3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 * SPDX-License-Identifier: GPL-2.0+
9 #include <environment.h>
11 #include <stdio_dev.h>
13 #include <linux/compiler.h>
16 DECLARE_GLOBAL_DATA_PTR;
18 static struct serial_device *serial_devices;
19 static struct serial_device *serial_current;
21 * Table with supported baudrates (defined in config_xyz.h)
23 static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
26 * serial_null() - Void registration routine of a serial driver
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
33 static void serial_null(void)
38 * on_baudrate() - Update the actual baudrate when the env var changes
40 * This will check for a valid baudrate and only apply it if valid.
42 static int on_baudrate(const char *name, const char *value, enum env_op op,
50 case env_op_overwrite:
52 * Switch to new baudrate if new baudrate is supported
54 baudrate = simple_strtoul(value, NULL, 10);
56 /* Not actually changing */
57 if (gd->baudrate == baudrate)
60 for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
61 if (baudrate == baudrate_table[i])
64 if (i == ARRAY_SIZE(baudrate_table)) {
65 if ((flags & H_FORCE) == 0)
66 printf("## Baudrate %d bps not supported\n",
70 if ((flags & H_INTERACTIVE) != 0) {
71 printf("## Switch baudrate to %d"
72 " bps and press ENTER ...\n", baudrate);
76 gd->baudrate = baudrate;
82 if ((flags & H_INTERACTIVE) != 0)
90 printf("## Baudrate may not be deleted\n");
96 U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
99 * serial_initfunc() - Forward declare of driver registration routine
100 * @name: Name of the real driver registration routine.
102 * This macro expands onto forward declaration of a driver registration
103 * routine, which is then used below in serial_initialize() function.
104 * The declaration is made weak and aliases to serial_null() so in case
105 * the driver is not compiled in, the function is still declared and can
106 * be used, but aliases to serial_null() and thus is optimized away.
108 #define serial_initfunc(name) \
110 __attribute__((weak, alias("serial_null")));
112 serial_initfunc(atmel_serial_initialize);
113 serial_initfunc(au1x00_serial_initialize);
114 serial_initfunc(mcf_serial_initialize);
115 serial_initfunc(mpc85xx_serial_initialize);
116 serial_initfunc(mpc8xx_serial_initialize);
117 serial_initfunc(mxc_serial_initialize);
118 serial_initfunc(ns16550_serial_initialize);
119 serial_initfunc(pl01x_serial_initialize);
120 serial_initfunc(pxa_serial_initialize);
121 serial_initfunc(sh_serial_initialize);
124 * serial_register() - Register serial driver with serial driver core
125 * @dev: Pointer to the serial driver structure
127 * This function registers the serial driver supplied via @dev with
128 * serial driver core, thus making U-Boot aware of it and making it
129 * available for U-Boot to use. On platforms that still require manual
130 * relocation of constant variables, relocation of the supplied structure
133 void serial_register(struct serial_device *dev)
135 #ifdef CONFIG_NEEDS_MANUAL_RELOC
137 dev->start += gd->reloc_off;
139 dev->stop += gd->reloc_off;
141 dev->setbrg += gd->reloc_off;
143 dev->getc += gd->reloc_off;
145 dev->tstc += gd->reloc_off;
147 dev->putc += gd->reloc_off;
149 dev->puts += gd->reloc_off;
152 dev->next = serial_devices;
153 serial_devices = dev;
157 * serial_initialize() - Register all compiled-in serial port drivers
159 * This function registers all serial port drivers that are compiled
160 * into the U-Boot binary with the serial core, thus making them
161 * available to U-Boot to use. Lastly, this function assigns a default
162 * serial port to the serial core. That serial port is then used as a
165 void serial_initialize(void)
167 atmel_serial_initialize();
168 au1x00_serial_initialize();
169 mcf_serial_initialize();
170 mpc85xx_serial_initialize();
171 mpc8xx_serial_initialize();
172 mxc_serial_initialize();
173 ns16550_serial_initialize();
174 pl01x_serial_initialize();
175 pxa_serial_initialize();
176 sh_serial_initialize();
178 serial_assign(default_serial_console()->name);
181 static int serial_stub_start(struct stdio_dev *sdev)
183 struct serial_device *dev = sdev->priv;
188 static int serial_stub_stop(struct stdio_dev *sdev)
190 struct serial_device *dev = sdev->priv;
195 static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
197 struct serial_device *dev = sdev->priv;
202 static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
204 struct serial_device *dev = sdev->priv;
209 static int serial_stub_getc(struct stdio_dev *sdev)
211 struct serial_device *dev = sdev->priv;
216 static int serial_stub_tstc(struct stdio_dev *sdev)
218 struct serial_device *dev = sdev->priv;
224 * serial_stdio_init() - Register serial ports with STDIO core
226 * This function generates a proxy driver for each serial port driver.
