u-boot/drivers/serial/serial-uclass.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2014 The Chromium OS Authors.
*/
#define LOG_CATEGORY UCLASS_SERIAL
#include <common.h>
#include <dm.h>
#include <env_internal.h>
#include <errno.h>
#include <malloc.h>
#include <os.h>
#include <serial.h>
#include <stdio_dev.h>
#include <watchdog.h>
#include <asm/global_data.h>
#include <dm/lists.h>
#include <dm/device-internal.h>
#include <dm/of_access.h>
#include <linux/delay.h>
DECLARE_GLOBAL_DATA_PTR;
/*
* Table with supported baudrates (defined in config_xyz.h)
*/
static const unsigned long baudrate_table[] = CFG_SYS_BAUDRATE_TABLE;
#if CONFIG_IS_ENABLED(SERIAL_PRESENT)
static int serial_check_stdout(const void *blob, struct udevice **devp)
{
int node = -1;
const char *str, *p, *name;
int namelen;
/* Check for a chosen console */
str = fdtdec_get_chosen_prop(blob, "stdout-path");
if (str) {
p = strchr(str, ':');
namelen = p ? p - str : strlen(str);
node = fdt_path_offset_namelen(blob, str, namelen);
if (node < 0) {
/*
* Deal with things like
* stdout-path = "serial0:115200n8";
*
* We need to look up the alias and then follow it to
* the correct node.
*/
name = fdt_get_alias_namelen(blob, str, namelen);
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, NULL, false)) {
if (device_get_uclass_id(*devp) == UCLASS_SERIAL &&
!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 (!IS_ENABLED(CONFIG_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_get_flags(dev) & 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_err(UCLASS_SERIAL, &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;
serial_setbrg();
#endif
return 0;
}
/* Called after relocation */
int serial_initialize(void)
{
/* Scanning uclass to probe devices */
if (IS_ENABLED(CONFIG_SERIAL_PROBE_ALL)) {
int ret;
ret = uclass_probe_all(UCLASS_SERIAL);
if (ret)
return ret;
}
return 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 int __serial_puts(struct udevice *dev, const char *str, size_t len)
{
struct dm_serial_ops *ops = serial_get_ops(dev);
do {
ssize_t written = ops->puts(dev, str, len);
if (written < 0)
return written;
str += written;
len -= written;
} while (len);
return 0;
}
static void _serial_puts(struct udevice *dev, const char *str)
{
struct dm_serial_ops *ops = serial_get_ops(dev);
if (!CONFIG_IS_ENABLED(SERIAL_PUTS) || !ops->puts) {
while (*str)
_serial_putc(dev, *str++);
return;
}
do {
const char *newline = strchrnul(str, '\n');
size_t len = newline - str;
if (__serial_puts(dev, str, len))
return;
if (*newline && __serial_puts(dev, "\r\n", 2))
return;
str += len + !!*newline;
} while (*str);
}
#ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
static void _serial_flush(struct udevice *dev)
{
struct dm_serial_ops *ops = serial_get_ops(dev);
if (!ops->pending)
return;
while (ops->pending(dev, false) > 0)
;
}
#endif
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)
schedule();
} 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);
}
#ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
void serial_flush(void)
{
if (!gd->cur_serial_dev)
return;
_serial_flush(gd->cur_serial_dev);
}
#endif
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 CONFIG_IS_ENABLED(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);
}
static void serial_stub_puts(struct stdio_dev *sdev, const char *str)
{
_serial_puts(sdev->priv, str);
}
#ifdef CONFIG_CONSOLE_FLUSH_SUPPORT
static void serial_stub_flush(struct stdio_dev *sdev)
{
_serial_flush(sdev->priv);
}
#endif
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
#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 = dectoul(value, NULL);
/* 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);
flush();
}
gd->baudrate = baudrate;
serial_setbrg();
udelay(50000);
if ((flags & H_INTERACTIVE) != 0)
while (1) {
if (getchar() == '\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);
#if CONFIG_IS_ENABLED(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 CFG_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;
}
#if CONFIG_IS_ENABLED(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;
STDIO_DEV_ASSIGN_FLUSH(&sdev, serial_stub_flush);
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 = sizeof(struct serial_dev_priv),
};
#endif