linux-stable-rt/arch/arm/plat-omap/sram.c

117 lines
3.1 KiB
C

/*
* linux/arch/arm/plat-omap/sram.c
*
* OMAP SRAM detection and management
*
* Copyright (C) 2005 Nokia Corporation
* Written by Tony Lindgren <tony@atomide.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <asm/mach/map.h>
#include <asm/io.h>
#include <asm/cacheflush.h>
#include "sram.h"
#define OMAP1_SRAM_BASE 0xd0000000
#define OMAP1_SRAM_START 0x20000000
#define SRAM_BOOTLOADER_SZ 0x80
static unsigned long omap_sram_base;
static unsigned long omap_sram_size;
static unsigned long omap_sram_ceil;
/*
* The amount of SRAM depends on the core type:
* 730 = 200K, 1510 = 512K, 5912 = 256K, 1610 = 16K, 1710 = 16K
* Note that we cannot try to test for SRAM here because writes
* to secure SRAM will hang the system. Also the SRAM is not
* yet mapped at this point.
*/
void __init omap_detect_sram(void)
{
omap_sram_base = OMAP1_SRAM_BASE;
if (cpu_is_omap730())
omap_sram_size = 0x32000;
else if (cpu_is_omap1510())
omap_sram_size = 0x80000;
else if (cpu_is_omap1610() || cpu_is_omap1621() || cpu_is_omap1710())
omap_sram_size = 0x4000;
else if (cpu_is_omap1611())
omap_sram_size = 0x3e800;
else {
printk(KERN_ERR "Could not detect SRAM size\n");
omap_sram_size = 0x4000;
}
printk(KERN_INFO "SRAM size: 0x%lx\n", omap_sram_size);
omap_sram_ceil = omap_sram_base + omap_sram_size;
}
static struct map_desc omap_sram_io_desc[] __initdata = {
{ OMAP1_SRAM_BASE, OMAP1_SRAM_START, 0, MT_DEVICE }
};
/*
* In order to use last 2kB of SRAM on 1611b, we must round the size
* up to multiple of PAGE_SIZE. We cannot use ioremap for SRAM, as
* clock init needs SRAM early.
*/
void __init omap_map_sram(void)
{
if (omap_sram_size == 0)
return;
omap_sram_io_desc[0].length = (omap_sram_size + PAGE_SIZE-1)/PAGE_SIZE;
omap_sram_io_desc[0].length *= PAGE_SIZE;
iotable_init(omap_sram_io_desc, ARRAY_SIZE(omap_sram_io_desc));
/*
* Looks like we need to preserve some bootloader code at the
* beginning of SRAM for jumping to flash for reboot to work...
*/
memset((void *)omap_sram_base + SRAM_BOOTLOADER_SZ, 0,
omap_sram_size - SRAM_BOOTLOADER_SZ);
}
static void (*_omap_sram_reprogram_clock)(u32 dpllctl, u32 ckctl) = NULL;
void omap_sram_reprogram_clock(u32 dpllctl, u32 ckctl)
{
if (_omap_sram_reprogram_clock == NULL)
panic("Cannot use SRAM");
return _omap_sram_reprogram_clock(dpllctl, ckctl);
}
void * omap_sram_push(void * start, unsigned long size)
{
if (size > (omap_sram_ceil - (omap_sram_base + SRAM_BOOTLOADER_SZ))) {
printk(KERN_ERR "Not enough space in SRAM\n");
return NULL;
}
omap_sram_ceil -= size;
omap_sram_ceil &= ~0x3;
memcpy((void *)omap_sram_ceil, start, size);
return (void *)omap_sram_ceil;
}
void __init omap_sram_init(void)
{
omap_detect_sram();
omap_map_sram();
_omap_sram_reprogram_clock = omap_sram_push(sram_reprogram_clock,
sram_reprogram_clock_sz);
}