OpenCloudOS-Kernel/arch/arm/mach-imx/cpu-imx5.c

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/*
* Copyright 2008-2010 Freescale Semiconductor, Inc. All Rights Reserved.
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*
* This file contains the CPU initialization code.
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include "hardware.h"
#include "common.h"
static int mx5_cpu_rev = -1;
#define IIM_SREV 0x24
static u32 imx5_read_srev_reg(const char *compat)
{
void __iomem *iim_base;
struct device_node *np;
u32 srev;
np = of_find_compatible_node(NULL, NULL, compat);
iim_base = of_iomap(np, 0);
WARN_ON(!iim_base);
srev = readl(iim_base + IIM_SREV) & 0xff;
iounmap(iim_base);
return srev;
}
static int get_mx51_srev(void)
{
u32 rev = imx5_read_srev_reg("fsl,imx51-iim");
switch (rev) {
case 0x0:
return IMX_CHIP_REVISION_2_0;
case 0x10:
return IMX_CHIP_REVISION_3_0;
default:
return IMX_CHIP_REVISION_UNKNOWN;
}
}
/*
* Returns:
* the silicon revision of the cpu
* -EINVAL - not a mx51
*/
int mx51_revision(void)
{
if (!cpu_is_mx51())
return -EINVAL;
if (mx5_cpu_rev == -1)
mx5_cpu_rev = get_mx51_srev();
return mx5_cpu_rev;
}
EXPORT_SYMBOL(mx51_revision);
#ifdef CONFIG_NEON
/*
* All versions of the silicon before Rev. 3 have broken NEON implementations.
* Dependent on link order - so the assumption is that vfp_init is called
* before us.
*/
int __init mx51_neon_fixup(void)
{
if (mx51_revision() < IMX_CHIP_REVISION_3_0 &&
(elf_hwcap & HWCAP_NEON)) {
elf_hwcap &= ~HWCAP_NEON;
pr_info("Turning off NEON support, detected broken NEON implementation\n");
}
return 0;
}
#endif
static int get_mx53_srev(void)
{
u32 rev = imx5_read_srev_reg("fsl,imx53-iim");
switch (rev) {
case 0x0:
return IMX_CHIP_REVISION_1_0;
case 0x2:
return IMX_CHIP_REVISION_2_0;
case 0x3:
return IMX_CHIP_REVISION_2_1;
default:
return IMX_CHIP_REVISION_UNKNOWN;
}
}
/*
* Returns:
* the silicon revision of the cpu
* -EINVAL - not a mx53
*/
int mx53_revision(void)
{
if (!cpu_is_mx53())
return -EINVAL;
if (mx5_cpu_rev == -1)
mx5_cpu_rev = get_mx53_srev();
return mx5_cpu_rev;
}
EXPORT_SYMBOL(mx53_revision);