[u-boot.git] / drivers / serial / serial.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2004
 * Wolfgang Denk, DENX Software Engineering, [email protected].
 */

#include <common.h>
#include <environment.h>
#include <serial.h>
#include <stdio_dev.h>
#include <post.h>
#include <linux/compiler.h>
#include <errno.h>

DECLARE_GLOBAL_DATA_PTR;

static struct serial_device *serial_devices;
static struct serial_device *serial_current;
/*
 * Table with supported baudrates (defined in config_xyz.h)
 */
static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;

/**
 * serial_null() - Void registration routine of a serial driver
 *
 * This routine implements a void registration routine of a serial
 * driver. The registration routine of a particular driver is aliased
 * to this empty function in case the driver is not compiled into
 * U-Boot.
 */
static void serial_null(void)
{
}

/**
 * on_baudrate() - Update the actual baudrate when the env var changes
 *
 * This will check for a valid baudrate and only apply it if valid.
 */
static int on_baudrate(const char *name, const char *value, enum env_op op,
	int flags)
{
	int i;
	int baudrate;

	switch (op) {
	case env_op_create:
	case env_op_overwrite:
		/*
		 * Switch to new baudrate if new baudrate is supported
		 */
		baudrate = simple_strtoul(value, NULL, 10);

		/* Not actually changing */
		if (gd->baudrate == baudrate)
			return 0;

		for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
			if (baudrate == baudrate_table[i])
				break;
		}
		if (i == ARRAY_SIZE(baudrate_table)) {
			if ((flags & H_FORCE) == 0)
				printf("## Baudrate %d bps not supported\n",
					baudrate);
			return 1;
		}
		if ((flags & H_INTERACTIVE) != 0) {
			printf("## Switch baudrate to %d"
				" bps and press ENTER ...\n", baudrate);
			udelay(50000);
		}

		gd->baudrate = baudrate;

		serial_setbrg();

		udelay(50000);

		if ((flags & H_INTERACTIVE) != 0)
			while (1) {
				if (getc() == '\r')
					break;
			}

		return 0;
	case env_op_delete:
		printf("## Baudrate may not be deleted\n");
		return 1;
	default:
		return 0;
	}
}
U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);

/**
 * serial_initfunc() - Forward declare of driver registration routine
 * @name:	Name of the real driver registration routine.
 *
 * This macro expands onto forward declaration of a driver registration
 * routine, which is then used below in serial_initialize() function.
 * The declaration is made weak and aliases to serial_null() so in case
 * the driver is not compiled in, the function is still declared and can
 * be used, but aliases to serial_null() and thus is optimized away.
 */
#define serial_initfunc(name)					\
	void name(void)						\
		__attribute__((weak, alias("serial_null")));

serial_initfunc(atmel_serial_initialize);
serial_initfunc(mcf_serial_initialize);
serial_initfunc(mpc85xx_serial_initialize);
serial_initfunc(mpc8xx_serial_initialize);
serial_initfunc(mxc_serial_initialize);
serial_initfunc(ns16550_serial_initialize);
serial_initfunc(pl01x_serial_initialize);
serial_initfunc(pxa_serial_initialize);
serial_initfunc(sh_serial_initialize);

/**
 * serial_register() - Register serial driver with serial driver core
 * @dev:	Pointer to the serial driver structure
 *
 * This function registers the serial driver supplied via @dev with
 * serial driver core, thus making U-Boot aware of it and making it
 * available for U-Boot to use. On platforms that still require manual
 * relocation of constant variables, relocation of the supplied structure
 * is performed.
 */
void serial_register(struct serial_device *dev)
{
#ifdef CONFIG_NEEDS_MANUAL_RELOC
	if (dev->start)
		dev->start += gd->reloc_off;
	if (dev->stop)
		dev->stop += gd->reloc_off;
	if (dev->setbrg)
		dev->setbrg += gd->reloc_off;
	if (dev->getc)
		dev->getc += gd->reloc_off;
	if (dev->tstc)
		dev->tstc += gd->reloc_off;
	if (dev->putc)
		dev->putc += gd->reloc_off;
	if (dev->puts)
		dev->puts += gd->reloc_off;
#endif

