OpenCloudOS-Kernel/arch/arm/mach-imx/cpu-imx27.c

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 1 Based on 2 normalized pattern(s): 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 this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details 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 51 franklin street fifth floor boston ma 02110 1301 usa 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 [no]_[pad]_[ctrl] any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details 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 51 franklin street fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 176 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190519154040.652910950@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-19 21:51:31 +08:00
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 2007 Freescale Semiconductor, Inc. All Rights Reserved.
* Copyright 2008 Juergen Beisert, kernel@pengutronix.de
*/
/*
* i.MX27 specific CPU detection code
*/
#include <linux/io.h>
#include <linux/module.h>
#include "hardware.h"
static int mx27_cpu_rev = -1;
static int mx27_cpu_partnumber;
#define SYS_CHIP_ID 0x00 /* The offset of CHIP ID register */
static int mx27_read_cpu_rev(void)
{
u32 val;
/*
* now we have access to the IO registers. As we need
* the silicon revision very early we read it here to
* avoid any further hooks
*/
val = imx_readl(MX27_IO_ADDRESS(MX27_SYSCTRL_BASE_ADDR + SYS_CHIP_ID));
mx27_cpu_partnumber = (int)((val >> 12) & 0xFFFF);
switch (val >> 28) {
case 0:
return IMX_CHIP_REVISION_1_0;
case 1:
return IMX_CHIP_REVISION_2_0;
case 2:
return IMX_CHIP_REVISION_2_1;
default:
return IMX_CHIP_REVISION_UNKNOWN;
}
}
/*
* Returns:
* the silicon revision of the cpu
* -EINVAL - not a mx27
*/
int mx27_revision(void)
{
if (mx27_cpu_rev == -1)
mx27_cpu_rev = mx27_read_cpu_rev();
if (mx27_cpu_partnumber != 0x8821)
return -EINVAL;
return mx27_cpu_rev;
}
EXPORT_SYMBOL(mx27_revision);