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Commit ec84aa0a authored by Martin Blumenstingl's avatar Martin Blumenstingl Committed by Greg Kroah-Hartman
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tty: serial: lantiq: implement earlycon support 



This allows enabling earlycon for devices with a Lantiq serial console
by splitting lqasc_serial_port_write() from lqasc_console_write() and
re-using the new function for earlycon's write callback.

The kernel-parameter name matches the driver name ("lantiq"), similar
to how other drivers implement this.

Signed-off-by: default avatarMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2aaa9573

Documentation/admin-guide/kernel-parameters.txt

+6 −0
Original line number Original line Diff line number Diff line
@@ -966,6 +966,12 @@ 
			serial port must already be setup and configured.

			serial port must already be setup and configured.

			Options are not yet supported.

			Options are not yet supported.





		lantiq,<addr>

			Start an early, polled-mode console on a lantiq serial

			(lqasc) port at the specified address. The serial port

			must already be setup and configured. Options are not

			yet supported.



		lpuart,<addr>

		lpuart,<addr>

		lpuart32,<addr>

		lpuart32,<addr>

			Use early console provided by Freescale LP UART driver

			Use early console provided by Freescale LP UART driver

drivers/tty/serial/Kconfig

+1 −0
Original line number Original line Diff line number Diff line
@@ -1161,6 +1161,7 @@ config SERIAL_LANTIQ 
	depends on LANTIQ

	depends on LANTIQ

	select SERIAL_CORE

	select SERIAL_CORE

	select SERIAL_CORE_CONSOLE

	select SERIAL_CORE_CONSOLE

	select SERIAL_EARLYCON

	help

	help

	  Support for console and UART on Lantiq SoCs.

	  Support for console and UART on Lantiq SoCs.

drivers/tty/serial/lantiq.c

+31 −7
Original line number Original line Diff line number Diff line
@@ -590,13 +590,20 @@ lqasc_console_putchar(struct uart_port *port, int ch) 
	ltq_w8(ch, port->membase + LTQ_ASC_TBUF);

	ltq_w8(ch, port->membase + LTQ_ASC_TBUF);

}

}





static void lqasc_serial_port_write(struct uart_port *port, const char *s,

				    u_int count)

{

	unsigned long flags;



	spin_lock_irqsave(&ltq_asc_lock, flags);

	uart_console_write(port, s, count, lqasc_console_putchar);

	spin_unlock_irqrestore(&ltq_asc_lock, flags);

}





static void

static void

lqasc_console_write(struct console *co, const char *s, u_int count)

lqasc_console_write(struct console *co, const char *s, u_int count)

{

{

	struct ltq_uart_port *ltq_port;

	struct ltq_uart_port *ltq_port;

	struct uart_port *port;

	unsigned long flags;





	if (co->index >= MAXPORTS)

	if (co->index >= MAXPORTS)

		return;

		return;
@@ -605,11 +612,7 @@ lqasc_console_write(struct console *co, const char *s, u_int count) 
	if (!ltq_port)

	if (!ltq_port)

		return;

		return;





	port = &ltq_port->port;

	lqasc_serial_port_write(&ltq_port->port, s, count);



	spin_lock_irqsave(&ltq_asc_lock, flags);

	uart_console_write(port, s, count, lqasc_console_putchar);

	spin_unlock_irqrestore(&ltq_asc_lock, flags);

}

}





static int __init

static int __init
@@ -659,6 +662,27 @@ lqasc_console_init(void) 
}

}

console_initcall(lqasc_console_init);

console_initcall(lqasc_console_init);





static void lqasc_serial_early_console_write(struct console *co,

					     const char *s,

					     u_int count)

{

	struct earlycon_device *dev = co->data;



	lqasc_serial_port_write(&dev->port, s, count);

}



static int __init

lqasc_serial_early_console_setup(struct earlycon_device *device,

				 const char *opt)

{

	if (!device->port.membase)

		return -ENODEV;



	device->con->write = lqasc_serial_early_console_write;

	return 0;

}

OF_EARLYCON_DECLARE(lantiq, DRVNAME, lqasc_serial_early_console_setup);



static struct uart_driver lqasc_reg = {

static struct uart_driver lqasc_reg = {

	.owner =	THIS_MODULE,

	.owner =	THIS_MODULE,

	.driver_name =	DRVNAME,

	.driver_name =	DRVNAME,