	dev->next = serial_devices;
	serial_devices = dev;
}

/**
 * serial_initialize() - Register all compiled-in serial port drivers
 *
 * This function registers all serial port drivers that are compiled
 * into the U-Boot binary with the serial core, thus making them
 * available to U-Boot to use. Lastly, this function assigns a default
 * serial port to the serial core. That serial port is then used as a
 * default output.
 */
void serial_initialize(void)
{
	atmel_serial_initialize();
	mcf_serial_initialize();
	mpc85xx_serial_initialize();
	mpc8xx_serial_initialize();
	mxc_serial_initialize();
	ns16550_serial_initialize();
	pl01x_serial_initialize();
	pxa_serial_initialize();
	sh_serial_initialize();

	serial_assign(default_serial_console()->name);
}

static int serial_stub_start(struct stdio_dev *sdev)
{
	struct serial_device *dev = sdev->priv;

	return dev->start();
}

static int serial_stub_stop(struct stdio_dev *sdev)
{
	struct serial_device *dev = sdev->priv;

	return dev->stop();
}

static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
{
	struct serial_device *dev = sdev->priv;

	dev->putc(ch);
}

static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
{
	struct serial_device *dev = sdev->priv;

	dev->puts(str);
}

static int serial_stub_getc(struct stdio_dev *sdev)
{
	struct serial_device *dev = sdev->priv;

	return dev->getc();
}

static int serial_stub_tstc(struct stdio_dev *sdev)
{
	struct serial_device *dev = sdev->priv;

	return dev->tstc();
}

/**
 * serial_stdio_init() - Register serial ports with STDIO core
 *
 * This function generates a proxy driver for each serial port driver.
 * These proxy drivers then register with the STDIO core, making the
 * serial drivers available as STDIO devices.
 */
void serial_stdio_init(void)
{
	struct stdio_dev dev;
	struct serial_device *s = serial_devices;

	while (s) {
		memset(&dev, 0, sizeof(dev));

		strcpy(dev.name, s->name);
		dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT;

		dev.start = serial_stub_start;
		dev.stop = serial_stub_stop;
		dev.putc = serial_stub_putc;
		dev.puts = serial_stub_puts;
		dev.getc = serial_stub_getc;
		dev.tstc = serial_stub_tstc;
		dev.priv = s;

		stdio_register(&dev);

		s = s->next;
	}
}

/**
 * serial_assign() - Select the serial output device by name
 * @name:	Name of the serial driver to be used as default output
 *
 * This function configures the serial output multiplexing by
 * selecting which serial device will be used as default. In case
 * the STDIO "serial" device is selected as stdin/stdout/stderr,
 * the serial device previously configured by this function will be
 * used for the particular operation.
 *
 * Returns 0 on success, negative on error.
 */
int serial_assign(const char *name)
{
	struct serial_device *s;

	for (s = serial_devices; s; s = s->next) {
		if (strcmp(s->name, name))
			continue;
		serial_current = s;
		return 0;
	}

	return -EINVAL;
}

/**
 * serial_reinit_all() - Reinitialize all compiled-in serial ports
 *
 * This function reinitializes all serial ports that are compiled
 * into U-Boot by calling their serial_start() functions.
 */
void serial_reinit_all(void)
{
	struct serial_device *s;

	for (s = serial_devices; s; s = s->next)
		s->start();
}

/**
 * get_current() - Return pointer to currently selected serial port
 *
 * This function returns a pointer to currently selected serial port.
 * The currently selected serial port is altered by serial_assign()
 * function.
 *
 * In case this function is called before relocation or before any serial
 * port is configured, this function calls default_serial_console() to
 * determine the serial port. Otherwise, the configured serial port is
 * returned.
 *
 * Returns pointer to the currently selected serial port on success,
 * NULL on error.
 */
static struct serial_device *get_current(void)
{
	struct serial_device *dev;

	if (!(gd->flags & GD_FLG_RELOC))
		dev = default_serial_console();
	else if (!serial_current)
		dev = default_serial_console();
	else
		dev = serial_current;

	/* We must have a console device */
	if (!dev) {
#ifdef CONFIG_SPL_BUILD
		puts("Cannot find console\n");
		hang();
#else
		panic("Cannot find console\n");
#endif
	}

	return dev;
}

/**
 * serial_init() - Initialize currently selected serial port
 *
 * This function initializes the currently selected serial port. This
 * usually involves setting up the registers of that particular port,
 * enabling clock and such. This function uses the get_current() call
 * to determine which port is selected.
 *
 * Returns 0 on success, negative on error.
 */
int serial_init(void)
{
	gd->flags |= GD_FLG_SERIAL_READY;
	return get_current()->start();
}

