[people/ms/u-boot.git] / drivers / serial / serial-uclass.c

/*
 * Copyright (c) 2014 The Chromium OS Authors.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <dm.h>
#include <environment.h>
#include <errno.h>
#include <os.h>
#include <serial.h>
#include <stdio_dev.h>
#include <watchdog.h>
#include <dm/lists.h>
#include <dm/device-internal.h>
#include <dm/of_access.h>

DECLARE_GLOBAL_DATA_PTR;

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

#if !CONFIG_VAL(SYS_MALLOC_F_LEN)
#error "Serial is required before relocation - define CONFIG_$(SPL_)SYS_MALLOC_F_LEN to make this work"
#endif

static int serial_check_stdout(const void *blob, struct udevice **devp)
{
	int node;

	/* Check for a chosen console */
	node = fdtdec_get_chosen_node(blob, "stdout-path");
	if (node < 0) {
		const char *str, *p, *name;

		/*
		 * Deal with things like
		 *	stdout-path = "serial0:115200n8";
		 *
		 * We need to look up the alias and then follow it to the
		 * correct node.
		 */
		str = fdtdec_get_chosen_prop(blob, "stdout-path");
		if (str) {
			p = strchr(str, ':');
			name = fdt_get_alias_namelen(blob, str,
					p ? p - str : strlen(str));
			if (name)
				node = fdt_path_offset(blob, name);
		}
	}
	if (node < 0)
		node = fdt_path_offset(blob, "console");
	if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, devp))
		return 0;

	/*
	 * If the console is not marked to be bound before relocation, bind it
	 * anyway.
	 */
	if (node > 0 && !lists_bind_fdt(gd->dm_root, offset_to_ofnode(node),
					devp)) {
		if (!device_probe(*devp))
			return 0;
	}

	return -ENODEV;
}

static void serial_find_console_or_panic(void)
{
	const void *blob = gd->fdt_blob;
	struct udevice *dev;

	if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
		uclass_first_device(UCLASS_SERIAL, &dev);
		if (dev) {
			gd->cur_serial_dev = dev;
			return;
		}
	} else if (CONFIG_IS_ENABLED(OF_CONTROL) && blob) {
		/* Live tree has support for stdout */
		if (of_live_active()) {
			struct device_node *np = of_get_stdout();

			if (np && !uclass_get_device_by_ofnode(UCLASS_SERIAL,
					np_to_ofnode(np), &dev)) {
				gd->cur_serial_dev = dev;
				return;
			}
		} else {
			if (!serial_check_stdout(blob, &dev)) {
				gd->cur_serial_dev = dev;
				return;
			}
		}
	}
	if (!SPL_BUILD || !CONFIG_IS_ENABLED(OF_CONTROL) || !blob) {
		/*
		 * Try to use CONFIG_CONS_INDEX if available (it is numbered
		 * from 1!).
		 *
		 * Failing that, get the device with sequence number 0, or in
		 * extremis just the first serial device we can find. But we
		 * insist on having a console (even if it is silent).
		 */
#ifdef CONFIG_CONS_INDEX
#define INDEX (CONFIG_CONS_INDEX - 1)
#else
#define INDEX 0
#endif
		if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
		    !uclass_get_device(UCLASS_SERIAL, INDEX, &dev) ||
		    (!uclass_first_device(UCLASS_SERIAL, &dev) && dev)) {
			gd->cur_serial_dev = dev;
			return;
		}
#undef INDEX
	}

#ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
	panic_str("No serial driver found");
#endif
}

