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author | Jiri Kosina <jkosina@suse.cz> | 2010-08-04 15:14:38 +0200 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2010-08-04 15:14:38 +0200 |
commit | d790d4d583aeaed9fc6f8a9f4d9f8ce6b1c15c7f (patch) | |
tree | 854ab394486288d40fa8179cbfaf66e8bdc44b0f /arch/arm/mach-imx/cpu-imx27.c | |
parent | 73b2c7165b76b20eb1290e7efebc33cfd21db1ca (diff) | |
parent | 3a09b1be53d23df780a0cd0e4087a05e2ca4a00c (diff) | |
download | op-kernel-dev-d790d4d583aeaed9fc6f8a9f4d9f8ce6b1c15c7f.zip op-kernel-dev-d790d4d583aeaed9fc6f8a9f4d9f8ce6b1c15c7f.tar.gz |
Merge branch 'master' into for-next
Diffstat (limited to 'arch/arm/mach-imx/cpu-imx27.c')
-rw-r--r-- | arch/arm/mach-imx/cpu-imx27.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/cpu-imx27.c b/arch/arm/mach-imx/cpu-imx27.c new file mode 100644 index 0000000..d8d3b2d --- /dev/null +++ b/arch/arm/mach-imx/cpu-imx27.c @@ -0,0 +1,64 @@ +/* + * 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); |