1 // SPDX-License-Identifier: GPL-2.0+
9 #include <serial.h>
25  * serial_null() - Void registration routine of a serial driver
27  * This routine implements a void registration routine of a serial
30  * U-Boot.
37  * on_baudrate() - Update the actual baudrate when the env var changes
64 		if (gd->baudrate == baudrate)  in on_baudrate()
83 		gd->baudrate = baudrate;  in on_baudrate()
106  * serial_initfunc() - Forward declare of driver registration routine
129  * serial_register() - Register serial driver with serial driver core
130  * @dev:	Pointer to the serial driver structure
132  * This function registers the serial driver supplied via @dev with
133  * serial driver core, thus making U-Boot aware of it and making it
134  * available for U-Boot to use. On platforms that still require manual
141 	if (dev->start)  in serial_register()
142 		dev->start += gd->reloc_off;  in serial_register()
143 	if (dev->stop)  in serial_register()
144 		dev->stop += gd->reloc_off;  in serial_register()
145 	if (dev->setbrg)  in serial_register()
146 		dev->setbrg += gd->reloc_off;  in serial_register()
147 	if (dev->getc)  in serial_register()
148 		dev->getc += gd->reloc_off;  in serial_register()
149 	if (dev->tstc)  in serial_register()
150 		dev->tstc += gd->reloc_off;  in serial_register()
151 	if (dev->putc)  in serial_register()
152 		dev->putc += gd->reloc_off;  in serial_register()
153 	if (dev->puts)  in serial_register()
154 		dev->puts += gd->reloc_off;  in serial_register()
157 	dev->next = serial_devices;  in serial_register()
162  * serial_initialize() - Register all compiled-in serial port drivers
164  * This function registers all serial port drivers that are compiled
165  * into the U-Boot binary with the serial core, thus making them
166  * available to U-Boot to use. Lastly, this function assigns a default
167  * serial port to the serial core. That serial port is then used as a
181 	serial_assign(default_serial_console()->name);  in serial_initialize()
186 	struct serial_device *dev = sdev->priv;  in serial_stub_start()
188 	return dev->start();  in serial_stub_start()
193 	struct serial_device *dev = sdev->priv;  in serial_stub_stop()
195 	return dev->stop();  in serial_stub_stop()
200 	struct serial_device *dev = sdev->priv;  in serial_stub_putc()
202 	dev->putc(ch);  in serial_stub_putc()
207 	struct serial_device *dev = sdev->priv;  in serial_stub_puts()
209 	dev->puts(str);  in serial_stub_puts()
214 	struct serial_device *dev = sdev->priv;  in serial_stub_getc()
216 	return dev->getc();  in serial_stub_getc()
221 	struct serial_device *dev = sdev->priv;  in serial_stub_tstc()
223 	return dev->tstc();  in serial_stub_tstc()
227  * serial_stdio_init() - Register serial ports with STDIO core
229  * This function generates a proxy driver for each serial port driver.
231  * serial drivers available as STDIO devices.
241 		strcpy(dev.name, s->name);  in serial_stdio_init()
254 		s = s->next;  in serial_stdio_init()
259  * serial_assign() - Select the serial output device by name
260  * @name:	Name of the serial driver to be used as default output
262  * This function configures the serial output multiplexing by
263  * selecting which serial device will be used as default. In case
264  * the STDIO "serial" device is selected as stdin/stdout/stderr,
265  * the serial device previously configured by this function will be
274 	for (s = serial_devices; s; s = s->next) {  in serial_assign()
275 		if (strcmp(s->name, name))  in serial_assign()
281 	return -EINVAL;  in serial_assign()
285  * serial_reinit_all() - Reinitialize all compiled-in serial ports
287  * This function reinitializes all serial ports that are compiled
288  * into U-Boot by calling their serial_start() functions.
294 	for (s = serial_devices; s; s = s->next)  in serial_reinit_all()
295 		s->start();  in serial_reinit_all()
299  * get_current() - Return pointer to currently selected serial port
301  * This function returns a pointer to currently selected serial port.
302  * The currently selected serial port is altered by serial_assign()
305  * In case this function is called before relocation or before any serial
307  * determine the serial port. Otherwise, the configured serial port is
310  * Returns pointer to the currently selected serial port on success,
317 	if (!(gd->flags & GD_FLG_RELOC))  in get_current()
338  * serial_init() - Initialize currently selected serial port
340  * This function initializes the currently selected serial port. This
349 	gd->flags |= GD_FLG_SERIAL_READY;  in serial_init()
350 	return get_current()->start();  in serial_init()
354  * serial_setbrg() - Configure baud-rate of currently selected serial port
356  * This function configures the baud-rate of the currently selected
357  * serial port. The baud-rate is retrieved from global data within
358  * the serial port driver. This function uses the get_current() call
365 	get_current()->setbrg();  in serial_setbrg()
369  * serial_getc() - Read character from currently selected serial port
371  * This function retrieves a character from currently selected serial
372  * port. In case there is no character waiting on the serial port,
381 	return get_current()->getc();  in serial_getc()
385  * serial_tstc() - Test if data is available on currently selected serial port
388  * currently selected serial port. This function never blocks. This
396 	return get_current()->tstc();  in serial_tstc()
400  * serial_putc() - Output character via currently selected serial port
401  * @c:	Single character to be output from the serial port.
403  * This function outputs a character via currently selected serial
404  * port. This character is passed to the serial port driver responsible
412 	get_current()->putc(c);  in serial_putc()
416  * serial_puts() - Output string via currently selected serial port
417  * @s:	Zero-terminated string to be output from the serial port.
419  * This function outputs a zero-terminated string via currently
420  * selected serial port. This function behaves as an accelerator
430 	get_current()->puts(s);  in serial_puts()
434  * default_serial_puts() - Output string by calling serial_putc() in loop
435  * @s:	Zero-terminated string to be output from the serial port.
437  * This function outputs a zero-terminated string by calling serial_putc()
449 		dev->putc(*s++);  in default_serial_puts()
456  * uart_post_test() - Test the currently selected serial port using POST
459  * Do a loopback test of the currently selected serial port. This
461  * The serial port is first configured into loopback mode and then
474 	/* Save current serial state */  in uart_post_test()
477 	saved_baud = gd->baudrate;  in uart_post_test()
479 	for (s = serial_devices; s; s = s->next) {  in uart_post_test()
481 		if (!s->loop)  in uart_post_test()
484 		/* Test the next device */  in uart_post_test()
496 		s->loop(1);  in uart_post_test()
498 		/* Test every available baud rate */  in uart_post_test()
500 			gd->baudrate = bauds[b];  in uart_post_test()
505 			 *  - terminal corruption  in uart_post_test()
506 			 *  - serial program reacting to sequences and sending  in uart_post_test()
508 			 *  - most serial drivers add in extra chars (like \r\n)  in uart_post_test()
517 					s->loop(0);  in uart_post_test()
525 					s->loop(0);  in uart_post_test()
532 		s->loop(0);  in uart_post_test()
535 		if (s->stop)  in uart_post_test()
536 			s->stop();  in uart_post_test()
540 	/* Restore previous serial state */  in uart_post_test()
542 	gd->baudrate = saved_baud;  in uart_post_test()