linux/arch/mips/loongson/common/early_printk.c
Huacai Chen 3adeb2566b MIPS: Loongson: Improve LEFI firmware interface
Machtypes of Loongson-3 machines become more and more, but there are
only small differences among different machtypes. Keeping a large table
of machtypes is very ugly and hard to extend. We found that the major
machtype differences are UARTs information (number of UARTs, UART IRQs,
UART clocks, etc.), platform devices (EC, temperature sensors, fan
controllers, etc.) and some workarounds (because of some CPU bugs or
mainboard bugs).

In this patch we improve the UEFI-like (LEFI) interface to make all
Loongson-3 machines use a same machtype "generic-loongson-machine".

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/8324/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:01 +01:00

42 lines
1.0 KiB
C

/* early printk support
*
* Copyright (c) 2009 Philippe Vachon <philippe@cowpig.ca>
* Copyright (c) 2009 Lemote Inc.
* Author: Wu Zhangjin, wuzhangjin@gmail.com
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/serial_reg.h>
#include <loongson.h>
#define PORT(base, offset) (u8 *)(base + offset)
static inline unsigned int serial_in(unsigned char *base, int offset)
{
return readb(PORT(base, offset));
}
static inline void serial_out(unsigned char *base, int offset, int value)
{
writeb(value, PORT(base, offset));
}
void prom_putchar(char c)
{
int timeout;
unsigned char *uart_base;
uart_base = (unsigned char *)_loongson_uart_base[0];
timeout = 1024;
while (((serial_in(uart_base, UART_LSR) & UART_LSR_THRE) == 0) &&
(timeout-- > 0))
;
serial_out(uart_base, UART_TX, c);
}