/* Called prior to relocation */
int serial_init(void)
{
	serial_find_console_or_panic();
	gd->flags |= GD_FLG_SERIAL_READY;

	return 0;
}

/* Called after relocation */
void serial_initialize(void)
{
	serial_init();
}

static void _serial_putc(struct udevice *dev, char ch)
{
	struct dm_serial_ops *ops = serial_get_ops(dev);
	int err;

	if (ch == '\n')
		_serial_putc(dev, '\r');

	do {
		err = ops->putc(dev, ch);
	} while (err == -EAGAIN);
}

static void _serial_puts(struct udevice *dev, const char *str)
{
	while (*str)
		_serial_putc(dev, *str++);
}

static int _serial_getc(struct udevice *dev)
{
	struct dm_serial_ops *ops = serial_get_ops(dev);
	int err;

	do {
		err = ops->getc(dev);
		if (err == -EAGAIN)
			WATCHDOG_RESET();
	} while (err == -EAGAIN);

	return err >= 0 ? err : 0;
}

static int _serial_tstc(struct udevice *dev)
{
	struct dm_serial_ops *ops = serial_get_ops(dev);

	if (ops->pending)
		return ops->pending(dev, true);

	return 1;
}

void serial_putc(char ch)
{
	if (gd->cur_serial_dev)
		_serial_putc(gd->cur_serial_dev, ch);
}

void serial_puts(const char *str)
{
	if (gd->cur_serial_dev)
		_serial_puts(gd->cur_serial_dev, str);
}

int serial_getc(void)
{
	if (!gd->cur_serial_dev)
		return 0;

	return _serial_getc(gd->cur_serial_dev);
}

int serial_tstc(void)
{
	if (!gd->cur_serial_dev)
		return 0;

	return _serial_tstc(gd->cur_serial_dev);
}

void serial_setbrg(void)
{
	struct dm_serial_ops *ops;

	if (!gd->cur_serial_dev)
		return;

	ops = serial_get_ops(gd->cur_serial_dev);
	if (ops->setbrg)
		ops->setbrg(gd->cur_serial_dev, gd->baudrate);
}

void serial_stdio_init(void)
{
}

#if defined(CONFIG_DM_STDIO)

#if CONFIG_IS_ENABLED(SERIAL_PRESENT)
static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
{
	_serial_putc(sdev->priv, ch);
}
#endif

static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
{
	_serial_puts(sdev->priv, str);
}

static int serial_stub_getc(struct stdio_dev *sdev)
{
	return _serial_getc(sdev->priv);
}

static int serial_stub_tstc(struct stdio_dev *sdev)
{
	return _serial_tstc(sdev->priv);
}
#endif

/**
 * 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);

#if CONFIG_IS_ENABLED(SERIAL_PRESENT)
static int serial_post_probe(struct udevice *dev)
{
	struct dm_serial_ops *ops = serial_get_ops(dev);
#ifdef CONFIG_DM_STDIO
	struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
	struct stdio_dev sdev;
#endif
	int ret;

#if defined(CONFIG_NEEDS_MANUAL_RELOC)
	if (ops->setbrg)
		ops->setbrg += gd->reloc_off;
	if (ops->getc)
		ops->getc += gd->reloc_off;
	if (ops->putc)
		ops->putc += gd->reloc_off;
	if (ops->pending)
		ops->pending += gd->reloc_off;
	if (ops->clear)
		ops->clear += gd->reloc_off;
#if CONFIG_POST & CONFIG_SYS_POST_UART
	if (ops->loop)
		ops->loop += gd->reloc_off
#endif
#endif
	/* Set the baud rate */
	if (ops->setbrg) {
		ret = ops->setbrg(dev, gd->baudrate);
		if (ret)
			return ret;
	}

#ifdef CONFIG_DM_STDIO
	if (!(gd->flags & GD_FLG_RELOC))
		return 0;
	memset(&sdev, '\0', sizeof(sdev));

	strncpy(sdev.name, dev->name, sizeof(sdev.name));
	sdev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT | DEV_FLAGS_DM;
	sdev.priv = dev;
	sdev.putc = serial_stub_putc;
	sdev.puts = serial_stub_puts;
	sdev.getc = serial_stub_getc;
	sdev.tstc = serial_stub_tstc;
	stdio_register_dev(&sdev, &upriv->sdev);
#endif
	return 0;
}

static int serial_pre_remove(struct udevice *dev)
{
#if CONFIG_IS_ENABLED(SYS_STDIO_DEREGISTER)
	struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);

