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Commit bd8d257f authored by Vladimir Murzin's avatar Vladimir Murzin Committed by Greg Kroah-Hartman
Browse files

serial: mps2-uart: add support for early console 



This adds support early console for MPS2 UART which can be enabled via
earlycon=mps2,0x40004000

Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: default avatarPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: default avatarVladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 041f031d

drivers/tty/serial/Kconfig

+1 −0
Original line number Original line Diff line number Diff line
@@ -1452,6 +1452,7 @@ config SERIAL_MPS2_UART_CONSOLE 
	bool "MPS2 UART console support"

	bool "MPS2 UART console support"

	depends on SERIAL_MPS2_UART

	depends on SERIAL_MPS2_UART

	select SERIAL_CORE_CONSOLE

	select SERIAL_CORE_CONSOLE

	select SERIAL_EARLYCON





config SERIAL_MPS2_UART

config SERIAL_MPS2_UART

	bool "MPS2 UART port"

	bool "MPS2 UART port"

drivers/tty/serial/mps2-uart.c

+28 −0
Original line number Original line Diff line number Diff line
@@ -450,6 +450,34 @@ static struct console mps2_uart_console = { 




#define MPS2_SERIAL_CONSOLE (&mps2_uart_console)

#define MPS2_SERIAL_CONSOLE (&mps2_uart_console)





static void mps2_early_putchar(struct uart_port *port, int ch)

{

	while (readb(port->membase + UARTn_STATE) & UARTn_STATE_TX_FULL)

		cpu_relax();



	writeb((unsigned char)ch, port->membase + UARTn_DATA);

}



static void mps2_early_write(struct console *con, const char *s, unsigned int n)

{

	struct earlycon_device *dev = con->data;



	uart_console_write(&dev->port, s, n, mps2_early_putchar);

}



static int __init mps2_early_console_setup(struct earlycon_device *device,

					   const char *opt)

{

	if (!device->port.membase)

		return -ENODEV;



	device->con->write = mps2_early_write;



	return 0;

}



OF_EARLYCON_DECLARE(mps2, "arm,mps2-uart", mps2_early_console_setup);



#else

#else

#define MPS2_SERIAL_CONSOLE NULL

#define MPS2_SERIAL_CONSOLE NULL

#endif

#endif