2022-02-17 11:35:56

by Richard Genoud

[permalink] [raw]
Subject: Re: [PATCH v2] tty: serial: atmel: add earlycon support



Le 17/02/2022 à 10:46, Michael Walle a écrit :
> Add early console support which relies on the bootloader for the
> initialization of the UART.
> Please note, that the compatibles are taken from at91-usart MFD
> driver.
>
> Signed-off-by: Michael Walle <[email protected]>
Acked-by: Richard Genoud <[email protected]>

> ---
> drivers/tty/serial/Kconfig | 1 +
> drivers/tty/serial/atmel_serial.c | 24 ++++++++++++++++++++++++
> 2 files changed, 25 insertions(+)
>
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index 0e5ccb25bdb1..407a98ec0791 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -139,6 +139,7 @@ config SERIAL_ATMEL_CONSOLE
> bool "Support for console on AT91 serial port"
> depends on SERIAL_ATMEL=y
> select SERIAL_CORE_CONSOLE
> + select SERIAL_EARLYCON
> help
> Say Y here if you wish to use an on-chip UART on a Atmel
> AT91 processor as the system console (the system
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index 2d09a89974a2..73d43919898d 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -2673,6 +2673,30 @@ static struct console atmel_console = {
> .data = &atmel_uart,
> };
>
> +static void atmel_serial_early_write(struct console *con, const char *s,
> + unsigned int n)
> +{
> + struct earlycon_device *dev = con->data;
> +
> + uart_console_write(&dev->port, s, n, atmel_console_putchar);
> +}
> +
> +static int __init atmel_early_console_setup(struct earlycon_device *device,
> + const char *options)
> +{
> + if (!device->port.membase)
> + return -ENODEV;
> +
> + device->con->write = atmel_serial_early_write;
> +
> + return 0;
> +}
> +
> +OF_EARLYCON_DECLARE(atmel_serial, "atmel,at91rm9200-usart",
> + atmel_early_console_setup);
> +OF_EARLYCON_DECLARE(atmel_serial, "atmel,at91sam9260-usart",
> + atmel_early_console_setup);
> +
> #define ATMEL_CONSOLE_DEVICE (&atmel_console)
>
> #else
Thanks !