	if (stdio_deregister_dev(upriv->sdev, true))
		return -EPERM;
#endif

	return 0;
}

UCLASS_DRIVER(serial) = {
	.id		= UCLASS_SERIAL,
	.name		= "serial",
	.flags		= DM_UC_FLAG_SEQ_ALIAS,
	.post_probe	= serial_post_probe,
	.pre_remove	= serial_pre_remove,
	.per_device_auto_alloc_size = sizeof(struct serial_dev_priv),
};
#endif
Commit	Line	Data
57d92753 SG	1	/*
	2	* Copyright (c) 2014 The Chromium OS Authors.
	3	*
	4	* SPDX-License-Identifier: GPL-2.0+
	5	*/
	6
	7	#include <common.h>
	8	#include <dm.h>
ad1b81c8	9	#include <environment.h>
57d92753	10	#include <errno.h>
57d92753 SG	11	#include <os.h>
	12	#include <serial.h>
	13	#include <stdio_dev.h>
c487fd47	14	#include <watchdog.h>
57d92753 SG	15	#include <dm/lists.h>
57d92753 SG	16	#include <dm/device-internal.h>
f93472a0	17	#include <dm/of_access.h>
57d92753 SG	18
	19	DECLARE_GLOBAL_DATA_PTR;
	20
ad1b81c8 SG	21	/*
	22	* Table with supported baudrates (defined in config_xyz.h)
	23	*/
	24	static const unsigned long baudrate_table[] = CONFIG_SYS_BAUDRATE_TABLE;
	25
f1896c45 AY	26	#if !CONFIG_VAL(SYS_MALLOC_F_LEN)
f1896c45 AY	27	#error "Serial is required before relocation - define CONFIG_$(SPL_)SYS_MALLOC_F_LEN to make this work"
57d92753 SG	28	#endif
57d92753 SG	29
d0960853 SG	30	static int serial_check_stdout(const void blob, struct udevice *devp)
	31	{
	32	int node;
	33
	34	/* Check for a chosen console */
	35	node = fdtdec_get_chosen_node(blob, "stdout-path");
	36	if (node < 0) {
	37	const char str, p, *name;
	38
	39	/*
	40	* Deal with things like
	41	* stdout-path = "serial0:115200n8";
	42	*
	43	* We need to look up the alias and then follow it to the
	44	* correct node.
	45	*/
	46	str = fdtdec_get_chosen_prop(blob, "stdout-path");
	47	if (str) {
	48	p = strchr(str, ':');
	49	name = fdt_get_alias_namelen(blob, str,
	50	p ? p - str : strlen(str));
	51	if (name)
	52	node = fdt_path_offset(blob, name);
	53	}
	54	}
	55	if (node < 0)
	56	node = fdt_path_offset(blob, "console");
	57	if (!uclass_get_device_by_of_offset(UCLASS_SERIAL, node, devp))
	58	return 0;
	59
	60	/*
	61	* If the console is not marked to be bound before relocation, bind it
	62	* anyway.
	63	*/
	64	if (node > 0 && !lists_bind_fdt(gd->dm_root, offset_to_ofnode(node),
	65	devp)) {
	66	if (!device_probe(*devp))
	67	return 0;
	68	}
	69
	70	return -ENODEV;
	71	}
	72
57d92753 SG	73	static void serial_find_console_or_panic(void)
57d92753 SG	74	{
6bdc593e	75	const void *blob = gd->fdt_blob;
469a579d	76	struct udevice *dev;
57d92753	77
b484b0da SG	78	if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
	79	uclass_first_device(UCLASS_SERIAL, &dev);
	80	if (dev) {
	81	gd->cur_serial_dev = dev;
	82	return;
	83	}
	84	} else if (CONFIG_IS_ENABLED(OF_CONTROL) && blob) {
f93472a0 SG	85	/* Live tree has support for stdout */
	86	if (of_live_active()) {
