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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: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Stephen Boyd 2014-09-15 17:22:51 -07:00 committed by Greg Kroah-Hartman
parent a86713b153
commit 0efe729634
3 changed files with 75 additions and 12 deletions
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12
Documentation/kernel-parameters.txt
View File

@ -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]

1
drivers/tty/serial/Kconfig
View File

@ -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"

74
drivers/tty/serial/msm_serial.c
View File

@ -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 = {