MIPS: Malta: use generic 8250 early console

This patch switches Malta from using the MIPS implementation of early
printk with Malta's prom_putchar to using the generic 8250_early
implementation. This offers a couple of advantages:

  - We duplicate less generic code.

  - The UART can be initialised rather than being reliant upon
    inheriting a valid setup from the bootloader.

The Malta console_config function is extended to initialise the early
console if no earlycon= kernel parameter is provided, inheriting the
modetty0 bootloader environment if present and falling back to a
default 38400n8r setup if not. This matches the behaviour used for the
regular console= parameter.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6183/
This commit is contained in:
Paul Burton 2013-12-02 16:48:38 +00:00 committed by Ralf Baechle
parent ae0d7cbc99
commit 23a91de41c
4 changed files with 33 additions and 75 deletions

View file

@ -320,7 +320,6 @@ config MIPS_MALTA
select SYS_HAS_CPU_MIPS64_R2
select SYS_HAS_CPU_NEVADA
select SYS_HAS_CPU_RM7000
select SYS_HAS_EARLY_PRINTK
select SYS_SUPPORTS_32BIT_KERNEL
select SYS_SUPPORTS_64BIT_KERNEL
select SYS_SUPPORTS_BIG_ENDIAN

View file

@ -9,7 +9,5 @@ obj-y := malta-amon.o malta-display.o malta-init.o \
malta-int.o malta-memory.o malta-platform.o \
malta-reset.o malta-setup.o malta-time.o
obj-$(CONFIG_EARLY_PRINTK) += malta-console.o
# FIXME FIXME FIXME
obj-$(CONFIG_MIPS_MT_SMTC) += malta-smtc.o

View file

@ -1,47 +0,0 @@
/*
* Carsten Langgaard, carstenl@mips.com
* Copyright (C) 1999,2000 MIPS Technologies, Inc. All rights reserved.
*
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
*
* Putting things on the screen/serial line using YAMONs facilities.
*/
#include <linux/console.h>
#include <linux/init.h>
#include <linux/serial_reg.h>
#include <asm/io.h>
#define PORT(offset) (0x3f8 + (offset))
static inline unsigned int serial_in(int offset)
{
return inb(PORT(offset));
}
static inline void serial_out(int offset, int value)
{
outb(value, PORT(offset));
}
int prom_putchar(char c)
{
while ((serial_in(UART_LSR) & UART_LSR_THRE) == 0)
;
serial_out(UART_TX, c);
return 1;
}

View file

@ -14,6 +14,7 @@
#include <linux/init.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/serial_8250.h>
#include <asm/cacheflush.h>
#include <asm/smp-ops.h>
@ -44,32 +45,39 @@ static void __init console_config(void)
char parity = '\0', bits = '\0', flow = '\0';
char *s;
if ((strstr(fw_getcmdline(), "console=")) == NULL) {
s = fw_getenv("modetty0");
if (s) {
while (*s >= '0' && *s <= '9')
baud = baud*10 + *s++ - '0';
if (*s == ',')
s++;
if (*s)
parity = *s++;
if (*s == ',')
s++;
if (*s)
bits = *s++;
if (*s == ',')
s++;
if (*s == 'h')
flow = 'r';
}
if (baud == 0)
baud = 38400;
if (parity != 'n' && parity != 'o' && parity != 'e')
parity = 'n';
if (bits != '7' && bits != '8')
bits = '8';
if (flow == '\0')
s = fw_getenv("modetty0");
if (s) {
while (*s >= '0' && *s <= '9')
baud = baud*10 + *s++ - '0';
if (*s == ',')
s++;
if (*s)
parity = *s++;
if (*s == ',')
s++;
if (*s)
bits = *s++;
if (*s == ',')
s++;
if (*s == 'h')
flow = 'r';
}
if (baud == 0)
baud = 38400;
if (parity != 'n' && parity != 'o' && parity != 'e')
parity = 'n';
if (bits != '7' && bits != '8')
bits = '8';
if (flow == '\0')
flow = 'r';
if ((strstr(fw_getcmdline(), "earlycon=")) == NULL) {
sprintf(console_string, "uart8250,io,0x3f8,%d%c%c", baud,
parity, bits);
setup_early_serial8250_console(console_string);
}
if ((strstr(fw_getcmdline(), "console=")) == NULL) {
sprintf(console_string, " console=ttyS0,%d%c%c%c", baud,
parity, bits, flow);
strcat(fw_getcmdline(), console_string);