/**
 * serial_setbrg() - Configure baud-rate of currently selected serial port
 *
 * This function configures the baud-rate of the currently selected
 * serial port. The baud-rate is retrieved from global data within
 * the serial port driver. This function uses the get_current() call
 * to determine which port is selected.
 *
 * Returns 0 on success, negative on error.
 */
void serial_setbrg(void)
{
	get_current()->setbrg();
}

/**
 * serial_getc() - Read character from currently selected serial port
 *
 * This function retrieves a character from currently selected serial
 * port. In case there is no character waiting on the serial port,
 * this function will block and wait for the character to appear. This
 * function uses the get_current() call to determine which port is
 * selected.
 *
 * Returns the character on success, negative on error.
 */
int serial_getc(void)
{
	return get_current()->getc();
}

/**
 * serial_tstc() - Test if data is available on currently selected serial port
 *
 * This function tests if one or more characters are available on
 * currently selected serial port. This function never blocks. This
 * function uses the get_current() call to determine which port is
 * selected.
 *
 * Returns positive if character is available, zero otherwise.
 */
int serial_tstc(void)
{
	return get_current()->tstc();
}

/**
 * serial_putc() - Output character via currently selected serial port
 * @c:	Single character to be output from the serial port.
 *
 * This function outputs a character via currently selected serial
 * port. This character is passed to the serial port driver responsible
 * for controlling the hardware. The hardware may still be in process
 * of transmitting another character, therefore this function may block
 * for a short amount of time. This function uses the get_current()
 * call to determine which port is selected.
 */
void serial_putc(const char c)
{
	get_current()->putc(c);
}

/**
 * serial_puts() - Output string via currently selected serial port
 * @s:	Zero-terminated string to be output from the serial port.
 *
 * This function outputs a zero-terminated string via currently
 * selected serial port. This function behaves as an accelerator
 * in case the hardware can queue multiple characters for transfer.
 * The whole string that is to be output is available to the function
 * implementing the hardware manipulation. Transmitting the whole
 * string may take some time, thus this function may block for some
 * amount of time. This function uses the get_current() call to
 * determine which port is selected.
 */
void serial_puts(const char *s)
{
	get_current()->puts(s);
}

/**
 * default_serial_puts() - Output string by calling serial_putc() in loop
 * @s:	Zero-terminated string to be output from the serial port.
 *
 * This function outputs a zero-terminated string by calling serial_putc()
 * in a loop. Most drivers do not support queueing more than one byte for
 * transfer, thus this function precisely implements their serial_puts().
 *
 * To optimize the number of get_current() calls, this function only
 * calls get_current() once and then directly accesses the putc() call
 * of the &struct serial_device .
 */
void default_serial_puts(const char *s)
{
	struct serial_device *dev = get_current();
	while (*s)
		dev->putc(*s++);
}

#if CONFIG_POST & CONFIG_SYS_POST_UART
static const int bauds[] = CONFIG_SYS_BAUDRATE_TABLE;

/**
 * uart_post_test() - Test the currently selected serial port using POST
 * @flags:	POST framework flags
 *
 * Do a loopback test of the currently selected serial port. This
 * function is only useful in the context of the POST testing framwork.
 * The serial port is first configured into loopback mode and then
 * characters are sent through it.
 *
 * Returns 0 on success, value otherwise.
 */
/* Mark weak until post/cpu/.../uart.c migrate over */
__weak
int uart_post_test(int flags)
{
	unsigned char c;
	int ret, saved_baud, b;
	struct serial_device *saved_dev, *s;

	/* Save current serial state */
	ret = 0;
	saved_dev = serial_current;
	saved_baud = gd->baudrate;

	for (s = serial_devices; s; s = s->next) {
		/* If this driver doesn't support loop back, skip it */
		if (!s->loop)
			continue;

		/* Test the next device */
		serial_current = s;

		ret = serial_init();
		if (ret)
			goto done;

		/* Consume anything that happens to be queued */
		while (serial_tstc())
			serial_getc();

		/* Enable loop back */
		s->loop(1);

		/* Test every available baud rate */
		for (b = 0; b < ARRAY_SIZE(bauds); ++b) {
			gd->baudrate = bauds[b];
			serial_setbrg();

