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Commit 4d9d7d89 authored by Tobias Klauser's avatar Tobias Klauser Committed by Greg Kroah-Hartman
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serial: altera_uart: add earlycon support 



Nios2 currently uses its own early printk implementation, rather than
using unified earlycon support to show boot messages on altera_uart.

Add earlycon support to altera_uart so that other archs may use it.
Also, this (together with the corresponding patch for altera_jtaguart)
will allow the early printk implementation in arch/nios2 to be removed
in a future patch.

Cc: Ley Foon Tan <lftan@altera.com>
Signed-off-by: default avatarTobias Klauser <tklauser@distanz.ch>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a4199f5e

drivers/tty/serial/Kconfig

+1 −0
Original line number Original line Diff line number Diff line
@@ -1392,6 +1392,7 @@ config SERIAL_ALTERA_UART_CONSOLE 
	bool "Altera UART console support"

	bool "Altera UART console support"

	depends on SERIAL_ALTERA_UART=y

	depends on SERIAL_ALTERA_UART=y

	select SERIAL_CORE_CONSOLE

	select SERIAL_CORE_CONSOLE

	select SERIAL_EARLYCON

	help

	help

	  Enable a Altera UART port to be the system console.

	  Enable a Altera UART port to be the system console.

drivers/tty/serial/altera_uart.c

+32 −0
Original line number Original line Diff line number Diff line
@@ -489,6 +489,38 @@ console_initcall(altera_uart_console_init); 




#define	ALTERA_UART_CONSOLE	(&altera_uart_console)

#define	ALTERA_UART_CONSOLE	(&altera_uart_console)





static void altera_uart_earlycon_write(struct console *co, const char *s,

				       unsigned int count)

{

	struct earlycon_device *dev = co->data;



	uart_console_write(&dev->port, s, count, altera_uart_console_putc);

}



static int __init altera_uart_earlycon_setup(struct earlycon_device *dev,

					     const char *options)

{

	struct uart_port *port = &dev->port;



	if (!port->membase)

		return -ENODEV;



	/* Enable RX interrupts now */

	writel(ALTERA_UART_CONTROL_RRDY_MSK,

	       port->membase + ALTERA_UART_CONTROL_REG);



	if (dev->baud) {

		unsigned int baudclk = port->uartclk / dev->baud;



		writel(baudclk, port->membase + ALTERA_UART_DIVISOR_REG);

	}



	dev->con->write = altera_uart_earlycon_write;

	return 0;

}



OF_EARLYCON_DECLARE(uart, "altr,uart-1.0", altera_uart_earlycon_setup);



#else

#else





#define	ALTERA_UART_CONSOLE	NULL

#define	ALTERA_UART_CONSOLE	NULL