227 * These proxy drivers then register with the STDIO core, making the
228 * serial drivers available as STDIO devices.
230 void serial_stdio_init(void)
232 struct stdio_dev dev;
233 struct serial_device *s = serial_devices;
236 memset(&dev, 0, sizeof(dev));
238 strcpy(dev.name, s->name);
239 dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT;
241 dev.start = serial_stub_start;
242 dev.stop = serial_stub_stop;
243 dev.putc = serial_stub_putc;
244 dev.puts = serial_stub_puts;
245 dev.getc = serial_stub_getc;
246 dev.tstc = serial_stub_tstc;
249 stdio_register(&dev);
256 * serial_assign() - Select the serial output device by name
257 * @name: Name of the serial driver to be used as default output
259 * This function configures the serial output multiplexing by
260 * selecting which serial device will be used as default. In case
261 * the STDIO "serial" device is selected as stdin/stdout/stderr,
262 * the serial device previously configured by this function will be
263 * used for the particular operation.
265 * Returns 0 on success, negative on error.
267 int serial_assign(const char *name)
269 struct serial_device *s;
271 for (s = serial_devices; s; s = s->next) {
272 if (strcmp(s->name, name))
282 * serial_reinit_all() - Reinitialize all compiled-in serial ports
284 * This function reinitializes all serial ports that are compiled
285 * into U-Boot by calling their serial_start() functions.
287 void serial_reinit_all(void)
289 struct serial_device *s;
291 for (s = serial_devices; s; s = s->next)
296 * get_current() - Return pointer to currently selected serial port
298 * This function returns a pointer to currently selected serial port.
299 * The currently selected serial port is altered by serial_assign()
302 * In case this function is called before relocation or before any serial
303 * port is configured, this function calls default_serial_console() to
304 * determine the serial port. Otherwise, the configured serial port is
307 * Returns pointer to the currently selected serial port on success,
310 static struct serial_device *get_current(void)
312 struct serial_device *dev;
314 if (!(gd->flags & GD_FLG_RELOC))
315 dev = default_serial_console();
316 else if (!serial_current)
317 dev = default_serial_console();
319 dev = serial_current;
321 /* We must have a console device */
323 #ifdef CONFIG_SPL_BUILD
324 puts("Cannot find console\n");
327 panic("Cannot find console\n");
335 * serial_init() - Initialize currently selected serial port
337 * This function initializes the currently selected serial port. This
338 * usually involves setting up the registers of that particular port,
339 * enabling clock and such. This function uses the get_current() call
340 * to determine which port is selected.
342 * Returns 0 on success, negative on error.
344 int serial_init(void)
346 gd->flags |= GD_FLG_SERIAL_READY;
347 return get_current()->start();
351 * serial_setbrg() - Configure baud-rate of currently selected serial port
353 * This function configures the baud-rate of the currently selected
354 * serial port. The baud-rate is retrieved from global data within
355 * the serial port driver. This function uses the get_current() call
356 * to determine which port is selected.
358 * Returns 0 on success, negative on error.
