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>
This commit is contained in:
Hans de Goede 2015-08-08 17:45:18 +02:00 committed by Simon Glass
parent bd48c0617b
commit 8c4585881d
2 changed files with 28 additions and 3 deletions

View File

@ -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

View File

@ -78,7 +78,9 @@ static void serial_find_console_or_panic(void)
#undef INDEX
}
#ifdef CONFIG_REQUIRE_SERIAL_CONSOLE
panic_str("No serial driver found");
#endif
}
/* Called prior to relocation */
@ -140,28 +142,40 @@ static int _serial_tstc(struct udevice *dev)
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);
}