diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 5 | ||||
| -rw-r--r-- | drivers/tty/serial/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/tty/serial/liteuart.c | 21 |
3 files changed, 27 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index cb89dbdedc46..17bdf5df404c 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1092,6 +1092,11 @@ the driver will use only 32-bit accessors to read/write the device registers. + liteuart,<addr> + Start an early console on a litex serial port at the + specified address. The serial port must already be + setup and configured. Options are not yet supported. + meson,<addr> Start an early, polled-mode console on a meson serial port at the specified address. The serial port must diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 682f9171c82c..24282ad99d85 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1553,6 +1553,7 @@ config SERIAL_LITEUART_CONSOLE bool "LiteUART serial port console support" depends on SERIAL_LITEUART=y select SERIAL_CORE_CONSOLE + select SERIAL_EARLYCON help Say 'Y' or 'M' here if you wish to use the FPGA-based LiteUART serial controller from LiteX SoC builder as the system console diff --git a/drivers/tty/serial/liteuart.c b/drivers/tty/serial/liteuart.c index 0b06770642cb..dbc0559a9157 100644 --- a/drivers/tty/serial/liteuart.c +++ b/drivers/tty/serial/liteuart.c @@ -370,6 +370,27 @@ static int __init liteuart_console_init(void) return 0; } console_initcall(liteuart_console_init); + +static void early_liteuart_write(struct console *console, const char *s, + unsigned int count) +{ + struct earlycon_device *device = console->data; + struct uart_port *port = &device->port; + + uart_console_write(port, s, count, liteuart_putchar); +} + +static int __init early_liteuart_setup(struct earlycon_device *device, + const char *options) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = early_liteuart_write; + return 0; +} + +OF_EARLYCON_DECLARE(liteuart, "litex,liteuart", early_liteuart_setup); #endif /* CONFIG_SERIAL_LITEUART_CONSOLE */ static int __init liteuart_init(void) |