const char *s)
429 {
430 	struct serial_device *dev = get_current();
431 	while (*s)
432 		dev->putc(*s++);
433 }
434 
435 #if CONFIG_POST & CONFIG_SYS_POST_UART
436 static const int bauds[] = CONFIG_SYS_BAUDRATE_TABLE;
437 
438 /**
439  * uart_post_test() - Test the currently selected serial port using POST
440  * @flags:	POST framework flags
441  *
442  * Do a loopback test of the currently selected serial port. This
443  * function is only useful in the context of the POST testing framwork.
444  * The serial port is firstly configured into loopback mode and then
445  * characters are sent through it.
446  *
447  * Returns 0 on success, value otherwise.
448  */
449 /* Mark weak until post/cpu/.../uart.c migrate over */
450 __weak
451 int uart_post_test(int flags)
452 {
453 	unsigned char c;
454 	int ret, saved_baud, b;
455 	struct serial_device *saved_dev, *s;
456 	bd_t *bd = gd->bd;
457 
458 	/* Save current serial state */
459 	ret = 0;
460 	saved_dev = serial_current;
461 	saved_baud = bd->bi_baudrate;
462 
463 	for (s = serial_devices; s; s = s->next) {
464 		/* If this driver doesn't support loop back, skip it */
465 		if (!s->loop)
466 			continue;
467 
468 		/* Test the next device */
469 		serial_current = s;
470 
471 		ret = serial_init();
472 		if (ret)
473 			goto done;
474 
475 		/* Consume anything that happens to be queued */
476 		while (serial_tstc())
477 			serial_getc();
478 
479 		/* Enable loop back */
480 		s->loop(1);
481 
482 		/* Test every available baud rate */
483 		for (b = 0; b < ARRAY_SIZE(bauds); ++b) {
484 			bd->bi_baudrate = bauds[b];
485 			serial_setbrg();
486 
487 			/*
488 			 * Stick to printable chars to avoid issues:
489 			 *  - terminal corruption
490 			 *  - serial program reacting to sequences and sending
491 			 *    back random extra data
492 			 *  - most serial drivers add in extra chars (like \r\n)
493 			 */
494 			for (c = 0x20; c < 0x7f; ++c) {
495 				/* Send it out */
496 				serial_putc(c);
497 
498 				/* Make sure it's the same one */
499 				ret = (c != serial_getc());
500 				if (ret) {
501 					s->loop(0);
502 					goto done;
503 				}
504 
505 				/* Clean up the output in case it was sent */
506 				serial_putc('\b');
507 				ret = ('\b' != serial_getc());
508 				if (ret) {
509 					s->loop(0);
510 					goto done;
511 				}
512 			}
513 		}
514 
515 		/* Disable loop back */
516 		s->loop(0);
517 
518 		/* XXX: There is no serial_stop() !? */
519 		if (s->stop)
520 			s->stop();
521 	}
522 
523  done:
524 	/* Restore previous serial state */
525 	serial_current = saved_dev;
526 	bd->bi_baudrate = saved_baud;
527 	serial_reinit_all();
528 	serial_setbrg();
529 
530 	return ret;
531 }
532 #endif
533