			/*
			 * Stick to printable chars to avoid issues:
			 *  - terminal corruption
			 *  - serial program reacting to sequences and sending
			 *    back random extra data
			 *  - most serial drivers add in extra chars (like \r\n)
			 */
			for (c = 0x20; c < 0x7f; ++c) {
				/* Send it out */
				serial_putc(c);

				/* Make sure it's the same one */
				ret = (c != serial_getc());
				if (ret) {
					s->loop(0);
					goto done;
				}

				/* Clean up the output in case it was sent */
				serial_putc('\b');
				ret = ('\b' != serial_getc());
				if (ret) {
					s->loop(0);
					goto done;
				}
			}
		}

		/* Disable loop back */
		s->loop(0);

		/* XXX: There is no serial_stop() !? */
		if (s->stop)
			s->stop();
	}

 done:
	/* Restore previous serial state */
	serial_current = saved_dev;
	gd->baudrate = saved_baud;
	serial_reinit_all();
	serial_setbrg();

	return ret;
}
#endif
Commit	Line	Data
83d290c5	1	// SPDX-License-Identifier: GPL-2.0+
281e00a3 WD	2	/*
	3	* (C) Copyright 2004
	4	* Wolfgang Denk, DENX Software Engineering, [email protected].
281e00a3 WD	5	*/
	6
	7	#include <common.h>
32057717	8	#include <environment.h>
281e00a3	9	#include <serial.h>
52cb4d4f	10	#include <stdio_dev.h>
7b826c2f MF	11	#include <post.h>
7b826c2f MF	12	#include <linux/compiler.h>
6d93e258	13	#include <errno.h>
281e00a3	14
d87080b7 WD	15	DECLARE_GLOBAL_DATA_PTR;
d87080b7 WD	16
a6e6f7f4 GF	17	static struct serial_device *serial_devices;
a6e6f7f4 GF	18	static struct serial_device *serial_current;
32057717 JH	19	/*
	20	* Table with supported baudrates (defined in config_xyz.h)
	21	*/
	22	static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
281e00a3	23
9cd2b9e4 MV	24	/**
	25	* serial_null() - Void registration routine of a serial driver
	26	*
	27	* This routine implements a void registration routine of a serial
	28	* driver. The registration routine of a particular driver is aliased
	29	* to this empty function in case the driver is not compiled into
	30	* U-Boot.
	31	*/
2a333aeb MV	32	static void serial_null(void)
	33	{
	34	}
	35
32057717 JH	36	/**
	37	* on_baudrate() - Update the actual baudrate when the env var changes
	38	*
	39	* This will check for a valid baudrate and only apply it if valid.
	40	*/
	41	static int on_baudrate(const char name, const char value, enum env_op op,
	42	int flags)
	43	{
	44	int i;
	45	int baudrate;
	46
	47	switch (op) {
	48	case env_op_create:
	49	case env_op_overwrite:
	50	/*
	51	* Switch to new baudrate if new baudrate is supported
	52	*/
	53	baudrate = simple_strtoul(value, NULL, 10);
	54
	55	/* Not actually changing */
	56	if (gd->baudrate == baudrate)
	57	return 0;
	58
9935175f	59	for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
32057717 JH	60	if (baudrate == baudrate_table[i])
	61	break;
	62	}
9935175f	63	if (i == ARRAY_SIZE(baudrate_table)) {
32057717 JH	64	if ((flags & H_FORCE) == 0)
	65	printf("## Baudrate %d bps not supported\n",
	66	baudrate);
	67	return 1;
	68	}
	69	if ((flags & H_INTERACTIVE) != 0) {
	70	printf("## Switch baudrate to %d"
	71	" bps and press ENTER ...\n", baudrate);
	72	udelay(50000);
	73	}
	74
	75	gd->baudrate = baudrate;
32057717 JH	76
	77	serial_setbrg();
	78
	79	udelay(50000);
	80
	81	if ((flags & H_INTERACTIVE) != 0)
	82	while (1) {
	83	if (getc() == '\r')
	84	break;
	85	}
	86
	87	return 0;
	88	case env_op_delete:
	89	printf("## Baudrate may not be deleted\n");
	90	return 1;
	91	default:
	92	return 0;
	93	}
	94	}
	95	U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
	96
9cd2b9e4 MV	97	/**
	98	* serial_initfunc() - Forward declare of driver registration routine
	99	* @name: Name of the real driver registration routine.
	100	*
	101	* This macro expands onto forward declaration of a driver registration
