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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/arm/mach-imx/cpu-imx27.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/arm/mach-imx/cpu-imx27.c')
-rw-r--r--kernel/arch/arm/mach-imx/cpu-imx27.c74
1 files changed, 74 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-imx/cpu-imx27.c b/kernel/arch/arm/mach-imx/cpu-imx27.c
new file mode 100644
index 000000000..fe8d36f7e
--- /dev/null
+++ b/kernel/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 <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 = __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);