android_kernel_xiaomi_sm8350/arch/sh/kernel/early_printk.c
Paul Mundt a80fd21e52 sh: earlyprintk= support and cleanups.
Allow multiple early printk consoles via earlyprintk=.

With this change earlyprintk is no longer enabled by default,
it must be specified on the kernel command line. Optionally
with ,keep to prevent unreg by tty_io.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2006-09-27 14:26:53 +09:00

192 lines
4.0 KiB
C

/*
* arch/sh/kernel/early_printk.c
*
* Copyright (C) 1999, 2000 Niibe Yutaka
* Copyright (C) 2002 M. R. Brown
* Copyright (C) 2004 - 2006 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/console.h>
#include <linux/tty.h>
#include <linux/init.h>
#include <asm/io.h>
#ifdef CONFIG_SH_STANDARD_BIOS
#include <asm/sh_bios.h>
/*
* Print a string through the BIOS
*/
static void sh_console_write(struct console *co, const char *s,
unsigned count)
{
sh_bios_console_write(s, count);
}
/*
* Setup initial baud/bits/parity. We do two things here:
* - construct a cflag setting for the first rs_open()
* - initialize the serial port
* Return non-zero if we didn't find a serial port.
*/
static int __init sh_console_setup(struct console *co, char *options)
{
int cflag = CREAD | HUPCL | CLOCAL;
/*
* Now construct a cflag setting.
* TODO: this is a totally bogus cflag, as we have
* no idea what serial settings the BIOS is using, or
* even if its using the serial port at all.
*/
cflag |= B115200 | CS8 | /*no parity*/0;
co->cflag = cflag;
return 0;
}
static struct console bios_console = {
.name = "bios",
.write = sh_console_write,
.setup = sh_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
};
#endif
#ifdef CONFIG_EARLY_SCIF_CONSOLE
#include <linux/serial_core.h>
#include "../../../drivers/serial/sh-sci.h"
#ifdef CONFIG_CPU_SH4
#define SCIF_REG 0xffe80000
#elif defined(CONFIG_CPU_SUBTYPE_SH72060)
#define SCIF_REG 0xfffe9800
#else
#error "Undefined SCIF for this subtype"
#endif
static struct uart_port scif_port = {
.mapbase = SCIF_REG,
.membase = (char __iomem *)SCIF_REG,
};
static void scif_sercon_putc(int c)
{
while (((sci_in(&scif_port, SCFDR) & 0x1f00 >> 8) == 16))
;
sci_out(&scif_port, SCxTDR, c);
sci_in(&scif_port, SCxSR);
sci_out(&scif_port, SCxSR, 0xf3 & ~(0x20 | 0x40));
while ((sci_in(&scif_port, SCxSR) & 0x40) == 0);
;
if (c == '\n')
scif_sercon_putc('\r');
}
static void scif_sercon_write(struct console *con, const char *s,
unsigned count)
{
while (count-- > 0)
scif_sercon_putc(*s++);
}
static int __init scif_sercon_setup(struct console *con, char *options)
{
con->cflag = CREAD | HUPCL | CLOCAL | B115200 | CS8;
return 0;
}
static struct console scif_console = {
.name = "sercon",
.write = scif_sercon_write,
.setup = scif_sercon_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
};
static void scif_sercon_init(int baud)
{
ctrl_outw(0, SCIF_REG + 8);
ctrl_outw(0, SCIF_REG);
/* Set baud rate */
ctrl_outb((CONFIG_SH_PCLK_FREQ + 16 * baud) /
(32 * baud) - 1, SCIF_REG + 4);
ctrl_outw(12, SCIF_REG + 24);
ctrl_outw(8, SCIF_REG + 24);
ctrl_outw(0, SCIF_REG + 32);
ctrl_outw(0x60, SCIF_REG + 16);
ctrl_outw(0, SCIF_REG + 36);
ctrl_outw(0x30, SCIF_REG + 8);
}
#endif
/*
* Setup a default console, if more than one is compiled in, rely on the
* earlyprintk= parsing to give priority.
*/
static struct console *early_console =
#ifdef CONFIG_SH_STANDARD_BIOS
&bios_console
#elif defined(CONFIG_EARLY_SCIF_CONSOLE)
&scif_console
#else
NULL
#endif
;
static int __initdata keep_early;
int __init setup_early_printk(char *opt)
{
char *space;
char buf[256];
strlcpy(buf, opt, sizeof(buf));
space = strchr(buf, ' ');
if (space)
*space = 0;
if (strstr(buf, "keep"))
keep_early = 1;
#ifdef CONFIG_SH_STANDARD_BIOS
if (!strncmp(buf, "bios", 4))
early_console = &bios_console;
#endif
#if defined(CONFIG_EARLY_SCIF_CONSOLE)
if (!strncmp(buf, "serial", 6)) {
early_console = &scif_console;
#ifdef CONFIG_CPU_SH4
scif_sercon_init(115200);
#endif
}
#endif
if (likely(early_console))
register_console(early_console);
return 1;
}
__setup("earlyprintk=", setup_early_printk);
void __init disable_early_printk(void)
{
if (!keep_early) {
printk("disabling early console\n");
unregister_console(early_console);
} else
printk("keeping early console\n");
}