	102	* routine, which is then used below in serial_initialize() function.
	103	* The declaration is made weak and aliases to serial_null() so in case
	104	* the driver is not compiled in, the function is still declared and can
	105	* be used, but aliases to serial_null() and thus is optimized away.
	106	*/
2a333aeb MV	107	#define serial_initfunc(name) \
	108	void name(void) \
	109	__attribute__((weak, alias("serial_null")));
	110
94a255df	111	serial_initfunc(atmel_serial_initialize);
94a255df	112	serial_initfunc(mcf_serial_initialize);
94a255df JH	113	serial_initfunc(mpc85xx_serial_initialize);
94a255df JH	114	serial_initfunc(mpc8xx_serial_initialize);
a943472c	115	serial_initfunc(mxc_serial_initialize);
94a255df	116	serial_initfunc(ns16550_serial_initialize);
39f61477	117	serial_initfunc(pl01x_serial_initialize);
94a255df	118	serial_initfunc(pxa_serial_initialize);
8bdd7efa	119	serial_initfunc(sh_serial_initialize);
f0eb1f61	120
9cd2b9e4 MV	121	/**
	122	* serial_register() - Register serial driver with serial driver core
	123	* @dev: Pointer to the serial driver structure
	124	*
	125	* This function registers the serial driver supplied via @dev with
	126	* serial driver core, thus making U-Boot aware of it and making it
	127	* available for U-Boot to use. On platforms that still require manual
	128	* relocation of constant variables, relocation of the supplied structure
	129	* is performed.
	130	*/
c52b4f79	131	void serial_register(struct serial_device *dev)
281e00a3	132	{
2e5167cc	133	#ifdef CONFIG_NEEDS_MANUAL_RELOC
f2760c4a MV	134	if (dev->start)
	135	dev->start += gd->reloc_off;
	136	if (dev->stop)
	137	dev->stop += gd->reloc_off;
	138	if (dev->setbrg)
	139	dev->setbrg += gd->reloc_off;
	140	if (dev->getc)
	141	dev->getc += gd->reloc_off;
	142	if (dev->tstc)
	143	dev->tstc += gd->reloc_off;
	144	if (dev->putc)
	145	dev->putc += gd->reloc_off;
	146	if (dev->puts)
	147	dev->puts += gd->reloc_off;
521af04d	148	#endif
281e00a3 WD	149
	150	dev->next = serial_devices;
	151	serial_devices = dev;
281e00a3 WD	152	}
281e00a3 WD	153
9cd2b9e4 MV	154	/**
	155	* serial_initialize() - Register all compiled-in serial port drivers
	156	*
	157	* This function registers all serial port drivers that are compiled
	158	* into the U-Boot binary with the serial core, thus making them
	159	* available to U-Boot to use. Lastly, this function assigns a default
	160	* serial port to the serial core. That serial port is then used as a
	161	* default output.
	162	*/
a6e6f7f4	163	void serial_initialize(void)
281e00a3	164	{
94a255df	165	atmel_serial_initialize();
94a255df	166	mcf_serial_initialize();
94a255df JH	167	mpc85xx_serial_initialize();
94a255df JH	168	mpc8xx_serial_initialize();
a943472c	169	mxc_serial_initialize();
94a255df	170	ns16550_serial_initialize();
39f61477	171	pl01x_serial_initialize();
94a255df	172	pxa_serial_initialize();
8bdd7efa	173	sh_serial_initialize();
7b953c51	174
a6e6f7f4	175	serial_assign(default_serial_console()->name);
281e00a3 WD	176	}
281e00a3 WD	177
654f8d0f	178	static int serial_stub_start(struct stdio_dev *sdev)
709ea543 SG	179	{
	180	struct serial_device *dev = sdev->priv;
	181
	182	return dev->start();
	183	}
	184
654f8d0f	185	static int serial_stub_stop(struct stdio_dev *sdev)
709ea543 SG	186	{
	187	struct serial_device *dev = sdev->priv;
	188
	189	return dev->stop();
	190	}
	191
654f8d0f	192	static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
709ea543 SG	193	{
	194	struct serial_device *dev = sdev->priv;
	195
	196	dev->putc(ch);
	197	}
	198
654f8d0f	199	static void serial_stub_puts(struct stdio_dev sdev, const char str)
709ea543 SG	200	{
	201	struct serial_device *dev = sdev->priv;
	202
	203	dev->puts(str);
	204	}
	205
49ddcf3e	206	static int serial_stub_getc(struct stdio_dev *sdev)
