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);