	87	struct device_node *np = of_get_stdout();
	88
	89	if (np && !uclass_get_device_by_ofnode(UCLASS_SERIAL,
	90	np_to_ofnode(np), &dev)) {
	91	gd->cur_serial_dev = dev;
	92	return;
	93	}
	94	} else {
	95	if (!serial_check_stdout(blob, &dev)) {
	96	gd->cur_serial_dev = dev;
	97	return;
	98	}
469a579d	99	}
af282245	100	}
6bdc593e	101	if (!SPL_BUILD \|\| !CONFIG_IS_ENABLED(OF_CONTROL) \|\| !blob) {
e9fc0583	102	/*
eb623b98 SR	103	* Try to use CONFIG_CONS_INDEX if available (it is numbered
	104	* from 1!).
	105	*
	106	* Failing that, get the device with sequence number 0, or in
	107	* extremis just the first serial device we can find. But we
	108	* insist on having a console (even if it is silent).
	109	*/
91155c65 SG	110	#ifdef CONFIG_CONS_INDEX
	111	#define INDEX (CONFIG_CONS_INDEX - 1)
	112	#else
	113	#define INDEX 0
	114	#endif
e9fc0583 SG	115	if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) \|\|
e9fc0583 SG	116	!uclass_get_device(UCLASS_SERIAL, INDEX, &dev) \|\|
753812cb	117	(!uclass_first_device(UCLASS_SERIAL, &dev) && dev)) {
e9fc0583 SG	118	gd->cur_serial_dev = dev;
	119	return;
	120	}
91155c65	121	#undef INDEX
e9fc0583 SG	122	}
e9fc0583 SG	123
8c458588	124	#ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
e9fc0583	125	panic_str("No serial driver found");
8c458588	126	#endif
57d92753 SG	127	}
	128
	129	/* Called prior to relocation */
	130	int serial_init(void)
	131	{
	132	serial_find_console_or_panic();
	133	gd->flags \|= GD_FLG_SERIAL_READY;
	134
	135	return 0;
	136	}
	137
	138	/* Called after relocation */
	139	void serial_initialize(void)
	140	{
e4d6ab0c	141	serial_init();
57d92753 SG	142	}
57d92753 SG	143
eea5a4cc	144	static void _serial_putc(struct udevice *dev, char ch)
57d92753	145	{
bac64467	146	struct dm_serial_ops *ops = serial_get_ops(dev);
57d92753 SG	147	int err;
57d92753 SG	148
c5917b4b AW	149	if (ch == '\n')
	150	_serial_putc(dev, '\r');
	151
57d92753	152	do {
bac64467	153	err = ops->putc(dev, ch);
57d92753	154	} while (err == -EAGAIN);
57d92753 SG	155	}
57d92753 SG	156
eea5a4cc	157	static void _serial_puts(struct udevice dev, const char str)
b8893327	158	{
eea5a4cc MY	159	while (*str)
eea5a4cc MY	160	_serial_putc(dev, *str++);
b8893327 SG	161	}
b8893327 SG	162
eea5a4cc	163	static int _serial_getc(struct udevice *dev)
57d92753	164	{
eea5a4cc MY	165	struct dm_serial_ops *ops = serial_get_ops(dev);
eea5a4cc MY	166	int err;
57d92753	167
eea5a4cc MY	168	do {
	169	err = ops->getc(dev);
	170	if (err == -EAGAIN)
	171	WATCHDOG_RESET();
	172	} while (err == -EAGAIN);
57d92753	173
eea5a4cc	174	return err >= 0 ? err : 0;
57d92753 SG	175	}
57d92753 SG	176
eea5a4cc	177	static int _serial_tstc(struct udevice *dev)
57d92753	178	{
eea5a4cc	179	struct dm_serial_ops *ops = serial_get_ops(dev);
57d92753 SG	180
57d92753 SG	181	if (ops->pending)
eea5a4cc	182	return ops->pending(dev, true);
