linux-zen-desktop/arch/arm/mach-omap1/sram-init.c

146 lines
3.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* OMAP SRAM detection and management
*
* Copyright (C) 2005 Nokia Corporation
* Written by Tony Lindgren <tony@atomide.com>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/set_memory.h>
#include <asm/fncpy.h>
#include <asm/tlb.h>
#include <asm/cacheflush.h>
#include <asm/mach/map.h>
#include "soc.h"
#include "sram.h"
#define OMAP1_SRAM_PA 0x20000000
#define SRAM_BOOTLOADER_SZ 0x80
#define ROUND_DOWN(value,boundary) ((value) & (~((boundary)-1)))
static void __iomem *omap_sram_base;
static unsigned long omap_sram_start;
static unsigned long omap_sram_skip;
static unsigned long omap_sram_size;
static void __iomem *omap_sram_ceil;
/*
* Memory allocator for SRAM: calculates the new ceiling address
* for pushing a function using the fncpy API.
*
* Note that fncpy requires the returned address to be aligned
* to an 8-byte boundary.
*/
static void *omap_sram_push_address(unsigned long size)
{
unsigned long available, new_ceil = (unsigned long)omap_sram_ceil;
available = omap_sram_ceil - (omap_sram_base + omap_sram_skip);
if (size > available) {
pr_err("Not enough space in SRAM\n");
return NULL;
}
new_ceil -= size;
new_ceil = ROUND_DOWN(new_ceil, FNCPY_ALIGN);
omap_sram_ceil = IOMEM(new_ceil);
return (void __force *)omap_sram_ceil;
}
void *omap_sram_push(void *funcp, unsigned long size)
{
void *sram;
unsigned long base;
int pages;
void *dst = NULL;
sram = omap_sram_push_address(size);
if (!sram)
return NULL;
base = (unsigned long)sram & PAGE_MASK;
pages = PAGE_ALIGN(size) / PAGE_SIZE;
set_memory_rw(base, pages);
dst = fncpy(sram, funcp, size);
set_memory_rox(base, pages);
return dst;
}
/*
* The amount of SRAM depends on the core type.
* 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.
* Note that we cannot use ioremap for SRAM, as clock init needs SRAM early.
*/
static void __init omap_detect_and_map_sram(void)
{
unsigned long base;
int pages;
omap_sram_skip = SRAM_BOOTLOADER_SZ;
omap_sram_start = OMAP1_SRAM_PA;
if (cpu_is_omap15xx())
omap_sram_size = 0x30000; /* 192K */
else if (cpu_is_omap1610() || cpu_is_omap1611() ||
cpu_is_omap1621() || cpu_is_omap1710())
omap_sram_size = 0x4000; /* 16K */
else {
pr_err("Could not detect SRAM size\n");
omap_sram_size = 0x4000;
}
omap_sram_start = ROUND_DOWN(omap_sram_start, PAGE_SIZE);
omap_sram_base = __arm_ioremap_exec(omap_sram_start, omap_sram_size, 1);
if (!omap_sram_base) {
pr_err("SRAM: Could not map\n");
return;
}
omap_sram_ceil = omap_sram_base + omap_sram_size;
/*
* Looks like we need to preserve some bootloader code at the
* beginning of SRAM for jumping to flash for reboot to work...
*/
memset_io(omap_sram_base + omap_sram_skip, 0,
omap_sram_size - omap_sram_skip);
base = (unsigned long)omap_sram_base;
pages = PAGE_ALIGN(omap_sram_size) / PAGE_SIZE;
set_memory_rox(base, pages);
}
static void (*_omap_sram_reprogram_clock)(u32 dpllctl, u32 ckctl);
void omap_sram_reprogram_clock(u32 dpllctl, u32 ckctl)
{
BUG_ON(!_omap_sram_reprogram_clock);
_omap_sram_reprogram_clock(dpllctl, ckctl);
}
int __init omap1_sram_init(void)
{
omap_detect_and_map_sram();
_omap_sram_reprogram_clock =
omap_sram_push(omap1_sram_reprogram_clock,
omap1_sram_reprogram_clock_sz);
return 0;
}