709ea543 SG	207	{
	208	struct serial_device *dev = sdev->priv;
	209
	210	return dev->getc();
	211	}
	212
49ddcf3e	213	static int serial_stub_tstc(struct stdio_dev *sdev)
709ea543 SG	214	{
	215	struct serial_device *dev = sdev->priv;
	216
	217	return dev->tstc();
	218	}
	219
9cd2b9e4 MV	220	/**
	221	* serial_stdio_init() - Register serial ports with STDIO core
	222	*
	223	* This function generates a proxy driver for each serial port driver.
	224	* These proxy drivers then register with the STDIO core, making the
	225	* serial drivers available as STDIO devices.
	226	*/
a6e6f7f4	227	void serial_stdio_init(void)
281e00a3	228	{
52cb4d4f	229	struct stdio_dev dev;
281e00a3 WD	230	struct serial_device *s = serial_devices;
281e00a3 WD	231
2ee66533	232	while (s) {
a6e6f7f4	233	memset(&dev, 0, sizeof(dev));
281e00a3	234
a6e6f7f4	235	strcpy(dev.name, s->name);
281e00a3 WD	236	dev.flags = DEV_FLAGS_OUTPUT \| DEV_FLAGS_INPUT;
281e00a3 WD	237
709ea543 SG	238	dev.start = serial_stub_start;
	239	dev.stop = serial_stub_stop;
	240	dev.putc = serial_stub_putc;
	241	dev.puts = serial_stub_puts;
	242	dev.getc = serial_stub_getc;
	243	dev.tstc = serial_stub_tstc;
addf9513	244	dev.priv = s;
281e00a3	245
a6e6f7f4	246	stdio_register(&dev);
281e00a3 WD	247
	248	s = s->next;
	249	}
	250	}
	251
9cd2b9e4 MV	252	/**
	253	* serial_assign() - Select the serial output device by name
	254	* @name: Name of the serial driver to be used as default output
	255	*
	256	* This function configures the serial output multiplexing by
	257	* selecting which serial device will be used as default. In case
	258	* the STDIO "serial" device is selected as stdin/stdout/stderr,
	259	* the serial device previously configured by this function will be
	260	* used for the particular operation.
	261	*
	262	* Returns 0 on success, negative on error.
	263	*/
7813ca9b	264	int serial_assign(const char *name)
281e00a3 WD	265	{
	266	struct serial_device *s;
	267
2ee66533	268	for (s = serial_devices; s; s = s->next) {
6d93e258 MV	269	if (strcmp(s->name, name))
	270	continue;
	271	serial_current = s;
	272	return 0;
281e00a3 WD	273	}
281e00a3 WD	274
6d93e258	275	return -EINVAL;
281e00a3 WD	276	}
281e00a3 WD	277
9cd2b9e4 MV	278	/**
	279	* serial_reinit_all() - Reinitialize all compiled-in serial ports
	280	*
	281	* This function reinitializes all serial ports that are compiled
	282	* into U-Boot by calling their serial_start() functions.
	283	*/
a6e6f7f4	284	void serial_reinit_all(void)
281e00a3 WD	285	{
	286	struct serial_device *s;
	287
a6e6f7f4	288	for (s = serial_devices; s; s = s->next)
89143fb3	289	s->start();
281e00a3 WD	290	}
281e00a3 WD	291
9cd2b9e4 MV	292	/**
	293	* get_current() - Return pointer to currently selected serial port
	294	*
	295	* This function returns a pointer to currently selected serial port.
	296	* The currently selected serial port is altered by serial_assign()
	297	* function.
	298	*
	299	* In case this function is called before relocation or before any serial
	300	* port is configured, this function calls default_serial_console() to
	301	* determine the serial port. Otherwise, the configured serial port is
	302	* returned.
	303	*
	304	* Returns pointer to the currently selected serial port on success,
	305	* NULL on error.
	306	*/
857c283e	307	static struct serial_device *get_current(void)
281e00a3	308	{
857c283e	309	struct serial_device *dev;
2ee66533	310
dee19416	311	if (!(gd->flags & GD_FLG_RELOC))
857c283e	312	dev = default_serial_console();
dee19416 MV	313	else if (!serial_current)
	314	dev = default_serial_console();
	315	else
	316	dev = serial_current;
857c283e	317
dee19416 MV	318	/* We must have a console device */
dee19416 MV	319	if (!dev) {
f1f1e9cb	320	#ifdef CONFIG_SPL_BUILD