57d92753 SG	183
	184	return 1;
	185	}
	186
eea5a4cc	187	void serial_putc(char ch)
57d92753	188	{
8c458588 HG	189	if (gd->cur_serial_dev)
8c458588 HG	190	_serial_putc(gd->cur_serial_dev, ch);
eea5a4cc	191	}
57d92753	192
eea5a4cc MY	193	void serial_puts(const char *str)
eea5a4cc MY	194	{
8c458588 HG	195	if (gd->cur_serial_dev)
8c458588 HG	196	_serial_puts(gd->cur_serial_dev, str);
57d92753 SG	197	}
57d92753 SG	198
b8893327 SG	199	int serial_getc(void)
b8893327 SG	200	{
8c458588 HG	201	if (!gd->cur_serial_dev)
	202	return 0;
	203
469a579d	204	return _serial_getc(gd->cur_serial_dev);
eea5a4cc MY	205	}
	206
	207	int serial_tstc(void)
	208	{
8c458588 HG	209	if (!gd->cur_serial_dev)
	210	return 0;
	211
469a579d	212	return _serial_tstc(gd->cur_serial_dev);
eea5a4cc MY	213	}
	214
	215	void serial_setbrg(void)
	216	{
8c458588 HG	217	struct dm_serial_ops *ops;
	218
	219	if (!gd->cur_serial_dev)
	220	return;
eea5a4cc	221
8c458588	222	ops = serial_get_ops(gd->cur_serial_dev);
eea5a4cc	223	if (ops->setbrg)
469a579d	224	ops->setbrg(gd->cur_serial_dev, gd->baudrate);
b8893327 SG	225	}
b8893327 SG	226
57d92753 SG	227	void serial_stdio_init(void)
	228	{
	229	}
	230
49ddcf3e MY	231	#if defined(CONFIG_DM_STDIO)
	232
	233	#if CONFIG_IS_ENABLED(SERIAL_PRESENT)
b8893327	234	static void serial_stub_putc(struct stdio_dev *sdev, const char ch)
57d92753	235	{
eea5a4cc	236	_serial_putc(sdev->priv, ch);
57d92753	237	}
236f2bd3	238	#endif
57d92753	239
49ddcf3e	240	static void serial_stub_puts(struct stdio_dev sdev, const char str)
57d92753	241	{
eea5a4cc	242	_serial_puts(sdev->priv, str);
57d92753 SG	243	}
57d92753 SG	244
49ddcf3e	245	static int serial_stub_getc(struct stdio_dev *sdev)
57d92753	246	{
eea5a4cc	247	return _serial_getc(sdev->priv);
57d92753 SG	248	}
57d92753 SG	249
49ddcf3e	250	static int serial_stub_tstc(struct stdio_dev *sdev)
57d92753	251	{
eea5a4cc	252	return _serial_tstc(sdev->priv);
57d92753	253	}
49ddcf3e	254	#endif
57d92753	255
ad1b81c8 SG	256	/**
	257	* on_baudrate() - Update the actual baudrate when the env var changes
	258	*
	259	* This will check for a valid baudrate and only apply it if valid.
	260	*/
	261	static int on_baudrate(const char name, const char value, enum env_op op,
	262	int flags)
	263	{
	264	int i;
	265	int baudrate;
	266
	267	switch (op) {
	268	case env_op_create:
	269	case env_op_overwrite:
	270	/*
	271	* Switch to new baudrate if new baudrate is supported
	272	*/
	273	baudrate = simple_strtoul(value, NULL, 10);
	274
	275	/* Not actually changing */
	276	if (gd->baudrate == baudrate)
	277	return 0;
	278
	279	for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
	280	if (baudrate == baudrate_table[i])
	281	break;
	282	}
	283	if (i == ARRAY_SIZE(baudrate_table)) {
	284	if ((flags & H_FORCE) == 0)
	285	printf("## Baudrate %d bps not supported\n",
