From 736d553886a72274e58ff8a0e8a2899978042b8f Mon Sep 17 00:00:00 2001 From: =?utf8?q?Andreas=20F=C3=A4rber?= Date: Sun, 6 Mar 2016 12:21:24 +0100 Subject: [PATCH] tty: serial: meson: Implement earlycon support MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Split off the bulk of the existing meson_serial_console_write() implementation into meson_serial_port_write() for implementing meson_serial_early_console_write(). Use "meson" as the earlycon driver name, courtesy of Nicolas. Signed-off-by: Nicolas Saenz Julienne Acked-by: Carlo Caione Signed-off-by: Andreas Färber Signed-off-by: Greg Kroah-Hartman --- Documentation/kernel-parameters.txt | 6 +++++ drivers/tty/serial/Kconfig | 1 + drivers/tty/serial/meson_uart.c | 42 ++++++++++++++++++++++++----- 3 files changed, 42 insertions(+), 7 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 0b3de80ec8f6..36e1c7ba831f 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1039,6 +1039,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. the driver will use only 32-bit accessors to read/write the device registers. + meson, + Start an early, polled-mode console on a meson serial + port at the specified address. The serial port must + already be setup and configured. Options are not yet + supported. + msm_serial, Start an early, polled-mode console on an msm serial port at the specified address. The serial port diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 13d4ed6caac4..aa86994ca734 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -213,6 +213,7 @@ config SERIAL_MESON_CONSOLE bool "Support for console on meson" depends on SERIAL_MESON=y select SERIAL_CORE_CONSOLE + select SERIAL_EARLYCON help Say Y here if you wish to use a Amlogic MesonX UART as the system console (the system console is the device which diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c index 024445aa0521..6aea0f4a9165 100644 --- a/drivers/tty/serial/meson_uart.c +++ b/drivers/tty/serial/meson_uart.c @@ -481,18 +481,13 @@ static void meson_console_putchar(struct uart_port *port, int ch) writel(ch, port->membase + AML_UART_WFIFO); } -static void meson_serial_console_write(struct console *co, const char *s, - u_int count) +static void meson_serial_port_write(struct uart_port *port, const char *s, + u_int count) { - struct uart_port *port; unsigned long flags; int locked; u32 val, tmp; - port = meson_ports[co->index]; - if (!port) - return; - local_irq_save(flags); if (port->sysrq) { locked = 0; @@ -516,6 +511,18 @@ static void meson_serial_console_write(struct console *co, const char *s, local_irq_restore(flags); } +static void meson_serial_console_write(struct console *co, const char *s, + u_int count) +{ + struct uart_port *port; + + port = meson_ports[co->index]; + if (!port) + return; + + meson_serial_port_write(port, s, count); +} + static int meson_serial_console_setup(struct console *co, char *options) { struct uart_port *port; @@ -554,6 +561,27 @@ static int __init meson_serial_console_init(void) } console_initcall(meson_serial_console_init); +static void meson_serial_early_console_write(struct console *co, + const char *s, + u_int count) +{ + struct earlycon_device *dev = co->data; + + meson_serial_port_write(&dev->port, s, count); +} + +static int __init +meson_serial_early_console_setup(struct earlycon_device *device, const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = meson_serial_early_console_write; + return 0; +} +OF_EARLYCON_DECLARE(meson, "amlogic,meson-uart", + meson_serial_early_console_setup); + #define MESON_SERIAL_CONSOLE (&meson_serial_console) #else #define MESON_SERIAL_CONSOLE NULL -- 2.20.1