dee19416 MV	321	puts("Cannot find console\n");
dee19416 MV	322	hang();
f1f1e9cb	323	#else
dee19416	324	panic("Cannot find console\n");
f1f1e9cb	325	#endif
dee19416 MV	326	}
dee19416 MV	327
857c283e SG	328	return dev;
857c283e SG	329	}
281e00a3	330
9cd2b9e4 MV	331	/**
	332	* serial_init() - Initialize currently selected serial port
	333	*
	334	* This function initializes the currently selected serial port. This
	335	* usually involves setting up the registers of that particular port,
	336	* enabling clock and such. This function uses the get_current() call
	337	* to determine which port is selected.
	338	*
	339	* Returns 0 on success, negative on error.
	340	*/
857c283e SG	341	int serial_init(void)
857c283e SG	342	{
093f79ab	343	gd->flags \|= GD_FLG_SERIAL_READY;
89143fb3	344	return get_current()->start();
281e00a3 WD	345	}
281e00a3 WD	346
9cd2b9e4 MV	347	/**
	348	* serial_setbrg() - Configure baud-rate of currently selected serial port
	349	*
	350	* This function configures the baud-rate of the currently selected
	351	* serial port. The baud-rate is retrieved from global data within
	352	* the serial port driver. This function uses the get_current() call
	353	* to determine which port is selected.
	354	*
	355	* Returns 0 on success, negative on error.
	356	*/
a6e6f7f4	357	void serial_setbrg(void)
281e00a3	358	{
857c283e	359	get_current()->setbrg();
281e00a3 WD	360	}
281e00a3 WD	361
9cd2b9e4 MV	362	/**
	363	* serial_getc() - Read character from currently selected serial port
	364	*
	365	* This function retrieves a character from currently selected serial
	366	* port. In case there is no character waiting on the serial port,
	367	* this function will block and wait for the character to appear. This
	368	* function uses the get_current() call to determine which port is
	369	* selected.
	370	*
	371	* Returns the character on success, negative on error.
	372	*/
a6e6f7f4	373	int serial_getc(void)
281e00a3	374	{
857c283e	375	return get_current()->getc();
281e00a3 WD	376	}
281e00a3 WD	377
9cd2b9e4 MV	378	/**
	379	* serial_tstc() - Test if data is available on currently selected serial port
	380	*
	381	* This function tests if one or more characters are available on
	382	* currently selected serial port. This function never blocks. This
	383	* function uses the get_current() call to determine which port is
	384	* selected.
	385	*
	386	* Returns positive if character is available, zero otherwise.
	387	*/
a6e6f7f4	388	int serial_tstc(void)
281e00a3	389	{
857c283e	390	return get_current()->tstc();
281e00a3 WD	391	}
281e00a3 WD	392
9cd2b9e4 MV	393	/**
	394	* serial_putc() - Output character via currently selected serial port
	395	* @c: Single character to be output from the serial port.
	396	*
	397	* This function outputs a character via currently selected serial
	398	* port. This character is passed to the serial port driver responsible
	399	* for controlling the hardware. The hardware may still be in process
	400	* of transmitting another character, therefore this function may block
	401	* for a short amount of time. This function uses the get_current()
	402	* call to determine which port is selected.
	403	*/
a6e6f7f4	404	void serial_putc(const char c)
281e00a3	405	{
857c283e	406	get_current()->putc(c);
281e00a3 WD	407	}
281e00a3 WD	408
9cd2b9e4 MV	409	/**
	410	* serial_puts() - Output string via currently selected serial port
	411	* @s: Zero-terminated string to be output from the serial port.
	412	*
	413	* This function outputs a zero-terminated string via currently
	414	* selected serial port. This function behaves as an accelerator
	415	* in case the hardware can queue multiple characters for transfer.
	416	* The whole string that is to be output is available to the function
