MIPS: JZ4740: Add prom support

Add support for initializing arcs_cmdline on JZ4740 based machines and
provides a prom_putchar implementation.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1404/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Lars-Peter Clausen 2010-06-19 04:08:17 +00:00 committed by Ralf Baechle
parent c3b9566de8
commit a8b7e9e8b0

68
arch/mips/jz4740/prom.c Normal file
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/*
* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
* JZ4740 SoC prom code
*
* 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.
*
* 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.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/serial_reg.h>
#include <asm/bootinfo.h>
#include <asm/mach-jz4740/base.h>
void jz4740_init_cmdline(int argc, char *argv[])
{
unsigned int count = COMMAND_LINE_SIZE - 1;
int i;
char *dst = &(arcs_cmdline[0]);
char *src;
for (i = 1; i < argc && count; ++i) {
src = argv[i];
while (*src && count) {
*dst++ = *src++;
--count;
}
*dst++ = ' ';
}
if (i > 1)
--dst;
*dst = 0;
}
void __init prom_init(void)
{
jz4740_init_cmdline((int)fw_arg0, (char **)fw_arg1);
mips_machtype = MACH_INGENIC_JZ4740;
}
void __init prom_free_prom_memory(void)
{
}
#define UART_REG(_reg) ((void __iomem *)CKSEG1ADDR(JZ4740_UART0_BASE_ADDR + (_reg << 2)))
void prom_putchar(char c)
{
uint8_t lsr;
do {
lsr = readb(UART_REG(UART_LSR));
} while ((lsr & UART_LSR_TEMT) == 0);
writeb(c, UART_REG(UART_TX));
}