1 files changed, 63 insertions, 0 deletions

diff --git a/arch/arm/mach-mx2/cpu_imx27.c b/arch/arm/mach-mx2/cpu_imx27.c
new file mode 100644
index 000000000000..d6b5c2e3377f
--- /dev/null
+++ b/arch/arm/mach-mx2/cpu_imx27.c
@@ -0,0 +1,63 @@
+/*
+ * 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 <asm/hardware.h>
+
+#include "crm_regs.h"
+
+static int cpu_silicon_rev = -1;
+static int cpu_partnumber;
+
+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(IO_ADDRESS(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);