linux/arch/arm/mach-mx2/cpu_imx27.c
Uwe Kleine-König bc9ea6c7f5 imx27: define and use MX27_IO_ADDRESS
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Rabin Vincent <rabin@rab.in>
Cc: Javier Martin <javier.martin@vista-silicon.com>
Cc: Valentin Longchamp <valentin.longchamp@epfl.ch>
Cc: Holger Schurig <hs4233@mail.mn-solutions.de>
2010-01-08 16:41:25 +01:00

64 lines
1.7 KiB
C

/*
* Copyright 2007 Freescale Semiconductor, Inc. All Rights Reserved.
* Copyright 2008 Juergen Beisert, kernel@pengutronix.de
*
* 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.
*/
/*
* i.MX27 specific CPU detection code
*/
#include <linux/io.h>
#include <linux/module.h>
#include <mach/hardware.h>
static int cpu_silicon_rev = -1;
static int cpu_partnumber;
#define SYS_CHIP_ID 0x00 /* The offset of CHIP ID register */
static void query_silicon_parameter(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 = __raw_readl(MX27_IO_ADDRESS(MX27_SYSCTRL_BASE_ADDR
+ SYS_CHIP_ID));
cpu_silicon_rev = (int)(val >> 28);
cpu_partnumber = (int)((val >> 12) & 0xFFFF);
}
/*
* Returns:
* the silicon revision of the cpu
* -EINVAL - not a mx27
*/
int mx27_revision(void)
{
if (cpu_silicon_rev == -1)
query_silicon_parameter();
if (cpu_partnumber != 0x8821)
return -EINVAL;
return cpu_silicon_rev;
}
EXPORT_SYMBOL(mx27_revision);