ARM: mx25: Print silicon revision on boot

Silicon revision is useful information to have during kernel boot.
Print the MX25 silicon revision.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Jason Liu <jason.hui@linaro.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 41 insertions, 0 deletions

diff --git a/arch/arm/mach-imx/cpu-imx25.c b/arch/arm/mach-imx/cpu-imx25.c
new file mode 100644
index 000000000000..6914bcbf84e4
--- /dev/null
+++ b/arch/arm/mach-imx/cpu-imx25.c
@@ -0,0 +1,41 @@
+/*
+ * MX25 CPU type detection
+ *
+ * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
+ * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved
+ *
+ * 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.
+ */
+#include <linux/module.h>
+#include <linux/io.h>
+#include <mach/hardware.h>
+#include <mach/iim.h>
+
+static int mx25_cpu_rev = -1;
+
+static int mx25_read_cpu_rev(void)
+{
+	u32 rev;
+
+	rev = __raw_readl(MX25_IO_ADDRESS(MX25_IIM_BASE_ADDR + MXC_IIMSREV));
+	switch (rev) {
+	case 0x00:
+		return IMX_CHIP_REVISION_1_0;
+	case 0x01:
+		return IMX_CHIP_REVISION_1_1;
+	default:
+		return IMX_CHIP_REVISION_UNKNOWN;
+	}
+}
+
+int mx25_revision(void)
+{
+	if (mx25_cpu_rev == -1)
+		mx25_cpu_rev = mx25_read_cpu_rev();
+
+	return mx25_cpu_rev;
+}
+EXPORT_SYMBOL(mx25_revision);