Unverified Commit c77bf360 authored by Anup Patel's avatar Anup Patel Committed by Palmer Dabbelt
Browse files

tty/serial: Add RISC-V SBI debug console based earlycon 



We extend the existing RISC-V SBI earlycon support to use the new
RISC-V SBI debug console extension.

Signed-off-by: default avatarAnup Patel <apatel@ventanamicro.com>
Reviewed-by: default avatarAndrew Jones <ajones@ventanamicro.com>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20231124070905.1043092-4-apatel@ventanamicro.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent f43fabf4

drivers/tty/serial/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -87,7 +87,7 @@ config SERIAL_EARLYCON_SEMIHOST 


config SERIAL_EARLYCON_RISCV_SBI

	bool "Early console using RISC-V SBI"

	depends on RISCV_SBI_V01

	depends on RISCV_SBI

	select SERIAL_CORE

	select SERIAL_CORE_CONSOLE

	select SERIAL_EARLYCON

drivers/tty/serial/earlycon-riscv-sbi.c

+24 −3
Original line number Diff line number Diff line
@@ -15,17 +15,38 @@ static void sbi_putc(struct uart_port *port, unsigned char c) 
	sbi_console_putchar(c);

}



static void sbi_console_write(struct console *con,

			      const char *s, unsigned n)

static void sbi_0_1_console_write(struct console *con,

				  const char *s, unsigned int n)

{

	struct earlycon_device *dev = con->data;

	uart_console_write(&dev->port, s, n, sbi_putc);

}



static void sbi_dbcn_console_write(struct console *con,

				   const char *s, unsigned int n)

{

	int ret;



	while (n) {

		ret = sbi_debug_console_write(s, n);

		if (ret < 0)

			break;



		s += ret;

		n -= ret;

	}

}



static int __init early_sbi_setup(struct earlycon_device *device,

				  const char *opt)

{

	device->con->write = sbi_console_write;

	if (sbi_debug_console_available)

		device->con->write = sbi_dbcn_console_write;

	else if (IS_ENABLED(CONFIG_RISCV_SBI_V01))

		device->con->write = sbi_0_1_console_write;

	else

		return -ENODEV;



	return 0;

}

EARLYCON_DECLARE(sbi, early_sbi_setup);