dm: serial: Add a REQUIRE_SERIAL_CONSOLE option for boards with no serial port
Currently the serial code assumes that there is always at least one serial
port (and panics / crashes due to null pointer dereferences when there is
none).
This makes it impossible to use u-boot on boards where there is no (debug)
serial port, because e.g. all uart pins are muxed to another function.
This commit adds a CONFIG_REQUIRE_SERIAL_CONSOLE Kconfig option, which
defaults to y (preserving existing behavior), which can be set to n on
such boards to make them work.
This commit only implements this for CONFIG_DM_SERIAL=y configs, as allowing
running without a serial port for CONFIG_DM_SERIAL=n configs is non trivial,
and is not necessary at this moment.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index fd126a8..a880eac 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -1,3 +1,14 @@
+config REQUIRE_SERIAL_CONSOLE
+ bool "Require a serial port for console"
+ # Running without a serial console is not supported by the
+ # non-dm serial code
+ depends on DM_SERIAL
+ default y
+ help
+ Require a serial port for the console, and panic if none is found
+ during serial port initialization (default y). Set this to n on
+ boards which have no debug serial port whatsoever.
+
config DM_SERIAL
bool "Enable Driver Model for serial drivers"
depends on DM
diff --git a/drivers/serial/serial-uclass.c b/drivers/serial/serial-uclass.c
index bbc366b..2a49697 100644
--- a/drivers/serial/serial-uclass.c
+++ b/drivers/serial/serial-uclass.c
@@ -78,7 +78,9 @@
#undef INDEX
}
+#ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
panic_str("No serial driver found");
+#endif
}
/* Called prior to relocation */
@@ -140,28 +142,40 @@
void serial_putc(char ch)
{
- _serial_putc(gd->cur_serial_dev, ch);
+ if (gd->cur_serial_dev)
+ _serial_putc(gd->cur_serial_dev, ch);
}
void serial_puts(const char *str)
{
- _serial_puts(gd->cur_serial_dev, 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 = serial_get_ops(gd->cur_serial_dev);
+ 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);
}