[deliverable/linux.git] / arch / arm / mach-mx2 / cpu_imx27.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);
Commit	Line	Data
f31405cc JB	1	/*
	2	* Copyright 2007 Freescale Semiconductor, Inc. All Rights Reserved.
	3	* Copyright 2008 Juergen Beisert, kernel@pengutronix.de
	4	*
	5	* This program is free software; you can redistribute it and/or
	6	* modify it under the terms of the GNU General Public License
	7	* as published by the Free Software Foundation; either version 2
	8	* of the License, or (at your option) any later version.
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
	17	* MA 02110-1301, USA.
	18	*/
	19
	20	/*
	21	* i.MX27 specific CPU detection code
	22	*/
	23
	24	#include <linux/io.h>
	25	#include <linux/module.h>
	26
a09e64fb	27	#include <mach/hardware.h>
f31405cc	28
f31405cc JB	29	static int cpu_silicon_rev = -1;
	30	static int cpu_partnumber;
	31
edfcea80 SH	32	#define SYS_CHIP_ID 0x00 /* The offset of CHIP ID register */
edfcea80 SH	33
f31405cc JB	34	static void query_silicon_parameter(void)
	35	{
	36	u32 val;
	37	/*
	38	* now we have access to the IO registers. As we need
	39	* the silicon revision very early we read it here to
	40	* avoid any further hooks
	41	*/
bc9ea6c7 UKK	42	val = __raw_readl(MX27_IO_ADDRESS(MX27_SYSCTRL_BASE_ADDR
bc9ea6c7 UKK	43	+ SYS_CHIP_ID));
f31405cc JB	44
	45	cpu_silicon_rev = (int)(val >> 28);
	46	cpu_partnumber = (int)((val >> 12) & 0xFFFF);
	47	}
	48
	49	/*
	50	* Returns:
	51	* the silicon revision of the cpu
	52	* -EINVAL - not a mx27
	53	*/
	54	int mx27_revision(void)
	55	{
	56	if (cpu_silicon_rev == -1)
	57	query_silicon_parameter();
	58
	59	if (cpu_partnumber != 0x8821)
	60	return -EINVAL;
	61
	62	return cpu_silicon_rev;
	63	}
	64	EXPORT_SYMBOL(mx27_revision);