	417	* implementing the hardware manipulation. Transmitting the whole
	418	* string may take some time, thus this function may block for some
	419	* amount of time. This function uses the get_current() call to
	420	* determine which port is selected.
	421	*/
a6e6f7f4	422	void serial_puts(const char *s)
281e00a3	423	{
857c283e	424	get_current()->puts(s);
281e00a3	425	}
7b826c2f	426
9cd2b9e4 MV	427	/**
	428	* default_serial_puts() - Output string by calling serial_putc() in loop
	429	* @s: Zero-terminated string to be output from the serial port.
	430	*
	431	* This function outputs a zero-terminated string by calling serial_putc()
	432	* in a loop. Most drivers do not support queueing more than one byte for
	433	* transfer, thus this function precisely implements their serial_puts().
	434	*
	435	* To optimize the number of get_current() calls, this function only
	436	* calls get_current() once and then directly accesses the putc() call
	437	* of the &struct serial_device .
	438	*/
bfb7d7a3 MV	439	void default_serial_puts(const char *s)
	440	{
	441	struct serial_device *dev = get_current();
	442	while (*s)
	443	dev->putc(*s++);
	444	}
	445
7b826c2f MF	446	#if CONFIG_POST & CONFIG_SYS_POST_UART
	447	static const int bauds[] = CONFIG_SYS_BAUDRATE_TABLE;
	448
9cd2b9e4 MV	449	/**
	450	* uart_post_test() - Test the currently selected serial port using POST
	451	* @flags: POST framework flags
	452	*
	453	* Do a loopback test of the currently selected serial port. This
	454	* function is only useful in the context of the POST testing framwork.
1b25e586	455	* The serial port is first configured into loopback mode and then
9cd2b9e4 MV	456	* characters are sent through it.
	457	*
	458	* Returns 0 on success, value otherwise.
	459	*/
7b826c2f MF	460	/* Mark weak until post/cpu/.../uart.c migrate over */
	461	__weak
	462	int uart_post_test(int flags)
	463	{
	464	unsigned char c;
	465	int ret, saved_baud, b;
	466	struct serial_device saved_dev, s;
7b826c2f MF	467
	468	/* Save current serial state */
	469	ret = 0;
	470	saved_dev = serial_current;
8e261575	471	saved_baud = gd->baudrate;
7b826c2f MF	472
	473	for (s = serial_devices; s; s = s->next) {
	474	/* If this driver doesn't support loop back, skip it */
	475	if (!s->loop)
	476	continue;
	477
	478	/* Test the next device */
	479	serial_current = s;
	480
	481	ret = serial_init();
	482	if (ret)
	483	goto done;
	484
	485	/* Consume anything that happens to be queued */
	486	while (serial_tstc())
	487	serial_getc();
	488
	489	/* Enable loop back */
	490	s->loop(1);
	491
	492	/* Test every available baud rate */
	493	for (b = 0; b < ARRAY_SIZE(bauds); ++b) {
8e261575	494	gd->baudrate = bauds[b];
7b826c2f MF	495	serial_setbrg();
	496
	497	/*
	498	* Stick to printable chars to avoid issues:
	499	* - terminal corruption
	500	* - serial program reacting to sequences and sending
	501	* back random extra data
	502	* - most serial drivers add in extra chars (like \r\n)
	503	*/
	504	for (c = 0x20; c < 0x7f; ++c) {
	505	/* Send it out */
	506	serial_putc(c);
	507
	508	/* Make sure it's the same one */
	509	ret = (c != serial_getc());
	510	if (ret) {
	511	s->loop(0);
	512	goto done;
	513	}
	514
	515	/* Clean up the output in case it was sent */
	516	serial_putc('\b');
	517	ret = ('\b' != serial_getc());
	518	if (ret) {
	519	s->loop(0);
	520	goto done;
	521	}
	522	}
	523	}
	524
	525	/* Disable loop back */
	526	s->loop(0);
	527
89143fb3 MV	528	/* XXX: There is no serial_stop() !? */
	529	if (s->stop)
	530	s->stop();
7b826c2f MF	531	}
	532
	533	done:
	534	/* Restore previous serial state */
	535	serial_current = saved_dev;
8e261575	536	gd->baudrate = saved_baud;
7b826c2f MF	537	serial_reinit_all();
	538	serial_setbrg();
	539
	540	return ret;
	541	}
	542	#endif