drivers/serial/serial-uclass.c - uboot-imx - Git at Google

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

 #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

 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
 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, false)) {
 		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;
 #ifdef CONFIG_SERIAL_SEARCH_ALL
 	int ret;
 #endif

 	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 working 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

 #ifdef CONFIG_SERIAL_SEARCH_ALL
 		if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
 		    !uclass_get_device(UCLASS_SERIAL, INDEX, &dev)) {
 			if (dev->flags & DM_FLAG_ACTIVATED) {
 				gd->cur_serial_dev = dev;
 				return;
 			}
 		}

 		/* Search for any working device */
 		for (ret = uclass_first_device_check(UCLASS_SERIAL, &dev);
 		     dev;
 		     ret = uclass_next_device_check(&dev)) {
 			if (!ret) {
 				/* Device did succeed probing */
 				gd->cur_serial_dev = dev;
 				return;
 			}
 		}
 #else
 		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;
 		}
 #endif

 #undef INDEX
 	}

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

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

 	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;
 }

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

 	/* Read all available chars into the RX buffer */
 	while (__serial_tstc(dev)) {
 		upriv->buf[upriv->wr_ptr++] = __serial_getc(dev);
 		upriv->wr_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
 	}

 	return upriv->rd_ptr != upriv->wr_ptr ? 1 : 0;
 }

 static int _serial_getc(struct udevice *dev)
 {
 	struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
 	char val;

 	if (upriv->rd_ptr == upriv->wr_ptr)
 		return __serial_getc(dev);

 	val = upriv->buf[upriv->rd_ptr++];
 	upriv->rd_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;

 	return val;
 }

 #else /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */

 static int _serial_getc(struct udevice *dev)
 {
 	return __serial_getc(dev);
 }

 static int _serial_tstc(struct udevice *dev)
 {
 	return __serial_tstc(dev);
 }
 #endif /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */

 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);
 }

 int serial_getconfig(struct udevice *dev, uint *config)
 {
 	struct dm_serial_ops *ops;

 	ops = serial_get_ops(dev);
 	if (ops->getconfig)
 		return ops->getconfig(dev, config);

 	return 0;
 }

 int serial_setconfig(struct udevice *dev, uint config)
 {
 	struct dm_serial_ops *ops;

 	ops = serial_get_ops(dev);
 	if (ops->setconfig)
 		return ops->setconfig(dev, config);

 	return 0;
 }

 int serial_getinfo(struct udevice *dev, struct serial_device_info *info)
 {
 	struct dm_serial_ops *ops;

 	if (!info)
 		return -EINVAL;

 	info->baudrate = gd->baudrate;

 	ops = serial_get_ops(dev);
 	if (ops->getinfo)
 		return ops->getinfo(dev, info);

 	return -EINVAL;
 }

 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 (ops->getconfig)
 		ops->getconfig += gd->reloc_off;
 	if (ops->setconfig)
 		ops->setconfig += gd->reloc_off;
 #if CONFIG_POST & CONFIG_SYS_POST_UART
 	if (ops->loop)
 		ops->loop += gd->reloc_off;
 #endif
 	if (ops->getinfo)
 		ops->getinfo += gd->reloc_off;
 #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;

 #if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
 	/* Allocate the RX buffer */
 	upriv->buf = malloc(CONFIG_SERIAL_RX_BUFFER_SIZE);
 #endif

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

	#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

	#if CONFIG_IS_ENABLED(SERIAL_PRESENT)
	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, false)) {
	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;
	#ifdef CONFIG_SERIAL_SEARCH_ALL
	int ret;
	#endif

	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 working 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

	#ifdef CONFIG_SERIAL_SEARCH_ALL
	if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) \|\|
	!uclass_get_device(UCLASS_SERIAL, INDEX, &dev)) {
	if (dev->flags & DM_FLAG_ACTIVATED) {
	gd->cur_serial_dev = dev;
	return;
	}
	}

	/* Search for any working device */
	for (ret = uclass_first_device_check(UCLASS_SERIAL, &dev);
	dev;
	ret = uclass_next_device_check(&dev)) {
	if (!ret) {
	/* Device did succeed probing */
	gd->cur_serial_dev = dev;
	return;
	}
	}
	#else
	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;
	}
	#endif

	#undef INDEX
	}

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

	/* Called prior to relocation */
	int serial_init(void)
	{
	#if CONFIG_IS_ENABLED(SERIAL_PRESENT)
	serial_find_console_or_panic();
	gd->flags \|= GD_FLG_SERIAL_READY;
	#endif

	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;
	}

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

	/* Read all available chars into the RX buffer */
	while (__serial_tstc(dev)) {
	upriv->buf[upriv->wr_ptr++] = __serial_getc(dev);
	upriv->wr_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;
	}

	return upriv->rd_ptr != upriv->wr_ptr ? 1 : 0;
	}

	static int _serial_getc(struct udevice *dev)
	{
	struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
	char val;

	if (upriv->rd_ptr == upriv->wr_ptr)
	return __serial_getc(dev);

	val = upriv->buf[upriv->rd_ptr++];
	upriv->rd_ptr %= CONFIG_SERIAL_RX_BUFFER_SIZE;

	return val;
	}

	#else /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */

	static int _serial_getc(struct udevice *dev)
	{
	return __serial_getc(dev);
	}

	static int _serial_tstc(struct udevice *dev)
	{
	return __serial_tstc(dev);
	}
	#endif /* CONFIG_IS_ENABLED(SERIAL_RX_BUFFER) */

	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);
	}

	int serial_getconfig(struct udevice dev, uint config)
	{
	struct dm_serial_ops *ops;

	ops = serial_get_ops(dev);
	if (ops->getconfig)
	return ops->getconfig(dev, config);

	return 0;
	}

	int serial_setconfig(struct udevice *dev, uint config)
	{
	struct dm_serial_ops *ops;

	ops = serial_get_ops(dev);
	if (ops->setconfig)
	return ops->setconfig(dev, config);

	return 0;
	}

	int serial_getinfo(struct udevice dev, struct serial_device_info info)
	{
	struct dm_serial_ops *ops;

	if (!info)
	return -EINVAL;

	info->baudrate = gd->baudrate;

	ops = serial_get_ops(dev);
	if (ops->getinfo)
	return ops->getinfo(dev, info);

	return -EINVAL;
	}

	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 (ops->getconfig)
	ops->getconfig += gd->reloc_off;
	if (ops->setconfig)
	ops->setconfig += gd->reloc_off;
	#if CONFIG_POST & CONFIG_SYS_POST_UART
	if (ops->loop)
	ops->loop += gd->reloc_off;
	#endif
	if (ops->getinfo)
	ops->getinfo += gd->reloc_off;
	#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;

	#if CONFIG_IS_ENABLED(SERIAL_RX_BUFFER)
	/* Allocate the RX buffer */
	upriv->buf = malloc(CONFIG_SERIAL_RX_BUFFER_SIZE);
	#endif

	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