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Commit 0efe7296 authored by Stephen Boyd's avatar Stephen Boyd Committed by Greg Kroah-Hartman
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tty: serial: msm: Add earlycon support 



Add support for DT based and command line based early console on platforms
with the msm serial hardware.

Cc: Rob Herring <robh@kernel.org>
Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a86713b1

Documentation/kernel-parameters.txt

+12 −0
Original line number Diff line number Diff line
@@ -942,6 +942,18 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
			must already be setup and configured. Options are not

			yet supported.



		msm_serial,<addr>

			Start an early, polled-mode console on an msm serial

			port at the specified address. The serial port

			must already be setup and configured. Options are not

			yet supported.



		msm_serial_dm,<addr>

			Start an early, polled-mode console on an msm serial

			dm port at the specified address. The serial port

			must already be setup and configured. Options are not

			yet supported.



		smh	Use ARM semihosting calls for early console.



	earlyprintk=	[X86,SH,BLACKFIN,ARM,M68k]

drivers/tty/serial/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -1070,6 +1070,7 @@ config SERIAL_MSM_CONSOLE 
	bool "MSM serial console support"

	depends on SERIAL_MSM=y

	select SERIAL_CORE_CONSOLE

	select SERIAL_EARLYCON



config SERIAL_MSM_HS

	tristate "MSM UART High Speed: Serial Driver"

drivers/tty/serial/msm_serial.c

+62 −12
Original line number Diff line number Diff line
@@ -845,22 +845,15 @@ static inline struct uart_port *get_port_from_line(unsigned int line) 
}



#ifdef CONFIG_SERIAL_MSM_CONSOLE

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

			      unsigned int count)

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

				unsigned int count, bool is_uartdm)

{

	int i;

	struct uart_port *port;

	struct msm_port *msm_port;

	int num_newlines = 0;

	bool replaced = false;

	void __iomem *tf;



	BUG_ON(co->index < 0 || co->index >= UART_NR);



	port = get_port_from_line(co->index);

	msm_port = UART_TO_MSM(port);



	if (msm_port->is_uartdm)

	if (is_uartdm)

		tf = port->membase + UARTDM_TF;

	else

		tf = port->membase + UART_TF;
@@ -872,7 +865,7 @@ static void msm_console_write(struct console *co, const char *s, 
	count += num_newlines;



	spin_lock(&port->lock);

	if (msm_port->is_uartdm)

	if (is_uartdm)

		reset_dm_count(port, count);



	i = 0;
@@ -881,7 +874,7 @@ static void msm_console_write(struct console *co, const char *s, 
		unsigned int num_chars;

		char buf[4] = { 0 };



		if (msm_port->is_uartdm)

		if (is_uartdm)

			num_chars = min(count - i, (unsigned int)sizeof(buf));

		else

			num_chars = 1;
@@ -910,6 +903,20 @@ static void msm_console_write(struct console *co, const char *s, 
	spin_unlock(&port->lock);

}



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

			      unsigned int count)

{

	struct uart_port *port;

	struct msm_port *msm_port;



	BUG_ON(co->index < 0 || co->index >= UART_NR);



	port = get_port_from_line(co->index);

	msm_port = UART_TO_MSM(port);



	__msm_console_write(port, s, count, msm_port->is_uartdm);

}



static int __init msm_console_setup(struct console *co, char *options)

{

	struct uart_port *port;
@@ -952,6 +959,49 @@ static int __init msm_console_setup(struct console *co, char *options) 
	return uart_set_options(port, co, baud, parity, bits, flow);

}



static void

msm_serial_early_write(struct console *con, const char *s, unsigned n)

{

	struct earlycon_device *dev = con->data;



	__msm_console_write(&dev->port, s, n, false);

}



static int __init

msm_serial_early_console_setup(struct earlycon_device *device, const char *opt)

{

	if (!device->port.membase)

		return -ENODEV;



	device->con->write = msm_serial_early_write;

	return 0;

}

EARLYCON_DECLARE(msm_serial, msm_serial_early_console_setup);

OF_EARLYCON_DECLARE(msm_serial, "qcom,msm-uart",

		    msm_serial_early_console_setup);



static void

msm_serial_early_write_dm(struct console *con, const char *s, unsigned n)

{

	struct earlycon_device *dev = con->data;



	__msm_console_write(&dev->port, s, n, true);

}



static int __init

msm_serial_early_console_setup_dm(struct earlycon_device *device,

				  const char *opt)

{

	if (!device->port.membase)

		return -ENODEV;



	device->con->write = msm_serial_early_write_dm;

	return 0;

}

EARLYCON_DECLARE(msm_serial_dm, msm_serial_early_console_setup_dm);

OF_EARLYCON_DECLARE(msm_serial_dm, "qcom,msm-uartdm",

		    msm_serial_early_console_setup_dm);



static struct uart_driver msm_uart_driver;



static struct console msm_console = {