From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/arm/mach-imx/cpu-imx27.c | 74 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 arch/arm/mach-imx/cpu-imx27.c (limited to 'arch/arm/mach-imx/cpu-imx27.c') diff --git a/arch/arm/mach-imx/cpu-imx27.c b/arch/arm/mach-imx/cpu-imx27.c new file mode 100644 index 000000000..fe8d36f7e --- /dev/null +++ b/arch/arm/mach-imx/cpu-imx27.c @@ -0,0 +1,74 @@ +/* + * 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 +#include + +#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 = __raw_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); -- cgit v1.2.3-54-g00ecf