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path: root/drivers/tty/serial/8250/8250_early.c
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Diffstat (limited to 'drivers/tty/serial/8250/8250_early.c')
-rw-r--r--drivers/tty/serial/8250/8250_early.c69
1 files changed, 10 insertions, 59 deletions
diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c
index c31a22b4f845..8e119682266a 100644
--- a/drivers/tty/serial/8250/8250_early.c
+++ b/drivers/tty/serial/8250/8250_early.c
@@ -29,15 +29,12 @@
#include <linux/tty.h>
#include <linux/init.h>
#include <linux/console.h>
-#include <linux/serial_core.h>
#include <linux/serial_reg.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
#include <asm/io.h>
#include <asm/serial.h>
-static struct earlycon_device *early_device;
-
unsigned int __weak __init serial8250_early_in(struct uart_port *port, int offset)
{
switch (port->iotype) {
@@ -90,7 +87,8 @@ static void __init serial_putc(struct uart_port *port, int c)
static void __init early_serial8250_write(struct console *console,
const char *s, unsigned int count)
{
- struct uart_port *port = &early_device->port;
+ struct earlycon_device *device = console->data;
+ struct uart_port *port = &device->port;
unsigned int ier;
/* Save the IER and disable interrupts preserving the UUE bit */
@@ -107,21 +105,6 @@ static void __init early_serial8250_write(struct console *console,
serial8250_early_out(port, UART_IER, ier);
}
-static unsigned int __init probe_baud(struct uart_port *port)
-{
- unsigned char lcr, dll, dlm;
- unsigned int quot;
-
- lcr = serial8250_early_in(port, UART_LCR);
- serial8250_early_out(port, UART_LCR, lcr | UART_LCR_DLAB);
- dll = serial8250_early_in(port, UART_DLL);
- dlm = serial8250_early_in(port, UART_DLM);
- serial8250_early_out(port, UART_LCR, lcr);
-
- quot = (dlm << 8) | dll;
- return (port->uartclk / 16) / quot;
-}
-
static void __init init_port(struct earlycon_device *device)
{
struct uart_port *port = &device->port;
@@ -147,52 +130,20 @@ static int __init early_serial8250_setup(struct earlycon_device *device,
const char *options)
{
if (!(device->port.membase || device->port.iobase))
- return 0;
+ return -ENODEV;
if (!device->baud) {
- device->baud = probe_baud(&device->port);
- snprintf(device->options, sizeof(device->options), "%u",
- device->baud);
- }
+ struct uart_port *port = &device->port;
+ unsigned int ier;
- init_port(device);
+ /* assume the device was initialized, only mask interrupts */
+ ier = serial8250_early_in(port, UART_IER);
+ serial8250_early_out(port, UART_IER, ier & UART_IER_UUE);
+ } else
+ init_port(device);
- early_device = device;
device->con->write = early_serial8250_write;
return 0;
}
EARLYCON_DECLARE(uart8250, early_serial8250_setup);
EARLYCON_DECLARE(uart, early_serial8250_setup);
-
-int __init setup_early_serial8250_console(char *cmdline)
-{
- char match[] = "uart8250";
-
- if (cmdline && cmdline[4] == ',')
- match[4] = '\0';
-
- return setup_earlycon(cmdline, match, early_serial8250_setup);
-}
-
-int serial8250_find_port_for_earlycon(void)
-{
- struct earlycon_device *device = early_device;
- struct uart_port *port = device ? &device->port : NULL;
- int line;
- int ret;
-
- if (!port || (!port->membase && !port->iobase))
- return -ENODEV;
-
- line = serial8250_find_port(port);
- if (line < 0)
- return -ENODEV;
-
- ret = update_console_cmdline("uart", 8250,
- "ttyS", line, device->options);
- if (ret < 0)
- ret = update_console_cmdline("uart", 0,
- "ttyS", line, device->options);
-
- return ret;
-}