[PATCH v4 3/5] tty/serial: Add RISC-V SBI debug console based earlycon
From: Anup Patel <hidden>
Date: 2023-11-18 03:39:54
Also in:
linux-riscv, linux-serial, lkml
Subsystem:
the rest, tty layer and serial drivers · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Jiri Slaby
We extend the existing RISC-V SBI earlycon support to use the new RISC-V SBI debug console extension. Signed-off-by: Anup Patel <redacted> Reviewed-by: Andrew Jones <redacted> --- drivers/tty/serial/Kconfig | 2 +- drivers/tty/serial/earlycon-riscv-sbi.c | 24 ++++++++++++++++++++---- 2 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 732c893c8d16..1f2594b8ab9d 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig@@ -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
diff --git a/drivers/tty/serial/earlycon-riscv-sbi.c b/drivers/tty/serial/earlycon-riscv-sbi.c
index 27afb0b74ea7..5351e1e31f45 100644
--- a/drivers/tty/serial/earlycon-riscv-sbi.c
+++ b/drivers/tty/serial/earlycon-riscv-sbi.c@@ -15,17 +15,33 @@ 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) +{ + sbi_debug_console_write(n, __pa(s)); +} + static int __init early_sbi_setup(struct earlycon_device *device, const char *opt) { - device->con->write = sbi_console_write; - return 0; + int ret = 0; + + 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 + ret = -ENODEV; + } + + return ret; } EARLYCON_DECLARE(sbi, early_sbi_setup);
--
2.34.1