linux/arch/arm/mach-imx/cpu-imx5.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 2008-2010 Freescale Semiconductor, Inc. All Rights Reserved.
*
* 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
*/
int mx51_revision(void)
{
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
*/
int mx53_revision(void)
{
if (mx5_cpu_rev == -1)
mx5_cpu_rev = get_mx53_srev();
return mx5_cpu_rev;
}
EXPORT_SYMBOL(mx53_revision);
#define ARM_GPC 0x4
#define DBGEN BIT(16)
/*
* This enables the DBGEN bit in ARM_GPC register, which is
* required for accessing some performance counter features.
* Technically it is only required while perf is used, but to
* keep the source code simple we just enable it all the time
* when the kernel configuration allows using the feature.
*/
void __init imx5_pmu_init(void)
{
void __iomem *tigerp_base;
struct device_node *np;
u32 gpc;
if (!IS_ENABLED(CONFIG_ARM_PMU))
return;
np = of_find_compatible_node(NULL, NULL, "arm,cortex-a8-pmu");
if (!np)
return;
if (!of_property_read_bool(np, "secure-reg-access"))
goto exit;
of_node_put(np);
np = of_find_compatible_node(NULL, NULL, "fsl,imx51-tigerp");
if (!np)
return;
tigerp_base = of_iomap(np, 0);
if (!tigerp_base)
goto exit;
gpc = readl_relaxed(tigerp_base + ARM_GPC);
gpc |= DBGEN;
writel_relaxed(gpc, tigerp_base + ARM_GPC);
iounmap(tigerp_base);
exit:
of_node_put(np);
}