	286	baudrate);
	287	return 1;
	288	}
	289	if ((flags & H_INTERACTIVE) != 0) {
	290	printf("## Switch baudrate to %d bps and press ENTER ...\n",
	291	baudrate);
	292	udelay(50000);
	293	}
	294
	295	gd->baudrate = baudrate;
	296
	297	serial_setbrg();
	298
	299	udelay(50000);
	300
	301	if ((flags & H_INTERACTIVE) != 0)
	302	while (1) {
	303	if (getc() == '\r')
	304	break;
	305	}
	306
	307	return 0;
	308	case env_op_delete:
	309	printf("## Baudrate may not be deleted\n");
	310	return 1;
	311	default:
	312	return 0;
	313	}
	314	}
	315	U_BOOT_ENV_CALLBACK(baudrate, on_baudrate);
	316
92c55b68	317	#if CONFIG_IS_ENABLED(SERIAL_PRESENT)
57d92753 SG	318	static int serial_post_probe(struct udevice *dev)
57d92753 SG	319	{
57d92753	320	struct dm_serial_ops *ops = serial_get_ops(dev);
236f2bd3	321	#ifdef CONFIG_DM_STDIO
e564f054	322	struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
236f2bd3 SG	323	struct stdio_dev sdev;
236f2bd3 SG	324	#endif
57d92753 SG	325	int ret;
57d92753 SG	326
484fdf5b MS	327	#if defined(CONFIG_NEEDS_MANUAL_RELOC)
	328	if (ops->setbrg)
	329	ops->setbrg += gd->reloc_off;
	330	if (ops->getc)
	331	ops->getc += gd->reloc_off;
	332	if (ops->putc)
	333	ops->putc += gd->reloc_off;
	334	if (ops->pending)
	335	ops->pending += gd->reloc_off;
	336	if (ops->clear)
	337	ops->clear += gd->reloc_off;
	338	#if CONFIG_POST & CONFIG_SYS_POST_UART
	339	if (ops->loop)
	340	ops->loop += gd->reloc_off
	341	#endif
	342	#endif
57d92753 SG	343	/* Set the baud rate */
	344	if (ops->setbrg) {
	345	ret = ops->setbrg(dev, gd->baudrate);
	346	if (ret)
	347	return ret;
	348	}
	349
236f2bd3	350	#ifdef CONFIG_DM_STDIO
57d92753 SG	351	if (!(gd->flags & GD_FLG_RELOC))
57d92753 SG	352	return 0;
57d92753 SG	353	memset(&sdev, '\0', sizeof(sdev));
	354
	355	strncpy(sdev.name, dev->name, sizeof(sdev.name));
7b3c4c3a	356	sdev.flags = DEV_FLAGS_OUTPUT \| DEV_FLAGS_INPUT \| DEV_FLAGS_DM;
57d92753 SG	357	sdev.priv = dev;
	358	sdev.putc = serial_stub_putc;
	359	sdev.puts = serial_stub_puts;
	360	sdev.getc = serial_stub_getc;
	361	sdev.tstc = serial_stub_tstc;
	362	stdio_register_dev(&sdev, &upriv->sdev);
236f2bd3	363	#endif
57d92753 SG	364	return 0;
	365	}
	366
	367	static int serial_pre_remove(struct udevice *dev)
	368	{
869588de	369	#if CONFIG_IS_ENABLED(SYS_STDIO_DEREGISTER)
e564f054	370	struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
57d92753	371
e98856fc	372	if (stdio_deregister_dev(upriv->sdev, true))
57d92753 SG	373	return -EPERM;
	374	#endif
	375
	376	return 0;
	377	}
	378
	379	UCLASS_DRIVER(serial) = {
	380	.id = UCLASS_SERIAL,
	381	.name = "serial",
9cc36a2b	382	.flags = DM_UC_FLAG_SEQ_ALIAS,
57d92753 SG	383	.post_probe = serial_post_probe,
	384	.pre_remove = serial_pre_remove,
	385	.per_device_auto_alloc_size = sizeof(struct serial_dev_priv),
	386	};
92c55b68	387	#endif