360 void serial_setbrg(void)
362 get_current()->setbrg();
366 * serial_getc() - Read character from currently selected serial port
368 * This function retrieves a character from currently selected serial
369 * port. In case there is no character waiting on the serial port,
370 * this function will block and wait for the character to appear. This
371 * function uses the get_current() call to determine which port is
374 * Returns the character on success, negative on error.
376 int serial_getc(void)
378 return get_current()->getc();
382 * serial_tstc() - Test if data is available on currently selected serial port
384 * This function tests if one or more characters are available on
385 * currently selected serial port. This function never blocks. This
386 * function uses the get_current() call to determine which port is
389 * Returns positive if character is available, zero otherwise.
391 int serial_tstc(void)
393 return get_current()->tstc();
397 * serial_putc() - Output character via currently selected serial port
398 * @c: Single character to be output from the serial port.
400 * This function outputs a character via currently selected serial
401 * port. This character is passed to the serial port driver responsible
402 * for controlling the hardware. The hardware may still be in process
403 * of transmitting another character, therefore this function may block
404 * for a short amount of time. This function uses the get_current()
405 * call to determine which port is selected.
407 void serial_putc(const char c)
409 get_current()->putc(c);
413 * serial_puts() - Output string via currently selected serial port
414 * @s: Zero-terminated string to be output from the serial port.
416 * This function outputs a zero-terminated string via currently
417 * selected serial port. This function behaves as an accelerator
418 * in case the hardware can queue multiple characters for transfer.
419 * The whole string that is to be output is available to the function
420 * implementing the hardware manipulation. Transmitting the whole
421 * string may take some time, thus this function may block for some
422 * amount of time. This function uses the get_current() call to
423 * determine which port is selected.
425 void serial_puts(const char *s)
427 get_current()->puts(s);
431 * default_serial_puts() - Output string by calling serial_putc() in loop
432 * @s: Zero-terminated string to be output from the serial port.
434 * This function outputs a zero-terminated string by calling serial_putc()
435 * in a loop. Most drivers do not support queueing more than one byte for
436 * transfer, thus this function precisely implements their serial_puts().
438 * To optimize the number of get_current() calls, this function only
439 * calls get_current() once and then directly accesses the putc() call
440 * of the &struct serial_device .
442 void default_serial_puts(const char *s)
444 struct serial_device *dev = get_current();
449 #if CONFIG_POST & CONFIG_SYS_POST_UART
450 static const int bauds[] = CONFIG_SYS_BAUDRATE_TABLE;
453 * uart_post_test() - Test the currently selected serial port using POST
454 * @flags: POST framework flags
456 * Do a loopback test of the currently selected serial port. This
457 * function is only useful in the context of the POST testing framwork.
458 * The serial port is first configured into loopback mode and then
459 * characters are sent through it.
461 * Returns 0 on success, value otherwise.
463 /* Mark weak until post/cpu/.../uart.c migrate over */
465 int uart_post_test(int flags)
468 int ret, saved_baud, b;
469 struct serial_device *saved_dev, *s;
471 /* Save current serial state */
473 saved_dev = serial_current;
474 saved_baud = gd->baudrate;
476 for (s = serial_devices; s; s = s->next) {
477 /* If this driver doesn't support loop back, skip it */
481 /* Test the next device */
488 /* Consume anything that happens to be queued */
489 while (serial_tstc())
492 /* Enable loop back */
495 /* Test every available baud rate */
496 for (b = 0; b < ARRAY_SIZE(bauds); ++b) {
497 gd->baudrate = bauds[b];
501 * Stick to printable chars to avoid issues:
502 * - terminal corruption
503 * - serial program reacting to sequences and sending
504 * back random extra data
505 * - most serial drivers add in extra chars (like \r\n)
507 for (c = 0x20; c < 0x7f; ++c) {
511 /* Make sure it's the same one */
512 ret = (c != serial_getc());
518 /* Clean up the output in case it was sent */
520 ret = ('\b' != serial_getc());
528 /* Disable loop back */
531 /* XXX: There is no serial_stop() !? */
537 /* Restore previous serial state */
538 serial_current = saved_dev;
539 gd->baudrate = saved_baud;